This SuperSeries is composed of the SubSeries listed below.
Human fetal hemoglobin expression is regulated by the developmental stage-specific repressor BCL11A.
No sample metadata fields
View SamplesDifferences in the amount of fetal hemoglobin (HbF) that persists into adulthood affect the severity of sickle cell disease and the beta-thalassemia syndromes. Genetic association studies have identified sequence variants in the gene BCL11A that influence HbF levels. Here we examine BCL11A as a potential regulator of HbF expression. The high HbF BCL11A genotype is associated with reduced BCL11A expression. Moreover, abundant expression of full-length forms of BCL11A is developmentally restricted to adult erythroid cells. Down-regulation of BCL11A expression in primary adult erythroid cells leads to robust HbF expression. Consistent with a direct role of BCL11A in globin gene regulation, we find that BCL11A occupies several discrete sites in the beta-globin gene cluster. BCL11A emerges as a therapeutic target for reactivation of HbF in beta-hemoglobin disorders.
Human fetal hemoglobin expression is regulated by the developmental stage-specific repressor BCL11A.
No sample metadata fields
View SamplesDifferences in the amount of fetal hemoglobin (HbF) that persists into adulthood affect the severity of sickle cell disease and the beta-thalassemia syndromes. Genetic association studies have identified sequence variants in the gene BCL11A that influence HbF levels. Here we examine BCL11A as a potential regulator of HbF expression. The high HbF BCL11A genotype is associated with reduced BCL11A expression. Moreover, abundant expression of full-length forms of BCL11A is developmentally restricted to adult erythroid cells. Down-regulation of BCL11A expression in primary adult erythroid cells leads to robust HbF expression. Consistent with a direct role of BCL11A in globin gene regulation, we find that BCL11A occupies several discrete sites in the beta-globin gene cluster. BCL11A emerges as a therapeutic target for reactivation of HbF in beta-hemoglobin disorders.
Human fetal hemoglobin expression is regulated by the developmental stage-specific repressor BCL11A.
No sample metadata fields
View SamplesWhile gene expression dynamics have been extensively catalogued during hematopoietic differentiation in the adult, less is known about transcriptome diversity of human hematopoietic stem cells (HSCs) during development. To characterize transcriptional and post-transcriptional changes in HSCs during development, we leveraged high-throughput genomic approaches to profile miRNAs, lincRNAs, and mRNAs. Our findings indicate that HSCs manifest distinct alternative splicing patterns in key hematopoietic regulators. Detailed analysis of the splicing dynamics and function of one such regulator, HMGA2, identified an alternative isoform that escapes miRNA-mediated targeting. We further identified the splicing kinase CLK3 that, by regulating HMGA2 splicing, preserves HMGA2 function in the setting of an increase in let-7 miRNA levels, delineating how CLK3 and HMGA2 form a functional axis that influences HSC properties during development. Collectively, our study highlights molecular mechanisms by which alternative splicing and miRNA-mediated post-transcriptional regulation impact the molecular identity and stage-specific developmental features of human HSCs. Overall design: RNA-seq of HPC-5F cells transduced with a control (CTRL), HMGA2-L (LONG), HMGA2-S (SHORT) or CLK3 ORF lentiviral over-expression vectors.
A CLK3-HMGA2 Alternative Splicing Axis Impacts Human Hematopoietic Stem Cell Molecular Identity throughout Development.
Specimen part, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Stabilization of the promoter nucleosomes in nucleosome-free regions by the yeast Cyc8-Tup1 corepressor.
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View SamplesFirst experiment: Cells were cultured in sulfur amino acid-free DMEM supplemented with 0.1 mM methionine + 0.1 mM cysteine (complete) or supplemented only with 0.1 mM methionine (cysteine-free). Cells were cultured in either medium for 42 h (Long + Cys; Long -Cys) or in cysteine-free medium for 36 h followed by 6 h in complete medium (Short +Cys)
HepG2/C3A cells respond to cysteine deprivation by induction of the amino acid deprivation/integrated stress response pathway.
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View SamplesThe yeast Ssn6-Tup1 complex regulates gene expression through a variety of mechanisms, including positioning of nucleosomes over promoters of some target genes to limit accessibility to the transcription machinery. To further define the functions of Ssn6-Tup1 in gene regulation and chromatin remodeling, we performed genome-wide profiling of changes in nucleosome organization and gene expression that occur upon loss of SSN6 or TUP1, and observed extensive nucleosome alterations in both promoters and gene bodies of derepressed genes. Our improved nucleosome profiling and analysis approaches revealed low-occupancy promoter nucleosomes (P nucleosomes) at locations previously defined as nucleosome-free regions. In the absence of SSN6 or TUP1, this P nucleosome is frequently lost, whereas nucleosomes are gained at -1 and +1 positions, accompanying up-regulation of downstream genes. Our analysis of public ChIP-seq data revealed that Ssn6 and Tup1 preferentially bind TATA-containing promoters, which are also enriched in genes derepressed upon loss of SSN6 or TUP1. These results suggest that stabilization of the P nucleosome on TATA-containing promoters may be a central feature of the repressive chromatin architecture created by the Ssn6-Tup1 corepressor, and that releasing the P nucleosome contributes to gene activation.
Stabilization of the promoter nucleosomes in nucleosome-free regions by the yeast Cyc8-Tup1 corepressor.
No sample metadata fields
View SamplesHepG2/C3A cells cultured for 42 h in complete or leucine-devoid medium
HepG2/C3A cells respond to cysteine deprivation by induction of the amino acid deprivation/integrated stress response pathway.
No sample metadata fields
View SamplesLeanness is associated with increased lifespan and is linked to favorable metabolic conditions promoting life extension.
Deficiency of the lipid synthesis enzyme, DGAT1, extends longevity in mice.
Sex, Specimen part
View SamplesMultipotent and pluripotent stem cells have significant potential as sources for cell replacement therapies. However, the low yield and quality of in vitro differentiated cells produced from various stem cell sources presents a significant limitation for therapeutic applications. The most mature use of these stem cell products is in the field of transfusion medicine, where stem cell-derived red blood cells (RBCs) have clinically-proven potential as alternative transfusion products. To improve upon current approaches for RBC production, we used insight from both common and rare human genetic variation of blood counts to focus on the SH2B3 gene. By producing loss of function of SH2B3 using targeted knockdown and genome editing approaches in human hematopoietic stem and progenitor cells, as well as human pluripotent stem cells, we are able to significantly improve both the quality and yield of in vitro derived RBCs. We illustrate how insight from human genetic variation can assist in the development of broadly applicable approaches that have tremendous value for regenerative medicine.
Targeted Application of Human Genetic Variation Can Improve Red Blood Cell Production from Stem Cells.
Specimen part
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