Using Controlled 2D and 3D Nanotopography to Unravel Tactile Senses of Motile Cel

描述（由申请人提供）：细胞向目标位置迁移的能力在许多生物过程中起着重要作用，例如组织和器官发育，伤口愈合以及免疫系统对入侵者的跟踪和捕获。细胞迁移包括细胞形状的变化、与周围环境粘附的动态变化以及提供定向指导的信号提示。化学信号信号是众所周知的，并且正在被详细研究：化学引诱剂的受体结合触发细胞内信号通路，放大化学引诱剂信号并触发细胞迁移和其他过程。最近的研究表明，机械刺激对细胞行为也有深远的影响，包括通过将细胞镀在与目标细胞类型相当的硬度表面上，可以引导细胞向目标细胞类型分化。越来越清楚的是，纳米形貌也为细胞提供了重要的机械刺激。在最近的许多研究中，具有数十纳米大小的峰谷的表面倾向于增强肌动蛋白细胞骨架的活性。然而，关于纳米形貌如何影响细胞骨架活性，以及纳米形貌刺激在多大程度上影响特定的细胞骨架功能，特别是细胞迁移，我们知之甚少。我们建议使用模式生物盘基盘齿龙来了解纳米地形线索如何在许多层面上影响细胞迁移，从细胞内信号的分子水平，到整个细胞的形状和迁移动力学，再到细胞群的集体行为。假设1：纳米级表面特征（纳米形貌）触发影响细胞运动和趋化信号通路的生化信号。纳米形貌也影响更大规模的表型，特别是细胞群的集体行为。假设2：表面纳米形貌的空间模式可以指导运动细胞（作为化学信号的替代或结合）。假设3：纳米形貌影响细胞沿纤维和通过三维纤维网络的迁移。为了验证这些假设，我们的具体目标是：目标1：测量和量化纳米图案，二维表面对细胞内信号，单个细胞的形状和运动以及集体细胞迁移的影响。目标2：确定纳米形貌的空间模式如何指导细胞迁移。目标3：利用具有可控纳米形貌的三维合成纤维网络，分析纳米和微观几何对细胞三维运动的影响。

DESCRIPTION (provided by applicant): The ability of cells to migrate toward a target location plays an important role in many biological processes such as tissue and organ development, wound healing, and the tracking and capture of invaders by the immune system. Cell migration involves changes in shape of the cell, dynamic changes in the adhesion to the surrounding, and signaling cues that provides directional guidance. Chemical signaling cues are well known and are being studied in detail: Receptor binding of chemo attractants triggers intracellular signaling pathways that amplify the chemo attractant signal and trigger cell migration and other processes. Recent work has shown that mechanical stimuli also have a profound effect on cell behavior, including the demonstration that one may guide cell differentiation toward a target cell type by plating cells on surfaces with stiffness comparable to the target cell type. It is becoming increasingly clear that nanotopography also provides an important mechanical stimulus for cells. Surfaces with peaks and valleys of size tens of nm tend to enhance the activity of the actin cytoskeleton in many recent studies. However, little is known about how nanotopography affects cytoskeletal activity, and to what degree nanotopographic stimuli affect specific cytoskeletal functions, in particular cell migration. We propose to use the model organism Dictyostelium discoideum to understand, how nanotopographic cues affect cell migration at many levels, from the molecular level of intracellular signals, to the shapes and migration dynamics of whole cells, to the collective behavior of cell groups. The research proposed here will address the following hypotheses: Hypothesis 1: Nanoscale surface features (nanotopography) trigger biochemical signals that influence cell motility and affect chemotactic signaling pathways. Nanotopography also affects larger-scale phenotypes, in particular collective behavior of groups of cells. Hypothesis 2: Spatial patterning of the nanotopography of a surface can direct motile cells (as an alternative to, or in combination with, chemical signals). Hypothesis 3: Nanotopography affects cell migration along fibers and through three dimensional fiber networks. To test these hypotheses, our specific aims are: Aim 1: Measure and quantify the effects that nanopatterned, 2D surfaces have on intracellular signals, shape and motility of individual cells, and collective cell migration. Aim 2: Determine how spatial patterning of nanotopography directs cell migration. Aim 3: Analyze the influence of nanoscopic and microscopic geometry on cell motion in three dimensions, using 3D synthetic fiber networks with controlled nanotopography. PUBLIC HEALTH RELEVANCE: Our goal is to develop custom surfaces and three dimensional structures with nanoscale features to investigate the effect of nanotopography on cell migration, and to develop new approaches to guide cell motion through nanotopographic cues. Our focus will be on studies that systematically elucidate how nanoscale surface features influence intracellular signals that in turn control cell behavior. Such understanding is urgently needed due to the widespread use of nanopatterned surfaces and nanoparticles in contact with cells, e.g. in implants and medical diagnostics.