title: BMP-2/6 heterodimer is more effective than BMP-2 or BMP-6 homodimers as inductor of differentiation of human embryonic stem cells.
abstract: BACKGROUND
  Bone Morphogenetic Protein (BMP) signaling pathways are involved in differentiation of stem cells into diverse cell types, and thus BMPs can be used as main guidance molecules for in vitro differentiation of human stem cells.
  
  
  RESULTS
  We have analyzed the ability for inducing differentiation of the heterodimer BMP-2/BMP-6 (BMP-2/6) compared to the homodimers BMP-2 or BMP-6, using human embryonic stem (hES) cells H9 as model system. When incubated in a medium with high concentration of basic fibroblastic growth factor (FGF2), 100 ng/ml of human recombinant BMPs induced morphological changes and differentiation of hES cells in 24 to 48 hours. After 5 days, expression of differentiation markers was induced and quantified by quantitative PCR (qPCR) and flow cytometry. BMP-2/6 exhibited stronger activity for the induction of the expression of trophectodermal (CDX2) and endodermal (SOX17, GATA4, AFP) markers than BMP-2 or BMP-6 homodimers. BMP-2/6 also induced the expression of BMPR2 gene more effectively than BMP-2 or BMP-6 when used at the same concentration and time. Moreover, the percentage of cells expressing the surface endodermal marker CXCR4 was also increased for the heterodimer when compared to both homodimers. BMP-2/6 was a more potent activator of Smad-dependent (SMAD1/5) and Smad-independent signaling (mitogen-activated protein kinases ERK and p38) than BMP-2 and BMP-6, and the activation of these pathways might play a role in its increased potency for inducing hES cell differentiation.
  
  
  CONCLUSIONS
  Therefore, we conclude that BMP-2/6 is more potent than BMP-2 or BMP-6 for inducing differentiation of hES cells, and it can be used as a more powerful substitute of these BMPs in in vitro differentiation guidance.
authors.affiliation: Structural Biology Laboratory, Salk Institute, La Jolla, California, USA.
authors.forename: Elvira
authors.initials: E
authors.lastname: Valera
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Isaacs
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Kawakami
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Izpisúa Belmonte
authors.forename: Senyon
authors.initials: S
authors.lastname: Choe
mesh_terms: D001483:Base Sequence; D015415:Biomarkers / Q000378:metabolism; D055396:Bone Morphogenetic Protein 2 / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D055418:Bone Morphogenetic Protein 6 / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D002454:Cell Differentiation / Q000502:physiology*; D002460:Cell Line; D003470:Culture Media; D017931:DNA Primers; D019281:Dimerization; D053595:Embryonic Stem Cells / Q000166:cytology*; D016222:Fibroblast Growth Factor 2 / Q000378:metabolism; D020869:Gene Expression Profiling; D006801:Humans; D016133:Polymerase Chain Reaction; D019718:Receptors, CXCR4 / Q000378:metabolism; D053773:Transforming Growth Factor beta1 / Q000378:metabolism
chemical_list: C525718:BMP2 protein, human; C525816:BMP6 protein, human; D015415:Biomarkers; D055396:Bone Morphogenetic Protein 2; D055418:Bone Morphogenetic Protein 6; C527276:CXCR4 protein, human; D003470:Culture Media; D017931:DNA Primers; D019718:Receptors, CXCR4; D053773:Transforming Growth Factor beta1; D016222:Fibroblast Growth Factor 2