The toxic effects and possible mechanisms of Bisphenol A on oocyte maturation of porcine in vitro

Abstract

Bisphenol A (BPA) and Di-(2-ethylhexyl) phthalate (DEHP) are widely used in the plastic industry such as water bottles, containers, packaging and toys. BPA and DEHP are shown to be the endocrine disruptors which disturb the endocrine system and are linked to several diseases including infertility. In this study, we investigated the effects of BPA exposure on porcine oocyte maturation and its possible reasons. Our results showed that: (i) the rates of oocyte maturation significantly decreased with 250 μM BPA treatment in vitro, but not DEHP. This might be due to the delayed cell cycle progression of oocyte maturation. (ii) BPA treatment resulted in abnormal cytoskeletons on porcine oocytes, showing with aberrant actin distribution, spindle morphology and chromosome alignment, which was further confirmed by the reduced p-MAPK level. (iii) The fluorescence intensity of histone methylation (H3K4me2) and DNA methylation (5 mC) levels were altered after BPA treatment, indicating that epigenetic modification was disturbed. (iv) BPA-exposed oocytes had higher rates of early stage apoptosis/autophagy, and this may be resulted from the increased level of oxidative stress. Collectively, our results indicated that porcine oocytes maturation was disrupted after BPA treatment through disrupting cytoskeletal dynamics, epigenetic modifications and inducing apoptosis/autophagy.

Isobutylparaben Negatively Affects Porcine Oocyte Maturation Through Increasing Oxidative Stress and Cytoskeletal Abnormalities

“…This study also provides a warning for women who are frequently exposed to IBP at high concentrations by using in vitro culture model of porcine cumulus oocyte complexes as can be seen in Figure . The reason we chose porcine oocytes as a model because oocyte size and maturation time are more like human than mouse (Santos et al ), and several articles have used porcine cumulus oocyte complexes to evaluate oocyte (Liu et al ; Han et al ; Wang et al ; Miao et al ; Liang et al ).…”

Global DNA Hypomethylation and Rassf1a and c-myc Promoter Hypermethylation in Rat Kidney Cells after Bisphenol A Exposure

“…7 Conversely, in another previous study, we observed no global methylation changes after 48 h exposure to BPA, whereas significant increase were shown on global level of 5-mC% (1.3 fold) after 10 μM of BPA for 96 h exposure in neuroblastoma (SHSY-5Y) cells. 9 According to results of this study, it has been shown that BPA caused global hypomethylation in rat liver 24 , human fetal liver samples 25 , and porcine oocyte culture at 250 μM of concentration 26 .…”

Endocrine Disruptors: Very Low Doses with Genuinely High Impacts on Male Reproduction

“…While the exposure of somatic cells creates health problems for exposed individuals, influence on gametes leads to an intergenerational effect when the burden is transduced to the next generation of daughters and sons [81]. Indeed, the exposure to bisphenols impairs genome-wide DNA methylation, as well as histone code in oocytes [71,82], followed by changes in the imprinting of genes in the embryo and placenta [83]. In spermatozoa, DNA methylation [84] is potentially affected by environmental pollutants, leading to aberrant gene imprinting [85,86].…”