Objective: To investigate the effect of SiO2 on the expression of matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in human silicotic alveolar macrophages (AM).
Methods: Human alveolar macrophages were collected from a silicotic patient by bronchoalveolar lavage and exposed to silicon dioxide for 3 h, 6 h, 12 h, 18 h, 24 h and 36 h. The expression of the MMP-9 in the AM were detected with zymography and immunological method and the expression of the TIMP-1 in the AM with immunological method.
Results: The expressions of MMP-9 in the AM increased clearly along with the time, reached peak at 24 h when detected with zymography (average optical density: 3.061+/-0.153 vs 2.851+/-0.164, P<0.05); and reached peak at 18h when detected with immunological method (average optical density: 0.386+/-0.037 vs 0.322+/-0.034, P<0.05). The expression of the TIMP-1 in the AM did not vary when detected with immunological method (P>0.05).
Conclusion: SiO2 may affect the expression of MMP-9 and MMP-9 activity in the cultured AM.