A5032169107- Cellular Mechanics and Interactions
- 3D Printing in Biomedical Research
- Cell Adhesion Molecules Research
- Force Microscopy Techniques and Applications
- Microtubule and mitosis dynamics
- Microfluidic and Bio-sensing Technologies
- Heat shock proteins research
- Advanced Fluorescence Microscopy Techniques
- Blood properties and coagulation
- Nuclear Structure and Function
- Nanofabrication and Lithography Techniques
- Erythrocyte Function and Pathophysiology
- RNA Research and Splicing
- Angiogenesis and VEGF in Cancer
- Spaceflight effects on biology
- Mathematical Biology Tumor Growth
- Bacterial biofilms and quorum sensing
- Lipid Membrane Structure and Behavior
- Enzyme Structure and Function
- Caveolin-1 and cellular processes
- Protein Kinase Regulation and GTPase Signaling
- Polymer Surface Interaction Studies
- Axon Guidance and Neuronal Signaling
- Hippo pathway signaling and YAP/TAZ
- thermodynamics and calorimetric analyses
Université Grenoble Alpes
2015-2024
Centre National de la Recherche Scientifique
2015-2024
Laboratoire Interdisciplinaire de Physique
2015-2024
Université Joseph Fourier
2012-2021
Laboratoire Matière et Systèmes Complexes
2002-2018
Université Paris Cité
2004-2018
Institut de Recherches en Technologies et Sciences pour le Vivant
2010
Délégation Paris 7
2009
Institut Curie
2009
Laboratoire d'Hydrodynamique
2004-2005
The organization of cells into epithelium depends on cell interaction with both the extracellular matrix (ECM) and adjacent cells. role cell–cell adhesion in regulation epithelial topology is well-described. ECM better known to promote migration provide a structural scaffold for anchoring, but its contribution multicellular morphogenesis less well-understood. We developed minimal model system investigate how affects spatial intercellular junctions. Fibronectin micropatterns were used...
In tissues, cell microenvironment geometry and mechanics strongly impact on physiology. Surface micropatterning allows the control of while deformable substrates tunable stiffness are well suited for mechanics. We developed a new method to micropattern extracellular matrix proteins poly-acrylamide gels in order simultaneously Microenvironment impinge functions by regulating development intra-cellular forces. measured these forces micropatterned cells. Micropattern was streamlined orient...
We compare and synthesize the results of two microrheological experiments on cytoskeleton single cells. In first one, creep function $J(t)$ a cell stretched between glass plates is measured after applying constant force step. second microbead specifically bound to transmembrane receptors driven by an oscillating optical trap, viscoelastic coefficient ${G}_{e}(\ensuremath{\omega})$ retrieved. Both exhibit power law behaviors: $J(t)={A}_{0}{(t∕{t}_{0})}^{\ensuremath{\alpha}}$...
The last step of cell division, cytokinesis, produces two daughter cells that remain connected by an intercellular bridge. This state often represents the longest stage division process. Severing bridge (abscission) requires a well-described series molecular events, but trigger for abscission remains unknown. We found pulling forces exerted on appear to regulate abscission. Counterintuitively, these prolonged connection, whereas release tension induced Tension triggered assembly ESCRT-III...
The nucleus has long been postulated to play a critical physical role during cell polarization and migration, but that not defined or rigorously tested. Here, we enucleated cells test the necessity of directed migration. Using mammalian (cytoplasts), found polarity establishment migration in one dimension (1D) two dimensions (2D) occur without nucleus. Cytoplasts directionally migrate toward soluble (chemotaxis) surface-bound (haptotaxis) extracellular cues collectively scratch-wound assays....
The shape of the cell nucleus can vary considerably during developmental and pathological processes; however, impact nuclear morphology on behavior is not known. Here, we observed that envelope flattens as cells transit from G1 to S phase inhibition myosin II prevents flattening impedes progression phase. Strikingly, show applying compressive force in absence II-mediated tension sufficient restore transition. Using a combination tools manipulate morphology, activates subset transcription...
Abstract Surface colonization underpins microbial ecology on terrestrial environments. Although factors that mediate bacteria–substrate adhesion have been extensively studied, their spatiotemporal dynamics during the establishment of microcolonies remains largely unexplored. Here, we use laser ablation and force microscopy to monitor single-cell course microcolony formation. We find forces rod-shaped bacteria Escherichia coli Pseudomonas aeruginosa are polar. This asymmetry induces...
Directional cell motility relies on the ability of single cells to establish a front-rear polarity and can occur in absence external cues. The initiation migration has often been attributed spontaneous polarization cytoskeleton components, while spatiotemporal evolution cell-substrate interaction forces yet be resolved. Here, we one-dimensional microfabricated assay that mimics complex vivo fibrillar environment being compatible with high-resolution force measurements, quantitative...
Mechanics has been a central focus of physical biology in the past decade. In comparison, how cells manage their size is less understood. Here, we show that parameter to both physics and physiology cell, its volume, depends on mechano-osmotic coupling. We found change volume depending rate at which they shape, when spontaneously spread or are externally deformed. Cells undergo slow deformation constant while fast leads loss. propose mechanosensitive pump leak model explain this phenomenon....
Abstract We compare the measurements of viscoelastic properties adherent alveolar epithelial cells by two micromanipulation techniques: (i) magnetic twisting cytometry and (ii) optical tweezers, using microbeads same size similarly attached to F-actin. The values equivalent Young modulus E, derived from linear viscoelasticity theory, become consistent when degree bead immersion in cell is taken into account. E-values are smaller than (ii): ∼34–58 Pa vs ∼29–258 Pa, probably because higher...
The endothelial CCM complex regulates blood vessel stability and permeability. Loss-of-function mutations in genes are responsible for human cerebral cavernous malformations (CCMs), which characterized by clusters of hemorrhagic dilated capillaries composed endothelium lacking mural cells altered sub-endothelial extracellular matrix (ECM). Association the CCM1/2 with ICAP-1, an inhibitor β1 integrin, prompted us to investigate whether interferes integrin signaling. We demonstrate that loss...
The structural and functional organization of biological tissues relies on the intricate interplay between chemical mechanical signaling. Whereas role constant transient perturbations is generally accepted, several studies recently highlighted existence long-range excitations (i.e., waves) at supracellular level. Here, we confine epithelial cell monolayers to quasi-one-dimensional geometries, force establishment tissue-level waves well-defined wavelength period. Numerical simulations based a...
Abstract An important channel of cell-to-cell communication is direct contact. The immune synapse a paradigmatic example such type interaction: it forms upon engagement antigen receptors in lymphocytes by antigen-presenting cells and allows the local exchange molecules information. Although mechanics has been shown to play an role this process, how forces organize impact on function unknown. We find that mechanical are spatio-temporally patterned at synapse: global pulsatile myosin II-driven...
Spontaneous mechanical oscillations occur in various types of biological systems where groups motor molecules are elastically coupled to their environment. By using an optical trap oppose the gliding motion a single bead-tailed actin filament over substrate densely coated with myosin motors, we mimicked this condition vitro. We show that minimal actomyosin system can oscillate spontaneously. Our finding accords quantitatively general theoretical framework oscillatory instabilities emerge...
Cells are able to sense and react their physical environment by translating a mechanical cue into an intracellular biochemical signal that triggers biological responses. This process, called mechanotransduction, controls essential cellular functions such as proliferation migration. The response external stimulation has been investigated with various static dynamic systems, so far limited global deformations or local through discrete substrates. To apply constraints at the single cell scale...
Endothelial integrity relies on a mechanical crosstalk between intercellular and cell-matrix interactions. This is compromised in hemorrhagic vascular lesions of patients carrying loss-of-function mutations cerebral cavernous malformation (CCM) genes. RhoA/ROCK-dependent cytoskeletal remodeling central to the disease, as it causes unbalanced cell adhesion towards increased cell-extracellular matrix adhesions destabilized cell-cell junctions. study reveals that CCM proteins directly...
Abstract The mechanical properties of biological tissues are key to their physical integrity and function. Although external loading or biochemical treatments allow the estimation these globally, it remains difficult assess how such stimuli compare with cell-generated contractions. Here we engineer microtissues composed optogenetically-modified fibroblasts encapsulated within collagen. Using light control activity RhoA, a major regulator cellular contractility, induce local contractions...
Cell contraction and proliferation, matrix secretion external mechanical forces induce compression during embryogenesis tumor growth, which in turn regulate cell metabolism or differentiation. How affects tissue contractility, a hallmark of function, is however unknown. Here we apply osmotic to microtissues either mouse colon adenocarcinoma CT26 cells, NIH 3T3 fibroblasts, human primary cancer-associated fibroblasts. Microtissues are anchored flexible pillars that serve as force transducers....
We describe the design of micropatterned surfaces for single cell studies, based on thermoresponsive polymer brushes. show that brushes made poly(N-isopropylacrylamide) grafted at high surface density display excellent protein and anti-adhesive properties. Such are readily patterned micron scale via deep UV photolithography. A proper choice adhesive pattern shapes, combined with temperature-dependent swelling properties PNIPAM, allow us to use brush as a microactuator which induces...