Neuropeptides and capsaicin stimulate the release of inflammatory cytokines in a human bronchial epithelial cell line.
The role of neuropeptides in initiating and modulating airway inflammation was examined in a human bronchial epithelial cell line (i.e. BEAS-2B). At a range of concentrations, exposure of BEAS-2B cells to Substance P (SP) or calcitonin gene related protein resulted in immediate increases in intracellular calcium ([Ca(2+)](i)), the synthesis of the transcripts for the inflammatory cytokines, IL-6, IL-8 and TNFalpha after 2 h exposure, and the release of their proteins after 6 h exposure. Addition of thiorphan (100 nM), an inhibitor of neutral endopeptidase, enhanced the levels of SP-stimulated cytokine release. Stimulation of IL-6 by SP occurred in a conventional receptor-mediated manner as demonstrated by its differential release by fragments SP 4-11 and SP 1-4 and by the blockage of IL-6 release with the non-peptide, NK-1 receptor antagonist, CP-99 994. In addition to the direct stimulation of inflammatory cytokines, SP (0.5 microM), in combination with TNFalpha (25 units/ml), synergistically stimulated IL-6 release. BEAS-2B cells also responded to the botanical irritant, capsaicin (10 microM) with increases in [Ca(2+)](i) and IL-8 cytokine release after 4 h exposure. The IL-8 release was dependent on the presence of extracellular calcium. Capsaicin-stimulated increases of [Ca(2+)](i) and cytokine release could be reduced to control levels by pre-exposure to capsazepine, an antagonist of capsaicin (i.e. vanilloid) receptor(s) or by deletion of extracellular calcium from the exposure media. The present data indicate that the BEAS-2B human epithelial cell line expresses neuropeptide and capsaicin-sensitive pathways, whose activation results in immediate increases of [Ca(2+)](i) stimulation of inflammatory cytokine transcripts and the release of their cytokine proteins.
Veronesi
B
B
National Health and Environmental Effects Research Laboratory, US Environmental Protection Agency, Research Triangle Park, NC 27711, USA. veronesi.bellina@epamail.epa.gov
Carter
J D
JD
Devlin
R B
RB
Simon
S A
SA
Oortgiesen
M
M
D001980:Bronchi / Q000166:cytology; D015740:Calcitonin Gene-Related Peptide / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism; D002211:Capsaicin / Q000494:pharmacology*; D002461:Cell Line, Transformed; D016207:Cytokines / Q000276:immunology / Q000378:metabolism*; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D015870:Gene Expression / Q000276:immunology; D006801:Humans; D015850:Interleukin-6 / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D016209:Interleukin-8 / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D010446:Peptide Fragments / Q000494:pharmacology*; D010880:Piperidines / Q000494:pharmacology; D011480:Protease Inhibitors / Q000494:pharmacology; D012333:RNA, Messenger / Q000032:analysis; D013373:Substance P / Q000494:pharmacology*; D015244:Thiorphan / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000276:immunology / Q000378:metabolism
D016207:Cytokines; D015850:Interleukin-6; D016209:Interleukin-8; D010446:Peptide Fragments; D010880:Piperidines; D011480:Protease Inhibitors; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; C080755:3-(2-methoxybenzylamino)-2-phenylpiperidine; D013373:Substance P; C032682:substance P (4-11); C042612:substance P (1-4); D015244:Thiorphan; D015740:Calcitonin Gene-Related Peptide; D002211:Capsaicin; D002118:Calcium