Project description:Importantly, mutations in nuclear envelope-encoding genes are the second-highest cause of familial dilated cardiomyopathy. One such nuclear envelope protein that causes cardiomyopathy in humans and affects mouse heart development is Lem2. However, its role in mechanically active tissue such as heart remains poorly understood.
Project description:Cardiac metabolism is deranged in heart failure, but underlying mechanisms remain unclear. Lysine demethylase 8 (Kdm8) represses gene expression in the embryo and controls metabolism in cancer. However, its function in cardiac homeostasis is unknown. We show that Kdm8 maintains a mitochondrial gene network active by repressing Tbx15 to prevent dilated cardiomyopathy leading to lethal heart failure. Deletion of Kdm8 in mouse cardiomyocytes increased H3K36me2 with activation of Tbx15 and repression of target genes in the NAD+ pathway before dilated cardiomyopathy initiates. Moreover, NAD+ supplementation prevented dilated cardiomyopathy in Kdm8 mutant mice and TBX15 overexpression blunted NAD+-activated cardiomyocyte respiration. Furthermore, KDM8 was downregulated in human hearts affected by dilated cardiomyopathy and higher TBX15 expression defines a subgroup of affected hearts with the strongest downregulation of genes encoding mitochondrial proteins. Thus, KDM8 represses TBX15 to maintain cardiac metabolism. Our results suggest that epigenetic dysregulation of metabolic gene networks initiates myocardium deterioration towards heart failure and could underlie heterogeneity of dilated cardiomyopathy.
Project description:Cardiac metabolism is deranged in heart failure, but underlying mechanisms remain unclear. Lysine demethylase 8 (Kdm8) represses gene expression in the embryo and controls metabolism in cancer. However, its function in cardiac homeostasis is unknown. We show that Kdm8 maintains a mitochondrial gene network active by repressing Tbx15 to prevent dilated cardiomyopathy leading to lethal heart failure. Deletion of Kdm8 in mouse cardiomyocytes increased H3K36me2 with activation of Tbx15 and repression of target genes in the NAD+ pathway before dilated cardiomyopathy initiates. Moreover, NAD+ supplementation prevented dilated cardiomyopathy in Kdm8 mutant mice and TBX15 overexpression blunted NAD+-activated cardiomyocyte respiration. Furthermore, KDM8 was downregulated in human hearts affected by dilated cardiomyopathy and higher TBX15 expression defines a subgroup of affected hearts with the strongest downregulation of genes encoding mitochondrial proteins. Thus, KDM8 represses TBX15 to maintain cardiac metabolism. Our results suggest that epigenetic dysregulation of metabolic gene networks initiates myocardium deterioration towards heart failure and could underlie heterogeneity of dilated cardiomyopathy.
Project description:A novel ppp1r13l sequence variation causes dilated cardiomyopathy and cardiac inflammation. This experiment explores the transcriptome of wa3 mice hearts which are carry deletion and insertion mutations in exon 12 of the Ppp1r13l gene that generate premature stop codon, and exhibit dilated cardio myopathy in a similar manner to a novel human mutation that was recently dicovered.
Project description:Global gene expression is altered in heart failure. This syndrome can be caused by cardiovascular diseases, including dilated cardiomyopathy (DCM), ischemic cardiomyopathy (ICM), hypertrophic cardiomyopathy, viral or toxic myocarditis, hypertension, and valvular diseases. We used microarrays to evaluate the impact of heart failure on human nucleocytoplasmic transport-related genes examining simultaneoulsly both dilated and ischemic human cardiomyopathies compared to normal hearts.
Project description:The goal of this study is to compare the transcriptome of heart failure patients (with ischemic or dilated cardiomyopathy) undergoing heart transplantation compared with healthy controls. We analyzed 36 human samples. 13 from ischemic and 13 from dilated human hearts compared with 10 healthy control donors.
Project description:Characterization of plasma metabolomic profile of 15 patients with advanced heart failure referred for heart transplantation (8 patients with chronic chagasic cardiomyopathy and 7 with idiopathic dilated cardiomyopathy) and 12 heart donor individuals using gas chromatography/quadrupole time-of-flight mass spectrometry.
