Proteinuria: from molecular to clinical applications in glomerulonephritis.

Glomerular diseases including diabetic nephropathy are the leading cause of ESRD worldwide. Proteinuria, the hallmark of renal damage in glomerular diseases, is dependent on two main factors: the alteration of the glomerular filtration barrier and its three layers (glomerular endothelial cells, basement membrane, and visceral epithelial cells (podocytes)), and the impairment of proteins reabsorption by proximal tubular epithelial cells. In recent years there has been a great increase of knowledge of the molecular structure of glomerular filtration barrier and of the molecular mechanisms involved in tubular reabsorption of proteins.