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

Stanford University, Stanford CA

Investigators

Abstract

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.