Project description:We characterized the metabolic and cardiac mitochondrial function in a mouse model of non-ischemic HF. Inhibition of nitric oxide synthesis and hypertension, which often present together, are two important risk factors in human non-ischemic HF. Compared with L-NAME L-NG-Nitroarginine methyl ester (L-NAME), an inhibitor of nitric oxide synthesis or Angiotensin II (AngII), a hypertensive agent treatment alone, L-NAME+AngII induced the most severe HF phenotype characterized by edema, hypertrophy, fibrosis, increased blood pressure and reduced ejection fractions. L-NAME+AngII treated mice had robust deterioration of cardiac mitochondrial function we observed. Microarray analyses revealed majority of the gene changes attributed to the combination of L-NAME+AngII. Pathway analyses indicated significant changes in metabolic pathways such as mitochondrial oxidative phosphorylation, fatty acid metabolism and tricarboxylic acid pathways etc.in L-NAME+AngII hearts. We conclude that combination of L-NAME+AngII exacerbates cardiac contractile and mitochondrial functional de-regulation compared with L-NAME and AngII alone, resulting in non-ischemic HF. This model of heart failure may be highly valuable in studying mechanisms and treatments for non-ischemic heart failure.
Project description:We characterized the metabolic and cardiac mitochondrial function in a mouse model of non-ischemic HF. Inhibition of nitric oxide synthesis and hypertension, which often present together, are two important risk factors in human non-ischemic HF. Compared with L-NAME L-NG-Nitroarginine methyl ester (L-NAME), an inhibitor of nitric oxide synthesis or Angiotensin II (AngII), a hypertensive agent treatment alone, L-NAME+AngII induced the most severe HF phenotype characterized by edema, hypertrophy, fibrosis, increased blood pressure and reduced ejection fractions. L-NAME+AngII treated mice had robust deterioration of cardiac mitochondrial function we observed. Microarray analyses revealed majority of the gene changes attributed to the combination of L-NAME+AngII. Pathway analyses indicated significant changes in metabolic pathways such as mitochondrial oxidative phosphorylation, fatty acid metabolism and tricarboxylic acid pathways etc.in L-NAME+AngII hearts. We conclude that combination of L-NAME+AngII exacerbates cardiac contractile and mitochondrial functional de-regulation compared with L-NAME and AngII alone, resulting in non-ischemic HF. This model of heart failure may be highly valuable in studying mechanisms and treatments for non-ischemic heart failure. Twelve week-old C57BL6 male mice were randomly assigned to 4 groups: 1. Control, 2. L-NAME treatment, 3. AngII treatment, 4. L-NAME+AngII treatment.L-NAME (0.3 mg/ml with 1% NaCl) was administered in drinking water. AngII (0.7 mg/kg/day) was administered via subcutaneous micro-osmotic pumps. L-NAME and AngII were administered to mice for 5 weeks and 4 weeks in combination to induce HF or alone to study the effects of the individual agents.
Project description:Ischemic and non-ischemic cardiomyopathies have distinct etiologies and underlying disease mechanisms, which require in-depth investigation for improved therapeutic interventions. The goal of this study was to use clinically obtained myocardium from healthy and heart failure patients, and characterize the changes in extracellular matrix (ECM) in ischemic and non-ischemic failing hearts, with and without mechanical unloading. Using tissue engineering methodologies, we also investigated how diseased human ECM, in the absence of systemic factors, can influence cardiomyocyte function. Heart tissues from heart failure patients with ischemic and non-ischemic cardiomyopathy were compared to explore differential disease phenotypes and reverse remodeling potential of left ventricular assisted device (LVAD) support at transcriptomic, proteomic and structural levels. The collected data demonstrated that the differential ECM compositions recapitulated the disease microenvironment and induced cardiomyocytes to undergo disease-like functional alterations. In addition, our study also revealed molecular profiles of non-ischemic and ischemic heart failure patients and explored the underlying mechanisms of etiology-specific impact on clinical outcome of LVAD support and tendency towards reverse remodeling.
Project description:Heart failure is a leading cause of cardiovascular mortality with limited options for treatment. We used 18 month-old apolipoprotein E (apoE)- deficient mice as a model of atherosclerosis-induced heart failure to analyze whether the anti-ischemic drug ranolazine could retard the progression of heart failure. The study showed that 2 months of ranolazine treatment improved cardiac function of 18 month-old apoE-deficient mice with symptoms of heart failure as assessed by echocardiography. To identify changes in cardiac gene expression induced by treatment with ranolazine a microarray study was performed with heart tissue from failing hearts relative to ranolazine-treated and healthy control hearts. The microarray approach identified heart failure-specific genes that were normalized during treatment with the anti-ischemic drug ranolazine. Microarray gene expression profiling was performed with heart tissue isolated from (i) untreated 18 month-old apoE-deficient mice with heart failure relative to (ii) 18 month-old apoE-deficient mice treated for two months with the anti-ischemic drug ranolazine (200 mg/kg), and (iii) age-matched non-transgenic C57BL/6J (B6) control mice.
Project description:Heart failure is a leading cause of cardiovascular mortality with limited options for treatment. We analyzed whether the anti-ischemic drug ranolazine could retard the progression of heart failure in an experimental model of heart failure induced by 6 months of chronic pressure overload. The study showed that 2 months of ranolazine treatment improved cardiac function of aortic constricted C57BL/6J (B6) mice with symptoms of heart failure as assessed by echocardiography. The microarray gene expression study of heart tissue from failing hearts relative to ranolazine-treated and healthy control hearts identified heart failure-specific genes that were normalized during treatment with the anti-ischemic drug ranolazine. Microarray gene expression profiling was performed with heart tissue isolated from three study groups: (i) untreated 10 month-old C57BL/6J (B6) mice with heart failure induced by 6 months of abdominal aortic constriction (AAC), (ii) 10 month-old B6 mice with 6 months of AAC and two months of treatment with the anti-ischemic drug ranolazine (200 mg/kg), and (iii) age-matched, untreated, sham-operated B6 control mice.
Project description:Heart failure is a leading cause of cardiovascular mortality with limited options for treatment. We analyzed whether the anti-ischemic drug ranolazine could retard the progression of heart failure in an experimental model of heart failure induced by 6 months of chronic pressure overload. The study showed that 2 months of ranolazine treatment improved cardiac function of aortic constricted C57BL/6J (B6) mice with symptoms of heart failure as assessed by echocardiography. The microarray gene expression study of heart tissue from failing hearts relative to ranolazine-treated and healthy control hearts identified heart failure-specific genes that were normalized during treatment with the anti-ischemic drug ranolazine.
Project description:Mammalian organs vary widely in regenerative capacity, and poorly regenerative organs, such as the heart are particularly vulnerable to organ failure. Once established, heart failure commonly results in in considerable mortality and early demise. The Hippo pathway, a kinase cascade that prevents adult cardiomyocyte proliferation and regeneration, is upregulated in human heart failure. We show that deletion of the Hippo pathway component Salvador (Salv) in mouse hearts with established ischemic heart failure after myocardial infarction induced a reparative genetic program characterized by increased scar border vascularity, reduced fibrosis, and recovery of pumping function to that of sham-operated controls. To isolate cardiomyocyte specific translating mRNA we used TRAP (translating ribosomal affinity purification) followed by RNA sequencing. Hippo deficient cardiomyocytes had increased expression of proliferative, and stress response genes. Interestingly the mitochondrial quality control gene, Park2 was among the stress response genes. Further genetic studies indicated that Park2 was essential for heart repair in both the neonatal mouse and the adult Salv conditional knockout mouse. Thus, suggesting a requirement for mitochondrial quality control in the regenerating myocardium. Our findings indicate that the failing heart has a previously unrecognized capacity for repair involving more than cardiomyocyte renewal.
Project description:Heart failure is a leading cause of cardiovascular mortality with limited options for treatment. We used 18 month-old apolipoprotein E (apoE)- deficient mice as a model of atherosclerosis-induced heart failure to analyze whether the anti-ischemic drug ranolazine could retard the progression of heart failure. The study showed that 2 months of ranolazine treatment improved cardiac function of 18 month-old apoE-deficient mice with symptoms of heart failure as assessed by echocardiography. To identify changes in cardiac gene expression induced by treatment with ranolazine a microarray study was performed with heart tissue from failing hearts relative to ranolazine-treated and healthy control hearts. The microarray approach identified heart failure-specific genes that were normalized during treatment with the anti-ischemic drug ranolazine.
Project description:LARP7 controls the SIRT1 activity and homeostasis, which is essential for mitochondrial biogenesis, energy production and cardiac function. The deprivation of LARP7 resulted from the activation ATM pathway attenuates the mitochondrial function and biogenesis and leads to the cardiomyopathy and heart failure. Method: Heart morphology and functions were assessed by gross anatomy, serial echocardiography and histology on sections; Mitochondrial morphology and activity were evaluated by TEM and seahorse assays. The therapeutic potential of LARP7 in heart failure was evaluated in mouse myocardial infarction model either with AAV9 infection or pharmacological inhibitor.