Understanding Why Cells Choose to Migrate Towards the Cathode: Directing Cell Motility Using Electric Fields

PI：Gagnon，Zachary RProposal#：1605553细胞如何感知、响应并朝向或远离外部线索是许多生物和医学现象的核心，包括胚胎发生、形态发生、免疫反应、伤口愈合和癌症转移。趋电性是细胞对外加电场的反应使其运动方向偏向的现象，在许多细胞过程中都很重要；然而，电场如何影响细胞内细胞骨架组织的潜在物理机制尚不清楚。这项计划中的研究的总体目标是确定在细胞中启动趋电性的物理机制。这一目标将通过观察电致迁移并使用精确的微流控电池限制室来量化静电细胞周围的离子活动来实现。智力优势是基于在确定物理入口点方面的创新战略和基本意义，在细胞趋电性过程中，电场在物理入口点被转换为下游化学信号。与专注于下游信号蛋白的传统趋电工作不同，这个项目专注于了解电场对细胞膜的直接影响。教育影响是通过为本科生和研究生提供新的课程和实验室培训，通过机构的“工程创新”计划延伸到高中生，通过巴尔的摩和查尔斯城中学的“科学技术”计划吸引6-8年级的学生，通过动手研究和社区外展扩大未被充分代表的群体对拟议研究项目的参与来实现的。细胞如何感觉、反应以及朝向或远离外部线索是许多生物和医学现象的核心，包括胚胎发生、形态发生、免疫反应、伤口愈合和癌症转移。许多真核细胞有内部指南针，使它们能够感知这些信号，通常是以化学吸引剂、电压或机械应力的梯度的形式，并将它们的运动偏向特定的方向。趋电性是细胞对外加电场的反应使其运动方向偏向的现象，在许多细胞过程中是重要的；然而，电场如何被传递到细胞内以影响细胞骨架组织的潜在物理机制尚不清楚。这项提议的总体目标是确定负责在细胞中启动趋电性的相关物理机制。这一目标将通过观察电致迁移并使用精确的微流控电池限制室来量化静电细胞周围的离子活动来实现。其具体目标是：1)发展和建立微流控几何结构，用于电趋化过程中电动离子通量的细胞膜水平分析；2)量化电场诱导的膜过程，包括电趋化过程中的离子流动和离子通道活动；3)了解下游细胞信号如何被这些上游电场诱导事件激活和转导。这项计划研究的智力价值基于创新战略和基本意义，即确定在细胞趋电性过程中电场转化为下游化学信号的物理入口点。与专注于下游信号蛋白的传统趋电工作不同，这个项目专注于了解电场对细胞膜的直接影响。通过为本科生和研究生提供新的课程和实验室培训，通过院校的“工程创新”计划接触高中生，通过巴尔的摩和查尔斯城中学的“科学技术学院”计划吸引6-8年级的学生，通过实践研究和社区推广，扩大代表不足的群体对拟议研究项目的参与，实现了教育影响。

PI: Gagnon, Zachary RProposal #: 1605553How a cell senses, responds, and moves towards or away from an external cue is central to many biological and medical phenomena including embryogenesis, morphogenesis, immune response, wound healing and cancer metastasis. Electrotaxis, the phenomenon by which cells bias their motion directionally in response to an externally applied electrical field, is important in a number of cellular processes; however, the underlying physical mechanism of how electric fields influence cytoskeletal organization within the cell is unknown. The overall goal of the planned research is to determine the physical mechanisms responsible for initiating electrotaxis in cells. The goal will be achieved by observing electrotactic migration and quantifying the ion activity surrounding electrotaxing cells using precise microfluidic cell confinement chambers. Intellectual merit is based on the innovative strategy and fundamental significance in determining the physical entry point where electric fields are converted into a downstream chemical signal during cellular electrotaxis. Unlike traditional electrotaxis work that focuses on downstream signaling proteins, this project focuses on understanding the immediate influences of the electric field at the cell membrane. Educational impact is achieved through providing new courses and laboratory training for undergraduate and graduate students, outreach to high school students through the institutions "Engineering Innovation" program, engaging 6th - 8th grade students through the "Science Academy Technology" program in Baltimore and Charles City Middle Schools and broadening the participation of underrepresented groups in the proposed research projects through hands-on research and community outreach.How a cell senses, responds, and moves towards or away from an external cue is central to many biological and medical phenomena including embryogenesis, morphogenesis, immune response, wound healing and cancer metastasis. Many eukaryotic cells have internal compasses that allow them to sense these cues, often in the form of gradients of chemoattractant, voltage, or mechanical stress, and bias their motion in a specific direction. Electrotaxis, the phenomenon by which cells bias their motion directionally in response to an externally applied electrical field, is important in a number of cellular processes; however, the underlying physical mechanism of how electric fields are transduced into the cell to influence cytoskeletal organization is unknown. The overall goal of this proposal is to determine the relevant physical mechanisms responsible for initiating electrotaxis in cells. The goal will be achieved by observing electrotactic migration and quantifying the ion activity surrounding electrotaxing cells using precise microfluidic cell confinement chambers. The specific objectives are: 1) to develop and build microfluidic confinement geometries for cell membrane level analysis of electrokinetic ion flux during electrotaxis, 2) to quantify the electric field-induced membrane processes including ion-flow and ion channel activity during electrotaxis, and 3) to understand how downstream cell signaling is activated and transduced by these upstream electric field-induced events. The intellectual merit of the planned research is based on the innovative strategy and fundamental significance in determining the physical entry point where electric fields are transduced into a downstream chemical signal during cellular electrotaxis. Unlike traditional electrotaxis work that focuses on downstream signaling proteins, this project focuses on understanding the immediate influences of the electric field at the cell membrane. Educational impact is achieved through providing new courses and laboratory training for undergraduate and graduate students, outreach to high school students through the institutions "Engineering Innovation" program, engaging 6th - 8th grade students through the "Science Academy Technology" program in Baltimore and Charles City Middle Schools and broadening the participation of underrepresented groups in the proposed research projects through hands-on research and community outreach.