Tyrosine Phosphorylation And Protein Expression Of Insulin Receptor Substrate 1 And 2 In The Endometrium From Patients With Polycystic Ovary Syndrome

OBJECTIVE: To explore molecular mechanisms of insulin resistance of polycystic ovary sndrome (PCOS) by determining the tyrosine phosphorylation and protein expression of insulin receptor substrate1 and 2 (IRS-1, IRS-2) in endometrium from patients with PCOSMETHODS: The endometrium samples from patients with PCOS with insulin resistance﹝n=15﹞controls﹝n=10﹞were collected. The expression of insulin receptor substrate-1and 2 and tyrosine phosphokinase were analyzed by immunohistochemistry, western blot and immunoprecipitation. The gray degree of sections was determined by image analysis system. The ray density was scan by gelatin image analysis system.RESULT:﹝1﹞The gray degree of IRS-1/2 expression﹝121.94±16,169.35±13﹞in endometrium in PCOS with insulin resistance were significantly higher than than those in controls﹝55.35±0.98,111.65±8.02﹞﹝P<0.01,P<0.05﹞, indicating that the expression of IRS-1and 2 were decreased in endometrium in PCOS with insulin resistance .The gray degree of tyrosine phosphorylation of IRS﹝141.98±22.5﹞in endometrium in PCOS with insulin resistance were significantly higher than those in controls﹝102.72±9.78﹞﹝P<0.05﹞, indicating that the expression of tyrosine phosphorylation was also decreased in endometrium in PCOS with insulin resistance.﹝2﹞The protein expression of IRS-1 and 2 in PCOS with insulin resistance(4.2±0.38 and 1.4±0.62)were significantly lower than those in control group(9.1±8.4 and 6.1±0.23),(P<0.01,P<0.01﹞.﹝3﹞tyrosine phosphorylation of IRS-1 and IRS-2 in PCOS group with insulin resistance( 1.6±0.64 and 1.5±0.23)were significantly lower than those in control group(1.4±0.42 and 3.4±0.47),(P<0.05,P<0.01﹞CONCLUSION: The signal transduction malfunction because of protein expression and tyrosine phosphorylation of IRS in endometrium may be one of mechanism leading to insulin resistance in endometrium from patients with PCOS.