Exosomal microRNA-140-3p from human umbilical cord mesenchymal stem cells attenuates joint injury of rats with rheumatoid arthritis by silencing SGK1

OBJECTIVE: Over the years, microRNAs (miRNAs) have been involved in the pathogenesis of rheumatoid arthritis (RA). We aim to investigate the role of human umbilical cord mesenchymal stem cells (HUCMSCs)-derived exosomal miR-140-3p in RA development. METHODS: Exosomes(exo) were isolated from human umbilical cord-derived mesenchymal stem cells (HUCMSCs), and this isolation was followed by the transfer of miR-140-3p. RA rat models were constructed by collagen II adjuvant and respectively treated with HUCMSCs-exo or HUCMSCs-exo carrying miR-140-3p mimic/inhibitor, and expression of miR-140-3p and serum- and glucocorticoid-inducible kinase 1 (SGK1) was assessed. Then, RA score and inflammation scoring, fibrosis degree and apoptosis, serum inflammatory response and oxidative stress in joint tissues were determined. The RA synovial fibroblasts (RASFs) were extracted from rats and identified. Conducted with relative treatment, the migration, proliferation and apoptosis in RASFs were determined. RESULTS: MiR-140-3p was decreased while SGK1 was increased in RA rats. HUCMSCs-exo or upregulated exosomal miR-140-3p improved pathological changes and suppressed inflammation, oxidative stress and fibrosis in RA rats, and also constrained and RASF growth. Overexpression of SGK1 reversed the inhibition of RASF growth caused by overexpression of miR-140-3p. CONCLUSION: Upregulated exosomal miR-140-3p attenuated joint injury of RA rats by silencing SGK1. This research provided further understanding of the role of exosomal miR-140-3p in RA development. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s10020-022-00451-2.