title: Activation of p38 mitogen-activated protein kinase and nuclear factor-kappaB in tumour necrosis factor-induced eotaxin release of human eosinophils.
abstract: The CC chemokine eotaxin is a potent eosinophil-specific chemoattractant that is crucial for allergic inflammation. Allergen-induced tumour necrosis factor (TNF) has been shown to induce eotaxin synthesis in eosinophils. Nuclear factor-kappaB (NF-kappaB) and mitogen-activated protein kinases (MAPK) have been found to play an essential role for the eotaxin-mediated eosinophilia. We investigated the modulation of NF-kappaB and MAPK activation in TNF-induced eotaxin release of human eosinophils. Human blood eosinophils were purified from fresh buffy coat using magnetic cell sorting. NF-kappaB pathway-related genes were evaluated by cDNA expression array system. Degradation of IkappaBalpha and phosphorylation of MAPK were detected by Western blot. Activation of NF-kappaB was determined by electrophoretic mobility shift assay. Eotaxin released into the eosinophil culture medium was measured by ELISA. TNF was found to up-regulate the gene expression of NF-kappaB and IkappaBalpha in eosinophils. TNF-induced IkappaBalpha degradation was inhibited by the proteasome inhibitor N-cbz-Leu-Leu-leucinal (MG-132) and a non-steroidal anti-inflammatory drug sodium salicylate (NaSal). Using EMSA, both MG-132 and NaSal were found to suppress the TNF-induced NF-kappaB activation in eosinophils. Furthermore, TNF was shown to induce phosphorylation of p38 MAPK time-dependently but not extracellular signal-regulated kinases (ERK). Inhibition of NF-kappaB activation and p38 MAPK activity decreased the TNF-induced release of eotaxin from eosinophils. These results indicate that NF-kappaB and p38 MAPK play an important role in TNF-activated signalling pathway regulating eotaxin release by eosinophils. They have also provided a biochemical basis for the potential of using specific inhibitors of NF-kappaB and p38 MAPK for treating allergic inflammation.
authors.affiliation: Department of Chemical Pathology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, NT, Hong Kong.
authors.forename: C K
authors.initials: CK
authors.lastname: Wong
authors.forename: J P
authors.initials: JP
authors.lastname: Zhang
authors.forename: W K
authors.initials: WK
authors.lastname: Ip
authors.forename: C W K
authors.initials: CW
authors.lastname: Lam
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D002478:Cells, Cultured; D054413:Chemokine CCL11; D019742:Chemokines, CC / Q000378:metabolism*; D002631:Chemotactic Factors, Eosinophil / Q000378:metabolism*; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D004268:DNA-Binding Proteins / Q000378:metabolism; D004789:Enzyme Activation; D004804:Eosinophils / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D020869:Gene Expression Profiling; D006801:Humans; D020672:I-kappa B Proteins; D007093:Imidazoles / Q000494:pharmacology; D007976:Leupeptins / Q000494:pharmacology; D020935:MAP Kinase Signaling System; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000378:metabolism*; D011725:Pyridines / Q000494:pharmacology; D012980:Sodium Salicylate / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D048051:p38 Mitogen-Activated Protein Kinases
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; C515456:CCL11 protein, human; D054413:Chemokine CCL11; D019742:Chemokines, CC; D002631:Chemotactic Factors, Eosinophil; D015853:Cysteine Proteinase Inhibitors; D004268:DNA-Binding Proteins; D020672:I-kappa B Proteins; D007093:Imidazoles; D007976:Leupeptins; D016328:NF-kappa B; C000606204:NFKBIA protein, human; D011725:Pyridines; D014409:Tumor Necrosis Factor-alpha; D000072000:NF-KappaB Inhibitor alpha; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; C093642:SB 203580; C072553:benzyloxycarbonylleucyl-leucyl-leucine aldehyde; D012980:Sodium Salicylate