多囊卵巢综合征合并胰岛素抵抗患者脂肪组织中磷脂酰肌醇3激酶的检测及其意义

Detection and significance of phosphatidylinositol 3-kinase in adipose tissue of polycystic ovary syndrome patients with insulin resistance

目的检测多囊卵巢综合征(PCOS)合并胰岛素抵抗(IR)患者脂肪组织中磷脂酰肌醇3激酶(PI-3K)的表达,探讨PCOS患者发生IR的机制。方法检测PCOS发生IR 19例患者(PCOS IR组)、PCOS未发生IR 10例患者(PCOS非IR组)及因单纯子宫肌瘤施行手术的15例患者(对照组)的空腹血清胰岛素(FIN)及空腹血糖(FPG)的水平。采用稳态模型(HOMA)法评价及计算IR指数(HOMA-IR)；采用蛋白印迹法检测脂肪组织中PI-3K蛋白的表达；采用RT-PCR技术检测PI-3K mRNA的表达；采用免疫沉淀技术、薄层层析及γ液体闪烁计数仪检测PI-3K的活性,设对照组平均PI-3K活性为100%。结果(1)PCOS IR组患者血清FIN为(25．2±3．8)mU/L,HOMA-IR为1．6±0．3；PCOS非IR组分别为(13．4±3．8)mU/L及0．9±0．3；对照组分别为(9．5±2．6)mU/L及0．5±0．3,3组分别比较,差异均有统计学意义(P＜0．05)。(2)PCOS IR组PI-3K蛋白及mRNA相对表达水平分别为0．65±0．10及0．92±0．12；PCOS非IR组分别为0．72±0．10及1．01±0．10；对照组分别为0．73±0．14及1．00±0．12,3组分别比较,差异均无统计学意义(P＞0．05)。(3)PCOS IR组PI- 3K活性下降为81%,PCOS非IR组下降为89%,PCOS IR组及PCOS非IR组分别与对照组比较,差异均有统计学意义(P＜0．01,P＜0．05)。PCOS IR组和PCOS非IR组PI-3K活性与HOMA-IR均呈显著负相关关系(r=-0．69,P＜0．01；r=-0．62,P＜0．05)。结论PCOS IR患者的PI-3K蛋白及mRNA的表达无明显改变,但PCOS患者PI-3K活性降低,可能是PCOS患者发生IR的机理之一。

Objective To investigate the expression of phosphatidylinositol 3-kinase （PI-3K） in adipose tissue of polycystic ovary syndrome patients （PCOS） , and explore molecular mechanisms of insulin resistance （IR） in PCOS. Methods Samples from patients with PCOS with IR （ n = 19 ）, PCOS without IR （n = 10） and controls （n = 15）were collected. Serum fasting insulin （FIN） and fasting plasma glucose （FPG） were measured. Insulin resistance index was calculated using homeostasis model assessment （HOMA） to analyze the relationship between these markers and IR. Western blot technique was used to detect the PI-3K p85 subunit. Gene expression of PI-3K p85 subunit was detected by reverse transcription polymerase chain reaction （RT-PCR） method. Kinase activity was detected by immunoprecipitation, thinlayer chromatography and gamma scintillation counting. Results （ 1 ） The levels of FIN [ （ 25.2 ± 3.8 ） mU/L] and HOMA-IR（ 1.6 ±0. 3） in PCOS with IR were significantly higher than those in PCOS without IR [（13.4 ±3.8）mU/L,0.9 ±0.3] and controls [（9.5 ±2.6）mU/L,0.5 ±0.3; all P〈0.05）. （2） There was no significant difference in the protein（0. 65 ±0. 10） and gene expression （0. 92±0. 12） of PI-3K p85 subunit in PCOS with IR compared with PCOS without IR （0. 72 ± 0. 10, 1.01 ± 0. 10） and controlgroups （0. 73 ± 0. 14,1.00 ± 0. 12 ; P 〉 0. 05 ）. （ 3 ） PI-3K activity in PCOS with IR （ 81% ） and PCOS without IR （89%） was significantly decreased （P 〈 0. 01, P 〈 0.05 ） and negatively correlated with HOMA- IR （r= -0.69,P〈0.01;r= -0.62,P〈0.05）. Conclusions No significant difference in the protein and gene expression of PI-3K p85 subunit in PCOS with IR is found. The decreased PI-3K activity may lead to IR of PCOS.