D-galactosamine-induced mouse hepatic apoptosis: possible involvement with tumor necrosis factor, but not with caspase-3 activity.
We investigated whether tumor necrosis factor (TNF) and caspase-3 activity are involved in the induction of hepatocellular apoptosis in D-galactosamine (D-GalN)-induced hepatotoxicity in mice. Acute hepatotoxicity was induced by the intraperitoneal injection of D-GalN into female BALB/c mice. D-GalN (0.75-3.0 g/kg) increased the serum glutamate pyruvate transaminase (s-GPT) activity and the percentage of liver DNA fragmentation, an indicator of hepatotoxicity, after 48 h, in a dose-dependent manner. Furthermore, after D-GalN (3.0 g/kg) administration, increased liver DNA fragmentation was detected biochemically at 24 h, then increased s-GPT activity accompanied by increased liver DNA fragmentation was observed after 48 h. The serum TNF (s-TNF) level and the TNF mRNA expression in the liver after D-GalN (3.0 g/kg, i.p.) administration were examined by an ELISA kit and reverse transcription polymerase chain reaction (RT-PCR), respectively, to investigate the relation between the s-GPT activity and liver DNA fragmentation. The s-TNF level and TNF mRNA expression in the liver after D-GalN (3.0 g/kg) administration were detected earlier than liver DNA fragmentation, then increased with time. However, there was almost no association of caspase-3 activity with the increase in liver DNA fragmentation. Increases in the s-TNF level, TNF mRNA expression and the percentage of DNA fragmentation in the liver and s-GPT activity were inhibited by dexamethasone (Dex; 0.4-2.5 mg/kg, i.p.) in a dose-dependent manner. Based on these findings, it was considered that the intracellular apoptosis signal in D-GalN-induced hepatotoxicity in mice did not depend on caspase-3 activity, and that other signals mediated by TNF may be involved.
Itokazu
Y
Y
Department of Applied Research, Central Research Laboratories, Zeria Pharmaceutical Co., Ltd., Saitama, Japan.
Segawa
Y
Y
Inoue
N
N
Omata
T
T
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology; D017209:Apoptosis; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism*; D053938:DNA Fragmentation / Q000187:drug effects; D003907:Dexamethasone / Q000494:pharmacology; D004347:Drug Interactions; D005260:Female; D005688:Galactosamine / Q000494:pharmacology*; D007371:Interferon-gamma / Q000235:genetics / Q000378:metabolism; D008099:Liver / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D012333:RNA, Messenger / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism*
D000893:Anti-Inflammatory Agents; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D005688:Galactosamine; D003907:Dexamethasone; D007371:Interferon-gamma; C505409:Casp3 protein, mouse; D053148:Caspase 3; D020169:Caspases