New immunohistologic findings on the differential role of cyclooxygenase 1 and cyclooxygenase 2 in nasal polyposis.
BACKGROUND
Cyclooxygenase 1 (Cox-1) plays a key role in arachidonic acid metabolism and in the pathophysiology and immunology of nasal polyposis in patients suffering from aspirin intolerance. We hypothesize that Cox-2 also might be relevant in the etiology of nasal polyps of aspirin-tolerant patients by their effects on inflammatory mediators as well as on microvascular permeability.


METHODS
Fifty-two surgical specimens were immunohistochemically labeled for Cox-1 and Cox-2. Specimens were taken from chronically inflamed mucosa (n = 19) and from nasal polyps (n = 19) during endonasal sinus surgery. Controls were obtained from healthy nasal respiratory mucosa (n = 14), harvested during turbinate surgery in patients with nasal obstruction without inflammatory disease. Staining intensities were semiquantitatively assessed and statistically analyzed.


RESULTS
In chronically inflamed tissue the expression of Cox-1 and Cox-2 was strongly labeled. However, in nasal polyps the staining pattern of Cox-1 was similar, but Cox-2 expression in epithelial cells was significantly less than in inflamed, nonpolypous specimens.


CONCLUSIONS
These data suggest that while Cox-1 is strongly up-regulated, Cox-2 expression is significantly lower in epithelial cells of nasal polyps than in those of chronic sinusitis without polyps. The relevance of this finding has to be discussed with respect to the regulatory function of Cox on the inflammatory reaction in nasal respiratory mucosa and its hypothetical role in alterations of capillary permeability via vascular permeability factor/vascular endothelial growth factor.
Gosepath
Jan
J
Department of Otolaryngology, Head and Neck Surgery, University of Mainz, School of Medicine, Mainz, Germany.
Brieger
Juergen
J
Mann
Wolf J
WJ
D000328:Adult; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D004848:Epithelium / Q000378:metabolism; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008565:Membrane Proteins; D008875:Middle Aged; D009298:Nasal Polyps / Q000378:metabolism* / Q000503:physiopathology; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism*; D020545:Respiratory Mucosa / Q000378:metabolism*
D008565:Membrane Proteins; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; C496511:PTGS1 protein, human; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases