concanavalin-a and Carbon-Tetrachloride-Poisoning

Aberrant expression of the chemokine CXC chemokine ligand (CXCL)10 has been linked to the severity of hepatitis C virus (HCV)-induced liver injury, but the underlying molecular mechanisms remain unclear. In this study, we describe a yet-unknown proapoptotic effect of CXCL10 in hepatocytes, which is not mediated through its cognate chemokine receptor, but the lipopolysaccharide receptor Toll-like receptor 4 (TLR4). To this end, we investigated the link of CXCL10 expression with apoptosis in HCV-infected patients and in murine liver injury models. Mice were treated with CXCL10 or neutralizing antibody to systematically analyze effects on hepatocellular apoptosis in vivo. Direct proapoptotic functions of CXCL10 on different liver cell types were evaluated in detail in vitro. The results showed that CXCL10 expression was positively correlated with liver cell apoptosis in humans and mice. Neutralization of CXCL10 ameliorated concanavalin A-induced tissue injury in vivo, which was strongly associated with reduced liver cell apoptosis. In vitro, CXCL10 mediated the apoptosis of hepatocytes involving TLR4, but not CXC chemokine receptor 3 signaling. Specifically, CXCL10 induced long-term protein kinase B and Jun N-terminal kinase activation, leading to hepatocyte apoptosis by caspase-8, caspase-3, and p21-activated kinase 2 cleavage. Accordingly, systemic application of CXCL10 led to TLR4-induced liver cell apoptosis in vivo.. The results identify CXCL10 and its noncognate receptor, TLR4, as a proapoptotic signaling cascade during liver injury. Antagonism of the CXCL10/TLR4 pathway might be a therapeutic option in liver diseases associated with increased apoptosis.

Topics: Animals; Apoptosis; Carbon Tetrachloride Poisoning; Caspases; Chemical and Drug Induced Liver Injury; Chemokine CXCL10; Concanavalin A; Hepatitis C; Hepatocytes; Humans; Liver; Mice; Receptors, CXCR3; Signal Transduction; Toll-Like Receptor 4

To investigate the protective effects of the granule of Sambucus chinensis Lindl on acute hepatic injury.. The acute liver-injury model induced by CCl4 or D-GalN or ConA was established in mice or rats.. The granule of Sambucus chinensis Lindl showed significantly protective effects on mice acute hepatic injury induced by CCl4 ,and the effects were concern of antagonizing lipoperoxidation and improving energy of Ca2+ -ATPase of theca mitochondria and microsome. It showed significantly protective effects on mice or rats acute hepatic injury induced by D-GalN or Con A, too.. The granule of Sambucus chinensis Lindl showed significantly protective effects against many kinds of chemical and immunological liver injuries.

Topics: Animals; Aspartate Aminotransferases; Biomarkers; Calcium-Transporting ATPases; Carbon Tetrachloride Poisoning; Chemical and Drug Induced Liver Injury; Concanavalin A; Drugs, Chinese Herbal; Liver; Male; Malondialdehyde; Mice; Plants, Medicinal; Rats; Rats, Wistar; Sambucus; Sodium-Potassium-Exchanging ATPase; Transaminases

Tetrathiomolybdate, an anticopper drug, has been shown to protect mice against pulmonary fibrosis from bleomycin. Our hypothesis is that it does so by inhibiting fibrosis-inducing cytokines. Indeed, we have good evidence, not yet published, that tetrathiomolybdate inhibits pulmonary levels of transforming growth factor-beta and tumor necrosis factor-alpha expression in these bleomycin experiments. Herein, we evaluate tetrathiomolybdate's effectiveness in mitigating hepatitis and fibrosis in mice from the hepatotoxins, concanavalin A and carbon tetrachloride, and its inhibition of cytokines as a possible mechanism. In short-term experiments, concanavalin A elevated serum amino leucine transferase levels several fold, and tetrathiomolybdate completely prevented this increase. In additional experiments, tetrathiomolybdate therapy reversed the elevated serum transaminase levels despite continued concanavalin A injections, with nearly significant serum interleukin-1beta inhibition. Concanavalin A given for 12 weeks produced mild fibrosis, whereas concomitant tetrathiomolybdate treatment resulted in normal histology. Carbon tetrachloride given for 12 weeks resulted in very high serum amino leucine transferase levels, high serum transforming growth factor-beta levels, cirrhosis as seen histologically, and increase in liver hydroxyproline, a measure of fibrosis. Concomitant tetrathiomolybdate partially and significantly protected against increases in amino leucine transferase and transforming growth factor-beta, fully protected against the increase in hydroxyproline, and resulted in normal histology. In conclusion, tetrathiomolybdate protects against the hepatitis and fibrosis produced by these hepatotoxins, probably by inhibiting the excessive increase in inflammatory and fibrotic cytokines.

Topics: Alanine Transaminase; Animals; Carbon Tetrachloride Poisoning; Chelating Agents; Concanavalin A; Copper; Cytokines; Hydroxyproline; Liver; Mice; Mice, Inbred BALB C; Mice, Inbred CBA; Molybdenum