The Effects Of Three Bisphenol A Substitutes On The Metabolism Of Triglyceride In Hepatic Cells

Objective:To observe whether BPA,BPAF,BPB and BPS can induce lipid accumulation in hepatic cells and the possible mechanism,and to provide some scientific basis for formulating environment and health standards for BPA and its analogues.Methods:In vivo experiment:thirty-two ICR mice were randomly divided into 4 groups(8 mice in each group): control group,BPB group,BPAF group and BPS group.BPA analogues were dissolved in corn oil and exposed by gavage at a dose of 300 μg/kg every other day for 4 weeks,and the pathological changes of liver were observed by HE staining.In vitro experiment:HL-7702 cells were treated with different concentrations of BPA,BPAF,BPB,BPS(0.1,1,10,50,100 μmol/L)as well as 0.1% DMSO(vehicle control)and 1 mmol/L OA(positive control)for 24 h,the cell viability was determined by MTT assay,the accumulation of lipid droplets in cells was observed by oil red O staining,the content of triglyceride(TAG)in cells was determined by GPO-PAP chemical-enzymatic method,q RT-PCRwas used to detect the expressions of triglyceride synthesis related genes1-acylglycerol-3-phosphate acyltransferase 2(AGPAT2),Lipin 2(LIPIN2),Diacylglycerol acyltransferase 2(DGAT2)and fatty acid synthesis related genes acetyl-Co A carboxylase1(ACC1),Fatty acid synthase(FASN),and fatty acid decomposition related genes Peroxisome proliferator-activated receptor α(PPARa),Carnitine ester acyltransferase 1(CPT1).Results:1.HE staining of mouse liver revealed that three BPA analogues,BPAF,BPB,and BPS,did not cause greater damage to mouse liver at our exposure dose(300 μg/kg).2.Compared with the negative control group,after HL-7702 cells were exposed to different concentrations of BPA for 24 h,there was no significant change in cell activity in each group.After HL-7702 cells were exposed to different concentrations of BPAF for 24 h,the cell activity was significantly decreased by 100 μmol/L BPAF,and there was no significant change in other groups.After HL-7702 cells were exposed to different concentrations of BPB for 24 h,the cell activity was significantly decreased by 100μmol/L BPB,and the cell activity was increased by 0.1 μmol/L BPB,and did not change significantly in the other dose groups.After HL-7702 cells were exposed to different concentrations of BPS for 24 h,and there were no significant changes in cell activity in each group.3.Oil red O staining showed that there was no accumulation of red lipid droplet in the cells of the negative control group and vehicle control group.There was significant accumulation of lipid droplet in the cells of 1 mmol/L OA group,and the number of lipid droplets was higher,and the size was different.Red lipid droplets of different sizes could be observed in 1,10,50 μmol/L BPA groups,1,10,50 μmol/L BPAF groups,1,10,50μmol/L BPB groups,and 1,10,50 μmol/L BPS groups.The quantification analysis of oil red O staining showed that compared with the negative control group,the content of oil red O in OA group was significantly increased,and the content of oil red O was significantly increased by 1 μmol/L BPAF and 1 μmol/L BPS.4.In our experiment,after eposure 24 h,compared with the negative control group,the triglyceride content in tracellular was significantly increased by 1,50 μmol/L BPA,10,50 μmol/L BPAF,1,10,50 μmol/L BPB,and 50 μmol/L BPS.5.In our experiment,after eposure 24 h,compared with the negative control group,the expression of AGPAT2 m RNA was increased by 50 μmol/L BPA,1、10、50 μmol/L BPAF,10μmol/L BPB,1、10 、50 μmol/L BPS,the expression of LIPIN2 m RNA was increased by 10 μmol/L BPAF,10 μmol/L BPB and 1、10 μmol/L BPS,the expression of DGAT2 m RNA was increased by 50 μmol/L BPA,10 μmol/L BPAF,10,50 μmol/L BPB and 1μmol/L BPS.6.In our experiment,after eposure 24 h,compared with the negative control group,the expression of ACC1 m RNA was increased by 10 μmol/L BPAF,and 10,50 μmol/L BPS,the expression of FASN m RNA was decreased by 50 μmol/L BPA,1,10,50 μmol/L BPB and the expression of FASN m RNA was increased by 1,10,50 μmol/L BPS.7.In our experiment,after eposure 24 h,compared with the negative control group,the expression of PPARα m RNA was increased by 10 μmol/L BPAF and 10,50 μmol/L BPS,the expression of CPT1 m RNA was increased by 50 μmol/L BPA,50 μmol/L BPB and 1 μmol/L BPS.Conclusions:1.BPAF,BPB,and BPS have little effect on liver damage in mice and do not cause liver fat accumulation at lower doses and short periods of exposure.2.BPA and its analogues BPAF,BPB,and BPS can cause a certain degree of fat accumulation and an increase in triglyceride content in HL-7702 cells.However,due to structural differences,the mechanism by which BPA and its analogues BPAF,BPB,and BPS cause triglyceride metabolism in HL-7702 cells to affect fat accumulation is not entirely consistent.BPAF,BPB,and BPS analogues may all promote an increase in triglyceride synthesis by upregulating the expression of AGPAT2、LIPIN2 and DGAT2 m RNA.BPB can alleviate fat accumulation to some extent by inhibiting fatty acid synthesis and promoting fatty acid decomposition.However,BPS simultaneously increases the expression of genes related to fatty acid breakdown and synthesis,leading to liver lipid metabolism disorders.In summary,although BPA analogues have the potential to cause liver cell fat accumulation,short-term exposure will not temporarily cause fatty liver.