Intracellular Force Generation Measured Through Nuclear Particle Tracking

Carnegie Mellon University, Pittsburgh PA

Investigators

Abstract

Individual molecular motors generate very small forces within cells, but the coordination and integration of these forces is responsible for large scale movements of an organism. The study of forces that a cell can generate has been of wide interest for decades but has been limited to visualizing how the environment around the cell deforms in response to the cell pulling. However, with proper image analysis tools for removing intrinsic movements of the cell itself, fluctuations within the cell nucleus also provide a metric for quantifying forces generated inside the cell. This methodology is in its infancy and will require effort to fully characterize and compare to established techniques. By determining the forces that cells generate, including if neighboring cells generate different forces, it is possible to understand how microscopic units of the body work together to form larger dynamic structures. Specifically, this is important in tissue formation during early embryonic development and in multicellular dysfunction associated with different disease states including cancer and vascular disease. The project will integrate undergraduate professional development with K-3 science outreach programs. The PI will develop a program to teach ethics to undergraduate students focusing on Comparative Ethics for Biomedical Engineers contrasting the different priorities of the patient, science and society. By removing intrinsic cellular translocation and rotation using image analysis post-processing, it is possible to correlate movements within the nucleus with force generation of the actin-myosin cytoskeleton. Utilizing this newly developed technique of intranuclear particle tracking it may be possible to measure how cells propagate mechanical stimuli applied within a monolayer through cell structures on short timescales before diffusion can occur and on long timescales as interconnected cells begin to adapt cellular structures in response to stress. This intracellular force transduction measurement within multicellular systems will allow investigation of heterogeneous tissue systems where traction force microscopy and other contemporary measurements have experimental limitations. Specifically, this investigation will include examining force transduction through a sheet of endothelial cells growing on smooth muscle cells in different vascular states in and inside cells of C. elegans during embryo development.