Eotaxin Increases Monolayer Permeability of Human Coronary Artery Endothelial Cells

Objective—The objective of this study was to determine the effects and molecular mechanisms of eotaxin, a newly discovered chemokine (CCL11), on endothelial permeability in the human coronary artery endothelial cells (HCAECs). Methods and Results—Cells were treated with eotaxin, and the monolayer permeability was studied by using a costar transwell system with a Texas Red–labeled dextran tracer. Eotaxin significantly increased monolayer permeability in a concentration-dependent manner. In addition, eotaxin treatment significantly decreased the mRNA and protein levels of endothelial junction molecules including zonula occludens-1 (ZO-1), occludin, and claudin-1 in a concentrationdependent manner as determined by real-time RT-PCR and Western blot analysis, respectively. Increased oxidative stress was observed in eotaxin-treated HCAECs by analysis of cellular glutathione levels. Furthermore, eotaxin treatment substantially activated the phosphorylation of MAPK p38. HCAECs expressed CCR3. Consequently, antioxidants (ginkgolide B and MnTBAP), specific p38 inhibitor SB203580, and anti-CCR3 antibody effectively blocked the eotaxin-induced permeability increase in HCAECs. Eotaxin also increased the phosphorylation of Stat3 and nuclear translocation of NFB in HCAECs. Conclusions—Eotaxin increases vascular permeability through CCR3, the downregulation of tight junction proteins, increase of oxidative stress, and activation of MAPK p38, Stat3, and NF-kB pathways in HCAECs. (Arterioscler Thromb Vasc Biol. 2009;29:2146-2152.)