title: Protease-activated receptor 2-dependent fluid secretion from airway submucosal glands by house dust mite extract.
abstract: BACKGROUND
  The submucosal gland (SMG) is important in the control of airway surface fluid. Protease-activated receptor (PAR) 2 contributes to the pathophysiology of allergies in response to nonspecific allergens bearing proteases and anion secretion. House dust mites (HDMs) have abundant proteases that can activate PAR2, but little is known about the direct effect of HDM on SMG secretion.
  
  
  OBJECTIVE
  The aim of this study was to investigate the effect of HDMs on glandular secretion and its mechanism in allergic patients, patients with chronic rhinosinusitis (CRS), or both.
  
  
  METHODS
  Inferior nasal turbinates were harvested from 55 patients and classified into 4 groups (the control, allergic rhinitis [AR], CRS, and AR+CRS groups). A microscope attached to a digital camera was used to quantify mucus bubbles from individual SMGs while stimulated with HDM extract, PAR2-activating peptide, and carbachol. PAR2 expression in the SMG was determined by means of immunostaining with anti-PAR2 mAb.
  
  
  RESULTS
  HDM induced a significantly higher secretion rate and number of responding glands in the AR and AR+CRS groups than in the control group. Interestingly, patients in the CRS group, who had no HDM-specific IgE antibody, showed a higher response than the control group, and its response was suppressed by a PAR2-selective antagonist. The responses to PAR2-activating peptide were similar to those to HDM, and their secretion rates positively correlated with HDM responses. PAR2 was highly expressed in all 3 disease groups with immunostaining.
  
  
  CONCLUSIONS
  HDM allergens can induce glandular secretion in patients with AR, CRS, or both, and PAR2 represents a possible mechanism for nonspecific hyperreactivity in inflammatory airway diseases.
authors.affiliation: Department of Otorhinolaryngology, Kang-Dong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea.
authors.forename: Hyung-Ju
authors.initials: HJ
authors.lastname: Cho
authors.forename: Hyun Jae
authors.initials: HJ
authors.lastname: Lee
authors.forename: Sang Cheol
authors.initials: SC
authors.lastname: Kim
authors.forename: Kyubo
authors.initials: K
authors.lastname: Kim
authors.forename: Yoo Suk
authors.initials: YS
authors.lastname: Kim
authors.forename: Chang-Hoon
authors.initials: CH
authors.lastname: Kim
authors.forename: Jeung-Gweon
authors.initials: JG
authors.lastname: Lee
authors.forename: Joo-Heon
authors.initials: JH
authors.lastname: Yoon
authors.forename: Jae Young
authors.initials: JY
authors.lastname: Choi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D039741:Antigens, Dermatophagoides / Q000276:immunology*; D002217:Carbachol / Q000494:pharmacology; D005088:Exocrine Glands / Q000378:metabolism*; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009093:Mucus / Q000378:metabolism; D009297:Nasal Mucosa / Q000378:metabolism*; D009842:Oligopeptides / Q000494:pharmacology; D010879:Piperazines / Q000494:pharmacology; D044464:Receptor, PAR-2 / Q000819:agonists / Q000037:antagonists & inhibitors / Q000276:immunology*; D012221:Rhinitis, Allergic, Perennial / Q000276:immunology*; D012852:Sinusitis / Q000276:immunology*; D055815:Young Adult
chemical_list: C518710:1-3-methylbutyryl-N4-6-aminohexanoyl-piperazine; C487404:2-furoyl-LIGRLO-amide; D039741:Antigens, Dermatophagoides; D009842:Oligopeptides; D010879:Piperazines; D044464:Receptor, PAR-2; D007073:Immunoglobulin E; D002217:Carbachol