The Patterns of Integrin Subunit Distribution in Glomerular Disease

Jin, Dong Kyu

Abstract

BACKGROUND: It has been known that integrins are not only simple glue which mediate cell-to-cell or cell to extra-cellular matrix but also function as signaling molecules at the surface of cell by conformational change. Because of the diversity of subunits and versatility of ligand recognition, integrins have been recognized as important molecules in kidney and the expression of integrin in normal human kidney has already been reported. METHODS: To know the significance of integrin expression in the pathogenesis of various renal diseases, we stained kidney specimens from the patients with membrano- proliferative glomerulonephritis(MPGN), minimal change nephrotic syndrome(MCNS) and membraneous nephropathy(MN) of lupus nephritis with 13 monoclonal antibodies of integrins. RESULTS: There was a significant change in the distribution of integrin subunits according to the types of glomerular diseases. Integrin subunit alpha2 was helpful in confirming the mesangial interposition as there was intense staining of subendotherial area in MPGN, while only the mesangium was stained with this unit in normal. In addition, an abundant staining of alpha4 and beta2 was observed and this finding indicated non-glomerular resident cell is participating in the MPGN, while in MN type of lupus nephritis, alpha2 staining was restricted to mesangium and alpha4 or beta2 integrin staining was negative. In the MN type of lupus nephritis, the remarkable finding was a ragged appearance in the subepithelial area, just below the glomerular basement membrane, which was visible in alpha3 and alphaV integrin staining. In MCNS, there was no difference in the staining pattern of integrin. CONCLUSION: Integrin subunits can be useful in evaluating the specific cell types which is actively involved in pathogenesis and these results suggest that alteration of integrin distribution can play an important role in the pathogenesis of glomerular diseases.