促甲状腺激素受体在甲状腺相关眼病球后组织中的基因和蛋白表达

Gene and protein expression of thyrotropin-receptor in retro-bulbar tissue from thyroid-associated ophthalmopathy

目的探讨促甲状腺激素受体(TSHR)在甲状腺相关眼病(TAO)患者球后脂肪和结缔组织中的基因和蛋白表达及其作用机制。方法实验组为TAO患者11例,对照组为非TAO患者10例,分别经手术获得TAO实验组及非TAO对照组患者的球后脂肪与结缔组织,提取总RNA,经RTPCR产物电泳观察TSHRmRNA的表达。基因表达阳性者进行免疫组织化学染色,观察其蛋白表达。结果从TAO实验组和非TAO对照组患者球后脂肪和结缔组织中提取总RNA,经RTPCR扩增TSHRmRNA片段,大小为521bp。TAO患者球后组织和结缔组织中TSHRmRNA阳性表达率为91%,非TAO对照组的阳性表达率为20%,二者比较差异有统计学意义(P=0.007)。在TAO患者组TSHR蛋白的阳性表达率为66.7%,而非TAO对照组患者无TSHR蛋白的表达。结论TAO实验组患者球后脂肪和结缔组织中TSHRmRNA呈高度表达,且有TSHR蛋白表达,而非TAO对照组均无表达,证实TAO患者球后组织中有活性TSHR蛋白存在,提示TSHR可能作为交叉抗原在TAO发病机制中起重要作用。

Objective To investigate gene and protein expression level of thyrotropin-receptor （TSHR） in retro-bulbar connective tissue and fat tissue in patients with thyroid-associated ophthalmopathy （TAO）. Methods Retro-bulbar tissues specimens were obtained from 11 cases of TAO patients and 10 control cases during the operation. RNA was extracted from the tissue specimens using single-step method of acid guanidinium-thiocyanate-phenol-chloroform extraction and TSHR mRNA was analyzed by reverse transcription polymerase chain reaction （RT-PCR）. Immunochemistry staining was performed in patients expressed TSHR, using a mouse polyclonal anti-TSHR peptide antibody to observe protein expression level of TSHR. Results The size of TSHR mRNA segment is 521 bp. The rate of TSHR mRNA expression in TAO retro-bulbar tissue was 91% and was 20% in the control cases, the former was significantly greater than the later. Protein expression rate was 66. 7% in TAO patients, and was negative in the controls. Conclusions High TSHR mRNA expression level and protein level in TAO retro-bulbar tissue and no expression in control tissue indicate that TSHR exists as a common antigen in the orbit and thyroid, and plays a key role in the pathogenesis of TAO.