Effects of fluid-induced shear on articular chondrocyte morphology and metabolism in vitro

Authors

  • R. Lane Smith,

    Corresponding author
    1. Orthopaedic Research Laboratory, Division of Orthopaedic Surgery, Department of Functional Restoration, Palo Alto, U.S.A.
    2. Rehabilitation Research and Development Center, Veterans Affairs Medical Center, Palo Alto, U.S.A.
    • Orthopaedic Research Laboratory, Division of Orthopaedic Surgery, 300 Pasteur Drive, Room R-144, Stanford University Medical Center, Stanford, CA 94305-5341, U.S.A.
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  • B. S. Donlon,

    1. Orthopaedic Research Laboratory, Division of Orthopaedic Surgery, Department of Functional Restoration, Palo Alto, U.S.A.
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  • M. K. Gupta,

    1. Orthopaedic Research Laboratory, Division of Orthopaedic Surgery, Department of Functional Restoration, Palo Alto, U.S.A.
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  • M. Mohtai,

    1. Orthopaedic Research Laboratory, Division of Orthopaedic Surgery, Department of Functional Restoration, Palo Alto, U.S.A.
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  • P. Das,

    1. Orthopaedic Research Laboratory, Division of Orthopaedic Surgery, Department of Functional Restoration, Palo Alto, U.S.A.
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  • D. R. Carter,

    1. Rehabilitation Research and Development Center, Veterans Affairs Medical Center, Palo Alto, U.S.A.
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  • J. Cooke,

    1. Department of Cardiovascular Surgery, Stanford University School of Medicine, Stanford, California, U.S.A.
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  • G. Gibbons,

    1. Department of Cardiovascular Surgery, Stanford University School of Medicine, Stanford, California, U.S.A.
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  • N. Hutchinson,

    1. Department of Molecular Immunology, Merck, Sharp and Dohme Research Laboratories, Rahway, New Jersey, U.S.A.
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  • D. J. Schurman

    1. Orthopaedic Research Laboratory, Division of Orthopaedic Surgery, Department of Functional Restoration, Palo Alto, U.S.A.
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Abstract

This study tested the effects of fluid-induced shear on high density monolayer cultures of adult articular chondrocytes. Fluid-induced shear (1.6 Pa) was applied by cone viscometer to normal human and bovine articular chondrocytes for periods of 24, 48, and 72 hours. At 48 and 72 hours, fluid-induced shear caused individual chondrocytes to elongate and align tangential to the direction of cone rotation. Fluid-induced shear stimulated glycosaminoglycan synthesis by 2-fold (p < 0.05) and increased the length of newly synthesized chains in human and bovine chondrocytes. In human chondrocytes, the hydrodynamic size of newly synthesized proteoglycans also was increased. After 48 hours of fluid-induced shear, the release of prostaglandin E2 from the chondrocytes was increased 10 to 20-fold. In human chondrocytes, mRNA signal levels for tissue inhibitor of metalloproteinase increased 9-fold in response to shear compared with the controls. In contrast, mRNA signal levels for the neutral metalloproteinases, collagenase, stromelysin, and 72 kD gelatinase, did not show such major changes. This study demonstrated that articular chondrocyte metabolism responds directly to physical stimulation in vitro and suggests that mechanical loading may directly influence cartilage homeostasis in vivo.

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