Production of monocyte chemoattractant protein-1 by cultured glomerular epithelial cells: inhibition by dexamethasone.

Glomerular epithelial cells (GECs) have been shown to be one class of target cells in immunological and nonimmunological glomerular injury of glomerulonephritis, some cases of which are accompanied by infiltration of glomeruli by monocytes/macrophages. In this study we tested whether GECs in culture produce monocyte chemoattractant protein-1 (MCP-1), a potential molecule responsible for monocyte recruitment in inflammation, and whether the production is inhibited by glucocorticoid. GECs were obtained from outgrowth of rat glomeruli. Levels of MCP-1 mRNA and protein were determined by Northern blot analysis and ELISA, respectively. Northern blot analysis revealed the expression of MCP-1 mRNA in cytokine-treated GECs. The expression of MCP-1 mRNA was inhibited by dexamethasone. Quantitative analysis by ELISA confirmed the production of MCP-1 protein by GECs and the inhibitory effect of dexamethasone. These results indicate that cytokine-treated GECs produce and secrete MCP-1 and that the MCP-1 production is inhibited by dexamethasone. We suggest that MCP-1 produced by GECs may play a role in the recruitment of monocytes/macrophages in glomerulonephritis and that the therapeutic effect glucocorticoid on the disease might include the inhibition of the production of MCP-1.