Regulation of uridine diphosphate-glucuronosyltransferase 2B15 expression during ovulation in the rat

[摘要] Uridine diphosphate-glucuronosyltransferase 2B15 (UGT2B15) conjugates 5α-androstane-3α, 17β-diol (3α-diol) to 3α-diol glucuronide (3α-diol G) in steroid target tissues.The present study investigated the regulation of UGT2B15 expression during the ovulatory process in the rat.Real-time PCR analysis revealed that treatment of immature rats with equine chorionic gonadotropin followed by human chorionic gonadotropin transiently stimulated UGT2B15 gene expression in granulosa cells of preovulatory follicles within 6 h.The progesterone receptor antagonist RU486 suppressed the gonadotropin-induced UGT2B15 expression.The expression of UGT2B15 and the levels of 3α-diol G were transiently increased by luteinizing hormone (LH) treatment in cultured preovulatory follicles.The LH-stimulated UGT2B15 mRNA level in cultured preovulatory follicles was inhibited by inhibitors of adenylyl cyclase, phosphoinositide 3-kinase and mitogen-activated protein kinase.Furthermore, a vitamin D receptor agonist (calcitriol) suppressed the LH-stimulated UGT2B15 expression in a dose-dependent manner.Taken together, these results indicate that gonadotropins transiently stimulate UGT2B15 expression and activity in preovulatory follicles, and UGT2B15 mRNA levels are regulated by the progesterone receptor and vitamin D receptor.

[学科分类] 内分泌与代谢学

[关键词] Uridine diphosphate-glucuronosyltransferase 2B15;3α-diol glucuronide;Ovulation;Vitamin D receptor