Effect of human silicotic alveolar macrophages on the expression of matrix metalloproteinase-1 and tissue inhibitor of metalloproteinases-1 in human lung fibroblasts / 中华劳动卫生职业病杂志

ABSTRACT

<p><b>OBJECTIVE</b>To study the effect of the cultured supernatant of human silicotic alveolar macrophages (AM) on the expression of matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in human lung fibroblasts (FB).</p><p><b>METHODS</b>Human alveolar macrophages were collected from a silicotic patients by bronchoalveolar lavage and exposed to SiO(2), then the cultured supernatant were incubated with human fetal lung fibroblasts for 6, 12, 18, 24, 36, 48 h. The immunocytochemical method was used to detect the level of expression of MMP-1 and TIMP-1 in lung fibroblasts.</p><p><b>RESULTS</b>The expression of MMP-1 in FB in 24 h incubation was lower in cultured supernatant of silicotic AM unexposed to SiO(2) than in blank control [integrated OD (IOD)] 0.103 +/- 0.014 vs 0.133 +/- 0.023), while the expression of TIMP-1 was higher (IOD 0.108 +/- 0.012 vs 0.065 +/- 0.006). The expression of MMP-1 in FB in cultured supernatant of AM exposed to SiO(2) for 24 h was further decreased (IOD 0.062 +/- 0.008 vs 0.133 +/- 0.023), while that of TIMP-1 was further increased (IOD 0.143 +/- 0.015 vs 0.065 +/- 0.006).</p><p><b>CONCLUSION</b>SiO(2) may affect the expression of MMP-1 and TIMP-1 system through AM mediation and participate in the formation of lung fibrosis.</p>