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

OBJECTIVESBy culturing primary early (8 to 12-weeks-old) human fetal hepatocytes with different conditions, to study the status of cell susceptibility to HBV.

METHODSDuring primary culture of 10-weeks-old human fetal hepatocytes with serum-free medium adding different differentiation-induced ingredients, to inoculate cell with HBV at certain time. Cell shape, function and markers of HBV infection are measured.

RESULTS6 days after seeding, markers of mature hepatocytes are observed in cells cultured with 2.5mmol/L phenobarbital sodium, and these cells show susceptibility to HBV. Other ingredients cannot render hepatocytes susceptible to HBV.

CONCLUSIONPhenobarbital sodium induces differentiation and susceptibility to HBV in primary culture of early human fetal hepatocytes.

Cell Differentiation ; drug effects ; Cells, Cultured ; Female ; Fetus ; virology ; Hepatitis B virus ; growth & development ; Hepatocytes ; cytology ; physiology ; virology ; Humans ; Phenobarbital ; pharmacology ; Pregnancy ; Pregnancy Trimester, First

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

OBJECTIVETo evaluate the possibility of hepatitis B virus (HBV) as a vector in liver-targeting gene therapy.

METHODSA fragment containing the small envelope gene of HBV was replaced with the reporter gene green fluorescent protein (GFP) to construct the recombinant HBV vector, which was transfected into HepG2 cells with liposome. The expression of GFP was observed with fluorescence microscope. The HBV cccDNA was testified using semi-nest PCR. The viral particles of the recombinant HBV in culture medium were detected by PCR as well as Southern blot.

RESULTSThe HBV vector carrying the interesting gene of GFP could express the functional protein in the transfected hepatocytes. However, the recombinant HBV vector was replication-deficient, which could not be packed and replicated in the hepatocytes to secrete mature recombinant HBV particles carrying the interesting gene of GFP when transfected solely but could when cotransfected with the recombinant and helper construct which lacked part of 5'-proximal HBV RNA packaging signal epsilon.

CONCLUSIONIt is possible that HBV is reconstructed as a liver-targeting vector for gene therapy.

Cell Transformation, Viral ; Cells, Cultured ; Gene Transfer Techniques ; Genes, Reporter ; Genetic Therapy ; methods ; Genetic Vectors ; genetics ; physiology ; Hepatitis B virus ; genetics ; physiology ; Hepatocytes ; cytology ; virology ; Humans ; Liver ; cytology ; virology ; Recombinant Proteins ; genetics ; 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

Hepatocytes are the primary targets of the hepatitis C virus (HCV). While immunosuppressive roles of HCV core protein have been found in several studies, it remains uncertain whether core protein expressed in hepatocytes rather than in immune cells affects the CD8+ T cell response. In order to transduce genes selectively into hepatocytes, we developed a baculoviral vector system that enabled primary hepatocytes to express a target epitope for CD8+ T cells, derived from ovalbumin (OVA), with or without HCV core protein. Culture of OVA-specific CD8+ T cells with hepatocytes infected with these baculoviral vectors revealed that core protein has no effect on proliferation or apoptosis of CD8+ T cells. Our results suggest that HCV core protein does not exert its suppressive role on the CD8+ T cell immune response through expression in hepatocytes.
Viral Core Proteins/*metabolism ; Ovalbumin/genetics/immunology ; Mice ; Hepatocytes/cytology/*virology ; Green Fluorescent Proteins/genetics ; Genetic Vectors ; Cell Proliferation ; CD8-Positive T-Lymphocytes/*immunology ; Baculoviridae/genetics ; Apoptosis ; Animals

Adult ; Cell Differentiation ; drug effects ; Cells, Cultured ; DNA, Viral ; analysis ; Female ; Fetus ; virology ; Hepatitis B virus ; genetics ; growth & development ; isolation & purification ; Hepatocytes ; cytology ; physiology ; virology ; Humans ; Nucleic Acid Hybridization ; methods ; Phenobarbital ; pharmacology ; Pregnancy ; Pregnancy Trimester, First

OBJECTIVEIn the present study, we systemically evaluated the ability of two bioactive compounds from traditional Chinese medicine, celastrol and pristimerin, to enhance recombinant adeno-associated virus (rAAV) serotype vector-mediated transgene expression both in human cell lines in vitro, and in murine hepatocytes in vivo.

METHODSHuman cell lines were infected with rAAV vectors with either mock treatment or treatment with celastrol or pristimerin. The transgene expression, percentage of nuclear translocated viral genomes and the ubiquitination of intracellular proteins were investigated post-treatment. In addition, nonobese diabetic/severe combined immunodeficient gamma (NSG) mice were tail vain-injected with rAAV vectors and co-administered with either dimethyl sulfoxide, celastrol, pristimerin or a positive control, bortezomib. The transgene expression in liver was detected and compared over time.

RESULTSWe observed that treatment with pristimerin, at as low as 1 μmol/L concentration, significantly enhanced rAAV2 vector-mediated transgene expression in vitro, and intraperitoneal co-administration with pristimerin at 4 mg/(kg·d) for 3 d dramatically facilitated viral transduction in murine hepatocytes in vivo. The transduction efficiency of the tyrosine-mutant rAAV2 vectors as well as that of rAAV8 vectors carrying oversized transgene cassette was also augmented significantly by pristimerin. The underlying molecular mechanisms by which pristimerin mediated the observed increase in the transduction efficiency of rAAV vectors include both inhibition of proteasomal degradation of the intracellular proteins and enhanced nuclear translocation of the vector genomes.

CONCLUSIONThese studies suggest the potential beneficial use of pristimerin and pristimerin-containing herb extract in future liver-targeted gene therapy with rAAV vectors.

Animals ; Cell Line ; Dependovirus ; genetics ; physiology ; Gene Expression ; drug effects ; Genetic Therapy ; Genetic Vectors ; genetics ; physiology ; Hepatocytes ; metabolism ; virology ; Humans ; Liver ; cytology ; metabolism ; virology ; Mice ; Transgenes ; drug effects ; Triterpenes ; pharmacology

Genetic Therapy ; Hepatitis B ; therapy ; virology ; Hepatocytes ; cytology ; Humans ; Interleukin-6 ; genetics ; physiology ; Liver Regeneration ; drug effects ; Receptors, Interleukin-6 ; genetics ; physiology ; Recombinant Fusion Proteins ; genetics ; physiology ; Signal Transduction

OBJECTIVETo establish a stable cell line that can replicate hepatitis B virus (HBV) DNA carrying the reverse transcriptase sequence derived from a clinical isolate.

METHODSNested PCR was used to amplify the HBV DNA fragment from the serum. The fragment was cloned into a plasmid that can support HBV replication in vitro by fragment substitution reaction (FSR), followed by the cloning of the neomycin expressing fragment downstream from HBV DNA. G418 selection was conducted after the transfection of HepG2 cells with the recombinant DNA. Real-time PCR and enzyme linked immunosorbent assay (ELISA) were used to screen stable cell lines that can replicate HBV DNA, and the replication of HBV DNA by the cell line was confirmed by using Southern blot analysis.

RESULTSFragment nt55-1654 amplified from the serum DNA was substituted to the plasmid pLL, generating the plasmid p11. The neomycin fragment was cloned into p11, leading to the plasmid p11-neo, and p11-neo was confirmed to be HBV-replication-competent. A stable cell line named 3-10 that can replicate HBV DNA was obtained.

CONCLUSIONSA stable cell line was established that can replicate HBV DNA carrying the reverse transcriptase sequence derived from a clinical isolate. Real-time PCR plus ELISA may help to rapidly screen out stable cell lines replicating HBV DNA.

Cell Line ; Cloning, Molecular ; DNA Replication ; DNA, Viral ; biosynthesis ; Genetic Vectors ; Hep G2 Cells ; Hepatitis B virus ; genetics ; Hepatocytes ; cytology ; virology ; Humans ; Plasmids ; RNA-Directed DNA Polymerase ; genetics ; Virus Replication ; genetics