College of Clinical Medicine, Bin Zhou Medical University, Yan Tai, PR China.
Department of Critical Care Medicine, Yu Huang Ding Hospital, Qingdao University, Yantai, PR China.
Toxicology. 2021 Feb 15;449:152665. doi: 10.1016/j.tox.2020.152665. Epub 2020 Dec 24.
Microplastics (MPs) are receiving increased attention as a harmful environmental pollutant. Studies have investigated that MPs have reproductive toxicity, but the mechanism is little known. Here, we aimed to investigate the effects of polystyrene microplastics (PS-MPs) on ovary in rats and the underlying molecular mechanisms. in vivo, thirty-two female Wistar rats were exposed to 0.5 μm PS-MPs at different concentrations (0, 0.015, 0.15 and 1.5 mg/d) for 90 days. And then, all animals were sacrificed, ovaries and blood were collected for testing. in vitro, granulosa cells (GCs) were separated from rat ovary and treated with 0、1、5、25 μg/mL PS-MPs and reactive oxygen species (ROS) inhibitor N-Acetyl-l-cysteine (NAC) respectively. Our results showed that PS-MPs could enter into GCs and result in the reducing of growing follicles number. And the Enzyme-linked immunosorbent assay (ELISA) manifested that PS-MPs could obviously decrease the level of anti-Müllerian hormone (AMH). In addition, PS-MPs induced oxidative stress, apoptosis of GCs and ovary fibrosis evidenced by assay kits, flow cytometry, immunohistochemistry, Masson's trichrome and Sirius red staining. Moreover, the western blot assay manifested that PS-MPs exposure significantly increased the expression levels of Wnt/β-Catenin signaling pathways-related proteins (Wnt, β-catenin, p-β-catenin) and the main fibrosis markers (transforming growth factor-β (TGF-β), fibronectin, α-smooth muscle actin (α-SMA). Additionally, the expression levels of Wnt and p-β-catenin, apoptosis of GCs decreased after NAC treatment. In summary, polystyrene microplastics cause fibrosis via Wnt/β-Catenin signaling pathway activation and granulosa cells apoptosis of ovary through oxidative stress in rats, both of which ultimately resulted in decrease of ovarian reserve capacity.
微塑料（MPs）作为一种有害的环境污染物，受到越来越多的关注。研究表明 MPs 具有生殖毒性，但机制尚不清楚。在这里，我们旨在研究聚苯乙烯微塑料（PS-MPs）对大鼠卵巢的影响及其潜在的分子机制。在体内，将 32 只雌性 Wistar 大鼠暴露于不同浓度（0、0.015、0.15 和 1.5mg/d）的 0.5μm PS-MPs 中 90 天。然后，处死所有动物，采集卵巢和血液进行检测。在体外，从大鼠卵巢中分离出颗粒细胞（GCs），并分别用 0、1、5、25μg/mL PS-MPs 和活性氧（ROS）抑制剂 N-乙酰-l-半胱氨酸（NAC）处理。结果表明，PS-MPs 可以进入 GCs，导致生长卵泡数量减少。酶联免疫吸附试验（ELISA）显示 PS-MPs 可明显降低抗苗勒管激素（AMH）水平。此外，PS-MPs 诱导的氧化应激、GCs 和卵巢纤维化的凋亡通过试剂盒、流式细胞术、免疫组织化学、Masson 三色和 Sirius 红染色证实。此外，Western blot 分析表明，PS-MPs 暴露显著增加了 Wnt/β-Catenin 信号通路相关蛋白（Wnt、β-catenin、p-β-catenin）和主要纤维化标志物（转化生长因子-β（TGF-β）、纤连蛋白、α-平滑肌肌动蛋白（α-SMA）的表达水平。此外，NAC 处理后，Wnt 和 p-β-catenin 的表达水平降低，GCs 的凋亡减少。综上所述，聚苯乙烯微塑料通过氧化应激引起大鼠卵巢纤维化，通过 Wnt/β-Catenin 信号通路激活和颗粒细胞凋亡，最终导致卵巢储备能力下降。
