Both MSC and Dexamethasone are effective methods to treat inflammatory diseases, and they are likely to be used in combination. The proliferation and migration ability is one of the main biological characteristics of MSC for repairing. However, the effect of inflammatory factors and Dex on these characteristics of MSC has not been fully understood. Therefore, this study aimed to determine the role of lncRNA DANCR in hASC proliferation and migration regulation induced by Dex and inflammatory factors, to clarify the effect and mechanism of glucocorticoids on MSC's characteristics to participate in tissue repair in an inflammatory environment.
hASCs were cultured and treated with dexamethasone and inflammation factors, and cell proliferation, migration abilities, and lncRNA DANCR mRNA expression were detected. Additionally, to determine the roles and mechanisms, lncRNA DANCR was knockdown or overexpressed before Dex or TNF-α treatments. MSC proliferation was tested by cell counting kit-8 and cell cycle assay. MSC migration ability was analyzed by a scratching test. Moreover, proliferation and migration-related genes were measured by a reverse transcription-polymerase chain reaction. Nuclear factor-kB (NF-κB) and PI3K-AKT-mTOR pathway proteins were investigated by western blot analysis. All values are expressed as the mean ± standard error of the mean. The differences between the groups were assessed using a two-tailed Student’s t-test.
Dex decreased the proliferation and migration of hASC in a dose-dependent manner. Dex could upregulate the expression of lncRNA DANCR that inhibited hASC proliferation and migration. Knockdown of DANCR reversed the inhibition of hASC proliferation and migration induced by Dex. Moreover, DANCR was decreased by inflammatory cytokines, and overexpression of DANCR alleviated the promotion of hASC proliferation and migration induced by TNF-α. Furthermore, mechanistic investigation validated that DANCR was involved in the NF-κB signaling pathway.
We identified a lncRNA, DANCR, involved in Dex and inflammation-affected hASC proliferation and migration, thus suggesting that concurrent application of hASCs with steroids should be avoided in clinical settings. DANCR may serve as a promising approach to regulate stem cell characteristics under an inflamed microenvironment. These findings further enrich our understanding of the functional versatility of lncRNAs in the crosstalk of inflammation conditions and stem cells. Keywords： DANCR; long non-coding RNA; Dexamethasone; TNF-α; hASC; proliferation; migration