Expression profile of the active and latent forms of TGF-β1, and TGF-β receptors in human glomerulonephritis

We examined the expression of transforming growth factor (TGF)beta1 and TGF-beta receptors (Rs) in proliferative (PGN) and non-proliferative (NPGN) human glomerulonephritis (GN). The glomerular immunoreactivity for the large latent TGF-betaI complex (LLTC) and small latent TGF-beta1 complex (TGF-beta1 LAP) was analysed in relation to the expression of the mature form of TGF-beta1, as well as of TGF-beta RI, II and III, including betaglycan and endoglin. A remarkable increase in the expression of LLTC and endoglin in mesangial areas was noted in NPGN. This was associated with variable increases in the podocyte staining for TGF-beta1 LAP, TGF-beta RI, TGF-beta RII, and betaglycan. In contrast, the mesangial expression of LLTC and endoglin decreased markedly in rapid-progressive GN with crescent formation. Thus, a link between the upregulation of LLTC and endoglin in the mesangium and the preservation of the glomerular architecture may be suggested.