Qualitative alterations in laminin expression in experimental XXXX .

@entity8 @entity19 @entity75 @entity1988 @entity2132 @entity17145 @entity631
Previous studies have revealed quantitative alterations in laminin-1 expression at the mRNA and protein levels during the development of @entity631 and @entity631 in @entity2132 in @entity19 , a model for @entity1988 . We have now studied the qualitative alterations in laminin expression with two monoclonal antibodies that recognize epitopes on either the E8 or the P1 fragment of laminin-1. Both of these fragments are involved in cell-matrix and matrix-matrix interactions. In normal glomeruli these laminin epitopes are present only in the mesangial matrix; during embryogenesis, however, they are also present in the glomerular basement membrane. The distribution of laminin epitopes was first studied by using immunofluorescence in kidneys of @entity19 with @entity2132 at different points in time after disease induction. Reflection contrast and immunoelectron microscopy were performed after in vivo injection of the horseradish peroxidase-coupled monoclonal antibodies. In glomeruli of @entity19 8 weeks after disease induction, both injected antibodies bound specifically in electron-dense immune deposits in the mesangium and subepithelially along the glomerular basement membrane as well as in the expanded mesangial matrix. At 11 and 12 weeks after disease induction, when focal and @entity17145 had developed, the antibodies additionally bound in the matrix subendothelially along the glomerular basement membrane and at the periphery of end-stage @entity75 . To study changes in the distribution of laminin epitopes over time, @entity19 were injected with either monoclonal antibody before induction of @entity2132 . The antibodies were detected 8 and 12 weeks later in the mesangial matrix of @entity19 with @entity1988 . Once @entity17145 had developed, the antibodies were additionally detected within the thickened glomerular capillary wall. The specific binding of anti-laminin monoclonal antibodies in electron-dense immune deposits further substantiates the hypothesis that anti-laminin autoantibodies participate in glomerular immune complex formation in this model, as suggested by earlier studies. Furthermore, our results show that the distribution of glomerular laminin epitopes in the matrix is altered during the development of @entity8 . These changes in the structure of the glomerular basement membrane may contribute to the abnormal cell-matrix and matrix-matrix interactions during the development of @entity8 in this model for @entity1988 .
