Role of cathepsin B-mediated apoptosis in fulminant hepatic failure in mice

AIM: To investigate the pathogenic role of cathepsin B and the protective effect of a cathepsin B inhibitor (CA074Me) 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 timedependent 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). CONCLUSION: 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.

Hepatoprotective effects of cathepsin B inhibitor on acute hepatic failure induced by lipopolysaccharide/D-galactosamine in mice

BACKGROUND:Increasing evidence suggests that the inactivation of cathepsin B attenuates hepatocyte apoptosis and liver damage.This study aimed to investigate the protective effects of a cathepsin B inhibitor(CA-074me) on lipopolysaccharide(LPS)/D-galactosamine(D-GalN)-induced acute hepatic failure(AHF) in mice.METHODS:Mice were intraperitoneally injected with a combination of LPS/D-GalN to induce AHF with or without CA-074me pretreatment.The cumulative survival rates were calculated 48 hours after the induction of AHF.As well as changes in biochemical indicators and liver histology,hepatocyte apoptosis was assessed using a TUNEL method.Serum tumor necrosis factor-α(TNF-α) production,caspase-3,caspase-8,and caspase-9 activity was evaluated.Cytosolic cytochrome c and Bcl-2 expression were measured by Western blotting.RESULTS:The marked elevation in serum aminotransferase activity and prothrombin time found in LPS/D-GalN-treated mice was significantly improved by pretreatment with CA074me.The efficacy of CA-074me was also confirmed by histological analysis and TUNEL assay.The survival rate significantly improved in LPS/D-GalN-induced mice given CA-074me compared with untreated mice.LPS/D-GalNinduced caspase-3 and caspase-9 activation was remarkably suppressed by CA-074me.However,the increased levels of serum TNF-α and elevated caspase-8 activity in AHF mice were not significantly reduced by CA-074me.Moreover,CA074me sharply reduced the increased expression of cytosolic cytochrome c and markedly augmented Bcl-2 expression.CONCLUSION:These results suggest that CA-074me has a protective effect in acute hepatic failure induced by LPS/D-GalN.

The therapeutic effect of CORM-3 on acute liver failure induced by lipopolysaccharide/D- galactosamine in mice

BACKGROUND： Acute liver failure （ALF） is a severe and life- threatening clinical syndrome resulting in a high mortality and extremely poor prognosis. Recently, a water-soluble CO-releas- ing molecule （CORM-3） has been shown to have anti-inflam- matory effect. The present study was to investigate the effect of CORM-3 on ALF and elucidate its underlying mechanism. METHODS： ALF was induced by a combination of LPS/D-GalN in mice which were treated with CORM-3 or inactive CORM-3 （iCORM-3）. The efficacy of CORM-3 was evaluated based on survival, liver histopathology, serum aminotransferase activi- ties （ALT and AST） and total bilirubin （TBiL）. Serum levels of inflammatory cytokines （TNF-α, IL-6, IL-1β and IL-10） and liver immunohistochemistry of NF-KB-p65 were determined; the expression of inflammatory mediators such as iNOS, COX-2 and TLR4 was measured using Western blotting. RESULTS： The pretreatment with CORM-3 significantly improved the liver histology and the survival rate of mice compared with the controls; CORM-3 also decreased the levels of ALT, AST and TBiL. Furthermore, CORM-3 significantly inhibited the increased concentration of pro-inflammatory cytokines （TNF-α, IL-6 and IL-1β） and increased the anti-in- flammatory cytokine （IL-10） productions in ALF mice. More- over, CORM-3 significantly reduced the increased expression of iNOS and TLR4 in liver tissues and inhibited the nudear ex- pression of NF-KB-p65. CORM-3 had no effect on the increased expression of COX-2 in the ALF mice. An iCORM-3 failed to prevent acute liver damage induced by LPS/D-GalN. CONCLUSION： These findings provided evidence that CORM-3 may offer a novel alternative approach for the management of ALF through anti-inflammatory functions.

The roles of serum IL-18, IL-10, TNF-α and sIL-2R in patients with chronic hepatitis C

To identify the roles of serum IL-18, IL- 10, TNF-α and sIL-2R in the pathogenisis of chronic hepatitis C and the effects of interferon on the men- tioned serum cytokines. Methods: The levels of IL-18, IL-10, TNF-α and sIL-2R were detected in 10 healthy controls, 24 a- symptomatic HCV carriers, and 27 patients with chronic hepatitis C (before and after IFN treatment) by enzyme linked immunosorbent assay (ELISA). Results: The levels of IL-18, IL-10, TNF-α and sIL- 2R in the patients of chronic hepatitis C were higher than those in the healthy controls (P<0.05) and in asymptomatic HCV carriers (P<0. 05). The values of the mentioned cytokines showed a significant posi- tive correlation to GPT. The levels of the mentioned cytokines decreased obviously after IFN treatment (P <0. 05), while the serum levels of IL-10 and sIL-2R reduced in sequence in no-response group, partial- response group and complete-response group. Conclusions: IL-18, IL-10, TNF-α and sIL-2R co- participate in the pathogenisis of chronic hepatitis C, and are used to evaluate the effect of IFN on the im- mune state of organisms, and IL-10 and sIL-2R are important for predicting the anti-viral efficacy of IFN.