Lampe P D, Nguyen B P, Gil S, Usui M, Olerud J, Takada Y, Carter W G
Divisions of Basic Sciences and Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA.
J Cell Biol. 1998 Dec 14;143(6):1735-47. doi: 10.1083/jcb.143.6.1735.
Wounding of skin activates epidermal cell migration over exposed dermal collagen and fibronectin and over laminin 5 secreted into the provisional basement membrane. Gap junctional intercellular communication (GJIC) has been proposed to integrate the individual motile cells into a synchronized colony. We found that outgrowths of human keratinocytes in wounds or epibole cultures display parallel changes in the expression of laminin 5, integrin alpha3beta1, E-cadherin, and the gap junctional protein connexin 43. Adhesion of keratinocytes on laminin 5, collagen, and fibronectin was found to differentially regulate GJIC. When keratinocytes were adhered on laminin 5, both structural (assembly of connexin 43 in gap junctions) and functional (dye transfer) assays showed a two- to threefold increase compared with collagen and five- to eightfold over fibronectin. Based on studies with immobilized integrin antibody and integrin-transfected Chinese hamster ovary cells, the interaction of integrin alpha3beta1 with laminin 5 was sufficient to promote GJIC. Mapping of intermediate steps in the pathway linking alpha3beta1-laminin 5 interactions to GJIC indicated that protein trafficking and Rho signaling were both required. We suggest that adhesion of epithelial cells to laminin 5 in the basement membrane via alpha3beta1 promotes GJIC that integrates individual cells into synchronized epiboles.
皮肤创伤会激活表皮细胞在暴露的真皮胶原蛋白、纤连蛋白以及分泌到临时基底膜中的层粘连蛋白5上迁移。间隙连接细胞间通讯（GJIC）被认为可将单个运动细胞整合为一个同步的群体。我们发现，伤口或外包培养中的人角质形成细胞生长物在层粘连蛋白5、整合素α3β1、E-钙黏蛋白和间隙连接蛋白连接蛋白43的表达上呈现平行变化。发现角质形成细胞在层粘连蛋白5、胶原蛋白和纤连蛋白上的黏附会差异性地调节GJIC。当角质形成细胞黏附在层粘连蛋白5上时，结构分析（连接蛋白43在间隙连接中的组装）和功能分析（染料转移）均显示，与胶原蛋白相比增加了两到三倍，与纤连蛋白相比增加了五到八倍。基于对固定化整合素抗体和整合素转染的中国仓鼠卵巢细胞的研究，整合素α3β1与层粘连蛋白5的相互作用足以促进GJIC。对连接α3β1-层粘连蛋白5相互作用与GJIC的途径中的中间步骤进行定位表明，蛋白质运输和Rho信号传导都是必需的。我们认为，上皮细胞通过α3β1与基底膜中的层粘连蛋白5黏附可促进GJIC，从而将单个细胞整合为同步的外包。
