The role of junctional adhesion molecule-C (JAM-C) in oxidized LDL-mediated leukocyte recruitment

SPECIFIC AIMSThe junctional adhesion molecule-C (JAM-C) was recently identified on platelets and endothelial cells as a counter-receptor for the leukocyte β2-integrin Mac-1 (CD11b/CD18), thereby mediating interactions between vascular cells. As Mac-1 is important for the recruitment of inflammatory cells to the atherosclerotic vessel wall or in restenosis, the aim of the present work was to investigate the expression of its counter-receptor JAM-C in the atherosclerotic vessel wall and to study the effect of oxidized LDL (oxLDL) on the expression of JAM-C as well as the role of JAM-C in oxLDL-mediated inflammatory cell recruitment.PRINCIPAL FINDINGS1. JAM-C is up-regulated in the arteriosclerotic vessel wallImmunostaining of normal human arteries revealed a weak expression of JAM-C in the endothelium and by individual smooth muscle cells in the media. In contrast, in arteriosclerotic vessels JAM-C was strongly expressed in endothelial cells and smooth muscle cells in the neointima and the media. To provide...