S-38-3: LONG NONCODING RNA P21 ALLEVIATES ENDOTHELIAL PROGENITOR CELLS DAMAGE AND PROMOTES ENDOTHELIAL REPAIR IN HYPERTENSION THROUGH ENHANCING AUTOPHAGY

Abstract

Objective: Vascular damage of hypertension has been the focus of hypertension treatment, and endothelial progenitor cells (EPCs) play an important role in the repair of vascular endothelial damage. Functional damage and decreased number of EPCs are observed in the peripheral circulation of hypertensive patients, but its mechanism is not yet elucidated. Methods: Peripheral circulating endothelial progenitor cells of hypertensive patients were labeled and detected by flow cytometry. At the same time, the endothelial progenitor cells of hypertensive patients were cultured in vitro to detect their cell function and aging. The rat bone marrow-derived endothelial progenitor cells were isolated and cultured in vitro. After the intervention of AngII, the cell function, autophagy, and cell senescence were detected. PCR and WB were used to measure the expression and phosphorylation of SESN2, AMPK and TSC2. Results: Our results showed that the number of EPCs in hypertensive patients is significantly lower than that of normal population, and the cell function decreases with a higher proportion of EPCs at later stages. A decrease in autophagy is responsible for the senescence and damage of EPCs induced by AngII. Moreover, lncRNA-p21 plays a critical regulator role in the senescence and dysfunction of EPCs. Furthermore, lncRNA-p21 activates SESN2/AMPK/TSC2 pathway by promoting the transcriptional activity of p53 and lncRNA-p21 overexpression enhanced autophagy via AMPK/TSC2/mTOR pathway to protect against AngII-induced EPC damage. EPCs with lncRNA-p21 knockdown showed poor adhesion ability and vascular repair function. These results suggest that lncRNA-p21 enhances autophagy to alleviate endothelial progenitor cells damage and promote endothelial repair in hypertension through SESN2/AMPK/TSC2 pathway. Conclusion: The data provide evidence that a reversal of decreased autophagy serves as the protective mechanism of EPC injury in hypertensive patients, and lncRNA-p21 is a new therapeutic target for vascular endothelial repair in hypertension.