Hepatitis C virus core protein induces energy metabolism disorders of hepatocytes by down-regulation of silent mating type information regulation 2 homolog-1 and adenosine monophosphate-activated protein kinase signaling pathway / 中华传染病杂志

ABSTRACT

Objective To study the role of silent mating type information regulation 2 homolog1 (SIRT1)-adenosine monophosphate (AMP)-activated protein kinase (AMPK) signaling pathway in hepatitis C virus core protein (HCV-core) induced energy metabolism disorders of hepatocytes.Methods HepG2 cells were transfected with recombined expressed plasmid pcDNA3.1-core.The level of reactive oxygen species (ROS),value of ATP/ADP and activity of AMPK α-2,and nicotinamide adenine dinucleotide (NAD)+/NADH in HepG2 cells expressing HCV-core were detected by flow cytometry,liquid scintillation counter and chromatometry,respectively.The activity of SIRT1 was detected with a fluorometric assay kit.Reverse transcription polymerase chain reaction (RT-PCR) and Western blot assay were performed to examine the expression of SIRT1 and AMPK α-2.Quantitative data were analyzed by t-test.Results It was confirmed by Western blot assay that HepG2 cells expressed HCV-core with relative molecular weight of 22 000.Compared to HepG2 cells,the level of ROS in HepG2 cells expressing HCV-core was significantly increased (1.0 ±0.1 vs 4.0±0.5,t=14.411,P＜0.01),the values of ATP/ADP were similar (8.2±2.2 vs 9.3±2.8,t=0.757,P＞0.05),AMPK α-2 (0.8±0.2 vs 0.2±0,t=7.345,P＜0.01),the values of NAD+/NADH (0.08±0.02 vs 0.02±0,t=7.348,P＜0.01),the activity of SIRT1 [(0.30±0.05) pmol· μg-1 · min-1 vs (0.15±0.04) pmol · μg 1 · min 1,t=5.738,P＜0.01] and the mRNA levels of SIRT1 (0.8±0.2 vs 0.4±0.1,t=4.382,P＜0.01) and AMPK α-2 mRNA (0.9±0.3 vs 0.2±0,t=5.715,P＜0.01),and the expression of SIRT1 (0.8±0.2 vs 0.3±0,t=5.941,P＜0.01) and phosphorylated AMPK protein (0.5±0.1 vs 0.1±0,t=9.608,P＜0.01) were all significantly decreased.Conclusion HCV core protein induces energy metabolism disorders of hepatocytes by down-regulation of SIRT1-AMPK signaling pathway.