MesP1 drives vertebrate cardiovascular differentiation through Dkk-1-mediated blockade of Wnt-signalling.
ES-cell-based cardiovascular repair requires an in-depth understanding of the molecular mechanisms underlying the differentiation of cardiovascular ES cells. A candidate cardiovascular-fate inducer is the bHLH transcription factor MesP1. As one of the earliest markers, it is expressed specifically in almost all cardiovascular precursors and is required for cardiac morphogenesis. Here we show that MesP1 is a key factor sufficient to induce the formation of ectopic heart tissue in vertebrates and increase cardiovasculogenesis by ES cells. Electrophysiological analysis showed all subtypes of cardiac ES-cell differentiation. MesP1 overexpression and knockdown experiments revealed a prominent function of MesP1 in a gene regulatory cascade, causing Dkk-1-mediated blockade of canonical Wnt-signalling. Independent evidence from ChIP and in vitro DNA-binding studies, expression analysis in wild-type and MesP knockout mice, and reporter assays confirm that Dkk-1 is a direct target of MesP1. Further analysis of the regulatory networks involving MesP1 will be required to preprogramme ES cells towards a cardiovascular fate for cell therapy and cardiovascular tissue engineering. This may also provide a tool to elicit cardiac transdifferentiation in native human adult stem cells.
David
R
R
Medizinische Klinik und Poliklinik I, Klinikum Grosshadern der LMU, D-81377 München, Germany. robert.david@med.uni-muenchen.de
Brenner
C
C
Stieber
J
J
Schwarz
F
F
Brunner
S
S
Vollmer
M
M
Mentele
E
E
Müller-Höcker
J
J
Kitajima
S
S
Lickert
H
H
Rupp
R
R
Franz
W-M
WM
D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000378:metabolism / Q000502:physiology*; D002454:Cell Differentiation; D047369:Chromatin Immunoprecipitation; D053595:Embryonic Stem Cells / Q000166:cytology; D004730:Endothelium, Vascular / Q000378:metabolism; D005786:Gene Expression Regulation; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism / Q000502:physiology*; D051379:Mice; D018345:Mice, Knockout; D008954:Models, Biological; D015398:Signal Transduction; D051153:Wnt Proteins / Q000378:metabolism*; D014982:Xenopus laevis / Q000378:metabolism
D051792:Basic Helix-Loop-Helix Proteins; D036341:Intercellular Signaling Peptides and Proteins; D051153:Wnt Proteins; C501127:Dkk1 protein, mouse; C101538:Mesp1 protein, mouse