title: Molecular regulation of LHCGR expression by miR-122 during follicle growth in the rat ovary.
abstract: We have previously reported that LHCGR expression in the ovary is regulated through a post-transcriptional mechanism involving an mRNA binding protein designated as LRBP, which is regulated, at least in part, by a non-coding RNA, miR-122. Our present study examined the regulatory role of miR-122 in FSH-induced LHCGR expression during follicle development. Treatment of rat granulosa cells concurrently with FSH and 17β estradiol showed, as expected, a time-dependent increase in LHCGR mRNA levels as well as hCG-induced progesterone production. However, miR-122 expression was decreased during the early time periods, which preceded the increased expression of LHCGR mRNA. The role of miR-122 in FSH-induced LHCGR mRNA expression was then examined by overexpressing miR-122 prior to FSH stimulation by infecting granulosa cells with an adenoviral vector containing a miR-122 insert (AdmiR-122). Pretreatment with AdmiR-122 resulted in complete abrogation of FSH- mediated upregulation of LHCGR. AdmiR-122 also blocked FSH-induced decrease in LRBP expression and increased the binding of LHCGR mRNA to LRBP. Based on these results, we conclude that miR-122 plays a regulatory role in LHCGR expression by modulating LRBP levels during FSH-induced follicle growth.
authors.affiliation: Departments of Obstetrics/Gynecology and Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI, 48109-0617, USA.
authors.forename: Bindu
authors.initials: B
authors.lastname: Menon
authors.affiliation: Departments of Obstetrics/Gynecology and Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI, 48109-0617, USA.
authors.forename: Thippeswamy
authors.initials: T
authors.lastname: Gulappa
authors.affiliation: Departments of Obstetrics/Gynecology and Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI, 48109-0617, USA. Electronic address: kmjmenon@umich.edu.
authors.forename: K M J
authors.initials: KM
authors.lastname: Menon
mesh_terms: D000818:Animals; D004958:Estradiol / Q000378:metabolism; D005260:Female; D005640:Follicle Stimulating Hormone / Q000378:metabolism; D006107:Granulosa Cells / Q000378:metabolism; D035683:MicroRNAs / Q000378:metabolism*; D006080:Ovarian Follicle / Q000378:metabolism*; D010053:Ovary / Q000378:metabolism*; D011374:Progesterone / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D011974:Receptors, LH / Q000378:metabolism*; D015854:Up-Regulation / Q000502:physiology
chemical_list: C000622692:LHCGR protein, rat; C580643:MIRN122 microRNA, rat; D035683:MicroRNAs; D012333:RNA, Messenger; D011974:Receptors, LH; D011374:Progesterone; D004958:Estradiol; D005640:Follicle Stimulating Hormone
keywords: Estradiol; Follicle stimulating hormone; Luteinizing hormone receptor; mRNA binding protein; miR-122; microRNA