Ann. occup. Hyg., Vol. 46, No. suppl_1, pp. 18-21, 2002
© 2002 British Occupational Hygiene Society
Published by Oxford University Press
Autoproliferation and Release of Growth Factors in Silica-Stimulated Rat2 Cells
1 Department of Occupational and Environmental Medicine, College of Medicine, The Catholic University of Korea 62 Youido-dong, Youngdunpo-gu, Seoul 150-010, Korea
2 Department of Pharmacology, College of Medicine, The Catholic University of Korea 62 Youido-dong, Youngdunpo-gu, Seoul 150-010, Korea
*Author to whom correspondence should be addressed. Tel. +82-2-3779-1401; fax: +82-2-782-6017; e-mail: nglim{at}catholic.ac.kr
In this study we have examined the effect of silica particles on the proliferation of Rat2 cells, a rat fibroblast cell line. The effect of silica on the production of platelet-derived growth factor AA (PDGF-AA) and transforming growth factor β (TGFβ) in Rat2 cells were evaluated using ELISA and immunocytochemical analysis. Silica induced a significant increase in growth factor levels produced by Rat2 cells. Production of growth factors in silica-stimulated Rat2 cells was dose dependent, reaching a maximum with the dose of 100 µg/cm2. Gene expression of these growth factors in Rat2 cells exposed to crystalline silica was evaluated by RT–PCR. The results of RT–PCR demonstrated that silica induced gene expression of PDGF-AA and TGFβ in Rat2 cells. The effect of Rat2 conditioned medium, obtained from the culture medium supernatant of silica-exposed Rat2 cells, on proliferation of Rat2 cells was assayed by the neutral red test. We found that Rat2 conditioned medium significantly induces proliferation of Rat2 cells. From these observations we suggest that silica directly stimulates Rat2 cells resulting in the generation of growth factors such as PDGF-AA and TGFβ.
fibroblasts • PDGF-AA silica • Rat2 cells • TGFβ