Podcasts about TLR4

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Best podcasts about TLR4

Latest podcast episodes about TLR4

The Autoimmune RESET
IBS, Leaky Gut & Autoimmune Arthritis: The LPS Connection You Need to Know

The Autoimmune RESET

Play Episode Listen Later Apr 13, 2025 29:46


Send us a textIBS, Leaky Gut & Autoimmune Arthritis: The LPS Connection You Need to KnowIn this episode, we're exploring a hidden driver behind joint pain, chronic bloating, and immune dysfunction: the link between IBS, leaky gut, and autoimmune arthritis — and how a molecule called lipopolysaccharide (LPS) may be at the root of it all.Join VJ Hamilton, registered nutritionist and autoimmune health specialist, as we unpack the science connecting gut permeability, systemic inflammation, and immune overactivation. You'll discover why gut health is never just about digestion — and how the state of your microbiome can influence everything from your joints to your energy levels.We also dive into:What LPS is and how it triggers inflammatory pathways in autoimmune diseaseWhy people with rheumatoid arthritis and other autoimmune conditions often show signs of gut dysbiosisThe latest research on TLR4, LPS-binding protein, and the immune response in arthritisHow to tell if gut permeability could be contributing to your symptoms (even without a formal diagnosis)Practical, evidence-based strategies to reduce LPS load and support gut-immune resiliencePlus, if you're ready to reduce inflammation from the inside out, I share key tools and resources that can help you identify hidden triggers, nourish your gut lining, and take a systems-based approach to managing autoimmunity.Resources Mentioned in the Episode

The Synthesis of Wellness
142. Neuroinflammation & Gut-Derived Lipopolysaccharides | Addressing Intestinal Dysbiosis, Intestinal Hyperpermeability, & Cognitive Function | Supporting the Gut-Microbiota-Brain Axis

The Synthesis of Wellness

Play Episode Listen Later Sep 27, 2024 21:23


In today's episode, we dive into the molecular mechanisms underlying neuroinflammation, with a particular focus on how gut-derived endotoxins, such as lipopolysaccharides (LPS), perturb the blood-brain barrier (BBB) and propagate neuroinflammatory cascades. In more detail, we'll discuss how intestinal dysbiosis and increased intestinal permeability can allow endotoxins such as LPS to enter systemic circulation and cross the blood-brain barrier (BBB), where they activate microglia via the TLR4 signaling pathway. We will explore symptoms including brain fog, memory impairment, mood disturbances, decreased concentration, and cognitive fatigue; as well as tools to support the gut-microbiota-brain axis. Topics: 1. Introduction to Neuroinflammation - Definition and general overview - Key brain cells: neurons, glial cells, and endothelial cells - Chronic neuroinflammation and microglial cells 2. Cellular Mechanisms of Neuroinflammation - Role of microglia in detecting damage or infection - Microglial activation through PRRs/TLRs - Release of pro-inflammatory cytokines and reactive oxygen species (ROS) - Impact on neurons and synaptic plasticity: memory and learning 3. Astrocytes in Neuroinflammation - Astrocytes' contribution to the inflammatory response 4. Chronic Neuroinflammation and Brain Health - Prolonged activation: oxidative stress, excitotoxicity, impaired synaptic function - Impairment of synaptic plasticity and cognitive decline - Mitochondrial dysfunction and cell death cascades - Compromised blood-brain barrier integrity 5. Contributing Factors to Neuroinflammation - Environmental toxins and pollutants, viral or bacterial infections, chronic sleep deprivation, and more 6. Intestinal Dysbiosis and Neuroinflammation - Role of Gram-negative bacteria and LPS (lipopolysaccharides) - Increased intestinal permeability and passage of LPS - LPS transport: transcellular and paracellular pathways - Impact on the blood-brain barrier (BBB) 7. LPS Activation of Microglia - LPS binding to TLR4 on immune cells - Microglial activation and cytokine release - Cognitive impairments and neurodegenerative processes 8. Intestinal Hyperpermeability - Bioindividual approaches: prebiotics, probiotics, polyphenols, bacteriophages - Support for intestinal mucus secretions and sources of mucilage - Butyrate - Glutamine 9. Beneficial Gut Microbiome-Derived Metabolites and Brain Health - Types of metabolites: SCFAs, tryptophan metabolites, polyphenol metabolites - Role of butyrate in crossing the BBB and modulating brain function - Influence on gene expression and synaptic plasticity - Contribution to gut barrier integrity and protection against endotoxins 10. Conclusion - Recap of neuroinflammation's impact on cognitive function + symptoms Thank you to our episode sponsor: 1. Check out ⁠⁠⁠⁠⁠Daily Nouri⁠⁠⁠⁠⁠ and use code ⁠⁠⁠⁠⁠CHLOE20⁠⁠⁠⁠⁠ for 20% off your order. Thanks for tuning in! Get Chloe's Book Today! "⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠75 Gut-Healing Strategies & Biohacks⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠" Follow Chloe on Instagram ⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠@synthesisofwellness⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠ Follow Chloe on TikTok @chloe_c_porter Visit ⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠synthesisofwellness.com⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠ to purchase products, subscribe to our mailing list, and more! --- Support this podcast: https://podcasters.spotify.com/pod/show/chloe-porter6/support

JJ Virgin Lifestyle Show
How To Build Muscle Almost 2x Faster (NEW RESEARCH)

JJ Virgin Lifestyle Show

Play Episode Listen Later Aug 11, 2024 16:58


In this episode, we're diving deep into the science of building muscle and speeding up those gains! If you're tired of feeling like progress is at a snail's pace, I've got three proven strategies that will help you see results faster.  First up, we're talking nutrition and the critical role of protein in muscle synthesis. Discover how optimal protein intake, especially the right amount of leucine, can trigger muscle growth. Plus, I've got a free 7-day protein challenge waiting for you at jjvirgin.com/7day to kickstart your journey. Next, we'll explore the power of pre-workout carbs and their surprising benefits. A 2016 study revealed that carbs before exercise can boost performance, reduce fatigue, and even enhance brain function during workouts. I'll share my personal experiments with fasted versus non-fasted workouts and why timing your carbs and protein around your exercise sessions is crucial for maximizing muscle gains. Supplements can make a significant difference, and I'll highlight the heavy hitters like creatine, vitamin D, and fish oil. Learn which supplemennt can supercharge your energy during high-intensity workouts, why vitamin D is essential for muscle function, and the muscle-building benefits of omega-3s from fish oil. Plus, I'll introduce you to a supplement that enhances mitochondrial health for better endurance and recovery. Finally, we'll touch on the importance of hormones like thyroid and estrogen in muscle building. Balancing these hormones can significantly impact your strength and muscle growth. I'll also share practical tips for incorporating recovery techniques such as sauna sessions, red light therapy, and massages into your routine to optimize muscle repair and growth. Don't miss out on these game-changing tips!   FULL show notes: https://www.jjvirgin.com/buildmuscle2024 Use my Eat Protein First Calculator: http://jjvirgin.com/proteinfirst Epsom Salt: https://amzn.to/3IxgmMm Vital Choice wild-caught seafood: https://vitalchoice.sjv.io/daKYGy Foam Roller: https://amzn.to/3PlAGE3 Kooru Cold Plunge: https://www.koorucoldplunges.com/ and use code JJVIP500 for $500 off. Timeline Mitopure (Urolithin A): https://www.timelinenutrition.com/partners/jj-virgin Sunlighten Sauna: https://get.sunlighten.com/JJVirgin use promo code JJVIRGIN when requesting pricing information for $600 off. Download my FREE Best Rest Sleep Cheat Sheet: https://jjvirgin.com/sleep Therasage saunas & red light therapy: https://therasage.com/discount/VIRGIN20?rfsn=7719794.ae138d&utm_source=refersion&utm_medium=affiliate&utm_campaign=7719794.ae138d use code VIRGIN20 for 20% off Study: Effect of Carbohydrate Intake on Maximal Power Output and Cognitive Performances: https://consensus.app/papers/carbohydrate-intake-maximal-power-output-cognitive-pomportes/687ae139a6255636ab549f00de5ed80b/?utm_source=chatgpt Study: Creatine Supplementation and Skeletal Muscle Metabolism for Building Muscle Mass- Review of the Potential Mechanisms of Action: https://consensus.app/papers/creatine-supplementation-skeletal-muscle-metabolism-farshidfar/818dd4ef9aa85e1c98179306d1259491/?utm_source=chatgpt Study: Changes in pro-inflammatory markers and leucine concentrations in response to Nordic Walking training combined with vitamin D supplementation in elderly women: https://consensus.app/papers/changes-proinflammatory-markers-leucine-concentrations-gmiat/498e3f96124d5e3183e554e3042209df/?utm_source=chatgpt Study: Fish oil increases muscle protein mass and modulates Akt/FOXO, TLR4, and NOD signaling in weanling piglets after lipopolysaccharide challenge: https://consensus.app/papers/increases-muscle-mass-modulates-aktfoxo-tlr4-signaling-liu/b643eda9cd955f3a896224cda5a710a2/?utm_source=chatgpt Study: Role of thyroid hormone in skeletal muscle physiology: https://consensus.app/papers/role-thyroid-hormone-muscle-physiology-bloise/7e60a07344355ccb920ad732999b043a/?utm_source=chatgpt Study: The Influence of Estrogen on Skeletal Muscle: https://consensus.app/papers/influence-estrogen-skeletal-muscle-enns/a09639083d7b5a0c8342fb88cb735309/?utm_source=chatgpt Study: Impact of Cortisol on Reduction in Muscle Strength and Mass: A Mendelian Randomization Study: https://consensus.app/papers/impact-cortisol-reduction-muscle-strength-mass-mendelian-katsuhara/90d796b0f5a055218acfb81b6d1dc716/?utm_source=chatgpt Study: A post-exercise infrared sauna session improves recovery of neuromuscular performance and muscle soreness after resistance exercise training: https://consensus.app/papers/postexercise-infrared-session-improves-recovery-ahokas/c114553985dd5522a0ee8994d2a0ec48/?utm_source=chatgpt Study: Low-level laser (light) therapy increases mitochondrial membrane potential and ATP synthesis in C2C12 myotubes with a peak response at 3-6 hours: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4355185/ Study: Enhanced skeletal muscle regrowth and remodeling in massaged and contralateral non‐massaged hindlimb: https://consensus.app/papers/enhanced-muscle-regrowth-remodelling-massaged-hindlimb-miller/2336402483345dcf984c34764d57ddb0/?utm_source=chatgpt Episode Sponsors:  Try Timeline: https://www.timelinenutrition.com/shop?rfsn=7082975.4b75243 Use code JJ10 for 10% off all products Go to qualialife.com/VIRGINWELLNESS to try Qualia risk free for up to 100 days and code VIRGINWELLNESS for an additional 15% off

Fix Your Sciatica Podcast
Turmeric and Sciatica Pain

Fix Your Sciatica Podcast

Play Episode Listen Later May 29, 2024 38:09


Meet Dr. Shivani Gupta, entrepreneur, and PhD in Turmeric. Today we discuss the benefits of Turmeric, Ayurvedic medicine, and how this amazing plant and curcumin extra can help with pain management. Here are some scientific studies citing the benefits of turmeric in pain management like sciatica:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3946321/These results indicated that curcumin exerted a therapeutic role in neuropathic pain by down-regulating p300/CBP HAT activity-mediated gene expression of BDNF and Cox-2https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7600446/https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10610406/CUR decreased CD11b and GFAP gene expression in the spinal cord. BDMC decreased IBA-1 in the spinal cord and amygdala as well as CD11b and GFAP in the spinal cord. Both CUR and BDMC reduced PGC1α gene expression in the amygdala, PINK1 gene expression in the spinal cord, and TLR4 in the spinal cord and amygdala, while they increased Complex I and SOD1 gene expression in the spinal cord. CUR and BDMC administration decreased mechanical hypersensitivity in NP by mitigating glial activation, oxidative stress, and mitochondrial dysfunction.You can hear more from Dr. Shivani at shivanigupta.com and check out her other site: https://fusionaryformulas.com/ (affiliate link)You can use “sciatica” to get 15% off your order!Are you looking for a more affordable way to manage your pain? Check out the patient advocate program here: ptpatientadvocate.comHere's the self cheat sheet for symptom management: https://ifixyoursciatica.gymleadmachine.co/self-treatment-cheat-sheet-8707Book a free strategy call: https://msgsndr.com/widget/appointment/ifixyoursciatica/strategy-callSupport this podcast at — https://redcircle.com/fix-your-sciatica-podcast/donationsAdvertising Inquiries: https://redcircle.com/brandsPrivacy & Opt-Out: https://redcircle.com/privacy

The Metabolic Classroom
Saturated Fat with Dr. Ben Bikman

The Metabolic Classroom

Play Episode Listen Later May 7, 2024 29:14


In this episode of The Metabolic Classroom, Professor Ben Bikman, an expert in metabolic research, discusses the debate surrounding saturated fat and its impact on insulin resistance.Dr. Bikman addresses misconceptions about saturated fat perpetuated by proponents of plant-based diets, who often blame meat-based saturated fats for insulin resistance. He refers to his own 2011 research, highlighting the role of toll-like receptor four (TLR4) activation in inducing inflammation and insulin resistance, particularly stimulated by saturated fats.Acknowledging limitations in his earlier work, Dr. Bikman transitions to discussing fat digestion and absorption, setting the stage for studies on the impact of dietary saturated fat on metabolic outcomes. He cites a study by Volk et al. (2014) contradicting the direct link between dietary saturated fat intake and plasma saturated fat levels. Further, he discusses research challenging the low-fat emphasis of diets like DASH, including a study by Chiu et al. (2016) showing comparable blood pressure reduction with a high-fat version.The lecture also covers a meta-analysis by Choi et al. (2020) supporting the benefits of ketogenic diets high in saturated fat for glycemic control and insulin resistance.Dr. Bikman emphasizes the importance of considering context, suggesting that saturated fat consumption without excessive carbohydrate intake may not necessarily lead to insulin resistance. However, he acknowledges studies indicating potential concerns with high saturated fat intake in hypercaloric, high-carb diets, advocating for balanced macronutrient consumption.00:01 - Introduction of the topic of saturated fat and insulin resistance, highlighting common misconceptions and his expertise in the field.02:33 - Role of TLR4: Research on toll-like receptor four (TLR4) activation and its connection to inflammation and ceramide synthesis, leading to insulin resistance.07:05 - Fat Digestion Primer: Explanation of fat digestion in the small intestine, emphasizing the formation of chylomicrons for fat transport into the bloodstream.11:55 - Study by Volk et al. (2014): Key study that challenges the idea of dietary saturated fat directly increasing plasma saturated fat levels, despite high consumption.16:41 - High-Fat DASH Diet Study: Research comparing a high-fat version of the DASH diet to the standard low-fat version, highlighting similar blood pressure reduction but improved lipid profiles with the high-fat diet.19:46 - Meta-analysis by Choi et al. (2020): Demonstrating the benefits of ketogenic diets, typically high in saturated fat, in improving glycemic control and insulin resistance.21:40 - Historical Trends: The paradox of decreasing saturated fat consumption over time while insulin resistance rates have increased, suggesting a more complex relationship.25:58 - Overfeeding Studies: Studies showing that overconsumption of carbohydrates, particularly refined sugars and starches, can increase liver fat and saturated fat production, contributing to insulin resistance.27:09 - Study by Luukkonen et al. (2018): Study indicating that in a hypercaloric, high-carb diet, high saturated fat intake may worsen insulin resistance compared to high unsaturated fat intake.28:06 - Conclusion: The need for nuanced understanding, context, and critical appraisal of research findings regarding the relationship between saturated fat, carbohydrate intake, and insulin resistance.https://www.insuliniq.com#InsulinResistance #SaturatedFat #MetabolicHealth #NutritionScience #HealthEducation #DietaryMyths #CellBiology #ResearchInsights #FatDigestion #KetogenicDiet #CardiometabolicHealth #DASHDiet #Inflammation #MedicalResearch #HealthDebunked Hosted on Acast. See acast.com/privacy for more information.

PaperPlayer biorxiv neuroscience
Proteomics and phosphoproteomics profiling in glutamatergic neurons and microglia in an iPSC model of Jansen de Vries Syndrome

PaperPlayer biorxiv neuroscience

Play Episode Listen Later Jul 8, 2023


Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2023.07.08.548192v1?rss=1 Authors: Aguilan, J., Pedrosa, E., Dolstra, H., Nur Baykara, R., Barnes, J., Zhang, J., Sidoli, S., Lachman, H. Abstract: Background: Jansen de Vries Syndrome (JdVS) is a rare neurodevelopmental disorder (NDD) caused by gain-of-function (GOF) truncating mutations in PPM1D exons 5 or 6. PPM1D is a serine/threonine phosphatase that plays an important role in the DNA damage response (DDR) by negatively regulating TP53 (P53). JdVS-associated mutations lead to the formation of a truncated PPM1D protein that retains catalytic activity and has a GOF effect because of reduced degradation. Somatic PPM1D exons 5 and 6 truncating mutations are well-established factors in a number of cancers, due to excessive dephosphorylation and reduced function of P53 and other substrates involved in DDR. Children with JdVS have a variety of neurodevelopmental, psychiatric, and physical problems. In addition, a small fraction has acute neuropsychiatric decompensation apparently triggered by infection or severe non-infectious environmental stress factors. Methods: To understand the molecular basis of JdVS, we developed an induced pluripotent stem cell (iPSC) model system. iPSCs heterozygous for the truncating variant (PPM1D+/tr), were made from a patient, and control lines engineered using CRISPR-Cas9 gene editing. Proteomics and phosphoprotemics analyses were carried out on iPSC-derived glutamatergic neurons and microglia from three control and three PPM1D+/tr iPSC lines. We also analyzed the effect of the TLR4 agonist, lipopolysaccharide, to understand how activation of the innate immune system in microglia could account for acute behavioral decompensation. Results: One of the major findings was the downregulation of POGZ in unstimulated microglia. Since loss-of-function variants in the POGZ gene are well-known causes of autism spectrum disorder, the decrease in PPM1D+/tr microglia suggests this plays a role in the neurodevelopmental aspects of JdVS. In addition, neurons, baseline, and LPS-stimulated microglia show marked alterations in the expression of several E3 ubiquitin ligases, most notably UBR4, and regulators of innate immunity, chromatin structure, ErbB signaling, and splicing. In addition, pathway analysis points to overlap with neurodegenerative disorders. Limitations: Owing to the cost and labor-intensive nature of iPSC research, the sample size was small. Conclusions: Our findings provide insight into the molecular basis of JdVS and can be extrapolated to understand neuropsychiatric decompensation that occurs in subgroups of patients with ASD and other NDDs. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC

PaperPlayer biorxiv cell biology
Extracellular vesicles promote autophagy in human microglia through lipid raft-dependent mechanisms

PaperPlayer biorxiv cell biology

Play Episode Listen Later Jul 3, 2023


Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2023.07.03.547488v1?rss=1 Authors: Romenskaja, D., Jonavice, U., Pivoriunas, A. Abstract: Autophagy dysfunction has been closely related with pathogenesis of many neurodegenerative diseases and therefore represents a potential therapeutic target. Extracellular vesicles (EVs) may act as a potent anti-inflammatory agents and also modulators of autophagy in target cells. However, the molecular mechanisms by which EVs modulate autophagy flux in human microglia remain largely unexplored. In the present study we investigated the effects of EVs derived from human oral mucosa stem cells on the autophagy in human microglia. We demonstrate that EVs promoted autophagy and autophagic flux in human microglia and that this process was dependent on the integrity of lipid rafts. LPS also activated autophagy, but combined treatment with EVs and LPS suppressed autophagy response indicating interference between these signalling pathways. Blockage of Toll-like receptor 4 (TLR4) with anti-TLR4 antibody suppressed EV-induced autophagy. Furthermore, blockage of EV- asscoiated HSP70 chaperone which is one of the endogenous ligands of the TLR4 also suppressed EV- induced lipid raft formation and autophagy. Pre-treatment of microglia with selective inhibitor of v{beta}3/v{beta}5 integrins cilengitide inhibited EV-induced autophagy. Finally, blockage of purinergic P2X4 receptor (P2X4R) with selective inhibitor 5-BDBD also suppressed of EV-induced autophagy. In conclusion, we demonstrate that EVs activate autophagy in human microglia through interaction with HSP70/TLR4, V{beta}3/V{beta}5, and P2X4R signalling pathways and that these effects depend on the integrity of lipid rafts. Our findings could be used for development of new therapeutic strategies targeting disease-associated microglia. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC

PaperPlayer biorxiv neuroscience
Naive Huntington's disease microglia mount a normal response to inflammatory stimuli but display impaired development of innate immune tolerance that can be counteracted by ganglioside GM1

PaperPlayer biorxiv neuroscience

Play Episode Listen Later Apr 6, 2023


Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2023.04.05.535712v1?rss=1 Authors: Steinberg, N., Galleguillos, D., Zaidi, A., Sipione, S. Abstract: Chronic activation and dysfunction of microglia have been implicated in the pathogenesis and progression of many neurodegenerative disorders, including Huntington Disease (HD). HD is a genetic condition caused by a mutation that affects the folding and function of huntingtin (HTT). Signs of microglia activation have been observed in HD patients even before the onset of symptoms. It is unclear, however, whether pro-inflammatory microglia activation in HD results from cell-autonomous expression of mutant HTT or is the response of microglia to a diseased brain environment, or both. In this study, we used primary microglia isolated from HD knock-in mice (Q140) and wild-type (Q7) mice to investigate their response to inflammatory conditions in vitro in the absence of confounding effects arising from brain pathology. We show that naive Q140 microglia do not undergo spontaneous pro-inflammatory activation and respond to inflammatory triggers, including stimulation of TLR4 and TLR2 and exposure to necrotic cells, with similar kinetics of pro-inflammatory gene expression as wild-type microglia. Upon termination of the inflammatory insult, the transcription of pro-inflammatory cytokines is tapered off in Q140 and wild-type microglia with similar kinetics. However, the ability of Q140 microglia to develop tolerance in response to repeated inflammatory stimulations is partially impaired, potentially contributing to the establishment of chronic neuroinflammation in HD. We further show that ganglioside GM1, a glycosphingolipid with anti-inflammatory effects in wild-type microglia, not only decreases the production of pro-inflammatory cytokines and nitric oxide in activated Q140 microglia, but also dramatically dampen microglia response to re-stimulation with LPS in an experimental model of tolerance. These effects are independent from the expression of interleukin 1 receptor associated kinase 3 (Irak-3), a strong modulator of LPS signaling involved in the development of innate immune tolerance and previously shown to be upregulated by immune cell treatment with gangliosides. Altogether, our data suggest that external triggers are required for HD microglia activation, but a cell-autonomous dysfunction that affects the ability of HD microglia to acquire tolerance might contribute to the establishment of neuroinflammation in HD. Administration of GM1 might be beneficial to attenuate chronic microglia activation and neuroinflammation. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC

Discover CircRes
February 2023 Discover CircRes

Discover CircRes

Play Episode Listen Later Feb 16, 2023 30:30


This month on Episode 45 of Discover CircRes, host Cynthia St. Hilaire highlights four original research articles featured in the February 3rd and February 17th issues of Circulation Research. This episode also features an interview with Dr Hind Lal and Dr Tousif Sultan from the University of Alabama at Birmingham about their study Ponatinib Drives Cardiotoxicity by S100A8/A9-NLRP3-IL-1β Mediated Inflammation.   Article highlights:   Pi, et al. Metabolomic Signatures in PAH   Carnevale, et al. Thrombosis TLR4-Mediated in SARS-CoV-2 Infection   Cai, et al. Macrophage ADAR1 in AAA   Koide, et al. sEVs Accelerate Vascular Calcification in CKD   Cindy St. Hilaire:        Hi, and welcome to Discover CircRes, the podcast of the American Heart Association's journal, Circulation Research. I'm your host, Dr Cynthia St. Hilaire from the Vascular Medicine Institute at the University of Pittsburgh, and today I'm going to be highlighting the articles from our February 3rd and 17th issues of Circulation Research. I'm also going to have a chat with Dr Hind Lal and Dr Tousif Sultan from the University of Alabama at Birmingham about their study, Ponatinib Drives Cardiotoxicity by S100A8/A9-NLRP3-IL-1β Mediated Inflammation. But before I get to the interviews, here are a few article highlights.   Cindy St. Hilaire:        The first article I want to highlight comes from the laboratory of Dr Peter Leary at the University of Washington, and the title is Metabolomic Signatures Associated With Pulmonary Arterial Hypertension Outcomes. Pulmonary Arterial Hypertension or PAH is a rare but life-threatening disease in which progressive thickening of the walls of the lung's blood vessels causes increased blood pressure and that increased blood pressure ultimately damages the heart's right ventricle.   Interestingly, progression to heart failure varies considerably among patients, but the reasons why there is variability are not well understood. To find out, this group turned their attention to patient metabolomes, which differ significantly from those of healthy people and thus may also change with severity. Blood samples from 117 PAH patients were analyzed for more than a thousand metabolites by mass spectrometry and the patient's progress was followed for the next three years. 22 patients died within a three-year period and 27 developed significant right ventricle dilation. Other measures of severity included pulmonary vascular resistance, exercise capacity and levels of BNP, which is a metric of heart health. Two metabolic pathways, those relating to polyamine and histidine metabolism, were found to be linked with all measures of severity suggesting a key role for them in disease pathology. While determining how these pathways influence disease as a subject for further study, the current findings may nevertheless lead to new prognostic indicators to inform patient care.   Cindy St. Hilaire:        The next article I want to discuss is coming from our February 3rd issue of Circulation Research and this is coming from the laboratory of Dr Francisco Violi at the University of Rome and the title is Toll-Like Receptor 4-Dependent Platelet-Related Thrombosis in SARS-CoV-2 Infection. Thrombosis can be a complication of COVID-19 and it is associated with poor outcomes, including death. However, the exact mechanism by which the virus activates platelets, which are the cells that drive thrombosis, is not clear. For one thing, platelets do not appear to express the receptor for SARS-CoV-2. They do however, express the TLR4 receptor and that's a receptor that mediates entry of other viruses as part of the immune response. And TLR4 is ramped up in COVID-19 patient platelets. This group now confirms that, indeed, SARS-CoV-2 interacts with TLR4, which in turn triggers thrombosis.   The team analyzed platelets from 25 patients and 10 healthy controls and they found that the platelet activation and thrombic activity were both boosted in the patient samples and could not be blocked using a TLR4 inhibitor. Additionally, immunoprecipitation and immunofluorescent experiments further revealed colocalization between the virus protein and the TLR4 receptor on patient platelets. The team went on to show that the signaling pathway involved reactive oxygen species producing factors p47phox and Nox2, and that inhibition of phox 47, like that of the TLR4 receptor itsel,f could prevent platelet activation. As such, this study suggests that inhibiting either of these proteins may form the basis of an antithrombotic treatment for COVID-19.   Cindy St. Hilaire:        The third article I want to highlight is coming from the lab of Shi-You Chen at University of Missouri and the title of this article is ADAR1 Non-Editing Function in Macrophage Activation and Abdominal Aortic Aneurysm. Macrophage activation plays a critical role in abdominal aortic aneurysm development, or AAA development. Inflammation is a component of this pathology; however, the mechanisms controlling macrophage activation and vascular inflammation in AAA are largely unknown. The ADAR1 enzyme catalyzes the conversion of adenosine to inosine in RNA molecules and thus this conversion can serve as a rheostat to regulate RNA structure or the gene coding sequence of proteins. Several studies have explored the role of ADAR1 in inflammation, but its precise contribution is not fully understood, so the objective of this group was to study the role of ADAR1 in macrophage activation and AAA formation.   Aortic transplantation was conducted to determine the importance of nonvascular ADAR1 in AAA development and dissection and angiotensin II infusion of ApoE knockout mice combined with a macrophage specific knockout of ADAR1 was used to study the role of ADAR1 macrophage specific contributions to AAA formation and dissection. Allograft transplantation of wild type abdominal aortas to ADAR1 haploinsufficient recipient mice significantly attenuated AAA formation. ADAR1 deficiency in hematopoietic stem cells also decreased the prevalence and the severity of AAA and it also inhibited macrophage infiltration into the aortic wall. ADAR1 deletion blocked the classic macrophage activation pathway. It diminished NF-κB signaling and it enhanced the expression of a number of anti-inflammatory microRNAs. Reconstitution of ADAR1 deficient but not wild type human monocytes to immunodeficient mice blocked the aneurysm formation in transplanted human arteries. Together these results suggest that macrophage ADAR1 promotes aneurysm formation in both mouse and human arteries through a novel mechanism of editing the microRNAs that target NF-κB signaling, which ultimately promotes vascular inflammation in AAA.     Cindy St. Hilaire:        The last article I want to highlight is also from our February 17th issue of Circulation Research and it is coming from the lab of Shintaro Mandai at Tokyo Medical and Dental University and the title of the article is Circulating Extracellular Vesicle Propagated MicroRNA signatures as a Vascular Calcification Factor in Chronic Kidney Disease. Chronic Kidney Disease or CKD accelerates vascular calcification in part by promoting the phenotypic switching of vascular smooth muscle cells to osteoblast like cells. This study investigated the role of circulating small extracellular vesicles or SUVs from the kidneys in promoting this osteogenic switch. CKD was induced in rats and in mice by an adenine induced tubular interstitial fibrosis and serum from these animals induced calcification in in vitro cultures of A-10 embryonic rat smooth muscle cells. Intraperitoneal administration of a compound that prevents SEV biosynthesis and release inhibited thoracic aortic calcification in CKD mice under a high phosphorus diet. In Chronic Kidney Disease, the microRNA transcriptome of SUVs revealed a depletion of four microRNAs and the expression of the microRNAs inversely correlated with kidney function in CKD patients.   In vitro studies found that transected microRNA mimics prevented smooth muscle cell calcification in vitro. In silico analyses revealed that VEGF-A was a convergent target of all four microRNAs and leveraging this, the group used in vitro and in vivo models of calcification to show the inhibition of the VEGF-A, VEGFR-2 signaling pathway mitigated calcification. So in addition to identifying a new potential therapeutic target, these SUV propagated microRNAs are a potential biomarker that can be used for screening patients to determine the severity of CKD and possibly even vascular calcification.   Cindy St. Hilaire:        Today I have with me Dr Hind Lal who's an associate professor of medicine at the University of Alabama Birmingham and his post-doctoral fellow and the lead author of the study Dr Tousif Sultan. And their manuscript is titled Ponatinib Drives Cardiotoxicity by S100A8/A9-NLRP3-IL-1β Mediated Inflammation. And this article is in our February 3rd issue of Circulation Research. So thank you both so much for joining me today.   Tousif Sultan:              Thank you.   Hind Lal:                     Thank you for taking time.   Cindy St. Hilaire:        So ponatinib, it's a tyrosine kinase inhibitor and from my understanding it's the only treatment option for a specific group of patients who have chronic myelogenous leukemia and they have to harbor a specific mutation. And while this drug helps to keep these patients alive essentially, it's extremely cardiotoxic. So cardiotoxicity is somewhat of a new field. So Dr Lal, I was wondering how did you get into this line of research?    Hind Lal:                    So I was fortunate enough to be in the lab of Dr Tom Force and he was kind of father of this new area, now is very developed, it's called cardio-oncology. On those days there were basically everything started in cardio-oncology. So I just recall the first tyrosine kinase approved by FDA was in 2000 and that was... Imagine and our paper came in Nature Medicine 2005 and discovering there is... so to elaborate it a little bit, the cancer therapy broadly divided in two parts. One is called non-targeted therapy like chemotherapy, radiations, et cetera, and then there are cytotoxic drugs. So those cytotoxic drugs because they do not have any targeted name on it so they are, cardiotoxic are toxic to any organ was very obvious and understanding. When these targeted therapy came, which is mainly kinase inhibitor are monoclonal antibodies. So these are targeted to a specific pathway that is activated only in the cancer cells but not in any other cells in the body so they were proposed as like magic bullets that can take off the cancer without any cardiotoxity or minimal side effects. But even in the early phase like 2005 to 2010, these came out, these so-called targeted, they are not very targeted and they are not also the magic bullets and they have serious cardiotoxicity.   Cindy St. Hilaire:        And so what's the mechanism of action of ponatinib in the leukemia and how does that intersect with the cardiovascular system?   Hind Lal:                     Yeah, so this is very good question I must say. So what we believe at this point because, so leukemia if you know is driven by the famous Philadelphia chromosome, which is a translicational gene, one part of human chromosome nine and one part of human chromosome 22 and they translocate make a new gene which is BCR-ABL gene. And because it was discovered in Philadelphia UPENN, is named that Philadelphia chromosome, which is very established mechanism, that's how CML is driven. But what we have discovered that the cardiotoxicity driven by totally, totally different from the ponatinib is one of the inflammatory So it's kind of goodening. So this question is so good. One kind of toxicity is called on-target, when toxicity is mediated by the same mechanism, what is the mechanism of the drug to cure the cancer? So in that case your absolute is minimal because if you manipulate that, the drug's ability to cure the cancer will be affected but if the toxicity and the efficacy is driven by two different mechanism, then as in case of ponatinib seems like it's NLRP3 and inflammasome related mechanism. So this can be managed by manipulating this pathway without hampering the drug efficacy on the cancer.   Cindy St. Hilaire:        So what exactly is cardiotoxicity and how does it present itself in these patients?   Hind Lal:                     So these drugs like ponatinib, they call broader CVD effects. So it's not just cardiac, so they also in hypertensives and atherosclerosis and thrombosis, those kind of thing. But our lab is primarily focused on the heart. So that's why in this paper we have given impresses on the heart. So what we believe at this point that ponatinib lead to this proinflammatory pathway described in this paper, which is just 108A9-NLRP3-IL-1β and this inflammatory pathway lead to a cytokine storm very much like in the COVID-19 and these cytokine storms lead to excessive myocarditis and then finally cardiac dysfunction.   Cindy St. Hilaire:        Is the cytokine storm just local in the cardiac tissue or is it also systemic in the patients? Is cardiotoxicity localized only or is it a more systemic problem?   Tousif Sultan:              I would like to add in this paper we have included that we look this cytokine things and explain blood circulation, bone marrow. So the effect is everywhere, it's not local. So we didn't check other organs, maybe other organs also being affected with the ponatinib treatment.   Cindy St. Hilaire:        And what's the initial phenotype of a patient has when they start to get cardiotoxicity, what's kind of like a telltale symptom?   Hind Lal:                     So good thing that in recent years cardio-oncology developed. So initially the patient that were going for cancer treatment, they were not monitored very closely. So they only end up in cardiology clinic when they are having some cardiac events already. So thanks to the lot of development and growth in the cardio-oncology field, now most patients who going for a long-term cancer treatment, they are closely monitored by cardiology clinics.   Cindy St. Hilaire:        Got it. So they can often catch it before a symptom or an event. That's wonderful.   Hind Lal:                     Yeah, so there's a lot of development in monitoring.   Cindy St. Hilaire:        Wonderful. So you were really interested in figuring out why ponatinib induces cardiotoxicity and you mentioned that really up until now it's been very difficult to study and that's because of the limitation of available murine models. If you just inject a wild type mouse with ponatinib, nothing happens really. So what was your approach to finding relatively good murine models? How did you go about that?   Hind Lal:                     So this is the top scientific question you can ask. So like science, the field is try and try again. So initially this is the first paper with the ponatinib toxicity using the real in vivo models. Any paper before this including ours studies published, they were done on the cellular model in hiPSC, that isolated cardiomyocytes. So you directly putting the ponatinib directly the isolated cells. So this is first case when we were trying to do in vivo, maybe other attempt in vivo but at least not published. So first we also treated the animals with ponatinib and that failed, we don't see any cardiotoxic effect. And then when we going back to the literature, the clinical data is very, very clear from pharmacovigilance that ponatinib is cardiotoxic in humans. So when we're not able to see any phenotype in mouse, we realize that we are not mimicking what's happening in the humans.   So we certainly missing something. Now once again I quote this COVID-19, so many people get infected with COVID-19 but people are having preexisting conditions are on high risk to developing CVD. So there was some literature on that line. So we use this very, very same concept that if there is preexisting conditions, so likely who'd have developing future cardiac event will be more. So we use two model in this paper one atherosclerosis model which is APoE null mice mice, another is tag branding which is pressure overload model for the heart and as soon as we start using what we call comorbidity model like patient is having some preexisting conditions and we very clearly see the robust defect of ponatinib on cardiac dysfunction.   Cindy St. Hilaire:        Yeah, it's really, really well done and I really like that you use kind of two different models of this. Do you think it's also going to be operative in maybe like the diabetic mirroring models? Do you think if we expand to other comorbidities, you might also recapitulate the cardiotoxicity?   Hind Lal:                     So you got all the best questions.   Cindy St. Hilaire:        Thank you. I try.   Hind Lal:                     So because this is CML drug and lot of the risk factor for cardiovascular and cancer are common and even metabolic disease. So most of the time these patients are elderly patients and they're having metabolic conditions and most of the time they have blood pressure or something CVD risk factors. So I agree with you, it'll be very relevant to expand this to the diabetes or metabolic models, but these were the first study, we put all our focus to get this one out so news is there then we can expand the field adding additional models et cetera. But I agree with you that will be very logical next step to do.   Cindy St. Hilaire:        Yeah. And so I guess going back to what you know from the human study or the clinical trials or the human observations, are different populations of patients with CML more predisposed to cardio toxicity than others or is that not known yet?   Hind Lal:                     So one other area called pharmacovigilance. So what pharmacovigilance does patient all over the world taking these drugs. So WHO have their own vigilance system and FDA have their own, so it's called BG-Base for the WHO and it's called the FAERS for the FDA. So one can go back in those data sets and see if X patient taking this Y drug and what kind of symptoms or adverse effect they are seeing and if these symptoms are associated with something else. So there is data that if patients having CVD risk factor, they are more prone to develop ponatinib induced cardiac events. But it needs more polish like you asked the just previous question, diabetes versus maybe blood pressure means hypertension, atherosclerosis, or thrombosis. So it has not been delineated further but in a one big bucket if patients are having CVD risk factor before they are more prone and more likely to develop the cardiac events.   Cindy St. Hilaire:        So after you established that these two murine models could pretty robustly recapitulate the human phenotype, what did you do next? How did you come upon the S100A8/A9-NLRP3-IL-1β signaling circuit? How did you get to that?   Hind Lal:                     So in basic science work, whenever we do mouse is called until we get there is cardiac dysfunction, it's called phenotype, right? So mouse had a cardiac phenotype. So next step is, "Why? What is leading to that phenotype?" That's what we call mechanism. So there the best idea to fit the mechanism is using one of the unbiased approaches like you do unbiased proteomics, unbiased RNC analysis, something like this that will analyze the entire transcript like RNC and say, "Okay, these pathway are," then you can do further analysis that will indicate these pathway are different, are altered. So in this case we used RNC analysis and it came out that this yes A8 and yes A9, 100A8 and nine, they were the most upregulated in this whole set. And thereafter we were very lucky. So we started this study at Vanderbilt, where my lab was and thereafter we very lucky to move here and found Sultan who had a lot of experience with this inflammation and immune system and then Sultan may add something on this so he'll be the better person to say something on this.   Tousif Sultan:              So after our RNC analysis, so we got this S100A8 and nine as top hit with the ponatinib treatment. So then we validated this finding with our flow cytometric, qRT PCR aand then we started which pathway is going to release cytokine and all that. So we found that is NLRP3 inflammasome.   Cindy St. Hilaire:        Yeah and well and I guess maybe step back, what is S100A8/A9? What are those? Tousif Sultan:              Yeah, S10A8/A9 is a calcium binding protein. So that's also called alarmin and they basically binds with the pathogen associated pattern and other TLR2 like receptors and then start inflammatory pathway to release cytokine and all that and it's stable in heterodimer form. So S100A8 heterodimer with A9 and then bind with TLR and a start in this inflammatory pathway.   Cindy St. Hilaire:        And what type of cell is that happening in? Is that happening in the immune cells only or is it also in the cardiomyocyte, or...?   Tousif Sultan:              Yeah, we have included all this data. So from where this alarmin is coming with ponatinib treatment, so literature also suggested that neutrophils and monocytes, those cells are the potential to release the alarmin. So here we also found these two type of cells, neutrophils and monocytes. They release huge alarmin with the treatment of ponatinib.   Cindy St. Hilaire:        And so really taking this really neat mechanism to the next level, you then tried attenuating it by using broad anti-inflammatory steroid dexamethasone but also by targeting these specific components, the NLRP and the S100A specific inhibitors and they worked well. It worked really nicely. Does your data show that any of these therapies work better than the other and then are these viable options to use in humans?   Hind Lal:                     Yeah, we have some data in the paper. Are very broad which help a lot in COVID patients, far very acute infections. So in this case, situation is very different cause most of CML patients will going to take ponatinib for lifelong, there is no remission, right? So in those case, its certainly not a very attractive option. We have shown data in the paper that dexamethasone help with the heart but lead to some metabolic changes. So we have compared those with the NLRP3 inhibitors, those metabolic alterations, dexa versus the NLRP3 inhibitors, CY-09. And we demonstrated that targeting is specifically with paquinimod, our NLRP3 inhibitor CY-09, feel better. It can still rescue the cardiac phenotype without having those adverse effect on metabolic parameters.   Cindy St. Hilaire:        That's wonderful. Do you think though that because you have to take ponatinib for life, that long-term NLRP inhibition would also cause problems or...?   Hind Lal:                     So because not every patient who taking ponatinib would develop the cardiac phenotype, right? Which is like a 10%, 12%, patient developing cardiac dysfunction. So I think someone like I strongly believe paquinimod, which is inhibitor of S100A9, will be really good option or at least we have enough data that make us nail for at least a small clinical trial. And we quickly moving on that. At UAB we have our clinical cardio-oncology program and we are already in touch with the director for the clinical cardio-oncology program. So what we trying to do in that small trial is if one of the standard therapy for heart like beta blocker or ARBs inhibitor, is there any preference like one work better than the other in the standard care? So first we doing that project, then we obviously looking forward if one small clinical trial can be done with paquinimod. I strongly believe it should be helpful.   Cindy St. Hilaire:        That is wonderful. And so do you think... There's other chemotherapeutic agents or probably even other non-cancer drugs that cause cardiotoxicity, do you think this mechanism, this pathway, this S100A-NLRP-IL-1β axis is operative in all cardiotoxicities or do you think it's going to be very specific to the ponatinib?   Hind Lal:                     So it's certainly not all, but it'll be certainly more than ponatinib. So in our lab we are using another kinase inhibitor, which is osimertinib and it's not published yet, but now we know that it's also cardiotoxic because it's taking metabolic root or energetics disruption but not this pro-inflammatory part, but we're doing another project which is strep pneumonia induced cardiac dysfunction, which is called pneumonia. So strep pneumoniae, which leads to the pneumonia ,and lot patient die because of the failing heart we see here in the hospitals and we see these pathways operational over there and we gearing up to do clinical trial on that aspect as well, but it's not generalized like all kind of heart will have the same mechanism.   Cindy St. Hilaire:        It's wonderful to see you're already taking those next steps towards really kind of bringing this to a translational/clinical study. So what was the most challenging aspect of this study?   Tousif Sultan:              The challenging aspect, ponatinib is a kinase inhibitor and that was surprising for us how it's activating immune cells. Generally kinase inhibitors, inhibits all the cells like that. So that was challenging. So we repeated it many times did in vitro experiment to confirm that. So we just added, just treated in vitro immune cells with the ponatinib and confirmed it. So that was little challenging.   Cindy St. Hilaire:        So what's next? You mentioned you're going to try some clinical trials, early stage clinical trials. What's next mechanistically, what do you want to go after?   Hind Lal:                     So what we are doing next and we are very, very eagerly trying to do that. So what it was done, we used the cardiac comorbidity models, but as you know, anybody who will take ponatinib will have cancer, right? So we strongly believe that we miss one factor. There was no cancer on these. So that is very logical next step. What that will allow us to do, what rescue experiment we'll have done in this paper. So we saw, "Okay, this rescue the cardiac phenotype, which is taken care of now," but very same time, we not able to demonstrate that this is happening without hurting the cancer efficacy. So if we have the dual comorbid mouse, which have CML a real thing and we have cardiac thing, then that will allow us to demonstrate, "Okay, we got something that can take care of the cardiac problem without hurting the efficacy on the cancer." And it will be best if you also help little bit to more potentiate the cancer efficacy.   Cindy St. Hilaire:        Yes. Excellent. Well, congratulations on a beautiful study, really exciting findings. Dr Lal and Dr Sultan, thank you so much for taking the time to talk with me today.   Tousif Sultan:              Thank you so much.   Hind Lal:                     Well thank you, Cynthia. We really appreciate your time. Thank you for having us.   Cindy St. Hilaire:        Yeah, it was great.   Cindy St. Hilaire:        That's it for our highlights from the February 3rd and February 17th issues of Circulation Research. Thank you so much for listening. Please check out the Circulation Research Facebook page and follow us on Twitter and Instagram with the handle @CircRes and #DiscoverCircRes. Thank you to our guests, Dr Hind Lal and Dr Tousif Sultan. This podcast is produced by Ishara Ratnayake, edited by Melissa Stoner and supported by the editorial team at Circulation Research. Some of the copy text for the highlighted articles was provided by Ruth Williams. I'm your host, Dr Cynthia St. Hilaire, and this is Discover CircRes, you're on-the-go source for most exciting discoveries in basic cardiovascular research. This program is copyright of the American Heart Association 2023. And the opinions expressed by the speakers in this podcast are their own and not necessarily those of the editors or of the American Heart Association. For more information, please visit ahajournals.org.  

PaperPlayer biorxiv neuroscience
Endogenous inflammatory mediators produced by injury activate TRPV1 and TRPA1 nociceptors to induce sexually dimorphic cold pain that is dependent on TRPM8 and GFRalpha3

PaperPlayer biorxiv neuroscience

Play Episode Listen Later Jan 23, 2023


Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2023.01.23.525238v1?rss=1 Authors: Yang, C., Yamaki, S., Jung, T., Kim, B., Huynh, R., McKemy, D. D. Abstract: The detection of environmental temperatures is critical for survival, yet inappropriate responses to thermal stimuli can have a negative impact on overall health. The physiological effect of cold is distinct among somatosensory modalities in that it is soothing and analgesic, but also agonizing in the context of tissue damage. Inflammatory mediators produced during injury activate nociceptors to release neuropeptides, such as CGRP and substance P, inducing neurogenic inflammation which further exasperates pain. Many inflammatory mediators induce sensitization to heat and mechanical stimuli but, conversely, inhibit cold responsiveness, and the identity of molecules inducing cold pain peripherally is enigmatic, as are the cellular and molecular mechanisms altering cold sensitivity. Here, we asked if inflammatory mediators that induce neurogenic inflammation via the nociceptive ion channels TRPV1 and TRPA1 lead to cold pain in mice. Specifically, we tested cold sensitivity in mice after intraplantar injection of lysophosphatidic acid (LPA) or 4-hydroxy-2-nonenal (4HNE), finding each induces cold pain that is dependent on the cold-gated channel TRPM8. Inhibition of either CGRP, substance P, or toll-like receptor 4 (TLR4) signaling attenuates this phenotype, and each neuropeptide produces TRPM8-dependent cold pain directly. Further, the inhibition of CGRP or TLR4 signaling alleviates cold allodynia differentially by sex. Lastly, we find that cold pain induced by inflammatory mediators and neuropeptides requires the neurotrophin artemin and its receptor GFRalpha3. These results demonstrate that tissue damage alters cold sensitivity via neurogenic inflammation, likely leading to localized artemin release that induces cold pain via GFRalpha3 and TRPM8. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC

PaperPlayer biorxiv neuroscience
Maternal diesel exposure and maternal choline supplementation interactions in fetal and placental immune factors

PaperPlayer biorxiv neuroscience

Play Episode Listen Later Jan 5, 2023


Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2023.01.04.522511v1?rss=1 Authors: Maurer, S. V., Bolton, J. L., Bilbo, S. D., Williams, C. L. Abstract: Air pollution causes widespread inflammatory changes in the body and brain. When exposure to air pollution occurs early in development, children exhibit impaired working memory ability (Sunyer et al., 2015). In addition, prenatal exposure to diesel particulate matter (DEP) increases inflammatory cytokine expression in the whole brain of embryonic day 18 (E18) males and leads to adverse long-term negative outcomes (Bolton et al., 2012). In contrast, dietary choline supplementation is negatively correlated with inflammatory cytokine production in adult rats and cultured human cells (Zhang et al., 2018; Jiang et al., 2014). When administered as a supplement to pregnant rats, choline also improves working memory in adulthood (Meck et al., 2008; Meck & Williams, 1999; 1997). The current study sought to determine if prenatal dietary choline supplementation protects against the effects of air pollution in the developing brain and in the placenta and fetal liver. These data revealed region-specific microglial morphology alterations in fetal brain and in inflammatory gene expression in the placenta and fetal liver (specifically, Tnf, Tlr2, Tlr4, and Itgam) due to maternal choline supplementation and/or maternal air pollution exposure. We found that DEP led to changes in microglial morphology in the fetal dentate gyrus of E18 male, but not female, fetuses. In the placenta and fetal liver of males, inflammatory gene expression was affected by both DEP and maternal choline supplementation. However, maternal choline supplementation alone upregulated inflammatory gene expression in females, which may indicate an alteration in maturation rate. These data further contribute to the growing literature indicating region- and tissue-specificity in the developmental immune system in the context of maternal exposures. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC

Authentic Biochemistry
Holiday Ethanol Use VIII. EtOH induced cAMP /CREB associated PKA kinase driven phosphorylation cascade co-opts the TLR4-mediated neuroinflammatory/neurotoxic CNS-microglial axis.DJGPhD.22.12.22.AB.

Authentic Biochemistry

Play Episode Listen Later Dec 23, 2022 30:00


References Neural Plasticity. 2019; 2019: 1648736. Molecular Pharmacology May 2017, 91 (5) 451-463. --- Send in a voice message: https://anchor.fm/dr-daniel-j-guerra/message

Blood Podcast
Sickle hemoglobin activates monocytes via TLR4, germinal center B cells provide a niche for T-cell lymphoma, and a combination immunosuppression regimen for acquired hemophilia A

Blood Podcast

Play Episode Listen Later Nov 3, 2022 17:37


In this week's episode, we will review a study that cell-free hemoglobin S was found to induce high levels of pro-inflammatory cytokine production in monocytes. The effect is mediated by Toll-like receptor 4, or TLR4, suggesting intriguing therapeutic possibilities for sickle cell disease.  Secondly, germinal center B cells with aberrant expression profiles undergo independent clonal evolution in the microenvironment of angioimmunoblastic T-cell lymphoma. New findings published in Blood elucidate mechanisms of disease pathogenesis and uncover a new potential target for treatment. Finally, an upfront combination of three immunosuppressive agents was highly effective and well tolerated in patients with acquired hemophilia A. Although prospective studies are needed, the triple regimen could be an attractive treatment option, particularly for elderly and frail patients.

The Energy Balance Podcast
Ep. 89: The Anti-Inflammatory Effects of Fruit Juice and The Hormonal Effects of PUFA vs. SFA

The Energy Balance Podcast

Play Episode Listen Later Oct 12, 2022 65:22


In this episode we discuss: Whether PUFA causes more oxidative stress than saturated fats How PUFA intake affects testosterone Whether fruit juice should be avoided for blood sugar regulation The effects of fruit juice on inflammatory markers and endotoxin Whether fruit juice has the same effects as soda   Check out the Energy Balance Solution group coaching program: https://jayfeldmanwellness.com/solution   Click here to check out the show notes: https://www.jayfeldmanwellness.com/ep-89-the-anti-inflammatory-effects-of-fruit-juice-and-the-hormonal-effects-of-pufa-vs-sfa/    Timestamps: 4:10 – the effects of different dietary fat compositions on phospholipid and neutral lipid compositions in the testicles   18:31 – the effects of different dietary fat composition on oxidative damage and antioxidant status in the testicles 29:44 – the effects of different dietary fat composition on hormone production and metabolism in the testicles  38:26 – introducing the next study discussing the effects of orange juice on a high-fat, high-carbohydrate meal in terms of inflammation and endotoxin   44:14 – the effects of orange juice on blood glucose and insulin sensitivity  47:55 – the effects of orange juice on ROS production, TLR2 and TLR4 expression, and plasma endotoxin  51:35 – factors that could account for the benefits of orange juice   

PaperPlayer biorxiv neuroscience
Site-Specific Knockdown of Microglia in the Locus Coeruleus Regulates Hypervigilant Responses to Social Stress in Female Rats

PaperPlayer biorxiv neuroscience

Play Episode Listen Later Oct 5, 2022


Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2022.10.03.509934v1?rss=1 Authors: Pate, B. S., Bouknight, S. J., Harrington, E. N., Mott, S. E., Augenblick, L. M., Smiley, C. E., Morgan, C. G., Calatayud, B. M., Martines-Muniz, G. A., Thayer, J. F., Wood, S. K. Abstract: Background: Women are at increased risk for psychosocial stress-related anxiety disorders, yet mechanisms regulating this risk are unknown. Psychosocial stressors activate microglia, and the resulting neuroimmune responses that females exhibit heightened sensitivity to may serve as an etiological factor in their elevated risk. However, studies examining the role of microglia during stress in females are lacking. Methods: Microglia were manipulated in the stress-sensitive locus coeruleus (LC) of female rats in the context of social stress in two ways. First, intra-LC lipopolysaccharide (LPS; 0 or 3g/side, n=5-6/group), a potent TLR4 agonist and microglial activator, was administered. One hour later, rats were exposed to control or an aggressive social defeat encounter between two males (WS, 15-min). In a separate study, females were treated with intra-LC or intra-central amygdala mannosylated liposomes containing clodronate (m-CLD; 0 or 25g/side, n=13-14/group), a compound toxic to microglia. WS-evoked burying, cardiovascular responses, and sucrose preference were measured. Brain and plasma cytokines were quantified, and cardiovascular telemetry assessed autonomic balance. Results: Intra-LC LPS augmented the WS-induced burying response and increased plasma corticosterone and interleukin-1{beta} (IL-1{beta}). Further, the efficacy and selectivity of microinjected m-CLD was determined. In the context of WS, intra-LC m-CLD attenuated the hypervigilant burying response during WS as well as the accumulation of intra-LC IL-1{beta}. Intra-central amygdala m-CLD had no effect on witness stress-evoked behavior. Conclusions: These studies highlight an innovative method for depleting microglia in a brain region specific manner and indicate that microglia in the LC differentially regulate hypervigilant WS-evoked behavioral and autonomic responses. Copy rights belong to original authors. Visit the link for more info Podcast created by PaperPlayer

PaperPlayer biorxiv neuroscience
Baseline and morphine-induced rat microglial phagocytic activity is regulated by sex, brain region, and density interactions ex vivo

PaperPlayer biorxiv neuroscience

Play Episode Listen Later Oct 4, 2022


Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2022.10.03.510683v1?rss=1 Authors: King'uyu, D., Nti-Kyemereh, L., Tram, M., Kopec, A. M. Abstract: Opioids have long been used for clinical pain management, but also have addictive properties that have contributed to the ongoing opioid epidemic. While opioid activation of opioid receptors is well known to contribute to reward and reinforcement, data now also suggest that opioid activation of immune signaling via toll-like receptor 4 (TLR4) may also play a role in addiction-like processes. TLR4 expression is enriched in immune cells in peripheral organs and blood and in the nervous system is primarily expressed in microglia, the resident immune cells of the central nervous system. In peripheral immune cells, morphine is repeatedly shown to decreases immune activation and phagocytosis in vivo and in vitro. Phagocytosis is an important immune effector that serves to clear damage, debris, and infection. Unlike peripheral immune cells, the effect of morphine on microglia is less well studied. Morphine is reported to both increase and decrease microglial phagocytosis. Several different factors contribute to microglial phagocytic activity, including sex, region, and local microglial density. We hypothesized that morphine increases phagocytic activity in microglia, but in a density-, dose-, region-, and sex-dependent manner ex vivo. To test this, we isolated microglia from adult male and female rat cortex and striatum and plated them ex vivo at a relatively low or high density. Microglia were incubated with neutral fluorescent microbeads to stimulate phagocytosis in the presence of one of four morphine doses. We found that brain region of origination and plating density, but not sex, impacted microglial phagocytosis at baseline. These heterogenous properties further diverge when morphine is applied causing emergence of effects not observed at baseline, maintenance of some baseline effects, and disappearance of effects observed at baseline. Further work is necessary to identify the precise interactions and signaling that is dominant in different sex, region, and density contexts to better understand the complex effects of opioids on microglial immunoregulation. Copy rights belong to original authors. Visit the link for more info Podcast created by PaperPlayer

PaperPlayer biorxiv neuroscience
MyD88-TLR4-dependent choroid plexus activation precedes perilesional inflammation and edema in intracerebral hemorrhage

PaperPlayer biorxiv neuroscience

Play Episode Listen Later Sep 6, 2022


Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2022.09.06.506660v1?rss=1 Authors: Akeret, K., Buzzi, R. M., Thomson, B. R., Schwendinger, N., Klohs, J., Schulthess, N., Baselgia, L., Hansen, K., Regli, L., Vallelian, F., Hugelshofer, M., Schaer, D. Abstract: The functional neurological outcome of patients with intracerebral hemorrhage (ICH) strongly relates to the degree of secondary brain injury (ICH SBI) evolving within days after the initial bleeding. Different mechanisms including the incitement of inflammatory pathways, dysfunction of the blood brain barrier (BBB), activation of resident microglia, and an influx of blood-borne immune cells, have been hypothesized to contribute to ICH SBI. Yet, the spatiotemporal interplay of specific inflammatory processes within different brain compartments has not been sufficiently characterized, limiting potential therapeutic interventions to prevent and treat ICH SBI. Using a whole-blood injection model in mice, we systematically characterized the spatial and temporal dynamics of inflammatory processes after ICH using 7 Tesla magnetic resonance imaging (MRI), spatial RNA sequencing (spRNAseq), functional BBB assessment, and immunofluorescence average intensity mapping. We identified a pronounced early response of the choroid plexus (CP) peaking at 12 to 24h, that was characterized by inflammatory cytokine expression, epithelial and endothelial expression of leukocyte adhesion molecules, and the accumulation of leukocytes. In contrast, we observed a delayed secondary reaction pattern at the injection site (striatum) peaking at 96h, defined by gene expression corresponding to perilesional leukocyte infiltration and correlating to the delayed signal alteration seen on MRI. Pathway analysis revealed a dependence of the early inflammatory reaction in the CP on toll-like receptor 4 (TLR4) signaling via myeloid differentiation factor 88 (MyD88). TLR4 and MyD88 knockout mice corroborated this observation, lacking the early upregulation of adhesion molecules and leukocyte infiltration within the CP 24h after whole-blood injection. In conclusion, we report a biphasic brain reaction pattern after ICH with a MyD88 TLR4 dependent early inflammatory response of the CP, preceding inflammation, edema and leukocyte infiltration at the lesion site. Pharmacological targeting of the early CP activation might harbor the potential to modulate the development of ICH SBI. Copy rights belong to original authors. Visit the link for more info Podcast created by PaperPlayer

PaperPlayer biorxiv neuroscience
ACAT1/SOAT1 Blockade Suppresses LPS-Mediated Neuroinflammation by Modulating the Fate of Toll-Like Receptor 4 in Microglia

PaperPlayer biorxiv neuroscience

Play Episode Listen Later Sep 2, 2022


Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2022.08.30.505911v1?rss=1 Authors: Li, H., Huynh, T. N., Duong, M. T., Gow, J., Chang, C. C., Chang, T. Y. Abstract: Background: Cholesterol is essential for growth and maintenance of mammalian cells. It is stored as cholesteryl esters by the enzymes acyl-CoA:cholesterol acyltransferases 1 & 2 (ACAT 1 & 2 ) (Sterol O-acyltransferase 1 & 2 ; SOATs in GenBank). ACAT1 blockade (A1B) in macrophages ameliorates various pro-inflammatory responses elicited by lipopolysaccharides (LPS) or by cholesterol loading. In mouse and human brains, Acat1 expression dominates over Acat2 and Acat1 is elevated in many neurodegenerative diseases and in acute neuroinflammation. However, the possible effects of ACAT1 blockade in neuroinflammation, regulated by mediators such as Toll-Like Receptor 4 (TLR4), has not been studied. Methods: We conducted LPS-induced acute neuroinflammation experiments in control vs myeloid specific or neuron specific Acat1 knockout (KO) mice. Furthermore, we evaluated LPS-induced neuroinflammation in the microglial cell line N9 with or without pre-treatment of the small molecule ACAT1-specific inhibitor K-604. Biochemical and microscopy assays were used to monitor inflammatory responses and the fate of TLR4. Results: In vivo studies revealed that Acat1 inactivation in myeloid cell lineage, but not in neurons, markedly attenuated LPS-induced activation of various pro-inflammatory response genes in hippocampus and cortex. Studies in cell culture showed that pre-incubating cells with K-604 significantly ameliorated the pro-inflammatory responses induced by LPS. In cells acutely treated with LPS (for 30 min), pre-incubation with K-604 significantly increased the endocytosis of TLR4, the major transmembrane signaling receptor that mediates LPS-dependent acute neuroinflammation. In cells chronically treated with LPS (for 24-48 hrs), pre-incubation with K-604 significantly decreased the total TLR4 protein content, presumably due to enhanced trafficking of TLR4 to the lysosomes for degradation. For ex vivo evidence, we isolated microglia from adult mice, and found that in mice without LPS stimulation, myeloid Acat1 inactivation altered cellular distribution of TLR4; in mice with LPS stimulation, myeloid Acat1 inactivation decreased the cellular content of TLR4. Conclusion: Blocking ACAT1 in mouse microglia alters the fate of TLR4 and suppresses its ability to participate in pro-inflammatory signaling cascade in response to LPS. Copy rights belong to original authors. Visit the link for more info Podcast created by PaperPlayer

MedCram
Episode 37. Near Infrared Light Reduces Inflammation via TLR4 In Vitro

MedCram

Play Episode Listen Later Aug 17, 2022 21:19


Roger Seheult, MD of MedCram explains how near infrared light reduces inflammation via TLR4. See all Dr. Seheult's videos at: https://www.medcram.com (This video was recorded on August 16, 2022) Roger Seheult, MD is the co-founder and lead professor at https://www.medcram.com He is Board Certified in Internal Medicine, Pulmonary Disease, Critical Care, and Sleep Medicine and an Associate Professor at the University of California, Riverside School of Medicine. MEDCRAM WORKS WITH MEDICAL PROGRAMS AND HOSPITALS: MedCram offers group discounts for students and medical programs, hospitals, and other institutions. Contact us at customers@medcram.com if you are interested. MEDIA CONTACT: Media Contact: customers@medcram.com Media contact info: https://www.medcram.com/pages/media-contact Video Produced by Kyle Allred FOLLOW US ON SOCIAL MEDIA: https://www.facebook.com/MedCram https://twitter.com/MedCramVideos https://www.instagram.com/medcram DISCLAIMER: MedCram medical videos are for medical education and exam preparation, and NOT intended to replace recommendations from your doctor. #COVID19 #Omicron #Coronavirus

Oncotarget
Press Release: Novel Regulatory Mechanism of GLI3 by Toll-like Receptor Signaling

Oncotarget

Play Episode Listen Later Aug 9, 2022 4:35


A new research paper was published in Oncotarget on August 3, 2022, entitled, “A novel mechanism of regulation of the oncogenic transcription factor GLI3 by toll-like receptor signaling.” The transcription factor GLI3 is a member of the GLI family and has been shown to be regulated by canonical hedgehog (HH) signaling through smoothened (SMO). Little is known about SMO-independent regulation of GLI3. “Hedgehog (HH) signaling is well known for its role in embryonic development, cancer and inflammation [1–4]. At the center of HH signaling are the 2 receptors patched (PTCH1) and smoothened (SMO) along with GLI transcription factors [5]. In the absence of HH ligand, PTCH1 inhibits SMO.” In this study, researchers (Stephan J. Matissek, Mona Karbalivand, Weiguo Han, Ava Boutilier, Estefania Yzar-Garcia, Laura L. Kehoe, Devin Storm Gardner, Adam Hage, Krista Fleck, Vicki Jeffers, Ricardo Rajsbaum, and Sherine F. Elsawa) from the University of New Hampshire and University of Texas Medical Branch identified toll-like receptor (TLR) signaling as a novel pathway regulating GLI3 expression. The researchers showed that GLI3 expression is induced by LPS/TLR4 in human monocyte cell lines and peripheral blood CD14+ cells. Further analysis identified TRIF, but not MyD88, signaling as the adapter used by TLR4 to regulate GLI3. Using pharmacological and genetic tools, they identified IRF3 as the transcription factor regulating GLI3 downstream of TRIF. “Furthermore, using additional TLR ligands that signal through TRIF such as the TLR4 ligand, MPLA and the TLR3 ligand, Poly(I:C), we confirm the role of TRIF-IRF3 in the regulation of GLI3.” They found that IRF3 directly binds to the GLI3 promoter region and this binding was increased upon stimulation of TRIF-IRF3 with Poly(I:C). Using Irf3−/− MEFs, the researchers found that Poly(I:C) stimulation no longer induced GLI3 expression. Finally, using macrophages from mice lacking Gli3 expression in myeloid cells (M-Gli3−/−), they found that in the absence of Gli3, LPS stimulated macrophages secrete less CCL2 and TNF-α compared with macrophages from wild-type (WT) mice. “Taken together, these results identify a novel TLR-TRIF-IRF3 pathway that regulates the expression of GLI3 that regulates inflammatory cytokines and expands our understanding of the non-canonical signaling pathways involved in the regulation of GLI transcription factors.” DOI: https://doi.org/10.18632/oncotarget.28261 Correspondence to: Sherine F. Elsawa – Email: sherine.elsawa@unh.edu Keywords: GLI3, inflammation, TLR About Oncotarget: Oncotarget (a primarily oncology-focused, peer-reviewed, open access journal) aims to maximize research impact through insightful peer-review; eliminate borders between specialties by linking different fields of oncology, cancer research and biomedical sciences; and foster application of basic and clinical science. To learn more about Oncotarget, visit Oncotarget.com and connect with us on social media: Twitter – https://twitter.com/Oncotarget Facebook – https://www.facebook.com/Oncotarget YouTube – www.youtube.com/c/OncotargetYouTube Instagram – https://www.instagram.com/oncotargetjrnl/ LinkedIn – https://www.linkedin.com/company/oncotarget/ Pinterest – https://www.pinterest.com/oncotarget/ LabTube – https://www.labtube.tv/channel/MTY5OA SoundCloud – https://soundcloud.com/oncotarget For media inquiries, please contact: media@impactjournals.com. Oncotarget Journal Office 6666 East Quaker Str., Suite 1A Orchard Park, NY 14127 Phone: 1-800-922-0957 (option 2)

The Gary Null Show
The Gary Null Show - 08.02.22

The Gary Null Show

Play Episode Listen Later Aug 2, 2022 52:58


Videos: All Found on Youtube TikTok Is Worse Than You Thought Joe Reviews TikTok's Crazy Terms of Service   HEALTH NEWS  Lutein may counter cognitive aging, study finds A stable gut helps elite athletes perform better Could Spirulina modify the microbiome to protect against age-related damage? It doesn't matter much which fiber you choose—just get more fiber Plant-based meat ‘healthier and more sustainable than animal products,' according to new study Pine Bark Extract Treats Meniere's Disease Lutein may counter cognitive aging, study finds University of Illinois, July 25, 2022 Spinach and kale are favorites of those looking to stay physically fit, but they also could keep consumers cognitively fit, according to a new study from University of Illinois researchers. The study, which included 60 adults aged 25 to 45, found that middle-aged participants with higher levels of lutein – a nutrient found in green leafy vegetables such as spinach and kale, as well as avocados and eggs — had neural responses that were more on par with younger individuals than with their peers. The findings were published in the journal Frontiers in Aging Neuroscience. “Now there's an additional reason to eat nutrient-rich foods such as green leafy vegetables, eggs and avocados,” said Naiman Khan, a professor of kinesiology and community health at Illinois. “We know these foods are related to other healthbenefits, but these data indicate that there may be cognitive benefits as well.” Lutein is a nutrient that the body can't make on its own, so it must be acquired through diet. Lutein accumulates in brain tissues, but also accumulates in the eye, which allows researchers to measure levels without relying on invasive techniques. The Illinois researchers measured lutein in the study participants' eyes by having participants look into a scope and respond to a flickering light. Then, using electrodes on the scalp, the researchers measured neural activity in the brain while the participants performed a task that tested attention. “The neuro-electrical signature of older participants with higher levels of lutein looked much more like their younger counterparts than their peers with less lutein,” Walk said. “Lutein appears to have some protective role, since the data suggest that those with more lutein were able to engage more cognitive resources to complete the task.” Next, Khan's group is running intervention trials, aiming to understand how increased dietary consumption of lutein may increase lutein in the eye, and how closely the levels relate to changes in cognitive performance. A stable gut helps elite athletes perform better Anglia Ruskin University, July 29, 2022 New research has found that microbial instability in the gut could hinder the performance of elite endurance athletes, and that short-term, high-protein diets are associated with this type of imbalance. Researchers from across the UK analyzed the performance and gut health of a group of well-matched, highly trained endurance runners, to explore the impact of both high-protein and high-carbohydrate diets. The study found that in those following a high-protein regime, this resulted in a disturbance in the stability of the gut microbiome. This was also accompanied by a 23.3% reduction in time trial performance. Analysis found a significantly reduced diversity and altered composition of the gut phageome, as well as higher levels of certain types of virals and bacterial compartments. Those participants whose gut microbiome was more stable performed better during time trials. Those following a high-carbohydrate diet resulted in an improved time trial performance of 6.5%. Could Spirulina modify the microbiome to protect against age-related damage? Louvain Drug Research Institute (Belgium), July 28, 2022 Spirulina might help protect against age-related liver inflammation by modifying pathways in the microbiome, say researchers. Consumption of spirulina could help protect against hepatic inflammation in the elderly, according to the new animal research published in Nutrients. Belgian researchers carried out tests on mice, which suggest that the algae Spirulina has an impact on the gut microbiota, which in turn activates the immune system in the gut and improves inflammation in the liver that is associated with ageing. Led by senior author Professor Nathalie Delzenne from the Louvain Drug Research Institute in Belgium, the team said oral feeding of Spirulina was found to modulates several immunological functions involving, among others, the TLR4 pathway in old mice. “The fact that its oral consumption can influence both gut immunity and systemic sites, such as the liver, suggests that its immune action is not confined to the gut immune system,” wrote the team – who said the findings open the way to new therapeutic tools “in the management of immune alterations in aging, based on gut microbe-host interactions.” Furthermore, they suggested that improvement of the homeostasis in the gut ecosystem ‘could be essential' during the aging process, “and, in this perspective, dietary manipulation of the gut microbiota of the elderly with Spirulina, may represent a tool for preserving a healthy gastrointestinal microbial community in addition to its beneficial effects on immune function.” It doesn't matter much which fiber you choose—just get more fiber Duke University, July 30, 2022 That huge array of dietary fiber supplements in the drugstore or grocery aisle can be overwhelming to a consumer. They make all sorts of health claims too, not being subject to FDA review and approval. So how do you know which supplement works and would be best for you? A rigorous examination of the gut microbes of study participants who were fed three different kinds of supplements in different sequences concludes that people who had been eating the least amount of fiber before the study showed the greatest benefit from supplements, regardless of which ones they consumed. “The people who responded the best had been eating the least fiber to start with,” said study leader Lawrence David, an associate professor of molecular genetics and microbiology at Duke University. When your gut bugs are happily munching on a high-fiber diet, they produce more of the short-chain fatty acids that protect you from diseases of the gut, colorectal cancers and even obesity. And in particular, they produce more of a fatty acid called butyrate, which is fuel for your intestinal cells themselves. Butyrate has been shown to improve the gut's resistance to pathogens, lower inflammation and create happier, healthier cells lining the host's intestines. “We didn't see a lot of difference between the fiber supplements we tested. Rather, they looked interchangeable,” David said during a tour of his sparkling new lab in the MSRB III building Plant-based meat ‘healthier and more sustainable than animal products,' according to new study University of Bath (UK), July 30, 2022 Plant-based dietary alternatives to animal products are better for the environment and for human health when compared with the animal products they are designed to replace, say the authors of a new study. A new paper published in Future Foods argues that because these foods are “specifically formulated to replicate the taste, texture, and overall eating experience of animal products,” they are a much more effective way of reducing demand for meat and dairy than simply encouraging people to cook vegetarian whole foods. The study, conducted by psychologists at the University of Bath, concludes that plant-based meat and dairy alternatives “offer a healthier and more environmentally sustainable solution which takes into account consumer preferences and behavior.” The review examined 43 studies into the health and environmental impacts of plant-based foods, as well as consumer attitudes. One study found that almost 90% of consumers who ate plant-based meat and dairy were in fact meat-eaters or flexitarians; another found that plant-based products with a similar taste, texture, and price to processed meat had the best chance of replacing meat. The paper also found that these plant-based products caused lower levels of greenhouse gas emissions than the animal products they were replacing. One paper found replacing 5% of German beef consumption with pea protein could reduce CO2emissions by up to eight million tons a year. Another found that compared to beef burgers, plant-based burgers were associated with up to 98% less greenhouse gas emissions. Studies focusing on the healthiness of plant-based products also found they tend to have better nutritional profiles compared to animal products, with one paper finding that 40% of conventional meat products were classified as ‘less healthy' compared to just 14% of plant-based alternatives based on the UK's Nutrient Profiling Model. Others found plant-based meat and dairy were good for weight loss and building muscle mass, and could be used to help people with specific health conditions. Food producers may be able to add ingredients such as edible fungi, microalgae or spirulina to plant-based foods, boosting properties such as amino acids, vitamins B and E and antioxidants. Future innovations in processing and ingredients are likely to lead to further nutritional improvements. Pine Bark Extract Treats Meniere's Disease University of Chieti-Pescara (Italy), July 17, 2022  Research from Italy's University of Chieti-Pescara has found that a patented pine bark extract significantly treats Meniere's disease. Ménière's disease is a type of vertigo caused by a condition of the inner ear, discovered by the French doctor, Prosper Ménière in the mid-nineteenth century. Dr. Ménière found the vertigo disorder, which produces a low-pitched tinnitus of varying intensity depending upon the person and the degree of the condition; can eventually result in a complete loss of hearing. Symptoms include periodic headaches, dizziness, nausea and vomiting along with vertigo attacks that can last hours to weeks. The researchers studied 107 patients with Ménière's disease – each with varying intensity of symptoms. The researchers split the 120 patients into two groups and for six months, and both groups were given conventional treatment. In addition, one group was given 150 milligrams per day of Pycnogenol – a patented pine bark extract from the French Maritime pine tree. They found that after three months of treatment, the pine bark extract group showed significantly better improvement than the control group. A full 45 percent of the pine bark extract group had a complete recovery after three months compared to 23 percent of the placebo group. After six months, a full 87 percent of the pine bark extract group experienced recovery – became asymptomatic. Meanwhile, 34 percent of the control group (conventional treatment) recovered after six months. The patients were given 200 milligrams per day of Pycnogenol for 8 weeks and crossed over with a placebo.

Authentic Biochemistry
Membrane Biochemistry XXIII. DNA recombination and methylation associated autoimmune and cancer pathology via TLR4 and membrane lipid rafts. DJGPhD.28.7.22. Authentic Biochemistry

Authentic Biochemistry

Play Episode Listen Later Jul 28, 2022 29:59


References Dr Guerra's notes Oncotarget. 2016 Jan 26; 7(4): 4195–4209 FEBS J. 2017 Jun; 284(11): 1590–1605 Biochim Biophys Acta Mol Basis Dis. 2021 Oct 1;1867(10):166184. Biol. Cell (2007)99, 129–140 --- Send in a voice message: https://anchor.fm/dr-daniel-j-guerra/message

The Gary Null Show
The Gary Null Show - 07.28.21

The Gary Null Show

Play Episode Listen Later Jul 28, 2021 58:49


CoQ10 supplementation associated with improved trauma patient outcomes Urmia University of Medical Sciences (Iran) July 23 2021.    Findings from a trial reported on July 12, 2021 in the Journal of Nutritional Science revealed benefits for hospitalized traumapatients who were given supplements that contained coenzyme Q10.  The trial enrolled 40 men and women with traumatic injury and low plasma levels of CoQ10. Participants received a placebo or 400 milligrams CoQ10 daily for seven days. Blood samples collected at the beginning and end of the trial were analyzed for interleukin 6 (IL-6), which may be elevated during inflammation, and the oxidative stress markers malondialdehyde (MDA) and thiobarbituric acid reactive substances (TBARS). Body composition was also assessed at these time points, as well secondary outcomes that included Sequential Organ Failure Assessment (SOFA) and the Glasgow Coma Scale (GCS).  While interleukin-6 levels at the beginning of the study were similar between the CoQ10 and placebo groups at an average of 175.05 pg/mL and 177.82 pg/mL, they were reduced by 76.99 pg/mL in the CoQ10 group and 17.35 pg/mL in the placebo group. MDA values averaged 232.37 picograms per milliliter (pg/mL) and 239.96 pg/mL and were lowered by 88.84 pg/ml among participants who received CoQ10 and by 26.23 pg/mL among those who received a placebo. In comparison with the placebo group, fat free mass, skeletal muscle mass and body cell mass increased among those who received CoQ10. GCS and SOFA scores, and duration of hospital stay, ICU stay and ventilator use also improved among treated patients.  “To date, no randomized clinical trial study has been conducted to evaluate the effect of CoQ10 supplementation in traumatic mechanical ventilated patients and we hypothesized that CoQ10 administration in these patients could have beneficial effects on biochemical and clinical factors,” the authors wrote. “We have shown that CoQ10 could improve some of the clinical and anthropometric parameters in patients with a traumatic injury.”     Nigella sativa (black seed) prevents covid-induced vascular damage, scientists conclude   Oriental Institute of Science and Technology (India), July 27, 2021 New research published in the journal Vascular Pharmacology shows that Nigella sativa, also known as black seed or black cumin, binds to ACE2 in the lungs, effectively stopping the Wuhan coronavirus (Covid-19) from inducing inflammation and vascular damage. Researchers out of India investigated the effects of nigellidine, an indazole alkaloid of black seed, using molecular docking for binding to different angiotensin-binding proteins, as well as the Chinese Virus spike glycoprotein. They found that nigellidine “strongly binds” to the Chinese Virus spike protein at what is known as the hinge region or active site opening, which may in turn hamper its binding to the nCoV2-ACE2 surface. “Nigellidine effectively binds in the Angiotensin-II binding site / entry pocket,” the study explains. “Nigellidine showed strong binding to mono / multi-meric ACE1.” This process of ACE blocking could, the study goes on to suggest, restore angiotensin levels and restrict vasoturbulence in Chinese Virus patients, while the receptor blocking could help to stop resulting inflammation and vascular impairment. “Nigellidine may slow down the vaso-fluctuations due to Angiotensin deregulations in Covid patients,” the paper further explains. “Angiotensin II-ACE2 binding (ACE-value -294.81) is more favorable than nigellidine-ACE2. Conversely, nigellidine-ACE1 binding-energy / Ki is lower than nigellidine-ACE2 values indicating a balanced-state between constriction-dilatation.” Nigellidine also binds to the viral spike proteins, which when taken by Chinese Virus patients, and especially those who fall in the elderly category, could greatly reduce their risk of suffering complications or death. Nigellidine impairs SARS-CoV-2 infection, “cytokine storm” through numerous mechanisms In a related study that was published last year in the journal Europe PMC, researchers learned that nigellidine inhibits the Chinese Virus infection in several other ways. It was discovered early on in the “pandemic” that many of those who tested “positive” for the virus were suffering associated “cytokine storms,” in which their immune systems were over-responding and causing more damage, or even death. Nigellidine was then studied and discovered to possess certain properties that inhibit cytokine storms, as well as impede the SARS CoV-2 virus from causing infection. It is also hepato- and reno-protective, meaning it protects against liver damage. Beyond this, nigellidine was determined to possess unique immunomodulatory and anti-inflammatory characteristics, as well as antioxidant potential strong enough to inhibit important proteins associated with the Chinese Virus. In their quest to uncover possible “drug” candidates to protect patients against hyper-inflammation and other associated problems, the researchers learned that nigellidine – and more than likely other black seed constituents – helps tremendously with preventing negative side effects. Along with nigellicine, nigellidine is found in the seed coat of Nigella sativa. Both of these constituents in their sulfated forms are extremely bioavailable, and along with thymoquinone and dithymoquinone, two other black seed components, they show strong antioxidant, antibacterial, anti-hypertensive, anti-inflammatory and immunomodulatory effects. Black seed extracts have been shown in other experiments to decrease oxidative stress, effectively lowering the risk of inflammation-related diseases. We now know that this includes the Wuhan coronavirus (Covid-19). Black seed is also recognized as a metabolic protector, helping to improve lipid and blood sugar levels. “Most importantly, in SARS CoV-2 infection ACE-2 mediated impairment of aldosterone system may be repaired by,” the study further explains, providing relevant information to the current “pandemic.” “Vasorelaxant and anti-hypertensive function of [black seed] helps in the modulation of renin angiotensin system (RAS) or the diuretic activity, which is one of the major targets of COVID. It might have great protective role during post infective secondary disorder of the peripheral vasculature namely cardiac and renal systems. In most of the instances patients die due to this organ dysfunction/failure in COVID-19 infection.” By quelling inflammation, black seed could save lives from covid Laboratory studies have found that intake of Nigella sativa significantly improves the parameters for hyperglycemia and diabetes control, as well as glycated hemoglobin and insulin resistance. Based on this, experts believe that nigellidine specifically could play an important role in fighting the Chinese Virus by “docking” to the proteins and inflammatory molecules that can cause a cytokine storm – mainly TNF-? receptors such as TNFR1, TNFR2 and IL1R. “In the experimental rat model the source of this drug Nigella sativa; black cumin seed extracts were tested for its role on antioxidant, hepatic and renal status,” the paper states. “This work will help in the urgent therapeutic intervention against COVID-19 global pandemic.” “In the current study, we have decisively shown by molecular modeling that nigellidine can bind in the active sites of several important proteins of SARS CoV 2, several host receptors specific for SARS CoV-2 induced inflammatory markers IL1, IL6, TNF-?. Moreover, the extract from black cumin seed has been shown in experimental rat to be highly antioxidative, hepato- and reno-protective. Further studies are necessary to verify the potential effects of nigellidine in in vivo laboratory experimental animal model.”   Vitamin D supplementation improves recovery time of children with pneumonia at pediatric hospital Cairo University (Egypt), July 20, 2021 According to news reporting originating from Cairo, Egypt, by NewsRx correspondents, research stated, “Despite the well-recognized effect of vitamin D in metabolism and homeostasis, there is now growing interest in its probable association with pneumonia. This study aims to supply vitamin D3 (Cholecalciferol) (100,000 IU) to pneumonic children to minimize the duration of illness and improve their outcome.” Our news editors obtained a quote from the research from Cairo University, “A double-blinded, randomized, placebo-controlled trial was conducted in a Pediatric Cairo University affiliated hospital. An intervention arm (93 children) and a control arm (98 children), who had pneumonia with an insufficient or deficient level of vitamin D and whose parental permission was obtained, were enrolled in the trial. All children were treated with antibiotics according to WHO guidelines. Children were given a single injection of 1 mL of 100,000 IU of vitamin D3 or placebo. Clinical data were recorded every eight hours for all children. Outcomes were assessed 7 days after vitamin D injection. The primary outcome variable was the change in serum level of 25(OH)D, while the secondary outcomes were the medical state of the assigned cases (improvement or death) and duration between enrollment and hospital discharge for improved cases. In the supplementation group, the percentage of patients who suffered either deficient (38.7%) or insufficient levels (61.3%) of 25 (OH)D at day one had significantly decreased in the seventh day to (11.8%) and (52.7%), respectively. Kaplan--Meier plots highlighted that the median time to recover of the placebo group was significantly longer than that of the supplementation group (Log Rank P value < .001). VDD was detected in pediatric critical care children.” According to the news editors, the research concluded: “In pneumonic children with high VDD, it is illustrated that Vitamin D supplementation is accompanied by lowered mortality risk and pSOFA scores, reduced time to recover, and improved PaO2/FiO(2).”   Physical activity could combat fatigue, cognitive decline in cancer survivors University of Illinois, July 26, 2021 A new study indicates that cancer patients and survivors have a ready weapon against fatigue and "chemo brain": a brisk walk. Researchers at the University of Illinois, along with collaborators at Digital Artefacts in Iowa City, Iowa, and Northeastern University in Boston, looked at the association between physical activity, fatigue and performance on cognitive tasks in nearly 300 breast cancer survivors. "The data suggest that being more physically active could reduce two of the more commonly reported symptoms in breast cancer survivors: fatigue and cognitive impairment," said study leader Edward McAuley, a professor of kinesiology and community health at Illinois. "Most people think, 'If I exercise, I'll become tired.' In our study, exercise actually was associated with reduced fatigue, which in turn was associated with better cognitive function." Cognitive impairment, such as memory problems or shortened attention spans, is a common complaint among cancer patients and survivors, and is thought to be similar to decline due to aging. Past Illinois research has explored the effect of physical fitness on age-related cognitive decline, so the researchers wondered whether cancer survivors would respond similarly to exercise. "Other studies of cancer survivors have relied on small samples of cancer survivors, and used self-reporting measures of physical activity and cognitive function, which can be very biased," said postdoctoral researcher Diane Ehlers, the first author of the study, which is published in the journal Breast Cancer Research and Treatment. "What makes our study novel is that we had objective measures for both physical activity and cognitive performance, and a nationwide sample of breast cancer survivors." The researchers worked with Digital Artefacts -- developer of the commercial neuroscience app BrainBaseline - to create an iPad app tailored to this study. The app included questionnaires and activities designed to measure attention, memory and multitasking skills. The researchers also sent each participant an accelerometer to track daily physical activity. "We found that higher levels of daily moderate-to-vigorous physical activity were associated with better performance on the cognitive tasks measuring attention, memory and multitasking," Ehlers said. "What was notable was that physical activity's effect on cognitive performance was mediated by fatigue. This provides evidence that physical activity interventions targeting fatigue in cancer patients and survivors might provide promising models for improving cognitive function as well." Next, the researchers plan to conduct further studies to establish causation and further explore the pathways of how physical exercise improves cognitive performance. They are working with Digital Artefacts to conduct an iPhone-based study and focusing on diverse populations of breast cancer survivors. "The message for cancer patients and survivors is, get active!" Ehlers said. "Even if it's 10-minute bouts of brisk walking. It's not a magical cure-all, but we've seen many benefits of physical activity for cancer patients and survivors."   Cannabidiol promotes oral ulcer healing by inactivating CMPK2-mediated NLRP3 inflammasome Sichuan University (China), July 26, 2021 Xingying Qi, West China Hospital of Stomatology, Sichuan University, Chengdu, China, presented the oral session "Cannabidiol Promotes Oral Ulcer Healing by Inactivating CMPK2-Mediated NLRP3 Inflammasome" at the virtual 99th General Session & Exhibition of the International Association for Dental Research (IADR), held in conjunction with the 50th Annual Meeting of the American Association for Dental Research (AADR) and the 45th Annual Meeting of the Canadian Association for Dental Research (CADR), on July 21-24, 2021. The oral ulcer is a common oral inflammatory lesion with severe pain but little effective treatment is currently available. Cannabidiol (CBD) is recently emerging as a therapeutic agent for inflammatory diseases. However, the underlying mechanisms are not fully elucidated. Qi and colleagues sought to investigate whether and how CBD could play a therapeutic role in the oral ulcer. Oral ulcer models were performed in the tongue of C57BL/6 mice by acid etching or mechanical trauma, followed by CBD local administration. Samples were harvested for macroscopic and histological evaluation. CBD oral spray on acid- or trauma-induced oral ulcers on mice tongues inhibited inflammation, relieved pain and accelerated lesions closure in a dose-dependent manner. The results show that CBD accelerates oral ulcer healing by inhibiting CMPK2-mediated NLRP3 inflammasome activation and pyroptosis, which is mediated mostly by PPARγ in nucleus and partially by CB1 in plasma membrane. This data may shed light on the development of new therapeutic strategies for oral ulcers.   Algal solution: Could Spirulina modify the microbiome to protect against age-related damage? Louvain Drug Research Institute (Belgium), July 25 2021 Spirulina might help protect against age-related liver inflammation by modifying pathways in the microbiome, say researchers. Consumption of spirulina could help protect against hepatic inflammation in the elderly, according to the new animal research published in Nutrients. Belgian researchers carried out tests on mice, which suggest that the algae Spirulina has an impact on the gut microbiota, which in turn activates the immune system in the gut and improves inflammation in the liver that is associated with ageing. Led by senior author Professor Nathalie Delzenne from the Louvain Drug Research Institute in Belgium, the team said oral feeding of Spirulina was found to modulates several immunological functions involving, among others, the TLR4 pathway in old mice. “The fact that its oral consumption can influence both gut immunity and systemic sites, such as the liver, suggests that its immune action is not confined to the gut immune system,” wrote the team – who said the findings open the way to new therapeutic tools “in the management of immune alterations in aging, based on gut microbe-host interactions.” Furthermore, they suggested that improvement of the homeostasis in the gut ecosystem ‘could be essential' during the aging process, “and, in this perspective, dietary manipulation of the gut microbiota of the elderly with Spirulina, may represent a tool for preserving a healthy gastrointestinal microbial community in addition to its beneficial effects on immune function.” Study details Delzenne and colleagues noted that while the possible cardiovascular and immune support benefits of Spirulina have been fairly widely reported, the new study brings a fresh approach by testing whether the effects could be related to a modulation of gut micrbiota. In the trial, young mice aged three months were fed a standard diet, while older mice aged 24 months were fed a standard diet either with or without 5% Spirulina for six weeks. Upton supplementation with Spirulina, the team reported several changes to gut microbiota composition, including an increase in Roseburia and Lactobacillus populations. “Interestingly, parameters related to the innate immunity are upregulated in the small intestine of Spirulina-treated mice,” said the team. “Furthermore, the supplementation with Spirulina reduces several hepatic inflammatory and oxidative stress markers that are upregulated in old mice versus young mice.” Expression of several genetic and biochemical markers of inflammation and immunity were altered by supplementation with Spirulina, said the team. In particular, the transcription factor Foxp3 – involved in the differentiation of T cells into regulatory T cells (Tregs) – and MCP1 were increased due to Spirulina supplementation in old mice. Old mice that consumed Spirulina also showed activation of several immune parameters including Foxp3 in the ileum – suggesting an improvement of the gut immune function upon Spirulina treatment in this segment, said the Belgian researchers. Furthermore, Spirulina supplementation upregulated both TLR2 and TLR4 expression in the ileum of aged mice. “In accordance with these results, a solution of Spirulina (5%) exhibited a TLR4 agonist activity similar to the one reached in old-SP mice, suggesting a direct effect of the Spirulina, itself, on the TLR4 pathway,” they added. Microbiome mechanisms While the positive effect of Spirulina on the microbiome and liver inflammation is clear, the team noted that the mechanism by which the algae could change the composition of the intestinal microbiota remains unanswered. One possible mechanism could be the presence of antimicrobial substances produced by Spirulina, they said. “On the other hand, antimicrobial peptides (AMPs) could be mediators of the nutritional modulation of the gut microbiota.” “In the present study, RegIIIγ and Pla2g2 were increased by the supplementation with Spirulina, suggesting that the host contributes to the reduction and modification of the microbial community by modulating the production of specific AMPs,” they added.

O Super Nutricionista
021 A obesidade, inflamação e o consumo de gorduras

O Super Nutricionista

Play Episode Listen Later May 31, 2021 10:28


Já parou pensar que o padrão alimentar pode desencadear processos inflamatórios? E que a perpetuação deste padrão pode levar a obesidade e a obesidade a diversas outras doenças?Pois então, neste episódio irei abordar sobre como a alimentação e o consumo de determinados alimentos pioram a inflamação e como reduzi-la.Confira mais um episódio do Super Nutricionista! Pesquise por "Dicas Curtas" no seu app de podcast favorito, Spotify, Deezer, Youtube ou acesse nosso site!#supernutricionista #dicascurtas #podcastbrasil #podcastbr #podcast | dicascurtas.com.brLink do grupo no Facebook: https://www.facebook.com/O-Super-Nutricionista-587990535217695Quer entender qual a melhor maneira para se alimentar bem e cuidar de sua saúde? A partir de agora você vai ficar por dentro das melhores dicas sobre nutrição e alimentação saudável com o Super Nutricionista... Mais um expert do Dicas Curtas. Conheça os demais experts em nosso site: dicascurtas.com.br Dicas Curtas, dicas rápidas e fáceis de consumir ________________________________Seja um apoiador do Dicas CurtasCom incentivos a partir de R$1 você ajudará o Dicas Curtas a alcançar mais pessoas, incluir novos experts e poder ter acesso a conteúdos exclusivos e participar de lives ao vivo com o expert de sua preferência!Tudo isso em um grupo destinado apenas a apoiadores no Facebook.Para ser um apoiador basta acessar: https://apoia.se/dicascurtas________________________________

Generative Energy Podcast
#56: Serotonin and Servitude | Cortisol, Aldosterone, and Hair Loss | Silica, Endotoxin, and TLR4 with Georgi Dinkov

Generative Energy Podcast

Play Episode Listen Later May 10, 2021 93:56


00:00 - Catch-up with Georgi Dinkov, the unraveling COVID narrative 04:53 - Is being around vaccinated people harmful? 14:43 - Stress (cortisol) causes hair loss, hair loss as a marker of circulatory disease, aldosterone, PTH, estrogen, trilostane, progesterone 20:20 - Estrogens cause obesity / PCOS in women, DHT is protective 27:22 - Low DHT can cause hypogonadism symptoms even in eugonadal men 33:00 - Vitamin D (topical) safe and effective for removing scars 36:45 - Vitamin D deficiency impairs muscles by lowering energy production, nitric oxide theory of aging, CRH, prostaglandins 46:23 - Is Georgi doing anything at the moment to prepare for an uncertain future? 50:10 - Ruby Ridge, Waco, Timothy McVeigh 58:53 - Serotonin and oxytocin promote gullibility, trainability, and servility 01:06:51 - What's happening in India? Bogus PCR cycle threshold 01:10:47 - Endotoxin (LPS) may be the cause of fatal lung damage in COVID-19 01:14:37 - Pyrucet for cancer? 01:16:31 - Silica, present in most supplements/food, activates the endotoxin receptor (TLR4), EMF, Danny purchased a Mercola EMF tent

The Gary Null Show
The Gary Null Show - 03.03.21

The Gary Null Show

Play Episode Listen Later Mar 3, 2021 56:53


Chaga mushrooms, a natural way to regrow hair?  Tokushima University (Japan), February 28 2021 Alopecia areata is a condition characterized by hair falling out in patches. Research suggests it is caused by the immune system attacking the hair follicles, causing them to shrink and slow down hair production. Because of this, alopecia is called an autoimmune disorder. According to statistics, alopecia is a common autoimmune disorder that affects about 6.8 million people in the U.S. alone. One in five people who suffer from alopecia has a family member with the same condition. Hair loss, however, can vary from nothing more than a few patches to complete loss of hair on the scalp or the entire body. There are currently no mainstream cures for alopecia, and the reason why the immune system attacks hair follicles is still unknown. But in a recent study, researchers at Tokushima University in Japan reported a natural medicine that can potentially reverse the effects of alopecia. Inonotus obliquus, commonly known as chaga, is a parasitic fungus that grows on birch and other trees. It is traditionally used to treat gastrointestinal diseases as well as to maintain healthy hair in many countries in Asia. The researchers screened chaga mushrooms for useful phytochemicals and found that it contains plenty of potential anti-alopecia agents. They discussed their findings in detail in an article published in the Journal of Natural Medicines. Compounds in chaga mushroom promote proliferation of hair follicles Chaga mushrooms refer to the resting body, or sclerotium, of I. obliquus. In countries like China, Korea, Japan and Russia, these mushrooms are known for their favorable effects on lipid metabolism and cardiac function. Research has also found that they possess antibacterial, anti-inflammatory, antioxidant and anti-tumor properties, and even exhibit antiviral properties against the hepatitis C virus and the human immunodeficiency virus. On the other hand, phytochemical analysis of chaga mushrooms reveal that they are rich in polysaccharides, triterpenes and polyphenols. They also contain two components commonly derived from birch trees, namely, betulin (or betulinol) and betulinic acid. Studies show that betulin can help lower cholesterol levels and increase insulin sensitivityin mice, while betulinic acid can activate signaling pathways that lead to cancer cell death. According to Japanese researchers, chaga mushrooms are used in Mongolia to make shampoo that helps with the maintenance of strong, healthy hair. This prompted them to investigate whether chaga mushrooms can be used for the treatment of alopecia. Bioassay-guided fractionation of chaga mushroom extracts allowed them to identify five lanostane-type triterpenes whose structures they confirmed using spectroscopy. The researchers then conducted proliferation assays using human follicle dermal papilla cells (HFDPCs) and found that four of the five triterpenes can promote the proliferation of HFDPCs. The compounds were identified as lanosterol, inotodiol, lanost-8,24-diene-3B,21-diol and trametenolic acid. The researchers also reported that these lanostane-type triterpenes were more potent than minoxidil, a conventional treatment for male-pattern baldness that’s used to promote hair growth. Based on these findings, the researchers concluded that the lanostane-type triterpenes in chaga mushrooms are potent anti-alopecia agents that can be used to stimulate hair growth naturally.      Association of serum folate, vitamin A and vitamin C levels with greater bone mineral density Tiajin Fifth Central Hospital (China), February 22, 20221 According to news originating from the Tianjin Fifth Central Hospital research stated, “The conclusions on the associations of specific vitamin levels with bone mineral density (BMD) were controversial. Therefore, the aims of this study were to examine the associations of serum vitamins levels with BMD and the modified effect of race/ ethnicity on these associations in the US adults.” The news editors obtained a quote from the research from Tianjin Fifth Central Hospital: “This study was from the third National Health and Nutrition Examination Survey. All participants aged 18 years with complete data were eligible. Serum vitamins A, B9, B12, C, and E levels were assayed using the Quantaphase II Radioassay Kit (Bio-Rad). Dual-energy X-ray absorptiometry was employed to measure BMD, including femur neck and the total hip. There were 6023 participants included in the final analysis. Serum folate, vitamins A and C levels were positively associated with BMD. No significant associations of serum vitamins B12 and E levels with BMD were observed. There were positive associations of serum folate level (b = 0.00027 and 0.00032; and 95% CI: 0.00002-0.00057 and 0.00002-0.00063, respectively), vitamin A level (b = 0.01132 and 0.01115; and 95% CI: 0.00478-0.01787 and 0.00430-0.01799, respectively), and vitamin C level (b = 0.00027 and 0.00029; and 95% CI: 0.00012-0.00042 and 0.00013-0.00045, respectively) with BMD at femur neck and the total hip only in the Not Hispanic participants.” According to the news editors, the research concluded: “Elevated serum folate, vitamins A and C levels were associated with a higher BMD. Furthermore, sex and race/ ethnicity modified the associations of serum vitamins levels with BMD.”     Study shows mother's diet may boost immune systems of premature infants Johns Hopkins University, February 25, 2021 Medical researchers have long understood that a pregnant mother's diet has a profound impact on her developing fetus's immune system and that babies -- especially those born prematurely -- who are fed breast milk have a more robust ability to fight disease, suggesting that even after childbirth, a mother's diet matters. However, the biological mechanisms underlying these connections have remained unclear. Now, in a study published Feb. 15, 2021, in the journal Nature Communications, a Johns Hopkins Medicine research team reports that pregnant mice fed a diet rich in a molecule found abundantly in cruciferous vegetables -- such as broccoli, Brussels sprouts and cauliflower -- gave birth to pups with stronger protection against necrotizing enterocolitis (NEC). NEC is a dangerous inflammatory condition that destroys a newborn's intestinal lining, making it one of the leading causes of mortality in premature infants. The team also found that breast milk from these mothers continued to confer immunity against NEC in their offspring.  Seen in as many as 12% of newborn babies weighing less than 3.5 pounds at birth, NEC is a rapidly progressing gastrointestinal emergency in which normally harmless gut bacteria invade the underdeveloped wall of the premature infant's colon, causing inflammation that can ultimately destroy healthy tissue at the site. If enough cells become necrotic (die) so that a hole is created in the intestinal wall, the bacteria can enter the bloodstream and cause life-threatening sepsis. In earlier mouse studies, researchers at Johns Hopkins Medicine showed that NEC results when the underdeveloped intestinal lining in premature infants produces higher-than-normal amounts of a protein called toll-like receptor 4 (TLR4). TLR4 in full-term babies binds with bacteria in the gut and helps keep the microbes in check. However, in premature infants, TLR4 can act like an immune system switch, with excess amounts of the protein mistakenly directing the body's defense mechanism against disease to attack the intestinal wall instead. "Based on this understanding, we designed our latest study to see if indole-3-carbinole, or I3C for short, a chemical compound common in green leafy vegetables and known to switch off the production of TLR4, could be fed to pregnant mice, get passed to their unborn children and then protect them against NEC after birth," says study senior author David Hackam, M.D., Ph.D., surgeon-in-chief at Johns Hopkins Children's Center and professor of surgery at the Johns Hopkins University School of Medicine. "We also wanted to determine if I3C in breast milk could maintain that protection as the infants grow."  In the first of three experiments, Hackam and his colleagues sought to induce NEC in 7-day old mice, half of which were born from mothers fed I3C derived from broccoli during their pregnancies and half from mothers fed a diet without I3C. They found that those born from mothers given I3C throughout gestation were 50% less likely to develop NEC, even with their immune systems still immature at one week after birth. The second experiment examined whether breast milk with I3C could continue to provide infant mice with protection against NEC. To do this, the researchers used mice genetically bred without the binding site on intestinal cells for I3C known as the aryl hydrocarbon receptor (AHR). When AHR-lacking pups were given breast milk from mice fed a diet containing I3C, they could not process the compound. Therefore, they developed severe NEC 50% more frequently than infant mice that had the I3C receptor.  The researchers say this shows in mice -- and suggests in humans -- that AHR must be activated to protect babies from NEC and that what a mother eats during breastfeeding -- in this case, I3C -- can impact the ability of her milk to bolster an infant's developing immune system.  In confirmatory studies, Hackam and his colleagues looked at the amounts of AHR in human tissue obtained from infants undergoing surgery for severe NEC. They found significantly lower than normal levels of the receptor, suggesting that reduced AHR predisposes infants to the disease. Finally, the researchers searched for a novel drug that could be given to pregnant women to optimize AHR's positive effect and reduce the risk of NEC in the event of premature birth. After screening in pregnant mice a variety of compounds already approved by the U.S. Food and Drug Administration for other clinical uses, the researchers observed that one, which they called A18 (clinically known as lansoprazole, a drug approved for the treatment of gastrointestinal hyperacidity), activates the I3C receptor, limits TLR4 signaling and prevents gut bacteria from infiltrating the intestinal wall.  To show the relevance of what they saw in mice, the researchers tested A18 in the laboratory on human intestinal tissue removed from patients with NEC and found the drug produced similar protective results. "These findings enable us to imagine the possibility of developing a maternal diet that can not only boost an infant's overall growth, but also enhance the immune system of a developing fetus and, in turn, reduce the risk of NEC if the baby is born prematurely," says Hackam.   Plant-based diets improve cardiac function, cognitive health Boston University Medical School, February 25, 2021 What if you could improve your heart health and brain function by changing your diet? Boston University School of Medicine researchers have found that by eating more plant-based food such as berries and green leafy vegetables while limiting consumption of foods high in saturated fat and animal products, you can slow down heart failure (HF) and ultimately lower your risk of cognitive decline and dementia. Heart failure (HF) affects over 6.5 million adults in the U.S. In addition to its detrimental effects on several organ systems, presence of HF is associated with higher risk of cognitive decline and dementia. Similarly, changes in cardiac structure and function (cardiac remodeling) that precede the appearance of HF are associated with poor cognitive function and cerebral health.  The adoption of diets, such as the Mediterranean diet (MIND) and the Dietary Approaches to Stop Hypertension (DASH), which are characterized by high intakes of plant-based foods are among lifestyle recommendations for the prevention of HF. However, whether a dietary pattern that emphasizes foods thought to promote the maintenance of neurocognitive health also mitigates changes in cardiac structure and function (cardiac remodeling) has been unclear until now. The researchers found the MIND diet, which emphasizes consumption of berries and green leafy vegetables while limiting intakes of foods high in saturated fat and animal products, positively benefited the hearts' left ventricular function which is responsible for pumping oxygenated blood throughout the body. The researchers evaluated the dietary and echocardiographic data of 2,512 participants of the Framingham Heart Study (Offspring Cohort), compared their MIND diet score to measures of cardiac structure and function and observed that a dietary pattern that emphasizes foods thought to promote the maintenance of neurocognitive health also mitigates cardiac remodeling. According to the researchers previous studies have highlighted the importance of diet as a modifiable risk factor for cognitive decline and dementia. "Our findings highlight the importance of adherence to the MIND diet for a better cardiovascular health and further reduce the burden of cardiovascular disease in the community," explained corresponding author Vanessa Xanthakis, PhD, assistant professor of medicine and biostatistics at BUSM and an Investigator for the Framingham Heart Study. Although Xanthakis acknowledges that following a healthy diet may not always be easy or fit with today's busy schedules, people should make a concerted effort to adhere to healthy eating to help lower risk of disease and achieve better quality of life.         Fear of memory loss impacts well-being and quality of life Trinity College Dublin, February 23, 2021 Research from the Global Brain Health Institute (GBHI) at Trinity College suggests that experiencing high levels of fear about dementia can have harmful effects on older adults' beliefs about their memory and general well-being. To date, few studies have measured the impact of dementia-related fear on daily functioning, despite its clinical relevance. In this new study, published in the journal Aging and Mental Health, researchers investigated if fear of memory decline predicted increased memory failures and poorer quality of life in older adults. Dr. Francesca Farina, Atlantic Fellow for Equity in Brain Health at GBHI, in collaboration with researchers at the University of Cambridge, University of Maastricht and Northwestern University developed a novel scale—known as the Fear of Memory Loss (FAM) scale—to capture different components of fear related to memory loss. Using the scale, healthy older adults aged 55+ were assessed with respect to the different dimensions of fear. Questions probed specific fears like becoming dependent on others, being treated differently by friends or colleagues, and loss of identity, as well as coping strategies like avoiding social situations for fear of embarrassment. Findings from the study showed that having higher levels of fear about dementia was associated with reporting more memory lapses and a lower quality of life. Notably, these results were independent of performance on memory tests and the level of reported anxiety. That is, fears about dementia had a negative influence on peoples' beliefs regardless of how they performed on an objective lab-based memory test, or how they rated their anxiety levels. Key findings: Heightened fear of memory loss significantly predicted lower quality of life and increased self-reported memory failures, after controlling for objective memory performance and general anxiety. There was no difference in the level of fear expressed between those with and without a family history of dementia. Though surprising, this result is consistent with evidence of widespread fear of dementia among the general population. Over half of respondents (57%) said they worried about losing their memory and feared how people would treat them if this happened. The novel FAM scale highlights the important role played by avoidance behaviors in maintaining fear, along with subjective experiences and cognitions. Findings also have important healthcare implications. Fear of dementia is a psychological process that can be modified using interventions such as psycho-education and psychotherapy. The researchers propose a preliminary fear-avoidance model, where perceived changes in memory result in fear, which over time, creates avoidance and social withdrawal. This combination of fear and avoidance has a negative impact on everyday functioning, which then impairs mood and sense of self. Identifying effective ways to challenge fears about dementia could prove beneficial to individuals and society. On the individual level, reducing fear could lead to improvements in how people view their memory function and quality of life. At the societal level, acknowledging and addressing fears about dementia would help to eliminate stigma associated with the condition. Dr. Francesca Farina, Atlantic Fellow at GBHI, and lead author said: "Almost 80% of the general public are concerned about developing dementia, according to the World Alzheimer Report 2019. Evidence also suggests that these fears increase with age. Given global population aging and the increased visibility of dementia, it is crucial that we find ways to address peoples' fears. Understanding and tackling these fears will serve to promote brain health and well-being, and reduce societal stigma for people living with disease and their carers." Tackling Fear and Stigma Through Art Data from the study inspired "Remembering What I Have Forgotten': a fictional diary written from the perspective of someone experiencing symptoms of dementia. Created by Irish artist Aoibheann Brady, student at the National College of Art and Design, the diary aims to capture the feelings and perspectives of people experiencing memory loss. Through the medium of a diary, "Remembering What I Have Forgotten' offers a realistic insight into the experience of dementia, with entries such as "I feel more withdrawn and am not going out or connecting" and "I am anxious that I will make mistakes." This diary, however, was not written by a person—but by a software application known as a chatbot, which had been trained on anonymous interviews with healthcare professionals and carers of people living with dementia. Aoibheann Brady, creator of "Remembering What I Have Forgotten' said: "With this project, I aimed to create work that is a crossover between art and science. I hope it helps demonstrate, to younger generations and members of the art world, that dementia is something that should be considered more in artistic practices."     Diet of fish and olive oils beneficially modifies membrane properties in striatal rat synaptosomes National Institute of Neurology & Neurosurgery (Mexico), February 25, 2021 According to news reporting originating in Mexico City, Mexico, research stated, “Essential fatty acids (EFAs) and non-essential fatty acids (nEFAs) exert experimental and clinical neuroprotection in neurodegenerative diseases. The main EFAs, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), nEFAs, and oleic acid (OA) contained in olive and fish oils are inserted into the cell membranes, but the exact mechanism through which they exert neuroprotection is still unknown.” The news reporters obtained a quote from the research from the National Institute of Neurology & Neurosurgery, “In this study, we assessed the fatty acids content and membrane fluidity in striatal rat synaptosomes after fatty acid-rich diets (olive- or a fish-oil diet, 15% w/w). Then, we evaluated the effect of enriching striatum synaptosomes with fatty acids on the oxidative damage produced by the prooxidants ferrous sulfate (FeSO4) or quinolinic acid (QUIN). Lipid profile analysis in striatal synaptosomes showed that EPA content increased in the fish oil group in comparison with control and olive groups. Furthermore, we found that synaptosomes enriched with fatty acids and incubated with QUIN or FeSO4 showed a significant oxidative damage reduction.” According to the news reporters, the research concluded: “Results suggest that EFAs, particularly EPA, improve membrane fluidity and confer antioxidant effect.” This research has been peer-reviewed.     Soy intake is associated with lowering blood pressure in adults: A meta-analysis of randomized double-blind placebo-controlled trials Shiraz University of Medical Sciences (Iran), February 24, 2021 Soy has several beneficial effects on cardiovascular disease (CVD); however, results of clinical trial studies are equivocal. Thus, the present study sought to discern the efficacy of soy intake on blood pressure. Methods The search process was conducted in PubMed, Scopus, Web of Science, and Cochrane Library, to ascertain studies investigating the efficacy of soy intake on blood pressure in adults, published up to June 2020. A random-effects model was applied to pool mean difference and 95% confidence intervals (CIs). Meta-regression analysis was performed to discern potential sources of heterogeneity. Begg’s and Egger’s methods were conducted to assess publication bias. Results Pooled effects from 17 studies revealed a significant improvement in systolic blood pressure (SBP) (-1.64; -3.25 to -0.04 mmHg; I2 = 50.5 %) and diastolic blood pressure (DBP) (-1.21; -2.29 to -0.12 mmHg, I2 = 50.7 %) following soy consumption, in comparison with controls. Subgroup analysis demonstrated a reduction in both SBP and DBP in younger participants with lower baseline blood pressure and intervention durations of

PaperPlayer biorxiv bioinformatics
A vaccine built from potential immunogenic pieces derived from the SARS-CoV-2 spike glycoprotein

PaperPlayer biorxiv bioinformatics

Play Episode Listen Later Sep 24, 2020


Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.09.24.312355v1?rss=1 Authors: Marchan, J. G. Abstract: Coronavirus Disease 2019 (COVID-19) represents a new global threat demanding a multidisciplinary effort to fight its etiological agent, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this regard, immunoinformatics may aid to predict prominent immunogenic regions from critical SARS-CoV-2 structural proteins, such as the spike (S) glycoprotein, for their use in prophylactic or therapeutic interventions against this rapidly emerging coronavirus. Accordingly, in this study, an integrated immunoinformatics approach was applied to identify cytotoxic T cell (CTC), T helper cell (THC), and Linear B cell (BC) epitopes from the S glycoprotein in an attempt to design a high-quality multi-epitope vaccine. The best CTC, THC, and BC epitopes showed high viral antigenicity, lack of allergenic or toxic residues, and suitable HLA-viral peptide interactions. Remarkably, SARS-CoV-2 receptor-binding domain (RBD) and its receptor-binding motif (RBM) harbour several potential epitopes. The structure prediction, refinement, and validation data indicate that the multi-epitope vaccine has an appropriate conformation and stability. Three conformational epitopes and an efficient binding between Toll-like receptor 4 (TLR4) and the vaccine model were observed. Importantly, the population coverage analysis showed that the multi-epitope vaccine could be used globally. Notably, computer-based simulations suggest that the vaccine model has a robust potential to evoke and maximize both immune effector responses and immunological memory to SARS-CoV-2. Further research is needed to accomplish with the mandatory international guidelines for human vaccine formulations. Copy rights belong to original authors. Visit the link for more info

Discover CircRes
September 2020 Discover CircRes

Discover CircRes

Play Episode Listen Later Sep 17, 2020 24:24


This month on Episode 16 of the Discover CircRes podcast, host Cindy St. Hilaire highlights four featured articles from the August 28 and September 11 issues of Circulation Research. This episode features an in-depth conversation with Drs Andrew Murphy and Michelle Flynn from The Baker Heart and Diabetes Institute at Monash University in Melbourne, Australia regarding their study Transient Intermittent Hyperglycemia Accelerates Atherosclerosis By Promoting Myelopoiesis.   Article highlights:   Fish, et al. KRAS Mutations Cause Arteriovenous Malformations   Ehling, et al. B55a in Vascular Biology   Barrett, et al.  Platelet Activity and Vascular Health in COVID-19   Furmanik, et al. Nox5 in VSMC Phenotype and Calcification     Cindy St. Hilaire:  Hi. Welcome to Discover CircRes, the podcast to the American Heart Association's journal, Circulation Research. I'm your host, Dr Cindy St. Hilaire, from the Vascular Medicine Institute at the University of Pittsburgh. And today I'm going to share with you four articles selected from our late August and early September issues of Circulation Research. I'm also going to speak with Drs Andrew Murphy and Michelle Flynn from The Baker Heart and Diabetes Institute at Monash University in Melbourne, Australia regarding their study Transient Intermittent Hyperglycemia Accelerates Atherosclerosis By Promoting Myelopoiesis. So first, the highlights. The first article I'm sharing with you is titled Somatic Gain of KRAS Function in the Endothelium is Sufficient to Cause Vascular Malformations that Require MEK but not PI 3-Kinase Signaling. First authors are Jason Fish, Carlos Perfecto Flores-Suarez, and Emily Boudreau. And the corresponding authors are Jason Fish and Joshua Wythe, and they're from University of Toronto and Baylor College of Medicine. Arterial venous malformations, or AVMs, are tangles of blood vessels in which the arteries are directly connected to the veins without going through the capillary bed. These are thought to be present from birth and when they occur in the brain, they can cause an array of symptoms such as headaches or seizures, but they are also the leading cause of hemorrhagic stroke in children and young adults. This is because the venous system is not muscularized to respond to the pressure forces that are exerted on arteries. These pressure forces cause distension and eventual leakage at the site of AVMs. Vessel tissue recovered from patients undergoing AVM repair has been shown to contain sematic gain of function mutations in the protein RAS GTPase, which is encoded by the gene, KRAS. However, whether these gain of function mutations directly cause AVMs has not been established. This study now shows that endothelial cells with constitutive expression of gain of function KRAS mutants in mice and zebra fish causes vascular malformations and cranial hemorrhages. Inhibiting a MEK kinase, which is a downstream mediator of RAS signaling, prevented hemorrhages in the mutant KRAS carrying fish. In vitro studies also showed that overactive RAS GTPase protein caused excessive angiogenic behavior of endothelial cells. Together, this work confirms the link between gain of function KRAS mutations and brain AVMs, and suggests that MEK inhibition could be a potential strategy for nonsurgical treatment. The second article I want to share with you is titled B55a/PP2A Limits Endothelial Cell Apoptosis During Vascular Remodeling: A Complimentary Approach To Kill Pathological Vessels. The first author is Manuel Ehling and the corresponding author is Massimiliano Mazzone. And the work was completed at Leuven Center for Cancer Biology in Belgium. Building a mammalian vascular system is a dynamic process that is dependent on both growth of new vessels, as well as the pruning of unwanted ones. But while much is known about molecular mechanisms underlying angiogenesis, comparatively little is understood about the mechanisms regulating vascular pruning. This study discovered that suppression of the protein phosphatase 2 subunit, B55A, is a key protein regulating the pruning process. They found that in mouse vascular development, B55a is widely expressed. However, in adult mice expression is restricted only to sites of active angiogenesis. Deletion of B55a in mice caused death in mid to late stages of embryogenesis as a result of vascular problems that appeared to be due to excessive vessel pruning. Switching off B55a in adult mice when the vascular development is for the most part complete did not cause any apparent problems. They did find though, that inhibition of B55a significantly delayed growth of tumors that form from the injection of cancerous cells. Inhibition of B55a produced tumors with less dense vasculature and reduced metastatic potential. Thus, the author suggests that ramping up blood vessel pruning, be it inhibition of B55a, could be a novel strategy for limiting tumor growth. The next article I want to share is titled Platelet and Vascular Biomarkers Associated With Thrombosis and Death in COVID-19. The first author is Tessa Barrett and the corresponding author is Jeffrey Berger, and they're from New York University. Our knowledge of the complications of COVID-19 is evolving every day. Laboratory testing done to date suggests that approximately 30% of hospitalized COVID-19 patients go on to develop thrombotic events. Platelets are central characters in both arterial and venous thrombosis, and it is known that virus platelet interactions can stimulate a pro-coagulant and inflammatory state during a viral infection. Further, recent studies have reported COVID-19 patients have hyperactive platelets and autopsies of COVID-19 patients exhibit micro and macro thrombi across vascular beds, even in patients without clinical thrombosis. This group then hypothesized that biomarkers of platelet activation are associated with incident thrombosis or death in COVID-19 patients. To test this, they randomly selected 100 COVID-19 positive patients and analyzed banked samples collected on the day of the COVID-19 diagnosis to investigate in vivo platelet activity, as well as vascular health biomarkers. They show for the first time that biomarkers of platelet activation at the time of diagnosis are associated with thrombosis or death in patients hospitalized with COVID-19. Their findings suggest platelet activation mechanisms may contribute to adverse events and highlight the potential role of antiplatelet therapy in this disease. The last article I want to share with you before we switch to our interview is titled Reactive Oxygen-Forming Nox5 Links Vascular Smooth Muscle Cell Phenotypic Switching and Extracellular Vesicle-Mediated Vascular Calcification. The first authors are Malgorzata Furmanik and Martijn Chatrou. And the corresponding author is Leon Schurgers from Maastricht University in The Netherlands. Vascular calcification is an active process regulated by several mechanisms, including vascular smooth muscle cell apoptosis, osteochondral genic transdifferentiation, extracellular vesicle release, and cellular senescence. In healthy adult arteries, smooth muscle cells maintain a contractile phenotype. However, various insults such as oxidative or mechanical stress, can induce smooth muscle cells to lose their contractility and this process of de-differentiation is termed phenotypic switching. And phenotypic switching is thought to precede the development of vascular disease. Patients with conditions such as chronic kidney disease have mineral imbalances in their circulation and also exhibit higher levels of vascular calcification. However, the mechanisms behind these observations are not well defined. This group found that extracellular calcium can enter the smooth muscle cells via extracellular vesicles and this increased cytosolic calcium concentration. Increased calcium induces expression and activity of Nox5 in NADPH oxidase. Activation of Nox5 increased production of reactive oxygen species, which in turn decreased contractile marker expression, and also promoted calcification in vitro. Intracellular calcium signaling also further enhanced extracellular vesicle secretion, and decreased extracellular vesicle uptake. This then promoted the accumulation of extracellular vesicles in the extracellular matrix, which is a mechanism that promotes calcification. Together, these data suggest that mineral imbalances, such as those seen in chronic kidney disease patients, contribute to loss of smooth muscle cell contractility, which promotes osteochondral genic transdifferentiation. For the interview portion today, I have with me Drs Andrew Murphy and Michelle Flynn from the Baker Heart and Diabetes Institute and Monash University in Melbourne Australia. And we're going to be discussing their manuscript titled Transient Intermittent Hyperglycemia Accelerates Atherosclerosis by Promoting Myelopoiesis. But really I like the running title, which is Hyperglycemic Spikes Accelerate Atherosclerosis. So thank you both very much for joining me today. Michelle Flynn: Thanks for having us. Cindy St. Hilaire: So before we start to ‘stalk a bit about what the details of this study is, could you maybe give us a little primer on what you've done that led up to this study? Andrew Murphy: Yeah, so this really was a continuation of a study that began actually when I was in my postdoc in Allan Tall lab and working with Ira Goldberg’s lab with the postdoc  Prabhakara R Nagareddy there. We've shown along with Ed Fisher’s group at NYU, that mice that had established atherosclerotic lesions that were then made diabetic, failed to have lesion regression compared to those that were non-diabetic with normalized plasma cholesterol levels. We showed that if we gave an SGLT-2 inhibitor to normalize glucose that regression then started to occur. And then we found that this was primarily driven by myelopoiesis, suddenly increased production of monocytes, which through that entered the plaque. And so from that, that was in the hyperglycemic model which is sort of a very rare patient group these days, because most people are on well-controlled glucosteroid drugs. And really the SGLT-2 inhibitors have been a game changer in that scenario. And what we were trying to do with this study was bring it into a more clinically relevant setting that might show the potential importance of glucose on a much larger population. Cindy St. Hilaire: Excellent. Maybe you could give us an introduction to the link between what's known about diabetes and cardiovascular disease and the interplay? Michelle Flynn: So diabetic and pre-diabetic patients actually account for 65% of all cardiovascular deaths, which really indicates that diabetes itself plays a major factor alongside other things like obesity and hypercholesterolemia. And so we've previously shown that hyperglycemia was actually driving atherosclerosis in a chronic hyperglycemic setting. So given that kind of vascular disease actually affects both diabetic and pre-diabetic patients, we suspected that it may not just be chronic hyperglycemia or really intense hyperglycemia that could be driving this issue. And so what we were actually looking at in this paper was how more transient levels of hyperglycemia, which actually occur quite often in both diabetic patients and pre-diabetic patients, how much this can contribute to cardiovascular disease. Andrew Murphy: I guess this link between poor glucose control and cardiovascular disease is obviously very well established. The interesting part is that HbA1c only predicts part of the risk. If you look at fasting blood glucose, again, that's only partially responsible, but if you look at postprandial or two hour glucose loads, you'll see that that is more predictive of cardiovascular events than the other two measures. And it seems to be a continuum. So even if you are a healthy or non-diabetic individual, you obviously still have those postprandial events and depending how high that goes up is thought to be a predictive of future cardiovascular outcomes. And so obviously that's worse than people with pre-diabetes and then again worse with people that have actual, full blown diabetes. Cindy St. Hilaire: And what is a transient hyperglycemic event? What would do that in maybe you and me who don't have diabetes versus someone who has diabetes or is pre-diabetic? Michelle Flynn: So essentially what we're modeling with this transient hyperglycemia is that postprandial increase in glucose after you have a meal, which in people who have impaired glucose tolerance is going to be more pronounced than in someone who has a normal glucose tolerance. Cindy St. Hilaire: Got it. And so how did you test this in the mice? Michelle Flynn: We did this by developing a novel model of transient hyperglycemia. So we used ordinary wild type mice that weren't diabetic, and we injected them with glucose intraperitoneally, which then increased blood glucose levels in the plasma after about 15 minutes up to about 15 to 20 millimolar. And then after about two hours, this decreased back down to baseline levels. So this was very similar to what you actually see in a postprandial event. And by doing this four times throughout the day, we were able to mimic what you might see in a patient who has had several meals across the day who has impaired glucose tolerance. Andrew Murphy: One other advantage with the model that we used was that we were trying to really isolate the effects of glucose. And so by injecting glucose intraperitoneally in otherwise healthy mice, it bypasses the incretin response, which we know loses efficacy, I guess, in people that are diabetic. And so we were just really mimicking acute glucose rises that would occur after a meal. And then obviously in this wild type mouse the insulin response would then kick in to clear the glucose so it really tests that glucose hypothesis. Cindy St. Hilaire: So it's really digging in deeply on the actual sugar component, not just eating in general or other aspects. So in some of your experiments, or I guess in actually most of them, you show that the injection of glucose, it increased the plaque size in these mice, but it didn't alter the cholesterol levels. So can you explain a bit what's going on there? A little bit about the mechanism you discovered and kind of specifically introducing RAGE and the S100A8 and A9 axis? Michelle Flynn: Yeah, so what we showed was that regardless of cholesterol levels, we were seeing an increase in clot plaque size, and this was actually driven by the monocytes and neutrophils which were increased in the circulation of these mice. And then these are able to infiltrate into the plaque where they promote plaque progression. And what we found was that the increase in monocytes and neutrophils was due to an increase in their production within the bone marrow. And this was in turn due to the signaling by a protein heterodimer of S100A8 and A9, which signals via the receptor RAGE in the bone marrow on the progenitors of these cells, which induces their proliferation and differentiation. And then that produces an increase in the production of those immune cells, which promote plaque progression. Cindy St. Hilaire: Interesting. So it's really independent of kind of the basic thing that everyone thinks about, or I guess as non-scientists think about, is cholesterol. The public really focus on cholesterol, but what your study's showing is there's this whole other glucose mediated immune arm to it. What else does this S100A8-A9 regulate? Andrew Murphy: So S100A8 and A9 has some intracellular roles, which may direct the development of the model itself, but really a lot of its extracellular roles and so on is promoting sterile inflammation, chemotaxis, so activation of local immune cells. And in the context of diabetes and obesity, many of other diseases, it can signal via RAGE, as Michelle said, but it can also signal by TLR4. And so it seems as though in those diseases driven mainly by glucose, such as the modeling of postprandial hyperglycemia or all kinase in general, it will signal via RAGE, but we've also shown in the setting of obesity that it will signal via TLR4 to stimulate things like interleukin 1 beta. We've also had a paper just recently in Circulation  with Prabhakara Nagareddy’s group where we've shown post myocardial infarction that prime neutrophils in the heart to eventually release IL1-beta and cause myelopoiesis in that way. Cindy St. Hilaire: Wow, so this is really kind of an early activator of a much bigger immune response, whether it's in atherosclerosis or MI or probably, I don't know, a handful other things, I guess, right? Andrew Murphy: It seems to be really important when neutrophils are involved. So in a setting of an MI, we know that they come into the heart very early and become activated and it really makes them about 40% of the cytosol proteins of the cells. So when it degranulates or lyses, they are kind of neutral, at least in the predominant protein. Cindy St. Hilaire: Okay. So this is released in NETs in NETosis then? Andrew Murphy: That's what we're sort of discovering so far. So I guess all I can say is, stay tuned, this is a story for another day. Cindy St. Hilaire: Okay. That's really interesting though. Andrew Murphy: We haven’t looked in gglucose driven events yet. Cindy St. Hilaire: Yeah and actually one of the interesting things I've learned from your study, I had known about GLUT1 and that GLUT1 was I guess the constituently active of the glucose transporters, but I didn't realize it was so high on neutrophils and that neutrophils were so dependent metabolically on glucose. Can you maybe tell a little bit more about that story? Michelle Flynn: Yes. So the neutrophil itself is actually very highly dependent on glycolysis because it doesn't actually have many mitochondria. So compared to most cells, they have very few mitochondria so they can't really rely upon the oxidative phosphorylation for their general metabolism. And so they predominantly rely on glucose coming into the cell and then being shuttled through glycolysis to generate their energy. And yeah this does seem to be predominantly due to uptake of glucose through GLUT1. Cindy St. Hilaire: And then that excess glucose, the byproduct, is reactive oxygen species and upregulation and this cascade of- Michelle Flynn: Yes, yes that's correct. Cindy St. Hilaire: Okay, great. So currently we use HbA1c as a biomarker for overall kind of glucose regulation in diabetic patients. And based on your studies and perhaps the studies of others, would neutrophil numbers or even S100A8 or A9 be a better metric to figure out where a pre-diabetic or even a healthy patient is in terms of their glucose tolerability? Michelle Flynn: Yeah. That could actually be an interesting marker to look at. Given that neutrophils and S100 are also associated with obesity and diabetes in general, and as well as the risk for cardiovascular disease. So with the progression of diabetes, you could expect that the levels of these would increase as well. Andrew Murphy: We've shown previously when we first discovered that the S100 was important in diabetes, that in the Pittsburgh study with Trevor Orchard's group, he had followed people with type one diabetes for 20 years, that those that did develop a cardiovascular event had a higher S100A8 and A9 levels and that correlated with neutrophils. And so it certainly seems to be a marker of predictive outcomes. And so those that do have poorer glycemic control will have higher neutrophils. That's well known. And so perhaps you're right that probably in combination with HbA1c or things like two hour post glucose challenges, S100A8 and A9 and perhaps neutrophil counts would also be a nice predictive measure of potential cardiovascular outcomes of that person. Cindy St. Hilaire: Wow. That'd be really great because you could then maybe kind of more fine tune and predict which patients might be more or less susceptible to cardiovascular events. Andrew Murphy: That's right. Yeah. I think one other important aspect would be if HbA1c is deemed to be relatively well under control, yet you still have a high level of S100A8 and A9, that perhaps those transient spikes are contributing. You're not picking that up in the HbA1c, which looks like the average over approximately a month. And so that could be a nice way to add value onto that score. Cindy St. Hilaire: Interesting. I didn't realize it was that stable about over a month. All right. So I'm relatively healthy. I'm not pre-diabetic, but if I eat a whole bunch of cake or a whole bunch of ice cream or drink a lot of beer, does that create un me a transient hyperglycemic event that is of the same range we're talking about and what do your findings suggest for people who are relatively healthy and things we should be aware about regarding eating habits and things like that? Andrew Murphy: Yeah. I think it's a really good question. And it's sort of hard to give you an exact answer to that right now. We need to look at that in people, model these sort of same spikes in people, but what we I guess don't know yet, even in the preclinical models is how high and how long does that glucose have to be? And I think that's one of the most important questions first. So is there a danger zone where these neutrophils start be the innate senses of hyperglycemia that start to then release S100A8 and A9 to cause these downstream events? But what our data does show is that if you're doing this, having a binge night or a binge day once a week for your life, then that's probably not going to be a great thing. Cindy St. Hilaire: Yeah. All right. So you need to figure out is one scoop of ice cream okay, but two not so great. Andrew Murphy: Maybe if it's two different flavors it'll be okay. Cindy St. Hilaire: Maybe, right? That's great. So, I mean, is there a way we could potentially therapeutically target this signaling axis or is it too ubiquitous in terms of what it regulates? Is there a way to harness what you've found potentially in the clinic? Michelle Flynn: Yeah, so there's an inhibitor of S100A8 and A9 that prevents its binding to RAGE. It's currently approved as an Orphan Drug for systemic sclerosis in both the US and the UK. And that drug itself, we tested in our preclinical mouse model, and we found that it was in fact able to prevent their production of these immune cells, as well as prevent the accelerated atherosclerosis in response to these transient hypoglycemic spikes. Andrew Murphy: So another sort of line of thinking that we're exploring is that we could actually target neutrophil metabolism itself. And so now we're sort of understanding, are there certain proteins that are more abundantly expressed in neutrophils and not other cells in the body that would regulate glycolysis? I know that might sound a bit of a pie in the sky sort of idea, because glycolytic pathway's quite regulated, but there we have found some proteins that are rich in neutrophils and not other cells that may be responsible for the early steps of glycolysis. And so whether that can be harnessed or not, we'll have to see in the future, but it might be a way of more directly targeting neutrophils rather than approaching that's important in sterile inflammation. Cindy St. Hilaire: That makes sense. That is such a cool idea and this is really such a beautiful story. It's one of those papers that you just read it and it's just such a logical progression, but it's also really interesting and I really appreciated all those bone marrow transplants. I did those in grad school, so well done. It's a beautiful story. And then I'm just really happy that you published it with us. So thank you so much for joining me today. Andrew Murphy: Yeah thanks for having us. Michelle Flynn: Thank you. Cindy St. Hilaire: That's it for highlights from the late August and early September issues of Circulation Research. Thank you so much for listening. Please check out the Circulation Research Facebook page and follow us on Twitter and Instagram with the handle @CircRes and #DiscoverCircRes. Thank you to our guests, Drs Andrew Murphy and Michelle Flynn. This podcast is produced by Rebecca McTavish and Ashara Ratnayaka, edited by Melissa Stoner, and supported by the Editorial Team of Circulation Research. Some of the copy text for the highlighted articles is provided by Ruth Williams. I'm your host, Dr Cindy St. Hilaire, and this is Discover CircRes, your on-the-go source for the most exciting discoveries in basic cardiovascular research.  

PaperPlayer biorxiv neuroscience
POMC-specific knockdown of Tril reduces body adiposity and increases hypothalamic leptin responsiveness

PaperPlayer biorxiv neuroscience

Play Episode Listen Later Jun 27, 2020


Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.06.25.172379v1?rss=1 Authors: Moura-Assis, A., de Lima-Junior, J. C., Nogueira, P. A., Simabuco, F. M., Gaspar, J. M., Junior, J. D., Velloso, L. A. Abstract: In a public dataset of transcripts differentially expressed in selected neuronal subpopulations of the arcuate nucleus, we identified TLR4-interactor with leucine-rich repeats (Tril) as a potential candidate for mediating the harmful effects of a high-fat diet in proopiomelanocortin (POMC) neurons. The non-cell-specific inhibition of Tril in the arcuate nucleus resulted in reduced hypothalamic inflammation, protection against diet-induced obesity associated with increased whole-body energy expenditure and increased systemic glucose tolerance. The inhibition of Tril, specifically in POMC neurons, resulted in a trend for protection against diet-induced obesity, increased energy expenditure and increased hypothalamic sensitivity to leptin. Thus, Tril emerges as a new component of the complex mechanisms that promote hypothalamic dysfunction in experimental diet-induced obesity. Copy rights belong to original authors. Visit the link for more info

Generative Energy Podcast
#27: Thyroid Function & Pulse Rate | Weaponized Culture | Finasteride as an "Insane Decision" with Ray Peat and Georgi Dinkov

Generative Energy Podcast

Play Episode Listen Later May 30, 2020 143:04


00:06:54 - Skip setup music 00:07:18 - Global warming, China, Russia 00:09:43 - Does Ray think war is on the horizon? 00:10:49 - Relationship between empires, handling of the citizenry, artificial intelligence 00:12:55 - Why is the US destroying its own population? 00:14:49 - Why does the ruling class exert so much effort in creating conflict with regular people? 00:19:31 - Power-elites and killer austerity 00:22:17 - CIA and Massad -- Rothschild Zionism 00:22:18 - "...We in the West are victims of a long-held agenda not of our making and without doubt not in our interests." Is the US Waging Israel's Wars? by Linda S. Heard (2006) 00:24:09 - Self-censoring in the current culture 00:00:00 - "Not allowing people to go through their pain, and protecting them from it, may turn out to be a kind of overprotection, which in turn implies a certain lack of respect for the integrity and the intrinsic nature and the future development of the individual." Abraham Maslow (1961) 00:27:15 - What is Rothschild Zionism? 00:28:24 - Donald Trump: 'First Jewish president'? 00:31:37 - At one point did the power structure switch? 00:32:04 - Rupert Murdoch as an agent of the Rothschilds 00:32:33 - The manufactured race war 00:35:49 - The Samson Option 00:38:19 - The FBI and CIA as organized crime 00:38:20 - Government agents' directly involved' in most high-profile US terror plots "Nearly all of the highest-profile domestic terrorism plots in the United States since 9/11 featured the 'direct involvement' of government agents or informants, a new report says." 00:39:39 - COINTELPRO, the New Left, Congress for Cultural Freedom 00:41:38 - Project Northwoods 00:41:39 - The CIA's 'Strategy of Tension' during Operation Gladio: "You were supposed to attack civilians, women, children, innocent people outside the political arena. For one simple reason: To force the Italian public to turn to the state [to ask for greater security]." Vincent Vinciguerra 00:43:10 - Is an evil empire sustainable? 00:45:35 - "No, a person is never again the same after reacting to an aluminum adjuvant. The official figures of the US government show clearly that the epidemic of chronic diseases began with the massive increase of vaccinations in 1989." RP (2020) 00:48:12 - Heraclitus, process philosophy 00:51:23 - Transgenerational effects of vaccines 00:54:54 - GMO crops, transgenerational allergenic genes 00:58:09 - TLR4, endotoxin, vaccines, inflammation, aspirin, angiotensin 01:06:55 - Sexual liberation as a weapon, Kinsey, Rockefellers, orgasm 01:09:51 - "High estrogen does sometimes cause insatiable sexual interest, partly because it increases adrenal androgens, and partly by inhibiting satisfying orgasms." RP 01:13:48 - Abstention vs. exploring the behavior 01:16:05 - Is sexuality a liberating force in nature? 01:17:40 - Estrogen as a signal that the environment is bad and to reproduce as fast as possible 01:19:13 - What's a healthy libido? 01:20:15 - Finasteride is an "insane decision" 01:22:35 - When finasteride does regrow scalp hair -- what is happening? 01:24:53 - Is DHT important for intestinal function? 01:26:54 - The finasteride cult and the "cure" for baldness 01:31:02 - How does progesterone help with hair growth? 01:36:07 - Anti-estrogens for hair growth? 01:37:16 - GABA agonists 01:41:01 - What is more effective: thyroid or CO2? 01:42:28 - Can the thyroid gland completely fail? 01:44:46 - Thyroid function and pulse rate +more

This Week in Microbiology
212: A coronavirus outbreak and IRF4 deficiency in Whipple’s disease

This Week in Microbiology

Play Episode Listen Later Feb 6, 2020 55:26


The TWiM team reviews the coronavirus outbreak that began in Wuhan, China, and the finding that an IRF deficiency underlies Whipple’s disease.  2019-nCoV case tracking (JHU) Clinical features of infection with 2019-nCoV (Lancet) Early transmission dynamics of 2019-nCoV (NEJM) Isolation of 2019-nCoV (NEJM) TLR4 defect in Whipple’s disease (eLife) Become a Patron of TWiM! Music used on TWiM is composed and performed by Ronald Jenkees and used with permission. Send your microbiology questions and comments to twim@microbe.tv

Ben Greenfield Life
16 Reasons You're Not Burning Fat (& How To Lose Weight The Right Way)

Ben Greenfield Life

Play Episode Listen Later Jun 8, 2019 66:40


Several months ago, I filled you in on "". But what you learned in that article only scratched the surface of the multiple mechanisms underlying why the human body can be resistant to fat loss, and how to achieve truly sustainable, long-lasting weight loss in a safe and efficient manner. So during today's solosode, you'll discover... -How fat actually gets burnt...6:20 Law of conservation of mass: Mass, in an isolated system, is neither created nor destroyed by chemical reactions or physical transformations Fat is primarily disposed of via the breath Calories, as well as excess carbs and proteins, are converted into triglycerides and stored in lipid droplets of adipocytes Excess dietary fat undergoes lipolysis, and then reesterification Triglycerides are composed of carbon, hydrogen, and oxygen Oxidation: requires inhalation of oxygen Study: For 22 pounds of fat to be oxidized, 64 pounds of oxygen must be inhaled Results in 61 pounds of carbon dioxide excreted via the lungs and 24 pounds of water excreted via urine, sweat, feces, and breath Average of 17,000 breaths per day will excrete .32 lbs of carbon Sources of carbon (other than eating coal) are: dietary carbs, proteins, and fats If you didn't get all that, get this: Losing fat means consuming less carbon than you've exhaled. Even small quantities of food can foil your efforts at weight loss. The simple solution is to move more and eat less. The 16 reasons you're not burning fat the way you'd like – Chronic Inflammation...12:35 High levels of transforming growth actor beta cause irregular appetite and glucose regulation : calcium-dependent zinc-containing endopeptidases : Aids in the growth of new blood vessels; correlated with obesity Nitric oxide synthase Toll-like receptor 4 (TLR4) = meta inflammation Nos uncoupling (genetic factors) Sugar can be inflammatory but is more quickly metabolized than things like vegetable oil Chronic stress is a factor: overstimulation of the limbic system Cell Danger Response (CDR) – Glycemic variability (GV)...21:05 Refers to the blood glucose variations during the day If GV gets out of control, the body does one of two things: transfers sugar into muscles, or stores as body fat It will become fat tissue if you're not active enough throughout the day Be "ruthlessly" cognizant of blood sugar fluctuations 6 Strategies to control GV Strength training Pre-breakfast fasted cardio Book: Post-prandial walk Standing Plants, herbs, spices Fiber – Cortisol and stress...30:45 Cortisol suppresses insulin secretion (HRV) (Save $50 with code: GREENFIELDOURA) – Sleep deprivation...34:20 A single night of partial sleep can be deleterious Neuro endocrine effect: reduces levels of leptin; increases levels of – Snacking and post-workout calories...35:25 "Grazing" or 6-8 small meals per day is a myth Snacking increases your GV and eliminates benefits of fasting Your body releases more growth hormone during intermittent fasting Grazing throws metabolism into sugar burning mode It takes 3 days, or 4 weeks of extreme calorie restriction for the body to down regulate metabolism The need for protein and carbs right after a workout is a myth The exception: two a day workouts – You're not moving enough...39:47 Fool your body into thinking it's in the "hunter gatherer" mode – Too much exercise...41:30 Excessive exercise, along with other stressors can lead to increased levels of cortisol and inflammation  by Ben Greenfield Too much of the same exercise Not enough recovery days Sweet spot: 2-3 days per week, lift heavy stuff 2-3 days high-intensity interval training – Chronic cardio...43:35 Your body will catabolize muscle and store fat High-intensity cardio 2-3 days per week Reduced subcutaneous adiposity of body fat among people who follow these guidelines – The SAID Principle...46:00 Specific Adaptation to Imposed Demands Sometimes the best workout plan is the one you're not currently doing Keep the body guessing 5 modifications: Combine exercises Article "" Active rest periods Train outside Change the center of gravity Workout at a different time of day – Lack of cold therapy...50:00 Cold is a strong metabolic stimulus Cold thermogenesis occurs when protons are forced across the inner membrane and turned into heat Beige adipose tissue Every day, 2-5 minutes cold exposure (cold shower, cold river or lake) 3x3 cold (Use code: BEN10CFB to save 10%) – Hormonal imbalance...52:25 – Toxin and chemical exposure...54:40 – Food allergies and intolerances...56:30 – Micro-nutrient deficiencies... Antioxidants – Thyroid...59:00 – Disordered eating...1:01:01 Your body expects food at a certain time of day Results in irregular metabolism Easier to track calorie consumption when you eat the same thing, at the same time of day – Final comments...1:03:25 Everybody and every body is different It could be possible your body has reached its desired weight – And much more! Resources mentioned: – Article: – – – Book: – , UCSD – Book: – – – – – – (Save $50 with code: GREENFIELDOURA) – – –  by Ben Greenfield – (Use code: BEN10CFB to save 10%) – – – Episode sponsors: – If you are looking for a professional that can personally help you optimize your mind, body, and spirit to become the best version of yourself, and who knows exactly how I work with my own clients, just head on over to view our ! – : Now you can get all your healthy superfoods in one glass...with No Shopping, No Blending, No Juicing, and No Cleanup. Get a 20% discount on your entire order when you use discount code: BENG20 – : Delivers healthy 100% grass-fed and finished beef, free-range organic chicken, and heritage breed pork directly to your door on a monthly basis. All their products are humanely raised and NEVER given antibiotics or hormones. New subscribers will receive 2 LBS of FREE wild-caught Alaskan salmon + $20 OFF their first box by going to – : Halo Sport revolutionized physical training by being the first-ever product that can increase your neuroplasticity by putting your brain into a state that neuroscientists called hyperlearning. The fully upgraded Halo Sport 2 was just announced and it’s pre-selling for just $279 (less than half the price of the first model) when you use code: GREENFIELD Got a question for me about today's podcast? Just leave a comment below and I'll reply!  

The Staying Young Show 2.0 - Entertaining | Educational | Health & Wellness

  Show Topic: Nutrition in the News Co-Hosts:  Judy Gaman, Walter Gaman, Mark Anderson Guest: none   Segment 1 Intro – 30 sec. Everyone wants to eat healthy and live longer. There have been so many new studies that have emerged on nutrition that we decided to talk about nutrition in the news – what you need to know.   Prebiotics, Probiotics, and anti-biotics. Manipulating the gut biome showed that a disturbance in the gut microbiome directly affected the chances of developing metabolic syndrome according to a study out of John Hopkins University. Metabolic syndrome is characterized by a large waist, increased blood sugar, and often increased blood pressure. Toll-like receptor 4 (TLR4), a protein that receives chemical signals to activate inflammation is now linked to the start and development of metabolic syndrome. In the research, TLR4 was affected by changes in the gut micro biome. Check out the study! New research shows that low calorie diets or crash diets after a heart event may actually worsen symptoms and inhibit recovery. This seems counter intuitive because. One week into a fasting study participants saw that total body fat, visceral fat and liver fat had all significantly fallen by an average of 6%, 11%, and 42%, respectively. This was accompanied by significant improvements in insulin resistance, fasting total cholesterol, triglycerides, glucose and blood pressure. The problem was that heart fat content had risen by 44% and patients showed a deterioration in heart function. Low calorie diets or fasting periods are still good when used intermittently in healthy patients, but heart patients may need to avoid them. Check out the study! Boston University School of Medicine has a new study showing that couples that who drink sodas may have a harder time getting pregnant. Females who consumed at least one soda per day had 25 percent lower chance of getting pregnant; male consumption was associated with 33 percent lower chance of getting their significant other pregnant. Check out the study!   MUSIC FOR DOC SHOCK (JIM) THAT MUSIC MEANS ITS TIME FOR DOC SHOC. A TIME WHEN WE FIND SOMETHING SHOCKING IN THE NEWS OR WE'RE SHOCKED IT MADE THE NEWS. There is more evidence that the diet we eat can help or hinder disease from spreading. Researchers out of Cedars-Sinai Medical Center, found a link between the spread of a particular type of breast cancer and increased levels of the amino acid, asparagine. Asparagine is found in dairy, whey, beef, chicken, eggs, seafood, asparagus, potatoes, beans, seeds, soy, and even nuts. Since the variety of foods is so vast, it's hard to say go vegan or vegetarian. This research was done on mice, but if the same holds true for humans, special diets that limit or eliminate asparagine may become part of the cancer treatment regimen. Read the study!   Follow us on Facebook! Tweet us on Twitter! Download the show on iTunes! Visit our website! Call us at  844-well 100   Segment 2 Intro – 10 sec. About tease – 1 min. –Download the podcasts of the show and Daily Medical Minutes to stayyoungamerica.com or just searching StayingYoungShow 2.0.   ANDERSON - Immortal minute – 2 min.   Older Olympians are crediting their nutrition and exercise routine combined for their long-lasting stamina Probiotics and probiotic enhanced milk intake in pregnant women has been linked to less complications during birth Among 2,000 people surveyed in a recent study, 1 in 3 people are distracted when eating and 29 percent said their phone accompanies every meal they eat. A study by a research team from the University of Pennsylvania found that eating fish at least once a week can raise children's IQ by nearly 5 points in the Wechsler Intelligence Scale 2018's list of “best diets overall” is a tie between the Mediterranean and DASH Diets The DASH eating plan requires no special foods and instead provides daily and weekly nutritional goals. This plan recommends: Eating vegetables, fruits, and whole grains Including fat-free or low-fat dairy products, fish, poultry, beans, nuts, and vegetable oils Limiting foods that are high in saturated fat, such as fatty meats, full-fat dairy products, and tropical oils such as coconut, palm kernel, and palm oils Limiting sugar-sweetened beverages and sweets. Based on these recommendations, the following table shows examples of daily and weekly servings that meet DASH eating plan targets for a 2,000-calorie-a-day diet. Daily and Weekly DASH Eating Plan Goals for a 2,000-Calorie-a-Day Diet Food Group Daily Servings Grains 6–8 Meats, poultry, and fish 6 or less Vegetables 4–5 Fruit 4–5 Low-fat or fat-free dairy products 2–3 Fats and oils 2–3 Sodium 2,300 mg*   Weekly Servings Nuts, seeds, dry beans, and peas 4–5 Sweets 5 or less *1,500 milligrams (mg) sodium lowers blood pressure even further than 2,300 mg sodium daily. When following the DASH eating plan, it is important to choose foods that are: Low in saturated and trans fats Rich in potassium, calcium, magnesium, fiber, and protein Lower in sodium     Tease 20 sec. – TAKE THE SURVEY!!!!    www.stayyoungamerica.com SHOUT OUT TO MILITARY, Facebook (stay young media group) , download podcasts – follow us on twitter @StayYoungMedia coming up  - Coming up – micronutrients   Segment 3 Intro – 15 sec. Judy – Tease the upcoming Dementia Defender 844-WELL100   Our own experience with nutrition and health     Judy tease DD – grab a pen!  844-well100. Podcasts itunes, stayyoungamerica.com – 45 sec. Exit – 30 sec.   Segment 4 –   Intro – sec 15   Tease DD 844-Well100 – If you're just tuning in, catch this and every episode on iTunes under Staying Young Show 2.0 or follow us on TWITTTER @StayYoungMedia   Medical Mania Trivia – Mike True or false. Your heart creates enough energy in one day to drive a truck 20 miles (True) If stretched out, all the DNA in your body, end to end, would be enough to reach A.) Across a football field B.) From Florida to California C.) to Pluto and back (To Pluto and back – 10 billion miles) What makes up most the dust under your bed? (Your own dead skin) In a lifetime, the average brain holds how many bits of data? A.) Hundreds of thousands B.) Millions C.) Quadrillions (Quadrillions – that is one million billion bits of separate pieces of information) The gastrointestinal tract that runs from your mouth to your anus is how long (in feet)? (30 feet)     Open discussion   DEMENTIA DEFENDER THIS DEMENTIA DEFENDER IS BROUGHT TO YOU BY SMART NEW YOU AND DR. CHARLES POWELL. IF YOU HAVE SLEEP APNEA AND YOU'RE READY TO DITCH YOUR C-PAP MACHINE CALL  214-524-6333. HARD: There is a clothing store in Bartlesville. The owner has devised his own method of pricing items. A vest costs $20, socks cost $25, a tie costs $15 and a blouse costs $30. Using the method, how much would a pair of underwear cost? Thank you for listening to the Staying Young Show! With all the mixed messages on health, you need information that you can use and that you can trust. Listen in as the experts discuss all topics health related. It's time to STAY YOUNG and stay healthy! Each week we tackle a topic and often with leading scientists, best-selling authors, and even your favorite celebrities! As a listener of our show, your input is important to us. Please take a moment to fill out this quick survey so we can serve you better - Survey For more information on The Staying Young Show, please visit our website, and subscribe to the show in iTunes, Stitcher, or your favorite podcast app. You can also reach out to our host, Judy Gaman on www.judygaman.com for book purchasing, and speaking opportunities in your area!

The Journal of Immunology ImmunoCasts
[IMMUNOCAST] PILLARS OF IMMUNOLOGY

The Journal of Immunology ImmunoCasts

Play Episode Listen Later Sep 16, 2016 7:38


Dr. Gabriel Núñez speaks about a 1999 article by Shizuo Akira's group which showed by both functional and genetic studies that TLR4 is the receptor for LPS.

Science Signaling Podcast
Science Signaling Podcast, 29 July 2014

Science Signaling Podcast

Play Episode Listen Later Jul 28, 2014 11:33


Nick Gay discusses how the adaptor protein TMED7 targets the pathogen-sensing receptor TLR4 to the plasma membrane.

Science Signaling Podcast
Science Signaling Podcast, 14 May 2013

Science Signaling Podcast

Play Episode Listen Later May 13, 2013 13:18


A deubiquitinase helps control the inflammatory response.

This Week in Virology
TWiV 214: This is your brain on polyomavirus

This Week in Virology

Play Episode Listen Later Jan 6, 2013 77:41


Hosts: Vincent Racaniello, Rich Alan Dove, and Kathy Spindler Vincent, Alan, and Kathy discuss how coagulation factor X binding to adenovirus activates the innate immune system, and a novel polyomavirus associated with brain tumors in raccoons. Links for this episode: Coagulation factor X activates innate immunity to adenovirus (Science) A decorated virus cannot hide (Science) Reflecting on goals for Science Polyomavirus associated with raccoon brain tumors (EID) MPNST Moore tumor viruses - TWiV 160 Treating CLL with lentivirus vectors (NEJM) Letters read on TWiV 214 Weekly Science Picks Alan - Parasite of the DayKathy - Tour of International Space StationVincent - Earth as Art Listener Pick of the Week Robin - Angell on Big PharmaMichael - Flu jokesJim - Database of Ted talks; Downloadable Ted Talks Send your virology questions and comments (email or mp3 file) to twiv@twiv.tv

Medizin - Open Access LMU - Teil 21/22
Bacterial lipopolysaccharides form procollag-enendotoxin complexes that trigger cartilage inflammation and degeneration: implications for the development of rheumatoid arthritis

Medizin - Open Access LMU - Teil 21/22

Play Episode Listen Later Jan 1, 2013


Introduction: We have previously reported that bacterial toxins, especially endotoxins such as lipopolysaccharides (LPS), might be important causative agents in the pathogenesis of rheumatoid arthritis (RA) in an in vitro model that simulates the potential effects of residing in damp buildings. Since numerous inflammatory processes are linked with the nuclear factor-kappa B (NF-kappa B), we investigated in detail the effects of LPS on the NF-kappa B pathway and the postulated formation of procollagen-endotoxin complexes. Methods: An in vitro model of human chondrocytes was used to investigate LPS-mediated inflammatory signaling. Results: Immunoelectron microscopy revealed that LPS physically interact with collagen type II in the extracellular matrix (ECM) and anti-collagen type II significantly reduced this interaction. BMS-345541 (a specific inhibitor of I kappa B kinase (IKK)) or wortmannin (a specific inhibitor of phosphatidylinositol 3-kinase (PI-3K)) inhibited the LPS-induced degradation of the ECM and apoptosis in chondrocytes. This effect was completely inhibited by combining BMS345541 and wortmannin. Furthermore, BMS-345541 and/or wortmannin suppressed the LPS-induced upregulation of catabolic enzymes that mediate ECM degradation (matrix metalloproteinases-9, -13), cyclooxygenase-2 and apoptosis (activated caspase-3). These proteins are regulated by NF-kappa B, suggesting that the NF-kappa B and PI-3K pathways are involved in LPS-induced cartilage degradation. The induction of NF-kappa B correlated with activation of I kappa B alpha kinase, I kappa B alpha phosphorylation, I kappa B alpha degradation, p65 phosphorylation and p65 nuclear translocation. Further upstream, LPS induced the expression of Toll-like receptor 4 (TLR4) and bound with TLR4, indicating that LPS acts through TLR4. Conclusion: These results suggest that molecular associations between LPS/TLR4/collagen type II in chondrocytes upregulate the NF-kappa B and PI-3K signaling pathways and activate proinflammatory activity.

Medizinische Fakultät - Digitale Hochschulschriften der LMU - Teil 15/19
Die Funktion des Interferon-regulierenden Faktors 4 in intrarenalen Antigen-präsentierenden Zellen beim akuten Nierenversagen

Medizinische Fakultät - Digitale Hochschulschriften der LMU - Teil 15/19

Play Episode Listen Later Dec 20, 2012


Die Ischämie-Reperfusion in der Niere führt zur Aktivierung des angeborenen Immunsystems mit nachfolgender steriler Entzündungsreaktion und Gewebeschädigung der Niere, das v.a. das Tubulussystem betrifft. Es werden v.a. residente dendritische Zellen aktiviert, die die größte Immunzellpopulation in der Niere darstellen.In der weiteren Signaltransduktion sind v.a. TLR2 und TLR4 involviert, die über MyD88 proinflammatorischen Zytokinen/Chemokinen induzieren. Die proinflammatorische Wirkung wird dabei u.a. über IRF5 bewirkt, das an MyD88 andockt. Diese Funktion wird von IRF4 gehemmt, das als kompetitiver Faktor IRF5 von seiner Bindungsstelle verdrängt. Die negativ regulatorische Wirkung von IRF4 schützt die Niere vor zu starker Entzündung und dadurch vor zu starker Gewebeschädigung. Dadurch wird das Ausmaß des aktuen Nierenversagens reduziert. IRF4 wird durch Sauerstoffradikale im Rahmen der Ischämie-Reperfusion induziert. Nach der Gewebeschädigung und Induktion einer Entzündung wird IRF4 erst verzögert exprimiert, um die Entzündung wieder zu begrenzen.

Tierärztliche Fakultät - Digitale Hochschulschriften der LMU - Teil 06/07

Die vorliegende Arbeit untersuchte die Rolle der Perizyten bei steriler Inflammation. Bisher war in diesem Zusammenhang der Einfluss der Perizyten nicht bekannt, ebenso wenig ob und wie sie zu Entzündungsreaktionen beitragen. Weiterhin war der Einfluss der Perizyten auf die interstitielle Migration myeloider Zellen in vivo unerforscht. Hier konnte gezeigt werden, dass Perizyten durch eine Vielzahl von Rezeptoren wie TLR2, TLR4, TNFR1, FPR2 in der Lage sind inflammatorische Reize zu detektieren und daraufhin einen proinflammatorischen Phänotyp annehmen. Dieser ist durch die vermehrte Expression von NLRP3 sowie des Adhäsionsmoleküls ICAM-1 und die Sekretion von Chemokinen wie CXCL1, IL8 und CCL2 gekennzeichnet. Weiterhin wird das Chemokin-ähnliche Molekül MIF von aktivierten Perizyten sowohl sezerniert als auch an der Oberfläche präsentiert. Die ausgeschütteten Chemokine beeinflussen wiederum Monozyten und neutrophile Granulozyten durch ihre chemotaktische Wirkung. Auch konnte ein anti-apoptotischer sowie aktivierender Effekt der Perizyten auf neutrophile Granulozyten gezeigt werden, was die Überlebensdauer dieser Zellen im interstitiellen Gewebe signifikant verlängert. Anhand eines Mausmodells und der 2-Photonen Mikroskopie wurde gezeigt, dass Perizyten auch in vivo einen entscheidenden Beitrag zur Rekrutierung neutrophiler Granulozyten und Monozyten zur Inflammation leisten. Zum ersten Mal wurde die Interaktion myeloider Zellen mit Perizyten in vivo visualisiert und genauer charakterisiert. Diese Interaktion beeinflusst die interstitielle Migration neutrophiler Granulozyten und Monozyten abhängig davon, ob ein Stimulus für gerichtete oder ungerichtete Migration vorliegt. Es wurde deutlich, dass Perizyten sowohl einen chemotaktischen als auch einen haptotaktischen Reiz auf myeloide Leukozyten ausüben, was an einer Polarisierung der Zellen zu erkennen ist. Ebenso tragen sie durch die Interaktion zur Aktivierung der myeloiden Zellen in vivo bei. Diese Arbeit leistet demnach einen Beitrag zur genaueren Definition der Rolle von Perizyten bei steriler Inflammation. Hierfür wurden die zellulären und molekularen Mechanismen in vitro und die in vivo ablaufenden Prozesse bei der interstitiellen Migration myeloider Zellen genauer charakterisiert. Dabei konnten Perizyten als neuer Zelltyp identifiziert werden, der Gewebeschäden detektiert und aktiv zur akuten Entzündungsreaktion beiträgt indem er die Rekrutierung und Funktionalität myeloider Leukozyten unterstützt.

This Week in Virology
TWiV #154 - Symbiotic safecrackers

This Week in Virology

Play Episode Listen Later Oct 21, 2011 77:03


Vincent, Alan, and Rich are very enthusiastic about two studies that show how gut bacteria help viral invaders.

Science Signaling Podcast
Science Signaling Podcast, 3 May 2011

Science Signaling Podcast

Play Episode Listen Later May 2, 2011 15:01


Two related ligands that activate the same receptor have different effects on immune system stimulation and inflammation.

Fakultät für Geowissenschaften - Digitale Hochschulschriften der LMU
Homology Modeling of Toll-Like Receptor Ligand-Binding Domains

Fakultät für Geowissenschaften - Digitale Hochschulschriften der LMU

Play Episode Listen Later May 26, 2010


Toll-like receptors (TLRs) are in the front-line during the initiation of an innate immune response against invading pathogens. TLRs are type I transmembrane proteins that are expressed on the surface of immune system cells. They are evolutionarily conserved between insects and vertebrates. To date, 13 groups of mammalian TLRs have been identified, ten in humans and 13 in mice. They share a modular structure that consists of a leucine-rich repeat (LRR) ectodomain, a single transmembrane helix and a cytoplasmic Toll/interleukin-1 receptor (TIR) domain. Most TLRs have been shown to recognize pathogen-associated molecular patterns (PAMPs) from a wide range of invading agents and initiate intracellular signal transduction pathways to trigger expression of genes, the products of which can control innate immune responses. The TLR signaling pathways, however, must be under tight negative regulation to maintain immune balance because over-activation of immune responses in the body can cause autoimmune diseases. The TLR ectodomains are highly variable and are directly involved in ligand recognition. So far, crystal structures are missing for most TLR ectodomains because structure determination by X-ray diffraction or nuclear magnetic resonance (NMR) spectroscopy experiments remains time-consuming, and sometimes the crystallization of a protein can be very difficult. Computational modeling enables initial predictions of three-dimensional structures for the investigation of receptor-ligand interaction mechanisms. Computational methods are also helpful to develop new TLR agonists and antagonists that have therapeutic significance for diseases. In this dissertation, an LRR template assembly approach for homology modeling of TLR ligand-binding domains is discussed. To facilitate the modeling work, two databases, TollML and LRRML, have been established. With this LRR template assembly approach, the ligand-binding domains of human TLR5-10 and mouse TLR11-13 were modeled. Based on the models of human TLR7, 8 and 9, we predicted potential ligand-binding residues and possible configurations of the receptor-ligand complex using a combined procedure. In addition, we modeled the cytoplasmic TIR domains of TLR4 and 7, the TLR adaptor protein MyD88 (myeloid differentiation primary response protein 88) and the TLR inhibitor SIGIRR (Single immunoglobulin interleukin-1 receptor-related molecule) to investigate the structural mechanism of TLR negative regulation.

Medizinische Fakultät - Digitale Hochschulschriften der LMU - Teil 11/19
Expression der Membranantigene CD14, CD16, HLA-DR sowie der Toll-Like-Rezeptoren TLR2, TLR3 und TLR4 auf Blutmonozyten von Patienten mit Nierenerkrankungen

Medizinische Fakultät - Digitale Hochschulschriften der LMU - Teil 11/19

Play Episode Listen Later May 20, 2010


Thu, 20 May 2010 12:00:00 +0100 https://edoc.ub.uni-muenchen.de/11548/ https://edoc.ub.uni-muenchen.de/11548/1/Beeck_Stefan.pdf Beeck, Stefan

Journal Club Imunoterapia Tumoral
Edição#19: Apresentação cruzada.

Journal Club Imunoterapia Tumoral

Play Episode Listen Later Nov 16, 2008 10:25


Nesta edição do podcast, apresento-vos o artigo submetido por Schubert et al. Nature Immunology. 2008, volume 9: 558, do Institute for Molecular Medicine and Experimental Immunology, Friedrich Wilhelms University, Bona, Alemanha. Este artigo demonstra como o processo de apresentação cruzada decorre em células dendriticas. A apresentação cruzada, do inglês "cross-presentation", é o processo de apresentação de antigénios extracelulares via moléculas de MHC classe I. Os autores demonstram num modelo onde células dendriticas pulsadas são ovalbumina, que o antigénio é capturada pelos receptores de manose em vesiculas de endocitose primárias. Ovalbumina é também colocalizada neste endosomas primários com o complexo TAP (Transporter Associated with antigen Processing). A estimulação de clones T CD8 especificos do peptideo SIINFEKL é dependente da acção do proteasoma, e dependente da fusão dos endosomas primários com a membrana celular. O segundo facto de relevância demonstrado pelos autores é a necessidade de um processo inflamatório (endotoxinas) crucial para a ocorrência da apresentação cruzada, nomeadamente devido a necessidade de TLR4, um receptor TOLL-LIKE-RECEPTOR e o mediador de signalização MyD88 serem necessários ao processo. Estas evidências, parecem sugerir que provavelmente o processo de apresentação cruzada poderá ocorrer somente em presença de elevadas quantidades de antigénio e processos inflamatórios onde LPS esteja envolvido em grandes quantidades. Algo de raro ... Até breve!

Medizinische Fakultät - Digitale Hochschulschriften der LMU - Teil 09/19
Der Einfluß der TLR4-Polymorphismen Asp299Gly und Thr399Ile auf die Pathogenese und den Phänotyp des Morbus Crohn

Medizinische Fakultät - Digitale Hochschulschriften der LMU - Teil 09/19

Play Episode Listen Later Oct 23, 2008


Thu, 23 Oct 2008 12:00:00 +0100 https://edoc.ub.uni-muenchen.de/9454/ https://edoc.ub.uni-muenchen.de/9454/1/Staudinger_Tanja.pdf Staudinger, Tanja

tanja morbus crohn pathogenese tlr4 polymorphismen ddc:600 der einflu
Medizinische Fakultät - Digitale Hochschulschriften der LMU - Teil 08/19
Assoziation mütterlicher und fetaler mRNA-Niveaus von CD14 und Toll-like Rezeptor 2 und 4 mit allergischen Erkrankungen der Mutter

Medizinische Fakultät - Digitale Hochschulschriften der LMU - Teil 08/19

Play Episode Listen Later Jan 24, 2008


Der Kontakt mit Mikroorganismen im frühen Kindesalter oder bereits in utero kann die Entwicklung des Immunsystems und folglich die Entstehung von atopischen Erkrankungen beeinflussen. Toll-like Rezeptoren (TLR) - wie das TLR2 und TLR4 - und das Cluster of Differentiation 14 (CD14) sind maßgeblich an der Erkennung von Mikroorganismen beteiligt. Wir stellten die Hypothese auf, dass mütterliche Allergien mit erniedrigten mRNA-Expressionsniveaus für TLR2, TLR4 und CD14 im Blut der Mütter sowie im Nabelschnurblut ihrer Kinder einhergehen. Für die vorliegende Arbeit konnten im Rahmen einer europäischen Multizentrum-Studie 185 gesunde schwangere Probandinnen aus Deutschland (n = 48), Ungarn (n = 50) und Spanien (n = 87) untersucht werden. Bei Geburt wurde peripheres Blut der Probandinnen sowie Nabelschnurblut derer Kinder gewonnen. Nach RNA-Isolation und cDNA-Synthese wurde mittels Real-Time RT-PCR die mRNA-Expression von TLR2, TLR4 und CD14 quantifiziert. Bei 42 Nabelschnurblutproben in der deutschen Subpopulation bestimmten wir außerdem den Anteil der TLR2+-, TLR4+-und CD14+-Monozyten in der Durchflusszytometrie. Zur Auswertung wurden bivariate und multivariate Regressionsanalysen durchgeführt. Mütterliche Allergien waren assoziiert mit signifikant erniedrigten mRNA-Expressionsniveaus für TLR2, TLR4 und CD14 in mütterlichem sowie im Nabelschnurblut. Ferner korrelierten die mRNA-Expressionsniveaus in mütterlichem Blut signifikant mit denen in fetalem Blut. Der durchflusszytometrisch untersuchte Prozentsatz der TLR2+-, TLR4+-und CD14+-Monozyten korrelierte mit den dazugehörigen mRNA-Expressionsniveaus für TLR2 (r = 0,5 ; p < 0,01) und TLR4 (r = 0,61 ; p < 0,01), jedoch nicht mit CD14 (r = 0,1 ; p = 0,34).

Journal Club Imunoterapia Tumoral
Edição #10: Efeitos na apresentação de antigénios via MHC classe II pelas celulas dendriticas maturas in vivo

Journal Club Imunoterapia Tumoral

Play Episode Listen Later Jan 14, 2008 25:26


Olá, Viva. Décima edição do podcast "Journal Club Imunoterapia tumoral". Apresento-vos o artigo Dendritic cell preactivation impairs MHC class II presentation of vaccines and endogenous viral antigens Young et al 2007 PNAS 104: 17753 Este artigo demonstra que células dendriticas no seu estado maturo in vivo são incapazes de induzir respostas imunológicas específicas de um antigénio, e sobretudo que a razão que justifica este comportamento é a ausência de sintese das moléculas alpha e beta do heterodimero MHC classe II após maturação. Os autores observam que mesmo após maturação, as células continuam a apresentar capacidade de endocitose e capacidade de degradar antigénios solúveis e antigénios endogenos à célula dendritica, tais como antigénios virais. As células dendriticas são células fundamentais no desenvolvimento de respostas imunológicas in vivo sobretudo pela sua capacidade de induzirem a activação de linfócitos T naive. Para induzir a maturação das células dendriticas in vivo, os autores injectam CpG 1668 em ratinhos, o que gera uma maturação generalizada das células dendriticas encontradas no baço destes ratinhos. Semelhante fenómeno pode ser encontrado em condições de choque séptico ou em situações de infecções parasiticas como por exemplo a malária. O CpG são moléculas de ADN lineares ricas em sequências de nucleotideos citosina e guanina e que tem a propriedade de induzir fortes respostas imunológicas. Tal acontece porque existem nas células do sistema imunológico receptores que se ligam a este tipo de moléculas muito comuns em agentes infecciosos: os receptores Toll-like.  Estes receptores Toll-like são vários e reconhecem cada um deles um tipo específico de moléculas, eg TLR9 reconhece CpG, TLR4 reconhece LPS, TLR3 reconhece Poly I:C. Para mais informações deem uma olhada no link seguinte do wikipedia. Embora in vitro existam vários estudos sobre os aspectos funcionais das células dendriticas, estudos in vivo são raros. Este estudo é por isso valioso para reforçar o nosso conhecimento dos processos imunológicos. Um abraço e até breve. Pedro

Medizin - Open Access LMU - Teil 15/22
Association between variations in the TLR4 gene and incident type 2 diabetes is modified by the ratio of total cholesterol to HDL-cholesterol

Medizin - Open Access LMU - Teil 15/22

Play Episode Listen Later Jan 1, 2008


Background: Toll-like receptor 4 (TLR4), the signaling receptor for lipopolysaccharides, is an important member of the innate immunity system. Since several studies have suggested that type 2 diabetes might be associated with changes in the innate immune response, we sought to investigate the association between genetic variants in the TLR4 gene and incident type 2 diabetes. Methods: A case-cohort study was conducted in initially healthy, middle-aged subjects from the MONICA/KORA Augsburg studies including 498 individuals with incident type 2 diabetes and 1,569 noncases. Seven SNPs were systematically selected in the TLR4 gene and haplotypes were reconstructed. Results: The effect of TLR4 SNPs on incident type 2 diabetes was modified by the ratio of total cholesterol to high- density lipoprotein cholesterol (TC/HDL-C). In men, four out of seven TLR4 variants showed significant interaction with TC/HDL-C after correction for multiple testing (p < 0.01). The influence of the minor alleles of those variants on the incidence of type 2 diabetes was observed particularly for male patients with high values of TC/HDL-C. Consistent with these findings, haplotype-based analyses also revealed that the effect of two haplotypes on incident type 2 diabetes was modified by TC/HDL-C in men (p < 10(-3)). However, none of the investigated variants or haplotypes was associated with type 2 diabetes in main effect models without assessment of effect modifications. Conclusion: We conclude that minor alleles of several TLR4 variants, although not directly associated with type 2 diabetes might increase the risk for type 2 diabetes in subjects with high TC/HDL-C. Additionally, our results confirm previous studies reporting sex-related dissimilarities in the development of type 2 diabetes.

Medizin - Open Access LMU - Teil 15/22
Toll-like receptor stimulation induces higher TNF-alpha secretion in peripheral blood mononuclear cells from patients with hyper IgE syndrome

Medizin - Open Access LMU - Teil 15/22

Play Episode Listen Later Jan 1, 2008


Hyper IgE syndromes (HIES) are primary immunodeficiency disorders of unknown pathogenesis. Patients are typically affected with `cold' abscesses of the skin, recurrent cyst-forming pneumonia, chronic mucocutaneous candidiasis and other less frequent features such as progressive skeletal abnormalities. Defective signaling in the Toll-like receptor (TLR) pathways has been suggested as a responsible pathologic mechanism, however, in previous reports, 10 patients revealed no defect in inflammatory cytokine responses to different TLR ligands. Here, we report the increase in pro-inflammatory cytokines TNF-alpha and IL-8, following TLR2 and TLR4 stimulation in a larger cohort of 25 additional patients with HIES, and provide a meta-analysis of the TLR data in HIES. Copyright (C) 2008 S. Karger AG, Basel.

Medizinische Fakultät - Digitale Hochschulschriften der LMU - Teil 07/19
Untersuchung des CARD15-Gens in Patienten mit Morbus Crohn, Colitis ulcerosa und Colitis indeterminata und Korrelation des Genotyps mit dem Phänotyp

Medizinische Fakultät - Digitale Hochschulschriften der LMU - Teil 07/19

Play Episode Listen Later Nov 8, 2007


Die Untersuchung genetischer Prädispositionsfaktoren in der Ätiologie der chronisch-entzündlichen Darmerkrankungen (CED) führte zur Identifikation von zahlreichen so genannten Suszeptibilitätsgenen, die eine Rolle in der Pathophysiologie der CED spielen könnten. Im Jahre 2001 wurde das so genannte NOD2-/CARD15-Gen in der perizentrischen Region des Chromosoms 16 identifiziert. Drei Hauptmutationen in diesem 12 Exons umfassenden Gen konnten mit einem Morbus Crohn (MC) assoziiert werden (c.2104C>T (p.R702W) in Exon 4, c.2722G>C (p.G908R) in Exon 8 und c.3020insC (p.1007fs) in Exon 11). Ist ein Allel durch eine dieser Mutationen verändert, so ist im Vergleich zur Normalbevölkerung das relative Risiko, an einem Morbus Crohn zu erkranken, ungefähr dreimal so hoch. Im Falle einer Veränderung beider CARD15-Allele steigt das Erkrankungsrisiko sogar um das 30 bis 40fache. Weiterhin konnte in klinischen Studien gezeigt werden, dass diese CARD15-Mutationen mit einer rascheren Progression der Erkrankung und mit einem penetrierenden und stenosierenden Verlauf assoziiert sind. Ziel der im Rahmen dieser Doktorarbeit durchgeführten Studien war es, die genetischen Analysen für den Kliniker nutzbar zu machen und die Bedeutung der Genotypisierung in der klinischen Diagnostik und Therapieplanung genauer zu definieren. Ein weiteres Hauptinteresse war die Identifizierung genetisch determinierter Subpopulationen von CED-Patienten, die ein homogenes Krankheitsbild aufweisen. Da sich in verschiedenen Studien zeigte, dass gerade homozygote und zusammengesetzt heterozygote Merkmalsträger von CARD15-Mutationen unter einer besonders schweren CED leiden, sollte eine effektive und auch in der täglichen Routine leicht anwendbare Detektionsstrategie entwickelt werden, um solche Patienten einfach identifizieren zu können. Durch die Untersuchung der drei Hauptmutationen des CARD15-Gens (p.R702W, p.G908R und p.1007fs) bei 445 CED-Patienten und eine anschließend durchgeführte Genotyp-Phänotyp-Korrelation konnte solch eine Population von Hochrisiko-Patienten identifiziert werden, die für die Insertionsmutation p.1007fs homozygot war. Dabei handelt es sich um die größte je in der Literatur veröffentlichte Subkohorte von MC-Patienten (n = 19) mit diesem Genotyp, die durch ein sehr homogenes Krankheitsbild charakterisiert war. Alle Betroffenen litten unter einem progressiv verlaufenden Morbus Crohn mit der häufigen Notwendigkeit einer operativen Intervention, und sie mußten mit Immunsuppressiva behandelt werden, um eine Remission der Erkrankung zu erreichen. In einer weiteren Studie wurde eine zweite Subgruppe von CED-Patienten identifiziert, die ebenfalls unter einer raschen Progression der Erkrankung litt. Es handelte sich dabei um zusammengesetzt heterozygote Merkmalsträger, deren zweite, seltenere Mutation durch eine limitierte DNA-Sequenzanalyse der Exons 4, 5, 6, 8 und 11 des CARD15-Gens detektiert werden konnte. Durch diese Detektionsstrategie war es theoretisch möglich, bis zu 96,6 % der bis dahin beschriebenen mutierten Allele effektiv zu identifizieren. Von den acht neuen CARD15-Varianten spielt die Mehrheit wahrscheinlich eine Rolle in der Pathophysiologie der CED. Im Rahmen einer ebenfalls am Universitätsklinikum München-Grosshadern durchgeführten prospektiven doppelblinden Studie sollte anschließend anhand des Phänotyps der CED-Patienten der assoziierte Genotyp vorhergesagt werden. Hierbei konnte die Insertionsmutation p.1007fs als Vorhersagewert für einen stenosierenden Verlauf des Morbus Crohn im terminalen Ileum identifiziert werden. Trotz kontroverser Diskussionen über den wirklichen Nutzen und die Konsequenzen der Kenntnis des CARD15-Mutationsstatus eines CED-Patienten im klinischen Alltag, d. h. für die Diagnostik und eventuell für die weitere Therapieplanung, scheint bei Betrachtung der Ergebnisse der im Rahmen dieser Doktorarbeit durchgeführten Studien eine Genotypisierung von CED-Patienten durchaus sinnvoll zu sein. Angesichts der Häufigkeiten und der Lokalisation der CARD15-Mutationen ist sicherlich eine initiale Fokussierung auf die drei Hauptmutationen des CARD15-Gens (p.R702W, p.G908R und p.1007fs) zum Beispiel mittels RLFP-Analysen sinnvoll. Eine Untersuchung weiterer Regionen des CARD15-Gens durch Sequenzierung der DNA ist vorzugsweise bei Patienten angebracht, die sich bereits in jungen Jahren mit einem schweren Krankheitsbild präsentieren. Insgesamt können nur etwa 20 % der genetischen Prädisposition für einen Morbus Crohn durch CARD15-Mutationen erklärt werden, wobei zwischen 35 und 45 % der MC-Patienten Träger von CARD15-Mutationen sind. Demzufolge müssen Veränderungen in weiteren Suszeptibilitätsgenen für die genetische Prädisposition verantwortlich sein. Seit der Erstbeschreibung des CARD15-Gens wurden dementsprechend weitere Gene bzw. Genveränderungen beschrieben, die ebenfalls eine Rolle in der Entstehung einer CED spielen könnten. DLG5, SCL22A4 und SLC22A5, Gene der HLA-Region, CARD4 und TLR4 sind solche potentiellen Suszeptibilitätsgene.

Fakultät für Biologie - Digitale Hochschulschriften der LMU - Teil 02/06
Interaktionen des humanpathogenen Schimmelpilzes Aspergillus fumigatus mit Wirtszellen

Fakultät für Biologie - Digitale Hochschulschriften der LMU - Teil 02/06

Play Episode Listen Later Jul 27, 2007


Aspergillus fumigatus ist ein opportunistischer Krankheitserreger, der ubiquitär in der Umwelt vorhanden ist. Die schwerwiegende Krankheit, die er verursacht, ist die invasive Aspergillose, welche nur bei immungeschwächten Patienten auftritt und bis heute nur sehr schwierig zu diagnostizieren und zu heilen ist. Die Sporen von A. fumigatus können aufgrund ihrer geringen Größe bis in die Alveolen der Lunge gelangen. Dort bilden Makrophagen die erste Verteidigungslinie, indem sie die Sporen phagozytieren. Die Phagozytose ist Bestandteil der angeborenen Immunantwort und ein initialer Schritt bei der Bekämpfung von A. fumigatus-Sporen durch Makrophagen. Das Verstehen dieses Prozesses gewinnt durch die stetige Zunahme der Patienten mit invasiver Aspergillose immer größere Bedeutung und ist Gegenstand intensivster Forschung. Im Rahmen dieser Dissertation wurden die Interaktionen von murinen und humanen Makrophagen mit A. fumigatus-Sporen untersucht. Die Fragestellung wurde aus zwei unterschiedlichen Perspektiven betrachtet. Zum einen wurde die Oberfläche der A. fumigatus-Sporen analysiert; zum anderen wurden die Interaktionen von A. fumigatus mit phagozytierenden Zellen erforscht. Um die Phagozytose von A. fumigatus-Sporen in murinen und humanen Zellen genauer charakterisieren zu können, wurde in dieser Arbeit der so genannte „Biotin-Calcofluor Staining Assay“ (BCS-Assay) entwickelt. Mit Hilfe dieser Methode war es möglich, zwischen extra- und intrazellulären Sporen zu unterscheiden, ohne auf die Anwesenheit von Antikörpern angewiesen zu sein. Mit Hilfe von diversen Inhibitoren konnte der Mechanismus der Phagozytose genauer untersucht werden. So konnte gezeigt werden, dass die Aufnahme von A. fumigatus-Sporen ein Aktin-abhängiger Prozess ist und dass Makrophagen für die Phagozytose die Aktivierung der Phosphoinositid 3 Phosphat-Kinasen und von Tyrosin-Kinasen benötigen, insbesondere diejenigen der scr Familie. Butanedion Monoxim, ein Inhibitor der Myosinmotor-Aktivität, blockierte ebenfalls effizient die Sporenaufnahme. Die weiteren Untersuchungen der Phagozytoseprozesse von A. fumigatus-Sporen erfolgten u.a. mit Hilfe von Fluoreszenz- und elektronenmikroskopischer Aufnahmen. In der Immunfluoreszenz ließen sich Tyrosin-phosphorylierte Proteine in den Aufnahmestrukturen detektieren, und elektronenmikroskopische Aufnahmen infizierter Makrophagen zeigten so gennante „Ruffle“-Strukturen. Diese Tatsache deutet darauf hin, dass A. fumigatus-Sporen durch einen „Trigger“-ähnlichen Mechanismus aufgenommen werden. Im weiteren Verlauf der Arbeit wurden die Rezeptoren der Phagozytose von A. fumigatus-Sporen charakterisiert. Die Ergebnisse von Meier und ihren Kollegen zeigten bereits, dass die Erkennung von A. fumigatus durch Makrophagen mittels Toll-like Rezeptor 2 und TLR4 erfolgt. In der vorliegenden Arbeit wurde nun auch der Frage nachgegangen, welche Rolle TLR2 und TLR4 bei der Phagozytose von A. fumigatus-Sporen spielen. Hierzu wurden aus den Mausstämmen C3H/HeN (WT), C3H/HeJ (TLR4-), C3H/HeN TLR2-/- (TLR2-) und C3H/HeJ TLR2-/- (TLR2-/4-) murine Peritonealmakrophagen mittels Peritoneallavage entnommen, mit A. fumigatus-Sporen infiziert und mit Hilfe des BCS-Assays ausgewertet. Es konnte gezeigt werden, dass Toll-like Rezeptor 2 und nicht Toll-like Rezeptor 4 für eine effiziente Phagozytose benötigt wird. Dieses Ergebnis ließ sich wiederum mit Hilfe eines anti TLR2-Antikörpers bestätigen, da dieser auch die Phagozytose von A. fumigatus-Sporen, aber nicht von Kontrollbeads blockieren konnte. Des Weiteren wurde untersucht, ob der von Brown und seinen Mitarbeitern entdeckte Dectin-1 Rezeptor ein potentieller Phagozytoserezeptor von A. fumigatus-Sporen ist (Brown et al., 2001). Es konnte gezeigt werden, dass Laminarin, ein lösliches ß 1-3 Glucan, die Phagozytose von A. fumigatus-Sporen durch Makrophagen blockierte. Außerdem ließ sich mit einem anti-Dectin-1 Antikörper die Phagozytose von A. fumigatus-Sporen in Makrophagen hemmen. Zudem ließ sich Dectin-1 mit diesem Antikörper in infizierten Makrophagen in der Immunfluoreszenz detektieren. Mit einem weiteren Antikörper konnte beta-1-3 Glucan, ein wichtiger Bestandteil der pilzlichen Zellwand, auf ruhenden Sporen detektiert werden. Es zeigte sich, dass die Menge an  1-3 Glucan eine wichtige Rolle bei der Eliminierung von A. fumigatus-Sporen spielt. Vergleiche zwischen ruhenden und angeschwollenen Sporen zeigten, dass angeschwollene Sporen, welche größere Mengen an ß 1-3 Glucan auf ihrer Oberfläche besitzen, effizienter phagozytiert werden können. Auch die A. fumigatus pksP-Mutante, welche mehr  1-3 Glucan auf ihrer Oberfläche besaß, wurde effizienter phagozytiert. Betrachtet man die intrazelluläre Signaltransduktionskaskade, so deuten die Daten darauf hin, dass die Dectin-1-gesteuerte Phagozytose von A. fumigatus-Sporen abhängig von der Syk-Kinase verläuft. Die Ergebnisse der vorliegenden Arbeit zeigen, dass Dectin-1 und TLR2 für eine effiziente Phagozytose von A. fumigatus-Sporen benötigt werden. Die Ergebnisse legen allerdings nahe, dass außer Dectin-1 und TLR 2 noch weitere Rezeptoren bei der Phagozytose von A. fumigatus-Sporen beteiligt sind. Ein genaues Verständnis der bei der Phagozytose ablaufenden Erkennungsprozesse und der nachgeschalteten Signaltransduktionskaskaden könnte in Zukunft ausgenutzt werden, um die Effiziens der Phagozytose auch in immungeschwächten Patienten zu erhöhen und sie so zu schützen.

Medizinische Fakultät - Digitale Hochschulschriften der LMU - Teil 06/19
Die plasmazytoide und die myeloide dendritische Zelle: Zusammenhang von Toll-like Rezeptor-Expression und Sensitivität gegenüber Lipopolysaccharid und CpG-DNA

Medizinische Fakultät - Digitale Hochschulschriften der LMU - Teil 06/19

Play Episode Listen Later Nov 16, 2006


Die beiden Pathogen-assoziierten molekularen Muster, CpG-Oligonukleotide, als Imitate bakterieller DNA, und LPS, sind in der Lage, das menschliche Immunsystem zu stimulieren. Vor Entdeckung der Toll-like Rezeptoren konnte nicht zwischen direkten und indirekten Effekten von CpG-Oligonukleotiden und LPS auf Zellen des menschlichen Immunsystems unterschieden werden. Durch die Entdeckung der Toll-like Rezeptoren und vor allem die Charakterisierung von TLR9 als Rezeptor für CpG und TLR4 als Rezeptor für LPS entstand die Möglichkeit, die Zielzellen von PAMPs an Hand der Expression der dazugehörigen Rezeptoren zu definieren. Dendritische Zellen sind im Immunsystem des Menschen essenziell für die Auslösung einer Immunantwort. Sie sind in der Lage, eindringende Pathogene an Hand von PAMPs schnell und sicher zu erkennen, und daraufhin eine passende Immunantwort zu initiieren. Zwei Subpopulationen von dendritischen Zellen konnten kürzlich im peripheren Blut identifiziert werden: Plasmazytoide dendritische Zellen (PDC) und myeloide dendritische Zellen (MDC). In der vorliegenden Arbeit wurden die Unterschiede zwischen PDC und MDC in ihren Reaktionen auf CpG-Oligonukleotide, LPS und CD40 Ligand charakterisiert. Funktionelle Untersuchungen zeigten, dass nur PDC und nicht MDC direkte Zielzellen von CpG-ODN im humanen Immunsystem darstellen, während LPS MDC aktiviert, jedoch nicht PDC. Damit konsistent konnte auf molekularbiologischer Ebene nachgewiesen werden, dass PDC TLR9 exprimieren, jedoch nicht TLR4, während MDC den für die Erkennung von LPS notwendigen Rezeptor TLR4 besitzen, aber TLR9 nicht exprimieren. In gemischten Populationen reagierten auch myeloide dendritische Zellen auf CpG-Oligodesoxynukleotide, was auf eine indirekte Aktivierung durch plasmazytoide dendritische Zellen hinweist. PDC reagierten nach Stimulation mit ODN 2006 mit einer Hochregulation von Reifemarkern und kostimulatorischer Moleküle, der Expression von Chemokinrezeptoren, der Produktion proinflammatorischer Chemokine und einer verminderten Apoptoserate. Nach Stimulation mit ODN 2216 sezernierten sie große Mengen IFN-α, während ODN 2006 für die Induktion von IFN-α eine Kostimulation mit CD40 Ligand benötigte. Weder ODN 2006, ODN 2216 oder CD40 Ligand alleine waren in der Lage, IL-12 in PDC zu induzieren, die synergistische Stimulation von PDC mit CpG-ODN und CD40 Ligand führen jedoch zur Produktion großer Mengen an IL-12. Unter optimaler Stimulation mit ODN 2006 und CD40 Ligand können PDC damit gleichzeitig IL-12 und IFN-α produzieren. Das Verhältnis der produzierten Zytokine ist dabei abhängig vom Differenzierungsgrad der PDC. Durch zunehmende Ausreifung der PDC mit IL-3 verschiebt sich nach der Stimulation das Produktionsverhältnis an sezernierten Zytokinen zugunsten von IL-12. Ausreifung mit ODN 2006 ermöglicht PDC, zudem naive allogene CD4 Zellen zu aktivieren, und induziert in Kokulturen IL-12-abhängig ein Th1-gerichtetes Zytokinprofil in den CD4 T-Zellen. IFN-α schien dabei eine geringe Rolle zu spielen. Durch die Charakterisierung der PDC als TLR9-tragende Zielzelle für CpG-DNA, trägt diese Arbeit entscheidend dazu bei, die PDC als Schlüsselzelle für die physiologischen Wirkungen von TLR9-Liganden zu identifizieren und zu verstehen. Dies ist von hoher Relevanz für die Entwicklung therapeutischer Anwendungen von CpG-ODN in der Tumortherapie, Asthmabehandlung, Infektionsprophylaxe und als Adjuvans bei Impfungen.

Medizinische Fakultät - Digitale Hochschulschriften der LMU - Teil 05/19
Untersuchungen zur Rolle von Toll-like Rezeptoren bei der immunologischen Erkennung von Aspergillus

Medizinische Fakultät - Digitale Hochschulschriften der LMU - Teil 05/19

Play Episode Listen Later Apr 27, 2006


Die natürliche Immunität spielt bei der Erkennung und Eliminierung von A. fumigatus eine entscheidende Rolle. Dieser Prozeß findet ständig in uns statt, und funktioniert so gut, dass jeder gesunde Mensch eine invasive Aspergillose nicht zu fürchten braucht. Mit welchen Werkzeugen und Mechanismen unser Immunsystem den Schimmelpilz A. fumigatus wahrzunehmen und zu eliminieren vermag, ist bis heute nicht vollständig aufgeklärt. Auch konnte bisher nicht geklärt werden, warum ausgerechnet A. fumigatus invasive Aspergillosen verursacht, obwohl seine Sporen nur einen kleinen Prozentsatz der in der Luft vorhandenen Aspergillus Sporen ausmachen. Bisher konnten keine Virulenzfaktoren identifiziert werden, deren Abwesenheit die Invasivität und Tödlichkeit dieses Pilzes vollständig supprimiert (Latge, 2001; Stynen et al., 1995; Rementeria et al., 2005). Ob ein Unterschied in der immunologischen Antwort zwischen pathogenen und apathogenen Pilzen der Gattung Aspergillus besteht ist ebenfalls bis heute nicht bekannt. Um betroffenen Patienten in Zukunft besser helfen und um Risikopatienten besser schüzten zu können, ist es unerlässlich, den Prozeß der Eliminierung durch das Immunsystem besser zu verstehen. Dies war das Ziel dieser Arbeit Toll-like Rezeptoren sind wichtige Werkzeuge der natürlichen Immunität. Ob sie bei der Erkennung von A. fumigatus eine Bedeutung haben und ob der Verlust bestimmter Toll-like Rezeptoren zu einem Ausbleiben der Immunantwort im Maussystem, oder zu einer Veränderung derselben führt, sollte mit dieser Arbeit untersucht werden. Zu Beginn dieser Arbeit gab es dazu bereits erste Hinweise: Wang et al. beschreiben 2001 die Notwendigkeit der Anwesenheit eines funktionellen TLR4 für die adäquate Zytokinproduktion von humanen Blut-Monozyten als Antwort auf die Stimulation mit Hyphenmaterial von A. fumigatus in vitro (Wang et al., 2001). Jedoch konnten bis zu diesem Zeitpunkt die Beteiligung anderer TLRs nicht getestet werden und daher war nicht bekannt, ob nicht auch andere TLRs an der Erkennung von A. fumigatus beteiligt sind. Durch Transfektion von humanen HEK293 Zellen wurden mit dieser Arbeit diejenigen TLRs identifiziert, die das Erkennungs-Signal von A. fumigatus in das Zellinnere weiterleiten. Die so für das humane System identifizierten Rezeptoren wurden mit Hilfe von Knock-out-Mäusen genauer auf ihrer Bedeutung für die Antwort auf A. fumigatus im Mausmodell untersucht. Ob eine Rekrutierung von TLRs, wie sie bereits von Underhill et al. für Zymosan von Saccharomyces cerevisiae gezeigt werden konnte, auch im Zuge der Erkennung von A. fumigatus stattfindet, sollte ebenfalls beschrieben werden. Ob diese Effekte ausschließlich für die Situation in vitro eine Bedeutung haben oder ob sich die Ergebnisse auch auf die Situation in vivo übertragen lassen, wurde schließlich mit Hilfe eines Infektions-Modells in der Maus untersucht.

Medizinische Fakultät - Digitale Hochschulschriften der LMU - Teil 03/19
Untersuchung der Interaktion von Makrophagen mit dem humanpathogenen Hefepilz Candida albicans: Toll-like Rezeptoren und NF-кB Aktivierung

Medizinische Fakultät - Digitale Hochschulschriften der LMU - Teil 03/19

Play Episode Listen Later Sep 13, 2004


Der opportunistisch humanpathogene Hefepilz Candida albicans gehört bei vielen gesunden Menschen zur mikrobiellen Schleimhautflora, kann jedoch bei abwehrgeschwächten Patienten oberflächliche Infektionskrankheiten sowie lebensbedrohliche Organmykosen verursachen. Obwohl der Immunstatus des Wirtes für eine Infektion mit diesem Erreger von entscheidender Bedeutung ist, trägt auch eine Reihe von Virulenzfaktoren, insbesondere die sekretorischen Aspartatproteasen (Saps), zur Pathogenität von C. albicans bei. Die angeborene Immunität ist in der Lage, derartige Pathogene schon beim Erstkontakt zu erkennen und zu bekämpfen. Haupteffektoren dieser schnellen, angeborenen Immunantwort sind Makrophagen und neutrophile Granulozyten. Mitglieder der Toll-Proteinfamilie, sogenannte Toll-like Rezeptoren (TLRs), wurden kürzlich als Rezeptoren auf diesen Immunzellen in Säugern identifiziert. Sie erkennen unterschiedliche Erreger anhand von in der Evolution hoch konservierten Strukturen, den Pathogen-assoziierten molekularen Mustern (PAMPs), was zur Aktivierung des Transkriptionsfaktors NF-кB und zur Freisetzung von Zytokinen führt. Sowohl TLR2 als auch TLR 4 wurden kürzlich für die Erkennung von C. albicans diskutiert. Zielsetzung dieser Arbeit war es, die Interaktion von Makrophagen mit C. albicans im Hinblick auf die Aktivierung von Toll-like Rezeptoren und die nukleäre Translokation von NF-кB zu untersuchen. Neben dem lebenden C. albicans-Isolat wurden zudem drei weitere Präparationen untersucht: Mit den Antimykotika (AM) Amphotericin B, Nystatin und Itraconazol vorbehandelte Keime, durch Hitze inaktivierte Keime sowie Sap-inaktivierte Keime. Die Zellstimulationsexperimente wurden mit murinen Wildtyp-Makrophagen, TLR2- bzw. TLR4- defizienten Einzelknockoutmutanten und mit TLR2/4-Doppelknockoutmutanten durchgeführt. Die TLR-vermittelte Aktivierung von NF-кB wurde mit Gelshifts (EMSA) nachgewiesen. Mit Western Blots wurden die intrazellulären Signaltransduktionswege untersucht. Der Hitze-inaktivierte Stamm bewirkte keine Translokation von NF-кB in Wildtyp-Makrophagen. Eine Inhibition der Saps bewirkte keine Abschwächung der NF-кB Induktion, so dass im Umkehrschluss dieser bedeutende Virulenzfaktor die TLR-vermittelte NF-кB Aktivierung nicht beeinflusst. Der lebende Stamm benutzte sowohl TLR2 als auch TLR4 für die Induktion von NF-кB. Nach Vorstimulation der Makrophagen mit Interferon-γ ließ sich jedoch eine klare TLR2-Abhängigkeit – unabhängig von TLR4 – in der Aktivierung von NF-кB und in der Induktion von TNF-α zeigen. In beiden Fällen wurden die Makrophagen erst ab einer Candida-Dichte von 106 Zellen pro 100 µl PBS stimuliert. Für den AM-vorbehandelten Stamm ergab sich eine deutliche TLR2-Abhängigkeit in der Regulation von NF-кB, welche durch die Präinkubation der Makrophagen mit IFN-γ nicht beeinflusst wurde. AM-vorbehandelte Keime konnten NF-кB in den Makrophagen erst ab einer Dichte von 107 Zellen pro 100 µl PBS aktivieren. Zusammenfassend zeigen diese Ergebnisse, dass lebende und AM-vorbehandelte Keime im Gegensatz zur Hitze-inaktivierten Präparation und zu den Saps relevante PAMP-Strukturen für eine TLR-vermittelte NF-кB Hochregulation besitzen. Die Beteiligung beider Rezeptoren, TLR2 und TLR4, belegt beim lebenden Stamm das Konzept, dass immunkompetente Zellen sich mehrerer TLRs bedienen, um die Immunantwort möglichst spezifisch und fein zu regulieren. Beim AM-vorbehandelten Stamm scheint den Antimykotika Amphotericin B, Nystatin und Itraconazol eine besondere Rolle zuzukommen, da diese die Integrität der Pilzmembran stören und somit TLR2-aktivierende PAMPs aus Zellwand und/oder Zytosol freisetzen. Neben dem direkten Effekt auf die Pilzmembran kommt es somit zusätzlich zu einer indirekten, TLR2 vermittelten Stimulation der Makrophagen. Untersuchungen der Signaltransduktion (Stimulation von Wildtyp-Makrophagen mit dem AM-vorbehandelten C. albicans-Isolat) ergaben eine vorübergehende, zeitlich eng begrenzte Induktion von NF-кB, die durch den Inhibitor IкB-α reguliert wird. Gleichzeitig wurden im zeitlichen Verlauf der Stimulation auch MAP Kinasen (ERK, p38, JNK) und c-Jun, eine Subeinheit des Transkriptionsfaktors AP-1, phosphoryliert. Diese simultane Aktivierung beider Transkriptionsfaktoren weist auf eine feinregulierte Immunantwort der Makrophagen gegenüber C. albicans hin und legt zudem einen Cross-Talk zwischen NF-кB und AP-1 nahe.

Medizinische Fakultät - Digitale Hochschulschriften der LMU - Teil 02/19
Expression of functional active Toll like receptor 4 in normal and adenomatous pituitary cells

Medizinische Fakultät - Digitale Hochschulschriften der LMU - Teil 02/19

Play Episode Listen Later Mar 18, 2004


In der vorliegenden Arbeit wurde erstmals die Expression und Bedeutung des Toll-like Rezeptors 4 (Tlr4) in normalen und adenomatösen epithelialen Hypophysenzellen untersucht. Tlr4 ist der Rezeptor für bakterielle Lipopolysaccharide und ist daher an der Induktion der angeborenen Immunantwort bei Infektions- oder Entzündungsprozessen beteiligt, die durch gram-negative Bakterien verursacht werden. Zusätzlich könnte der Tlr4 eine Rolle bei der Tumorgenese spielen, da Tumor-assoziierte Komponenten der extrazellulären Matrix oder Heat-Shock Proteine ebenfalls aktivierende Liganden des Tlr4 repräsentieren. In vorhergehenden Arbeiten wurde gezeigt, dass in der normalen Hypophyse der Tlr4 vorwiegend in follikulostellaren (FS) Zellen exprimiert wird und für immun-endokrine Interaktionen von Bedeutung ist. In der vorliegenden Doktorarbeit wurde eine sporadische Expression des Tlr4 auch in allen endokrinen Vorderlappenzellen nachgewiesen. Außerdem wurde eine heterogene Expression des Tlr 4 auch in 26 von 67 untersuchten Adenomen gezeigt. In den meisten Fällen wurde in Tlr4-positiven Adenomen eine verstreute Expression in weniger als 5% aller Adenomzellen beobachtet. Die Tlr4 Expression korrelierte nicht mit einem speziellen Adenomtyp (hormonaktiv oder –inaktiv) oder Phänotyp (Mikro- oder Makroadenom). Der adenomatöse Tlr4 war funktionell aktiv, da LPS in Tlr4-positiven, IL-6-sezernierenden Adenomen die IL-6 Sekretion dosisabhängig stark stimulierte. Das synthetische Glukokortikoid Dexamethason und der p38α MAP Kinase Inhibitor SB 203580 waren potente Inhibitoren der LPS-induzierten IL-6 Sekretion. Eine heterogen Tlr4 Expresion wurde auch in endokrinen Hypophysenzelllinien gefunden, von denen manche Tlr4-positiv waren (kortikotrope AtT20 und inaktive humane HP75 Zellen), während laktosomatotrope GH3 und gonadotrope αT3-1 Zellen keinen Tlr4 exprimierten. LPS hatte in AtT20 und GH3 Zellen keinen Einfluß auf die Hormonsekretion. Im Gegensatz dazu supprimiert LPS das Wachstum von AtT20 Zellen, nicht aber von GH3 Zellen, was darauf hinweist, daß LPS direkt das Wachstum von Tlr4-positiven Zellen inhibiert. Zusammengefasst weisen diese Egebnisse darauf hin, daß während transienter oder chronischer infektiöser bzw. inflammatorischer Prozesse, die durch gram-negative Bakterien induziert worden sind, LPS da Wachstum von Hypophysentumoren beeinflussen könnte. Ob LPS in vivo die Hypophysentumor-Entwicklung inhibiert oder stimuliert, hängt von der Co-Expression und Stimulation von IL-6 (ein Progressionsfaktor für Hypophysentumoren) durch LPS in Tlr4-positiven Adenomen ab und vom Einsetzen und dem Ausmaß des Anstiegs von anti-inflammatorisch wirksamen Glukokortikoiden. Nicht nur LPS, sondern auch das bei Krebserkrankungen eingesetzte Chemotherapeutikum Taxol, von dem man annimmt, dass es durch Tlr4 wirksam ist, inhibierte das Wachstum von AtT20 Zellen. Das läßt vermuten, dass in Tlr4-positiven Adenomen auch noch weitere Liganden des Tlr4 wie z.B. andere bakterielle oder virale Bestandteile, Pharmaka oder intratumorale Fragmente der extrazellulären Matrix die Entwicklung von Hypophysentumoren beeinflussen. Dies muss in zukünftigen Studien noch geklärt werden, ebenso wie die Frage, ob der Tlr4 allgemein eine Rolle für die Tumorgenese in anderen Tlr4-positiven epithelialen Tumoren spielt.