Influence Of Insulin And Angiotensinâ…¡on Nuclear Factor-kB Activation In Human Endothelial Cells And Xuezhikang Intervention To Their Effects

[Objective] To observe the influence of insulin and angiotensinⅡ(AngⅡ)on nuclear factor-κB(NF-κB )activation and the effect of Xuezhikang intervention on the factor, to investigate the proatherogenic effect of insulin and angiotensinⅡand the non-lipid mechanisms of Xuezhikang on anti-atherosclerosis. [Methods] Cultured passage 2-3 of human umbilical vein endothelial cells strain (ECV-304)in vitro were incubated with 0.5%FBS for 24hrs, then divided into seven groups at random. Except the control group ,the other six groups were stimulated respectively by insulin﹙100uI/ml﹚,AngⅡ﹙5×10-8mol/ml﹚,insulin+AngⅡ,insulin+Xuezhikang﹙150ug/ml﹚,AngⅡ+Xuezhikang,insulin+AngⅡ+Xuezhikang. Cells were incubated with Xuezhikang for 2hrs before co-incubated with insulin or/and AngⅡin the groups containing Xuezhikang, then adhesion rates between monocyte cells and endothelial cells were calculated by cell counting after treatment with stimulus for different time(2h,4h,8h); after co-incubation for 4hrs, immunocytochemical method was employed to evaluate nuclear translocation of NF-κB subumit p65;NF-κB activity was measured by fluorescent labeling and flow cytometry;NF-κB subumit p65 expression was measured by immunocytochemical method. [Results] ①Stimulated by insulin,AngⅡor insulin+AngⅡfor four or eight hours, the adhesion rates of endothelail cells to monocyte cells were 40.83±5.85,40.00±9.49,47.50±6.89,41.67±8.76 and 52.50±8.22,47.50±6.89 respectively, increased significantly compared to controls(19.17±5.85,20.67±4.47)(P<0.05), the adhesion rates of the group treated with insulin+AngⅡwere higher than the one which treated only with insulin or AngⅡ(P<0.05);the adhesion rates of the groups with Xuezhikang were reduced to 26.67±6.06,25.00±7.75,25.00±6.32,25.83±5.86 and 28.33±8.16,28.33±6.83(P<0.05),which shows Xuezhikang could inhibit the increment of adhesion rates caused by insulin or AngⅡ;there is no statistical difference between the groups compared to each other after treated for two hours (P>0.05). ②Either insulin or AngⅡstimulated nuclear translocation of NF-κB after treatment for 4h, Xuezhikang could almost completely inhibit this change.③NF-κB activities of control group(3.26±0.37)was lower than which of the groups stimulated by insulin(6.55±0.53)or AngⅡ(7.23±0.36)or insulin+AngⅡ(10.29±0.69)(P<0.05);insulin+AngⅡelevated NF-κB activities more effectually than insulin or AngⅡ(P<0.05);pro-incubated with Xuezhikang for two hours, NF-κB activity obviously fell(4.44±0.49,3.98±0.24,5.02±0.39)(P<0.05).④Either insulin or AngⅡor Xuezhikang could not effect NF-κB expression(P>0.05). [Conclusions] Both insulin and AngⅡpromoted endotherlial cells adhesion to monocyte cells and activate NF-κB, so are pro-atherosclerosis, Xuezhikang exhibitd the ability to inhibit both endotherlial cells adhesion to monocyte cells and activation of NF-κB induced by insulin or AngⅡ,which demonstrated that Xuezhikang has protective effect on anti-atherosclerosis independent of cholesterol-lowering effect.