title: Exposure to cardiomyogenic stimuli fails to transdifferentiate human umbilical cord blood-derived mesenchymal stem cells.
abstract: The ability of human umbilical cord blood-derived mesenchymal stem cells (UCBMSCs) to transdifferentiate towards cardiomyocytes remains unclear. The aim of this study was to direct UCBMSCs to the cardiac lineage by exposure to: (1) 5-azacytidine (AZ) or dimethyl sulfoxide (DMSO); (2) a combination of growth factors involved in early cardiomyogenesis (BMP-2 + bFGF + IGF-1); (3) the Wnt signaling activators lithium chloride (LiCl) and phorbol-12-myristate-13-acetate (PMA); and (4) direct contact with neonatal rat cardiomyocytes. Expression of cardiomyocyte-specific proteins and beta-catenin were assessed by quantitative RT-PCR, immunofluorescence and Western blot. Cocultures of human UCBMSCs with neonatal rat cardiomyocytes were also analyzed for the presence of calcium oscillations and changes in electrical potential using Fura Red and di-4-ANEPPS confocal imaging, respectively. Induction of cardiac-specific proteins was not detected in 5-AZ- or DMSO-treated cells. Following DMSO addition, beta-catenin cytoplasmic expression increased, but did not translocate into cell nuclei to promote cardiac gene activation. Likewise, neither co-stimulation with BMP-2 + bFGF + IGF-1, nor exposure to LiCl and PMA resulted in the acquisition of a cardiac phenotype by UCBMSCs. Direct contact with neonatal rat cardiomyocytes promoted neither the expression of cardiomyocyte-specific proteins, nor the presence of calcium rhythmic oscillations and potential-dependent fluorescence emission in UCBMSCs. The cardiomyogenic stimuli investigated in this study failed to transdifferentiate human UCBMSCs. Alternative strategies or regulatory factors and signaling pathways may be better suited to recruit UCBMSCs into cardiac cell lineage.
authors.affiliation: ICREC (Heart Failure and Cardiac Regeneration) Program, Cardiology Service, Hospital de la Santa Creu i Sant Pau, ICCC, 08025 Barcelona, Spain, sroura@santpau.cat
authors.forename: Santiago
authors.initials: S
authors.lastname: Roura
authors.forename: Jordi
authors.initials: J
authors.lastname: Farré
authors.forename: Leif
authors.initials: L
authors.lastname: Hove-Madsen
authors.forename: Cristina
authors.initials: C
authors.lastname: Prat-Vidal
authors.forename: Carolina
authors.initials: C
authors.lastname: Soler-Botija
authors.forename: Carolina
authors.initials: C
authors.lastname: Gálvez-Montón
authors.forename: Marta
authors.initials: M
authors.lastname: Vilalta
authors.forename: Antoni
authors.initials: A
authors.lastname: Bayes-Genis
mesh_terms: D000273:Adipose Tissue / Q000166:cytology / Q000502:physiology; D000818:Animals; D001374:Azacitidine / Q000494:pharmacology*; D055396:Bone Morphogenetic Protein 2 / Q000494:pharmacology; D002454:Cell Differentiation / Q000187:drug effects*; D002478:Cells, Cultured; D018920:Coculture Techniques; D004121:Dimethyl Sulfoxide / Q000494:pharmacology*; D005312:Fetal Blood / Q000166:cytology* / Q000187:drug effects / Q000502:physiology; D005346:Fibroblast Growth Factors / Q000494:pharmacology; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology; D036341:Intercellular Signaling Peptides and Proteins / Q000494:pharmacology*; D018021:Lithium Chloride / Q000494:pharmacology; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000502:physiology; D032383:Myocytes, Cardiac / Q000166:cytology* / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D013234:Stem Cells / Q000166:cytology / Q000502:physiology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D051153:Wnt Proteins / Q000187:drug effects / Q000502:physiology
chemical_list: C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D036341:Intercellular Signaling Peptides and Proteins; D051153:Wnt Proteins; D005346:Fibroblast Growth Factors; D007334:Insulin-Like Growth Factor I; D018021:Lithium Chloride; D001374:Azacitidine; D013755:Tetradecanoylphorbol Acetate; D004121:Dimethyl Sulfoxide