The incorporation of extracellular vesicles from MSC into HSC increase their clonogenic capacity and engraftment ability

ABSTRACT: Treatment of graft failure after allogeneic stem cell transplantation with mesenchymal stromal cells (MSC) is being evaluated clinically. MSC can exert their functions by the release of extracellular vesicles (EV). Our aim is to analyze changes induced in hematopoietic stem cells (HSC) after the incorporation of MSC-EV. MSC were isolated from healthy donors. MSC-EV were isolated by ultracentrifugation and characterized by flow cytometry (FC), Western-blot, electron microscopy and Nanosight. EV incorporation into HSC was analyzed by FC and confocal microscopy. To study HSC gene expression, RT-PCR and arrays were performed. Apoptosis and cell cycle were evaluated by FC and clonal growth by clonogenic assays in methylcellulose. The engraftment capacity of HSC was analyzed four weeks after transplantation in NOD-SCID mice. Our results showed that MSC-EV presented the characteristic morphology, size and inmunophenotype and were able to be incorporated into HSC. MSC-EV incorporation induced an a down-regulation of pro-apoptotic genes, an overexpression of genes involved in colony formation and cell proliferation together with an activation of the JAK-STAT pathway in HSC. A significant decrease in apoptosis (p=0.001), an increase of the percentage of cells in phase S and an increased CD44 expression (p=0.013) were confirmed by FC in HSC with MSC-EV. In addition, these HSC displayed a higher CFU-GM clonogenic potential (p=0.010). Finally, in the xenotransplantation model, the engraftment ability of human HSC with MSC-EV was significantly higher (p= 0.027). In summary, the incorporation of MSC-EV induces genomic and functional changes in HSC, increasing their clonogenic capacity and their engraftment ability.

ORGANISM(S): Homo sapiens

PROVIDER: GSE120803 | GEO | 2020/10/31

REPOSITORIES: GEO