Effect of Notch pathway on lipid accumulation induced by mono-2-ethylhexyl phthalate on 3T3-L1 cells

Background: Mono-2-ethylhexyl phthalate (MEHP) is a major metabolite of di (2-ethylhexyl) phthalate (DEHP). Our previous researches have shown that MEHP can induce lipid accumulation in preadipocytes, while, the underlying mechanism is unclear. The present study was undertaken to clarify the effect of Notch pathway on lipid accumulation induced by MEHP. Methods: 3T3-L1 preadipocytes were exposed to MEHP (0, 10, 50, 250 mu M and 0.1%DMSO) for the whole differentiation phase. Then the level of TG and cell cycle were detected. RT-PCR was used to detect the mRNA expression and Western blot was used to detect the expression of protein by Notch pathway genes and lipid metabolic related genes. Results: In this study, the level of TG in the 250 mu M and 250 mu M MEHP groups was significantly higher than that in the control, DMSO and 10 mu M MEHP groups (P < 0.05). The relative mRNA level of Notch-1, Notch-3, Notch-4, Jagged-2 and Dll-4 in 250 mu M group was higher than other groups (P < 0.05). The expression of Notch signal pathway proteins increased in MEHP treated groups, and the expression of Notch-2, Jagged-1, Jagged-2, Dll-1 and Dll-4 in 250 mu M group were significantly higher than control group (P < 0.05). The expression of lipid metabolic related gene mRNA and protein increased in MEHP treated groups, and 250 mu M MEHP group was higher than other groups (P < 0.05). The intracellular TG content was significantly correlated with the expression levels of Notch-1 and Jagged-2 mRNA (P < 0.05). Conclusion: In this study, we have found that MEHP exposure could increase the TG content in 3T3-L1 cells. The expression of Notch pathway mRNA and proteins were disturbed by the MEHP. Notch-1 and its ligand Jagged-2 play a critical role in the abnormal lipid metabolism in 3T3-L1 cells caused by MEHP.

Automated summary

Exposure to MEHP can increase intracellular TG content in 3T3-L1 cells, leading to abnormal expression of Notch pathway genes and lipid metabolic related genes, with Notch-1 and Jagged-2 playing critical roles in this process.