Role of transforming growth factor-beta 1 in glomerulonephritis

The role of transforming growth factor-beta 1 (TGF-beta 1) in human glomerulonephritis is still poorly understood. The relationship between expression of TGF-beta 1 protein or TGF-beta 1 mRNA and tissue damage was investigated using the enzyme-antibody and in situ hybridization method in frozen slices of renal tissue from 30 patients: 25 with glomerulonephritis (18 with immunoglobulin A nephropathy; two with focal glomerulosclerosis, one with membranous nephropathy, one with crescentic glomerulonephritis and three with lupus nephritis) and five control patients with minimal change disease. The expression of TGF-beta 1 mRNA was high in sclerotic and proliferative glomeruli, as well as in the tubular epithelial cells within tubulointerstitial lesions. There was significant correlation between the severity of tissue damage in immunoglobulin A nephropathy and the presence of TGF-beta 1 protein and TGF-beta 1 mRNA. These findings suggest that TGF-beta 1 is involved in glomerulosclerosis and the development of tubulointerstitial lesions, indicating its potential importance in the progression and aggravation of immunoglobulin A nephropathy.