The Expression of Matrix Metalloproteinases and Tissue Inhibitors of

Background: Idiopathic interstitial pneumonia is characterized by fibroblast proliferation and extracellular matrix (ECM) accumulation. Matrix metalloproteases (MMPs) and tissue inhibitors of metalloproteases (TIMPs) have been shown to regulate remodeling of the ECM, which indicates that they are important factors in the process of lung fibrosis. Therefore, we evaluated the expres-sion of MMPs and TIMPs in tissues obtained from patients with idiopathic interstitial pneumonia and control tissues. Methods: Thirty-seven patients who were diagnosed with IIP (22: IPF, 13: NSIP, 2: COP) and 5 controls were enrolled in this study. The MMP-2 and-9 activity in lung tissue ob-tained from these patients was analyzed using gelatin zymography and the levels of TIMP-1 and-2 were measured by western blotting. We also evaluated the expression of MMP-2 and-9, as well as that of TIMP-1 and-2 in lung tissue using immunohistochemistry. Results: The levels of MMP-2 and MMP-9 were significantly increased in patients with IPF compared to those with NSIP and COP. The activities of TIMP-1 and-2 were also higher in patients with IPF than NSIP/COP patients an