Role of p38 mitogen-activated protein kinase and extracellular signal-regulated protein kinase kinase in adenosine A2B receptor-mediated interleukin-8 production in human mast cells.
The endogenous nucleoside adenosine is thought to play a role in the pathophysiology of asthma by stimulating mast cells. We previously showed that the human mast cell line HMC-1 expresses A2A and A2B receptors, and that both receptors activate adenylate cyclase via Gs-protein but that only A2B receptors are also coupled to phospholipase C via Gq proteins. Stimulation of A2B but not A2A receptors induced production of interleukin-8 (IL-8) from HMC-1 cells. The mechanism by which adenosine promotes IL-8 synthesis has not been defined. In this study, we tested the hypothesis that mitogen-activated protein kinase (MAPK) signaling pathways are involved in this process. Stimulation of HMC-1 with the stable adenosine analog NECA (5'-N-ethylcarboxamidoadenosine) activated p21(ras) and both p42 and p44 isoforms of extracellular signal-regulated kinase (ERK). NECA (10 microM) induced a 1.9 +/- 0. 06-fold increase in ERK activity, whereas 10 microM of the selective A2A agonist CGS 21680 (4-((N-ethyl-5'-carbamoyladenos-2-yl)-aminoethyl)-phenylpropionic acid) had no effect. NECA, in parallel with the activation of ERK, also stimulated the p46 isoform of c-Jun N-terminal kinase (MEK) and p38 MAPK. Furthermore, the selective MAPK/ERK kinase 1 inhibitor PD 98059 (2'-amino-3'-methoxyflavone), and p38 MAPK inhibitors SB 202190 (4-(4-fluorophenyl)-2-(4-hydroxyphenyl)-5-(4-pyridyl)1H-imidazole) and SB 203580 (4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)1H- imidaz ole) blocked A2B receptor-mediated production of IL-8. These results indicate that extracellular adenosine can regulate ERK, c-Jun N-terminal kinase, and p38 MAPK signaling cascades and that activation of ERK and p38 MAPK pathways are essential steps in adenosine A2B receptor-dependent stimulation of IL-8 production in HMC-1.
Feoktistov
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Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University, Nashville, Tennessee 37232-6300, USA. Igor.Feoktiskov@mcmail.vanderbilt.edu
Goldstein
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Biaggioni
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D000241:Adenosine / Q000378:metabolism; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism*; D002478:Cells, Cultured; D004789:Enzyme Activation; D006801:Humans; D016209:Interleukin-8 / Q000096:biosynthesis* / Q000378:metabolism; D048031:JNK Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4; D008407:Mast Cells / Q000378:metabolism*; D020929:Mitogen-Activated Protein Kinase Kinases; D020928:Mitogen-Activated Protein Kinases; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism; D043704:Receptor, Adenosine A2B; D018047:Receptors, Purinergic P1 / Q000378:metabolism*; D015398:Signal Transduction; D014443:Tyrosine / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases
D016209:Interleukin-8; D043704:Receptor, Adenosine A2B; D018047:Receptors, Purinergic P1; D014443:Tyrosine; D011494:Protein Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4; D020929:Mitogen-Activated Protein Kinase Kinases; D000241:Adenosine