Insults to the cerebral cortex, such as trauma, ischemia or infections, may result in the development of epilepsy, one of the most common neurological disorders. Previous studies have suggested that perturbations in neurovascular integrity and breakdown of the blood-brain barrier (BBB) lead to neuronal hypersynchronization and epileptiform activity, but the underlying mechanisms are unknown. As with BBB opening, treatment with albumin or with TGF-1 results in the development of hypersynchronized epileptiform activity. Given the latent period before the appearance of epileptiform activity, we hypothesized the underlying mechanism is a transcriptional response which would be similar for BBB breakdown and exposure to albumin or TGF-1. In search of a common pathway and transcriptional activation pattern we performed a genome wide analysis. Genomic expression analyses demonstrated similar expression patterns for BBB opening, albumin and TGF-1 exposure. Most importantly, TGF- pathway blockers suppressed most albumin-induced transcriptional changes.
Astrocytic dysfunction in epileptogenesis: consequence of altered potassium and glutamate homeostasis?
Sex
View SamplesMyeloproliferative neoplasms are frequently associated with aberrant constitutive tyrosine kinase (TK) activity resulting from point mutations or chimaeric fusion genes, such as BCR ABL1 or JAK2 V617F. We report here for the first time in hematological malignancies, two novel fusion genes involving the TK RET, BCR-RET and FGFR1OP-RET, in chronic myelo monocytic leukemia (CMML) cases. The two RET fusion genes lead to the aberrant activation of RET, are able to transform hematopoietic cells and skew the hematopoietic differentiation program towards the monocytic/macrophage lineage. We also report that the BCR-RET fusion protein is insensitive to Imatinib but sensitive to Sorafenib in vivo. CMML is an hematopoietic malignancy associated with the frequent activation of the RAS pathway. The RET fusion genes seems to constitutively mimic the same signaling pathway than RAS mutations. Overall, the RET fusion genes behaviors in the monocytic lineage underlie the role of the normal RET TK activity during the physiological monocytic differentiation.
RET fusion genes are associated with chronic myelomonocytic leukemia and enhance monocytic differentiation.
Cell line
View SamplesPhysical exercise training is a known protective factor against cardiovascular morbidity and mortality. Nevertheless, the underlying specific molecular mechanisms still remain uncompletely explored. To identify molecular mechanisms by which exercise training induces this favorable phenotype a genomic approach was used in an animal model of mild exercise previously demonstrated by our group to induce cardioprotection.
Gene expression profile of rat left ventricles reveals persisting changes following chronic mild exercise protocol: implications for cardioprotection.
No sample metadata fields
View Samplesaffy_ccr_maize - affy_ccr_maize - Cinnamoyl-CoA reductase (CCR) catalyzes a key step in monolignol biosynthesis. We show that downregulation of CCR in maize was associated with lower lignin content and a strong decrease in H units. Concomitantly, these cell wall modifications were associated with higher digestibility. On another hand, immunocytochemistry indicated a modification of lignification pattern and cellulose content. Transcript profiling was used as comprehensive phenotyping tools to investigate how CCR downregulation impacted metabolism and the biosynthesis of other cell wall polymers. -2 wild type and 2 CCR mutants were compared. Plants were grown in greenhouse condition and harvested at 7-8 leaf stages.
Characterization of a cinnamoyl-CoA reductase 1 (CCR1) mutant in maize: effects on lignification, fibre development, and global gene expression.
No sample metadata fields
View SamplesMalting is seed germination under strictly controlled environmental conditions. Malting quality is a complex phenotype that combines a large number of interrelated components, each of which shows complex inheritance. Currently, only a few genes involved in determining malting quality have been characterized. This study combined transcript profiling with phenotypic correlations to identify candidate genes for malting quality.
Differentially expressed genes during malting and correlation with malting quality phenotypes in barley (Hordeum vulgare L.).
No sample metadata fields
View SamplesThe goal of this experiment was to investigate the molecular mechanism of how Set-beta regulates neurite growth. Set-betas subcellular localization is regulated by posttranslational modifications. We found that Set-beta suppresses neurite growth of purified postnatal rat retinal ganglion cell (RGC) primary neurons when it is overexpressed in the nucleus, whereas recruiting Set-beta to cellular membrane by fusing myr-tag to its N-terminus promotes neurite growth. Here, we transfected purified by immunopanning postnatal rat RGC with wild-type Set-beta which localizes to the nucleus, myr-Set-beta which is recruited to cellular membranes, and mCherry control, and analyzed with microarrays Set-betas subcellular localization-dependent effects on gene expression. We found that wild-type Set- regulated expression of significantly more genes than myr-Set-, consistent with wild-type Set-s nuclear localization and previously described roles in regulating transcription. These data reveal potential downstream gene effectors regulating neurite growth, and specific candidate genes could be validated and tested in future experiments.
Regulating Set-β's Subcellular Localization Toggles Its Function between Inhibiting and Promoting Axon Growth and Regeneration.
Specimen part
View SamplesTumors contain a fraction of cancer stem cells that maintain the propagation of the disease. The CD34CD38_ cells, isolated from acute myeloid leukemia (AML), were shown to be enriched leukemic stem cells (LSC). We isolated the CD34CD38_ cell fraction from AML and compared their gene expression profiles to the CD34CD38 cell fraction, using microarrays. We found 409 genes that were at least twofold over- or underexpressed between the two cell populations. These include underexpression of DNA repair, signal transduction and cell cycle genes, consistent with the relative quiescence of stem cells, and chromosomal aberrations and mutations of leukemic cells. Comparison of the LSC expression data to that of normal hematopoietic stem cells (HSC) revealed that 34% of the modulated genes are shared by both LSC and HSC, supporting the suggestion that the LSC originated within the HSC progenitors. We focused on the Notch pathway since Jagged-2, a Notch ligand was found to be overexpressed in the LSC samples. We show that DAPT, an inhibitor of gamma-secretase, a protease that is involved in Jagged and Notch signaling, inhibits LSC growth in colony formation assays. Identification of additional genes that regulate LSC self-renewal may provide new targets for therapy.
Gene expression profiles of AML derived stem cells; similarity to hematopoietic stem cells.
Specimen part
View SamplesIn this experiment, mucous neck cells from the gastric epithelium of normal, adult C57/B6 mice were laser-capture microdissected to determine gene expression in neck cells relative to pit cells, parietal cells, and zymogenic cells, whose expression profiles were previously deposited in GEO.
Evolution of the human gastrokine locus and confounding factors regarding the pseudogenicity of GKN3.
No sample metadata fields
View SamplesGene expression study of DSG2 silenced human microvascular endothelial cells
Desmoglein-2-integrin Beta-8 interaction regulates actin assembly in endothelial cells: deregulation in systemic sclerosis.
Specimen part
View SamplesMaintenance of vascular integrity in the adult animal is needed for survival and critically dependent on the endothelial lining, which controls barrier function, blood fluidity, and flow dynamics. However, nodal regulators that coordinate endothelial identity and function in the adult animal remain poorly characterized. Here we show that endothelial KLF2 and KLF4 control a large segment of the endothelial transcriptome thereby affecting virtually all key endothelial functions. Inducible endothelial-specific deletion of Klf2 and/or Klf4 reveals that a single allele of either gene is sufficient for survival, but absence of both (EC-DKO) results in acute death from myocardial infarction, heart failure, and stroke. EC-DKO animals exhibit profound compromise in vascular integrity and profound dysregulation of the coagulation system. Collectively, these studies establish an absolute requirement for KLF2/4 for maintenance of endothelial and vascular integrity in the adult animal. Overall design: Eight-to-ten-week old mice were intraperitoneally injected with tamoxifen to trigger endothelial-specific gene deletion of KLF2 and/or KLF4. At day 6 post-injection, endothelial cells were isolated from the heart and total RNA was purified.
KLF2 and KLF4 control endothelial identity and vascular integrity.
Specimen part, Subject
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