Abstract: Objective The aim of this study was to investigate the effect of different concentrations of glucose or oleic acid on expression and activity of silent information regulator 1 (SIRT1) and adenosine monophosphate-activated protein kinase (AMPK) in hepatitis C virus (HCV) infected hepatocytes.Methods Plasmid expressing HCV core protein was transfected into HepG2 cells, which were incubated for 24 hours in serum-free DMEM medium with different final concentrations of glucose or oleic acid. The activity and expression of SIRT1 and AMPK were detected using scintillation counting and western blot, respectively. Results With increasing glucose concentration(1 g/L, 2 g/L, 4.5 g/L), SIRT1 activity (1.0±0.2, 0.6±0.15, 0.2±0.05) and expression (0.9±0.2, 0.4±0.1, 0.1±0.05) were decreased, AMPK activity (1.0±0.2, 0.5±0.08, 0.22±0.05) and expression (0.9±0.2, 0.4±0.1, 0.2±0.05) were decreased. With the increase of oleic acid concentration(0, 300 μM/L, 500 μM/L), SIRT1 activity (1.0±0.2, 0.6±0.1, 0.2±0.05) and expression (0.9±0.2, 0.5±0.1, 0.2±0.05) were decreased, AMPK activity (1.0±0.2, 0.5±0.1, 0.1±0.05) and expression of p-AMPK (0.9±0.2, 0.5±0.1, 0.2±0.05) were decreased.Conclusion High glucose and high oleic acid may down-regulate the activity and expression of SIRT1-AMPK signaling pathway in HCV infected hepatocytes.

Key words: Hepatitis C virus, HCV, High glucose, High oleic acid, Silent information regulator 1, SIRT1, Adenosine monophosphate activated protein kinase