Insigneo Institute for in silico Medicine, University of Sheffield, Sheffield, United Kingdom.
Department of Mechanical Engineering, University of Sheffield, Sheffield, United Kingdom.
PLoS One. 2018 Oct 25;13(10):e0206056. doi: 10.1371/journal.pone.0206056. eCollection 2018.
The hyaluronic acid component of the glycocalyx plays a role in cell mechanotransduction by selectively transmitting mechanical signals to the cell cytoskeleton or to the cell membrane. The aim of this study was to evaluate the mechanical link between the hyaluronic acid molecule and the cell cytoskeleton by means of atomic force microscopy single molecule force spectroscopy. Hyaluronic acid molecules on live cells were targeted with probes coated with hyaluronic acid binding protein. Two different types of events were observed when the detachment of the target molecule from the probe occurred, suggesting the presence of cytoskeleton- and membrane-anchored molecules. Membrane-anchored molecules facilitated the formation of tethers when pulled. About 15% of the tested hyaluronic acid molecules were shown to be anchored to the cytoskeleton. When multiple molecules bonded to the probe, specific detachment patterns were observed, suggesting that a cytoskeletal bond needed to be broken to improve the ability to pull tethers from the cell membrane. This likely resulted in the formation of tethering structures maintaining a cytoskeletal core similar to the ones observed for cells over-expressing HA synthases. The different observed rupture events were associated with separate mechanotransductive mechanisms in an analogous manner to that previously proposed for the endothelial glycocalyx. Single cytoskeleton anchored rupture events represent HA molecules linked to the cytoskeleton and therefore transmitting mechanical stimuli into the inner cell compartments. Single membrane tethers would conversely represent the glycocalyx molecules connected to areas of the membrane where an abundance of signalling molecules reside.
糖萼中的透明质酸成分通过选择性地将机械信号传递到细胞骨架或细胞膜来在细胞力学转导中发挥作用。本研究旨在通过原子力显微镜单分子力谱来评估透明质酸分子与细胞骨架之间的机械联系。用涂有透明质酸结合蛋白的探针靶向活细胞上的透明质酸分子。当目标分子从探针上脱离时，观察到两种不同类型的事件，这表明存在与细胞骨架和膜锚定的分子。当拉动时，膜锚定的分子有助于形成连接。约 15%的测试透明质酸分子被证明锚定在细胞骨架上。当多个分子与探针结合时，观察到特定的脱离模式，这表明需要打破细胞骨架键才能提高从细胞膜上拉出线的能力。这可能导致形成维持细胞骨架核心的连接结构，类似于过度表达 HA 合酶的细胞中观察到的结构。不同观察到的断裂事件与类似的内皮糖萼中提出的单独力学转导机制相关。单个细胞骨架锚定的断裂事件代表与细胞骨架相连的 HA 分子，因此将机械刺激传递到细胞内部隔室。相反，单个膜系绳将代表与膜上存在大量信号分子的区域相连的糖萼分子。
