Role of cathepsin B-mediated apoptosis in fulminant hepatic failure in mice.
OBJECTIVE
To investigate the pathogenic role of cathepsin B and the protective effect of a cathepsin B inhibitor (CA-074Me) in fulminant hepatic failure in mice.


METHODS
LPS/D-Gal N was injected into mice of the model group to induce fulminant hepatic failure; the protected group was administered CA-074me for 30 min before LPS/D-Gal N treatment; the normal group was given isochoric physiologic saline. Liver tissue histopathology was determined with HE at 2, 4, 6 and 8 h after Lps/D-Gal injection. Hepatocyte apoptosis was examined by TUNEL method. The expression of cathepsin B in liver tissues was investigated by immunohistochemistry, Western blot and RT-PCR.


RESULTS
Compared with the normal group, massive typical hepatocyte apoptosis occurred in the model group; the number of apoptotic cells reached a maximum 6 h after injection. The apoptosis index (AI) in the protected group was clearly reduced (30.4 +/- 2.8 vs 18.1 +/- 2.0, P < 0.01 ). Cathepsin B activity was markedly increased in drug-treated mice compared with the normal group (P < 0.01). Incubation with LPS/D-Gal N at selected time points resulted in a time-dependent increase in cathepsin B activity, and reached a maximum by 8 h. The expression of cathepsin B was significantly decreased in the protected group (P < 0.01).


CONCLUSIONS
Cathepsin B plays an essential role in the pathogenesis of fulminant hepatic failure, and the cathepsin B inhibitor CA-074me can attenuate apoptosis and liver injury.
Yan
Bing-Zhu
BZ
Department of Infectious Diseases, Second Clinical Hospital of Harbin Medical University, Harbin 150086, China.
Wang
Wei
W
Chen
Li-Yan
LY
Bi
Man-Ru
MR
Lu
Yan-Jie
YJ
Li
Bao-Xin
BX
Yang
Bao-Shan
BS
D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D002401:Cathepsin B / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D017931:DNA Primers; D004151:Dipeptides / Q000627:therapeutic use; D005688:Galactosamine / Q000494:pharmacology; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D008070:Lipopolysaccharides / Q000494:pharmacology; D008099:Liver / Q000187:drug effects / Q000201:enzymology / Q000473:pathology; D017114:Liver Failure, Acute / Q000188:drug therapy / Q000201:enzymology / Q000503:physiopathology*; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D012313:RNA / Q000235:genetics / Q000302:isolation & purification; D020133:Reverse Transcriptase Polymerase Chain Reaction
C400541:CA 074 methyl ester; D017931:DNA Primers; D004151:Dipeptides; D008070:Lipopolysaccharides; D012313:RNA; D005688:Galactosamine; D002401:Cathepsin B; C533915:Ctsb protein, mouse