title: Tbx5 overexpression favors a first heart field lineage in murine embryonic stem cells and in Xenopus laevis embryos.
abstract: The T-box transcription factor Tbx5 is involved in several developmental processes including cardiogenesis. Early steps of cardiac development are characterised by the formation of two cardiogenic lineages, the first (FHF) and the second heart field (SHF) lineage, which arise from a common cardiac progenitor cell population. To further investigate the function of Tbx5 during cardiogenesis, we generated a murine embryonic stem cell line constitutively overexpressing Tbx5. Differentiation of these cells is characterised by an earlier and increased appearance of contracting cardiomyocytes that beat with a higher frequency than control cells. In semi-quantitative and quantitative RT-PCR analyses, we observed an up-regulation of cardiac marker genes such as Troponin T, endogenous Tbx5, and Nkx2.5 and a down-regulation of others like BMP4 and Hand2. Similar data were gained in Xenopus laevis arguing for a conserved function of Tbx5. Furthermore, markers of the conduction system and atrial cardiomyocytes were increased.
authors.affiliation: Institute for Biochemistry and Molecular Biology, Ulm University, Albert-Einstein-Allee 11, Ulm, Germany
authors.forename: Franziska
authors.initials: F
authors.lastname: Herrmann
authors.forename: Karin
authors.initials: K
authors.lastname: Bundschu
authors.forename: Susanne J
authors.initials: SJ
authors.lastname: Kühl
authors.forename: Michael
authors.initials: M
authors.lastname: Kühl
mesh_terms: D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism; D055415:Bone Morphogenetic Protein 4 / Q000235:genetics / Q000378:metabolism; D002454:Cell Differentiation / Q000502:physiology*; D002460:Cell Line; D019070:Cell Lineage / Q000502:physiology*; D015536:Down-Regulation / Q000502:physiology; D053595:Embryonic Stem Cells / Q000166:cytology / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D006325:Heart Atria / Q000166:cytology / Q000196:embryology*; D000072576:Homeobox Protein Nkx-2.5; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D032383:Myocytes, Cardiac / Q000166:cytology / Q000378:metabolism; D020825:T-Box Domain Proteins / Q000096:biosynthesis* / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D020107:Troponin T / Q000235:genetics / Q000378:metabolism; D029867:Xenopus Proteins / Q000235:genetics / Q000378:metabolism; D014982:Xenopus laevis
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D055415:Bone Morphogenetic Protein 4; D000072576:Homeobox Protein Nkx-2.5; D018398:Homeodomain Proteins; D020825:T-Box Domain Proteins; D014157:Transcription Factors; D020107:Troponin T; D029867:Xenopus Proteins; C525810:Bmp4 protein, mouse; C498768:Hand2 protein, Xenopus; C498766:Hand2 protein, mouse; C092720:NKX2-5 protein, Xenopus; C484469:Nkx2-5 protein, mouse; C103172:T-box transcription factor 5; C525812:bmp4 protein, Xenopus