The Exploration Of The Effect And Mechanism Of High Shear Stress On Vascular Endothelial Cells Autophagy

Objective:In this paper,we observed the effect of high shear stress on the autophagy state of human umbilical vein endothelial cells(HUVECs).To explore the role of P53 pathway in high shear stress-induced autophagy.It provides a theoretical basis for the difference in the distribution of atherosclerosis caused by shear stress.Methods: 1.Human umbilical vein endothelial cells(HUVECs)were placed in a parallel plate flow chamber system to simulate the fluid shear force of vascular endothelial cells in vivo.2.After high shear stress working on 0min,5min,15 min,30min,45 min and 60 min respectively,Western blot were used to measure the protein expression of autophagy associated genes microtubule-associated protein 1 light chain 3(LC3)and P62.3.HUVECs without shear stress as a control group,the experimental groups were treated or not treated with bafilomycinA1 before high shear stress for 60 min.Western blot was used to measure the levels of LC3 II /LC3 I and P62.4.The expression of P53 protein in the non-shear stress group and the high shear stress group was compared by western blot.The transcription level of the P53 target gene Sesn1 under high and low shear stress was detected by qPCR.5.HUVECs with high shear stress 0min AS control group,the experimental groups were treated or not treated with Pifithrin-? before acting with high shear stress for 60 min.Then total protein was extracted and the autophagy-related proteins LC3 II /LC3 I and p62 were measured by western blot.Results: 1.The ratio of LC3II/LC3 I was significantly increased in high shear stress and the mostly obvious point was HSS15min(P<0.05 vs.HSS0 min,P<0.05 vs.HSS15min).The level of p62 protein showed a trend of increasing firstly and then decreasing,which reached the highest level at HSS30min(P<0.05 vs.HSS0 min,P<0.05 vs.HSS30min).2.The levels of the LC3 II /LC3 I and p62 protein were significantly higher in the experimental group pretreated with bafilomycinA1 than the other two groups(P < 0.05 vs.HSS0 min ?HSS60min).3.The level of P53 protein in the experimental group was increased to the control group(P<0.05 vs.HSS0min).The transcription level of the P53 target gene Sesn1 was significantly changed under different shear stress.The low shear stress down-regulated the sesn1 transcription level and the high shear stress up-regulated the Sesn1 transcription level(P<0.05 vs.0SS).4.The ratio of LC3 II /LC3 I did not change and the p62 was up-regulated when treated with P53 inhibitor at high shear stress 60 min.(P<0.05 vs.HSS60min)Conclusion: These results suggested that high shear stress facilitate the autophagy of human umbilical vein endothelial cells,which may be achieved by activating the P53 pathway.