Canonical Wnt signalling regulates the self-renewal of most if not all stem cell systems. In the blood system, the role of Wnt signalling has been subject of much debate, with positive and negative roles of Wnt signalling proposed for hematopoietic stem cells (HSC). As we have shown previously, this controversy can be largely explained by the effects of different dosages of Wnt signalling. What remained unclear however, was why high Wnt signals would lead to loss of reconstituting capacity. To better understand this phenomenon, we have taken advantage of a series of hypomorphic mutant Apc alleles resulting in a broad range of Wnt dosages in HSCs, purified those HSCs and performed whole genome gene expression analyses. Gene expression profiling and functional studies show that HSCs with APC mutations lead to high Wnt levels , enhanced differentiation and diminished proliferation, but have no effect on apoptosis, collectively leading to loss of stemness. Thus, we provide mechanistic insight into the role of APC mutations and Wnt signalling in HSC biology. As Wnt signals are explored in various in vivo and ex vivo expansion protocols for HSCs, our findings also have clinical ramifications.
High Levels of Canonical Wnt Signaling Lead to Loss of Stemness and Increased Differentiation in Hematopoietic Stem Cells.
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View SamplesAdipose stroma in the mouse mammary gland undergoes remodeling throughout the 5 stages of development. These include nulliparous (virgin;never been pregnant), pregnant, lactating, involuting and regressed.
Pregnancy-associated breast cancers are driven by differences in adipose stromal cells present during lactation.
Specimen part
View SamplesMicroarrays were used to determine relative global gene expression changes in WT and BRCA1-mutation carrier breast epithelium as well as tumors created from WT and BRCA1-mutation carrier breast epithelial cells.
Genetic predisposition directs breast cancer phenotype by dictating progenitor cell fate.
Specimen part, Disease, Disease stage
View SamplesThe brain renin-angiotensin system (RAS) stimulates resting metabolic rate in part through a mechanism involving suppression of the circulating RAS. This effect appears to be mediated through a reduction in angiotensin AT2 receptor (AT2R) signaling within inguinal fat. To examine the molecular mechanisms underlying this effect, mice with hyperactivity of the brain RAS (“sRA” mice, expressing human renin via the synapsin promoter and human angiotensinogen via its own promoter) and littermate controls were chronically infused with vehicle or the AT2R specific agonist, CGP-42112a (CGP, 90 ng/hr, 8 wk, sc). To identify altered signaling pathways, total RNA was isolated from inguinal adipose tissue and transcript abundance was quantitated by RNA-Seq. Overall design: Four groups of mice were studied: controls receiving either a saline infusion (CON) or a specific angiotensin type 2 receptor agonist (CON_CGP), transgenic mice with specific activation of the brain renin-angiotensin receiving either a saline infusion (SRA) or a specific angiotensin type 2 receptor agonist (SRA_CGP). A sample size of N=3-4 was used for each of the four groups.
Suppression of Resting Metabolism by the Angiotensin AT2 Receptor.
Sex, Specimen part, Cell line, Subject
View SamplesWe used a whole genome approach to identify major functional gene categories (including xenobiotic transporters and metabolizing enzymes) whose expression depends on gestational age. STUDY DESIGN: We compared gene expression profiles of 1st (45-59 days) and 2nd trimester (109-115 days), and C-section term placentae. RESULTS: In 1st trimester placentae, genes related to cell cycle, DNA, aminoacids and carbohydrate metabolism were significantly overrepresented, while genes related to signal transduction were downregulated. In the organism defense category, we identified genes involved in chemical response, metabolism, and transport. Analysis of signal transduction pathways suggested, and subsequently confirmed independently, that the Wnt pathway was regulated by gestational age. CONCLUSIONS: Our study will serve as a reference database to gain insight into the regulation of gene expression in the developing placentae and, thus, allow comparisons with placentae from complicated pregnancies such as those in women experiencing gestational diabetes, pre-eclampsia and teratogenic sequelae.
Profiling gene expression in human placentae of different gestational ages: an OPRU Network and UW SCOR Study.
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View SamplesExon usage analysis in in vitro cultured fibroblast cells. To assay the genome-wide splicing changes during cellular senescence, we performed splicing analysis on young and old normal fibroblasts, and in fibroblasts +/- tert (telomerase protein subunit Tert immortalized).
Progerin and telomere dysfunction collaborate to trigger cellular senescence in normal human fibroblasts.
Specimen part, Disease, Disease stage, Subject
View SamplesThe goal of this study is to investigate if endogenous RNA in exosomes activates RIG-I through unshielding. Overall design: transcription profiling of exosomal RNA isolated from breast cancer patients before, during and after radiation therapy.
Exosome RNA Unshielding Couples Stromal Activation to Pattern Recognition Receptor Signaling in Cancer.
Subject
View SamplesThe goal of this study is to investigate if endogenous RNA in exosomes activates RIG-I through unshielding. Overall design: transcription profiling for exosomal RNA isolated from stroma cell (MRC5) or stroma/breast cancer cell co-culture (MRC5 and 1833).
Exosome RNA Unshielding Couples Stromal Activation to Pattern Recognition Receptor Signaling in Cancer.
Cell line, Subject
View SamplesNetworks of coordinated alternative splicing (AS) events play critical roles in development and disease. However, a comprehensive knowledge of the factors that regulate these networks is lacking. We describe a high-throughput system for systematically linking trans-acting factors to endogenous RNA regulation events. Using this system, we identify hundreds of factors associated with diverse regulatory layers that positively or negatively control AS events linked to cell fate. Remarkably, more than one third of the new regulators are transcription factors. Further analyses of the zinc finger protein Zfp871 and BTB/POZ domain transcription factor Nacc1, which regulate neural and stem cell AS programs, respectively, reveal roles in controlling the expression of specific splicing regulators. Surprisingly, these proteins also appear to regulate target AS programs via binding RNA. Our results thus uncover a large ‘missing cache’ of splicing regulators among annotated transcription factors, some of which dually regulate AS through direct and indirect mechanisms. Overall design: RNA-Seq of N2A cells upon RNAi-mediated knockdown of Mbnl1/Mbnl2 or Nacc1, or control knockdown (1 replicate each), as well as upon knockdown of Srrm4 or Zfp871, or control knockdown (2 replicates each) vast-tools.AltSplicing_Mbnl.Nacc1.tab: Primary vast-tools output for Mbnl and Nacc1 knockdowns vast-tools.AltSplicing_Srrm4.Zfp871.tab: Primary vast-tools output for Srrm4 and Zfp871 knockdowns AltSplicing_Mbnl.Nacc1.tab: Filtered PSI values and differential AS annotation for Mbnl and Nacc1 knockdowns AltSplicing_Srrm4.Zfp871.tab: Filtered PSI values and differential AS annotation for Srrm4 and Zfp871 knockdowns Expression_Mbnl.Nacc1.tab: Raw and read counts per gene, normalized expression and fold-change for Mbnl and Nacc1 knockdowns Expression_Srrm4.Zfp871.tab: Raw read counts per gene, normalized expression and fold-change (edgeR analysis) for Srrm4 and Zfp871 knockdowns
Multilayered Control of Alternative Splicing Regulatory Networks by Transcription Factors.
Cell line, Subject
View SamplesUnrestrained receptor tyrosine kinase (RTK) signaling and epigenetic deregulation are root causes of tumorigenesis. We establish linkage between these processes by demonstrating that aberrant RTK signaling unleashed by oncogenic HRasG12V or loss of negative feedback through Sprouty gene deletion remodels histone modifications associated with active typical and super-enhancers. However, while both lesions disrupt the Ras-Erk axis, the expression programs, enhancer signatures, and transcription factor networks modulated upon HRasG12V-transformation or Sprouty deletion are largely distinct. Oncogenic HRasG12V elevates histone 3 lysine 27 acetylation (H3K27ac) levels at enhancers near the transcription factor Gata4 and the kinase Prkcb, as well as their expression levels. We show that Gata4 is necessary for the aberrant gene expression and H3K27ac marking at enhancers, and Prkcb is required for the oncogenic effects of HRasG12V-driven cells. Taken together, our findings demonstrate that dynamic reprogramming of the cellular enhancer landscape is a major effect of oncogenic RTK signaling. Overall design: We assessed gene expression changes upon loss of feedback regulation through Sprouty (Spry) deletion, and upon unrestrained signaling driven by mutant oncogenes. RNA-seq was performed in biological triplicate; replicate number is included in the sample name. Spry124fl/fl (VEC) and Spry124-/- (CRE) MEFs were profiled in three conditions: unsynchronized (U), serum starved (S), and serum starved and FGF treated (F). Spry124fl/fl (VEC) MEFs transduced with empty vector (EV) control or the indicated oncogenes (KRasG12V, HRasG12V, and BRafV600E) as well as Spry124-/- (CRE) MEFs transduced with EV control were profiled in the unsynchronized state.
Deregulation of the Ras-Erk Signaling Axis Modulates the Enhancer Landscape.
No sample metadata fields
View Samples