TNF琢对体外培养的人脂肪细胞葡萄糖摄取和IRS-1酪氨酸磷酸化的影响  

Effect of TNFα on Glucose Uptake and IRS-1 Tyrosine Phosphorylation in Cultured Human Fat Cells

作　　者：王竹晨[1] 顾熊飞[2] 卢汉平[3] 高锦辉[3] 杨冬梓[1] 邝健全[1] 

机构地区：[1]中山大学附属第二医院妇产科,广东广州510120 [2]中山大学生物化学教研室,广东广州510120 [3]中山大学核医学教研室,广东广州510120

出　　处：《中山大学学报（医学科学版）》2005年第1期48-50,60,共4页Journal of Sun Yat-Sen University:Medical Sciences

基　　金：广东省卫生厅科研基金资助课题(2001189)

摘　　要：【目的】探讨肿瘤坏死因子琢(TNF琢)对体外培养的人脂肪细胞胰岛素刺激的葡萄糖摄取和胰岛素受体底物1(IRS-1)酪氨酸磷酸化的影响,为多囊卵巢综合征(PCOS)的胰岛素抵抗(IR)病因学研究提供新的实验依据。【方法】脂肪细胞葡萄糖摄取的测定采用3H标脱氧右旋葡萄糖(2-[3H]DG)吸收法,IRS-1酪氨酸磷酸化的检测采用免疫沉淀、Western印迹和增强化学发光蛋白免疫印迹法及图像分析。【结果】①胰岛素(100nmol/L)作用下,TNF琢刺激浓度分别为0、5ng/mL、10ng/mL、20ng/mL时,脂肪细胞2-[3H]DG的摄取分别为(652±203)U,(609±172)U,(511±135)U和(404±168)U,当TNF琢刺激浓度达20ng/mL时,脂肪细胞对葡萄糖摄取的降低有显著性差异(P<0.05)。②胰岛素(100nmol/L)刺激下IRS-1的酪氨酸磷酸化在TNF琢(5ng/mL)作用时(74.50%±16.86%)较无TNF琢作用(94.00%±14.70%)有所降低,但无显著性差异;当TNF琢刺激浓度分别为10ng/mL(31.16%±10.44%)和20ng/mL(27.33%±9.63%)时,胰岛素(100nmol/L)刺激后IRS-1的酪氨酸磷酸化明显降低(P<0.001)。【结论】①TNF琢刺激浓度的升高可抑制体外培养的人脂肪细胞胰岛素刺激的葡萄糖摄取。②TNF琢可抑制体外培养的人脂肪细胞胰岛素刺激的IRS-1的酪氨酸磷酸化,并存在一定的量效关系。To study the effect of tumor necrosis factor alpha (TNF α) on glucose uptake and insulin receptor substrate I (IRS-1) tyrosine phosphorylation in cultured fat cells in order to provide new experimental data for probing into the pathogenesis of IR in polycystic ovary syndrome (PCOS). Glucose uptake was assayed using 2-DG. IRS-1 tyrosine phosphorylation was detected with the immunoprecipitation, Western blot analysis, and ECL immunoblotting. (1) In presence of INS (100 nmol/L) stimulation and with the stimulating concentration of TNFα of 0, 5 ng/mL, 10 ng/mL, 20 ng/mL, respectively, 2-DG uptake in adipocytes were (652±203)U, (609±172)U, (511±135)U, and (405±168)U, respectively. As the stimulating concentration of TNFα reached 20 ng/mL, the difference was significant (P<0.05=. (2) With INS (100 nmol/L) stimulation, IRS-1 tyrosine phosphorylation in the group with (5 ng/mL) TNFα (74.50%±16.86%) was lower than that without TNFα(94.00%±14.70%), but the difference was not significant (P > 0.05). More reduction in TRS-1 tyrosine phosphorylation was observed when TNFα increased to 10 ng/mL (31.16%±10.44%, P < 0.001) and 20 ng/mL (27.33%±9.63%, P < 0.001). [Conclusion] (1) TNFα can reduce glucose uptake stimulated by INS in cultured human adipocytes. (2) TNFα can reduce IRS-1 tyrosine phosphorylation with INS stimulation in cultured human adipocytes. As the stimulating concentration of TNFα increases, it decreases more markedly which might restrain insulin-signaling transduction downstream of INS receptor and induce IR.

关 键 词：IRS-1 TNFα 脂肪细胞 葡萄糖摄取 酪氨酸磷酸化 体外培养 胰岛素 刺激 蛋白免疫印迹法 信号传导 

分 类 号：R587.1[医药卫生—内分泌] R711.75[医药卫生—内科学]