Abstract
Vascular calcification is common in patients with advanced and end-stage renal failure and is thought to contribute to their increased cardiovascular mortality. Recently, it became apparent that this calcification is an active, regulated process similar to osteogenesis. Several proteins have been implicated in this process. During the last decade, it was reported that Vitamin K-dependent proteins have been exclusively related to the regulation of tissue calcification. Matrix Gla (γ-carboxyglutamic acid) protein (MGP) is one of the vitamin K-dependent extracellular matrix proteins. Another important molecule is Osteopontin (OPN). OPN may be an important regulator of arterial mineral deposition under conditions of injury and disease. However the relation between vascular calcification and these proteins is still unclear in a uremic state. We examined the effect of vitamin K2 (VitK2) on experimental vascular calcification induced by vitamin D3 (VitD3) in adriamycin (ADR)-induced uremic rats. We evaluated the serum samples (Urea nitrogen (UN), Creatinin (Cr), Albumin (Alb), Calcium (Ca) and Phosphate (P)), histologic examination, calcification assay and genetic analysis. The results show that the MGP mRNA expression was significantly higher and the OPN mRNA expression was lower in the ADRDK group (Adriamycin + VitK2 diet + Calcitriol i.p. 3 times/week) than in the ADRD group (Adriamycin + Nomal diet + Calcitriol i.p. 3 times/week). This in vitro experiment suggests that VitK2 may have inhibitory effects on uremic vascular calcification.
