Evaluation of the force and spatial dynamics of macrophage podosomes by multi-particle tracking.
Podosomes are submicron adhesive and mechanosensitive structures formed by macrophages, dendritic cells and osteoclasts that are capable of protruding into the extracellular environment. Built of an F-actin core surrounded by an adhesion ring, podosomes assemble in a network interconnected by acto-myosin cables. They have been shown to display spatiotemporal instability as well as protrusion force oscillations. To analyse the entire population of these unstable structures, we have designed an automated multi-particle tracking adapted to both topographical and fluorescence data. Here we describe in detail this approach and report the measurements of individual and collective characteristics of podosome ensembles, providing an integrated picture of their activity from the complementary angles of organisation, dynamics, mobility and mechanics. We believe that this will lead to a comprehensive view of podosome collective behaviour and deepen our knowledge about the significance of mechanosensing mediated by protrusive structures.
IPBS (Institut de Pharmacologie et de Biologie Structurale), UMR CNRS 5089, 205 route de Narbonne, F 31077 Toulouse, France; Univ de Toulouse, UPS, F 31400 Toulouse, France.
Amsha
A
Proag
IPBS (Institut de Pharmacologie et de Biologie Structurale), UMR CNRS 5089, 205 route de Narbonne, F 31077 Toulouse, France; Univ de Toulouse, UPS, F 31400 Toulouse, France.
Anaïs
A
Bouissou
CNRS, LAAS, 7 avenue du colonel Roche, F 31400 Toulouse, France; Univ de Toulouse, INSA, F 31400 Toulouse, France.
Christophe
C
Vieu
IPBS (Institut de Pharmacologie et de Biologie Structurale), UMR CNRS 5089, 205 route de Narbonne, F 31077 Toulouse, France; Univ de Toulouse, UPS, F 31400 Toulouse, France. Electronic address: isabelle.maridonneau-parini@ipbs.fr.
Isabelle
I
Maridonneau-Parini
IPBS (Institut de Pharmacologie et de Biologie Structurale), UMR CNRS 5089, 205 route de Narbonne, F 31077 Toulouse, France; Univ de Toulouse, UPS, F 31400 Toulouse, France. Electronic address: renaud.poincloux@ipbs.fr.
Renaud
R
Poincloux
D002478:Cells, Cultured; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D008264:Macrophages / Q000502:physiology* / Q000648:ultrastructure; D018625:Microscopy, Atomic Force; D008856:Microscopy, Fluorescence; D000069261:Podosomes / Q000502:physiology* / Q000648:ultrastructure
Collective dynamics; Force; Macrophages; Mechanosensing; Multiparticle tracking; Podosomes