Endothelial cells use dynamic actin to facilitate lymphocyte transendothelial migration and maintain the monolayer barrier.
Bottom Line: The actin cytoskeleton of the endothelial cell (EC) is known to facilitate transmigration, but the cellular and molecular mechanisms are not well understood.We found that docking structure formation involves the localization and activation of Arp2/3 complex by WAVE2.Finally, we found that ECs in resting endothelial monolayers use lamellipodial protrusions dependent on WAVE2 to form and maintain contacts and junctions between cells.
Affiliation: Department of Cell Biology and Physiology, Washington University, St. Louis, MO 63110.Show MeSH
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Mentions: To investigate the molecular basis for the loss of monolayer integrity upon depletion of WAVE2, we examined the molecular composition of cell contacts and cell–cell junctions using immunofluorescence. In control monolayers, VE-cadherin was predominantly organized in a pattern typical for mature junctions—continuous linear structures coinciding with cell–cell contacts (Figure 6A). In contrast, WAVE-depleted monolayers showed very few VE-cadherin–positive cell junctions (Figure 6A). The number of gaps in the junctions increased from 3.0 ± 1.0/fov (mean ± SD, N = 6 fov) in control monolayers to 11.2 ± 2.3/fov in WAVE2-knockdown monolayers. This difference was statistically significant, with p < 0.001.
Affiliation: Department of Cell Biology and Physiology, Washington University, St. Louis, MO 63110.