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Biology subjects

Cambria, E.

Publications and source records attributed to Cambria, E..

5 recordsLinked to original sources

A mechanically actuated lung microvascular model reveals that breathing-like deformation enhances tumor cell extravasation

The lung is a common site of metastasis and is continuously deformed by breathing. Whether physiological breathing mechanics influence tumor cell extravasation is unknown. To address this, we developed a mechanically actuated microphysiological system combining perfusable lung-specific microvascular networks with breathing-like cyclic deformation. Under static conditions, lung-specific networks exhibited more lung-like vascular features and higher tumor cell extravasation rates than generic networks. The mechanically actuated device reproduced physiological tissue and vascular deformation, while 24 h of cyclic actuation did not alter vessel viability, permeability, or morphology compared with unactuated controls. Pre-actuation for 24 h, followed by tumor cell perfusion under static conditions, did not alter subsequent extravasation, whereas actuation initiated immediately after perfusion significantly increased extravasation compared with unactuated controls. This biomimetic platform enables direct investigation of how breathing-like vascular deformation influences metastasis and provides a versatile tool for studying vascular mechanobiology in the lung and other mechanically active organs.

bioengineering↗

IntravChip: a vascularized and perfused microfluidic model of the primary tumor microenvironment to collect intravasated tumor cells

Hematogenous metastasis is initiated when tumor cells (TCs) intravasate into the vasculature, yet intravasation remains poorly understood because it is difficult to observe in vivo and intravasated TCs are challenging to isolate. To address these challenges, we developed IntravChip, a continuously perfused microfluidic platform containing a vascularized primary tumor microenvironment (TME) enabling the observation of TC intravasation, and a downstream chamber to collect intravasated TCs. The IntravChip can support a high TC concentration in the TME while maintaining complete vascular perfusion, which we found was necessary to collect intravasated cells. Using MDA-MB-231 breast TCs, we identified an optimal initial TC seeding density that, by day 9, yields a densely populated TME and 100-440 collected intravasated TCs. We validated the IntravChip across several TC types, showing that MDA-MB-231 and MV3 TCs have the highest intravasation rates while MCF-7 TCs have low intravasation efficiency. We also show that the IntravChip is compatible with super-resolution nano-imaging. Our devices enabled high-quality STORM imaging, which revealed that H3K9me3 nanodomains are significantly differentially distributed in intravasated MDA-MB-231 tumor cells compared to those residing in the TME. Finally, the IntravChip was validated as a platform to test the effects of anti-cancer drugs on tumor cells and on the vasculature. We showed that a 5 M concentration of sorafenib reduced intravasation events by 69% without impacting the morphology of the microvascular networks (MVNs), while a 10 M concentration led to a significant decrease in vessel diameter. This platform enables quantitative analysis of TC intravasation, collection of intravasated TCs for characterization, and screening of anti-metastatic therapies.

bioengineering↗

Remodeling of self-assembled microvascular networks under long term flow

The incorporation of a functional perfusable microvascular network (MVN) is a common requirement for most organ on-chip-models. Long-term perfusion of MVNs is often required for the maturation of organ phenotypes and disease pathologies and to model the transport of cells and drugs entering organs. In our microphysiological system, we observe that flow can recover perfusion in regressed MVNs and maintain perfusable MVNs for at least 51 days. Throughout the 51 days, however, the MVNs are continuously remodeling to align with the direction of bulk flow and only appear to attain morphological homeostasis with the use of maintenance medium without growth factors. We observed that the flow resistance of the MVNs decreases over time, and using a computational model, we show that stable vessels have higher flow rates and velocities compared to regressing vessels. Cytokine analysis suggests that static conditions generate an inflammatory state, and that continuous flow reduces inflammation over an extended period. Finally, through bulk RNA sequencing we identify that both the endothelial and fibroblast cells are actively engaged in vascular and matrix remodeling due to flow and that these effects persist for at least 2 weeks. This MPS can be applied to study hemodynamically driven processes, such as metastatic dissemination or drug distribution, or to model long-term diseases previously not captured by MPS, such as chronic inflammation or aging-associated diseases.

biophysics↗

Myofibroblasts reduce angiogenesis and vasculogenesis in a vascularized microphysiological model of lung fibrosis

Lung fibrosis, characterized by chronic and progressive scarring, has no cure. Hallmarks are the accumulation of myofibroblasts and extracellular matrix, as well as vascular remodeling. The crosstalk between myofibroblasts and vasculature is poorly understood, with conflicting reports on whether angiogenesis and vessel density are increased or decreased in lung fibrosis. We developed a microphysiological system that recapitulates the pathophysiology of lung fibrosis and disentangles myofibroblast-vascular interactions. Lung myofibroblasts maintained their phenotype in 3D without exogenous TGF-{beta} and displayed anti-angiogenic and anti-vasculogenic activities when cultured with endothelial cells in a microfluidic device. These effects, including decreased endothelial sprouting, altered vascular morphology, and increased vascular permeability, were mediated by increased TGF-{beta}1 and reduced VEGF secretion. Pharmacological interventions targeting these cytokines restored vascular morphology and permeability, demonstrating the potential of this model to screen anti-fibrotic drugs. This system provides insights into myofibroblast-vascular crosstalk in lung fibrosis and offers a platform for therapeutic development.

bioengineering↗

Effects of early life stress on bone homeostasis in mice and humans

Bone pathology is frequent in stressed individuals. A comprehensive examination of mechanisms linking life stress, depression and disturbed bone homeostasis is missing. In this translational study, mice exposed to early life stress (MSUS) were examined on bone microarchitecture (CT), metabolism (qPCR), and neuronal stress mediator expression (qPCR) and contrasted with a sample of depressive patients with or without early life stress by analyzing bone mineral density [BMD] (DXA) and metabolic changes in serum (osteocalcin, PINP, CTX-I). MSUS mice showed a significant decrease in NGF, NPYR1, VIPR1 and TACR1 expression, higher innervation density in bone and increased serum levels of CTX-I, suggesting a milieu in favor of catabolic bone turnover. MSUS mice had a significantly lower body weight compared to control mice, and this caused minor effects on bone micro-CT. Depressive patients with experiences of childhood neglect also showed a catabolic pattern. A significant reduction in BMD was observed in depressive patients with childhood abuse and stressful life events during childhood. Therefore, future studies on prevention and treatment strategies for both mental and bone disease should consider early life stress as a risk factor for bone pathologies.

physiology↗