Different follicle-stimulating hormone exposure regimens during antral follicle growth alter gene expression in the cumulus-oocyte complex in mice.
Follicle-stimulating hormone (FSH) and oocyte-secreted factors influence granulosa cell differentiation and follicle development. Whereas FSH stimulates the expression of mural cell transcripts, oocyte-secreted factors regulate specific cumulus cell genes and suppress the appearance of mural cell transcripts. This study addresses the extent to which clinically relevant changes in FSH doses applied during antral follicle development in vitro could alter the expression of oocyte and cumulus cell transcripts. A 12-day culture system in which mouse ovarian preantral follicles can grow to preovulatory follicles was used. The following three FSH regimens were considered: 1) continuous exposure to an FSH level of 10 mIU/ml (control), 2) decreasing concentrations of FSH (low FSH), and 3) an FSH level of 25 mIU/ml (high FSH) as soon as the antrum is formed. Transcripts in oocytes (Gdf9, Bmp15, and Fgf8) and in cumulus cells (Amh, Lhcgr, Ar, and Pfkp) were quantified by real-time PCR. Under high FSH, the three oocyte transcripts were upregulated, while in cumulus cells a shutdown of the Amh signal and substantial increases in Lhcgr and Ar expression were measured. In contrast, low FSH tended to reduce Lhcgr to levels comparable to those in vivo. Levels of Pfkp were not affected by FSH doses. These results demonstrate that a 2.5-fold increase in FSH changes both oocyte and cumulus cell transcript levels. Conversely, a decrease in FSH does not affect transcript levels but seems to limit inappropriate Lhcgr expression. Modulating FSH within physiological ranges during the antral phase of culture alters cumulus cell differentiation.
Sánchez
Flor
F
Follicle Biology Laboratory, Vrije Universiteit Brussel, Brussels, Belgium. fsanchez@vub.ac.be
Adriaenssens
Tom
T
Romero
Sergio
S
Smitz
Johan
J
D000818:Animals; D054304:Anti-Mullerian Hormone / Q000096:biosynthesis / Q000235:genetics; D055430:Bone Morphogenetic Protein 15 / Q000096:biosynthesis / Q000235:genetics; D003433:Crosses, Genetic; D054885:Cumulus Cells / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D005260:Female; D051524:Fibroblast Growth Factor 8 / Q000096:biosynthesis / Q000235:genetics; D005640:Follicle Stimulating Hormone / Q000494:pharmacology*; D018507:Gene Expression Regulation, Developmental; D055429:Growth Differentiation Factor 9 / Q000096:biosynthesis / Q000235:genetics; D007770:L-Lactate Dehydrogenase / Q000096:biosynthesis / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D009865:Oocytes / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D006080:Ovarian Follicle / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D011944:Receptors, Androgen / Q000096:biosynthesis / Q000235:genetics; D011974:Receptors, LH / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction
C525902:Bmp15 protein, mouse; D055430:Bone Morphogenetic Protein 15; C496457:Fgf8 protein, mouse; C525898:Gdf9 protein, mouse; D055429:Growth Differentiation Factor 9; D012333:RNA, Messenger; D011944:Receptors, Androgen; D011974:Receptors, LH; D051524:Fibroblast Growth Factor 8; D054304:Anti-Mullerian Hormone; D005640:Follicle Stimulating Hormone; D007770:L-Lactate Dehydrogenase