Ex vivo physiological compression of human osteoarthritis cartilage modulates cellular and matrix components

PLoS One. 2019 Sep 24;14(9):e0222947. doi: 10.1371/journal.pone.0222947. eCollection 2019.

Abstract

Mechanical stimulation appears to play a key role in cartilage homeostasis maintenance, but it can also contribute to osteoarthritis (OA) pathogenesis. Accumulating evidence suggests that cartilage loading in the physiological range contributes to tissue integrity maintenance, whereas excessive or reduced loading have catabolic effects. However, how mechanical stimuli can regulate joint homeostasis is still not completely elucidated and few data are available on human cartilage. We aimed at investigating human OA cartilage response to ex vivo loading at physiological intensity. Cartilage explants from ten OA patients were subjected to ex vivo controlled compression, then recovered and used for gene and protein expression analysis of cartilage homeostasis markers. Compressed samples were compared to uncompressed ones in presence or without interleukin 1β (IL-1β) or interleukin 4 (IL-4). Cartilage explants compressed in combination with IL-4 treatment showed the best histological scores. Mechanical stimulation was able to significantly modify the expression of collagen type II (collagen 2), aggrecan, SOX9 transcription factor, cartilage oligomeric matrix protein (COMP), collagen degradation marker C2C and vascular endothelial growth factor (VEGF). Conversely, ADAMTS4 metallopeptidase, interleukin 4 receptor alpha (IL4Rα), chondroitin sulfate 846 epitope (CS846), procollagen type 2 C-propeptide (CPII) and glycosaminoglycans (GAG) appeared not modulated. Our data suggest that physiological compression of OA human cartilage modulates the inflammatory milieu by differently affecting the expression of components and homeostasis regulators of the cartilage extracellular matrix.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Biomarkers / metabolism
  • Biomechanical Phenomena
  • Cartilage, Articular / cytology
  • Cartilage, Articular / immunology*
  • Cartilage, Articular / pathology
  • Chondrocytes / cytology
  • Chondrocytes / immunology*
  • Chondrocytes / metabolism
  • Cytokines / immunology
  • Cytokines / metabolism
  • Extracellular Matrix / immunology*
  • Extracellular Matrix / metabolism
  • Female
  • Gene Expression Profiling
  • Humans
  • Male
  • Mechanotransduction, Cellular / immunology*
  • Osteoarthritis / immunology
  • Osteoarthritis / pathology*
  • Tissue Culture Techniques

Substances

  • Biomarkers
  • Cytokines

Grants and funding

This work was supported by Italian Health Ministry 5x1000 Fund, by Bologna University RFO Fund and by “Ricerca corrente Rizzoli Orthopaedic Institute” funds. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.