熊果酸和坡膜酸通过上调乌头酸脱羧酶1表达促进巨噬细胞内毒素耐受作用的研究

Promoting effects of ursolic acid and pomolic acid in endotoxin tolerance of macrophages by up-regulating the expression of aconitate decarboxylase 1

目的研究熊果酸(ursolic acid,UA)和坡膜酸(pomolic acid,PA)上调乌头酸脱羧酶1(aconitate decarboxylase 1,IRG1)表达从而促进巨噬细胞内毒素耐受的活性机制。方法用脂多糖(lipopolysaccharide,LPS)刺激RAW264.7细胞两次构建巨噬细胞内毒素耐受模型;将细胞分为空白对照组、LPS组以及LPS+IRG1过表达组,检测IRG1高表达状态下巨噬细胞在两次LPS刺激下IL-6、TNF-α的分泌情况;将细胞分为LPS组和不同浓度的UA和PA干预组,检测两次LPS刺激下各组巨噬细胞IL-6、TNF-α的分泌和IRG1表达情况。结果过表达IRG1后,与空白对照组相比,LPS组的巨噬细胞在第二次LPS刺激下,IL-6和TNF-α的分泌均受到抑制(P<0.01);与LPS组相比,实验所设的LPS+UA和LPS+PA各浓度组均能有效减少巨噬细胞在受到LPS第二次刺激时IL-6和TNF-α的分泌,并能上调细胞中IRG1蛋白的表达水平(P<0.01)。结论UA和PA的干预能够促进巨噬细胞内毒素耐受,且与二者上调细胞中IRG1蛋白表达有关。

Objective To investigate the promoting effects of ursolic acid(UA)and pomolic acid(PA)in endotoxin tolerance of macrophages by up-regulating the expression of aconitate decarboxylase(IRG1).Methods Lipopolysaccharide(LPS)was used to stimulate RAW264.7 cells twice to construct macrophage endotoxin tolerance model.Cells were divided into the blank control group,LPS group and LPS+IRG1 overexpression group,and the secretion of IL-6 and TNF-αin macrophages with overexpression of IRG1 under two times of LPS stimulation were detected.Then,the cells were divided into LPS group and UA and PA intervention groups with different concentrations.The secretion of IL-6 and TNF-αand the expression of IRG1 with two times of LPS stimulation were checked.Results After the overexpression of IRG1,compared with the control group,the secretion of IL-6 and TNF-αfrom macrophages in LPS group was inhibited by the second LPS stimulation(P<0.01).Compared with LPS group,the concentration groups of LPS+UA and LPS+PA set showed significant decrease in the secretion of IL-6 and TNF-α,and increase in the expression level of IRG1 protein in macrophages after the second stimulation of LPS(P<0.01).Conclusion The intervention of UA and PA could promote endotoxin tolerance of macrophages,and it is related to the up-regulation of IRG1 protein expression in macrophages.