OBJECTIVETo investigate the role of the host-encoded silent information regulator 1 (SIRT1) on hepatocytes' lipid metabolism under conditions of hepatitis C virus (HCV) infection and assess its potential effects on virus replication in vitro.

METHODSThe Huh-7.5 human hepatocyte cell line was used as the control group and Huh-7.5 cells stably expressing the HCV replicon (Huh7.5-HCV) were used as the experimental group. Effects of interferon (IFN) treatment and activation of SIRT1 by resveratrol were also observed. The mRNA and protein expression levels of SIRT1 were detected by real time (q)PCR and western blotting. Effects on SIRT1 protein activity were tested by measuring the levels of reactive oxygen species (ROS) and the nicotinamide adenine dinucleotide (NAD+)/beta-nicotinamide adenine dinucleotide, reduced (NADH) by flow cytometry and chromatometry, and the levels of triacylglycerol (TG), total cholesterol (TC), and fatty acid beta oxidation rate by enzymatic analysis and liquid scintillation counting. Effects on mRNA expression of SIRT1 downstream lipid-metabolism genes were measured by qPCR.

RESULTSThe Huh7.5-HCV cells had a significantly higher level of ROS (3.8+/-0.5 vs. Huh-7.5: 1.0+/-0.2; t = 12.736, P less than 0.01) but significantly lower levels of NAD+/NADH (0.03+/-0.01 vs. 0.12+/-0.03; t = 6.971, P less than 0.01), SIRT1 activity (0.3+/-0.1 vs. 1.0+/-0.2, 0.9+/-0.2, F = 6.766, P less than 0.01), SIRT1 mRNA (0.4+/-0.1 vs. 1.0+/-0.3, 0.9+/-0.2, F = 5.864, P less than 0.01), and SIRT1 protein (0.3+/-0.1 vs. 0.8+/-0.2, 0.9+/-0.2, F = 5.419, P less than 0.01). The lower levels of SIRT1 in Huh7.5-HCV cells accompanied decreased phosphorylation of the forkhead box O1 (FoxO1), which not only up-regulated the downstream genes of SREBP-1c, FAS, ACC, SREBP-2, HMGR and HMGS (which increased fatty acid synthesis) but also down-regulated the downstream genes of PPAR and CPT1A genes (which decreased fatty acid beta oxidation). IFN treatment restored all of the aforementioned changes. Resveratrol-induced SIRT activation improved the perturbations in lipid metabolism pathways, as evidenced by an increase in fatty acid beta oxidation and a decrease in TG and TC synthesis, as well as inhibited HCV replication.

CONCLUSIONHCV may decrease the NAD+/NADH ratio in hepatocytes, leading to a down-regulation of SIRT1 activity and expression and perturbing the downstream expression profile of lipid metabolism-related factors, ultimately causing lipid metabolism disorders and establishing a permissive intracellular environment for HCV replication.

Cell Line ; Hepacivirus ; physiology ; Hepatocytes ; metabolism ; virology ; Humans ; Lipid Metabolism Disorders ; etiology ; metabolism ; Sirtuin 1 ; metabolism ; Triglycerides ; metabolism ; Virus Replication

OBJECTIVETo investigate relationship between glucose metabolic disorders and expression of insulin receptor (IR) and tyrosine protein kinase (TPK) in posthepatitic cirrhosis hepatocyte and HBV DNA expression in pancreatic cells.

METHODSTo detect HBV DNA in paraffin-embedded pancreatic and hepatic tissues from 12 posthepatitic cirrhosis patients with positive serum HBV markers by using in situ hybridization (ISH) with a digoxigenin labelled probe. The amount of IR and TPK have been evaluated by immunohistochemical quantitative analysis using image analyzer in hepatocyte of 12 patients positive for HBV markers with posthepatitic cirrhosis in serum. Immunofluorescent histochemical double staining technique was used. HBsAg and IR were observed under confocal laser scanning microscope.

RESULTSEleven of 12 cirrhosis patients? hepatocytes were HBV DNA positive, including 7 patients (7/7) with impaired glucose tolerance (IGT) and 4 patients (4/5) with normal glucose tolerance (NGT). Eight of 12 pancreatic cells were HBV DNA positive, including 7 patients (7/7) with IGT, but only one patient (1/5) with NGT-HBV DNA was found positive in pancreatic cells in significantly more subjects in IGT group than in NGT group (P less than 0.01).IR and TPK amount in hepatocyte of IGT was significantly less than that of NGT patients with posthepatitic cirrhosis (P less than 0.01). IR amount was closely related to the TPK in cirrhosis hepatocyte r=0.82597(P less than 0.01). HBV DNA was mainly localized in the nuclei of hepatocyte and pancreatic acinar and islet cells. Immunofluorescent histochemical double-staining showed that HBsAg was partly localized in the IR positive areas of hepatocytes and pancreatic islet cells.

CONCLUSIONHBV can invade acinar cells of pancreas and islet cells, which might be a direct cause of insulin-dependent diabetes mellitus-like the disorder and insulin absence after HBV infection. Decrease of IR and TPK might be main cause of noninsulin-dependent diabetes mellitus-like disorder after having hepatitis or posthepatitic cirrhosis.

DNA, Viral ; analysis ; Female ; Glucose Metabolism Disorders ; complications ; metabolism ; virology ; Hepatitis B virus ; genetics ; Hepatocytes ; metabolism ; virology ; Humans ; In Situ Hybridization ; Liver Cirrhosis ; complications ; metabolism ; virology ; Male ; Middle Aged ; Pancreas ; cytology ; virology ; Protein-Tyrosine Kinases ; metabolism ; Receptor, Insulin ; metabolism

Animals ; Apoptosis ; Carcinoma, Hepatocellular ; pathology ; virology ; Cell Line, Tumor ; Cell Proliferation ; Hepatitis B virus ; Hepatocytes ; pathology ; virology ; Humans ; Liver Neoplasms ; pathology ; virology ; Trans-Activators ; genetics ; metabolism ; physiology

Subcellular localizaton of HBcAg have been found to be related to the activity of liver disease and HBV replication. The aim of this study was to determine whether the degree of expression of HBcAg in the hepatocyte nucleus and cytoplasm reflects the level of viral replication and histological activity in chronic HBV infection. A total of 102 patients with biopsy proven chronic hepatitis B were included. There was a highly significant correlation between the levels of HBV DNA in serum and the degree of expression of HBcAg in the nucleus for HBeAg-positive(p=0.000) and negative patients(p=0.04). There was a highly significant, correlation between the degrees of expression of HBcAg in hepatocyte cytoplasm and histologic activities (p<0.01) for HBeAg-positive patients. The degrees of expression of HBcAg in the hepatocyte cytoplasm correlated positively with the lobular activities (p<0.01), but not correlated with the portal activity and fibrosis for HBeAg-negative patients. In conclusion, in the young patients with chronic B viral hepatitis, the degree of expression of HBcAg in the hepatocyte nucleus may affect viral load, and the degree of expression of HBcAg in the hepatocyte cytoplasm may affect histologic activities of liver disease.
Male ; Liver/pathology/virology ; Humans ; Hepatocytes/pathology/*virology ; Hepatitis B, Chronic/*pathology/*virology ; Hepatitis B e Antigens/metabolism ; Hepatitis B Core Antigens/*metabolism ; DNA, Viral/blood ; Cytoplasm/virology ; Cell Nucleus/virology ; Adult ; Adolescent

OBJECTIVETo search for the optimal approach for hepatocyte-directed differentiation of hepatic progenitor cells and investigate the molecular mechanism of the hepatic differentiation.

METHODSHepatic progenitor cells were infected with recombinant adenovirus which containing human LIF, BMP2 or BMP9 gene. The maturation and differentiation of progenitor cells were examined by PAS staining and ICG uptake methods at 4, 7 and 10 days post infection. The production of Albumin (Alb) was measured by luciferase activity at day 4, 7, 10 and 14.

RESULTSPAS staining assay revealed that BMP2 and BMP9 enhanced glycogen storage in hepatic progenitor cells most obviously at day 7. The percentages of positive cells were 30% and 45% respectively at 7 days post-infection. Meanwhile, 40% and 30% cells were positive by ICG uptake assay after BMP2 and BMP9 induction. Luciferase activity indicated that BMP9 induced ALB-Luc activity most significantly at day 7. However, less inductive activity was found in LIF-treated group.

CONCLUSIONThese results indicated tuat hepatic progenitor cells were differentiated into hepatocyte-like cells by BMPs and LIF induction.

Adenoviridae ; Bone Morphogenetic Proteins ; pharmacology ; Cell Differentiation ; Cells, Cultured ; Hepatocytes ; cytology ; metabolism ; virology ; Humans ; Leukemia Inhibitory Factor ; pharmacology ; Stem Cells ; cytology ; metabolism ; virology

OBJECTIVETo investigate whether the PD-L expression in the liver cell lines transinfected with HBV (HepG2.2.15 cells) can be up-regulated after cytokines stimulating.

METHODSTo apply the liver cell lines (HepG2 cells and HepG2.2.15 cells) as a model, the cells were stimulated with IL-4, IFN-alpha and IFN-gamma (final concentration were 10 ng/ml, stimulated for 12 hours) and RT-PCR was carried out to determine the PD-L expression before and after cytokines stimulating.

RESULTSWhether or not transinfected with HBV, IFN-alpha and IFN-gamma both can induce the liver cell lines (HepG2 cells and HepG2.2.15 cells) PD-L1 expression while IL-4 can not; IL-4, IFN-alpha, IFN-gamma all can induce the PD-L2 expression in HepG2.2.15 cells which was transinfected with HBV, only IFN-gamma can induce the PD-L2 expression in HepG2 cells which was not transinfected with HBV.

CONCLUSIONIFN-alpha, IFN-gamma both can induce the PD-L1 expression in HepG2 cells and HepG2.2.15 cells, while it is easy for cytokines to induce the PD-L2 expression in HepG2.2.15 cells which was transinfected with HBV, this may provide a potential mechanism of the molecular basis for chronic HBV infection.

Cell Line, Tumor ; Cytokines ; genetics ; metabolism ; Gene Expression ; Hepatitis B ; metabolism ; pathology ; Hepatitis B virus ; Hepatocytes ; metabolism ; virology ; Humans ; Liver ; pathology

OBJECTIVETo study the influence of hepatitis B virus (HBV) replication and expressions of different viral genes on CDC37 level in hepatocytes.

METHODSWe amplified and cloned 6 HBV genes (P, preS1, preS2, S, C and X) into pCMV expression vectors, which were transfected in Huh7 and HepG2 hepatoma cell lines, and CDC37 expression level in the cells was detected using Western blotting. Wealso cloned the promoter sequence of CDC37 into pGL3 vector, and co-transfected pGL3 with pCMV recombinant plasmids into Huh7 and HepG2 cells and the fluorescent signals were detected. To study the influence of HBV replication on CDC37 expression, we constructed 1.28-copy overlength genomes of HBV genotypes B, C, D and CD recombinant. The overlength HBV genomes were transformed into Adeasier-1 cells for recombination and into 293 cells for packaging. Huh7 and HepG2 cell lines infected with the packaged HBV recombinant adenoviruses were examined for CDC37 expression with Western blotting.

RESULTSWestern blotting showed that the expression of different HBV genes did not obviously affect the protein level of CDC37 in the hepatocytes. The protein expression of HBV genes had no effect on the activity of CDC37 promoter. Huh7 and HepG2 cells infected with 1.28-copy HBV replicon showed no significant changes in the expression level of CDC37.

CONCLUSIONHBV replication and its gene expression have no effect on the level of CDC37 in hepatocytes in vitro.

Adenoviridae ; Cell Cycle Proteins ; metabolism ; Chaperonins ; metabolism ; Gene Expression Regulation, Viral ; Genetic Vectors ; Hep G2 Cells ; Hepatitis B virus ; genetics ; physiology ; Hepatocytes ; virology ; Humans ; Transfection ; Virus Replication

OBJECTIVETo investigate the effect of hepatitis B virus (HBV) X protein (HBx) on host cell cycle and HBV replication using cultured primary mouse hepatocytes to gain further insights into the mechanism of HBx-mediated modulation of cell cycle.

METHODSPrimary cultured mouse hepatocytes were transfected with HBx-expressing (pHBV) or HBx-selected (pHBV triangle X) plasmids, which were generated with sequences of the HBV ayw subtype 1.2 and included the green fluorescent protein (GFP) reporter gene. The levels of cell cycle proteins (p16, cyclin D1, p21, cyclin E and cyclin A) were measured with Western blotting, and HBV DNA was analyzed by Southern blotting and real-time PCR.

RESULTSThe freshly isolated hepatocytes showed no significant differences in levels of cell cycle proteins. However, at 48 hours post-transfection, the levels of cyclin D1, p21 and cyclin E were significantly higher and the level of p16 was significantly lower in the pHBV-transfected hepatocytes than in the pHBV triangle X-transfected hepatocytes (t = 15.713, 22.897, 14.680, and -19.584, respectively, P less than 0.05). The level of cyclin A was not different between the two groups (t = 0.142, P more than 0.05). At 72 hours post-transfection, the level of HBV DNA was higher in pHBV-transfected hepatocytes (rcDNA: 3288.336+/-448.011; dslDNA: 6458.318+/-182.163; ssDNA: 2760.613+/-393.561) than in pHBV triangle X-transfected hepatocytes (rcDNA: 515.721+/-62.530; dslDNA: 2122.228+/-28.347; ssDNA: 1632.013+/-207.021) and in the blank (untransfected) control group (P less than 0.05). Real-time PCR analysis of HBV DNA copy number per cell confirmed these results, (pHBV-transfected: 987.50+/-47.80 vs. pHBV triangle X-transfected: 303.67+/-33.94; t = 20.203, P less than 0.05).

CONCLUSIONSThe HBx protein can affect the levels of cell cycle proteins, which may induce quiescent hepatocytes to enter the G1 phase of the cell cycle and stay in this phase instead of entering the S phase, thereby promoting HBV intracellular replication.

Animals ; Cell Cycle ; Cell Cycle Proteins ; genetics ; metabolism ; Cell Line ; Hepatocytes ; cytology ; virology ; Male ; Mice ; Mice, Inbred C57BL ; Plasmids ; Trans-Activators ; genetics ; metabolism ; Transfection

OBJECTIVETo study the inhibitory effect of binding peptides on duck hepatitis B virus (DHBV) replication in duck hepatocytes.

METHODSSpecific binding peptides to duck hepatitis B virus polymerase (DHBVP) were screened by phage display technology (PDT), then were sequenced and synthesized. Binding peptides were added into primary culture of duck hepatocytes infected with DHBV in vitro. DHBV-DNA in the cytoplasm, cell nucleus and medium supernatant was assayed over time.

RESULTSSeven binding peptides were obtained after 3-round screening by PDT. Duck primary hepatocytes infected by DHBV were treated with above obtained binding peptides. The DHBV-DNA levels in medium supernatant and cytoplasm of duck hepatocytes treated with synthesized peptides (the 3rd and the 6th peptide) were significantly lower than those of control cells (P<0.05).

CONCLUSIONSpecific binding peptides to DHBVP could inhibit the replication of DHBV.

Animals ; Cells, Cultured ; Ducks ; Hepadnaviridae Infections ; virology ; Hepatitis B Virus, Duck ; drug effects ; genetics ; Hepatitis, Viral, Animal ; virology ; Hepatocytes ; virology ; Peptide Nucleic Acids ; pharmacology ; RNA-Directed DNA Polymerase ; metabolism ; Virus Replication ; drug effects

OBJECTIVETo detect p24 antigen of human immunodeficiency virus (HIV)-1 in the liver biopsy specimens of patients with HIV infection.

METHODSLiver biopsy samples from 14 patients with HIV/AIDS (11 man, 3 women; age range 27-52 years; infection time range 8-13 years) were examined by immunohistochemistry prospectively.

RESULTSIntracellular expression of HIV-1 p24 antigen was detected in Kupffer cells, endothelial cells and hepatocytes. There were more HIV-positive liver cells in the patients with severer liver damage than those with milder liver damage (t=2.5189, P=0.0270).

CONCLUSIONThese findings indicate that HIV-1 could replicate in the liver of HIV-infected patients and might be related to the liver cells apoptosis.

Adult ; Female ; HIV Core Protein p24 ; biosynthesis ; HIV Infections ; metabolism ; virology ; HIV-1 ; physiology ; Hepatocytes ; metabolism ; pathology ; Host-Pathogen Interactions ; Humans ; Immunohistochemistry ; Liver ; metabolism ; pathology ; virology ; Male ; Middle Aged