Selective Enzymatic Digestion of Proteoglycans and Collagens Alters Cartilage T1rho and T2 Relaxation Times.

Published

Journal Article

Our objective was to determine the relationship of T1rho and T2 relaxation mapping to the biochemical and biomechanical properties of articular cartilage through selective digestion of proteoglycans and collagens. Femoral condyles were harvested from porcine knee joints and treated with either chondroitinase ABC (cABC) followed by collagenase, or collagenase followed by cABC. Magnetic resonance images were acquired and cartilage explants were harvested for biochemical, biomechanical, and histological analyses before and after each digestion. Targeted enzymatic digestion of proteoglycans with cABC resulted in elevated T1rho relaxation times and decreased sulfated glycosaminoglycan content without affecting T2 relaxation times. In contrast, extractable collagen and T2 relaxation times were increased by collagenase digestion; however, neither was altered by cABC digestion. Aggregate modulus decreased with digestion of both components. Overall, we found that targeted digestion of proteoglycans and collagens had varying effects on biochemical, biomechanical, and imaging properties. T2 relaxation times were altered with changes in extractable collagen, but not changes in proteoglycan. However, T1rho relaxation times were altered with proteoglycan loss, which may also coincide with collagen disruption. Since it is unclear which matrix components are disrupted first in osteoarthritis, both markers may be important for tracking disease progression.

Full Text

Duke Authors

Cited Authors

  • Collins, AT; Hatcher, CC; Kim, SY; Ziemian, SN; Spritzer, CE; Guilak, F; DeFrate, LE; McNulty, AL

Published Date

  • January 2019

Published In

Volume / Issue

  • 47 / 1

Start / End Page

  • 190 - 201

PubMed ID

  • 30288634

Pubmed Central ID

  • 30288634

Electronic International Standard Serial Number (EISSN)

  • 1573-9686

International Standard Serial Number (ISSN)

  • 0090-6964

Digital Object Identifier (DOI)

  • 10.1007/s10439-018-02143-7

Language

  • eng