Ken Shimizu1, Tomoko Nakamura2, Natsuki Nakanishi1, Yukiyo Kasahara1, Takashi Nagai1, Tomohiko Murase1, Satoko Osuka1,3, Maki Goto1, Akira Iwase4, Fumitaka Kikkawa1. 1. Department of Obstetrics and Gynecology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, 466-8550, Japan. 2. Department of Obstetrics and Gynecology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, 466-8550, Japan. tomonakamura@med.nagoya-u.ac.jp. 3. Department of Maternal and Perinatal Medicine, Nagoya University Hospital, 65 Tsurumai-cho, Showa-ku, Nagoya, 466-8550, Japan. 4. Department of Obstetrics and Gynecology, Gunma University Graduate School of Medicine, 3-39-22, Showa-machi, Maebashi, 371-8511, Japan.
Abstract
PURPOSE: Follicle-stimulating hormone receptor (FSHR) expression in granulosa cells is critical in enabling follicles to achieve accelerated growth. Although FSHR expression has been reported to be epigenetically regulated, the mechanism is unclear. Cooperation between oocytes and granulosa cells is also essential for normal follicular growth. Among oocyte-derived factors, bone morphogenetic protein 15 (BMP15) promotes follicular growth and is suggested to have epigenetic effects. We examined the role of BMP15 in the acquirement of FSHR in human granulosa cells. METHODS: Immortalized non-luteinized human granulosa (HGrC1) cells were stimulated with trichostatin A (TSA) or BMP15 to analyze FSHR expression, histone modifications, and USF1/2 binding at the FSHR promoter region. Histone acetyl transferase (HAT) activity and phosphorylation of Smad 1/5/8 and p38 MAPK were examined with or without BMP15, SB203580, and LDN193189. CYP19A1 expression and estradiol production were also studied. RESULTS: TSA and BMP15 induced FSHR mRNA expression in a dose-dependent manner and histone modifications were observed with increased binding of USF1/2. BMP15 increased FSHR protein expression, which was suppressed by LDN193189. BMP15 increased phosphorylation of Smad 1/5/8 and significantly increased HAT activity, which was inhibited by LDN193189, but not by SB203580. BMP15 increased phosphorylation of p38 MAPK and USF1. LDN193189 suppressed BMP15-induced phosphorylation of both p38 MAPK and USF1, whereas SB203580 suppressed the phosphorylation of USF1. BMP15 increased CYP19A1 mRNA expression and estradiol production. CONCLUSION: BMP15 induced FSHR expression in human granulosa cells through Smad and non-Smad pathways. This mechanism of FSHR induction by BMP15 may be utilized for controlling follicular growth.
PURPOSE:Follicle-stimulating hormone receptor (FSHR) expression in granulosa cells is critical in enabling follicles to achieve accelerated growth. Although FSHR expression has been reported to be epigenetically regulated, the mechanism is unclear. Cooperation between oocytes and granulosa cells is also essential for normal follicular growth. Among oocyte-derived factors, bone morphogenetic protein 15 (BMP15) promotes follicular growth and is suggested to have epigenetic effects. We examined the role of BMP15 in the acquirement of FSHR in human granulosa cells. METHODS: Immortalized non-luteinized human granulosa (HGrC1) cells were stimulated with trichostatin A (TSA) or BMP15 to analyze FSHR expression, histone modifications, and USF1/2 binding at the FSHR promoter region. Histone acetyl transferase (HAT) activity and phosphorylation of Smad 1/5/8 and p38 MAPK were examined with or without BMP15, SB203580, and LDN193189. CYP19A1 expression and estradiol production were also studied. RESULTS:TSA and BMP15 induced FSHR mRNA expression in a dose-dependent manner and histone modifications were observed with increased binding of USF1/2. BMP15 increased FSHR protein expression, which was suppressed by LDN193189. BMP15 increased phosphorylation of Smad 1/5/8 and significantly increased HAT activity, which was inhibited by LDN193189, but not by SB203580. BMP15 increased phosphorylation of p38 MAPK and USF1. LDN193189 suppressed BMP15-induced phosphorylation of both p38 MAPK and USF1, whereas SB203580 suppressed the phosphorylation of USF1. BMP15 increased CYP19A1 mRNA expression and estradiol production. CONCLUSION:BMP15 induced FSHR expression in human granulosa cells through Smad and non-Smad pathways. This mechanism of FSHR induction by BMP15 may be utilized for controlling follicular growth.
Entities:
Keywords:
Bone morphogenetic protein 15; Follicle stimulating hormone; Granulosa; Small mothers against decapentaplegic