Biology subjects

Adie, S. G.

Publications and source records attributed to Adie, S. G..

4 recordsLinked to original sources

bioRxiv2025

Valve endothelial monolayer fissuring via RhoA activity induces 3D calcific aortic valve lesion emergence as revealed by a longitudinal live-imaging platform

Calcific aortic valve disease (CAVD) is a degenerative disease with wide prevalence in the aging population and a low survival rate after onset of symptoms, yet there are no effective pharmacological treatments. Many patients present to the clinic with symptoms at end-stages of CAVD, when the disease may be irreversible. The ability to identify and live-trace calcific lesion emergence in-vivo would allow for the identification of disease biomarkers and discovery of therapeutic targets at earlier, more treatable stages. In this work, we establish a new multimodal in-vitro CAVD platform consisting of lineage traced-VEC and VIC cells in a 3D model combined with live optical coherence and fluorescence microscopy to unravel VEC, VIC, and matrix transitional events during calcific lesion formation. We discover that fissuring of the endothelial monolayer combined with the formation of dense aggregates in adjacent regions is a key biomarker of the onset of lesion formation. This coincides with the formation of dense VIC and ECM conglomerates under endothelial aggregates, an additional biomarker of pathogenesis. Further, we discover that fibrotic tissue compaction is correlated with but not necessary for lesion formation. Additionally, we identify RhoA activation in disease-treated samples. We demonstrate that RhoA inhibition through ROCK, but not Rac1 inhibition, prevents delamination of the endothelial monolayer, fibrotic remodeling, and emergence of calcific lesions. Together, this work establishes a new longitudinal live-imaging platform that identifies emergent cell and matrix biological signatures of CAVD onset and enables the evaluation of therapeutic interventions. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=64 SRC="FIGDIR/small/660489v1_ufig1.gif" ALT="Figure 1"> View larger version (24K): org.highwire.dtl.DTLVardef@dc378org.highwire.dtl.DTLVardef@19c37d5org.highwire.dtl.DTLVardef@11581c6org.highwire.dtl.DTLVardef@fb0a6a_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗

bioRxiv2021

Light-sheet photonic force optical coherence elastography for high-throughput quantitative 3D micromechanical imaging

Microscale mechanical properties of the extracellular matrix (ECM) and dynamic cell-ECM interactions play an important role in physiological processes and disease. However, it remains a challenge for current mechanical characterization methods to combine quantitative 3D imaging of ECM mechanics with cellular-scale resolution and dynamic monitoring of cell-mediated changes to pericellular viscoelasticity. Here, we present light-sheet photonic force optical coherence elastography (LS-pfOCE) to address these challenges by leveraging a light-sheet for parallelized, non-invasive, and localized mechanical loading. We demonstrate the capabilities of LS-pfOCE by imaging the micromechanical heterogeneity of fibrous 3D collagen matrices and perform a live-cell study to image micromechanical heterogeneity induced by NIH-3T3 cells seeded in 3D fibrin constructs. We also show that LS-pfOCE is able to quantify temporal variations in pericellular viscoelasticity in response to altered cellular activity. By providing access to the spatiotemporal variations in the micromechanical properties of 3D complex biopolymer constructs and engineered cellular systems, LS-pfOCE has the potential to drive new discoveries in the rapidly growing field of mechanobiology.

biophysics↗

bioRxiv2020

Computational 4D-OCM for label-free imaging of collective cell invasion and force-mediated deformations in collagen

Traction force microscopy (TFM) is an important family of techniques used to measure and study the role of cellular traction forces (CTFs) associated with many biological processes. However, current standard TFM methods rely on imaging techniques that do not provide the experimental capabilities necessary to study CTFs within 3D collective and dynamic systems embedded within optically scattering media. Traction force optical coherence microscopy (TF-OCM) was developed to address these needs, but has only been demonstrated for the study of isolated cells embedded within optically clear media. Here, we present computational 4D-OCM methods that enable the study of dynamic invasion behavior of large tumor spheroids embedded in collagen. Our multi-day, time-lapse imaging data provided detailed visualizations of evolving spheroid morphology, collagen degradation, and collagen deformation, all using label-free scattering contrast. These capabilities, which provided insights into how stromal cells affect cancer progression, significantly expand access to critical data about biophysical interactions of cells with their environment, and lay the foundation for future efforts toward volumetric, time-lapse reconstructions of collective CTFs with TF-OCM.

biophysics↗

bioRxiv2018

Quantitative reconstruction of time-varying 3D cell forces with traction force optical coherence microscopy

Cellular traction forces (CTFs) play an integral role in both physiological processes and disease, and are a topic of interest in mechanobiology. Traction force microscopy (TFM) is a family of methods used to quantify CTFs in a variety of settings. State-of-the-art 3D TFM methods typically rely on confocal fluorescence microscopy, which can impose limitations on acquisition speed, volumetric coverage, and temporal sampling or coverage. In this report, we present the first quantitative implementation of a new TFM technique: traction force optical coherence microscopy (TF-OCM). TF-OCM leverages the capabilities of optical coherence microscopy and computational adaptive optics (CAO) to enable the quantitative reconstruction of 3D CTFs in scattering media with minute-scale temporal resolution. We applied TF-OCM to quantify CTFs exerted by isolated NIH-3T3 fibroblasts embedded in Matrigel, with five-minute temporal sampling, using images which spanned a 500x500x500 m3 field-of-view. Due to the reliance of TF-OCM on computational imaging methods, we have provided extensive discussion of the underlying equations, assumptions, and failure modes of these methods. TF-OCM has the potential to advance studies of biomechanical behavior in scattering media, and may be especially well-suited to the study of cell collectives such as spheroids, a prevalent model in mechanobiology research.

bioengineering↗