Project description:To investigate the physiological characteristics of cardiac fibroblasts (CF) from pediatric dilated cardiomyopathy (DCM) patients, CFs were harvested from left ventricular free wall at the heart transplantation. We then performed RNA-seq for 7 different lines of CFs.
Project description:Succinate dehydrogenase, which is known as mitochondrial complex II, has proven to be a fascinating machinery, attracting renewed and increased interest in its involvement in human diseases. Herein, we find that succinate dehydrogenase assembly factor 4 (SDHAF4) is downregulated in cardiac muscle in response to pathological stresses and in diseased hearts from human patients. Cardiac loss of Sdhaf4 suppresses complex II assembly and results in subunit degradation and complex II deficiency in fetal mice. These defects are exacerbated in young adults with globally impaired metabolic capacity and activation of dynamin-related protein 1, which induces excess mitochondrial fission and mitophagy, thereby causing progressive dilated cardiomyopathy and lethal heart failure in animals. Targeting mitochondria via supplementation with fumarate or inhibiting mitochondrial fission improves mitochondrial dynamics, partially restores cardiac function and prolongs the lifespan of mutant mice. Moreover, the addition of fumarate is found to dramatically improve cardiac function in myocardial infarction mice. These findings reveal a vital role for complex II assembly in the development of dilated cardiomyopathy and provide additional insights into therapeutic interventions for heart diseases.
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:This study attempts at investigating the changes in cardiac gene expression that occur in Dilated Cardiomyopathy (DCM). DCM in Dobermans and Boxers are the focus of this study. Control heart tissue as well as Pacing tissue used is from mongrel dogs. Keywords: control vs pacing vs disease; strain specific disease 3 Dobermans-DCM, 4 Boxers-DCM, 3 mongrels-control and 3 mongrels-pacing
Project description:We used NGS of rna to understand transcriptome wide changes that occur in the left ventricles of pediatric idiopathic dilated cardiomyopathy patients.
Project description:Dilated cardiomyopathy (DCM) is characterized by left ventricular dilation and continuous systolic dysfunction. Mitochondrial impairment is critical in DCM, but the mechanism remains to be elucidated. Here we explored the cardio-protective role of a heart-enriched long non-coding RNA (lncRNA), named dilated cardiomyopathy repressive transcript (DCRT), via maintaining mitochondrial function. We found the lncRNA DCRT was highly enriched in normal heart tissue and its expression was significantly down-regulated in myocardium of DCM patients. DCRT knockout in mice spontaneously developed cardiac dysfunction with cardiac enlargement and mitochondrial impairment. DCRT transgenic or overexpressed mice attenuated cardiac dysfunction induced by transverse aortic constriction (TAC) treatment.
Project description:Dilated cardiomyopathy (DCM) is a common cause of heart failure and a leading cause of cardiac transplantation in western countries. The robust predictive expression profile of cardiomyopathic and NF hearts as well as the functional classification can help to identify promising candidates for DCM and may improve the early diagnosis of cardiomyopathy. Keywords: disease state analysis