Alteration in Extracellular Matrix Components in Preeclamptic Nephropathy

ABSTRACT

The preeclamptic nephropathy is characterized by swelling of endothelial cells, interposition of mesangial cells and matrix, subendothelial deposits of incompletely defined material, and thickening of the capillary walls. To determine the distribution of extracellular matrix (ECM) components in preeclamptic nephropathy, the immunohistochemical study was performed in ten renal biopsy cases using antisera to human type I, III, IV, and VI collagens, fibronectin, and laminin. In preeclamptic nephropathy, the accumulation of type IV and VI collagens, fibronectin was observed in moderate amount in the mesangium and, to some extent, in the thickened capillary walls, particularly in the subendothelial layer. In segmentally sclerotic lesions seen in six cases, the amount of type IV collagen was partly decreased, whereas those of type VI collagen and fibronectin were slightly increased. Type I collagen was expressed to a mild degree in the expanded mesangium and segmentally sclerotic lesions. The results suggest that the expression of ECM in the mesangium is increased in preeclamptic nephropathy, and the deposition of ECM components may be involved in the development and the reparative process of the characteristic glomerular lesions. The formation of sclerotic lesions may be linked to the alternative accumulation of ECM components.