Biochemical composition of the glomerular extracellular matrix in patients with diabetic kidney disease

Table 4 Different composition of glomerular extracellular matrix (glomerular basement membrane and mesangial matrix) in normal subjects and patients with diabetes

	Normal glomeruli	Diabetic kidney disease
Heparan sulfate proteoglycans	GBM and mesangial matrix	Decreased amount
Laminin	Predominantly in the GBM	Inconsistent
Fibronectin-1	Mainly in the mesangial matrix	It varies according to DKD stage
Type I collagen	Inconsistent	No detectable
Type III collagen	Absent	Abundant
Type IV collagen	Abundant in the GBM	Reduced GBM amount
Type V collagen	Similar to type IV collagen	Increased mesangial amount
Type VI collagen	GBM and mesangial matrix	Increased mesangial amount

GBM: Glomerular basement membrane; DKD: Diabetic kidney disease.