Androgen/androgen receptor pathway regulates expression of the genes for cyclooxygenase-2 and amphiregulin in periovulatory granulosa cells

• Published in: Molecular and cellular endocrinology 2013-04, Vol.369 (1-2), p.42-51
• Main Authors: Yazawa, Takashi, Kawabe, Shinya, Kanno, Masafumi, Mizutani, Tetsuya, Imamichi, Yoshitaka, Ju, Yunfeng, Matsumura, Takehiro, Yamazaki, Yukiko, Usami, Yoko, Kuribayashi, Mayu, Shimada, Masayuki, Kitano, Takeshi, Umezawa, Akihiro, Miyamoto, Kaoru
• Format: Article
• Language: English
• Subjects: Amphiregulin; Androgen; Androgen receptor; Androgen Receptor Antagonists - pharmacology; androgen receptors; Androgens - pharmacology; Animals; antagonists; blood serum; Chorionic Gonadotropin - pharmacology; chromatin; Cox-2; Cyclooxygenase 2 - genetics; Cyclooxygenase 2 - metabolism; Dihydrotestosterone - pharmacology; EGF Family of Proteins; Female; female fertility; Flutamide - pharmacology; gel electrophoresis; genes; Glycoproteins - genetics; Glycoproteins - metabolism; granulosa cells; Granulosa Cells - drug effects; Granulosa Cells - metabolism; human chorionic gonadotropin; Intercellular Signaling Peptides and Proteins - genetics; Intercellular Signaling Peptides and Proteins - metabolism; Mice; Mice, Inbred C57BL; Ovulation; phenotype; precipitin tests; prostaglandin synthase; prostaglandins; superovulation
• ISSN: 0303-7207; 1872-8057
• DOI: 10.1016/j.mce.2013.02.004

► 11-KT and testosterone were robustly elevated at the periovulatory stage. ► AR is strongly expressed in the cumulus cells within mature follicles. ► AR regulates the expression of Cox-2 and Areg in periovulatory granulosa cells. ► AR directly binds to the promoter regions of Cox-2 and Areg. It is well known that the androgen/androgen receptor (AR) pathway is involved in both male and female fertility in mammals. AR knockout female mice are reported to exhibit various abnormalities in follicle development, and a subfertile phenotype. In exogenous gonadotropin-induced superovulation, serum androgen levels were robustly elevated in female mice at the periovulatory stage after human chorionic gonadotropin (hCG) treatment. At this stage, ovarian AR proteins were strongly expressed in cumulus cells. Because these results suggested that the androgen/AR pathway is involved in ovulation, we investigated the expression of ovulation-related genes in the mouse ovary treated with the nonaromatizable androgen, 5α-dihydrotestosterone (DHT). DHT treatment induced the expression of the genes for cyclooxyganase-2 (Cox-2 or prostaglandin endoperoxidase synthase 2) and the epidermal growth factor-like factor, amphiregulin (Areg), in the ovary, whereas their hCG-induced expression was suppressed by the AR antagonist flutamide. These genes were also induced by DHT in AR-expressing primary granulosa and granulosa tumor-derived cells. Reporter assays, electrophoretic shift mobility assays and chromatin immunoprecipitation assays demonstrated that androgen response sequence(s) existing upstream of each gene were responsible for androgen responsiveness and were occupied by the AR in periovulatory granulosa cells. Our results suggest that the androgen/AR pathway is involved in the ovulatory process via expression of the Cox-2 and Areg genes in periovulatory granulosa cells.