Podcasts about c1q

Could inhibition of C1q effectively halt the progression of GA? Joel Pearlman, MD, sat down to discuss findings from the phase 2 ARCHER study, which evaluated ANX007 (Annexon) in patients with GA. He tells us what happened when patients were dosed with ANX007 for 1 year—and what occurred when patients stopped receiving treatment. And later, Dimitra Skondra, MD, fills us in on the latest research regarding potential interactions between metformin and AMD development in non-diabetic patients. Does the future of care include metformin as prophylaxis? Stick with us to find out. 

This episode digs into the pathophysiology of urticaria vasculitis from anti-C1q to the story of bradykinin. ·       Intro 0:11 ·       In this episode 0:22 ·       Review of episode 83 1:23 ·       Listen to previous episode, The Complement System for Dunces 4:09 ·       Anti-C1q antibodies 6:26 ·       Lupus, anti-C1q and lupus nephritis 9:33 ·       What happens when you inject anti-C1q in a mouse? 12:56 ·       The allergy component: anti-C1q, urticaria and angioedema 17:36 ·       Bradykinin-mediated angioedema and C1q deficiency 24:20 ·       What is the kinin kallikrein system? 26:21 ·       French researchers in 1909: human urine injected in dogs 27:30 ·       How is this relevant to urticarial vasculitis? 31:08 ·       SERPING1 gene mutation 31:23 ·       Summary 32:06 ·       COPD association with urticarial vasculitis 33:51 ·       Coming up in episode 85 35:28 ·       Thanks for listening 35:45 Disclosures: Brown reports no relevant financial disclosures. We'd love to hear from you! Send your comments/questions to Dr. Brown at rheuminationspodcast@healio.com. Follow us on Twitter @HRheuminations @AdamJBrownMD @HealioRheum. References: Busse P, et al. J Allergy Clin Immunol Pract. 2022;doi:10.1016/j.jaip.2021.11.011. Davis MDP, et al. J Allergy Clin Immunol Pract. 2018;doi:10.1016/j.jaip.2018.05.006. Dorn JM, et al. Ann Allergy Asthma Immunol. 2023;doi:10.1016/j.anai.2023.06.014. Marzano AV, et al. J Allergy Clin Immunol. 2022;doi:10.1016/j.jaci.2022.02.007. Siegert CE, et al. Clin Immunol Immunopathol. 1993;doi:10.1006/clin.1993.1066. Stojan G, et al. Lupus. 2016;doi:10.1177/0961203316645205. Venzor J, et al. Clin Rev Allergy Immunol. 2002;doi:10.1385/CRIAI:23:2:201. Wisnieski JJ, et al. Medicine. 1995;doi:10.1097/00005792-199501000-00003.

Title:  Histological assessment of C1q expression and deposition at the neuromuscular junction (NMJ) in Tibialis Anterior (TA) Tissue of SOD1G93A Mouse Model   Authors: Joseph Vereen, MS, Annexon Biosciences, Brisbane, CA Alessia Tassoni, PhD, Annexon Biosciences, Brisbane, CA Larry Mattheakis, PhD, Annexon Biosciences, Brisbane, CA Ellen Cahir-McFarland ,PhD, Annexon Biosciences, Brisbane, CA Ted Yednock, PhD, Annexon Biosciences, Brisbane, CA Yaisa Andrews-Zwilling, PhD, Annexon Biosciences, Brisbane, CA  

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2023.02.23.529740v1?rss=1 Authors: Pradhan, A. K., Neumueller, T., Klug, C., Fuchs, S., Schlegel, M., Ballmann, M., Tartler, K. J., Pianos, A., Garcia-Sanchez, M., Liere, P., Schumacher, M., Kreutzer, M., Rupprecht, R., Rammes, G. Abstract: Alzheimer's disease (AD) is characterized by the accumulation of {beta}-amyloid peptide (A{beta}). There is increasing evidence that depression may precede AD and may be an early manifestation of dementia, suggesting common mechanisms underlying both diseases. Ligands targeting the mitochondrial translocator protein (18 kDa) (TSPO), promote neurosteroidogenesis and may be neuroprotective. Moreover, TSPO is upregulated in AD. To study whether the TSPO ligand XBD173 may exert early neuroprotective effects in AD pathology we investigated the impact of XBD173 on amyloid toxicity and neuroplasticity in mouse models. We show that XBD173 (emapunil), via neurosteroid-mediated signaling via delta subunit-containing GABAA receptors, prevents the neurotoxic effect of A{beta} on long-term potentiation (CA1-LTP) in the hippocampus and prevents the loss of spines. Chronic but not acute administration of XBD173 ameliorates spatial learning deficits in transgenic AD mice with arctic mutation (ArcA{beta}) mice. The heterozygous TSPO-knockout crossed with the transgenic arctic mutation model of AD mice (het TSPOKO X ArcA{beta}) treated with XBD173 does not show this improvement in spatial learning suggesting TSPO is needed for procognitive effects of XBD173. The neuroprotective profile of XBD173 in AD pathology is further supported by a reduction in plaques and soluble A{beta} levels in the cortex, increased synthesis of neurosteroids, rescued spine density, reduction of complement protein C1q deposits, and reduced astrocytic phagocytosis of functional synapses both in the hippocampus and cortex. Our findings suggest that XBD173 may exert therapeutic effects via TSPO in a mouse model of AD. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2023.02.15.528700v1?rss=1 Authors: Stoner, A., Fu, L., Nicholson, L., Zheng, C., Toyonaga, T., Spurrier, J., Laird, W., Cai, Z., Strittmatter, S. M. Abstract: BackgroundCellular prion protein (PrPC) is a high-affinity cell-surface receptor for Amyloid-{beta} oligomers (A{beta}o). In certain overexpression models of Alzheimers Disease (AD), pharmacology and genetics demonstrate its essential role for synaptic plasticity impairment, memory deficits and synapse loss. However, PrPCs role in AD-related phenotypes with endogenous expression levels, its role in tau accumulation and its effect on imaging biomarkers are unknown. The necessity of PrPC for transcriptomic alterations driven by A{beta} across cell types is unexplored. MethodsThe role of PrPC was examined as a function of age in homozygous AppNL-G-F/hMapt double knock-in mice (DKI). Phenotypes of AppNL-G-F/hMapt mice with a deletion of Prnp expression (DKI; Prnp-/-) were compared with DKI mice with intact Prnp, mice with a targeted deletion of Prnp (Prnp-/-), and mice with intact Prnp (WT). Phenotypes examined included behavioral deficits, synapse loss by PET imaging, synapse loss by immunohistology, tau pathology, gliosis, inflammatory markers, and snRNA-seq transcriptomic profiling. ResultsBy 9 months age, DKI mice showed learning and memory impairment, but DKI; Prnp-/- and Prnp-/- groups were indistinguishable from WT. Synapse loss in DKI brain, measured by [18F]SynVesT-1 SV2A PET or anti-SV2A immunohistology, was prevented by Prnp deletion. Accumulation of Tau phosphorylated at aa 217 and 202/205, C1q tagging of synapses, and dystrophic neurites were all increased in DKI mice but each decreased to WT levels with Prnp deletion. In contrast, astrogliosis, microgliosis and A{beta} levels were unchanged between DKI and DKI; Prnp-/- groups. Single-nuclei transcriptomics revealed differential expression in neurons and glia of DKI mice relative to WT. For DKI; Prnp-/- mice, the majority of neuronal genes differentially expressed in DKI mice were no longer significantly altered relative to WT, but most glial DKI-dependent gene expression changes persisted. The DKI-dependent neuronal genes corrected by Prnp deletion associated bioinformatically with synaptic function. Additional genes were uniquely altered only in the Prnp-/-or the DKI; Prnp-/- groups. ConclusionsA functional Prnp gene is required in AppNL-G-F/hMapt double knock-in mice for synapse loss, phospho-tau accumulation and neuronal gene expression. These data support the efficacy of targeting the A{beta}o-PrPC interaction to prevent A{beta}o-neurotoxicity and pathologic tau accumulation in AD. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2022.10.17.512618v1?rss=1 Authors: Iweka, C. A., Seigneur, E. M., Hernandez, A. L., Herrera Paredes, S., Cabrera, M., Blacher, E., Pasternak, C., Longo, F., de Lecea, L., Andreasson, K. Abstract: Aging is associated with loss of circadian immune responses and circadian gene transcription in peripheral macrophages. Microglia, the resident macrophages of the brain, also show diurnal rhythmicity in regulating local immune responses and synaptic remodeling. To investigate the interaction between aging and microglial circadian rhythmicity, we examined mice deficient in the core clock transcription factor, BMAL1. Aging Cd11bcre;Bmallox/lox mice demonstrated accelerated cognitive decline in association with suppressed hippocampal long-term potentiation and increases in immature dendritic spines. C1q deposition at synapses and synaptic engulfment were significantly decreased in aging Bmal1-deficient microglia, suggesting that BMAL1 plays a role in regulating synaptic pruning in aging. In addition to accelerated age-associated hippocampal deficits, Cd11bcre;Bmallox/lox mice also showed deficits in the sleep-wake cycle with increased wakefulness across light and dark phases. These results highlight an essential role of microglial BMAL1 in maintenance of synapse homeostasis in the aging brain. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2022.09.22.509106v1?rss=1 Authors: Zhou, J., Wade, S. D., Graykowski, D., Xiao, M.-F., Zhao, B., Giannini, L. A., Hanson, J. E., van Swieten, J. C., Sheng, M., Worley, P. F., Dejanovic, B. Abstract: Complement overactivation mediates microglial synapse elimination in neurological diseases like Alzheimer disease and frontotemporal dementia (FTD), but how complement activity is regulated in the brain remains largely unknown. We identified that the secreted neuronal pentraxin Nptx2 binds complement C1q and thereby regulates its activity in the brain. Nptx2-deficient mice show increased complement activity and C1q-dependent microglial synapse engulfment and loss of excitatory synapses. In a neuroinflammation culture model and in aged TauP301S mice, AAV-mediated neuronal overexpression of Nptx2 was sufficient to restrain complement activity and ameliorate microglia-mediated synapse loss. Analysis of human CSF samples from a genetic FTD cohort revealed significantly reduced levels of Nptx2 and Nptx2-C1q protein complexes in symptomatic patients, which correlated with elevated C1q and activated C3. Together, these results show that Nptx2 regulates complement activity and microglial synapse elimination in the healthy and diseased brain and that diminished Nptx2 levels might exacerbate complement-mediated neurodegeneration in FTD patients. Copy rights belong to original authors. Visit the link for more info Podcast created by PaperPlayer

The pipeline in retina is bursting! Which datasets shared at the ASRS 2021 meeting provided insights into the future of retina? Mark Barakat, MD, joins the podcast to discuss topline results from a study examining the suprachoroidal delivery of RGX-314 (RegenxBio). And Nancy Holekamp, MD, stops by to educate us on the potential for targeting C1q in the complement cascade in patients with geographic atrophy. What's the latest with the phase 2 ARCHER study? Find out on this episode.

We discuss blockade of complement component C1q as a novel treatment for geographic atrophy with Donald Fong, MD, Vice President Ophthalmology Clinical Development, Annexon.

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.11.10.376301v1?rss=1 Authors: Quint, W. H., Matecko-Burmann, I., Schilcher, I., Loeffler, T., Scholl, M., Burmann, B. M., Vogels, T. Abstract: Background: Alzheimers disease (AD) and other tauopathies are neurodegenerative disorders characterized by cellular accumulation of aggregated tau protein. Tau pathology within these disorders is accompanied by chronic neuroinflammation, such as activation of the classical complement pathway by complement initiation factor C1q. Additionally, about half of the AD cases present with inclusions composed of aggregated alpha-synuclein called Lewy bodies. Lewy bodies in disorders such as Parkinsons disease and Lewy body dementia also frequently occur together with tau pathology. Immunotherapy is currently the most promising treatment strategy for tauopathies. However, the presence of multiple pathological processes within tauopathies makes it desirable to simultaneously target more than one disease pathway. Methods: Herein, we have developed three bispecific antibodies based on published antibody binding region sequences. One bispecific antibody binds to tau plus alpha-synuclein and two bispecific antibodies bind to tau plus C1q. Results: The affinity of the bispecific antibodies to their targets compared to their monospecific counterparts ranged from nearly identical to one order of magnitude lower. All bispecific antibodies retained binding to aggregated protein in patient-derived brain sections. The bispecific antibodies also retained their ability to inhibit aggregation of recombinant tau, regardless of whether the tau binding sites were in IgG or scFv format. Mono- and bispecific antibodies inhibited cellular seeding induced by AD-derived pathological tau with similar efficacy. Finally, both Tau-C1q bispecific antibodies completely inhibited the classical complement pathway. Conclusion: Bispecific antibodies that bind to multiple pathological targets may therefore present a promising approach to treat tauopathies and other neurodegenerative disorders. Copy rights belong to original authors. Visit the link for more info

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.11.04.368977v1?rss=1 Authors: Takuwa, H., Orihara, A., Takado, Y., Shimojo, M., Ishikawa, A., Takahash, M., Barron, A. M., Ono, M., Maeda, J., Masamoto, K., Akatsu, H., Tolkovsky, A. M., Ji, B., Tomita, Y., Ito, H., Zhang, M.-R., Goedert, M., Spillantini, M. G., Lee, V. M.-Y., Trojanowski, J. Q., Maehara, T., Suhara, T., Sahara, N., Higuchi, M. Abstract: Fibrillary tau pathologies have been implicated in Alzheimer's and allied neurodegenerative diseases, while mechanisms by which neurons bearing tau tangles die remain enigmatic. To address this issue, we pursued tau and related key pathologies macroscopically by PET and MRI and microscopically by intravital two-photon laser optics. Time-course macroscopic assays of tau transgenic mice demonstrated intimate associations of tau deposition and increase of an inflammatory microglial marker, translocator protein (TSPO), with regional brain atrophy. Longitudinal microscopy of these mice revealed a rapid turnover of tau lesions resulting from continuous generation of new tau aggregates followed by loss of neurons and their fibrillar contents. This technology also allowed the capturing of the disappearance of tangle-bearing neurons several days after being engulfed by activated microglia. Notably, a therapeutic TSPO ligand profoundly suppressed the mobility and phagocytotic activity of microglia and improved neuronal survival in this model, supporting the involvement of primary phagocytosis of viable neurons by microglia in tau-primed neuronal death. Finally, partial depletion of microglia revealed roles of immune factors, MFG-E8 and C1q, as 'eat-me' signals for an immediate attraction of phagocytic microglia towards the elimination of tangle-loaded neurons. Copy rights belong to original authors. Visit the link for more info

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.10.25.334201v1?rss=1 Authors: Chang, C.-P., Chang, Y.-G., Chuang, P.-Y., Nguyen, A. T. N., Chou, F.-Y., Cheng, S.-J., Chen, H.-M., Jin, L.-W., Carvalho, K., Huin, V., Buee, L., Blum, D., Liao, Y.-F., Lin, C.-J., Chern, Y. Abstract: Tau hyperphosphorylation favors the formation of neurofibrillary tangles and triggers the gradual loss of neuronal functions in tauopathies, including Alzheimer's disease. Herein, we demonstrated that chronic treatment with an inhibitor (J4) of equilibrative nucleoside transporter 1 (ENT1), which plays a critical role in controlling adenosine homeostasis and purine metabolism in the brain, exerted beneficial effects in a mouse model of tauopathy (Thy-Tau22, Tau22). Chronic treatment with J4 improved spatial memory deficits, mitochondrial dysfunction, synaptic plasticity impairment, and gliosis. Immunofluorescence assays showed that J4 not only reduced Tau hyperphosphorylation but also normalized the reduction in mitochondrial mass and suppressed the abnormal activation of AMP-activated protein kinase (AMPK), a pathogenic feature that is also observed in the brains of patients with tauopathies. Given that AMPK is an important energy sensor, our findings suggest that energy dysfunction is associated with tauopathy and that J4 may exert its protective effect by improving energy homeostasis. Bulk RNA-seq analysis revealed that J4 also mitigated immune signature associated with Tau pathology including C1q upregulation and A1 astrocyte markers. Collectively, our findings suggest that identifying strategies for normalizing energy and neuroimmune dysfunctions in tauopathies through adenosinergic signaling modulation may pave the way for the development of treatments for Alzheimer's disease. Copy rights belong to original authors. Visit the link for more info

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.09.24.311662v1?rss=1 Authors: He, L., Kulminski, A. Abstract: The growing availability of large-scale single-cell data revolutionizes our understanding of biological mechanisms at a finer resolution. In differential expression and co-expression analyses of multi-subject single-cell data, it is important to take into account both subject-level and cell-level overdispersions through negative binomial mixed models (NBMMs). However, the application of NBMMs to large-scale single-cell data is computationally demanding. In this work, we propose an efficient NEgative Binomial mixed model Using a Large-sample Approximation (NEBULA) ), which analytically solves the high-dimensional integral in the marginal likelihood instead of using the Laplace approximation. Our benchmarks show that NEBULA dramatically reduces the running time by orders of magnitude compared to existing tools. We showed that NEBULA controlled false positives in identifying marker genes, while a simple negative binomial model produced spurious associations. Leveraging NEBULA, we decomposed between-subject and within-subject overdispersions of an snRNA-seq data set in the frontal cortex comprising ~80,000 cells from a cohort of 48 individuals for Alzheimer's diseases (AD). We observed that subpopulations and known subject-level covariates contributed substantially to the overdispersions. We carried out cell-type-specific transcriptome-wide within-subject co-expression analysis of APOE. The results revealed that APOE was most co-expressed with multiple AD-related genes, including CLU and CST3 in astrocytes, TREM2 and C1q genes in microglia, and ITM2B, an inhibitor of the amyloid-beta peptide aggregation, in both cell types. We found that the co-expression patterns were different in APOE2+ and APOE4+ cells in microglia, which suggest an isoform-dependent regulatory role in the immune system through the complement system in microglia. NEBULA opens up a new avenue for the broad application of NBMMs in the analysis of large-scale multi-subject single-cell data. Copy rights belong to original authors. Visit the link for more info

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.06.18.146720v1?rss=1 Authors: Sterling, J. K., Adetunji, M., Guttha, S., Bargoud, A., Uyhazi, K., Ross, A. G., Dunaief, J. L., Cui, Q. N. Abstract: Glaucoma is the leading cause of irreversible blindness worldwide and is characterized by the death of retinal ganglion cells. Reduction of intraocular pressure (IOP) is the only therapeutic mechanism available to slow disease progression. However, glaucoma can continue to progress despite normalization of IOP. New treatments are needed to reduce vision loss and improve outcomes for patients who have exhausted existing therapeutic avenues. Recent studies have implicated neuroinflammation in the pathogenesis of neurodegenerative diseases of both the retina and the brain, including glaucoma and Parkinson's disease. Pro-inflammatory A1 astrocytes contribute to neuronal cell death in multiple disease processes and have been targeted therapeutically in mouse models of Parkinson's disease. Microglial release of pro-inflammatory cytokines C1q, IL-1, and TNF- is sufficient to drive the formation of A1 astrocytes. The role of A1 astrocytes in glaucoma pathogenesis has not been explored. Using a mouse model of glaucoma, we demonstrated that IOP elevation was sufficient to trigger production of C1q, IL-1, and TNF- by infiltrating macrophages followed by resident microglia. These three cytokines drove the formation of A1 astrocytes in the retina. Furthermore, cytokine production and A1 astrocyte transformation persisted following IOP normalization. Ablation of this pathway, by either genetic deletions of C1q, IL-1, and TNF-, or treatment with glucagon-like peptide-1 receptor agonist NLY01, reduced A1 astrocyte transformation and RGC death. Together, these results highlight a new neuroinflammatory mechanism behind glaucomatous neurodegeneration that can be therapeutically targeted by NLY01 administration. Copy rights belong to original authors. Visit the link for more info

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.05.29.120220v1?rss=1 Authors: Holden, S. S., Aboubakr, O., Higashikubo, B., Cho, F. S., Chang, A. H., Morningstar, A., Mathur, V., Kuhn, L. J., Suri, P., Sankaranarayanan, S., Andrews-Zwilling, Y., Aronica, E., Yednock, T., Paz, J. T. Abstract: While traumatic brain injury (TBI) acutely disrupts the cortex, most TBI-related disabilities reflect secondary injuries that accrue over time. The thalamus is a likely site of secondary damage because of its reciprocal connections with the cortex. Using a mouse model of cortical injury that does not directly damage subcortical structures, we found a chronic increase in C1q expression specifically in the corticothalamic circuit. Increased C1q expression co-localized with neuron loss and chronic inflammation, and correlated with altered cortical rhythms. Blocking C1q counteracted most of these outcomes, suggesting that C1q is a disease modifier in TBI. Since the corticothalamic circuit is important for sensory processing, attention, cognition, and sleep, all of which can be impaired by TBI, this circuit could be a new target for treating TBI-related disabilities. Copy rights belong to original authors. Visit the link for more info

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.05.11.088443v1?rss=1 Authors: Griffin, P., Sheehan, P. W., Dimitry, J. M., Guo, C., Kanan, M. F., Lee, J., Zhang, J., Musiek, E. S. Abstract: The circadian clock has been shown to regulate various aspects of brain health including microglial and astrocyte activation. Here we report that deletion of the master clock protein BMAL1 induces robust increases in the expression of complement genes such as C3, C4b and C1q in the hippocampus. Loss of downstream REV-ERBalpha-mediated transcriptional repression led to increases in C4b in neurons and astrocytes as well as C3 protein in microglia and astrocytes. REV-ERBalpha deletion induced complement C3/C4b gene expression and increased microglial phagocytosis of synapses in the CA3 region of the hippocampus. Finally, we observed diurnal variation in the degree of microglial synaptic phagocytosis in wild type mice which was abrogated by REV-ERBalpha deletion. This work uncovers the BMAL1-REV-ERBalpha axis as a regulator of complement expression and synaptic phagocytosis in the brain, thereby illuminating a novel mechanism of synaptic regulation by the circadian clock. Copy rights belong to original authors. Visit the link for more info

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.04.24.059584v1?rss=1 Authors: Scott-Hewitt, N. J., Perrucci, F., Morini, R., Erreni, M., Mahoney, M., Witkowska, A., Carey, A., Faggiani, E., Schutz, L. T., Mason, S., Tamborini, M., Passoni, L., Filipello, F., Jahn, R., Stevens, B., Matteoli, M. Abstract: Neuronal circuits assembly requires the fine equilibrium between synapse formation and elimination. Microglia, through the elimination of supernumerary synapses, have an established role in this process. While the microglial receptor TREM2 and the soluble complement proteins C1q and C3 are recognized key players in this process, the neuronal molecular components that tag synapses to be eliminated are still undefined. Here we show that exposed phosphatidylserine (PS) represents a neuronal "eat-me" signal enabling microglial-mediated synapse pruning. In hippocampal neuron and microglia co-cultures, synapse elimination can be prevented by blocking accessibility of exposed PS using Annexin V or through microglial loss of TREM2. In vivo, exposed PS is detectable at both hippocampal and retinogeniculate synapses, where exposure coincides with the onset of synapse elimination and increased PS engulfment by microglia. Mice deficient in C1q, which fail to properly refine retinogeniculate connections, display elevated exposed PS and reduced PS engulfment by microglia. These data provide mechanistic insight into microglial-mediated synapse pruning and identify a novel role of developmentally regulated PS exposure that is common among developing brain structures. Copy rights belong to original authors. Visit the link for more info

The Immune hosts discuss how the complement system functions, and its role in early synapse loss in a mouse model of Alzheimer's disease. Hosts: Vincent Racaniello, Stephanie Langel, and Cynthia Leifer Become a patron of Immune! Links for this episode Complement and microglia cause synapse loss in Alzheimer's(Science) Superresolution structured illumination microscopy Image credit Weekly Science Picks Steph- Social Media for Social Change in Scienceand Structured Illumination Microscopy video Cindy- 314 Action Vincent- Making American great again requires acting on scientific knowledge Music by Steve Neal. Immune logo image by Blausen Medical. Send your immunology questions and comments to immune@microbe.tv

Dr. Carolyn Lam:               Welcome to Circulation on the Run, your weekly podcast summary and backstage pass to the journal and its editors. I'm Dr. Carolyn Lam, Associate Editor from the National Heart Center and Duke National University of Singapore.                                                 Our journal this week features novel data informing the choice between conscious sedation and general anesthesia for transcatheter aortic valve replacement. A very relevant discussion for those of us who see these patients. Stay tuned, that's coming right up after these summaries.                                                 Subclinical hyperthyroidism is known to be associated with an increased risk of atrial fibrillation, but the association with thyroid function in the normal range or subclinical hypothyroidism is unclear. That is, until today's study, which shows us that variation in thyroid function within the normal range is associated with atrial fibrillation.                                                 First author, Dr. Baumgartner, corresponding author, Dr. Rodondi and colleagues from University of Bern in Switzerland, conducted a systematic review and obtained individual participant data in more than 30,000 participants from 11 prospective cohort studies that measured thyroid function at baseline and assessed incident atrial fibrillation, which occurred in 8.6% of individuals.                                                 They found that in youth thyroid individuals, there was a significant increase in the risk of atrial fibrillation with increasing free T4 levels within the reference range. Risks did not differ significantly by age and sex.                                                 Conversely, there was no association between TSH levels within the reference range, or subclinical hypothyroidism and the risk of atrial fibrillation. Thus, free thyroxin levels might add to further assessment of atrial fibrillation risks. Further studies are needed to investigate whether these findings apply to thyroxine treated patients.                                                 The next study provides insight into how exercise promotes metabolic remodeling in the heart. First author, Dr. Gibb, corresponding author, Dr. Hill and colleagues from University of Louisville, use radiometric, immunologic, metabolomic and biochemical assays to measure changes in myocardial glucose metabolism in mice subjected to acute and chronic treadmill exercise.                                                 They found that in the heart, glucose utilization via glycolysis was reduced during exercise and in the early recovery period after exercise. Low rates of myocardial glycolysis were sufficient to activate gene programs that instigate physiologic cardiac growth. Metabolic inflexibility of the heart, such as occurs in heart failure and diabetes, was sufficient to diminish mitochondrial function.                                                 Phosphofructokinase mediated changes in metabolism appeared to regulate genes involved in processes critical for metabolic remodeling, transcription, cell division, differentiation, cell proliferation and contraction. Thus, this study provides important preclinical evidence, showing how exercise-induced changes in glucose metabolism may promote physiologic cardiac growth.                                                 The next study addresses the question of whether antiarrhythmic drugs are safe and effective when non-shockable rhythms evolved to shockable rhythms during resuscitation for out of hospital cardiac arrests. In this study from first and corresponding author, Dr. Kudenchuk of University of Washington and his colleagues, patients who initially presented with non-shockable out of hospital cardiac arrests were randomized upon subsequently developing shock refractory VF or VT to receive amiodarone, lidocaine or placebo by paramedics.                                                 The primary outcome was survival to hospital discharge, with secondary outcomes, including discharge functional status and adverse drug-related effects. The authors found that outcome from non-shockable turned shockable out of hospital cardiac arrest was poor, but not invariably fatal. Though not statistically significant, point estimates for survival showed a trend to greater survival after amiodarone or lidocaine than placebo without increased risk of adverse effects or disability. Together, these findings may signal a clinical benefit that invites further investigation.                                                 The final study provides experimental data supporting the importance of a novel Cardiokine governing the local environment in infarcted hearts and determining the fate of implanted cells. This novel Cardiokine is C1q/tumor necrosis factor-related protein-9, or CTRP9, which is a novel pro survival Cardiokine that is significantly down regulated after myocardial infarction.                                                 In today's study by co-first authors, Drs. Yan and Guo and co-corresponding authors Drs. Ma and Wang from Thomas Jefferson University in Philadelphia, mice were subjected to myocardial infarction and treated with adipose-derived mesenchymal stem cells, CTRP9 or their combination. The authors found that administration of adipose-derived mesenchymal stem cells alone failed to exert significant cardio protection.                                                 However, administration of these cells in addition to CTRP9 further enhanced the cardioprotective effect of CTRP9, suggesting a synergistic effect. CTRP9 promoted adipose-derived mesenchymal stem cell proliferation, survival, migration and attenuated cardio myocyte cell death by signaling mechanisms that included binding with N-cadherin, activation of ERK, MMP9, and ERK-Nrf2 signaling and upregulation or secretion of antioxidative proteins.                                                 In summary, these results suggest that CTRP9 is a Cardiokine critical in maintaining a healthy microenvironment facilitating stem cell engraftment in infarcted myocardial tissue. Well, that wraps it up for your summaries, now for our feature discussion.                                                 Conscious sedation is very frequently used during transcatheter aortic valve replacement, or TAVR, but with limited evidence as to the safety and efficacy of this practice. Well, that is until this week's journal and this feature paper. We're so lucky to have with us the corresponding author, Dr. Jay Giri from Hospital of University of Pennsylvania, to discuss his novel findings, as well as Dr. Dharam Kumbhani, Associate Editor from UT Southwestern.                                                 Jay, tell us your study findings and how this really helps us to characterize anesthesia choice and clinical outcomes of at least U.S. patients undergoing TAVR. Dr. Jay Giri :                        We looked at 11,000 patients treated over a 15-month period in 2014 and 2015 with percutaneous transfemoral TAVR. Notably, this was a time period that was identified as the start of the era of conscious sedation for TAVR in the United States.                                                 Also, this five quarter period that we looked at represented a time of relative technological stability where only two valve types, the Sapien XT and original Medtronic CoreValve were being used in America.                                                 Looking at that 15-month period when conscious sedation was first being used in TAVR, we elected to compare those patients to a propensity matched group of patients who underwent TAVR by, what at that time was, the more traditional approach of general anesthesia.                                                 Our primary outcome within hospital mortality, because we had complete followup for this outcome. We also looked at 30-day outcomes for which we had about 90% followup. What we discovered was actually an associated reduction in mortality, an absolute reduction of about 1% in the patients who were treated with conscious sedation.                                                 We also noted that they had modest decreases in the hospital length of stay, as well as significant decreases in the rates of ICU length of stay and the rates of pressor or inotrope use during the procedure. Obviously, the most provocative of the findings was the fact that we seemed to discover, after propensity matching a slight improvement in in-hospital mortality that held true at 30 days, as well. Dr. Carolyn Lam:               Thank you, Jay. What important findings ... I mean, mainly because, we really didn't have much data, did we? About conscious sedation and TAVR before this. Now, it's observational data, and I suppose the question always becomes what about bias by indication? More well patients get selected for conscious sedation versus general anesthesia, perhaps? Or even the other way around. Could you elaborate a little bit on how you think that may have impacted results and the measures you took to look at that? Dr. Jay Giri :                        I think it was something that we were highly aware of and I also have to give credit to Dr. Kumbhani and the editorial staff at circulation for pushing us on that issue of selection bias for the two procedures. The obvious concern here, when you saw that there was a potential mortality reduction with conscious sedation patients, was that perhaps the conscious sedation patients actually represented a healthier cohort to start with, or they were perhaps treated at centers that were more highly experienced and by operators that were more highly experienced with TAVR in general.                                                 We tried to account for this in a number of different fashions. The first, as we mentioned, was with an inverse probability treatment weighted analysis that accounted for 51 co-variants that were balanced between the groups. Additionally, we did adjust for site characteristics and utilized a hierarchical method technique to take into account both the experience of sites and operators.                                                 Finally and most importantly, we performed what's called a falsification end point analysis in a postdoc fashion to verify that it looked like other outcomes outside of things, like mortality, length of stay, things we would expect to be influenced by sedation type, ended up being equal between the two groups. Falsification end point analysis represents, essentially, a negative control. You're supposed to theorize for potential outcomes that you would think would not be influenced by your intervention. In this case, those outcomes we theorized were vascular complications, major bleeding and pacemaker implantation, which we theorized would not be influenced by sedation type. In fact, we discovered that those outcomes were similar after adjustment, even though they had some differences before adjustment. Dr. Dharam Kumbhani:  Jay, I want to congratulate you and your team on this paper. You guys really picked a very important topic to look at and then you jump ... as you outlined, you jumped through a lot of statistical hoops and try to really provide evidence for a field in which a randomized controlled trial is probably going to be just logistically probably hard to conduct, just given the sample size requirements, which also you've provided in your discussion.                                                 I think all the metrics that you looked at as far as utilization of therapies and length of stay, things like that, I think many people believe that and you were the first one to systematically evaluate and show that.                                                 As you alluded to, I think that mortality, and Carolyn mentioned that, as well. I think the mortality findings are very interesting. Again, it's always hard when you have observational data to really put a lot of stock into that and you guys, as you outline, looked at so many different ways of doing that.                                                 Again, I guess, observational data are always inherently going to have that limitation, no matter what statistical rigor we put them through. They were definitely very thought-provoking and, as you outlined, it's definitely come at the right time as the field is exploding and more and more centers are getting facile at it.                                                 The other thing that you mentioned, but which I want to make sure that people fully understand is that you also provided a very elegant analysis looking at site volumes, because traditionally the sites that are doing conscious sedation have done a number of TAVR's before and there is a very clear cumulative volume outcomes association, for TAVR.                                                 By accounting for the totality of experience, so you adjusted for the cumulative volume that sites have been doing this, so these are not just the high volume, high throughput centers, which have a lot of experience doing 150, 200 TAVR's a year, that thereby have really good outcomes by virtue of being expert, both as operators and as sites, but rather potentially something that is related to conscious sedation aspect itself. You guys really stepped up and provided a very elegant analysis to try to dissociate the two issues here. Dr. Carolyn Lam:               Dharam, and you just provided a very elegant explanation of the thought processes that were going on with our editors about this paper. I join you in congratulating Jay. Just a question. This is the best available evidence now, what are we going to do about it? I mean, Dharam, you're an inventionist, what now? Dr. Dharam Kumbhani:  The issues were not so much related to efficacy, initially. The initial concerns were related to safety, and Jay's paper clearly addresses that. Then, in addition to that, it says, "Well, it's not just that it's a safe procedure, but it's also effective with potential patient level and hospital level benefits from having a robust conscious sedation program."                                                 I guess the one question that I have about conscious sedation and, Jay, I would love to hear your thoughts on this, as well, is it is possible but it is usually not done, TEE's or transesophageal echos are typically not done when you're doing conscious sedation. It is possible, as I said. As you move towards lower risk patients, on the one hand, these would be ideal patients for conscious sedation because then it's almost like a day procedure, in some ways for them.                                                 But on the other hand, the fidelity of being able to look for even small paravalvular leaks, things like that, may be harder with a transthoracic echo. I don't know, as we expand towards the oldest populations, whether we'll see a greater adoption of conscious sedation, or whether there'll be some scaling back. Dr. Jay Giri :                        Two points on that. The first is, I totally agree that it's relatively unusual for a transesophageal echo to be performed in the setting of conscious sedation. There's no question, secondly that transesophageal echo allows for the most rigorous evaluation of paravalvular leaks.                                                 It is striking, though, that the rates of paravalvular leaks, due to technological improvements to the valves, are significantly improving. Even since the time of our study two years ago, a new generation of valves is consistently coming out with leak rates in pretty well-conducted analyses that are in the low, single digit percentages for moderate leak or more.                                                 Part of I think the move towards conscious sedation, even initially and especially as we go forward, is predicated on the fact of continuing technological improvements that essentially almost solve the leak problem.                                                 I think it's true that there's always going to be a very small minority of patients that are stuck with concerns about paravalvular leak at the end of their TAVR procedure. For those who have moderate or greater leak, I think that the threshold for escalating care, even to intubation and TEE to evaluate that leak, I think should be relatively low in a lower risk population.                                                 However, I think the point that you bring up about the potential harm of trace or trivial leaks, or mild leaks, which may not be perfectly interpreted with transthoracic echo and aortograms and [inaudible 00:16:41] assessments at the time of the valve placement. It's something we're going to have to keep a close eye on.                                                 From a practical standpoint, I believe this train has left the station. Totally unscientific, but around the time they released the paper online. I just shot out a poll on Twitter and got about a couple of hundred responses from folks, what they're doing now.                                                 Now, Twitter certainly, probably doesn't represent the average transcatheter valve operator in the world, but I was surprised to see that over 70% of the respondents favored a conscious sedation approach at this point in time, which obviously is much higher than what we saw in our paper from two years ago. Dr. Carolyn Lam:               Well, audience, I'm sure you enjoyed that. Thank you for joining us today. Don't forget to tune in again next week.

Dr Christian Klein (Roche Pharma Research and Early Development, Roche Glycart AG, Schlieren, Switzerland) talks to ecancertv at the 1st Immunotherapy of Cancer Conference ( ITOC ) meeting in Munich. He describes a novel class of monomeric tumour-targeted immunocytokines that comprise a single IL-2 variant (IL2v) with abolished CD25 binding that is fused to the C-terminus of a tumour specific antibody with a heterodimeric Fc devoid of FcgR and C1q binding. For tumour targeting, human/humanized high affinity antibodies against CEA or FAP were selected. CEA- and FAP-IL2v activity was tested on effector cells by assessing the activation of P-STAT5, cell proliferation, sensitivity to Fas-induced apoptosis, expression of activation markers and cytokine release upon treatment. Compared to classical IL-2-based immunocytokines, CEA-IL2v and FAP-IL2v demonstrate superior safety, PK and tumour targeting due to abolished CD25 binding, monovalency and high-affinity to tumour antigens while failing to preferentially induce Tregs. CEA-IL2v and FAP-IL2v retain the capacity to activate and expand NK and CD8 effector T cells both in the periphery and tumour microenvironment supporting their further nonclinical and clinical investigation for immunotherapy of cancer.

Background. Natural IgM containing anti-Gal antibodies initiates classic pathway complement activation in xenotransplantation. However, in ischemia-reperfusion injury, IgM also induces lectin pathway activation. The present study was therefore focused on lectin pathway as well as interaction of IgM and mannose-binding lectin (MBL) in pig-to-human xenotransplantation models. Methods. Activation of the different complement pathways was assessed by cell enzyme-linked immunosorbent assay using human serum on wild-type (WT) and alpha-galactosyl transferase knockout (GalTKO)/hCD46-transgenic porcine aortic endothelial cells (PAEC). Colocalization of MBL/MASP2 with IgM, C3b/c, C4b/c, and C6 was investigated by immunofluorescence in vitro on PAEC and ex vivo in pig leg xenoperfusion with human blood. Influence of IgM on MBL binding to PAEC was tested using IgM depleted/repleted and anti-Gal immunoabsorbed serum. Results. Activation of all the three complement pathways was observed in vitro as indicated by IgM, C1q, MBL, and factor Bb deposition on WT PAEC. MBL deposition colocalized with MASP2 (Manders' coefficient 3D] r(2) = 0.93), C3b/c (r(2) = 0.84), C4b/c (r(2) = 0.86), and C6 (r(2) = 0.80). IgM colocalized with MBL (r(2) = 0.87) and MASP2 (r(2) = 0.83). Human IgM led to dose-dependently increased deposition of MBL, C3b/c, and C6 on WT PAEC. Colocalization of MBL with IgM (Pearson's coefficient 2D] r(p)(2) = 0.88), C3b/c (r(p)(2) = 0.82), C4b/c (r(p)(2) = 0.63), and C6 (r(p)(2) = 0.81) was also seen in ex vivo xenoperfusion. Significantly reduced MBL deposition and complement activation was observed on GalTKO/hCD46-PAEC. Conclusion. Colocalization of MBL/MASP2 with IgM and complement suggests that the lectin pathway is activated by human anti-Gal IgM and may play a pathophysiologic role in pig-to-human xenotransplantation.

The long pentraxin PTX3 has multiple roles in innate immunity. For example, PTX3 regulates C1q binding to pathogens and dead cells and regulates their uptake by phagocytes. It also inhibits P-selectin-mediated recruitment of leukocytes. Both of these mechanisms are known to be involved in autoimmunity and autoimmune tissue injury, e.g. in systemic lupus erythematosus, but a contribution of PTX3 is hypothetical. To evaluate a potential immunoregulatory role of PTX3 in autoimmunity we crossed Ptx3-deficient mice with Fas-deficient (lpr) C57BL/6 (B6) mice with mild lupus-like autoimmunity. PTX3 was found to be increasingly expressed in kidneys and lungs of B6lpr along disease progression. Lack of PTX3 impaired the phagocytic uptake of apoptotic T cells into peritoneal macrophages and selectively expanded CD4/CD8 double negative T cells while other immune cell subsets and lupus autoantibody production remained unaffected. Lack of PTX3 also aggravated autoimmune lung disease, i.e. peribronchial and perivascular CD3+ T cell and macrophage infiltrates of B6lpr mice. In contrast, histomorphological and functional parameters of lupus nephritis remained unaffected by the Ptx3 genotype. Together, PTX3 specifically suppresses autoimmune lung disease that is associated with systemic lupus erythematosus. Vice versa, loss-of-function mutations in the Ptx3 gene might represent a genetic risk factor for pulmonary (but not renal) manifestations of systemic lupus or other autoimmune diseases.

Unmethylierte bakterielle DNA, die reich an CG Sequenzen ist stimuliert das angeborene Immunsystem. Die Vermittlung dieser Wirkung erfolgt über den Toll-like Rezeptor 9. Reine CG Sequenzen sind im Organismus nicht stabil, da sie sehr rasch von den körpereigenen Nukleasen abgebaut werden. Mit synthetisch hergestellten Oligodeoxyribonukleotiden, sogenannten CpG-ODNs, kann eine Nukleaseresistenz erzielt werden und der immunstimulatorische Effekt nachgeahmt werden. Weiterhin wirken sich CpG-ODNs positiv auf den Verlauf von bakteriellen Infektionen, Tumoren und Prioninfektionen aus. Man weiß, dass eine Aktivierung des Immunsystems durch einmalige Gabe von CpG-ODNs nur über einen kurzen Zeitraum stattfindet. Die CpG-ODNs führen im Organismus innerhalb von Minuten zu einem mRNA Anstieg und innerhalb von Stunden zu einer kurzfristigen Zytokinsekretion und IgM Produktion, werden dann aber rasch abgebaut, so dass der immunstimulatorische Effekt in der Regel nur kurz anhält. Um CpG-ODN als Therapeutikum besser nutzen zu können liegt der Wunsch nahe, die Wirkung von CpG-ODN zu verlängern. Eine mögliche Strategie ist hierbei eine repetitive Applikation. Ziel dieser Arbeit war, den immunstimulatorischen Effekt von repetitiver CpG-ODN-Gabe besser zu verstehen und mit der Repetition die Wirkung zu verlängern. Damit könnte CpG-ODN als Therapeutikum bei bakteriellen Infektionen, Tumoren und bei Prionerkrankungen wirkungsvoll eingesetzt werden. In dieser Arbeit wurden jeweils 12 Gruppen zu je 5 Mäusen gebildet, wobei die jeweiligen Gruppen an 5, 7 oder 21 aufeinanderfolgenden Tagen jeweils eine CpG-ODN, NaCl oder Neg-ODN Applikation i.p. erhielten. Die Mäuse wurden anschließend an Tag 7 oder 28 während bzw. nach der Behandlung getötet. So erhielt man folgende Gruppen: 5x-CpG-ODN, NaCl oder Neg-ODN behandelte, an Tag 7 getötete Mäuse 5x-CpG-ODN, NaCl oder Neg-ODN behandelte, an Tag 28 getötete Mäuse 7x-CpG-ODN, NaCl oder Neg-ODN behandelte, an Tag 7 getötete Mäuse 21x-CpG-ODN, NaCl oder Neg-ODN behandelte, an Tag 28 getötete Mäuse Im Verlauf der Arbeit, die die immunmodulatorische Wirkung auf das Gehirn und die Leber der Maus untersucht, konnten zusammenfassend folgende Ergebnisse herausgearbeitet werden, die mittels Real time PCR und Immunhistologie gewonnen wurden. Im Gehirn führt CpG-ODN zu einer mindestens einwöchigen Hochregulierung der mRNA von TNFα. Des Weiteren kommt es zu einer mindestens zweitägigen C1q und IFNg Hochregulierung. Eine IL-12p40 Hochregulierung findet nur ca. 18 Stunden statt, während eine STAT3 Hochregulierung nicht nachweisbar ist. In der histologischen Betrachtung finden sich in der HE Färbung keine pathologischen Veränderungen der Hirnarchitektur und in einer immunhistologischen Färbung mit CD 11b und GFAP bindenden Antikörpern keine Unterschiede zwischen den CpG-ODN, NaCl oder Neg-ODN behandelten Tieren. In der Leber findet sich eine signifikante Hochregulierung von IL-12p40 über mindestens drei Wochen und eine C1q, TNFα und IFNg Hochregulierung von mindestens einer Woche. Histologisch finden sich in der HE Färbung massive Leukozyteninfiltrate über mindestens zwei Tage. In der Immunhistologie sieht man an den Infiltraten beteiligte aktivierte Makrophagen, T und B-Lymphozyten, jeweils dargestellt mit CD 11b, CD 8 und B220 bindenden Antikörpern. Es zeigte sich, dass eine repetitive CpG-ODN-Gabe eine verlängerte stimulatorische Wirkung auf das Immunsystem ausübt, was Voraussetzung für den Einsatz als Therapeutikum ist. Besonders bemerkenswert ist die Tatsache, dass man durch periphere Gabe von CpG-ODN im Gehirn eine Immunstimulierung erreichen kann. Diese könnte im Rahmen einer Therapie von Prionerkrankungen, anderen Gehirninfektionen, Morbus Alzheimer oder Gehirntumoren Anwendung finden. Allerdings sind noch weitere Studien nötig, um Risiken wie Hepatotoxizität oder Autoimmunität besser abschätzen zu können und den Mechanismus zu erforschen, wie durch periphere Gabe von CpG-ODN eine immunologische Gehirnaktivierung erreichen wird. Eine wichtige Frage für die Zukunft ist hierbei, ob die Wirkung von CpG-ODN direkt auf die Gehirnzellen wirkt oder ob es einen second messenger gibt, der die Blut-Hirn-Schranke überwindet.