Exosomes derived from mesenchymal stem cells regulate Treg/Th17 balance in aplastic anemia by transferring miR-23a-3p.

Imbalanced Th17/Treg ratio is implicated in the pathogenesis of aplastic anemia. Studies have indicated that bone marrow-derived mesenchymal stem cells-derived exosomes (BMSC-Exo) could correct imbalanced Th17/Treg in aplastic anemia, but the mechanism remains not fully understand. This study was designed to investigate whether BMSC-Exo regulates the Th17/Treg balance in aplastic anemia by transferring miR-23a-3p. Here, miR-23a-3p inhibitor was utilized to knockdown the expression of miR-23a-3p in BMSC-Exo. A co-culture system of CD4 T cells from aplastic anemia patients and BMSC-Exo was used to explore the effects of BMSC-Exo on the Th17/Treg balance and the underlying mechanism in aplastic anemia. The patients with aplastic anemia exhibited Th17/Treg imbalance favoring the Th17 cells. BMSC-Exo could balance the percentage of Th17 and Treg cells in aplastic anemia, but the effects of BMSC-Exo can be eliminated when miR-23a-3p expression was silenced in BMSCs. IL-6 was a direct target of miR-23a-3p. IL-6 overexpression could abrogate BMSC-Exo-induced balance in Th17/Treg ratio. Overall, BMSC-Exo could balance Th17/Treg ratio in aplastic anemia via suppressing IL-6 expression by transferring miR-23a-3p at least in part. These data indicated miR-23a-3p may be a potential target for the treatment of aplastic anemia. Our study may provide a new idea for the therapy of the disease.