PROTOONCOGENE EXPRESSION IN HUMAN GLOMERULAR-DISEASES

The expression of the protein products and mRNA of c-fos, c-myc, p53, and c-raf was examined in normal renal tissues and biopsy specimens fr om 73 patients with various glomerular diseases. Immunofluorescent sta ining showed that there were cell nuclei stained for c-Fos, c-Myc, and p53, and cytoplasm positive for c-Raf, in the glomeruli of patients w ith proliferative types of glomerulonephritis, including IgA nephritis and lupus nephritis, and in patients with focal glomerular sclerosis. Glomerular expression of c-fos and c-myc mRNA was detected by irt sit u hybridization, The number of proto-oncogene-positive glomerular cell s was significantly higher in lupus nephritis, IgA nephritis, and foca l segmental sclerosis, as compared with minimal change nephrotic syndr ome and normal specimens, In IgA nephritis, the population of glomerul ar cells positive for c-Fos and c-Myc and the grade of c-Raf immunorea ctivity were significantly correlated with the proportion of prolifera ting cell nuclear antigen (PCNA)-positive glomerular cells, with histo logical grading of mesangial hypercellularity and matrix increase, and with the magnitude of proteinuria, These data indicate that proto-onc ogene expression is associated with mesangial proliferation and matrix expansion in proliferative types of glomerulonephritis and in focal g lomerular sclerosis.