Yue Junjie, Sun Caiting, Tang Jinyuan, Zhang Qiyuan, Lou Mengjie, Sun Hongwen, Zhang Lianying
Tianjin Key Laboratory of Hazardous Waste Safety Disposal and Recycling Technology, School of Environmental Science and Safety Engineering, Tianjin University of Technology, Tianjin 300384, China.
Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China.
Toxicology. 2023 Mar 15;487:153452. doi: 10.1016/j.tox.2023.153452. Epub 2023 Feb 9.
2-Ethylhexyl diphenyl phosphate (EHDPP) is a commonly used organophosphorus flame retardant and food packaging material. Because of its high lipophilic and bioaccumulative properties, adipocytes are the primary target of EHDPP. However, the toxicity of EHDPP on preadipocytes and the potential mechanism have not been fully elucidated. MicroRNAs (miRNAs) are thought to be an important mediator that contribute to the toxicity of environmental contaminants. To identify the miRNAs specifically responsible for EHDPP exposure and their role in EGDPP's toxicity in preadipocytes, the adipogenic effects and miRNA expression profiling were performed on 3T3-L1 preadipocytes exposed to EHDPP. EHDPP at concentrations of 1-10 μM promoted adipocyte differentiation, as evidenced by lipid staining, triglyceride content, and expression of adipogenesis markers. MiRNA-seq analysis revealed that 7 differentially expressed miRNAs were recognized under EHDPP exposure, with miR-155-5p being the top down-regulated miRNA. Quantitative reverse transcription PCR (RT-qPCR) analysis showed that miR-155-5p level fell sharply during the first 2 days and continued to fall dose-dependently throughout the EHDPP exposure period. MiR-155-5p inhibition promotes adipocyte differentiation, whereas its overexpression counteracted EHDPP-induced adipogenesis. Luciferase reporter assay identified CCAAT/enhancer-binding protein beta (C/EBPβ) as a target of miR-155-5p in 3T3-L1 preadipocytes in response to EHDPP. Taken together, EHDPP exposure down-regulated miR-155-5p, which then increased C/EBPβ and peroxisome proliferator-activated receptor γ (PPARγ) expression and promoted adipogenesis in preadipocytes.
2-乙基己基二苯基磷酸酯（EHDPP）是一种常用的有机磷阻燃剂和食品包装材料。由于其高亲脂性和生物累积性，脂肪细胞是EHDPP的主要靶标。然而，EHDPP对前脂肪细胞的毒性及其潜在机制尚未完全阐明。微小RNA（miRNA）被认为是导致环境污染物毒性的重要介质。为了确定对EHDPP暴露有特异性作用的miRNA及其在EHDPP对前脂肪细胞毒性中的作用，对暴露于EHDPP的3T3-L1前脂肪细胞进行了成脂作用和miRNA表达谱分析。浓度为1-10μM的EHDPP促进了脂肪细胞分化，脂质染色、甘油三酯含量和成脂标志物表达均证明了这一点。miRNA测序分析显示，在EHDPP暴露下识别出了7种差异表达的miRNA，其中miR-155-5p是下调最明显的miRNA。定量逆转录PCR（RT-qPCR）分析表明，miR-155-5p水平在最初2天急剧下降，并在整个EHDPP暴露期间持续呈剂量依赖性下降。抑制miR-155-5p可促进脂肪细胞分化，而其过表达则抵消了EHDPP诱导的成脂作用。荧光素酶报告基因检测确定CCAAT/增强子结合蛋白β（C/EBPβ）是3T3-L1前脂肪细胞中miR-155-5p在EHDPP作用下的靶标。综上所述，EHDPP暴露下调了miR-155-5p，进而增加了C/EBPβ和过氧化物酶体增殖物激活受体γ（PPARγ）的表达，并促进了前脂肪细胞的成脂作用。
