cytochrome-c-t and Liver-Failure

Hepatic failure (HF) is caused by several factors, which induce liver cell damage and dysfunction. However, the specific mechanism of HF remains to be fully elucidated. The present study aimed to investigate the underlying cause of hepatocyte injury and liver dysfunction. Liver cells were isolated from healthy female Sprague‑Dawley rats, aged between 6 and 8 weeks, weighing ~230 g. The liver cells were cultured in RPMI‑1640 medium containing 10% fetal bovine serum. An MTT assay was used to examine the inhibitory rate of liver growth in each group. Flow cytometric analysis was performed to detect liver cells undergoing apoptosis. The protein expression levels of poly (ADP‑ribose) polymerase (PARP) and cytochrome c (Cyt C) were detected by western blotting. The level of calmodulin‑dependent kinase (CaMK) was assessed using an ELISA. The results indicated that the growth inhibitory rate of rat liver cells was significantly increased following treatment with increasing concentrations of NH4Cl. The results of flow cytometric analysis demonstrated that the apoptotic rate in the BAPTA‑acetoxymethyl ester group was significantly lower compared with the NH4Cl group (P<0.05). Treatment with NH4Cl increased the protein expression levels of PARP and Cyt C in the liver cells. The mRNA expression of CaMK decreased gradually following treatment with increasing concentrations of NH4Cl for 6, 12 and 24 h. The results suggested that hepatocyte injury and liver dysfunction may be caused by inducing apoptosis via the PARP and Cyt C pathways. Additionally, downregulation of CaMK may be associated with the apoptosis observed in hepatocyte injury.

Topics: Ammonium Chloride; Animals; Apoptosis; Calcium-Calmodulin-Dependent Protein Kinases; Cell Proliferation; Cytochromes c; Disease Models, Animal; Female; Hepatocytes; Hyperammonemia; Liver Failure; Poly(ADP-ribose) Polymerases; Rats; Signal Transduction

The hepatoprotective effects and molecular mechanisms of baicalein on acute liver failure induced by d-galactosamine (d-GalN)/lipopolysaccharides (LPS) were investigated in vivo. Mice were administered with different doses of baicalein (50, 100 or 150mg/kg, p.o.) 1h before injection of d-GalN (700mg/kg)/LPS (10μg/kg) and then sacrificed 6h after treatment with d-GalN/LPS. Pretreatment with baicalein prevented d-GalN/LPS-induced liver damage by preventing associated increases of serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) and by reducing serum tumor necrosis factor α (TNF-α), nitric oxide (NO) or inducible nitric oxide synthase (iNOS) expressions. The molecular mechanisms involved in baicalein-induced inhibition of d-GalN/LPS-caused apoptosis were associated with the protection of mitochondria, increasing the Bcl-2/Bax ratio, blocking the release of cytochrome c, and suppressing the phosphorylation of IκBα, ERK and JNK. Moreover, baicalein activated c-FLIP(L), XIAP and cIAP2 proteins, potentially blocking the recruitment of NF-κB signaling molecules. The results support the investigation of baicalein as a therapeutic candidate for acute liver apoptosis or injury and indicate that baicalein might inhibit liver apoptosis by mediating one or more of these pathways.

Topics: Alanine Transaminase; Animals; Apoptosis; Aspartate Aminotransferases; CASP8 and FADD-Like Apoptosis Regulating Protein; Caspase 3; Cytochromes c; Cytoprotection; Disease Models, Animal; Flavanones; Galactosamine; Gene Expression Regulation, Enzymologic; Lipopolysaccharides; Liver; Liver Failure; Male; Mice; Mice, Inbred C57BL; Mitogen-Activated Protein Kinases; NF-kappa B; Nitric Oxide; Nitric Oxide Synthase Type II; Proto-Oncogene Proteins c-bcl-2; Tumor Necrosis Factor-alpha; X-Linked Inhibitor of Apoptosis Protein

Recent studies in lymphohemopoietic cells show that transferrin (Tf), a pivotal component of iron transport and metabolism, also exerts cytoprotective functions. We show here in a murine model that Tf interferes with Fas-mediated hepatocyte death and liver failure. The mechanism involves the downregulation of apoptosis via BID, cytochrome c, caspase-3 and caspase-9, and upregulation of antiapoptotic signals via Bcl-xL. The results obtained with iron-saturated Tf, Apo-Tf and the iron-chelator salicylaldehyde isonicotinoyl hydrazone indicate that the observed antiapoptotic effect of Tf was not mediated by iron alone. In conclusion, the data suggest that Tf has broader functions than previously recognized and may serve as a cytoprotective agent.

Topics: Animals; Antibodies, Monoclonal; Apoptosis; bcl-X Protein; BH3 Interacting Domain Death Agonist Protein; Carrier Proteins; Caspase 3; Caspase 9; Caspases; Cell Line; Cytochromes c; Cytoprotection; Enzyme Activation; fas Receptor; Female; Hepatocytes; Humans; Iron; Liver Failure; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Proto-Oncogene Proteins c-bcl-2; Signal Transduction; Transferrin

In the process of apoptosis, it is known that the transition of cytochrome c from mitochondria into the cytosol occurs, and tumor necrosis factor (TNF)-alpha is one of the molecules responsible for this event. But in the state of hypercytokine induced by D-galactosamine (D-GaIN)/Lipopolysaccharide (LPS), the localization of cytochrome c is little known.. Rats were administrated with D-GaIN(700 mg/kg)/LPS(200 microg/kg). Blood and tissue samples were collected and examined for levels of pro-inflammatory cytokines, the apoptosis of liver cells, and the localization of cytochrome c.. Before administration of D-GaIN/LPS, cytochrome c was definitely localized in the mitochondria. At 2 h after simultaneous administration of D-GaIN/LPS, cytochrome c had accumulated in the cytosol following abrupt increases of plasma TNF-alpha. Massive cell destruction due to apoptosis proved by Terminal deoxynucleo-tidyl transferase-mediated dUTP nick end labeling staining was observed in liver tissue 4 h later and markedly increased levels of cytochrome c were detected in the plasma 12 h after D-GaIN/LPS administration.. Liver injury induced by simultaneous administration of D-GaIN/LPS was closely associated with the production of TNF-alpha, and also with the dynamic movement of cytochrome c from the mitochondria into the cytosol, and then into the systemic circulation. The detection of plasma cytochrome c levels may be a useful clinical tool for the detection of apoptosis in vivo.

Topics: Animals; Apoptosis; Biological Transport, Active; Blotting, Western; Cell Survival; Cells, Cultured; Cytochromes c; Cytosol; Disease Models, Animal; Female; Galactosamine; Hepatocytes; Immunohistochemistry; In Situ Nick-End Labeling; Lipopolysaccharides; Liver Failure; Mitochondria; Random Allocation; Rats; Rats, Wistar; Sensitivity and Specificity; Tumor Necrosis Factor-alpha