PLASMALEMMAL PROTEINS OF CULTURED VASCULAR ENDOTHELIAL-CELLS EXHIBIT APICAL BASAL POLARITY - ANALYSIS BY SURFACE-SELECTIVE IODINATION
PLASMALEMMAL PROTEINS OF CULTURED VASCULAR ENDOTHELIAL-CELLS EXHIBIT APICAL BASAL POLARITY - ANALYSIS BY SURFACE-SELECTIVE IODINATION
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DOI：
10.1083/jcb.103.6.2389
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发表时间：
1986-12-01
影响因子：
7.8
通讯作者：
GIMBRONE, MA
中科院分区：
文献类型：
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作者：
MULLER, WA;GIMBRONE, MA
体内血管内皮似乎起极化上皮的作用。为了确定细胞极性是否存在于质膜的水平，我们已经检查了培养的内皮细胞单层的外部处理质膜蛋白质在顶端和基底细胞表面的差异分布的证据。使用乳过氧化物酶珠选择性标记融合内皮单层的顶面、非酶促重悬细胞的总表面和倒置在聚-L-赖氨酸包被的盖玻片上的单层的底面，同时在所有样品中保持> 98%的活力。比较每个表面获得的SDS PAGE放射性碘标记模式显示了一些特定的带显着丰富的顶端或基底表面。这种极化分布涉及膜相关的以及完整的膜蛋白，并观察到在几个菌株的牛主动脉内皮细胞，以及在原代和传代的人脐静脉内皮细胞。相比之下，两种形态非极化的细胞类型，牛主动脉平滑肌和小鼠腹腔巨噬细胞，没有显示差异定位的完整的膜蛋白的融合单层形成之前建立。当倒置（基底侧向上）单层返回培养，顶端侧向上的模式在几天内重新表达。这些结果表明，质膜蛋白的细胞表面选择性表达是体外活内皮细胞的固有特性。这种顶端/基底膜结构的不对称性可能为体内极化内皮功能提供了基础。
Vascular endothelium in vivo appears to function as a polarized epithelium. To determine whether cellular polarity exists at the level of the plasma membrane, we have examined cultured endothelial monolayers for evidence of differential distribution of externally disposed plasmalemmal proteins at apical and basal cell surfaces. Lactoperoxidase beads were used to selectively label the apical surfaces of confluent endothelial monolayers, the total surfaces of nonenzymatically resuspended cells, and the basal surfaces of monolayers inverted on poly-L-lysine-coated coverslips, while maintaining > 98% viability in all samples. Comparison of the SDS PAGE radioiodination patterns obtained for each surface revealed a number of specific bands markedly enriched on either apical or basal surface. This polarized distribution involved membrane-associated as well as integral membrane proteins and was observed in several strains of bovine aortic endothelial cells, as well as in both primary and passaged human umbilical vein endothelial cells. In contrast, two morphologically nonpolarized cell types, bovine aortic smooth muscle and mouse peritoneal macrophages, did not display differential localization of integral membrane proteins was established before the formation of a confluent monolayer. When inverted (basal-side-up) monolayers were returned to culture, the apical-side-up pattern was reexpressed within a few days. These results demonstrate that cell-surface-selective expression of plasmalemmal proteins is an intrinsic property of viable endothelial cells in vitro. This apical/basal asymmetry of membrane structure may provide a basis for polarized endothelial functions in vivo.