Differentially Expressed miRNA in Inflammatory Mucosa of Chronic Rhinosinusitis

Chronic sinusitis (chronic rhinosinusitis, CRS) is a chronic inflammatory disease of the nasal cavity and paranasal sinuses, pathogenesis of which is not yet completely elucidated. MicroRNA has been shown to extensively be involved in immune response. To analyze the differential expression of miRNAs in chronic sinusitis, with or without nasal polyps (nasal polyps, NP), seven miRNAs (miR- 181b, miR-26b, miR-155, miR-146a, miR-125b, miR-124 and miR-92a) that are associated with inflammation were selected to be quantifying by RT-qPCR in 40 clinical samples and 5 controls. When compared to the normal control group, results showed that, in all patients with CRS, miR- 125b, miR-155 and miR-146a were up-regulated (P < 0.05), while miR-92a, miR-26b and miR- 181b were down-regulated (P < 0.05). MiR124 expression levels were not found to have significant changes. In relation to CRS without NP, miR-125b and miR-155 were significantly up-regulated while miR-92a, miR-26b, miR-181b were down-regulated in NP patients. Furthermore, the miR-92a and miR-26b expression levels were significantly reduced while miR-146a and miR124 expression levels had no significant changes in the NP samples. The RT-qPCR results indicate that the miRNAs were differentially expressed in CRS patients and various inflammation severities could lead to this difference. The results from this study may further reveal the relationship between miRNA expressions and inflammation. These results can also provide an important mechanism (primitive data) on the occurrence of chronic sinusitis and nasal polyps.