胰岛素样生长因子-I和人绒毛膜促性腺激素对成年大鼠Leydig细胞葡萄糖转运蛋白基因表达调控

Regulation of Insulin-like Growth Factor-I and Human Chorionic Gonadotropin on the Expression of Glucose Transporters Gene in Adult Rat Leydig Cells

目的:研究胰岛素样生长因子I(IGF I)和人绒毛膜促性腺激素(hCG)对成年大鼠睾丸Leydig细胞中葡萄糖转运蛋白(GLUT)基因表达的影响,为进一步探讨Leydig细胞中睾酮的合成、分泌与葡萄糖代谢的关系提供依据。方法:采用改良的Klinefelter方法从成年大鼠睾丸中分离获得Leydig细胞;用反转录聚合酶链技术检测IGF I和hCG对原代培养的Leydig细胞中GLUT基因表达的调控作用。结果:分离得到纯度为98%的大鼠Leydig细胞,并与对照组比较,hCG可显著增加Leydig细胞中GLUT8基因mRNA的表达水平(P<0.001),且此作用具有剂量依赖性与时效性。当在试验组细胞中单独加入IGF I或IGF I和hCG作用于细胞后,发现IGF I(100ng mL)可显著增加Leydig细胞中GLUT8基因mRNA的表达(P<0.01),也可与hCG协同作用显著提高GLUT8基因的mRNA表达,该结果与IGF I(100ng mL)和hCG(10ng mL)能协同作用极显著增加睾酮合成水平(P<0.001)的结果是相吻合的。在大鼠Leydig细胞中,无论10ng mL或100ng mL还是两者同时作用于细胞,都不能影响GLUT1和GLUT3基因的mRNA水平。结论:在成年大鼠Leydig细胞中,IGF I和hCG对细胞中的GLUT8基因表达的调节作用具有特异性,其协同作用能显著提高细胞中GLUT8基因mRNA水平,增强细胞摄取葡萄糖的能力,给细胞提供更多的代谢能源,最终增加Leydig细胞睾酮的合成与分泌。

Objective:To study the effects of insulin-like growth factor-I(IGF-I)and human chorionic gonadotropin(hCG)on expressions of glucose transporters(GLUT)gene and testosterone production in adult rat Leydig cells and the relationship between steroidogenesis and glucose metabolism in adult rat Leydig cells. Methods:The modified Klinefelter's method was used to isolate the rat Leydig cells. The regulatory effects of IGF-I and hCG on GLUT gene expression in primary cultured rat Leydig cells were investigated by reverse transcription-polymerase chain reaction. Results:The rat Leydig cells with the purity of 98% were isolated. hCG caused dose-and time-dependent increases of GLUT8 mRNA levels.IGF-I(100?ng/mL)could also increase GLUT8 mRNA expression significantly. IGF-I and hCG had synergistic effects on GLUT8 mRNA expression(P<0.001).This result was consistant to the result from the experiment in which IGF-I(100?ng/mL)and hCG(10?ng/mL)could increase testosterone level synergistically(P<0.001).However,in primary cultured rats Leydig cells, neither GLUT1 nor GLUT3 mRNA expression was affected by the treatment of hCG(10?ng/mL)or IGF-I(100?ng/mL),and the combination of hCG(10?ng/mL)and IGF-I(100?ng/mL). Conclusion:In adult rat Leydig cells, the regulatory effects of IGF-I and hCG on GLUT8 mRNA expression are specific. IGF-I and hCG can increase GLUT8 mRNA expression level synergistically,then increase the glucose uptake by GLUT and provide more energy for metabolism in Leydig cells.