Regulation of Atg5 on hepatic lipid deposition induced by bisphenol A

Abstract:

Objective：To investigate the effects of autophagy related protein Atg5 on hepatic lipid deposition caused by bisphenol A （BPA） in HepG2 cells. Methods：HepG2 cells were cultured and divided into control group，different concentrations of BPA groups（1，10 μmol/L），and positive control group（a mixture of free fatty acids（FFAs）：oleate 200 μmol/L plus palmitate 400 μmol/L），treated for 24 h. The content of intracellular triglyceride（TG） was measured by enzymic assay kit，and oil red O staining was used to determine the intracellular lipid droplet formation visually. Western blot and real-time PCR were used to detect the protein and mRNA expression of Atg5，respectively. Immunofluorescence was used to detect the expression of Atg5. Results：①The level of TG was significantly higher in 10 μmol/L BPA group than in control group（0.197±0.033，0.094±0.014，P=0.031）. ②Oil red O staining also showed that 10 μmol/L BPA promoted lipid accumulation in HepG2 cells. ③The mRNA expression levels of Atg5 in 10μM BPA group did not change compared with that in control group（0.93±0.088；1.017 5±0.062 4，t=0.811，P=0.428），however，the protein expression levels of Atg5 was lower in 10 μmol/L BPA group than that in control group（0.519±0.059；1.00，t=0.8101，P=0.000）. Besides，immunofluo－rescence indicated that the fluorescent dots were obviously reduced in 10 μmol/L BPA group than in control group. Conclusion：Atg5 could be involved in hepatic lipid deposition induced by BPA.