Department of Functional Molecular Biology, Graduate School of Medicine, Yamaguchi University, Yamaguchi, Japan.
Biotechniques. 2009 Sep;47(3):757-67. doi: 10.2144/000113217.
Living cells are constantly subjected to various mechanical stimulations. They must sense the mechanical aspects of their environment and respond appropriately for proper cell function. In general, cells adhere to substrata. Thus, the cells must receive and respond to mechanical stimuli mainly from the substrata. For example, migrating cells can create their own polarity and migrate in a certain direction even in the absence of any attractive substance. In order to generate such polarity, cells must sense mechanical stimuli from the substrata and transduce these stimuli into intracellular signals. To investigate the relationship between signals derived from mechanical stimuli and related cell functions, one of the most commonly used techniques is the application of mechanical stimuli via stretching of elastic substrata. Here, we developed a new stretching device using a shape-memory alloy (SMA). An SMA has three advantages as an actuator of stretching devices: (i) the cost of the SMA required for the device is inexpensive, approximately 30 USD, (ii) the size of an SMA is very small (0.62 mm in diameter and 22 mm in length), and (iii) an SMA does not generate any vibrating noise, which can negatively affect cells. In response to the cyclic stretching by the new stretching device, Dictyostelium discoideum cells migrated perpendicular to the stretching direction and the migrating speed increased significantly. To our knowledge, this is the first report indicating that migrating cells can create their own polarity by the mechanical stimuli from the substrata.
活细胞不断受到各种机械刺激。它们必须感知环境的机械方面，并做出适当的反应以维持正常的细胞功能。通常情况下，细胞会附着在基质上。因此，细胞必须主要从基质接收并响应机械刺激。例如，迁移的细胞可以在没有任何有吸引力的物质的情况下产生自己的极性并朝着某个特定的方向迁移。为了产生这种极性，细胞必须感知来自基质的机械刺激，并将这些刺激转化为细胞内信号。为了研究机械刺激衍生的信号与相关细胞功能之间的关系，最常用的技术之一是通过弹性基质的拉伸来施加机械刺激。在这里，我们使用形状记忆合金 (SMA) 开发了一种新的拉伸装置。SMA 作为拉伸装置的致动器具有三个优点：(i) 该装置所需 SMA 的成本低廉，约为 30 美元，(ii) SMA 的尺寸非常小（直径为 0.62 毫米，长度为 22 毫米），以及 (iii) SMA 不会产生任何可能会对细胞产生负面影响的振动噪声。响应新拉伸装置的循环拉伸，Dictyostelium discoideum 细胞垂直于拉伸方向迁移，迁移速度显著提高。据我们所知，这是第一个表明迁移细胞可以通过基质的机械刺激产生自己的极性的报告。
