Biology subjects

Janel, S.

Publications and source records attributed to Janel, S..

3 recordsLinked to original sources

bioRxiv2025

Gut-on-Chip Methodology Based on 3D-Printed Molds: A Cost-Effective and Accessible Approach

1Gut-on-chips (GoC) represent a disruptive technology with great potential to understand the underlying mechanisms of gut health and pathology. Researchers who want to implement this approach, can either use expensive commercial microfluidic chips or build them from scratch in their lab. However, the design of such devices demands specific technical skills and expertise in computer assisted design (CAD). Additionally, the fabrication of the master molds for the chip production is very costly, time consuming and requires dedicated microfabrication facilities. Thus, the diffusion of these models in biology and health research laboratories remains limited due to this technological complexity and lack of affordability. In order to break these two bottlenecks, we present here the 3DP-{micro}Gut with open access designs and a simple fabrication approach based on a commercial 3D printer intended for general users. To ensure a good reproducibility with a sufficient number of available replicates for biological experiments, the method has been optimized to allow the production of multiple GoC per batch. The chips were also improved for confocal live imaging microscopy analyses. The chips are designed to be compatible with different types of microfluidics pumps, from stand-alone to completely integrated instrumentation. As a proof of concept, Caco-2 cells were seeded inside the fabricated GoC to validate their biocompatibility and functionality. After 7 days of maturation, cells self-differentiated in a 3D epithelium resembling in vivo expected structures. In summary we proposed a low-cost and open access GoC design and fabrication method with medium throughput. These results demonstrate the advantage of using 3D SLA printing to accelerate GoC implementation for gut physiopathology research.

bioengineering↗

bioRxiv2023

Reliable, standardized measurements for cell mechanical properties

Atomic force microscopy (AFM) has become indispensable for studying biological and medical samples. More than two decades of experiments have revealed that cancer cells are softer than healthy cells (for measured cells cultured on stiff substrates). The softness or, more precisely, the larger deformability of cancer cells, primarily independent of cancer types, could be used as a sensitive marker of pathological changes. The wide application of biomechanics in clinics would require designing instruments with specific calibration, data collection, and analysis procedures. For these reasons, such development is, at present, still very limited, hampering the clinical exploitation of mechanical measurements. Here, we propose a standardized operational protocol (SOP), developed within the EU ITN network Phys2BioMed, which allows the detection of the biomechanical properties of living cancer cells regardless of the nanoindentation instruments used (AFMs and other indenters) and the laboratory involved in the research. We standardized the cell cultures, AFM calibration, measurements, and data analysis. This effort resulted in a step-by-step SOP for cell cultures, instrument calibration, measurements, and data analysis, leading to the concordance of the results (Youngs modulus) measured among the six EU laboratories involved. Our results highlight the importance of the SOP in obtaining a reproducible mechanical characterization of cancer cells and paving the way toward exploiting biomechanics for diagnostic purposes in clinics.

biophysics↗

bioRxiv2021

Optineurin links Hace1-dependent Rac ubiquitylation to integrin-mediated mechanotransduction to control bacterial invasion and cell division

Extracellular matrix (ECM) elasticity is perceived by cells via focal adhesion structures, which transduce mechanical cues into chemical signalling to conform cell behaviour. Although the contribution of ECM compliance to the control of cell migration or division has been extensively studied, little has been reported regarding infectious processes. We have studied how mechanical properties of the ECM impact invasion of cells by the extraintestinal Escherichia coli pathogen UTI89. We show that UTI89 takes advantage, via its CNF1 toxin, of integrin mechanoactivation to trigger its invasion into cells. We identified OPTN as a protein regulated by ECM stiffness whose function is required for bacterial invasion and integrin mechanical coupling and for stimulation of HACE1 E3 ligase activity towards the Rac1 GTPase. We showed that OPTN knockdown cells display enhanced Rac1 activation, strong mechanochemical adhesion signalling and increased cyclin D1 translation, together with enhanced cell proliferation independent of ECM stiffness. Despite such features, OPTN knockdown cells displayed defective traction force buildup associated with limited cellular invasion by UTI89. Together, our data indicate that OPTN, through a new role in mechanobiology, supports CNF1-producing uropathogenic E. coli invasion and links HACE1-mediated ubiquitylation of Rac1 to ECM mechanical properties and integrin mechanotransduction.

cell biology↗