Protein kinases negatively affect nuclear factor-kappa B activation by tumor necrosis factor-alpha at two different stages in promyelocytic HL60 cells.
HL60 and EL4 cells incubated with tumor necrosis factor-alpha (TNF-alpha) plus staurosporin, a potent inhibitor of protein kinases, showed at least 2-fold increased levels of nuclear factor-kappa B (NF-kappa B) activity compared with TNF-alpha alone both during rapid NF-kappa B activation from the cytosolic pool and protein synthesis-dependent NF-kappa B activation. NF-kappa B activation by phorbol 12-myristate 13-acetate (PMA) and interleukin-1 was inhibited by staurosporin. Staurosporin treatment hardly affected the TNF-alpha-induced increase in mRNA for the p51 subunit of NF-kappa B but interfered with any phorbol ester (PMA)-induced increase in p51 mRNA. Thus, induction of NF-kappa B and p51 mRNA by TNF-alpha was not mediated by a staurosporin-sensitive factor, but NF-kappa B activation by TNF-alpha was even reduced by action of a staurosporin-sensitive factor. Decreased levels of phosphorylation of TNF-R alpha (TNF receptor type alpha) after staurosporin-treatment correlated with increased induction of NF-kappa B by TNF-alpha. Staurosporin-treatment did not affect TNF-R levels. Although protein kinase C stimulation by PMA inhibited NF-kappa B activation by TNF-alpha, its action mechanism may be different from that of the staurosporin-sensitive factor. PMA induced disappearance of TNF-R alpha by shedding into the surrounding medium, with kinetics similar to those of its inhibition of NF-kappa B activation by TNF-alpha. Phosphorylation may not mediate receptor shedding, since PMA treatment did not detectably affect TNF-R alpha phosphorylation.
Hohmann
H P
HP
Pharmaceutical Research Department, F. Hoffmann-La Roche Ltd., Basel, Switzerland.
Remy
R
R
Aigner
L
L
Brockhaus
M
M
van Loon
A P
AP
D000470:Alkaloids / Q000494:pharmacology; D015152:Blotting, Northern; D002460:Cell Line; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology; D007700:Kinetics; D015473:Leukemia, Promyelocytic, Acute; D046911:Macromolecular Substances; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D047428:Protein Kinase Inhibitors; D011494:Protein Kinases / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D012334:RNA, Neoplasm / Q000235:genetics / Q000302:isolation & purification; D011994:Recombinant Proteins / Q000494:pharmacology; D019311:Staurosporine; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D000470:Alkaloids; D007375:Interleukin-1; D046911:Macromolecular Substances; D016328:NF-kappa B; D047428:Protein Kinase Inhibitors; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D011494:Protein Kinases; D019311:Staurosporine; D013755:Tetradecanoylphorbol Acetate