Increasing fetal hemoglobin (HbF) levels in adult red blood cells provides clinical benefit to patients with sickle cell disease and some forms of beta-thalassemia. To identify potentially druggable HbF regulators in adult human erythroid cells, we employed a protein kinase-domain focused CRISPR/Cas9-based genetic screen with a newly optimized sgRNA scaffold. The screen uncovered the heme-regulated inhibitor HRI (also known as EIF2AK1), an erythroid-specific kinase that controls protein translation, as an HbF repressor. HRI depletion markedly increased HbF production in a specific manner and reduced sickling in cultured erythroid cells. Diminished expression of the HbF repressor BCL11A accounted in large part for the effects of HRI depletion. Taken together, these results suggest HRI as a potential therapeutic target for hemoglobinopathies. Overall design: A CRISPR-screen reveals HRI kinase as a fetal hemoglobin repressor and further validated in HUDEP2 and CD34+ derived primary erythroid cultures.
Domain-focused CRISPR screen identifies HRI as a fetal hemoglobin regulator in human erythroid cells.
Specimen part, Disease, Subject
View SamplesTo investigate the epigenetic landscape at the interface between mother and fetus, we provide a comprehensive analysis of parent of origin bias in the placenta. Using F1 interspecies hybrids, we sequenced RNA from 23 individual midgestation placentas, five late stage placentas, and two yolk sac samples and then used SNPs to determine whether transcripts were preferentially generated from the maternal or paternal allele. In the placenta, we find 103 genes that show significant and reproducible parent-of-origin bias, of which 78 are novel candidates. Most (96%) show a strong maternal bias which, using multiple models, we demonstrate is not due to maternal decidual contamination. Analysis of the X chromosome also reveals paternal expression of Xist and several genes that escape inactivation, most significantly Rps4x, Fhl1, and Slc38a5. Finally, sequencing individual placentas allowed us to reveal notable expression similarity between littermates. In all, we observe a striking preference for maternal transcription in the midgestation mouse placenta and a dynamic imprinting landscape in extraembryonic tissues, reflecting the complex nature of epigenetic pathways in the placenta. Overall design: 3''-end Sequencing for Expression Quantification (3SEQ) and SNP Analysis to observe parent-of-origin bias in 28 placental samples at two time points and 2 yolk sac samples
Maternal bias and escape from X chromosome imprinting in the midgestation mouse placenta.
Specimen part, Subject
View SamplesWe profiled genome-wide gene expression of 170 individual mid-gestation (embryonic day 11.5) whole mouse embryos derived from a 2-generation interspecies mouse cross and asked to what extent genetic variation drives four important parameters of regulatory architecture: allele-specific expression (ASE), imprinting, trans-regulatory effects, and maternal effect. The inbred strain C57BL/6J and wild-derived inbred strain CAST/EiJ were used in reciprocal crosses to generate F1 embryos. F1 progeny were backcrossed to C57BL/6J in reciprocal crosses to generate 154 N2 embryos. We employed a backcross design, in which N2 offspring have genotypically distinct parents, to enable comparison of gene expression for offspring from each side of the reciprocal cross. Our findings demonstrate that genetic variation contributes to widespread gene expression differences during mammalian embryogenesis. Overall design: Transcriptome analysis of E11.5 mouse embryos: 16 F1 embryos from reciprocally crossed C57BL/6J and CastEi/J parents; and 154 N2 embryos from reciprocal backcross of F1s to the C57BL/6J parent.
Constraint and divergence of global gene expression in the mammalian embryo.
No sample metadata fields
View SamplesWe recently identified ISRIB as a potent inhibitor of the integrated stress response (ISR). ISRIB renders cells resistant to the effects of eIF2a phosphorylation and enhances long-term memory in rodents (10.7554/eLife.00498). Here we show by genome-wide in vivo ribosome profiling that translation of a restricted subset of mRNAs is induced upon ISR activation. ISRIB substantially reversed the translational effects elicited by phosphorylation of eIF2a and induced no major changes in translation or mRNA levels in unstressed cells. eIF2a phosphorylation-induced stress granule (SG) formation was blocked by ISRIB. Strikingly, ISRIB addition to stressed cells with pre-formed SGs induced their rapid disassembly, liberating mRNAs into the actively translating pool. Restoration of mRNA translation and modulation of SG dynamics may be an effective treatment of neurodegenerative diseases characterized by eIF2a phosphorylation, SG formation and cognitive loss. Overall design: Ribosome profiling with paired RNA-seq
The small molecule ISRIB reverses the effects of eIF2α phosphorylation on translation and stress granule assembly.
No sample metadata fields
View SamplesPlant compensatory responses depends on transcriptional reprogramming. We used microarray analysis to understand the differential gene expression pattern between clipped (herbivore browsed)
Overcompensation in response to herbivory in Arabidopsis thaliana: the role of glucose-6-phosphate dehydrogenase and the oxidative pentose-phosphate pathway.
Specimen part
View SamplesThe goal of this study is to measure Arabidopsis mRNA transcription and mRNA decay rates genome wide at two temperatures, and thus to calculate the temperature coefficient of both processes. Sensing and response to ambient temperature is important for controlling growth and development of many organisms, in part by regulating mRNA levels. mRNA abundance can change with temperature, but it is unclear whether this results from changes to transcription or decay rates and whether passive or active temperature regulation is involved. Results Using a base analogue labelling method we directly measured the temperature coefficient (Q10) of mRNA synthesis and degradation rates of the Arabidopsis transcriptome. We show that for most genes transcript levels are buffered against passive increases in transcription rates by balancing passive increases in the rate of decay. Strikingly, for temperature-responsive transcripts, increasing temperature raises transcript abundance primarily by promoting faster transcription relative to decay and not vice versa, suggesting a global transcriptional mechanism process exists for the activethat controls of mRNA abundance by temperature/
Direct measurement of transcription rates reveals multiple mechanisms for configuration of the Arabidopsis ambient temperature response.
Specimen part, Treatment, Time
View SamplesIn this study, using a Patient Derived Xenograft (PDX) system established by transplanting primary tumors from pre-metastatic breast cancer patients we demonstrate that development of distant organ metastases correlates with the presence of Bone Marrow Disseminated Tumor Cells (BM DTCs) in the PDX mice. Comparative gene expression analysis of bone marrow (BM) from tumor bearing PDX mice which developed metastatic disease was carried out with BM from non-tumor bearing controls.
Identifying biomarkers of breast cancer micrometastatic disease in bone marrow using a patient-derived xenograft mouse model.
Specimen part
View SamplesmRNA expression in the spinal cords of the G93A-SOD1 familial ALS transgenic mouse model was compared to that in nontransgenic (Normal mouse) and transgenic mice expressing wild-type (WT)SOD1. Gene Ontology (GO)analysis was used to characterize differences in expression between G93A-SOD1 mouse and nontransgenic mouse spinal cord. Changes in multiple GO categories were found. Many of these were associated with subsystems involving cell-cell communication and intracellular signal transduction. Expression profiles of mice expressing WT-SOD1 did not differ from nontransgenic mice. In contrast, protein profiling using proteomics technology indicated changes in mitochondrial protein expression in the G93A-SOD1 mouse spinal cord that were not found in the mRNA expression analysis.
Informatics-assisted protein profiling in a transgenic mouse model of amyotrophic lateral sclerosis.
Age
View SamplesIntroduction: Mechanisms that contribute to the pathogenesis of liver damage caused by hepatitis C virus (HCV) are not fully understood. Our previous work on liver biopsies from chronic HCV patients has shown modulation of the expression of certain cell cycle proteins indicating HCV-induced modifications of cell cycle events. We therefore hypothesize that HCV infection disrupts normal regulation of cell cycle that contributes to disease progression. Objective: To identify molecular disruptions during the course of HCV-associated disease progression, using liver biopsy specimens of chronic hepatitis C patients. Methods: Liver biopsy samples classified on histological basis as early (fibrosis stage 0-1) or advanced (fibrosis stage 3-4) disease stage were studied using oligonucleotide array ( HG U133 Plus 2.0, Affymetrix GeneChip System). For comparison, liver specimens from patients with non-viral hepatitis were also analyzed by microarray. Expression data was analyzed using Genespring (GX 7.2) and Ingenuity Pathway analysis (3.0). The differential expression of selected cell cycle genes (cyclin D2, KPNA2, HERC5 and Bcl-2) identified after microarray analysis was confirmed by quantitative real-time RT-PCR. Results: Microarray analysis revealed two-fold or greater transcriptional change in 792 genes of the total 38,500 known human genes in HCV-advance disease stage (HCV-A) as compared to HCV-early disease stage (HCV-E). Most of the genes have a defined role in immune response, extracellular matrix and cell cycle and apoptosis.
Gene profiling of early and advanced liver disease in chronic hepatitis C patients.
Specimen part, Disease, Disease stage
View SamplesInduced pluripotent stem cells (iPSCs) have been generated from various somatic cells under feeder-layer conditions. These feeder-derived iPSCs generated in different labs exhibit greater variability than between different traditional embryo derived hESC lines. For that reason, it is important to develop a standard and defined system for deriving autologous patient stem cells. We have generated iPSCs under feeder-free conditions using Matrigel coated vessels in chemically defined medium, mTeSR1. These feeder-free derived iPSCs are in many ways similar to feeder-derived iPSCs and also to hESCs, with respect to their pluripotent gene expression (OCT4, NANOG, SOX2), protein expression (OCT4, NANOG, SSEA4, TRA160) and differentiation capabilities.
Human induced pluripotent stem cells derived under feeder-free conditions display unique cell cycle and DNA replication gene profiles.
Specimen part
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