Effect of SiO2 on the expression of MMP-9,TIMP-1 in human alveolar macrophages and type III collagen in human lung fibroblasts

The objective is to explore the effect of SiO2 on collagen pathology deposition, and discuss its effect mediated by human alveolar macrophage (AM)-expressed matrix metalloproteinase (MMP)/tissue inhibitor of metalloproteinase (TIMP. In the method, AMs were collected from a silicotic patient by bronchoalveolar lavage and exposed to SiO2 or cultured in DMEM without serum respiration for 2, 6,12, 18 and 24h cultured human embryo lung fibroblast were allocated into a treated group, a control group, and a blank group. HELF was incubated with the cultured supernatant of AMs for 6, 12, 18, 24, 36 and 48h. Immunocytochemistry and Western blot technology were used to detect MMP-9 and TIMP-1 expressions in AM and C III expression in supernatant of HELF respiration. The results of SiO2 stimulated expressions of MMP-9 (at all time points) and TIMP-1 (at 12, 18, and 24h) in AM compared with control group (P < 0.05 or P < 0.01) showed that the expression of MMP-9 was remarkably more than that of TIMP-1 at all time points (P < 0.001). The expression of C III in supernatant of HELF incubated with supernatant of AM exposed to SiO2 increased compared with control group (P < 0.05 or P < 0.01). In conclusion, SiO2 can stimulate expressions of MMP-9 and TIMP-1 in AM. Through AM mediation SiO2 can accelerate the expression of C III. AM plays an important role in pathological accumulation of collagen through MMPs/TIMPs system.

Zhu, Lan; Feng, Li; Yi, Xue; Wang, Xian-hua; Ma, Xiao-bing ;Full Source: Xiandai Yufang Yixue 2011, 38(14), 2797-2800 (Ch) ;