Prenatal Exposure to Di(2-Ethylhexyl) Phthalate Causes Long-Term Transgenerational Effects on Female Reproduction in Mice

Abstract

Di(2-ethylhexyl) phthalate (DEHP) is a plasticizer in many consumer products. Although DEHP is a known endocrine disruptor, little is known about the effects of DEHP exposure on female reproduction. Thus, this study tested the hypothesis that prenatal DEHP exposure affects follicle numbers, estrous cyclicity, and hormone levels in multiple generations of mice. Pregnant CD-1 mice were orally dosed with corn oil (vehicle control) or DEHP (20 and 200 µg/kg/d and 500 and 750 mg/kg/d) from gestational day 11 until birth. The F1 females were mated with untreated males to create the F2 generation, and the F2 females were mated with untreated males to create the F3 generation. At 1 year, ovaries, hormones, and estrous cycles were analyzed in each generation. Prenatal DEHP exposure altered estrous cyclicity (750 mg/kg/d), increased the presence of ovarian cysts (750 mg/kg/d), and decreased total follicle numbers (750 mg/kg/d) in the F1 generation. It also decreased anogenital distance (200 µg/kg/d) and altered follicle numbers (200 µg/kg/d and 500 mg/kg/d) in the F2 generation, and it altered estrous cyclicity (20 and 200 µg/kg/d and 500 and 750 mg/kg/d) and decreased folliculogenesis (200 µg/kg/d and 500 mg/kg/d) in the F3 generation. Further, prenatal DEHP increased estradiol levels (F1 and F3), decreased testosterone levels (F1, F2, and F3), decreased progesterone levels (F2), altered gonadotropin hormone levels (F1 and F3), and decreased inhibin B levels (F1 and F3). Collectively, these data show that prenatal exposure to DEHP has multigenerational and transgenerational effects on female reproduction and it may accelerate reproductive aging.

Passing experiences on to future generations: endocrine disruptors and transgenerational inheritance of epimutations in brain and sperm

“…[4,5,18] in the brain. Since then, other EDCs, especially bisphenol A [22], tributyltin [29] and phthalates [30] have also been demonstrated to have adverse transgenerational phenotypes. Limited evidence from our lab also showed transgenerational effects of PCBs [7,31,32].…”

Germline-dependent transmission of male reproductive traits induced by an endocrine disruptor, di-2-ethylhexyl phthalate, in future generations

“…Many well-characterized mechanisms for these dose-specific effects include receptor down-regulation at high doses versus up-regulation at low doses 76 . Although transgenerational exposure to phthalates has been shown to have both low-dose and non-monotonic effects, the mechanism for these effects is still largely understudied 33,34,[77][78][79] .…”

“…Indeed, exposure to DEHP during the fetal period increases the chances of epigenetic changes that have long-lasting developmental and functional impacts 28 . For instance, prenatal exposure to DEHP has been implicated in decreased anogenital distance, reduced testosterone levels, and poor semen quality [29][30][31][32] , and it accelerates reproductive aging, resulting in premature reproductive senescence in male as well as female mice 33,34 .…”

“…Therefore, in this study, we kept the F3 males for more than one year so that we could follow their reproductive function at similar time-points as assessed in the F1 generation. Further, a number of studies have assessed the transgenerational impact of prenatal DEHP exposure on reproductive function and reported that DEHP induces reproductive dysfunction in the F2 and F3 generations 34,36,48,49 . Interestingly, the impacted future generations display a wide range of heterogeneity in their reproductive traits.…”

The impact of di-2-ethylhexyl phthalate on sperm fertility

“…Exposure to EDCs poses a significant risk to reproductive health and fetal development (Brehm et al 2018;Hannon, Niermann, and Flaws 2016). While it is known that DEHP impairs sperm motility and chromatin DNA stability (Sumner et al 2019;Pant et al 2011), its mechanism of action and direct effect on sperm fertilizing capacity have not been elucidated.…”