COEXPRESSION OF A NOVEL GLOMERULAR-BASEMENT-MEMBRANE MATRIX MATERIAL IN MESANGIAL CELL-CULTURE AND GLOMERULOSCLEROSIS

After in vivo administration of purified antibody against cultured mes angial cell (anti-MG IgG), glomerular basement membrane (GEM) was sele ctively bound. The glomerular bound anti-MG IgG exhibited a monospecif icity for a 109-kDa antigen extracted from cultured mesangial cells an d normal GEM. The antigen was not digestible by collagenase, heparitin ase, or chondroitinase and was revealed by immunoelectron microscopy o f a normal glomerular component to be predominantly distributed along the lamina rara externa of GEM and to be absent in mesangium. The ampl e expression of the antigen in puromycin aminonucleoside nephrosis imp lies that it represents a significant sclerotic material in glomerulon ephritis. Abnormal production of GEM components by mesangial cells may play an important role in glomerulosclerosis. (C) 1995 Academic Press ,Inc.