BMSCs调控JAK2/STAT3途径对肝硬化动物模型Th17/Treg失衡的影响及其机制

BMSCs regulates JAK2/STAT3 pathway to affect the Th17/Treg imbalance in cirrhotic rats

目的探讨骨髓间充质干细胞(BMSCs)对肝硬化大鼠Janus激活激酶2(JAK2)/信号转导和转录激活因子3(sSTAT3)信号通路以及T辅助细胞17(Th17)/调节性T细胞(Treg)平衡的影响。方法建立大鼠肝硬化模型并进行BMSCs干预。ELISA法检测血清谷丙转氨酶(ALT)和谷草转氨酶(AST),HE染色观察肝组织病理损伤,Masson染色观察肝组织纤维化程度并计算胶原蛋白的体积分数(collagen volume fraction,CVF),RT-PCR检测肝组织p-JAK2、p-STAT3、TGF-β1、IL-6 mRNA表达,Western blot检测肝组织p-JAK2、p-STAT3、TGF-β1、IL-6蛋白表达,流式细胞仪检测Th17、Treg百分比并计算比值。结果肝硬化大鼠ALT、AST显著升高,染色可见明显肝坏死和纤维化,p-JAK2、p-STAT3、TGF-β1、IL-6 mRNA和蛋白表达升高,Th17、Th17/Treg显著下降(P<0.05)。BMSCs干预可以显著降低ALT、AST,减轻肝损伤和纤维化程度,下调p-JAK2、p-STAT3、TGF-β1、IL-6 mRNA和蛋白表达,上调Th17、Th17/Treg(P<0.05)。结论BMSCs可以减轻肝硬化大鼠的炎症反应和纤维化程度,下调JAK2/STAT3信号通路磷酸化和Th17/Treg平衡。

This study was designed to explore the effect of bone marrow-derived mesenchymal stem cells(BMSCs)on Janus activating kinase 2(JAK2)/signal transducer,activator of transcription 3(STAT3)signal pathway and T helper cells 17(Th17)/regulatory T cells(Treg)balance in cirrhotic rats.Liver cirrhosis model was established in rats and intervened by BMSCs injection.ELISA was used to detect serum alanine aminotransferase(ALT)and aspartate aminotransferase(AST);the pathological damage of liver tissue was observed by HE staining;the fibrosis degree of liver tissue was observed by Masson staining.Collagen volume fraction(CVF)was calculated,while the mRNA and protein expression of p-JAK2,p-STAT3,TGF-β1 and IL-6 in liver tissue were detected by RT-PCR and Western blotting,respectively.The percentage of Th17 and Treg were detected by flow cytometry and the ratio was calculated.Data showed that there were liver necrosis and fibrosis in liver cirrhosis rats,and the levels of ALT and AST were increased,the mRNA and protein expression of p-JAK2,p-STAT3,TGF-β1 and IL-6 were increased,while Th17 level and Th17/Treg ratio were decreased(P<0.05).BMSCs intervention could significantly reduce ALT and AST,alleviate liver injury and fibrosis,downregulate p-JAK2,p-STAT3,TGF-β1 and L-6 mRNA and protein expression,and upregulated Th17 and Th17/Treg(P<0.05).Taken together,BMSCs can reduce the inflammatory reaction and fibrosis degree of liver cirrhosis rats,and down regulate JAK2/STAT3 signal pathway phosphorylation and Th17/Treg balance.