Human cathelicidin antimicrobial peptide is up-regulated in the eosinophilic mucus subgroup of chronic rhinosinusitis patients.
BACKGROUND
Eosinophilic mucus chronic rhinosinusitis (EMCRS) patients are a subgroup of CRS with a poorer prognosis due to frequent recurrences of disease. The cathelicidin antimicrobial peptide (CAMP) is an important innate defense peptide but its role in CRS is not well characterized. The purpose of this study was to investigate CAMP mRNA and protein expression from EMCRS, CRS, and normal control patients.


METHODS
Biopsy specimens of nasal mucosa and nasal polyps were taken from 59 CRS patients and 9 controls. CAMP mRNA and protein levels were analyzed by real-time quantitative reverse-transcriptase polymerase chain reaction, immunoassay, Western blot, and immunohistochemistry.


RESULTS
The expression of CAMP mRNA was significantly increased in EMCRS patients compared with CRS patients (p = 0.0004). By immunohistochemistry, expression of CAMP was localized to nasal epithelial, submucosal glands, and inflammatory subepithelial cells. Western blotting confirmed the presence of CAMP in EMCRS, CRS, and control patients. However, we did not detect statistically significant differences in the protein levels in tissue homogenates between EMCRS, CRS, and control patients.


CONCLUSIONS
This study shows expression of CAMP in nasal mucosa supporting its role in innate defenses against inhaled pathogens. Although CAMP mRNA was up-regulated in EMCRS patients, there were no statistically significant differences in protein levels in the nasal mucosa of EMCRS compared with CRS patients and controls.
Ooi
Eng Hooi
EH
Department of Surgery-Otorhinolaryngology Head and Neck Surgery, University of Adelaide, South Australia, Australia.
Wormald
Peter-John
PJ
Carney
A Simon
AS
James
Craig Lloyd
CL
Tan
Lor Wai
LW
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D023181:Antimicrobial Cationic Peptides / Q000235:genetics* / Q000378:metabolism; D015153:Blotting, Western; D054804:Cathelicidins; D002908:Chronic Disease; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D009297:Nasal Mucosa / Q000737:chemistry; D012333:RNA, Messenger; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012220:Rhinitis / Q000503:physiopathology*; D012852:Sinusitis / Q000503:physiopathology*; D015854:Up-Regulation / Q000502:physiology
D023181:Antimicrobial Cationic Peptides; D054804:Cathelicidins; D012333:RNA, Messenger