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蓄积性，脂肪细胞是 EHDPP 的主要目标。然而，EHDPP 对前脂肪细胞的毒性及其潜在机制尚未完全阐明。MicroRNA (miRNA) 被认为是导致环境污染物毒性的重要介质。为了鉴定专门负责 EHDPP 暴露的 miRNA 及其在前脂肪细胞中 EGDPP 毒性中的作用，对暴露于 EHDPP 的 3T3-L1 前脂肪细胞进行了脂肪形成效应和 miRNA 表达谱分析。浓度为 1-10 μM 的 EHDPP 促进脂肪细胞分化，脂质染色、甘油三酯含量和脂肪生成标志物的表达证明了这一点。MiRNA-seq 分析显示，在 EHDPP 暴露下可识别出 7 种差异表达的 miRNA，其中 miR-155–5p 是下调最多的 miRNA。定量逆转录 PCR (RT-qPCR) 分析表明，miR-155–5p 水平在前 2 天急剧下降，并在整个 EHDPP 暴露期间继续下降，呈剂量依赖性。MiR-155-5p 抑制促进脂肪细胞分化，而其过表达抵消了 EHDPP 诱导的脂肪生成。荧光素酶报告基因测定将 CCAAT/增强子结合蛋白 β (C/EBPβ) 鉴定为 3T3-L1 前脂肪细胞中 miR-155–5p 的靶标，以响应 EHDPP。总之，EHDPP 暴露下调 miR-155–5p，然后增加 C/EBPβ 和过氧化物酶体增殖物激活受体 γ (PPARγ) 的表达并促进前脂肪细胞的脂肪生成。