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) ;