The transcription factor c-MYC intron binding protein 1 (MIBP1) binds to various genomic regulatory regions, including intron 1 of c-MYC. This factor is highly expressed in post-mitotic neurons in the fetal brain and may be involved in various biological steps, such as neurological and immunological processes. In this study, we globally characterized the transcriptional targets of MIBP1 and proteins that interact with MIBP1. Microarray hybridization followed by Gene Set Enrichment Analysis revealed that genes involved in the pathways downstream of MYC, NF-B, and TGF- were downregulated when HEK293 cells stably overexpressed MIBP1. In silico transcription factor binding site analysis of the promoter regions of these downregulated genes showed that the NF-B binding site was the most overrepresented. The upregulation of genes known to be in the NF-B pathway after the knockdown of endogenous MIBP1 in HT1080 cells supports the view that MIBP1 is a downregulator of the NF-B pathway. We also confirmed the binding of the MIBP1 to the NF-B site. By immunoprecipitation and mass spectrometry, we detected O-linked -N-acetylglucosamine (O-GlcNAc) transferase (OGT) as a prominent binding partner of MIBP1. Analyses using deletion mutants revealed that a 154-amino acid region of MIBP1 was necessary for its OGT binding and O-GlcNAcylation. A luciferase reporter assay showed that NF-B-responsive expression was repressed by MIBP1, and stronger repression by MIBP1 lacking the 154-amino acid region was observed. Our results indicate that the primary effect of MIBP1 expression is the downregulation of the NF-B pathway, and that this effect is attenuated by O-GlcNAc signaling.
Genome-wide repression of NF-κB target genes by transcription factor MIBP1 and its modulation by O-linked β-N-acetylglucosamine (O-GlcNAc) transferase.
Cell line
View SamplesRNA expression analysis was performed to compare patterns to DNA copy number changes and sensitivity to BCL2 inhibitors.
Integrative genomic analysis of small-cell lung carcinoma reveals correlates of sensitivity to bcl-2 antagonists and uncovers novel chromosomal gains.
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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.).
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View SamplesRNA expression analysis was performed to compare patterns to sensitivity to BCL2 inhibitors (ABT-263).
ABT-263: a potent and orally bioavailable Bcl-2 family inhibitor.
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View SamplesSporadic Creutzfeldt-Jakob disease (sCJD) is the most prevalent form of human prion disease and it is characterized by the presence of neuronal loss, spongiform degeneration, chronic inflammation and the accumulation of misfolded and pathogenic prion protein (PrPSc). The molecular mechanisms underlying these alterations are largely unknown, but the presence of intracellular neuronal calcium (Ca+2) overload, a general feature in models of prion diseases, is suggested to play a key role in prion pathogenesis. Here we describe the presence of massive regulation of Ca+2 responsive genes in sCJD brain tissue, accompanied by two Ca+2-dependent processes: endoplasmic reticulum stress and the activation of the cysteine proteases Calpains 1/2. Pathogenic Calpain activation in sCJD is linked to the cleavage of their cellular substrates, impaired autophagy and lysosomal damage, which is partially reversed by Calpain inhibition in a cellular prion model. Calpain 1 treatment enhances seeding activity of PrPSc in a prion conversion assay. Neuronal lysosomal impairment caused by Calpain over activation leads to the release of the lysosomal protease Cathepsin S that in sCJD mainly localises in axons. Additionally, massive Cathepsin S overexpression is detected in microglial cells. Alterations in Ca+2 homeostasis and activation of Calpain-Cathepsin axis already occur at pre-clinical stages of the disease as detected in a humanized sCJD mouse model. Altogether our work indicates that unbalanced Calpain-Cathepsin activation is a relevant contributor to the pathogenesis of sCJD at multiple molecular levels and a potential target for therapeutic intervention. Overall design: To identify differentially expressed genes during development of sCJD pathology we analysed the expression levels in the cortical region of tg340-PRNP129MM mice infected with sCJD MM1 brain homogenates at pre-clinical (120 dpi) and clinical (180 dpi) stages.
Altered Ca<sup>2+</sup> homeostasis induces Calpain-Cathepsin axis activation in sporadic Creutzfeldt-Jakob disease.
Subject, Time
View SamplesTET-family enzymes convert 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC) in DNA. Tet1 and Tet2 are Oct4-regulated enzymes that together sustain 5hmC in mouse embryonic stem (ES) cells. ES cells depleted of Tet1 by RNAi show diminished expression of the Nodal antagonist Lefty1, and display hyperactive Nodal signalling and skewed differentiation into the endoderm-mesoderm lineage in embryoid bodies in vitro. In Fgf4- and heparin-supplemented culture conditions that favor derivation of trophoblast stem (TS) cells, Tet1-depleted ES cells activate the trophoblast stem cell lineage determinant Elf5 and can colonize the placenta in mid-gestation embryo chimeras. Consistent with these findings, Tet1-depleted ES cells form aggressive hemorrhagic teratomas with increased endoderm, reduced neuroectoderm and ectopic appearance of trophoblastic giant cells. Thus Tet1 functions to regulate the lineage differentiation potential of ES cells. Here, we performed whole-genome transcriptome profiling of ES cells stably depleted of Tet1 by shRNA knockdown (Tet1-kd) cultured in either standard ES cell or in TS cell culture conditions. Gene expression changes in Tet1-kd ES cells were fairly modest compared to control (GFP-kd) cells, although gene ontology (GO) analysis of differentially expressed genes yielded many terms related to embryonic development and cell cycle regulation. In TS cell culture conditions, a core set of genes defining trophectodermal cell differentiation, including Cdx2, Eomes and Tead4, was enriched in Tet1-kd compared to GFP-kd cells.
Tet1 and Tet2 regulate 5-hydroxymethylcytosine production and cell lineage specification in mouse embryonic stem cells.
Specimen part
View SamplesDetailed information about stage-specific changes in gene expression is crucial for understanding the gene regulatory networks underlying development and the various signal transduction pathways contributing to morphogenesis. Here, we describe the global gene expression dynamics during early murine limb development, when cartilage, tendons, muscle, joints, vasculature, and nerves are specified and the musculoskeletal system of the limbs is established. We used whole-genome microarrays to identify genes with differential expression at 5 stages of limb development (E9.5 to 13.5), during fore-limb and hind-limb patterning. We found that the onset of limb formation is characterized by an up-regulation of transcription factors, which is followed by a massive activation of genes during E10.5 and E11.5 which tampers off at later time points. Among 3520 genes identified as significantly up-regulated in the limb, we find ~30% to be novel, dramatically expanding the repertoire of candidate genes likely to function in the limb. Hierarchical and stage-specific clustering identified expression profiles that correlate with functional programs during limb development and are likely to provide new insights into specific tissue patterning processes. Here we provide for the first time, a comprehensve analysis of developmentally regulated genes during murine limb development, and provide some novel insights into the expression dynamics governing limb morphogenesis.
Global gene expression analysis of murine limb development.
Specimen part
View SamplesSnail is a transcriptional repressor, which induces epithelial-mesenchymal transition. However, overall functions of Snail remain to be elucidated. This microarray was performed to investigate the influence of Snail expression on mRNA transcription levels in a lung adenocarcinoma cell line, II-18.
Epithelial-mesenchymal transition abolishes the susceptibility of polarized epithelial cell lines to measles virus.
Cell line
View SamplesIn most metazoan nuclei, heterochromatin is located at the nuclear periphery in contact with the nuclear lamina, which provides mechanical stability to the nucleus. We show that in cultured cells, chromatin de-compaction by the nucleosome binding protein HMGN5 decreases the sturdiness, elasticity, and rigidity of the nucleus. Mice overexpressing HMGN5, either globally or only in the heart, are normal at birth but develop hypertrophic heart with large cardiomyoctyes, deformed nuclei and disrupted lamina, and die of cardiac malfunction. Chromatin de-compaction is seen in cardiomyocytes of newborn mice but misshaped nuclei with disrupted lamina are seen only in adult cardiomyocytes, suggesting that loss of heterochromatin diminishes the ability of the nucleus to withstand the mechanical forces of the contracting heart. Thus, heterochromatin enhances the ability of the nuclear lamina to maintain the sturdiness and shape of the eukaryotic nucleus; a structural role for chromatin that is distinct from its genetic functions.
Chromatin decompaction by the nucleosomal binding protein HMGN5 impairs nuclear sturdiness.
Specimen part
View SamplesTo realize cell transplantation therapy for Parkinson's disease (PD), the grafted neurons should be integrated into the host neuronal circuit in order to restore the lost neuronal function. Here, using wheat germ agglutinin-based trans-synaptic tracing, we show that integrin 5 is selectively expressed in striatal neurons that are innervated by midbrain dopaminergic (DA) neurons from the mouse experiments. Additionally, we found that integrin 51 was activated by the administration of estradiol-2-benzoate (E2B) in striatal neurons of adult female rats. Importantly, we observed that the systemic administration of E2B into hemi-parkinsonian rat models facilitates the functional integration of grafted DA neurons derived from human induced pluripotent stem cells into the host striatal neuronal circuit via the activation of integrin 51. Finally, methamphetamine-induced abnormal rotation was recovered earlier in E2B-administrated rats than in rats that received other regimens. Our results suggest that the simultaneous administration of E2B with stem cell-derived DA progenitors can enhance the efficacy of cell transplantation therapy for PD.
Estradiol Facilitates Functional Integration of iPSC-Derived Dopaminergic Neurons into Striatal Neuronal Circuits via Activation of Integrin α5β1.
Specimen part
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