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: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.
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:Mouse heart development arises fromMesp1 expressing cardiovascular progenitors that are specified at the early stage of gastrulation. Lineage tracing and clonal analysisof Mesp1 progenitors revealed that heart development arises from distinct populations of Mesp1+ cardiovascular progenitors (CPs) expressing Mesp1 at different time points during gastrulation that contribute to different heart regions and different cardiovascular lineages. However, it remains unclear what are the molecular mechanisms that control the early regional and lineage segregation of Mesp1 CPs. Here, we performedsingle cell RNA-sequencing of FACS isolated Mesp1 CPs in WT and Mesp1 null embryos at different times to define the cellular and molecular heterogeneity of the Mesp1CPs, identify the role of Mesp1 in regulating cellular heterogeneity and uncover the mechanisms associated with lineage and regional segregation during the early stages of gastrulation.We showed that Mesp1 CPs isolated at E6.75 and E7.25 are molecularly distinct and make the continuum betweenepiblast and later mesodermal cells including hematopoietic progenitors. Single cell transcriptome of Mesp1 deficient CPsshowed that Mesp1 is required for the exitof thepluripotent state and the induction of the cardiovascular gene expression program in vivo.Using dimensional reduction analysis, we identified distinct populations of Mesp1 CPs that correspond to progenitors committed to different celllineages and regions of the heart, identifying the molecular features associated with the early lineage and regional segregation. Notch1CREER lineage tracing, a marker preferentially expressed by one of the different Mesp1CP subpopulations, during the early stage of gastrulation marked almost exclusively ECs, demonstrating theexistence of an early Mesp1 subpopulation committed to the EC fate.This study uncoversthe cellular and molecular heterogeneity associated with early lineage restriction and regional segregation of the heart at the early stage of gastrulation.
Project description:Previously, we reported that the transcription factor Mesp1 promotes the cell fates of cardiomyocytes, smooth muscle, and vascular endothelium. Recently, hematopoietic stem cells (HSCs) were shown to derive from hemogenic endothelium. Since Mesp1 regulates development of endothelium, it potentially could influence gene expression related to hematopoietic development. Our present fate mapping study found that Mesp1-cre efficiently labeled hematopoietic lineages in vivo. This result suggested that Mesp1 might be expressed in progenitors of the hematopoietic system, such as hemogenic endothelium. To test this, we purified Flk1+ Tie2+ endothelium derived from differentiating ES cells with or without Mesp1 induction, and used microarray expression analysis to identify genes strongly up-regulated by Mesp1.