姜黄素抑制肝星状细胞MyD88及信号通路细胞因子表达的研究

The study of curcumin inhibited MyD88 and cytokines of signaling pathway in hepatic stellate cells

目的探讨姜黄素在肝星状细胞MyD88依赖性途径中的作用机制。方法体外培养大鼠肝星状细胞株HSC-T6,将HSCT6分为空白对照组、Control siRNA组、MyD88 siRNA干扰组、姜黄素组、姜黄素+Control siRNA组、姜黄素+MyD88 siRNA干扰组,siRNA处理组给予siRNA干扰48 h后,姜黄素组加入姜黄素作用24 h,各组均在收集细胞前12 h给予LPS诱导,收集各组细胞,Western blotting法检测MyD88蛋白表达;RT-PCR术检测细胞因子mRNA的表达。结果 MyD88 siRNA干扰、姜黄素均可降低MyD88蛋白的表达(P<0.05),同时给予MyD88 siRNA干扰和姜黄素作用时,MyD88蛋白下降更明显(P<0.05)。MyD88 siRNA干扰后TLR2、TLR4 mRNA表达差异无统计学意义(P>0.05),姜黄素作用后TLR2、TLR4的mRNA表达降低,二者同时作用其下降更显著(P<0.05);MyD88 siRNA干扰、姜黄素处理后NF-κB、TNF-α、IL-1βmRNA表达均降低,二者同时作用后其下降更明显(P<0.05)。结论姜黄素可能通过抑制MyD88蛋白表达和MyD88依赖途径上的多种细胞因子的mRNA表达而阻断MyD88依赖性信号通路的转导,促进活化的HSCs凋亡,从而发挥其抗肝纤维化的作用。

Objective To investigate the mechanism of MyD88-dependent signaling pathway of HSCs induced by curcumin. Methods HSCs were divided into control group, control siRNA group, MyD88 siRNA group, curcumin group, curcumin ＋ control siRNA group, curcumin ＋ MyD88 siRNA group, siRNA groups were interfered by siRNA for 48 hours, curcumin was added into curcumin groups for 24 hours to collect cells. LPS was put into all groups, then in- cubated HSCs with LPS for 12 hours. The expression of MyD88 protein was observed by Western blotting, cell apoptosis was detected by flow cytometry. Results Both MyD88 siRNA and curcumin could down-regulate the expression of MyD88 protein （P 〈 0.05） , the expression of MyD88 protein was more obviously decreased in MyD88 siRNA ＋ curcu- rain group. Curcumin could down-regulate the expression of TLR2 and TLR4 mRNA （P 〈 0.05） , while MyD88 siRNA had no significant difference on them. Both curcumin and MyD88 siRNA could reduce the expression of NF-κB, TNF-α, IL-1β mRNA, respectively （P 〈 0.05）. All five cytokines above were significantly lower in MyD88 siRNA ＋ curcumin group. Conclusion Curcumin could prevent liver fibrosis. It may block MyD88-dependent signaling pathway and in- duce apoptosis of activated HSCs by inhibiting the expression of MyD88 protein and cytokines mRNA.