Our study describes in detail the role of Bmp2 during cardiac valve developmnent and its implication in Notch pathway activation. Overall design: Hearts were isolated from WT and Bmp2GOF;Nkx2.5-Cre mouse embryos at stage E9.5 and their expression profile characterized by RNA-seq
Bmp2 and Notch cooperate to pattern the embryonic endocardium.
Specimen part, Subject
View SamplesThe zebrafish heart remarkably regenerates after a severe ventricular damage followed by inflammation, fibrotic tissue deposition and removal concomitant with cardiac muscle replacement. We have investigated the role of the endocardium in this regeneration process. 3D-whole mount imaging in injured hearts revealed that GFP-labelled endocardial cells in ET33mi-60A transgenic fish become rapidly activated and highly proliferative at 3 days post cryoinjury (dpci). Endocardial cells extensively expand within the injury site and organize to form a coherent structure at 9 dpci that persists throughout the regeneration process. Upon injury, endocardial cells strongly up-regulate the Notch pathway ligand delta like4 (dll4) and the Notch receptors notch1b, notch2 and notch3. Expression profiling showed that Notch signalling inhibition affects endocardial gene expression and genes related to extracellular matrix remodelling and inflammation. Gain- and loss-of-function experiments revealed that Notch is required for the organization of the endocardium, attenuation of the inflammatory response and cardiomyocyte proliferation. These results demonstrate a novel structural and signalling role for the endocardium during heart regeneration. Overall design: RNA was extracted from apical tip of heart ventricles 72h after cryoinjured adult zebrafish heart treated with DMSO (Controls) or RO gamma secretase inhibitor at 24 and 48h post injury.
Notch signalling restricts inflammation and <i>serpine1</i> expression in the dynamic endocardium of the regenerating zebrafish heart.
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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.
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View SamplesSoxR and SoxS constitute an intracellular signal response system that rapidly detects changes in superoxide levels and modulates gene expression in E. coli.
Rapid changes in gene expression dynamics in response to superoxide reveal SoxRS-dependent and independent transcriptional networks.
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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.
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View SamplesTo explore the primary cause of Dilated Cardiomyopathy in heart samples from DCM-diagnosed patients who had undergone heart transplant (hDCM), we set out to identify differentially expressed genes by massively parallel sequencing of heart samples. Overall design: Methods: Heart mRNA profiles from DCM-diagnosed patients who had undergone heart transplant (hDCM) were generated by deep sequencing, in triplicate, using Illumina GAIIx.
Bmi1 limits dilated cardiomyopathy and heart failure by inhibiting cardiac senescence.
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View SamplesTo explore the primary cause of Dilated Cardiomyopathy in Bmi1-null mice, we set out to identify differentially expressed genes by massively parallel sequencing of heart samples from Bmi1f/f;aMHCTM-Cretg/+ mice versus aMHCTM-Cretg/+ control mice (17 weeks postinduction). Overall design: Methods: Heart mRNA profiles of 17-weeks post-induction Bmi1f/f; MHCTM-Cretg/+ mice and MHCTM-Cretg/+ control mice were generated by deep sequencing, in triplicate, using Illumina GAIIx. Sequence reads were pre-processed with Cutadapt 1.2.1, to remove TruSeq adapters and mapped on the mouse transcriptome (Ensembl gene-build GRCm38.v70) using RSEM v1.2.3. The Bioconductor package EdgeR was used to normalize data with TMM and to test for differential expression of genes using GLM.
Bmi1 limits dilated cardiomyopathy and heart failure by inhibiting cardiac senescence.
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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 SamplesThis SuperSeries is composed of the SubSeries listed below.
Systems genetics identifies a co-regulated module of liver microRNAs associated with plasma LDL cholesterol in murine diet-induced dyslipidemia.
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View SamplesGenetic variation, in addition to environmental influences like diet, can govern the expression levels of microRNAs (miRNAs). MiRNAs are commonly found to operate cooperatively in groups to regulate gene expression. To investigate this, we combined small RNA sequencing, clinical phenotypes, and microarray data measuring gene expression from an outbred mouse model, the Diversity Outbred population. In the DO population, each individual has a distinct genome that is a mosaic of 8 inbred founder strains. We used these data to identify co-regulated modules of miRNAs and genes that are influenced by genetics and diet, and identify relationships between the modules and phenotypes in over 200 DO mice.
Systems genetics identifies a co-regulated module of liver microRNAs associated with plasma LDL cholesterol in murine diet-induced dyslipidemia.
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