A western-style diet, with and without chronic androgen treatment, alters the number, structure and function of small antral follicles in ovaries of young adult monkeys

This study examined the small antral follicles (SAFs) in ovaries of young adult rhesus monkeys following consumption of a western-style diet (WSD), with or without chronically elevated androgen levels since before puberty. Cholesterol or testosterone (T; n=6/group) implants were placed subcutaneously beginning at 1 yr of age, with addition of a WSD (high fat/fructose) at 5.5 yrs. Ovaries from treated females and age-matched controls were collected at 7 yrs of age. Compared to controls, consumption of a WSD, with and without T treatment, increased the numbers of SAFs per ovary (P<0.001), due to the presence of more atretic follicles (P<0.01). Immunostaining for the cellular proliferation markers (pRb and pH3) was greater in granulosa cells of healthy SAFs (P<0.01), while staining for the cell cycle inhibitor (p21) was higher in atretic SAFs (P<0.01). Intense CYP17A1 staining was observed on the theca of SAFs from WSD+/- T groups, compared to controls. Microarray analyses of the transcriptome in SAFs isolated from a subgroup (n=3/grp) of WSD and WSD+T treated females and controls consuming a standard diet, identified mRNA levels for 1944 genes changed >2-fold (p<0.05) among the three groups. Pathway analyses identified several gene pathways altered by WSD and/or WSD+T associated with lipid, carbohydrate and lipid metabolism, plus ovarian processes. Alterations of several SAF mRNAs are similar to those observed in follicular cells from women with PCOS. These data indicate chronic exposure to a WSD in the presence and absence of chronically elevated T alters structure and function of SAFs within primate ovaries. Affymetrix Microarray analyses of the transcriptome in SAFs isolated from ovaries of WSD and WSD+T treated rhesus macaque females and controls consuming a standard diet. Presumptive healthy SAFs were chosen for transcriptome evaluation based on criteria similar to previous studies: the presence of a clear antrum lacking dark oocytes or granulosa cells. Isolated SAFs were pooled by female/ovary (3.7±0.3 SAFs/ovary, n=3 ovaries/group), cleaned of extraneous stroma using 30-gauge needles, ruptured, and entire cellular contents (follicle wall/granulosa cells and cumulous-oocyte complex) placed into lysis buffer for RNA isolation (Absolutely RNA Nanoprep Kit, Agilent Technologies, Inc. USA).