Myocardial infarction (MI) often results in left ventricular (LV) remodeling followed by heart failure (HF). It is of great clinical importance to understand the molecular mechanisms that trigger transition from compensated LV injury to HF and to identify relevant diagnostic biomarkers. In this study, we performed transcriptional profiling of LVs in rats with a wide range of experimentally induced infarct sizes and of peripheral blood mononuclear cells (PBMCs) in animals that developed HF.
Transcriptional profiling of left ventricle and peripheral blood mononuclear cells in a rat model of postinfarction heart failure.
Specimen part
View SamplesMechanical forces are essential for normal fetal lung development. However, the cellular and molecular mechanisms regulating this process remain largely unknown. In the present study, we used oligonucleotide microarray technology to investigate gene expression profile in cultured E19 rat fetal lung type II epithelial cells exposed to a level of mechanical strain similar to that observed in utero. Significance Analysis of Microarrays (SAM) identified 92 genes differentially expressed by strain. Interestingly, several members of the solute carrier family of amino acid transporters, genes involved in amino acid synthesis and development, and amiloride-sensitive epithelial sodium channel gene were induced by strain. These results were confirmed by quantitative real-time polymerase chain reaction (qRT-PCR). Thus, this study identifies genes induced by strain that may be important for amino acid signaling pathways, protein synthesis and development in fetal type II cells. In addition, these data suggest that mechanical forces may contribute to facilitate lung fluid reabsorption in preparation for birth. Taken together, the present investigation provides further insights into how mechanical forces may modulate fetal lung development.
DNA microarray reveals novel genes induced by mechanical forces in fetal lung type II epithelial cells.
Sex, Specimen part
View SamplesHeart failure (HF) is the most common cause of morbidity and mortality in the developed countries, especially considering the present demographic tendencies in those populations.
Gene expression profiling reveals potential prognostic biomarkers associated with the progression of heart failure.
Specimen part
View SamplesDespite a substantial progress in diagnosis and therapy, acute myocardial infarction (MI) is a major cause of mortality in the general population. A novel insight into the pathophysiology of myocardial infarction obtained by studying gene expression should help to discover novel biomarkers of MI and to suggest novel strategies of therapy. The aim of our study was to establish gene expression patterns in leukocytes from acute myocardial infarction patients.
Altered gene expression pattern in peripheral blood mononuclear cells in patients with acute myocardial infarction.
Specimen part, Subject
View SamplesWe identify sites of combinatorial control by performing high throughput ChIP experiments on p300, CREB-binding protein (CBP), the deacetylase SIRT1 and on multiple DNA-binding transcription factors in three different tissues. We present a quantitative model of transcriptional regulation that reveals the contribution of each binding site to tissue-specific gene expression in several mouse cell types. Binding to both evolutionarily conserved and non-conserved sequences is found to contribute significantly to transcriptional regulation. We demonstrate that binding location strongly predicts the expression level of nearby genes.
A quantitative model of transcriptional regulation reveals the influence of binding location on expression.
Specimen part
View SamplesChromosome 5q deletions (del(5q)) are common in high-risk (HR) Myelodysplastic Syndrome (MDS) and Acute Myeloid Leukemia (AML); however, the gene regulatory networks that sustain these aggressive diseases are unknown. Reduced miR-146a expression in del(5q) HR-MDS/AML and miR-146a-/- hematopoietic stem/progenitor cells (HSPC) results in TRAF6/NF- activation. Increased survival and proliferation of HSPC from miR-146alow HR-MDS/AML is sustained by a neighboring haploid gene, SQSTM1 (p62), expressed from the intact 5q allele. Overexpression of p62 from the intact allele occurs through NF-B-dependent feedforward signaling mediated by miR-146a deficiency. p62 is necessary for TRAF6-mediated NF-B signaling, as disrupting the p62-TRAF6 signaling complex results in cell cycle arrest and apoptosis of MDS/AML cells. Thus, del(5q) HR-MDS/AML employs an intrachromosomal gene network involving loss of miR-146a and haploid overexpression of p62 via NF-B to sustain TRAF6/NF-B signaling for cell survival and proliferation. Interfering with the p62-TRAF6 signaling complex represents a therapeutic option in miR-146a-deficient and aggressive del(5q) MDS/AML.
Myeloid malignancies with chromosome 5q deletions acquire a dependency on an intrachromosomal NF-κB gene network.
Sex, Specimen part
View SamplesFollow-up work was performed for SF3A2, a gene among the hits identified in a red blood cell trait GWAS-informed shRNA screen. Differential splicing effects were assayed to investigate resulting effects on the differentiating erythroid cell spliceome and explore potential modifier relationships with other known splicing defects associated with human disease. Overall design: Examination of differential splicing events resulting from knockdown of splicing factor 3a subunit 2 (SF3A2) in three unique donor CD34+ cells populations undergoing erythroid differentiation. Two shRNA targeting SF3A2 were tested, along with a negative control shRNA targeting luciferase (which should not be expressed) using paired-end sequencing.
Gene-centric functional dissection of human genetic variation uncovers regulators of hematopoiesis.
Specimen part, Subject
View SamplesCohesin complex members have recently been identified as putative tumor suppressors in hematologic and epithelial malignancies. The cohesin complex guides chromosome segregation, however cohesin-mutant leukemias do not show genomic instability. We hypothesized reduced cohesin function alters chromatin structure and disrupts cis-regulatory architecture of hematopoietic progenitors. We investigated the consequences of Smc3 deletion in normal and malignant hematopoiesis. Bi-allelic Smc3 loss induced bone marrow aplasia with premature sister chromatid separation, and revealed an absolute requirement for cohesin in hematopoietic stem cell function. In contrast, Smc3 haploinsufficiency increased self-renewal in vitro and in vivo including competitive transplantation. Smc3 haploinsufficiency reduced coordinated transcriptional output, including reduced expression of transcription factors and other genes associated with lineage commitment. Smc3 haploinsufficiency cooperated with Flt3-ITD to induce acute leukemia in vivo, with potentiated Stat5 signaling and altered nucleolar topology. These data establish a dose-dependency for cohesin in regulating chromatin structure and hematopoietic stem cell function. Overall design: mRNA-seq in murine c-kit+ cells for the following genotypes: Smc3 fl/+, Smc3 del/+, Flt3-ITD, Smc3 fl/del Flt3-ITD
Dose-dependent role of the cohesin complex in normal and malignant hematopoiesis.
Specimen part, Subject
View SamplesThe splicing factor SF3B1 is the most commonly mutated gene in the myelodysplastic syndromes (MDS), particularly in patients with refractory anemia with ring sideroblasts (RARS). MDS is a disorder of the hematopoietic stem cell and we thus studied the transcriptome of CD34+ cells from MDS patients with SF3B1 mutations using RNA-sequencing. Genes significantly differentially expressed at the transcript and/or exon level in SF3B1 mutant compared to wildtype cases include genes involved in MDS pathogenesis (ASXL1, CBL), iron homeostasis and mitochondrial metabolism (ALAS2, ABCB7, SLC25A37) and RNA splicing/processing (PRPF8, HNRNPD). Many genes regulated by a DNA damage-induced BRCA1-BCLAF1-SF3B1 protein complex showed differential expression/splicing in SF3B1 mutant cases. Our data indicate that SF3B1 plays a critical role in MDS by affecting the expression and splicing of genes involved in specific cellular processes/pathways, many of which are relevant to the known RARS pathophysiology, suggesting a causal link. Overall design: RNA-Seq was performed to compare the transcriptome of bone marrow CD34+ cells from eight MDS patients with SF3B1 mutation, four MDS patients with no known splicing mutation and five healthy controls.
Disruption of SF3B1 results in deregulated expression and splicing of key genes and pathways in myelodysplastic syndrome hematopoietic stem and progenitor cells.
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View SamplesGene expression analysis on purified human long-term hematopoietic stem cells (LT-HSC; CD34+CD38-CD90+) and short-term HSC (ST-HSC; CD34+CD38-CD90-) derived from healthy control patients and patients with myelodysplastic syndrome (MDS)
Stem and progenitor cells in myelodysplastic syndromes show aberrant stage-specific expansion and harbor genetic and epigenetic alterations.
Specimen part, Disease, Disease stage
View Samples