Investigating the Mechanics of Cell Division with A Side-View Atomic Force Microscope

细胞分裂对生命至关重要；它是人类从胚胎发育到成年的基础，也是创伤愈合等再生过程和癌症等病理过程的基础。虽然细胞分裂是一个内在的机械过程，但人们对其物理性质知之甚少。这项基础研究将使用一种名为“原子力显微镜”(AFM)的装置来测量一个细胞产生的微小作用力，以及细胞分裂成两个细胞过程中的硬度变化。此外，原子力显微镜将被用来测量细胞分裂是如何通过施加力量而改变的。由于细胞分裂是生物学中的一个基本过程，这项工作的结果将有助于理解生物体的发育和生长、组织发育、组织再生和癌症。这项研究中采用的跨学科方法，包括将工程学的尖端技术应用于细胞生物学研究，将对工程师和生物学家的教育产生积极影响，包括那些来自代表性不足群体的人。此外，在项目期间建造的新型测量设备将作为当前团队及其同事未来研究的资源。在组织中，细胞分裂在所有维度上都受到邻近细胞和细胞外基质的物理限制。细胞分裂必须能够以空间和时间协调的方式产生显著的力，以创造伴随细胞分裂的形态变化，在某些情况下，必须在经历生理力的同时做到这一点。细胞如何产生并对这种力量做出反应尚不清楚，因为细胞分裂主要是在培养在平坦的培养皿表面的细胞中进行的。这个项目的目标是阐明细胞在细胞分裂过程中如何产生和对力做出反应，并改变它们的结构属性。我们将建造并使用高分辨率侧视成像原子力显微镜来直接测量细胞在细胞分裂的每个阶段产生的力，同时沿着垂直于样品表面的平面在外向荧光中成像细胞分裂中的动态细胞骨架和染色体重排。通过这个工具，我们旨在解决关于细胞分裂机制的以下重要问题：(1)细胞在细胞分裂过程中所产生的力是什么？它们是如何产生的？(2)细胞在细胞分裂的每个阶段中，细胞的粘弹性性质是如何变化的？(3)外力对细胞分裂的影响是什么？

Cell division is essential for life; it underlies the development of humans from embryo to full-grown adult, as well as regenerative processes such as wound healing and pathologies such as cancer. While cell division is an inherently mechanical process, its physical nature is poorly understood. This fundamental research will use a device called an "atomic force microscope" (AFM) to measure the small forces created by a cell and the stiffness changes of the cell during division into two cells. In addition, the AFM will be used to measure how the division of cells is changed by application of force. As cell division is an essential process in biology, the results of this work will contribute to understanding development and growth of organisms, tissue development, tissue regeneration, and cancer. The interdisciplinary approach taken in this research, involving the application of cutting edge techniques in engineering to the study of cell biology, will have a positive impact on the education of engineers and biologists including those from underrepresented groups. In addition, the novel measurement device built during the project will remain as a resource for future research by the current team and their colleagues.In tissues, cell division is physically restricted in all dimensions by neighboring cells and extracellular matrix. Dividing cells must be able to generate significant forces in a spatially and temporally coordinated manner to create the morphological changes accompanying cell division, and in some contexts must do this while experiencing physiological forces. How cells generate and respond to such forces remains unclear, as cell division has been primarily studied in cells cultured on flat petri dish surfaces. The objective of this project is to elucidate how cells generate and respond to forces, and alter their structural properties, during cell division. We will construct and use a high-resolution side-view imaging atomic force microscope to directly measure forces generated by cells during each stage of cell division while simultaneously imaging the dynamic cytoskeletal and chromosomal rearrangements in dividing cells in epi-fluorescence along a plane perpendicular to the sample surface. With this tool, we aim to address the following important questions regarding the mechanics of cell division: (1) What are the forces generated by cells following during cell division and how are they generated?; (2) How do the viscoelastic properties of cells change during each stage of cell division?; and finally (3) what is the effect of applied force on cell division?