Fig. 2.

Schematic representation of some ‘new players’ in leukocyte TEM. a Summary of ephrin-Eph interactions implicated in TEM. As detailed in the body text, several ephrin-Eph receptor interactions have been implicated in leukocyte TEM. These involve Eph receptors and ephrin ligands on endothelial cells, as well as on transmigration leukocytes or cancer cells. Some of these interactions result in increased permeability, and effects on ICAM-1 and VCAM-1 recruitment or expression which drives TEM and atherosclerosis. However, the underlying signaling pathways remain to be further elucidated. PC prostate cancer. b The ReticulonA/B proteins have been found to negatively regulate p60Src/Pyk2-mediated tyrosine phosphorylation of VE-cadherin, downstream from ICAM-1 clustering. ReticulonA/B proteins are largely residing in the endoplasmic reticulum, but are also found at the plasma membrane. The TRPC6 calcium channel as well as the Pannexin 1 ATP transporter have both been identified as positive regulators of leukocyte TEM. TRPC6 regulates, downstream, from clustered PECAM-1, the LBRC which mediated TEM. Pannexin 1-driven ATP export can activate leukocytes, thus stimulating TEM in the extracellular milieu. LBRC later border recycling compartment