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In the recently published manuscript entitled "GDF15 a rising modulator of immunity and a strategy in Coronavirus disease 2019 (COVID-19) in relationship with iron metabolism" and we examined the potential properties of Growth and differentiation factor 15 (GDF15) as an emerging modulator of immunity in COVID-19. We commented new aspects of the biology of GDF15 and investigated the potential value of GDF15 as a biomarker. Is GDF15 a biomarker of the inflammatory process and oxidative stress state? Recently, it was reported that 1500 clinical trials related to COVID-19 have been registered, but none have yet found an optimal strategy. In these conditions, more clinical studies are needed before any of these agents can be considered antiviral agents.

Regulated cell death (RCD) has a significant impact on development, tissue homeostasis, and the occurrence of various diseases. Among different forms of RCD, ferroptosis is considered as a type of reactive oxygen species (ROS)-dependent regulated necrosis. ROS can react with polyunsaturated fatty acids (PUFAs) of the lipid (L) membrane via the formation of a lipid radical L• and induce lipid peroxidation to form L-ROS. Ferroptosis is triggered by an imbalance between lipid hydroperoxide (LOOH) detoxification and iron-dependent L-ROS accumulation. Intracellular iron accumulation and lipid peroxidation are two central biochemical events leading to ferroptosis. Organelles, including mitochondria and lysosomes are involved in the regulation of iron metabolism and redox imbalance in ferroptosis. In this review, we will provide an overview of lipid peroxidation, as well as key components involved in the ferroptotic cascade. The main mechanism that reduces ROS is the redox ability of glutathione (GSH). GSH, a tripeptide that includes glutamic acid, cysteine, and glycine, acts as an antioxidant and is the substrate of glutathione peroxidase 4 (GPX4), which is then converted into oxidized glutathione (GSSG). Increasing the expression of GSH can inhibit ferroptosis. We highlight the role of the xc- GSH-GPX4 pathway as the main pathway to regulate ferroptosis. The system xc-, composed of subunit solute carrier family members (SLC7A11 and SLC3A2), mediates the exchange of cystine and glutamate across the plasma membrane to synthesize GSH. Accumulating evidence indicates that ferroptosis requires the autophagy machinery for its execution. Ferritinophagy is used to describe the removal of the major iron storage protein ferritin by the autophagy machinery. Nuclear receptor coactivator 4 (NCOA4) is a cytosolic autophagy receptor used to bind ferritin for subsequent degradation by ferritinophagy. During ferritinophagy, stored iron released becomes available for biosynthetic pathways. The dysfunctional ferroptotic response is implicated in a variety of pathological conditions. Ferroptosis inducers or inhibitors targeting redox- or iron metabolism-related proteins and signal transduction have been developed. The simultaneous detection of intracellular and extracellular markers may help diagnose and treat diseases related to ferroptotic damage.

Great attention is being paid to the evaluation of new markers in blood circulation for the estimation of tissue metabolism disturbance. This endogenous disturbance may contribute to the onset and progression of cardiometabolic disease. In addition to their role in energy production and metabolism, mitochondria play a main function in cellular mechanisms, including apoptosis, oxidative stress and calcium homeostasis. Mitochondria produce mitochondrial-derived peptides that mediate the transcriptional stress response by translocating into the nucleus and interacting with deoxyribonucleic acid. This class of peptides includes humanin, mitochondrial open reading frame of the 12S ribosomal ribonucleic acid type c (MOTS-c) and small humanin-like peptides. Mitochondrial-derived peptides are regulators of metabolism, exerting cytoprotective effects through antioxidative stress, anti-inflammatory responses and antiapoptosis; they are emerging biomarkers reflecting mitochondrial function, and the circulating concentration of these proteins can be used to diagnose cardiometabolic dysfunction. The aims of this review are: (1) to describe the emerging role for mitochondrial-derived peptides as biomarkers; and (2) to discuss the therapeutic application of these peptides.

Osteoporosis (OP) and cardiovascular diseases (CVD) are both important causes of mortality and morbidity in aging patients. There are common mechanisms underlying the regulation of bone remodeling and the development of smooth muscle calcification; a temporal relationship exists between osteoporosis and the imbalance of mineral metabolism in the vessels. Vascular calcification appears regulated by mechanisms that include both inductive and inhibitory processes. Multiple factors are implicated in both bone and vascular metabolism. Among these factors, the superfamily of tumor necrosis factor (TNF) receptors including osteoprotegerin (OPG) and its ligands has been established. OPG is a soluble decoy receptor for receptor activator of nuclear factor-kB ligand (RANKL) and TNF-related apoptosis-inducing ligand (TRAIL). OPG binds to RANKL and TRAIL, and inhibits the association with their receptors, which have been labeled as the receptor activator of NF-kB (RANK). Sustained release of OPG from vascular endothelial cells (ECs) has been demonstrated in response to inflammatory proteins and cytokines, suggesting that OPG/RANKL/RANK system plays a modulatory role in vascular injury and inflammation. For the development of potential therapeutic strategies targeting vascular calcification, critical consideration of the implications for bone metabolism must be taken into account to prevent potentially detrimental effects to bone metabolism.

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; Among the numerous molecules that are being studied for their potential utility as biomarkers of cardiovascular diseases, much interest has been shown in the superfamily of tumor necrosis factor (TNF) receptors. Members of this family include osteoprotegerin (OPG) and its ligands, which are receptor activators of nuclear factor κB ligand (RANKL) and TNF-related apoptosis-inducing ligand (TRAIL). These signals may be expressed and regulated, and their functions could be involved in several physiological and pathological processes. The relationship between bone regulatory proteins and vascular biology has attracted attention, and it has been suggested that OPG may mediate vascular calcification and cardiometabolic diseases. OPG is steadily released from vascular endothelial cells in response to inflammatory stimuli, suggesting that it plays a modulatory role in vascular injury, inflammation, and atherosclerosis. Vascular calcification, a hallmark of atherosclerosis, is similar to bone remodeling. It is an actively regulated mechanism that includes both inductive and inhibitory processes. There is a temporal link between the development of osteoporosis and vascular calcification, which is particularly marked in post-menopausal women and the elderly. The precise nature of the link between bone metabolism, vascular calcification and cardiovascular disease is largely unknown but increasing evidence suggests that the triad of RANK/RANKL/OPG may be important in the initiation of various diseases. An increased release of OPG is associated with increased cardiovascular risk and it is suggested that increased OPG levels resulting from vascular damage correspond to a protective mechanism. Circulating OPG levels could be used as independent biomarkers of cardiovascular disease in patients with acute or chronic cardiometabolic disease and thus an improved prognosis

Introduction Perinatal environment, such as nutritional state, is of major importance for short- and long-term cardio-metabolic status. Postnatal overfeeding (PNOF) induced in rodents by litter size reduction at birth reproduces the effects of childhood overnutrition and was shown to affect the cardiovascular function and to predispose to cardiovascular pathologies. The aim of our work was to follow the evolution of cardiac function for 28 days after in vivo myocardial infarction in control or PNOF mice. Method C57BL/6 male mice were raised in litter adjusted to 9 or 3 pups for control and PNOF group respectively. After weaning, mice of both groups had free access to standard diet and water. At 4 months, they were subjected to permanent ligation of the left anterior descending artery (LAD) to induce myocardial infarction or to sham surgery. Echocardiographic measurements were acquired at baseline and 1, 7, 15 and 28 days after surgery for cardiac function evaluation. Twenty-eight days after surgery, the left ventricle (LV) and lungs were weighed and infarct size was assessed. Results At basal state, no difference of cardiac function was observed between the 4 groups. In both control and PNOF mice subjected to LAD ligation, the fractional area change (FAC) was significantly decreased 24 h after surgery and the systolic/diastolic LV area was significantly increased 7 d after surgery, and both remained stable until 28 d. However, no differences neither in LV contractile function nor in infarct size were noticed between control and PNOF mice, except for an increased LV mass in PNOF mice. Conclusion While all groups of mice subjected to myocardial infarction developed heart failure, as demonstrated by decreased LV contractility and dilation, there were no differences between control and PNOF groups. Further measures will be done in order to assess circulating biomarkers as cardiac troponin I (cTnI), brain natriuretic peptide (BNP) and growth differentiation factor-15 (GDF-15).

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.

Introduction Nutritional disturbances during the postnatal period may be responsible for a predisposition, or “programming”, to increased cardio-metabolic risk and to a progressive alteration of left ventricular contractility in adulthood. This nutritional perinatal programming may also lead to an alteration of cellular pathways involved in cardiac protection, such as the specific RISK and SAFE pathways, highlighted during pre- and post-ischemic conditioning or those of sirtuins (SIRT), histone deacetylases involved in the regulation of essential biological process. Purpose Our aim was to evaluate in mice the impact of postnatal overfeeding (PNOF) on cardiac sensitivity to ischemia-reperfusion (I-R) injury in vivo and on the myocardial expression of genes involved in heart protection against ischemia. Methods PNOF was induced by the reduction of litter size of C57/BL6 mice immediately after birth: normally-fed group (NF) was composed of 9 male pups/mother and overfed group (OF) of 3 pups/mother. In vivo ischemia-reperfusion injury was induced by the ligation of the anterior interventricular artery for 45 minutes followed by 24 h of reperfusion in hearts from 6-months aged mice. The gene expressions of proteins of interest composing the cardioprotective pathways (RISK pathway: Akt, ERK; SAFE pathway: JAK/STAT3; Sirtuins: SIRT1) were measured by RT-qPCR in mice aged 4 and 6 months. Results PNOF induced in OF group an early and permanent increase in body weight (+23%, p Conclusion Nutritional programming through short-term PNOF induced a long-lasting decrease in the expression of signaling pathways involved in cardiac cellular protection, which could explain why 6-months old mice show increased susceptibility to myocardial I-R injury in vivo. The mechanism of these alterations needs further exploration, but could involve alterations in cardiomyocyte's balance between apoptotic and regenerative pathways, and epigenetic modifications. Acknowledgement/Funding French Fundation

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.

Introduction Nutritional disturbances during the postnatal period may be responsible for a predisposition in adulthood to increased cardio-metabolic risk and a greater myocardial vulnerability to ischemia. However, these data have mainly been obtained in young male mice, but less is known for females and for older animals. Objective Evaluate the impact of postnatal overfeeding on: – cardiac sensitivity after in vivo ischemia-reperfusion (I-R) on both sexes; – in young (4 months), adult (6 months) and mature (12 months) mice. Methods PNOF was induced by reduction of litter size of C57/BL6 mice immediately after birth: normally-fed group (NF) litters were composed of 9 pups/mother and overfed group litters (OF) of 3 pups/mother. The in vivo ischemia was induced by a 45 min ligation of the left anterior interventricular artery, followed by 24 hours of reperfusion, in hearts from 4-, 6- and 12-months aged male and female mice. The area at risk (AAR) was determined by Evans blue coloration and the infarct size by TTC staining. Results PNOF induced an early and permanent increase in body weight in OF group, for males (4 months: +13%; 6 months: +23%; 12 months: +23%) and female mice (4 months: +23%; 6 months: +27%; 12 months: +15%). A significant increase of infarct size was observed in hearts of overfed male mice aged at all ages (4 months: +37%, 6 months: +32% and 12 months: +38% of AAR), but for females, infarct size was significant increased at 4 months (+34%), but not at 6 and 12 months. However, in all female groups (NF and OF) we observed a higher post-surgical mortality and a greater data variability as compared to males. Conclusion Nutritional programming through short-term PNOF induced a higher susceptibility to myocardial I-R injury in vivo at all ages in male mice, but only in young females. The mechanism of this sexual dimorphism in our model is not well understood, but could involve distinct levels of cardioprotective pathways expression, related to hormonal status.

Introduction Growth differentiation factor 15 (GDF15) is a stress-responsive cytokine, which can be produced under certain pathological situations, mainly related to inflammatory stress, aging and disease. While clinical data suggest that GDF15 is a powerful risk factor in several high cardiovascular risks situations such as myocardial infarction and coronary artery disease, experimental studies rather consider this cytokine as a cardioprotective molecule. Objective We therefore aimed to clarify the direct cardiac effects of GDF15 during ischemia-reperfusion (I-R) injury, at concentrations found in patients with high cardiovascular risk, such as these of patients presenting with acute myocardial infarction or stroke. Method Wistar male rats (250–400 g) were anesthetized with isoflurane before their hearts were isolated and perfused in a Langendorff model. Hearts were perfused either with saline (control groups) or 2000 ng/L of GDF15 upstream the coronary bed (GDF15 groups) for 10 minutes, then subjected to either 20 or 30 minutes of global normothermic total ischemia, followed by 2 h of reperfusion. Results GDF15 induced a better recovery of most contractile parameters after 30 minutes of ischemia (higher left ventricular developed pressure, better heart rate recovery, better recovery in left ventricular contractility and relaxation, P Conclusion These preliminary results demonstrate for the first time in an ex vivo isolated heart model, that exogenous preischemic short-term administration of 2000 ng/L exerts cardioprotective properties towards ischemia reperfusion injury, improving recovery of functional parameters and decreasing cardiac cell death.

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; Background and aims: The prevalence of obesity is increasing worldwide at an alarming rate. Altered early nutrition, in particular postnatal overfeeding (PNOF), is a risk factor for impaired cardiac function in adulthood. In the understanding of the initiation or progression of heart diseases, NLRP3 inflammasome and non-coding RNAs have been proposed as key players. In this context, the aim of this study was to decipher the role of NLRP3 inflammasome and its post transcriptional control by micro-RNAs in the regulation of cardiac metabolic function induced by PNOF in mice. Methods and results: Based on a model of mice exposed to PNOF through litter size reduction, we observed increased cardiac protein expression levels of NLRP3 and ETS-1 associated with alterations in insulin signaling. Additionally, miR-193b levels were down-regulated in the adult hearts of overfed animals. In a cardiomyocyte cell line, transfection with miR-193b induced down-regulation of ETS-1 and NLRP3 and improved insulin signaling. Conclusions: These findings suggest that the miR-193b could be involved in cardiac phenotypic changes observed in adulthood induced by PNOF likely through the regulation of ETS-1 and NLRP3 expression, and through this of insulin signaling.

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.

Nutritional disturbances during the postnatal period may be responsible for a predisposition in adulthood to increased cardio-metabolic risk and a greater myocardial vulnerability to ischemia. This nutritional perinatal programming may also lead to an alteration of cellular pathways involved in cardiac protection, such as the specific RISK and SAFE pathways, highlighted during pre- and post-ischemic conditioning or those of sirtuins (SIRT), histone deacetylases involved in the regulation of essential biological process. Therefore, our goal was to evaluate the impact of postnatal overfeeding (PNOF) on myocardial expression of genes involved in heart protection against ischemia. PNOF was induced by reduction of litter size of C57/BL6 mice immediately after birth: normally-fed group (NF) was composed of 9 pups/mother and overfed group (OF) of 3 pups/mother. The gene expressions of proteins of interest composing the cardioprotective pathways (RISK pathway: Akt, ERK, SAFE pathway: JAK/STAT3, Sirtuins: SIRT1) were measured by RT-qPCR in mice aged 24 days, 4 and 6 month. PNOF induced an early and permanent increase in body weight in OF group. An early rise (at 24 days) of the gene expression of JAK, ERK1 and SIRT-1 was observed in OF group, whereas at 4 months the expression of these cardioprotective pathways was decreased, represented by a reduction in the gene expression of ERK1, Akt, JAK, STAT3 and SIRT1. To conclude, over time, in PNOF-treated mice, a decrease in the expression of signaling pathways involved in cardiac cellular protection occurs, which could explain why adult animals show increased susceptibility to cardiac ischemic lesions. The mechanism of this alteration of expression is not yet understood, but it could involve epigenetic modifications.

Introduction Nutritional disturbances during the postnatal period may be responsible for a predisposition, or “programming”, to increased cardio-metabolic risk and to a progressive alteration of left ventricular contractility in adulthood. Aim Our aim was to evaluate in mice the impact of postnatal overfeeding (PNOF) on cardiac sensitivity to ischemia-reperfusion (I-R) injury in vivo and on the myocardial expression of genes involved in heart protection against ischemia. Method PNOF was induced by the reduction of litter size of C57/BL6 mice immediately after birth: normally-fed group (NF) was composed of 9 male pups/mother and overfed group (OF) of 3 pups/mother. In vivo I-R injury was induced by the ligation of the anterior interventricular artery for 45 minutes followed by 24h of reperfusion in hearts from 6-months aged mice. The gene expressions of proteins of interest composing the cardioprotective pathways (RISK pathway: Akt, ERK; SAFE pathway: JAK/STAT3; Sirtuins: SIRT1) were measured by RT-qPCR in mice aged 4 and 6 months. Results PNOF induced in OF group an early and permanent increase in body weight (+ 23%, P Conclusion Nutritional programming through short-term PNOF induced a long-lasting decrease in the expression of signaling pathways involved in cardiac cellular protection, which could explain why 6-months old mice show increased susceptibility to myocardial I-R injury in vivo. The mechanism of these alterations needs further exploration, but could involve alterations in cardiomyocyte's balance between apoptotic and regenerative pathways.

Background New-onset atrial fibrillation (NOAF) is common after acute myocardial infarction (AMI) and associated with short and long-term mortality. We aimed to elucidate the pathophysiological mechanisms involved. Objective To investigate the relationship between circulating biomarkers (Galectin 3, GDF-15), heart rate variability parameters (pNN50, SDNN) using continuous electrographic monitoring (CEM) and the occurrence of NOAF during AMI. Methods From the RICO survey, all consecutive patients with AMI admitted in the coronary care unit (CCU) of Dijon between May 2017 to February 2018 were prospectively included. Patient with prior AF were excluded. Clinical data, plasma biomarkers and HRV parameters were analyzed to build predictive models of NOAF. Results Among the 380 analyzed patients, 47 (12%) developed AF during AMI. AF was asymptomatic in 90% of them. Median age was 67 years, 31% were women. AF patients had higher levels of Gal-3 (23.8 vs 12.5 ng/mL, P = 0.003) and GDF-15 (3238 vs 1980 pg/mL, P 1789 pg/mL (OR 3.69 (1.54–8.86), P = 0.004), STEMI (OR 3.50 (1.59–7.69), P = 0.002), Gal-3 > 16.8 ng/mL (OR 2.64 (1.30–5.37), P = 0.008) and CKD-EPI 16.8 ng/mL (OR 6.95 (2.18–22.18), P = 0.001), GDF-15 > 1789 pg/mL (OR 4.64 (1.44–14.89), P = 0.010) and STEMI (OR 4.09 (1.25–13.37), P = 0.020). Conclusion Our study highlights by a multimodal approach the involvement of inflammation, autonomic nervous system dysfunction and underlying atrial myopathy in the pathogenesis of NOAF after AMI.

We aimed to determine whether moderate diet restriction could restore cardiac, oxidative and metabolic alterations induced by postnatal overfeeding (PNOF). Litters of C57BL/6 male mice were either maintained at 9 (normal litter, NL), or reduced to 3 (small litter, SL) in order to induce PNOF. At 6 months, half of the NL and SL mice were subjected to 20% calorie-restriction (CR: NLCR, SLCR) for one month, while the other half continued to eat ad libitum (AL: NLAL, SLAL). Six-month old SL mice presented overweight, fat accumulation, hyperleptinemia, glucose intolerance, insulin resistance, increased cardiac ROS production and decreased left ventricular ejection fraction (LVEF). After CR, SL mice body weight was normalized; however, their fat mass and leptinemia were not decreased, glucose metabolism was improved and LVEF was increased. In SL mice, CR increased the cardiac mitochondrial respiratory rate and decreased cardiac ROS production. Hearts from SLCR mice showed better recovery and smaller postischemic infarct size. Intriguingly, no difference was observed between NLAL and NLCR mice for most of the parameters investigated. Short-term moderate CR not only normalized body weight in SL mice but also improved metabolic programming and reversed oxidative and cardiac dysfunction induced by PNOF.

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

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

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. The author hereby declares no conflict of interest

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 hepcidin-regulating 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±0.16g/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.

Complex interactions exist between cerebro- and cardiovascular diseases: while cardiac diseases are risk factors for cerebral ischemia, ischemic stroke may reciprocally induce heart dysfunctions. The aim of this study was to evaluate how prior cerebrovascular lesions may affect myocardial function and which signals are involved in these processes. Cerebral embolization was performed in adult Wistar male rats by the injection of microspheres into the left or right common carotid artery. Two or 24 hours after stroke or sham embolization, hearts were isolated and perfused ex vivo in the Langendorff mode. Two hours after stroke, the baseline left ventricular developed pressure of hearts from both stroke groups was diminished [106.6 ± 4.4 (left), 106.2 ± 4.7 (right) vs. 129.9 ± 2.7 (sham)] and 24 hours after surgery, the same alteration was observed [91.8 ± 3.7 (left), 104.0 ± 5.3 (right) vs. 120.9 ± 5.1 (sham)]. Echocardiographic measurements showed that left ventricular fractional shortening was altered from both stroke groups 2 hours [38.4 ± 0.4 (left), 38.1 ± 0.4 (right) vs. 41.5 ± 0.6 (sham)] and 7 days after surgery [38.2 ± 0.7 (left), 36.0 ± 0.7 (right) vs. 42.0 ± 0.5 (sham)]. Epinephrine, norepinephrine and growth differentiation factor 15 (GDF15) plasma levels were increased, 2 h after surgery, in rats from both stroke groups, as compared with sham operated. 24 h after surgery, catecholamine levels was also increased and GDF15 only for left stroke rats. Additionally, an increased expression of nitric oxide synthase-3 gene and protein was observed in hearts of stroke rats. Glutathione peroxidase-1 gene overexpression was also observed. To conclude, this study highlighted the deleterious consequences of stroke on cardiac function at different stroke time both ex vivo, in the isolated heart, and in vivo. The molecular mechanisms involved in these processes need to be further investigated in so far as they may involve the sympathetic nervous system and nitro-oxidative stress.

Postnatal overfeeding (OF) in rodents induces a permanent moderate increase in body weight, metabolic disorders and progressive alterations of cardiac function. Our aim was to determine whether moderate diet restriction could restore cardiac function in mature overfed mice. Immediately after birth, litters of C57BL/6 mice were either maintained at nine (normal-fed group, NF), or reduced to three in order to induce OF. At weaning, mice of both groups received a standard diet ad libitum (AL). At 6 months of age, half of the OF mice were assigned to a moderate 20% calorie restriction (CR, OF-CR) for one month, while NF and the other half of the OF mice continued to eat ad libitum (NF-AL, OF-AL). Cardiac function was followed using echocardiography and, at 7 months, the sensitivity to ischemia-reperfusion injury was evaluated in isolated perfused hearts. Six-month-old OF mice weighed 22.5% more than NF mice. Left ventricular fractional shortening (LVFS) and ejection fraction (LVEF) were decreased in OF mice (25.5% vs. 30.5% for LVFS; 50% vs. 58% for LVEF, P

Postnatal overfeeding (OF) in rodents induces early programming of cardio-metabolic risk: permanent moderate increase in body weight, metabolic disorders and progressive alterations of cardiac function in adulthood. Our aim was to determine whether moderate diet restriction, performed at the time where these disorders are acquired, could restore cardiac function and ameliorate post-ischemic recovery.Immediately after birth, litters of C57BL/6 mice were either maintained at 9 (normal-fed group, NF), or reduced to 3 in order to induce OF. At weaning, mice of both groups received a standard diet ad libitum (AL). At 6 months of age, half of the NF mice and OF mice were assigned to a moderate 20% calorie restriction (CR, NF-CR, OF-CR) for one month, while the other half of mice continued to eat AL (NF-AL, OF-AL). Cardiac function was followed using echocardiography and, at 7 months, the sensitivity to ischemia-reperfusion injury was evaluated in isolated perfused hearts.Six-month-old OF mice weighed 19.3% more than NF mice. Left ventricular fractional shortening (LVFS) and ejection fraction (LVEF, 51.4% vs. 57.6%, p

Background Doxorubicin (DOX), an anticancer anthracycline, is known to induce serious cardiotoxicity, which is believed to be mediated by oxidative stress and complex interactions with iron. However, the relations between iron metabolism and DOX-induced cardiotoxicity remain a matter of controversy. Methods Firstly, we used an in vivo murine model of iron overloading (IO) where male C57BL/6 mice received during 3 weeks (D0-D20) a daily dextran-iron injection (15 mg/kg/day.) and then (D21) a single dose of 6 mg/kg DOX. We evaluated cardiac function with echocardiography, myocardial gene's expression, nitro-oxidative stress levels and iron status. Secondly, the anti-proliferative activity of DOX, in combination with dextran-iron, was evaluated in vitro in cultures of cancerous cells (EMT-6) or cardiomyocytes (H9c2). Results At D30, there was a significant decrease in left-ventricular ejection fraction (LVEF) in all groups of DOX-treated mice. In IO mice treated by DOX, the LVEF fall was not majored and there was no increase in atrial natriuretic peptide mRNA cardiac gene-expression. IO alone resulted in cardiac hypertrophy and up-regulation of b-myosin heavy-chain expression. In myocardial tissue, electron spin resonance spectroscopy revealed an increase in nitro-oxidative stress in IO groups. While 1 μM of DOX induced a significant reduction of EMT-6 or H9c2 cells proliferation, dextran-iron (125-1000 μg/mL)alone did not modify cell viability and did not impair DOX cytotoxicity. Conclusions IO did not result in a significant increase in DOX cardiotoxicity neither in mice, nor in cardiomyocytes, and did not impair DOX capacity to inhibit cancerous cells proliferation.

Background: Doxorubicin (DOX), an anticancer anthracycline, is known to induce serious cardiotoxicity, which is believed to be mediated by oxidative stress and complex interactions with iron. However, the relations between iron metabolism and DOX-induced cardiotoxicity remain a matter of controversy. Methods: Firstly, we used an in vivo murine model of iron overloading (IO) where male C57BL/6 mice received during 3 weeks (D0-D20) a daily dextran-iron injection (15 mg/kg/day.) and then (D21) a single dose of 6 mg/kg DOX. We evaluated cardiac function with echocardiography, myocardial gene's expression, nitro-oxidative stress levels and iron status. Secondly, the anti-proliferative activity of DOX, in combination with dextran-iron, was evaluated in vitro in cultures of cancerous cells (EMT-6) or cardiomyocytes (H9c2). Results: At D30, there was a significant decrease in left-ventricular ejection fraction (LVEF) in all groups of DOX-treated mice. In IO mice treated by DOX, the LVEF fall was not majored and there was no increase in atrial natriuretic peptide mRNA cardiac gene-expression. IO alone resulted in cardiac hypertrophy and up-regulation of b-myosin heavy-chain expression. In myocardial tissue, electron spin resonance spectroscopy revealed an increase in nitro-oxidative stress in IO groups. While 1 μM of DOX induced a significant reduction of EMT-6 or H9c2 cells proliferation, dextran-iron (125-1000 μg/mL) alone did not modify cell viability and did not impair DOX cytotoxicity. Conclusions: IO did not result in a significant increase in DOX cardiotoxicity neither in mice, nor in cardiomyocytes, and did not impair DOX capacity to inhibit cancerous cells proliferation.

Trastuzumab (TRZ), a humanized monoclonal antibody against Human Epidermal Growth Factor Receptor 2 (HER2) oncogene, is believed to potentiate doxorubicin (DOX) cardiotoxicity, resulting in left ventricular dysfunction. Few data indicate that overweight could influence DOX-induced cardiotoxicity, and no study has already evaluated the impact of moderate overweight on the cardiotoxic effect of DOX alone or in combination with TRZ. Immediately after birth, litters of C57BL/6 mice were either maintained at 10 (normal litter, NL), or reduced to 3 (small litter, SL) in order to induce programming of ~15% overweight through postnatal overfeeding. At 4 months, in order to evaluate the potentiation of DOX cardiotoxicity by TRZ, NL and SL mice received a single intraperitoneal injection of either saline, DOX (6mg/kg), TRZ (10mg/kg) or the combination of both (DOX-TRZ). Transthoracic echocardiography was performed 24 hours before, 10 and 20 days after treatments, in order to evaluate the evolution of cardiac function. Twenty days after DOX administration, systolic dysfunction was observed only in overweight-SL group, while NL mice group kept a preserved left ventricular ejection fraction (LVEF). Moreover, in NL group, the function impairment appeared when TRZ was co-administrated. 48 hours after drug administration, gene expression of Erb-B2, the murine analog of HER2, was induced in the myocardium of DOX-treated mice, and its induction was potentiated by co-treatment with TRZ. Expression of natriuretic peptides (ANP, BNP) appeared to be potentiated in DOX-TRZ mice of both NL and SL groups, whereas the expression of b-MHC increased significantly in overweight- SL mice. In an acute model of DOX cardiotoxicity, moderately overweighed adult mice are more sensitive to cardiac systolic impairment. Moreover, our results show an early myocardial induction of TRZ-receptor after DOX and/or TRZ, and confirm the potentiating action of TRZ on DOX-induced cardiotoxicity in mice