MiR-211/STAT5A Signaling Modulates Migration of Mesenchymal Stem Cells to Improve its Therapeutic Efficacy.

Our previous study showed that the therapeutic effects of mesenchymal stem cells (MSCs) transplantation were improved by enhancing migration. MicroRNA-211 (miR-211) can modulate the migratory properties of some cell types by mechanisms that are not fully understood. This study was designed to investigate a possible role for miR-211 in MSC migration, and whether genetic manipulation of miR-211 in MSCs could be used to enhance its beneficial effects of cell transplantation. Transwell assays confirmed that MSCs migration of was significantly impaired by miR-211 knockdown but enhanced by miR-211 overexpression. MiR-211 overexpressing MSCs also exhibited significantly increased cell engraftment in the peri-infarct areas of female rat hearts 2 days after intravenous transplantation of male MSCs as shown by GFP tracking and SYR gene quantification. This conferred a significant decrease in infarct size and improved cardiac performance. By using a loss or gain of gene function approach, we demonstrated that miR-211 targeted STAT5A to modulate MSCs migration, possibly by interacting with MAPK signaling. Furthermore, the beneficial effects of miR-211 overexpression in MSCs were abolished by simultaneous overexpression of STAT5A whereas the negative effects of miR-211 silencing on MSC migration were rescued by simultaneous downregulation of STAT5A. Finally, using ChIP-PCR and luciferase assays, we provide novel evidence that STAT3 can directly bind to promoter elements that activate miR-211 expression. STAT3/miR-211/STAT5A signaling plays a key role in MSCs migration. Intravenous infusion of genetically modified miR-211 overexpressing MSCs conveys enhanced protection from adverse post-MI remodeling compared with unmodified MSCs. Stem Cells 2016;34:1846-1858.