Induction of MMP-9 in normal human bronchial epithelial cells by TNF-α via NF-κB-mediated pathway

Abstract

In this study, we determined whether the proinflammatory cytokines tumor necrosis factor (TNF)-α and interleukin-1β contribute to the regulation of matrix metalloproteinase (MMP)-9 in human bronchial epithelial cells and whether the induction of MMP-9 is regulated by the transcription factor nuclear factor (NF)-κB. We demonstrated that TNF-α induced MMP-9 at both the protein and mRNA levels in human bronchial epithelial cells and that interleukin-1β did not. In contrast, induction of the tissue inhibitor of metalloproteinase-1 by TNF-α was less than that of interleukin-1β. Increased expression of MMP-9 and NF-κB activation induced by TNF-α were inhibited by pyrrolidine dithiocarbamate and N-acetyl-l-cysteine but were not inhibited by curcumin. These results suggest that TNF-α induces the expression of MMP-9 in human bronchial epithelial cells and that this induction is mediated via the NF-κB-mediated pathway.