Abstract
Background
Umbilical cord mesenchymal stem cells (HUCMSCs)-based therapies were previously predicated in cartilage regeneration due to the chondrogenic potential of MSCs. However, chondrogenic differentiation of HUMSCs is limited by administration of growth factors like TGF-β that may cause cartilage hypertrophy. It has been reported the exosomes could modulate phenotypic expression of stem cells. However, the role of human chondrogenic derived exosomes (C-EXO) in chondrogenic differentiation of HUCMSCs has not been reported.
Results
In this study, we successfully isolated chondrocyte-derived exosomes (C-EXO) from human multi-finger cartilage and found that C-EXO efficiently promoted the proliferation and chondrogenic differentiation of HUCMSCs, evidenced by highly expressed aggrecan (ACAN), COL2A and SOX-9. Also, the expression of the fibrotic marker, COL1A and hypertrophic marker, COL10, was significantly lower than that induced by TGF-β. In vivo, stimulation of C-EXO accelerated HUCMSCs-mediated cartilage repair in rabbit models. Furthermore, C-EXO led to increasing autophagosomes during the process of chondrogenic differentiation, indicating that C-EXO promoted cartilage regeneration might be through the activation of autophagy.
Conclusions
This study suggests that C-EXO has an essential role in fostering chondrogenic differentiation and proliferation of HUCMSCs, which may be a stable supply for articular cartilage repair.
New trends for knee cartilage regeneration: from cell-free scaffolds to mesenchymal stem cells
