Adipogenic activity of 2-ethylhexyl diphenyl phosphate via peroxisome proliferator-activated receptor γ pathway

Recent studies have shown that exposure to some organophosphates, such as triphenyl phosphate (TPHP) and diphenyl phosphate (DPHP), can affect adipogenesis in preadipocytes. 2-Ethylhexyl diphenyl phosphate (EHDPP), an organophosphate, is frequently detected in various environmental media. However, there is less information about the toxicity effects and the mechanism by which EHDPP affects preadipocytes. In the present study, we investigated whether EHDPP could induce differentiation in 3T3-L1 preadipocytes through the peroxisome proliferator-activated receptor gamma (PPAR gamma) signaling pathway. The fluorescence competitive binding assay and the dual-luciferase reporter gene assay were used to assess the binding affinity and activation of PPAR gamma, and the results showed that EHDPP can bind to the ligand binding domain of PPAR gamma (PPAR gamma-LBD) and activate PPAR gamma in vitro. Exposure to EHDPP for 10 days extensively induced adipogenesis in 3T3-L1 preadipocytes as assessed by lipid accumulation and gene expression of adipogenic markers of fatty acid binding protein 4 (FABP4), lipoprotein lipase (Lpl), adiponectin (Adip), and fatty acid synthase (Fasn). Furthermore, the preadipocytes differentiation was blocked by the PPAR gamma-specific antagonist GW9662, indicating that the PPAR gamma signaling pathway plays an important part in 3T3-L1 cell differentiation induced by EHDPP. Taken together, EHDPP can bind to PPAR gamma-LBD, activate PPARy receptor, and induce cell differentiation via the PPAR gamma signaling pathway in 3T3-L1 preadipocytes. (C) 2019 Elsevier B.V. All rights reserved.