基于JNK/p38 MAPK信号通路探讨夏枯草胶囊对自身免疫性甲状腺炎大鼠的作用

Effects of Prunella vulgaris Capsules on autoimmune thyroiditis in rats based on JNK/p38 MAPK signal pathway

目的研究夏枯草胶囊对自身免疫性甲状腺炎(AIT)大鼠甲状腺滤泡细胞凋亡和c-Jun氨基末端激酶(JNK)/促分裂素原活化蛋白激酶(p38 MAPK)信号通路的影响。方法60只大鼠随机分为正常组、模型组、硒酵母组及夏枯草胶囊低、中、高剂量组,每组10只,使用高碘水喂养配合皮下注射猪甲状腺球蛋白(pTg)与弗氏佐剂(CFA、IFA)诱导AIT大鼠模型,造模后连续灌胃给药4周。ELISA法检测大鼠甲状腺功能(FT3、FT4、TSH)、甲状腺抗体(TPOAb、TGAb)及相关炎性指标(INF-γ、IL-10、IL-17、IL-35)水平,HE染色观察大鼠甲状腺病理变化,Western blot法检测大鼠甲状腺组织中磷酸化的JNK(p-JNK)、磷酸化的p38 MAPK(p-p38 MAPK)蛋白表达,免疫组化(IHC)法检测大鼠甲状腺组织B淋巴细胞瘤2(Bcl-2)和半胱氨酸蛋白酶3(caspase-3)阳性细胞表达。结果与模型组比较,夏枯草胶囊各剂量组及硒酵母组大鼠甲状腺淋巴浸润与滤泡破坏均有明显改善,血清FT3、FT4、TPOAb、TGAb、IFN-γ、IL-17水平,甲状腺组织中p-JNK、p-p38 MAPK蛋白表达及caspase-3阳性细胞比例均降低(P<0.05),血清TSH、IL-10、IL-35水平及甲状腺组织Bcl-2阳性细胞比例均升高(P<0.05)。结论夏枯草胶囊对AIT大鼠甲状腺的破坏具有保护作用,该作用与降低促炎细胞因子水平,抑制JNK/p38 MAPK信号通路的活化,进而减少甲状腺滤泡细胞凋亡有关。

AIM To study the effects of Prunella vulgaris Capsules on thyroid follicular cell apoptosis and JNK/p38 MAPK signal pathway in rats with autoimmune thyroiditis(AIT).METHODS Sixty rats were randomly divided into normal group,model group,selenium yeast group and P.vulgaris Capsules groups for low,medium and high dose intervention,respectively,with 10 rats in each group.After the AIT rat models were inducted by high iodine water feeding and subcutaneous injection of porcine thyroglobulin(pTg)and Freund's adjuvant(CFA,IFA),the rats were given 4-week continuous intragastric administration of the corresponding drug.The rats had their levels of thyroid function(FT3,FT4,TSH),thyroid antibodies(TPOAb,TGAb)and related inflammatory indices(INF-γ,IL-10,IL-17,IL-35)detected by ELISA;the pathological changes of thyroid observed by HE staining;the thyroid expressions of phosphorylated JNK(p-JNK)and phosphorylated p38 MAPK(p-p38 MAPK)proteins detected by Western blot;and the expressions of B lymphocyte tumor 2(Bcl-2)and caspase-3 positive cells observed by immunohistochemistry(IHC).RESULTS Compared with the model group,the groups intervened with P.vulgaris Capsules and selenium yeast shared improved thyroid follicle destruction and lymphocyte infiltration;decreased levels of serum FT3,FT4,TPOAb,TGAb,IFN-γ,IL-17,protein expressions of p-JNK and p-p38 MAPK in thyroid tissue and the proportion of caspase-3 positive cells(P<0.05);and increased levels of serum TSH,IL-10,IL-35 and the proportion of Bcl-2 positive cells in thyroid tissue(P<0.05).CONCLUSION The protective effects of P.vulgaris Capsules on thyroid damage of AIT rats may be associated with the reduced apoptosis of follicular cells because of the decreased levels of pro-inflammatory factors and inhibited activation of JNK/p38 MAPK signal pathway.