INTERLEUKIN-1 AND GLOMERULAR MESANGIAL CELLS

Our previous in vitro study demonstrated that interleukin-1 (IL-1) sti mulates gene expression and production of leukocyte chemotactic factor s, colony-stimulating factors and interleukin-6 in human mesangial cel ls in culture. Here we investigated whether IL-1 regulates its own gen e expression in human mesangial cells. Northern blot experiments showe d that IL-1 induced IL-1 mRNA expression in a dose-dependent manner. T he action of IL-1 on mesangial cells was mediated through the IL-1 rec eptor type I, which is constitutively expressed by mesangial cells. Re combinant IL-1 receptor antagonist blocked the IL-1 mRNA as well as in terleukin-6 and interleukin-8 gene expression induced by IL-1. These d ata support the crucial role played by IL-1 in regulating mesangial ce ll cytokine genes within the glomerulus during immunological or inflam matory processes.