Scl/Tal1 confers hemogenic competence and prevents cardiomyogenesis in embryonic endothelium. Here we show that Scl both directly activates a broad gene regulatory network required for hematopoietic stem/progenitor cell (HS/PC) development, and represses transcriptional regulators required for cardiogenesis. Cardiac repression occurs during a short developmental window through Scl binding to distant cardiac enhancers that harbor H3K4me1 at this stage. Scl binding to hematopoietic regulators extends throughout HS/PC and erythroid development and spreads from distant enhancers to promoters. Surprisingly, Scl complex partners Gata 1 and 2 are dispensable for hematopoietic versus cardiac specification and Scl binding to the majority of its target genes. Nevertheless, Gata factors co-operate with Scl to activate selected transcription factors to facilitate HS/PC emergence from hemogenic endothelium. These results uncover a dual function for Scl in dictating hematopoietic versus cardiac fate choice and suggest a mechanism by which lineage-specific bHLH factors direct the divergence of competing fates.
Scl binds to primed enhancers in mesoderm to regulate hematopoietic and cardiac fate divergence.
Specimen part, Cell line
View SamplesEndothelium in embryonic hematopoietic tissues generates hematopoietic stem/progenitor cells; however, it is unknown how its unique potential is specified. We show that transcription factor Scl/Tal1 is essential for both establishing the hematopoietic transcriptional program in hemogenic endothelium and preventing its misspecification to a cardiomyogenic fate. Scl-/- embryos activated a cardiac transcriptional program in yolk sac endothelium, leading to the emergence of CD31+Pdgfr+ cardiogenic precursors that generated spontaneously beating cardiomyocytes. Ectopic cardiogenesis was also observed in Scl-/- hearts, where the disorganized endocardium precociously differentiated into cardiomyocytes. Induction of mosaic deletion of Scl in Sclfl/flRosa26Cre-ERT2 embryos revealed a cell-intrinsic, temporal requirement for Scl to prevent cardiomyogenesis from endothelium. Scl-/- endothelium also upregulated the expression of Wnt antagonists, which promoted rapid cardiomyocyte differentiation of ectopic cardiogenic cells. These results reveal unexpected plasticity in embryonic endothelium such that loss of a single master regulator can induce ectopic cardiomyogenesis from endothelial cells.
Scl represses cardiomyogenesis in prospective hemogenic endothelium and endocardium.
Specimen part
View SamplesFoxp3+ regulatory T (Treg) cells prevent inflammatory disease but the mechanistic basis of suppression is not understood completely . Gene silencing by RNA interference can act in a cell-autonomous and non-cell-autonomous manner, providing mechanisms of inter-cellular regulation. Here, we demonstrate that non-cell-autonomous gene silencing, mediated by miRNA-containing exosomes, is a mechanism employed by Treg cells to suppress T cell-mediated disease. Treg cells transferred microRNAs (miRNA) to various immune cells, including T helper 1 (Th1) cells, suppressing Th1 cell proliferation and cytokine secretion. Use of Dicer-deficient or Rab27a and Rab27b double-deficient Treg cells to disrupt miRNA-biogenesis or the exosomal pathway, respectively, established a requirement for miRNAs and exosomes for Treg cell-mediated suppression. Transcriptional analysis and miRNA inhibitor studies showed that exosome-mediated transfer of Let-7d from Treg cell to Th1 cells contributed to suppression and prevention of systemic disease. These studies reveal a mechanism of Treg cell-mediated suppression mediated by miRNA-containing exosomes.
MicroRNA-containing T-regulatory-cell-derived exosomes suppress pathogenic T helper 1 cells.
Specimen part
View SamplesThe overall goal of this project is to investigate the role of TGF-beta signaling in tissue-tissue interactions between myogenic precursors of craniofacial muscles and cranial neural crest cells (CNCCs). Here, we conducted gene expression profiling of the tongue bud from mice at embryonic day E13.5 with a CNCC-specific conditional inactivation of the TGF-beta receptor type 1 gene Alk5. These mice provide a model of microglossia as well as disrupted extraocular and masticatory muscle development, which are congenital birth defects commonly observed in several syndromic conditions.
ALK5-mediated transforming growth factor β signaling in neural crest cells controls craniofacial muscle development via tissue-tissue interactions.
Sex, Specimen part
View SamplesThe overall goal of this project is to investigate the role of TGF-beta signaling in tissue-tissue interactions between myogenic precursors of craniofacial muscles and cranial neural crest cells (CNCCs). Here, we conducted gene expression profiling of the mandibular arch from mice at embryonic day E11.5 with a CNCC-specific conditional inactivation of the TGF-beta receptor type 1 gene Alk5. These mice provide a model of microglossia as well as disrupted extraocular and masticatory muscle development, which are congenital birth defects commonly observed in several syndromic conditions.
ALK5-mediated transforming growth factor β signaling in neural crest cells controls craniofacial muscle development via tissue-tissue interactions.
Sex, Specimen part
View SamplesGene expression in self-renewing epithelial tissues is controlled by cis- and trans-activating regulatory factors that mediate responses to exogenous agents capable of causing tissue damage, infection, inflammation, or tumorigenesis. We used network construction methods to analyze the genetic architecture of gene expression in normal mouse skin in a cross between tumor-susceptible Mus musculus and tumor-resistant Mus spretus. We demonstrate that gene expression motifs representing different constituent cell types within the skin such as hair follicle cells, haematopoietic cells, and melanocytes are under separate genetic control. Motifs associated with inflammation, epidermal barrier function and proliferation are differentially regulated in mice susceptible or resistant to tumor development. The intestinal stem cell marker Lgr5 is identified as a candidate master regulator of hair follicle gene expression, and the Vitamin D receptor (Vdr) links epidermal barrier function, inflammation, and tumor susceptibility.
Genetic architecture of mouse skin inflammation and tumour susceptibility.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Foxl2 functions in sex determination and histogenesis throughout mouse ovary development.
Sex, Subject
View SamplesComparison of Foxl2-null ovaries to wildtype ovaries, ovaries lacking Wnt4 or Kit, or testes, throughout mouse development.
Foxl2 functions in sex determination and histogenesis throughout mouse ovary development.
No sample metadata fields
View SamplesWe compare the transcriptome of two different clones of multipotent adult progenitor cells (MAPCs) using Affymetrix arrays.
Hematopoietic reconstitution by multipotent adult progenitor cells: precursors to long-term hematopoietic stem cells.
No sample metadata fields
View SamplesAnalysis of gene expression in lungs of C57BL/6J mice that develop chronic airway disease phenotypes after a single Sendai virus infection, compared with mice treated with UV-inactivated virus.
Persistent activation of an innate immune response translates respiratory viral infection into chronic lung disease.
Sex, Time
View Samples