title: Targeted loss of androgen receptor signaling in murine granulosa cells of preantral and antral follicles causes female subfertility.
abstract: Ovarian granulosa cells display strong androgen receptor (AR) expression, suggesting a functional role for direct AR-mediated actions within developing mammalian follicles. By crossing AR-floxed and anti-Müllerian hormone (AMH)-Cre recombinase mice, we generated granulosa cell-specific androgen receptor knockout mice (GCARKO). Cre expression, assessed by lacZ activity, localized to 70%-100% of granulosa cells in most preantral to antral follicles, allowing for selected evaluation of granulosa cell AR-dependent actions during follicle development. Relative to wild-type (WT) females, GCARKO females were subfertile, producing a 24% reduction in the number of litters (P < 0.05) over 6 mo and an age-dependent decrease in total number of pups born, evident from 6 mo of age (P < 0.05). Follicle dynamics were altered in GCARKO ovaries at 3 mo of age, with a significant reduction in large preantral and small antral follicle numbers compared to WT ovaries (P < 0.05). Global premature follicle depletion was not observed, but increased follicular atresia was evident in GCARKO ovaries at 6 mo of age, with an 81% increase in unhealthy follicles and zona pellucida remnants (P < 0.01). Cumulus cell expansion was decreased (P < 0.01) and oocyte viability was diminished in GCARKO females, with a significant reduction in the percentage of oocytes fertilized after natural mating and, thus, in the rate of progression to the two-cell embryo stage (P < 0.05). In addition, compared with age-matched WT females, 6-mo-old GCARKO females exhibited significantly prolonged estrous cycles (P ≤ 0.05), suggesting altered hypothalamic-pituitary-gonadal feedback signaling. In conclusion, our findings revealed that selective loss of granulosa cell AR actions during preantral and antral stages of development leads to a premature reduction in female fecundity through reduced follicle health and oocyte viability.
authors.affiliation: ANZAC Research Institute, Department of Andrology, Concord Hospital, University of Sydney, Sydney, New South Wales, Australia. kwalters@anzac.edu.au
authors.forename: Kirsty A
authors.initials: KA
authors.lastname: Walters
authors.forename: Linda J
authors.initials: LJ
authors.lastname: Middleton
authors.forename: Shai R
authors.initials: SR
authors.lastname: Joseph
authors.forename: Rasmani
authors.initials: R
authors.lastname: Hazra
authors.forename: Mark
authors.initials: M
authors.lastname: Jimenez
authors.forename: Ulla
authors.initials: U
authors.lastname: Simanainen
authors.forename: Charles M
authors.initials: CM
authors.lastname: Allan
authors.forename: David J
authors.initials: DJ
authors.lastname: Handelsman
mesh_terms: D000818:Animals; D054304:Anti-Mullerian Hormone / Q000235:genetics / Q000378:metabolism; D002470:Cell Survival; D003433:Crosses, Genetic; D054885:Cumulus Cells / Q000378:metabolism / Q000473:pathology; D030762:Estrous Cycle / Q000378:metabolism; D005260:Female; D005306:Fertilization; D005496:Follicular Atresia / Q000378:metabolism; D006107:Granulosa Cells / Q000378:metabolism* / Q000473:pathology; D006579:Heterozygote; D007247:Infertility, Female / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D018345:Mice, Knockout; D008822:Mice, Transgenic; D009866:Oogenesis; D006080:Ovarian Follicle / Q000378:metabolism / Q000473:pathology; D011944:Receptors, Androgen / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000378:metabolism; D045522:Recombinases / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D015044:Zona Pellucida / Q000378:metabolism / Q000473:pathology
chemical_list: D011944:Receptors, Androgen; D011994:Recombinant Proteins; D045522:Recombinases; D054304:Anti-Mullerian Hormone