Limits...
Endothelial cells use dynamic actin to facilitate lymphocyte transendothelial migration and maintain the monolayer barrier.

Mooren OL, Li J, Nawas J, Cooper JA - Mol. Biol. Cell (2014)

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.

View Article: PubMed Central - PubMed

Affiliation: Department of Cell Biology and Physiology, Washington University, St. Louis, MO 63110.

Show MeSH

Related in: MedlinePlus

WAVE2 controls the organization of actin-myosin fibers in ECs. Areas with well-spread cells were selected to reveal circumferential actin–myosin rings and stress fibers. (A) Control and WAVE2-knockdown endothelial monolayers stained for F-actin and myosin-IIA. Scale bar, 50 μm. (B) Line scans across representative actin–myosin rings in control and WAVE2-depleted cells. (C) WAVE2 influences changes in circumferential actin rings and stress fibers induced by TNFα. Arrows indicate the circumferential to linear change in actin organization that results from TNFα. When WAVE2 is depleted, circumferential actin is increased and stress fibers are decreased with and without TNFα. Scale bar, 50 μm.
© Copyright Policy - creative-commons
Related In: Results  -  Collection


getmorefigures.php?uid=PMC4263454&req=5

Figure 8: WAVE2 controls the organization of actin-myosin fibers in ECs. Areas with well-spread cells were selected to reveal circumferential actin–myosin rings and stress fibers. (A) Control and WAVE2-knockdown endothelial monolayers stained for F-actin and myosin-IIA. Scale bar, 50 μm. (B) Line scans across representative actin–myosin rings in control and WAVE2-depleted cells. (C) WAVE2 influences changes in circumferential actin rings and stress fibers induced by TNFα. Arrows indicate the circumferential to linear change in actin organization that results from TNFα. When WAVE2 is depleted, circumferential actin is increased and stress fibers are decreased with and without TNFα. Scale bar, 50 μm.

Mentions: Many WAVE2-depleted cells displayed rounded-up and blebbing morphologies, as noted earlier. These cells did not contain either circumferential F-actin or stress fibers (Supplemental Figure S5A, red stars). Therefore, for this analysis, we focused on cells that were in a monolayer and fully spread. We observed that the fluorescence intensity of myosin-II and F-actin in circumferential F-actin fibers in such cells was increased in WAVE2-depleted endothelial monolayers compared with control-cell monolayers (Figure 8, A and B). This finding suggests that increased tension from circumferential actin causes WAVE2-depleted cells to round up.


Endothelial cells use dynamic actin to facilitate lymphocyte transendothelial migration and maintain the monolayer barrier.

Mooren OL, Li J, Nawas J, Cooper JA - Mol. Biol. Cell (2014)

WAVE2 controls the organization of actin-myosin fibers in ECs. Areas with well-spread cells were selected to reveal circumferential actin–myosin rings and stress fibers. (A) Control and WAVE2-knockdown endothelial monolayers stained for F-actin and myosin-IIA. Scale bar, 50 μm. (B) Line scans across representative actin–myosin rings in control and WAVE2-depleted cells. (C) WAVE2 influences changes in circumferential actin rings and stress fibers induced by TNFα. Arrows indicate the circumferential to linear change in actin organization that results from TNFα. When WAVE2 is depleted, circumferential actin is increased and stress fibers are decreased with and without TNFα. Scale bar, 50 μm.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4263454&req=5

Figure 8: WAVE2 controls the organization of actin-myosin fibers in ECs. Areas with well-spread cells were selected to reveal circumferential actin–myosin rings and stress fibers. (A) Control and WAVE2-knockdown endothelial monolayers stained for F-actin and myosin-IIA. Scale bar, 50 μm. (B) Line scans across representative actin–myosin rings in control and WAVE2-depleted cells. (C) WAVE2 influences changes in circumferential actin rings and stress fibers induced by TNFα. Arrows indicate the circumferential to linear change in actin organization that results from TNFα. When WAVE2 is depleted, circumferential actin is increased and stress fibers are decreased with and without TNFα. Scale bar, 50 μm.
Mentions: Many WAVE2-depleted cells displayed rounded-up and blebbing morphologies, as noted earlier. These cells did not contain either circumferential F-actin or stress fibers (Supplemental Figure S5A, red stars). Therefore, for this analysis, we focused on cells that were in a monolayer and fully spread. We observed that the fluorescence intensity of myosin-II and F-actin in circumferential F-actin fibers in such cells was increased in WAVE2-depleted endothelial monolayers compared with control-cell monolayers (Figure 8, A and B). This finding suggests that increased tension from circumferential actin causes WAVE2-depleted cells to round up.

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.

View Article: PubMed Central - PubMed

Affiliation: Department of Cell Biology and Physiology, Washington University, St. Louis, MO 63110.

Show MeSH
Related in: MedlinePlus