The study of the mechanisms leading to cardiac hypertrophy is essential to better understand cardiac development and regeneration. Pathological conditions such as ischemia or pressure overload can induce a release of extracellular nucleotides within the heart. We recently investigated the potential role of nucleotide P2Y receptors in cardiac development. We showed that adult P2Y4-null mice displayed microcardia resulting from defective cardiac angiogenesis. Here we show that loss of another P2Y subtype called P2Y6, a UDP receptor, was associated with a macrocardia phenotype and amplified pathological cardiac hypertrophy. Cardiomyocyte proliferation and size were increased in vivo in hearts of P2Y6-null neonates, resulting in enhanced post-natal heart growth. We then observed that loss of P2Y6 receptor enhanced pathological cardiac hypertrophy induced after isoproterenol injection. We identified an inhibitory effect of UDP on in vitro isoproterenol-induced cardiomyocyte hyperplasia and hypertrophy. The present study identifies mouse P2Y6 receptor as a regulator of cardiac development and cardiomyocyte function. P2Y6 receptor could constitute a therapeutic target to regulate cardiac hypertrophy. Overall design: WT and P2Y6 KO mice aged between 8 and 12 weeks were intraperitoneally injected with 50 mg/kg/day isoproterenol or saline solution, daily during 7 days, then hearts were harvested and weighted. Ventricles were then stored for RNA extraction.
Loss of Mouse P2Y6 Nucleotide Receptor Is Associated with Physiological Macrocardia and Amplified Pathological Cardiac Hypertrophy.
Specimen part, Treatment, Subject
View SamplesThe recent interest in the role of bone marrow derived endothelial progenitor cells in the benefits of estrogen on cardiovascular health brought us to evaluate if estrogen could affect cardiac repair more broadly by regulating biological processes involved in the functional organization of the bone marrow stem cell niche.
Estrogen-induced gene expression in bone marrow c-kit+ stem cells and stromal cells: identification of specific biological processes involved in the functional organization of the stem cell niche.
Sex, Age
View SamplesCanonical Wnt signaling controls proliferation and differentiation of osteogenic progenitor cells, and tumor-derived secretion of the Wnt antagonist Dickkopf-1 (Dkk1) is correlated with osteolyses and metastasis in many bone malignancies. However, the role of Dkk1 in the oncogenesis of primary osteosarcoma (OS) remains unexplored. Here, we over-expressed Dkk1 in the OS cell line MOS-J. Contrary to expectations, Dkk1 had autocrine effects on MOSJ cells in that it increased proliferation and resistance to metabolic stress in vitro. In vivo, Dkk1 expressing MOS-J cells formed larger and more destructive tumors than controls. These effects were attributed in part to up-regulation of the stress response enzyme and cancer stem cell marker aldehyde-dehydrogenase-1 (ALDH1) through Jun-N-terminal kinase signaling. This is the first report linking Dkk1 to tumor stress resistance, further supporting the targeting of Dkk1 not only to prevent and treat osteolytic bone lesions but also to reduce numbers of stress-resistant tumor cells.
An unexpected role for a Wnt-inhibitor: Dickkopf-1 triggers a novel cancer survival mechanism through modulation of aldehyde-dehydrogenase-1 activity.
Specimen part, Cell line
View SamplesDiffuse infiltrating gliomas are the most common primary brain malignancy found in adults, and Glioblastoma multiforme, the highest grade glioma, is associated with a median survival of 7 months. Transcriptional profiling has been applied to 85 gliomas from 74 patients to elucidate glioma biology, prognosticate survival, and define tumor sub-classes. These studies reveal that transcriptional profiling of gliomas is more accurate at predicting survival than traditional pathologic grading, and that gliomas characteristically express coordinately regulated genes of one of four molecular signatures: neurogenesis, synaptic transmission, mitotic, or extra-cellular matrix. Elucidation of these survival associated molecular signatures will aid in tumor prognostication and define targets for future directed therapy.
Gene expression profiling of gliomas strongly predicts survival.
Sex, Age, Specimen part, Disease stage
View SamplesMigrated from 1.6 id: 1015897590491013 GEDP id: 760 In current clinical practice, histology-based grading of diffuse infiltrative gliomas is the best predictor of patient survival time. Yet histology provides little insight into the underlying biology of gliomas and is limited in its ability to identify and guide new molecularly targeted therapies. We have performed large-scale gene expression analysis using the Affymetrix HG U133 oligonucleotide arrays on 85 diffuse infiltrating gliomas of all histologic types to assess whether a gene expression-based, histology-independent classifier is predictive of survival and to determine whether gene expression signatures provide insight into the biology of gliomas. We found that gene expression-based grouping of tumors is a more powerful survival predictor than histologic grade or age. The poor prognosis samples could be grouped into three different poor prognosis groups, each with distinct molecular signatures. We further describe a list of 44 genes whose expression patterns reliably classify gliomas into previously unrecognized biological and prognostic groups: these genes are outstanding candidates for use in histology-independent classification of high-grade gliomas. The ability of the large scale and 44 gene set expression signatures to group tumors into strong survival groups was validated with an additional external and independent data set from another institution composed of 50 additional gliomas. This demonstrates that large-scale gene expression analysis and subset analysis of gliomas reveals unrecognized heterogeneity of tumors and is efficient at selecting prognosis-related gene expression differences which are able to be applied across institutions.
Gene expression profiling of gliomas strongly predicts survival.
Sex, Age, Specimen part, Disease, Disease stage
View SamplesA LysM Receptor-like Kinase Mediates Chitin Perception and Fungal Resistance in Arabidopsis
A LysM receptor-like kinase plays a critical role in chitin signaling and fungal resistance in Arabidopsis.
No sample metadata fields
View SamplesBackground: Glioblastomas are the most common primary brain tumour in adults. While the prognosis for patients is poor, gene expression profiling has detected signatures that can sub-classify GBMs relative to histopathology and clinical variables. One category of GBM defined by a gene expression signature is termed ProNeural (PN), and has substantially longer patient survival relative to other gene expression-based subtypes of GBMs. Age of onset is a major predictor of the length of patient survival where younger patients survive longer than older patients. The reason for this survival advantage has not been clear.
Gene expression analysis of glioblastomas identifies the major molecular basis for the prognostic benefit of younger age.
Sex, Age
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.
No sample metadata fields
View SamplesSoybean root hair transcriptional response to their inoculation by the symbiotic bacteria B. japonicum involved in soybean nodulation. We used the first generation of an Affymetrix microarray to quantify the abundance of the transcripts from soybean root hair cells inoculated and mock-inoculated by B. japonicum. This experiment was performed on a time-course from 6 to 48 hours after inoculation.
Complete transcriptome of the soybean root hair cell, a single-cell model, and its alteration in response to Bradyrhizobium japonicum infection.
Specimen part, Treatment, Time
View SamplesAn overview of small RNAs sequences existing in seed development and contrasted with vegetative tissues of the soybean Overall design: Four small RNA sequence populations from high throughput deep sequencing-by-synthesis and representing different tissues/organs of the soybean were characterized into small RNA classes, level of expresion, genes of origin and putative targeted genes
Divergent patterns of endogenous small RNA populations from seed and vegetative tissues of Glycine max.
Subject
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