Project description:Heart disease and failure is a leading cause of mortality worldwide. Left ventricular hypertrophy (LVH) and myocardial fibrosis are major risk factors for cardiovascular morbidity and mortality and the development of heart failure. Pathological LVH induced by sustained pressure-overload engages transcriptional programs including reactivation of canonical fetal genes and those inducing fibrosis. Histone lysine demethylases (KDMs) are emerging potent regulators of transcriptional reprogramming in cancer, though their potential role in abnormal growth and fibrosis in heart disease remains little understood. Here, we investigated gain and loss of function of an H3K9me2 specific demethylase, Kdm3a, in myocytes and in vivo, and show it promotes LVH and myocardial fibrosis in response to pressure-overload. Cardiomyocyte KDM3A activates the transcription of tissue-inhibitor of MMP type 1 (Timp1) with pro-fibrotic activity. By contrast, a pan-KDM inhibitor, JIB-04, suppresses TAC-induced LVH and fibrosis. JIB-04 inhibits KDM3A and suppresses the transcription of fibrotic genes that overlap with genes downregulated in Kdm3a-KO mice versus WT controls. Our study provides genetic and biochemical evidence for a pro-hypertrophic function of KDM3A and proof-of principle for pharmacological targeting of KDMs as an effective strategy to counter LVH and pathological fibrosis.
Project description:Heart disease and failure is a leading cause of mortality worldwide. Left ventricular hypertrophy (LVH) is a major risk factor for cardiovascular morbidity and mortality and the development of heart failure. Pathological LVH induced by sustained pressure-overload engages transcriptional programs including reactivation of canonical fetal genes and those inducing fibrosis. Histone lysine demethylases (KDMs) are emerging potent regulators of transcriptional reprogramming in cancer, though their potential role in abnormal growth and fibrosis in heart disease remains little understood. Here, we investigated gain and loss of function of an H3K9me2 specific demethylase, Kdm3a, in myocytes and in vivo, and show it promotes LVH and myocardial fibrosis in response to pressure-overload. Cardiomyocyte KDM3A activates the transcription of tissue-inhibitor of MMP type 1 (Timp1) with pro-fibrotic activity. By contrast, a pan-KDM inhibitor, JIB-04, suppresses TAC-induced LVH and fibrosis. JIB-04 inhibits KDM3A and suppresses the transcription of fibrotic genes that overlap with genes downregulated in Kdm3a-KO mice versus WT controls. Our study provides genetic and biochemical evidence for a pro-hypertrophic function of KDM3A and proof-of principle for pharmacological targeting of KDMs as an effective strategy to counter LVH and pathological fibrosis.
Project description:Aortic banding is an excellent model system to evaluate the process of development of left ventricular hypertrophy in response to hemodynamic stress. The Affymetrix GeneChip MgU74Av1 was used to analyze expression profiles of mice at different time points after surgical intervention for pressure-overload induced hypertrophy. More information about this model may be obtained at http://cardiogenomics.med.harvard.edu/groups/proj1/pages/band_home.html Keywords = Pressure overload, cardiac hypertrophy Keywords: time-course
Project description:Heart disease and failure is a leading cause of mortality worldwide. Left ventricular hypertrophy (LVH) and myocardial fibrosis are the major risk factor for cardiovascular morbidity and mortality and the development of heart failure. Pathological LVH induced by sustained pressure-overload engages transcriptional programs including reactivation of canonical fetal genes and those inducing fibrosis. Histone lysine demethylases (KDMs) are emerging potent regulators of transcriptional reprogramming in cancer, though their potential role in abnormal growth and fibrosis in heart disease remains little understood. Here, we investigated gain and loss of function of an H3K9me2 specific demethylase, Kdm3a, in myocytes and in vivo, and show it promotes LVH and myocardial fibrosis in response to pressure-overload. Cardiomyocyte KDM3A activates the transcription of tissue-inhibitor of MMP type 1 (Timp1) with pro-fibrotic activity. By contrast, a pan-KDM inhibitor, JIB-04, suppresses TAC-induced LVH and fibrosis. JIB-04 inhibits KDM3A and suppresses the transcription of fibrotic genes that overlap with genes downregulated in Kdm3a-KO mice versus WT controls. Our study provides genetic and biochemical evidence for a pro-hypertrophic function of KDM3A and proof-of principle for pharmacological targeting of KDMs as an effective strategy to counter LVH and pathological fibrosis.
Project description:Pressure overload-induced cardiac hypertrophy was examined in IL-18 knockout and littermate control mice. Keywords: genetic modification / disease model
Project description:Pathological cardiac hypertrophy is a major risk factor for the development of heart failure and sudden cardiac death, yet the molecular mechanism of cardiac hypertrophy is not fully understood. Recently, we found that the expression of Lin28a, a RNA-binding protein, was significantly upregulated during the early stages of cardiac hypertrophy. Interestingly, cardiac specific conditional deletion of Lin28a blunted pressure overload-induced cardiac hypertrophic responses. Given that Lin28a can bind to diverse mRNA to regulate their abundance and/or translation, we conducted RNA-seq to profile the cardiac transcriptome alteration without Lin28a under pressure overload. It showed that metabolic pathways, including glycolysis and biosynthetic pathway, were remarkedly affected. Thus, our study identifies Lin28a as a crucial regulator of cardiac hypertrophy via its role in metabolic programming.
Project description:Pressure overload-induced cardiac hypertrophy was examined in IL-18 knockout and littermate control mice. Experiment Overall Design: 4 groups with RNA pooled from 5-6 per group. Role of IL-18 on gene expression in cardiac hypertrophy induced by pressure overload (transaortic constriction)