Beal Jacob R, Bhurke Arpita, Carlson Kathryn E, Katzenellenbogen John A, Yu Jie, Flaws Jodi A, Bagchi Indrani C, Bagchi Milan K
Department of Molecular and Integrative Physiology, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA.
Department of Comparative Biosciences, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA.
Endocrinology. 2025 Apr 22;166(6). doi: 10.1210/endocr/bqaf087.
High levels of exposure to di(2-ethylhexyl) phthalate (DEHP), a known endocrine disruptor, have been linked to adverse pregnancy outcomes, yet the mechanisms by which it impacts human uterine functions remain unclear. Here we report that exposure of differentiating primary human endometrial stromal cells (HESCs) to an environmentally relevant concentration of DEHP or its primary metabolite, mono(2-ethylhexyl) phthalate, markedly reduces the expression of the estrogen-regulated transcription factor hypoxia-inducible factor 2-α (HIF2α). We also noticed a simultaneous decrease in RAB27B expression, which is crucial for the trafficking and secretion of extracellular vesicles (EVs). EVs enhance communication among various cell types within the pregnant uterus, thereby ensuring reproductive success. We found that estrogen receptor α (ERα) could no longer bind to the HIF2α regulatory region following phthalate treatment, and epigenetic analysis suggested that this may be due to hypermethylation of nearby CpG islands. Further investigation revealed a potential interaction between ERα and the transcription factor specificity protein 1 (Sp1) within the HIF2α regulatory region, which is affected by the inhibition of Sp1 binding to the phthalate-induced hypermethylated DNA. Additionally, our results suggest that the abnormal DNA methylation is likely due to increased expression of the DNA methyltransferase 1 (DNMT1) gene in response to phthalate exposure. Overall, this study provides valuable mechanistic insights into how phthalate-induced differential DNA methylation disrupts estrogenic regulation of the HIF2α gene and, consequently, EV secretion during HESC differentiation. This knowledge is essential for understanding how phthalates may lead to adverse reproductive outcomes by disrupting hormonal regulation of cell-to-cell communication in the uterus.
已知内分泌干扰物邻苯二甲酸二（2-乙基己基）酯（DEHP）的高暴露水平与不良妊娠结局有关，但其影响人类子宫功能的机制仍不清楚。在此，我们报告，将分化中的原代人子宫内膜基质细胞（HESC）暴露于环境相关浓度的DEHP或其主要代谢产物单（2-乙基己基）邻苯二甲酸酯，会显著降低雌激素调节的转录因子缺氧诱导因子2-α（HIF2α）的表达。我们还注意到RAB27B表达同时下降，RAB27B对细胞外囊泡（EV）的运输和分泌至关重要。EV可增强妊娠子宫内各种细胞类型之间的通讯，从而确保生殖成功。我们发现，邻苯二甲酸酯处理后，雌激素受体α（ERα）无法再与HIF2α调节区域结合，表观遗传分析表明，这可能是由于附近CpG岛的高甲基化所致。进一步研究揭示了ERα与HIF2α调节区域内转录因子特异性蛋白1（Sp1）之间的潜在相互作用，这种相互作用受到Sp1与邻苯二甲酸酯诱导的高甲基化DNA结合抑制的影响。此外，我们的结果表明，异常的DNA甲基化可能是由于DNA甲基转移酶1（DNMT1）基因表达增加以响应邻苯二甲酸酯暴露。总体而言，本研究为邻苯二甲酸酯诱导的差异性DNA甲基化如何破坏HIF2α基因的雌激素调节以及随后HESC分化过程中的EV分泌提供了有价值的机制见解。这些知识对于理解邻苯二甲酸酯如何通过破坏子宫内细胞间通讯的激素调节导致不良生殖结局至关重要。
