摘要
转染促甲状腺素受体（TSHR）shRNA的333-L1脂肪细胞以牛促甲状腺素（TSH）刺激，酶联免疫吸附法（ELISA）检测培养基中肿瘤坏死因子α（TNF-α）水平，Western印迹法检测胰岛素受体底物1（IRS-1）的蛋白表达，免疫沉淀法检测IRS-1酪氨酸磷酸化。结果显示，1mIU／mlTSH明显增加333-L1脂肪细胞TNF-01分泌[（341．85±12．00对522．67±36．22）ng／L，P〈0．01]；随着TSH刺激浓度的增加，IRS-1蛋白表达及其酪氨酸磷酸化明显降低（均P〈0．01），而以RNA干扰下调TSHR后上述作用消失。另外，TNF—α拈抗剂WP9QY也可逆转TSH对IRS-1的下调作用。这些结果提示TSH与333-L1脂肪细胞表面TSHR结合后，可能通过促进TNF-α分泌进而下调IRS-1的表达及其酪氨酸磷酸化，而参与胰岛素抵抗的发生。
3T3-L1 adipocytes transfected with TSH receptor （TSHR） shRNA were incubated with bovine TSH. The concentration of tumor necrosis factor （TNF）-α in culture medium was measured by enzyme linked immunosorbent asssy. Protein level of insulin receptor substrate 1 （ IRS-1 ） was quantified by Western blotting. Tyrosine phosphorylation of IRS-1 was measured by immunoprecipitation. The results showed that 1 mlU/ml TSH significantly sitmulated TNF-α release in 3T3-L1 adipocytes [ （ 341.85 ±12.00 vs 522.67 ±36.22 ） ng/L,P〈0.01 ], along with the decreases in IRS-1 protein expression and its tyrosine phosphorylation （P〈0. 01 ）. These effects disappeared when TSHR expression was down-regulated with RNA interference in 3T3-LI adipocytes. In addition, WP9QY, a TNF-α antagonist, blocked TSH-decreased IRS-1 expresssion. These results suggest that TSH down- regulates IRS-1 protein expression and its tyrosine phosphorylation through stimulating production of TNF-α, and thus contributes to the development of insulin resistance.
出处
《中华内分泌代谢杂志》
CAS
CSCD
北大核心
2014年第1期65-68,共4页
Chinese Journal of Endocrinology and Metabolism
基金
天津市应用基础及前沿技术研究计划重点项目（10JCZDJC19900）
天津医科大学科学基金（2011KY25）
关键词
胰岛素抵抗
促甲状腺素
肿瘤坏死因子Α
胰岛素受体底物1
小发夹RNA
Insulin resistance
Thyrotropic-stimulating hormone
Tumor necrosis factor-alpha
Insulin receptor substrate 1
Small hairpin RNA
