title: Nitric oxide induction of IRE1-alpha-dependent CREB phosphorylation in human glioma cells.
abstract: In this study, the function of nitric oxide (NO) in endoplasmic reticulum (ER)-related cell death in human glioma cells was investigated. Treatment of human CRT-MG cells with the NO donor S-nitroso-N-acetyl-d,l-penicillamine (SNAP) and thapsigargin, an ER stress inducer, increased cytosolic Ca(2+) and caused apoptosis in a dose-dependent manner. Expression of the ER-associated molecules inositol-requiring enzyme 1 (IRE1)-alpha, p-eIF, and Ero1-alpha were also elevated in thapsigargin- or NO donor-treated cells. Furthermore, thapsigargin and SNAP treatment increased IRE1-alpha nuclease activity, induced IRE1-alpha/TRAF2 complex formation, and increased p-JNK1/2 levels, suggesting that NO activates the IRE1-alpha/TRAF2/JNK pathway in the ER. Expression of IRE1-alpha increased concomitantly with cAMP responsive element binding protein (CREB) phosphorylation. siRNA knock down of IRE1-alpha reduced phospho-CREB levels and abolished its nuclear translocation. The levels of phospho-CREB and IRE1-alpha increased with NO donor concentration, which resulted in cell death. IRE1-alpha and phospho-CREB levels in glioblastoma U87MG cells were higher than those in normal astrocytes in response to NO. In addition, treatment with the intracellular cytokine interleukin-1beta induced cell death associated with NO and increased IRE1-alpha and p-CREB levels. These data reveal that intracellular NO affects IRE1-alpha-dependent CREB phosphorylation in human glioma cells. Therefore, an IRE1-alpha-dependent phospho-CREB signaling pathway responsive to NO/Ca(2+) may play an important role in regulating ER-related cell death in glioma.
authors.affiliation: Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Republic of Korea. yeonhkim@yonsei.ac.kr
authors.forename: Yeon Hyang
authors.initials: YH
authors.lastname: Kim
authors.forename: Han Seung
authors.initials: HS
authors.lastname: Joo
authors.forename: Doo-Sik
authors.initials: DS
authors.lastname: Kim
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D002118:Calcium / Q000378:metabolism; D002413:Cations, Divalent / Q000378:metabolism; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D004722:Endoribonucleases / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D005910:Glioma / Q000378:metabolism* / Q000473:pathology*; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D009569:Nitric Oxide / Q000494:pharmacology*; D010766:Phosphorylation / Q000187:drug effects; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D026423:S-Nitroso-N-Acetylpenicillamine / Q000494:pharmacology; D019284:Thapsigargin / Q000494:pharmacology
chemical_list: C115163:CREB1 protein, human; D002413:Cations, Divalent; D017362:Cyclic AMP Response Element-Binding Protein; D034741:RNA, Small Interfering; D009569:Nitric Oxide; D019284:Thapsigargin; D026423:S-Nitroso-N-Acetylpenicillamine; C528229:ERN1 protein, human; D017346:Protein Serine-Threonine Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D004722:Endoribonucleases; D002118:Calcium