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Aims Lymphatics are essential for cardiac health, and insufficient lymphatic expansion (lymphangiogenesis) contributes to development of heart failure (HF) after myocardial infarction. However, the regulation and impact of lymphangiogenesis in non-ischaemic cardiomyopathy following pressure-overload remains to be determined. Here, we investigated cardiac lymphangiogenesis following transversal aortic constriction (TAC) in C57Bl/6 and Balb/c mice, and in end-stage HF patients. Methods and results Cardiac function was evaluated by echocardiography, and cardiac hypertrophy, lymphatics, inflammation, oedema, and fibrosis by immunohistochemistry, flow cytometry, microgravimetry, and gene expression analysis. Treatment with neutralizing anti-VEGFR3 antibodies was applied to inhibit cardiac lymphangiogenesis in mice. We found that VEGFR3-signalling was essential to prevent cardiac lymphatic rarefaction after TAC in C57Bl/6 mice. While anti-VEGFR3-induced lymphatic rarefaction did not significantly aggravate myocardial oedema post-TAC, cardiac immune cell levels were increased, notably myeloid cells at 3 weeks and T lymphocytes at 8 weeks. Moreover, whereas inhibition of lymphangiogenesis did not aggravate interstitial fibrosis, it increased perivascular fibrosis and accelerated development of left ventricular (LV) dilation and dysfunction. In clinical HF samples, cardiac lymphatic density tended to increase, although lymphatic sizes decreased, notably in patients with dilated cardiomyopathy. Similarly, comparing C57Bl/6 and Balb/c mice, lymphatic remodelling post-TAC was linked to LV dilation rather than to hypertrophy. The striking lymphangiogenesis in Balb/c was associated with reduced cardiac levels of macrophages, B cells, and perivascular fibrosis at 8 weeks post-TAC, as compared with C57Bl/6 mice that displayed weak lymphangiogenesis. Surprisingly, however, it did not suffice to resolve myocardial oedema, nor prevent HF development. Conclusions We demonstrate for the first time that endogenous lymphangiogenesis limits TAC-induced cardiac inflammation and perivascular fibrosis, delaying HF development in C57Bl/6 but not in Balb/c mice. While the functional impact of lymphatic remodelling remains to be determined in HF patients, our findings suggest that under settings of pressure-overload poor cardiac lymphangiogenesis may accelerate HF development.

Aims Acute decompensated heart failure (ADHF), a live‐threatening complication of heart failure (HF), associates a further decrease of the already by HF‐impaired cardiac function with an increase in heart rate. We evaluated, using a new model of ADHF, whether heart rate reduction (HRR) opposes the acute decompensation‐related aggravation of cardiovascular dysfunction. Methods and results Cardiac output (echocardiography), cardiac tissue perfusion (magnetic resonance imaging), pulmonary wet weight, and in vitro coronary artery relaxation (Mulvany) were assessed 1 and 14 days after acute decompensation induced by salt‐loading (1.8 g/kg, PO) in rats with well‐established HF due to coronary ligation. HRR was induced by administration of the If current inhibitor S38844, 12 mg/kg PO twice daily for 2.5 days initiated 12 h or 6 days after salt‐loading (early or delayed treatment, respectively). After 24 h, salt‐loading resulted in acute decompensation, characterized by a reduction in cardiac output (HF: 130 ± 5 mL/min, ADHF: 105 ± 8 mL/min; P

IntroductionAlthough the physiological role of the C-terminal hydrolase domain of the soluble epoxide hydrolase (sEH-H) is well investigated, the function of its N-terminal phosphatase activity (sEH-P) remains unknown.ObjectivesThis study aimed to assess in vivo the physiological role of sEH-P.MethodsCRISPR/Cas9 was used to generate a novel knock-in (KI) rat line lacking the sEH-P activity.ResultsThe sEH-P KI rats has a decreased metabolism of lysophosphatidic acids to monoacyglycerols. KI rats grew almost normally but with less weight and fat mass gain while insulin sensitivity was increased compared to wild-type rats. This lean phenotype was more marked in males than in female KI rats and mainly due to decreased food consumption and enhanced energy expenditure. In fact, sEH-P KI rats had an increased lipolysis allowing to supply fatty acids as fuel to potentiate brown adipose thermogenesis under resting condition and upon cold exposure. The potentiation of thermogenesis was abolished when blocking PPARγ, a nuclear receptor activated by intracellular lysophosphatidic acids, but also when inhibiting simultaneously sEH-H, showing a functional interaction between the two domains. Furthermore, sEH-P KI rats fed a high-fat diet did not gain as much weight as the wild-type rats, did not have increased fat mass and did not develop insulin resistance or hepatic steatosis. In addition, sEH-P KI rats exhibited enhanced basal cardiac mitochondrial activity associated with an enhanced left ventricular contractility and were protected against cardiac ischemia-reperfusion injury.ConclusionOur study reveals that sEH-P is a key player in energy and fat metabolism and contributes together with sEH-H to the regulation of cardiometabolic homeostasis. The development of pharmacological inhibitors of sEH-P appears of crucial importance to evaluate the interest of this promising therapeutic strategy in the management of obesity and cardiac ischemic complications.

RationaleLymphatics are essential for cardiac health, and insufficient lymphatic expansion (lymphangiogenesis) contributes to development of heart failure (HF) after myocardial infarction. However, the regulation and impact of lymphatics in non-ischemic cardiomyopathy induced by pressure-overload remains to be determined.ObjectiveInvestigate cardiac lymphangiogenesis following transverse aortic constriction (TAC) in adult male or female C57Bl/6J or Balb/c mice, and in patients with end-stage HF.Methods & ResultCardiac function was evaluated by echocardiography, and cardiac hypertrophy, lymphatics, inflammation, edema, and fibrosis by immunohistochemistry, flow cytometry, microgravimetry, and gene expression analysis, respectively. Treatment with neutralizing anti-VEGFR3 antibodies was applied to inhibit cardiac lymphangiogenesis in mice.The gender- and strain-dependent mouse cardiac hypertrophic response to TAC, especially increased ventricular wall stress, led to lymphatic expansion in the heart. Our experimental findings that ventricular dilation triggered cardiac lymphangiogenesis was mirrored by observations in clinical HF samples, with increased lymphatic density found in patients with dilated cardiomyopathy. Surprisingly, the striking lymphangiogenesis observed post-TAC in Balb/c mice, linked to increased cardiac Vegfc, did not suffice to resolve myocardial edema, and animals progressed to dilated cardiomyopathy and HF. Conversely, selective inhibition of the essentially Vegfd-driven capillary lymphangiogenesis observed post-TAC in male C57Bl/6J mice did not significantly aggravate cardiac edema. However, cardiac immune cell levels were increased, notably myeloid cells at 3 weeks and T lymphocytes at 8 weeks. Moreover, while the TAC-triggered development of interstitial cardiac fibrosis was unaffected by anti-VEGFR3, inhibition of lymphangiogenesis increased perivascular fibrosis and accelerated the development of left ventricular dilation and cardiac dysfunction.ConclusionsWe demonstrate for the first time that endogenous cardiac lymphangiogenesis limits pressure-overload-induced cardiac inflammation and perivascular fibrosis, thus delaying HF development. While these findings remain to be confirmed in a larger study of HF patients, we propose that under settings of pressure-overload poor cardiac lymphangiogenesis may accelerate HF development.

International audience; Aims: In post-menopausal women, incidence of heart failure with preserved ejection fraction is higher than in men. Hormonal replacement therapies did not demonstrate benefits. We tested whether the non-steroidal mineralocorticoid receptor antagonist finerenone limits the progression of heart failure in ovariectomized (OVX) mice with metabolic disorders.Methods and results: Ovariectomy was performed in 4-month-old mice, treated or not at 7 months old for 1 month with finerenone (Fine) 1 mg/kg/day. Left ventricular (LV) cardiac and coronary endothelial functions were assessed by echocardiography, catheterization, and myography. Blood pressure was measured by plethysmography. Insulin and glucose tolerance tests were performed. Exercise capacity and spontaneous activity were measured on treadmill and in combined indirect calorimetric cages equipped with voluntary running wheel. OVX mice presented LV diastolic dysfunction without modification of ejection fraction compared with controls (CTL), whereas finerenone improved LV filling pressure (LV end-diastolic pressure, mmHg: CTL 3.48 ± 0.41, OVX 6.17 ± 0.30**, OVX + Fine 3.65 ± 0.55† , **P < 0.01 vs. CTL, † P < 0.05 vs. OVX) and compliance (LV end-diastolic pressure-volume relation, mmHg/RVU: CTL 1.65 ± 0.42, OVX 4.77 ± 0.37***, OVX + Fine 2.87 ± 0.26†† , ***P < 0.001 vs. CTL, †† P < 0.01 vs. OVX). Acetylcholine-induced endothelial-dependent relaxation of coronary arteries was impaired in ovariectomized mice and improved by finerenone (relaxation, %: CTL 86 ± 8, OVX 38 ± 3**, OVX + Fine 83 ± 7†† , **P < 0.01 vs. CTL, †† P < 0.01 vs. OVX). Finerenone improved decreased ATP production by subsarcolemmal mitochondria after ovariectomy. Weight gain, increased blood pressure, and decreased insulin and glucose tolerance in OVX mice were improved by finerenone. The exercise capacity at race was diminished in untreated OVX mice only. Spontaneous activity measurements in ovariectomized mice showed decreased horizontal movements, reduced time spent in a running wheel, and reduced VO2 and VCO2 , all parameters improved by finerenone.Conclusions: Finerenone improved cardiovascular dysfunction and exercise capacity after ovariectomy-induced LV diastolic dysfunction with preserved ejection fraction.

Epigenetic regulation of histone H3K27 methylation has recently emerged as a key step during alternative M2-like macrophage polarization, essential for cardiac repair after Myocardial Infarction (MI). We hypothesized that EZH2, responsible for H3K27 methylation, could act as an epigenetic checkpoint regulator during this process. We demonstrate for the first-time an EZH2 ectopic, and putative inactive, cytoplasmic localization of the epigenetic enzyme, during monocyte differentiation in vitro as well as in M2 macrophages in vivo during post-MI cardiac inflammation. Moreover, we show that pharmacological EZH2 inhibition, with GSK-343, resolves H3K27 methylation at the promoter of bivalent genes, thus enhancing their expression to promote human monocyte repair functions. In line with this protective effect, GSK-343 treatment accelerated cardiac inflammatory resolution preventing infarct expansion and subsequent cardiac dysfunction after MI in vivo. In conclusion, our study reveals that epigenetic modulation of cardiac-infiltrating immune cells may hold promise to limit adverse cardiac remodeling after MI.

Objective: Lymphatics play an essential pathophysiological role in promoting fluid and immune cell tissue clearance. Conversely, immune cells may influence lymphatic function and remodeling. Recently, cardiac lymphangiogenesis has been proposed as a therapeutic target to prevent heart failure after myocardial infarction (MI). We investigated the effects of gene therapy to modulate cardiac lymphangiogenesis post-MI in rodents. Second, we determined the impact of cardiac-infiltrating T cells on lymphatic remodeling in the heart. Approach and Results: Comparing adenoviral versus adeno-associated viral gene delivery in mice, we found that only sustained VEGF (vascular endothelial growth factor)-C C156S therapy, achieved by adeno-associated viral vectors, increased cardiac lymphangiogenesis, and led to reduced cardiac inflammation and dysfunction by 3 weeks post-MI. Conversely, inhibition of VEGF-C/-D signaling, through adeno-associated viral delivery of soluble VEGFR3 (vascular endothelial growth factor receptor 3), limited infarct lymphangiogenesis. Unexpectedly, this treatment improved cardiac function post-MI in both mice and rats, linked to reduced infarct thinning due to acute suppression of T-cell infiltration. Finally, using pharmacological, genetic, and antibody-mediated prevention of cardiac T-cell recruitment in mice, we discovered that both CD4 + and CD8 + T cells potently suppress, in part through interferon-γ, cardiac lymphangiogenesis post-MI. Conclusions: We show that resolution of cardiac inflammation after MI may be accelerated by therapeutic lymphangiogenesis based on adeno-associated viral gene delivery of VEGF-C C156S . Conversely, our work uncovers a major negative role of cardiac-recruited T cells on lymphatic remodeling. Our results give new insight into the interconnection between immune cells and lymphatics in orchestration of cardiac repair after injury.

Introduction: The SGLT2 inhibitor empagliflozin (EMPA) exerts beneficial cardiovascular effects in type-2 diabetes, but whether this occurs in chronic heart failure (CHF) is unknown. Thus we investigated, using a rat model whether EMPA exhibits protective effect in chronic heart failure (CHF). Methods: Rats with CHF were treated with EMPA (30 mg/kg PO for 7 days starting 83 days after coronary artery ligation or 90 days starting 7 days after coronary artery ligation) to assess effects on left ventricular (LV) function and hemodynamics (echocardiography, LV catheterization). Results: After 90 days untreated CHF rats presented LV systolic and diastolic dysfunction, illustrated by the decreases in LV end-systolic pressure (LV ESP) and in LV end-systolic pressure volume-relation (LV ESPVR) as well as the increases in LV end-diastolic pressure (LV EDP) and LV end-diastolic pressure volume-relation (LV EDPVR). Seven- and ninety-day EMPA treatment improved systolic and diastolic LV function, illustrated by the increases in LV ESP and in LV ESPVR as well as the reductions in LV EDP and in LV EDPVR. Conclusion: Short- and long-term EMPA treatment prevents LV dysfunction in rats with CHF. These results suggest that EMPA may exert protective effects in humans with CHF. Disclosure M. Soulié: None. Y. Stephan: None. L. Nicol: None. J. Henry: None. V. Richard: None. M. Pieper: Employee; Self; Boehringer Ingelheim Pharmaceuticals, Inc. P. Mulder: Research Support; Self; Bayer Healthcare Pharmaceuticals Inc., Boehringer Ingelheim Pharmaceuticals, Inc., Poxel SA. Funding Boehringer Ingelheim

Although optimal therapy for myocardial infarction includes reperfusion to restore blood flow to the ischemic region, ischemia/reperfusion (IR) also initiates an inflammatory response likely contributing to adverse left ventricular (LV) extracellular matrix (ECM) remodeling. Galectin-3 (Gal-3), a β-galactoside-binding-lectin, promotes cardiac remodeling and dysfunction. Our aim is to investigate whether Gal-3 pharmacological inhibition using modified citrus pectin (MCP) improves cardiac remodeling and functional changes associated with IR. Wistar rats were treated with MCP from 1 day before until 8 days after IR (coronary artery ligation) injury. Invasive hemodynamics revealed that both LV contractility and LV compliance were impaired in IR rats. LV compliance was improved by MCP treatment 8 days after IR. Cardiac magnetic resonance imaging showed decreased LV perfusion in IR rats, which was improved with MCP. There was no difference in LV hypertrophy in MCP-treated compared to untreated IR rats. However, MCP treatment decreased the ischemic area as well as Gal-3 expression. Gal-3 blockade paralleled lower myocardial inflammation and reduced fibrosis. These novel data showing the benefits of MCP in compliance and ECM remodeling in IR reinforces previously published data showing the therapeutic potential of Gal-3 inhibition.

Introduction Metabolic syndrome (MetS) is associated with Heart Failure with Preserved Ejection Fraction (HFpEF), characterized by diastolic dysfunction, notably affecting elderly menopausal women. To improve treatment strategies, deepened pathophysiological understanding of potential gender-specific mechanisms contributing to ventricular stiffening is needed. Objective We hypothesized that lymphatic alterations in the heart may contribute to cardiac inflammation and edema promoting cardiac fibrosis and dysfunction in a gender-specific manner. Method We investigated cardiovascular function by echocardiography, hemodynamic analyses, MRI, ex vivo coronary arteriography, and cardiac remodeling and inflammation by immunohistochemistry and flow cytometry in male and ovariectomized (ovx.) female obese Zucker (fa/fa) rats and their lean controls up to 24-weeks of age. Results Whereas body weight gain, insulin resistance, and diastolic dysfunction were similar in 24-weeks-old obese animals of both genders, only male obese rats displayed coronary endothelial dysfunction and reduced cardiac perfusion as compared to lean animals. In contrast, only female ovx. obese rats displayed significant cardiac hypertrophy as well as remodeling and rarefaction of cardiac lymphatics accompanied by persistent low-grade cardiac inflammation at both 14- and 24-weeks of age. The cardiac infiltration was characterized by increased levels of B lymphocytes, and both pro-inflammatory (M1) and non-classical (M2-like) monocytes, as well as increased frequency of M1 type macrophages. The monocytosis was linked to increased cardiac expression of CCL2. Studies are ongoing to determine chemokine expression changes in coronary endothelial cells. Conclusion In conclusion, our data show that gender-specific mechanisms involving cardiac lymphatics may underlie development of MetS-related diastolic dysfunction, suggesting novel therapeutic targets to prevent HFpEF in patients with MetS.

Background Exacerbation of heart failure (HF), better known as acute decompensated HF, is characterized by dyspnea, edema and fatigue, which is associated with a high morbi-mortality. O-linked β-N-acetylglucosamine (O-GlcNAc) is a key regulator of the cellular stress response and increased O-GlcNAc levels exerts protective effects in models of acute vascular injury and ischemia-reperfusion injury. However, whether increasing O-GlcNAc exerts similar protective effects in acute decompensation of HF is unknown. Objective We evaluated the cardiac effects of increasing O-GlcNAc levels by inhibiting O-GlcNAcase with Thiamet G (TG) in a rat model of acute decompensated HF. Methods Three months after coronary artery ligation resulting in established HF, rats received 2.5 ml water (control) or 1.8 g/kg NaCl (dissolved in 2.5 ml water) provoking acute decompensation. Left ventricular (LV) fractional shortening and cardiac output (echography) as well as LV tissue perfusion (MRI) were assessed 1 and 14 days after NaCl-loading, and TG was administered 12 hours after NaCl (25 mg/kg IP). Results NaCl provoked acute decompensation in rats with HF. Indeed, 1 day after NaCl, the HF-related impairments of LV fractional shortening, cardiac output and myocardial tissue perfusion were aggravated. Fourteen days after NaCl, cardiac output partially recovered, but fractional shortening and myocardial perfusion remained impaired. As soon as 12 hours after administration, TG improved fractional shortening, cardiac output and tended to increase myocardial perfusion. Moreover, 14 days after TG, cardiac output and myocardial perfusion were still improved. Conclusions These data show that in an experimental model salt-induced acute decompensation of HF, a curative treatment with TG improves both cardiac output as well as myocardial perfusion. The cellular mechanisms, i.e. post-translational protein O-GlcNAcylation, implicated in the effects of TG, are currently under investigation.

Heart failure (HF) following myocardial infarction (MI) is characterized by progressive alterations of left ventricular (LV) structure and function, named LV remodelling. Although several risk factors such as infarct size have been identified, HF remains difficult to predict in clinical practice. Recently, using phosphoproteomic technology, we found that serine(208)-phosphorylated troponin T (P-Ser(208)-TnT) decreases in LV of HF rats. Our aim was to determine the performance of P-Ser(208)-TnT as plasma biomarker of HF compared to conventional cardiac biomarkers such as B-type natriuretic peptide (BNP), cardiac troponin I (cTnI), C-reactive protein (CRP) or tissue inhibitor of metalloproteinase I (TIMP-1) measured by x-MAP technology, as well as its capacity to reflect a pharmacological improvement of HF. We observed a significant increase of BNP, TnT and cTnI levels and a significant decrease of P-Ser(208)-TnT and TIMP-1 in the plasma of 2-month-MI rats compared with control rats with no modulation of CRP level. Circulating levels of P-Ser(208)-TnT were shown to be associated with most of the echocardiographic and haemodynamic parameters of cardiac function. We verified that the decrease of P-Ser(208)-TnT was not because of an excess of phosphatase activity in plasma of HF rats. Two-month-MI rats treated with the heart rate reducing agent ivabradine had improved LV function and increased plasma levels of P-Ser(208)-TnT. Thus, circulating phosphorylated troponin T is a highly sensitive biological indicator of cardiac dysfunction and has the potentiality of a new biomarker of HF post-MI, and of a surrogate marker for the efficacy of a successful treatment of HF.

Background Exacerbation of chronic heart failure (HF), better known as acute decompensated HF, is characterized by a rapid further decrease of an already HF-related impaired cardiac function, which despite medical treatment only partially recovers. However, no representative experimental model of acute decompensated HF exists, limiting pre-clinical evaluation of emerging therapies and mechanistic understanding. Objective We evaluated the time course of cardiac dysfunction of acute decompensation in rats with chronic HF. Methods Three months after coronary artery ligation resulting in established chronic HF, rats received 2.5 ml tap water (control) or 1.8 g/kg NaCl (dissolved in 2.5 ml tap water) provoking acute decompensation. Cardiac output (echocardiography), LV tissue perfusion (MRI) and coronary endothelial function (Mulvany) were assessed 1 and 13 days after NaCl loading. Results One day after NaCl loading, the HF-related impairment of cardiac output was already aggravated (sham: 145±2 ml/min; HF: 125±3 ml/min; p Conclusion Our data show that in rats with HF, NaCl loading provokes immediately a further aggravation of cardiac and coronary dysfunctions. Moreover, the aggravation is sustained and only partially recovery over-time. This rat model allows the evaluation cardiac systolic and diastolic function of emerging therapies for humans with acute decompensation of chronic HF. The author hereby declares no conflict of interest

Background— Chronic heart failure (CHF) induces endothelial dysfunction in part because of decreased nitric oxide (NO · ) production, but the direct link between endothelial dysfunction and aggravation of CHF is not directly established. We previously reported that increased NO production via inhibition of protein tyrosine phosphatase 1B (PTP1B) is associated with reduced cardiac dysfunction in CHF. Investigation of the role of endothelial PTP1B in these effects may provide direct evidence of the link between endothelial dysfunction and CHF. Methods and Results— Endothelial deletion of PTP1B was obtained by crossing LoxP-PTP1B with Tie2-Cre mice. CHF was assessed 4 months after myocardial infarction. In some experiments, to exclude gene extinction in hematopoietic cells, Tie2-Cre/LoxP-PTP1B mice were lethally irradiated and reconstituted with bone marrow from wild-type mice, to obtain mouse with endothelial-specific deletion of PTP1B. Vascular function evaluated ex vivo in mesenteric arteries showed that in wild-type mice, CHF markedly impaired NO-dependent flow-mediated dilatation. CHF-induced endothelial dysfunction was less marked in endoPTP1B −/− mice, suggesting restored NO production. Echocardiographic, hemodynamic, and histological evaluations demonstrated that the selectively improved endothelial function was associated with reduced left ventricular dysfunction and remodeling, as well as increased survival, in the absence of signs of stimulated angiogenesis or increased cardiac perfusion. Conclusions— Prevention of endothelial dysfunction, by endothelial PTP1B deficiency, is sufficient to reduce cardiac dysfunction post myocardial infarction. Our results provide for the first time a direct demonstration that endothelial protection per se reduces CHF and further suggest a causal role for endothelial dysfunction in CHF development.

Objectives The study addresses the hypothesis that endothelial dysfunction in experimental arterial hypertension can be related to an alteration in epoxyeicosatrienoic acids (EETs) pathway and can be prevented by the inhibition of EETs degradation by soluble epoxide hydrolase (sEH). Methods and results Arterial hypertension was induced in FVB/N mice by renal artery stenosis ('two-kidney-one-clip', 2K1C). Seven weeks after surgery, increased aortic pressures (Millar tonometer; Millar Instruments, Houston, Texas, USA) and cardiac hypertrophy (echocardiography) were present in 2K1C mice as compared with control mice. Left coronary artery endothelium-dependent relaxations to acetylcholine were decreased in 2K1C mice without modification in the relaxing responses to NS309 and NS1619, the openers of calcium-activated potassium channels mediating the hyperpolarizing effect of EETs. The inhibitors of the EET-synthesizing enzymes cytochrome P450 epoxygenases, fluconazole and N-methylsulfonyl-6-(2-propargyloxyphenyl)-hexanamide (MSPPOH), reduced the coronary relaxations to acetylcholine in control but not in 2K1C mice. The sEH expression was increased in 2K1C mice. The sEH inhibitor 12-(3-adamantan-1-yl-ureido)dodecanoic acid administered for 2 weeks starting 5 weeks after surgery in 2K1C mice (25 mg/l in drinking water) reduced aortic pressures and cardiac hypertrophy, improved the coronary relaxations to acetylcholine and restored the inhibitory effect of fluconazole and MSPPOH on acetylcholine-induced relaxations, without modifying the relaxations to NS309 and NS1619. Conclusion These results demonstrate that a reduced EET-mediated relaxations related to an increased degradation by sEH contributes to coronary endothelial dysfunction in 2K1C hypertensive mice. Inhibiting sEH prevents endothelial dysfunction by restoring EET-mediated relaxations and thus, could represent a promising pharmacological intervention to limit cardiovascular morbidity and mortality in arterial hypertension.

Background Whether mycophenolate mofetil (MMF) can prevent the vascular endothelial dysfunction related to the administration of calcineurin inhibitor after organ transplantation remains unknown. Methods Four groups of Lewis rats, grafted with Brown Norway donor aortic abdominal allograft, received since the transplantation cyclosporine A (CsA, 5 mg/kg/day), MMF (40 mg/kg/day), CsA+MMF, or vehicle (control) for 2 weeks. Results Fifteen days after transplantation, all immunosuppressive regimens were equally effective in preventing graft rejection. When compared with control rats, the endothelium-dependent relaxation to acetylcholine was reduced, and the vasoconstrictor effect of phenylephrine was enhanced in thoracic aorta of CsA-treated rats but not in rats treated with MMF alone or combined with CsA without difference for the endothelium-independent relaxation to sodium nitroprusside. The relaxation to acetylcholine was abolished by the nitric oxide (NO)-synthase inhibitor N-nitro-l-arginine in all groups. Moreover, the endothelial NO-synthase protein dimer:monomer ratio in the thoracic aorta and the plasma nitrites concentrations, an indicator of NO availability, were decreased in CsA-treated rats but not in rats treated with MMF alone or combined with CsA. Conclusions This study demonstrates that MMF prevents systemic endothelial dysfunction and the enhanced sensitivity to vasoconstrictors related to CsA administration in a rat allograft aortic model through an increase in NO availability related to the improvement of endothelial NO-synthase functionality.

Our objective was to evaluate immediate acute changes in myocardial function during the autonomic storm of brain death (BD). Wistar rats were divided into four groups (n = 8/group): controls without any treatment, β-blocker (Esmolol®, 10 mg/kg), calcium channel blocker (Diltiazem®, 10 mg/kg), or alpha-blocker (Prazosin®, 0.3 mg/kg). Treatments were administered intravenously 5 min before BD induction. Echocardiography (ATL-5000, 8 MHz) was performed to measure left ventricular (LV) dimensions and fractional shortening at baseline, during BD induction and 5 min and 15 min after BD. In controls, BD was immediately associated with an increase in wall thickness and a decrease in LV cavity dimension. This myocardial wall hypertrophy was completely prevented by β-blockers, but not with calcium- and alpha-blockers. Extensive myocardial interstitial edema was found in all groups, except in the β-blocker group. Myocardial wall hypertrophy was also prevented during a longer follow-up of 180 min after BD in β-blocker group as opposed to controls. In conclusion, BD is associated with an immediate and severe myocardial damage related to an important interstitial edema which is prevented by β-blockers.

Introduction We previously demonstrated that the inhibition of soluble epoxide hydrolase, which metabolizes vasodilator and anti-inflammatory eicosanoids, displays protective effects against left ventricular dysfunction in a rat model of ischemic heart failure. However, its remains to be investigated the impact of sEH inhibition on pulmonary vascular and right heart dysfunctions that are known to aggravate the prognostic of left heart diseases. Objective To study the impact of sEH inhibition on pulmonary vascular and right heart dysfunctions in left heart diseases. Method Ischemic heart failure was induced by definitive coronary artery ligation in Sprague-Dawley rats. Pulmonary vascular function (Mulvany), edema (lung wet weight – dry weight), right ventricular function (cardiac MRI) and remodelling (right ventricular weight and fibrosis) were assessed in sham-operated rats and rats with HF treated or not by the sEH inhibitor TPPU (5 mg/L in drinking water) during 12 weeks. Results Rats with heart failure displayed a marked alteration in pulmonary smooth muscle constriction to norepinephrin and in pulmonary endothelial-dependent relaxation to acetylcholine, pulmonary edema, and an increase in right ventricular weight but not in fibrosis compared to sham-operated rats. TPPU did not modify these parameters in sham-operated rats but improved pulmonary relaxation to acetylcholine in rats with heart failure and reduced pulmonary edema without affecting right ventricular weight and fibrosis. Data obtained by cardiac MRI are currently being analysed. Conclusion These preliminary results demonstrate that sEH inhibition improves pulmonary endothelial function in rats with heart failure, which could contribute to the beneficial effects of this new pharmacological class in the context of left heart diseases. This work was co-supported by European Union and Region Normandie. Europe gets involved in Normandie with European Regional Development Fund (ERDF).

Systemic sclerosis (SSc) is a systemic inflammatory disorder, resulting in severe vascular dysfunction. The endothelin (ET) system has vasoconstrictor and profibrotic properties and has been shown to be activated in SSc. ET antagonists are currently used in SSc-related pulmonary arterial hypertension, but the endothelial impact of ET antagonists remains less known in SSc. We thus assessed the effects of the dual ET(A)-ET(B) antagonist, bosentan, on endothelial dysfunction in a murine model of SSc, the heterozygous tight-skin mice 1 (TSK1(+)). Six-week-old TSK1(+) were either untreated or treated for 6 weeks with bosentan (100 mg/kg/day), and compared with controls. Endothelial function was evaluated in isolated mesenteric resistance arteries, using a small vessel myograph. TSK1(+) displayed endothelial dysfunction, as shown by a decreased response of mesenteric arteries to acetylcholine, especially in the presence of L-nitro-arginine methyl ester (L-NAME), corresponding to NO-independent, prostaglandin-mediated relaxation. The NO-independent relaxation was partially restored in bosentan-treated TSK1(+), and this was abolished by a cyclo-oxygenase inhibitor. Therefore, the murine model of SSc, TSK1(+) exhibits severe endothelial dysfunction of peripheral resistance arteries. The ET antagonist bosentan prevents endothelial alterations, suggesting a major role of ET in the adverse vascular effects of SSc.

BACKGROUND Fucoidan, a new low molecular weight sulfated polysaccharide (LMWF), has previously been shown to mobilize bone marrow-derived progenitors cells via stimulation of stromal derived factor (SDF)-1 release. Mobilized progenitor cells have been suggested to repair intimal lesions after immune-mediated endothelial injury and thus prevent intimal proliferation. The aim of this study was to evaluate the effect of LMWF treatment in a rat aortic allograft model of transplant arteriosclerosis (TA). METHODS Aortic grafts were performed in Brown Norway (BN, donor) and Lewis (Lew, recipient) rats. The recipient rats were treated with LMWF (5 mg/kg/day) and sacrificed at 30 days. To determine the role of SDF-1 in mediating the effects of LMWF, a specific inhibitor of the SDF-1 receptor CXCR4, AMD 3100 (20 microg/kg/day), was used. The grafted segments were evaluated by morphometric (histochemical) analyses. RESULTS Untreated aortic allografts exhibited severe intimal proliferation, indicative of TA. In contrast, LMWF treatment significantly prevented allograft intimal proliferation as compared with controls (5.7+/-3 vs. 66.2+/-6 microm, P

ObjectiveThe humoral pathway is suggested as playing a key role in transplant arteriosclerosis. The humoral immunity is demonstrated in the present study to induce direct vascular lesion.MethodsTen abdominal aortic grafts were performed on 4 groups of rats: Brown Norway (BN) isografts, BN to Lewis (LEW) allografts, and two BN to nude (RNU) grafted groups with and without any humoral transfer. The humoral sera were obtained by skin grafts performed in BN to LEW combination. Lewis anti-BN alloantisera was transferred in nude recipients through intraperitoneal injections. The aortic wall was histologically studied with morphometric analysis on the 21st day. Two additional BN to RNU aortic graft groups were evaluated by immunohistochemistry on days 3 (10 rats) and 10 (10 rats).ResultsIn the absence of the humoral transfer, the BN aortic wall implanted in RNU remained intact. The humoral transfer induced a marked intimal proliferation (63 ± 4 vs 4 ± 1.1 μm; P < .001) and an adventitial cell infiltration (5.1 ± 0.7 vs 2.8 ± 0.6 × 103 c/mm2, P < .001). The medial thickness and the medial cell density were not modified. On day 3, the remaining endothelial cells were covered by immunoglobulin G deposits. On day 10 the endothelial cells disappeared completely and intimal proliferation occurred. In an additional cardiac graft group, transplant coronary arteriopathy was evidenced in 7 of the 9 nude recipients that had undergone the humoral transfer.ConclusionThe transplant arterial occlusive lesion is demonstrated here (1) to be induced by humoral antidonor immunity and (2) to be linked to an adventitial or perivascular inflammation.

International audience; C hronic heart failure (HF) after myocardial infarction (MI) is steadily increasing worldwide and remains a major cause of death. Mineralocorticoid receptor (MR) antagonists (MRAs) improve survival in patients with HF as illustrated by spironolactone in the RALES (Randomized Aldactone Evaluation Study) 1 trial and by eplerenone in the EPHESUS (Eplerenone Post-Acute Myocardial Infarction Heart Failure Efficacy and Survival Study) trial, 2 which only included patients with post-MI. Recently, the EMPHASIS (Eplerenone in Mild Patients Hospitalization and Survival Study in Heart Failure) study even showed that eplerenone is effective in slowing down the progression of mild-to-moderate HF. 3 However, MRAs are associated with side effects, such as hyperkalemia or gynecomastia; the latter is caused by the antiandrogenic properties of their steroidal structure. These adverse effects are responsible for the underuse of MRAs. 4 Understanding of the cell-specific contribution of MR to HF and of the effects of MRA on various cell subtypes will be useful for the future development of tissue-selective MR targeting approaches that would improve the benefit/risk ratio. 5 A crucial role of cardiomyocyte MR has been demonstrated in mice with cardiomyocyte-specific MR deletion, which allows improving left ventricular (LV) function after either MI 6 or pressure overload induced by transverse aortic constriction. 7 The deletion of MR specifically in fibroblasts does not affect cardiac failure after aortic constriction. 7 The role of vascular MR has been underlined recently: the MR expressed in vas-cular smooth muscle cells (VSMCs) is involved in age-related Abstract-Mineralocorticoid receptor (MR) antagonists slow down the progression of heart failure after myocardial infarction (MI), but the cell-specific role of MR in these benefits is unclear. In this study, the role of MR expressed in vascular smooth muscle cells (VSMCs) was investigated. Two months after coronary artery ligation causing MI, mice with VSMC-specific MR deletion (MI-MR SMKO) and mice treated with the MR antagonist finerenone (MI-fine) had improved left ventricular compliance and elastance when compared with infarcted control mice (MI-CTL), as well as reduced interstitial fibrosis. Importantly, the coronary reserve assessed by magnetic resonance imaging was preserved (difference in myocardial perfusion before and after induction of vasodilatation, mL mg −1 min −1 : MI-CTL: 1.1±0.5, nonsignificant; MI-MR SMKO : 4.6±1.6 [P

Background: Enhanced heart rate observed in metabolic syndrome (MS) contributes to the deterioration of left ventricular (LV) function via impaired LV filling and relaxation, increased myocardial O2 consumption, and reduced coronary perfusion. However, whether heart rate reduction (HRR) opposes LV dysfunction observed in MS is unknown. Methods: We assessed in Zucker fa/fa rats, a rat model of MS, the cardiovascular effects of HRR induced by the If current inhibitor S38844 (3 mg·kg−1·d−1). Results: Delayed short-term (4 days) and long-term (90 days) HRR induced by S38844 reduced LV end-diastolic pressure and LV end-diastolic pressure–volume relation, increased myocardial tissue perfusion, decreased myocardial oxidized glutathione levels, and preserved cardiac output, without modifying LV end-systolic pressure and LV end-systolic pressure–volume relation, although only long-term S38844 opposed LV collagen accumulation. Long-term S38844 improved flow-induced endothelium-dependent dilatation of mesenteric arteries, while metabolic parameters, such as plasma glucose levels, and Hb1c, were never modified. Conclusions: In rats with MS, HRR induced by the If inhibitor S38844 improved LV diastolic function and endothelium-dependent vascular dilatation, independent from modifications in metabolic status. Moreover, this improvement in cardiac function involves not only immediate effects such as improved myocardial perfusion and reduced oxidative stress but also long-term effects such as modifications in the myocardial structure.

Background— The lymphatic system regulates interstitial tissue fluid balance, and lymphatic malfunction causes edema. The heart has an extensive lymphatic network displaying a dynamic range of lymph flow in physiology. Myocardial edema occurs in many cardiovascular diseases, eg, myocardial infarction (MI) and chronic heart failure, suggesting that cardiac lymphatic transport may be insufficient in pathology. Here, we investigate in rats the impact of MI and subsequent chronic heart failure on the cardiac lymphatic network. Further, we evaluate for the first time the functional effects of selective therapeutic stimulation of cardiac lymphangiogenesis post-MI. Methods and Results— We investigated cardiac lymphatic structure and function in rats with MI induced by either temporary occlusion (n=160) or permanent ligation (n=100) of the left coronary artery. Although MI induced robust, intramyocardial capillary lymphangiogenesis, adverse remodeling of epicardial precollector and collector lymphatics occurred, leading to reduced cardiac lymphatic transport capacity. Consequently, myocardial edema persisted for several months post-MI, extending from the infarct to noninfarcted myocardium. Intramyocardial-targeted delivery of the vascular endothelial growth factor receptor 3–selective designer protein VEGF-C C152S , using albumin-alginate microparticles, accelerated cardiac lymphangiogenesis in a dose-dependent manner and limited precollector remodeling post-MI. As a result, myocardial fluid balance was improved, and cardiac inflammation, fibrosis, and dysfunction were attenuated. Conclusions— We show that, despite the endogenous cardiac lymphangiogenic response post-MI, the remodeling and dysfunction of collecting ducts contribute to the development of chronic myocardial edema and inflammation-aggravating cardiac fibrosis and dysfunction. Moreover, our data reveal that therapeutic lymphangiogenesis may be a promising new approach for the treatment of cardiovascular diseases.

International audience; Therapeutic angiogenesis has yet to fulfill its promise for the clinical treatment of ischemic diseases. Given the impact of macrophages during pathophysiological angiogenesis, we asked whether macrophages may similarly modulate vascular responses to targeted angiogenic therapies. Mouse matrigel plug assay and rat myocardial infarction (MI) model were used to assess angiogenic therapy with either VEGF-A or FGF-2 with HGF (F+H) delivered locally via albumin-alginate microcapsules. The infiltration of classical M1-type and alternative M2-like macrophages was assessed. Clodronate was used to prevent macrophage recruitment, and the VEGFR2 blocking antibody, DC101, to prevent VEGF-A signaling. At 3 weeks after matrigel implantation, the combination therapy (F+H) led to increased total, and specifically M2-like, macrophage infiltration versus control and VEGF-A plugs, correlating with the angiogenic response. In contrast, VEGF-A preferential recruited M1-type macrophages. In agreement with a direct role of M2-like macrophages in F+H-induced vessel growth, clodronate radically decreased angiogenesis. Further, DC101 reduced F+H-induced angiogenesis, without altering macrophage infiltration, revealing macrophage-derived VEGF-A as a crucial determinant of tissue responsiveness. Similarly, increased cardiac M2-like macrophage infiltration was found following F+H therapy post-MI, with strong correlation between macrophage levels and angiogenic and arteriogenic responses. In conclusion, M2-like macrophages play a decisive role, linked to VEGF-A production, in regulation of tissue responsiveness to angiogenic therapies including the combination of F+H. Our data suggest that future attempts at therapeutic revascularization in ischemic patients might benefit from coupling targeted growth factor delivery with either direct or indirect approaches to recruit pro-angiogenic macrophages in order to maximize therapeutic angiogenic/arteriogenic responses.

Selenoproteins are mediators of the essential micronutrient selenium, but their biological effects are not yet fully understood. Selenoprotein T (SelT), a recently discovered thioredoxin-like selenoprotein, is abundant during embryonic development but declines during adulthood. Bioinformatical studies suggested that SelT had antioxidant properties but its role has not already been established in vivo . Preliminary data obtained in our laboratory showed that myocardial infarction increases SelT protein expression in mouse heart as revealed by Western blotting analysis, suggesting that SelT may play a yet unrevealed role in the cardiovascular system. Thus, we sought to investigate SelT’s role in myocardial infarction. Male Wistar rats were subjected to either cardiac ischaemia (45 min) followed by reperfusion (I/R) or sham surgery. Five days before I/R, SelT (15 μg/kg/day, IP) or saline infusion was started by osmotic minipump. Eight days after myocardial infarction, left ventricular (LV) function was assessed by echocardiography, MRI and LV hemodynamics (pressurevolume loops). I/R resulted in a significant increase of LV systolic and diastolic diameters, in a decrease of cardiac output and fractional shortening. This was associated with a decrease of LV end-systolic pressure and an increase of LV end-diastolic pressure. SelT restored cardiac output and LV fractional shortening (+26% and +52%, respectively in comparison with I/R) associated with an improvement of LV end-diastolic/end-systolic pressures and LV tissue perfusion (–61%, +54% and +30%, respectively in comparison with I/R). Furthermore, SelT did not modify LV infarct size. SelT, administered before I/R, preserves LV function and perfusion in a rat model of myocardial infarction and might be a new therapeutic target in the treatment of this disease.

Mortality remains high in chronic heart failure (CHF) because under ACE inhibitor treatment other neurohumoral systems remain/become (de)activated, such as the endothelin and atrial natriuretic peptide pathways. Dual endothelin-converting enzyme-neutral endopeptidase (ECE-NEP) inhibition exerts beneficial effects in experimental CHF, but whether "triple" ACE-ECE-NEP inhibition is superior to ACE or ECE-NEP inhibition is unknown. We compared, in rats with CHF, ACE-ECE-NEP to ACE or ECE-NEP inhibition in terms of left ventricular (LV) hemodynamics and remodeling. Benazepril (2 mg/kg/d) or the ECE-NEP inhibitor CGS26303 (10 mg/kg/d) were administered alone or in combination (subcutaneously for 28 days starting 7 days after coronary ligation). ACE-ECE-NEP inhibition reduced blood pressure more markedly than ACE or ECE-NEP inhibition. All treatments increased cardiac output to the same extent, but ACE-ECE-NEP inhibition reduced LV diameter and LV end-diastolic pressure more markedly than ACE or ECE-NEP inhibition. The reduction of LV weight and collagen accumulation in the "viable" myocardium was most pronounced after ACE-ECE-NEP inhibition. These results, obtained in experimental CHF, illustrate a further improvement of LV hemodynamics and structure after ACE-ECE-NEP inhibition compared with either ACE or ECE-NEP inhibition, but whether this is associated with a further improvement of exercise tolerance and/or survival remains to be determined.

Objective : We assessed whether α1-adrenoreceptor (α1-AR) stimulation contributes to activation of myocardial NADPH oxidase in a rat model of cocaine-induced cardiac dysfunction. Methods and results : After 7 days of cocaine injection (2 × 7.5 mg/kg/day, i.p., Coc), NADPH activity assessed by chemiluminescence increases as well as phosphorylation of p47phox, one of the cytosolic components of NADPH oxidase. The α1-AR antagonist prazosin (Prz), administered 1 h before each cocaine injection (2 × 1 mg/kg/day, i.p., Coc+Prz), prevents these effects. Moreover, Prz pretreatment reduces left ventricular/body weight (LV/BW) ratio and partially prevents the cocaine-induced alterations in fractional shortening and cardiac index assessed by echocardiography. In order to confirm the involvement of α1-AR stimulation in NADPH oxidase up-regulation in vivo, we used phenylephrine (Phe) administration with the same protocol of injections as that used with cocaine (2 × 5 μg/kg/day, i.p.). After Phe administration, as expected, NADPH oxidase activity increases as well as phosphorylation of p47phox. These effects occur in the absence of sustained hemodynamic changes. Conclusion : This study demonstrates the involvement of the α1-AR in NADPH oxidase activation and in cocaine - induced LV dysfunction. We suggest that α1-AR stimulation, at least in part via NADPH oxidase induction, plays a critical role in the events leading to the cardiomyopathy observed after cocaine abuse.

Aims Oxidative stress, i.e. imbalance between reactive oxygen species (ROS) and antioxidant defences, contributes to the progression of chronic heart failure (CHF). Acute inhibition of xanthine oxidase (XO), which produces ROS, improves mechanical efficiency of the failing heart, but whether long-term XO inhibition exerts beneficial effects in CHF is unknown. Methods and results In rats with established CHF induced by left coronary ligation, we assessed the effects of a 5-day and a 10-week treatment with the XO inhibitor allopurinol (50 mg kg−1 day−1) on haemodynamics and left ventricular (LV) function and structure. Both acute and chronic allopurinol treatment increase cardiac output without modification of arterial pressure, but only chronic allopurinol treatment reduces LV end-diastolic pressure and LV relaxation constant. Chronic allopurinol treatment decreases both LV systolic and diastolic diameters, but acute allopurinol treatment only decreases LV systolic diameter. Moreover, chronic allopurinol decreases LV weight and collagen density. Despite XO inhibition after acute and chronic allopurinol treatment, as both treatments reduce uric acid plasma levels, only acute allopurinol treatment reduces LV ROS determined using electron spin resonance spectroscopy. However, the CHF-enhanced myocardial thiobarbituric acid reactive substances levels were never modified. Conclusion In experimental CHF, long-term allopurinol treatment, initiated in a pathological state of overt CHF, improves LV haemodynamics and function and prevents LV remodelling. These long-term effects are, at least partially, caused by a transient reduction of myocardial ROS shortly after initiation of allopurinol treatment, but whether other mechanism(s), independent of myocardial redox ‘status’, such as reduced inflammation, are implicated remains to be confirmed.

Background— In patients with congestive heart failure (CHF) receiving ACE inhibitors, acute administration of selective endothelin (ET) antagonists additionally improves systemic and cardiac hemodynamics. We investigated, in a rat model of CHF, whether such acute synergistic effects are sustained and accompanied, in the long term, by an additional limitation of left ventricular remodeling or an increase in survival. Methods and Results— Rats were subjected to coronary artery ligation and treated for 3 or 9 months with vehicle or with the ACE inhibitor trandolapril (Tr) (0.3 mg/kg −1 per day −1 ), the ET A antagonist LU 135252 (LU, 30 mg/kg −1 per day −1 ), or their combination starting 7 days after ligation. After 3 months, the combination decreased LV systolic- and end-diastolic pressures (−32% and −80%, respectively) more markedly than Tr (−21% and −61%, respectively) or LU alone (−14% and −48%, respectively). Echocardiographic studies revealed that all treatments limited LV dilatation and increased LV fractional shortening and cardiac index. All treatments equally reduced left ventricular collagen density, whereas only Tr or the combination reduced LV weight. Finally, although LU did not modify long-term survival, Tr and the combination of Tr with LU induced a similar improvement of survival. Conclusions— In this rat model, long-term combined administration of an ET A antagonist and an ACE inhibitor induces additional effects in terms of systemic and cardiac hemodynamics; however, this is not associated with an additional increase in long-term survival.

Background — The myocardial velocity gradient (MVG) is a recent index of regional myocardial function derived from endocardial and epicardial velocities obtained by tissue Doppler imaging (TDI). This index might be useful for discriminating between physiological and pathological left ventricular hypertrophy (LVH) and for documenting the early transition from compensated LVH to heart failure. We sought to compare MVG measured across the left ventricular posterior wall between normal rats and rats with physiological (exercise) and pathological (pressure-overload) LVH. Methods and Results — Wistar rats were assigned to one of the following groups: sedentary, exercise (swimming), and 2-month or 9-month abdominal aortic banding. Compared with sedentary rats, exercise and 2-month banding led to similar and significant LVH. After 2-month banding, conventional parameters of systolic function (left ventricular fractional shortening and dP/dt max ) were not affected. However, systolic and diastolic MVG were similar in exercise and sedentary rats but were significantly lower in rats with aortic banding. Aortic debanding after 2 months led to a full recovery of MVG, whereas MVG remained decreased when debanding was performed after 9 months. Conclusions — Myocardial contraction and relaxation assessed by TDI were impaired in pressure-overload LVH but not in exercise LVH. Therefore, TDI is more sensitive than conventional echocardiography for assessing myocardial dysfunction in pressure-overload LVH and for predicting early recovery in myocardial function after loading conditions normalization.

Not applicable

Objective— Cardiovascular dysfunction is a major cause of mortality in patients with sepsis. Recently, we showed that gene deletion or pharmacological inhibition of protein tyrosine phosphatase 1B (PTP1B) improves endothelial dysfunction and reduces the severity of experimental heart failure. However, the cardiovascular effect of PTP1B invalidation in sepsis is unknown. Thus, we explored the beneficial therapeutic effect of PTP1B gene deletion on lipopolysaccharide (LPS)-induced cardiovascular dysfunction, inflammation, and mortality. Approach and Results— PTP1B −/− or wild-type mice received LPS (15 mg/kg) or vehicle followed by subcutaneous fluid resuscitation (saline, 30 mL/kg). α-1–dependent constriction and endothelium-dependent dilatation, assessed on isolated perfused mesenteric arteries, were impaired 8 hours after LPS and significantly improved in PTP1B −/− mice. This was associated with reduced vascular expression of interleukin1-β, intercellular adhesion molecule-1, vascular cell adhesion molecule-1, cyclooxygenase-2, and inducible nitric oxide synthase mRNA. PTP1B gene deletion also limited LPS-induced cardiac dysfunction assessed by echocardiography, left ventricular pressure–volume curves, and in isolated perfused hearts. PTP1B −/− mice also displayed reduced LPS-induced cardiac expression of tumor necrosis factor-α, interleukin1-β, intercellular adhesion molecule-1, vascular cell adhesion molecule-1, and Gp91 phox , as well as of several markers of cellular infiltration. PTP1B deficiency also reduced cardiac P38 and extracellular signal–regulated protein kinase 1 and 2 phosphorylation and increased phospholamban phosphorylation. Finally, PTP1B −/− mice displayed a markedly reduced LPS-induced mortality, an effect also observed using a pharmacological PTP1B inhibitor. PTP1B deletion also improved survival in a cecal ligation puncture model of sepsis. Conclusions— PTP1B gene deletion protects against septic shock-induced cardiovascular dysfunction and mortality, and this may be the result of the profound reduction of cardiovascular inflammation. PTP1B is an attractive target for the treatment of sepsis.

AimsCardiac interleukin-1 beta (IL1-β) production is enhanced acutely after myocardial infarction and is involved in myocardial damages. We tested if early and delayed IL1-β modulations by IL-1β antibody, gevokizumab, prevent left ventricular (LV) remodeling and endothelial dysfunction induced by LV ischemia/reperfusion (I/R) in diabetic rats.MethodsGevokizumab (Gevo; 10mg/kg) was administered 1 hour (early) or 7 days (delayed) following reperfusion, after a 20 min of transient ischemia induced by LV artery occlusion and continued every week for 90 days. Delayed perindopril (1mg/kg) was used as a positive control. LV remodeling and function were assessed (Echocardiography) at 7 and 90 days. LV hemodynamics (Millar catheterization) and relaxation of isolated coronary arteries to acetylcholine (Mulvany wiregraph) were evaluated at 90 days. Collagen density and leukocytes infiltration were evaluated (Histology) at 90 days.ResultsAt 7 days, early Gevo limited the early LV expansion and reduction of FS induced by I/R. At 90 days both of early and delayed Gevo as well as perindopril limited in a similar manner, the LV late dilatation, the reduction of FS and LV systolic and diastolic dysfunction induced by I/R. At 90 days, GK coronary endothelium-dependent relaxation to acetylcholine was impaired by I/R (59±13 vs.17±4%, p

International audience; The protein tyrosine phosphatase 1B (PTP1B) modulates tyrosine kinase receptors, among which is the vascular endothelial growth factor receptor type 2 (VEGFR2), a key component of angiogenesis. Because PTP1B deficiency in mice improves left ven-tricular (LV) function 2 mo after myocardial infarction (MI), we hypothesized that enhanced angiogenesis early after MI via activated VEGFR2 contributes to this improvement. At 3 d after MI, capillary density was increased at the infarct border of PTP1B ؊/؊ mice [؉7؎2% vs. wild-type (WT), P ‫؍‬ 0.05]. This was associated with increased extracellular signal-regulated kinase 2 phosphorylation and VEGFR2 activation (i.e., phosphorylated-Src/Src/VEGFR2 and dissocia-tion of endothelial VEGFR2/VE-cadherin), together with higher infiltration of proangiogenic M2 macro-phages within unchanged overall infiltration. In vitro, we showed that PTP1B inhibition or silencing using RNA interference increased VEGF-induced migration and proliferation of mouse heart microvascular endo-thelial cells as well as fibroblast growth factor (FGF)-induced proliferation of rat aortic smooth muscle cells. At 8 d after MI in PTP1B ؊/؊ mice, increased LV capillary density (؉21؎3% vs. WT; P

International audience; Objectives: Endothelin-1 (ET-1), plays an important role in the pathophysiology of CHF and the pulmonary endothelium is an early hemodynamic target in diastolic left ventricular dysfunction. Therefore we hypothesized that the lung is a main source of humoral endothelin in CHF and that its secretion is proportional to the degree of heart failure. Methods and results: We used rats with coronary artery ligation as an experimental model of either compensated or decompensated heart failure, depending on infarct size. Reverse transcriptase polymerase chain reaction (RT-PCR) revealed that in the lung, the expression of preproET-1 mRNA was higher in decompensated HF than in control and compensated HF rats (P

Background —Chronic heart failure (CHF) impairs the endothelium-dependent, flow-mediated dilation (FMD) of small arteries. However, whether chronic angiotensin-converting enzyme (ACE) inhibition affects the impairment of FMD in CHF is unknown. We investigated the effects of long-term ACE inhibition on the FMD of peripheral arteries in rats with CHF and the mechanism(s) involved. Methods and Results —FMD was assessed in isolated, perfused gracilis muscle arteries from sham-operated, and untreated or ACE inhibitor-treated (perindopril 2 mg · kg −1 · day −1 for 10 weeks) rats with CHF (coronary artery ligation). The role of nitric oxide (NO), prostaglandins, and free radicals was assessed by pretreating the vessels with the NO synthase inhibitor N W -nitro- l -arginine, the cyclooxygenase inhibitor diclofenac, or the free radical scavenger N-2-mercaptopropionyl-glycine (MPG). Endothelial NO synthase mRNA expression was determined by reverse transcriptase polymerase chain reaction. In animals with hemodynamic and echographic signs of CHF, FMD was converted into vasoconstriction, and this was prevented by ACE inhibition. FMD of arteries from sham-operated or ACE inhibitor–treated CHF rats was abolished by N W -nitro- l -arginine. In untreated CHF rats, FMD was increased by diclofenac and MPG. In contrast, in arteries from ACE inhibitor–treated rats, neither diclofenac nor MPG affected FMD. In parallel, ACE inhibition prevented the reduction of endothelial NO synthase mRNA by CHF. Conclusions —In CHF, ACE inhibition normalized NO-dependent dilatation and suppressed the production of vasoconstrictor prostanoid(s), resulting in improved FMD. The improvement of FMD might contribute to the beneficial effects of ACE inhibition during CHF.

Background —Flow-mediated dilatation (FMD) of the peripheral arteries may be impaired in chronic heart failure (CHF), and this could contribute to the increased peripheral resistance and exercise intolerance that occur with this disease. Physical exercise improves the FMD of large conduit arteries in CHF, but whether a similar impairment also occurs in smaller arteries is unknown. The mechanisms of the changes in FMD after CHF or exercise are also unknown. Methods and Results —FMD was assessed in isolated, perfused, and preconstricted gracilis muscle arteries from sham-operated rats or CHF rats (coronary artery ligation) who were either sedentary or exercised (30-minute swimming period twice a day for 10 weeks, starting 7 days after ligation). In animals with hemodynamic and echographic signs of CHF, FMD was abolished and converted into vasoconstriction (percent change in diameter after 370 μL/min flow: sham, 42±5%; CHF, −4±3%; P P N ω -nitro- l -arginine (L-NA) but unaffected by the cyclooxygenase inhibitor diclofenac or the free radical scavenger N-(2-mercaptopropionyl)-glycine (MPG). In arteries from sedentary CHF rats, FMD was not modified by L-NA, but it was partially restored by diclofenac or MPG. In exercised CHF rats, FMD was abolished by L-NA and only moderately improved by diclofenac or MPG. Likewise, endothelial nitric oxide synthase mRNA expression (determined by reverse transcription polymerase chain reaction at the level of the gracilis muscle) was reduced by CHF, and this was prevented by exercise. Conclusions —CHF abolishes the FMD of small arteries by impairing the nitric oxide pathway, increasing oxidant stress, and releasing a prostanoid-contracting factor. Exercise partially restores FMD by increasing expression of endothelial nitric oxide synthase and preventing the production of vasoconstrictor prostanoids and free radicals. Such restoration of FMD might contribute to the increase in exercise capacity after physical exercise in CHF.

Background Plasma levels of the vasoconstrictor peptide endothelin (ET) are increased in chronic heart failure (CHF), and ET levels are a major predictor of mortality in this disease. Thus, ET may play a deleterious role in CHF. The purpose of this study was to assess the effects of chronic treatment with the ET receptor antagonist bosentan in a rat model of CHF. Methods and Results Rats were subjected to coronary artery ligation and were treated for 2 or 9 months with placebo or bosentan (30 or 100 mg · kg −1 · d −1 ). Bosentan 100 mg · kg −1 markedly increased survival (after 9 months: untreated, 47%; bosentan, 65%; P −1 ), which had no major hemodynamic or structural effects, also had no effect on survival. Conclusions Long-term treatment with an ET antagonist markedly increases survival in this rat model of CHF. This increase in survival is associated with decreases in both preload and afterload and an increase in cardiac output as well as decreased LV hypertrophy, LV dilatation, and cardiac fibrosis. Thus, chronic treatment with ET antagonists such as bosentan might be beneficial in human CHF and might increase long-term survival in this disease.