Effect of granulocyte-macrophage colony-stimulating factor deficiency on ovarian follicular cell function.
Granulocyte-macrophage colony-stimulating factor (GM-CSF), a cytokine secreted by lymphohaemopoietic and other cell lineages, is known to influence ovarian cyclicity and embryo development. The aim of this study was to examine the effect of GM-CSF on ovarian follicular cell function using GM-CSF-deficient (GM -/-) mice. Immature GM -/- and GM +/+ mice were stimulated with eCG, and cumulus-oocyte complexes and mural granulosa cells were collected 48 h later. Expression of GM-CSF receptor (GM-CSFR) alpha and beta mRNA subunits by cumulus-oocyte complexes and mural granulosa cells was examined using RT-PCR. Cumulus-oocyte complexes from both genotypes were found to express mRNA for the GM-CSFRalpha-subunit only, while the mural granulosa cells expressed both the alpha and beta receptor subunits. Cumulus-oocyte complexes recovered from GM -/- mice had approximately twice the number of cumulus cells per cumulus-oocyte complex than did those of GM +/+ mice (P < 0.05), even though the growth-promoting activity of denuded GM -/- oocytes was found to be equivalent to that of wild-type oocytes. GM-CSF deficiency was associated with marginally increased DNA synthesis in cumulus cells and significantly (P < 0.05) lower progesterone production by mural granulosa cells recovered from GM -/- compared with those recovered from GM +/+ mice. The addition of rec-mGM-CSF in vitro did not affect DNA synthesis in either cell type or progesterone production by mural granulosa cells, irrespective of GM-CSF status. There was no effect of GM-CSF deficiency on the capacity of FSH and insulin-like growth factor I to stimulate DNA synthesis in cumulus-oocyte complexes (approximately 15- and threefold, respectively) and in mural granulosa cells (approximately two- and threefold, respectively). Taken together, these data show that GM-CSF influences events associated with follicular maturation in mice. The effects of GM-CSF are not exerted directly in granulosa or cumulus cells, but appear to be mediated indirectly, perhaps through the agency of steroidogenesis-regulating secretions of local macrophage populations residing in the theca.
Gilchrist
R B
RB
The Reproductive Medicine Unit, Department of Obstetrics and Gynaecology, The University of Adelaide, The Queen Elizabeth Hospital, Woodville, SA 5011, Australia.
Rowe
D B
DB
Ritter
L J
LJ
Robertson
S A
SA
Norman
R J
RJ
Armstrong
D T
DT
D000704:Analysis of Variance; D000818:Animals; D002478:Cells, Cultured; D004247:DNA / Q000096:biosynthesis; D004305:Dose-Response Relationship, Drug; D005260:Female; D005640:Follicle Stimulating Hormone / Q000494:pharmacology; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000172:deficiency* / Q000235:genetics / Q000494:pharmacology; D006107:Granulosa Cells / Q000378:metabolism; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology; D051379:Mice; D018345:Mice, Knockout; D006080:Ovarian Follicle / Q000378:metabolism*; D011374:Progesterone / Q000096:biosynthesis; D016187:Receptors, Granulocyte-Macrophage Colony-Stimulating Factor / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D016187:Receptors, Granulocyte-Macrophage Colony-Stimulating Factor; D011374:Progesterone; D007334:Insulin-Like Growth Factor I; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D005640:Follicle Stimulating Hormone; D004247:DNA