Mechanically-stimulated ATP release from murine bone cells is regulated by a balance of injury and repair

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Abstract

Bone cells sense and actively adapt to physical perturbations to prevent critical damage. ATP release is among the earliest cellular responses to mechanical stimulation. Mechanical stimulation of a single murine osteoblast led to the release of 70 {plus minus} 24 amole ATP, which stimulated calcium responses in neighboring cells. Osteoblasts contained ATP-rich vesicles that were released upon mechanical stimulation. Surprisingly, interventions that promoted vesicular release reduced ATP release, while inhibitors of vesicular release potentiated ATP release. Searching for an alternative ATP release route, we found that mechanical stresses induced reversible cell membrane injury in vitro and in vivo. Ca²⁺/PLC/PKC-dependent vesicular exocytosis facilitated membrane repair, thereby minimizing cell injury and reducing ATP release. Priming cellular repair machinery prior to mechanical stimulation reduced subsequent membrane injury and ATP release, linking cellular mechanosensitivity to prior mechanical exposure. Thus, our findings position ATP release as an integrated readout of membrane injury and repair.

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All data generated or analysed during this study are included in the manuscript and supporting files. Source data files have been provided for Figures 1-6. Representative video recordings and confocal z-stacks are included as rich media files.

Article and author information

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Nicholas Mikolajewicz

Faculty of Dentistry, McGill University, Montreal, Canada

Competing interests
The authors declare that no competing interests exist.
Elizabeth A Zimmermann

Shriners Hospital for Children-Canada, Montreal, Canada

Competing interests
The authors declare that no competing interests exist.
Bettina M Willie

Shriners Hospital for Children-Canada, Montreal, Canada

Competing interests
The authors declare that no competing interests exist.

"This ORCID iD identifies the author of this article:" 0000-0003-2907-3580
Svetlana V Komarova

Faculty of Dentistry, McGill University, Montreal, Canada

For correspondence
svetlana.komarova@mcgill.ca

Competing interests
The authors declare that no competing interests exist.

"This ORCID iD identifies the author of this article:" 0000-0003-3570-3147

Funding

Canadian Institutes of Health Research (MOP-77643)

Svetlana V Komarova

Natural Sciences and Engineering Research Council of Canada (RGPIN-288253)

Svetlana V Komarova

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

Ethics

Animal experimentation: All procedures were approved by McGill's University's Animal Care Committee and complied with the ethical guidelines of the Canadian Council on Animal Care. (protocols # 2012-7127 and 2016-7821)

Copyright

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.