BACKGROUND: Hepatocyte growth factor (HGF) is an endogenously induced bioactive molecule that has strong anti-apoptotic and tissue repair activities. In this research, we identified APOA4 as a novel pharmacodynamic (PD) marker of the recombinant human HGF (rh-HGF), E3112. METHODS: rh-HGF was administered to mice, and their livers were investigated for the PD marker. Candidates were identified from soluble proteins and validated by using human hepatocytes in vitro and an animal disease model in vivo, in which its c-Met dependency was also ensured. RESULTS: Among the genes induced or highly enhanced after rh-HGF exposure in vivo, a soluble apolipoprotein, Apoa4, was found to be induced by rh-HGF in the murine liver. By using primary cultured human hepatocytes, the significant induction of human APOA4 was observed at the mRNA and protein levels, and it was inhibited in the presence of a c-Met inhibitor. Although mice constitutively expressed Apoa4 mRNA in the small intestine and the liver, the liver was the primary organ affected by administered rh-HGF to strongly induce APOA4 in a dose- and c-Met-dependent manner. Serum APOA4 levels were increased after rh-HGF administration, not only in normal mice but also in anti-Fas-induced murine acute liver failure (ALF), which confirmed the pharmacodynamic nature of APOA4. CONCLUSIONS: APOA4 was identified as a soluble PD marker of rh-HGF with c-Met dependency. It should be worthwhile to clinically validate its utility through clinical trials with healthy subjects and ALF patients.
Apolipoproteins A/blood , Biomarkers, Pharmacological/blood , Hepatocyte Growth Factor/pharmacokinetics , Hepatocytes/drug effects , Liver/drug effects , Animals , Apolipoproteins A/genetics , Apolipoproteins A/metabolism , Cells, Cultured , Gene Expression Regulation/drug effects , Hepatocyte Growth Factor/administration & dosage , Hepatocytes/metabolism , Humans , Liver/physiology , Liver Failure, Acute/blood , Liver Failure, Acute/etiology , Male , Mice, Inbred BALB C , Proto-Oncogene Proteins c-met/metabolism , Recombinant Proteins/administration & dosage , Recombinant Proteins/pharmacokinetics
Hepatocyte growth factor (HGF) is an endogenously expressed bioactive substance that has a strong anti-apoptotic effect. In this study, we biochemically and histologically characterized the effects of rh-HGF on in vitro human hepatocyte injury and mouse acute liver failure (ALF) models, both of which were induced by antibody-mediated Fas signaling. rh-HGF inhibited intracellular caspase-3/7 activation and cytokeratin 18 (CK-18) fragment release in both models. Histologically, rh-HGF dramatically suppressed parenchymal damage and intrahepatic hemorrhage. Among the laboratory parameters, prothrombin time (PT) was strongly preserved by rh-HGF, and PT was well correlated with the degree of intrahepatic hemorrhage. These results showed that the anti-apoptotic effect of rh-HGF on hepatocytes coincided strikingly with the suppression of intrahepatic hemorrhage. PT was considered to be the best parameter that correlated with the intrahepatic hemorrhages associated with hepatocellular damage. The action of rh-HGF might derive not only from its anti-apoptosis effects on liver parenchymal cells but also from its stabilization of structural and vasculature integrity.
Apoptosis/drug effects , Blood Coagulation/drug effects , Hemorrhage/metabolism , Hepatocyte Growth Factor/pharmacology , Hepatocytes/drug effects , Hepatocytes/metabolism , Liver Diseases/metabolism , Recombinant Proteins/pharmacology , Animals , Cells, Cultured , Disease Models, Animal , Hemorrhage/drug therapy , Hemorrhage/etiology , Humans , Inhibitory Concentration 50 , Liver Diseases/drug therapy , Liver Diseases/etiology , Liver Diseases/pathology , Liver Failure, Acute/blood , Liver Failure, Acute/drug therapy , Liver Failure, Acute/etiology , Liver Failure, Acute/pathology , Male , Mice , Prothrombin Time , fas Receptor/metabolism
