吡格列酮对PCOS卵巢颗粒细胞分泌雌激素的影响

Effects of pioglitazone on E_2 secretion in PCOS ovarian granulosa cells

目的观察吡格列酮对多囊卵巢综合征(PCOS)患者卵巢颗粒细胞雌激素分泌功能和其上P450芳香化酶(P450arom)、胰岛素受体底物-1(IRS-1)和胰岛素受体底物-2(IRS-2)表达的影响。方法对27例行体外受精-胚胎移植PCOS患者的颗粒细胞进行体外原代培养并分组,A组分别加入不同浓度(0、10、102、103、104nmol/L)吡格列酮、B组为不同浓度吡格列酮与卵泡刺激素(FSH,50ng/L)及C组为不同浓度吡格列酮与胰岛素样生长因子-Ⅰ(IGF-Ⅰ,50ng/L)。用放射免疫法检测培养上清液中雌二醇(E2)浓度,Real-time PCR法检测颗粒细胞上P450arom、IRS-1、IRS-2mRNA的表达变化。结果在A、B、C组中,人PCOS卵巢颗粒细胞培养48h的E2产生量差异有统计学意义(P<0.05),吡格列酮各浓度组间P450arom mRNA表达量差异有统计学意义(P<0.05),随着吡格列酮浓度的增加,E2水平和P450arom mRNA表达也随之下降;人PCOS卵巢颗粒细胞在相同浓度吡格列酮时,C组E2水平和P450arom mRNA表达明显高于B组(P<0.01)及A组(P<0.01),B组E2产生量和P450arom mRNA表达高于A组,差异有统计学意义(P<0.05);人PCOS卵巢颗粒细胞经不同浓度吡格列酮刺激48h,各浓度组间IRS-1、IRS-2mRNA表达差异有统计学意义(P<0.05),随着吡格列酮浓度的增加,IRS-1mRNA表达随之下降,IRS-2mRNA表达随之上升。结论吡格列酮可能直接或间接通过对P450arom的抑制,减少E2的生成,改善颗粒细胞上IRS-1和IRS-2表达的失衡,抑制PCOS卵巢的局部胰岛素抵抗状态;吡格列酮可抑制FSH和IGF-Ⅰ刺激卵巢颗粒细胞分泌雌激素的功能。

Objective To observe the effects of pioglitazone on secretion of E2 and expressions of P450 aromatase （P450arom）, insulin-receptor substrate-1 （IRS-1）, and insulin-receptor substrate-2 （IRS-2） mRNA in polycystic ovary syndrome （PCOS） ovarian granulosa cells. Methods In this study, granulosa cells that were fertilization-embryo transferred from 27 PCOS patients were primary cultured in vitro with different concentrations of pioglitazone （0, 10, 10^2 , 10^3 and 10^4 nmol/L） （Group A）, different concentrations of pioglitazone＋FSH （50 ng/L, Group B） and different concentrations of pioglitazone＋insulin-like growth factor I （IGF-I, 50 ng/L, Group C）. Estradiol concentrations in the culture supernatant were detected by radioimmunoassay; P450arom, IRS-1 and IRS-2 mRNA expressions on granulosa cells were detected by Real-time PCR. Results The levels of E2 secreted by granulosa cells and the expression of P450arom mRNA on granulosa cells of PCOS for 48 hours were different among Groups A, B and C （P〈0.05）. With increase in pioglitazone concentration, the level of E2 and the expression of P450arom mRNA declined, some of which correlated negatively with the concentration of pioglitazone. Among these groups, the level of E2 secretion and the expression of P450arom mRNA were higher in Group C than in Group B （P〈0.01） and Group A （P〈0.01） at the same concentration of pioglitazone. The level of E2 secretion and the expression of P450arom mRNA were higher in Group B than in Group A （P〈0.05） at the same concentration of pioglitazone. The expressions of IRS-1 and IRS-2 mRNA on granulosa cells of PCOS under pioglitazone stimulation for 48 hour were different among the groups of different pioglitazone concentrations （P〈0.05）. With increase in pioglitazone concentration, the expression of IRS-1 mRNA on granulosa cells of PCOS was decreased, but the expression of IRS-2 mRNA on granulosa cells of PCOS was increased. Conclusion Pioglitazone may decrease estrogen production by inhibiting p450 aromatase and adjusting the expressions of IRS-1 and IRS-2 on granulosa cells of PCOS to play a role in ovulation induction and ameliorate insulin resistance in ovary of PCOS. Pioglitazone can inhibit IGF-I and FSH in inducing E2 secretion by ovarian granulosa cells.