Protrusion force microscopy reveals oscillatory force generation and mechanosensing activity of human macrophage podosomes.
Podosomes are adhesion structures formed in monocyte-derived cells. They are F-actin-rich columns perpendicular to the substrate surrounded by a ring of integrins. Here, to measure podosome protrusive forces, we designed an innovative experimental setup named protrusion force microscopy (PFM), which consists in measuring by atomic force microscopy the deformation induced by living cells onto a compliant Formvar sheet. By quantifying the heights of protrusions made by podosomes onto Formvar sheets, we estimate that a single podosome generates a protrusion force that increases with the stiffness of the substratum, which is a hallmark of mechanosensing activity. We show that the protrusive force generated at podosomes oscillates with a constant period and requires combined actomyosin contraction and actin polymerization. Finally, we elaborate a model to explain the mechanical and oscillatory activities of podosomes. Thus, PFM shows that podosomes are mechanosensing cell structures exerting a protrusive force.
1] CNRS-IPBS (Institut de Pharmacologie et de Biologie Structurale), 205 route de Narbonne, F-31077 Toulouse, France [2] Université de Toulouse, UPS (Université Paul Sabatier Toulouse), F-31062 Toulouse, France [3] CNRS-LAAS (Laboratoire d'Analyse et d'Architecture des Systèmes), 7 avenue du colonel Roche, F-31077 Toulouse, France [4] Université de Toulouse, UPS, INSA, INP, ISAE; LAAS, F-31077 Toulouse, France.
Anna
A
Labernadie
1] CNRS-IPBS (Institut de Pharmacologie et de Biologie Structurale), 205 route de Narbonne, F-31077 Toulouse, France [2] Université de Toulouse, UPS (Université Paul Sabatier Toulouse), F-31062 Toulouse, France.
Anaïs
A
Bouissou
FEMTO-ST, UMR CNRS 6174, Université de Franche Comté, 24 rue de l'Epitaphe, F-25000 Besançon, France.
Patrick
P
Delobelle
Plateau Microscopie électronique, IEFG CNRS IFR 109, Bat. IBCG, 118 route de Narbonne, F-31062 Toulouse, France.
Stéphanie
S
Balor
CNRS UMR7600, Université Pierre et Marie Curie, 4 place Jussieu, F-75252 Paris, France.
Raphael
R
Voituriez
1] CNRS-IPBS (Institut de Pharmacologie et de Biologie Structurale), 205 route de Narbonne, F-31077 Toulouse, France [2] Université de Toulouse, UPS (Université Paul Sabatier Toulouse), F-31062 Toulouse, France.
Amsha
A
Proag
Centre de Microscopie Électronique Appliquée à la Biologie, Faculté de Médecine de Rangueil, F-31062 Toulouse, France.
Isabelle
I
Fourquaux
1] CNRS-LAAS (Laboratoire d'Analyse et d'Architecture des Systèmes), 7 avenue du colonel Roche, F-31077 Toulouse, France [2] Université de Toulouse, UPS, INSA, INP, ISAE; LAAS, F-31077 Toulouse, France.
Christophe
C
Thibault
1] CNRS-LAAS (Laboratoire d'Analyse et d'Architecture des Systèmes), 7 avenue du colonel Roche, F-31077 Toulouse, France [2] Université de Toulouse, UPS, INSA, INP, ISAE; LAAS, F-31077 Toulouse, France.
Christophe
C
Vieu
1] CNRS-IPBS (Institut de Pharmacologie et de Biologie Structurale), 205 route de Narbonne, F-31077 Toulouse, France [2] Université de Toulouse, UPS (Université Paul Sabatier Toulouse), F-31062 Toulouse, France.
Renaud
R
Poincloux
1] CNRS-IPBS (Institut de Pharmacologie et de Biologie Structurale), 205 route de Narbonne, F-31077 Toulouse, France [2] Université de Toulouse, UPS (Université Paul Sabatier Toulouse), F-31062 Toulouse, France.
Guillaume M
GM
Charrière
1] CNRS-IPBS (Institut de Pharmacologie et de Biologie Structurale), 205 route de Narbonne, F-31077 Toulouse, France [2] Université de Toulouse, UPS (Université Paul Sabatier Toulouse), F-31062 Toulouse, France.
Isabelle
I
Maridonneau-Parini
D000199:Actins / Q000502:physiology / Q000648:ultrastructure; D001683:Biological Clocks / Q000502:physiology*; D022081:Cell Surface Extensions / Q000502:physiology / Q000648:ultrastructure; D002478:Cells, Cultured; D006801:Humans; D008264:Macrophages / Q000166:cytology / Q000502:physiology* / Q000648:ultrastructure; D040542:Mechanotransduction, Cellular / Q000502:physiology*; D018625:Microscopy, Atomic Force / Q000379:methods*; D008855:Microscopy, Electron, Scanning; D008954:Models, Biological; D056004:Molecular Dynamics Simulation; D000069261:Podosomes / Q000502:physiology* / Q000648:ultrastructure
D000199:Actins