OBJECTIVEChronic rhinosinusitis was often exacerbated by viral infection. A disruption of the mechanisms that regulate the activity of matrix metalloproteinases (MMPs) during viral infection was one possible mechanism responsible for the exacerbation. The purpose of study was to achieve a better understanding of MMP expression in nasal epithelial cells after viral infection.

METHODSHuman nasal epithelial cells were isolated from nasal polyp specimens obtained during endoscopic endonasal surgery in chronic rhinosinusitis patients. The expression of MMP-2, MMP-9, and tissue inhibitor of metalloproteinase (TIMP)-1 mRNA in primary human nasal polyp epithelial cells after double stranded RNA (ds RNA) stimulation were investigated.

RESULTSAmong the genes whose expression was evaluated, only expression of MMP-9 mRNA increased significantly after dsRNA stimulation (22.61 +/- 5.47 fold increase, Z = -2.52, P = 0.012).

CONCLUSIONSThe significant up-regulation of MMP-9 mRNA, which was not modulated by TIMP-1, was an additional source of increased proteolytic activity in virus-infected upper airways that might contribute to the exacerbation of chronic rhinosinusitis with nasal polyps.

Cells, Cultured ; Epithelial Cells ; metabolism ; Gene Expression Regulation, Enzymologic ; Humans ; Matrix Metalloproteinase 2 ; genetics ; metabolism ; Matrix Metalloproteinase 9 ; genetics ; metabolism ; Nasal Polyps ; genetics ; metabolism ; Poly I-C ; pharmacology ; RNA, Double-Stranded ; genetics ; RNA, Messenger ; genetics ; Sinusitis ; genetics ; Tissue Inhibitor of Metalloproteinase-1 ; genetics ; metabolism