BACKGROUNDInsulin-like growth factor binding protein-related protein 1 (IGFBPrP1) can activate hepatic stellate cells and increase extracellular matrix (ECM) in vitro. However, the effects of IGFBPrP1 in mice with hepatic fibrosis, and the mechanisms of these effects, are currently unknown. We aim to address these issues in this study.

METHODSIntraperitoneal injection of thioacetamide (TAA) is a classic method for establishing a mouse model of hepatic fibrosis. Using this model, we administered anti-IGFBPrP1 antibody, again via intraperitoneal injection. The morphological changes of liver fibrosis were observed with both HE and Masson stainning. The immunohistochemical assays and Western blotting were used to measure changes in IGFBPrP1, α-smooth muscle actin (α-SMA) and ECM in liver tissues, and the expression of transforming growth factor-β1 (TGF-β1) and Smad3. Data were statistically analyzed using one-way analysis of variance (ANOVA), the SNK-q test for inter-group differences.

RESULTSThe Masson staining analysis showed that compared with normal control group, content of collagen fiber in TAA5w group was significantly increased (P < 0.01), and it was significantly decreased in TAA5w/aIGFBPrP1 group compared with in TAA5w group (P < 0.01). The expression of hepatic IGFBPrP1, α-SMA, TGF-β1, Smad3, collagen I and fibronectin (FN) was significantly up-regulated in the TAA5w group (P < 0.01). Anti-IGFBPrP1 treatment reversed these changes (P < 0.01).

CONCLUSIONSIGFBPrP1 plays an important role in the development of hepatic fibrosis. Anti-IGFBPrP1 prevents fibrosis in mice by suppressing the activation of hepatic stellate cells, inhibiting the synthesis of major components of the ECM (namely, collagen I and FN). The mechanism for this suppression of fibrosis is associated with the TGF-β1/Smad3 signaling pathways.

Actins ; metabolism ; Animals ; Antibodies ; therapeutic use ; Blotting, Western ; Immunohistochemistry ; Insulin-Like Growth Factor Binding Proteins ; immunology ; metabolism ; Liver Cirrhosis ; drug therapy ; metabolism ; Male ; Mice ; Thioacetamide ; toxicity

OBJECTIVE: This study was designed to evaluate hematological disorders and the orchestrating roles of hepcidin and IL-6 in rat models of thioacetamide (TAA) and carbon tetrachloride (CCl4) hepatotoxicity. METHODS: Rats were intraperitoneally injected with TAA (10 mg/100 g rat weight dissolved in isosaline) or CCl4 (100 μL/100 g rat weight diluted as 1:4 in corn oil) twice weekly for eight consecutive weeks to induce subchronic liver fibrosis. Blood and tissue samples were collected and analyzed. RESULTS: CCl4 but not TAA significantly decreased the RBCs, Hb, PCV, and MCV values with minimal alterations in other erythrocytic indices. Both hepatotoxins showed leukocytosis, granulocytosis, and thrombocytopenia. By the end of the experiment, the erythropoietin level increased in the CCl4 model. The serum iron, UIBC, TIBC, transferrin saturation%, and serum transferrin concentration values significantly decreased, whereas that of ferritin increased in the CCl4 model. TAA increased the iron parameters toward iron overload. RT-PCR analysis revealed increased expression of hepatic hepcidin and IL-6 mRNAs in the CCl4 model and suppressed hepcidin expression without significant effect on IL-6 in the TAA model. CONCLUSION These data suggest differences driven by hepcidin and IL-6 expression between CCl4 and TAA liver fibrosis models and are of clinical importance for diagnosis and therapeutics of liver diseases.
Animals ; Blood Chemical Analysis ; Carbon Tetrachloride ; toxicity ; Hepcidins ; pharmacology ; Injections, Intraperitoneal ; Interleukin-6 ; pharmacology ; Iron ; blood ; metabolism ; Leukocytosis ; chemically induced ; therapy ; Liver Cirrhosis ; chemically induced ; therapy ; Male ; Rats ; Thioacetamide ; toxicity ; Thrombocytopenia ; chemically induced ; therapy ; Transferrin ; metabolism

Thioacetamide (TA) is converted into a hyperacetylating agent which causes hepatic necrosis, regeneration, cirrhosis and cancerous transformation. One of the most characteristic toxicities of TA in rat is observed with a 50 mg/kg per day which induces nucleolar enlargement different from that in regenerating liver. From TA-treated liver, the nucleoli were isolated and characterized for an altered nucleolar signal transduction system. Immunochemistry revealed that the poisoned nucleoli had increased levels of both nucleolus specific proteins (nucleophosmin and nucleolin) and various signal molecules (CK2, Erk1/2, p38, protein kinases A and C, and cyclin A). Using flow cytometry, the nucleoli were found to be in G2-arrested nuclei. Manifestation of the nucleolar enlargement could be readily observed using an ex vivo hepatocyte culture. There were two types of nucleolar enlargement. One was observed in normal hepatocytes with light density of enlarged nucleoli. The other was in TA-treated hepatocytes with dense and compact density of enlarged nucleoli, which contained a 3 to 5-fold higher nudeophosmin content than the control. In vitro induction of nucleolar enlargement with TA was possible. As soon as the hepatocytes anchored on a collagen coat, exogeneous TA (higher than 1 microg/mL) could induce dense and compact nucleoli. However, when an exogeneous drug was added after monolayer formation (1 day), no drug-induced nucleolar enlargement was observed.
Animal ; Cells, Cultured ; Flow Cytometry ; G2 Phase/drug effects ; Hepatocytes/ultrastructure ; Hepatocytes/drug effects* ; Male ; Nucleolus Organizer Region/physiology ; Nucleolus Organizer Region/drug effects* ; Rats ; Rats, Sprague-Dawley ; Signal Transduction/drug effects ; Thioacetamide/toxicity*

Hepatic fibrogenesis, a complex process that involves a marked accumulation of extracellular matrix components, activation of cells capable of producing matrix materials, cytokine release, and tissue remodeling, is regulated by matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs). The MMP-TIMP balance can regulate liver fibrogenesis. The aim of this study was to evaluate the expression patterns of MMPs and TIMPs during thioacetamide (TAA)-induced liver fibrogenesis. Chronic liver injury was induced with TAA (200 mg/kg i.p.) for 4 or 7 weeks in male Sprague-Dawley rats. Hepatic injury and fibrosis were assessed by hematoxylin-eosin (H&E) staining, and collagen deposition was confirmed by Sirius Red staining. The level of hepatic injury was quantified by serological analysis. The transcriptional and translational levels of alpha-smooth muscle actin (alpha-SMA), MMPs, and TIMPs in the liver were measured by Western blotting, RT-PCR, and immunohistochemistry. MMP, TIMP, and alpha-SMA were observed along fibrotic septa and portal spaces around the lobules. TAA treatment increased transcription of both MMPs and TIMPs, but only TIMPs showed increased translation. The dominant expression of TIMPs may regulate the function of MMPs to maintain liver fibrosis induced by TAA.
Animals ; Collagen/metabolism ; Extracellular Matrix/chemistry/metabolism ; *Liver Cirrhosis/chemically induced/metabolism/pathology ; Male ; Matrix Metalloproteinases/genetics/*metabolism ; Rats ; Rats, Sprague-Dawley ; Thioacetamide/*toxicity ; Tissue Inhibitor of Metalloproteinases/genetics/*metabolism

BACKGROUND/AIMS: Eukaryotic cell cycle is regulated by signal transduction pathways mediated by complexes of cyclin dependent kinases (CDKs) and their partner cyclins, or by interaction with CDK inhibitors. Thioacetamide (TA) is a weak hepatocarcinogen causing several types of liver damage in a dose dependent manner and ultimately producing malignant transformation. We investigated alterations of expression of cell cycle regulators in the rat liver, involved in G1 entry and progression during TA administration. METHODS: We studied expression patterns of cyclin D1, CDK4, CDK6, p21(CIP1) and p16(INK4a) during daily intraperitoneal injection of low dose TA (50 mg/kg) till 7 day. We used western blot and immunohistochemistry for detection. RESULTS: Expression of cyclin D1, CDK4, CDK6 and p21(CIP1) increased from 6 hour and peaked at 2, 3 day, then decreased next 2 days, and re-increased at 6 day. Cytoplasmo-nuclear translocation of cyclin D1 and p21(CIP1) was evident within 1 day and prominent at 2 and 7 day. Expression of p16(INK4a) increased immediately after TA treatment and remarkably increased from 3 day and progressed till 7 day, showing cytoplasmic location, suggestive of inactive form. Most of in situ immunoreactions occurred at the centrilobular hepatocytes. Concomitant nuclear translocation of p21(CIP1) and cyclin D1, different with p16(INK4a) suggests that p21(CIP1) might be a transporter for nuclear translocation rather than cell cycle inhibitor. CONCLUSIONS: Daily administration of low dose TA makes cell cycle open and G1 progress, possibly due to cyclin D1, CDK4 and CDK 6, their transporter p21(CIP1), and inactive p16(INK4a), which occur at quiescent hepatocytes, not stem cells.
Animals ; Cell Cycle Proteins/*metabolism ; Cyclin D1/metabolism ; Cyclin-Dependent Kinase 4/metabolism ; Cyclin-Dependent Kinase 6/metabolism ; Cyclin-Dependent Kinase Inhibitor p16/metabolism ; Cyclin-Dependent Kinase Inhibitor p21/metabolism ; G1 Phase ; Immunohistochemistry ; Liver/*drug effects/enzymology/metabolism ; Liver Diseases/chemically induced/metabolism/pathology ; Male ; Rats ; Rats, Sprague-Dawley ; Thioacetamide/*toxicity

Parthenolide (PT), a sesquiterpene lactone derived from the plant feverfew, has pro-apoptotic activity in a number of cancer cell types. We assessed whether PT induces the apoptosis of hepatic stellate cells (HCSs) and examined its effects on hepatic fibrosis in an in vivo model. The effects of PT on rat HSCs were investigated in relation to cell growth inhibition, apoptosis, NF-kappaB binding activity, intracellular reactive oxygen species (ROS) generation, and glutathione (GSH) levels. In addition, the anti-fibrotic effects of PT were investigated in a thioacetamide-treated rat model. PT induced growth inhibition and apoptosis in HSCs, as evidenced by cell growth inhibition and apoptosis assays. PT increased the expression of Bax proteins during apoptosis, but decreased the expression of Bcl-2 and Bcl-XL proteins. PT also induced a reduction in mitochondrial membrane potential, poly(ADP-ribose) polymerase cleavage, and caspase-3 activation. PT inhibited TNF-alpha-stimulated NF-kappaB binding activity in HSCs. The pro-apoptotic activity of PT in HSCs was associated with increased intracellular oxidative stress as evidenced by increased intracellular ROS levels and depleted intracellular GSH levels. Furthermore, PT ameliorated hepatic fibrosis significantly in a thioacetamide-treated rat model. In conclusion, PT exhibited pro-apoptotic effects in rat HSCs and ameliorated hepatic fibrosis in a thioacetamide-induced rat model.
Animals ; Apoptosis/*drug effects ; Gene Expression/drug effects ; Hepatic Stellate Cells/*drug effects ; Humans ; Liver Cirrhosis/chemically induced/*drug therapy ; Membrane Potential, Mitochondrial/drug effects ; NF-kappa B/metabolism ; Oxidative Stress/drug effects ; Rats ; Reactive Oxygen Species/metabolism ; Sesquiterpenes/*administration & dosage ; Thioacetamide/toxicity ; Tumor Necrosis Factor-alpha/metabolism ; bcl-2-Associated X Protein/metabolism ; bcl-X Protein/metabolism

BACKGROUND/AIMS: Ischemic preconditioning (IP) decreases severity of liver necrosis and has anti-apoptotic effects in previous studies using liver regeneration in normal rats. This study assessed the effect of IP on liver regeneration after hepatic resection in cirrhotic rats. METHODS: To induce liver cirrhosis, thioacetamide (300 mg/kg) was injected intraperitoneally into Sprague-Dawley rats twice per week for 16 weeks. Animals were divided into four groups: non-clamping (NC), total clamping (TC), IP, and intermittent clamping (IC). Ischemic injury was induced by clamping the left portal pedicle including the portal vein and hepatic artery. Liver enzymes alanine transaminase (ALT) and aspartate aminotransferase (AST) were measured to assess liver damage. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) staining for apoptosis and proliferating cell nuclear antigen (PCNA) staining for cell replication were also performed. RESULTS: Day-1 ALT and AST were highest in IP, however, levels in NC and IC were comparably low on days 1-7. There was no significant correlation of AST or ALT with experimental groups (P=0.615 and P=0.186). On TUNEL, numbers of apoptotic cells at 100x magnification (cells/field) were 31.8+/-24.2 in NC, 69.0+/-72.3 in TC, 80.2+/-63.1 in IP, and 21.2+/-20.8 in IC (P<0.05). When regeneration capacity was assessed by PCNA staining, PCNA-positive cells (cells/field) at 400x were 3.4+/-6.0 in NC, 16.9+/-69 in TC, 17.0+/-7.8 in IP and 7.4+/-7.6 in IC (P<0.05). CONCLUSIONS: Although regeneration capacity in IP is higher than IC, the liver is vulnerable to ischemic damage in cirrhotic rats. Careful consideration is needed in applying IP in the clinical setting.
Alanine Transaminase/blood ; Animals ; Apoptosis ; Aspartate Aminotransferases/blood ; Constriction ; Hepatectomy/methods ; Hepatic Artery ; *Ischemic Preconditioning ; Liver/blood supply ; Liver Cirrhosis, Experimental/chemically induced/complications/*pathology ; *Liver Regeneration ; Proliferating Cell Nuclear Antigen/metabolism ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury/complications/enzymology/pathology ; Thioacetamide/toxicity