Meinsohn MC, Morin F, Bertolin K, Duggavathi R, Schoonjans K, Murphy BD. The Orphan Nuclear Receptor Liver Homolog Receptor-1 (Nr5a2) Regulates Ovarian Granulosa Cell Proliferation.
J Endocr Soc 2017;
2:24-41. [PMID:
29379893 PMCID:
PMC5779114 DOI:
10.1210/js.2017-00329]
[Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 11/22/2017] [Indexed: 12/29/2022] Open
Abstract
In mouse ovaries, liver receptor homolog-1 [nuclear receptor subfamily 5, group A,
member 2 (Nr5a2)] expression is restricted to granulosa cells. Mice with Nr5a2
depletion in this cell population fail to ovulate. To determine whether Nr5a2 is
essential for granulosa cell proliferation during follicular maturation, we generated
granulosa-specific conditional knockout mice (genotype Nr5a2 floxed Cre-recombinase
driven by the anti-Müllerian type II receptor, hereafter cKO) with Nr5a2
depletion from primary follicles forward. Proliferation in cKO granulosa cells was
substantially reduced relative to control (CON) counterparts, as assessed by
bromodeoxyuridine incorporation, proliferative cell nuclear antigen expression, and
fluorescent-activated cell sorting. Microarray analysis revealed >2000
differentially regulated transcripts between cKO and CON granulosa cells. Major gene
ontology pathways disrupted were proliferation, steroid biosynthesis, female gamete
formation, and ovulatory cycle. Transcripts for key cell-cycle genes, including
Ccnd1, Ccnd2, Ccne1,
Ccne2, E2f1, and E2f2, were in
reduced abundance. Transcripts from other cell-cycle-related factors, including
Cdh2, Plagl1, Cdkn1a,
Prkar2b, Gstm1, Cdk7, and
Pts, were overexpressed. Although the follicle-stimulating
hormone and estrogen receptors were overexpressed in the cKO animals, in
vivo treatment with estradiol-17β failed to
rescue decreased proliferation. In vitro inactivation of Nr5a2 using
the ML180 reverse agonist similarly decreased cell-cycle-related gene transcripts and
downstream targets, as in cKO mice. Pharmacological inhibition of
β-catenin, an Nr5a2 cofactor, decreased cyclin gene
transcripts and downstream targets. Terminal deoxynucleotidyltransferase-mediated
deoxyuridine triphosphate nick end labeling immunofluorescence and quantitative
polymerase chain reaction of pro/antiapoptotic and autophagic markers showed no
differences between cKO and CON granulosa cells. Thus, Nr5a2 is essential for
granulosa cell proliferation, but its depletion does not alter the frequency of
apoptosis nor autophagy.
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