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

Abstract

Objective To examine the small antral follicle (SAF) cohort in ovaries of adult rhesus monkeys following consumption of a western-style diet (WSD), with or without chronically elevated androgen levels since before puberty. Design Cholesterol or testosterone (T; n=6/group) implants were placed subcutaneously in female rhesus macaques beginning at 1 yr of age (pre-pubertal), with addition of a WSD (high fat/fructose) at 5.5 yrs (menarche ~2.6 yrs). Ovaries were collected at 7 yrs of age. One ovary/female was embedded in paraffin for morphological and immunohistochemical analyses. The SAFs (<2.5mm) were dissected from the other ovary obtained at/near menses in a subgroup of females (n=3/group), and processed for microarray analyses of the SAF transcriptome. Ovaries of adult monkeys consuming a standard macaque diet (low in fats and sugars) were obtained at similar stages of the menstrual cycle and used as controls for all analyses. Setting National primate research center Animals Adult, female rhesus monkeys (Macaca mulatta) Interventions None Main outcome measures Histological analyses, SAF counts and morphology, protein localization and abundance in SAFs, transcriptome in SAFs (mRNAs) Results Compared to controls, consumption of a WSD, with and without T treatment, increased the numbers of SAFs per ovary, due to the presence of more atretic follicles. Numbers of granulosa cells expressing cellular proliferation markers (pRb and pH3) was greater in healthy SAFs, while numbers of cells expressing the cell cycle inhibitor (p21) was higher in atretic SAFs. Intense CYP17A1 staining was observed in the theca cells of SAFs from WSD+/− T groups, compared to controls. Microarray analyses of the transcriptome in SAFs isolated from WSD and WSD+T treated females and controls consuming a standard diet, identified 1944 genes whose mRNA levels changed ≥2-fold among the three groups. Further analyses identified several gene pathways altered by WSD and/or WSD+T associated with steroid, carbohydrate and lipid metabolism, plus ovarian processes. Alterations in levels of several SAF mRNAs are similar to those observed in follicular cells from women with polycystic ovary syndrome (PCOS). Conclusion These data indicate that consumption of a WSD high in fats and sugars in the presence and absence of chronically elevated T alters the structure and function of SAFs within primate ovaries.

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

“…When main effects are significant, different lower case letters indicate significant differences between individual groups; asterisks (* vs **) denote trend towards differences. When no symbols are present, there were no differences detected by pairwise comparisons androgen (~6 years) [41,42]. In this previous study, we also observed increased numbers of atretic small antral follicles in vivo and increased numbers of degenerating oocytes following follicle culture after WSD and T+WSD treatments.…”

Chronic hyperandrogenemia in the presence and absence of a western-style diet impairs ovarian and uterine structure/function in young adult rhesus monkeys

“…Ovarian structure in the early follicular phase (Days 1-3; ovarian size, number of antral follicles, antral follicle location within the ovary) was analyzed in all females (n = 10/group) by 3D/4D Doppler ultrasound (GE Voluson 730 Expert, GE Healthcare, Milwaukee, WI, USA) under ketamine sedation (10 mg/kg) using previously validated methods (Bishop et al, 2009;McGee et al, 2014). Polycystic ovarian morphology (PCOM) was determined for each ovary using defined characteristics (Bishop et al, 2016). Near the mid-cycle E2 surge and again at mid-luteal phase (6-8 days post-LH surge), a subset of monkeys (n = 6/group) were sedated with ketamine and placed under inhaled isoflurane anesthesia (1.5% isoflurane mixed with 100% oxygen at a flow rate of 1.5 l/min; Portable Anesthesia Machine, Patterson Veterinary Supply, Inc. Greeley, CO, USA).…”

“…An important question then is discerning how putative causative factors, such as elevated T or metabolic perturbations, interact to produce PCOS symptoms. In our recent pilot study (McGee et al, 2014;Bishop et al, 2016), combined administration of T with an obesogenic westernstyle diet (WSD) decreased insulin sensitivity and altered features of ovarian function in female rhesus monkeys. Although the protocol provided intriguing evidence for some PCOS-like effects of chronic T+WSD treatment, it was limited in experimental design and unable to distinguish effects of T or WSD alone, or if the effects of T and WSD were additive or synergistic.…”

Short-term Western-style diet negatively impacts reproductive outcomes in primates

“…Moreover, determining whether a similar proinflammatory follicular microenvironment, embryonic arrest, and differential gene expression, which is observed when the females are on a WSD for a longer period of time (i.e., more than a year of continual WSD consumption) and develop metabolic dysfunction, should also be determined. We note that there are already published findings of adverse effects from long-term WSD consumption on rhesus macaque ovarian and uterine structure and function ( 82 , 83 ), but — to our knowledge — there are not yet studies on oocyte fertilization and preimplantation development during COS cycles; this is a current research focus of our group. The results of these studies will help determine the precise impact of WSD on infertility and its confounding effects on IVF success ( 8 , 84 ).…”