Berberine Encapsulated in Exosomes Derived from Platelet-Rich Plasma Promotes Chondrogenic Differentiation of the Bone Marrow Mesenchymal Stem Cells via the Wnt/β-Catenin Pathway

Cartilage regenerative medicine, wherein the stem cells from adults exert a crucial role, has high potential in the treatment of defective articular cartilage. Recently, Bone marrow mesenchymal stem cells (BMSCs) are being increasingly recognized as an alternative source of adult stem cells, which are capable of differentiating into several cell types (e.g., adipocytes, chondrocytes, and osteoblasts). However, their proliferative properties and tendency to dedifferentiate restrict their use in clinical settings. Recently, a possible bioactive material PRP-exos (exosomes derived from platelet-rich plasma), has emerged, which can effectively facilitate the differentiation and proliferation of cells. Recent studies have reported that berberine (Ber), known to have anti-inflammatory properties, plays a role in osteogenesis. Since biological molecules are used in combinations, we attempted to assess the effect of Exos-Ber (PRP-exos in combination with Ber) on the chondrogenic differentiation of BMSCs in vitro. In this study, Exos-Ber was observed to promote the proliferation of BMSCs and cause their chondrogenic differentiation in vitro. Additionally, Exos-Ber could promote the migration of BMSCs and increase the protein expression of the chondrogenic genes (Collagen II, SOX9, Aggrecan). After treatment with Exos-Ber, significant induction of β-catenin expression was observed, which could be repressed successfully by adding β-catenin Inhibitor XAV-939. Interestingly, the repression of the Wnt/β-catenin axis also resulted in reduced gene expression levels of Collagen II, SOX9, and Aggrecan. These observations indicated that Exos-Ber facilitated the differentiation of chondrogenic BMSCs by modulating the Wnt/β-catenin axis, which offers innovative insights into the reconstruction of cartilage.