亚硫酸钠对与脂肪细胞共培养的肝细胞脂肪代谢的影响OA

Objective To investigate whether sodium sulfite(Na2SO3)affects lipid metabolism in hepatocytes by interfering with adiponectin secretion from adipocytes.Methods 3T3-L1 preadipocytes were induced to differentiate into mature adipocytes.Adipo-cytes,HepG2 cells,and their co-cultured cells were treated with complete medium(negative control),different concentrations of Na2SO3(0.02,0.1,0.5,2.5 mmol/L),and 1 mmol/L oleic acid(OA,positive control),respectively.The levels of free fatty acid(FFA)and adiponectin in adipocyte culture supernatants were measured using enzyme-linked immunosorbent assay(ELISA),and triglyceride(TG)content was measured by the glycerol-3-phosphate oxidase-peroxidase(GPO-POD)method.Western blot was used to detect the relative expressions of TG metabolism-related proteins:sterol regulatory element-binding protein-1c(SREBP-1c),acetyl-CoA carboxylase(ACC),fatty acid synthase(FASN),adenosine monophosphate-activated protein kinase(AMPKα),and carnitine palmitoyltransferase 1(CPT-1).Results Compared with negative control group,FFA levels in the adipocyte culture supernatant were significantly reduced in all Na2SO3 treatment groups(P<0.001),and adiponectin levels were significantly decreased(P<0.01).The 2.5 mmol/L Na2SO3 caused an increase in TG content in co-cultured HepG2 cells(P<0.001).In HepG2 cells cultured alone,com-pared with the negative control,all concentrations of Na2SO3 did not significantly alter the expressions of SREBP-1c,p-ACC,AMPKα,and CPT-1(P>0.05),and 2.5 mmol/L Na2SO3 increased ACC and FASN protein expressions(P<0.05).In the co-cultured HepG2 cells,compared with the negative control,all concentrations of Na2SO3 increased protein expressions of ACC and AMPKα(P<0.05).Conclusion Exposure to low doses of Na2SO3 does not increase TG in hepatocytes.High doses of Na2SO3(2.5 mmol/L)may significantly elevate TG level in hepatocytes by inhibiting adiponectin secretion from adipocytes.