BACKGROUND:Prior experimentation has shown that loss of the tyrosine kinase(TK) signaling domain of the Ron receptor leads to marked hepatocyte protection in a model of lipopolysaccharideinduced acute liver failure(AL...BACKGROUND:Prior experimentation has shown that loss of the tyrosine kinase(TK) signaling domain of the Ron receptor leads to marked hepatocyte protection in a model of lipopolysaccharideinduced acute liver failure(ALF) in D-galactosamine(GalN)sensitized mice.The aim of this study was to identify the role of Ron in the regulation of hepatic gene expression.METHODS:Microarray analyses were performed on liver RNA isolated sequentially from wild-type(WT) and TK-/mice during the progression of ALF.Gene array data were validated using Western and immunohistochemistry analyses as well as with ex vivo culture systems.RESULTS:At baseline,101 genes were differentially expressed between WT and TK-/-livers,which regulate processes involved in hypoxia,proliferation,apoptosis and metabolism.One hour after ALF induction,WT livers exhibited increased cytokine expression compared to TK-/-livers,and after 4 hours,an induction of suppressor of cytokine signaling(SOCS) genes as well as JAK-STAT pathway activation were prominent in TK-/livers compared to controls.CONCLUSION:Our studies suggest a novel hepato-protective mechanism in Ron TK-/-mice wherein increased and sustained SOCS production and JAK-STAT activation in the hepatocyte may inhibit the destructive proinflammatory milieu and promote survival factors which blunt hepatic death and the ensuing development of ALF.展开更多
基金supported by grants from the Public Health Services DK-73552 (WSE)the Digestive Diseases Research Development Center DK-064403 (WSE and LMA)from the National Institutes of Healthby grant project #8950(WSE) from Shriner's Hospital for Children
文摘BACKGROUND:Prior experimentation has shown that loss of the tyrosine kinase(TK) signaling domain of the Ron receptor leads to marked hepatocyte protection in a model of lipopolysaccharideinduced acute liver failure(ALF) in D-galactosamine(GalN)sensitized mice.The aim of this study was to identify the role of Ron in the regulation of hepatic gene expression.METHODS:Microarray analyses were performed on liver RNA isolated sequentially from wild-type(WT) and TK-/mice during the progression of ALF.Gene array data were validated using Western and immunohistochemistry analyses as well as with ex vivo culture systems.RESULTS:At baseline,101 genes were differentially expressed between WT and TK-/-livers,which regulate processes involved in hypoxia,proliferation,apoptosis and metabolism.One hour after ALF induction,WT livers exhibited increased cytokine expression compared to TK-/-livers,and after 4 hours,an induction of suppressor of cytokine signaling(SOCS) genes as well as JAK-STAT pathway activation were prominent in TK-/livers compared to controls.CONCLUSION:Our studies suggest a novel hepato-protective mechanism in Ron TK-/-mice wherein increased and sustained SOCS production and JAK-STAT activation in the hepatocyte may inhibit the destructive proinflammatory milieu and promote survival factors which blunt hepatic death and the ensuing development of ALF.
