萝卜硫素对自身免疫性甲状腺炎小鼠的作用及机制

Effect and mechanism of sulforaphane on mice with autoimmune thyroiditis

目的 研究萝卜硫素对自身免疫性甲状腺炎小鼠的药效及机制。方法 采用皮下多点注射猪甲状腺球蛋白联合高碘水的方法构建小鼠自身免疫性甲状腺炎模型,随后将模型小鼠随机分为模型组及给药组(雷公藤多苷片组、萝卜硫素低、中、高剂量组),每组10只。空白对照组和模型组采用灌胃方式给予等体积生理盐水,雷公藤多苷片组以及萝卜硫素低、中、高剂量组的灌胃剂量分别为5、5、10、20 mg/(kg·d),给药干预4周。取材后检测各组小鼠血清甲状腺球蛋白抗体(TGAb)、甲状腺过氧化物酶抗体(TPOAb)、IL-6、IL-17和IL-23的水平,HE染色法观察甲状腺组织病理学变化;Western blot法检测甲状腺组织表皮生长因子受体(EGFR)和转录因子NF-E2相关因子(Nrf2)蛋白的表达水平。结果 与空白对照组比较,模型组的血清TGAb、TPOAb、IL-6、IL-17和IL-23的含量明显升高(P<0.01),甲状腺组织中可见大量炎症细胞浸润。甲状腺组织EGFR蛋白表达水平明显上调(P<0.01),Nrf2蛋白的表达水平明显下调(P<0.01)。与模型组比较,萝卜硫素给药组明显降低血清TGAb、TPOAb、IL-6、IL-17和IL-23的含量(P<0.05),减轻甲状腺组织炎症细胞的浸润程度,下调甲状腺组织EGFR蛋白的表达水平,上调Nrf2蛋白的表达水平。结论 萝卜硫素通过降低促炎症因子水平,同时下调甲状腺组织EGFR蛋白的表达水平,上调Nrf2蛋白的表达水平,从而改善甲状腺功能。

Objective To observe the effect and mechanism of sulforaphane on mice with autoimmune thyroiditis.Methods The mouse model of autoimmune thyroiditis was established by subcutaneous multi-point injection of porcine thyroglobulin combined with high iodine water. Then, the model mice were randomly divided into a model group and administration groups(Tripterygium wilfordii polyglycoside tablet group, sulforaphane low-dose,medium-dose and high-dose groups), with ten mice in each group. The blank control group and model group were given constant volume of normal saline intragastrically, and the tripterygium glycosides tablet group and sulforaphane low-dose, medium-dose and high-dose groups were given 5 mg/(kg·d), 5 mg/(kg·d), 10 mg/(kg·d),20 mg/(kg·d) intragastrically for four weeks. After samples were collected, the levels of thyroid globulin antibody(TGAb), thyroid peroxidase antibody(TPOAb), IL-6, IL-17 and IL-23 in the serum of mice in each group were determined. The pathological changes of the thyroid were observed by hematoxylin-eosin(HE) staining. The expression levels of epidermal growth factor receptor(EGFR) and transcription factor NF-E2 associated factor(Nrf2) proteins in thyroid tissues were detected by Western blot. Results Compared with the blank control group,the contents of serum TGAb, TPOAb, IL-6, IL-17 and IL-23 in the model group were significantly increased(P<0.01), and a large number of inflammatory cells could be seen in thyroid tissue. The expression level of EGFR protein in thyroid tissue was significantly up-regulated(P<0.01), and the expression level of Nrf2 protein was significantly down-regulated(P<0.01). Conclusion Sulforaphane can improve thyroid function by reducing the level of pro-inflammatory factors, down-regulating the expression level of EGFR protein and up-regulating the expression level of Nrf 2.