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

描述（由申请人提供）：细胞向靶位置迁移的能力在许多生物学过程中起着重要作用，如组织和器官发育、伤口愈合以及免疫系统对入侵者的追踪和捕获。细胞迁移涉及细胞形状的变化、与周围环境粘附的动态变化以及提供方向指导的信号线索。化学信号传导线索是众所周知的，正在详细研究：化学引诱剂的受体结合触发细胞内信号传导途径，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，机械刺激也对细胞行为产生深远的影响，包括证明可以通过将细胞接种在具有与靶细胞类型相当的刚度的表面上来引导细胞向靶细胞类型分化。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，具有几十nm大小的峰和谷的表面倾向于增强肌动蛋白细胞骨架的活性。然而，鲜为人知的是如何nanotopography影响细胞骨架活性，以及在何种程度上nanotopographic刺激影响特定的细胞骨架功能，特别是细胞迁移。我们建议使用的模式生物Dictyosteelium discoideum了解，如何nanotopographic线索影响细胞迁移在许多层面上，从分子水平的细胞内信号，整个细胞的形状和迁移动力学，细胞群的集体行为。这里提出的研究将解决以下假设：假设1：纳米尺度的表面特征（nanotopography）触发生化信号，影响细胞运动和影响趋化信号通路。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。假设二：表面的纳米形貌的空间图案化可以引导运动细胞（作为化学信号的替代或与化学信号组合）。假设3：纳米形貌影响细胞沿沿着纤维和通过三维纤维网络的迁移。为了测试这些假设，我们的具体目标是：目标1：测量和量化纳米图案化的2D表面对细胞内信号，单个细胞的形状和运动性以及集体细胞迁移的影响。目的2：确定纳米形貌的空间图案化如何指导细胞迁移。目标3：使用具有可控纳米形貌的3D合成纤维网络，分析纳米和微观几何形状对三维细胞运动的影响。 公共卫生相关性：我们的目标是开发定制的表面和三维结构与纳米级的功能，以调查纳米形貌对细胞迁移的影响，并开发新的方法来引导细胞运动通过纳米形貌线索。我们的重点将是系统地阐明纳米级表面特征如何影响细胞内信号，进而控制细胞行为的研究。由于纳米图案化表面和纳米颗粒与细胞接触的广泛使用，例如在植入物和医疗诊断中，迫切需要这种理解。

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.