LncRNA ACART protects cardiomyocytes from apoptosis by activating PPAR-/Bcl-2 pathway

Cardiomyocyte apoptosis is an important process occurred during cardiac ischaemia-reperfusion injury. Long non-coding RNAs (lncRNA) participate in the regulation of various cardiac diseases including ischaemic reperfusion (I/R) injury. In this study, we explored the potential role of lncRNA ACART (anti-cardiomyocyte apoptosis-related transcript) in cardiomyocyte injury and the underlying mechanism for the first time. We found that ACART was significantly down-regulated in cardiac tissue of mice subjected to I/R injury or cultured cardiomyocytes treated with hydrogen peroxide (H2O2). Knockdown of ACART led to significant cardiomyocyte injury as indicated by reduced cell viability and increased apoptosis. In contrast, overexpression of ACART enhanced cell viability and reduced apoptosis of cardiomyocytes treated with H2O2. Meanwhile, ACART increased the expression of the B cell lymphoma 2 (Bcl-2) and suppressed the expression of Bcl-2-associated X (Bax) and cytochrome-C (Cyt-C). In addition, PPAR-gamma was up-regulated by ACART and inhibition of PPAR-gamma abolished the regulatory effects of ACART on cell apoptosis and the expression of Bcl-2, Bax and Cyt-C under H2O2 treatment. However, the activation of PPAR-gamma reversed the effects of ACART inhibition. The results demonstrate that ACART protects cardiomyocyte injury through modulating the expression of Bcl-2, Bax and Cyt-C, which is mediated by PPAR-gamma activation. These findings provide a new understanding of the role of lncRNA ACART in regulation of cardiac I/R injury.