Development of specialized cell types and structures in the vertebrate heart is regulated by spatially-restricted molecular pathways. Disruptions in these pathways can cause severe congenital cardiac malformations or functional defects. To better understand these pathways and how they regulate cardiac development and function we used tomo-seq, combining high-throughput RNA sequencing with tissue sectioning, to establish a genome-wide expression dataset with high spatial resolution for the developing zebrafish heart. Analysis of the dataset revealed over 1100 genes differentially expressed in sub-compartments. Pacemaker cells in the sinoatrial region induce heart contractions, but little is known about the mechanisms underlying their development and function. Using our transcriptome map, we identified spatially restricted Wnt/ß-catenin signaling activity in pacemaker cells, which was controlled by Islet-1 activity. Moreover, Wnt/ß-catenin signaling at a specific developmental stage in the myocardium controls heart rate by regulating pacemaker cellular response to parasympathetic stimuli. Thus, this high-resolution transcriptome map incorporating all cell types in the embryonic heart can expose spatially-restricted molecular pathways critical for specific cardiac functions. Overall design: To generate spatially-resolved RNA-seq data for the developing zebrafish hearts (2 days post fertilization), we cryosectioned 3 hearts, extracted RNA from the individual sections, amplified and barcoded mRNA using the CEL-seq protocol (Hashimshony et al., Cell Reports, 2012) with a few modifications. Libraries were sequenced on Illumina NextSeq using 75bp paired end sequencing. Sample Heart #1 is the primary sample. Heart #2 and #3 are biological replicates used for comparison.
Spatially resolved RNA-sequencing of the embryonic heart identifies a role for Wnt/β-catenin signaling in autonomic control of heart rate.
Specimen part, Subject
View SamplesCardiomyopathies-associated metabolic pathologies (e.g. T2D and insulin resistance) are a leading cause of mortality. It is known that the association between the pathologies works in both directions, where heart failure can lead to metabolic derangements such as insulin resistance. This intricate crosstalk exemplifies the importance of a fine coordination between one of the most energy demanding organs and an equilibrated carbohydrate metabolism. In this light, to assist in the understanding of the role of insulin regulated glucose transporters and the development of cardiomyopathies, we set out to study GLUT12. GLUT12 is a novel insulin regulated GLUT expressed in the main insulin sensitive tissues such as cardiac and skeletal muscle and adipose tissue. This study investigates the role of GLUT12 in heart failure and diabetes by developing a model for glut12 deficiency in zebrafish. Overall design: 6 samples in total were analyzed. 3 replicates from control samples (injected with contol MO) and 3 replicates from glut12 morphant samples (injected with glut12 splice MO). In each sample 10 embryos were pooled.
GLUT12 deficiency during early development results in heart failure and a diabetic phenotype in zebrafish.
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View SamplesWe used a mouse strain in which one Tbx3 gene was replaced with the yellow fluorescent protein variant Venus. Luminal cells had either very high Tbx3 promoter activity or not at all.
Transcriptional repressor Tbx3 is required for the hormone-sensing cell lineage in mammary epithelium.
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View SamplesIn contrast to mammals, zebrafish regenerate heart injuries via proliferation of cardiomyocytes located at the wound border. Here, we show that tomo-seq can be used to identify whole-genome transcriptional profiles of the injury zone, the border zone and the healthy myocardium. Interestingly, the border zone is characterized by the re-expression of embryonic cardiac genes that are also activated after myocardial infarction in mouse and human, including targets of Bone Morphogenetic Protein (BMP) signaling. Endogenous BMP signaling has been reported to be detrimental to mammalian cardiac repair. In contrast, we find that genetic or chemical inhibition of BMP signaling in zebrafish reduces cardiomyocyte dedifferentiation and proliferation, ultimately compromising myocardial regeneration, while bmp2b overexpression is sufficient to enhance it. Our results provide a resource for further studies on the molecular regulation of cardiac regeneration and reveal intriguing differential cellular responses of cardiomyocytes to a conserved signaling pathway in regenerative versus non-regenerative hearts. Overall design: To generate spatially-resolved RNA-seq data for injured zebrafish hearts (3 and 7 days-post-injury), we cryosectioned samples, extracted RNA from the individual sections, and amplified and barcoded mRNA using the CEL-seq protocol (Hashimshony et al., Cell Reports, 2012) with a few modifications. Libraries were sequenced on Illumina NextSeq using 75bp paired end sequencing.
Spatially Resolved Genome-wide Transcriptional Profiling Identifies BMP Signaling as Essential Regulator of Zebrafish Cardiomyocyte Regeneration.
Specimen part, Subject
View SamplesHypertension is a dominating risk factor for cardiovascular disease. To characterize the genomic response to hypertension, we administered vehicle or angiotensin II to mice and performed gene expression analyses. AngII treatment resulted in a robust increase in blood pressure and altered expression of 235 genes in the aorta, including Gucy1a3 and Gucy1b3 which encode subunits of soluble guanylyl cyclase (sGC). Western blotting and immunohistochemistry confirmed repression of sGC associated with curtailed relaxation via sGC activation. Analysis of transcription factor binding motifs in promoters of differentially expressed genes identified enrichment of motifs for RBPJ, a component of the Notch signaling pathway, and the Notch coactivators FRYL and MAML2 were reduced. Gain and loss of function experiments demonstrated that JAG/NOTCH signaling controls sGC expression together with MAML2 and FRYL. Reduced expression of sGC, correlating with differential expression of MAML2 in stroke prone and spontaneously hypertensive rats was also seen and RNA-Seq data demonstrated correlations between JAG1, NOTCH3, MAML2 and FRYL and the sGC subunits GUCY1A3 and GUCY1B3 in human coronary artery. Notch signaling thus provides a constitutive drive on expression of the major nitric oxide receptor (GUCY1A3/GUCY1B3) in arteries from mice, rats, and humans, and this control mechanism is disturbed in hypertension.
Hypertension reduces soluble guanylyl cyclase expression in the mouse aorta via the Notch signaling pathway.
Specimen part
View SamplesThe atrioventricular (AV) node is a recurrent source of potentially life-threatening arrhythmias. Nevertheless, limited data are available on its developmental control or molecular phenotype. We used a novel AV node-specific reporter mouse to gain insight into the gene programs determining the formation and phenotype of the AV node. In the transgenic reporter, green fluorescent protein (GFP) expression was driven by 160 kbp of Tbx3 and flanking sequences. GFP was selectively expressed in the AV canal of embryos, and in the AV node of adults, while all other Tbx3+ conduction system components, including the AV bundle, were devoid of GFP expression. Fluorescent AV nodal (Tbx3BAC-Egfp) and complementary working (NppaBAC336-Egfp) myocardial cell populations of E10.5 embryos and E17.5 fetuses were purified using fluorescence-activated cell sorting, and their expression profiles were assessed by microarray analysis. We constructed a comprehensive list of sodium, calcium, and potassium channels specific for the nodal or working myocard. Furthermore, the data revealed that the AV node and the working myocardium phenotypes diverge during development, but that the functional gene classes characteristic for both compartments are maintained. Interestingly, the AV node-specific gene repertoire consisted of multiple neurotrophic factors not yet appreciated to play a role in nodal development. These data present the first genome-wide transcription profiles of the AV node during development, providing valuable information concerning its molecular identity.
Gene expression profiling of the forming atrioventricular node using a novel tbx3-based node-specific transgenic reporter.
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View SamplesThe role of peroxisome proliferator-activated receptor (PPAR) activation on global gene expression and mitochondrial fuel utilization were investigated in human myotubes. Only 21 genes were up-regulated and 3 genes were down-regulated after activation by the PPAR agonist GW501516. Pathway analysis showed up-regulated mitochondrial fatty acid oxidation, TCA cycle and cholesterol biosynthesis. GW501516 increased oleic acid oxidation and mitochondrial oxidative capacity by 2-fold. Glucose uptake and oxidation were reduced, but total substrate oxidation was not affected, indicating a fuel switch from glucose to fatty acid. Cholesterol biosynthesis was increased, but lipid biosynthesis and mitochondrial content were not affected. This study confirmed that the principal effect of PPAR activation was to increase mitochondrial fatty acid oxidative capacity. Our results further suggest that PPAR activation reduced glucose utilization through a switch in mitochondrial substrate preference by up-regulating pyruvate dehydrogenase kinase isozyme 4 and genes involved in lipid metabolism and fatty acid oxidation.
PPARδ activation in human myotubes increases mitochondrial fatty acid oxidative capacity and reduces glucose utilization by a switch in substrate preference.
Sex, Age, Specimen part, Treatment
View SamplesTitle: Transcriptome analysis of human endometrial tissues from healthy post-menoupausal women reflecting the endometrial response to 3-weeks treatment with tibolone, E2 and E2+MPA.
Molecular analysis of human endometrium: short-term tibolone signaling differs significantly from estrogen and estrogen + progestagen signaling.
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View SamplesMetabolic fluxes may be regulated "hierarchically," e.g., by changes of gene expression that adjust enzyme capacities (V(max)) and/or "metabolically" by interactions of enzymes with substrates, products, or allosteric effectors. In the present study, a method is developed to dissect the hierarchical regulation into contributions by transcription, translation, protein degradation, and posttranslational modification. The method was applied to the regulation of fluxes through individual glycolytic enzymes when the yeast Saccharomyces cerevisiae was confronted with the absence of oxygen and the presence of benzoic acid depleting its ATP. Metabolic regulation largely contributed to the approximately 10-fold change in flux through the glycolytic enzymes. This contribution varied from 50 to 80%, depending on the glycolytic step and the cultivation condition tested. Within the 50-20% hierarchical regulation of fluxes, transcription played a minor role, whereas regulation of protein synthesis or degradation was the most important. These also contributed to 75-100% of the regulation of protein levels.
The fluxes through glycolytic enzymes in Saccharomyces cerevisiae are predominantly regulated at posttranscriptional levels.
No sample metadata fields
View SamplesAcetate, propionate and butyrate are the main short-chain fatty acids (SCFAs) that arise from the fermentation of fibers by the colonic microbiota. While many studies focus on the regulatory role of SCFAs, their quantitative role as a catabolic or anabolic substrate for the host has received relatively little attention. To investigate this aspect, we infused conscious mice with physiological quantities of stable isotopes [1-13C]acetate, [2-13C]propionate or [2,4-13C2]butyrate directly into the cecum, which is the natural production site in mice, and analyzed their interconversion by the microbiota as well as their metabolism by the host. Cecal interconversion - pointing to microbial cross-feeding - was high between acetate and butyrate, low between butyrate and propionate and almost absent between acetate and propionate. As much as 62% of infused propionate was used in whole-body glucose production, in line with its role as gluconeogenic substrate. Conversely, glucose synthesis from propionate accounted for 69% of total glucose production. The synthesis of palmitate and cholesterol in the liver was high from cecal acetate (2.8% and 0.7%, respectively) and butyrate (2.7% and 0.9%, respectively) as substrates, but low or absent from propionate (0.6% and 0.0%, respectively). Label incorporation due to chain elongation of stearate was approximately 8-fold higher than de novo synthesis of stearate. Microarray data suggested that SCFAs exert only a mild regulatory effect on the expression of genes involved in hepatic metabolic pathways during the 6h infusion period. Altogether, gut-derived acetate, propionate and butyrate play important roles as substrates for glucose, cholesterol and lipid metabolism.
Gut-derived short-chain fatty acids are vividly assimilated into host carbohydrates and lipids.
Sex, Specimen part, Treatment
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