Cartilage responses to inflammatory stimuli and adipose stem/stromal cell-derived conditioned medium: Results from an ex vivo model.

Introduction: Osteoarthritis (OA), a chronic inflammatory joint disorder, still lacks effective therapeutic interventions. Consequently, the development of convenient experimental models is crucial. Recently, research has focused on the plasticity of Mesenchymal Stem/stromal Cells, particularly adipose-derived ones (ASCs), in halting OA progression. This study investigates the therapeutic potential of a cell-free approach, ASC-derived conditioned medium (CM), in reversing cytokine-induced OA markers in an Methods: 4 mm cartilage punches, derived from the femoral heads of patients undergoing total hip replacement, were treated with 10 ng/ml TNFα, 1 ng/ml IL-1β, or a combination of both, over a 3-day period. Analysis of OA-related markers, such as MMP activity, the release of NO and GAGs, and the expression of Results: The 3-day treatment with both 10ng/ml TNFα and 1ng/ml IL-1β significantly increased MMP activity and NO release, without affecting GAG release. The addition of CM significantly downregulated the abnormal MMP activity induced by the inflammatory stimuli, while also mildly reducing Conclusion: The proposed cartilage explant model offers encouraging evidence of the therapeutic potential of ASC-derived CM against OA, and it could serve as a convenient