Human rhinovirus infection up-regulates MMP-9 production in airway epithelial cells via NF-{kappa}B.
Human rhinovirus (HRV) infections up-regulate proinflammatory mediators and growth factors that are associated with exacerbations of inflammatory airway diseases, such as asthma and chronic obstructive pulmonary disease (COPD). Matrix metalloproteinase (MMP)-9 was shown to be increased in the airways of patients with asthma and COPD. We sought to determine whether HRV infection modulated the expression of MMP-9 and its highest-affinity inhibitor, the tissue inhibitor of metalloproteinase (TIMP)-1, and we explored the mechanism by which this modulation occurs. In vitro studies, using RT-PCR, ELISA, zymography, and a fluorescent activity assay, demonstrated that MMP-9 mRNA, protein, and activity were increased upon infection with HRV, whereas TIMP-1 mRNA and protein remained unchanged. These results were verified in vivo, using nasal lavage samples obtained from subjects with confirmed rhinovirus infections. Human rhinovirus infections were shown to up-regulate NF-kappaB, and NF-kappaB has also been reported to play a role in the expression of MMP-9. We therefore investigated the role of NF-kappaB in HRV-induced MMP-9 expression. Using two inhibitors of IkappaBalpha kinase beta, we observed a concentration-dependent decrease in HRV-induced MMP-9 expression. The role of NF-kappaB in HRV-induced MMP-9 expression was further confirmed using MMP-9 promoter luciferase constructs, which demonstrated that an NF-kappaB site at -620/-607 base pairs was necessary for HRV-induced MMP-9 expression. Electrophoretic mobility shift assays and supershift assays confirmed the nuclear translocation and binding of p50/p65 NF-kappaB subunits to an MMP-9-specific NF-kappaB oligonucleotide. This increase in MMP-9 may be a mechanism by which rhinovirus infections contribute to airway inflammation and, potentially, to airway remodeling.
Tacon
Claire E
CE
Department of Medicine, Snyder Institute of Infection, Immunity, and Inflammation, University of Calgary, Alberta, Canada.
Wiehler
Shahina
S
Holden
Neil S
NS
Newton
Robert
R
Proud
David
D
Leigh
Richard
R
D001980:Bronchi / Q000201:enzymology* / Q000821:virology*; D004847:Epithelial Cells / Q000201:enzymology* / Q000821:virology*; D005347:Fibroblasts / Q000378:metabolism; D020869:Gene Expression Profiling; D015971:Gene Expression Regulation, Enzymologic; D015967:Gene Expression Regulation, Viral; D006367:HeLa Cells; D006801:Humans; D007249:Inflammation; D020780:Matrix Metalloproteinase 9 / Q000096:biosynthesis*; D016328:NF-kappa B / Q000378:metabolism*; D010850:Picornaviridae Infections / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D012229:Rhinovirus / Q000378:metabolism*; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000378:metabolism
D016328:NF-kappa B; D012333:RNA, Messenger; D019715:Tissue Inhibitor of Metalloproteinase-1; D020780:Matrix Metalloproteinase 9