Real-time imaging of vascular endothelial-cadherin during leukocyte transmigration across endothelium
Real-time imaging of vascular endothelial-cadherin during leukocyte transmigration across endothelium
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DOI：
10.4049/jimmunol.167.4.2323
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发表时间：
2001-08-15
影响因子：
4.4
通讯作者：
Luscinskas, FW
中科院分区：
文献类型：
--
作者：
Shaw, SK;Bamba, PS;Luscinskas, FW
血管内皮钙粘蛋白（Vascular endothelial-cadherin，VE-cadherin）是内皮细胞粘附连接的组成部分，其在白细胞向内皮迁移中的作用一直存在争议。使用VE-钙粘蛋白/绿色荧光蛋白融合构建体（VEcadGFP），模拟天然分子，我们可视化内皮连接结构的变化在真实的时间在人中性粒细胞和单核细胞在体外流动模型中的迁移。我们观察到大量的轮回只发生在细胞边界（paracellarely）。令人惊讶的是，通过VECadGFP连接分布中的瞬时间隙的从头形成，以及通过预先存在的间隙，都发生了迁移。在白细胞到达连接处后形成4-6 μ m大小的从头间隙，而预先存在的间隙甚至在白细胞与有助于连接的内皮细胞相互作用之前就存在。白细胞回移后5分钟内，间隙迅速重新闭合。迁移的白细胞似乎在连接平面中将VEcadGFP推到一边，并且这种移位的材料随后扩散回来重新填充连接。据我们所知，这是第一个例子，在横向连接的分子事件已被跟踪在真实的时间在轮回。
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 mum 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.