Oscillatory shear stress activates integrin β3, blocking autophagic flux in endothelial cells and promoting endothelial cells senescence.

Abstract

Atherosclerosis is an age-related cardiovascular disease. The intersections and bends of blood vessels under the direct action of oscillatory shear stress (OSS) are susceptible to atherosclerotic plaque formation, and the expression of age-related factors is significantly increased in plaques. However, the molecular mechanism by which OSS promotes vascular senescence is still unclear. In this study, we found that the expression of age-related factors, such as P16 and P21, was increased in human aortic endothelial cells (HAECs) exposed to OSS. We also found that the expression of autophagy-related gene 5 (ATG5), microtubule-associated protein 1 light chain 3β (MAP1LC3B), and beclin 1 (BECN1) was increased in HAECs exposed to OSS. The expression of sequestosome-1 (SQSTM1/P62) was also increased. Immunofluorescence confirmed that OSS impaired autophagic flux in HAECs by inhibiting the binding of autophagosomes to lysosome, thereby promoting endothelial cell (EC) senescence. The OSS-sensitive gene integrin β3 (ITGB3), which is closely related to EC autophagy and senescence, was screened by proteomics analysis of HAECs in the control and OSS-treated groups. The protein and mRNA expression of ITGB3 was significantly increased in HAECs exposed to OSS. ITGB3 overexpression in HAECs significantly affected the autophagic flux of ECs and promoted EC senescence, resulting in an increase in cells in the G0/G1 phase and cell cycle arrest. ITGB3 knockdown significantly inhibited the block of OSS-induced autophagic flux and senescence in ECs. In addition, in vivo studies showed that treatment with the ITGB3 inhibitor Cyclo(arginine-glycine-aspartate-tyrosine-lysine) [Cyclo(RGDyK)] significantly inhibited high-fat diet-induced plaque formation in the aortae of apolipoprotein E (ApoE)-/- mice. In conclusion, OSS blocks HAECs autophagic flux and promotes senescence via ITGB3 activation, thereby affecting the development of atherosclerosis.