title: Role of calcium in tumor necrosis factor-alpha production by activated macrophages.
abstract: The role of calcium in the production of tumor necrosis factor-alpha (TNF-alpha) by the lipopolysaccharide (LPS)-stimulated macrophage cell line, J774.1, was investigated. Flow cytometric measurement of intracellular calcium concentration ([Ca]i) using 2-(3,6-bis(acetyl-oxy)-2,7-dichloro-9H-xanthen-9-yl)benzoic acid (fluo-3)-loaded J774.1 cells revealed that LPS at more than 0.1 microgram/ml increased [Ca]i transiently in the presence or absence of serum, and that a mixture of a calcium chelator, ethyleneglycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA), and a calcium release blocker from intracellular store sites, 8-(diethylamino)-octyl-3,4,5-trimethoxybenzoate hydrochloride (TMB-8), inhibited the [Ca]i response induced by LPS. In concordance with this, production of TNF-alpha was inhibited by EGTA and/or TMB-8. These reagents also reduced the level of TNF-alpha mRNA significantly. These results indicate that the transient increase of [Ca]i plays a role in LPS-induced expression of TNF-alpha by the macrophage cell line.
authors.affiliation: Department of Biomolecular Science, Faculty of Science, Toho University, Chiba.
authors.forename: N
authors.initials: N
authors.lastname: Watanabe
authors.forename: J
authors.initials: J
authors.lastname: Suzuki
authors.forename: Y
authors.initials: Y
authors.lastname: Kobayashi
mesh_terms: D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002460:Cell Line; D004533:Egtazic Acid / Q000494:pharmacology; D005707:Gallic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology; D008262:Macrophage Activation; D008264:Macrophages / Q000378:metabolism*; D051379:Mice; D012333:RNA, Messenger / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis*
chemical_list: D008070:Lipopolysaccharides; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D000001:Calcimycin; D004533:Egtazic Acid; C006014:8-(N,N-diethylamino)octyl-3,4,5-trimethoxybenzoate; D005707:Gallic Acid; D002118:Calcium