The endothelial transcription factor Erg (Ets Related Gene) plays an important role in homeostasis and angiogenesis by regulating many endothelial functions including survival and junction stability. Here we show that Erg regulates endothelial cell migration. Transcriptome profiling of Erg-deficient endothelial cells (EC) identified 80 genes involved in cell migration as candidate Erg targets, including regulators of the Rho GTPases. Inhibition of Erg expression in human umbilical vein endothelial cells (HUVEC) resulted in decreased migration in vitro, whilst Erg over-expression using adenovirus caused increased migration. Live-cell imaging of Erg-deficient HUVEC showed a reduction in lamellipodia, in line with decreased motility. Both actin and tubulin cytoskeletons were disrupted in Erg-deficient EC, with a dramatic increase in tubulin acetylation. Amongst the most significant microarray hit was the cytosolic histone deacetylase (HDAC)-6, a regulator of cell migration. Rescue experiments confirmed that HDAC6 mediates the Erg-dependent regulation of tubulin acetylation and actin localization.
The transcription factor Erg regulates expression of histone deacetylase 6 and multiple pathways involved in endothelial cell migration and angiogenesis.
Specimen part
View SamplesTo describe normal cardiac and brain development during late first and early second trimester in human fetuses using microarray and pathways analysis and the creation of a corresponding normal database. RNA from recovered tissues was used for transcriptome analysis with Affymetrix 1.0 ST microarray chip. From the amassed data we investigated differences in cardiac and brain development within the 10-18 GA period dividing the sample by GA in three groups: 10-12 (H1), 13-15(H2) and 16-18(H3) weeks. A fold change of 2 or above adjusted for a false discovery rate of 5% was used as initial cut-off to determine differential gene expression for individual genes. Test for enrichment to identify functional groups were carried out using the Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG). Array analysis correctly identified the cardiac specific genes, and transcripts reported to be differentially expressed were confirmed by qRT-PCR.
Metabolic gene profile in early human fetal heart development.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Genome-wide DNA methylation as an epigenetic consequence of Epstein-Barr virus infection of immortalized keratinocytes.
Specimen part
View SamplesThe oral cavity is the persistent reservoir for EBV with lifelong infection of resident epithelial and B cells. Infection of these cell types results in distinct EBV gene expression patterns that are regulated by epigenetic modifications involving DNA methylation and chromatin structure. Such regulation of EBV gene expression relies on viral manipulation of the host epigenetic machinery that may inadvertently result in long-lasting, oncogenic host epigenetic reprogramming. To test this hypothesis in the context of EBV infection of epithelial cells, we established a transient infection model to identify the epigenetic consequences after EBV infection of immortalized normal oral keratinocytes and subsequent viral loss.
Genome-wide DNA methylation as an epigenetic consequence of Epstein-Barr virus infection of immortalized keratinocytes.
Specimen part
View SamplesBecause it excises thymine from GT mismatches, TDG was proposed to counter mutagenesis by 5-methylcytosine deamination. Yet, TDG was also observed to attack 5-methycytosine itself, making it a candidate DNA demethylase, and interactions with transcription factors implicated additional functions in gene regulation. Unlike other DNA glycosylases, TDG is essential for embryonic development. Fibroblasts from Tdg null embryos show massively impaired gene regulation, and this correlates with imbalanced histone modification and CpG methylation. TDG associates with the promoters of affected genes in MEFs and in embryonic stem cells, but epigenetic aberrations appear only in differentiated cells. TDG also contributes to the maintenance of active and bivalent chromatin during cell differentiation, using its DNA glycosylase activity to counter aberrant de novo methylation. Thus, TDG dependent DNA repair stabilizes epigenetic states during cell differentiation.
Embryonic lethal phenotype reveals a function of TDG in maintaining epigenetic stability.
Specimen part
View SamplesZEB2 is a multi-zinc-finger transcription factor known to play a significant role in early neurogenesis and in EMT-dependent tumor metastasis. While the function of ZEB2 in T lymphocytes is unknown, activity of the closely related family member ZEB1 has been implicated in lymphocyte development. Here, we find that ZEB2 expression is upregulated by activated T cells, specifically in the KLRG1hi effector CD8+ T cell subset. Loss of ZEB2 expression results in a significant loss of antigen-specific CD8+ T cells following primary and secondary infection with a severe impairment in the generation of the KLRG1hi effector-memory cell population. We show that ZEB2, which can bind DNA at tandem, consensus E-box sites, regulates gene expression of several E-protein targets and may directly repress CD127 and IL-2 in CD8+ T cells responding to infection. Furthermore, we find that T-bet binds to highly conserved T-box-sites in the ZEB2 gene and that T-bet and ZEB2 regulate similar gene-expression programs in effector T cells, suggesting that T-bet acts upstream and through regulation of ZEB2. Taken together, we place ZEB2 in a larger transcriptional network that is responsible for the balance between terminal differentiation and formation of memory CD8+ T cells.
Transcriptional repressor ZEB2 promotes terminal differentiation of CD8+ effector and memory T cell populations during infection.
Sex, Age, Specimen part
View SamplesStabilized Alpha-Helix peptides of BCL9 HD2 (SAH-BCL9) block BCL9 and B9L interactions with beta-catenin and specifically downregulate Wnt target gene expression.
Targeted disruption of the BCL9/β-catenin complex inhibits oncogenic Wnt signaling.
Specimen part, Cell line, Treatment
View SamplesDisrupted skin barrier due to altered keratinocyte differentiation is common in pathologic conditions such as atopic dermatitis, ichthyosis and psoriasis. However, the molecular cascades governing keratinocyte terminal differentiation are still poorly understood. We have previously demonstrated that a dominant mutation in ZNF750 leads to a clinical phenotype that reminiscent of psoriasis and seborrheic dermatitis. We defined ZNF750 as a nuclear effector that is strongly activated in and essential for keratinocyte terminal differentiation. ZNF750 knockdown in HaCaT keratinocytes markedly reduced the expression of epidermal late differentiation markers, including gene subsets of epidermal differentiation complex and skin barrier formation such as FLG, LOR, SPINK5, ALOX12B and DSG1, known to be mutated in various human skin diseases. Furthermore, ZNF750 over-expression in undifferentiated cells induced terminal differentiation genes. Thus, ZNF750 is a regulator of keratinocyte terminal differentiation, and with its downstream targets can serve in future elucidation of therapeutics for common disease of skin barrier
ZNF750 is expressed in differentiated keratinocytes and regulates epidermal late differentiation genes.
Specimen part
View SamplesAn understanding of the mechanisms regulating white adipose tissue (WAT) formation is key for developing of new tools to treat obesity and its related diseases. Here, we identify DEPTOR as a positive regulator of adipogenesis whose expression is associated with obesity. In a polygenic mouse model of obesity/leanness, Deptor is part of the Fob3a QTL linked to obesity and we fine that Deptor is the highest priority candidate gene regulating WAT accumulation in this model. Using a doxycycline-inducible mouse model for Deptor overexpression, we confirmed that Deptor promotes WAT expansion in vivo. DEPTOR expression is elevated in WAT of obese humans and strongly correlates with the degree of obesity. We show that DEPTOR is induced during adipogenesis and that its overexpression cell-autonomously promotes, while its suppression blocks, adipogenesis. DEPTOR positively regulates adipogenesis by promoting the activity of the pro-adipogenic factors Akt/PKB and PPAR-gamma. These results establish DEPTOR as a physiological regulator of adipogenesis and provide new insights into the molecular mechanisms controlling WAT formation.
DEPTOR cell-autonomously promotes adipogenesis, and its expression is associated with obesity.
Sex, Specimen part
View SamplesOb/ob mice were given 0, 12.5 or 25 ng/hr leptin through an osmotic pump. After 12 days, livers RNA was prepared and illumina microarrays were done. We tested whether leptin can ameliorate diabetes independent of weight loss by defining the lowest dose at which leptin treatment of ob/ob mice reduces plasma [glucose] and [insulin]. We found that a leptin dose of 12.5 ng/hour significantly lowers blood glucose and that 25 ng/hour of leptin normalizes plasma glucose and insulin without significantly reducing body weight, thus establishing that leptin exerts its most potent effects on glucose metabolism. To find possible mediators of this effect, we profiled liver mRNA using microarrays and identified IGF Binding Protein 2 as being regulated by leptin with a similarly high potency. Over-expression of IGFBP2 by an adenovirus reversed diabetes in insulin resistant ob/ob, Ay/a and diet-induced obese mice (DIO), as well as insulin deficient streptozotocin-treated mice. Hyperinsulinemic clamp studies showed a three-fold improvement in hepatic insulin sensitivity following IGFBP2 treatment in ob/ob mice. These results show that IGFBP2 can regulate glucose metabolism, a finding with potential implications for the pathogenesis and treatment of diabetes.
Antidiabetic effects of IGFBP2, a leptin-regulated gene.
Specimen part, Time
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