The bHLH transcription factor stem cell leukemia gene (Scl) is a master regulator for hematopoiesis essential for hematopoietic specification and proper differentiation of the erythroid and megakaryocyte lineages. However, the critical downstream targets of Scl remain undefined. Here, we identified a novel Scl target gene, transcription factor myocyte enhancer factor 2 C (Mef2C) from Sclfl/fl fetal liver progenitor cell lines. Analysis of Mef2C-/- embryos showed that Mef2C, in contrast to Scl, is not essential for specification into primitive or definitive hematopoietic lineages. However, adult VavCre+Mef2Cfl/fl mice exhibited platelet defects similar to those observed in Scl deficient mice. The platelet counts were reduced, while platelet size was increased and the platelet shape and granularity was altered. Furthermore, megakaryopoiesis was severely impaired in vitro. ChIP-on-chip analysis revealed that Mef2C is directly regulated by Scl in megakaryocytic cells, but not in erythroid cells. In addition, an Scl independent requirement for Mef2C in B-lymphoid homeostasis was observed in Mef2C-deficient mice, characterized as severe age-dependent reduction of specific B cell progenitor populations reminiscent of premature aging. In summary, this work identifies Mef2C as an integral member of hematopoietic transcription factors with distinct upstream regulatory mechanisms and functional requirements in megakaryocyte and B-lymphoid lineages.
Mef2C is a lineage-restricted target of Scl/Tal1 and regulates megakaryopoiesis and B-cell homeostasis.
No sample metadata fields
View SamplesComparison of R1 embryonic stem cells response to DMSO and retinoic acid and control
Meta-analysis of differentiating mouse embryonic stem cell gene expression kinetics reveals early change of a small gene set.
Specimen part, Cell line, Compound
View SamplesWe discovered a rare missense mutation in NR1H4 (R436H), which encodes the farnesoid X receptor (FXR), associating with lower levels of total cholesterol in the Icelandic population. To explore the effects of R436H we used CRISPR-Cas9 to generate homozygous NR1H4 R436H and NR1H4 knockout human iPSC lines which we differentiated to hepatocytes. Hepatocytes were treated with an FXR agonist for 24 hours and transcript abundance measured by RNA-seq. The global response to FXR activation in NR1H4 R436H cells was very similar to that of wild-type cells showing that it is not a loss-of-function mutation. However, we did observe subtle gene expression differences compatible with an effect on lipids when we compared R436H agonist treated hepatocytes to wild-type agonist treated hepatocytes. Overall design: RNA-seq was performed on wild-type, NR1H4 knockout and NR1H4 R436H iPSC-derived hepatocytes treated with FXR agonist GW4064.
Predicted loss and gain of function mutations in ACO1 are associated with erythropoiesis.
Specimen part, Treatment, Subject
View SamplesSpermatogonia expressing the highest levels of ID4 (ID4-GFP Bright) represent a population highly enriched for spermatogonial stem cells (SSC) while those expressing lower levels (ID4-GFP Dim) are the putative immediate progenitors. Comparing the transcriptome of these populations can provide insight into the SSC to progenitor transition. Overall design: Comparison of transcriptomes of ID4-GFP Bright and ID4-GFP Dim spermatogonia from postnatal day 8 mouse pups
ID4 levels dictate the stem cell state in mouse spermatogonia.
Specimen part, Subject
View SamplesFanconi anemia (FA) is a genetic disorder characterized by congenital abnormalities, bone marrow failure and increased susceptibility to cancer. Of the fifteen FA proteins, Fanconi anemia group C (FANCC) is one of eight FA core complex components of the FA pathway. Unlike other FA core complex proteins, FANCC is mainly localized in the cytoplasm, where it is thought to function in apoptosis, redox regulation, cytokine signaling and other processes. Previously, we showed that regulation of FANCC involved proteolytic processing during apoptosis. To elucidate the biological significance of this proteolytic modification, we searched for molecular interacting partners of proteolytic FANCC fragments. Among the candidates obtained, the transcriptional corepressor protein C-terminal binding protein-1 (CtBP1) interacted directly with FANCC and other FA core complex proteins. Although not required for stability of the FA core complex or ubiquitin ligase activity, CtBP1 is essential for proliferation, cell survival and maintenance of chromosomal integrity. Expression profiling of CtBP1-depleted and FA-depleted cells revealed that several genes were commonly up- and down-regulated, including the Wnt antagonist Dickkopf-1 (DKK1). These findings suggest that FA and Wnt signaling via CtBP1 could share common effectors.
Fanconi anemia proteins interact with CtBP1 and modulate the expression of the Wnt antagonist Dickkopf-1.
Cell line
View SamplesCalcific aortic valve disease is the most common form of valvular heart disease in the Western World. Milder degrees of aortic valve calcification is called aortic sclerosis and severe calcification with impaired leaflet motion is called aortic stenosis.
MicroRNA-125b and chemokine CCL4 expression are associated with calcific aortic valve disease.
Specimen part, Disease, Disease stage
View SamplesThe proliferation and survival of hematopoietic stem cells (HSCs) has to be strictly coordinated to ensure the timely production of all blood cells. Here we report that the splice factor and RNA binding protein hnRNP L (heterogeneous nuclear ribonucleoprotein L) is required for hematopoiesis, since its genetic ablation in mice reduces almost all blood cell lineages and causes premature death of the animals. In agreement with this, we observed that hnRNP L deficient HSCs lack both the ability to self-renew and foster hematopoietic differentiation in transplanted hosts. They also display mitochondrial dysfunction, elevated levels of ?H2AX, are Annexin V positive and incorporate propidium iodide indicating that they undergo cell death. Lin(-)c-Kit(+) fetal liver cells from hnRNP L deficient mice show high p53 protein levels and up-regulation of p53 target genes. In addition, cells lacking hnRNP L up-regulated the expression of the death receptors TrailR2 and CD95/Fas and show Caspase-3, Caspase-8 and Parp cleavage. Treatment with the pan-caspase inhibitor Z-VAD-fmk, but not the deletion of p53, restored cell survival in hnRNP L deficient cells. Our data suggest that hnRNP L is critical for the survival and functional integrity of HSCs by restricting the activation of caspase-dependent death receptor pathways. Overall design: fetal liver cells from either hnRNPL wild-type or hnRNPL KO embryos were analysed for differential expression and alternative splicing by RNA-Seq. RNA-Seq was carried out in biological triplicate for each sample type. Each sample is a single embryo.
Heterogeneous Nuclear Ribonucleoprotein L is required for the survival and functional integrity of murine hematopoietic stem cells.
No sample metadata fields
View SamplesMegakaryocytes isolated from Gfi1b flox/flox mice carrying PF4-Cre or not, and from Gfi1b flox/flox mice carrying ROSA-Cre-ERT with or without tamoxifen injection were analyzed for differential expression by RNA-Seq Overall design: A sample of each Gfi1b wild-type and Knock-Out from each model was analyzed
Gfi1b regulates the level of Wnt/β-catenin signaling in hematopoietic stem cells and megakaryocytes.
No sample metadata fields
View SamplesAims: establishment of reference samples to investigate gene expression selective for endocrine or ductal-exocrine cells within the adult human pancreas. To this end, human islet endocrine cells, FACS-enriched in insulin+ cells, (n=3) and human exocrine ductal cells (n=2) are compared on Affymetrix HG133A platform with duplicate hybridizations of a panel of other primary human tissues.
Clusters of conserved beta cell marker genes for assessment of beta cell phenotype.
Specimen part
View SamplesThe study was designed to capture the in vivo adaptations of nutrient-sensing pancreatic beta cells to fed or fasted (24h) state.
Clusters of conserved beta cell marker genes for assessment of beta cell phenotype.
Sex, Age, Specimen part
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