Podcasts about nfat

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2023.03.31.535090v1?rss=1 Authors: Wetzel, A., Lei, S. H., Liu, T., Hughes, M. P., Peng, Y., McKay, T., Waddington, S. N., Granno, S., Rahim, A. A., Harvey, K. Abstract: Background: Parkinson`s disease (PD) is a progressive late-onset neurodegenerative disease leading to physical and cognitive decline. Mutations of leucine-rich repeat kinase 2 (LRRK2) are the most common genetic cause of PD. LRRK2 is a complex scaffolding protein with known regulatory roles in multiple molecular pathways. Two prominent examples of LRRK2-modulated pathways are Wingless/Int (Wnt) and nuclear factor of activated T-cells (NFAT) signaling. Both are well described key regulators of immune and nervous system development as well as maturation. The aim of this study was to establish the physiological and pathogenic role of LRRK2 in Wnt and NFAT signaling in the brain, as well as the potential contribution of the non-canonical Wnt/Calcium pathway. Methods: In vivo cerebral Wnt and NFATc1 signaling activity was quantified in LRRK2 G2019S mutant knock-in (KI) and LRRK2 knockout (KO) male and female mice with repeated measures over 28 weeks, employing lentiviral luciferase biosensors, and analyzed using a mixed-effect model. To establish spatial resolution, we investigated tissues, and primary neuronal cell cultures from different brain regions combining luciferase signaling activity, immunohistochemistry, qPCR and western blot assays. Results were analyzed by unpaired t-test with Welch`s correction or 2-way ANOVA with post hoc corrections. Results: In vivo Wnt signaling activity in LRRK2 KO and LRRK2 G2019S KI mice was increased significantly ~3-fold, with a more pronounced effect in males (~4-fold) than females (~2-fold). NFATc1 signaling was reduced ~0.5-fold in LRRK2 G2019S KI mice. Brain tissue analysis showed region-specific expression changes in Wnt and NFAT signaling components. These effects were predominantly observed at the protein level in the striatum and cerebral cortex of LRRK2 KI mice. Primary neuronal cell culture analysis showed significant genotype-dependent alterations in Wnt and NFATc1 signaling under basal and stimulated conditions. Wnt and NFATc1 signaling was primarily dysregulated in cortical and hippocampal neurons respectively. Conclusions: Our study further built on knowledge of LRRK2 as a Wnt and NFAT signaling protein. We identified complex changes in neuronal models of LRRK2 PD, suggesting a role for mutant LRRK2 in the dysregulation of NFAT, and canonical and non-canonical Wnt signaling. 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/2023.03.18.532760v1?rss=1 Authors: Field, J. T., Chapman, D., Ghavami, S., West, A. R., Saleem, A., Kindrachuk, J., Triggs-Raine, B., Gordon, J. W. Abstract: Mitochondrial quality control is critical in muscle to ensure both contractile and metabolic function. Nix is a BCL-2 family member, mitophagy receptor, and has recently been implicated in muscle atrophy and aging. In human and rodent myotubes, we previously demonstrated that Nix orchestrates both mitochondrial calcium and mTOR signaling in responsive to a lipotoxic stress leading mitochondrial turnover and impaired insulin signaling. Human GWAS suggests altered Nix expression could predispose individuals to manifestations of mitochondrial disease. To understand the role of Nix in skeletal muscle, we generated a muscle-specific Nix knockout model. Nix knockout mice displayed a ragged-red fibre phenotype, which was more evident in male mice, along with accumulation of senescent mitochondria and sarcoplasmic reticulum. Intriguingly, Nix knockout mice were more insulin sensitive with a corresponding increase in glycogen-rich muscle fibres. Kinome- and gene expression analyses revealed that Nix knockout impairs NFAT and canonical myostatin signaling, with alterations in muscle fibre-type composition and evidence of regeneration. Soleus muscle displayed reduced myoglobin, MYH2, and TNNT1 expression, along with increased in MYH4. Mechanistic experiments in C2C12 myotubes demonstrated that Nix expression increased during differentiation and following electrical pacing in parallel with PGC-1, and is both necessary and sufficient to modulate mitophagy, nuclear calcium signaling, and gene expression. Collectively, these observations indicate that in addition to a role in cell death and mitophagy, Nix maintains sarcoplasmic reticulum and calcium homeostasis, and modulates the oxidative muscle phenotype. 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/2023.02.21.529374v1?rss=1 Authors: Sant'anna, R., Robbs, B. K., Araujo, J. F., dos Santos, P. P., Konig, A., Outeiro, T. F., Foguel, D. Abstract: Soluble oligomeric forms of alpha-synuclein (aSyn-O) are believed to be one of the main toxic species in Parkinson's disease (PD) leading to degeneration of dopaminergic neurons. aSyn-O can induce neural Ca2+ influx, over activating downstream pathways leading to PD phenotype. Nuclear factor of activated T-cell family (NFAT) transcription factors are activated by calcineurin (CN), a phosphatase regulated by Ca2+ levels. NFAT is involved in the regulation of synaptic plasticity, axonal growth, neuronal survival and directly regulates the expression of several related genes in different cell types. Although an involvement of Ca2+ and CN in PD development has already been reported, the involvement of NFAT is still unclear. Here, we investigated the role of NFAT signaling in neuronal degeneration induced by extracellular aSyn. We demonstrate that aSyn-O are toxic to neurons leading to cell death, loss of neuron ramification and reduction of synaptic proteins which are completely reversed by inhibition of CN with ciclosporin-A or with VIVIT, a NFAT specific inhibitor. Furthermore, aSyn-O induce NFAT nuclear translocation and transactivation. After the analysis of a panel of 91 genes related to various cellular processes involved in PD/synucleinopathies by real-time qPCR, and further validation at protein level we found that aSyn-O modulates the gene involved in the maintenance of synapses, synapsin 1 (Syn 1). Syn1 mRNA and protein and synaptic puncta are drastically reduced in cells treated with aSyn-O. This is the first demonstration of a direct role of NFAT in aSyn-O-induced toxicity and Syn1 gene regulation, and has strong implications in our understanding of the molecular underpinnings of synucleinopathies. 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/2023.01.27.525873v1?rss=1 Authors: Poth, V., Do, H. T. T., Foerderer, K., Tschernig, T., Alansary, D., Helms, V., Niemeyer, B. A. Abstract: Balanced Ca2+ homeostasis is essential for cellular functions. STIM2 mediated Store-Operated Ca2+ Entry (SOCE) regulates cytosolic and ER Ca2+ concentrations, stabilizes dendritic spine formation and drives presynaptic spontaneous transmission and ER stress in neurons. Recently identified alternative spliced variants expand the STIM protein repertoire, uncover unique functions and facilitate our understanding of tissue specific regulation of SOCE. Here, we describe an addition to this repertoire, a unique short STIM2 variant (STIM2.3/STIM2G) present only in old world monkeys and humans with expression in humans starting with the beginning of brainwave activity and upon synapse formation within the cerebral cortex. In contrast to the short STIM1B variant, STIM2.3/STIM2G increases SOCE upon stimulation independently of specific spliced in residues. Basal cluster formation is reduced and analyses of several additional deletion and point mutations delineate the role of functional motifs for Ca2+ entry, NFAT activation and changes in neuronal gene expression. In addition, STIM2.3/STIM2G shows reduced binding and activation of the energy sensor AMPK. In the context of reduced STIM2.3 splicing seen in postmortem brains of patients with Huntingtons disease, our data suggests that STIM2.3/STIM2G is an important regulator of neuronal Ca2+ homeostasis, potentially involved in synapse formation/maintenance and evolutionary expansion of brain complexity. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC

Reference Alcohol Clin Exp Res. 2011 Aug; 35(8): 1435–1444 --- Send in a voice message: https://anchor.fm/dr-daniel-j-guerra/message

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2022.10.23.513385v1?rss=1 Authors: Hammad, A. S., Yu, F., Horgen, F. D., Machaca, K. Abstract: Store-operated calcium entry (SOCE) contributes to several physiological and pathological conditions including transcription, secretion, immunodeficiencies, and cancer. SOCE has been shown to be important for breast cancer cell migration where knockdown of SOCE components (STIM1 or Orai1) decreases cancer metastasis. Here we show unexpectedly that STIM1 knockout (KO) metastatic MDA-MB-231 breast cancer cells migrate faster and have enhance invasion capacity compared to parental cells. In contrast, Orai1-KO cells, which have similar levels of SOCE inhibition as STIM1-KO, migrate slower than the parental cell line. This shows that the enhanced migration phenotype of STIM1-KO cells is not due to the loss of a Ca2+ entry through SOCE, rather it involves transcriptional remodeling. Interestingly, NFATC2 is significantly downregulated in STIM1-KO cells and overexpression of NFATC2 reversed the enhanced migration of STIM1-KO cells. This demonstrates that STIM1 modulates NFATC2 expression independently of its role in SOCE. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC

This week, please join author Andrew Chapman and Guest Editor Harvey White as they discuss the article "Coronary Artery and Cardiac Disease in Patients With Type 2 Myocardial Infarction: A Prospective Cohort Study." Dr. Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast summary and backstage pass to the Journal and its editors. We're your co-hosts. I'm Dr. Carolyn Lam, Associate Editor from the National Heart Center and Duke National University of Singapore. Dr. Greg Hundley: And I'm Dr. Greg Hundley, Associate Editor and Director of the Pauley Heart Center at VCU Health in Richmond, Virginia. Dr. Greg Hundley: Well, Carolyn, this week's feature on April 19th refers to coronary artery and cardiac disease in patients with type two myocardial infarction. And we will have more to learn about that, but how about we grab a cup of coffee and get started with some of the other articles in the issues. Dr. Carolyn Lam: Please? You first. Dr. Greg Hundley: Thanks Carolyn. So Carolyn, this team investigated the observational and causal associations of 90 cardiovascular proteins, which were measured using affinity based proteomic assays to estimate their association with incident heart failure. And so to accomplish this, the team, led by Dr. Thomas Lumbers from University College of London, utilized a fixed effect meta-analysis of four population-based studies comprising a total of 3,000 plus participants with 732 heart failure events. Now, the causal effects of heart failure associated proteins were then investigated by Mendelian randomization using CIS protein, quantitative loci, genetic instruments identified from genome-wide association studies or GWAS and over 30,000 individuals. Dr. Carolyn Lam: Wow! Big study, important stuff. So what did they find? Dr. Greg Hundley: Right Carolyn, several things. So 44 of 90 proteins were positively associated with the risk of incident heart failure. Now, among these eight proteins had evidence of a causal association with heart failure that was robust to multiverse sensitivity analysis. Higher CSF1, Galectin-3 and KIM-1 or kidney injury molecule one were positively associated with the risk of heart failure, whereas higher adrenomedullin chitinase-3 like-protein-1, cathepsin L1, and fibroblast growth factor 23, and matrix metalloproteinase 12 were protective. And so Carolyn in summary, the team identified 44 circulating proteins that were associated with incident heart failure of which eight showed evidence of a causal relationship, and seven were identified as being drugable, including adrenomedullin, which represents a particularly promising drug target. Dr. Greg Hundley: Additionally, Carolyn, this is a really interesting study as the teams approach demonstrates a tractable roadmap for the triangulation of population genomic and proteomic data for the prioritization of therapeutic targets for complex human diseases. Dr Carolyn Lam: Wow! Super cool. Yeah, indeed the methodology is significant there too. Thanks Greg. Well, this next paper deals with hypertrophic cardiomyopathy and we know that familial hypertrophic cardiomyopathy is the most common inherited cardiac disease and is typically caused by mutations in genes encoding sarcomeric proteins that regulate cardiac contractility. But how exactly is the dysregulated sarcomeric force production sensed and how does that lead to pathological remodeling? Dr. Carolyn Lam: Well, today's authors and they are Dr. Qyang from Yale University School of Medicine and colleagues gained insights from a severe phenotype of an individual with hypertrophic cardiomyopathy and a second genetic alteration in a sarcomeric mechanosensing protein. They derived cardiomyocytes from patient specific induced pluripotent stem cells and developed robust, engineered heart tissues to study human cardiac mechanobiology at both cellular and tissue levels. They further used computational modeling for muscle contraction and rescue of disease phenotype via gene editing and pharmacological interventions to identify a new mechanotransduction pathway in hypertrophic cardiomyopathy. Dr. Greg Hundley: Wow, Carolyn! Tell us more about this new pathway. Dr. Carolyn Lam: The study presents a novel biomechanical mechanism by which enhanced myofilament contractile force generation due to sarcomeric mutations, destabilize the muscle limb protein Z-disc mechanosensory complex, and this leads to disinhibition of calcineurin nuclear factor of activated T-cells or NFAT signaling and consequently leads to hypertrophy. Normalization of hypercontractile force in proband cardiomyocytes either with gene editing approaches or with ectomyosin crossbridge inhibitor mavacamten, resulted in an increase in Muscle Lim Protein levels, a decrease in that calcineurin and fat activity and a rescue from the hypertrophic cardiomyopathy defects. Dr. Carolyn Lam: The authors provided evidence that the common Muscle Lim Protein W4R variant is an important modifier that worsens the disease severity of hypertrophic cardiomyopathy, but alone does not appear sufficient to cause disease. All in all, these data established a foundation for developing innovative mechanism-based treatments for hypertrophic cardiomyopathy that stabilize the Z-disc Muscle Lim Protein mechanosensory complex. Dr. Greg Hundley: Oh, wow Carolyn! What a really nice mechanistic study and important new information too. Well, Carolyn, my next paper comes to us from Dr. Anthony Rosenzweig, Massachusetts General Hospital at the Harvard Medical School and Carolyn the LV myocardium increases in mass in response to pathological as well as physiological stimuli. The former or pathologic hypertrophy, often proceeds cardiomyocyte loss and heart failure. The latter or physiologic, paradoxically protects the heart enhances cardiomyogenesis. The mechanisms underlying these differences remain incompletely understood. Now, while long non-encoding RNAs are important in cardiac development and disease associated with pathologic hypertrophy, less is known about their roles in physiologic hypertrophy or cardiomyogenesis. Dr Carolyn Lam: Oh, interesting! So what did these authors find about link RNAs and physiologic hypertrophy? Dr Greg Hundley: Right, Carolyn. So in this study of mice, the authors identified exercise regulated cardiac link RNAs termed lncExACT and lncExACT1 was evolutionarily conserved and decreased in exercised hearts, but increased in experimental heart failure. Cardiac lncExACT1 over expression caused pathological hypertrophy and heart failure while lncExACT1 inhibition induced physiologic hypertrophy and cardiomyogenesis protecting against cardiac fibrosis and dysfunction. Dr. Greg Hundley: Now, lncExACT1 functioned by regulating microRNA 222 calcineurine signaling, and Hippo/Yap1 signaling through DCHS2. Cardiomyocyte DCH2 over expression in zebra fish induced pathological hypertrophy and impaired cardiac regeneration promoting scarring after this injury. In contrast mirroring DCH2 deletion, induced physiological hypertrophy and promoted cardiomyogenesis. Dr. Carolyn Lam: Oh, wow, Greg! Okay. Could you wrap it up for us? What's the take home message? Dr. Greg Hundley: You bet, Carolyn. These studies identify that lncExACT1 DCHS2 is a novel pathway regulating cardiac hypertrophy and cardiomyogenesis. lncExACT1 DCHS2 acts as a master switch, toggling the heart between physiological and pathological growth to determine functional outcomes, providing a potentially tractable therapeutic target for harnessing the benefits of exercise. Dr Carolyn Lam: Oh, thank you, Greg. Well, also in this issue is an In-Depth paper by Dr. Luesebrink on “Percutaneous Transvalvular Micro Exhale Flow Pump Support in Cardiology.” There's a Research Letter by Dr. Shekhar on “Age and Racial or Ethnic Disparities in Pediatric Out-of-Hospital Cardiac Arrest.” Dr. Greg Hundley: Right, Carolyn. Well, Carolyn from the mailbag, we have a Letter to the Editor from Dr. Gronda entitled “The Failing Heart and SGLT2 inhibitor Renal Effects: Are They Mutually Engaged in Business?” We also have from Dr. Viskin, an ECG challenge entitled “Sinus Node Dysfunction with a Nice Twist.” And finally, Carolyn, there's a Perspective piece from Dr. Schulman entitled “The Price and Quality of the Generic Pharmaceutical Market.” Well, how about at Carolyn we get on our feature discussion involving type two myocardial infarction. Dr. Carolyn Lam: Yay! Let's go. Dr. Greg Hundley: Well, listeners, welcome to our feature discussion on this April 19th and we have with us today, Dr. Andrew Chapman from Edinburg, Scotland and Dr. Harvey White from Auckland, New Zealand. Welcome gentlemen. And we'll start with you, Andrew. First, could you describe for us some of the background information that went into the preparation of your study? Dr Andrew Chapman: Good morning and good evening and thank you very much for the invitation. So type two myocardial infarction is an interesting diagnosis. It was first introduced in around 2007 in recognition that patients could have heart injury when they were in hospital with other problems that led to an imbalance in myocardial oxygen supply, or an unmet need in myocardial oxygen demand, without the presence of atherothrombotic coronary artery disease. We don't know a great deal about these patients. Dr. Andrew Chapman: There have been a number of observational cohort studies, including from ourselves in Scotland, which have demonstrated the outcomes for this patient group are poor. We know only around one-third of patients with type two MI, survive to five years after diagnosis. And we also know, and previously demonstrated from patients in Scotland that those with underlying coronary artery disease actually had the worst outcomes and were at increased risk of future myocardial infarction events due to plaque rupture. So we hypothesized that patients with type two myocardial infarction may have failed a physiological stress test due to another illness and we wanted to investigate what the prevalence of underlying coronary artery disease and/or structural heart disease was, using a panel of different imaging modalities. Dr. Greg Hundley: And so Andrew tell us the hypothesis that you wanted to address? Dr. Andrew Chapman: So we believed that observational evidence suggested that coronary artery disease was important in patients with type two myocardial infarction and we felt that this was increasing their susceptibility to these events. Our primary hypothesis was that the majority of patients with type two myocardial infarction would have underlying coronary artery disease, which was previously quiescent undetected. Dr. Greg Hundley: Tell us a little bit about the study design and the study population that you use to answer this question. Dr. Andrew Chapman: Demand MI is to our knowledge, the first prospective observational cohort study in which patients who were in hospital with evidence of myocardial injury, so a raised cardiac troponin, were screened for the presence of supplier demand imbalance and the clinical diagnosis of type two MI. Now, in those patients that we were able to recruit, we did obviously have important exclusion criteria, but we designed a series of different investigations depending on individual patient risk factors and the appropriateness of such, but the primary goal was to undertake coronary angiography, ideally using an invasive coronary angiogram, which would allow us to undertake additional testing, such as plaque imaging and pressure wire study, to look for the functional consequences of stenosis. In those not fit for an invasive angiogram, we undertook CT coronary angiography. And in all patients we undertook structural imaging and we aimed to do cardiac MRI in all. Due to the coronavirus pandemic and for other reasons, we used echocardiography where MRI was not available. Dr. Greg Hundley: And so the total number of subjects here was how many? Dr. Andrew Chapman: We recruited 100 patients with a clinical diagnosis of type two myocardial infarction. Dr. Greg Hundley: Very good. And so now, Andrew, what were your results? Dr. Andrew Chapman: It's a really fascinating study, obviously, in my opinion. So we recruited 100 patients with a clinical diagnosis of type two myocardial infarction who had evidence of supplier demand and balance, a raised cardiac troponin concentration and evidence of symptoms and/or signs of myocardial ischemia. So in line with the universal definition criteria. Of 100 patients after undertaking coronary imaging, we reclassified the diagnosis in seven. Dr. Andrew Chapman: In five patients, we found that there was evidence of either plaque rupture or a stent thrombosis. And in two patients, we found evidence of myocarditis and stress cardiomyopathy respectively. The first principle finding is that actually despite careful characterization and really detailed screening, we were correct in 93 of 100 patients and we got the diagnosis wrong in seven. The principle hypothesis related to the prevalence of coronary artery disease and this was, as alluded to, undertaking with invasive and noninvasive imaging. But overall, the prevalence of coronary artery disease was 68% of those with type two myocardial infarction and this was obstructive in 30%. Dr. Andrew Chapman: We also undertook structural imaging as mentioned. We observed evidence of left ventricular systolic dysfunction in 34% of patients, of around a third, and perhaps most surprisingly, although we had a clear diagnosis of myocardial infarction in these patients, we only found imaging evidence of in part pattern late gadolinium enhancement, which is considered the gold standard for its diagnosis of myocardial infarction. We only observed that in 42%, which raises some interesting questions. Dr. Andrew Chapman: One of the principle clinical findings of the study is that these underlying conditions of coronary artery disease and left ventricular impairment, both of which are readily treatable with secondary prevention. These conditions were previously unrecognized in 60% of patients and only one-third were on appropriate evidence-based treatment, which gives me some cause for optimism, that there may be a role here for targeted treatment, which could plausibly, plausibly impact on outcomes. Dr. Greg Hundley: And Andrew, just a clarification point, maybe a subgroup analysis, any differences in your findings in regarding men versus women? Dr. Andrew Chapman: Excellent question. And in most studies of type two myocardial infarction, it's thought that this condition is more prevalent in women than men, but undoubtedly in all observational cohorts, there is selection bias as you will only diagnose a type two myocardial infarction if a clinician requests to test troponin in the first place. In our study, interestingly, we recruited more men than women. We had 56% men and we did not find any differences by sex in our analysis. Dr. Greg Hundley: Well listeners, what an excellent description from Dr. Chapman. A very interesting study. And we now want to turn to one of our editors, guest editors, Dr. Harvey White, and Harvey, we want to thank you for your work here with us at the American Heart Association and Circulation, and you receive many articles to review. What attracted you to this particular article and how do we put in context, these results with others that have been published pertaining to type two myocardial infarction? Dr. Harvey White: Thanks, Greg, it's a pleasure to work for Circulation. This paper is very close to my heart because I introduced the typing system in 2007 and it had minimal support and people said, "Why do we need a typing system? We've got killer class and Canadian class and you've done a troponin release system as well". And people stood up and then I laid out the type one plaque rupture. We know the pathophysiology and we know the treatment. Type two, I'd worked on beta blockers, supply and demand and I thought we should define the pathophysiology and define the treatment. That's 2007, which is 15, 16 years ago. And Andrew's paper is really lovely. As I said, it's close to my heart and he inches things forward. I've written an editorial, which I call "Zooming in on the enigmas of type two MI" and enigma means mystery or it's unclear, uncertain. Dr. Harvey White: And that's for sure we don't have full support for the diagnosis. It's become very practical, used in clinical trials and clinically, but we don't know how to manage it and we don't know how to define the groups. Andrew and colleague study is very nice. It's prospective and it has set out to define the coronary artery disease. I've tried for about 10 years to subdivide type two and to those without coronary disease and those with coronary disease. And you could also have a type C, which hasn't been investigated or unknown. And Andrew has answered one of the enigmas and it's really interesting. Large proportion, normal coronary arteries, diagnosis was changed a little bit based on the finding of thrombus. We're challenged with that finding because all MIs have thrombus at PM and really type one should be ruptured plaque. But Andrew changed the diagnosis in a few where one was an OTC, a marvelous case with marvelous pictures, changed the diagnosis. So I like the study and I like the findings. Thanks. Dr. Greg Hundley: Very nice. Well, Andrew, what a perspective and listeners getting just to listen to Dr. White is really quite exciting for me. Andrew, what do you see as the next study to be performed in this sphere of research? Dr. Andrew Chapman: I think we've gone some way to provide some insights into the underlying pathophysiology of this condition and these coexistent conditions of coronary artery disease and left ventricular impairment, which might increase an individual's susceptibility to a type two myocardial infarction. The question is what can we do about it and does targeted treatment with secondary prevention therapies for coronary disease and treatment for heart failure left ventricular impairment, does that improve outcomes? Dr. Andrew Chapman: The next study for me is clear. The next study for me, needs to be a randomized controlled trial, whereby patients with type two myocardial infarction are randomized to current best practice or risk stratification by a cardiologist with an interest in this condition, followed by targeted investigation for coronary disease and LV impairment and thereafter treatment as appropriate. This will be a trial of a complex intervention. I'm very grateful that we've received funding in Scotland already for this pilot phase of this trial, which we've called Targets Type Two and we'll begin recruitment for that trial in August of this year. Dr. Andrew Chapman: I must acknowledge colleagues in this area are looking at coronary disease and type two myocardial infraction. Professor Derek Chew is leading a study called Act Two, which is already recruiting and that will also provide invaluable information as to the prevalence of coronary disease and the potential benefits of treatment of that coronary disease in patients with this condition. Dr. Greg Hundley: And Harvey. How about your, what is your perspective in terms of the next series of studies perhaps that need to be performed in this space? Dr. Harvey White: There's a number and I like very much, Andrew's suggestion. The study that we're doing is randomizing to angiography or not angiography working with Derek Chew. I think all patients with MI should have coronary angiography. It's simple, it takes about 10 minutes. There's obviously some contraindications, but the information as Andrew has pointed out is really so useful. He found dissection, he found an embolus. Normal coronary arteries that in my view changes the management. Whether you should do an angiogram is very important. Randomization to various treatments. That's important. I would like to get more information about the objective evidence of type two MI, the criteria for low hemoglobin, shortness of breath, low blood pressure, high blood pressure, and so forth. There's a lot to do. As Andrew pointed out, the outcome may be worse than type one that's becoming more common and I think these studies will be very, very important. Dr. Greg Hundley: Very nice well listeners. We want to thank Dr Andrew Chapman as lead investigator and Dr Harvey White as guest editor for bringing us this study using advanced imaging of patients with type two myocardial infarction, which identified coronary artery disease in two-thirds and left ventricular dysfunction in one-third, and also highlighting that unrecognized and untreated coronary or cardiac disease occurs in many patients with type two MI and gives us pause for thought on a series of studies that may be performed in the future. Dr. Greg Hundley: Well, on behalf of Carolyn and myself, we want to wish you a great week and we will catch you next week on the run. Dr. Greg Hundley: This program is copyright of the American heart association, 2022. The opinions expressed by speakers in this podcast are their own and not necessarily those of the editors or of the American Heart Association. For more, please visit AHAjournals.org.

This week's show features a panel discussion between authors Adrian Wells and Hyeon Chang Kim as they discuss their articles "Improving the Effectiveness of Psychological Interventions for Depression and Anxiety in Cardiac Rehabilitation PATHWAY—A Single-Blind, Parallel, Randomized, Controlled Trial of Group Metacognitive Therapy" and "Associations of Ideal Cardiovascular Health and Its Change During Young Adulthood With Premature Cardiovascular Events: A Nationwide Cohort Study." Dr. Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast summary and backstage pass to the journal and its editors. We're your co-hosts. I'm Dr. Carolyn Lam, Associate Editor from the National Heart Center and Duke National University of Singapore. Dr. Greg Hundley: And I'm Dr. Greg Hundley, also your co-host. And Associate Editor, Director of the Pauley Heart Center, VCU Health in Richmond, Virginia. Dr. Carolyn Lam: Greg, we're starting off the month with double features, and these are just so interesting. The first paper talks about psychological interventions for depression and anxiety in cardiac rehabilitation. And the next talks about ideal cardiovascular health and its change during young adulthood and how that relates to premature cardiovascular events. Cool, huh? Dr. Greg Hundley: Absolutely. Well, Carolyn. How about we grab a cup of coffee and start discussing some of the other articles in the issue? And I could go first. Carolyn, the first article that I've got is from Mrs. Elizabeth Jordan from Ohio State University Wexner Medical Center. And it really pertains to cardiomyopathies. And remember, Carolyn, classically, we categorize hypertrophic, dilated, and arrhythmogenic right ventricular cardiomyopathy. And each has a signature genetic theme. Hypertrophic cardiomyopathy and ARVC are largely understood as genetic diseases of sarcomere or desmosome proteins. But in contrast, there are over 250 genes spanning more than 10 gene ontologies that have been implicated in dilated cardiomyopathy. And therefore, it really represents a very complex and diverse genetic architecture. So to clarify this, a systematic curation of evidence to establish the relationship of genes with dilated cardiomyopathy was conducted by an international panel with clinical and scientific expertise in dilated cardiomyopathy genetics. And they evaluated evidence supporting monogenic relationships of genes with idiopathic dilated cardiomyopathy. Dr. Carolyn Lam: Oh, wow. That sounds like a lot of work. And what did they find, Greg? Dr. Greg Hundley: Right, Carolyn. So in the curation of 51 genes, 19 had high evidence. 12 are definitive strong, and seven moderate. And notably, these 19 genes only explain the minority of cases, leaving the remainder of dilated cardiomyopathy genetic architecture really incompletely addressed. And clinical genetic testing panels include most high evidence genes. However also, the panel noted that genes lacking robust evidence are very commonly observed clinically. Dr. Greg Hundley: So Carolyn, the take home message from this international panel is that while dilated cardiomyopathy genetic testing panels include an average of about 60 genes, when curating published evidence for dilated cardiomyopathy, only 19 have really emerged as high levels of evidence. And then in this study, 51 genes were evaluated. And the 19 genes appraised as high evidence were recommended to be routinely used in the genetic evaluation of dilated cardiomyopathy. And one more point. Rare variants from genes without moderate, strong, or definitive evidence should not be used in clinical practice to predict dilated cardiomyopathy risk most importantly when also you're screening at risk family members. Dr. Carolyn Lam: Wow. Very nice. Stunning numbers. Well, my paper is identifying a novel therapeutic target in pulmonary arterial hypertension. Do you want to know what that is? Dr. Greg Hundley: Ah, yes, Carolyn. Very interesting. So what is it? Dr. Carolyn Lam: It's switch-independent 3A. Which is an epigenetic modifier, which is drastically down-regulated in pulmonary arterial hypertension patients and rodent models of pulmonary arterial hypertension. And strongly associated with decreased bone morphogenic protein receptor type two, or BMPR2 expression. So this switch-independent 3A overexpression up-regulated BMPR2 expression by modulating critical epigenetic pathways and decreasing a specific transcription factor binding to the BMPR2 promoter in pulmonary vascular smooth muscle cells. Furthermore, aerosolized lung-targeted gene transfer of adeno-associated virus zero type one and containing switch-independent 3A reversed and prevented pulmonary arterial hypertension phenotype in preclinical animal models. So this beautiful study, from Dr. Hadri from Icahn School of Medicine at Mount Sinai in New York and colleagues, really suggests that switch-independent 3A can be a clinically relevant molecule for the treatment of pulmonary arterial hypertension. Dr. Greg Hundley: Wow, Carolyn. Really nice. Very intricate science for the study of pulmonary hypertension. Well, my next paper actually comes to us from Dr. Joe Hill and colleagues at UT Southwestern Medical Center. And Carolyn, as we know, cardiac hypertrophy is an independent risk factor for heart failure. Of course, the leading cause of morbidity and mortality globally. And the calcineurin NFAT, or nuclear factor of activated T-cells pathway, and the MAP kinase ERK, or extra cellular signal regulated kinase pathway, contributes to the pathogenesis of cardiac hypertrophy as an interdependent network of signaling cascades. However, Carolyn, how these pathways interact really remains unclear. And so Dr. Hill and colleagues engineered a cardiomyocyte-specific ETS2, a member of the E26 transformation specific sequence or ETS domain family knockout mouse, and investigated the role of ETS2 in cardiac hypertrophy. Primary cardiomyocytes were also used to evaluate ETS2 function in cell growth. Dr. Carolyn Lam: Wow. Okay. So what were the results, Greg? Dr. Greg Hundley: Right, Carolyn. Three main findings. First, ETS2 is activated by ERK1/2, or extracellular signal-regulated kinase 1/2, in both hypertrophied murine hearts and in human dilated cardiomyopathy. Second, ETS2 is required for both pressure overload, and calcineurin induced cardiac hypertrophy responses involving signaling cascades distinct from, but interdependent with ERK1/2 signaling. And third, this group discovered that ETS2 synergizes with NFAT to transactivate RCAN1-4, an established downstream target of NFAT, or nuclear factor of activated T-cells. And they identified an MIR-223 as a novel transcriptional target of NFAT ETS2 in cardiomyocytes. Dr. Carolyn Lam: Wow. Wow. That sounds like a lot of detailed work. Could you tell us what the clinical implications are, Greg? Dr. Greg Hundley: You bet, Carolyn. So in aggregate, these findings unveil a previously unrecognized molecular interaction between two conical hypertrophic signaling pathways, MAP kinase-driven hypertrophy, and calcineurin driven hypertrophy. And therefore, as pathological cardiac hypertrophy is an established risk factor for heart failure development, this unveiling of novel signaling mechanisms really is of potential clinical relevance. Dr. Carolyn Lam: Thanks, Greg. Well, let's round up with what else there is in this week's issue. There's a Frontiers paper by Dr. Chris Granger. And it's a big call to action to the cardiology community, to incorporate SGLT2 inhibitors and GLP-1 receptor agonists for cardiovascular and kidney disease risk reduction. There's a Joint Opinion piece from the American Heart Association, World Heart Federation, American College of Cardiology, and European Society of Cardiology on, “The Tobacco Endgame: Eradicating a Worsening Epidemic,” by Dr. Elkind. Dr. Greg Hundley: Oh great, Carolyn. Well, I've got an On My Mind piece from Professor Bhatt. And it's entitled, “Does SGLT1 inhibition Add Benefit to SGLT2 Inhibition in Type 2 Diabetes Mellitus?” And next, Dr. Viskin has an ECG Challenge entitled, “Long QT Syndrome and Torsade de Pointes Ultimately Treated With Quinidine, The Concept of Pseudo Torsade de Pointes.” And then finally, there's a Letter to the Editor by Dr. Lu regarding the article, “Association of Body Mass Index and Age with Morbidity and Mortality in Patients Hospitalized with COVID-19, Results from the American Heart Association COVID-19 Cardiovascular Disease Registry.” Well, Carolyn, I can't wait to get on to this double feature. Dr. Carolyn Lam: Me too. Let's go. Dr. Greg Hundley: Welcome, listeners, to our feature discussion today. And again, we're going to create today a forum, because we have two very interesting papers to present during this timeframe. Our first is going to come to us from Dr. Adrian Wells from University of Manchester. And our second paper will come to us from Dr. Hyeon Chang Kim from Yonsei University. I want to welcome you both, gentlemen. And Adrian, I would like to start with you. Tell us a little bit about the background related to your study. And then what was the hypothesis that you wanted to address? Dr. Adrian Wells: Okay, well thank you for inviting me to take part in this podcast. Following cardiac events, around one in three individuals will develop significant anxiety and depression symptoms. And we know that anxiety and depression can have an impact on prognosis, quality of life, future outcomes. Psychological treatment isn't routinely offered in cardiac rehabilitation for anxiety and depression, despite the fact that we identified that many of our patients felt that they would benefit from a psychological intervention to address these issues. And they felt that their needs were not really being met. So our primary question was, can we improve psychological outcomes in patients with cardiovascular disease? Dr. Greg Hundley: Very nice. And Adrian, what was your study population? And also, what was your study design? Dr. Adrian Wells: So we selected patients who entered cardiac rehabilitation in the UK. So these are patients with acute coronary syndrome, revascularization, stable heart failure, heart transplantation, and so on. And so, a wide group of individuals. We recruited 332 patients, all of whom had had anxiety and depression scores of eight or more. So these were people showing mild to severe levels of psychological distress. We conducted a two arm single blind randomized controlled trial, with 332 patients who were randomly allocated to one of these two conditions. And we assessed anxiety and depression symptoms before treatment at four months and at 12 months. Dr. Greg Hundley: Describe a little bit some of the specifics of your intervention. And then what did you find? Dr. Adrian Wells: We use relatively recent new treatment called metacognitive therapy. And this was delivered in a group format over six sessions. And we trained cardiac rehabilitation staff, nurse consultants, physiotherapists, in the delivery of this intervention. Metacognitive therapy works on helping patients discover unhelpful patterns of thinking, such as worrying and ruminating ,and excessive threat monitoring. And to reduce those patterns of thinking that contribute to anxiety, depression, and poor adaptation following stressful life experiences. Dr. Greg Hundley: And what did you find? Dr. Adrian Wells: Well, what we found was that the addition of metacognitive therapy to treatment to usual cardiac rehabilitation, significantly improved outcomes at four months and 12 months. What was striking about this was that our effect sizes were modest and moderate to large. They seem to be larger than those obtained in other studies or psychological treatments. And of note, the treatment seemed to impact well on both anxiety and depression symptoms. Whereas other types of intervention evaluated in the past have tended to treat the depression, but not so much the anxiety. Dr. Greg Hundley: Very good. So it sounds like a group-based intervention. And I'm assuming maybe participants interacted not only with your staff, but with one another. How would you put your results really in the context with other research that's going on in this space? Dr. Adrian Wells: Well, there have been a number of studies in the past that have looked at individual and group-based treatments, and patient preference for different types of intervention. I think this is the first study to use a clear manualized intervention that's based on the psychological theory of mechanisms that contribute to the maintenance of psychological problems. Obviously, this tended to use more prescriptive interventions like anxiety management, stress management, taking techniques from a range of different sources. So I think there's a difference of conceptual basis to this kind of intervention. And it's something that is highly manualized and structured, and in fact can be delivered by a range of different healthcare professionals. Dr. Greg Hundley: Very nice. And also during cardiovascular rehab. Correct? Dr. Adrian Wells: Absolutely, yeah. During cardiac rehab. One interesting finding... And we were a little concerned that this might adversely affect attendance at cardiac rehab. But we found that the treatment was well tolerated, and it didn't have any negative impact on attendance at these other sessions. Dr. Greg Hundley: Excellent. Well, congratulations on this new finding. Well, listeners, we're next going to turn to Dr. Hyeon Chang Kim from Yonsei University in Korea. And Yong-Chan, could you describe for us also the background related to your study, and the hypothesis that your research wanted to test? Dr. Hyeon Chang Kim: Thank you for inviting me to this wonderful discussion. South Korea is among the countries with the lowest cardiovascular mortality in the world. And the rate is even decreasing. However, cardiovascular risk factor is worsening. Especially in younger generation in Korea. So these young people may not have a very high cardiovascular risk, but I wanted to know the potential impact of worsening cardiovascular risk profile in this younger Korean generation. And furthermore, I wanted to know how much we can lead youth cardiovascular risk by improving their cardiovascular health profile. Dr. Greg Hundley: Very nice. And so tell us about your study design and what was the study population, related to your study? Dr. Hyeon Chang Kim: My study is basically based on the national health checkup program and national health insurance claim database. In Korea, adults over the age of 20 and employed workers of all ages are required to take general health checkup every two years. The participation rate is between 70 and 80%. So we identified three and a half million adults, age 20 to 39 years, who complete the health checkup. And cardiovascular health scores was calculated as the number of ideal cardiovascular health component, which include non-smoking, moderate physical activity three times a week, body mass index below 2030, normal blood pressure, normal cholesterol and normal fasting glucose. So the score can range from zero to six. And higher score meaning better cardiovascular health. Our outcomes were myocardial infarction, stroke, heart failure, and cardiovascular deaths in about 16 years. In addition, we also evaluate the risk of cardiovascular disease. According to two year change in how the vascular health score using repeated health checkup data. Dr. Greg Hundley: Very nice. So evaluating a set of behavioral patterns and risk factors in younger individuals, and then predicting what their longer term adverse cardiovascular outcomes would be. So what did you find? Dr. Hyeon Chang Kim: So even in this relatively low risk population, better cardiovascular health score was associated with significantly lower cardiovascular risk. About 20% reduction per one point higher score. And more importantly, people with improving cardiovascular score over two years showed leading toward cardiovascular risk. Even if their baseline cardiovascular health score was very low. Dr. Greg Hundley: Really unique findings. Tell us about the impact of your results relative to other studies published in this space. And was this also.... This was unique, because it's an Asian population, Dr. Hyeon Chang Kim: Asian population. And we are among the very low risk population. And even in this low risk population, cardiovascular health score was... Fear can be a good predictor of cardiovascular risk. And compared to many Western countries, we have very low cardiovascular risk. And our population was younger than most other studies. So we can provide some evidence that even in the higher risk population, they can do much better, based on our study. Another important thing, we can check the impact of a changing cardiovascular score, even in the younger generation. Dr. Greg Hundley: Very good. And just as a frame of reference for our listeners. Give us some characteristics, if you wouldn't mind, on what really constitutes practically a low risk score, versus what would constitute a high risk score Dr. Hyeon Chang Kim: In this younger Korean population, their cigarette smoking, and their obesity, and physical inactivity are the most common causes of worsening cardiovascular profile. And the behavioral risk factor also can attack the blood glucose and cholesterol blood pressure. So in this younger generation, they're keeping the good behavior. Past behavior is very important and it's beneficial in the very long-term. Dr. Greg Hundley: Very nice, well listeners. We're going to turn to our experts here. Two very interesting studies. And ask them both, what do they think is the next study that needs to be performed in their respective areas of research? So Yong-Chan, we'll start with you. Since we just discussed your paper. What do you think is the next study to be performed really in this sphere of research. Dr. Hyeon Chang Kim: Korea is a relatively low cardiovascular risk, has a very small size, and no racial diversity. But even in this country, disparity and inequality in cardiovascular health is becoming an important issue. So I want to identify subcultural relatively poor cardiovascular health among younger population. And also I want to find ways to improve their cardiovascular score. The conventional approaches, such as education and mass campaign, are less effective oppose this younger adults have a poor socioeconomic status. So, we may need to develop newer target-specific strategies to improve their cardiovascular health. Dr. Greg Hundley: Good. And Dr. Wells, our agent will turn next to you. What do you see is the next area of investigation or research study that needs to be performed in your sphere of interests? Dr. Adrian Wells: Well, I think the next step is to look at rollout of this intervention. Is that feasible, and how acceptable is this to cardiac services? In fact, the National Institute of Health Research have just awarded us some funding to examine feasibility and barriers to implementation in the healthcare system. In addition to that, we're beginning to examine the effects of metacognitive therapy with other health conditions, such as cancer in children and adolescents. Dr. Greg Hundley: Nice. Well listeners, we have had just a wonderful discussion today from both Dr. Adrian Wells from University of Manchester. Who brought to us combining a group-mediated, psychological stress-reducing, anxiety-reducing, intervention to the cardiac rehab sphere. And how impactful that was in reducing both anxiety, and overall depressive symptoms. And then also exciting research from Dr. Hyeon Chang Kim from South Korea. Identifying for us that in Asian population, as well as what we know in other races, those individuals in their twenties to thirties with favorable lifestyle habits, have reduced cardiovascular risk much later in life. Dr. Greg Hundley: Well, on behalf of both Carolyn and myself, we want to wish you a great week. And we'll catch you next week on the run. Dr. Greg Hundley: This program is copyright of the American Heart Association, 2021. The opinions expressed by speakers in this podcast are their own, and not necessarily those of the editors, or of the American Heart Association. For more, visit ahajournals.org.  

Does inorganic arsenic in drinking water lead to cardiac hypertrophy? In this episode, host Dominic Del Re (Rutgers New Jersey Medical School) interviews lead author Mark Kohr (Johns Hopkins University) and expert Nicole Purcell (Huntington Medical Research Institutes) about the new study by Kohr and colleagues, which studied the effects of an environmentally-relevant level of inorganic arsenic in the drinking water of male and female mice. Kabir et al were inspired by the public health crisis in Bangladesh caused by arsenic contaminated drinking water. In their study the authors found increased systolic blood pressure, increased LV mass and wall thickness, and induction of the fetal gene program in male mice, but not in female mice. Kohr and co-authors found arsenic promoted calcineurin NFAT signaling but did not disrupt nitric oxide-dependent mechanisms of cardioprotection. The authors uncover sex differences in the cardiovascular response to arsenic, as well as a clear mechanistic link between this environmental risk factor – arsenic in drinking water – and cardiac pathology. Can this work be translated on a larger scale to inspire everyday interventions to mitigate adverse environmental effects on human heart health? To find out, listen now.   Raihan Kabir, Prithvi Sinha, Sumita Mishra, Obialunanma V. Ebenebe, Nicole Taube, Chistian U. Oeing, Gizem Keceli, Rui Chen, Nazareno Paolocci, Ana Rule, Mark J. Kohr Inorganic arsenic induces sex-dependent pathological hypertrophy in the heart Am J Physiol Heart Circ Physiol, published March 24, 2021. DOI: 10.1152/ajpheart.00435.2020

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.11.13.379982v1?rss=1 Authors: Thiel, G., Tandl, D. H., Sponagel, T., Fuck, S., Smit, T., Hehlgans, S., Jakob, B., Fournier, C., Roedel, F., Roth, B., Moroni, A. Abstract: Radiation therapy is efficiently employed for eliminating cancer cells and reducing tumor growth. To further improving its therapeutic application it is mandatory to unravel the molecular effects of ionizing irradiation and to understand whether they support or counteract tumor therapy. Here we examine the impact of X-ray irradiation on immune activation of human T cells with single doses typically employed in tumor therapy. We discover that exposing cells to radiation triggers in a population of leukemic Jurkat T cells and in peripheral blood mononuclear cells (PBMCs) a canonical Ca2+ signaling cascade, which elicits immune activation of these cells. An early step in the signaling cascade is the initiation of sustained oscillations of the cytosolic Ca2+ concentration, an event mediated by store operated Ca2+ entry (SOCE) via an X-ray induced clustering of the Calcium Release-Activated Calcium Modulator 1 with the stromal interaction molecule 1 (Oari1/STIM1). A functional consequence of the Ca2+ signaling cascade is the translocation of the transcription factor nuclear factor of activated T cells (NFAT) from the cytosol into the nucleus where it elicits the expression of genes required for immune activation. These data imply that a direct activation of blood immune cells by ionizing irradiation has an impact on toxicity and therapeutic effects of radiation therapy. Copy rights belong to original authors. Visit the link for more info

What can three mutations in thin filament regulatory proteins associated with dilated cardiomyopathy tell us about the highly variable phenotypes of DCM? Listen as Associate Editor Crystal Ripplinger (University of California Davis) interviews lead author Paul Robinson (University of Oxford) and expert Michael Greenberg (Washington University in St. Louis) about the latest work by Robinson and co-authors. By studying functional changes in cardiomyocyte contraction, calcium handling and signaling, Robinson and co-authors hoped to identify common pathway activations in troponin T, troponin I and tropomyosin mutations. Why did the authors opt to study DCM mutations in guinea pig cardiomyocytes rather than in a mouse model? Given the substantial number of mutations in both pediatric and adult-onset DCM, what are the implications here for precision medicine in the treatment of this disease? Listen to learn more.   Paul Robinson, Alexander J. Sparrow, Suketu Patel, Marta Malinowska, Svetlana N. Reilly, Yin-Hua Zhang, Barbara Casadei, Hugh Watkins, Charles Redwood Dilated cardiomyopathy mutations in thin-filament regulatory proteins reduce contractility, suppress systolic Ca2+, and activate NFAT and Akt signaling Am J Physiol Heart Circ Physiol, published July 21, 2020. DOI: doi.org/10.1152/ajpheart.00272.2020

¡Gracias por escuchar! Los medicamentos antimaláricos, hidroxicloroquina y cloroquina, son fármacos moduladores de las enfermedades reumáticas introducidos por serendipia y empíricamente para el tratamiento de diversas enfermedades reumáticas. Ni la cloroquina ni la hidroxicloroquina se sometieron al proceso de desarrollo de fármacos convencional, pero su uso se ha convertido en parte importante de los tratamiento actuales para la artritis reumatoide, lupus eritematoso sistémico, síndrome de anticuerpos antifosfolípido y síndrome de Sjögren primario. En este episodio exploraremos sus principales características desde la perspectiva farmacológica.Les pido amablemente dejen sus comentarios en tukua.podbean.com y la calificación a este y otros episodios en iTunes.Estas son algunas referencias de utilidad:Ruiz-Irastorza, G. et al. Clinical efficacy and side effects of antimalarials in systemic lupus erythematosus: a systematic review. Ann. Rheum. Dis. 69, 20–28 (2010).Ostensen, M. et al. 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Francesco Marangoni, Center for Immunology and Inflammatory Diseases, Massachusetts General Hospital, Charlestown, MA, USA speaks on "Analysis of NFAT Signaling Dynamics in Tumor-Associated T Cells by Functional Intravital Imaging". This seminar has been recorded by ICGEB Trieste

Der humane Thyreotropin-Rezeptor (TSH-R) steuert die zentralen Funktionen der Schilddrüse und ist der wichtigste Regulator für deren Wachstum und Differenzierung. Er gehört zur Superfamilie der G-Protein-gekoppelten Rezeptoren (GPCR) und kann nach einer Stimulation mit TSH die G-Proteine aller vier Familien (Gs, Gi/o, Gq/11 und G12/13) aktivieren. Dabei werden die meisten zellulären Reaktionen wie die Proliferation der Schilddrüsenepithelzellen und die Bereitstellung der Schilddrüsenhormone einer Aktivierung von Gs zugeordnet. Zu Gs-unabhängigen Signalwegen des TSH-R war dagegen erst wenig bekannt. Da der Gq/11-vermittelte Signalweg durch die Aktivierung der Phospholipase C und Proteinkinase C in maligne Prozesse von Schilddrüsenzellen involviert sein könnte, sollten in der vorliegenden Arbeit Gq/11-abhängige Effektoren des TSH-R in humanen Schilddrüsenkarzinomzellen identifiziert und näher charakterisiert werden. Als Modellsystem wurden FTC 133 wt TSH-R Zellen verwendet, eine follikuläre Schilddrüsenkarzinom-Zelllinie, die den humanen TSH-R überexprimiert. In diesen wurde die Aktivierung des Calcium/Calcineurin-abhängigen Transkriptionsfaktors NFAT nach TSH-Stimulation erstmalig beschrieben. Bei einer anschließenden Reihenuntersuchung der NFAT-abhängigen Zielgene Autotaxin, VEGF, c-Myc, Regulator von Calcineurin 1 (RCAN1) und Cyclooxygenase-2 (Cox-2) wurden c-Myc, RCAN1 und Cox-2 als TSH-regulierte Gene identifiziert. Die Induktion von c-Myc war unabhängig von NFAT, dagegen bestätigten Expressionsstudien mit Calcineurin-Inhibitoren und dem spezifischen NFAT-Inhibitor INCA-6, dass RCAN1 und Cox-2 durch eine NFAT-Aktivierung induziert wurden. Diese Aktivierung wurde durch Gq/11-Proteine vermittelt, denn nach spezifischer Herunterregulation der Gq- und G11-α-Untereinheiten mittels siRNA konnten die Zielgene nicht mehr TSH-abhängig induziert werden. Weitere Analysen zum Mechanismus der NFAT-Aktivierung zeigten, dass eine Erhöhung der intrazellulären Calciumionenkonzentration ([Ca2+]i) allein über intrazelluläre Speicher nicht ausreichend war. Um NFAT zu aktivieren, mussten zusätzlich Calciumionen aus dem Extrazellulärraum einströmen. Untersuchungen mit dem STIM1-Inhibitor SKF-96365 wiesen dabei auf einen Calciumioneneinstrom über Speicher-operierte Ionenkanäle hin. Zusätzlich zur NFAT-regulierten Genexpression wurde in dieser Arbeit die TSH-induzierte Expression des Metallothioneins MT1X in FTC 133 wt TSH-R Zellen und in primären Thyreozyten analysiert. Die mRNA Induktion dieses Cystein-reichen und zytoprotektiven Proteins war ebenfalls abhängig von einer Expression der Gq/11-Proteine. Eine Erhöhung der [Ca2+]i reichte jedoch nicht aus, um MT1X signifikant zu induzieren. Zur gesteigerten Expression war darüber hinaus auch die Aktivierung der Proteinkinase C notwendig. In der vorliegenden Dissertation konnten somit RCAN1, Cox-2 und MT1X als Gq/11-regulierte Zielgene des humanen TSH-R charakterisiert werden. Dabei wurde eine NFAT-regulierte Genexpression nach einer TSH-Stimulation erstmalig gezeigt. Die präsentierten Ergebnisse weisen damit auf eine bisher unbeachtete biologische Rolle von Gq/11-abhängigen Signalwegen des humanen TSH-R in der Schilddrüse hin.

More than 50% of the world's population harbor Helicobacter pylori in their stomach mucosa. The chronic gastric infection is associated with several diseases including peptic ulcer disease and gastric carcinoma. One of the most thoroughly studied virulence factors produced by H. pylori is the Vacuolating Cytotoxin A (VacA). All isolated H. pylori strains possess the vacA gene, although significant sequence diversity was noticed in vacA genes across H. pylori isolates. VacA protein is produced and secreted as an 88 kD mature toxin. The protein binds to the host cells and is internalized. Inside the host cells, it causes “vacuole”-like membrane vesicles in the cytoplasm of gastric epithelial cells. Besides vacuolation, VacA exerts various other effects on target cells. VacA also forms membrane-embedded pores at the inner-mitochondrial membrane, resulting in mitochondrial dysfunction by cytochrome c release and apoptosis induction. VacA suppresses nuclear translocation of nuclear factor of activated T-cells (NFAT) resulting in down regulation of interleukin-2 (IL2) gene transcription to efficiently block proliferation of T-cells. The aim of this work was to understand the effects of VacA on intracellular calcium signalling in T-lymphocytes by considering the fact that VacA inhibits the Ca2+-calmodulin-dependent phosphatase calcineurin and induces cell cycle arrest. However, the exact mechanism how VacA exerts this response in T-cells is not known. Therefore, in this thesis various cell lines were used to study the effects of VacA on calcium influx. Calcium influx was found to be affected in the presence of VacA protein in the human Jurkat E6.1 T-cell line and primary human CD4+ T-cells activated by phorbol myristate acetate (PMA). Once inside T-cells, it could be shown that VacA suppresses the increase of the cytosolic free calcium concentration after stimulation by the calcium ionophore ionomycin and thapsigargin. Ionomycin forms pores in the cytoplasmic membrane, whereas thapsigargin blocks the sarcoplasmic/endoplasmic reticulum calcium ATPase (SERCA) and thereby causes depletion of the endoplasmic reticulum (ER) calcium store. In contrast, a VacA mutant, which was constructed by deletion of the hydrophobic region (amino acids 6-27), was unable to induce vacuolation activity and to block Ca2+ influx. A major result of this work was to demonstrate that one of the main components of store operated calcium entry (SOCE), the ER localized calcium sensor protein STIM1, is a target of VacA. Using co-localization studies and yeast two-hybrid (YTH) assays, it was found that VacA localizes to the lumen of the ER where it binds to the cEF-hand domain of STIM1. Furthermore, these data show that VacA strongly reduced the movements of the STIM1 towards the plasma membrane localized calcium channel ORAI1 after Ca2+ store depletion by thapsigargin. A YTH screen identified cEF-hand domain of STIM1 as the target of VacA to inhibit calcium influx. The results obtained in this work showing involvement of VacA in the modulation of intracellular calcium signalling will provide new insights that are required to understand how VacA inhibits T-cell proliferation and signalling.

T cells recognizing myelin auto-antigens penetrate into the CNS to induce inflammatory autoimmune disease following complex sequential interactions with individual components of the vascular blood-brain barrier (BBB), particularly endothelial cells, and perivascular phagocytes. To determine the functional consequences of these processes, two-photon intravital imaging was performed to compare the behavior of three myelin-specific GFP-expressing T cell lines with different potentials for transferring Experimental Autoimmune Encephalomyelitis. Imaging documented that, irrespective of their pathogenic potential, all T cell lines reached the CNS and interacted with vascular endothelial cells indistinguishably, crawling on the luminal surface, preferably against blood flow, before crossing the vessel wall. In striking contrast, after extravasation the T cell motility and their interactions with perivascular antigen presenting cells (APCs) varied dramatically. While highly encephalitogenic T cells showed a low motility, made stable contacts with local APCs and became activated, the corresponding contacts of weakly encephalitogenic T cells remained short, their motility high and their activation marginal. Supplying auto-antigen, via either local injection or by transfer of antigen-pulsed meningeal APCs, lowered their motility and prolonged the contact duration of weakly encephalitogenic T cells to values characteristic for highly pathogenic ones. Only after exogenous antigen supply, the weakly encephalitogenic T cells became activated, infiltrated the CNS parenchyma, and triggered clinical EAE, suggesting that the strength of the antigen-dependent signals received by immigrating effector T cells from leptomeningeal APCs is crucial for their pathogenic effect within the target tissue. To directly correlate the activation of encephalitogenic T cells with their dynamic behavior in the CNS, a truncated fluorescent derivative of nuclear factor of activated T cells (NFAT) was introduced as a real-time activation indicator. Two-photon imaging documented the activation of the auto-reactive T cells extravasated into the perivascular space, but not within the vascular lumen. Activation correlated with reduced T cell motility, and it was related to contacts with the local APCs. However, it did not necessarily lead to a long-lasting arrest, as individual, activated T cells SUMMARY 2 were able to sequentially contact other APCs. A spontaneous cytosol-nuclear translocation of the marker was noted only in T cells with a high pathogenic potential. The translocation implied the presentation of an auto-antigen, as the weakly pathogenic T cells, which remained silent in the untreated hosts, were activated upon the instillation of exogenous auto-antigen. It is proposed here that the presentation of local auto-antigen by BBB-associated APCs provides stimuli that guide autoimmune T cells to the CNS destination and enable them to attack the target tissue. In addition, a theoretical, physicist approach was used for modeling T cell activation in the leptomeningeal space. Assuming that T cells have evolved to gain their activation signal in a way that is energetically optimal for them, two possible scenarios for T cell activation were compared. The first one assumes that, after finding an APC presenting the epitope of interest, the T cell will stop and interact with the APC until it becomes fully activated. The second model considers the possibility that a T cell can accumulate activation signals from different APCs while scanning them without stopping, until a certain threshold is exceeded and the T cell becomes activated. Using this approach, it is proposed that the T cells in EAE are more likely to become activated following the first scenario. However, in a more natural environment such as a lymph node, the second scenario could give them some advantages

Primate-specific Mas-related G protein-coupled receptors-X1 (MRGPR-X1) are highly enriched in dorsal root ganglia (DRG) neurons and induce acute pain. Herein, we analyzed effects of MRGPR-X1 on serum response factors (SRF) or nuclear factors of activated T cells (NFAT), which control expression of various markers of chronic pain. Using HEK293, DRG neuron-derived F11 cells and cultured rat DRG neurons recombinantly expressing human MRGPR-X1, we found activation of a SRF reporter gene construct and induction of the early growth response protein-1 via extracellular signal-regulated kinases-1/2 known to play a significant role in the development of inflammatory pain. Furthermore, we observed MRGPR-X1-induced up-regulation of the chemokine receptor 2 (CCR2) via NFAT, which is considered as a key event in the onset of neuropathic pain and, so far, has not yet been described for any endogenous neuropeptide. Up-regulation of CCR2 is often associated with increased release of its endogenous agonist chemokine ligand 2 (CCL2). We also found MRGPR-X1-promoted release of CCL2 in a human connective tissue mast cell line endogenously expressing MRGPR-X1. Thus, we provide first evidence to suggest that MRGPR-X1 induce expression of chronic pain markers in DRG neurons and propose a so far unidentified signaling circuit that enhances chemokine signaling by acting on two distinct yet functionally co-operating cell types. Given the important role of chemokine signaling in pain chronification, we propose that interruption of this signaling circuit might be a promising new strategy to alleviate chemokine-promoted pain.

The severe acute respiratory syndrome (SARS) was first observed in the Chinese province Guangdong in November 2002. The disease quickly spread around the globe via air travelling and caused a worldwide epidemic. Several research institutions together with the World Health Organisation (WHO) identified the SARS-coronavirus (SARS-CoV) as the causative agent of this disease. During the epidemic, about 8,000 people were infected with a mortality of approximately 10%. Although no new infections have been observed since the summer of 2003, a recurrence of the pathogen cannot be excluded. Up to now, no specific therapy against the virus have been available. Viruses contain a very compact genome, which does not encode all proteins necessary for independant replication. Thus, viruses necessarily depend on host proteins and have to interact directly with them. The analysis of protein-protein interactions between SARS-CoV and human host cells contributes to a better understanding of the viral replication and pathogenicity. Prior to this work, an automated, genome-wide yeast-two-hybrid (Y2H) screen between all 28 proteins of SARS-CoV and the gene products of three human cDNA libraries had been performed, and approximately 460, mostly new protein-protein interactions had been identified. The aim of this work was to confirm newly identified virus-host SARS-CoV protein interactions and to functionally analyse them to identify new targets for antiviral therapy. 89 newly identified protein-protein interactions were examined via a modified LUMIER binding-assay to confirm individual interactions. 37 out of 89 protein interactions were found to be positive, resulting in a confirmation rate of 42%. In subsequent functional analyses of protein-protein interactions between the SARS-CoV non-structural protein 1 (Nsp1) and proteins of the immunophilin family, two different functional consequences were observed. First, it could be shown that SARS-CoV Nsp1 boosts the expression of genes regulated via the calcineurin/NFAT-signalling cascade. The increased expression of NFAT-regulated genes in SARS-CoV infection may cause the cytokine dysregulation described in SARS patients which leads to severe lung tissue destructions and which correlates with high mortality. The considerably less harmful human coronavirus HCoV-NL63 and mouse coronavirus (MHV) did not boost the expression of NFAT-regulated genes. It was thus hypothesized that the therapy of the cytokine dysregulation with the immunosuppressive drug Cyclosporine A (CspA) might improve the course of the disease. In addition, it could be shown for the first time that the replication of the SARS-CoV can be inhibited by the immunosuppressive drug CspA. Subsequent experiments showed a similar inhibition of the viral replication of the less harmful human coronavirus HCoV-NL63 and HCoV-229E mediated by CspA. In cooperation with several groups of the ”SARS-Zoonose- Verbund”, further inhibition experiments were performed with animal coronaviruses like FCoV, IBV Bd and TGEV PUR46, which showed a similar antiviral effect of CspA. The two cellular proteins Cyclophilin A and FK506 binding-protein 1A were shown to be essential for viral replication of HCoV-NL63. The findings of this work may contribute to a better understanding of the interactions between SARS-CoV and infected host cells and their innate immune response. The application of the general coronaviral inhibitor CspA identified in this study and of non-immunosuppressive CspA analogues like DEBIO-025 procures promising options for anti-coronaviral therapy.

Das humanpathogene Bakterium H. pylori persistiert im Gastroduodenaltrakt für Jahre oder sogar Jahrzehnte und löst durch die Kolonisation der Magenmukosa eine chronische Entzündungsreaktion aus. In den meisten Fällen bleibt diese symptomlos, es können jedoch auch schwerwiegende Erkrankungen wie ein Magen- oder Zwölffingerdarm-Geschwür oder Magenkrebs daraus hervorgehen. Obwohl die Infektion eine starke zelluläre und humorale Immunantwort hervorruft, kann H. pylori durch das Immunsystem nicht eliminiert werden. In dieser Arbeit wurde der Einfluss von H. pylori auf die Proliferation und Aktivierung von CD4+ T-Zellen untersucht. Dabei zeigte sich, dass H. pylori zwei Faktoren besitzt, um die Expansion der T-Zellen zu hemmen. Der eine, nicht näher charakterisierte Faktor scheint mit der Oberfläche der Bakterien assoziiert zu sein und inhibiert die Proliferation der T-Zellen bei direktem Kontakt der Bakterien mit den Zellen. Der zweite Faktor wurde als vakuolisierendes Zytotoxin VacA identifiziert, das, wie bisher bekannt war, in Epithelzellen die Bildung saurer Vakuolen auslöst. T-Zellen produzieren, wenn sie aktiviert werden, den Wachstumsfaktor IL- 2, beginnen sich zu vermehren und setzen eine Immunreaktion gegen das Pathogen in Gang. Das VacA-Toxin hemmt jedoch die Bildung von IL-2 und bewirkt eine Hemmung des Zellzyklus bei T-Zellen, indem es die Expression der Cycline D3 und E reprimiert. Diese sind essentiell für die Aktivierung des Retinoblastom-Proteins, das den Übergang des Zellzyklus von der G1- in die S-Phase vermittelt. Durch die Hemmung der IL-2-Produktion und die Erniedrigung der Oberflächenlokalisation von CD25, der -Kette des IL-2-Rezeptors, unterbricht VacA die Signaltransduktion, die normalerweise über den IL-2-Rezeptor zur Expression der Cycline führt. Die Hemmung der IL-2-Produktion durch VacA erfolgt auf transkriptioneller Ebene, indem die Aktivierung des Transkriptionsfaktors NFAT (Nuclear Factor of Activated T cells) verhindert wird. Die anderen für die Transkription des IL-2-Gens essentiellen Transkriptionsfaktoren AP-1 und NF-B werden durch VacA nicht beeinflusst. Die Stimulation der T-Zellen aktiviert zwei Haupt-Signalwege: einer führt über den MAPKinase / ERK-Kinase Weg zur Aktivierung von AP-1 und NF-B, der andere löst eine Erhöhung der Calcium-Konzentration im Zytoplasma aus, was die Ca2+-abhängige Phosphatase Calcineurin aktiviert. Calcineurin dephosphoryliert daraufhin den Transkriptionsfaktor NFAT und NFAT wird in den Zellkern transportiert, wo es zusammen mit AP-1 und NF-B die Transkription des IL-2-Gens initiiert. Es konnte gezeigt werden, dass VacA die Translokation von NFAT in den Kern durch Hemmung der Phosphatase-Aktivität von Calcineurin verhindert. Dies hat zur Folge, dass NFAT-abhängige Gene, wie das IL-2- Gen oder das für CD25 codierende Gen, nicht abgelesen werden können. Dass Calcineurin ein geeignetes Zielmolekül ist, um eine Immunantwort zu unterdrücken, zeigen auch die medizinisch bedeutsamen Substanzen FK506 (Tacrolimus) und Cyclosporin A. Beide V Zusammenfassung 91 Substanzen verursachen durch Hemmung von Calcineurin eine starke Immunsuppression. In DNA-Microarray-Analysen wurde untersucht, ob VacA einen ähnlich drastischen Effekt auf die Funktion der T-Zellen hat wie FK506. Dabei zeigte der Vergleich der Genexpression von VacA- und FK506-behandelten T-Zellen, dass VacA eine Untergruppe der Gene, die auch von FK506 reprimiert werden, herunterreguliert, wie z.B. die Gene für die Zytokine Macrophage Inflammatory Protein (MIP)-1, MIP-1, Single C Motif-1 (SCM-1) und SCM- 1. VacA scheint also die Genaktivität von T-Zellen ähnlich wie FK506 zu modulieren, was auf einen ähnlichen Mechanismus, nämlich die Calcineurin-Hemmung schließen lässt. Da das VacA-Toxin ein sekretiertes Protein ist, das auch in den tieferen Schichten des Magengewebes nachgewiesen werden kann, erreicht H. pylori nicht nur die vereinzelt im Magenepithel vorkommenden T-Zellen, sondern auch die T-Zellen, die bei der Infektion in die Lamina propria, eine tiefere Schicht der Magenmukosa, einwandern. Durch die Unterdrückung der T-Zell-Aktivierung und die Repression von Zytokin-Genen, die wichtig sind für die Modulation der Immunantwort, induziert H. pylori so vermutlich eine lokale Immunsuppression, die seine Eliminierung durch das Immunsystem verhindert und eine chronische Infektion des Magens ermöglicht. In einem zweiten Projekt wurde die Spaltung von CagA in ein 100 kD- und ein Tyrosinphosphoryliertes 40 kD- Fragment nach dessen Translokation in diverse Zelltypen untersucht. Dabei konnte gezeigt werden, dass die Prozessierung nicht nur in Makrophagen, sondern auch in dendritischen Zellen und in T-Zellen auftritt. Die Spaltung scheint von der Tyrosin-Phosphorylierung des CagA-Proteins und von Calcium abhängig zu sein. Dabei wurde die Ca2+-abhängige Protease Calpain in einem in vitro-Ansatz als ein CagAprozessierendes Enzym identifiziert. Auch in Makrophagen kann die Spaltung von CagA in P100 und P40P-Tyr durch den Calpain-Inhibitor Calpeptin verhindert werden. Die Tatsache, dass transloziertes CagA in allen getesteten eukaryontischen Zelltypen außer der Magenepithelzellinie AGS prozessiert wird, deutet darauf hin, dass diese Prozessierung eine biologische Bedeutung hat.