Effects of Oxidized LDL on Monocyte Trans-endothelial Migration

摘要

The effects of oxidized LDL (oxLDL) on monocytes transendothelial migration (TEM) were investigated with an in vitro 3D-live-cell TEM assay system. Nevertheless, oxLDL did not enhance initial monocyte adhesion to endothelium and monocyte locomotion speed on EC's, total number of migrated monocytes was increased with oxLDL. OxLDL upregulated PECAM-1 and downregulated VE-cadherin on endothelial junctions without monocyte addition, both of which could promote monocyte entry by enhanced homophilic binding to monocyte PECAM-1, and by disrupted junctional barrier, respectively. These data indicate that before monocyte adhesion, endothelial junctions changed their conformation to more monocyte-acceptable state response to oxLDL, resulting the stage-specific promotion of monocyte TEM (stage initiation of invasion) with no enhancement of its initial adhesion or migration speed.