PI3K/AKT/mTOR信号通路通过调控Th17细胞分化参与EAT小鼠甲状腺自身免疫损伤

PI3K/AKT/mTOR signaling pathway participates in thyroid autoimmune injury of EAT mice by regulating Th17 cells differentiation

目的探讨磷脂酰肌醇-3-激酶/蛋白激酶B/雷帕霉素靶蛋白(PI3K/AKT/mTOR)信号通路在自身免疫性甲状腺炎发病中的作用及机制。方法将24只雌性C57BL/6小鼠随机分为正常对照(NC)组、实验性自身免疫性甲状腺炎(EAT)组、LY294002干预组(LY29400225 mg/kg和50 mg/kg)。采用苏木素-伊红、免疫组织化学染色检测甲状腺组织淋巴细胞及Th17细胞浸润,Western blotting检测p-AKT(Thr308)、p-AKT(Ser473)、p-m TOR(Ser2448)、S6K1、S6K2、白细胞介素(IL)-17A蛋白表达水平,流式细胞术检测小鼠脾脏单个核细胞(SMCs)中Th17细胞的比例,酶联免疫吸附试验检测血清甲状腺球蛋白抗体(TgAb)滴度及IL-17A浓度。结果EAT组小鼠p-AKT(Thr308)、p-AKT(Ser473)、p-mTOR(Ser2448)、S6K1、S6K2、IL-17A蛋白表达水平、SMCs中Th17细胞比例、血清IL-17A浓度及TgAb滴度较NC组均明显升高,甲状腺炎症程度加重,LY294002干预后上述指标及甲状腺炎症程度均较EAT组减轻,并呈浓度依赖性。结论PI3K/AKT/mTOR信号通路通过调控Th17细胞分化参与EAT小鼠甲状腺自身免疫损伤的发生发展。

Objective To explore the role and mechanism of phosphatidylinositol 3-kinase/protein kinase B/mechanistic target of rapamycin kinase(PI3K/AKT/mTOR)signaling in autoimmune thyroiditis(AIT).Methods 24 female C57BL/6 mice were randomly divided into four groups:a normal control(NC)group,an experimental autoimmune thyroiditis(EAT)group,and two groups treated with LY294002(25 mg/kg or 50 mg/kg LY294002).The degree of thyroiditis was observed by hematoxylin and eosin staining.The percentage of Th17 cells in the spleen mononuclear cells(SMCs)was determined by flow cytometry.Enzyme-linked immunosorbent assay was used to measure the concentrations of thyroglobulin antibody(TgAb)and interleukin-17A(IL-17A)in the serum.Western blotting was conducted to detect the protein levels of IL-17A,p-AKT(Thr308),p-AKT(Ser473),p-mTOR(Ser2448),S6K1,and S6K2 in the different groups.Results Compared with the NC group,the infiltration of Th17 cells and the expressions of IL-17A,p-AKT(Ser473),p-AKT(Thr308),p-mTOR(Ser2448),S6K1,and S6K2 rose remarkably in EAT mice.After the PI3K pathway was blocked,the degree of thyroiditis was significantly alleviated,followed by the proportion of Th17 cells,and the expression of IL-17A and PI3K pathway-related molecules decreased in a dose-dependent manner.Conclusion PI3K/AKT/mTOR signaling pathway participates in thyroid autoimmune jnjury of EAT mice by regulating Th17 cells differentiation.