Atractylodes lancea volatile oils target ADAR2-miR-181a-5p signaling to mesenchymal stem cell chondrogenic differentiation.

Atractylodeslancea Rhizoma (Rhizoma atractylodis [RA]) has long been recommended for the treatment of arthritis in traditional Chinese medicine, but its mechanism of action is still unclear. RA contains a large amount of Atractylodes lancea volatile oils (Atr). In this study, we investigated whether Atr can promote mesenchymal stem cells (MSCs) chondrogenic differentiation. The Atr were extracted from RA by steam distillation method, and the effect of Atr on MSCs was detected by the CCK8 assay. The optimal concentration of Atr for MSCs cultivation was 3 µg/ml. The differentially expressed miR-181a-5p was screened by miRNA microarray assay, and its mimics and inhibitors were transfected into MSCs. It was found that the inhibitor of miR-181a-5p could upregulate cartilage-specific genes such as SOX9, COL2A1, and ACAN. Meanwhile, we also found that the expression of gene editing enzyme ADAR2 was significantly increased in the chondrogenic differentiation of MSCs induced by Atr, and the bases of precursor sequence of miR-181a-5p were changed from A to G. After ADAR2 deletion, the expression of cartilage-specific genes was significantly down-regulated and the precursor sequence bases of miR-181a-5p were not changed. Bioinformatics analysis revealed that the predicted target gene of miR-181a-5p was yingyang1 (YY1), and the targeting relationship was verified by dual-luciferase reporter assay. After deleting YY1, the expression of cartilage-specific genes was significantly down-regulated. In conclusion, our study demonstrated that Atr can promote chondrogenic differentiation of MSC through regulation of the ADAR2-miR-181a-5p signaling pathway. This may provide a new insight into the possible mechanism of traditional Chinese medicine (Atr) in treating inflammatory joint diseases.