Hepatocyte growth factor (HGF) modulates matrix turnover in human glomeruli

BACKGROUND: The imbalance between synthesis and degradation of mesangial matrix causes glomerulosclerosis and leads to renal failure. Hepatocyte growth factor (HGF) has been shown to reduce the progression in murine models of chronic renal failure. The present study evaluated the effect of HGF on the extracellular matrix turnover and on c-met receptor in human glomeruli. METHODS: Human glomeruli microdissected from donor kidney biopsies before transplantation were incubated with culture media containing HGF (50 ng/mL). After 24 and 48 hours, the expression of c-met, (alpha2) IV collagen, transforming growth factor-beta (TGF-beta), metalloprotease (MMP) 2 and 9 and of the inhibitor of MMP-2, tissue inhibitors of metalloprotease-1 (TIMP-1), was evaluated by polymerase chain reaction (PCR). beta-actin was used as housekeeping gene. The production of collagen type IV and TGF-beta was evaluated by enzyme-linked immunosorbent assay (ELISA) and Western blotting and the activity of MMP by zymography. RESULTS: (alpha2) IV collagen, TGF-beta, and TIMP-1 mRNA levels were markedly decreased in glomeruli treated with HGF at 24 and 48 hours. The expression of c-met was up-regulated by HGF treatment. HGF reduced the production of collagen type IV and TGF-beta. MMP-2 but not MMP-9 mRNA level was increased in HGF-treated glomeruli, although the gelatinolytic activity of the supernatant was not changed. By light microscopic examination kidney biopsies neither showed glomerular hypercellularity nor mesangial expansion. CONCLUSION: HGF reduced expression and synthesis of TGF-beta and collagen type IV and increased MMP-2 mRNA level in normal human glomeruli. These results suggest an antifibrotic effect of HGF on glomerular cells and may explain its beneficial role in glomerulosclerosis.