OSTEOPONTIN EXPRESSION IN PARTICLE-INDUCED LUNG DISEASE

Abstract

□ Osteopontin (OPN) is a secreted cytokine with cell adhesive and chemoattractive functions whose expression is induced by a variety of environmental toxicants. It has been implicated in the pathogenesis of several pulmonary granulomatous and fibrotic conditions. For these reasons the authors investigated OPN expression in experimental particle-induced lung disease using a titanium dioxide exposure model in the rat. Under exposure conditions that resulted in fibroproliferative lung disease, rats had significant increases in total lung OPN mRNA expression and increased levels of OPN protein in bronchoalveolar lavage fluid (BALF) prior to the development of lesions. OPN immunoreactivity studies of lesion development provide evidence that this multifunctional cytokine may be important in the pathogenesis of particle-induced lung disease. Findings suggest that OPN may serve as an important biomarker for particle-induced lung disease.

Keywords:

• lung injury
• osteopontin
• particulate matter
• pulmonary fibrosis

Notes

The current address of Jeffrey I. Everitt is GlaxoSmithKline, Research Triangle Park, North Carolina, USA.

The authors thank Ms. L. Pluta and Ms. F. Trasti for their technical assistance and Dennis House for statistical analysis. This work was supported in part by the American Chemistry Council and the Conseil Europeen des Federations de L'Industrie Chimique.