gms | German Medical Science

Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2017)

24.10. - 27.10.2017, Berlin

Modulation of injury-induced chondrocyte death by CCN2, a novel master regulator of cartilage homeostasis

Meeting Abstract

  • presenting/speaker Maximilian Holweg - Siegfried Weller Institut für Unfallmedizinische Forschung, Berufsgenossenschaftliche Unfallklinik Tübingen, Klinik für Unfall- und Wiederherstellungschirurgie, Tübingen, Germany
  • Adrian Meder - Berufsgenossenschaftliche Unfallklinik Tübingen, Klinik für Unfall- und Wiederherstellungschirurgie, Tübingen, Germany
  • Norbert P. Südkamp - Universitätsklinikum Freiburg, Klinik für Orthopädie und Unfallchirurgie, Freiburg, Germany
  • Björn Gunnar Ochs - Klinikum der Albert-Ludwigs-Universität Freiburg, Department Orthopädie und Traumatologie, Freiburg, Germany
  • Karen A. Böhme - Klinikum der Albert-Ludwigs-Universität Freiburg, Department Orthopädie und Traumatologie, Freiburg, Germany
  • Bodo Kurz - CAU Kiel, Anatomisches Institut, Kiel, Germany
  • Bernd Rolauffs - Klinikum der Albert-Ludwigs-Universität Freiburg, Department Orthopädie und Traumatologie, Freiburg, Germany

Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2017). Berlin, 24.-27.10.2017. Düsseldorf: German Medical Science GMS Publishing House; 2017. DocGR16-587

doi: 10.3205/17dkou518, urn:nbn:de:0183-17dkou5181

Veröffentlicht: 23. Oktober 2017

© 2017 Holweg et al.
Dieser Artikel ist ein Open-Access-Artikel und steht unter den Lizenzbedingungen der Creative Commons Attribution 4.0 License (Namensnennung). Lizenz-Angaben siehe http://creativecommons.org/licenses/by/4.0/.


Gliederung

Text

Objectives: Post-traumatic osteoarthritis (PTOA) is a degenerative disease that affects the whole joint and can lead to severe disability. A relevant factor in the early disease stage is trauma-induced articular cartilage damage associated with sGAG loss and chondrocyte death. The development of novel therapeutic strategies aims to reduce post-traumatic cell death but effective clinical therapies for preventing PTOA are not available. We hypothesized that post-traumatic chondrocyte death can be reduced by using a 'novel' cartilage homeostasis master regulator with the ability to fine-tune FGF-2 signaling termed CCN2, also known as connective tissue growth factor. The rationale was that trauma releases FGF-2 from the damaged matrix and the released FGF-2 activates MAP kinase signaling cascades, which have been implicated in chondrocyte viability. Thus, using recombinant CCN2 as an in vitro post-traumatic therapeutic agent for cartilage trauma promises to decrease chondrocyte death.

Methods: We generated cartilage explants (4mm diameter, 300µm thickness, n=5 per group) from macroscopically intact cartilage tissue obtained from joint replacement patients (n=5). Using an incubator-housed, PC-controlled loading machine for applying a compressive biomechanical trauma, we applied a single compression as "injury" down to 65% of the explant height within ½ second and subsequent release of the compression. Similarly injured explants were treated with soluble human recombinant CCN2 and non-injured disks served as controls. Post-injury, all explants were cultured in standard medium until stained at days 1 and 3 for viability (Invitrogen). Cell death was determined at the surface and at 150 and 300µm depths as percentage of total cells. sGAG explant content and loss into the medium were determined with the DMMB-Assay. Statistical analyses were performed with SigmaPlot (Systat) with p<0.05 as significance level.

Results and Conclusion: Cell death was significantly higher in injured than non-injured explants (p<0.05). Incubation with soluble CNN2 after injury led to a significant decrease of cell death, compared to injured explants without CCN2 at days 1 and 3 (Day 1: injury without CCN2: 18.85±2.10%, injury with CCN2: 12.52±1.00%, p<0.05; day 3: injury without CCN2: 17.70±1.40%, injury with CCN2: 12.58±1.00%, p<0.05). sGAG loss into the medium was not significantly different between injured explants with and without CCN2 incubation. This pilot study evaluated a novel strategy for alleviating chondrocyte death after compressive injury. We demonstrated that in the early phase after trauma the percentage of dead chondrocytes can be reduced using CCN2, a 'novel' master regulator of cartilage homeostasis. Further experiments need to address open questions pertaining to the underlying signaling, the effects on catabolic, anabolic, and inflammatory processes affected by CCN2, and its efficacy in combination with other substances intended for post-traumatic therapies.