Oocyte-Derived Factors (GDF9 and BMP15) and FSH Regulate AMH Expression Via Modulation of H3K27AC in Granulosa Cells

Abstract

Anti-Müllerian hormone (AMH) produced by ovarian granulosa cells (GCs) plays a crucial role in ovarian function. It is used as a diagnostic and/or prognostic marker of fertility as well as for pathophysiological conditions in women. In this study, we investigated the underlying mechanism for regulation of AMH expression in GCs using primary mouse GCs and a human GC tumor-derived KGN cell line. We find that growth differentiation factor 9 (GDF9) and bone morphogenetic factor 15 (BMP15) together (GDF9 + BMP15), but not when tested separately, significantly induce AMH expression in vitro and in vivo (serum AMH). Our results show that GDF9 + BMP15 through the PI3K/Akt and Smad2/3 pathways synergistically recruit the coactivator p300 on the AMH promoter region that promotes acetylation of histone 3 lysine 27 (H3K27ac), facilitating AMH/Amh expression. Intriguingly, we also find that FSH inhibits GDF9 + BMP15-induced increase of AMH/Amh expression. This inhibition occurs through FSH-induced protein kinase A/SF1-mediated expression of gonadotropin inducible ovarian transcription factor 1, a transcriptional repressor, that recruits histone deacetylase 2 to deacetylate H3K27ac, resulting in the suppression of AMH/Amh expression. Furthermore, we report that ovarian Amh mRNA levels are significantly higher in Fshβ-null mice (Fshβ-/-) compared with those in wild-type (WT) mice. In addition, ovarian Amh mRNA levels are restored in Fshβ-null mice expressing a human WT FSHβ transgene (FSHβ-/-hFSHβWT). Our study provides a mechanistic insight into the regulation of AMH expression that has many implications in female reproduction/fertility.

FSH inhibits AMH to support ovarian estradiol synthesis in infantile mice

“…In adult and juvenile ovaries, the expression of AMH disappears from mural granulosa cells at the antral stage, when the follicle supposedly requires FSH for its subsequent growth and maturation. The role played by the oocyte-derived factors GDF9 and BMP15 on FSHmediated repression of Amh has been recently highlighted in mouse primary cultures of granulosa cells and in the tumor-derived granulosa KGN cell line (Roy et al 2018). This study indicates that Amh expression implies a tight dialog between granulosa cells and the oocyte.…”

“…FSH can regulate AMH expression either positively or negatively in granulosa cells, depending on follicular stage, species and experimental approaches (Baarends et al 1995, Taieb et al 2011, Hardy et al 2016, Roy et al 2018.…”

“…FSH may, thus, be a direct regulator of Amh expression in these follicles. The possibility that it involves FSH-mediated activation of the canonical cAMP/ protein kinase A (PKA) pathway to regulate Amh promoter activity is supported by a recent study in primary cultures of mouse granulosa cells and in KGN cells (Roy et al 2018).…”

“…In the ovary, FSH regulates the expression of the anti-Müllerian hormone (AMH, also called Müllerian-inhibiting substance or MIS) either positively (Taieb et al 2011) or negatively (Baarends et al 1995, Hardy et al 2016, Roy et al 2018, depending on the experimental model. AMH is a member of the transforming growth factor β family, which in the ovary is specifically expressed in granulosa cells of growing follicles from the primary to the antral stage.…”

The Effect of Folic Acid Supplementation in the Ovary and Upon Embryo Development

“…Anti-Mullerian hormone (AMH) is a factor safeguarding the ovarian reserve, which is expressed in the GCs and downregulates primordial follicle recruitment (Durlinger et al, 1999). AMH expression has been described to be regulated by TGFβ family members GDF9/BMP15 promoting histone acetylation of H3K27, increasing Amh in mouse GCs; meanwhile, this effect is inhibited by follicle-stimulating hormone (FSH) (Roy et al, 2018).…”