Dissecting regional variations in stress fiber mechanics in living cells with laser nanosurgery.
Dissecting regional variations in stress fiber mechanics in living cells with laser nanosurgery.
复制标题
利用激光纳米手术剖析活细胞中应力纤维力学的区域变化。
DOI：
10.1016/j.bpj.2010.08.071
复制
发表时间：
2010
影响因子：
3.4
通讯作者：
Kumar,Sanjay
中科院分区：
文献类型：
--
作者：
Tanner,Kandice;Boudreau,Aaron;Bissell,MinaJ;Kumar,Sanjay
细胞以空间异质方式将收缩应力分布在细胞外基质上的能力是许多细胞行为的基础，包括运动和组织组装。在这里，我们研究了这种现象的生物物理基础，通过使用飞秒激光nanosurgery测量粘弹性反冲和细胞形状的贡献收缩应力纤维（SF）位于特定的隔间的活细胞。在光致破裂和反冲，肌球蛋白轻链激酶依赖性的SF位于沿着细胞周边显示低得多的有效弹性和较高的平台收缩距离比Rho相关激酶依赖性的SF位于细胞中心，切断外周纤维独特地触发一个戏剧性的收缩的整个细胞在几分钟内的纤维照射。图像相关光谱显示，当一个人口的SFs是cross-dissipated，肌动蛋白密度流向其他人口。此外，周围纤维的消散降低了弹性并增加了中心纤维的平台收缩距离，并且在这些条件下切断中心纤维触发细胞收缩。总之，这些研究结果表明，不同的肌球蛋白激活剂调节的SF表现出不同的机械性能和细胞形状的贡献。他们还表明，一些纤维可以吸收成分，并承担其他纤维的机械作用，以稳定细胞形状。
The ability of a cell to distribute contractile stresses across the extracellular matrix in a spatially heterogeneous fashion underlies many cellular behaviors, including motility and tissue assembly. Here we investigate the biophysical basis of this phenomenon by using femtosecond laser nanosurgery to measure the viscoelastic recoil and cell-shape contributions of contractile stress fibers (SFs) located in specific compartments of living cells. Upon photodisruption and recoil, myosin light chain kinase-dependent SFs located along the cell periphery display much lower effective elasticities and higher plateau retraction distances than Rho-associated kinase-dependent SFs located in the cell center, with severing of peripheral fibers uniquely triggering a dramatic contraction of the entire cell within minutes of fiber irradiation. Image correlation spectroscopy reveals that when one population of SFs is pharmacologically dissipated, actin density flows toward the other population. Furthermore, dissipation of peripheral fibers reduces the elasticity and increases the plateau retraction distance of central fibers, and severing central fibers under these conditions triggers cellular contraction. Together, these findings show that SFs regulated by different myosin activators exhibit different mechanical properties and cell shape contributions. They also suggest that some fibers can absorb components and assume mechanical roles of other fibers to stabilize cell shape.