Contact guidance requires spatial control of leading-edge protrusion.
Contact guidance requires spatial control of leading-edge protrusion.
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DOI：
10.1091/mbc.e16-11-0769
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发表时间：
2017-04-15
影响因子：
3.3
通讯作者：
Gardel ML
中科院分区：
文献类型：
--
作者：
Ramirez-San Juan GR;Oakes PW;Gardel ML
接触引导的亚细胞机制还不完全清楚。微孔修饰底物的使用和突起动力学的定量分析表明，接触引导主要通过突起的空间调节和肌球蛋白II和rac1介导的反馈来调节。在体内，来自细胞外基质(ECM)的几何信号对于调节细胞的形状、黏附和迁移至关重要。在接触引导过程中，ECM的纤维状结构促进了细长的细胞形状和沿纤维的迁移。细胞感知ECM几何形状并将其转化为形状和迁移方向的变化的亚细胞机制尚不清楚。在这里，我们设计了线性纤维连接蛋白特征来模拟纤维状细胞外基质，并阐明了接触引导的机制。通过系统地改变图案线间距，我们表明2-μm间距足以促进平行于ECM或接触导引的细胞形状伸长和迁移。随着行距的增加，接触导引增加，而不影响迁移速度。为了阐明接触引导的亚细胞机制，我们对突起动力学进行了定量分析，发现结构化的ECM定向细胞突起平行于ECM。这种突起的空间组织依赖于肌球蛋白II的收缩能力，以及黏附和RAC介导的突起活动之间的反馈，因此我们发现抑制Arp2/3可以促进接触引导。总之，我们的数据支持接触指导的模型，在该模型中，ECM对片状脂膜施加空间约束，从而导致细胞形状延长并强制迁移方向。
Subcellular mechanisms underlying contact guidance are incompletely understood. Use of micoropatterned substrates and quantitative analysis of protrusion dynamics shows that contact guidance is mediated predominately though spatial regulation of protrusions and mediated through myosin II– and Rac1-mediated feedbacks. In vivo, geometric cues from the extracellular matrix (ECM) are critical for the regulation of cell shape, adhesion, and migration. During contact guidance, the fibrillar architecture of the ECM promotes an elongated cell shape and migration along the fibrils. The subcellular mechanisms by which cells sense ECM geometry and translate it into changes in shape and migration direction are not understood. Here we pattern linear fibronectin features to mimic fibrillar ECM and elucidate the mechanisms of contact guidance. By systematically varying patterned line spacing, we show that a 2-μm spacing is sufficient to promote cell shape elongation and migration parallel to the ECM, or contact guidance. As line spacing is increased, contact guidance increases without affecting migration speed. To elucidate the subcellular mechanisms of contact guidance, we analyze quantitatively protrusion dynamics and find that the structured ECM orients cellular protrusions parallel to the ECM. This spatial organization of protrusion relies on myosin II contractility, and feedback between adhesion and Rac-mediated protrusive activity, such that we find Arp2/3 inhibition can promote contact guidance. Together our data support a model for contact guidance in which the ECM enforces spatial constraints on the lamellipodia that result in cell shape elongation and enforce migration direction.