Matrix metalloproteinase (MMP)-9 is thought to be involved in the etiopathogenesis of chronic rhinosinusitis (CRS) with nasal polyps and cleaves collagen IV, causing hyperpermeability of the basement membrane within mucosal tissue. It is known that MMP-9 expression is negatively affected by sirtuin (SIRT)-1 in human monocytotic cells, retinal endothelial cells, and epithelial carcinoma cells. However, it is unknown which factors affect MMP-9 expression and activity in human nasal epithelial cells (HNECs). To examine factors affecting MMP-9 expression and activity in HNECs, HNECs were stimulated with Toll-like receptor (TLR) agonists, followed by quantitative PCR, immunofluorescence, and zymography to examine MMP-9 expression and activity. MMP-9 expression was evaluated in sinonasal tissue of control subjects without CRS, and patients with CRS without nasal polyps and those with CRS with nasal polyps, in relation to the expression of SIRT1 using a tissue microarray. The effect of SIRT1 stimulation/inhibition on MMP-9 expression in HNECs was also tested. TLR3 agonists increased MMP-9 mRNA expression (473 fold, P = 0.0198) and activity (20.4-fold, P < 0.05). SIRT1 activation or inhibition reciprocally affected MMP-9 expression in the presence of TLR3 agonists. MMP-9 and SIRT1 expression within the epithelial layer of sinonasal tissue was inversely correlated only in patients with CRS but not in control subjects. TLR3 agonists increased MMP-9 expression and activity in HNECs, and the effect was abolished in the presence of SIRT1 activation. SIRT1 and MMP-9 expression was inversely correlated in CRS tissue, supporting SIRT1 as a possible therapeutic target for nasal polyp formation.
Keywords: MMP-9; Poly (I:C); SIRT1; chronic rhinosinusitis; nasal polyps.