title: Bone morphogenetic protein 4 supports the initial differentiation of hen (Gallus gallus) granulosa cells.
abstract: In the hen ovary, selection of a follicle into the preovulatory hierarchy occurs from a small cohort of prehierarchal (6-8 mm) follicles. Prior to follicle selection the granulosa layer remains in an undifferentiated state despite elevated follicle-stimulating hormone receptor (FSHR) expression. The present studies describe a role for bone morphogenetic protein 4 (BMP4) in supporting FSHR mRNA expression in granulosa cells from prehierarchal follicles and promoting differentiation at follicle selection. Culture of undifferentiated granulosa cells in culture medium alone resulted in a significant decline in levels of FSHR mRNA (by ~80% compared to freshly collected cells). By comparison, granulosa cultured with BMP4 (10-100 ng/ml) maintained FSHR and expression at approximately in vivo levels. Because both granulosa and theca tissues from prehierarchal follicles express BMP4, it is suggested that BMP4 acts in a paracrine and/or autocrine fashion to support elevated FSHR expression prior to follicle selection. Granulosa cells cultured with BMP4 for 24 h also initiated FSH-induced cAMP production and indirectly initiated anti-Mullerian hormone (AMH), CYP11A, and STAR expression plus progesterone production. However, pretreatment with the BMP antagonist NOGGIN or the mitogen-activated protein kinase (MAPK) agonist transforming growth factor alpha attenuated or blocked each action promoted by BMP4. We conclude that prior to and immediately after selection, BMP4 serves to support FSHR expression within the granulosa layer, yet prior to selection, multiple factors (including inhibitory MAPK signaling, AMH, and BMP antagonists) can modulate FSHR expression and suppress FSH-mediated cell signaling to prevent granulosa cell differentiation prior to follicle selection.
authors: Center for Reproductive Biology and Health, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
authors: Dongwon
authors: D
authors: Kim
authors: Olga
authors: O
authors: Ocón-Grove
authors: A L
authors: AL
authors: Johnson
mesh_terms: D000818:Animals; D054304:Anti-Mullerian Hormone / Q000096:biosynthesis; D055415:Bone Morphogenetic Protein 4 / Q000494:pharmacology*; D002352:Carrier Proteins / Q000494:pharmacology; D002454:Cell Differentiation / Q000187:drug effects* / Q000502:physiology; D002478:Cells, Cultured; D002645:Chickens; D002786:Cholesterol Side-Chain Cleavage Enzyme / Q000096:biosynthesis; D000242:Cyclic AMP / Q000096:biosynthesis; D005260:Female; D005640:Follicle Stimulating Hormone / Q000494:pharmacology; D006107:Granulosa Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D006080:Ovarian Follicle / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D010750:Phosphoproteins / Q000096:biosynthesis; D011962:Receptors, FSH / Q000235:genetics / Q000378:metabolism; D016211:Transforming Growth Factor alpha / Q000494:pharmacology; D000098682:Steroidogenic Acute Regulatory Protein; D000099176:Noggin Protein
chemical_list: D054304:Anti-Mullerian Hormone; D055415:Bone Morphogenetic Protein 4; D002352:Carrier Proteins; D002786:Cholesterol Side-Chain Cleavage Enzyme; D000242:Cyclic AMP; D005640:Follicle Stimulating Hormone; D010750:Phosphoproteins; D011962:Receptors, FSH; D016211:Transforming Growth Factor alpha; D000098682:Steroidogenic Acute Regulatory Protein; D000099176:Noggin Protein
keywords: CYP11A; FSH; FSH receptor; NOGGIN; STAR; bone morphogenetic protein 4; cAMP; cyclic adenosine monophosphate; differentiation; follicle; follicle-stimulating hormone; granulosa cells; hen; ovary; progesterone; selection; transforming growth factor alpha