Osteopontin and Tamma-Horsefall proteins – Macromolecules of myriad values

In the past two decades, calcium oxalate urolithiasis (COU) has been a frustrating problem worldwide. Several recent studies, indicate that the macromolecules are of greater importance to the inhibitory effects on crystal growth and aggregation. Various macromolecules modulate various steps of stone formation. Osteopontin and Tamm-Horsfall glycoprotein are two important proteins involved in the process of retention of crystals and stone formation. Osteopontin is a potent inhibitor of crystallization of calcium phosphate and calcium oxalate, the most common crystals found in the urine and kidney stones. On the other side it is a multifunction protein. It is involved in divers’ biological processes. Tamm-Horsfall glycoprotein modulates aggregation and growth of supersaturated salts and their crystals, respectively. It in addition contributes to the colloid osmotic pressure of urine, helping to prevent urinary tract infections. The aim of this review is to outline some important aspects of these two macromolecules especially regarding renal stone diseases.