Blavatnik School of Computer Science, Tel Aviv University, Tel Aviv, Israel.
PLoS One. 2012;7(9):e44671. doi: 10.1371/journal.pone.0044671. Epub 2012 Sep 6.
Collective cell migration plays a major role in embryonic morphogenesis, tissue remodeling, wound repair and cancer invasion. Despite many decades of extensive investigations, only few analytical tools have been developed to enhance the biological understanding of this important phenomenon. Here we present a novel quantitative approach to analyze long term kinetics of bright field time-lapse wound healing. Fully-automated spatiotemporal measures and visualization of cells' motility and implicit morphology were proven to be sound, repetitive and highly informative compared to single-cell tracking analysis. We study cellular collective migration induced by tyrosine kinase-growth factor signaling (Met-Hepatocyte Growth Factor/Scatter Factor (HGF/SF)). Our quantitative approach is applied to demonstrate that collective migration of the adenocarcinoma cell lines is characterized by simple morpho-kinetics. HGF/SF induces complex morpho-kinetic coordinated collective migration: cells at the front move faster and are more spread than those further away from the wound edge. As the wound heals, distant cells gradually accelerate and enhance spread and elongation -resembling the epithelial to mesenchymal transition (EMT), and then the cells become more spread and maintain higher velocity than cells located closer to the wound. Finally, upon wound closure, front cells halt, shrink and round up (resembling mesenchymal to epithelial transition (MET) phenotype) while distant cells undergo the same process gradually. Met inhibition experiments further validate that Met signaling dramatically alters the morpho-kinetic dynamics of the healing wound. Machine-learning classification was applied to demonstrate the generalization of our findings, revealing even subtle changes in motility patterns induced by Met-inhibition. It is concluded that activation of Met-signaling induces an elaborated model in which cells lead a coordinated increased motility along with gradual differentiation-based collective cell motility dynamics. Our quantitative phenotypes may guide future investigation on the molecular and cellular mechanisms of tyrosine kinase-induced coordinate cell motility and morphogenesis in metastasis.
细胞集体迁移在胚胎形态发生、组织重塑、伤口修复和癌症侵袭中起着重要作用。尽管经过了几十年的广泛研究，但只有少数分析工具被开发出来，以增强对这一重要现象的生物学理解。在这里，我们提出了一种新的定量方法来分析明场延时伤口愈合的长期动力学。与单细胞跟踪分析相比，全自动的时空测量和细胞运动的可视化以及细胞内隐形态的可视化被证明是可靠的、可重复的和高度信息丰富的。我们研究了由酪氨酸激酶-生长因子信号（Met-肝细胞生长因子/散射因子（HGF/SF））诱导的细胞集体迁移。我们的定量方法被应用于证明腺癌细胞系的集体迁移具有简单的形态动力学特征。HGF/SF 诱导复杂的形态动力学协调集体迁移：位于前沿的细胞比远离伤口边缘的细胞移动更快，扩散程度更高。随着伤口的愈合，远处的细胞逐渐加速并增强扩散和伸长-类似于上皮到间质转化（EMT），然后细胞比靠近伤口的细胞更扩散并保持更高的速度。最后，当伤口闭合时，前沿细胞停止、收缩并变圆（类似于间质到上皮转化（MET）表型），而远处的细胞逐渐经历相同的过程。Met 抑制实验进一步验证了 Met 信号显著改变了愈合伤口的形态动力学。机器学习分类被应用于证明我们的发现具有普遍性，甚至可以揭示 Met 抑制诱导的运动模式的细微变化。结论是，Met 信号的激活诱导了一个精细的模型，其中细胞沿着协调的增加的运动性以及逐渐基于分化的集体细胞运动动力学进行引导。我们的定量表型可能会指导未来对酪氨酸激酶诱导的协调细胞运动和形态发生的分子和细胞机制的研究。
