Nonhuman primate models of polycystic ovary syndrome

https://doi.org/10.1016/j.mce.2013.01.013Get rights and content

Abstract

With close genomic and phenotypic similarity to humans, nonhuman primate models provide comprehensive epigenetic mimics of polycystic ovary syndrome (PCOS), suggesting early life targeting for prevention. Fetal exposure to testosterone (T), of all nonhuman primate emulations, provides the closest PCOS-like phenotypes, with early-to-mid gestation T-exposed female rhesus monkeys exhibiting adult reproductive, endocrinological and metabolic dysfunctional traits that are co-pathologies of PCOS. Late gestational T exposure, while inducing adult ovarian hyperandrogenism and menstrual abnormalities, has less dysfunctional metabolic accompaniment. Fetal exposures to dihydrotestosterone (DHT) or diethylstilbestrol (DES) suggest androgenic and estrogenic aspects of fetal programming. Neonatal exposure to T produces no PCOS-like outcome, while continuous T treatment of juvenile females causes precocious weight gain and early menarche (high T), or high LH and weight gain (moderate T). Acute T exposure of adult females generates polyfollicular ovaries, while chronic T exposure induces subtle menstrual irregularities without metabolic dysfunction.

Highlights

► Early-to-mid gestation testosterone excess recapitulates PCOS phenotypes in monkeys. ► Transient maternal and fetal hyperglycemia accompany testosterone exposure. ► Epigenetic changes in visceral fat implicate altered TGF-β signaling. ► T-exposed monkeys may provide a close, epigenetic molecular mimic of PCOS.

Introduction

Polycystic ovary syndrome (PCOS) afflicts 15% of women in their reproductive years (Fauser et al., 2012), increasing a woman’s lifetime risk of type 2 diabetes mellitus (type 2 DM) and cardiovascular disease (Wild et al., 2010). Progress towards prevention of PCOS, however, has been hindered by an incomplete knowledge of its pathogenesis. Polycystic ovary syndrome is characterized by at least two of the following criteria: hyperandrogenism, intermittent or absent menstrual cycles (often accompanied by luteinizing hormone (LH) excess), and increased numbers of small ovarian antral follicles (Fauser et al., 2012). While a hyperandrogenic polycystic ovary is central to PCOS pathophysiology (Gilling-Smith et al., 1997, Franks et al., 2008, Nelson et al., 1999), visceral obesity and insulin resistance are frequent co-morbidities (Ehrmann et al., 2006, Kiddy et al., 1990). Pre- or peri-pubertal metabolic dysfunction is one of the first phenotypic traits observed in adolescent girls likely to develop PCOS (Coviello et al., 2006, Marshall, 2006), an alarming finding since obesity now affects ∼15% of American children (Dietz, 1998, Hedley et al., 2004). Overweight or obese adolescent girls have higher circulating androgen levels than their lean counterparts (Ibanez et al., 2003, Chhabra et al., 2005, McCartney et al., 2006), with such hyperandrogenism predisposing adolescents to PCOS (Rosenfield, 2007, Zumoff et al., 1983, McCartney, 2010).

Twin (Vink et al., 2006) and genetic (Goodarzi, 2008, Urbanek et al., 2007, Ewens et al., 2010) studies demonstrate high heritability of PCOS, particularly hyperandrogenism (Legro et al., 1998). The most reliable PCOS gene candidate is a member of the TGF-ß superfamily encoding for the extra-cellular matrix protein, fibrillin 3 (Ewens et al., 2010). The allelic fibrillin variant, A8, is linked with PCOS and manifests a distinct metabolic phenotype, even in immediate male kin, which includes insulin resistance (Urbanek et al., 2007). Circulating levels of the TGF-ß superfamily peptide, anti-mullerian hormone (AMH), are derived from ovarian granulosa cells and are elevated in women and adolescents with PCOS (Pellatt et al., 2010, Siow et al., 2005, Hart et al., 2010), as well as in infant girls born to women with PCOS (Sir-Petermann et al., 2012, Crisosto et al., 2012). As daughters born to PCOS women are at increased risk for PCOS in adulthood (Vink et al., 2006), their contribution to evaluation of PCOS antecedents is relevant, particularly because reproductive and metabolic features of PCOS are established in these young girls before signs and symptoms fully manifest in adulthood (Rosenfield, 2007, Franks, 2002, Shayya and Chang, 2010, Roe and Dokras, 2011).

Consistent with an early onset of PCOS pathophysiology, aspects of PCOS-like phenotypes are reliably produced in females rhesus monkeys (Abbott et al., 2002, Abbott et al., 2005), sheep (Padmanabhan and Veiga-Lopez, 2011, this issue), and rats and mice (Walters et al., 2012; McNeilly, this issue) by in utero exposure to fetal male levels of testosterone (T), suggesting that the intrauterine environment may fundamentally affect the etiology of PCOS in such prenatal androgenized (PA) females (Abbott et al., 2008a, Abbott et al., 2008b). Furthermore, adult female macaques have been identified with naturally occurring PCOS-like traits in which high T levels may be heritable (Arifin et al., 2008; DH Abbott, unpublished results). Consequently, fetal T programming of PCOS-like reproductive traits has been formulated as the fetal origins of PCOS hypothesis (Abbott et al., 2002), but the underlying cellular and molecular mechanisms are still poorly understood.

This review will thus examine nonhuman primate contributions to animal models for PCOS, focusing on reproductive, endocrinological and metabolic phenotypes generated by T or other steroids throughout life and the insights regarding PCOS pathogenesis such experimental manipulations provide. As rhesus monkeys share ∼93% of their genome with humans (Gibbs et al., 2007), their human-like reproductive (Kaplan et al., 2010), metabolic (Zhang et al., 2011), developmental (Trounson and Grieshammer, 2012) and aging (Colman et al., 2009) traits provide readily translatable outcomes for human disease.

Section snippets

PCOS-like phenotypes

Adult female rhesus monkeys previously exposed to fetal male levels of T during early-to-mid gestation provide the most comprehensive epigenetic mimic of PCOS in women (Abbott et al., 2005, Abbott et al., 2009, Xu et al., 2011). Fetal male T levels are achieved in fetal female monkeys by means of daily subcutaneous (s.c.) injections of their dams with 10–15 mg testosterone propionate (TP) for 15–40 consecutive days between 40 and 80 days of gestation (early-to-mid gestation T exposure, E) or for

In utero exogenous T: fetal programming for PCOS-like metabolic dysfunction in female monkeys

EPA fetal monkeys develop many PCOS-like metabolic traits as adults (Abbott et al., 2005, Abbott et al., 2009, Dumesic et al., 2005, Zhou et al., 2007a), including increased visceral and total abdominal adiposity, hyperlipidemia, insulin resistance, impaired insulin secretion, hyperglycemia and type 2 DM. Emulating PCOS women, most EPA monkeys respond to six months of daily treatment with the thiazolidinedione insulin sensitizer, pioglitazone, by decreasing insulin resistance and fasted basal

Molecular epigenetic signature of fetal T exposure in female monkeys

Alteration of the epigenome is a mechanism whereby gestational T excess (Xu et al., 2011, Auger et al., 2011, Hogg et al., 2012), or its hyperglycemic consequences (Pirola et al., 2010, Pirola et al., 2011), reprogram gene expression in EPA monkeys enabling development of PCOS-like traits in adulthood. Differentially methylated genes identified in EPA infant (>100) and adult (>300) visceral fat are involved in the regulation of adipogenesis, intermediate metabolism and cell proliferation.

Clinical significance for PCOS of in utero T induction of PCOS-like phenotypes in monkeys

With the certainty of a PCOS-like phenotype in adulthood. EPA monkeys provide opportunities to determine fetal, infant and juvenile antecedents of PCOS that will enable early targeting of amelioration or prevention in humans. In addition, as TP injections given to pregnant monkey dams impair the dams’ abilities to regulate blood glucose, as in humans, subsequent maternal hyperglycemia results in increased fetal exposure to glucose and increased fetal and neonatal growth. Infant EPA female

Acknowledgements

The authors thank Amber K. Edwards at the Wisconsin National Primate Research Center (WNPRC) and Dr. Alice F. Tarantal at the California National Primate Research Center (CNPRC) for expert technical assistance. This work was supported by the National Institutes of Health R01-RR013635 to D.H.A., R01-DK079888 to M.O.G., U01-HD044650 to D.A.D., P50-HD044405 to Andrea Dunaif, T32-DK07786 to Michael J. MacDonald (Postdoctoral Fellows Training Award), P51-RR000167 to WNPRC, P51-RR000169 to CNPRC,

References (120)

  • R. Hart et al.

    Serum antimullerian hormone (AMH) levels are elevated in adolescent girls with polycystic ovaries and the polycystic ovarian syndrome (PCOS)

    Fertil. Steril.

    (2010)
  • A.G. Hendrickx et al.

    Long-term evaluation of the diethylstilbestrol (DES) syndrome in adult female rhesus monkeys (Macaca mulatta)

    Reprod. Toxicol.

    (1987–1988)
  • N. Raja-Khan et al.

    A variant in the fibrillin-3 gene is associated with TGF-beta and inhibin B levels in women with polycystic ovary syndrome

    Fertil. Steril.

    (2010)
  • Y. Siow et al.

    Serum Müllerian-inhibiting substance levels in adolescent girls with normal menstrual cycles or with polycystic ovary syndrome

    Fertil. Steril.

    (2005)
  • A. Trounson et al.

    Chimeric primates: embryonic stem cells need not apply

    Cell

    (2012)
  • A.D. Abbott et al.

    Early-to-mid gestation fetal testosterone increases right hand 2D:4D finger length ratio in polycystic ovary syndrome-like monkeys

    PLoS ONE

    (2012)
  • D.H. Abbott

    Fibrillin 3 in the fetal ovary: can it contribute to polycystic ovary syndrome? Expert Rev

    Endocrinol. Metab.

    (2012)
  • D.H. Abbott et al.

    Nonhuman primates as models for human adrenal androgen production: function and dysfunction

    Rev. Endocr. Metab. Disord.

    (2009)
  • D.H. Abbott et al.

    The effects of neonatal exposure to testosterone on the development of behaviour in female marmoset monkeys

    Ciba Found Symp.

    (1978)
  • D.H. Abbott et al.

    Developmental origin of polycystic ovary syndrome – a hypothesis

    J. Endocrinol.

    (2002)
  • D.H. Abbott et al.

    Androgen excess fetal programming of female reproduction: a developmental aetiology for polycystic ovary syndrome?

    Hum. Reprod. Update

    (2005)
  • D.H. Abbott et al.

    Endocrine antecedents of polycystic ovary syndrome in fetal and infant prenatally androgenized female rhesus monkeys

    Biol. Reprod.

    (2008)
  • Abbott, D.H., Roy, S.K., Manikkam, M., Tarantal, A.F., Dumesic, D.A., Padmanabhan, V., 2008b. Diminished ovarian...
  • D.H. Abbott et al.

    Fetal, infant, adolescent and adult phenotypes of polycystic ovary syndrome in prenatally androgenized female rhesus monkeys

    Am. J. Primatol.

    (2009)
  • D.H. Abbott et al.

    Experimentally induced gestational androgen excess disrupts glucoregulation in rhesus monkey dams and their female offspring

    Am. J. Physiol. Endocrinol. Metab.

    (2010)
  • H. Anderson et al.

    Infants of women with polycystic ovary syndrome have lower cord blood androstenedione and estradiol levels

    J. Clin. Endocrinol. Metab.

    (2010)
  • E. Arifin et al.

    Polycystic ovary syndrome with endometrial hyperplasia in a cynomolgus monkey (Macaca fascicularis)

    Vet. Pathol.

    (2008)
  • C.J. Auger et al.

    Epigenetic control of vasopressin expression is maintained by steroid hormones in the adult male rat brain

    Proc. Natl. Acad. Sci. USA

    (2011)
  • J.A. Barry et al.

    Umbilical vein testosterone in female infants born to mothers with polycystic ovary syndrome is elevated to male levels

    J. Obstet. Gynaecol.

    (2010)
  • P. Beck-Peccoz et al.

    Maturation of hypothalamic-pituitary-gonadal function in normal human fetuses: circulating levels of gonadotropins, their common alpha-subunit and free testosterone, and discrepancy between immunological and biological activities of circulating follicle-stimulating hormone

    J. Clin. Endocrinol. Metab.

    (1991)
  • R.B. Billiar et al.

    The effect of chronic and acyclic elevation of circulating androstenedione or estrone concentrations on ovarian function in the rhesus monkey

    Endocrinology

    (1985)
  • S.K. Blank et al.

    The origins and sequelae of abnormal neuroendocrine function in polycystic ovary syndrome

    Hum. Reprod. Update

    (2006)
  • S.K. Blank et al.

    Neuroendocrine effects of androgens in adult polycystic ovary syndrome and female puberty

    Semin. Reprod. Med.

    (2007)
  • S.K. Blank et al.

    Modulation of gonadotropin-releasing hormone pulse generator sensitivity to progesterone inhibition in hyperandrogenic adolescent girls–implications for regulation of pubertal maturation

    J. Clin. Endocrinol. Metab.

    (2009)
  • S. Chhabra

    Progesterone inhibition of the hypothalamic gonadotropin-releasing hormone pulse generator: evidence for varied effects in hyperandrogenemic adolescent girls

    J. Clin. Endocrinol. Metab.

    (2005)
  • R.J. Colman et al.

    Caloric restriction delays disease onset and mortality in rhesus monkeys

    Science

    (2009)
  • A.J. Conley et al.

    Adrenarche in Non-human Primates: the evidence for it and the need to re-define it

    J. Endocrinol.

    (2012)
  • A.D. Coviello et al.

    Adolescent girls with polycystic ovary syndrome have an increased risk of the metabolic syndrome associated with increasing androgen levels independent of obesity and insulin resistance

    J. Clin. Endocrinol. Metab.

    (2006)
  • W.H. Dietz

    Health consequences of obesity in youth: childhood predictors of adult disease

    Pediatrics

    (1998)
  • A.K. Dubey et al.

    Serum and CSF concentrations of testosterone and LH related to negative feedback in male rhesus monkeys

    Neuroendocrinology

    (1984)
  • D.A. Dumesic et al.

    Impaired developmental competence of oocytes in adult prenatally androgenized female rhesus monkeys undergoing gonadotropin stimulation for in vitro fertilization

    J. Clin. Endocrinol. Metab.

    (2002)
  • D.A. Dumesic et al.

    Reduced intrafollicular androstenedione and estradiol levels in early-treated prenatally androgenized female rhesus monkeys receiving follicle-stimulating hormone therapy for in vitro fertilization

    Biol. Reprod.

    (2003)
  • D.A. Dumesic et al.

    Early origins of polycystic ovary syndrome

    Reprod. Fertil. Dev.

    (2005)
  • D.A. Dumesic et al.

    Early prenatal androgenization results in diminished ovarian reserve in adult female rhesus monkeys

    Hum. Reprod.

    (2009)
  • D.A. Ehrmann

    Prevalence and predictors of the metabolic syndrome in women with polycystic ovary syndrome

    J. Clin. Endocrinol. Metab.

    (2006)
  • K.G. Ewens

    Family-based analysis of candidate genes for polycystic ovary syndrome

    J. Clin. Endocrinol. Metab.

    (2010)
  • C. Faiman et al.

    Effects of long-term testosterone exposure on ovarian function and morphology in the rhesus monkey

    Anat. Rec.

    (1988)
  • B.C. Fauser et al.

    Consensus on women’s health aspects of polycystic ovary syndrome (PCOS): the Amsterdam ESHRE/ASRM-Sponsored 3rd PCOS consensus workshop group

    Fertil. Steril.

    (2012)
  • S. Franks et al.

    Follicle dynamics and anovulation in polycystic ovary syndrome

    Hum. Reprod. Update

    (2008)
  • E.M. Foecking et al.

    Neuroendocrine consequences of prenatal androgen exposure in the female rat: absence of luteinizing hormone surges, suppression of progesterone receptor gene expression, and acceleration of the gonadotropin-releasing hormone pulse generator

    Biol. Reprod.

    (2005)
  • Cited by (0)

    View full text