The Expressions Of IL-37 And IL-8 MRNA And Protein In Nasal Polyp Tissues And Their Significances

Objective: Nasal polyp is a common chronic inflammatory disease of nose and sinus. The pathophysiological mechanisms of nasal polyp remain poorly understand. This study is aimed to investigate the expressions of LL-37 and IL-8 in nasal polyp tissues and their significances.Methods: Thirty-one nasal polyp tissues from patients with chronic sinusitis who accepted functional endoscopic sinus surgery (FESS) were randomly selected as studying in our hospital. Another 11 inferior turbinate specimens from patients with the deviation of nasal septum who were performed corrective procedure served as controls. The expression level of LL-37 and IL-8 mRNA were analyzed by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR), and the expressions of LL-37 and IL-8 protein were detected by immunohistochemical staining in nasal polyp and inferior turbinate tissues, respectively. Student's t-tests, X~2-tests and Pearson correlation analysis were applied as statistics analytical methods.Results: (1) LL-37 mRNA was all positively expressed in 31 nasal polyps tissues and 11 inferior turbinate tissues by RT-PCR analysis. LL-37 mRNA was obviously over-expressed in nasal polyp tissues than that in inferior turbinate tissues (P<0.01). LL-37 protein was positively expressed in nasal polyp tissues of 29 cases (29/31, 93.55%), and in inferior turbinate tissues (5/11, 45.45%) by immunohistochemical staining. There was significant difference between the positive expression rate of LL-37 protein in nasal polyp tissues and in inferior turbinate tissues (P<0.01). (2) IL-8 mRNA was all positively expressed in 31 nasal polyp tissues and 11 inferior turbinate tissues by RT-PCR analysis. IL-8 mRNA was obviously over-expressed in nasal polyp tissues than that in inferior turbinate tissues (P<0.01). IL-8 protein was positively expressed in nasal polyp tissues of 28 cases (28/31, 90.32%), and in inferior turbinate tissues of six cases (6/11, 54.54%) by immunohistochemical staining. There was significant difference between the positive expression rate of IL-8 protein in nasal polyp tissues and in inferior turbinate tissues (P<0.01). (3) There was a positive relationship between the mRNA expression levels of LL37 and IL-8(r=0.524, P<0.01), and between the expression of LL-37 and IL-8 protein in nasal polyp tissues(pearsonX~2=19.954 , P<0.01). (4)There was not significant difference between the positive expression of LL-37 mRNA and protein of nasal polyp tissues in II type III stage, III type patients and II type I stage, II type II stage patients(P>0.05). The expressions of IL-8 mRNA and protein in nasal polyp tissues of II type III stage and III type patients were significantly higher than those in II type I stage and II type II stage patients(P<0.01). Conclusion: (1) The expressions of LL-37 and IL-8 in normal nasal mucosa suggest that they may play a role in the maintaining the health of nasal mucosa as a part of innate immunity. (2) The expressions LL-37 and IL-8 are significantly higher in nasal polyp tissues than those in inferior turbinate tissues, and showing they may modulate the pathogenisis and development of nasal polyps. (3) The expressions of IL-8 in nasal polyp tissues suggest the order of severity of sinusitis. (4) The positive relationship between LL-37 and IL-8 expression in nasal polyp tissues suggest that LL-37 may enhance human body's immune function by acquired immune reaction.