Bioengineering approaches to map mechanotransduction in the living cell

描述（由申请人提供）：绘制活细胞机械转导图的生物工程方法摘要机械力强烈影响我们体内几乎每个组织和器官的生长和形态。然而，关于单个细胞感知这些机械信号并将其转化为细胞内生物化学和基因表达变化的机制，我们知之甚少——这一过程被称为机械转导。我们发现，令人惊讶的是，局部表面应力集中在细胞质中，并沿着细胞骨架迅速传播到远处的位置，以激活特定的酶，这与现有的机械转导流行模型有很大的不同。在修订后的续期申请中，我们提出了三个目标。目的1是剖析生长因子诱导和应激诱导的Src和Rac激活之间的分子差异。目的2是验证核蛋白coilin-SMN的物理相互作用可以被细胞表面的局部应力直接改变的假设。目的3：阐明机械信号介导胚胎干细胞扩散和分化的机制。拟议的生物工程研究将活细胞的机械量化与生化和生物学测量相结合。实验方法是用高时空分辨率测量细胞质和亚核结构变形，同时量化活细胞的生化活性、蛋白质动力学和基因表达。目前的项目可能对阐明细胞质和细胞核深处负责调节基因表达和分化的机械转导的特定位点和蛋白质复合物具有启示意义。越来越多的证据表明，异常的机械力可能通过改变活细胞的形态和功能，促进各种疾病的发展，如动脉粥样硬化、哮喘、早衰症和癌症进展。本研究可能提供一种独特的方法来确定机械转导的潜在结构和分子靶点，以便将来进行治疗干预。

DESCRIPTION (provided by applicant): Bioengineering approaches to map mechanotransduction in the living cell Abstract Mechanical forces strongly influence the growth and form of virtually every tissue and organ in our bodies. Yet little is known about the mechanism by which individual cells sense these mechanical signals and transduce them into changes in intracellular biochemistry and gene expression - a process known as mechanotransduction. We find that, surprisingly, a local surface stress is concentrated in the cytoplasm and propagated rapidly along the cytoskeleton to distant sites to activate specific enzymes, representing drastic departures from existing prevailing models of mechanotransduction. In this revised renewal application we propose three aims. Aim 1 is to dissect the molecular differences between growth factor induced and stress-induced Src and Rac activation. Aim 2 is to test the hypothesis that physical interactions of nuclear proteins coilin-SMN can be directly altered by a local stress at the cell surface. Aim 3 is to elucidate mechanisms of mechanical signaling mediated spreading and differentiation in embryonic stem cells. The proposed bioengineering research combines mechanical quantification of the living cell with biochemical and biological measurements. The experimental approach is to measure with high spatial and temporal resolution the cytoplasmic and subnuclear structural deformation and simultaneously quantify biochemical activities, protein dynamics, and gene expressions in a living cell. The current project may have implications in elucidating specific loci and protein complexes of mechanotransduction at sites deep in the cytoplasm and the nucleus that are responsible for regulation of gene expression and differentiation. A growing body of evidence demonstrates that abnormal mechanical forces may contribute to the development of various diseases, such as atherosclerosis, asthma, progeria, and cancer progression, by altering form and function of living cells. The present study may provide a unique way to identify potential structural and molecular targets of mechanotransduction for therapeutic intervention in the future. PUBLIC HEALTH RELEVANCE: A growing body of evidence demonstrates that abnormal mechanical forces may contribute to the development of various diseases, such as atherosclerosis, asthma, progeria, and cancer progression, by altering form and function of living cells. The present study may provide a unique way to identify potential structural and molecular targets of mechanotransduction for therapeutic intervention in the future.