Department of Medicine, Snyder Institute of Infection, Immunity, and Inflammation, University of Calgary, Alberta, Canada.
Am J Respir Cell Mol Biol. 2010 Aug;43(2):201-9. doi: 10.1165/rcmb.2009-0216OC. Epub 2009 Sep 25.
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.
人鼻病毒（HRV）感染会上调与哮喘和慢性阻塞性肺疾病（COPD）等炎症性气道疾病恶化相关的促炎介质和生长因子。基质金属蛋白酶（MMP）-9 已被证明在哮喘和 COPD 患者的气道中增加。我们试图确定 HRV 感染是否调节 MMP-9 及其最高亲和力抑制剂组织金属蛋白酶抑制剂（TIMP）-1 的表达，并探讨发生这种调节的机制。体外研究使用 RT-PCR、ELISA、凝胶电泳和荧光活性测定表明，感染 HRV 后 MMP-9 mRNA、蛋白和活性增加，而 TIMP-1 mRNA 和蛋白保持不变。这些结果在体内得到了验证，使用从确诊 HRV 感染患者中获得的鼻冲洗样本。已证明 HRV 感染可上调 NF-kappaB，并且 NF-kappaB 也已被报道在 MMP-9 的表达中发挥作用。因此，我们研究了 NF-kappaB 在 HRV 诱导的 MMP-9 表达中的作用。使用两种 IkappaBalpha 激酶 beta 抑制剂，我们观察到 HRV 诱导的 MMP-9 表达呈浓度依赖性下降。使用 MMP-9 启动子荧光素酶构建体进一步证实了 NF-kappaB 在 HRV 诱导的 MMP-9 表达中的作用，该构建体表明-620/-607 碱基对处的 NF-kappaB 位点对于 HRV 诱导的 MMP-9 表达是必需的。电泳迁移率变动分析和超迁移分析证实了 p50/p65 NF-kappaB 亚基向 MMP-9 特异性 NF-kappaB 寡核苷酸的核易位和结合。这种 MMP-9 的增加可能是 HRV 感染导致气道炎症并可能导致气道重塑的机制之一。
