Dataset Information

Myocardial ATGL overexpression decreases the reliance on fatty acid oxidation and protects against pressure overload-induced cardiac dysfunction.

ABSTRACT: Alterations in myocardial triacylglycerol content have been associated with poor left ventricular function, suggesting that enzymes involved in myocardial triacylglycerol metabolism play an important role in regulating contractile function. Myocardial triacylglycerol catabolism is mediated by adipose triglyceride lipase (ATGL), which is rate limiting for triacylglycerol hydrolysis. To address the influence of triacylglycerol hydrolysis on myocardial energy metabolism and function, we utilized mice with cardiomyocyte-specific ATGL overexpression (MHC-ATGL). Biochemical examination of MHC-ATGL hearts revealed chronically reduced myocardial triacylglycerol content but unchanged levels of long-chain acyl coenzyme A esters, ceramides, and diacylglycerols. Surprisingly, fatty acid oxidation rates were decreased in ex vivo perfused working hearts from MHC-ATGL mice, which was compensated by increased rates of glucose oxidation. Interestingly, reduced myocardial triacylglycerol content was associated with moderately enhanced in vivo systolic function in MHC-ATGL mice and increased isoproterenol-induced cell shortening of isolated primary cardiomyocytes. Most importantly, MHC-ATGL mice were protected from pressure overload-induced systolic dysfunction and detrimental structural remodeling following transverse aortic constriction. Overall, this study shows that ATGL overexpression is sufficient to alter myocardial energy metabolism and improve cardiac function.

SUBMITTER: Kienesberger PC

PROVIDER: S-EPMC3272983 | biostudies-literature | 2012 Feb

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Myocardial ATGL overexpression decreases the reliance on fatty acid oxidation and protects against pressure overload-induced cardiac dysfunction.

Kienesberger Petra C PC Pulinilkunnil Thomas T Sung Miranda M Y MM Nagendran Jeevan J Haemmerle Guenter G Kershaw Erin E EE Young Martin E ME Light Peter E PE Oudit Gavin Y GY Zechner Rudolf R Dyck Jason R B JR

Molecular and cellular biology 20111212 4

Alterations in myocardial triacylglycerol content have been associated with poor left ventricular function, suggesting that enzymes involved in myocardial triacylglycerol metabolism play an important role in regulating contractile function. Myocardial triacylglycerol catabolism is mediated by adipose triglyceride lipase (ATGL), which is rate limiting for triacylglycerol hydrolysis. To address the influence of triacylglycerol hydrolysis on myocardial energy metabolism and function, we utilized mi ...[more]

PMID: 22158969

Similar Datasets

Project description:BACKGROUND: Heart failure (HF) is one of the leading causes of mortality worldwide. Extracellular vesicles (EVs) including small EVs, or exosomes and their molecular cargo are known to modulate cell to cell communication during multiple cardiac diseases. However, the role of systemic EV biogenesis inhibition in the models of HF is not well documented and remains unclear. METHODS: We investigated the role of circulating exosomes during cardiac dysfunction and remodeling in a mouse transverse aortic constriction (TAC) model of HF. Importantly, we investigate the efficacy of Tipifarnib (Tip), a recently identified exosome biogenesis inhibitor that targets the critical proteins (Rab27a, nSmase2 and Alix) involved in exosome biogenesis for this mouse model of HF. In this study, 10-week-old male mice underwent TAC surgery, were randomly assigned to groups with and without Tip treatment (10 mg/kg three times/week) and monitored for 8 weeks and a comprehensive assessment was conducted through performed echocardiographic, histological, and biochemical studies. RESULTS: TAC significantly elevated circulating plasma exosomes and markedly increased cardiac left ventricular (LV) dysfunction, cardiac hypertrophy, and fibrosis. Furthermore, injection of plasma exosomes from TAC mice induced LV dysfunction and cardiomyocyte hypertrophy in uninjured mice without TAC. On the contrary, treatment of Tip in TAC mice reduced circulating exosomes to baseline and remarkably improved LV functions, hypertrophy, and fibrosis. Tip treatment also drastically altered the miRNA profile of circulating post-TAC exosomes, including miR331-5p which was highly downregulated both in TAC circulating exosomes and in TAC cardiac tissue. Mechanistically, miR331-5p is crucial for inhibiting fibroblast-to-myofibroblast transition by targeting HOXC8, a critical regulator of fibrosis. Tipifarnib treatment in TAC mice upregulated the expression of miR331-5p that acts as potent repressor for one of the fibrotic mechanisms mediated by HOXC8. CONCLUSIONS: Our study underscores the pathological role of exosomes in HF and fibrosis in response to pressure overload. Tipifarnib mediated inhibition of exosome biogenesis and cargo sorting may serve as a viable strategy to prevent progressive cardiac remodeling to HF.

Dataset Information

Myocardial ATGL overexpression decreases the reliance on fatty acid oxidation and protects against pressure overload-induced cardiac dysfunction.

Publications

Myocardial ATGL overexpression decreases the reliance on fatty acid oxidation and protects against pressure overload-induced cardiac dysfunction.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure