title: LH-Induced Steroidogenesis in the Mouse Ovary, but Not Testis, Requires Matrix Metalloproteinase 2- and 9-Mediated Cleavage of Upregulated EGF Receptor Ligands.
abstract: Oocyte maturation and cumulus cell expansion depend on luteinizing hormone (LH)-mediated upregulation of membrane-bound epidermal growth factor (EGF)-like ligands, including amphiregulin, epiregulin, and betacellulin. These ligands then transactivate the EGF receptor (EGFR) after release by matrix metalloproteinases (MMPs). However, direct measurement of released EGF-like ligands or MMPs from granulosa cells has not been formally evaluated, nor has direct identification of responsible MMPs. Here we address these issues by analyzing LH-induced steroidogenesis, which is also MMP and EGFR dependent, in freshly isolated mouse primary granulosa cells. We demonstrate a correlation between amphiregulin and epiregulin mRNA induction and steroid production in LH-treated granulosa cells as well as in ovaries of human chorionic gonadotropin-treated mice. In contrast, LH does not alter Mmp1, Mmp2, Mmp3, Mmp8, Mmp9, or Adam17 mRNA expression. We demonstrate that, in primary mouse granulosa cells, LH triggers release of soluble amphiregulin that correlates with steroid production, both of which are blocked by MMP2/9 inhibition, confirming that MMP2/9 likely regulates LH-induced amphiregulin release and downstream processes. Notably, LH does not alter secretion of MMP2/9 from primary granulosa cells, nor does it modulate MMP activity. These findings indicate that, in the ovary, LH dictates EGFR-mediated processes not by regulating MMPs, but instead by increasing EGF-like ligand availability. In contrast, LH stimulation of primary mouse Leydig cells does not induce EGF-like ligand expression or require MMP2/9 for steroidogenesis, confirming marked differences in LH receptor-induced processes in the testes. Our results suggest that MMP inhibition may be a means of attenuating excess ovarian steroid production in diseases like polycystic ovary syndrome.
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Rochester School of Medicine and Dentistry, Rochester, New York.
authors.forename: Allison
authors.initials: A
authors.lastname: Light
authors.affiliation: Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Rochester School of Medicine and Dentistry, Rochester, New York Stephen_Hammes@urmc.rochester.edu.
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Hammes
mesh_terms: D066258:Amphiregulin; D000818:Animals; D066255:EGF Family of Proteins / Q000096:biosynthesis; D066260:Epiregulin / Q000096:biosynthesis / Q000235:genetics; D066246:ErbB Receptors / Q000235:genetics / Q000378:metabolism*; D005260:Female; D006107:Granulosa Cells / Q000187:drug effects / Q000201:enzymology; D007985:Leydig Cells / Q000187:drug effects / Q000378:metabolism; D008024:Ligands; D007986:Luteinizing Hormone / Q000494:pharmacology*; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000235:genetics / Q000378:metabolism*; D020780:Matrix Metalloproteinase 9 / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D010053:Ovary / Q000201:enzymology / Q000378:metabolism*; D061251:Primary Cell Culture; D013256:Steroids / Q000096:biosynthesis*; D013737:Testis / Q000201:enzymology / Q000378:metabolism*; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D066258:Amphiregulin; C587849:Areg protein, mouse; D066255:EGF Family of Proteins; D066260:Epiregulin; C587881:Ereg protein, mouse; D008024:Ligands; D013256:Steroids; D007986:Luteinizing Hormone; C541485:EGFR protein, mouse; D066246:ErbB Receptors; D020778:Matrix Metalloproteinase 2; C522362:Mmp2 protein, mouse; D020780:Matrix Metalloproteinase 9; C501830:Mmp9 protein, mouse
keywords: amphiregulin; granulosa cells; matrix metalloproteinase; ovary; steroid hormones/steroid hormone receptors; steroidogenesis; testis