PAR-2 activation regulates IL-8 and GRO-alpha synthesis by NF-kappaB, but not RANTES, IL-6, eotaxin or TARC expression in nasal epithelium.
BACKGROUND
The effects of protease-activated receptor-2 (PAR-2) stimulation on inflammation mechanisms of chronic rhinosinusitis (CRS) are still unknown.


METHODS
PAR-2 receptor expression was investigated by immunohistochemistry and Taqman mRNA analysis in the mucosa of different rhinosinusitis entities. In primary nasal epithelial cell cultures, the function of PAR-2 and its ability to produce CXC, CC chemokines, and IL-6 were measured by calcium mobilization and stimulation tests. Inhibition tests were performed using cortisone, serine protease inhibitors, cysteine protease inhibitors, Pertussis toxin (PTX) and nuclear transcription factor (NF-kappaB) inhibition (BAY 11-7085). Signal transduction pathways were analysed by electromobility shift assays (EMSA) and NF-kappaB binding studies.


RESULTS
The expression of PAR-2 was found to be increased in CRS specimens. The activation of PAR by trypsin or PAR-2-specific activating peptide (AP) caused an increase in cytosolic calcium, as well as the release of the CXC chemokines IL-8 and growth-related oncogene (GRO)-alpha, but not the release of CC chemokines or IL-6. AP-induced CXC chemokine was sensitive to PTX and activation of NF-kappaB was inhibited by BAY11-7085. Furthermore, a serine protease inhibitor significantly inhibited chemokine synthesis stimulated by trypsin and culture supernatants of staphylococci, whereas steroids and cysteine protease inhibitors had little effect.


CONCLUSIONS
PAR-2 plays a role in serine protease-mediated regulation - staphylococcal and non-staphylococcal origin - of IL-8 and GRO-alpha in nasal epithelial cells, but not in the regulation of CC chemokines. PAR-2 may therefore be involved in the pathophysiology of CRS and NP at different sites of activation, namely (i) proteases, (ii) the PAR-2 receptor itself or (iii) the application of novel agents that block NF-kappaB/IkappaB-alpha signalling.
Rudack
C
C
Department of Otorhinolaryngology, Head and Neck Surgery, IZK Münster and Boltzmann Institute for Immunobiology of the Skin, Münster, Germany. rudack@uni-muenster.de
Steinhoff
M
M
Mooren
F
F
Buddenkotte
J
J
Becker
K
K
von Eiff
C
C
Sachse
F
F
D000208:Acute Disease; D000328:Adult; D000368:Aged; D001426:Bacterial Proteins / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D016022:Case-Control Studies; D002478:Cells, Cultured; D054413:Chemokine CCL11; D054414:Chemokine CCL17; D018946:Chemokine CCL5 / Q000378:metabolism; D054360:Chemokine CXCL1; D019742:Chemokines, CC / Q000378:metabolism; D019743:Chemokines, CXC / Q000096:biosynthesis*; D002908:Chronic Disease; D017077:Culture Media, Conditioned / Q000378:metabolism; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000378:metabolism; D016209:Interleukin-8 / Q000096:biosynthesis*; D008297:Male; D008875:Middle Aged; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism*; D009297:Nasal Mucosa / Q000187:drug effects / Q000276:immunology / Q000378:metabolism* / Q000382:microbiology; D009298:Nasal Polyps / Q000201:enzymology / Q000276:immunology / Q000378:metabolism; D009570:Nitriles / Q000494:pharmacology; D010455:Peptides / Q000494:pharmacology; D037342:Pertussis Toxin / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D044464:Receptor, PAR-2 / Q000819:agonists / Q000235:genetics / Q000378:metabolism*; D012220:Rhinitis / Q000201:enzymology / Q000276:immunology / Q000378:metabolism* / Q000382:microbiology; D012697:Serine Endopeptidases / Q000378:metabolism*; D015842:Serine Proteinase Inhibitors / Q000494:pharmacology; D015398:Signal Transduction; D012852:Sinusitis / Q000201:enzymology / Q000276:immunology / Q000378:metabolism* / Q000382:microbiology; D013211:Staphylococcus aureus / Q000201:enzymology; D013450:Sulfones / Q000494:pharmacology; D014357:Trypsin / Q000378:metabolism
C416282:BAY 11-7085; D001426:Bacterial Proteins; C515456:CCL11 protein, human; C106230:CCL17 protein, human; C475829:CXCL1 protein, human; D054413:Chemokine CCL11; D054414:Chemokine CCL17; D018946:Chemokine CCL5; D054360:Chemokine CXCL1; D019742:Chemokines, CC; D019743:Chemokines, CXC; D017077:Culture Media, Conditioned; C508600:IL6 protein, human; D015850:Interleukin-6; D016209:Interleukin-8; D016328:NF-kappa B; D009570:Nitriles; D010455:Peptides; D012333:RNA, Messenger; D044464:Receptor, PAR-2; D015842:Serine Proteinase Inhibitors; D013450:Sulfones; C002010:4-(2-aminoethyl)benzenesulfonylfluoride; D037342:Pertussis Toxin; D012697:Serine Endopeptidases; D014357:Trypsin; D002118:Calcium