Fig. 5.

Inflammatory primed MSC secretomes do not induce inflammatory changes in untreated chondrocytes. To analyze functional significance of inflammatory primed MSCs on cartilage health, inflammatory primed MSCs were cultured for 48 h and conditioned media assumed to represent the secretome from primed MSCs. This primed MSC secretome was then placed on (a) untreated or (b) IL-1 β-stimulated chondrocytes. a Conditioned media from IFN-γ-primed MSCs induced downregulation in ACAN and upregulation of CXCL10 compared to untreated control chondrocytes. b In IL-1β-stimulated chondrocytes, conditioned media from IFN-γ-primed MSCs also induced downregulation in ACAN and upregulation of CXCL10 compared to untreated control chondrocytes. All conditioned media groups induced downregulation of IL-6 and PTGS2 genes. Box and whisker plots represent n = 8 individual horses. *Group significantly different from control IL-1β-stimulated chondrocyte gene expression based on a 95% confidence interval. MSC mesenchymal stem cell, poly I:C polyinosinic:polycytidylic acid, IFN-γ interferon gamma, ACAN aggrecan, MMP-13 collagenase 3, PTGS2 prostaglandin-endoperoxide synthase 2, CXCL10 C-X-C motif chemokine 10, CCL2 C-C motif chemokine 2, IL interleukin