School of Chemistry and Environmental Engineering, Wuhan Institute of Technology, Wuhan 430072, China.
State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Sci Total Environ. 2022 Sep 10;838(Pt 3):156389. doi: 10.1016/j.scitotenv.2022.156389. Epub 2022 May 30.
Methylparaben (MeP) is a ubiquitous pollutant in aquatic environment, which has caused severe pollution worldwide. However, aquatic toxicology of MeP is still largely unknown. In the present study, adult zebrafish were exposed to environmentally realistic concentrations of MeP (0, 1, 3, and 10 μg/L) for 28 days. In terms of the antimicrobial nature, dysregulation of gut microbiota and zebrafish health by MeP were elucidated after exposure. High-throughput amplicon sequencing showed that MeP subchronic exposure was able to disrupt the composition and diversity of gut microbial community, which was characterized by the alterations in alpha diversity and divergent distribution by principal component analysis. In addition, MeP exposure increased the body length and body weight of female fish, implying stimulated growth at low doses. In male intestine, consistent increases were notable in goblet cell density, tight junction protein (TJP) 2 expression, and serotonin neurotransmitter concentration after MeP exposure. In contrast, female intestine exposed to MeP had lower density of goblet cells, inhibited expression of TJP2, reduced concentration of serotonin, but up-regulated transcription of pro-inflammatory cytokine. Under the stress of MeP pollutant, intestinal catalase antioxidant enzyme was activated, thus contributing to the removal of oxidative free radicals. Correlation analysis verified the modulation of TJP2 expression by Lactobacillus probiotic bacteria. Disturbances in goblet cell, tight junctions, and serotonin by MeP may be combined to interfere with gut barrier function. Overall, the present study highlights the impairment of intestinal health by environmentally realistic concentrations of MeP, which necessitates an urgent risk assessment.
对羟基苯甲酸甲酯（MeP）是一种普遍存在于水生环境中的污染物，已在全球范围内造成严重污染。然而，MeP 的水生毒理学仍知之甚少。在本研究中，成年斑马鱼在环境现实浓度的 MeP（0、1、3 和 10μg/L）下暴露 28 天。从抗菌性质来看，MeP 暴露后阐明了其对肠道微生物群和斑马鱼健康的失调作用。高通量扩增子测序表明，MeP 亚慢性暴露能够破坏肠道微生物群落的组成和多样性，这表现在 alpha 多样性和主成分分析的分歧分布的改变上。此外，MeP 暴露增加了雌性鱼的体长和体重，这意味着在低剂量下刺激生长。在雄性肠道中，MeP 暴露后，粘蛋白细胞密度、紧密连接蛋白（TJP）2 表达和 5-羟色胺神经递质浓度一致增加。相比之下，暴露于 MeP 的雌性肠道中，粘蛋白细胞密度降低，TJP2 表达受到抑制，5-羟色胺浓度降低，但促炎细胞因子的转录水平升高。在 MeP 污染物的应激下，肠道过氧化氢酶抗氧化酶被激活，从而有助于清除氧化自由基。相关性分析证实了益生菌乳酸菌对 TJP2 表达的调节。MeP 对粘蛋白细胞、紧密连接和 5-羟色胺的干扰可能会联合起来干扰肠道屏障功能。总的来说，本研究强调了环境现实浓度的 MeP 对肠道健康的损害，这需要进行紧急风险评估。
