Project description:We explored the role of mammalian ETS1/2 and Mesp homologues of cardiogenic transcription factors of Ciona intestinalis, to convert primary human dermal fibroblasts into cardiac progenitors. ETS1/2 and Mesp homologues of cardiogenic transcription factors of Ciona intestinalis, to convert primary human dermal fibroblasts into cardiac progenitors. Here we show murine Ets2 has an obligatory role for directing cardiac progenitors during cardiopoesis in embryonic stem cells. ETS2 converted fibroblasts into KDR/Flk1+ replicative cells but, like the purported cardiac master regulatory gene Mesp1, could not by itself generate cardiac progenitors de novo from fibroblasts. Co-expression of both Ets2 and Mesp1, however, successfully reprogrammed differentiated fibroblasts into cardiac progenitors, as shown by the de novo appearance of core cardiac transcription factors, gap junction proteins, sarcomeric proteins, electrical activity and contractility. ETS2 and Mesp1 sit at the pinnacle of the cardiopoesis regulatory hierarchy and are well suited for treating human heart disease. Co-expression of both Ets2 and Mesp1, reprogrammed differentiated fibroblasts into cardiac progenitors
Project description:We explored the role of mammalian ETS1/2 and Mesp homologues of cardiogenic transcription factors of Ciona intestinalis, to convert primary human dermal fibroblasts into cardiac progenitors. ETS1/2 and Mesp homologues of cardiogenic transcription factors of Ciona intestinalis, to convert primary human dermal fibroblasts into cardiac progenitors. Here we show murine Ets2 has an obligatory role for directing cardiac progenitors during cardiopoesis in embryonic stem cells. ETS2 converted fibroblasts into KDR/Flk1+ replicative cells but, like the purported cardiac master regulatory gene Mesp1, could not by itself generate cardiac progenitors de novo from fibroblasts. Co-expression of both Ets2 and Mesp1, however, successfully reprogrammed differentiated fibroblasts into cardiac progenitors, as shown by the de novo appearance of core cardiac transcription factors, gap junction proteins, sarcomeric proteins, electrical activity and contractility. ETS2 and Mesp1 sit at the pinnacle of the cardiopoesis regulatory hierarchy and are well suited for treating human heart disease. Co-expression of both Ets2 and Mesp1, reprogrammed differentiated fibroblasts into cardiac progenitors All sample were done in triplicates, controls were NHDF and ETS2 only infected cells. NHDF were first infected with Doxycyline redulated (Doxy-) ETS2 lentivirus and supplemented with doxycycline for 1 week, sequentially cells were infected with Doxy-Mesp1 and treated for 1 more week. Cells were then aggegated to form EB and hangdrop for 1 week, at the end of that period cells were plated and samples were taken every 24 hrs
Project description:A hESC MESP1-MCHERRY reporter line was used to isolate and study the molecular character of MESP1 expressing pre-cardiac progenitors, derived from hESC. MESP1 is a key-transcription factor for pre-cardiac mesoderm and is marking the progenitor for almost all cells of the heart. This reporter line was used to study cardiac differentiation and the derivation of early cardiac progenitors in vitro. hESCs were differentiated towards the cardiac lineage, expressing MESP1-mCherry at day 3 of differentiation. Total RNA obtained from isolated MESP1-mCherry expressing progenitors was compared to that of non-MESP1-expressing progenitors and undifferentiated hESCs in order to characterize MESP1-specific transcription factors and proteins.
Project description:Cardiac development arises from two sources of mesoderm progenitors, the first (FHF) and the second heart field (SHF). Mesp1 has been proposed to mark the most primitive multipotent cardiac progenitors common for both heart fields. Here, using clonal analysis of the earliest prospective cardiovascular progenitors in a temporally controlled manner during the early gastrulation, we found that Mesp1 progenitors consist of two temporally distinct pools of progenitors restricted to either the FHF or the SHF. FHF progenitors were unipotent, while SHF progenitors, were either uni- or bipotent. Microarray and single cell RT-PCR analysis of Mesp1 progenitors revealed the existence of molecularly distinct populations of Mesp1 progenitors, consistent with their lineage and regional contribution. Altogether, these results provide evidence that heart development arises from distinct populations of unipotent and bipotent cardiac progenitors that independently express Mesp1 at different time points during their specification, revealing that the regional segregation and lineage restriction of cardiac progenitors occurs very early during gastrulation. We used microarrays to characterize the molecular mechanisms that control Mesp1 progenitor specification and lineage segregation during the early stage of cardiac mesoderm formation, 50 Mesp1 H2B-GFP+ or Mesp1 H2B-GFP- cells at E6.5 or E7.5 from mouse embryos were sorted for RNA extraction, amplification and hybridization on Affimetrix microarrays. Microaarrays were performed on Mouse Genome 430 PM strip Affymetrix array. The overall design was repeated in two different biological samples.
Project description:Cardiac development arises from two sources of mesoderm progenitors, the first (FHF) and the second heart field (SHF). Mesp1 has been proposed to mark the most primitive multipotent cardiac progenitors common for both heart fields. Here, using clonal analysis of the earliest prospective cardiovascular progenitors in a temporally controlled manner during the early gastrulation, we found that Mesp1 progenitors consist of two temporally distinct pools of progenitors restricted to either the FHF or the SHF. FHF progenitors were unipotent, while SHF progenitors, were either uni- or bipotent. Microarray and single cell RT-PCR analysis of Mesp1 progenitors revealed the existence of molecularly distinct populations of Mesp1 progenitors, consistent with their lineage and regional contribution. Altogether, these results provide evidence that heart development arises from distinct populations of unipotent and bipotent cardiac progenitors that independently express Mesp1 at different time points during their specification, revealing that the regional segregation and lineage restriction of cardiac progenitors occurs very early during gastrulation. We used microarrays to characterize the molecular mechanisms that control Mesp1 progenitor specification and lineage segregation during the early stage of cardiac mesoderm formation,
Project description:A hESC MESP1-MCHERRY reporter line was used to isolate and study the molecular character of MESP1 expressing pre-cardiac progenitors, derived from hESC. MESP1 is a key-transcription factor for pre-cardiac mesoderm and is marking the progenitor for almost all cells of the heart. This reporter line was used to study cardiac differentiation and the derivation of early cardiac progenitors in vitro.
Project description:A hESC MESP1 reporter line was used to isolate MESP1 expressing pre-cardiac progenitors. These progenitor were replated and fulter differentiated in culture. At four sequential timepoints upon further differentiation, samples were isolated for gene expression analysis, in order to identify key cardiac transcription factors and molecules. hESCs were differentiated towards the cardiac lineage. MESP1-mCherry expressing progenitors were isolated at day 3 of differentiation and replated as aggregates, in presence of Wnt-inhibitor Xav939. Two days after replating (D5), four days (D7), seven days (D10), ad 11 days (D14), total RNA of each sample was isolated for gene expression analysis. MESP1-mCherry positive derivatives were compared to MESP1-mCherry negative derivatives, in order to identify cardiac-specific regulators and cell surface markers.
Project description:During embryogenesis, the cardiac cell fate is acquired as early as gastrulation. There is compelling evidence that embryonic stem cells (ESC) can recapitulate early steps in cardiogenesis. Identification from human pluripotent stem cells of early cardiovascular cell progenitors, at the origin of the first cardiac lineage, would shed light on human normal and pathological cardiogenesis and would pave the way toward cell therapy for cardiac degenerative diseases. Here, we report the isolation, and a phenotypic characterisation of an early Oct-4+, SSEA-1+, Mesp1+ population of cardiovascular progenitors derived from human pluripotent stem cells. This multipotential progenitor features the capability to generate cardiomyocytes as well as smooth muscle and endothelial cells. We further bring a proof of concept that these progenitors can be used in cardiac regenerative medicine as allografted in infarcted non human primate myocardium, they differentiate in ventricular myocytes without any adverse effect. One RNA sample from HUESC-POU5F1 was compared in dye-swap to undifferentiated HUESC. Three distinct RNA samples from BMP2-induced SSEA1+ cells were compared in dye-swap to paired remaining SSEA1-. Reference samples correspond to undifferentiated HUESC and to SSEA1 negative cells, respectively. population respectivement.
Project description:Progenitor cells of the first and second heart fields (FHF and SHF) depend on cardiac-specific transcription factors for their differentiation. In mouse mutant embryos, we define the hierarchy of signaling events that controls the expression of cardiac-specific transcription factors during commitment of SHF progenitors at E9.25. Wnt and Bmp act downstream of Notch/RBPJ at this developmental stage. Mutation of Axin2, the negative regulator of canonical Wnt signaling, enhances Wnt and Bmp signals and suffices to rescue the cardiac differentiation arrest caused by loss of RBPJ. By analysis of isolated cardiac progenitors, embryo cultures in the presence of pharmacological inhibitors, and Bmp triple mutants, we could classify the expression of heart-specific transcription factors of SHF progenitors according to their dependence on either Wnt or Bmp signals, Nkx2-5, Isl1, Baf60c and Gata4, SRF, Mef2c, respectively. Total RNA from whole embryonic hearts of control mice was compared to MesP1-cre:RBPJlox/lox (KO), MesP1-cre:RBPJlox/lox//Axin2-/- (DKO), MesP1-cre:RBPJlox/+//Axin2-/- (hetDKO) and MesP1-cre:RBPJlox/lox//Axin2+/- (DKOhet) mutant mouse embryos.
Project description:During embryogenesis, the cardiac cell fate is acquired as early as gastrulation. There is compelling evidence that embryonic stem cells (ESC) can recapitulate early steps in cardiogenesis. Identification from human pluripotent stem cells of early cardiovascular cell progenitors, at the origin of the first cardiac lineage, would shed light on human normal and pathological cardiogenesis and would pave the way toward cell therapy for cardiac degenerative diseases. Here, we report the isolation, and a phenotypic characterisation of an early Oct-4+, SSEA-1+, Mesp1+ population of cardiovascular progenitors derived from human pluripotent stem cells. This multipotential progenitor features the capability to generate cardiomyocytes as well as smooth muscle and endothelial cells. We further bring a proof of concept that these progenitors can be used in cardiac regenerative medicine as allografted in infarcted non human primate myocardium, they differentiate in ventricular myocytes without any adverse effect.