title: Cholestasis increases tumor necrosis factor-related apoptotis-inducing ligand (TRAIL)-R2/DR5 expression and sensitizes the liver to TRAIL-mediated cytotoxicity.
abstract: Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), a potential chemotherapeutic agent for cancer, is not thought to be hepatotoxic. We have recently demonstrated, however, that bile acids increase TRAIL-R2/DR5 expression in a human liver cell line and render these cells susceptible to TRAIL-mediated apoptosis. These data suggest TRAIL may be hepatotoxic in cholestasis. The aim of this study was to directly assess TRAIL hepatotoxicity in bile duct-ligated mice, a model of extrahepatic cholestasis. Bile duct-ligated mice (3 days) were used for these studies. TRAIL-R2/DR5 expression was assessed by real-time and immunoblot analysis. The TRAIL death-inducing signaling complex (DISC) was evaluated by immunoprecipitation and immunoblot techniques. Bile duct ligation increased both liver TRAIL-R2/DR5 mRNA and protein expression (>10-fold). Following TRAIL administration (60 microg/mouse, i.v.) to bile duct ligation (BDL) mice, terminal deoxynucleotidyl transferase dUTP nick-end labeling-positive hepatocytes, liver tissue caspase 3-like activity, and serum alanine aminotransferase values increased significantly compared with vehicle-treated BDL mice. The effect of TRAIL on the liver was direct, as the TRAIL DISC (Fas-associated death domain and procaspase 8 protein) was detected in liver tissue. TRAIL-mediated hepatocyte apoptosis in bile duct-ligated mice was associated with significant hepatotoxicity, as assessed by histopathology, although there was no animal mortality. In conclusion, these data define conditions under which TRAIL is hepatotoxic.
authors.affiliation: Division of Gastroenterology and Hepatology, Mayo Medical School, Clinic, and Foundation, 200 First Street SW, Rochester, MN 55905, USA.
authors.forename: Hajime
authors.initials: H
authors.lastname: Higuchi
authors.forename: Steven F
authors.initials: SF
authors.lastname: Bronk
authors.forename: Makiko
authors.initials: M
authors.lastname: Taniai
authors.forename: Ali
authors.initials: A
authors.lastname: Canbay
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Gores
mesh_terms: D000410:Alanine Transaminase / Q000378:metabolism; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D051017:Apoptosis Regulatory Proteins; D015153:Blotting, Western; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D002779:Cholestasis / Q000378:metabolism*; D003135:Common Bile Duct / Q000502:physiology; D022781:Hepatocytes / Q000187:drug effects / Q000473:pathology; D020287:In Situ Nick-End Labeling; D008099:Liver / Q000378:metabolism / Q000473:pathology*; D008297:Male; D008562:Membrane Glycoproteins / Q000633:toxicity*; D051379:Mice; D008810:Mice, Inbred C57BL; D011233:Precipitin Tests; D012333:RNA, Messenger / Q000096:biosynthesis; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D018124:Receptors, Tumor Necrosis Factor / Q000096:biosynthesis*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000502:physiology; D053221:TNF-Related Apoptosis-Inducing Ligand; D014409:Tumor Necrosis Factor-alpha / Q000633:toxicity*
chemical_list: D051017:Apoptosis Regulatory Proteins; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D018124:Receptors, Tumor Necrosis Factor; D053221:TNF-Related Apoptosis-Inducing Ligand; C505639:TNFRSF10B protein, human; C505653:TNFSF10 protein, human; C505640:Tnfrsf10b protein, mouse; C505654:Tnfsf10 protein, mouse; D014409:Tumor Necrosis Factor-alpha; D000410:Alanine Transaminase; C505407:CASP3 protein, human; C505409:Casp3 protein, mouse; D053148:Caspase 3; D020169:Caspases