Histamine antagonizes serotonin and growth factor-induced mitogen-activated protein kinase activation in bovine tracheal smooth muscle cells.
We examined the effects of the bronchoconstrictor agonists serotonin (5-hydroxytryptamine; 5-HT) and histamine on mitogen-activated protein (MAP) kinase activation in cultured bovine tracheal myocytes. Kinase renaturation assays demonstrated activation of the 42- and 44-kDa MAP kinases within 2 min of 5-HT exposure. MAP kinase activation was mimicked by alpha-methyl-5-HT and reduced by pretreatment with either phorbol 12,13-dibutyrate or forskolin, suggesting activation of the 5-HT2 receptor, protein kinase C, and Raf-1, respectively. Raf-1 activation was confirmed by measurement of Raf-1 activity, and the requirement of Raf-1 for 5-HT-induced MAP kinase activation was demonstrated by transient transfection of cells with a dominant-negative allele of Raf-1. Histamine pretreatment significantly inhibited 5-HT and insulin-derived growth factor-1-induced MAP kinase activation. Attenuation of MAP kinase activation was reversed by cimetidine, mimicked by forskolin, and accompanied by cAMP accumulation and inhibition of Raf-1, suggesting activation of the H2 receptor and cAMP-dependent protein kinase A. However, histamine treatment inhibited Raf-1 but not MAP kinase activation following treatment with either platelet-derived growth factor or epidermal growth factor, implying a Raf-1-independent MAP kinase activation pathway. In summary, our data suggest a model whereby 5-HT activates MAP kinase via a protein kinase C/Raf-1 pathway, and histamine attenuates MAP kinase activation by serotonin via activation of cAMP-dependent protein kinase A and inhibition of Raf-1.
Hershenson
M B
MB
Department of Pediatrics, University of Chicago, Illinois 60637-1470, USA.
Chao
T S
TS
Abe
M K
MK
Gomes
I
I
Kelleher
M D
MD
Solway
J
J
Rosner
M R
MR
D000818:Animals; D016085:Bronchoconstrictor Agents / Q000494:pharmacology; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D002417:Cattle; D002478:Cells, Cultured; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D006133:Growth Substances / Q000494:pharmacology; D006632:Histamine / Q000494:pharmacology*; D009130:Muscle, Smooth / Q000187:drug effects* / Q000201:enzymology*; D011493:Protein Kinase C / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D019908:Proto-Oncogene Proteins c-raf; D011985:Receptors, Serotonin / Q000378:metabolism; D012701:Serotonin / Q000494:pharmacology; D014132:Trachea / Q000187:drug effects* / Q000201:enzymology*
D016085:Bronchoconstrictor Agents; D006133:Growth Substances; D011518:Proto-Oncogene Proteins; D011985:Receptors, Serotonin; D012701:Serotonin; D006632:Histamine; D017346:Protein Serine-Threonine Kinases; D019908:Proto-Oncogene Proteins c-raf; D017868:Cyclic AMP-Dependent Protein Kinases; D011493:Protein Kinase C; D017871:Calcium-Calmodulin-Dependent Protein Kinases