PHENOTYPIC CHANGES OF THE MESANGIUM IN DIABETIC NEPHROPATHY

In diabetic nephropathy there is accumulation of matrix proteins, Over production of these matrix proteins considered to be due to the phenot ypic change of mesangial cell. In order to detect the phenotypic chang e of the mesangial cell, renal biopsy specimens from patients with dia betic nephropathy were stained with antibodies against various types o f collagens and contractile-associated protein, caldesmon, Type III co llagen was not stained in the glomerulus and type VI collagen showed m esangial pattern from normal controls, In diabetes, mesangial staining of type III collagen and increases in type VI collagen were observed in the mesangium. Increased mesangial staining of caldesmon was noted in the glomerulus from diabetic nephropathy in contrast to only vessel staining from normal controls. These results indicate that phenotypic changes are noted in the mesangium in diabetes. Expression of contrac tile-associated protein such as caldesmon, would serve as a useful mar ker to predict glomerulosclerosis.