Biology subjects

Passier, R.

Publications and source records attributed to Passier, R..

8 recordsLinked to original sources

bioRxiv2026

Roles of Neuromedin-U and Endothelin-1 in human cardiac organoid differentiation

During recent years, many new culture methods have been established to generate cardiomyocytes, using signaling and patterning factors that play important roles in mammalian heart development. Here, we identify two additional pathways of interest using a cardiac differentiation roadmap that we have generated, involving the endothelin 1 receptor EDNRA gene, and the Neuromedin family signaling peptide gene NMU. Treatment with NMU had most effect in ventricular lineages where it normally is not abundantly expressed, leading to a significant shift from ventricular cardiomyocyte (vCM) differentiation to non-myocytes, as shown with reporters and cell type-specific markers, which was associated with an increased beating frequency. This was not observed in atrial cultures. Treating atrial cultures with endothelin 1 (ET-1, EDN1) increased the number of atrial cardiomyocytes (aCM), while reducing repolarization times, increasing the contraction frequencies and altering the patterns of action potential propagations across the tissue. In ventricular cultures, a reduction in ventricular cardiomyocyte (vCM) numbers was observed, suggesting a combinatorial effect of ET-1 and retinoic acid (RA) on cardiomyocyte differentiation. These results identify ET-1 and NMU as important signaling factors for cardiomyocyte differentiation and electrophysiology of cardiac organoids, with ET-1 enhancing aCM differentiation when added around the time of posteriorization of the second heart field. NMU added without RA reduces the number of vCMs in the culture while it changes the organoids to exhibit a more atrial-like beating frequency.

developmental biology↗

bioRxiv2026

Xolographic printing of cell-dense engineered living matter via iodixanol-driven enhancement of type II photoinitiation

Type II photoinitiators are essential for numerous applications, including advanced 3D printing techniques such as Xolography. Despite offering tunable wavelengths and reaction mechanisms, their limited photoreactivity hinders widespread adoption. Solutions to increase reactivity, particularly in aqueous solutions and in a biocompatible manner, are urgently needed. Here, we report the surprising finding that iodixanol enhances reactivity of type II photoinitiation systems. Supplementing Xolographic print resins with iodixanol increases photoreactivity, which reduces print times and light dosage tenfold, and enables printing of previously unprintable material formulations. Surprisingly, iodixanol supplementation also improves cell viability in a dose-dependent manner, while reducing cell-mediated light scattering. Together, this enables accurate Xolographic printing of highly cell-dense bioresins, which facilitated the biofabrication of engineered living matter with up to 100 M cells mL-1 (>40% cells by volume) with a resolution of ~65 microns. These advances enabled the first demonstration of tissue function in Xolographically-printed materials. Human induced pluripotent stem cell-derived cardiomyocytes were printed into contractile cardiac-like engineered living matter, which exhibited enhanced cell-cell contact and synchronous contractions, confirming tissue level function. As a highly water soluble, cytocompatible, and clinically approved compound, iodixanol therefore represents a valuable and translatable solution to improve the reactivity of type II photoinitiation systems, which enables volumetric biofabrication of highly cell dense living matter. This unlocks a new role for iodixanol in a wide variety of fields including dentistry, chemistry, organic photovoltaics, tissue engineering, and 3D printing.

bioengineering↗

bioRxiv2026

Proteome modulation by opposite inotropic drugs in human engineered cardiac tissue revealed by topology-driven cross-modal integration

Engineered heart tissues (EHTs) represent an innovative platform enabling physiologically relevant in vitro evaluation of drug-induced cardiac responses. While functional characterization remains central to EHTs, molecular profiling is increasingly used to elucidate mechanisms underlying drug-induced phenotypes. Proteomics provides broad molecular characterization of drug responses at the protein level, yet the complexity, heterogeneity, and high dimensionality of proteomics datasets challenge conventional statistical approaches, which are not designed for cross-modal integration and streamlined multi-omics analysis. In this study, we developed an innovative framework based on topological data analysis (TDA) for the integration of large proteomics profiles and functional readouts to investigate system-level responses to drugs with opposing inotropic effects, epinephrine and doxorubicin. Samples were organized into a topological connectivity network according to multimodal similarity enabling simultaneous exploration of treatments, cardiac function and proteome alterations. Highly correlated features were then used for pathway enrichment analysis, which revealed strong similarities between the enrichment profiles associated with contractile force and epinephrine. These findings are consistent with the positive inotropic effect of epinephrine, whereas doxorubicin exhibited an opposing enrichment profile. Energy homeostasis, mitochondrial translation and proteostasis emerged as the major cellular processes displaying opposite associations with the two inotropic drugs, highlighting a link between cardiac contractility and perturbations in these processes. In conclusion, our TDA-based framework successfully integrated functional and proteomic data to uncover treatment-specific remodeling in EHTs, offering a modular and scalable approach that could be adapted to other in vitro organ models for systems-level mechanistic studies and next-generation drug development.

bioinformatics↗

bioRxiv2025

A human engineered mini-heart platform for mimicking ventricular pump function

Engineered cardiac tissue models for in vitro physiological studies often fail to replicate the pump function of the heart. Despite promising advancements, the use of engineered cardiac chambers is often hindered by complex fabrication processes and invasive characterization techniques. Here, we engineered a human cardiac chamber, referred to as a mini-heart, by employing a novel sacrificial molding approach within a customized bioreactor. The mini-hearts pumping capability was confirmed through optical recording of fluid displacement at the engineered tissue inlet, enabling the non-invasive acquisition of hemodynamic parameters such as stroke volume, stroke work, ejection fraction, and developed pressure. Morphological analysis of the engineered tissues revealed organized sarcomeres and extracellular matrix self-determination, highlighting the advantage of our degradable mold technology. Additionally, we have measured calcium transients during both spontaneous and electrically-paced beating, and observed a positive inotropic response to the {beta}-adrenergic agonist drug isoproterenol. Altogether, our biomimicking engineered tissue platform provides a robust tool for exploring cardiac pressure-volume dynamics, thereby facilitating complex disease modelling and drug screening applications in vitro.

bioengineering↗

bioRxiv2024

Single-cell roadmap of cardiac differentiation identifies roles for ZNF711 and retinoic acid in balanced epicardial and cardiomyocyte lineage commitment

Stem cell-based models of human heart tissue and cardiac differentiation employ monolayer and 3D organoid cultures with different properties, cell type composition, and maturity. Here we show how cardiac monolayer, embryoid body, and engineered heart tissue trajectories compare in a single-cell roadmap of atrial and ventricular differentiation conditions. Using a multiomic approach and gene-regulatory network inference, we identified regulators of the epicardial, atrial and ventricular cardiomyocyte lineages. We identified ZNF711 as a regulatory switch and safeguard for cardiomyocyte commitment. We show that ZNF711 ablation prevents cardiomyocyte differentiation in the absence of retinoic acid, causing progenitors to be diverted more prominently to epicardial and other lineages. Retinoic acid rescues this shift in lineage commitment and promotes atrial cardiomyocyte differentiation by regulation of shared and complementary target genes, showing an interplay between ZNF711 and retinoic acid in cardiac lineage commitment. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=77 SRC="FIGDIR/small/588683v2_ufig1.gif" ALT="Figure 1"> View larger version (33K): org.highwire.dtl.DTLVardef@e3733forg.highwire.dtl.DTLVardef@a34e61org.highwire.dtl.DTLVardef@16eccdcorg.highwire.dtl.DTLVardef@14bb7a5_HPS_FORMAT_FIGEXP M_FIG C_FIG HIGHLIGHTSO_LIWe present an atlas of cardiac differentiation under different culture conditions, showing progenitor trajectories and cell states reminiscent of the fetal heart. C_LIO_LIMultiome and chromatin accessibility analysis identified candidate regulators of cardiomyocyte and non-cardiomyocyte lineages. C_LIO_LIDistinct trajectories of lineage commitment and differentiation under different culture conditions shows plasticity of first and second heart field progenitors and different ratios of cardiomyocyte and non-myocyte lineages. C_LIO_LIZNF711 is required for balanced commitment to epicardial and ventricular cardiomyocyte lineages. Retinoic acid rescues a requirement for ZNF711 in cardiomyocyte differentiation, promoting both atrial cardiomyocyte and epicardial differentiation. C_LI

developmental biology↗

bioRxiv2021

Fluidic Circuit Board with Modular Sensor and Valves Enables Stand-Alone, Tubeless Microfluidic Flow Control in Organs-on-Chips

Organs-on-chips are a unique class of microfluidic in vitro cell culture models, in which the in vivo tissue microenvironment is mimicked. Unfortunately, its widespread use is hampered by their operation complexity and incompatibility with end-user research settings. To address these issues, many commercial and non-commercial platforms have been developed for semi-automated culture of organs-on-chips. However, these organ-on-chip culture platforms each represent a closed ecosystem, with very little opportunity to interchange and integrate components from different platforms or to develop new ones. The Translational Organ-on-Chip Platform (TOP) is a multi-institutional effort to develop an open platform for automated organ-on-chip culture and integration of components from various developers. Central to TOP is the fluidic circuit board (FCB), a microfluidic plate with the form factor of a typical well plate. The FCB enables microfluidic control of multiple components like sensors or organ-on-chip devices through an interface based on openly available standards. Here, we report an FCB to integrate commercial and in-house developed components forming a stand-alone flow control system for organs-on-chips. The control system is able to achieve constant and pulsatile flow recirculation through a connected organ-on-chip device. We demonstrate that this system is able to automatically perfuse a heart-on-chip device containing co-cultures of cardiac tissues derived from human pluripotent stem cell-derived cardiomyocytes and monolayers of endothelial cells for five days. Altogether, we conclude that open technology platforms allow the integration of components from different sources to form functional and fit-for-purpose organ-on-chip systems. We anticipate that open platforms will play a central role in catalysing and maturing further technological development of organ-on-chip culture systems.

bioengineering↗

bioRxiv2021

Generation and Culture of Cardiac Microtissues in a Microfluidic Chip with a Reversible Open Top Enables Electrical Pacing, Dynamic Drug Dosing and Endothelial Cell Co-Culture

Cardiovascular disease morbidity has increased worldwide in recent years while drug development has been affected by failures in clinical trials and lack of physiologically relevant models. Organs-on-chips and human pluripotent stem cell technologies aid to overcome some of the limitations in cardiac in vitro models. Here, a bi-compartmental, monolithic heart-on-chip device that facilitates porous membrane integration in a single fabrication step is presented. Moreover, the device includes open-top compartments that allow facile co-culture of human pluripotent stem cell-derived cardiomyocytes and human adult cardiac fibroblast into geometrically defined cardiac microtissues. The device can be reversibly closed with a glass seal or a lid with fully customized 3D-printed pyrolytic carbon electrodes allowing electrical stimulation of cardiac microtissues. A subjacent microfluidic channel allowed localized and dynamic drug administration to the cardiac microtissues, as demonstrated by a chronotropic response to isoprenaline. Moreover, the microfluidic channel could also be populated with human induced pluripotent stem-derived endothelial cells allowing co-culture of heterotypic cardiac cells in one device. Overall, this study demonstrates a unique heart-on-chip model that systematically integrates the structure and electromechanical microenvironment of cardiac tissues in a device that enables active perfusion and dynamic drug dosing. Advances in the engineering of human heart-on-chip models represent an important step towards making organ-on-a-chip technology a routine aspect of preclinical cardiac drug development.

bioengineering↗

bioRxiv2017

Versatile open software to quantify cardiomyocyte and cardiac muscle contraction in vitro and in vivo

Contraction of muscle reflects its physiological state. Methods to quantify contraction are often complex, expensive and tailored to specific models or recording conditions, or require specialist knowledge for data extraction. Here we describe an automated, open-source software tool (MUSCLEMOTION) adaptable for use with standard laboratory and clinical imaging equipment that enables quantitative analysis of normal cardiac contraction, disease phenotypes and pharmacological responses. MUSCLEMOTION allowed rapid and easy measurement of contractility in (i) single cardiomyocytes from primary adult heart and human pluripotent stem cells, (ii) multicellular 2D-cardiomyocyte cultures, 3D engineered heart tissues and cardiac organoids/microtissues in vitro and (iii) intact hearts of zebrafish and humans in vivo. Good correlation was found with conventional measures of contraction in each system. Thus, using a single method for processing video recordings, we obtained reliable pharmacological data and measures of cardiac disease phenotype in experimental cell- and animal models and human echocardiograms.

physiology↗