A novel platform for in situ investigation of cells and tissues under mechanical strain
A novel platform for in situ investigation of cells and tissues under mechanical strain
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DOI：
10.1016/j.actbio.2010.02.035
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发表时间：
2010-08-01
影响因子：
9.7
通讯作者：
Saif, T. A.
中科院分区：
文献类型：
--
作者：
Ahmed, W. W.;Kural, M. H.;Saif, T. A.
机械微环境影响细胞的迁移、增殖、分化和凋亡等反应。细胞在体内受到机械拉伸，例如，胚胎发生过程中的上皮细胞，目前的方法不能高分辨率地原位观察施加应变下的细胞和组织，这可能揭示细胞内的动力学和细胞机械敏感性的起源。开发了一种新型的聚二甲基硅氧烷衬底，能够对细胞和组织施加高达45%的拉伸和压缩应变，同时允许使用高分辨率光学元件进行原位观察。用数字图像相关方法对底物的应变场进行了实验表征，并用有限元方法对其变形进行了模拟，采用Mooney-Rivlin超弹性本构关系，发现95%的底物区域的底物应变是均匀的。在实时成像过程中，对单个转GFP-肌动蛋白的成纤维细胞和表达GFP的整个转基因果蝇胚胎施加机械应变，观察到三种生物反应线索：(1)成纤维细胞中完整的肌动蛋白应激纤维的动态旋转；(2)成纤维细胞中肌动蛋白的活性和肌动蛋白聚合；(3)果蝇胚胎运动神经元中活跃的轴突收缩。新的平台可以作为研究细胞和组织机械反应的重要工具，包括由Elsevier Ltd出版的完整胚胎(C)2010物质学报，版权所有
The mechanical micro-environment influences cellular responses such as migration, proliferation, differentiation and apoptosis. Cells are subjected to mechanical stretching in vivo, e g, epithelial cells during embryogenesis Current methodologies do not allow high-resolution in situ observation of cells and tissues under applied strain, which may reveal intracellular dynamics and the origin of cell mechanosensitivity. A novel polydimethylsiloxane substrate was developed, capable of applying tensile and compressive strain (up to 45%) to cells and tissues while allowing in situ observation with high-resolution optics. The strain field of the substrate was characterized experimentally using digital image correlation, and the deformation was modeled by the finite element method, using a Mooney-Rivlin hyperelastic constitutive relation The substrate strain was found to be uniform for >95% of the substrate area As a demonstration of the system, mechanical strain was applied to single fibroblasts transfected with GFP-actin and whole transgenic Drosophila embryos expressing GFP in all neurons during live imaging Three observations of biological responses clue to applied strain are reported (1) dynamic rotation of intact actin stress fibers in fibroblasts; (2) lamellipodia activity and actin polymerization in fibroblasts, (3) active axonal contraction in Drosophila embryo motor neurons. The novel platform may serve as an important tool in studying the mechanoresponse of cells and tissues, including whole embryos (C) 2010 Acta Materialia Inc Published by Elsevier Ltd All rights reserved