Buckling of actin stress fibers: A new wrinkle in the cytoskeletal tapestry
Buckling of actin stress fibers: A new wrinkle in the cytoskeletal tapestry
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DOI：
10.1002/cm.10056
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发表时间：
2002-08-01
影响因子：
--
通讯作者：
Yin, FCP
中科院分区：
文献类型：
--
作者：
Costa, KD;Hucker, WJ;Yin, FCP
细胞内张力被认为是细胞骨架结构和细胞功能的重要决定因素。然而，关于细胞骨架张力的许多细节仍然知之甚少，因为这些力不能在活细胞中直接测量。因此，我们已经开发出一种方法来表征的幅度和分布的预延伸的肌动蛋白应力纤维（SFs）由于静息张力在细胞骨架。使用定制的装置，将人主动脉内皮细胞（HAEC）在涂覆有纤连蛋白样聚合物的预拉伸的硅酮基底上培养。释放的基板引起的SF在粘附的细胞中的缩短方向对齐，以屈曲时，迅速压缩（5%缩短每秒或更大）超过其卸载松弛长度。随后，肌动蛋白细胞骨架在5秒内完全解体，并在60秒内重新组装。用罗丹明鬼笔环肽固定和染色的细胞的数字荧光显微照片中的屈曲定量表明在非屈曲HAEC中0-26%的SF延伸前的不均匀分布。局部变异性表明单个细胞内细胞骨架张力和/或刚度的异质性。这些研究结果提供了新的信息的大小和分布的细胞骨架张力和肌动蛋白应力纤维的动力学，该方法提供了一种新的方法来阐明特定的细胞骨架元素和交联蛋白在非肌肉细胞的力产生装置的作用。
Intracellular tension is considered an important determinant of cytoskeletal architecture and cell function. However, many details about cytoskeletal tension remain poorly understood because these forces cannot be directly measured in living cells. Therefore, we have developed a method to characterize the magnitude and distribution of pre-extension of actin stress fibers (SFs) due to resting tension in the cytoskeleton. Using a custom apparatus, human aortic endothelial cells (HAECs) were cultured on a pre-stretched silicone substrate coated with a fibronectin-like polymer. Release of the substrate caused SFs aligned in the shortening direction in adhered cells to buckle when compressed rapidly (5% shortening per second or greater) beyond their unloaded slack length. Subsequently, the actin cytoskeleton completely disassembled in 5 sec and reassembled within 60 sec. Quantification of buckling in digital fluorescent micrographs of cells fixed and stained with rhodamine phalloidin indicated a nonuniform distribution of 0-26% pre-extension of SFs in non-locomoting HAECs. Local variability suggests heterogeneity of cytoskeletal tension and/or stiffness within individual cells. These findings provide new information about the magnitude and distribution of cytoskeletal tension and the dynamics of actin stress fibers, and the approach offers a novel method to elucidate the role of specific cytoskeletal elements and crosslinking proteins in the force generating apparatus of non-muscle cells.