Transendothelial migration of leukocytes and signalling mechanisms in response to the neuropeptide secretoneurin.
Secretoneurin (SN), a newly discovered neuropeptide, may be implicated in inflammatory responses as it was shown to modulate leukocyte, endothelial and mesenchymal cell functions. Neutrophils placed above pulmonary arterial or venous endothelial monolayers migrated through this cellular barrier in response to apical or basal stimulation with SN in a dose-dependent manner. At optimal concentrations of 10(-6) to 10(-8) M, SN was nearly equally effective in stimulating neutrophil transmigration as was tumor necrosis factor-alpha at 10 ng/ml or a chemotactic gradient of formyl-Met-Leu-Phe (10(-8) M). Stimulation of transendothelial migration appears to be specific, since a trypsin digest of SN was ineffective and excess concentrations of anti-SN antibodies completely abolished the effect. Inhibition of cyclooxygenase or nitric oxide synthase did not affect the action of SN. Preincubation of endothelial cells with pertussistoxin (PTx) or choleratoxin (CTx), and the presence of staurosporine significantly inhibited transmigration, suggesting that SN uses a signalling pathway that is coupled to G-proteins and protein kinase C in endothelium. Moreover, SN treatment resulted in transient elevation of cytoplasmatic calcium concentration in endothelial cells. These data support the hypothesis that SN might contribute to neurogenic inflammation in vivo and reveal signalling mechanisms of SN in endothelial cells.
Kähler
Christian M
CM
Department of Internal Medicine, Division of General Internal Medicine, Faculty of Medicine, University of Innsbruck, Anichstrasse 35, 6020 Innsbruck, Austria.
Schratzberger
Peter
P
Kaufmann
Gerhard
G
Hochleitner
Boris
B
Bechter
Oliver
O
Götsch
Claudia
C
Wöll
Ewald
E
Marschang
Peter
P
Herold
Manfred
M
Wiedermann
Christian J
CJ
D000818:Animals; D001241:Aspirin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D002417:Cattle; D002448:Cell Adhesion / Q000187:drug effects; D002460:Cell Line; D002478:Cells, Cultured; D002634:Chemotaxis, Leukocyte / Q000187:drug effects*; D004730:Endothelium, Vascular / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009479:Neuropeptides / Q000235:genetics / Q000276:immunology / Q000494:pharmacology*; D020556:Neutrophil Infiltration / Q000187:drug effects; D009504:Neutrophils / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism; D011480:Protease Inhibitors / Q000494:pharmacology; D011651:Pulmonary Artery; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D053381:Secretogranin II; D015398:Signal Transduction / Q000187:drug effects*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
D009479:Neuropeptides; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D011480:Protease Inhibitors; D012333:RNA, Messenger; D053381:Secretogranin II; D014409:Tumor Necrosis Factor-alpha; C081159:secretoneurin; D001241:Aspirin; D002118:Calcium; D019331:NG-Nitroarginine Methyl Ester