Adachi Taiji, Sato Katsuya, Higashi Norio, Tomita Yoshihiro, Hojo Masaki
Department of Mechanical Engineering and Science, Graduate School of Engineering, Kyoto University, Yoshida-honmachi, Sakyo, Kyoto 606-8501, Japan.
J Mech Behav Biomed Mater. 2008 Jan;1(1):43-50. doi: 10.1016/j.jmbbm.2007.06.003. Epub 2007 Aug 20.
Biochemical signals related to a mechanosensory mechanism by which cells sense mechanical stimuli have been gradually clarified by biological approaches such as blocking specific signaling pathways; however, mechanical signals such as deformation/strain, which is transduced into biochemical signals through this mechanism, particularly at the cellular structural component level in a single cell, have not yet been clearly understood. This in vitro study focuses on an intracellular calcium signaling response to an applied localized deformation in a single osteoblast-like MC3T3-E1 cell, and observed localized deformation of a cell membrane and the calcium ion flux from an extracellular medium. The localized deformation was applied to a cell by indenting a microsphere onto the cell membrane using a glass microneedle. The cellular calcium signaling response and cell membrane deformation were simultaneously observed using fluorescent dyes in a vertical section under a confocal laser-scanning microscope with high spatial and temporal resolutions. Our results observed in the vertical section showed that the initiation point of the calcium ion flux is collocated at the displaced microsphere around which stretch membrane deformation was observed.
通过诸如阻断特定信号通路等生物学方法，与细胞感知机械刺激的机械感觉机制相关的生化信号已逐渐明晰；然而，诸如变形/应变等机械信号，通过该机制转化为生化信号，特别是在单细胞的细胞结构成分层面，目前尚未得到清晰的理解。这项体外研究聚焦于单个成骨样MC3T3-E1细胞对施加的局部变形的细胞内钙信号反应，并观察了细胞膜的局部变形以及细胞外介质中的钙离子通量。通过使用玻璃微针将微球压入细胞膜，对细胞施加局部变形。在具有高空间和时间分辨率的共聚焦激光扫描显微镜下，使用荧光染料在垂直切片中同时观察细胞钙信号反应和细胞膜变形。我们在垂直切片中观察到的结果表明，钙离子通量的起始点位于位移微球处，在其周围观察到拉伸膜变形。
