Protrusion force microscopy reveals oscillatory force generation and mechanosensing activity of human macrophage podosomes

A. Labernadie , A. Bouissou , P. Delobelle , S. Balor , R. Voituriez , A. Proag , I. Fourquaux , C. Thibault , C. Vieu , R. Poincloux , G.M. Charriere , I. Maridonneau-Parini

Bibtex , URL
NATURE COMMUNICATIONS, 5, 5343
Published 01 Nov. 2014
DOI: 10.1038/ncomms6343
ISSN: 2041-1723

Abstract

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.

This publication is related to:

Stochastic dynamics of reactive and living systems