碘化钠对人甲状腺上皮细胞TNF-α、IL-1β分泌的影响

Effects of Sodium Iodide on the Secretion of TNF-α and IL-1β in Human Thyrocytes

为研究碘化钠 (NaI)对人甲状腺上皮细胞 (TEC )分泌细胞因子TNF α和IL 1β的影响 ,以探讨碘在GD病 (GD )发病中的可能机制 ,取手术切除的GD病患者甲状腺组织和甲状腺腺瘤患者瘤旁正常甲状腺组织 ,进行细胞培养。以不同浓度的NaI (10 8～ 10 3 mol/L )刺激单层培养的甲状腺细胞 ,采用放射免疫测定技术测定刺激前后甲状腺细胞培养上清液中细胞因子TNF α和IL 1β的含量。同时以透射电镜观察NaI刺激后甲状腺细胞的形态学改变。结果 :(1)正常甲状腺细胞能分泌少量的TNF α和IL 1β。GD的甲状腺细胞TNF α和IL 1β的分泌量与正常TEC相比显著增加 (P <0 0 1) ;(2 )当NaI浓度为 10 8～10 3 mol/L时 ,正常人甲状腺细胞TNF α、IL 1β的分泌量与 0mol/L组相比无显著性差异 (P >0 0 5 ) ;透射电镜示正常甲状腺细胞无损伤型改变 ;(3)当NaI浓度为 10 6～ 10 3 mol/L时 ,GD甲状腺细胞TNF α的分泌量显著增加 (P <0 0 5 ) ;当NaI浓度为 10 8～ 10 3 mol/L时 ,GD甲状腺细胞IL 1β的分泌量显著增加 (P <0 0 5 )。NaI浓度超过 10 6mol/L时 ,透射电镜示GD甲状腺细胞出现损伤型改变。表明高浓度的碘不仅造成GD甲状腺细胞的直接损伤 ,而且可以增加甲状腺细胞细胞因子TNF α和IL 1β的分泌 。

To investigate the effects of sodium iodide on the secretions of TNF-α and IL-1β in human thyrocytes in order to evaluate its significance in the pathogenesis of autoimmune thyroid disease,the thyroid tissues from patients with Graves' disease (GD) and the normal tissues around para-adenoma of thyroid were cultivated in the presence of different concentrations of sodium iodide (10 -8～10 -3mol/L). The contents of cytokines in the supernatants of cultured thyroid cells were determined by radioimmunoassay (RIA). It was found that small amounts of TNF-α and IL-1β were detected in the supernatants of normal throcyte cultures,but the levels of these cytokines in the supernatants of GD patient cultures increased significantly in comparison with those of the normal thyrocytes. There was no significant difference in the amounts of cytokine secretion between the concentrations of sodium iodide of 10 -8～10 -3mol/L and 0 mol/L. When the concentrations of sodium iodide were 10 -6～10 -3mol/L,the level of TNF-α in the supernatants of GD patient cultures was significantly higher than that of the 0 mol/L group,but if the concentration of sodium iodide was over 10 -6mol/L,there appeared damaging changes in the GD patient thyrocytes as showed in TEM examinations. It concludes that high concentration of sodium iodide not only causes the direct damages of GD patient thyrocytes,but also induces the secretions of TNF-α and IL-1β in thyrocytes,especially the GD patient thyrocytes. These results suggest that high concentration of sodium iodide may play a role in the pathogenesis of GD.