title: Proinflammatory cytokine-induced cellular senescence of biliary epithelial cells is mediated via oxidative stress and activation of ATM pathway: a culture study.
abstract: Cellular senescence is reportedly involved in cholangiopathy in primary biliary cirrhosis and oxidative stress is proposed as a pathogenetic factor in biliary epithelial cells (BECs). This study investigated the involvement of proinflammatory cytokines (IFN-beta, IFN-gamma and TNF-alpha) and ataxia telangiectasia-mutated (ATM)/p53/ p21(WAF1/Cip1) pathway with respect to oxidative stress in cellular senescence of BECs. H(2)O(2) treatment (oxidative stress) induced phosphorylation (activation) of ATM and p53 and also p21(WAF1/Cip1) expression in BECs. Treatment with inflammatory cytokines generated reactive oxygen species (ROS) in cultured BECs followed by activation of the ATM/p53/p21(WAF1/Cip1) pathway and the induction of cellular senescence. Pre-treatment with ATM inhibitor (2-aminopurine) and antioxidant (N-acetylcysteine) significantly blocked the cellular senescence of BECs induced by oxidative stress or inflammatory cytokines. In conclusion, proinflammatory cytokines induce ROS generation and activate the ATM/p53/p21(WAF1/Cip1) pathway, followed by biliary epithelial senescence. This senescent process may be involved in the development of destructive cholangiopathy in humans.
authors.affiliation: Department of Human Pathology, Kanazawa University Graduate School of Medicine, Kanazawa, Japan.
authors.forename: Motoko
authors.initials: M
authors.lastname: Sasaki
authors.forename: Hiroko
authors.initials: H
authors.lastname: Ikeda
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Sato
authors.forename: Yasuni
authors.initials: Y
authors.lastname: Nakanuma
mesh_terms: D015075:2-Aminopurine / Q000494:pharmacology; D000111:Acetylcysteine / Q000494:pharmacology; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D064007:Ataxia Telangiectasia Mutated Proteins; D001653:Bile Ducts, Intrahepatic / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D018797:Cell Cycle Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D002478:Cells, Cultured; D016922:Cellular Senescence; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism; D016207:Cytokines / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004847:Epithelial Cells / Q000187:drug effects / Q000201:enzymology*; D006861:Hydrogen Peroxide / Q000494:pharmacology; D018836:Inflammation Mediators / Q000378:metabolism*; D016899:Interferon-beta / Q000378:metabolism; D007371:Interferon-gamma / Q000378:metabolism; D051379:Mice; D016877:Oxidants / Q000494:pharmacology; D018384:Oxidative Stress / Q000187:drug effects; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D015398:Signal Transduction; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D025521:Tumor Suppressor Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*
chemical_list: D000975:Antioxidants; C493957:Cdkn1a protein, mouse; D018797:Cell Cycle Proteins; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016207:Cytokines; D004268:DNA-Binding Proteins; D004791:Enzyme Inhibitors; D018836:Inflammation Mediators; D016877:Oxidants; D017382:Reactive Oxygen Species; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D016159:Tumor Suppressor Protein p53; D025521:Tumor Suppressor Proteins; D015075:2-Aminopurine; D016899:Interferon-beta; D007371:Interferon-gamma; D006861:Hydrogen Peroxide; C576324:ATM protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; C576325:Atm protein, mouse; D017346:Protein Serine-Threonine Kinases; D000111:Acetylcysteine