Effects of pigment epithelium-derived factor on lipid metabolism in HepG2 hepatocytes

Abstract:

【Abstract】Objective：To investigate the effects of pigment epithelium-derived factor（ＰＥＤＦ） on lipid metabolism in HepG2 hepato－cytes. Methods：HepG2 hepatocytes were treated with recombinant human PEDF or PEDF antibody. The key enzymes of lipid metabolism were detected by real time quantitative PCR and Western blot；intracellular triglyceride（TG） content was determined by enzymatic method. Results：（1）PEDF decreased the mRNA levels of sterol regulatory element-binding protein1（SREBP1），fatty acid synthase（FAS），acetyl coenzyme A carboxylase1（ACC1） and HMG-coA reductases（HMGR） by 39%，38%，61%，32% respectively（P<0.05），while increased the mRNA level of adipose triglyceride lipase（ATGL） by 98%（P<0.05）. On the contrary，PEDF an－tibody increased the mRNA levels of SREBP1，FAS，ACC1，HMGR by 92%，56%，67%，42% respectively（P<0.05），and decreased the mRNA level of ATGL by 51%（P<0.05）. （2）Besides，PEDF decreased the protein levels of FAS，ACC1，HMGR by 58%，54%，43% respectively（P<0.05），and increased the protein level of ATGL by 20%（P<0.05）. While PEDF antibody increased the protein levels of FAS，ACC1，HMGR expression by 41%，39%，48% respectively（P<0.05），and decreased the protein level of ATGL by 40%（P<0.05）. （3）PEDF significantly reduced intracellular TG content[（410.40±13.43） mg/g vs. （234.70±35.70） mg/g，P<0.05]，but PEDF antibody treated group showed an increase tendency of TG content，however without significant difference[（410.40±13.43） mg/g vs. （440.32±25.67） mg/g，P=0.67]. Conclusion：In HepG2 hepatocytes，PEDF reduced the intracellular TG content by inhibiting fatty acid synthesis，and promoting lipolysis.