Ovarian follicle growth is a dynamic process that requires exquisite regulation. Follicles are restrained at the preantral stage until they are stimulated by follicle stimulating hormone (FSH). FSH signals through its cell-surface receptor via cAMP and cAMP-dependent protein kinase (PKA). The requirement for PKA is demonstrated by the ability of the specific PKA inhibitor peptide, PKI, to block acute signaling events, such as histone H3 phosphorylation and activation of the extracellular regulated kinase ERK, as well as to prevent induction of genes/proteins required for development of the preovulatory phenotype. However, FSH-stimulated granulosa cell maturation is also blocked by chemical inhibitors of the phosphoinositide-3 (PI-3) kinase pathway. PI-3 kinase and its downstream kinase target AKT are classically activated by the insulin or insulin-like growth factor 1 receptors upon binding the adaptor protein insulin receptor substrates (IRS) 1/2. FSH-stimulated AKT phosphorylation is also blocked by PKI. We hypothesize that PKA uniquely orchestrates all of the FSH-regulated signaling pathways to direct granulosa cell differentiation. We also hypothesize that FSH signals through the PI-3 kinase pathway by inducing the transcription factor hypoxia inducible factor-1alpha (HIF-1alpha) and inhibiting signals from the transcription factor FKHR that repress granulosa cell maturation. In this proposal we will test the hypotheses that FSH signals via PKA to activate PI-3 kinase via the adapters IRS1 and/or IRS2, that FSH via PI-3 kinase induces HIF-1alpha and that HIF-1alpha is a key positive signal leading to induction of FSH-responsive genes, and that signaling from FKHR which maintains granulosa cells in an undifferentiated state is neutralized by its phosphorylation via the PI-3 kinase pathway. Induction of key regulatory genes that characterize mature granulosa cells therefore requires regulated signaling not only through CREB, histone H3, and ERK but also through PI-3 kinase targets HIF-1alpha and FKHR. Understanding how follicular maturation is regulated can translate into safer and more effective treatments for fertility.

Agency
National Institute of Health (NIH)
Institute
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Type
Research Program Projects (P01)
Project #
5P01HD021921-19
Application #
7337393
Study Section
Special Emphasis Panel (ZHD1)
Project Start
Project End
Budget Start
2006-12-01
Budget End
2007-11-30
Support Year
19
Fiscal Year
2007
Total Cost
$445,176
Indirect Cost
Name
Northwestern University at Chicago
Department
Type
DUNS #
005436803
City
Chicago
State
IL
Country
United States
Zip Code
60611
Que, Emily L; Duncan, Francesca E; Bayer, Amanda R et al. (2017) Zinc sparks induce physiochemical changes in the egg zona pellucida that prevent polyspermy. Integr Biol (Camb) 9:135-144
Vanorny, Dallas A; Mayo, Kelly E (2017) The role of Notch signaling in the mammalian ovary. Reproduction 153:R187-R204
Xiao, Shuo; Duncan, Francesca E; Bai, Lu et al. (2015) Size-specific follicle selection improves mouse oocyte reproductive outcomes. Reproduction 150:183-92
Que, Emily L; Bleher, Reiner; Duncan, Francesca E et al. (2015) Quantitative mapping of zinc fluxes in the mammalian egg reveals the origin of fertilization-induced zinc sparks. Nat Chem 7:130-9
Xiao, Shuo; Zhang, Jiyang; Romero, Megan M et al. (2015) In vitro follicle growth supports human oocyte meiotic maturation. Sci Rep 5:17323
Cordeiro, Marília H; Kim, So-Youn; Ebbert, Katherine et al. (2015) Geography of follicle formation in the embryonic mouse ovary impacts activation pattern during the first wave of folliculogenesis. Biol Reprod 93:88
Kong, Betty Y; Duncan, Francesca E; Que, Emily L et al. (2015) The inorganic anatomy of the mammalian preimplantation embryo and the requirement of zinc during the first mitotic divisions. Dev Dyn 244:935-47
Kim, So-Youn; Ebbert, Katherine; Cordeiro, Marilia H et al. (2015) Cell autonomous phosphoinositide 3-kinase activation in oocytes disrupts normal ovarian function through promoting survival and overgrowth of ovarian follicles. Endocrinology 156:1464-76
Hong, Young Pyo; Gleber, Sophie-Charlotte; O'Halloran, Thomas V et al. (2014) Alignment of low-dose X-ray fluorescence tomography images using differential phase contrast. J Synchrotron Radiat 21:229-34
Kong, B Y; Duncan, F E; Que, E L et al. (2014) Maternally-derived zinc transporters ZIP6 and ZIP10 drive the mammalian oocyte-to-egg transition. Mol Hum Reprod 20:1077-89

Showing the most recent 10 out of 210 publications