[Effects of silicotic alveolar macrophages exposed to SiO2 on the expression of type III collagen and type III procollagen in human lung fibroblasts].

UNLABELLED: Effects of silicotic alveolar macrophages exposed to SiO2 on the expression of type III collagen and type

OBJECTIVE

To study the effects of supernatant of alveolar macrophages (AM) exposed to SiO2 on the expression of type III collagen and type III procollagen in human lung fibroblasts (HELF) and the intervention effects of anti-TGF-beta1 antibody.

METHODS

AMs collected from a silicotic by bronchoalveolar lavage were divided into 2 parts, one part was exposed to SiO2 and other part served as control. The supernatant was obtained from AMs cultured for 18 h. HELF were divided into (1) exposure group, which was added with supernatant from AMs exposed to SiO2; (2) control group, which was added with the supernatant from AMs not exposed to SiO2; (3) blank control group, which was added with DMEM; (4) exposure group plus anti-TGF-beta1 antibody (10 microg/ml); (5) control group plus anti-TGF-beta1 antibody (10 microg/ml). (1)-(3) groups were cultured for 6, 12, 18, 24, 36, 48h, respectively. (4)-(5) groups were cultured for 18, 24, 36, respectively. Immunocytochemical test and Western blot assay were used to detect pC III expression levels in HELF and C III expression levels in the supernatant of HELF culture, respectively.

RESULTS

The pC III expression levels of exposure group were 0.1423 +/- 0.0107, 0.1624 +/- 0.0011, 0.1925 +/- 0.0050, 0.2421 +/- 0.0097 and 0.2103 +/- 0.0103, respectively, which were significantly higher than those (0.1212 +/- 0.0079, 0.1414 +/- 0.0058, 0.1620 +/- 0.0081, 0.1965 +/- 0.0103, 0.1715 +/- 0.0116) of control group (P < 0.05 or P < 0.01). The C III levels of exposure group were (0.2559 +/- 0.0061, 0.3249 +/- 0.0110, 0.4171 +/- 0.0193, 0.5441 +/- 0.0452, 0.4751 +/- 0.0252), respectively, which were significantly higher than control group (0.2296 +/- 0.0121, 0.2778 +/- 0.0116, 0.3367 +/- 0.0269, 0.3722 +/- 0.0214). The pC III and C III expression levels of exposure plus anti-TGF-beta1 antibody group were significantly lower than those of control plus anti-TGF-beta1 antibody group (P < 0.05 or P < 0.01).

CONCLUSION

AMs exposed to SiO2 can induce the elevated pC IIII and C III expression levels in HELF by TGFbetaP1 to some extent.