Qiu Hong-yu, Chu Yong-li, Li Min, Sun Yong-yu, Li Hong-fa
Department of Obstetrics and Gynecology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022.
Zhonghua Fu Chan Ke Za Zhi. 2005 Feb;40(2):116-9.
To explore molecular mechanisms of insulin resistance of polycystic ovary syndrome (PCOS) by determining the tyrosine phosphorylation and protein expression of insulin receptor substrate-2 (IRS-2) in adipose tissue from patients with PCOS.
Serum and subcutaneous adipose tissue samples from patients with PCOS with insulin resistance (n = 19), PCOS without insulin resistance (n = 17) and controls (n = 20) were collected. The expression of IRS-2 in adipose tissue was assessed by Western blot. Immunohistochemistry was used to detect the distribution of IRS-2 in adipose tissues of all patients. The tyrosine phosphorylation of IRS-2 was measured by immunoprecipitation and enhanced chemiluminescent immunoblotting technique.
(1) There was no significant difference of the protein expression of IRS-2 in PCOS with insulin resistance 1.15 +/- 0.26 compared to those in PCOS without insulin resistance 1.13 +/- 0.26 and control group 1.00 +/- 0.25 (P > 0.05); (2) The tyrosine phosphorylation of IRS-2 was significantly decreased in PCOS with insulin resistance 0.77 +/- 0.16 compared to that of PCOS without insulin resistance 0.91 +/- 0.25 and control groups 1.00 +/- 0.12 (P < 0.05). There was no significant difference between PCOS without insulin resistance and control groups (P > 0.05).
The decrease of tyrosine phosphorylation of IRS-2 in PCOS patients, which induces impairment of the insulin signal pathway, may be one of the mechanisms leading to insulin resistance.
通过测定多囊卵巢综合征（PCOS）患者脂肪组织中胰岛素受体底物-2（IRS-2）的酪氨酸磷酸化及蛋白表达，探讨PCOS胰岛素抵抗的分子机制。
收集PCOS伴胰岛素抵抗患者（n = 19）、PCOS不伴胰岛素抵抗患者（n = 17）及对照组（n = 20）的血清和皮下脂肪组织样本。采用蛋白质印迹法评估脂肪组织中IRS-2的表达。免疫组织化学法检测所有患者脂肪组织中IRS-2的分布。通过免疫沉淀和增强化学发光免疫印迹技术测定IRS-2的酪氨酸磷酸化。
（1）PCOS伴胰岛素抵抗组IRS-2蛋白表达为1.15±0.26，与PCOS不伴胰岛素抵抗组1.13±0.26及对照组1.00±0.25相比，差异无统计学意义（P>0.05）；（2）PCOS伴胰岛素抵抗组IRS-2的酪氨酸磷酸化水平为0.77±0.16，显著低于PCOS不伴胰岛素抵抗组0.91±0.25及对照组1.00±0.12（P<0.05）。PCOS不伴胰岛素抵抗组与对照组之间差异无统计学意义（P>0.05）。
PCOS患者IRS-2酪氨酸磷酸化水平降低，导致胰岛素信号通路受损，可能是导致胰岛素抵抗的机制之一。
