Institute of Physical Chemistry, University of Göttingen , Tammannstr. 6, 37077 Göttingen, Germany.
Third Institute of Physics, University of Göttingen , Friedrich-Hund-Platz 1, 37077 Göttingen, Germany.
Nano Lett. 2017 May 10;17(5):3320-3326. doi: 10.1021/acs.nanolett.7b01558. Epub 2017 Apr 27.
The biological process of the epithelial-to-mesenchymal transition (EMT) allows epithelial cells to enhance their migratory and invasive behavior and plays a key role in embryogenesis, fibrosis, wound healing, and metastasis. Among the multiple biochemical changes from an epithelial to a mesenchymal phenotype, the alteration of cellular dynamics in cell-cell as well as cell-substrate contacts is crucial. To determine these variations over the whole time scale of the EMT, we measure the cell-substrate distance of epithelial NMuMG cells during EMT using our newly established metal-induced energy transfer (MIET) microscopy, which allows one to achieve nanometer axial resolution. We show that, in the very first hours of the transition, the cell-substrate distance increases substantially, but later in the process after reaching the mesenchymal state, this distance is reduced again to the level of untreated cells. These findings relate to a change in the number of adhesion points and will help to better understand remodeling processes associated with wound healing, embryonic development, cancer progression, or tissue regeneration.
上皮-间充质转化（EMT）的生物学过程使上皮细胞增强其迁移和侵袭行为，并在胚胎发生、纤维化、伤口愈合和转移中发挥关键作用。在从上皮到间充质表型的多种生化变化中，细胞-细胞以及细胞-基质接触中细胞动力学的改变至关重要。为了在 EMT 的整个时间尺度上确定这些变化，我们使用新建立的金属诱导能量转移（MIET）显微镜测量 EMT 期间上皮 NMuMG 细胞与细胞-基质的距离，这使得能够实现纳米级的轴向分辨率。我们表明，在过渡的最初几个小时内，细胞-基质的距离大大增加，但在达到间充质状态后，这个距离再次减少到未处理细胞的水平。这些发现与粘附点数量的变化有关，并将有助于更好地理解与伤口愈合、胚胎发育、癌症进展或组织再生相关的重塑过程。
