Human embryonic stem cells (hESC) display substantial heterogeneity in gene expression, implying the existence of discrete substates within the stem cell compartment. To determine whether these substates impact fate decisions of hESC we used a GFP reporter line to investigate the properties of fractions of putative undifferentiated cells defined by their differential expression of the endoderm transcription factor, GATA6, together with the hESC surface marker, SSEA3. By single cell cloning, we confirmed that substates characterized by expression of GATA6 and SSEA3 include pluripotent stem cells capable of long term self-renewal. When clonal stem cell colonies were formed from GATA6-positive and GATA6-negative cells, more of those derived from GATA6-positive cells contained spontaneously differentiated endoderm cells than similar colonies derived from the GATA6-negative cells. We characterized these discrete cellular states using single cell transcriptomic analysis, identifying a potential role for SOX17 in the establishment of the endoderm biased stem cell state. Overall design: Examination of 4 different cell substates within one human embryonic stem cell line as determine by the expression status of GATA6 and SSEA3
Identification and Single-Cell Functional Characterization of an Endodermally Biased Pluripotent Substate in Human Embryonic Stem Cells.
Specimen part, Subject
View SamplesMany genes determining cell identity are regulated by clusters of Mediator-bound enhancer elements collectively referred to as super-enhancers. These super-enhancers have been proposed to manifest higher-order properties important in development and disease. Here we report a comprehensive functional dissection of one of the strongest putative super-enhancers in erythroid cells. By generating a series of mouse models, deleting each of the five regulatory elements of the a-globin super-enhancer individually and in informative combinations, we demonstrate that each constituent enhancer seems to act independently and in an additive fashion with respect to hematological phenotype, gene expression, chromatin structure and chromosome conformation, without clear evidence of synergistic or higher-order effects. Our study highlights the importance of functional genetic analyses for the identification of new concepts in transcriptional regulation. Overall design: Mouse fetal liver erythroid RNA-seq. The RNA of the erythroid cells was metabolically labelled using 4-thiourdine nucleotide analogue supplementation of viable cells in culture. RNA transcripts that incorporated the analogue and hence were synthesised during this period of exposure, were then isolated from the pre-exiting bulk RNA by the addition of a biotin moiety and pull down.
Genetic dissection of the α-globin super-enhancer in vivo.
Specimen part, Subject
View SamplesWe attempted to identify alterations in gene expression that occur during the progression from normal breast to ductal carcinoma in situ (DCIS) with the aim to elucidate significant genes and pathways underlying the premalignant transformation. To determine the expression changes that are common to multiple DCIS models (MCF10.DCIS, SUM102 and SUM225) and normal mammary epithelial cells (MCF10A), we grew the cells in three dimensional overlay culture with reconstituted basement membrane and used the extracted RNA for 76 cycles of deep sequencing (mRNA-Seq) using Illumina Genome Analyzer GAIIx. Analysis of mRNA-Seq results showed 295 consistently differentially expressed transcripts in DCIS models as compared to MCF10A. These differentially expressed genes are associated with a number of signaling pathways such as integrin, fibroblast growth factor and TGFß signaling. Many differentially expressed transcripts in DCIS were found to be involved in cell-cell signaling, cell-cell adhesion and cell proliferation. We further investigated ALDH5A1 gene that encodes for the enzyme, aldehyde dehydrogenase 5A1, which is involved in glutamate metabolism. Further, inhibition of ALDH5A1 with different pharmacological drugs resulted in significant inhibition of cell growth and proliferation in the DCIS models. Overall design: Four cell lines examined: normal mammary epithelial cell line (one sample) and three ductal carcinoma in situ cell lines (three samples). Each sample has two duplicates
RNA-Seq of human breast ductal carcinoma in situ models reveals aldehyde dehydrogenase isoform 5A1 as a novel potential target.
Disease, Cell line, Subject
View SamplesWhole brain irradiation remains important in the management of brain tumors. Although necessary for improving survival outcomes, cranial irradiation also results in cognitive decline in long-term survivors. A chronic inflammatory state characterized by microglial activation has been implicated in radiation-induced brain injury, and here we present a comprehensive transcriptional profile of irradiated microglia.
Aging-like changes in the transcriptome of irradiated microglia.
Age, Specimen part
View SamplesWe report a method for deriving oligodendrocyte lineage cells from human pluripotent stem cells (hPSCs) in three-dimensional (3D) culture called human oligodendrocyte spheroids (hOLS). To characterize oligodendrocyte-lineage cells in hOLS, we isolated O4+ cells by immunopanning and performed deep single cell RNA sequencing. We sequenced 295 cells and compared their profiles to unsorted cells isolated from primary human fetal cortex, primary human adult cortex, and hCS. Clustering of all cells using the t-distributed stochastic neighbor embedding (tSNE) approach revealed a distinct populations of SOX10+ oligodendrocytes, within which the O4+ cells derived from hOLS clustered most closely to oligodendrocyte progenitor cells (OPCs) and mature oligodendrocytes from the primary human adult cortical tissue. Additionally, subpopulations of OPCs, newly formed oligodendrocytes, and myelinating oligodendrocytes derived were observed in the hOLS-derived cluster. To further assess the state of oligodendrocyte-lineage cells in hOLS, we performed a Monocle analysis which revealed a spectrum of oligodendrocyte-lineage stages in hOLS ranging from dividing cells that closely resembled primary OPCs to mature cells that closely resembled primary oligodendrocytes. Overall design: Examination of gene expression in single oligodendrocyte-lineage cells derived from human pluripotent stem cells in three-dimensional culture
Differentiation and maturation of oligodendrocytes in human three-dimensional neural cultures.
Subject
View SamplesAstrocytes were purified from postnatal day 2 mouse cortices by immunopanning with HepaCAM. Inhibitors and DMSO were added on in-vitro day 2. HBEGF was depleted on the cell prep day and till in-vitro day 7. In-vitro day 2, 7 and 14 samples were collected on designed timepointed. Overall design: Three EGFR inhibitor samples and three relative DMSO control samples, three P53 inhibitor samples and three relative DMSO control samples, two HBEGF samples and two HBEGF withdrawal samples, three samples for each in-vitro day 2, 7 and 14.
Astrocyte-to-astrocyte contact and a positive feedback loop of growth factor signaling regulate astrocyte maturation.
Specimen part, Cell line, Subject
View SamplesThe entorhinal cortex of the mouse seems to be sensitive to molecular mechanisms that have been linked to the pathology of Alzheimer's disease. In this microarray study we are interested in comparing the expression profile of the left versus the right EC of the mouse, in order to understand if there is a significant difference in gene expression that might reveal any insights into the differential activation of these areas.
Molecular drivers and cortical spread of lateral entorhinal cortex dysfunction in preclinical Alzheimer's disease.
Age, Specimen part
View SamplesTo quantitative analysis of transcriptome changes caused by lnc-OPC knockdown during OPC differentiation from NSC, lentivirus-based short hairpin RNAs were used to knockdown the lnc-OPC expression in a neural stem cell culture . Subsequently, puromycin-selected NSCs were differentiated to OPC in culture for three days.RNA-Seq was performed on the polyadenylated fraction of RNA isolated from cell samples. DEseq was used for differential gene expression analysis caused by lnc-OPC knockdown. GO functional term enrichment analysis of differential gene expression caused by lnc-OPC knockdown, revealed significant enrichment of 'oligodendrocyte development', 'oligodendrocyte differentiation', 'glia cell development', and 'axon ensheathment' terms that are associated with oligodendrogenesis. Overall design: mRNA profiles of differentiiated NSC samples after lnc-OPC knockdown by RNA-sequencing.
Comprehensive Identification of Long Non-coding RNAs in Purified Cell Types from the Brain Reveals Functional LncRNA in OPC Fate Determination.
Specimen part, Cell line, Subject
View SamplesTo better understand the transcriptome of mouse neural stem cells (including known genes and novel long non coding RNA genes), RNA-Seq was performed on the polyadenylated fraction of RNA isolated from cell samples. Read mapping and transcriptome construction were done by using optimized pipeline which integrate Tophat followed by Cufflinks. Overall design: mRNA profiles of mouse neural stem cells were generated by RNA-sequencing.
Comprehensive Identification of Long Non-coding RNAs in Purified Cell Types from the Brain Reveals Functional LncRNA in OPC Fate Determination.
Specimen part, Cell line, Subject
View SamplesX-chromosome inactivation (XCI) provides a dosage compensation mechanism where, in each female cell, one of the two X chromosomes is randomly silenced. However, some genes on the inactive X chromosome and outside the pseudoautosomal regions escape from XCI and are expressed from both alleles (escapees). We investigated XCI at single-cell resolution combining deep single cellRNA sequencing with whole-genome sequencing to examine allelic-specific expression in 935 primary fibroblast and 48 lymphoblastoid single cells from five female individuals. In this framework we integrated an original method to identify and exclude doublets of cells. In fibroblast cells, we have identified 55 genes as escapees including five novel escapee genes. Moreover, we observed that all genes exhibit a variable propensity to escape XCI in each cell and cell type and that each cell displays a distinct expression profile of the escapee genes. A metric, the Inactivation Score—defined as the mean of the allelic expression profiles of the escapees per cell—enables us to discover a heterogeneous and continuous degree of cellular XCI with extremes represented by “inactive” cells, i.e., cells exclusively expressing the escaping genes from the active X chromosome and “escaping” cells expressing the escapees from both alleles. We found that this effect is associated with cell-cycle phases and, independently, with the XIST expression level, which is higher in the quiescent phase (G0). Single-cell allele-specific expression is a powerful tool to identify novel escapees in different tissues and provide evidence of an unexpected cellular heterogeneity of XCI. Overall design: Single-cell RNA seq study on 935 human fibroblasts and 48 lymphoblastoid cells from 5 female individuals, in order to investigate the X chromosome nactivation mechanism on a single cell level and to identify escapee genes
Single cell transcriptome in aneuploidies reveals mechanisms of gene dosage imbalance.
Specimen part, Subject
View Samples