title: Arachidonic acid-selective cytosolic phospholipase A2 is crucial in the cytotoxic action of tumor necrosis factor.
abstract: The role of phospholipase A2 (PLA2) in the cytotoxic action of tumor necrosis factor (TNF) was examined. Recently, we described the characterization of TNF-resistant sublines isolated from TNF-sensitive cell line L929 (Hayakawa, M., Oku, N., Takagi, T., Hori, T., Shibamoto, S., Yamanaka, Y., Takeuchi, K., Tsujimoto, M., and Ito, F. (1991) Cell Struct. Funct. 16, 333-340). The most remarkable features of these TNF-resistant sublines were the defects in TNF-stimulated arachidonate metabolism. In this study, we characterized the PLA2 activities of these sublines and found a significant decrease in the activity in one of the TNF-resistant sublines, C12 cells. The enzymological features, such as Ca2+ requirement and substrate specificity, suggested that the high molecular weight arachidonoyl-selective cytosolic PLA2 (cPLA2) was involved in the TNF action. Northern hybridization analysis demonstrated the reduced expression of high molecular weight cPLA2 in C12 cells. Furthermore, expression of a cloned cPLA2 cDNA in C12 cells increased the sensitivity of cells to the TNF cytotoxicity. These results indicate the crucial role of the high molecular weight cPLA2 in the TNF-induced cytolysis.
authors.affiliation: Department of Biochemistry, Faculty of Pharmaceutical Sciences, Setsunan University, Osaka, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Hayakawa
authors.forename: N
authors.initials: N
authors.lastname: Ishida
authors.forename: K
authors.initials: K
authors.lastname: Takeuchi
authors.forename: S
authors.initials: S
authors.lastname: Shibamoto
authors.forename: T
authors.initials: T
authors.lastname: Hori
authors.forename: N
authors.initials: N
authors.lastname: Oku
authors.forename: F
authors.initials: F
authors.lastname: Ito
authors.forename: M
authors.initials: M
authors.lastname: Tsujimoto
mesh_terms: D000818:Animals; D016718:Arachidonic Acid / Q000378:metabolism*; D001483:Base Sequence; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology; D002470:Cell Survival / Q000187:drug effects*; D003001:Cloning, Molecular; D006801:Humans; D007700:Kinetics; D007739:L Cells; D051379:Mice; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D010741:Phospholipases A / Q000235:genetics / Q000378:metabolism*; D054467:Phospholipases A2; D010957:Plasmids; D011061:Poly A / Q000235:genetics / Q000302:isolation & purification; D016133:Polymerase Chain Reaction; D012313:RNA / Q000235:genetics / Q000302:isolation & purification; D012333:RNA, Messenger; D011994:Recombinant Proteins / Q000378:metabolism / Q000633:toxicity; D013379:Substrate Specificity; D014158:Transcription, Genetic; D014409:Tumor Necrosis Factor-alpha / Q000633:toxicity*
chemical_list: D009838:Oligodeoxyribonucleotides; D012333:RNA, Messenger; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D011061:Poly A; D016718:Arachidonic Acid; D012313:RNA; D010741:Phospholipases A; D054467:Phospholipases A2; D002118:Calcium