Search

miRNA-132/212 are small regulators of gene expression with a function that fulfills a vital function in diverse biological processes including neuroprotection of cells with prolonged longevity in neurons and the cardiovascular system. In neurons, miRNA-132 appears to be essential for controlling differentiation, development, and neural functioning. Indeed, it also universally promotes axon evolution, nervous migration, plasticity as well, it is suggested to be neuroprotective against neurodegenerative diseases. Moreover, miRNA-132/212 disorder leads to neural developmental perturbation, and the development of degenerative disorders covering Alzheimer’s, Parkinson’s, and epilepsy’s along with psychiatric perturbations including schizophrenia. Furthermore, the cellular mechanisms of the miRNA-132/212 have additionally been explored in cardiovascular diseases models. Also, the miRNA-132/212 family modulates cardiac hypertrophy and autophagy in cardiomyocytes. The protective and effective clinical promise of miRNA-132/212 in these systems is discussed in this review. To sum up, the current progress in innovative miRNA-based therapies for human pathologies seems of extreme concern and reveals promising novel therapeutic strategies.

It remains unclear whether serum PCSK9 levels can predict the severity of the disease and the risk of future events in patients with coronary artery disease (CAD). We aimed to evaluate the association between PCSK9 levels, metabolic parameters, severity of CAD on coronary angiography (SYNTAX score), and the risk of in-hospital events and at one-year follow-up.From September 2015 to December 2016, serum PCSK9 levels were measured on admission in patients not previously receiving statin therapy, and admitted for an acute myocardial infarction (MI), in an intensive care unit from a university hospital. In a total of 648 patients (mean age: 66 years, 67% male), median PCSK9 was 263 ng/ml, higher for females compared with males (270 vs 256 ng/ml, p = 0.009). Serum PCSK9 was associated with LDL cholesterol (r = 0.083, p = 0.036), total cholesterol (r = 0.136, p = 0.001) and triglycerides (r = 0.137, p = 0.001). A positive association was also observed in the subgroup of patients with CRP10 mg/L (p 0.001), but not with NT-proBNP, troponin and creatine kinase. PCSK9 levels were similar whatever the SYNTAX score or the number of significant coronary lesions. PCSK9 levels were not associated with in-hospital events (death, recurrent MI and stroke) and events (cardiovascular death, cardiovascular events, recurrent MI) at one-year follow-up.In this large cohort of patients hospitalized for acute MI and not previously receiving statin therapy, PCSK9 levels was not associated with the severity or the recurrence of cardiovascular events. The clinical utility of measuring PCSK9 levels for this category of patients therefore appears limited.

Simple Summary Protons (H+) and molecular hydrogen (H2) in the cell are critical in a wide variety of processes. New cancer treatment uses H2, a biologically inactive gas. H2 can rapidly penetrate cell membranes and reach subcellular components to protect nuclear DNA and mitochondria. H2 reduces oxidative stress, exerts anti-inflammatory effects, and acts as a modulator of apoptosis. Exogenous H2 is a protective therapy that can be used in cancer. Cyclotrons and synchrotrons are currently used to produce protons. Proton beam radiotherapy (PBT) offers great promise for the treatment of a wide variety of cancers. H2 and different types of H2 donors may represent a novel therapeutic strategy in cancer treatment. Abstract Understanding the structure and dynamics of the various hydrogen forms has been a subject of numerous studies. Protons (H+) and molecular hydrogen (H2) in the cell are critical in a wide variety of processes. A new cancer treatment uses H2, a biologically inactive gas. Due to its small molecular weight, H2 can rapidly penetrate cell membranes and reach subcellular components to protect nuclear DNA and mitochondria. H2 reduces oxidative stress, exerts anti-inflammatory effects, and acts as a modulator of apoptosis. Exogenous H2, administered by inhalation, drinking H2-rich water, or injecting H2-rich saline solution, is a protective therapy that can be used in multiple diseases, including cancer. In particle therapy, cyclotrons and synchrotrons are the accelerators currently used to produce protons. Proton beam radiotherapy (PBT) offers great promise for the treatment of a wide variety of cancers due to the sharp decrease in the dose of radiation at a defined point. In these conditions, H2 and different types of H2 donors may represent a novel therapeutic strategy in cancer treatment.

Objective: We assessed the association between pre-stroke cognitive status and 90-day case-fatality. Methods: Patients with ischemic stroke (IS) or spontaneous intracerebral hemorrhage (ICH) were prospectively identified among residents of Dijon, France, between 2013 and 2015, using a population-based registry. Association between pre-stroke cognitive status and case-fatality at 90 days was evaluated using Cox regression. Results: Seven hundred sixty-two patients were identified, and information about pre-stroke cognitive status was obtained for 716 (92.6%) of them, including 603 IS (84.2%) and 113 ICH (15.8%). Before stroke, 99 (13.8%) patients had mild cognitive impairment (MCI) and 98 (13.7%) had dementia. Patients with cognitive impairment were older, had a higher prevalence of several risk factors, more severe stroke, more frequent ICH, and less admission to stroke unit. Case-fatality rate at 90 days was 11.7% in patients without cognitive impairment, 32.3% in MCI patients, and 55.1% in patients with dementia. In multivariable analyses, pre-existing MCI (hazard ratio [HR] 2.22, 95% CI 1.21–4.05, p = 0.009) and dementia (HR 4.35, 95% CI 2.49–7.61, p < 0.001) were both associated with 90-day case-fatality. Conclusion: Pre-stroke MCI and dementia were both associated with increased mortality. These associations were not fully explained by baseline characteristics, pre-stroke dependency, stroke severity or patient management, and underlying reasons need to be investigated.

International audience; Growth and differentiation factor 15 (GDF15) belongs to the transforming growth factor-β (TGF-β) superfamily proteins. GDF15 acts as an inflammatory marker, and it plays a role in pathogenesis of tumors, ischemic diseases, metabolic disorders, and neurodegenerative processes. GDF15 is not normally expressed in the tissue; it is prominently induced following 'injury'. GDF15 functions are critical for the regulation of endothelial adaptations after vascular damage. Recently, four research groups simultaneously identified glial-derived neurotrophic factor (GDNF)-family receptor α-like (GFRAL) in the brain, an orphan receptor as the receptor for GDF15, signaling through the coreceptor RET. In this article, new aspects of the biology of GDF15 and receptor GFRAL, and their relationship with various pathologies, are commented on.

International audience

International audience; The potential use of stem cell-based therapies for the repair and regeneration of various tissues and organs is a major goal in repair medicine. Stem cells are classified by their potential to differentiate into functional cells. Compared with other sources, adipose-derived stem cells (ADSCs) have the advantage of being abundant and easy to obtain. ADSCs are considered to be tools for replacing, repairing, and regenerating dead or damaged cells. The capacity of ADSCs to maintain their properties depends on the balance of complex signals in their microenvironment. Their properties and the associated outcomes are in part regulated by reactive oxygen species, which mediate the oxidation-reduction state of cells as a secondary messenger. ADSC therapy has demonstrated beneficial effects, suggesting that secreted factors may provide protection. There is evidence that ADSCs secrete a number of cytokines, growth factors, and antioxidant factors into their microenvironment, thus regulating intracellular signaling pathways in neighboring cells. In this review, we introduce the roles of ADSCs in the protection of cells by modulating inflammation and immunity, and we develop their potential therapeutic properties.

International audience; Nutritional environment in the perinatal period has a great influence on health and diseases in adulthood. In rodents, litter size reduction reproduces the effects of postnatal overnutrition in infants and reveals that postnatal overfeeding (PNOF) not only permanently increases body weight but also affects the cardiovascular function in the short-and long-term. In addition to increased adiposity, the metabolic status of PNOF rodents is altered, with increased plasma insulin and leptin levels, associated with resistance to these hormones, changed profiles and levels of circulating lipids. PNOF animals present elevated arterial blood pressure with altered vascular responsiveness to vasoactive substances. The hearts of overfed rodents exhibit hypertrophy and elevated collagen content. PNOF also induces a disturbance of cardiac mitochondrial respiration and produces an imbalance between oxidants and antioxidants. A modification of the expression of crucial genes and epigenetic alterations is reported in hearts of PNOF animals. In vivo, a decreased ventricular contractile function is observed during adulthood in PNOF hearts. All these alterations ultimately lead to an increased sensitivity to cardiac pathologic challenges such as ischemia-reperfusion injury. Nevertheless, caloric restriction and physical exercise were shown to improve PNOF-induced cardiac dysfunction and metabolic abnormalities, drawing a path to the potential therapeutic correction of early nutritional programming.

International audience; Impaired early nutrition influences the risk of developing metabolic disorders in later life. We observed that transient postnatal overfeeding (OF) in mice induces long-term hepatic alterations, characterized by microsteatosis, fibrosis associated with oxidative stress (OS), and stress-induced premature senescence (SIPS). In this study, we investigated whether such changes can be reversed by moderate calorie restriction (CR). C57BL/6 male mice pups were maintained during lactation in litters adjusted to nine pups in the normal feeding (NF) group and three pups in the transient postnatal OF group. At six months of age, adult mice from the NF and OF groups were randomly assigned to an ad libitum diet or CR (daily energy supply reduced by 20%) for one month. In each group, at the age of seven months, analysis of liver structure, liver markers of OS (superoxide anion, antioxidant defenses), and SIPS (lipofuscin, p53, p21, p16, pRb/Rb, Acp53, sirtuin-1) were performed. CR in the OF group reduced microsteatosis, decreased levels of superoxide anion, and increased protein expression of catalase and superoxide dismutase. Moreover, CR decreased lipofuscin staining, p21, p53, Acp53, and p16 but increased pRb/Rb and sirtuin-1 protein expression. CR did not affect the NF group. These results suggest that CR reduces hepatic disorders induced by OF.

International audience; The superfamily of tumor necrosis factor (TNF) receptors includes osteoprotegerin (OPG) and its ligands, which are receptor activators of nuclear factor kappa-B ligand (RANKL) and TNF-related apoptosis-inducing ligand (TRAIL). The OPG/RANKL/RANK system plays an active role in pathological angiogenesis and inflammation as well as cell survival. It has been demonstrated that there is crosstalk between endothelial cells and osteoblasts during osteogenesis, thus establishing a connection between angiogenesis and osteogenesis. This OPG/RANKL/RANK/TRAIL system acts on specific cell surface receptors, which are then able to transmit their signals to other intracellular components and modify gene expression. Cytokine production and activation of their receptors induce mechanisms to recruit monocytes and neutrophils as well as endothelial cells. Data support the role of an increased OPG/RANKL ratio as a possible marker of progression of endothelial dysfunction in metabolic disorders in relationship with inflammatory marker levels. We review the role of the OPG/RANKL/RANK triad in vascular function as well as molecular mechanisms related to the etiology of vascular diseases. The potential therapeutic strategies may be very promising in the future.

Several meta-analyses describing the effect of n-3 polyunsaturated fatty acids on the survival rate of the victims of an acute coronary event do not clearly support a beneficial impact of these fatty acids. Yet, animal studies consistently show n-3 PUFA-induced protection against ischemia-reperfusion-induced myocardial injuries. The impact on reperfusion arrhythmias of these PUFAs is more controversial. The literature shows the anti-arrhythmic properties of circulating n-3 PUFAs. However, when these fatty acids are incorporated in the cardiac membrane, they protect the myocardial tissue vis a vis cellular damage but they can be either pro- or anti-arrhythmic during reperfusion, depending on the severity of tissue injuries. The latter elements can explain the lack of beneficial effect observed in the meta-analyses, but a proper use of n-3 PUFAs may provide advantages in terms of survival rate. This review discusses the different results obtained in humans and animals and presents several strategies to enhance the beneficial effects of n-3 PUFAs.

Stroke outcome is dependent on brain-derived neurotrophic factor (BDNF)-dependent neuroplasticity. As peripheral blood mononuclear cells (PBMC) contain BDNF, diapedesis of these cells might be followed by BDNF delivery to the ischemic brain. To test this hypothesis, we investigated the association between BDNF levels in PBMC and functional outcome in patients with ischemic stroke. BDNF was measured in PBMC that were isolated from ischemic stroke patients ( n = 40) just before (day 0) and after (days 1 and 3) fibrinolysis. Three months after stroke, patients were stratified using the modified Rankin Scale (mRS) according to the unfavorable (mRS scores 3–6) and favorable (mRS scores 0–2) functional outcome. We used univariate and multivariate logistic regressions to assess the relationship between BDNF levels in PBMC and functional outcome. BDNF levels in PBMC decreased from day 0 to day 3 in patients with unfavorable outcome, while they remained stable in patients with favorable outcome. Patients with favorable outcome exhibited at day 3 higher PBMC-BDNF levels than patients with unfavorable outcome and the levels were associated with good outcome (odd ratio: 12.0; 95% confidence interval, 1.4–106.2, P = 0.023). PBMC-BDNF levels remained a predictor of stroke outcome after adjusting from cardiovascular risk, interval between admission and fibrinolysis, stroke severity from hospital admission to discharge, lymphocytes count, neutrophils/lymphocytes ratio at admission. Favorable functional outcome in ischemic stroke patients that benefited from fibrinolysis was predicted by a high BDNF level in PBMC, suggesting that PBMC might serve as a cellular vector to deliver BDNF to the ischemic brain. Impact statement There are a great number of arguments suggesting that BDNF could be involved in stroke recovery dependent of neuroplasticity. Methods that can enhance BDNF levels in the ischemic brain could therefore have great clinical value. Peripheral blood mononuclear cells (PBMC) that contain BDNF and infiltrate early and sustainably the ischemic brain might be used as a cellular vector to deliver BDNF to the ischemic brain and consequently promote recovery. This work is important in this field to show if this BDNF derived from BDNF could exert a positive action on stroke recovery. Our main results showed that a high BDNF level at day 3 after hospital admission was associated with a 12.4 fold increase in favorable outcome after adjusting for still recognized prognostic markers. The new information in this field is this finding identifies PBMC as an attractive cellular vector to deliver BDNF to the ischemic brain.

Background and Purpose— For years, the relationship between cardiac and neurological ischemic events has been limited to overlapping pathophysiological mechanisms and common risk factors. However, acute stroke may induce dramatic changes in cardiovascular function. The aim of this study was to evaluate how prior cerebrovascular lesions affect myocardial function and signaling in vivo and ex vivo and how they influence cardiac vulnerability to ischemia-reperfusion injury. Methods— Cerebral embolization was performed in adult Wistar male rats through the injection of microspheres into the left or right internal carotid artery. Stroke lesions were evaluated by microsphere counting, tissue staining, and assessment of neurological deficit 2 hours, 24 hours, and 7 days after surgery. Cardiac function was evaluated in vivo by echocardiography and ex vivo in isolated perfused hearts. Heart vulnerability to ischemia-reperfusion injury was investigated ex vivo at different times post-embolization and with varying degrees of myocardial ischemia. Left ventricles (LVs) were analyzed with Western blotting and quantitatve real-time polymerase chain reaction. Results— Our stroke model produced large cerebral infarcts with severe neurological deficit. Cardiac contractile dysfunction was observed with an early but persistent reduction of LV fractional shortening in vivo and of LV developed pressure ex vivo. Moreover, after 20 or 30 minutes of global cardiac ischemia, recovery of contractile function was poorer with impaired LV developed pressure and relaxation during reperfusion in both stroke groups. Following stroke, circulating levels of catecholamines and GDF15 (growth differentiation factor 15) increased. Cerebral embolization altered nitro-oxidative stress signaling and impaired the myocardial expression of ADRB1 (adrenoceptor β1) and cardioprotective Survivor Activating Factor Enhancement signaling pathways. Conclusions— Our findings indicate that stroke not only impairs cardiac contractility but also worsens myocardial vulnerability to ischemia. The underlying molecular mechanisms of stroke-induced myocardial alterations after cerebral embolization remain to be established, insofar as they may involve the sympathetic nervous system and nitro-oxidative stress.

International audience; Aging is a complicated pathophysiological process accompanied by a wide array of biological adaptations. The physiological deterioration correlates with the reduced regenerative capacity of tissues. The rejuvenation of tissue regeneration in aging organisms has also been observed after heterochronic parabiosis. With this model, it has been shown that exposure to young blood can rejuvenate the regenerative capacity of peripheral tissues and brain in aged animals. An endogenous compound called growth differentiation factor 11 (GDF11) is a circulating negative regulator of cardiac hypertrophy, suggesting that raising GDF11 levels could potentially treat or prevent cardiac diseases. The protein GDF11 is found in humans as well as animals. The existence of endogenous regulators of regenerative capacity, such as GDF11, in peripheral tissues and brain has now been demonstrated. It will be important to investigate the mechanisms with therapeutic promise that induce the regenerative effects of GDF11 for a variety of age-related diseases.

Although secondary prevention in patients with arterial vascular diseases has improved, a gap between recommendations and clinical practice may exist.We aimed to evaluate temporal trends in the premorbid use of preventive treatments in patients with ischemic cerebrovascular events (ICVE) and prior vascular disease.Patients with acute ICVE (ischemic stroke/TIA) were identified through the population-based stroke registry of Dijon, France (1985-2010). Only those with history of arterial vascular disease were included and were classified into four groups: patients with previous coronary artery disease only (CAD), previous peripheral artery disease only (PAD), previous ICVE only, and patients with at least two different past vascular diseases (polyvascular group). We assessed trends in the proportion of patients who were treated with antihypertensive treatments and antithrombotics at the time of their ICVE using multivariable logistic regression models.Among the 5309 patients with acute ICVE, 2128 had a history of vascular disease (mean age 77.3±11.9, 51% men; 25.1% CAD 7.5% PAD, 39.8% ICVE, and 27.5% poylvascular). A total of 45.8% of them were on antithrombotics, 64.1% on antihypertensive treatment, and 34.4% on both. Compared with period 1985-1993, periods 1994-2002 and 2003-2010 were associated with a greater frequency of prior-to-ICVE use of antithrombotics (adjusted OR=5.94; 95% CI: 4.61-7.65, P0.01, and adjusted OR=6.92; 95% CI: 5.33-8.98, P0.01, respectively) but not of antihypertensive drugs. Consistent results were found when analyses were stratified according to the type of history of arterial vascular disease.Patients with ICVE and previous vascular disease were still undertreated with recommended preventive therapies.

International audience; Objectives: We aimed to investigate whether SDMA-symmetric dimethylarginine-the symmetrical stereoisomer of ADMA-might be a marker of left ventricular function in AMI.Background: Asymmetric dimethylarginine (ADMA) has been implicated in the prognosis after acute myocardial infarction (AMI) and heart failure (HF).Methods: Cross sectional prospective study from 487 consecutive patients hospitalized 2, and death.Results: Patients were analysed based on SDMA tertiles. Sex, diabetes, dyslipidemia, and prior MI were similar for all tertiles. In contrast, age and hypertension increased across the tertiles (p

IF 3.350; International audience; The mechanisms of aging and senescence include various endogenous and exogenous factors. Among cardiovascular diseases, heart failure is a typical age-related disease. New strategies to restore cardiomyocyte cells have been reported: endogenous substances that can regenerate the heart's cardiomyocytes have been described: follistatin like 1 (FSTL1), growth-differentiation factor 11 (GDF11) and insulin-like growth factor 1 (IGF-I). Manipulation of the different anti and pro-pathways is essential to discover new approaches to regenerative therapies. (C) 2016 Elsevier Inc. All rights reserved.

Background Dysfunctional iron storage and transport are common in patients with chronic heart failure and associated with poor prognosis. Body iron could contribute to the pathogenesis of coronary artery disease (CAD) through its ability to induce oxidative stress. However, studies on the relationship between iron metabolism and CAD have yielded conflicting results. Patients and methods from the obseRvatoire des Infarctus de Cote d’Or (RICO) survey, 31 consecutive patients admitted in Intensive Care Unit for a first AMI were included. Serum concentrations of iron, transferrin, ferritin, the iron-regulatory hormone hepcidin and erythroferrone (a new hepcidinregulating hormone), transferrin saturation and total iron binding capacity were assessed on admission. Results Mean age was 65±16 yrs, 61% were male, 51% had hypertension, 23% diabetes, 45% dyslipidemia and 32% were smokers. There was a trend toward a higher serum hepcidin concentration in men (99.8 versus 56.3 ng/ml, p=0.181). Heart rate on admission was negatively associated with an erythroferrone concentration (r=-0.428, p=0.023). Haemoglobin level and hematocrit were positively correlated with erythroferrone concentration (p=0.027 and p=0.021). Moreover, a lower serum transferrin concentration was found in patients with heart failure on admission (1.93±0.16 g/l, vs 2.32±0.42, p=0.001). Ferritin concentration was positively related with infarct size, as assessed by Creatine Kinase peak (r=0.535, p=0.002) and there was a trend toward a positive correlation with erythroferrone concentration (r=0.314, p=0.085). Conclusion Elucidating the metabolic circuits regulated by peptidic hormones will provide valuable insights into complex networks governing iron availability in acute myocardial infarction. The author hereby declares no conflict of interest

Background Atrial fibrillation (AF), whether silent or symptomatic, is a frequent and severe complication of acute myocardial infarction (AMI). Asymmetric dimethylarginine (ADMA), an endogenous eNOS inhibitor, is a risk factor for endothelial dysfunction. We addressed the relationship between ADMA plasma levels and AF occurrence in AMI. Methods 273 patients hospitalized for AMI were included. Continuous electrocardiographic monitoring (CEM) e48 hours was recorded and ADMA was measured by High Performance Liquid Chromatography on admission blood sample. Results The incidence of silent and symptomatic AF was 39(14%) and 29 (11%), respectively. AF patients were markedly older than patients without AF (≈ 20 y). There was a trend towards higher ADMA levels in patients with symptomatic AF than in patients with silent AF or no AF (0.53 vs 0.49 and 0.49 μmol/L, respectively). After matching on age, we found that patients with symptomatic AF had a higher heart rate on admission and a higher rate of patients with LV dysfunction (28% vs. 3%, p=0.025). Patients who developed symptomatic AF had a higher ADMA level (0.53 vs. 0.43 μmol/L; p=0.001). Multivariate logistic regression analysis to estimate symptomatic AF occurrence showed that ADMA was independently associated with symptomatic AF (OR: 2.46 [1.21-5.00], p=0.013) beyond history of AF, LVEF Conclusion We show that high ADMA level is associated with the occurrence of AF. Although no causative role can be concluded from our observational study, our work further supports the hypothesis that endothelial dysfunction is involved in the pathogenesis of AF in AMI. The author hereby declares no conflict of interest

For years, the relationship between cardiac and neurological ischemic events has been mainly attributed to overlapping pathophysiological mechanisms and common risk factors. However, acute stroke may induce dramatic alterations of cardiovascular function. The aim of this work was to evaluate how prior cerebrovascular lesions affect myocardial function in vivo and ex vivo , as well as myocardial vulnerability to ischemic injury. Cerebral embolization was performed in adult Wistar male rats by the injection of microspheres into the left internal carotid artery. Left ventricular function, investigated in vivo using echocardiography (1 hour, 24 hours and 7 days after the embolization), was not significantly impaired; however, the heart rate was significantly increased in the stroke group (+7.2%). Epinephrine (E) and norepinephrine (NE) plasma levels increased in rats from the stroke group (E: 47.3±2.1 vs. 24.3±8.7 and NE: 22.7±4.2 vs. 10.9±3.7). One hour after stroke or sham embolization, hearts were isolated and perfused ex vivo in the Langendorff mode. In hearts from the stroke group, the baseline left ventricular developed pressure was diminished (-11%); moreover, a greater myocardial vulnerability to ischemic injury was observed, with impaired coronary flow recovery after 40 minutes of total global normothermic ischemia. Our study provides original exciting data indicating that myocardial vulnerability to ischemia can be worsened by prior ischemic stroke, a situation that does not agree with the concept of remote preconditioning. The underlying molecular mechanisms of the stroke-induced myocardial alterations after cerebral embolization remain to be established, insofar as they may involve the sympathetic nervous system. The author hereby declares no conflict of interest

Glutathione is considered the major natural antioxidant, protecting cells from oxidative stress. Patel and colleagues used plasma levels of the aminothiols cystine and glutathione to quantify oxidative stress in patients with coronary artery disease, and show that the cystine/glutathione ratio is associated with increased mortality. Is this a new approach for clinical risk stratification?

Myocardial infarction (MI) induces a sterile inflammatory response that contributes to adverse cardiac remodeling. The initiating mechanisms of this response remain incompletely defined. We found that necrotic cardiomyocytes released a heat-labile proinflammatory signal activating MAPKs and NF-κB in cardiac fibroblasts, with secondary production of cytokines. This response was abolished in Myd88−/− fibroblasts but was unaffected in nlrp3-deficient fibroblasts. Despite MyD88 dependency, the response was TLR independent, as explored in TLR reporter cells, pointing to a contribution of the IL-1 pathway. Indeed, necrotic cardiomyocytes released IL-1α, but not IL-1β, and the immune activation of cardiac fibroblasts was abrogated by an IL-1R antagonist and an IL-1α–blocking Ab. Moreover, immune responses triggered by necrotic Il1a−/− cardiomyocytes were markedly reduced. In vivo, mice exposed to MI released IL-1α in the plasma, and postischemic inflammation was attenuated in Il1a−/− mice. Thus, our findings identify IL-1α as a crucial early danger signal triggering post-MI inflammation.

Background Atrial fibrillation (AF), whether silent or symptomatic, is a frequent and severe complication of acute myocardial infarction (AMI). Asymmetric dimethylarginine (ADMA), an endogenous eNOS inhibitor, is a risk factor for endothelial dysfunction. We addressed the relationship between ADMA plasma levels and AF occurrence in AMI. Methods 273 patients hospitalized for AMI were included. Continuous electrocardiographic monitoring (CEM) ≥48 hours was recorded and ADMA was measured by High Performance Liquid Chromatography on admission blood sample. Results The incidence of silent and symptomatic AF was 39(14%) and 29 (11%), respectively. AF patients were markedly older than patients without AF (≈20y). There was a trend towards higher ADMA levels in patients with symptomatic AF than in patients with silent AF or no AF (0.53 vs 0.49 and 0.49 µmol/L, respectively). After matching on age, we found that patients with symptomatic AF had a higher heart rate on admission and a higher rate of patients with LV dysfunction (28% vs. 3%, p=0.025). Patients who developed symptomatic AF had a higher ADMA level (0.53 vs. 0.43 µmol/L; p=0.001). Multivariate logistic regression analysis to estimate symptomatic AF occur-rence showed that ADMA was independently associated with symptomatic AF (OR: 2.46 [1.21-5.00], p=0.013) beyond history of AF, LVEF Conclusion We show that high ADMA level is associated with the occur-rence of AF. Although no causative role can be concluded from our observational study, our work further supports the hypothesis that endothelial dysfunction is involved in the pathogenesis of AF in AMI.

The maintenance of stable extracellular and intracellular iron concentrations requires the coordinated regulation of iron transport into plasma. Iron is a fundamental cofactor for several enzymes involved in oxidation-reduction reactions. The redox ability of iron can lead to the production of oxygen free radicals, which can damage various cellular components. Therefore, the appropriate regulation of systemic iron homeostasis is decisive in vital processes. Hepcidin has emerged as the central regulatory molecule of systemic iron homeostasis. It is synthesized in hepatocytes and in other cells and released into the circulation. It inhibits the release of iron from enterocytes of the duodenum and from macrophages by binding to the iron exporter protein, ferroportin (FPN). FPN is a transmembrane protein responsible for iron export from cells into the plasma. Hepcidin is internalized with FPN and both are degraded in lysosomes. The hepcidin-FPN axis is the principal regulator of extracellular iron homeostasis in health and disease. Its manipulation via agonists and antagonists is an attractive and novel therapeutic strategy. Hepcidin agonists include compounds that mimic the activity of hepcidin and agents that increase the production of hepcidin by targeting hepcidin-regulatory molecules. The inhibition of hepcidin could be a potentially attractive therapeutic strategy in patients suffering from anaemia or chronic inflammation. In this review, we will summarize the role of hepcidin in iron homeostasis and its contribution to the pathophysiology of inflammation and iron disorders. We will examine emerging new strategies that modulate hepcidin metabolism.

International audience; Anticancer drugs continue to cause significant reductions in left ventricular ejection fraction resulting in congestive heart failure. The best-known cardiotoxic agents are anthracyclines such as doxorubicin. For several decades, cardiotoxicity was almost exclusively associated with anthracyclines, for which cumulative dose-related cardiac damage was the use-limiting step. Human epidermal growth factor receptor 2 (HER2; ErbB2) has been identified as an important target for breast cancer. Trastuzumab (TRZ), a humanized anti-HER2 monoclonal antibody, is currently recommended as first-line treatment for patients with metastatic HER2+ tumours. The use of TRZ may be limited by the development of drug intolerance, such as cardiac dysfunction. Cardiotoxicity has been attributed to free-iron-based, radical-induced oxidative stress. Many approaches have been promoted to minimize these serious side effects, but they are still clinically problematic. A new approach to personalized medicine for cancer that involves molecular screening for clinically relevant genomic alterations and genotype-targeted treatments is emerging.

International audience; Objective: Growth differentiation factor-15 (GDF-15) has been identified as a strong marker of cardiovascular disease; however, no data are available concerning the role of GDF-15 in the occurrence of organ dysfunction during coronary artery bypass grafting (CABG) associated with cardiopulmonary bypass (CPB). Methods: Five arterial blood samples were taken sequentially in 34 patients from anesthesia induction (IND) until 24 h after arrival at the intensive care unit (ICU). Plasma levels of GDF-15, follistatin-like 1 (FLST1), myeloperoxidases (MPO), hydroperoxides and plasma antioxidant status (PAS) were measured at each time-point. Markers of cardiac (cardiac-troponin I, cTnI) and renal dysfunction (neutrophil gelatinase-associated lipocalin, NGAL) and other classical biological factors and clinical data were measured. Results: Plasma GDF-15 levels increased gradually during and after surgery, reaching nearly three times the IND levels in the ICU (3,0756284 ng/L vs. 1,061690 ng/L, p,0.001). Plasma MPO levels increased dramatically during surgery, attaining their highest level after unclamping (UNCLAMP) (49611 ng/mL vs. 1,6796153 ng/mL, p,0.001) while PAS significantly decreased between IND and UNCLAMP (p,0.05), confirming the high oxidative status induced by this surgical procedure. ICU levels of GDF-15 correlated positively with cTnI and NGAL (p = 0.006 and p = 0.036, respectively), and also with hemoglobin and estimated glomerular filtration rate (eGFR). Among all the post-operative biomarkers available, only eGFR, NGAL and GDF-15 measured at ICU arrival were significantly associated with the onset of acute kidney injury (AKI). Patients with a EuroSCORE .3 were shown to have higher GDF-15 levels. Conclusions: During cardiac surgery associated with CPB, GDF-15 levels increased substantially and were associated with markers of cardiac injury and renal dysfunction.

L-Arginine (L-Arg) is a conditionally essential amino acid in the human diet. The most common dietary sources of L-Arg are meat, poultry and fish. L-Arg is the precursor for the synthesis of nitric oxide (NO); a key signaling molecule via NO synthase (NOS). Endogenous NOS inhibitors such as asymmetric-dimethyl-L-Arg inhibit NO synthesis in vivo by competing with L-Arg at the active site of NOS. In addition, NOS possesses the ability to be "uncoupled" to produce superoxide anion instead of NO. Reduced NO bioavailability may play an essential role in cardiovascular pathologies and metabolic diseases. L-Arg deficiency syndromes in humans involve endothelial inflammation and immune dysfunctions. Exogenous administration of L-Arg restores NO bioavailability, but it has not been possible to demonstrate, that L-Arg supplementation improved endothelial function in cardiovascular disease such as heart failure or hypertension. L-Arg supplementation may be a novel therapy for obesity and metabolic syndrome. The utility of l-Arg supplementation in the treatment of L-Arg deficiency syndromes remains to be established. Clinical trials need to continue to determine the optimal concentrations and combinations of L-Arg, with other protective compounds such as tetrahydrobiopterin (BH4 ), and antioxidants to combat oxidative stress that drives down NO production in humans.

International audience; Background: Postnatal overfeeding (OF) in rodents induces a permanent moderate increase in body weight in adulthood. However, the repercussions of postnatal OF on cardiac gene expression, cardiac metabolism and nitro-oxidative stress are less well known. Methodology/Principal Findings: Immediately after birth, litters of C57BL/6 mice were either maintained at 10 (normal-fed group, NF), or reduced to 3 in order to induce OF. At weaning, mice of both groups received a standard diet. The cardiac gene expression profile was determined at weaning and cardiac metabolism and oxidative stress were assessed at 7 months. The cardiac expression of several genes, including members of the extracellular matrix and apelin pathway, was modified in juvenile OF mice. In adult mice, OF led to an increase in body weight (+30%) and to significant increases in plasma cholesterol, insulin and leptin levels. Myocardial oxidative stress, SOD and catalase activity and mRNA expression were increased in OF mice. In vivo, diastolic and systolic blood pressures were significantly higher and LV shortening and ejection fraction were decreased in OF mice. Ex vivo, after 30 min of ischemia, hearts isolated from OF mice showed lower functional recovery and larger infarct size (31% vs. 54%, p,0.05). Increases in collagen deposition and expression/activity of matrix-metalloproteinase-2 were observed in adult OF mouse hearts. Moreover, an increase in the expression of SOCS-3 and a decrease in STAT-3 phosphorylation were observed in ventricular tissues from OF mice. Conclusions/Significance: Our study emphasizes that over-nutrition during the immediate postnatal period in mice leads to early changes in cardiac gene expression, which may permanently modify the heart's structural organization and metabolism and could contribute to a greater susceptibility to myocardial ischemia-reperfusion injury.

International audience; Small amounts of carbon monoxide (CO) are continuously produced in mammals. The intracellular levels of CO can increase under stressful conditions following the induction of HO-1 (heme oxygnase-1), a ubiquitous enzyme responsible for the catabolism of heme. Unlike nitric oxide, which is a free radical, CO does not contain free electrons but may be involved in oxidative stress. The carbonate radical has been proposed to be a key mediator of oxidative damage resulting from peroxynitrite production, likewise, the precursor of the carbonate radical anion being bicarbonate and carbon dioxide. We report herein some of the transcription factors and protein kinases involved in the regulation of vascular HO-1 expression. Beyond its widely feared toxicity, CO has revealed a very important biological activity as a signaling molecule with marked protective actions namely against apoptosis and endothelial oxidative damage. Abnormal metabolism and function of CO contribute to the pathogenesis and development of cardiovascular diseases. Important results have been reported in which CO and CO-releasing molecules (CO-RMs) prevent intimal hyperplasia by arresting hyperproliferative vascular smooth muscle cells and increased mobilization and recruitment of bone-marrow-derived progenitor cells. Clinical studies have demonstrated beneficial properties of CO-RMs in transplantation. The anti-inflammatory properties of CO and CO-RMs have been demonstrated in a multitude of animal models of inflammation, suggesting a possible therapeutic application for inflammatory diseases. The development of a technology concerning CO-RMs that controls the delivery and action of CO under different pathological conditions represents a major step forward in the development of CO-based pharmaceuticals with therapeutic applications.

Known for years as professional APCs, dendritic cells (DCs) are also endowed with tumoricidal activity. This dual role of DC as killers and messengers may have important implications for tumor immunotherapy. However, the tumoricidal activity of DCs has mainly been investigated in animal models. Cancer cells inhibit antitumor immune responses using numerous mechanisms, including the induction of immunosuppressive/ tolerogenic DCs that have lost their ability to present Ags in an immunogenic manner. In this study, we evaluated the possibility of generating tumor killer DCs from patients with advanced-stage cancers. We demonstrate that human monocyte-derived DCs are endowed with significant cytotoxic activity against tumor cells following activation with LPS. The mechanism of DC-mediated tumor cell killing primarily involves peroxynitrites. This observed cytotoxic activity is restricted to immature DCs. Additionally, after killing, these cytotoxic DCs are able to activate tumor Ag-specific T cells. These observations may open important new perspectives for the use of autologous cytotoxic DCs in cancer immunotherapy strategies.

International audience; To evaluate the effects of alpha-lipoic acid (AL) in a model of doxorubicin (DOX)-induced cardiotoxicity, male Wistar rats were treated with DOX (1 mg/kg/d; 10 d) in combination or not with AL (50 mg/kg/d; 15 d). Plasma oxidative stress was determined by hydroperoxides (ROOH) and the ascorbyl radical/ascorbate ratio. One and two months later, the functional parameters of the hearts were determined in vivo by catheterization and cardiac oxidative stress was assessed by malonedialdehyde (MDA) and O₂*⁻ (dihydroethidium fluorescence) content in tissue. After two months, body weight was higher in the DOX-AL group than in DOX (+16%), but this was due to ascites. Histological liver alterations were observed in both the DOX and DOX-AL groups. Plasma ROOH concentrations decreased after 10 days of AL treatment, but were greater in both the DOX and DOX-AL groups. After two months, a decrease in the cardiac contractility index (-27% and -29%, respectively) and cardiac hypertrophy were observed in DOX and DOX-AL. These dysfunctions were associated with 1) a reduction in plasma ascorbate levels and an increase in the ascorbyl/ascorbate ratio and 2) an increase MDA and O₂*⁻ content in cardiac tissue. In conclusion, a cumulative dose of 10 mg/kg doxorubicin induced functional alterations in the heart associated with plasma and cardiac oxidative stress. The co-administration of the antioxidant compound AL had no beneficial effects in this situation.

International audience; Background: Western diet, rich in saturated fatty acids and cholesterol, is associated with increased cardiovascular risk. We thus investigated in female mice the influence of this diet on plasma antioxidant status, vascular wall thickening and cardiac function. Methods and Results: Adult female C57BL/6J wild type (WT) and LDLR–/– mice were fed a normal diet (ND) or a high-fat diet (HFD) for 17 weeks. HFD induced an increase in plasma lipids and vitamin C (Vit C) levels in both groups but at a much higher level in LDLR–/– and a decrease in plasma ascorbyl free radical levels to Vit C ratio (an endogenous oxidative stress index) in LDLR–/–. We only found a slight decrease in circulating antioxidant status evaluated by the Oxygen Radical Absorbance Capacity (ORAC) assay in WT, but not in LDLR–/–. Echocardiography evidenced an increase in arterial wall thickness in aortic arch at atherosclerosis predilection sites in HFD LDLR–/– as compared to ND LDLR–/– and HFD WT. This result was confirmed by histology. Furthermore, histological examination of aortic valves showed an increase in atherosclerotic lesions. Our study, using echocardiography, show that chronic HFD does not induce any major modifications of systolic function in the both mice groups. Conclusions: High-fat intake in mice causes serious disturbances in lipid plasma levels associated to variations of circulating antioxidant status due, at least in part, to an increase in Vit C. At this stage, atherosclerotic lesions, observed in aortic arch and valve, do not impair cardiac function in HFD-fed mice.

Carbon monoxide (CO) is believed to mediate many of the cytoprotective effects attributed to the activation of heme oxygenase (HO-1), the enzyme responsible for CO production. Recently, the study of CO-releasing molecules (CO-RMs) has provided a new approach for the delivery of CO. In the present study, we examined whether the cardioprotective properties of CO-RM2 in isolated rat hearts subjected to an ischemia-reperfusion (I/R) sequence were associated with the presence of CO. In addition, the antioxidant properties of CO-RM2 were evaluated. In hearts pretreated with CO-RM2, the improvement in contractile function at the end of the reperfusion period after 20 min of global total ischemia was significantly greater than in controls. These beneficial effects were accompanied by a reduction in 1) LDH activity release 2) infarct size 3) ventricular superoxide production. The improvement in myocardial function and the reduction in oxidative stress were not observed when hearts were pretreated with inactivated CO-RM2 (iCO-RM2). Additionally, CO-RM2, but not iCO-RM2, was found to exert antioxidant properties. These results suggest that the production of CO is a necessary factor in the cardioprotective and antioxidant actions of CO-releasing compound. These results may open up new ground for a novel class of cardioprotective compounds.

International audience; Objectives: We investigated the relationship between prior statin therapy and leukocyte telomere length (LTL), as well as their interaction with potential new biomarkers of oxidative deoxyribonucleic acid (DNA) lesions and reactive oxygen species-induced inflammation.Methods and results: From patients admitted for an acute myocardial infarction, LTL was assessed by quantitative polymerase chain reaction (Q-PCR), and leukocyte Finkel-Biskis-Jinkins osteosarcoma (FOS) and 8-oxoguanine DNA glycosylase (OGG1) messenger ribonucleic acid (mRNA) levels were measured by retrotranscription Q-PCR. Patients under prior chronic statin therapy were compared with patients without statin therapy. Although patients on statin therapy were older, their mean LTL was longer than patients not under statin therapy (1.29 ± 0.11 vs. 1.25 ± 0.11 T/S ratio, p = 0.008). In contrast, FOS and OGG1 mRNA levels were similar for the 2 groups. LTL decreased with increasing age, FOS, and OGG1 mRNA levels. Statin therapy remained associated with longer LTL, even after adjustment for confounding factors (p = 0.001), and in younger patients (≤ 64 y). Even in groups matched for propensity scores for statin use, LTL was markedly longer in patients under statin therapy.Conclusions: Our observational study showed that statin therapy was associated with longer LTL. These data bring to light opportunities to identify new targets for early primary preventive treatment strategies. Moreover, our study raised FOS and OGG1 as new relevant biomarkers of LTL.

International audience; OBJECTIVE: Analysis of the leukocyte transriptome, in particular the Finkel-Biskis-Jinkins Osteosarcoma (c-Fos) gene, which has a prominent role in inflammation, provides new insights into atherosclerosis mechanisms. Although smoking is a major risk factor, the links between smoking status and coronary artery disease (CAD) remains unclear. We aimed to analyze the relationship between smoking status and c-Fos expression in circulating leukocytes of patients with CAD. METHODS: c-Fos expression was measured by RT-Q-PCR, from blood leukocytes of 239 consecutive patients after acute myocardial infarction (MI). The patients were asked about their smoking status and stratified into 3 groups: current smokers (CS) (N = 85), past smokers (PS) (N = 78) and never smokers (NS) (N = 76). RESULTS: NS had a higher risk profile including hypertension, and CS were younger than PS and NS (-13 years and 17 years respectively). There was only a trend towards lower CRP levels in NS and PS than in CS. The mean c-Fos transcript level was slightly higher in CS than in PS and NS (0.924 vs. 0.908 and 0.861 AU, respectively; p = 0.005). By univariate analysis, neither age, nor sex, nor CRP nor white blood cell count was associated with c-Fos transcript levels. By multivariate analysis, CS (vs. PS + NS) was the strongest predictor of the c-Fos transcript level, (B = 0.042 ± 0.014, p = 0.003), even after adjustment for confounding factors (i.e. hypertension, chronic medication, family history of CAD, and prior MI). CONCLUSION: Our work suggests that c-Fos transcript level in blood leukocyte could be considered a cumulative biomarker of smoking. As the c-Fos gene has been put forward as a new factor in the progression and severity of atherosclerosis, it could be considered a novel potential pathway of tobacco toxicity in coronary artery disease.

International audience; Heart failure is characterized by a great number of metabolic and histological defects, however, previous studies did not provide strong evidence of a correlation between the antioxidant status of myocardial tissue itself and cardiac function. The goal of our study was to assess, in patients with heart failure consecutive to dilated cardiomyopathy (DCM), alterations in norepinephrine (NE), lipid peroxidation (malonedialdehyde: MDA) and iron levels in different parts of the myocardium and aorta, in relation to functional parameters. Biopsied heart samples were obtained from 12 DCM patients and from 4 brain-dead organ donors (Controls). The left ventricular ejection fraction (LVEF) was reduced to 19.1±2.6% in DCM. For all patients, the distribution of NE in the atria, ventricles and vessels was different, but NE content in control hearts was systematically higher than in cardiomyopathy patients. MDA levels tended to be higher in the different samples from the DCM group in comparison with the values obtained in the C group; the values were significantly decreased (p

International audience; Background and aim: Reactive oxygen species (ROS) play an important role in the pathogenesis of many diseases including cardiovascular diseases. Several methods have been developed for the direct or indirect measurement of oxygen free radical and its by-products. The current study was designed to validate the new Free Oxygen Radicals Test (FORT) and to investigate the potential relationships between ROS and clinical or biological factors in male patients with acute myocardial infarction (AMI). Methods: We analysed FORT values in samples from 66 patients with AMI. Results: FORT values ranged from 324 to 1198 FORT units, with a median value of 581 (494-754) FORT units. In univariate analysis, FORT values were positively related only to LVEF

In the past few years, a growing interest has been given to the possible antioxidant functions of a natural acid, synthesized in human tissues: alpha-lipoic acid (ALA). Both the oxidized (disulfide) and reduced (dithiol: dihydrolipoic acid, DHLA) forms of ALA show antioxidant properties. ALA administered in the diet accumulates in tissues, and a substantial part is converted to DHLA via a lipoamide dehydrogenase. Commercial ALA is usually a racemic mixture of the R and S forms. Chemical studies have indicated that ALA scavenges hydroxyl radicals, hypochlorous acid, and singlet oxygen. ALA exerts antioxidant effects in biological systems not only through direct ROS quenching but also via transition metal chelation. ALA has been shown to possess a number of beneficial effects both in the prevention and treatment of diabetes in experimental conditions. ALA presents beneficial effects in the management of symptomatic diabetic neuropathy and has been used in this context in Germany for more than 30 years. In cardiovascular disease, dietary supplementation with ALA has been successfully employed in a variety of in vivo models: ischemia-reperfusion, heart failure, and hypertension. More mechanistic and human in vivo studies are needed to determine whether optimizing the dietary intake of ALA can help to decrease cardiovascular diseases. A more complete understanding of cellular biochemical events that influence oxidative damage is required to guide future therapeutic advances.

International audience; Severe septic states in humans are responsible for intense intravascular oxidative stress, which induces numerous adaptive mechanisms. We determined time sequence changes in total plasma antioxidant capacity (TAC) and major plasma antioxidant concentrations, which have not been fully explained in septic conditions. A cohort of 56 consecutive septic patients (septic shock n = 37, severe sepsis n = 19) and six healthy volunteers. We compared TAC and antioxidant levels in patients with one of two degrees of septic states, at the onset of illness, to those of healthy volunteers. Thereafter, over a 10-day follow-up, we observed daily the time sequence changes of the two septic populations in terms of TAC and antioxidants. At the onset, there was no difference between the three groups in terms of TAC values (healthy subjects 2.18 +/- 0.04; severe sepsis 2.03 +/- 0.07; septic shock 2.09 +/- 0.09), then an equivalent time decline was observed in the two septic populations whatever the severity. TAC was statistically linked to uric acid, proteins in particular albumin and bilirubin (multivariate analysis), but no correlation was found with any vitamin (A, C and E). A sharp and persistent decrease in vitamin C concentrations was underlined. TAC, unaffected at first, deteriorated over time whatever the severity of the infection in these critically ill patients. TAC, unable to distinguish severe sepsis and septic shock, is unlikely to be a particularly useful outcome measure.

International audience; Among their pleiotropic effects, statins exert antioxidant and anti-inflammatory properties. The aim of this study was to evaluate in normotensive (WKY) and in spontaneously hypertensive rats (SHR) the effect of rosuvastatin (ROSU) treatment on (1) plasma inflammation markers and endogenous NO synthase inhibitor (ADMA) levels, (2) reactive oxygen species (ROS) generated by circulating leukocytes and (3) vascular oxidative stress and tissue inflammation markers. Plasma cytokines were higher in SHR than in WKY, except for IL-4, which was lower in SHR than in WKY. SHR monocytes exhibited higher production of ROS than did WKY monocytes. In the experimental conditions, ROSU did not modify plasma cholesterol levels in SHR but attenuated the increase in systolic blood pressure. In SHR only, ROSU lessened pro-inflammatory cytokines and ADMA levels, increased IL-4 and reduced ROS production in circulating monocytes. These results demonstrate the beneficial effects of ROSU in SHR, independently of any lowering of cholesterol levels.

To evaluate the mechanisms and the impact of the angiotensin-converting enzyme inhibitor perindopril (P) in a model of doxorubicin (D)-induced cardiotoxicity, male Wistar rats received D (1 mg/kg/d, IP for 10 days), P (2 mg/kg/d by gavage from day 1 to day 18), D (for 10 days) + P (for 18 days) or saline. D decreased systolic blood pressure and body and heart weights. Left ventricular diastolic diameter was increased by D (P < 0.01), but it was not attenuated by P. D decreased plasma vitamin C (P < 0.05) and increased the ascorbyl radical/vitamin C ratio (P < 0.01). This ratio was attenuated by P. No difference was found among groups in cardiac troponin I, brain natriuretic peptide concentrations, and tissue oxidative stress (OS). Myocardial MCP-1 expression was higher in the D group. Cardiac kinin receptor (B1R and B2R) expression was not affected by D, yet binding sites for B2R and B1R were increased in D+P and P groups, respectively (P < 0.05). In conclusion, D induced cardiac functional alterations, inflammation and plasma OS whereas tissue OS, and cardiac kinin receptors expression were not modified. P did not improve cardiac performance, but it modulated kinin receptor expression and enhanced antioxidant defense.

International audience; Aging triggers several abnormalities in muscle glycolytic fibers including increased proteolysis, reactive oxygen species (ROS) production and apoptosis. Since the mitochondria are the main site of substrate oxidation, ROS production and programmed cell death, we tried to know whether the cellular disorders encountered in sarcopenia are due to abnormal mitochondrial functioning. Gastrocnemius mitochondria were extracted from adult (6 months) and aged (21 months) male Wistar rats. Respiration parameters, opening of the permeability transition pore and ROS production, with either glutamate (amino acid metabolism) or pyruvate (glucose metabolism) as a respiration substrate, were evaluated at different matrix calcium concentrations. Pyruvate dehydrogenase and respiratory complex activities as well as their contents measured by Western blotting analysis were determined. Furthermore, the fatty acid profile of mitochondrial phospholipids was also measured. At physiological calcium concentration, state III respiration rate was lowered by aging in pyruvate conditions (-22%), but not with glutamate. The reduction of pyruvate oxidation resulted from a calcium-dependent inactivation of the pyruvate dehydrogenase system and could provide for the well-known proteolysis encountered during sarcopenia. Matrix calcium loading and aging increased ROS production. They also reduced the oxidative phosphorylation. This was associated with lower calcium retention capacities, suggesting that sarcopenic fibers are more prone to programmed cell death. Aging was also associated with a reduced mitochondrial superoxide dismutase activity, which does not intervene in toxic ROS overproduction but could explain the lower calcium retention capacities. Despite a lower content, cytochrome c oxidase displayed an increased activity associated with an increased n-6/n-3 polyunsaturated fatty acid ratio of mitochondrial phospholipids. In conclusion, we propose that mitochondria obtained from aged muscle fibers display several functional abnormalities explaining the increased proteolysis, ROS overproduction and vulnerability to apoptosis exhibited by sarcopenic muscle. These changes appear to be related to modifications of the fatty acid profile of mitochondrial lipids.

International audience; The optimization of the expression of recombinant 6-His-tagged HPO lyase in Yarrowia lipolytica is described: 1800U/L of culture was detected at 24h of culture on a medium containing olive oil as the sole carbon source. The enzyme was purified by IMAC and showed an optimal pH at 5.5, an optimal temperature at 20^\circC and a Km value of 9μM with 13-HPOD substrate. The participation of radicals during the catalysis of purified bell pepper fruit hydroperoxide lyase has been observed by electron paramagnetic resonance spectroscopy and the yet unidentified radical species might be an alkyl or alkoxyl radical linked to the enzyme.

International audience; Previous studies indicate that adenosine supplementation or nitric oxide synthase (NOS) inhibition during reperfusion exert protective effects against myocardial ischemia-reperfusion (I/R) injury. We wanted to test the hypothesis that NOS inhibition before I/R also protects the myocardium against further injury and aimed to determine the involvement of adenosine receptors in a perfused rat heart model. Rats were injected with 10 mg/kg of L-NAME (N(omega)-nitro-L-arginine methyl ester) or L-NAME + SPT (8-(p-sulfophenyl)-theophylline)--an adenosine antagonist - at 2 x 25 mg/kg or with a saline buffer, 24 hrs prior to heart excision. The hearts, perfused retrogradely were subjected to 60 min of global ischemia followed by 120 min reperfusion. L-NAME decreased NOx (nitrite and nitrate) production (16.2 +/- 3.2 vs. 7.0 +/- 1.8 micromol/L; P

Cardiovascular ischemic heart disease remains one of the main cause of morbidity and mortality worldwide. Reperfusion is essential to blunt cell death during ischemia. However, post-ischemic reperfusion exacerbates cell death during the first minute of reperfusion. This is mainly explained by the activation of the mitochondrial permeability transition pore (mPTP). A vicious circle between overproduction of mitochondrial ROS (mtROS) and matrix mitochondrial calcium overload (Ca2+) is proposed today as a main trigger of mPTP activation during IR. Thus, the aim of this work, was to i) proposed new strategy to blunt this vicious circle and protect mitochondria during IR or ii) better understand the underlying mechanisms of natural cardioprotective strategy. Targeting mitochondria with antioxidant is a promising strategy. In this work, we identified a natural antioxidant, sinapine, able to target mitochondrial oxidative stress. We reported that sinapine but not sinapic acid limit mitochondrial oxidative stress and ROS production during cardiac IR. In our second study, we decipher the role of nitric oxide in exercise-induced cardioprotection. We reported that exercise training resulted in eNOS translocation to mitochondria which impact the bioavailability of NO and the S-nitrosylation of mitochondrial key proteins involved in cardioprotection. Finally, we reported that S-nitrosylation played a key role in the protection of mitochondria during stress situations mimicking cardiac ischemia-reperfusion. Keywords, L’infarctus du myocarde constitue la première cause de mortalité cardiovasculaire. A ce jour, la seule stratégie permettant de limiter la mort cellulaire au cours de l’ischémie cardiaque est la reperfusion. Néanmoins, elle est à l’origine de lésions qui lui sont propres. L’établissement d’un cercle vicieux entre la surproduction d’espèces réactives oxygénées mitochondriales (EROmt) et la surcharge calcique (Ca2+) matricielle semble être un acteur clé de l’exacerbation de la mort cellulaire dans les premiers instants de la reperfusion. Dans ce contexte, l’objectif de ce travail de thèse a été de développer et/ou de mieux comprendre les mécanismes sous-jacents de stratégies naturelles permettant de limiter l’établissement de ce cercle vicieux pour permettre une protection des mitochondries au cours de l’ischémie-reperfusion. Notre première stratégie a été d’identifier dans la nature des molécules antioxydantes dont les propriétés physico-chimiques permettent de cibler le stress oxydant mitochondrial. Nous avons pu identifier un antioxydant naturel, la sinapine dont les propriétés chimiques pourraient lui conférer un tropisme mitochondrial. On a ainsi pu démontrer in vitro, in cellulo, ex vivo et in vivo que la sinapine était capable de cibler le stress oxydant mitochondrial et ainsi diminuer la sensibilité du cœur à l’IR. La deuxième étude de ce travail de thèse consistait à mieux identifier les mécanismes cellulaires sous-jacents à la cardioprotection par l’exercice physique. Une attention toute particulière a été portée sur le rôle clé joué par la signalisation du monoxyde d’azote (NO) au niveau mitochondrial. En effet, le NO est bien décrit comme pouvant moduler la production d’EROmt et comme permettant de protéger le cœur au cours de l’IR. Néanmoins, à ce jour, l’impact de l’exercice sur la signalisation eNOS-NO au niveau mitochondrial est mal connu. Nous avons pu observer qu’un entraînement modéré de 5 semaines était à l’origine d’une translocation de la eNOS au niveau des mitochondries et que celle-ci était associée à une augmentation de la biodisponibilité du NO au niveau mitochondrial et à une modification du s-nitrosoprotéome. Enfin, nous avons pu montrer que la S-nitrosylation joue un rôle clé dans la protection des mitochondries en situation de stress permettant de mimer l’ischémie-reperfusion. Mots

The severity of myocardial infarction (MI) is linked to organ failure caused by decreased cardiac output and impaired microcirculation with tissue hypoxia; which can ultimately lead to cardiogenic shock. Photoacoustic imaging (PA), a non-invasive hybrid technique combining laser pulses and ultrasonic waves, allows an analysis of the oxygen saturation (sO2) of organs in real time. The objective of this work was to assess the relevance of PA imaging for measuring hypoxia, after MI of the left ventricle (LV) or of the right ventricle (RV), at the myocardium level in order to determine the involvement of hypoxia in the mechanisms of ventricular interdependence, then in peripheral organs (kidney, liver) and in the brain.For each experimental model, LV MI induced by permanent ligation of the left anterior descending artery (LAD) and RV MI induced by right coronary (RC) ligation, two groups of mice were compared: Sham group versus LV MI or RV MI. Echocardiographic parameters (LVEF, Cardiac output (CO), Strain) and PA (sO2) (VevoLAZR, ViualSonics®) measurements were performed on heart, brain, kidney and liver at H4, D1 and D7 after MI. Plasma biomarkers (creatinine, ASAT, ALAT, lactate) were assayed at each time point. After LV MI, LV function was impaired from H4. We observed a strong correlation between LV dysfunction and myocardial sO2. The PA analysis showed a significant early decrease between LV MI (versus Sham) of -5.9% at the cerebral level, -6.4% at the renal level and -7.3% at the hepatic level. The kinetics of the biomarkers, creatinine, ASAT and ALAT correlated with tissue alteration of sO2 4h after LV IM, but there was no correlation between lactate and tissue sO2. Pericytes depletion was found at cardiac and renal levels in the LV MI group 24 hours after LAD ligation. RV IM caused RV failure resulting in LV diastolic dysfunction with quasi-normal systolic function (preserved LVEF) but decreased CO. Preliminary PA analysis found a hypoxic tendency in the brain, RV, LV and kidneys, but not in the liver.In conclusion, post-MI cardiac failure in mice leads to hypoxia of peripheral organs and the brain, detectable by PA as early as 4 hours after surgery. The sO2 appears to be a marker of early tissue damage to identify hypoxia by hypoperfusion and, thereby, impaired microcirculation. This new approach could be used very early on to detect and monitor tissue suffering in real time, in a non-invasive manner, and thus rapidly adapt therapeutic management., La gravité de l’infarctus du myocarde (IDM) est liée aux défaillances d’organes engendrées par la baisse du débit cardiaque et une altération de la microcirculation avec hypoxie tissulaire ; ce qui peut aboutir au stade ultime à un choc cardiogénique. L’imagerie photoacoustique (PA), technique hybride non invasive couplant impulsions laser et onde ultrasonore, permet une analyse de la saturation en oxygène (sO2) des organes en temps réel. Ce travail avait pour objectif d’évaluer la pertinence de l’imagerie PA pour mesurer l’hypoxie, après un IDM du ventricule gauche (VG) puis un IDM du ventricule droit (VD), au niveau du myocarde ; ceci afin de déterminer l’implication de l’hypoxie dans les mécanismes de l’interdépendance ventriculaire, puis au niveau des organes périphériques (rein, foie) et du cerveau.Pour chaque modèle expérimental, IDM VG par ligature coronaire gauche (CG) et IDM VD par ligature coronaire droite, deux groupes de souris ont été comparés : groupe contrôle Sham versus IDM VG ou VD. Des mesures échocardiographiques (ETT) (FEVG, Débit cardiaque (DC), Strain) et PA (sO2) (VevoLAZR, ViualSonics®) ont été effectuées sur cœur, cerveau, rein et foie à H4, J1 et J7 après l’IDM. Les biomarqueurs plasmatiques (créatinine, ASAT, ALAT, lactate) étaient dosés à chaque temps.Après un IDM VG, la fonction VG était altérée dès H4. Nous avons observé une forte corrélation entre la dysfonction VG et la sO2 myocardique. L’analyse PA montrait une diminution significative précoce entre IDM VG versus Sham de -5.9 % au niveau cérébral, -6.4 % au niveau rénal et -7.3 % au niveau hépatique. La cinétique des biomarqueurs, créatinine, ASAT et ALAT était corrélée à l’altération tissulaire de la sO2 mais il n’y avait aucune corrélation entre le lactate et la sO2 tissulaire. Une raréfaction des péricytes a été retrouvée aux niveaux cardiaque et rénal dans le groupe IDM VG 24h après la ligature CG.L’IDM VD provoquait une défaillance VD entrainant une dysfonction diastolique du VG avec fonction systolique préservée (FEVG conservée) mais un DC diminué. L’analyse PA préliminaire retrouvait une tendance hypoxique au niveau cérébral, VD, VG et rénal, mais pas hépatique.La défaillance cardiaque post-IDM chez la souris entraine une hypoxie des organes périphériques et du cerveau, détectable en PA dès 4h après la chirurgie. La sO2 semble être un marqueur de souffrance tissulaire précoce pour identifier une hypoxie par hypoperfusion et de ce fait une altération de la microcirculation. Cette nouvelle approche pourrait être utilisable très précocement pour dépister et suivre en temps réel la souffrance tissulaire, de façon non invasive, et ainsi adapter rapidement la prise en charge thérapeutique.

For years, the relationship between cardiac and neurological ischemic events has been limited to overlapping pathophysiological mechanisms and common risk factors. However, acute stroke may induce dramatic changes in cardiovascular function.The aim of this study was to evaluate how prior cerebrovascular lesions affect myocardial function and signaling in vivo and ex vivo, and how they influence cardiac vulnerability to ischemia-reperfusion injury and the expression of cardiac genes and proteins involved in cardioprotective pathways.Thus, in our work, we studied cardiac function in a rat stroke model induced by cerebral embolization.The main results show that experimental stroke 1/ impaired cardiac function both in vivo and ex vivo, 2/ impaired myocardial recovery following ischemia, 3/ involved sympathetic nervous system, 4/ involved nitro-oxidative stress, 5/ impaired one of the cardioprotective pathways, 6/ involved GDF15 at cerebral and cardiac levels.Our findings indicate that stroke not only impairs cardiac contractility and also worsens myocardial vulnerability to ischemia. The underlying molecular mechanisms of stroke-induced myocardial alterations after cerebral embolization remain to be established insofar as they may involve the cytokine GDF-15., Pendant des années, les relations entre les événements ischémiques cardiaques et neurologiques ont été considérées comme étant liées à des mécanismes physiopathologiques similaires et à des facteurs de risque communs. Cependant, un accident vasculaire cérébral (AVC) aigu peut induire des changements importants de la fonction cardiovasculaire.Le but de cette étude était d'évaluer l'incidence de lésions ischémiques cérébrovasculaires préalables sur la fonction du myocarde in vivo et ex vivo ainsi que leur influence sur la vulnérabilité cardiaque aux lésions d'ischémie-reperfusion et sur l’expression cardiaque de gènes et de protéines impliquées dans les voies de cardioprotection.Ainsi, dans notre travail, nous avons étudié la fonction cardiaque dans un modèle d’AVC induit par embolisation cérébrale chez le rat.Les principaux résultats montrent que l’AVC 1/ altère la fonction cardiaque in vivo et ex vivo, 2/ altère la récupération du myocarde suite à une ischémie, 3/ implique le système nerveux autonome sympathique, 4/ implique le stress nitro-oxydant, 5/ altère une des voies de cardioprotection, 6/ implique le GDF15 au niveau cérébral et cardiaque.L’AVC constituerait ainsi un facteur de mauvais pronostique cardiaque.

Ischemic cardiac diseases are the most frequent and deleterious pathologies leading to important cardiovascular-related mortality worldwide. One of the alternative therapies consists to treat these patients using cardiac surgery. Cardiopulmonary bypass was developed to greatly improve this surgical procedure. However, some adverse effects can occur during cardiac surgery associated with cardiopulmonary bypass due to the inflammatory response. This phenomenon is the result of various mechanisms including oxidative stress and inflammatory cytokines which lead to multi-organ failure and then to myocardial and renal injuries occurring during the peri- and post-operative periods.The first part of this work was designed to evaluate in the context of cardiac surgery the kinetics of plasma GDF-15 levels, an oxidative stress and inflammation related cytokine. Our prospective study demonstrated for the first time the kinetic increase in plasma GDF-15 levels which were associated to postoperative cardiac and renal injuries.Currently, operative risk evaluation is based on score calculation including clinical criteria. These risk scores present some limitations. Concerning other cardiac patients out of surgical fields, the risk assessment is defined using clinical parameters and biomarkers evaluation (cardiac troponin, BNP, Nt-proBNP). Thus, we aimed to determine whether pre-operative GDF-15 as plasma biomarker could help to identify patients at high risk of renal injuries. We found that patients with the highest pre-operative plasma GDF-15 levels are at risk for post-operative acute kidney injury., La circulation extracorporelle compte parmi les progrès techniques majeurs associés à la chirurgie cardiaque. Elle constitue aussi l’une des causes de complications principales car responsable d’une réponse inflammatoire généralisée qui résulte de la conjugaison des effets du stress oxydant et des cytokines libérés, contribuerait à la dysfonction multi-organe aboutissant aux complications myocardiques et rénales survenant au cours des périodes per- et postopératoires. La première partie de notre travail avait pour objectif d’explorer l’évolution des taux circulants du GDF-15, cytokine associée au stress oxydant et à l’inflammation, dans ce contexte de chirurgie cardiaque. Notre étude prospective a démontré pour la première fois que cette procédure est accompagnée de l’augmentation du GDF-15 dont les taux plasmatiques sont associés aux lésions postopératoires cardiaques et rénales.L’évaluation du risque opératoire repose sur un ensemble de scores dont le calcul est basé essentiellement sur des caractéristiques cliniques. Ces scores présentent toutefois un certaines limitations. Chez les patients « médicaux » atteints de pathologies cardiovasculaires la stratification du risque est définie en associant des caractéristiques cliniques à l’évaluation des taux circulants de biomarqueurs. L’objectif de cette seconde partie a donc été de mettre en évidence le pouvoir prédictif du GDF-15 en tant que biomarqueur circulant dans la survenue de complications rénales au cours de la chirurgie cardiaque sous CEC. Nous avons mis en évidence que les patients présentant des taux préopératoires élevés de GDF-15 sont à risque de développer une insuffisance rénale aigue postopératoire.

Postnatal overfeeding (PNOF) in rodents induces early programming of cardio-metabolic risk. Our aim was to determine if a moderate diet restriction could restore cardio-metabolic alterations induced by PNOF.Immediately after birth, litters of C57BL/6 mice were either maintained at 9 (normal litter, NL), or reduced to 3 (small litter, SL) to induce PNOF. At weaning, all mice received a standard diet ad libitum (AL). At 6 month of age, half of the NL and SL mice were assigned to a moderate 20% calorie restriction (CR: NLCR, SLCR) for one month, while the other mice continued to eat AL (AL: NLAL, SLAL). Glucose and insulin tolerance tests, cardiac function (echocardiography), body composition (Echo-MRI), cardiac sensitivity to ischemia-reperfusion injury, mitochondrial function, reactive oxygen species (ROS) generation (EPR spectroscopy) and insulin signaling were assessed before and/or after one month of CR.Adult SL mice presented overweight, fat accumulation, hyperleptinemia, glucose intolerance, insulin resistance and decreased left ventricular ejection fraction (LVEF). After one month of moderate CR, body weight of SLCR was normalized to this of NLAL however their fat mass and leptinemia were not decreased. Glucose metabolism was improved and LVEF was increased In SLCR. After 30 min of global ischemia, hearts isolated from SLCR mice showed better recovery and smaller infarct size than this of others groups. CR increased the cardiac mitochondrial respiratory rate in SLCR mice whereas cardiac ROS production was significantly decreased in SLCR mice. Insulin signaling in heart was affected neither by PNOF nor by CR. Intriguingly, no difference was observed in NLCR mice for most of the parameters investigated.Our results confirmed the programming of early overfeeding on metabolic and cardiac function. A short-term moderate CR in not only normalized body weight in SL mice but also ameliorate the metabolic programming and reverse the cardiac dysfunction induced by PNOF., La suralimentation postnatale (SAPN) chez les rongeurs induit des modifications cardio-métaboliques à l'âge adulte. Notre objectif a été de déterminer si une restriction calorique (RC) modérée pouvait restaurer ces altérations cardio-métaboliques et améliorer la récupération post-ischémique dans un modèle de cœur perfusé in vitro.Après la naissance, des souriceaux C57BL/6 ont été répartis au nombre de 9 par portée pour les groupes témoins (Normoalimentées: NA), ou au 3 par portée pour induire la SAPN. Après le sevrage, les souris ont eu un accès libre à une nourriture standard et à l’eau. A 6 mois, la moitié des souris des deux groupes a été soumise à une RC de 20% (NARC, SARC) pendant un mois, tandis que l’autre moitié a continué à se nourrir ad libitum (NAAL, SAAL). Des paramètres métaboliques et de la fonction cardiaque ont été évalués avant et après RC. A 7 mois, nous avons évalué au niveau du myocarde la sensibilité aux lésions d'ischémie-reperfusion et le niveau stress oxydant cardiaque. Les souris SAPN adultes présentent un surpoids, une accumulation de graisses, une hyperleptinemie, une intolérance au glucose, une résistance à l’insuline, ainsi qu’une diminution de la fraction d'éjection ventriculaire gauche (FEVG). Après un mois de RC, le poids corporel de SARC est revenu à la normale bien que ni la masse grasse ni la leptinémie n’aient diminué. Nous avons noté une amélioration du métabolisme au glucose et de la FEVG chez les souris SARC. Sur cœur isolé perfusé après 30 min d'ischémie globale, la taille de l'infarctus des souris SARC est la plus faible. La RC est associé à une amélioration de la fonction de la chaine respiratoire mitochondriale chez les souris SARC et à une diminution de la production des radicaux libres. Cependant, les effets bénéfiques de la RC n’ont pas été retrouvés pour la plupart des paramètres mesurés chez les souris NARC. Notre étude a confirmé le rôle de la programmation de SAPN sur la fonction cardio-métabolique. Une RC modérée, à court terme, permet de diminuer le poids corporel, mais aussi d’améliorer le métabolisme du glucose, d’améliorer la fonction cardiaque et de diminuer la susceptibilité aux lésions d'ischémie-reperfusion chez les souris SAPN.

Cancer treatment has advanced considerably in recent years, allowing a reduction in mortality. Longer life expectancy of patients has helped to highlight the delayed onset of cardiovascular toxicity induced by these chemotherapies. The pathophysiological mechanisms responsible for these cardiac dysfunctions are complex, entangled and remain partially unknown. A better understanding of the phenomena involved in these cardiotoxicities is needed to prevent their occurrence. Therefore, we have developed two different experimental approaches to understand the pathophysiological mechanisms involved in the cardiac toxicity of anthracyclines and trastuzumab.A first experimental study aimed to clarify the role of iron in heart failure induced by anthracyclines. We have demonstrated that a tissular iron overload in mice prior to doxorubicin injection does not increase the cardiotoxicity of chemotherapy. On the contrary, the involvement of anti-radical defenses following the iron load could reduce cardiac oxidative damage generated by doxorubicin. In view of these data, the role of iron chelators in cardioprotection against anthracyclines has to be questioned.Our second experimental work was to elucidate the role of overweight in the development of anthracycline and trastuzumab cardiotoxicity. Using a mouse model of moderate overweight and of increased risk of cardiometabolic induced postnatal programming, we have highlighted the role of overweight on the development of anthracycline cardiotoxicity; whereas trastuzumab cardiotoxicity did not appear to be increased by overweight. Our work also clarified the conditions in which there are cumulative cardiac alterations when doxorubicin and trastuzumab are associated., Notre deuxième travail expérimental visait à élucider le rôle de la surcharge pondérale dans le développement de la cardiotoxicité des anthracyclines et du trastuzumab. Grâce à un modèle murin de surpoids modéré et de risque cardio-métabolique accru induits par programmation post-natale, nous avons mis en évidence le rôle potentiateur d’une surcharge pondérale sur le développement de la cardiotoxicité aux anthracyclines ; alors que la cardiotoxicité du trastuzumab ne semble pas être en revanche majorée par le surpoids. Nos travaux ont également permis de préciser les conditions dans lesquelles existent des potentialisations des effets lors de l’association doxorubicine et trastuzumab.