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Microscale frictional strains determine chondrocyte fate in loaded cartilage

Cornell Affiliated Author(s)

Author

E.D. Bonnevie
M.L. Delco
L.R. Bartell
N. Jasty
Itai Cohen
L.A. Fortier
L.J. Bonassar

Abstract

Mounting evidence suggests that altered lubricant levels within synovial fluid have acute biological consequences on chondrocyte homeostasis. While these responses have been connected to increased friction, the mechanisms behind this response remain unknown. Here, we combine a frictional bioreactor with confocal elastography and image-based cellular assays to establish the link between cartilage friction, microscale shear strain, and acute, adverse cellular responses. Our incorporation of cell-scale strain measurements reveals that elevated friction generates high shear strains localized near the tissue surface, and that these elevated strains are closely associated with mitochondrial dysfunction, apoptosis, and cell death. Collectively, our data establish two pathways by which chondrocytes negatively respond to friction: an immediate necrotic response and a longer term pathway involving mitochondrial dysfunction and apoptosis. Specifically, in the surface region, where shear strains can exceed 0.07, cells are predisposed to acute death; however, below this surface region, cells exhibit a pathway consistent with apoptosis in a manner predicted by local shear strains. These data reveal a mechanism through which cellular damage in cartilage arises from compromised lubrication and show that in addition to boundary lubricants, there are opportunities upstream of apoptosis to preserve chondrocyte health in arthritis therapy. © 2018 Elsevier Ltd

Date Published

Journal

Journal of Biomechanics

Volume

74

Number of Pages

72-78,

URL

https://www.scopus.com/inward/record.uri?eid=2-s2.0-85046765284&doi=10.1016%2fj.jbiomech.2018.04.020&partnerID=40&md5=2cde36ca3a02d12f5a9fa9c4af460106

DOI

10.1016/j.jbiomech.2018.04.020

Research Area

Group (Lab)

Itai Cohen Group

Funding Source

1K08AR068470
1S10RR025502
T32OD011000
5 UL1 TR000457-09
CMMI 1536463

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