Biology subjects

Bouten, C.

Publications and source records attributed to Bouten, C..

7 recordsLinked to original sources

bioRxiv2026

Increased Nuclear Susceptibility to Mechanical Stress in Phospholamban R14del Cardiomyopathy: A New Perspective on Disease Heterogeneity

Background: Clinical presentation of phospholamban (PLN) R14del cardiomyopathy is highly variable, from asymptomatic carriers to rapidly progressing heart failure. which cannot be fully explained by its known disturbance of sarcoplasmic reticulum calcium handling. Nuclear calcium signalling, shaped by sarcoplasmic reticulum calcium release, plays a key role in regulating gene expression and the cellular response to mechanical stress. However, how the R14del variant affects nuclear signalling under mechanical loading remains unclear. Objective: To uncover the impact of the PLN R14del variation on mechanosensing, nuclear calcium handling and its link to the variable clinical representation of this cardiomyopathy. Methods: Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) carrying the PLN R14del variant, an isogenic control, and wildtype control were subjected to mechanical stimulation by cyclic stretch or cultured on substrates with physiological (10-20 kPa) and pathological (65-85 kPa) stiffness. Nuclear morphology, cytoskeletal organisation and nuclear body formation were assessed via immunofluorescence. Traction force microscopy was used to assess mechanical stress and force generation. Cardiac tissues from PLN R14del cardiomyopathy patients, dilated cardiomyopathy patients, and healthy controls were analysed under mechanical loading (at left ventricular assist device implantation) and unloading (at heart transplantation). Living myocardial slices from a PLN R14del patient were maintained under overloading or physiological loading conditions. Results: PLN R14del hiPSC-CMs showed impaired nuclear calcium handling and, under mechanical stress, exhibited impaired mechanotransduction and elevated nuclear bodies. A strain-avoidance response was triggered but failed to prevent apoptosis. Nuclear abnormalities were confirmed in patient myocardial slices and cardiac biopsies which normalized upon relative mechanical unloading. Conclusion: PLN R14del increases nuclear susceptibility to mechanical stress, linking nuclear dysfunction to new disease insights and highlighting potential for mechanobiology-based therapeutic interventions.

cell biology↗

bioRxiv2026

Functional Performance of Electrospun Tissue-Engineered Heart Valve Scaffolds Across Geometries Under Aortic Conditions

Electrospun, bioresorbable polymer scaffolds represent a compelling platform for tissue-engineered heart valves (TEHVs) owing to their fibrous microstructure, tunable mechanics and inherent capacity to support host-cell infiltration and remodeling. While recent in-vitro parametric studies of bioprosthetic heart valve (BHV) geometry have used silicone cast valves and Doppler echocardiography to link design parameters to hemodynamic performance and leaflet strain, the characterization of the functional behavior of electrospun whole-valve TEHV scaffolds across clinically relevant aortic conditions and across distinct leaflet geometries remains limited. Here, we present an end-to-end workflow in which polycaprolactone (PCL) is electrospun directly onto parametrized, 3D-printed mandrels derived from two established analytical leaflet geometry models, yielding 21 whole-valve scaffolds across five geometries without cutting or suturing of flat fiber sheets. Fiber diameter, orientation and scaffold porosity were assessed by scanning electron microscopy and confirmed to be consistent across scaffolds and geometries. A subset of 8 scaffolds were tested in a pulse duplicator under hypotensive, normotensive and hypertensive aortic conditions, achieving a mean geometric orifice area of 44.51% of the total valve area and demonstrating physiological opening and closing behavior throughout. These results emphasize electrospun whole-valve TEHVs as hemodynamically competent constructs at clinically relevant aortic conditions and provide a reproducible, geometry-driven fabrication and evaluation framework to further support their translation toward regenerative heart valve replacement.

bioengineering↗

bioRxiv2024

The impact of channel geometry and flow regime on endothelial orientation and morphology in vessel-on-chip

This study investigates the impact of channel geometry and applied flow on the morphology and function of endothelial cells (ECs) within vessel-on-chip (VoC) models. Traditional organ-on-chip models often utilize rectangular cross-section channels, resulting in flat walls, sharp corners, and non-uniform wall shear stress profiles, which do not accurately mimic physiological conditions. Tubular channels with a circular cross-section provide a more in vivo-like geometry and result in a physiological uniform wall shear stress. Here, sugar 3D-printing is used for fabricating tubular channels, and stereolithography 3D-printing is applied for making rectangular channels. Using these models, the effects of both channel geometry and various flow conditions on the orientation and morphology of ECs, from both blood and lymph vessels, is explored. The research demonstrates that ECs in tubular channels exhibit a more uniform coverage and circumferential alignment/migration compared to rectangular channels. Unidirectional and bidirectional flow conditions induce alignments parallel to flow, overruling the circumferential alignment induced by curvature in tubular channels. The combination of tubular geometry and pulsatile flow induces enhanced circumferential orientation, different from rectangular channels in which cells remain primarily aligned along the flow direction under pulsatile flow. In summary, our systematic study shows that the channel curvature determines the cell orientation in static conditions, and that adding flow results in a competing effect between geometry and flow for which the resulting cell alignment depends on the flow conditions. Additionally, the study examines the initial adhesive interactions between monocytes and ECs, revealing that EC orientation induced by different flow regimes impacts monocyte rolling velocities. This finding is important for understanding immune cell motility and adhesion in healthy and diseased states. This study underlines the importance of the combined effect of channel geometry and flow conditions in VoC models, and it provides a strong motivation for the continued development of advanced OoC systems with ever more representative geometrical designs and flow control, to maximize the potential of OoC to revolutionize biomedical research and personalized medicine by providing more accurate and functional models of human physiology.

bioengineering↗

bioRxiv2023

Environmental stiffness restores mechanical homeostasis in vimentin-depleted cells

Recent experimental evidence indicates a role for the intermediate filament vimentin in regulating cellular mechanical homeostasis, but its precise contribution remains to be discovered. Mechanical homeostasis requires a balanced bi-directional interplay between the cells microenvironment and the cellular morphological and mechanical state - this balance being regulated via processes of mechanotransduction and mechanoresponse, commonly referred to as mechanoreciprocity. Here, we systematically analyze vimentin-expressing and vimentin-depleted cells in a swatch of in vitro cellular microenvironments varying in stiffness and/or ECM density. We find that vimentin-expressing cells maintain mechanical homeostasis by adapting cellular morphology and mechanics to micromechanical changes in the microenvironment. However, vimentin-depleted cells lose this mechanoresponse ability on short timescales, only to reacquire it on longer time scales. Indeed, we find that the morphology and mechanics of vimentin-depleted cell in stiffened microenvironmental conditions can get restored to the homeostatic levels of vimentin-expressing cells. Additionally, we observed vimentin-depleted cells increasing collagen matrix synthesis and its crosslinking, a phenomenon which is known to increase matrix stiffness, and which we now hypothesize to be a cellular compensation mechanism for the loss of vimentin. Taken together, our findings provide further insight in the regulating role of intermediate filament vimentin in mediating mechanoreciprocity and mechanical homeostasis.

biophysics↗

bioRxiv2023

Engineering a Scalable and Orthogonal Platform for Synthetic Communication in Mammalian Cells

The rational design and implementation of synthetic, orthogonal mammalian communication systems has the potential to unravel fundamental design principles of mammalian cell communication circuits and offer a framework for engineering of designer cell consortia with potential applications in cell therapeutics and artificial tissue engineering. We lay here the foundations for the engineering of an orthogonal, and scalable mammalian synthetic intercellular communication platform that exploits the programmability of synthetic receptors and selective affinity and tunability of diffusing coiled-coil (CC) peptide heterodimers. Leveraging the ability of CCs to exclusively bind to a selected cognate receptor, we demonstrate orthogonal receptor activation, as well as Boolean logic computations. Next, we reveal synthetic intercellular communication based on synthetic receptors and secreted multidomain CC ligands and demonstrate a minimal, three-cell population system that can perform distributed AND gate logic. Our work provides a modular and scalable framework for the engineering of complex cell consortia, with the potential to expand the aptitude of cell therapeutics and diagnostics.

synthetic biology↗

bioRxiv2021

Cardiac fibroblast mechanoresponse guides anisotropic organization of hiPSC-derived cardiomyocytes in vitro

The human myocardium is a mechanically active tissue typified by anisotropic organization of the resident cells (cardiomyocytes (CMs) and cardiac fibroblasts (cFBs)) and the extracellular matrix (ECM). Upon ischemic injury, the anisotropic tissue is replaced by disorganized scar tissue, eventually resulting in loss of coordinated contraction. Efforts to re-establish tissue anisotropy in the injured myocardium are hampered by a lack of understanding on how CM and/or cFB structural organization is affected by the two major physical cues inherent in the myocardium: ECM organization and cyclic mechanical strain. Herein, we investigate the singular and combined effect of ECM (dis)organization and cyclic strain in a 2D human in vitro co-culture model of the myocardial microenvironment. We show that (an)isotropic ECM protein patterning can guide the orientation of CMs and cFBs, both in mono- and co-culture. Subsequent application of uniaxial cyclic strain - mimicking the local anisotropic deformation of beating myocardium - causes no effect when applied parallel to the anisotropic ECM. However, when cultured on isotropic substrates, cFBs, but not CMs, orient away from the direction of cyclic uniaxial strain (strain avoidance). In contrast, CMs show strain avoidance via active remodeling of their sarcomeres only when co-cultured with at least 30% cFBs. Paracrine signaling or N-cadherin-mediated communication between CMs and cFBs were no contributing factors, but our findings suggest that the mechanoresponsive cFBs provide structural guidance for CM orientation and elongation. Our study therefore highlights a synergistic mechanobiological interplay between CMs and cFBs in shaping tissue organization, which is of relevance for regenerating functionally organized myocardium.

biophysics↗

bioRxiv2018

Entropic forces drive cellular contact guidance

Contact guidance--the widely-known phenomenon of cell alignment induced by anisotropic environmental features--is an essential step in the organization of adherent cells, but the mechanisms by which cells achieve this orientational ordering remain unclear. Here we seeded myofibroblasts on substrates micropatterned with stripes of fibronectin and observed that contact guidance emerges at stripe widths much greater than the cell size. To understand the origins of this surprising observation, we combined morphometric analysis of cells and their subcellular components with a novel statistical framework for modelling non-thermal fluctuations of living cells. This modelling framework is shown to predict not only the trends but also the statistical variability of a wide range of biological observables including cell (and nucleus) shapes, sizes and orientations, as well as stress-fibre arrangements within the cells with remarkable fidelity. By comparing observations and theory, we identified two regimes of contact guidance: (i) guidance on stripe widths smaller than the cell size (w [≤] 160 m), which is accompanied by biochemical changes within the cells, including increasing stress-fibre polarisation and cell elongation, and (ii) entropic guidance on larger stripe widths, which is governed by fluctuations in the cell morphology. Overall, our findings suggest an entropy-mediated mechanism for contact guidance associated with the tendency of cells to maximise their morphological entropy through shape fluctuations.

biophysics↗