Influence Of Ang-(1-7) On The Expression Of Talin1Induced By Ang Ⅱ In Endothelial Cells And Its Mechanism

Renin-angiotensin system(RAS) is one of the most important regulation systems, which has played an important role on regulating physiological function, especially at cardiovascular and cerebrovascular diseases development. Integrin is a major receptor family present in the cell surface, which can induce the conglutination between cells and extracellular matrix, activated integrin αIIbβ3is mainly involved in thrombus formation through inducing platelets adhesion and aggregation. Talin1,as the essential factor in the process of activating αIIbβ3, is recently specially concerned. Previous work have proved that angiotensin-(1-7)[Ang-(1-7)] could significantly inhibit the experimental thrombosis induced by angiotensin Ⅱ(AngⅡ). However, whether Ang-(1-7) and AngⅡ can affect thrombosis formation by means of regulating talin1has not been reported. In this study, we will observe the influence of Ang-(1-7) on the expression of talin1induced by AngⅡ in endothelial cells, and then explore the possible mechanism.Objective To observe the effects of Ang-(1-7) on the expression of talin1induced by Ang Ⅱ in human umbilical vein endothelium derived cell line(HUVECs) and to explore its mechanisms.Methods HUVECs were cultured in DMEM. Samples in part1were devided into the following groups:①different concentrations of AngⅡ(10-10～10-6mol/L),②10-7mol/L AngⅡ at different time points(0,2,4,6,8,10,12h),③different concentrations of Ang-(1-7)(10-9～10-6mol/L),④Ang-(1-7) at different time points(0,2,4,6,8,10,12h). Samples in part2were devided into the following groups:control, AngⅡ, Ang-(1-7), PDTC, Ang-(1-7)+AngⅡ, Ang-(1-7)+AngⅡ+PDTC. Talin1antigen was measured by ELISA Kit. Talin1mRNA was examined by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR).Results①Compared with control, a gradual increase in talin1antigen (r=0.965, P<0.05) and talin1mRNA (P<0.05), were due to the increasing concentration of AngⅡ(10-10～10-6mol/L) treated in HUVECs, and peak appeared in the10-7mol/L. Treated cells with Ang Ⅱ (10-7mol/L)0,2,4,6,8,10,12h later, compared with control, a gradual increase in talin1antigen, and peak appeared at4h(P<0.01).②Compared with control, Ang-(1-7) had no marked effects on talin1antigen when used alone. When pretreated with Ang-(1-7)(10-9～10-6mol/L), then treated by Ang Ⅱ, it inhibited the expression of talin1at antigen and mRNA level in the dose-dependent manner (r=-0.987, P<0.05), and10-6mol/L was the strongest concentration. When coexistence of Ang-(1-7) and Ang Ⅱ after0,2,4,6,8,10,12h, Ang-(1-7) could inhibit talin1induced by Ang Ⅱ, and4h was the most obvious stage(P<0.01).③Compared with control, PDTC, which is the inhibitor of NF-κB pathway,had no marked effects on talin1antigen when used alone (P>0.05), but PDTC could significantly inhibited the effects of Ang-(1-7) on talin1expression induced by Ang Ⅱ (P<0.05) at antigen level as well as mRNA.Conclusion①The present data suggested that Ang Ⅱ could increase the expression of talin1in time-dependent and dose-dependent manner.②Ang-(1-7) could inhibit this effect at mRNA level in time-dependent and dose-dependent manner.③NF-κB pathway participates in the inhibitory process that Ang-(1-7) inhibited the expression of talin1induced by Ang Ⅱ.