Diethylhexyl phthalate (DEHP) is a typical environmental pollutant and poses a potential threat to organisms by disrupting the lipid metabolism. This study found that DEHP at environmental concentrations, led to lipid accumulation in female zebrafish, as indicated by significant increases in the content of total cholesterol, triglycerides and the lipid droplets, in a concentration-dependent manner. However, how DEHP induces the lipid accumulation remains poorly understood. Our results demonstrated that DEHP up-regulated the expression of fat synthesis related-genes fas, acc, acs, elvol6, scd and dgat1, and increased the enzymatic activity of fatty acid synthase and acetyl-CoA carboxylase. Furthermore, the expression of several key transcription factors that regulate fat synthesis was detected, among which active sterol regulatory element-binding protein-1 (SREBP-1) was significantly increased. When active SREBP-1 was inhibited with specific inhibitor or knocked down by transient transfection, the expression of lipid synthesis-related genes was significantly decreased in DEHP group, indicating that DEHP disrupted the lipid synthesis via SREBP-1 pathway. Additionally, molecular docking revealed direct interaction sites between DEHP and SREBP-1. Our findings revealed that DEHP could directly activate SREBP-1-mediated lipid synthesis, providing theoretical basis for DEHP threatening biological health.
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