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: Kirsty A Walters, Linda J Middleton, Shai R Joseph, Rasmani Hazra, Mark Jimenez, Ulla Simanainen, Charles M Allan, David J Handelsman
• Journal: Biology of reproduction (Biol Reprod) Vol. 87 Issue 6 Pg. 151 (Jun 2012) ISSN: 1529-7268 [Electronic] United States
• PMID: 23115271 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Receptors, Androgen
• Recombinant Proteins
• Recombinases
• Anti-Mullerian Hormone

Topics

• Animals
• Anti-Mullerian Hormone (genetics, metabolism)
• Cell Survival
• Crosses, Genetic
• Cumulus Cells (metabolism, pathology)
• Estrous Cycle (metabolism)
• Female
• Fertilization
• Follicular Atresia (metabolism)
• Granulosa Cells (metabolism, pathology)
• Heterozygote
• Infertility, Female (etiology, metabolism, pathology)
• Mice
• Mice, Knockout
• Mice, Transgenic
• Oogenesis
• Ovarian Follicle (metabolism, pathology)
• Receptors, Androgen (deficiency, genetics, metabolism)
• Recombinant Proteins (biosynthesis, metabolism)
• Recombinases (genetics, metabolism)
• Signal Transduction
• Zona Pellucida (metabolism, pathology)