biomedicines Review Endothelial Barrier Function and Leukocyte Transmigration in Atherosclerosis Thijs J. Sluiter 1,2 , Jaap D. van Buul 3 , Stephan Huveneers 4, Paul H. A. Quax 1,2 and Margreet R. de Vries 1,2,* 1 Department of Vascular Surgery, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands;
[email protected] (T.J.S.);
[email protected] (P.H.A.Q.) 2 Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands 3 Sanquin Research and Landsteiner Laboratory, Leeuwenhoek Centre for Advanced Microscopy, Swammerdam Institute for Life Sciences, University of Amsterdam, 1066 CX Amsterdam, The Netherlands;
[email protected] 4 Department of Medical Biochemistry, Amsterdam Cardiovascular Sciences, Amsterdam University Medical Center, Location AMC, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands;
[email protected] * Correspondence:
[email protected]; Tel.: +31-(71)-526-5147 Abstract: The vascular endothelium is a highly specialized barrier that controls passage of fluids and migration of cells from the lumen into the vessel wall. Endothelial cells assist leukocytes to extravasate and despite the variety in the specific mechanisms utilized by different leukocytes to cross different vascular beds, there is a general principle of capture, rolling, slow rolling, arrest, crawling, and ultimately diapedesis via a paracellular or transcellular route. In atherosclerosis, the barrier function of the endothelium is impaired leading to uncontrolled leukocyte extravasation and Citation: Sluiter, T.J.; van Buul, J.D.; vascular leakage. This is also observed in the neovessels that grow into the atherosclerotic plaque Huveneers, S.; Quax, P.H.A.; de Vries, leading to intraplaque hemorrhage and plaque destabilization.