Precise spatiotemporal regulation of genetic programs, driven by cellspecific super-enhancers, is paramount for the function of cell lineages. Studies have suggested that insulated neighborhoods, formed by the zincfinger protein CTCF, sequester genes and their associated enhancers thus preventing them from trespassing on off-target genes. Although this could explain the enhancer-gene-specificity conundrum, there is limited genetic evidence that the search space of cell-specific super-enhancers is constrained by CTCF. We have addressed this question in the Wap locus with its exceptional mammary-specific super-enhancer, which is separated by five CTCF sites from neighboring genes. Three of these sites are positioned between the Wap super-enhancer and the widely expressed Ramp3. Enhancer deletions demonstrated that the Wap super-enhancer controls Ramp3 expression despite the presence of three parting CTCF sites. Individual and combinatorial deletions of these CTCF sites revealed cell-specific functions of the conserved anchor site. Although unable to block super-enhancer activity, it muffled its impact on Ramp3 in mammary tissue. Unexpectedly, this CTCF site was obligatory for Ramp3 expression in cerebellum, suggesting the coinciding presence of regulatory elements. While our results suggest a surprisingly limited in vivo role for a CTCF anchor in blocking a mammary-specific super-enhancer, they also implicate this site in cerebellum-specific gene activation. Our study illustrates additional complexities of CTCF sites supporting tissue-specific functions. Overall design: Total RNA-seq was done for mammary tissue at pregnancy day 18.
Facultative CTCF sites moderate mammary super-enhancer activity and regulate juxtaposed gene in non-mammary cells.
Specimen part, Cell line, Subject
View SamplesTransciptome analysis of CD34+ enriched human HSPC lentivirally transduced with cohesin WT or mutant
Leukemia-Associated Cohesin Mutants Dominantly Enforce Stem Cell Programs and Impair Human Hematopoietic Progenitor Differentiation.
Specimen part
View SamplesGene expression in placenta from 5 smoking and 5 non-smoking mothers analyzed by Affymetrix Hg133_plus2 microarrays.
Microarray analysis of the global alterations in the gene expression in the placentas from cigarette-smoking mothers.
No sample metadata fields
View SamplesUnderstanding the contribution of abnormal genetic and epigenetic programs to acute myeloid leukemia (AML) is necessary for the integrated design of targeted therapies. To investigate this, we determined the effect of epigenetic reprogramming on leukemic behavior by generating induced pluripotent stem cells (iPSCs) from AML patient samples harboring MLL rearrangements. AML-derived iPSCs (AML-iPSCs) retained leukemic mutations, but reset leukemic DNA methylation/gene expression patterns and lacked leukemic potential. However, when differentiated into hematopoietic cells, AML-iPSCs reacquired the ability to give rise to leukemia in vivo and reestablished leukemic methylation/gene expression patterns, including an aberrant MLL signature, indicating that epigenetic reprogramming was insufficient to eliminate leukemic behavior. In one case, we identified distinct AML-iPSC KRAS mutant and wildtype subclones that demonstrated differential growth properties and therapeutic susceptibilities, predicting KRAS wildtype clonal relapse due to increased cytarabine resistance. Increased cytarabine resistance was further observed in a cohort of KRAS wildtype MLL-rearranged AML samples, demonstrating the utility of AML-iPSCs in predicting subclonal relapse and facilitating clonal targeting in AML. Overall design: RNA seq profiling of normal and leukemic differentiated and iPSC populations
Human AML-iPSCs Reacquire Leukemic Properties after Differentiation and Model Clonal Variation of Disease.
Specimen part, Subject
View SamplesIn the diploid genome, genes come in two copies, which can have different DNA sequence and where one is maternal and one is paternal. In a particular cell, a gene could potentially be expressed from both copies (biallelic expression) or only one (monoallelic). We performed RNA-Sequencing on individual cells, from zygote to the cells of the late blastocyst, and also individual cells from the adult liver. Using first generation crosses between two distantly related mouse strains, CAST/Ei and C57BL/6, we determined the expression separately from the maternal and paternal alleles. We found that half of the genes were expressed by only one allele, randomly so that some cells would express the paternal allele, some the maternal and a few cell both alleles. We also observed the spread of the progressive inactivation of the paternal X chromosome. Overall design: First generation mouse strain crosses were used to study monoallelic expression on the single cell level
Single-cell RNA-seq reveals dynamic, random monoallelic gene expression in mammalian cells.
No sample metadata fields
View SamplesOne of the most common genetic alterations in acute myeloid leukemia is the internal tandem duplication (ITD) in the FLT3 receptor for cytokine FLT3 ligand (FLT3L). The constitutively active FLT3-ITD promotes the expansion of transformed progenitors, but also has pleiotropic effects on normal hematopoiesis. We analyzed the effect of FLT3-ITD on dendritic cells (DCs), which express FLT3 and can be expanded by FLT3L administration. We report that young pre-leukemic mice with the Flt3ITD knock-in allele manifest an expansion of all DCs including classical (cDCs) and plasmacytoid (pDCs). The expansion originated in DC progenitors, occurred in a cell-intrinsic manner and was further enhanced in Flt3ITD/ITD mice. The mutation caused the downregulation of Flt3 on the surface of DCs and reduced their responsiveness to Flt3L. Flt3ITD mice showed enhanced capacity to support T cell proliferation, including a cell-extrinsic expansion of regulatory T cells (Tregs). Accordingly, these mice restricted alloreactive T cell responses during graft-versus-host reaction, but failed to control autoimmunity in the absence of Tregs. Thus, the FLT3-ITD mutation directly affects DC development, thereby indirectly modulating T cell homeostasis and supporting Treg expansion. This effect of FLT3-ITD may subvert immunosurveillance and promote leukemogenesis in a cell-extrinsic manner. Overall design: Sorted splenic dendritic cell subsets from either Flt3+/+ or Flt3ITD/+ mice were sequenced for mRNA profiling. For each subset per genotype contains 2-3 replicates, all from independent experiments.
Leukemia-associated activating mutation of Flt3 expands dendritic cells and alters T cell responses.
Specimen part, Cell line, Subject
View SamplesMelasma is a commonly acquired hyperpigmentary disorder of the face, but its pathogenesis is poorly understood and its treatment remains challenging. We conducted a comparative histological study on lesional and perilesional normal skin to clarify the histological nature of melasma. Significantly, higher amounts of melanin and of melanogenesis-associated proteins were observed in the epidermis of lesional skin, and the mRNA level of tyrosinase-related protein 1 was higher in lesional skin, indicating regulation at the mRNA level. However, melanocyte numbers were comparable between lesional and perilesional skin. A transcriptomic study was undertaken to identify genes involved in the pathology of melasma. A total of 279 genes were found to be differentially expressed in lesional and perilesional skin. As was expected, the mRNA levels of a number of known melanogenesis-associated genes, such as tyrosinase, were found to be elevated in lesional skin. Bioinformatics analysis revealed that the most lipid metabolism-associated genes were downregulated in lesional skin, and this finding was supported by an impaired barrier function in melasma. Interestingly, a subset of Wnt signaling modulators, including Wnt inhibitory factor 1, secreted frizzled-related protein 2, and Wnt5a, were also found to be upregulated in lesional skin. Immunohistochemistry confirmed the higher expression of these factors in melasma lesions.
Transcriptional profiling shows altered expression of wnt pathway- and lipid metabolism-related genes as well as melanogenesis-related genes in melasma.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Promoter DNA methylation patterns of differentiated cells are largely programmed at the progenitor stage.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Epigenetic priming of inflammatory response genes by high glucose in adipose progenitor cells.
Specimen part
View SamplesWe surveyed DNA methylation profiles of all human RefSeq promoters in relation to gene expression and differentiation in adipose tissue, bone marrow and muscle mesenchymal progenitors, as well as in bone marrow-derived hematopoietic progenitors. We unravel strongly overlapping DNA methylation profiles between adipose stem cells (ASCs), bone marrow mesenchymal stem cells (BMMSCs) and muscle progenitor cells (MPCs), while hematopoietic progenitor cells (HPCs) are more epigenetically distant from MSCs seen as a whole. Differentiation resolves a fraction of methylation patterns common to MSCs, generating epigenetic divergence.
Promoter DNA methylation patterns of differentiated cells are largely programmed at the progenitor stage.
Specimen part
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