Objectives: To investigate the effect of subacute exposure of Di (2-ethylhexyl) phthalate (DEHP) on endometrial decidualization and early pregnancy miscarriage in mice.
Methods: CD1 mice were orally administrated with 300 (low-dose group), 1000 (medium-dose group), or 3000 mg·kg－1·d－1 DEHP (1/10 LD50, high-dose group) for 28 days, respectively. An early natural pregnancy model and an artificially induced decidualization model were established. The uterine tissues were collected on D7 of natural pregnancy and D8 of artificially induced decidualization, respectively. The effects of a subacute exposure to DEHP on the decidualization of mice were detected by HE staining, Masson staining, TUNEL assay, and Western blotting. A model of spontaneous abortion was constructed in mice after subacute exposure to 300 mg·kg－1·d－1 DEHP, and the effect of impaired decidualization on pregnancy was investigated by observing the pregnancy outcome on the 10th day of gestation.
Results: Compared with the control group, the conception rate was significantly decreased in the high-dose DEHP subacute exposure group (P<0.05). HE staining showed that, compared with the control group, the decidual stromal cells in the low- and medium-dose exposure groups were disorganized, the nuclei of the cells were irregular, the cytoplasmic staining was uneven, and the number of polymorphonuclear cells was significantly reduced. Masson staining showed that compared with the control group, the collagen fibers in the decidua region of the DEHP low-dose group and the medium-dose group were more distributed, more abundant and more disorderly. TUNEL assay showed increased apoptosis in the decidua area compared to the control group. Western blotting showed that the expression of BMP2, a marker molecule for endometrial decidualization, was significantly reduced (P<0.05 or P<0.01). The abortion rate and embryo resorption rate were increased, and the number of embryos, uterine wet weight, uterine area and placenta wet weight were decreased in DEHP low-dose group compared to the control group stimulated by mifepristone, an abortifacient drug (P<0.05 or P<0.01).
Conclusions: Subacute exposure to DEHP leads to impaired endometrial decidualization during early pregnancy and exacerbates the risk of adverse pregnancy outcomes in mice.
目的: 探究邻苯二甲酸酯类增塑剂邻苯二甲酸二（2-乙基）己酯（DEHP）亚急性暴露对小鼠子宫内膜蜕膜反应和流产风险的影响。方法: 分别选取300、1000、3000 mg·kg－1·d－1三个浓度梯度的DEHP对CD1小鼠进行经口亚急性暴露28 d。建立DEHP亚急性暴露小鼠早期自然妊娠模型和人工诱导假孕小鼠蜕膜反应模型，分别取自然妊娠第7天子宫组织和人工诱导蜕膜反应小鼠妊娠第8天诱导侧子宫组织，通过苏木精-伊红染色（HE染色）、Masson染色、TUNEL检测、蛋白质印迹法检测DEHP亚急性暴露对小鼠蜕膜反应的影响。构建300 mg·kg－1·d－1 DEHP亚急性暴露小鼠自然流产模型，观察妊娠第10天的妊娠结局，探究蜕膜反应受损对小鼠妊娠的影响。结果: 与空白对照组比较，DEHP大剂量组受孕率显著性降低（P<0.05）；HE染色显示DEHP小剂量组和中剂量组蜕膜基质细胞排列杂乱、细胞核形态不规则、胞浆染色不均、多核细胞数显著降低；Masson染色显示DEHP小剂量组和中剂量组蜕膜组织的胶原纤维分布更多、数量增多、排列杂乱；TUNEL检测显示暴露组蜕膜组织细胞凋亡增加；蛋白质印迹法检测显示暴露组子宫内膜蜕膜反应标志分子BMP2蛋白表达水平显著降低（P<0.05或P<0.01）；在米非司酮流产刺激下DEHP小剂量组小鼠流产率、胚胎吸收率显著升高，胚胎数、子宫湿重、子宫面积、胎盘湿重显著减少（P<0.05或P<0.01）。结论: DEHP亚急性暴露导致小鼠子宫内膜蜕膜反应受损加重小鼠妊娠流产风险。.
Keywords: Abortion; Decidual reaction; Di (2-ethylhexyl) phthalate; Mice; Mifepristone.