Signalling to translational activation of tumour necrosis factor-alpha expression in human THP-1 cells.
Monocytic THP-1 cells expressed tumour necrosis factor-alpha (TNF-alpha) mRNA, but hardly any detectable TNF-alpha protein and a partially activated MAP kinase ERK-2 in the unstimulated state. Stimulation with phorbol ester led to expression of TNF-alpha protein without significant changes in mRNA, a response that was sensitive to the MEK-1/2 inhibitors PD98059 and U0126. A calcium signal also led to expression of TNF-alpha protein, but now accompanied by a rapid increase in mRNA. A synergistic effect between phorbol ester and calcium ionophore was evident at the level of TNF-alpha protein, but not its mRNA. Stimulation with anisomycin led to a TNF-alpha expression that was sensitive to the p38 inhibitor SB203580. Actinomycin D lowered TNF-alpha mRNA in a similar way as PD98059 but was less inhibitory on PMA- or anisomycin-induced formation of TNF-alpha, thus confirming that these agents acted by causing translational derepression. Thus, in THP-1 cells MAP kinase pathways involving MEK-1/2 and possibly ERK-2 as well as the human p38 analogue were essential for basal TNF-alpha mRNA expression and translational activation.
Andersson
K
K
Department of Cell and Molecular Biology, Section for Molecular Pathogenesis, Lund University, S-221 00, Lund, Sweden.
Sundler
R
R
D000841:Anisomycin / Q000494:pharmacology; D015152:Blotting, Northern; D015153:Blotting, Western; D002070:Butadienes / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D002460:Cell Line; D003513:Cycloheximide / Q000494:pharmacology; D003609:Dactinomycin / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D007476:Ionophores / Q000494:pharmacology; D020935:MAP Kinase Signaling System; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009000:Monocytes / Q000378:metabolism; D009570:Nitriles / Q000494:pharmacology; D014176:Protein Biosynthesis; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D011725:Pyridines / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D015398:Signal Transduction; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis / Q000378:metabolism*; D048051:p38 Mitogen-Activated Protein Kinases
D002070:Butadienes; D004791:Enzyme Inhibitors; D005419:Flavonoids; D007093:Imidazoles; D007476:Ionophores; D009570:Nitriles; D011500:Protein Synthesis Inhibitors; D011725:Pyridines; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; C113580:U 0126; D003609:Dactinomycin; D000841:Anisomycin; D003513:Cycloheximide; D019950:Mitogen-Activated Protein Kinase 1; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D013755:Tetradecanoylphorbol Acetate; C093642:SB 203580; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one; D002118:Calcium