Synovial mesenchymal stem cell-derived exosomes delivering GRPEL1 activate PINK1-mediated mitophagy to promote cartilage repair in arthritis

Figure 8 Cartilage degeneration assessment after synovial mesenchymal stem cell-derived exosomes GrpE-like 1 delivery in rat osteoarthritis model. A: Immunofluorescence analysis of collagen II, aggrecan, and matrix metalloproteinase-13 in rat cartilage tissue across experimental groups, visualizing key cartilage matrix and degradation markers; B-D: Quantitative fluorescence intensity analysis of collagen II (B), aggrecan (C) and matrix metalloproteinase-13 (D), revealing matrix protein preservation and potential cartilage regeneration. Scale bar: 50 μm. ^bP < 0.01 vs Control; ^dP < 0.01 vs OA; ^fP < 0.01 vs OA + Exo-oeNC; ^hP < 0.01 vs OA + Exo-shNC. MMP-13: Matrix metalloproteinase-13.