26dkou340 10.3205/26dkou340 urn:nbn:de:0183-26dkou3402 Meeting Abstract Winkler Winkler Jonas J

Institute of Orthopaedic Research and Biomechanics, Ulm University Hospital, Ulm, Deutschland

author Pilão Pilão Sofia S

Institute of Orthopaedic Research and Biomechanics, Ulm University Hospital, Ulm, Deutschland

author Neidliger-Wilke Neidliger-Wilke Cornelia C

Institute of Orthopaedic Research and Biomechanics, Ulm University Hospital, Ulm, Deutschland

author Ignatius Ignatius Anita A

Institute of Orthopaedic Research and Biomechanics, Ulm University Hospital, Ulm, Deutschland

author Risbud Risbud Makarand M

Department of Orthopaedic Surgery, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA

author Illien-Junger Illien-Junger Svenja S

Department of Orthopaedics, Emory University School of Medicine, Atlanta, GA, USA

author Teixeira Teixeira Graciosa G

Institute of Orthopaedic Research and Biomechanics, Ulm University Hospital, Ulm, Deutschland

author German Medical Science GMS Publishing House

Düsseldorf

610 20261020 engl This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 License. Dieser Artikel ist ein Open-Access-Artikel und steht unter den Lizenzbedingungen der Creative Commons Attribution 4.0 License (Namensnennung). M0659 340 Deutsche Gesellschaft für Orthopädie und Unfallchirurgie Deutsche Gesellschaft für Orthopädie und Orthopädische Chirurgie Deutsche Gesellschaft für Unfallchirurgie Berufsverband für Orthopädie und Unfallchirurgie Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2026) Grundlagenforschung | Geweberegeneration Berlin 20261020 20261023 DKOU26_Abs_2279 TextObjectives and questions: Intervertebral disc (IVD) degeneration (IVDD) is characterized by inflammation, extracellular matrix breakdown, and progressive cell loss. The mesenchymal stromal cell (MSC)-derived secretome (Sec) has shown anti-inflammatory and anti-catabolic effects in vitro in human disc cell cultures (Tilotta et al., 2023). Sec effects in more complex systems, however, remain unclear. This study aimed to establish a murine three-dimensional spine culture model using SM/J mice that develop natural IVDD at 17 weeks of age (Choi et al., 2018) and to assess the therapeutic potential of MSC-derived Sec in this setting.Material and methods: Sec was generated by culturing bone marrow-derived MSCs from C57BL/6J mice for 48h. Lumbar and caudal segments from 17-week-old SM/J mice (n=4-8/group) were harvested and either analyzed immediately (fresh) or cultured under: (i) control medium, medium with Sec at (ii) 1 µg total protein/mL (Sec-1), or (iii) 100 µg total protein/mL (Sec-100). On day 3, lumbar IVDs were analyzed by qPCR for apoptotic (Bcl2), inflammatory (Il6), catabolic (Mmp3), and matrix (Col1a1, Col2a1) genes. On day 15, caudal IVDs were assessed for cell viability (TUNEL, Ki67), matrix composition (safranin O/fast green, picrosirius red), and inflammatory/catabolic markers (IL-6, MMP-3). Statistics: one-way ANOVA or Kruskal-Wallis tests (p<0.05).Results: Ex vivo culture for 3 days exacerbated the degenerative phenotype of lumbar IVD cells compared with fresh samples, with increased Bcl2, Il6, and Mmp3 expression and decreased Col1a1 and Col2a1 (p<0.05; Figure 1A-D ). By day 15, caudal IVDs showed increased apoptosis in the annulus fibrosus (AF) and nucleus pulpous (NP) and greater AF fibrosis compared with fresh tissues (p<0.05). Notably, IL-6 immunopositivity, but not MMP-3, was lower in controls than in fresh IVDs (p<0.05; Figure 1E-G ). Sec-1 downregulated Bcl2 and Il6 expression (p<0.05). Sec-100 downregulated Bcl2, Il6, and Mmp3 expression, reduced apoptosis in AF and NP (p<0.05), and attenuated AF fibrosis (p<0.05). Despite reduced inflammatory gene expression, IL-6 protein levels were higher in Sec-100 than in untreated controls (p<0.05), whereas MMP-3 was unchanged. Cell proliferation was not affected.Discussion and conclusions: The ex vivo spine culture preserved key features of spontaneous SM/J disc degeneration (Choi et al., 2018) and sustained a pro-degenerative environment suitable for therapeutic testing. MSC-derived Sec exerted dose-dependent protection by reducing apoptosis, fibrotic remodeling, and inflammatory/catabolic gene expression without affecting proliferation, indicating improved cellular homeostasis rather than cell turnover. Higher IL-6 protein despite lower gene expression likely reflects residual cytokines within the Sec, consistent with its complex bioactive composition (Vizoso et al., 2017). Overall, this model provides a relevant platform to evaluate regenerative therapies in naturally degenerated IVDs, enhancing translational relevance beyond injury-based models. 0

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