Department of Preventive Medicine, Fujian Provincial Key Laboratory of Environment factors and Cancer, Key Laboratory of Environment and Health, School of Public Health, Fujian Medical University, No. 1 Xuefu North Road, University Town, Fuzhou, 350122, China.
Department of Health Inspection and Quarantine, School of Public Health, Fujian Medical University, No. 1 Xuefu North Road, University Town, Fuzhou, 350122, China.
Environ Toxicol. 2018 May;33(5):535-544. doi: 10.1002/tox.22540. Epub 2018 Jan 31.
Although studies have shown that di(2-ethylhexyl) phthalate (DEHP) can disrupt ovarian function, few reports have focused on follicular development in mice between the weaning period and maturity, especially with respect to microRNA (miRNA) expression. In this study, 21-day-old ICR mice were administered DEHP at doses of 0, 100, 400, and 1600 mg/(kg d) for 6 weeks by gavage. After DEHP administration, a significant decrease in the expression of follicle development-related factors (including c-kit, kitl, gdf9, and atm) was observed by quantitative real-time PCR (RT-PCR), but no significant difference in the proteins encoded by these genes was observed by Western blot. Bisulfite sequencing suggested that the total methylation percentages of promoter regions of these genes were not notably altered after DEHP exposure. However, RT-PCR revealed a significantly increased expression of ovarian miRNAs (let-7b, miR-17-5p miR-181a, and miR-151), which inhibit follicular granulosa cell proliferation. Overall, this study showed that DEHP administration from weaning to maturity could suppress the mRNA expression of follicular development factors, and this effect was not achieved through changes in the methylation of DNA in CpG islands of development factors. In addition, DEHP was shown to induce miRNAs to inhibit the proliferation of follicular granulosa cells and the anti-apoptosis function of KITL and GDF9 while increasing bax/bcl expression to further promote the apoptosis of granulosa cells.
虽然研究表明邻苯二甲酸二（2-乙基己基）酯（DEHP）可以破坏卵巢功能，但很少有报道关注断奶期到成熟期之间小鼠卵泡发育过程中的 microRNA（miRNA）表达。在这项研究中，21 日龄 ICR 小鼠通过灌胃接受 DEHP 剂量为 0、100、400 和 1600mg/（kg·d），共 6 周。DEHP 给药后，通过实时定量 PCR（RT-PCR）观察到与卵泡发育相关的因子（包括 c-kit、kitl、gdf9 和 atm）的表达显著下降，但这些基因编码的蛋白质没有明显差异通过 Western blot 观察到。亚硫酸氢盐测序表明，这些基因启动子区域的总甲基化百分比在 DEHP 暴露后没有明显改变。然而，RT-PCR 显示卵巢 miRNA（let-7b、miR-17-5p、miR-181a 和 miR-151）的表达显著增加，这些 miRNA 抑制卵泡颗粒细胞增殖。总体而言，这项研究表明，从断奶到成熟期间给予 DEHP 可抑制卵泡发育因子的 mRNA 表达，这种作用不是通过 CpG 岛中发育因子的 DNA 甲基化变化来实现的。此外，DEHP 被证明可以诱导 miRNA 抑制卵泡颗粒细胞的增殖和 KITL 和 GDF9 的抗凋亡功能，同时增加 bax/bcl 的表达，以进一步促进颗粒细胞的凋亡。
