Developmental Programming: Impact of Prenatal Testosterone Excess on Steroidal Machinery and Cell Differentiation Markers in Visceral Adipocytes of Female Sheep

Abstract

Prenatal testosterone (T)-treated female sheep manifest reduced adipocyte size and peripheral insulin resistance. The small adipocyte phenotype may reflect defects in adipogenesis and its steroidal machinery. To test whether prenatal T treatment from gestational days 30 to 90 alters the visceral adipose tissue (VAT) steroidal machinery and reduces adipocyte differentiation, we examined expression of the steroidogenic enzymes, steroid receptors, and adipocyte differentiation markers at fetal day 90 and postnatal ages 10 and 21 months. Because gestational T treatment increases fetal T and maternal insulin, the contributions of these were assessed by androgen receptor antagonist or insulin sensitizer cotreatment, either separately (at fetal day 90 and 21 months of age time points) or together (10 months of age). The effects on adipogenesis were assessed in the VAT-derived mesenchymal stem cells (AT-MSCs) from pre- and postpubertal time points to evaluate the effects of pubertal steroidal changes on adipogenesis. Our results show that VAT manifests potentially a predominant estrogenic intracrine milieu (increased aromatase and estrogen receptor α) and reduced differentiation markers at fetal day 90 and postnatal 21 months of age. These changes appear to involve both androgenic and metabolic pathways. Preliminary findings suggest that prenatal T treatment reduces adipogenesis, decreases expression of differentiation, and increases expression of commitment markers at both pre- and postpubertal time points. Together, these findings suggest that (1) increased commitment of AT-MSCs to adipocyte lineage and decreased differentiation to adipocytes may underlie the small adipocyte phenotype of prenatal T-treated females and (2) excess T-induced changes in steroidal machinery in the VAT likely participate in the programming/maintenance of this defect.

Developmental programming: Changes in mediators of insulin sensitivity in prenatal bisphenol A-treated female sheep

“…This coupled with increased ESR1 (p < 0.05 for medium and high dose, by t test) and the trend for decreased AR mRNA expression (p = 0.09 for high dose only by t test) indicates a predominant tendency for intracrine estrogenic milieu in the VAT of prenatal BPA-treated sheep. An estrogenic intracrine milieu is not consistent with this adipocyte hypertrophy phenotype [19] and contrasts with the observations in prenatal testosterone-treated female sheep where an increase in estrogenic milieu in the VAT accompanies smaller adipocytes [73,74]. Estrogens have been shown to reduce adipocyte cell size by decreasing adipocyte lipid storage and increasing lipolysis [33,75].…”

Mechanisms of intergenerational transmission of polycystic ovary syndrome

“…In agreement, prenatal Zfp423 knockout in mice fed a high-fat diet exaggerates diet-induced obesity, ectopic fat deposition and insulin resistance (Shao et al 2017). In support of developmental programming as a contributor to such events, studies of prenatally testosterone-treated juvenile female sheep show increased ASC commitment to preadipocytes and decreased preadipocyte differentiation of visceral adipocytes, with the later prevented by dual prenatal flutamide/rosiglitazone co-treatment (Puttabyatappa et al 2018).…”

“…This altered adipocyte morphology in early adult, prenatally testosterone-treated sheep occurs when visceral adiposity and insulin sensitivity are still normal and precedes metabolic dysfunction in later life, perhaps as a compensatory adaptation to the perturbed intrauterine environment (Cardoso et al 2016). Interestingly, reduced adipocyte size in prenatally testosterone-treated sheep is not reversed with flutamide co-treatment, implying endocrine-metabolic mechanisms apart from androgen, including possible estrogen action in this species (Cardoso et al , Puttabyatappa et al 2018).…”

Ovine prenatal growth-restriction and sex influence fetal adipose tissue phenotype and impact postnatal lipid metabolism and adiposity in vivo from birth until adulthood

“…Oestrogen receptors (ERα, ERβ) are present in the brown fat of human fetuses at mid-pregnancy, and ERα expression increases with gestational age over the range 15 to 23 weeks suggestive of a role for oestrogen in adipose tissue differentiation [76]. Similarly, the visceral fat of sheep fetuses express these receptors at mid (day 90, [77]) and later (day120, [78]) gestation and abundance is enhanced in females when fetal oestrogen concentrations are increased as a consequence of maternal testosterone treatment (model of polycystic ovary syndrome, [77,79]).…”