High extensibility of stress fibers revealed by in vitro micromanipulation with fluorescence imaging
High extensibility of stress fibers revealed by in vitro micromanipulation with fluorescence imaging
复制标题
通过荧光成像体外显微操作揭示应力纤维的高延展性
DOI：
10.1016/j.bbrc.2013.03.093
复制
发表时间：
2013
影响因子：
3.1
通讯作者：
Shinji Deguchi
中科院分区：
文献类型：
--
作者：
Tsubasa S. Matsui;Masaaki Sato;Shinji Deguchi
应力纤维（SF），肌动蛋白和肌球蛋白丝的亚细胞束，在其末端与细胞粘附物物理连接。通过SFs传递的细胞内力在细胞粘附调节和下游信号传导中起着重要作用。然而，生物物理特性固有的单个SF仍然知之甚少，部分原因是SF周围的其他细胞质成分，限制嵌入材料的变形。为了表征其独立于其他结构组分的固有特性，我们从血管平滑肌细胞中分离SF，并通过体外操作对其进行机械拉伸，同时用荧光量子点沿其长度沿着观察应变。SF沿着其整个长度伸长，长度约为无应力长度的4倍。这种令人惊讶的高延展性超出了由存在于SF中的肌动蛋白丝和肌球蛋白II双极丝的串联连接所解释的，从而表明在其被动生物物理性质中涉及其他结构组分。
Stress fibers (SFs), subcellular bundles of actin and myosin filaments, are physically connected at their ends to cell adhesions. The intracellular force transmitted via SFs plays an essential role in cell adhesion regulation and downstream signaling. However, biophysical properties intrinsic to individual SFs remain poorly understood partly because SFs are surrounded by other cytoplasmic components that restrict the deformation of the embedded materials. To characterize their inherent properties independent of other structural components, we isolated SFs from vascular smooth muscle cells and mechanically stretched them by in vitro manipulation while visualizing strain with fluorescent quantum dots attached along their length. SFs were elongated along their entire length, with the length being approximately 4-fold of the stress-free length. This surprisingly high extensibility was beyond that explained by the tandem connection of actin filaments and myosin II bipolar filaments present in SFs, thus suggesting the involvement of other structural components in their passive biophysical properties.