| First Author | Laurent AC | Year | 2015 |
| Journal | Cardiovasc Res | Volume | 105 |
| Issue | 1 | Pages | 55-64 |
| PubMed ID | 25411381 | Mgi Jnum | J:230297 |
| Mgi Id | MGI:5755933 | Doi | 10.1093/cvr/cvu242 |
| Citation | Laurent AC, et al. (2015) Exchange protein directly activated by cAMP 1 promotes autophagy during cardiomyocyte hypertrophy. Cardiovasc Res 105(1):55-64 |
| abstractText | AIMS: Stimulation of beta-adrenergic receptors (beta-AR) increases cAMP production and contributes to the pathogenesis of cardiac hypertrophy and failure through poorly understood mechanisms. We previously demonstrated that Exchange protein directly activated by cAMP 1 (Epac1)-induced hypertrophy in primary cardiomyocytes. Among the mechanisms triggered by cardiac stress, autophagy has been highlighted as a protective or harmful response. Here, we investigate whether Epac1 promotes cardiac autophagy and how altered autophagy has an impact on Epac1-induced cardiomyocyte hypertrophy. METHODS AND RESULTS: We reported that direct stimulation of Epac1 with the agonist, Sp-8-(4-chlorophenylthio)-2'-O-methyl-cAMP (Sp-8-pCPT) promoted autophagy activation in neonatal cardiomyocytes. Stimulation of beta-AR with isoprenaline (ISO) mimicked the effect of Epac1 on autophagy markers. Conversely, the induction of autophagy flux following ISO treatment was prevented in cardiomyocytes pre-treated with a selective inhibitor of Epac1, CE3F4. Importantly, we found that Epac1 deletion in mice protected against beta-AR-induced cardiac remodelling and prevented the induction of autophagy. The signalling mechanisms underlying Epac1-induced autophagy involved a Ca(2+)/calmodulin-dependent kinase kinase beta (CaMKKbeta)/AMP-dependent protein kinase (AMPK) pathway. Finally, we provided evidence that pharmacological inhibition of autophagy using 3-methyladenine (3-MA) or down-regulation of autophagy-related protein 5 (Atg5) significantly potentiated Epac1-promoted cardiomyocyte hypertrophy. CONCLUSION: Altogether, these findings demonstrate that autophagy is an adaptive response to antagonize Epac1-promoted cardiomyocyte hypertrophy. |
