Tate, M. L. K. | Search bioRxiv

bioRxiv2024

Tuning mechanical milieux of tissue templates and their cellular inhabitants to guide mechanoadaptation

Mechanomics describes the adaptation of mesenchymal stem cells (MSCs) to their mechanical environment, via cytoskeletal remodeling, as well as changes in shape and volume, ultimately resulting in emergent lineage commitment. Here we elucidated effects of exogenous microtubule stabilization, using paclitaxel (PAX), on stem cells capacity to sense and adapt to changes in their local mechanical environment. We studied the interplay between the living, evolving cells and their mechanical environment using established experimental and computational tools for respective delivery and prediction of shape and volume changing stresses. Stiffened and volumetrically larger microtubule-stabilized MSCs and their experienced significantly different normal and shear stress compared to control cells when exposed to identical bulk laminar flow (0.2 dyn/cm2) for one hour. These spatiotemporal mechanical cues transduced to the nucleus via the cytoskeleton, triggering significantly different changes in gene expression indicative of emergent lineage commitment than those observed in control cells. Using a paired computational model, we further predicted a range of mechanoadaptation responses of microtubule-stabilized cells to scaled up flow magnitudes (1 and 2 dyn/cm2). Hence, MSCs adapt to as well as modulate their own mechanical environment via cytoskeletal remodeling and lineage commitment - microtubule stabilization changes not only MSCs mechanoadaptive machinery, their capacity to adapt, and their lineage commitment, but also their mechanical environment. Taken as a whole, these studies corroborate our working hypothesis that MSCs and their mechanoadaptive machinery serve as sensors and actuators, intrinsically linked to their lineage potential via mechanoadaptive feedback loops which are sensitive to exogenous modulation via biochemical and biophysical means. ClassificationBiological Systems Engineering, Computational Simulations, Cell Biology, Biophysics

bioengineering↗

bioRxiv2019

Sample preparation protocol enabling nano-to-mesoscopic mapping of cellular connectomes and their habitats in human tissues and organs

Multibeam scanning electron microscopy (multiSEM) provides a technical platform for seamless nano-to-mesoscale mapping of cells in human tissues and organs, which is a major new initiative of the U.S. National Institutes of Health. Developed for rapid throughput imaging of minute defects on semiconductor wafers, multiSEM has recently been adapted for imaging of human organs, their constituent tissues, and their respective cellular inhabitants. Through integration of geospatial approaches, statistical and network modelling, advances in computing and the management of immense datasets, as well as recent developments in machine learning that enable the automation of big data analyses, multiSEM and other cross-cutting imaging technologies have the potential to exert a profound impact on elucidation of disease mechanisms, translating to improvements in human health. Here we provide a protocol for acquisition and preparation of sample specimen sizes of diagnostic relevance for human anatomy and physiology. We discuss challenges and opportunities to integrate this approach with multibeam scanning electron microscopy work flows as well as multiple imaging modalities for mapping of organ and tissue structure and function.

systems biology↗