Prenatal exposure to an environmentally relevant phthalate mixture alters oxidative stress, apoptosis, cell cycle regulators, and steroidogenic factors in the ovaries of F1 mice

Abstract

Phthalates are synthetic chemical compounds found in consumer products and known endocrine-disrupting chemicals. However, it is not well known if prenatal exposure to phthalate mixtures can affect reproductive health in female offspring. Thus, this study tested the hypothesis that prenatal exposure to an environmentally relevant phthalate mixture disrupts long-term ovarian function in adult F1 mice. Pregnant CD-1 dams were dosed orally with vehicle control (corn oil) or phthalate mixture (20 μg/kg/day-500 mg/kg/day) from gestational day 10 until birth. After birth, the F1 female ovaries and sera were collected on postnatal day (PND) 60, 3 months, and 6 months. F1 ovaries were used for evaluation of the proliferative marker, Ki67, and to quantify gene expression of steroidogenic regulators, antioxidant enzymes, apoptotic factors and cell cycle regulators. Sera were collected to measure sex steroid hormone levels. At PND60, prenatal exposure to the mixture decreased the expression of Star, Cyp11a1, Bad, and Casp3 in F1 females at PND60 compared to controls. At 3 months, the mixture decreased expression of Cyp11a1, Hsd3b1, Sod1, Casp3, Casp8, and Fas and increased gene expression of Star and Gpx in F1 ovaries compared to the controls. At 6 months, the mixture decreased testosterone levels and expression of Gsr, Bad, Bok, Casp8, Fas and Traf3, and it increased expression of Star in F1 females compared to the controls. Collectively, these data suggest that the prenatal exposure to an environmentally relevant phthalate mixture may have long-term consequences on ovarian health and function in F1 females long after initial exposure.