Targeted Loss of Androgen Receptor Signaling in Murine Granulosa Cells of Preantral and Antral Follicles Causes Female Subfertility

• Published in: Biology of reproduction Vol. 87; no. 6; p. 151
• Main Authors: WALTERS, Kirsty A, MIDDLETON, Linda J, JOSEPH, Shai R, HAZRA, Rasmani, JIMENEZ, Mark, SIMANAINEN, Ulla, ALLAN, Charles M, HANDELSMAN, David J
• Format: Journal Article
• Language: English
• Published: Madison, WI Society for the Study of Reproduction 01-06-2012
• Subjects: Animals; Anti-Mullerian Hormone - genetics; Anti-Mullerian Hormone - metabolism; Biological and medical sciences; Cell Survival; Crosses, Genetic; Cumulus Cells - metabolism; Cumulus Cells - pathology; Estrous Cycle - metabolism; Female; Fertilization; Follicular Atresia - metabolism; Fundamental and applied biological sciences. Psychology; Granulosa Cells - metabolism; Granulosa Cells - pathology; Heterozygote; Infertility, Female - etiology; Infertility, Female - metabolism; Infertility, Female - pathology; Mice; Mice, Knockout; Mice, Transgenic; Oogenesis; Ovarian Follicle - metabolism; Ovarian Follicle - pathology; Receptors, Androgen - deficiency; Receptors, Androgen - genetics; Receptors, Androgen - metabolism; Recombinant Proteins - biosynthesis; Recombinant Proteins - metabolism; Recombinases - genetics; Recombinases - metabolism; Signal Transduction; Vertebrates: reproduction; Zona Pellucida - metabolism; Zona Pellucida - pathology; Ovary; Signal transduction; Reproduction; Subfertility; Female genital system; Androgen receptor; Female; Granulosa; granulosa cell; Ovarian follicle; ovarian function; female reproduction
• ISSN: 0006-3363; 1529-7268
• DOI: 10.1095/biolreprod.112.102012

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.