Bone morphogenetic protein-2a (BMP-2a) is expressed in calcified human atherosclerotic plaques and in cultured aortic wall cells, suggesting that arterial calcification may be a regulated process similar to bone formation, possibly mediated by pericyte-like cells. The study used in situ hybridization and cell culture to show that BMP-2a is expressed in calcified atherosclerotic lesions and that cultured aortic cells form calcified nodules resembling those in bone. These nodules contain cells with immunocytochemical features of microvascular pericytes, which can differentiate into osteoblasts. Immunohistochemistry revealed pericyte-like cells in the intima of bovine and human aorta. These findings suggest that arterial calcification is a regulated process, possibly involving pericyte-like cells. The mineral content of the calcified nodules was consistent with hydroxyapatite, and the cells producing BMP-2a and calcium mineral were not identified. However, the calcified nodules formed by artery wall cells resembled those formed by microvascular pericytes and contained cells with morphological and staining characteristics similar to pericytes. These findings support the concept that arterial calcification is an organized process with similarities to bone formation, rather than a passive precipitation of calcium phosphate. The study also highlights the potential for preventive or therapeutic interventions targeting arterial calcification.Bone morphogenetic protein-2a (BMP-2a) is expressed in calcified human atherosclerotic plaques and in cultured aortic wall cells, suggesting that arterial calcification may be a regulated process similar to bone formation, possibly mediated by pericyte-like cells. The study used in situ hybridization and cell culture to show that BMP-2a is expressed in calcified atherosclerotic lesions and that cultured aortic cells form calcified nodules resembling those in bone. These nodules contain cells with immunocytochemical features of microvascular pericytes, which can differentiate into osteoblasts. Immunohistochemistry revealed pericyte-like cells in the intima of bovine and human aorta. These findings suggest that arterial calcification is a regulated process, possibly involving pericyte-like cells. The mineral content of the calcified nodules was consistent with hydroxyapatite, and the cells producing BMP-2a and calcium mineral were not identified. However, the calcified nodules formed by artery wall cells resembled those formed by microvascular pericytes and contained cells with morphological and staining characteristics similar to pericytes. These findings support the concept that arterial calcification is an organized process with similarities to bone formation, rather than a passive precipitation of calcium phosphate. The study also highlights the potential for preventive or therapeutic interventions targeting arterial calcification.