Primitive erythropoiesis in the mouse yolk sac is followed by definitive erythropoiesis resulting in adult erythrocytes. In comparison to definitive erythropoiesis little is known about the genes that control the embryonic erythroid program. The purpose of this study was to generate a profile of mouse embryonic yolk sac erythroid cells and identify novel regulatory genes differentially expressed in erythroid compared to non-erythroid (epithelial cells).
Identification of erythroid-enriched gene expression in the mouse embryonic yolk sac using microdissected cells.
No sample metadata fields
View SamplesThe origin of humans was accompanied by the emergence of new behavioral and cognitive functions, including language and specialized forms of abstract representation. However, the molecular foundations of these human capabilities are poorly understood. Because of the extensive similarity between human and chimpanzee DNA sequences, it has been suggested that many of the key phenotypic differences between species result primarily from alterations in the regulation of genes rather than in their sequences.
Elevated gene expression levels distinguish human from non-human primate brains.
Sex, Age, Specimen part
View SamplesGeneration of abundant engraftable hematopoietic cells from autologous tissues promises new therapies for hematologic diseases. Differentiation of pluripotent stem cells into hematopoietic cells results in emergence of cells that have poor engraftment potential. To circumvent this hurdle, we have devised a vascular niche model to phenocopy the developmental microenvironment of hemogenic cells thereby enabling direct transcriptional reprogramming of human endothelial cells (ECs) into hematopoietic cells. In this approach, transduction of human umbilical vein ECs (HUVECs) or adult human dermal microvascular ECs (hDMECs) with transcription factors (TFs), FOSB, GFI1, RUNX1, and SPI1 (FGRS) and induction with a instructive vascular niche feeder layer in a xenobiotic- and serum-free microenvironment results in generation of long-term engraftable hematopoietic multilineage progenitors (rEC-HMLPs). The rEC-HMLPs had robust proliferative and multilineage colony forming units (CFU) potential, including granulocytic/monocytic, megakaryocytic, erythroid and lymphoid lineages. When transplanted, hDMEC-derived rEC-HMLPs were capable of long-term multilineage primary and secondary hematopoietic engraftment. A subset of engrafted rEC-HMLPs phenotypically and functionally resembled cord blood cells. By conditionally expressing the FGRS TFs, we further optimized reprogramming of ECs into rEC-HMLPs manifesting features of self-renewing multi-potent progenitor populations (MPPs). Our approach replicates critical aspects of hematopoietic development and essential role of vascular niche induction in orchestrating hematopoietic specification and may prove useful for engineering autologous engraftable hematopoietic cells for treatment of inherited and acquired blood disorders. . Overall design: Transcriptome sequencing of rEC-HMLPs, hDMECs, HUVECs and other cell types
Wnt inhibition promotes vascular specification of embryonic cardiac progenitors.
No sample metadata fields
View SamplesThe retinal pigment epithelial (RPE) cell line ARPE-19 provides a widely-used alternative to native RPE. However, retention of the native RPE phenotype becomes problematic after multiple passages. We wished to determine if suitable culture conditions and differentiation could restore RPE-appropriate gene expression to ARPE-19. ARPE-19 cells at passages p9 to p12, grown in DMEM containing high glucose and pyruvate with 1% fetal bovine serum, were differentiated for up to 4 months. Using RNA-Seq, we compared the transcriptome of ARPE-19 cells kept in long-term culture with those cultured for 4 days. The 4 month cells developed the classic native RPE phenotype with heavy pigmentation. RNA-Seq analysis provided a comprehensive view of the relative abundance and differential expression of genes in the 4 month cells. Of the 16,757 genes with detectable signals, nearly 2435 genes were upregulated, and 931 genes were down-regulated with a fold change differences of 2 or more. Genes characteristic of RPE, including RPE65, RDH5 and RDH10, were greatly increased in ARPE-19 cells maintained at confluence for 4 months. Comparison with microarray data sets from human primary cell lines revealed important overall similarities in expression of "signature" genes. The results of this study demonstrate that ARPE-19 cells can express genes specific to native human RPE cells when appropriately cultured, and thus, can provide a relevant system to study differentiated cellular functions of RPE in vitro. Overall design: RNA-Seq profiles of ARPE-19 cells grown for 4 days or 4 months; triplicate replicates were sequenced.
Appropriately differentiated ARPE-19 cells regain phenotype and gene expression profiles similar to those of native RPE cells.
Specimen part, Cell line, Subject
View SamplesAstrocytes, the most abundant cells in the central nervous system, promote synapse formation and help refine neural connectivity. Although they are allocated to spatially distinct regional domains during development, it is unknown whether region-restricted astrocytes are functionally heterogeneous. Here we show that postnatal spinal cord astrocytes express several region-specific genes, and that ventral astrocyte-encoded Semaphorin3a (Sema3a) is required for proper motor neuron and sensory neuron circuit organization. Loss of astrocyte-encoded Sema3a led to dysregulated motor neuron axon initial segment orientation, markedly abnormal synaptic inputs, and selective death of but not of adjacent motor neurons. Additionally, a subset of TrkA+ sensory afferents projected to ectopic ventral positions. These findings demonstrate that stable maintenance of a positional cue by developing astrocytes influences multiple aspects of sensorimotor circuit formation. More generally, they suggest that regional astrocyte heterogeneity may help to coordinate postnatal neural circuit refinement.
Astrocyte-encoded positional cues maintain sensorimotor circuit integrity.
Specimen part
View SamplesThe Krppel-like factors, KLF1 and KLF2, positively regulate embryonic -globin expression, and have additional overlapping roles in embryonic (primitive) erythropoiesis. KLF1-/-KLF2-/- double knockout mice are anemic at embryonic day 10.5 (E10.5) and die by E11.5, in contrast to single knockouts. To investigate the combined roles of KLF1 and KLF2 in primitive erythropoiesis, expression profiling of E9.5 erythroid cells was performed. A limited number of genes had a significantly decreasing trend of expression in wild-type, KLF1-/- and KLF1-/-KLF2-/-. Among these, c-myc emerged as a central node in the most significant gene network. c-myc expression is synergistically regulated by KLF1 and KLF2, and both factors bind the c-myc promoters. To characterize the role of c-myc in primitive erythropoiesis, ablation was performed specifically in mouse embryonic proerythroblast cells. After E9.5, these embryos exhibit an arrest in the normal expansion of circulating red cells and develop anemia analogous to KLF1-/-KLF2-/-. In the absence of c-myc, circulating erythroid cells do not show the normal increase in - and -like globin expression, but interestingly, have accelerated erythroid maturation, between E9.5 and E11.5. This study reveals a novel regulatory network by which KLF1 and KLF2 regulate c-myc, to control the primitive erythropoietic program.
Kruppel-like factor 1 (KLF1), KLF2, and Myc control a regulatory network essential for embryonic erythropoiesis.
Specimen part
View SamplesThe EZH2 histone methyltransferase is required for B cells to form germinal centers (GCs). Here we show that EZH2 mediates GC formation through repression of cyclin-dependent kinase inhibitor CDKN1A (p21Cip1). Deletion of Cdkn1a rescued the GC reaction in Ezh2 knockout mice. To study the effects of EZH2 in primary GC B cells we generated and validated a 3D B cell follicular organoid system that mimics the endogenous GC reaction. Using this system we found that depletion of EZH2 suppressed G1 to S phase transition of GC B cells in a Cdkn1a dependent manner. GC B cells of Cdkn1a;Ezh2 double knockout mice exhibited high levels of phospho Rb, indicating that loss of Cdkn1a allows progression of cell cycle. Moreover, we show that the transcription factor E2F1 plays a major role in inducing EZH2 upregulation during the GC reaction. E2F1 deficient mice manifest impaired GC responses, which was rescued by restoring EZH2 expression, thus defining a positive feedback loop whereby EZH2 controls GC B cell proliferation by suppressing CDKN1A, allowing cell cycle progression with a concomitant phosphorylation of Rb and release of E2F1. Overall design: gene expression profiles of murine B cells
EZH2 enables germinal centre formation through epigenetic silencing of CDKN1A and an Rb-E2F1 feedback loop.
Specimen part, Disease, Cell line, Subject, Time
View SamplesNeural stem cells (NSC) derived from human parthenogenic stem cells (hpSC) have been observed to show stronger positive functional effects than hpSC-derived dopaminergic neuron precursors (DAP) in treatment of induced Parkinson Disease in animal models. RNAseq of the two types of cells were normalized and analyzed to compare gene expression profiles. Overall design: cDNA library of hpsC, NSC and DAP triplicates were sequenced using Illumina HiSeq 2000. The sequence reads were mapped to hg19 reference genome and hits that passed quality filters were analyzed for differential expression.
Proof of concept studies exploring the safety and functional activity of human parthenogenetic-derived neural stem cells for the treatment of Parkinson's disease.
No sample metadata fields
View SamplesDevelopmental pathways that orchestrate the fleeting transition of endothelial cells into haematopoietic stem cells remain undefined. Here we demonstrate a tractable approach for fully reprogramming adult mouse endothelial cells to haematopoietic stem cells (rEC-HSCs) through transient expression of the transcription-factor-encoding genes Fosb, Gfi1, Runx1, and Spi1 (collectively denoted hereafter as FGRS) and vascular-niche-derived angiocrine factors. The induction phase (days 0-8) of conversion is initiated by expression of FGRS in mature endothelial cells, which results in endogenous Runx1 expression. During the specification phase (days 8-20), RUNX1+ FGRS-transduced endothelial cells commit to a haematopoietic fate, yielding rEC-HSCs that no longer require FGRS expression. The vascular niche drives a robust self-renewal and expansion phase of rEC-HSCs (days 20-28). rEC-HSCs have a transcriptome and long-term self-renewal capacity similar to those of adult haematopoietic stem cells, and can be used for clonal engraftment and serial primary and secondary multi-lineage reconstitution, including antigen-dependent adaptive immune function. Inhibition of TGF? and CXCR7 or activation of BMP and CXCR4 signalling enhanced generation of rEC-HSCs. Pluripotency-independent conversion of endothelial cells into autologous authentic engraftable haematopoietic stem cells could aid treatment of haematological disorders. Overall design: Expression profiling by high throughput sequencing data; GPL17021 Illumina HiSeq 2500 (Mus musculus)
Conversion of adult endothelium to immunocompetent haematopoietic stem cells.
Specimen part, Subject
View SamplesBy silencing of RALA, a downstream member of the RAS signal transduction pathway, we aimed to determine whether genes downstream of a mutated KRAS (codon 12 or 13) or a mutated BRAF can have significant functions in colorectal cancer carcinogenesis.
Effects of RAL signal transduction in KRAS- and BRAF-mutated cells and prognostic potential of the RAL signature in colorectal cancer.
Specimen part, Cell line, Treatment
View Samples