Cell shape, cytoskeletal mechanics, and cell cycle control in angiogenesis
Cell shape, cytoskeletal mechanics, and cell cycle control in angiogenesis
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DOI：
10.1016/0021-9290(95)00095-x
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发表时间：
1995-12-01
影响因子：
2.4
通讯作者：
Wang, N
中科院分区：
文献类型：
--
作者：
Ingber, DE;Prusty, D;Wang, N
毛细血管内皮细胞可以通过改变细胞-细胞外基质的相互作用而在生长和分化之间切换，从而调节细胞的形状。研究的目的是确定细胞形状在细胞周期进程中何时发挥其生长调节作用，并探索细胞骨架结构和力学在这一控制机制中的作用。当G(0)-同步化细胞在含有碱性成纤维细胞生长因子(FGF)的特定培养基中培养在涂有增加密度的纤维连接蛋白或合成整合素配体(RGD-含肽)的培养皿中时，细胞伸展、核伸展和DNA合成都平行增加。为了确定细胞在细胞外基质上贴壁和铺展进入S时相所需的最短时间，在细胞接种后不同时间用胰酶去除细胞或用细胞松弛素D诱导细胞回缩。这两种方法都表明，细胞必须保持伸展大约12-15小时，因此，G(1)的大部分，才能进入S阶段。在这个限制点通过后，正常情况下“锚定依赖”的内皮细胞即使在圆形和悬浮状态下也会开启DNA合成。含有肌动蛋白的微丝在形状依赖的生长控制中的重要性通过在细胞松弛素D(25-1000 ng ml(-1))存在的情况下培养细胞而得到证实：细胞扩展、核扩展和DNA合成受到剂量依赖性的抑制。相反，诺可达唑诱导的微管解体对细胞或核的扩散几乎没有影响，仅部分抑制了DNA的合成。有趣的是，诺考达唑与次佳剂量的细胞松弛素D(100 ng ml(-1))的结合导致了对伸展和生长的有效抑制，这表明微管是多余的结构元件，当微丝部分受损时，它可以提供关键的承载功能。当用磁性扭转细胞仪直接测量活细胞的细胞骨架硬度时，观察到诺可达唑和细胞松弛素D之间的协同作用相似。这些结果强调了依赖于基质的细胞和核形状的变化以及不同细胞骨架细丝系统之间的高阶结构相互作用对于控制血管生成过程中毛细血管细胞的生长的重要性。
Capillary endothelial cells can be switched between growth and differentiation by altering cell-extracellular matrix interactions and thereby, modulating cell shape. Studies were carried out to determine when cell shape exerts its growth-regulatory influence during cell cycle progression and to explore the role of cytoskeletal structure and mechanics in this control mechanism. When G(0)-synchronized cells were cultured in basic fibroblast growth factor (FGF)-containing defined medium on dishes coated with increasing densities of fibronectin or a synthetic integrin ligand (RGD-containing peptide), cell spreading,nuclear extension, and DNA synthesis all increased in parallel. To determine the minimum time cells must be adherent and spread on extracellular matrix (ECM) to gain entry into S phase, cells were removed with trypsin or induced to retract using cytochalasin D at different times after plating. Both approaches revealed that cells must remain extended for approximately 12-15 h and hence, most of G(1), in order to enter S phase. After this restriction point was passed, normally 'anchorage-dependent' endothelial cells turned on DNA synthesis even when round and in suspension. The importance of actin-containing microfilaments in shape-dependent growth control was confirmed by culturing cells in the presence of cytochalasin D (25-1000 ng ml(-1)): dose-dependent inhibition of cell spreading, nuclear extension, and DNA synthesis resulted. In contrast, induction of microtubule disassembly using nocodazole had little effect on cell or nuclear spreading and only partially inhibited DNA synthesis. Interestingly, combination of nocodazole with a suboptimal dose of cytochalasin D (100 ng ml(-1)) resulted in potent inhibition of both spreading and growth, suggesting that microtubules are redundant structural elements which can provide critical load-bearing functions when microfilaments are partially compromised. Similar synergism between nocodazole and cytochalasin D was observed when cytoskeletal stiffness was measured directly in living cells using magnetic twisting cytometry. These results emphasize the importance of matrix-dependent changes in cell and nuclear shape as well as higher order structural interactions between different cytoskeletal filament systems for control of capillary cell growth during angiogenesis.