维生素D在NOD.H-2^h4小鼠实验性自身免疫性甲状腺炎中的作用研究

Role of vitamin D in experimental autoimmune thyroiditis in NOD.H-2^h4 mice

目的探讨维生素D在NOD.H-2^h4小鼠(4周龄、平均体质量约20 g)实验性自身免疫性甲状腺炎中的作用。方法选取45只雌性NOD.H-2^h4小鼠随机分为3组:对照组NOD.H-2^h4小鼠(15只)同步用无菌双蒸水喂养8周;实验组NOD.H-2^h4小鼠(15只)使用含0.005%(50 mg/L)碘化钠的无菌双蒸水(大约为100倍正常碘的摄入量)喂养8周,同时每2天给予无菌花生油5μg/kg口服;维生素D干预组NOD.H-2^h4小鼠(15只)使用含0.005%(50 mg/L)碘化钠的无菌双蒸水(大约为100倍正常碘的摄入量)喂养8周,同时每2天给予5μg/kg活性维生素D3口服。所有NOD.H-2^h4小鼠均在实验第8周后经麻醉处死。各组NOD.H-2^h4小鼠血液标本抽取后离心,分离血清,采用电化学发光免疫分析法检测甲状腺素、甲状腺球蛋白抗体(TgAb)、甲状腺过氧化物酶抗体(TPOAb)水平;采用ELISA检测NOD.H-2^h4小鼠血清白细胞介素(IL)-17、IL-23水平;留取NOD.H-2^h4小鼠甲状腺,HE染色观察淋巴细胞浸润情况,并计算自身免疫性甲状腺炎的发生率。结果实验组和维生素D干预组NOD.H-2^h4小鼠自身免疫性甲状腺炎发生率分别为93.3%和86.6%,与对照组比较,差异均有统计学意义(P<0.05);与对照组比较,实验组和维生素D干预组NOD.H-2^h4小鼠血清TgAb、TPOAb、IL-17、IL-23水平均明显升高,差异均有统计学意义(P<0.05);与实验组比较,维生素D干预组NOD.H-2^h4小鼠甲状腺组织形态破坏及淋巴细胞浸润程度明显降低,血清TgAb、TPOAb、IL-17、IL-23水平均明显下降,差异均有统计学意义(P<0.05)。结论维生素D可能与自身免疫性甲状腺炎的发病及严重程度有关。

Objective To investigate the role of vitamin D in experimental autoimmune thyroiditis in NOD.H-2^h4 mice(4-week-old,average weight about 20 g).Methods A total of 45 female NOD.H-2^h4 mice were randomly divided into three groups.NOD.H-2^h4 mice in the control group(15 cases)was fed with sterile double distilled water for 8 weeks.NOD.H-2^h4 mice in the experiment group(15 cases)were given sterile double distilled water containing 0.005%(50 mg/L)of sodium iodide(100 times the normal iodine intake)for 8 weeks,and sterile peanut oil(5μg/kg)every 2 days orally.The vitamin D intervention group(15 cases)was first given sterile double distilled water containing 0.005%(50 mg/L)of sodium iodide(100 times the normal iodine intake)for 8 weeks,followed by oral administration of active Vitamin D3(5μg/kg)every 2 days.All NOD.H-2^h4 mice were killed by anesthetized after 8 weeks.Blood samples from each group were centrifuged and serum was separated.The levels of thyroxine,thyroid globulin antibody(TgAb)and thyroid peroxidase antibody(TPOAb)were determined by electrochemiluminescence immunoassay.The levels of interleukin(IL)-17 and IL-23 in serum of NOD.H-2^h4 mice were determined by enzyme-linked immunosorbent assay(ELISA).Thyroid of NOD.H-2^h4 mice was retained,and HE staining was used to observe the infiltration of lymphocytes and the incidence rate of autoimmune thyroiditis was calculated.Results The incidence rates of autoimmune thyroiditis in NOD.H-2^h4 mice in the experiment group and the vitamin D intervention group were 93.3%and 86.6%respectively,and compared with the control group,the differences were statistically significant(P<0.05).Compared with the control group,the serum levels of TgAb,TPOAb,IL-17 and IL-23 were significantly increased in the experiment group and the vitamin D intervention group,and the differences were statistically significant(P<0.05).Compared with the experiment group,NOD.H-2^h4 mice in the vitamin D intervention group had significantly reduced thyroid tissue destruction and lymphocyte infiltration,and significantly decreased serum TgAb,TPOAb,IL-17 and IL-23 levels,and the differences were statistically significant(P<0.05).Conclusion Vitamin D may be related to the incidence and severity of autoimmune thyroiditis.