SHIFTS IN ACTIN-MICROTUBULE FORCES IN THE ENDOTHELIUM

内皮肌动蛋白微管力的变化

• 批准号: 6520305
• 负责人: Alan B Moy
• 金额: $ 26.9万
• 依托单位: UNIVERSITY OF IOWA
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-07-01 至 2005-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6520305
• 关键词: actins; biomechanics; cell adhesion; cyclic AMP; mathematical model; microtubules; myosins; tissue /cell culture; vascular endothelium; vascular endothelium permeability

DESCRIPTION: (Verbatim from Applicant's abstract): Inflammatory edema is mediated by cytoskeletal-based mechanical forces, which induce endothelial-cell retraction. Agents that increase intracellular cAMP protect the endothelium from inflammatory mediators. Understanding the mechanisms by which edemagenic agents and cAMP agonists remodel the endothelial cytoskeleton, which, in turn, regulates barrier function, is critical to precisely develop treatments. We previously reported that edemagenic agents disrupt barrier function independent of expression of actin-myosin contraction. Expression of actin-myosin contraction increases inflammatory edema by impacting the restoration of barrier function. Increased intracellular cAMP does not protect barrier function through inhibition of actin-myosin tension development, but does so by uncoupling this contractile load from disrupting cell adhesion. The PI, a new investigator, will test the hypothesis in human endothelial cells that microtubules modulate endothelial-cell adhesion through a counterbalance force with actin-myosin filaments. By modulating microtubule assembly, the expression of centripetal actin-myosin tension can have differential effects on cell adhesion. To test this hypothesis we have taken an interdisciplinary approach that uses cell biology and engineering to address this fundamental question. In Aim 1, we will test whether changes in microtubule assembly remodel mechanical forces through shifts in load-bearing forces between microtubules and actin-myosin elements. In Aim 2, we will localize whether microtubules and actin-myosin forces are directed at cell-cell or cell-matrix sites. In Aim 3, we will then test whether changes in microtubule assembly alter cell adhesion based on shifts in load-bearing forces, and whether physiological stimuli utilize this basic mechanism. In Aim 4, we will test an alternative hypothesis that changes in microtubule assembly alter cell adhesion through crosstalk communication through integrin-ligand interactions. We have assembled an interdisciplinary group of biologists, a physician, a physicist and engineers. We will use a mathematical model of transendothelial impedance to localize changes in cell adhesion. We will directly measure centripetal tension and cell stiffness. We will measure biochemical changes in myosin, actin and microtubules. We will utilize molecular approaches and quantitative dynamic imaging approaches in living cells to further validate our hypothesis. We believe that the results of these studies will greatly advance vascular and cell biology.

描述：（逐字摘自申请人摘要）：炎症性水肿是 由基于细胞间隙的机械力介导，其诱导内皮细胞 收回增加细胞内cAMP的药物保护内皮 从炎症介质。了解水肿的机制 药物和cAMP激动剂重塑内皮细胞骨架，反过来， 调节屏障功能，对于精确开发治疗至关重要。我们 先前报道，水肿剂破坏屏障功能， 肌动蛋白-肌球蛋白收缩的表达。肌动蛋白-肌球蛋白的表达 收缩增加炎症水肿通过影响恢复 屏障功能细胞内cAMP增加不保护屏障 通过抑制肌动蛋白-肌球蛋白张力的发展发挥作用，但这样做是通过 将这种收缩负荷与破坏细胞粘附分开。一个新的PI 研究者将在人内皮细胞中检验这一假设， 微管通过平衡力调节内皮细胞粘附 肌动蛋白-肌球蛋白丝。通过调节微管组装， 向心肌动蛋白-肌球蛋白张力的变化对细胞 粘连为了验证这一假设，我们采取了跨学科的方法 利用细胞生物学和工程学来解决这个基本问题。在 目的1，我们将测试微管组装重塑的变化是否是机械的， 通过微管之间的承重力的变化而产生的力， 肌动蛋白-肌球蛋白元件在目标2中，我们将定位微管和 肌动蛋白-肌球蛋白力指向细胞-细胞或细胞-基质位点。在目标3中， 然后，我们将测试微管组装的变化是否会改变细胞粘附， 基于承重力的变化，以及生理刺激是否 利用这一基本机制。在目标4中，我们将检验一个备择假设 微管组装的变化通过串扰改变了细胞粘附 通过整合素-配体相互作用进行通讯。我们制定了一份 生物学家、内科医生、物理学家和工程师组成的跨学科小组。 我们将使用跨内皮阻抗的数学模型来定位 细胞粘附的变化。我们将直接测量向心张力和细胞 刚度我们将测量肌球蛋白、肌动蛋白和 微管我们将利用分子方法和定量动态 活细胞的成像方法，以进一步验证我们的假设。我们 相信这些研究的结果将大大促进血管和 细胞生物学