Abstract 14287: Ang II-induced Pathological Autophagy is Inhibited by IL-10 via Akt Dependent Inhibition of Beclin 1 in Mice Heart

Abstract

Although, autophagy is an essential cellular salvage process to maintain cellular homeostasis, pathological autophagy can lead to cardiac abnormalities and ultimately heart failure. Therefore, a tight regulation on autophagic process would be important to treat chronic heart failure. Previously, we have shown that IL-10 strongly improved cardiac function in chronic heart failure models, but the role of IL-10 in regulation of pathological autophagy is not yet investigated. We tested the hypothesis that IL-10 inhibits angiotensin II-induced pathological autophagy and thus improved cardiac function. Pathological autophagy was induced in wild type (WT) and IL10-knockout mice by angiotensin II infusion. Ang II-induced left ventricular dysfunction and hypertrophic remodeling were accentuated in IL-10 KO mice compared to WT mice. IL-10 KO mice showed exaggerated autophagy with reduced AKT phosphorylation. In neonatal rat ventricular cardiomyocytes, Ang II activated beclin1 and LC3 levels and inhibited AKT/mTORC1 and AKT-Bcl2 signaling. IL-10 inhibited Ang II-induced autophagic marker proteins. Additionally, IL-10 restored Ang II effects on AKT/mTORC1 and AKT-Bcl2 signaling. Both pharmacological/molecular inhibition of AKT via PI3K inhibitor (LY290002) or Akt siRNA, attenuated IL-10 effects on the Ang II-induced pathological autophagy, confirming that IL-10 mediated regulation of pathological autophagy is AKT dependent. Similar results were observed with mTORC1 inhibitor rapamycin. Chloroquine (a lysosome inhibitor) strongly inhibits Ang II-induced autophagic flux. However, chloroquine did not affect IL-10 effects on autophagic flux, suggesting that IL-10 inhibits stress-induced pathological autophagy. Finally, as physical interaction of Bcl2 with beclin 1 is important to inhibit autophagy and IL-10 is strong activator of Bcl2, we performed immunoprecipitation experiment. Immunoprecipitation data suggested that Ang II disrupt the physical interaction of beclin 1 with Bcl2 and IL-10 reestablished this physical interaction to reduce autophagy. Our data give a novel role of IL-10 in regulation of pathological autophagy and thus can act as a potential therapeutic molecule in treatment of chronic heart disease.