Abstract:

Objective To study the effect of fibroblast growth factor-21 (FGF-21)on the lipid metabolism of  nonalcoholic fatty liver disease（NAFLD）cell model  induced in vitro and its potential mechanism.Methods The concentrations of medical fat emulsion (MFE) and FGF-21 were selected by MTT assay.And the NAFLD cells were divided into  control group,model group,leaving fat emulsion group and FGF-21 therapy group.Oil red O staining was used to observe lipid droplet under light microscope.The intracellular  triacylglycerol (TG) levels  in each group were observed by hol-automatic biochemistry.The expressions of carnitine palmitovl transferase-1 (CPT-1),peroxisome proliferator-activated receptor-gamma (PPARγ) and sterol regulatory element binding protein-1c (SREBP-1c) were determined by immunocytochemistry.Results The 0.1% medical fat emulsion (MFE) was chosen by  MTT assay as the best concentration for the induction of NAFLD cells in vitro.The intracellular TG level of NAFLD  cells was increased significantly compared with normal liver cells HL7702 (P＜0.01),and there was a large quantity of orange-red lipid droplet in cytoplasm of NAFLD cells;meanwhile,the expression of CPT-1 protein got lower,and the expressions of  PPARγ  and SREBP-1c proteins got higher.MTT assay showed the best management concentration of FGF-21 was 0.5 mg/L for setting up  NAFLD-effect model,the intracellular TG level in  FGF-21 group was decreased significantly compared with model group(P＜0.01);the expression level of CPT-1 protein was increased (P＜0.01),and the expressions of  PPARγ and SREBP-1c proteins were decreased in  FGF-21 group.Conclusion  FGF-21 is helpful to relieve accumnlation of TG in NAFLD cells,and it decrease the expressions of PPARγ and SREBP-1c protein and increase the expression of CPT-1 protein in HL7702 cells.

Key words: fibroblast growth factor-21;nonalcoholic fatty liver disease;medical fat emulsion