Developmental programming: prenatal steroid excess disrupts key members of intra-ovarian steroidogenic pathway in sheep

PADMANABHAN, V; SALVETTI NR; MATILLER, V; ORTEGA HH

Grand Rapids

Congreso; 47th Annual Meeting, Society for the Study of Reproduction (SSR); 2014

Society for the Study of Reproduction (SSR)

Prenatal testosterone (T) excess disrupts ovarian cyclicity, increases circulating estradiol levels, follicular recruitment and persistence culminating in polycystic (accumulation of antral follicles) ovarian morphology similar to women with PCOS, and alters ovarian steroid receptor protein expression. Using prenatal T- and dihydrotestosterone (DHT)- treated sheep comparatively, we tested whether prenatal T excess by androgenic or estrogenic action disrupts the steroid biosynthetic machinery in a cell, follicle stage, age and treatment-specific manner consistent with the ovarian disruptions and increased estradiol release. Impact of prenatal T / DHT treatments from days 30-90 of gestation on ovarian steroidogenic acute regulatory protein (STAR), 3 beta-hydroxysteroid dehydrogenase (HSD3B), cytochrome P450 17A1 (CYP17A1) and cytochrome P450 19A1(CYP19A1) were examined on fetal day 90, 140, 10 months (postpubertal) and 21 months (adult, no DHT group) of age by immunocytochemistry using streptavidin-biotin immunoperoxidase method. Image Pro-Plus 3.0.1 was used for image analysis. Average density within each cell type and follicular stage at each age were analyzed using ANOVA followed by Duncan?s multiple range tests. A p value of <0.05 was considered significant. Results revealed that HSD3B and CYP19A1 were expressed at all follicular stages with HSD3B in both granulosa and theca and CYP19A1 only in granulosa cells. CYP17A1 was evident only in the theca of preantral and theca interna of antral follicles. All 4 markers changed in a cell, follicle stage, age and treatment-specific manner, some programmed by androgenic and others by estrogenic actions of T. Prenatal T / DHT treatment increased STAR expression in preantral follicles of postpubertal and adult females. Granulosa cell HSD3B expression was increased in primary follicles of prenatal T and DHT females on fetal day 90, reduced in primary and preantral follicles of T females on fetal day 140, reduced in small preantral follicles of T but increased in primary, large preantral and antral follicles of DHT females at 10 months, reduced in primary but increased in antral follicles of T females at 21 months. An increase in HSD3B was also evident in theca of large preantral follicles at 21 months. CYP19A1 was reduced by both T and DHT in primordial and primary follicles at fetal day 90, increased in primordial, primary and preantral follicles at fetal day 140, reduced in all follicle classes at 10 months and in antral follicles at 21months. CYP17A1 was reduced in the theca interna of antral follicles by T, but not DHT in 10 and 21 month old females. While changes in expression at fetal day 90 may reflect direct response to T / DHT treatment, the transient decrease in HSD3B and increase in CYP19A1 at fetal day 140 as opposed to increase in HSD3B and decrease in CYP19A1 in ovaries of adults is suggestive of potential attempt by the fetus to adapt to the initial insult. Reduced granulosa cell CYP19A1 and thecal CYP17A1 in adults likely disrupt the intrafollicular androgen / estrogen balance contributing to follicular persistence. The reduced CYP19A1 in antral follicles of adult females indicates that the increase in circulating estradiol release likely arises from the increased number of persisting follicles and not the result of increased estradiol production from individual follicles. These findings may be of translational relevance to women with PCOS, who manifest similar ovarian morphology.