Membrane-derived microvesicles (MV) are released from the surface of activated eukaryotic cells and exert pleiotropic effects on surrounding cells. We found that MV derived from embryonic stem cells enhanced survival and improved expansion of murine hematopoietic stem cells, upregulated the expression of early pluripotent (Oct-4, Nanog, Rex-1) and early hematopoietic stem cell (Scl, HoxB4, GATA 2) markers in these cells, and induced phosphorylation of MAPK and Akt. We postulate that embryonic stem cell-derived MVs may efficiently expand hematopoietic stem cells by stimulating them with MV expressed ligands as well as increase their pluripotency after horizontal transfer of mRNA.
