凋亡相关蛋白Fas/FasL和BcL-2在自身免疫性甲状腺病中的表达及意义

目的:探讨桥本氏甲状腺炎(HT)及弥漫性毒性甲状腺肿(DTG)细胞凋亡相关蛋白Fas/FasL和BcL-2的表达及意义.方法:采用免疫组化S-P法进行检测.结果:HT及DTG滤泡细胞表达Fas蛋白,阳性率分别为40%和60%,正常甲状腺组织滤泡细胞则未见表达.HT及DTG分别与正常甲状腺组织相比有显著差异P＜0.01.在正常甲状腺组织,HT及DTG中均有滤泡细胞表达FasL和BcL-2,而FasL的表达三者相比均无显著差异.BcL-2的表达在正常甲状腺组织和DTG中较强,而在HT中的表达较弱,与正常甲状腺组织和DTG相比有显著差异P＜0.01.结论:结果提示在HT中滤泡细胞通过表达Fas和FasL,经过Fas与FasL的作用导致部分滤泡细胞凋亡,并通过BcL-2表达的减弱,降低了抗凋亡的作用.在DTG中由于滤泡细胞通过增强BcL-2的表达,从而使得Fas和FasL介导的滤泡细胞凋亡作用减弱.我们认为凋亡相关蛋白的表达在自身免疫性甲状腺病的发生发展中有重要作用.

Expression and significance of apoptosis-related protein Fas/FasL and BcL-2 in autoimmune thyropathy

Objective:To investigate the expression of apoptosis-related protein Fas/FasL and BcL-2 and their significance in Hashimoto's thyroiditis (HT) and diffuse toxic goiter(DTG).Methods:Immunohistochemical staining(S-P method) was used to detect expression of apoptosis-related protein in formalin-fixed and paraffin-embeded tissues from 30 cases of HT,25 cases of DTG,and 22 normal thyroid tissues.Results:Fas-positive thyrocytes were observed in HT and DTG,while expression of Fas protein in normal thyroid tissues was negative.The positive rates of Fas expression were 40% and 60% in HT and DTG respectively,compared with the normal thyroid tissues,there was a significant difference ( P <0.01).FasL-positive thyrocytes and BcL-2-positive thyrocytes were observed in HT,DTG and the normal thyroid tissues,but there was not a significant difference in intensity of FasL-positive staining ( P >0.05).Expressions of BcL-2 in normal thyroid tissues and DTG were stronger,while no significant correlation was found between them.In HT the staining of follicles for BcL-2 was very weak, and there was significant difference compared with that in the normal thyroid tissues and DTG.Conclusion:LIU Chun,et al (Department of Internal Medicine,College of Clinical Medicine,Chongqing Medical University) Abstract Objective:To investigate the expression of apoptosis-related protein Fas/FasL and BcL-2 and their significance in Hashimoto's thyroiditis (HT) and diffuse toxic goiter(DTG).Methods:Immunohistochemical staining(S-P method) was used to detect expression of apoptosis-related protein in formalin-fixed and paraffin-embeded tissues from 30 cases of HT,25 cases of DTG,and 22 normal thyroid tissues.Results:Fas-positive thyrocytes were observed in HT and DTG,while expression of Fas protein in normal thyroid tissues was negative.The positive rates of Fas expression were 40% and 60% in HT and DTG respectively,compared with the normal thyroid tissues,there was a significant difference ( P <0.01).FasL-positive thyrocytes and BcL-2-positive thyrocytes were observed in HT,DTG and the normal thyroid tissues,but there was not a significant difference in intensity of FasL-positive staining ( P >0.05).Expressions of BcL-2 in normal thyroid tissues and DTG were stronger,while no significant correlation was found between them.In HT the staining of follicles for BcL-2 was very weak, and there was significant difference compared with that in the normal thyroid tissues and DTG.Conclusion:Our results suggest that the follicular cells in HT undergo apoptosis through expression of Fas/FasL and interaction between them.The down-regulation of BcL-2 expression in thyrocytes can decrease BcL-2-mediated suppression for apoptosis.Overexpression of BcL-2 in DTG could render thyrocytes resistant to Fas/FasL-mediated apoptosis.We conclude that the expression of apoptosis-related protein plays an important role in the pathogenesis of HT and DTG.