Gene expression of pdgf and pdgf receptor in various forms of glomerulonephritis

Platelet-derived growth factor (PDGF) is an important mitogenic factor for various cells. In order to elucidate the role of PDGF in the development of human glomerulonephritis, we examined the gene and protein expression of the PDGF-B chain (PDGF-B) and PDGF-β receptor (PDGFR-β) in renal biopsy specimens from patients with various forms of glomerulonephritis using a nonradioactive in situ hybridization and an immunohistochemical technique. The mRNA expression of PDGF-B and PDGFR-β was significant-ly increased in the glomeruli of patients with mesangial proliferative glomeru- lonephritis (IgA nephropathy, Henoch-Schonlein purpura nephritis, and lupus nephritis) compared with those in normal glomeruli. In cases with increased protein expression of PDGF-B and PDGFR-β, each mRNA expression was also increased. The degree of glomerular injury was positively correlated with the number of mRNA-positive cells for both PDGF and PDGF receptor. There was also a positive correlation between the number of mRNA-positive cells for PDGF-B and PDGFR-β. PDGF-B and PDGFR-β were also ex-pressed on cells of the capillary wall, cellular crescents and infiltrated cells in the intcrstitium. The results suggest that PDGF acts as an important and com- mon mediator for the development of various forms of human mesangial pro-liferative glomerulonephritis. Furthermore, PDGF may participate in cres- cent formation and tubulo-interstitial injury.