title: Regulation of the processing and release of tumor necrosis factor alpha in a human macrophage cell line.
abstract: The proteolytic cleavage of a variety of membrane proteins, including pro-tumor necrosis factor alpha (pro-TNF-alpha), is induced by various reagents such as phorbol 12-myristate 13-acetate (PMA). In this study we generated a human macrophage cell line that constitutively produces TNF-alpha, and examined how the processing and release of TNF-alpha are regulated. The processing and release of TNF-alpha were enhanced by PMA through a protein kinase C-dependent pathway. Although only hydroxamate matrix metalloproteinase (MMP) inhibitors inhibited the basal processing and release of TNF-alpha, the PMA-induced processing and release of TNF-alpha were inhibited not only by MMP inhibitors but also by 1,10-phenanthroline, 3,4-dichloroisocoumarin (3,4-DCI), iodoacetamide, and Nalpha-p-tosyl-L-phenylalanine chloromethyl ketone (TPCK). Hydroxamate MMP inhibitors and 1,10-phenanthroline inhibited the processing of TNF-alpha on the cell surface, whereas 3,4-DCI, iodoacetamide, and TPCK inhibited the transport of TNF-alpha to the cell surface. These results suggest that serine and/or cysteine protease(s) may be involved in PMA-induced processing and/or transport to the cell surface.
authors.affiliation: Department of Biomolecular Science, Faculty of Science, Toho University, Chiba, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Nakada-Tsukui
authors.forename: N
authors.initials: N
authors.lastname: Watanabe
authors.forename: Y
authors.initials: Y
authors.lastname: Kobayashi
mesh_terms: D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002478:Cells, Cultured; D010450:Endopeptidases / Q000378:metabolism; D018922:HL-60 Cells; D006801:Humans; D008264:Macrophages / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D011480:Protease Inhibitors / Q000494:pharmacology; D011498:Protein Precursors / Q000235:genetics / Q000378:metabolism; D011499:Protein Processing, Post-Translational / Q000187:drug effects / Q000276:immunology*; D011817:Rabbits; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*
chemical_list: D011480:Protease Inhibitors; D011498:Protein Precursors; D014409:Tumor Necrosis Factor-alpha; C061153:tumor necrosis factor precursor; D010450:Endopeptidases; D013755:Tetradecanoylphorbol Acetate