To identify novel Nurr1 target genes we have used microarrays strategies in rat midbrain primary cultures, enriched in dopaminergic neurons, by the action of basic fibroblast growth factor (bFGF, 20ng/ml) and Sonic hedgedog (SHH), following upregulation of Nurr1 expression by depolarization.To this aim we have treated the cultures after 9 days in vitro for 2h with high KCl and collected 30 min or 2 h after the end of depolarization (2h + 30 min or 2h + 2h). With this experimental protocol we have identify a putative Nurr1 regulator and Nurr1 target
Bdnf gene is a downstream target of Nurr1 transcription factor in rat midbrain neurons in vitro.
Specimen part
View SamplesVentricular chambers are essential for the rhythmic contraction and relaxation that occurs in every hearbeat throughout life. Congenital abnormalities in ventricular chamber formation cause severe human heart defects. How the early trabecular meshwork of myocardial fibres forms and subsequently develops into mature chambers is still poorly understood. Here we show that Notch signalling first connects chamber endocardium and myocardium to sustain trabeculation and later coordinates ventricular patterning and compaction with coronary vessel development to give rise to the mature chamber via a temporal sequence of ligand signalling determined by the glycosyltransferase Manic Fringe (Mfng). The early endocardial expression of Mfng favours Dll4-Notch1 signalling, Which induces trabeculation in the developing ventricle.Ventricular maturation and compaction in turn require Mfng and Dll4 downregulation in the endocardium, Which allows myocardial Jag1- And Jag2- Signalling to Notch1 in this tissue.Timely and spatial perturbation of this signalling equilibrium severely disrupts heart chamber formation. Our results open a new research avenue into the pathogenesis of cardiomyopathies. Overall design: Dll4 and Notch1 conditional KOs using Nfact1 and/or Tie2 driven Cre expression: RNA was isolated from pooled whole hearts of 8 (Nfact1) or 9 (Tie2) E9.5 embryos per replicate. Dll4flox;Nfatc1-Cre and WT siblings (4 KO and 4 WT replicates), Notch1flox;Nfatc1-Cre and WT siblings (3 KO and 2 WT replicates), Dll4flox;Tie2-Cre and WT siblings (3 KO and 3 WT replicates). Jag1, Jag2 and Jag1Jag2 conditional KOs using cTnT driven Cre expression: RNA was isolated from pooled heart ventricles of 4 E15.5 embryos per replicate. Jag1flox;cTnT-Cre and WT siblings (3 KO and 3 WT replicates), Jag2flox;cTnT-Cre and WT siblings (3 KO and 2 WT replicates). Jag1flox;jag2flox;cTnT-Cre and WT siblings (3 KO and 2 WT replicates). MFng Gain Of Function using Tie2 driven Cre expression: RNA was isolated from pooled heart ventricles of 4 E15.5 embryos per replicate. MFng;Tie2-Cre and WT siblings (4 GOF and 4 WT replicates). For Dll4, Noth1 and Jag1 KOs, libraries were prepared using the standard Illumina TrueSeq RNASeq library preparation kit and sequenced in a GAIIx Illumina sequencer using a 75bp single end elongation protocol. For Jag2 and Jag1Jag2 KOs and MFng GOF libraries were prepared prepared using the NEBNext Ultra RNA Library Prep Kit for Illumina and sequenced in a HiSeq2500 Illumina sequencer using a 61bp single end elongation protocol
Sequential Notch activation regulates ventricular chamber development.
No sample metadata fields
View SamplesHypermethylation of tumor suppressor gene (TSG) promoters confers growth advantages to cancer cells, but how these changes arise is poorly understood. Here, we report that tumor hypoxia reduces the activity of oxygen-dependent TET enzymes, which catalyze DNA de-methylation through 5-methylcytosine oxidation. This occurs independently of hypoxia-associated alterations in TET gene expression, basal metabolism, HIF activity or nuclear reactive oxygen species, but directly depends on oxygen shortage. Hypoxia-induced loss of TET activity increases hypermethylation at gene promoters in vitro, while also in patients, gene promoters are markedly more methylated in hypoxic than normoxic tumors. Affected genes are frequently involved in DNA repair, cell cycle regulation, angiogenesis and metastasis, indicating cellular selection of hypermethylation events. Overall, up to 50% of the tumor-associated hypermethylation is ascribable to hypoxia across various cancer types. Accordingly, spontaneous murine breast tumors become hypermethylated when rendered hypoxic through vessel pruning, whereas vessel normalisation rescues this effect. Tumor hypoxia thus acts as a novel regulator underlying DNA methylation. Overall design: RNAseq of MCF7 cells grown under hypoxic and normoxic conditions. Submission includes data on 5 independent RNAseq experiments, each containing biological replicates grown under hypoxic conditions (0.5% oxygen), and under normoxic conditions.
Tumour hypoxia causes DNA hypermethylation by reducing TET activity.
Subject
View SamplesCells grown in forced suspension culture mimic the early steps of metastasis. In order to determine what might be driving the ability of TNBC cells to survive in suspension, a global gene expression profiling experiment was performed. Human triple negative breast cancer (TNBC) cell line BT549 was grown in attached or forced suspension conditions for 24 hours, then RNA was harvested to look for changes in global gene expression.
Androgen Receptor Supports an Anchorage-Independent, Cancer Stem Cell-like Population in Triple-Negative Breast Cancer.
Specimen part
View SamplesAim: To determine the role of NOTCH during the response-to-injury and subsequent chronic inflammatory process of the arterial wall underlying atherosclerosis. Methods and results: We have generated an endothelial-specific RBPJK depleted mice using the Cdh5 cadherin promoter (ApoE-/-;RBPJflox/flox;Cdh5- CreERT). Endothelial-specific deletion of the Notch effector RBPJK or systemic deletion of the Notch1 receptor in athero-susceptible ApoE-/- mice fed a HC diet for 6 weeks resulted in reduced atherosclerosis in the aortic arch and sinus. Intravital microscopy revealed decreased leukocyte rolling on the endothelium of ApoE-/-;RBPJflox/flox;Cdh5- CreERT, that correlated with the lesser presence of leukocyts and macrophages in the vascular wall. Consistent with this, transcriptome analysis revealed that proinflammatory and endothelial activation pathways were downregulated in atherosclerotic tissue of RBPJk-mutant mice.. Jagged1 signaling upregulation in endothelial cells promotes the physical interaction and nuclear translocation of the intracellular domain of the Notch1 receptor (N1ICD) with NF-kB,. This N1ICD and NF-kB interaction is required for reciprocal transactivation of target genes including vascular cell adhesion molecule-1 (Vcam1). Conclusions: Notch signaling pathway inactivation decreases leukocyte rolling, thereby preventing endothelial dysfunction and vascular inflammation. Thus attenuating Notch signaling may constitute a useful therapeutic strategy for atherosclerosis. Key words: atherosclerosis, endothelium, signaling pathways, Notch, NF-kB, transcriptional regulation Overall design: RNA was isolated from the aortic arches of three ApoE-/-;RBPJflox/flox and three ApoE-/-; RBPJflox/flox;Cdh5-CreERTmice
Endothelial Jag1-RBPJ signalling promotes inflammatory leucocyte recruitment and atherosclerosis.
No sample metadata fields
View SamplesImmortalized, amelanotic melanocytes isolted from skin of Balb/c express enzymatically-inactive tyrosinase due to a homozygous point mutation (TGT->TCT) in tyrosinase gene, resulting in a lack of melanin . To serve as a control cell line, pigmentation was restored in these cells by correcting the point mutation using an RNA-DNA oligonucleotide (kingly gift from Dr. Alexeev Y. Vitali).
Melanocyte-secreted fibromodulin promotes an angiogenic microenvironment.
Specimen part
View SamplesOur studies identify a mechanism of signaling crosstalk during valve morphogenesis that sheds light on the origin of congenital heart defects associated with reduced Notch function. Overall design: Aortic and pulmonary cardiac valves were isolated by laser microdissection from WT and Jag1flox;Nkx2.5-Cre mouse embryos at stage E14.5, and their expression profile characterized by RNA-Seq.
Sequential Ligand-Dependent Notch Signaling Activation Regulates Valve Primordium Formation and Morphogenesis.
Specimen part, Subject
View SamplesLeft ventricular noncompaction (LVNC) Causes prominent ventricular trabeculations and reduces cardiac systolic function. The clinical presentation of LVNC ranges from asymptomatic to heart failure. We show that germline mutations in human MIB1 (mindbomb homolog 1), which encodes an E3 ubiquitin ligase that promotes endocytosis of the NOTCH ligands DELTA and JAGGED, cause LVNC in autosomal-dominant pedigrees, with affected individuals showing reduced NOTCH1 activity and reduced expression of target genes. Functional studies in cells and zebrafish embryos and in silico modeling indicate that MIB1 functions as a dimer, which is disrupted by the human mutations. Targeted inactivation of Mib1 in mouse myocardium causes LVNC, a phenotype mimicked by inactivation of myocardial Jagged1 or endocardial Notch1. Myocardial Mib1 mutants show reduced ventricular Notch1 activity, expansion of compact myocardium to proliferative, immature trabeculae and abnormal expression of cardiac development and disease genes. These results implicate NOTCH signaling in LVNC and indicate that MIB1 mutations arrest chamber myocardium development, preventing trabecular maturation and compaction. Overall design: RNA was isolated from the ventricles of 16 WT and 16 Mib1flox; CTnT-cre hearts at E14.5 and then pooled into four replicates.
Mutations in the NOTCH pathway regulator MIB1 cause left ventricular noncompaction cardiomyopathy.
No sample metadata fields
View SamplesBackground and aims: Cholangiocarcinoma (CCA) is a heterogeneous group of malignancies with features of biliary tract differentiation. Incidence is increasing worldwide and these cancers collectively represent the second most common primary liver tumour. CCAs are characterized by genetic and epigenetic alterations that determine their pathogenesis. Hypermethylation of the SOX17 promoter was recently reported in human CCA tumours. SOX17 seems to be a key transcription factor for biliary embryogenesis. Here, we evaluated the role of SOX17 in cholangiocyte differentiation and in cholangiocarcinogenesis. Methods: SOX17 expression and function was evaluated during the differentiation of human induced pluripotent stem cells (iPSC) into cholangiocytes, in the dedifferentiation of normal human cholangiocytes (NHC) and in cholangiocarcinogenesis. Lentiviruses overexpressing or knocking-down SOX17 (Lent-SOX17 and Lent-shRNA-SOX17, respectively) were used. Gene expression arrays were performed. Results: SOX17 expression is highly induced in the later stages of cholangiocyte differentiation from iPSC, and mediates the acquisition of the biliary markers cytokeratin (CK) 7 and 19, as well as fibronectin. In addition, SOX17 becomes progressively downregulated in NHC over serial cell passages in vitro and this event is associated with cellular senescence; however, experimental SOX17 knocking-down in differentiated NHC decreased the expression of both CK7 and 19 without affecting cellular senescence. SOX17 expression is reduced in CCA cells compared to NHC, as well as in human CCA tissue compared to human gallbladder tissue or NHC. In a murine xenograft model, overexpression of SOX17 in CCA cells decreased their tumorigenic capacity related to increased oxidative stress and apoptosis. Interestingly, overexpression of SOX17 in NHC did not affect their survival. Moreover, SOX17 overexpression inhibited the Wnt/-catenin-dependent proliferation in CCA cells and was associated with upregulation of biliary epithelial markers and restoration of the primary cilium length. Both Wnt3a and TGF1 decreased SOX17 expression in NHC in a DNMT1-dependent manner. Inhibition of DNMT1 in CCA cells with siRNAs or pharmacological drugs upregulated SOX17 expression. Conclusion: SOX17 regulates the cholangiocyte phenotype and becomes epigenetically downregulated in CCA. SOX17 acts as a tumour suppressor in CCA, and restoration of its expression may have important therapeutic value.
SOX17 regulates cholangiocyte differentiation and acts as a tumor suppressor in cholangiocarcinoma.
Specimen part, Treatment
View SamplesmiRNAs are small non-coding RNAs that inhibit translation and promote mRNA decay. The levels of mature miRNAs are the result of different rates of transcription, processing, and turnover. The non-canonical polymerase Gld2 has been implicated in the stabilization of miR-122 possibly by catalyzing 3’ monoadenylation, however, there is little evidence that this relationship is one of cause and effect. Here, we biochemically characterize Gld2 involvement in miRNA monoadenylation and its effect on miRNA stability. We find that Gld2 directly monoadenylates and stabilizes specific miRNA populations in human fibroblasts and that sensitivity to monoadenylation-induced stability depends on nucleotides in the miRNA 3‘ end. These results establish a novel mechanism of miRNA stability and resulting post-transcriptional gene regulation. Overall design: Sequencing of miRNAs to assess amount and 3'' end monoadenylation state upon Gld2 knock-down.
Specific miRNA stabilization by Gld2-catalyzed monoadenylation.
Specimen part, Subject
View Samples