基于TLR-4/Caspase-3信号通路参与黄芩苷治疗非酒精性脂肪性肝炎的机制研究

Preliminary Study on Mechanism of Baicalin in Treatment of Nonalcoholic Steatohepatitis by TLR-4/Caspase-3 Pathway

目的探讨黄芩苷对游离脂肪酸诱导的非酒精性脂肪肝性肝炎(nonalcoholic steatohepatitis,NASH)细胞模型中甘油三酯积累和炎症的影响,以及与TLR-4调控的凋亡信号通路的关系。方法制备NASH细胞模型后,用不同浓度的黄芩苷作用于后,通过油红染色观察NASH模型内脂质的含量,通过流式细胞术检测NASH细胞凋亡情况,通过WB及PCR法检测了TLR-4/Caspase-3信号通路的表达情况,并通过Elisa法研究细胞上清中下游细胞因子IL-1β及TNF-α的表达情况。结果油红O染色显示NASH细胞模型内油脂增多,而不同浓度黄芩苷可以减少细胞内的甘油三酯的积累。通过流式细胞术,发现黄芩苷可以明显减少NASH细胞模型的凋亡情况。黄芩苷可下调TLR-4、NF-kB,BAX,Caspase-3的基因表达水平,而上调凋亡关键基因BCL-2的表达,同时可下调炎性细胞因子IL-1β和TNF-α的表达水平。结论黄芩苷可以通过抑制TLR-4/Caspase-3凋亡信号通路改善NASH的炎症情况及脂肪沉积,从而达到治疗NASH的作用。

Objective To investigate the effects of baicalin on triglyceride accumulation and inflammation in free fatty acid-induced nonalcoholic steatohepatitis(NASH)cell model and its relationship with toll-like receptor 4(TLR-4)regulated apoptosis signaling pathway.Methods After the Nash cell model was prepared and treated with baicalin of different concentrations,the lipid content in the Nash model was observed by oil red staining.The apoptosis of Nash cells was detected by flow cytometry,the expression of TLR-4/caspase-3 signal pathway was detected by Western Blot and PCR methods and the expressions of interleukin-1β(IL-1β)and tumor necrosis factor-α(TNF-α)in the middle and lower reaches of cell supernatant was measured by ELISA.Results The Oil red O staining showed that the oil in NASH cell model increased and different concentrations of baicalin could reduce the accumulation of triglycerides in NASH cells.Through flow cytometry,it was found that baicalin could significantly reduce the apoptosis of Nash cell model.Baicalin can down regulate the gene expression levels of TLR-4,nuclear factor-kB(NF-kB),Bax and caspase-3,up regulate the expression of apoptosis key gene Bcl-2,and down regulate the expressions of IL-1βand TNF-α.Conclusion Baicalin can improve the inflammation and fat deposition of Nash through TLR-4/caspase-3 apoptotic signaling pathway,so as to achieve the therapeutic effect of NASH.