Administering of 2-acetylaminofluorene (2-AAF) before a two-thirds partial hepatectomy (PHx) results in suppression of hepatocyte proliferation and stimulation of oval cell proliferation. The objectives of this study was to examine the oval cell behaviour and associated transforming growth factor-beta1 (TGF-beta1) protein expression by combining 2-AAF with selective hepatic damage caused by PHx. We also studied the temporal relationship between TGF-beta1 expression, and proliferation and apoptosis of oval cells. Oval cells emerged from the portal areas and became more numerous with time fanning out into the periportal and midzonal hepatic parenchyma. Both smooth muscle actin (SMA) and TGF-beta1 immunostain revealed that TGF-beta1-positive cells were SMA-positive hepatic stellate cells (HSCs). Coinciding with the proliferation of oval cells, an increase expression of TGF-beta1 produced by SMA-positive HSCs was observed, thereafter apoptosis of oval cells reached its peak. This result implicated that TGF-beta1 produced by HSCs is intimately associated with proliferation and apoptosis of oval cells, and plays a role in the cessation of oval cell activation and remodeling of liver parenchyma in 2-AAF induced liver regeneration.
2-Acetylaminofluorene ; Animal ; Apoptosis/physiology* ; Hepatectomy ; Immunohistochemistry ; In Situ Nick-End Labeling ; Liver/ultrastructure ; Liver/metabolism* ; Liver/cytology ; Liver Regeneration/physiology* ; Liver Regeneration/drug effects ; Male ; Rats ; Rats, Sprague-Dawley ; Transforming Growth Factor beta/metabolism*

OBJECTIVETo investigate the effects of augmenter of liver regeneration (ALR) on the proliferation of hepatocytes and hepatic tumor cells and the expression of ALR in herpatocellular carcinoma (HCC).

METHODSPrimary rat hepatocytes, QGY and HepG2 cells were cultured separately with ALR from different species. Cell proliferation was detected by their 3H-TdR uptake. The expression of ALR was examined in 9 normal hepatic tissues and 21 HCC cases using immunohistochemistry method.

RESULTSDifferent ALRs could stimulate the proliferation of HepG2 and QGY cells in a dose-dependent way in vitro, but all ALR had no influence in the proliferation of primary rat hepatocytes. The expression of ALR was absent in normal hepatic tissues, but present in all HCC hepatic tissues. However, the expression of ALR had no relationship with the differentiation and size of the carcinomas.

CONCLUSIONALR might play an important role in the occurrence and development of HCC.

Animals ; Carcinoma, Hepatocellular ; metabolism ; Hepatocytes ; metabolism ; Liver Neoplasms ; metabolism ; Liver Regeneration ; drug effects ; physiology ; Male ; Proteins ; genetics ; metabolism ; Rats ; Rats, Wistar

Methylation events play a critical role in various cellular processes including regulation of gene transcription and proliferation. We observed that methyltransferase activity underwent time-dependent changes in the cytosol of the rat hepatocytes upon partial hepatectomy. However, any change in the methylation of nuclear proteins is not clear during hepatocyte proliferation. The nuclear fraction possesses basal level of methyltransferase to catalyze methylation of several proteins ranging from 7 to 70 kD prior to any hepatecmony. The specific p16 (16 kD) band was transiently and heavily methylated post 1 day hepatectomy, and then became non- detectable, but not in the control liver. Methylation of p16 band was completely inhibited by exogenously added histones, particularly 2AS, 1, 2A and 2B subtypes. The methylated p16 protein remains stable in either acid or alkali- induced demethylation conditions, indicating that methylation is not likely to occur on isoaspartyl or C-terminal cysteinyl residues. Exogenous addition of non-hydrolyzable GTP caused a dose- dependent suppression of a p16 methylation suggesting that G-proteins might play a role as an endogenous methylation inhibitor in vivo. Taken together, we have identified the proliferation event associated-methylation of the nuclear p16 protein in the hepatocytes undergoing liver regeneration.
Alkalies/pharmacology ; Animals ; Cell Proliferation ; Guanosine 5'-O-(3-Thiotriphosphate)/pharmacology ; Hepatectomy ; Hepatocytes/drug effects/*metabolism ; Histones/pharmacology ; Liver Regeneration/drug effects/*physiology ; Methylation/drug effects ; Nuclear Proteins/*metabolism ; Rats ; Research Support, Non-U.S. Gov't ; Sodium Chloride/pharmacology

OBJECTIVETo observe the effect of D-galactosamine (D-GaIN) and lipopolysaccharide (LPS) on liver tissue regeneration and repair in mice following liver injury induced by partial hepatectomy.

METHODSA total of 40 male BALB/c mice were randomly assigned into 2 equal groups to receive intraperitoneal injections of D-GaIN (500 mg/kg) plus LPS (50 µg/kg, given 1 h later) or two doses of saline 24 h prior to 1/3 hepatectomy. The liver weight/body weight (LW/BW) ratio and liver regeneration rate were observed at different time points after partial hepatectomy. Liver cell injury was assessed using HE staining, hepatocyte proliferation evaluated with BrdU staining, and the oval cell proliferation observed with immunohistochemistry.

RESULTSIn mice receiving saline injection, the liver volume was nearly restored 9 days after partial hepatectomy, while in mice with D-GaIN and LPS injections, the liver failed to recover the normal volume even at 14 days, showing a significant difference in the liver regeneration rate between them [(22.6∓105.93)% vs (9.49∓32.55)%, P<0.001]. Significant degenerative changes of the hepatic cells were found in D-GaIN/LPS-treated group, while only mild inflammatory reaction was observed in saline-treated group after partial hepatectomy. Obvious hepatocyte proliferation was observed at day 7 in saline-treated group but not in D-GaIN/LPS-treated group. Oval cell proliferation in the portal area occurred 3 days after partial hepatectomy in D-GaIN/LPS-treated group.

CONCLUSIOND-GaIN and LPS can obviously inhibit hepatocyte regeneration after liver injury in mice. D-GaIN and LPS combined with partial hepatectomy can induce oval cell proliferation.

Animals ; Cell Proliferation ; drug effects ; Galactosamine ; pharmacology ; Hepatectomy ; methods ; Lipopolysaccharides ; pharmacology ; Liver ; cytology ; injuries ; physiopathology ; Liver Regeneration ; drug effects ; physiology ; Male ; Mice ; Mice, Inbred BALB C ; Stem Cells ; cytology

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

OBJECTIVEThis study was conducted to determine the histopathological and biochemical effects of Thymus algeriensis essential oil (TEO) on hydrogen peroxide (H2O2)-induced oxidative stress in liver and kidney tissues of rats.

METHODSRats were treated in six groups and were exposed for 2 weeks to low (LD; 100 μmol/L) and high doses (HD; 1 mmol/L) of H2O2 in the presence or absence of TEO (180 mg/kg). Liver and kidney atrophy was measured by using biochemical and histopathological assays.

RESULTSOur study demonstrated that H2O2 induced liver and kidney atrophy, as evidenced by the significant elevation of serum aminotransferase, urea, and creatinine levels compared with those in the control rats. Urea levels were estimated by evaluating the activity of serum urease that hydrolyzes urea into CO2 and ammonia. However, TEO treatment significantly alleviated oxidative stress in the H2O2-induced liver and kidney toxicity model by reducing the levels of malondialdehyde concomitantly with marked elevations in superoxide dismutase, catalase, glutathione peroxidase, and glutathione S-transferase, as well as decrease in glutathione activity.

CONCLUSIONOur data demonstrated that TEO protected against H2O2 toxicity by decreasing oxidant levels and DNA damage, as well as increasing antioxidant levels, indicating that TEO has a spectrum of antioxidant and DNA-protective properties.

Animals ; Antioxidants ; pharmacology ; Hydrogen Peroxide ; metabolism ; toxicity ; Kidney ; drug effects ; physiology ; Lipid Metabolism ; drug effects ; Liver ; drug effects ; physiology ; Male ; Malondialdehyde ; metabolism ; Oils, Volatile ; pharmacology ; Oxidative Stress ; drug effects ; Plant Extracts ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Regeneration ; drug effects ; Thymus Plant ; chemistry

OBJECTIVETo investigate the effect of ursodeoxycholic acid (UDCA) on liver regeneration after 70% partial hepatectomy (PH) in bile duct obstructive (BDO) rats.

METHODSWistar rats were randomly divided into N-PH group in which normal rats were operated with 70% PH, BDO-PH group in which 70% PH were operated after two week's BDO, and BDO-PH UDCA or sterile saline treatment group in which UDCA (15mg kg(-1) d(-1)) or saline was administrated during BDO and after 70% PH. The hepatic pathological changes were observed. BrdU labeling of hepatocytes, the mRNA expression of intrahepatic hepatocyte growth factor (HGF) and its receptor (Met gene) after 70% PH were measured by immunohistochemical analysis and RT-PCR, respectively.

RESULTSImprovements of hepatic function and pathological changes were induced by UDCA administration after BDO. The expression of hepatic HGF/Met mRNA after 70% PH in BDO-PH UDCA treatment group rats was significantly increased compared with N-PH group rats (P<0.05), BrdU peak labelling of hepatocytes (59.39% +/- 10.82%) in BDO-PH UDCA treatment group rats was significantly higher than that (36.22% +/- 8.37%) in BDO-PH group rats (t=4.149, P<0.01) and without significance compared with N-PH group rats (68.64% +/- 11.26%, t=1.451, P >0.05).

CONCLUSIONSUDCA promotes liver regeneration after 70% PH in BDO rats by remission of hepatic pathological changes and elevating hepatic mRNA expression of HGF and Met.

Animals ; Cholestasis ; genetics ; physiopathology ; surgery ; Gene Expression Regulation ; drug effects ; Hepatectomy ; Hepatocyte Growth Factor ; genetics ; Liver ; physiology ; surgery ; Liver Regeneration ; drug effects ; Male ; Proto-Oncogene Proteins c-met ; genetics ; RNA, Messenger ; drug effects ; genetics ; metabolism ; Rats ; Rats, Wistar ; Ursodeoxycholic Acid ; pharmacology

BACKGROUND: The clinical trials emerged centromere protein E inhibitor GSK923295 as a promising anticancer drug, but its function in hepatocellular carcinoma (HCC) remain needs to be fully elucidated, especially as chemotherapy after hepatectomy for liver tumors. We aimed to describe anti-HCC activities of GSK923295 and compare its antiproliferative effects on liver regeneration after partial hepatectomy (PH). METHODS: All subjects were randomized to treatment with either vehicle or GSK923295. Antitumor activity of GSK923295 was assessed by xenograft growth assays. The C57BL/6 mice were subjected to 70% PH and the proliferation was calculated by liver coefficient, further confirmed by immunohistochemistry. The proliferation and cell cycle analysis of liver cell AML12 and HCC cells LM3, HUH7, and HepG2 were investigated using the cell counting kit-8 assay and Flow Cytometry. The chromosome misalignment and segregation in AML12 cells were visualized by immunofluorescence. RESULTS: Treatment with GSK923295 induced antiproliferation in HCC cell lines. It also caused delay on HCC tumor growth instead of regression both in a HCC cell line xenograft model and patient-derived tumor xenograft model. With microarray analysis, CENtromere Protein E was gradually increased in mouse liver after PH. Exposure of liver cells to GSK923295 resulted in delay on a cell cycle in mitosis with a phenotype of misaligned chromosomes and chromosomes clustered. In 70% PH mouse model, GSK923295 treatment also remarkably reduced liver regeneration in later stage, in parallel with the mitotic marker phospho-histone H3 elevation. CONCLUSION The anticancer drug GSK923295 causes a significant delay on HCC tumor growth and liver regeneration after PH in later stage.
Animals ; Antineoplastic Agents ; therapeutic use ; Blotting, Western ; Bridged Bicyclo Compounds, Heterocyclic ; therapeutic use ; Carcinoma, Hepatocellular ; drug therapy ; surgery ; Cell Cycle ; drug effects ; Cell Proliferation ; drug effects ; Chromosomal Proteins, Non-Histone ; antagonists & inhibitors ; Electrophoresis, Polyacrylamide Gel ; Female ; Fluorescent Antibody Technique ; Humans ; Immunohistochemistry ; Liver Neoplasms ; drug therapy ; surgery ; Liver Regeneration ; physiology ; Mice ; Mice, Inbred C57BL ; Real-Time Polymerase Chain Reaction ; Sarcosine ; analogs & derivatives ; therapeutic use ; Xenograft Model Antitumor Assays