Department of Chemistry and Biotechnology, Tallinn University of Technology, Tallinn, Estonia.
Institute for Risk Assessment Sciences, Utrecht University, Utrecht, the Netherlands.
Environ Int. 2024 Sep;191:108960. doi: 10.1016/j.envint.2024.108960. Epub 2024 Aug 15.
The plasticizer di(2-ethylhexyl) phthalate (DEHP) is known to have endocrine-disrupting properties mediated by its many metabolites that form upon exposure in biological systems. In a previous study, we reported an inverse association between DEHP metabolites in the human ovarian follicular fluid (FF) and the responsiveness of the follicles to controlled ovarian stimulation during in vitro fertilization (IVF) treatments. Here, we explored this association further through molecular analysis of the ovarian FF samples. Ninety-six IVF patients from Swedish (N = 48) and Estonian (N = 48) infertility clinics were selected from the previous cohort (N = 333) based on the molar sum of DEHP metabolites in their FF samples to arrive at "high" (mean 7.7 ± SD 2.3 nM, N = 48) and "low" (0.8 ± 0.4 nM, N = 48) exposure groups. Extracellular miRNA levels and concentrations of 15 steroid hormones were measured across FF samples. In addition, FF somatic cells, available for the Estonian patients, were used for RNA sequencing. Differential expression (DE) and interactions between miRNA and mRNA networks revealed that the expression levels of genes in the cholesterol biosynthesis and steroidogenesis pathways were significantly decreased in the high compared to the low DEHP group. In addition, the DE miRNAs were predicted to target key enzymes within these pathways (FDR < 0.05). A decreased 17-OH-progesterone to progesterone ratio was observed in the FF of the high DEHP group (p < 0.05). Additionally, the expression levels of genes associated with inflammatory processes were elevated in the FF somatic cells, and a computational cell-type deconvolution analysis suggested an increased immune cell infiltration into the high DEHP follicles (p < 0.05). In conclusion, elevated DEHP levels in FF were associated with a significantly altered follicular milieu within human ovaries, involving a pro-inflammatory environment and reduced cholesterol metabolism, including steroid synthesis. These results contribute to our understanding of the molecular mechanisms of female reprotoxic effects of DEHP.
塑化剂邻苯二甲酸二（2-乙基己基）酯（DEHP）已知具有内分泌干扰特性，这是由其在生物系统中暴露后形成的许多代谢物介导的。在之前的研究中，我们报告了人类卵巢卵泡液（FF）中 DEHP 代谢物与体外受精（IVF）治疗中卵泡对控制性卵巢刺激的反应之间呈负相关。在这里，我们通过对卵巢 FF 样本的分子分析进一步探讨了这种相关性。从之前的队列（N=333）中，根据其 FF 样本中 DEHP 代谢物的摩尔总和，从瑞典（N=48）和爱沙尼亚（N=48）不孕诊所中选择了 96 名 IVF 患者，分为“高”（平均 7.7±2.3 nM，N=48）和“低”（0.8±0.4 nM，N=48）暴露组。测量了 FF 样本中的细胞外 miRNA 水平和 15 种类固醇激素的浓度。此外，还利用爱沙尼亚患者的 FF 体细胞进行了 RNA 测序。miRNA 和 mRNA 网络的差异表达（DE）和相互作用表明，与低 DEHP 组相比，高 DEHP 组胆固醇生物合成和类固醇生成途径中的基因表达水平显著降低。此外，预测 DE miRNAs 可靶向这些途径中的关键酶（FDR<0.05）。在高 DEHP 组的 FF 中观察到 17-OH-孕酮与孕酮的比值降低（p<0.05）。此外，FF 体细胞中与炎症过程相关的基因表达水平升高，计算细胞类型去卷积分析表明高 DEHP 卵泡中的免疫细胞浸润增加（p<0.05）。总之，FF 中 DEHP 水平升高与人类卵巢中卵泡环境的显著改变有关，涉及促炎环境和胆固醇代谢减少，包括类固醇合成。这些结果有助于我们理解 DEHP 对女性生殖毒性的分子机制。
