Characterizing the Long Non-Coding RNA Profile of Endometrial Mesenchymal Stem/Stromal Cell-Derived Extracellular Vesicles and Their Anti-Inflammatory Role in Osteoarthritis.

Endometrial tissue-derived mesenchymal stem/stromal cells (eMSCs) have potential therapeutic properties partially exerted via their secreted extracellular vesicles (EVs). eMSC-EVs contain cargos with regenerative and immunomodulatory properties. Specifically, the miRNA profile of CD146High eMSC-EVs has been shown to promote anti-inflammatory M2 macrophage polarization in vitro. Herein, we aimed to characterize the lncRNA profile of CD146High and CD146Low eMSC-EVs and further assess their immunomodulatory and anabolic therapeutic function in osteoarthritis (OA). We hypothesized that the CD146High eMSC-EVs lncRNA profile is enriched with potent anti-inflammatory and pro-anabolic cartilage effects when compared to the CD146Low eMSC-EVs lncRNA profile. Human endometrial tissue was collected, and the eMSCs were magnetically sorted to yield the CD146High and CD146Low eMSC subpopulations. The eMSC-EVs were isolated via ultracentrifugation and CD63 magnetic immunoselection methods and characterized by nanosight and flow cytometry analyses. Our results showed that CD146High eMSC-EVs display an lncRNA profile with both anabolic and catabolic features, exerting a more dynamic effect on chondrocyte gene expression than CD146Low eMSC-EVs, suggesting a potential benefit of using CD146High eMSC-EVs to attenuate the negative effects of inflammation in OA. CD146High eMSC-EVs also demonstrated greater endothelial repair capacity under inflammatory stress. In conclusion, cell-free CD146High eMSC-EV has therapeutic potential through its protective anti-inflammatory effects, warranting further pre-clinical investigation.