Global versus local matrix remodeling drives rotational versus invasive collective migration of epithelial cells.

The coordinated movement of cell collectives is essential for normal epithelial tissue development, maintenance, and cancer progression. Here, we report on a minimal 3D extracellular matrix (ECM) system wherein both invasive collective migration (ICM) and rotational collective migration (RCM) arise spontaneously from individually seeded epithelial cells of mammary and hepatic origin, regardless of whether they express adherens junctions, and lead to ductal-like and acinar-like structures, respectively. Quantitative microscopy and cellular Potts modeling reveal that initial differences in cell protrusion dynamics and matrix-remodeling localization generate RCM and ICM behavior in confining 3D ECM.

Holotomographic microscopy reveals label-free quantitative dynamics of endothelial cells during endothelialization.

Holotomograhic microscopy (HTM) has emerged as a non-invasive imaging technique that offers high-resolution, quantitative 3D imaging of biological samples. This study explores the application of HTM in examining endothelial cells (ECs). HTM overcomes the limitations of traditional microscopy methods in capturing the real-time dynamics of ECs by leveraging the refractive index (RI) to map 3D distributions label-free.

Divergent iron regulatory states contribute to heterogeneity in breast cancer aggressiveness.

Contact with dense collagen I (Col1) can induce collective invasion of triple negative breast cancer (TNBC) cells and transcriptional signatures linked to poor patient prognosis. However, this response is heterogeneous and not well understood. Using phenotype-guided sequencing analysis of invasive vs.

Divergent iron-regulatory states contribute to heterogeneity in breast cancer aggressiveness.

Primary tumors with similar mutational profiles can progress to vastly different outcomes where transcriptional state, rather than mutational profile, predicts prognosis. A key challenge is to understand how distinct tumor cell states are induced and maintained. In triple negative breast cancer cells, invasive behaviors and aggressive transcriptional signatures linked to poor patient prognosis can emerge in response to contact with collagen type I.

Adhesion tunes speed and persistence by coordinating protrusions and extracellular matrix remodeling.

Cell migration through 3D environments is essential to development, disease, and regeneration processes. Conceptual models of migration have been developed primarily on the basis of 2D cell behaviors, but a general understanding of 3D cell migration is still lacking due to the added complexity of the extracellular matrix. Here, using a multiplexed biophysical imaging approach for single-cell analysis of human cell lines, we show how the subprocesses of adhesion, contractility, actin cytoskeletal dynamics, and matrix remodeling integrate to produce heterogeneous migration behaviors.

Non-invasive sensing of transepithelial barrier function and tissue differentiation in organs-on-chips using impedance spectroscopy.

Here, we describe methods for combining impedance spectroscopy measurements with electrical simulation to reveal transepithelial barrier function and tissue structure of human intestinal epithelium cultured inside an organ-on-chip microfluidic culture device. When performing impedance spectroscopy measurements, electrical simulation enabled normalization of cell layer resistance of epithelium cultured statically in a gut-on-a-chip, which enabled determination of transepithelial electrical resistance (TEER) values that can be compared across device platforms. During culture under dynamic flow, the formation of intestinal villi was accompanied by characteristic changes in impedance spectra both measured experimentally and verified with simulation, and we demonstrate that changes in cell layer capacitance may serve as measures of villi differentiation.

Organs-on-Chips with combined multi-electrode array and transepithelial electrical resistance measurement capabilities.

Here we demonstrate that microfluidic cell culture devices, known as Organs-on-a-Chips can be fabricated with multifunctional, real-time, sensing capabilities by integrating both multi-electrode arrays (MEAs) and electrodes for transepithelial electrical resistance (TEER) measurements into the chips during their fabrication. To prove proof-of-concept, simultaneous measurements of cellular electrical activity and tissue barrier function were carried out in a dual channel, endothelialized, heart-on-a-chip device containing human cardiomyocytes and a channel-separating porous membrane covered with a primary human endothelial cell monolayer. These studies confirmed that the TEER-MEA chip can be used to simultaneously detect dynamic alterations of vascular permeability and cardiac function in the same chip when challenged with the inflammatory stimulus tumor necrosis factor alpha (TNF-α) or the cardiac targeting drug isoproterenol.

Organs-on-chips with integrated electrodes for trans-epithelial electrical resistance (TEER) measurements of human epithelial barrier function.

Trans-epithelial electrical resistance (TEER) is broadly used as an experimental readout and a quality control assay for measuring the integrity of epithelial monolayers cultured under static conditions in vitro, however, there is no standard methodology for its application to microfluidic organ-on-a-chip (organ chip) cultures. Here, we describe a new microfluidic organ chip design that contains embedded electrodes, and we demonstrate its utility for assessing formation and disruption of barrier function both within a human lung airway chip lined by a fully differentiated mucociliary human airway epithelium and in a human gut chip lined by intestinal epithelial cells. These chips with integrated electrodes enable real-time, non-invasive monitoring of TEER and can be applied to measure barrier function in virtually any type of cultured cell.