Litton Christian, Benny Paula, Lambertini Luca, Ma Yula, Riel Jonathan, Weingrill Rodrigo, Urschitz Johann, Chen Jia, Lee Men-Jean
Department of Obstetrics and Gynecology, Maine Medical Center, Portland, ME 04102, USA.
Department of Obstetrics and Gynecology, John A. Burns School of Medicine, University of Hawaii, Honolulu, HI 96822, USA.
Toxics. 2024 Sep 9;12(9):659. doi: 10.3390/toxics12090659.
Bisphenol A and phthalate are known endocrine disruptors and capable of inducing epigenetic changes in the human population. However, their impact on the placenta is less well studied. Our objective was to measure the effect of exposure to bisphenol A and benzyl butyl phthalate in first-trimester HTR8-SVneo and third-trimester 3A-sub E trophoblast cells by profiling the DNA methylation pattern of the imprinting control region of the IGF2 (insulin-like growth factor) and H19 genes.
Human placental HTR8-SVneo and 3A-sub E cell lines were treated with two sub-lethal concentrations of bisphenol A and benzyl butyl phthalate. Demethylating agent, 5-azacytidine, was used as a positive control. Cells were harvested on post-treatment days 1 and 4. The methylation profile of six CpG dinucleotide sites, part of the CTCF 6 binding site of the IGF2/H19 imprinting control region, was determined by pyrosequencing.
In the first-trimester HTR8-SVneo cell line, we observed a significant increased methylation of the CpG sites 3, 4 when treated with a high concentration of bisphenol A or benzyl butyl phthalate while increased methylation at site 6 for both high and low dose treatment on day 4. Demethylation of the CpG sites 1, 4, and 6 was observed when treated with 5-azacytidine on day 4. In the third-trimester 3A-sub E cell line, no significant changes in the methylation profile were observed under any treatment conditions.
The results of this study demonstrate the capability of epigenetic changes in human placenta cells induced by bisphenol A and benzyl butyl phthalate. The observed methylation changes only in the first-trimester HTR8-SVneo cells phthalate may reflect a window of epigenetic susceptibility related to these environmental toxicants.
双酚A和邻苯二甲酸酯是已知的内分泌干扰物，能够在人群中诱导表观遗传变化。然而，它们对胎盘的影响研究较少。我们的目的是通过分析胰岛素样生长因子2（IGF2）和H19基因印记控制区的DNA甲基化模式，来测量双酚A和邻苯二甲酸苄基丁酯暴露对孕早期HTR8-SVneo细胞和孕晚期3A-sub E滋养层细胞的影响。
用人胎盘HTR8-SVneo和3A-sub E细胞系分别用两种亚致死浓度的双酚A和邻苯二甲酸苄基丁酯处理。去甲基化剂5-氮杂胞苷用作阳性对照。在处理后的第1天和第4天收获细胞。通过焦磷酸测序确定IGF2/H19印记控制区CTCF 6结合位点的六个CpG二核苷酸位点的甲基化谱。
在孕早期HTR8-SVneo细胞系中，当用高浓度双酚A或邻苯二甲酸苄基丁酯处理时，我们观察到CpG位点3、4的甲基化显著增加，而在第4天，高剂量和低剂量处理时位点6的甲基化均增加。在第4天用5-氮杂胞苷处理时，观察到CpG位点1、4和6的去甲基化。在孕晚期3A-sub E细胞系中，在任何处理条件下均未观察到甲基化谱的显著变化。
本研究结果证明了双酚A和邻苯二甲酸苄基丁酯可诱导人胎盘细胞发生表观遗传变化。仅在孕早期HTR8-SVneo细胞中观察到的甲基化变化可能反映了与这些环境毒物相关的表观遗传易感性窗口。
