Exosomal LINC01106 From PRP-Treated ADSCs Alleviates Chondrocyte Inflammatory Injury by Sponging miR-34a-5p to Upregulate SIRT1 Expression.

Abstract

ObjectiveOsteoarthritis (OA) is characterized by progressive cartilage degeneration driven by inflammation-induced chondrocyte injury, while effective disease-modifying therapies are still lacking. Exosome-based cell-free approaches are emerging as promising alternatives, but their key molecular mediators remain incompletely defined.DesignAdipose-derived stem cells (ADSCs) were pretreated with platelet-rich plasma (PRP) to enhance exosomal function. Isolated exosomes were characterized, and LINC01106 expression was modulated by overexpression or knockdown. Interleukin (IL)-1β-stimulated chondrocytes were used to assess apoptosis, inflammatory cytokine secretion, oxidative stress, and extracellular matrix degradation. The LINC01106/miR-34a-5p/SIRT1 axis was examined using luciferase reporter assays, quantitative real-time polymerase chain reaction (PCR), Western blotting, and immunofluorescence.ResultsPRP pretreatment markedly increased LINC01106 enrichment in ADSC-derived exosomes. LINC01106-rich exosomes significantly reduced chondrocyte apoptosis, suppressed tumor necrosis factor-α (TNF-α) and IL-6 secretion, alleviated oxidative stress, and attenuated matrix metalloproteinase (MMP)-mediated matrix degradation under IL-1β stimulation. Mechanistically, LINC01106 acted as a competing endogenous RNA that sequestered miR-34a-5p, thereby restoring SIRT1 expression. Rescue experiments demonstrated that miR-34a-5p overexpression or SIRT1 silencing abolished these protective effects. In addition, LINC01106-enriched exosomes inhibited nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) pathway activation in a SIRT1-dependent manner.ConclusionPRP-stimulated ADSC-derived exosomes confer potent chondroprotective effects through the LINC01106/miR-34a-5p/SIRT1 pathway, highlighting a promising cell-free therapeutic strategy for OA.