AIM: To investigate a pathophysiological role of cathepsin W (CatW), a putative thiol-dependent cysteine protease,which is specifically expressed in cytotoxic lymphocytes,in different types of chronic inflammation of the gastric mucosa.METHODS: Gastric and duodenal biopsies of patients with Helicobacter pylori ( H pylori)-associated active gastritis ( Hp,n = 19), chemically induced reactive gastritis (CG, n = 17),autoimmune atrophic gastritis (AIG, n = 20), lymphocytic corpus gastritis (LG, n = 29), celiac disease (CD, n = 10),and corresponding controls (n = 24) were analyzed by immunohistochemistry for the expression of CatW and CD45. Furthermore, immunohistochemical double staining with anti-CD3 and anti-cathepsin was performed for the samples of AIG.RESULTS: Median values of CatW-expressing cells among CD45-positive immune cells were between 2% and 6% for normal gastric mucosa, CG, and LG, whereas the corresponding value was significantly increased for AIG (24.7%, P＜0.001) and significantly decreased for HP (0.7%, P＜0.05). Double staining with anti-CD3 and antiCatW antibodies revealed that ＞90% of CatW-expressing cells in gastric mucosa of AIG were T cells. Duodenal mucosa had significantly more CatW/CD45-positive cells than normal gastric mucosa (median: 17.8% vs 2%, P＜0.01).The corresponding proportion of CatW/CD45-positive cells was decreased in CD compared to duodenal mucosa (median: 2.1% vs 17.8%, P＜0.05).CONCLUSION: The opposite findings regarding the presence of CatW-positive cells in AIG (increase) and CD (decrease) reflects the different cellular composition of immune cells involved in the pathogenesis of these diseases.
AIM:To analyze the role of CYLD for receptor-mediated cell death of murine hepatocytes in acute liver injury models.METHODS:Hepatocyte cell death in CYLD knockout mice(CYLD-/-)was analyzed by application of liver injury models for CD95-(Jo2)and tumor necrosis factor(TNF)-α-[D-Gal N/lipopolysaccharide(LPS)]induced apoptosis.Liver injury was assessed by measurement of serum transaminases and histological analysis.Apoptosis induction was quantified by cleaved PARP staining and Western blotting of activated caspases.Nuclear factor(NF)-κB,ERK,Akt and jun amino-terminal kinases signaling were assessed.Primary Hepatocytes were isolated by two step-collagenase perfusion and treated with recombinant TNF-αand with the CD95-ligand Jo2.Cell viability was analyzed by MTT-assay.RESULTS:Livers of CYLD-/-mice showed increased anti-apoptotic NF-κB signaling.In both applied liver injury models CYLD-/-mice showed a significantly reduced apoptosis sensitivity.After D-Gal N/LPS treatment CYLD-/-mice exhibited significantly lower levels of alanine aminotransferase(ALT)(295 U/L vs 859 U/L,P<0.05)and aspartate aminotransferase(AST)(560 U/L vs 1025 U/L,P<0.01).After Jo injection CYLD-/-mice showed 2-fold lower ALT(50 U/L vs 110 U/L,P<0.01)and lower AST(250 U/L vs 435 U/L,P<0.01)serumlevels compared to WT mice.In addition,isolated CYLD-/-primary murine hepatocytes(PMH)were less sensitive towards death receptor-mediated apoptosis and showed increased levels of Bcl-2,XIAP,c IAP1/2,survivin and c-FLIP expression upon TNF-and CD95-receptor triggering,respectively.Inhibition of NF-κB activation by the inhibitor of NF-κB phosphorylation inhibitor BAY 11-7085 inhibited the expression of antiapoptotic proteins and re-sensitized CYLD-/-PMH towards TNF-and CD95-receptor mediated cell death.CONCLUSION:CYLD is a central regulator of apoptotic cell death in murine hepatocytes by controlling NF-κB dependent anti-apoptotic signaling.
