title: FSH modulates the expression of inhibin-alpha and the secretion of inhibins via orphan nuclear receptor NUR77 in ovarian granulosa cells.
abstract: It has been previously reported that follicle-stimulating hormone (FSH) regulates the expression of inhibin-alpha in human granulosa cells, but the precise molecular pathway remains unknown. In the present study, we investigated the role of the orphan nuclear receptor, NUR77, in both the transcriptional regulation of the inhibin α-subunit gene and the secretion of inhibins. Our results showed that in a human granulosa cell tumor-derived cell line (KGN) and in human granulosa-lutein cells (hGL), FSH induced the expression of NUR77 and inhibin-alpha, although inhibin-alpha expression did not increased following FSH treatment if NUR77 was knocked down. Furthermore, simply overexpressing or reducing NUR77 levels affected inhibin-alpha expression, while NUR77 overexpression improved the secretion of inhibin A and B from human granulosa cells. In addition, chromatin immunoprecipitation-PCR, avidin-biotin-conjugated DNA precipitation, and luciferase reporter assays confirmed that NUR77 directly regulated the transcription of the inhibin-alpha gene through the specific NGFI-B response element located within its promoter. In the ovarian granulosa cells of the Nur77 knockout mice, the mRNA levels of inhibin-alpha were decreased relative to wild-type mice. These data indicate a role of NUR77 in the regulation of inhibin-alpha in ovarian granulosa cells.
authors.affiliation: Department of Obstetrics and Gynecology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Center for Reproductive Medicine, Nanjing, China.
authors.forename: Qin-Yuan
authors.initials: QY
authors.lastname: He
authors.forename: Li-Jun
authors.initials: LJ
authors.lastname: Ding
authors.forename: Hai-Xiang
authors.initials: HX
authors.lastname: Sun
authors.forename: Bin
authors.initials: B
authors.lastname: Yu
authors.forename: An-Yi
authors.initials: AY
authors.lastname: Dai
authors.forename: Ning-Yuan
authors.initials: NY
authors.lastname: Zhang
authors.forename: Bin
authors.initials: B
authors.lastname: Wang
authors.forename: Gui-Jun
authors.initials: GJ
authors.lastname: Yan
authors.forename: Pei-Zhen
authors.initials: PZ
authors.lastname: Xu
authors.forename: Ya-Li
authors.initials: YL
authors.lastname: Hu
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001360:Avidin; D001710:Biotin; D015153:Blotting, Western; D047369:Chromatin Immunoprecipitation; D017931:DNA Primers / Q000235:genetics; D005260:Female; D005293:Ferritins; D005640:Follicle Stimulating Hormone / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000502:physiology*; D055785:Gene Knockdown Techniques; D006107:Granulosa Cells / Q000378:metabolism*; D006801:Humans; D007265:Inhibins / Q000378:metabolism*; D008156:Luciferases; D051379:Mice; D018345:Mice, Knockout; D057105:Nuclear Receptor Subfamily 4, Group A, Member 1 / Q000235:genetics / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D017931:DNA Primers; C539821:NR4A1 protein, human; D057105:Nuclear Receptor Subfamily 4, Group A, Member 1; C051805:avidin-ferritin biotin; C094377:inhibin-alpha subunit; D001360:Avidin; D007265:Inhibins; D001710:Biotin; D005640:Follicle Stimulating Hormone; D005293:Ferritins; D008156:Luciferases