Collaborative Research: Biomechanical mechanisms conferring wound resilience in single-celled organisms

伤口弹性是生物系统中维持体内平衡和生存所必需的共同特征。该项目将确定自由生活的单细胞生物Stentor coeruleus的伤口恢复原理，这种生物在剧烈的机械创伤中显示出强大的伤口愈合能力。该项目有可能为合成细胞和软微型机器人的工程新功能——伤口弹性——奠定基础，并将使这些技术在工业应用中更加强大。三位研究者之间的合作为细胞生物学、工程学和数学建模方面的培训和劳动力发展提供了一个独特的机会。这项工作的结果将被纳入研究生课程和社交媒体，以提高公众对非模式生物的兴趣。所有研究人员将继续招募代表性不足的少数族裔，通过向K-12学生推广，并参加湾区科学节和每年在加州旧金山举行的创客大会。本项目的总体目标是研究蓝纹斯坦托如何利用生物力学机制来预防伤口的上游伤害，以及伤口的下游伤害，从而从导致质膜开口的机械伤口中获得强大的愈合。关注Stentor的理由是：1)它是一种自由生活的单细胞生物，发现于由于自然流动或捕食而受到高机械应力的环境中。原则上，这些细胞必须具有防止频繁受伤和在受伤发生时允许愈合的特性。2)它的伤口愈合能力比大多数其他细胞更强。它能够在24小时内从严重的伤口中强劲地恢复，并从小到原始细胞大小的1/27的细胞碎片中再生。这种特性允许对损伤条件进行扰动，并在不立即引起细胞死亡的情况下测量其对修复过程的影响，从而为探索自我修复机制提供了一个强大的平台。3)开展了高通量基因敲低和损伤实验。Stentor的基因组已经测序，Stentor基因表达的分子操作工具已经开发出来，为Stentor伤口修复的分子理解铺平了道路。该项目将测试细胞骨架在赋予细胞伤口抵抗力方面的作用，以及大规模机械力产生在补充生化愈合模式以关闭日益严重的伤口方面的作用。该项目结合了细胞生物学、微流体学和机械生物学建模，包括使用微流体学产生精确的流动条件，以高通量的方式对细胞造成伤害，以及开发集成生化和机械过程的数学模型。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Wound resilience is a common trait in biological systems necessary for homeostasis and survival. This project will identify wound resilience principles in the free-living single-celled organism Stentor coeruleus, known to display robust wound healing capacity from drastic mechanical wounds. This project has the potential to lay the foundation for engineering new functions—wound resilience—in synthetic cells and soft micro-robots, and will make the technologies more robust for industrial applications. The collaboration between the three investigators provides a unique opportunity for training and workforce development at the interface of cell biology, engineering, and mathematical modeling. Results from this work will be incorporated into graduate courses and social media to raise public interest in non-model organisms. All investigators will continue to recruit underrepresented minorities to STEM via outreach targeted to K-12 students and participation in the Bay Area Science Festival and the Maker Faire held yearly in San Francisco, CA.The overall goal of this project is to investigate how Stentor coeruleus employs biomechanical mechanisms both upstream of wounding for wound prevention, and downstream of wounding for robust healing from mechanical wounds that cause an opening in the plasma membrane. The rationales to focus on Stentor are: 1) It is a free-living unicellular organism found in environments that can be subject to high mechanical stresses due to natural flows or predation. In principle, these cells must possess properties that prevent frequent wounding and allow healing if wounding occurs. 2) Its wound healing capacity is more robust than most other cells. It is capable of recovering robustly from drastic wounds and regenerating from cell fragments as small as 1/27th of the original cell size in 24 hours. This property allows the perturbation of the wounding conditions and the measurement of their effect on the repair process without immediately causing cell death, thereby providing a robust platform for probing the self-repair mechanism. 3) High-throughput gene knockdown and wounding experiments have been developed. Stentor’s genome has been sequenced, and tools for molecular manipulation of Stentor gene expression have been developed to pave the way to a molecular understanding of Stentor wound repair. This project will test the role of the cytoskeleton in conferring wound resistance to the cell, and the role of large-scale mechanical force generation in complementing biochemical healing modes to close wounds of increasing severity. The project combines cell biology, microfluidics, and mechanobiology modeling, involving the use of microfluidics to generate precise flow conditions to inflict wounds on cells in a high throughput manner, and the development of mathematical models integrating biochemical and mechanical processes.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.