title: Accumulation of instability in serial differentiation and reprogramming of parthenogenetic human cells.
abstract: Human leukocyte antigen-homozygous parthenogenetic stem cells (pSC) could provide a source of progenitors for regenerative medicine, lowering the need for immune suppression in patients. However, the high level of homozygosis and the lack of a paternal genome might pose a safety challenge for their therapeutic use, and no study so far has evaluated the spread and significance of gene expression changes across serial potency changes in these cells. We performed serial rounds of differentiation and reprogramming to assess pSC gene expression stability, likely of epigenetic source. We first derived pSC from activated MII oocytes, and differentiated them to parthenogenetic mesenchymal stem cells (pMSC). We then proceeded to induce pluripotency in pMSC by over expression of the four transcription factors Oct4, Sox2, Klf4 and c-Myc. pMSC-derived iPS (piPS) were further differentiated into secondary pMSC (pMSC-II). At every potency change, we characterized the obtained lines both molecularly and by functional differentiation, and performed an extensive genome-wide expression study by microarray analysis. Although overall gene expression of parthenogenetic cells resembled that of potency-matched biparental lines, significantly broader changes were brought about upon secondary differentiation of piPS to pMSC-II compared with matched biparental controls; our results highlight the effect of the interplay of epigenetic reprogramming on a monoparental background, as well as the importance of heterozygosis and biparental imprinting for stable epigenetic reprogramming.
authors.affiliation: Stem Cell Bank, Center for Regenerative Medicine in Barcelona, 08003 Barcelona, Spain.
authors.forename: Rita
authors.initials: R
authors.lastname: Vassena
authors.forename: Nuria
authors.initials: N
authors.lastname: Montserrat
authors.forename: Beatriz
authors.initials: B
authors.lastname: Carrasco Canal
authors.forename: Begoña
authors.initials: B
authors.lastname: Aran
authors.forename: Lorena
authors.initials: L
authors.lastname: de Oñate
authors.forename: Anna
authors.initials: A
authors.lastname: Veiga
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Izpisua Belmonte
mesh_terms: D002454:Cell Differentiation; D065150:Cellular Reprogramming; D053595:Embryonic Stem Cells / Q000166:cytology / Q000378:metabolism; D006650:Histocompatibility Testing; D006801:Humans; D057026:Induced Pluripotent Stem Cells / Q000166:cytology* / Q000378:metabolism; D000090062:Kruppel-Like Factor 4; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism; D018895:Microsatellite Repeats; D010312:Parthenogenesis / Q000235:genetics*