Abstract: Osteoarthritis (OA) is a joint degenerative disease in which there is cartilage loss and chronic synovial inflammation. Currently, available treatments are solely palliative, offering no regenerative or curative options. Mesenchymal stem/stromal cells (MSCs) and their extracellular vesicles (EVs) have risen as an attractive candidate of choice; however, clinical trials have not reflected the promising pre-clinical data. Therefore, there is a need to improve the therapeutic properties of MSCs. We have shown that by inducing a glycolytic metabolism in MSCs (MSCglyco) we enchance teir regenerative and anti-inflammatory properties, which also release EVs that reflect these properties, thus making them very appealing for developing new therapies for OA. MSC were treated with oligomycin to induce a glycolytic metabolism. EVs were isolated through ultracentrifugation, quantified by nanoparticle tracking analysis (NTA) and characterized through flow cytometry, western blot, and transmission electron microscopy (TEM). EVs from MSCglyco were added to the in vitro culture media of either chondrocytes or synovial macrophages, both from OA patients. After 24 hours we evaluated EV internalization and OA-associated markers in both target cells. MSCglyco derived EV-treated synovial macrophages phenotypes were further analyzed with single cell RNA sequencing. Finally, we injected EVs from MSCglyco into a collagenase-induced osteoarthritis (CIOA) murine model to assess their regenerative and anti-apoptotic effects in vivo. EVs from MSCglyco showed no significant differences in identity markers compared to those from naive MSC and were internalized by both target cells. Indeed, EVs from MSCglyco promoted a recovery of the healthy chondrocyte phenotype, while also decreasing inflammatory markers in synovial macrophages. Moreover, single cell data revealed an increase in pro-regenerative macrophage populations upon treatment with EVs from MSCglyco. Indeed, our in vivo data reveals cartilage regeneration and a decrease in bone mineralization and chondrocyte apoptosis upon intraarticular injection of MSCglyco derived EVs. Our results show significant evidence of EVs from MSCglyco acting as a multifunctional treatment for OA, targeting both main symptoms, cartilage loss and synovial inflammation.
Funding Source: Research supported by ANID-Chile through Beca Doctorado Nacional folio 21220015; FONDECYT Regular Nº1211353; FONDECYT Iniciación Nº11220549; FONDEF-ID: 21I10194; IMPACT-FB 210024 and TA24I10054.
