Figure 2.

Vascular calcification. Vascular calcification is an active process regulated by factors known to be involved in the process of osteogenesis. Vascular smooth muscle cells are able to differentiate towards osteoblast-like cells, promoted by a variety of stimuli, including BMP, RANKL, oxidative stress, inflammation and estrogen deficiency. These osteoblastic cells produce osteocalcin and ALP, important factors in mineralisation. ^# Excessive vitamin D promotes mineralisation. * It is not clear whether OPN promotes or inhibits calcification in the arterial wall, in bone mineralisation it is a known mineralisation inhibitor. Abbreviations: ALP, alkaline phosphatase; BMP, bone morphogenetic protein; Cbfa1, core binding factor-α1; MGP, matrix GLA protein; Msx2, msh homeobox 2; OPG, osteoprotegerin; OPN, osteopontin; ox-LDL, oxidized low density lipoprotein; RANKL, receptor activator of nuclear factor-B ligand; VSMC, vascular smooth muscle cell; Wnt, combination of wingless and Int.