Circulating Exosomes Derived-miR-146a from Systemic Lupus Erythematosus Patients Regulates Senescence of Mesenchymal Stem Cells.

The senescence of mesenchymal stem cells (MSCs) plays a crucial role in the development and progression of systemic lupus erythematosus (SLE). Exosomes, small spherical bilayer proteolipid vesicles, contribute to the communication between various cells and their microenvironment by transferring information via their cargo, including the proteins, lipids, and RNAs. While exosomal miRNAs participate in various biological activities, correlations of circulating exosomes with senescent signs of BM-MSCs remain unclear. In our study, we aimed at exploring the roles of circulating exosomal miRNAs in the senescence of MSCs. We found that exosomes derived from SLE serum could increase the proportions of SA--gal positive cells, disorganize cytoskeletons, and reduce growth rates. Moreover, the expression of miR-146a declined significantly in serum exosomes of SLE patients compared with healthy controls. miR-146a could be internalized into MSCs via exosomes and participate in MSCs senescence through targeting TRAF6/NF-B signaling. These results clarified the novel mechanism of MSCs senescence in SLE patients.