HEPATOPROTECTIVE ACTIVITY OF MONASCUS PURPUREUS (RED RICE YEAST) IN DIABETIC RATS ALONE OR IN COMBINATION WITH PIOGLITAZONE: AN EFFECT MEDIATED THROUGH CYTOKINES, ANTIOXIDANTS AND LIPID BIOMARKERS

Objective: Diabetes induces many complications such as cardiovascular problems, cataracts, kidney damage and polyneuropathy. Streptozotocin (STZ) induced diabetes is considered one of the most common animal models in rats. The present study investigated the effects of Monascus purpureus (MP) alone or in combination with pioglitazone on glucose level and on liver in streptozotocin (STZ) diabetic rats.Methods: In this study were divided into five experimental groups (normal, untreated STZ-diabetic (60 mg/kg B.W., IP), treated STZ-diabetic with Monascus purpureus (500 mg/kg B. W, oral), treated STZ-diabetic with pioglitazone (10 mg/kg B.W., oral) and treated STZ-diabetic with MP (250 mg/kg B. W, oral)+pioglitazone (10 mg/kg B.W., oral)). Treatment continued for 14 d then blood sampling was done to assess blood glucose. At the end of the study, the animals were fasted overnight, anesthetized with sodium pentobarbital (60 mg/kg i.p.), and sacrificed to collect tissues samples (liver, pancreases).Results: Throughout the experimental period, all treatments significantly (P<.05) lowered serum glucose, triglycerides, cholesterol, c-peptide and IL-6. In addition, hepatic cholesterol and triglycerides levels were also lowered. Moreover, the treated diabetic rats showed higher activity of reduced glutathione (P<.05) in the liver compared with the diabetic control rats and inhibited diabetes induced elevation in the level of malondialdehyde in liver.Conclusion: The results of this study clearly demonstrated that MP act by many ways, including anti-hyperglycemic, antioxidant effects and pancreatic β-cell protection. From these points, it seems that MP may be a useful supplement to alleviate the development of diabetes and its complications

Unveiling the pathogenic mechanisms of NPR2 missense variants: insights into the genotype-associated severity in acromesomelic dysplasia and short stature

Introduction: Natriuretic peptide receptor 2 (NPR2 or NPR-B) plays a central role in growth development and bone morphogenesis and therefore loss-of-function variations in NPR2 gene have been reported to cause Acromesomelic Dysplasia, Maroteaux type 1 and short stature. While several hypotheses have been proposed to underlie the pathogenic mechanisms responsible for these conditions, the exact mechanisms, and functional characteristics of many of those variants and their correlations with the clinical manifestations have not been fully established.Methods: In this study, we examined eight NPR2 genetic missense variants (p.Leu51Pro, p.Gly123Val, p.Leu314Arg, p.Arg318Gly, p.Arg388Gln, p.Arg495Cys, p.Arg557His, and p.Arg932Cys) Acromesomelic Dysplasia, Maroteaux type 1 and short stature located on diverse domains and broadly classified as variants of uncertain significance. The evaluated variants are either reported in patients with acromesomelic dysplasia in the homozygous state or short stature in the heterozygous state. Our investigation included the evaluation of their expression, subcellular trafficking and localization, N-glycosylation profiles, and cyclic guanosine monophosphate (cGMP) production activity.Results and Discussion: Our results indicate that variants p.Leu51Pro, p.Gly123Val, p.Leu314Arg, p.Arg388Gln have defective cellular trafficking, being sequestered within the endoplasmic reticulum (ER), and consequently impaired cGMP production ability. Conversely, variants p.Arg318Gly, p.Arg495Cys, and p.Arg557His seem to display a non-statistically significant behavior that is slightly comparable to WT-NPR2. On the other hand, p.Arg932Cys which is located within the guanylyl cyclase active site displayed normal cellular trafficking profile albeit with defective cGMP. Collectively, our data highlights the genotype-phenotype relationship that might be responsible for the milder symptoms observed in short stature compared to acromesomelic dysplasia. This study enhances our understanding of the functional consequences of several NPR2 variants, shedding light on their mechanisms and roles in related genetic disorders which might also help in their pathogenicity re-classification

Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990-2015: a systematic analysis for the Global Burden of Disease Study 2015

Forouzanfar MH, Afshin A, Alexander LT, et al. Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990-2015: a systematic analysis for the Global Burden of Disease Study 2015. LANCET. 2016;388(10053):1659-1724.Background The Global Burden of Diseases, Injuries, and Risk Factors Study 2015 provides an up-to-date synthesis of the evidence for risk factor exposure and the attributable burden of disease. By providing national and subnational assessments spanning the past 25 years, this study can inform debates on the importance of addressing risks in context. Methods We used the comparative risk assessment framework developed for previous iterations of the Global Burden of Disease Study to estimate attributable deaths, disability-adjusted life-years (DALYs), and trends in exposure by age group, sex, year, and geography for 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks from 1990 to 2015. This study included 388 risk-outcome pairs that met World Cancer Research Fund-defined criteria for convincing or probable evidence. We extracted relative risk and exposure estimates from randomised controlled trials, cohorts, pooled cohorts, household surveys, census data, satellite data, and other sources. We used statistical models to pool data, adjust for bias, and incorporate covariates. We developed a metric that allows comparisons of exposure across risk factors-the summary exposure value. Using the counterfactual scenario of theoretical minimum risk level, we estimated the portion of deaths and DALYs that could be attributed to a given risk. We decomposed trends in attributable burden into contributions from population growth, population age structure, risk exposure, and risk-deleted cause-specific DALY rates. We characterised risk exposure in relation to a Socio-demographic Index (SDI). Findings Between 1990 and 2015, global exposure to unsafe sanitation, household air pollution, childhood underweight, childhood stunting, and smoking each decreased by more than 25%. Global exposure for several occupational risks, high body-mass index (BMI), and drug use increased by more than 25% over the same period. All risks jointly evaluated in 2015 accounted for 57.8% (95% CI 56.6-58.8) of global deaths and 41.2% (39.8-42.8) of DALYs. In 2015, the ten largest contributors to global DALYs among Level 3 risks were high systolic blood pressure (211.8 million [192.7 million to 231.1 million] global DALYs), smoking (148.6 million [134.2 million to 163.1 million]), high fasting plasma glucose (143.1 million [125.1 million to 163.5 million]), high BMI (120.1 million [83.8 million to 158.4 million]), childhood undernutrition (113.3 million [103.9 million to 123.4 million]), ambient particulate matter (103.1 million [90.8 million to 115.1 million]), high total cholesterol (88.7 million [74.6 million to 105.7 million]), household air pollution (85.6 million [66.7 million to 106.1 million]), alcohol use (85.0 million [77.2 million to 93.0 million]), and diets high in sodium (83.0 million [49.3 million to 127.5 million]). From 1990 to 2015, attributable DALYs declined for micronutrient deficiencies, childhood undernutrition, unsafe sanitation and water, and household air pollution; reductions in risk-deleted DALY rates rather than reductions in exposure drove these declines. Rising exposure contributed to notable increases in attributable DALYs from high BMI, high fasting plasma glucose, occupational carcinogens, and drug use. Environmental risks and childhood undernutrition declined steadily with SDI; low physical activity, high BMI, and high fasting plasma glucose increased with SDI. In 119 countries, metabolic risks, such as high BMI and fasting plasma glucose, contributed the most attributable DALYs in 2015. Regionally, smoking still ranked among the leading five risk factors for attributable DALYs in 109 countries; childhood underweight and unsafe sex remained primary drivers of early death and disability in much of sub-Saharan Africa. Interpretation Declines in some key environmental risks have contributed to declines in critical infectious diseases. Some risks appear to be invariant to SDI. Increasing risks, including high BMI, high fasting plasma glucose, drug use, and some occupational exposures, contribute to rising burden from some conditions, but also provide opportunities for intervention. Some highly preventable risks, such as smoking, remain major causes of attributable DALYs, even as exposure is declining. Public policy makers need to pay attention to the risks that are increasingly major contributors to global burden. Copyright (C) The Author(s). Published by Elsevier Ltd

Caractérisation dynamique du réseaux moléculaire dans un modèle contrôle de coeur de souris soumis à l’ischémie-reperfusion

Cardiovascular diseases represent a major health burden worldwide. According to the World Health Organization, 17 million people are dying each year by heart diseases which account to 31% of total deaths globally. Among these diseases is myocardial infarction (MI). Several efforts have been made to decrease the associated mortality rates but unfortunately, only few has succeeded to date. This failure is contributed to several factors, among them is the misunderstanding of the mechanism responsible for the progression of the disease.Our understanding of the MI pathology has been greatly improved by the approaches that have been widely used in the previous decades, relying mainly on studying molecules/pathways separately. However, this knowledge was not enough to make a difference clinically. Therefore, deciphering the interconnections between molecules has become an urge for better understanding of the diseases’ progression. In this regard, the work in this doctoral thesis involves different aspects of the MI pathology. The general aim of this work is to improve the dynamic analytical approach using systems biology tools, where new mechanistic information is decoded. Firstly, in a 3D heart model, we propose a chain of methods using clarified mouse heart and fluorescence microscopy to molecularly characterize the area at risk in the myocardium of IR and cardioprotected mice based on its redox state. In addition, we aim to develop a new analytical approach using dynamical large-scale transcriptomic data for characterizing the dynamic transcripts expression. Applying this approach on a control mouse model (mice subjected to anesthesia and surgical interventions), we show that Il-6 is a major mediator of the activated inflammatory reaction. In conclusion, this analytical approach highlights the necessity of the sapatio-temporal analysis to characterize the molecular events occurring in response to MILes maladies cardiovasculaires représentent un important problème de santé publique à travers le monde. Parmi ces pathologies, l’infarctus du myocarde (IM) a fait l’objet de nombreux essais visant à diminuer sa sévérité. Néanmoins peu ont remporté leur pari. Cet échec peut avoir plusieurs composantes parmi lesquelles la méconnaissance de la complexité des mécanismes moléculaires impliqués. Notre compréhension de l’IM a cependant été nettement améliorée grâce à des méthodes utilisées pendant les dernières décennies et qui consistaient à étudier séparément un nombre limité d’acteurs moléculaires impliqués dans un mécanisme simple et linéaire. Cependant, l’échec des essais cliniques basés sur ces approches réductionnistes ont montré leurs limites. L’émergence de la biologie des systèmes, ces dernières années, a stimulé les recherches visant à mieux intégrer et comprendre la nature complexe et stochastique des réseaux moléculaires et leur dynamique dans la progression des pathologies. L’objectif général de cette thèse a consisté en le développement et l’amélioration de méthode d’analyses et de combinaison des données spatio-temporelles issus d’expériences réalisées sur un modèle d’infarctus du myocarde chez la souris. L’objectif scientifique visait à caractériser les principaux signaux dynamiques au cours de la séquence d’ischémie-reperfusion. A cet effet, nous avons tout d’abord développé une chaîne de méthode utilisant la clarification d’organe et la microscopie de fluorescence permettant de quantifier, en 3 dimensions, la zone du myocarde soumise au choc oxydant lors de la reperfusion. Dans une seconde partie, nous avons développé une nouvelle chaîne analytique pour caractériser la dynamique d’expression des transcrits. Appliquée aux animaux contrôles (soumis à la chirurgie et l’anesthésie), nous mettrons, grâce à cette chaîne de méthode, le rôle majeur de la voie de l’interleukine 6 dans le développement de la réponse immunitaire et nous concluons ainsi sur la nécessité de réaliser une analyse dynamique du modèle expérimental pour caractériser sa réponse à l’échelle moléculaire et éviter toute surinterprétation de la réponse à l’I

Caractérisation dynamique du réseaux moléculaire dans un modèle contrôle de coeur de souris soumis à l’ischémie-reperfusion

Cardiovascular diseases represent a major health burden worldwide. According to the World Health Organization, 17 million people are dying each year by heart diseases which account to 31% of total deaths globally. Among these diseases is myocardial infarction (MI). Several efforts have been made to decrease the associated mortality rates but unfortunately, only few has succeeded to date. This failure is contributed to several factors, among them is the misunderstanding of the mechanism responsible for the progression of the disease.Our understanding of the MI pathology has been greatly improved by the approaches that have been widely used in the previous decades, relying mainly on studying molecules/pathways separately. However, this knowledge was not enough to make a difference clinically. Therefore, deciphering the interconnections between molecules has become an urge for better understanding of the diseases’ progression. In this regard, the work in this doctoral thesis involves different aspects of the MI pathology. The general aim of this work is to improve the dynamic analytical approach using systems biology tools, where new mechanistic information is decoded. Firstly, in a 3D heart model, we propose a chain of methods using clarified mouse heart and fluorescence microscopy to molecularly characterize the area at risk in the myocardium of IR and cardioprotected mice based on its redox state. In addition, we aim to develop a new analytical approach using dynamical large-scale transcriptomic data for characterizing the dynamic transcripts expression. Applying this approach on a control mouse model (mice subjected to anesthesia and surgical interventions), we show that Il-6 is a major mediator of the activated inflammatory reaction. In conclusion, this analytical approach highlights the necessity of the sapatio-temporal analysis to characterize the molecular events occurring in response to MILes maladies cardiovasculaires représentent un important problème de santé publique à travers le monde. Parmi ces pathologies, l’infarctus du myocarde (IM) a fait l’objet de nombreux essais visant à diminuer sa sévérité. Néanmoins peu ont remporté leur pari. Cet échec peut avoir plusieurs composantes parmi lesquelles la méconnaissance de la complexité des mécanismes moléculaires impliqués. Notre compréhension de l’IM a cependant été nettement améliorée grâce à des méthodes utilisées pendant les dernières décennies et qui consistaient à étudier séparément un nombre limité d’acteurs moléculaires impliqués dans un mécanisme simple et linéaire. Cependant, l’échec des essais cliniques basés sur ces approches réductionnistes ont montré leurs limites. L’émergence de la biologie des systèmes, ces dernières années, a stimulé les recherches visant à mieux intégrer et comprendre la nature complexe et stochastique des réseaux moléculaires et leur dynamique dans la progression des pathologies. L’objectif général de cette thèse a consisté en le développement et l’amélioration de méthode d’analyses et de combinaison des données spatio-temporelles issus d’expériences réalisées sur un modèle d’infarctus du myocarde chez la souris. L’objectif scientifique visait à caractériser les principaux signaux dynamiques au cours de la séquence d’ischémie-reperfusion. A cet effet, nous avons tout d’abord développé une chaîne de méthode utilisant la clarification d’organe et la microscopie de fluorescence permettant de quantifier, en 3 dimensions, la zone du myocarde soumise au choc oxydant lors de la reperfusion. Dans une seconde partie, nous avons développé une nouvelle chaîne analytique pour caractériser la dynamique d’expression des transcrits. Appliquée aux animaux contrôles (soumis à la chirurgie et l’anesthésie), nous mettrons, grâce à cette chaîne de méthode, le rôle majeur de la voie de l’interleukine 6 dans le développement de la réponse immunitaire et nous concluons ainsi sur la nécessité de réaliser une analyse dynamique du modèle expérimental pour caractériser sa réponse à l’échelle moléculaire et éviter toute surinterprétation de la réponse à l’I

Caractérisation dynamique du réseaux moléculaire dans un modèle contrôle de coeur de souris soumis à l’ischémie-reperfusion

Cardiovascular diseases represent a major health burden worldwide. According to the World Health Organization, 17 million people are dying each year by heart diseases which account to 31% of total deaths globally. Among these diseases is myocardial infarction (MI). Several efforts have been made to decrease the associated mortality rates but unfortunately, only few has succeeded to date. This failure is contributed to several factors, among them is the misunderstanding of the mechanism responsible for the progression of the disease.Our understanding of the MI pathology has been greatly improved by the approaches that have been widely used in the previous decades, relying mainly on studying molecules/pathways separately. However, this knowledge was not enough to make a difference clinically. Therefore, deciphering the interconnections between molecules has become an urge for better understanding of the diseases’ progression. In this regard, the work in this doctoral thesis involves different aspects of the MI pathology. The general aim of this work is to improve the dynamic analytical approach using systems biology tools, where new mechanistic information is decoded. Firstly, in a 3D heart model, we propose a chain of methods using clarified mouse heart and fluorescence microscopy to molecularly characterize the area at risk in the myocardium of IR and cardioprotected mice based on its redox state. In addition, we aim to develop a new analytical approach using dynamical large-scale transcriptomic data for characterizing the dynamic transcripts expression. Applying this approach on a control mouse model (mice subjected to anesthesia and surgical interventions), we show that Il-6 is a major mediator of the activated inflammatory reaction. In conclusion, this analytical approach highlights the necessity of the sapatio-temporal analysis to characterize the molecular events occurring in response to MILes maladies cardiovasculaires représentent un important problème de santé publique à travers le monde. Parmi ces pathologies, l’infarctus du myocarde (IM) a fait l’objet de nombreux essais visant à diminuer sa sévérité. Néanmoins peu ont remporté leur pari. Cet échec peut avoir plusieurs composantes parmi lesquelles la méconnaissance de la complexité des mécanismes moléculaires impliqués. Notre compréhension de l’IM a cependant été nettement améliorée grâce à des méthodes utilisées pendant les dernières décennies et qui consistaient à étudier séparément un nombre limité d’acteurs moléculaires impliqués dans un mécanisme simple et linéaire. Cependant, l’échec des essais cliniques basés sur ces approches réductionnistes ont montré leurs limites. L’émergence de la biologie des systèmes, ces dernières années, a stimulé les recherches visant à mieux intégrer et comprendre la nature complexe et stochastique des réseaux moléculaires et leur dynamique dans la progression des pathologies. L’objectif général de cette thèse a consisté en le développement et l’amélioration de méthode d’analyses et de combinaison des données spatio-temporelles issus d’expériences réalisées sur un modèle d’infarctus du myocarde chez la souris. L’objectif scientifique visait à caractériser les principaux signaux dynamiques au cours de la séquence d’ischémie-reperfusion. A cet effet, nous avons tout d’abord développé une chaîne de méthode utilisant la clarification d’organe et la microscopie de fluorescence permettant de quantifier, en 3 dimensions, la zone du myocarde soumise au choc oxydant lors de la reperfusion. Dans une seconde partie, nous avons développé une nouvelle chaîne analytique pour caractériser la dynamique d’expression des transcrits. Appliquée aux animaux contrôles (soumis à la chirurgie et l’anesthésie), nous mettrons, grâce à cette chaîne de méthode, le rôle majeur de la voie de l’interleukine 6 dans le développement de la réponse immunitaire et nous concluons ainsi sur la nécessité de réaliser une analyse dynamique du modèle expérimental pour caractériser sa réponse à l’échelle moléculaire et éviter toute surinterprétation de la réponse à l’I

Caractérisation dynamique du réseaux moléculaire dans un modèle contrôle de coeur de souris soumis à l’ischémie-reperfusion

Cardiovascular diseases represent a major health burden worldwide. According to the World Health Organization, 17 million people are dying each year by heart diseases which account to 31% of total deaths globally. Among these diseases is myocardial infarction (MI). Several efforts have been made to decrease the associated mortality rates but unfortunately, only few has succeeded to date. This failure is contributed to several factors, among them is the misunderstanding of the mechanism responsible for the progression of the disease.Our understanding of the MI pathology has been greatly improved by the approaches that have been widely used in the previous decades, relying mainly on studying molecules/pathways separately. However, this knowledge was not enough to make a difference clinically. Therefore, deciphering the interconnections between molecules has become an urge for better understanding of the diseases’ progression. In this regard, the work in this doctoral thesis involves different aspects of the MI pathology. The general aim of this work is to improve the dynamic analytical approach using systems biology tools, where new mechanistic information is decoded. Firstly, in a 3D heart model, we propose a chain of methods using clarified mouse heart and fluorescence microscopy to molecularly characterize the area at risk in the myocardium of IR and cardioprotected mice based on its redox state. In addition, we aim to develop a new analytical approach using dynamical large-scale transcriptomic data for characterizing the dynamic transcripts expression. Applying this approach on a control mouse model (mice subjected to anesthesia and surgical interventions), we show that Il-6 is a major mediator of the activated inflammatory reaction. In conclusion, this analytical approach highlights the necessity of the sapatio-temporal analysis to characterize the molecular events occurring in response to MILes maladies cardiovasculaires représentent un important problème de santé publique à travers le monde. Parmi ces pathologies, l’infarctus du myocarde (IM) a fait l’objet de nombreux essais visant à diminuer sa sévérité. Néanmoins peu ont remporté leur pari. Cet échec peut avoir plusieurs composantes parmi lesquelles la méconnaissance de la complexité des mécanismes moléculaires impliqués. Notre compréhension de l’IM a cependant été nettement améliorée grâce à des méthodes utilisées pendant les dernières décennies et qui consistaient à étudier séparément un nombre limité d’acteurs moléculaires impliqués dans un mécanisme simple et linéaire. Cependant, l’échec des essais cliniques basés sur ces approches réductionnistes ont montré leurs limites. L’émergence de la biologie des systèmes, ces dernières années, a stimulé les recherches visant à mieux intégrer et comprendre la nature complexe et stochastique des réseaux moléculaires et leur dynamique dans la progression des pathologies. L’objectif général de cette thèse a consisté en le développement et l’amélioration de méthode d’analyses et de combinaison des données spatio-temporelles issus d’expériences réalisées sur un modèle d’infarctus du myocarde chez la souris. L’objectif scientifique visait à caractériser les principaux signaux dynamiques au cours de la séquence d’ischémie-reperfusion. A cet effet, nous avons tout d’abord développé une chaîne de méthode utilisant la clarification d’organe et la microscopie de fluorescence permettant de quantifier, en 3 dimensions, la zone du myocarde soumise au choc oxydant lors de la reperfusion. Dans une seconde partie, nous avons développé une nouvelle chaîne analytique pour caractériser la dynamique d’expression des transcrits. Appliquée aux animaux contrôles (soumis à la chirurgie et l’anesthésie), nous mettrons, grâce à cette chaîne de méthode, le rôle majeur de la voie de l’interleukine 6 dans le développement de la réponse immunitaire et nous concluons ainsi sur la nécessité de réaliser une analyse dynamique du modèle expérimental pour caractériser sa réponse à l’échelle moléculaire et éviter toute surinterprétation de la réponse à l’I

Caractérisation dynamique du réseaux moléculaire dans un modèle contrôle de coeur de souris soumis à l’ischémie-reperfusion

Les maladies cardiovasculaires représentent un important problème de santé publique à travers le monde. Parmi ces pathologies, l’infarctus du myocarde (IM) a fait l’objet de nombreux essais visant à diminuer sa sévérité. Néanmoins peu ont remporté leur pari. Cet échec peut avoir plusieurs composantes parmi lesquelles la méconnaissance de la complexité des mécanismes moléculaires impliqués. Notre compréhension de l’IM a cependant été nettement améliorée grâce à des méthodes utilisées pendant les dernières décennies et qui consistaient à étudier séparément un nombre limité d’acteurs moléculaires impliqués dans un mécanisme simple et linéaire. Cependant, l’échec des essais cliniques basés sur ces approches réductionnistes ont montré leurs limites. L’émergence de la biologie des systèmes, ces dernières années, a stimulé les recherches visant à mieux intégrer et comprendre la nature complexe et stochastique des réseaux moléculaires et leur dynamique dans la progression des pathologies. L’objectif général de cette thèse a consisté en le développement et l’amélioration de méthode d’analyses et de combinaison des données spatio-temporelles issus d’expériences réalisées sur un modèle d’infarctus du myocarde chez la souris. L’objectif scientifique visait à caractériser les principaux signaux dynamiques au cours de la séquence d’ischémie-reperfusion. A cet effet, nous avons tout d’abord développé une chaîne de méthode utilisant la clarification d’organe et la microscopie de fluorescence permettant de quantifier, en 3 dimensions, la zone du myocarde soumise au choc oxydant lors de la reperfusion. Dans une seconde partie, nous avons développé une nouvelle chaîne analytique pour caractériser la dynamique d’expression des transcrits. Appliquée aux animaux contrôles (soumis à la chirurgie et l’anesthésie), nous mettrons, grâce à cette chaîne de méthode, le rôle majeur de la voie de l’interleukine 6 dans le développement de la réponse immunitaire et nous concluons ainsi sur la nécessité de réaliser une analyse dynamique du modèle expérimental pour caractériser sa réponse à l’échelle moléculaire et éviter toute surinterprétation de la réponse à l’IMCardiovascular diseases represent a major health burden worldwide. According to the World Health Organization, 17 million people are dying each year by heart diseases which account to 31% of total deaths globally. Among these diseases is myocardial infarction (MI). Several efforts have been made to decrease the associated mortality rates but unfortunately, only few has succeeded to date. This failure is contributed to several factors, among them is the misunderstanding of the mechanism responsible for the progression of the disease.Our understanding of the MI pathology has been greatly improved by the approaches that have been widely used in the previous decades, relying mainly on studying molecules/pathways separately. However, this knowledge was not enough to make a difference clinically. Therefore, deciphering the interconnections between molecules has become an urge for better understanding of the diseases’ progression. In this regard, the work in this doctoral thesis involves different aspects of the MI pathology. The general aim of this work is to improve the dynamic analytical approach using systems biology tools, where new mechanistic information is decoded. Firstly, in a 3D heart model, we propose a chain of methods using clarified mouse heart and fluorescence microscopy to molecularly characterize the area at risk in the myocardium of IR and cardioprotected mice based on its redox state. In addition, we aim to develop a new analytical approach using dynamical large-scale transcriptomic data for characterizing the dynamic transcripts expression. Applying this approach on a control mouse model (mice subjected to anesthesia and surgical interventions), we show that Il-6 is a major mediator of the activated inflammatory reaction. In conclusion, this analytical approach highlights the necessity of the sapatio-temporal analysis to characterize the molecular events occurring in response to M

TRPV1 Channels Are New Players in the Reticulum–Mitochondria Ca2+ Coupling in a Rat Cardiomyoblast Cell Line

International audienceThe Ca2+ release in microdomains formed by intercompartmental contacts, such as mitochondria-associated endoplasmic reticulum membranes (MAMs), encodes a signal that contributes to Ca2+ homeostasis and cell fate control. However, the composition and function of MAMs remain to be fully defined. Here, we focused on the transient receptor potential vanilloid 1 (TRPV1), a Ca2+-permeable ion channel and a polymodal nociceptor. We found TRPV1 channels in the reticular membrane, including some at MAMs, in a rat cardiomyoblast cell line (SV40-transformed H9c2) by Western blotting, immunostaining, cell fractionation, and proximity ligation assay. We used chemical and genetic probes to perform Ca2+ imaging in four cellular compartments: the endoplasmic reticulum (ER), cytoplasm, mitochondrial matrix, and mitochondrial surface. Our results showed that the ER Ca2+ released through TRPV1 channels is detected at the mitochondrial outer membrane and transferred to the mitochondria. Finally, we observed that prolonged TRPV1 modulation for 30 min alters the intracellular Ca2+ equilibrium and influences the MAM structure or the hypoxia/reoxygenation-induced cell death. Thus, our study provides the first evidence that TRPV1 channels contribute to MAM Ca2+ exchanges

Regression of fibrosis by cilostazol in a rat model of thioacetamide-induced liver fibrosis: Up regulation of hepatic cAMP, and modulation of inflammatory, oxidative stress and apoptotic biomarkers.

In liver fibrosis, conversion of fibroblasts to profibrogenic myofibroblasts significantly drives the development of the disease. A crucial role of cyclic adenosine monophosphate (cAMP) in regulation of fibroblast function has been reported. Increase in cAMP levels has been found to decrease fibroblast proliferation, inhibit their conversion to myofibroblast, and stimulate their death. cAMP is generated by adenyl cyclase (AC), and degraded by cyclic nucleotide phosphodiesterase (PDE). In this study, the antifibrotic effect of a PDE inhibitor, cilostazol (Cilo), on a rat model of liver fibrosis induced by thioacetamide (TAA) was investigated. Four groups of rats were used; the first group received the vehicles and served as the normal control group, while liver fibrosis was induced in the other groups using (TAA, 200 mg/kg/biweekly for 8 successive weeks, ip). The last two groups were treated with Cilo (50 and 100 mg/kg/day, po, respectively). Induction of liver fibrosis in TAA-treated rats was observed as evidenced by the biochemical and histopathological findings. On the other hand, a potent antifibrotic effect was observed in the groups treated with Cilo, with preference to the higher dose. In these groups, a significant increase in the liver content of cAMP was demonstrated that was accompanied by reduction in the hepatic expression of key fibrogenic cytokines, growth factors, and inflammatory biomarkers, including interleukin-6, tumor necrosis factor-alpha, nuclear factor kappa B, and transforming growth factor-beta as compared to TAA group. Moreover, amelioration of TAA-induced oxidative stress and apoptosis in the liver has been observed. These findings reveal the antifibrotic effect of Cilo against TAA-induced liver fibrosis in rats, and suggest regulation of cAMP pathway, together with the modulation of oxidative stress, inflammation, and apoptosis as mechanistic cassette underlines this effect