Mutations of the splicing factor U2AF1 are frequent in the myeloid malignancy myelodysplastic syndromes (MDS) and in other cancers. Patients with MDS suffer from peripheral blood cytopenias, including anemia, and increasing bone marrow blasts. We investigated the impact of the common U2AF1 S34F mutation on cellular function and mRNA splicing in the main cell lineages affected in MDS. We demonstrated that U2AF1 S34F expression in human hematopoietic progenitors impairs erythroid differentiation, and skews granulomonocytic differentiation towards granulocytes. RNA-sequencing of erythroid and granulomonocytic colonies revealed that U2AF1 S34F induced a higher number of cassette exon splicing events in granulomonocytic than erythroid cells, and altered mRNA splicing of many transcripts (expressed in both cell types) in a lineage-specific manner. The introduction of isoform changes identified in the target genes H2AFY and STRAP into hematopoietic progenitors recapitulated phenotypes associated with U2AF1 S34F expression in erythroid and/or granulomonocytic cells, suggesting a causal link. Importantly, we provided evidence showing that isoform modulation of the U2AF1 S34F target genes H2AFY and STRAP rescues the erythroid differentiation defect in U2AF1 S34F MDS cells, raising the possibility of using splicing modulators therapeutically. These data have critical implications for understanding MDS phenotypic heterogeneity, and for the development of new targeted therapies. Overall design: RNA sequencing was performed to identify the aberrant splicing events associated with U2AF1 S34F mutation (n=3) compared to U2AF1 wild-type (n=3) and empty vector control (n=3) in BFU-E and CFU-G/M colonies respectively.
The U2AF1S34F mutation induces lineage-specific splicing alterations in myelodysplastic syndromes.
Subject
View SamplesGene expression analysis of purified endothelial cells (Ecs), mesenchymal stem cells (MSCs) and mononuclear cells (MNCs) from wild-type and Flt3-ITD knock-in mice. Overall design: Differentially expressed genes analysis of haematopoietic and niche cell populations from Flt3-ITD mice
Niche-mediated depletion of the normal hematopoietic stem cell reservoir by Flt3-ITD-induced myeloproliferation.
No sample metadata fields
View SamplesIn this randomised placebo-controlled trial, irritable bowel syndrome (IBS) patients were treated with faecal material from a healthy donor (n=8, allogenic FMT) or with their own faecal microbiota (n=8, autologous FMT). The faecal transplant was administered by whole colonoscopy into the caecum (30 g of stool in 150 ml sterile saline). Two weeks before the FMT (baseline) as well as two and eight weeks after the FMT, the participants underwent a sigmoidoscopy, and biopsies were collected at a standardised location (20-25 cm from the anal verge at the crossing with the arteria iliaca communis) from an uncleansed sigmoid. In patients treated with allogenic FMT, predominantly immune response-related genes sets were induced, with the strongest response two weeks after FMT. In patients treated with autologous FMT, predominantly metabolism-related gene sets were affected.
Allogenic Faecal Microbiota Transfer Induces Immune-Related Gene Sets in the Colon Mucosa of Patients with Irritable Bowel Syndrome.
Age, Specimen part, Subject
View SamplesSF3B1, SRSF2 and U2AF1 are the most frequently mutated splicing factor genes in MDS. We have performed a comprehensive analysis to determine the impact of these commonly mutated splicing factors on pre-mRNA splicing in the stem/progenitor cells and in the erythroid and myeloid precursors in splicing factor mutant MDS. Using RNA-seq, we determined the aberrantly spliced genes and dysregulated pathways in bone marrow CD34+ cells of a large group of 82 MDS patients. Splicing factor mutations in MDS result in different mechanistic alterations in splicing and largely affect different genes, but these converged in common dysregulated pathways and cellular processes, including RNA splicing, translation and mitochondrial dysfunction, indicating that these mutations operate through common mechanisms in MDS. Many of these dysregulated pathways and cellular processes can be linked to the known disease pathophysiology and to the phenotypes associated with splicing factor mutations in MDS, whilst several others have not been previously associated with MDS, such as sirtuin signalling. Overall design: RNA-sequencing was performed on bone marrow CD34+ hematopoeitic stem and progenitor cells from patients with myelodysplastic syndrome and healthy controls to identify differential splicing between samples with mutations in the splicing factor SF3B1, SRSF2 or U2AF1 comparative to samples from myelodysplactic syndrome patients without mutations in these splicing factors and healthy controls. Processed data for the CD34+ hematopoeitic stem and progenitor cells are available in the files: CPM_table.txt.gz, Count_table.txt.gz and TPM_table.txt.gz. RNA-sequencing was also performed on monocytic, granulocytic and erythroid precursors from the bone marrow of patients with myelodysplastic syndrome and healthy controls to identify aberrant splicing in samples with mutations in splicing factors SF3B1 and SRSF2 comparative from healthy controls. Processed data for the monocytic, granulocytic and erythroid precursors are available in the files: CPM_table_fractions.txt, Count_table_fractions.txt and TPM_table_fractions.txt.
Impact of spliceosome mutations on RNA splicing in myelodysplasia: dysregulated genes/pathways and clinical associations.
Specimen part, Disease, Subject
View SamplesEstablishment of an in vitro system to explore molecular mechanisms of mastitis susceptibility in cattle by comparative expression profiling of Escherichia coli and Staphylococcus aureus inoculated primary cells sampled from cows with different genetic predisposition for somatic cell score
Comparative expression profiling of E. coli and S. aureus inoculated primary mammary gland cells sampled from cows with different genetic predispositions for somatic cell score.
Disease, Treatment, Time
View SamplesGoal of this study is to identify the transcriptome of human male germ cell subtypes during normal spermatogenesis as a reference for subfertility.
Unraveling transcriptome dynamics in human spermatogenesis.
No sample metadata fields
View SamplesDecreased bile secretion in rodents by either ligation of the common bile duct or induction of cirrhosis causes changes in the small intestine, including bacterial overgrowth and translocation across the mucosal barrier. Oral administration of bile acids inhibits these effects. The genes regulated by FXR in ileum suggested that it might contribute to the enteroprotective actions of bile acids. To test this hypothesis, mice were administered either GW4064 or vehicle for 2 days and then subjected to bile duct ligation (BDL) or sham operation. After 5 days, during which GW4064 or vehicle treatment was continued, the mice were killed and their intestines were analyzed for FXR target gene expression.
Regulation of antibacterial defense in the small intestine by the nuclear bile acid receptor.
Sex, Treatment
View SamplesObstruction of bile flow results in bacterial proliferation and mucosal injury in the small intestine that can lead to the translocation of bacteria across the epithelial barrier and systemic infection. These adverse effects of biliary obstruction can be inhibited by administration of bile acids. Here we show that the farnesoid X receptor (FXR), a nuclear receptor for bile acids, induces genes involved in enteroprotection and inhibits bacterial overgrowth and mucosal injury in ileum caused by bile duct ligation. Mice lacking FXR have increased ileal levels of bacteria and a compromised epithelial barrier. These findings reveal a central role for FXR in protecting the distal small intestine from bacterial invasion and suggest that FXR agonists may prevent epithelial deterioration and bacterial translocation in patients with impaired bile flow. In this report we have examined the role of FXR in the ileum. We demonstrate that it plays a crucial role in preventing bacterial overgrowth and maintaining the integrity of the intestinal epithelium
Regulation of antibacterial defense in the small intestine by the nuclear bile acid receptor.
Sex, Compound
View SamplesThe study is relevant to an understanding of the forces that lead to sex differences in the brain and other somatic tissues. Many neural and psychiatric diseases affect men and women differently, so the understanding of sex differences in brain function impacts on our understanding of why the male and female brain differ in their susceptibility to disease.
Sex bias and dosage compensation in the zebra finch versus chicken genomes: general and specialized patterns among birds.
No sample metadata fields
View SamplesThe study is relevant to an understanding of the forces that lead to sex differences in the brain. Many neural and psychiatric diseases affect men and women differently, so the understanding of sex differences in brain function impacts on our understanding of why the male and female brain differ in their susceptibility to disease.
Sex bias and dosage compensation in the zebra finch versus chicken genomes: general and specialized patterns among birds.
No sample metadata fields
View Samples