collective cell migration
- wound healing, morphogenesis, bone remodelling…
- two or more cells
- cells physically and functionally connected via proteins
- polarity of the population
- modification of the environment to create a path
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| Term | Definition |
|---|---|
| collective cell migration | - wound healing, morphogenesis, bone remodelling… - two or more cells - cells physically and functionally connected via proteins - polarity of the population - modification of the environment to create a path |
| zebrafish > lateral line primordium (LLP) | - 100 cells - from the head to the tail - 3000 μm, 42h - rosettes (20 cells) deposition |
| chemical gradient | A difference in concentration (or chemical potential) of a molecule or ion across a membrane or space. |
| what does a chemical gradient do? | energetic drivers—they store free energy that can be converted into work |
| examples of a chemical gradient | High K⁺ inside a cell, low K⁺ outside Proton gradient across mitochondria Diffusion of a neurotransmitter |
| mechanical gradient | A difference in physical force, pressure, tension, shear, or deformation across a system. |
| examples of mechanical gradient | Membrane tension on mechanosensitive channels (e.g., Piezo1, TREK/TRAAK) Osmotic pressure differences causing swelling Tissue stretch, compression, shear flow on endothelial cells |
| what does mechanical gradient do? | change the energy landscape of proteins or membranes, commonly altering gating of mechanosensitive channels |
| lattice models in modelling collective migration | H(t) = Htension + Hshape + Hmigration-polarity |
| lattice models are ____ | - explicit and detailed description of cell functions - analysis of rearrangement - parameters far from experimental observations |
| phase-field models | measure: - force balance (ie static mechanical equilibrium) - tissue mechanics - cell-cell and cell-substrate friction and active stress |
| cell-cell interactions via a free energy functional | F = Fch + Farea + Fcell-cell |
| examples of phase field models | - shape-based anisotropic active stress - velocity alignment - collective motion |
| vertex models | - polygones vertices - rearrangement inducing appearance and disappearance of vertices and specific rules implementation |
| voronoi models | - polygones centers - dynamic network |
| energy function | - areas and perimeters - polar forces at vertices or centers |
| voronoi models uses | - confluent tissues with no space between cells - epithelial populations - role of cell geometry and topological rearrangement - no internal dissipation nor anisotropic active stress |
| particles models | - cell as one or two circular particles - central interparticle potential - attraction and repulsion - active polar force to account for cell motility |
| uses of particles models | - no details for cell shape and polarity - epithelial and mesenchymal cells - tissue stress tensor |
| continuum models | multicellular scale |
| populations described by fields | - velocity, polarity, density, … - free energy of quiescent media - density andpolarity dynamics - force balance - consitutive law - boundary conditions |
| hybrid continuum model | links discrete cell-level representations with continuum fields (like density, stress, or chemical concentrations) to capture both individual and tissue-scale dynamics in a single framework. |
| intra-synchronization | active deformations & adhesion forces |
| inter-synchronization | coordination between cells in order to be as efficient as possible |
| ellipse geometry | rows and columns of cells |
| regulatized heaviside functions (geometry) | - cell network - active and quiescent cells - extracellular matrix (ECM) |
| geometry measrures the ____ of each cell | frontal and rear edge |
| constitutive laws of quiescent cells and ECM | - generalized viscoelastic Maxwell model - no active strain |
| intra-synchronization between active strain and adhesion forces | - frontal protrusion and rear adhesion - frontal adhesion and rear contraction |
| strain gradient signal is an example of | inter-synchronization |
| strain gradient signal | - all the cell are active - the active deformation decreases from the stern to the bow of the population (gradient) |
| worm-like migration is an example of | inter-synchronization |
| worm-like migration | - travelling wave with pulse signal - successive activation and deactivation the cells - repetitive wave |
| tsunami-like migration is an example of | inter-synchronization |
| tsunami-like migration | - tsunami-like migration - a cell only migrates if a space is created around it - permanent activation of cells |
| random-signal inter-synchronization | - all the cells are active - migration out of phase - each cell has its own migration period |
| most efficient modes of inter-synchronization | worm-like and tsunami-like migrations |
| least efficient modes of inter-synchronization | strain gradient and random migration |
| what is the most efficient cells in inter-synchronization? | leader cells (propulsion system) |
| where are the highest stresses in inter-synchronization? | central cells and during the least efficient modes of migration |
| what are not stand-alone factors? | inter-synchronization and randomness |