Increased expression of glycoprotein 340 in the ethmoid sinus mucosa of patients with chronic sinusitis.

OBJECTIVES

To investigate the expression and distribution of glycoprotein 340 (gp340), a secretory glycoprotein, in normal human sinus mucosa and inflammatory sinus mucosa and evaluate the possible effects of gp340 on the development of chronic sinusitis. Glycoprotein 340 was identified as a key element in the innate host defense mechanism on many mucosal surfaces and is directly involved in defense functions aimed at clearing gram-positive and gram-negative bacteria.

DESIGN

Prospective study.

SETTING

Tertiary academic institution.

PATIENTS: Normal sinus mucosa was obtained from the ethmoid sinus mucosa of 8 patients with blowout fractures undergoing endoscopic reduction. Inflammatory sinus mucosa was taken from 25 patients with chronic polypoid sinusitis during endoscopic sinus surgery.

INTERVENTION: Semiquantitative reverse transcription-polymerase chain reaction (RT-PCR), immunohistochemical analysis, and Western blotting were performed.

MAIN OUTCOME MEASURES: The expression level and distributional pattern of gp340 in normal and inflammatory sinus mucosa were analyzed.

RESULTS

Transcripts of the gp340 gene were detected in all human sinus tissues analyzed by RT-PCR. Immunohistochemical analysis revealed that gp340 is mainly localized in submucosal gland of both normal and inflammatory sinus mucosa. Semiquantitative RT-PCR and Western blot analysis showed the increased expression levels of gp340 in the inflammatory sinus mucosa compared with the normal sinus mucosa.

CONCLUSION

These results suggest that gp340 may play a constitutive role in nasal defense and may be up-regulated in response to inflammation, participating in antimicrobial defense in chronic sinusitis.