Identification of Cofilin-1 Induces G0/G1 Arrest and Autophagy in Angiotensin-(1-7)-treated Human Aortic Endothelial Cells from iTRAQ Quantitative Proteomics

The angiotensin-converting enzyme 2/angiotensin-(1-7)/Mas axis is a pathway that acts against the detrimental effects of the renin-angiotensin system. However, the effects of angiotensin-(1-7) on endothelial protein expression and the related phenotypes are unclear. We performed a duplicate of iTRAQ quantitative proteomic analysis on human aortic endothelial cells (HAECs) treated with angiotensin-(1-7) for 6 hours. Cofilin-1 was identified as a highly abundant candidate with consistent >30% coverage and >1.2-fold overexpression in the angiotensin-(1-7)-treated group. Gene ontology analysis showed that the "regulation-of-mitosis" was significantly altered, and cell cycle analysis indicated that the 6-hour angiotensin-(1-7) treatment significantly induced G0/G1 arrest. Knockdown of the cofilin-1 (CFL1) gene suggested the G0/G1 phase arrest was mediated by the modulation of p27 and the p21/Cyclin/CDK complex by Cofilin-1. Interestingly, quiescent HAECs escaped G0/G1 arrest upon angiotensin-(1-7) treatment for 24 hours, and angiotensin-(1-7) induced autophagy by upregulating Beclin-1 and microtubule-associated protein 1 light chain 3b-II expression, which was also attenuated by A779 pre-treatment and CFL1 knockdown. After pre-treatment with 3-methyladenine (3MA), treatment with angiotensin-(1-7) for 24 h induced significant G0/G1 phase arrest and apoptosis, suggesting a pro-survival role of autophagy in this context. In conclusion, Cofilin-1 plays a dominant role in angiotensin-(1-7)-induced G0/G1 arrest and autophagy to maintain cellular homeostasis in HAECs.