Gene expression of CC chemokines in experimental acute tubulointerstitial nephritis

The infiltration of mononuclear leukocytes into glomeruli or the interstiti um is a feature in most forms of glomerular diseases. CC chemokines, mostly chemoattractants for mononuclear leukocytes, are molecules that are potent ially responsible for the recruitment of these cells in the kidney. We prev iously reported that the gene expression of six CC chemokines-MCP-1, MCP-3, MIP-1 alpha, MIP-1 beta, RANTES, and TCA3-was enhanced in a rat model of c rescentic glomerulonephritis, the most severe form of glomerulonephritis. I n this study we analyzed their gene expression in a model of another type o f kidney disease, acute nephrosis accompanied by tubulointerstitial lesions , which is induced by an injection of puromycin aminonucleoside. Because le ukocyte infiltration in this model is much more prominent in the interstiti um than in glomeruli, we analyzed their gene expression in the renal cortex . On day 3, when the level of urinary protein was slightly but significantl y increased but the number of interstitial leukocytes was unchanged, the en hanced expression of mRNAs for MCP-1, MCP-3, and TCA3 was observed. On day 5, the numbers of interstitial monocytes and lymphocytes significantly incr eased, and the levels of the mRNA expression of the above chemokines were s till higher than the control animals, whereas the levels of mRNAs for MIP-1 alpha, MIP-1 beta, and RANTES were not higher or were only slightly higher than the control ones. These results suggest that multiple CC chemokines m ay play a role in the recruitment of leukocytes in this model and that the expression pattern of CC chemokines depends on the type of kidney injury.