gms | German Medical Science

German Congress of Orthopaedics and Traumatology (DKOU 2021)

26. - 29.10.2021, Berlin

Impact of platelet-rich plasma derived factors on bone marrow mesenchymal stromal cell-derived extracellular vesicles

Meeting Abstract

  • presenting/speaker Noah Volkmann - IZKF Group Tissue Regeneration in Musculoskeletal Diseases, Bernhard-Heine Centrum für Bewegungsforschung, Universität Würzburg, Würzburg, Germany
  • Drenka Trivanovic - IZKF Group Tissue Regeneration in Musculoskeletal Diseases, Bernhard-Heine Centrum für Bewegungsforschung, Universität Würzburg, Würzburg, Germany
  • Maximilian Rudert - Orthopädische Klinik König-Ludwig-Haus, Lehrstuhl für Orthopädie der Universität Würzburg, Würzburg, Germany
  • Marietta Herrmann - IZKF Group Tissue Regeneration in Musculoskeletal Diseases, Bernhard-Heine Centrum für Bewegungsforschung, Universität Würzburg, Würzburg, Germany

Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2021). Berlin, 26.-29.10.2021. Düsseldorf: German Medical Science GMS Publishing House; 2021. DocAB86-640

doi: 10.3205/21dkou587, urn:nbn:de:0183-21dkou5878

Published: October 26, 2021

© 2021 Volkmann et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 License. See license information at http://creativecommons.org/licenses/by/4.0/.


Outline

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Objectives: Extracellular vesicles (EVs) isolated from mesenchymal stromal cells (MSC) appeared to be meaningful "cell-free" players in the conception of novel treatments for musculoskeletal pathologies. Platelet-rich plasma (PRP) is considered to be used in tissue repair strategies, where PRP effects on MSC function are of particular interest. Previously, we observed a stimulatory role of PRP on immune-regulatory functions of MSCs. Here, we aimed to explore whether and how EV biogenesis can be involved in PRP-mediated effects on MSC functions.

Methods: MSC were isolated from acetabular bone marrow of patients undergoing hip arthroplasty. PRP was collected from pooled apheresis thrombocyte concentrates with 10-fold increased platelet content.MSC were exposed to 10% PRP-conditioned, serum free medium (PRP-CM), as well as GW4869 (inhibitor of EV generation) for 72 and 48 hours, respectively. MSC viability and transcriptional activity were assessed. After additional 48 hours, supernatant was collected and MSC-EVs were purified by filtration and sequential ultracentrifugation. Obtained MSC-EVs were characterized by nanoparticle tracking analysis (NTA), western blot, bead-based flow cytometry and monitored by scanning transmission electron microscopy (STEM).

Results and Conclusion: Purified MSC-EVs showed highest positivity for typical EV markers CD81 and CD63, while CD9+ and MSC-markers CD44+, CD73+ EVs were present to a lesser extent. PRP-CM or GW4869 treatment only moderately impacted their expression. EV morphology was confirmed by STEM and EV size determined to be in the size range of 50 to 250 nm in diameter by NTA. We found that GW4869 effects on EV-biogenesis genes (Alix1, Tsg101, Vamp7 and Pld2) were dependent on the presence of standard or ultra-filtered fetal calf serum (FCS). PRP-CM pretreatment could to a certain extent restore EV-biogenesis gene expression abolished upon FCS withdrawal. Similar effects of PRP-CM were achieved when immunomodulatory gene (Cox2, Il-6 and Ido-1) expression in MSCs was investigated. Our findings indicate a possible link between EV-related activities and immune-regulatory functions of MSCs. Future studies will stress to which extent obtained MSC-EVs can control immune cell activity and substitute MSCs in experimental and clinical settings.