To investigate whether MCP-1, CINC, RANTES, osteopontin and ICAM-1 mRNA could be induced in cultured rat mesangial cells by interleukin-1beta(IL-1beta), tumor necrosis factor-alpha (TNF-alpha) and lipopolysaccharide (LPS), and whether MCP-1 and CINC gene expression could be modulated by dexamethasone, Northern blot assays were performed. IL-1beta induced MCP-1, CINC, RANTES and ICAM-1 gene expression in a time dependent manner. IL-1beta-induced MCP-1, CINC and ICAM-1 mRNA amount were maximal at 3 hours exposure around 14.5, 15.7, 2.2 folds increase and IL-1beta-induced RANTES mRNA at 24 hours around 2.0 folds. TNF-alpha and LPS also induced MCP-1 and ICAM-1 gene expression. TNF-alpha also induced RANTES gene expression but LPS did not. On the other hand, IL-1beta, TNF-alpha and LPS had little effect on osteopontin gene expression but fetal calf serum could increase osteopontin mRNA. Dexamethasone suppressed the IL-1beta-induced MCP-1 and CINC mRNA. These results suggest that, through these gene expressions, mesangial cells are able to communicate directly or indirectly with macrophages or neutrophils, which may lead to glomerulosclerosis.