Tumor necrosis factor alpha-induced activation of downstream NF-kappaB site of the promoter mediates epithelial ICAM-1 expression and monocyte adhesion. Involvement of PKCalpha, tyrosine kinase, and IKK2, but not MAPKs, pathway.
TNF-alpha induced an increase in intercellular adhesion molecule-1 (ICAM-1) expression in human A549 epithelial cells and immunofluorescence staining confirmed this result. The enhanced ICAM-1 expression was shown to increase the adhesion of U937 cells to A549 cells. Tyrosine kinase inhibitors (genistein or tyrphostin 23) or phosphatidylcholine-specific phospholipase C (PC-PLC) inhibitor (D 609) attenuated TNF-alpha-induced ICAM-1 expression. TNF-alpha produced an increase in protein kinase C (PKC) activity and this effect was inhibited by D 609. PKC inhibitors (staurosporine, Ro 31-8220, calphostin C, or Go 6976) also inhibited TNF-alpha-induced response. 12-O-Tetradecanoylphorbol-13-acetate (TPA), a PKC activator, stimulated ICAM-1 expression, this effect was inhibited by genistein or tyrphostin 23. Treatment of cells with TNF-alpha resulted in stimulation of p44/42 MAPK, p38, and JNK. However, TNF-alpha-induced ICAM-1 expression was not affected by either MEK inhibitor, PD 98059, or p38 inhibitor, SB 203580. A cell-permeable ceramide analog, C(2) ceramide, also stimulated the activation of these three MAPKs, but had no effect on ICAM-1 expression. NF-kappaB DNA-protein binding and ICAM-1 promoter activity were enhanced by TNF-alpha and these effects were inhibited by D 609, calphostin C, or tyrphostin 23, but not by PD 98059 or SB 203580. TPA also stimulated NF-kappaB DNA-protein binding and ICAM-1 promoter activity, these effects being inhibited by genistein or tyrphostin 23. TNF-alpha- or TPA-induced ICAM-1 promoter activity was inhibited by dominant negative PKCalpha or IKK2, but not IKK1 mutant. IKK activity was stimulated by both TNF-alpha and TPA, and these effects were inhibited by Ro 31-8220 or tyrphostin 23. These data suggest that, in A549 cells, TNF-alpha activates PC-PLC to induce activation of PKCalpha and protein tyrosine kinase, resulting in the stimulation of IKK2, and NF-kappaB in the ICAM-1 promoter, then initiation of ICAM-1 expression and neutrophil adhesion. However, activation of p44/42 MAPK, p38, and JNK is not involved in this event.
Chen
C
C
Department of Pharmacology, College of Medicine, National Taiwan University, Number 1, Jen-Ai Road, First Section, 10018, Taipei, Taiwan, ROC. ccchen@ha.mc.ntu.edu.tw
Chou
C
C
Sun
Y
Y
Huang
W
W
D002448:Cell Adhesion; D002467:Cell Nucleus / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004847:Epithelial Cells / Q000187:drug effects / Q000276:immunology*; D006801:Humans; D051550:I-kappa B Kinase; D018799:Intercellular Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism*; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology; D020935:MAP Kinase Signaling System; D009000:Monocytes / Q000276:immunology*; D009154:Mutation; D016328:NF-kappa B / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology; D051571:Protein Kinase C-alpha; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000502:physiology; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000502:physiology; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D010738:Type C Phospholipases / Q000037:antagonists & inhibitors; D020298:U937 Cells
D004791:Enzyme Inhibitors; D007527:Isoenzymes; D016328:NF-kappa B; D014409:Tumor Necrosis Factor-alpha; D018799:Intercellular Adhesion Molecule-1; D011505:Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases; C496559:CHUK protein, human; D051550:I-kappa B Kinase; C496560:IKBKB protein, human; C496565:IKBKE protein, human; C496628:PRKCA protein, human; D011493:Protein Kinase C; D051571:Protein Kinase C-alpha; D010738:Type C Phospholipases