a Department of Biomedicine , Laboratory for Signal Transduction, University Hospital Basel and University of Basel , Basel , Switzerland.
Cell Adh Migr. 2018 Jan 2;12(1):69-85. doi: 10.1080/19336918.2017.1319545. Epub 2017 May 25.
Vascular smooth muscle cell (SMC) switching between differentiated and dedifferentiated phenotypes is reversible and accompanied by morphological and functional alterations that require reconfiguration of cell-cell and cell-matrix adhesion networks. Studies attempting to explore changes in overall composition of the adhesion nexus during SMC phenotype transition are lacking. We have previously demonstrated that T-cadherin knockdown enforces SMC differentiation, whereas T-cadherin upregulation promotes SMC dedifferentiation. This study used human aortic SMCs ectopically modified with respect to T-cadherin expression to characterize phenotype-associated cell-matrix adhesion molecule expression, focal adhesions configuration and migration modes. Compared with dedifferentiated/migratory SMCs (expressing T-cadherin), the differentiated/contractile SMCs (T-cadherin-deficient) exhibited increased adhesion to several extracellular matrix substrata, decreased expression of several integrins, matrix metalloproteinases and collagens, and also distinct focal adhesion, adherens junction and intracellular tension network configurations. Differentiated and dedifferentiated phenotypes displayed distinct migrational velocity and directional persistence. The restricted migration efficiency of the differentiated phenotype was fully overcome by reducing actin polymerization with ROCK inhibitor Y-27632 whereas myosin II inhibitor blebbistatin was less effective. Migration efficiency of the dedifferentiated phenotype was diminished by promoting actin polymerization with lysophosphatidic acid. These findings held true in both 2D-monolayer and 3D-spheroid migration models. Thus, our data suggest that despite global differences in the cell adhesion nexus of the differentiated and dedifferentiated phenotypes, structural actin cytoskeleton characteristics per se play a crucial role in permissive regulation of cell-matrix adhesive interactions and cell migration behavior during T-cadherin-induced SMC phenotype transition.
血管平滑肌细胞 (SMC) 在分化和去分化表型之间的转换是可逆的，并伴随着形态和功能的改变，这需要重新配置细胞-细胞和细胞-基质黏附网络。目前缺乏研究试图探索在 SMC 表型转变过程中黏附连接体的整体组成变化。我们之前的研究表明，T-钙黏蛋白敲低可促进 SMC 分化，而 T-钙黏蛋白上调可促进 SMC 去分化。本研究使用 T-钙黏蛋白表达异位修饰的人主动脉 SMC 来表征与表型相关的细胞-基质黏附分子表达、黏附斑结构和迁移模式。与去分化/迁移的 SMC（表达 T-钙黏蛋白）相比，分化/收缩的 SMC（T-钙黏蛋白缺陷）表现出对几种细胞外基质底物的粘附增加，几种整合素、基质金属蛋白酶和胶原蛋白的表达减少，以及独特的黏附斑、黏着斑连接和细胞内张力网络结构。分化和去分化表型表现出不同的迁移速度和方向持续性。用 ROCK 抑制剂 Y-27632 降低肌动蛋白聚合可完全克服分化表型的受限迁移效率，而肌球蛋白 II 抑制剂 blebbistatin 效果较差。用溶血磷脂酸促进肌动蛋白聚合可降低去分化表型的迁移效率。这些发现不仅在 2D 单层和 3D 球体迁移模型中成立。因此，我们的数据表明，尽管分化和去分化表型的细胞黏附连接体存在全局差异，但结构肌动蛋白细胞骨架特征本身在 T-钙黏蛋白诱导的 SMC 表型转变过程中对细胞-基质黏附相互作用和细胞迁移行为的许可调节中起着至关重要的作用。
