Chronically elevated androgen and/or consumption of a Western-style diet impairs oocyte quality and granulosa cell function in the nonhuman primate periovulatory follicle.

Purpose: To investigate the impact of chronically-elevated androgens in presence and absence of an obesogenic diet on oocyte quality in the naturally-selected primate periovulatory follicle. Methods: Rhesus macaques were treated using a 2-by-2 factorial design (n=10/treatment) near onset of menarche with implants containing either cholesterol (C) or testosterone (T; 4-5 fold increase above C) and a standard or “Western-style” diet alone (WSD), or in combination (T+WSD). Following ~3.5 years of treatment, females underwent controlled ovulation (COv; n=7-10/treatment) cycles, and contents of the naturally-selected periovulatory follicle were aspirated. Follicular fluid (FF) was analyzed for cytokines, chemokines, growth factors, and steroids. RNA was extracted from luteinizing granulosa cells (LGCs) and assessed by RNA-seq. Results: Only healthy, metaphase (M) I/II-stage oocytes (100%) were retrieved in the C group, whereas degenerated oocytes were prevalent in other groups (33-43%; overall effect of WSD and T, p=0.1). Levels of two chemokines and one growth factor were reduced (p<0.04) in FF of follicles with a MI/MII oocyte in WSD+T (CCL11) or T and WSD+T groups (CCL2 and FGF2) compared to C and/or WSD. Intrafollicular cortisol was elevated in T compared to C follicles (p<0.02). Changes in expression pattern of 640+ gene products were detected in LGC samples from follicles with degenerated oocytes versus MI/MII-stage oocytes. Pathway analysis on RNAs altered by T and/or WSD found enrichment of genes mapping to steroidogenic and immune cell pathways. Conclusions: Female primates experiencing hyperandrogenemia and/or consuming a WSD exhibit an altered intrafollicular microenvironment and reduced oocyte quality/competency, despite displaying menstrual cyclicity. Overall design: Biological Replicates