Real-time imaging of vascular endothelial-cadherin during leukocyte transmigration across endothelium.
Vascular endothelial-cadherin (VE-cadherin) is a component of the adherens junctions of endothelial cells whose role in endothelial transmigration of leukocytes has been controversial. Using a VE-cadherin/green fluorescent protein fusion construct (VEcadGFP) that mimics the native molecule, we visualized alterations in endothelial junctional structure in real time during transmigration of human neutrophils and monocytes in an in vitro flow model. We observed abundant transmigration occurring exclusively at the cell borders (paracellularly). Surprisingly, transmigration occurred both through de novo formation of transient gaps in VEcadGFP junctional distribution, and also through preexisting gaps. De novo gaps 4-6 microm in size were formed after a leukocyte arrived at a junction, whereas preexisting gaps were present even before the leukocyte had interacted with the endothelial cells contributing to a junction. Gaps rapidly resealed within 5 min after leukocyte transmigration. Migrating leukocytes appeared to push aside VEcadGFP in the plane of the junction, and this displaced material subsequently diffused back to refill the junction. To our knowledge, this is the first example where molecular events at the lateral junction have been tracked in real time during transmigration.
Shaw
S K
SK
Vascular Research Division, Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA. sshaw@rics.bwh.harvard.edu
Bamba
P S
PS
Perkins
B N
BN
Luscinskas
F W
FW
D015703:Antigens, CD; D015820:Cadherins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D002450:Cell Communication / Q000235:genetics; D002460:Cell Line; D002463:Cell Membrane Permeability / Q000235:genetics; D002465:Cell Movement / Q000235:genetics; D003598:Cytoskeletal Proteins / Q000378:metabolism; D051180:Desmoplakins; D015194:Diffusion Chambers, Culture / Q000379:methods; D004730:Endothelium, Vascular / Q000166:cytology* / Q000378:metabolism / Q000502:physiology*; D005822:Genetic Vectors / Q000096:biosynthesis / Q000502:physiology; D049452:Green Fluorescent Proteins; D018056:Hemorheology; D006801:Humans; D007089:Image Enhancement / Q000295:instrumentation / Q000379:methods*; D007365:Intercellular Junctions / Q000378:metabolism; D007700:Kinetics; D007962:Leukocytes / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D008164:Luminescent Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D008856:Microscopy, Fluorescence / Q000295:instrumentation / Q000379:methods*; D009000:Monocytes / Q000166:cytology / Q000378:metabolism / Q000502:physiology; D009504:Neutrophils / Q000166:cytology / Q000378:metabolism / Q000502:physiology; D015534:Trans-Activators; D014162:Transfection; D051176:beta Catenin; D000099152:Cadherin 5
D015703:Antigens, CD; D015820:Cadherins; D003598:Cytoskeletal Proteins; D051180:Desmoplakins; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins; D015534:Trans-Activators; D051176:beta Catenin; D000099152:Cadherin 5; C495270:CTNNB1 protein, human