Abstract
Prenatal exposure to excess testosterone (T) programs peripheral insulin resistance and dyslipidemia along with tissue-specific increases in ectopic lipid accumulation, oxidative stress and insulin resistance in liver and muscle of the early adult female sheep. Prenatal T increased inflammation and oxidative stress in the visceral (VAT) but not subcutaneous (SAT) adipose tissue, with no effect on insulin sensitivity in both depots. These systemic and tissue-specific metabolic changes are reminiscent of defects such as non-alcoholic fatty liver disease (NFLAD) common among aged individuals. Because it is known that gestational insults can program premature aging of reproductive organs and chronic cardiovascular abnormalities, we hypothesized that programming of premature cellular senescence is one of the ways through which gestational T induces premature aging of metabolic systems during early adulthood. To test this hypothesis, mitochondrial oxidative phosphorylation (OXPHOS) and telomere length, as measure of cellular senescence, were assessed in liver, muscle, VAT and SAT collected from control and prenatal T- (100mg T propionate twice a week from days 30-90 of gestation) -treated female sheep at 21 months of age. Genomic DNA was subjected to TeloTAGG Telomere Length Assay (Sigma-Aldrich, St Louis, MO) and whole tissue protein lysates analyzed by immunoblot using Total OXPHOS Human WB Antibody Cocktail (ab110411, Abcam, Cambridge, MA). Data were analyzed by Student’s t test and Cohen’s effect size analysis. Prenatal T-treatment induced 1) a trend (p = 0.09) towards a large magnitude increase in shorter telomere fragments (0.08 -3.6 KB) in the liver and 2) a non-significant large magnitude decrease in shorter telomere fragments in muscle and SAT without having any effect in the VAT. Prenatal T also induced a large magnitude increase in mitochondrial OXPHOS protein complexes II and IV in liver, without having an effect at the level of the muscle, VAT and SAT. These findings are suggestive that prenatal T-treatment induced hepatic defects may involve premature cellular senescence. The relevance of parallel increase in mitochondrial OXPHOS in the liver is unclear and remains to be explored. The defects observed in the muscle and SAT may occur independent of cellular senescence or alterations in mitochondrial function. The lack of change in telomere length and mitochondrial OXPHOS in spite of increased inflammation and oxidative stress in the VAT is suggestive of a potential protective function in play, consistent with maintenance of the insulin sensitivity in this tissue. This study, therefore, raises the possibility that metabolic defects programmed by gestational insults may involve premature aging of metabolic organs in a tissue-specific manner and have translational bearing in conditions associated with hyperandrogenic states.
MON-LB039 Developmental Programming: Prenatal Testosterone Excess Induces Endoplasmic Reticulum (ER) Stress in the Metabolic Tissues of the Female Sheep
