title: Embryonic stem cell-derived microvesicles reprogram hematopoietic progenitors: evidence for horizontal transfer of mRNA and protein delivery.
abstract: Membrane-derived vesicles (MV) are released from the surface of activated eucaryotic cells and exert pleiotropic effects on surrounding cells. Since the maintenance of pluripotency and undifferentiated propagation of embryonic stem (ES) cells in vitro requires tight cell to cell contacts and effective intercellular signaling, we hypothesize that MV derived from ES cells (ES-MV) express stem cell-specific molecules that may also support self-renewal and expansion of adult stem cells. To address this hypothesis, we employed expansion of hematopoietic progenitor cells (HPC) as a model. We found that ES-MV (10 microg/ml) isolated from murine ES cells (ES-D3) in serum-free cultures significantly (i) enhanced survival and improved expansion of murine HPC, (ii) upregulated the expression of early pluripotent (Oct-4, Nanog and Rex-1) and early hematopoietic stem cells (Scl, HoxB4 and GATA 2) markers in these cells, and (iii) induced phosphorylation of MAPK p42/44 and serine-threonine kinase AKT. Furthermore, molecular analysis revealed that ES-MV express Wnt-3 protein and are selectively highly enriched in mRNA for several pluripotent transcription factors as compared to parental ES cells. More important, this mRNA could be delivered by ES-MV to target cells and translated into the corresponding proteins. The biological effects of ES-MV were inhibited after heat inactivation or pretreatment with RNAse, indicating a major involvement of protein and mRNA components of ES-MV in the observed phenomena. We postulate that ES-MV may efficiently expand HPC by stimulating them with ES-MV expressed ligands (e.g., Wnt-3) as well as increase their pluripotency after horizontal transfer of ES-derived mRNA.
authors.affiliation: Stem Cell Biology Program, James Graham Brown Cancer Center, University of Louisville, Louisville, KY 40202, USA.
authors.forename: J
authors.initials: J
authors.lastname: Ratajczak
authors.forename: K
authors.initials: K
authors.lastname: Miekus
authors.forename: M
authors.initials: M
authors.lastname: Kucia
authors.forename: J
authors.initials: J
authors.lastname: Zhang
authors.forename: R
authors.initials: R
authors.lastname: Reca
authors.forename: P
authors.initials: P
authors.lastname: Dvorak
authors.forename: M Z
authors.initials: MZ
authors.lastname: Ratajczak
mesh_terms: D000818:Animals; D000950:Antigens, Ly / Q000378:metabolism; D001692:Biological Transport / Q000235:genetics; D002450:Cell Communication / Q000235:genetics*; D002460:Cell Line; D021961:Cell Membrane Structures / Q000235:genetics / Q000502:physiology*; D002470:Cell Survival / Q000502:physiology; D003593:Cytoplasm / Q000378:metabolism; D004622:Embryo, Mammalian / Q000166:cytology; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D008565:Membrane Proteins / Q000378:metabolism; D051379:Mice; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D050814:Octamer Transcription Factor-3 / Q000378:metabolism; D010766:Phosphorylation; D039904:Pluripotent Stem Cells / Q000166:cytology / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism*; D014162:Transfection; D051153:Wnt Proteins / Q000378:metabolism*; D060508:Wnt3 Protein
chemical_list: D000950:Antigens, Ly; C074650:Ly6a protein, mouse; D008565:Membrane Proteins; D050814:Octamer Transcription Factor-3; D012333:RNA, Messenger; C555507:WNT3 protein, human; D051153:Wnt Proteins; D060508:Wnt3 Protein; C555508:Wnt3 protein, mouse; D051057:Proto-Oncogene Proteins c-akt; D020928:Mitogen-Activated Protein Kinases