Project description:To establish changes in cardiac transcription profiles brought about by heart failure we collected myocardial samples from patients undergoing cardiac transplantation whose failure arises from different etiologies (e.g. idiopathic dilated cardiomyopathy, ischemic cardiomyopathy, alcoholic cardiomyopathy, valvular cardiomyopathy, and hypertrophic cardiomyopathy) and from "normal" organ donors whose hearts cannot be used for transplants. The transcriptional profile of the mRNA in these samples will be measured with gene array technology. Changes in transcriptional profiles can be correlated with the physiologic profile of heart-failure hearts acquired at the time of transplantation. Keywords: other
Project description:To establish changes in cardiac transcription profiles brought about by heart failure we collected myocardial samples from patients undergoing cardiac transplantation whose failure arises from different etiologies (e.g. idiopathic dilated cardiomyopathy, ischemic cardiomyopathy, alcoholic cardiomyopathy, valvular cardiomyopathy, and hypertrophic cardiomyopathy) and from "normal" organ donors whose hearts cannot be used for transplants. The transcriptional profile of the mRNA in these samples will be measured with gene array technology. Changes in transcriptional profiles can be correlated with the physiologic profile of heart-failure hearts acquired at the time of transplantation. Keywords: other
Project description:Heart failure is driven by the interplay between master regulatory transcription factors and dynamic alterations in chromatin structure. Coordinate activation of developmental, inflammatory, fibrotic and growth regulators underlies the hallmark phenotypes of pathologic cardiac hypertrophy and contractile failure. While transactivation in this context is known to be associated with recruitment of histone acetyl-transferase enzymes and local chromatin hyperacetylation, the role of epigenetic reader proteins in cardiac biology is unknown. We therefore undertook a first study of acetyl-lysine reader proteins, or bromodomains, in heart failure. Using a chemical genetic approach, we establish a central role for BET-family bromodomain proteins in gene control during the evolution of heart failure. BET inhibition suppresses cardiomyocyte hypertrophy in a cell-autonomous manner, confirmed by RNA interference in vitro. Following both pressure overload and neurohormonal stimulation, BET inhibition potently attenuates pathologic cardiac remodeling in vivo. Integrative transcriptional and epigenomic analyses reveal that BET proteins function mechanistically as pause-release factors critical to activation of canonical master regulators and effectors that are central to heart failure pathogenesis. Specifically, BET bromodomain inhibition in mice abrogates pathology-associated pause release and transcriptional elongation, thereby preventing activation of cardiac transcriptional pathways relevant to the gene expression profile of failing human hearts. This study implicates epigenetic readers in cardiac biology and identifies BET co-activator proteins as therapeutic targets in heart failure. ChIP-Seq of mouse heart tissues from mice induced with heart failure and treated with JQ1 BET bromodomain inhibitor
Project description:In this study, we employed descending aortic constriction (DAC) technique to establish a minipig heart failure model. The cardiac phenotypes, pathological and cellular changes, fibrotic signaling activation, and gene expression profiles have been explored.
Project description:To identify a novel target for the treatment of heart failure, we examined gene expression in the failing heart. Among the genes analyzed, 12/15 lipoxygenase (12/15-LOX) was markedly up-regulated in heart failure. To determine whether increased expression of 12/15-LOX causes heart failure, we established transgenic mice that overexpressed 12/15-LOX in cardiomyocytes. Echocardiography showed that 12/15-LOX transgenic mice developed systolic dysfunction. Cardiac fibrosis increased in 12/15-LOX transgenic mice with advancing age, and was associated with the infiltration of macrophages. Consistent with these observations, cardiac expression of monocyte chemoattractant protein-1 (Mcp-1) was up-regulated in 12/15-LOX transgenic mice compared with wild-type mice. Treatment with 12-hydroxy-eicosatetraenotic acid, a major metabolite of 12/15-LOX, increased MCP-1 expression in cardiac fibroblasts and endothelial cells, but not in cardiomyocytes. Inhibition of Mcp-1 reduced the infiltration of macrophages into the myocardium and prevented both systolic dysfunction and cardiac fibrosis in 12/15-LOX transgenic mice. Likewise, disruption of 12/15-LOX significantly reduced cardiac Mcp-1 expression and macrophage infiltration, thereby improving systolic dysfunction induced by chronic pressure overload. Our results suggest that cardiac 12/15-LOX is involved in the development of heart failure and that inhibition of 12/15-LOX could be a novel treatment for this condition. Heart failure is still one of the leading causes of death worldwide. Therefore, it is important to elucidate the underlying mechanisms of heart failure and develop more effective treatments for this condition. To clarify the molecular mechanisms of heart failure, we performed microarray analysis using cardiac tissue samples obtained from a hypertensive heart failure model (Dahl salt-sensitive rats). ~300 genes showed significant changes of expression in the failing hearts compared with control hearts. Among the genes analyzed, 12/15-lipoxygenase (12/15-LOX) was most markedly up-regulated in failing hearts compared with control hearts .