CAREER: Genome Regulation and Nuclear Rheology

人类基因组的测序提供了丰富的科学信息，但是由于对控制基因表达的机制知之甚少，这些信息是有限的。力在调节基因表达中的作用是一个新兴的、独特的多学科研究领域。机械力在生物体发育和细胞和组织的适当维护中是重要的。具体来说，内皮细胞上的剪切应力改变了基因表达和细胞行为。细胞中有许多已知的机械传感器，但短时间的信号事件不足以解释细胞的长期反应和永久变化。细胞核内的DNA组成了基因组，具有独特的机械特性，能够对施加的压力的大小和持续时间做出相应的反应。细胞核变形可能是重要的，因为基因在细胞核内的位置与它们的表达相关。这笔拨款将检验一个假设，即细胞核的重组有助于调节受力细胞中的基因表达。内皮细胞的亚核重组将在剂量依赖的细胞外剪切应力下使用荧光蛋白的实时粒子跟踪进行监测。细胞核结构蛋白的上调和下调决定了核力学在细胞外剪应力刺激下调控基因表达和基因运动的作用。化学刺激的血管生成，血管形成，对亚核重组，基因表达和细胞表型的影响将被特别检查。通过将亚核重排、基因可及性和基因表达的变化与核力学的变化相关联，可以确定DNA在细胞中承受压力的程度。与单个核结构蛋白的修饰相关的变化弥补了核的纳米结构和微尺度力学之间的差距。该项目旨在证明一种新的细胞机械转导形式，使用颗粒跟踪，生物操作和基因分析相结合，在细胞剪切应力下进行。虽然该项目将使用新颖的工程技术和方法回答重要的生物学问题，但它也将展示生物学与工程学相结合的力量。与力相关的基因调控的变化，独立于或增强化学因素，将帮助科学家和工程师更好地控制细胞的各种技术应用，包括组织工程和干细胞治疗领域。在科学、工程和医学的交汇处工作包括许多独特的伦理情况。正在与应用伦理学中心合作开发促进课堂道德行为和良好研究实践的研讨会和网络教程，并将在研究生研究、本科生实验室和夏季研究课程中强调。

0954421DahlThe sequencing of the human genome has provided a wealth of scientific information, but this information is limited since mechanisms which control gene expression are poorly understood. The role of force in regulating gene expression is an emerging and uniquely multi-disciplinary area of study. Mechanical force is important during organism development and for proper maintenance of cells and tissues. Specifically, shear stress on endothelial cells alters gene expression and changes cell behavior. There are many known mechanosensors in cells, but short-lived signaling events are not sufficient to explain both the long-time responses and permanent changes of cells. The DNA inside the nucleus, which is organized into the genome, has unique mechanical properties capable of responding proportionally to both the magnitude and duration of applied stress. Nuclear deformation may be important since placement of genes within the nucleus is correlated with their expression. This grant will test the hypothesis that the reorganization of the nucleus helps regulate gene expression in cells exposed to force. Subnuclear reorganization in endothelial cells will be monitored under dose dependent extracellular shear stress using real time particle tracking of fluorescent proteins. Nuclear structural proteins will be up- and down-regulated to determine the role of nuclear mechanics on controlling gene expression and gene movement stimulated by extracellular shear stress. The effects of chemically-stimulated angiogenesis, blood vessel formation, on subnuclear reorganization, gene expression and cellular phenotype will specifically be examined. By correlating changes in subnuclear rearrangement, gene accessibility and gene expression with changes in nuclear mechanics, the amount of force the DNA experiences in a cell under stress can be determined. The changes associated with modifications of individual nuclear structural proteins bridges the gap between nanoscale structure and microscale mechanics of the nucleus. This project aims to prove a new form of cellular mechanotransduction using a combination of particle tracking, biological manipulation, and gene analysis in cells under shear stress. While this project will answer important biological questions using novel engineering techniques and approaches, it will also show the power of combining biology with engineering.Changes in gene regulation associated with force, independent of or to enhance chemical factors, will help scientists and engineers to better control cells for a variety of technological applications including areas of tissue engineering and stem cell therapies. Working at the interface of science, engineering and medicine includes many unique ethical situations. Seminars and web-based tutorials promoting ethical conduct in the classroom and good research practices are being developed in collaboration with the Center for Applied Ethics and will be stressed throughout graduate research, undergraduate laboratory and summer research curricula.