Detection of Vascular Dendritic Cells and Extracellular Calcium-Binding Protein S-100 in Foci of Calcification in Human Arteries.

Abstract

A new explanation of why calcification develops in arterial vessels is proposed. Some of recently described CD1a+/S-100+ vascular dendritic cells have been found to undergo destruction in athero-prone areas of the aorta and in atherosclerotic lesions (Bobryshev and Lord, Arch. Histol. Cytol., 1995). Lysis of these vascular dendritic cells should release their cellular components into the extracellular space, including S-100 which belongs to the family of calcium-binding proteins. In the present study we examined the possible association of vascular dendritic cells with calcification in atherosclerosis and found that vascular dendritic cells were present in early foci of calcification in the arterial intima and in atherosclerotic lesions. This finding suggests the possible involvement of vascular dendritic cells in the process of arterial wall calcification. Vascular dendritic cells and calcifying vascular cells may be related where a subset of vascular dendritic cells represents calcifying vascular cells in the arterial wall. Extracellularly distributed S-100 protein was also found in association with early calcified deposits. The detection of calcium-binding S-100 protein in the extracellular matrix suggests that molecular mechanisms are involved in atherosclerotic calcification, which is quite different from the previously postulated mechanisms involving bone-associated proteins.