Abstract

Osteoclasts are unique in their capacity to degrade bone tissue. To achieve this process, osteoclasts form a specific structure called the sealing zone, which creates a close contact with bone and confines the release of protons and hydrolases for bone degradation. The sealing zone is composed of actin structures called podosomes nested in a dense actin network. The organization of these actin structures inside the sealing zone at the nano scale is still unknown. Here, we combine cutting-edge microscopy methods to reveal the nanoscale architecture and dynamics of the sealing zone formed by human osteoclasts on bone surface. Random illumination microscopy allowed the identification and live imaging of densely packed actin cores within the sealing zone. A cross-correlation analysis of the fluctuations of actin content at these cores indicates that they are locally synchronized. Further examination shows that the sealing zone is composed of groups of synchronized cores linked by a-actinin1 positive filaments, and encircled by adhesion complexes. Thus, we propose that the confinement of bone degradation mediators is achieved through the coordination of islets of actin cores and not by the global coordination of all podosomal subunits forming the sealing zone.

Data availability

All data generated or analysed during this study are included in the manuscript and supporting files; Source Data files have been provided for Figures 1, 2, 3, 4 and 5.

Article and author information

Author details

  1. Marion Portes

    Institute de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS, UPS, Toulouse, France
    Competing interests
    The authors declare that no competing interests exist.
  2. Thomas Mangeat

    Centre de Biologie Intégrative, Université de Toulouse, CNRS, Toulouse, France
    Competing interests
    The authors declare that no competing interests exist.
  3. Natacha Escallier

    Institute de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS, UPS, Toulouse, France
    Competing interests
    The authors declare that no competing interests exist.
  4. Ophélie Dufrancais

    Institute de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS, UPS, Toulouse, France
    Competing interests
    The authors declare that no competing interests exist.
  5. Brigitte Raynaud-Messina

    Institute de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS, UPS, Toulouse, France
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-7637-1997
  6. Christophe Thibault

    Laboratoire d'analyse et d'architectures des systèmes (LAAS), Université de Toulouse, CNRS, Toulouse, France
    Competing interests
    The authors declare that no competing interests exist.
  7. Isabelle Maridonneau-Parini

    Institute de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS, UPS, Toulouse, France
    Competing interests
    The authors declare that no competing interests exist.
  8. Christel Vérollet

    Institute de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS, UPS, Toulouse, France
    For correspondence
    verollet@ipbs.fr
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-1079-9085
  9. Renaud Poincloux

    Institute de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS, UPS, Toulouse, France
    For correspondence
    poincloux@ipbs.fr
    Competing interests
    The authors declare that no competing interests exist.

Funding

Agence Nationale de la Recherche (ANR16-CE13)

  • Christel Vérollet

Fondation pour la Recherche Médicale (FRM DEQ2016 0334894)

  • Isabelle Maridonneau-Parini

Human Frontier Science Program (RGP0035/2016)

  • Isabelle Maridonneau-Parini

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Reviewing Editor

  1. Maria Grano, University of Bari, Italy

Ethics

Human subjects: Monocytes from healthy subjects were provided by Etablissement Français du Sang (EFS), Toulouse, France, under contract 21/PLER/TOU/IPBS01/20130042. According to articles L12434 and R124361 of the French Public Health Code, the contract was approved by the French Ministry of Science and Technology (agreement number AC 2009921). Written informed consents were obtained from the donors before sample collection.

Version history

  1. Received: November 16, 2021
  2. Preprint posted: December 11, 2021 (view preprint)
  3. Accepted: June 20, 2022
  4. Accepted Manuscript published: June 21, 2022 (version 1)
  5. Accepted Manuscript updated: June 23, 2022 (version 2)
  6. Version of Record published: July 5, 2022 (version 3)

Copyright

© 2022, Portes et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

Metrics

  • 1,051
    views
  • 332
    downloads
  • 4
    citations

Views, downloads and citations are aggregated across all versions of this paper published by eLife.

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Open citations (links to open the citations from this article in various online reference manager services)

Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)

  1. Marion Portes
  2. Thomas Mangeat
  3. Natacha Escallier
  4. Ophélie Dufrancais
  5. Brigitte Raynaud-Messina
  6. Christophe Thibault
  7. Isabelle Maridonneau-Parini
  8. Christel Vérollet
  9. Renaud Poincloux
(2022)
Nanoscale architecture and coordination of actin cores within the sealing zone of human osteoclasts
eLife 11:e75610.
https://doi.org/10.7554/eLife.75610

Share this article

https://doi.org/10.7554/eLife.75610

Further reading

    1. Cell Biology
    2. Stem Cells and Regenerative Medicine
    Rajdeep Banerjee, Thomas J Meyer ... David D Roberts
    Research Article

    Extramedullary erythropoiesis is not expected in healthy adult mice, but erythropoietic gene expression was elevated in lineage-depleted spleen cells from Cd47−/− mice. Expression of several genes associated with early stages of erythropoiesis was elevated in mice lacking CD47 or its signaling ligand thrombospondin-1, consistent with previous evidence that this signaling pathway inhibits expression of multipotent stem cell transcription factors in spleen. In contrast, cells expressing markers of committed erythroid progenitors were more abundant in Cd47−/− spleens but significantly depleted in Thbs1−/− spleens. Single-cell transcriptome and flow cytometry analyses indicated that loss of CD47 is associated with accumulation and increased proliferation in spleen of Ter119CD34+ progenitors and Ter119+CD34 committed erythroid progenitors with elevated mRNA expression of Kit, Ermap, and Tfrc. Induction of committed erythroid precursors is consistent with the known function of CD47 to limit the phagocytic removal of aged erythrocytes. Conversely, loss of thrombospondin-1 delays the turnover of aged red blood cells, which may account for the suppression of committed erythroid precursors in Thbs1−/− spleens relative to basal levels in wild-type mice. In addition to defining a role for CD47 to limit extramedullary erythropoiesis, these studies reveal a thrombospondin-1-dependent basal level of extramedullary erythropoiesis in adult mouse spleen.

    1. Cell Biology
    Makiko Kashio, Sandra Derouiche ... Makoto Tominaga
    Research Article

    Reports indicate that an interaction between TRPV4 and anoctamin 1 (ANO1) could be widely involved in water efflux of exocrine glands, suggesting that the interaction could play a role in perspiration. In secretory cells of sweat glands present in mouse foot pads, TRPV4 clearly colocalized with cytokeratin 8, ANO1, and aquaporin-5 (AQP5). Mouse sweat glands showed TRPV4-dependent cytosolic Ca2+ increases that were inhibited by menthol. Acetylcholine-stimulated sweating in foot pads was temperature-dependent in wild-type, but not in TRPV4-deficient mice and was inhibited by menthol both in wild-type and TRPM8KO mice. The basal sweating without acetylcholine stimulation was inhibited by an ANO1 inhibitor. Sweating could be important for maintaining friction forces in mouse foot pads, and this possibility is supported by the finding that wild-type mice climbed up a slippery slope more easily than TRPV4-deficient mice. Furthermore, TRPV4 expression was significantly higher in controls and normohidrotic skin from patients with acquired idiopathic generalized anhidrosis (AIGA) compared to anhidrotic skin from patients with AIGA. Collectively, TRPV4 is likely involved in temperature-dependent perspiration via interactions with ANO1, and TRPV4 itself or the TRPV4/ANO 1 complex would be targeted to develop agents that regulate perspiration.