Project description:Heart failure (HF) is driven by the interplay between regulatory transcription factors and dynamic alterations in chromatin structure. Pathologic gene transactivation in HF is associated with recruitment of histone acetyl-transferases and local chromatin hyperacetylation. We therefore assessed the role of acetyl-lysine reader proteins, or bromodomains, in HF. Using a chemical genetic approach, we establish a central role for BET family bromodomain proteins in gene control during HF pathogenesis. BET inhibition potently suppresses cardiomyocyte hypertrophy in vitro and pathologic cardiac remodeling in vivo. Integrative transcriptional and epigenomic analyses reveal that BET proteins function mechanistically as pause-release factors critical to expression of genes that are central to HF pathogenesis and relevant to the pathobiology of failing human hearts. This study implicates epigenetic readers as essential effectors of transcriptional pause release during HF pathogenesis and identifies BET coactivator proteins as therapeutic targets in the heart.
Project description:Heart failure (HF) is driven via interplay between master regulatory transcription factors and dynamic alterations in chromatin structure. While pathologic gene transactivation in this context is known to be associated with recruitment of histone acetyl-transferases 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 HF. Using a chemical genetic approach, we establish a central role for BET-family bromodomain proteins in gene control during HF pathogenesis. BET inhibition potently suppresses cardiomyocyte hypertrophy in vitro and 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 HF pathogenesis and relevant to the pathobiology of failing human hearts. This study implicates epigenetic readers in cardiac biology and identifies BET co-activator proteins as therapeutic targets in HF. Gene expression analysis of mouse hearts subjected to either trans aortic constriction (TAC) or sham surgeries followed by treamtent with dmso vehicle or the BET bromodomain inhibitor JQ1
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:Heart failure (HF) is driven via interplay between master regulatory transcription factors and dynamic alterations in chromatin structure. While pathologic gene transactivation in this context is known to be associated with recruitment of histone acetyl-transferases 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 HF. Using a chemical genetic approach, we establish a central role for BET-family bromodomain proteins in gene control during HF pathogenesis. BET inhibition potently suppresses cardiomyocyte hypertrophy in vitro and 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 HF pathogenesis and relevant to the pathobiology of failing human hearts. This study implicates epigenetic readers in cardiac biology and identifies BET co-activator proteins as therapeutic targets in HF. Gene expression analysis of neonatal rat ventricular mycotes (NRVM) subjected to phenylephrine (PE) treatment followed by treatment with vehicle (DMSO) or the BET bromodomain inhibitor JQ1
Project description:Heart failure (HF) is driven via interplay between master regulatory transcription factors and dynamic alterations in chromatin structure. While pathologic gene transactivation in this context is known to be associated with recruitment of histone acetyl-transferases 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 HF. Using a chemical genetic approach, we establish a central role for BET-family bromodomain proteins in gene control during HF pathogenesis. BET inhibition potently suppresses cardiomyocyte hypertrophy in vitro and 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 HF pathogenesis and relevant to the pathobiology of failing human hearts. This study implicates epigenetic readers in cardiac biology and identifies BET co-activator proteins as therapeutic targets in HF.
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.
Project description:Heart failure (HF) is driven via interplay between master regulatory transcription factors and dynamic alterations in chromatin structure. While pathologic gene transactivation in this context is known to be associated with recruitment of histone acetyl-transferases 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 HF. Using a chemical genetic approach, we establish a central role for BET-family bromodomain proteins in gene control during HF pathogenesis. BET inhibition potently suppresses cardiomyocyte hypertrophy in vitro and 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 HF pathogenesis and relevant to the pathobiology of failing human hearts. This study implicates epigenetic readers in cardiac biology and identifies BET co-activator proteins as therapeutic targets in HF.
Project description:Recruitment of the RNA polymerase II (Pol II) transcription initiation apparatus to promoters by specific DNA-binding transcription factors is well recognized as a key regulatory step in gene expression. We report here that promoter-proximal pausing is a general feature of transcription by Pol II in mammalian cells and thus an additional step where regulation of gene expression occurs. This suggests that some transcription factors recruit the transcription apparatus to promoters, whereas others effect promoter-proximal pause release. Indeed, we find that the transcription factor c-Myc, a key regulator of cellular proliferation, plays a major role in Pol II pause release rather than Pol II recruitment at its target genes. We discuss the implications of these results for the role of c-Myc amplification in human cancer.