Lymphangiogenesis, the CCR7 Receptor, and Human Atherosclerosis

The role of UNC5b in ox-LDL inhibiting migration of RAW264.7 macrophages and the involvement of CCR7

The formation of macrophage foam cells by ingesting ox-LDL and focal retention in the subendothelial space are the hallmarks of the early atherosclerotic lesion. The C-C chemokine receptor type 7 (CCR7) is positively correlated with the macrophage migration. But the mechanism of CCR7 regulation is not fully clearness. In the present study, we demonstrates that expression in UNC5b and netrin-1 was enhanced in respond to ox-LDL in Raw264.7 macrophage and associated with decreasing cell migration. Interestingly, it was found that ox-LDL significantly downregulate CCR7 gene expression. The expression of CCR7 in mRNA and protein levels were decreased in ox-LDL treated Raw264.7 macrophage when we over expression of UNC5b with pcDNA3.1-UNC5b plasmid. We got the inverse results after silence UNC5b gene with siUNC5b. Meanwhile, the data show that in ox-LDL inducement, UNC5b down-regulated CCR7, and then inhibited macrophage migration. This novel phenomenon is of a crucial highlights to understand deeply the pathogenesis of atherosclerosis. The molecular mechanism of CCR7 regulation deserves intensive study.