血必净对LPS诱导血管内皮细胞NO产生和iNOS及核转录因子κB蛋白表达的影响

Influence of Xuebijing in production of NO and expressions of iNOS and NF-κB induced by LPS in vascular endothelial cells

目的:探讨血必净对脂多糖(LPS)诱导血管内皮细胞(VEC)损伤的保护作用,研究在血必净干预下一氧化氮(NO)产生、诱导型一氧化氮合酶(iNOS)表达及信号转导机制。方法:将体外培养的VEC分为对照组、LPS(1mg·L-1)组、LPS(1mg·L-1)+血必净(25g·L-1)组、LPS(1mg·L-1)+吡咯烷二硫代氨基甲酸盐(PDTC,20μmol·L-1)组,在给予LPS前预先用血必净和PDTC孵育1h。采用Western blotting法检测iNOS和核转录因子-κB p65(NF-κB p65)蛋白的表达情况,采用Griess法检测上清液中NO的水平。结果:与对照组比较,LPS组VEC中NO水平、iNOS和NF-κB p65蛋白表达水平明显升高(P<0.01)。与LPS组比较,LPS+血必净组VEC中NO水平、iNOS和NF-κB p65蛋白表达水平明显降低(P<0.05或P<0.01);与LPS组比较,LPS+PDTC组VEC中NO水平和iNOS及NF-κB p65蛋白表达水平均明显降低(P<0.05或P<0.01)。LPS+血必净组与LPS+PDTC组比较,VEC中NO水平和iNOS蛋白表达水平差异无统计学意义(P>0.05),LPS+PDTC组VEC中NF-κB p65蛋白表达水平明显低于LPS+血必净组(P<0.05)。结论:血必净能抑制VEC中NO的产生和iNOS蛋白的表达,其机制可能是通过抑制NF-κB而抑制炎症反应。

Objective To investigate the protective effects of Xuebijing（XBJ）on the injury of vascular endothelial cells（VEC）induced by lipopolysaccharide （LPS）,and to study the mechanisms of the production of nitric oxide （NO）and the expressions of inducible nitric oxide sytnhase （iNOS）and signal transduction under XBJ intervention condition.Methods The cultured VEC were divided into control group, LPS （1 mg · L-1 ）group, LPS （1 mg·L-1）＋XBJ（25 g·L-1）group,LPS（1 mg·L-1）＋pyrrolidine dithiocarbamate（PDTC,20μmol·L-1） group;XBJ and PDTC were administrated 1 h before incubation of with LPS.Western blotting method was used to detect the expressions of iNOS and NF-κB p65 protein.The level of NO in the supernatant was measured by Griess reagent.Results Comparaed with control group,the NO level and the expression levels of iNOS protein and NF-κB p65 protein in VEC in LPS group were significantly increased（P〈0.01）.Compared with LPS group,the NO level and the expression levels of iNOS protein and NF-κB p65 protein in VEC in LPS＋XBJ group were significantly decreased （P〈0.05 or P〈0.01）;the NO level and the expression levels of NF-κB p65 protein and iNOS protein in VEC in LPS＋PDTC group were significantly decreased（P〈0.05 or P〈0.01）.There were no significant differences of the NO levels and the expression levels of iNOS protein between LPS＋XBJ group and LPS ＋PDTC group （P〉0.05）,but the expression level of NF-κB p65 protein in LPS＋PDTC group was lower than that in LPS＋XBJ group（P〈0.05）.Conclusion XBJ can inhibit the production of NO and the expression of iNOS protein in VEC;its mechanism may be related to inhibiting the activation of NF-κB to control inflammation.