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GSE11927
Escherichia coli
2 Downloadable Samples
Affymetrix E. coli Genome 2.0 Array (ecoli2)
Description
Adherence of pathogenic Escherichia coli strains to intestinal epithelia is essential for infection. For enterohemorrhagic E. coli (EHEC) serotype O157:H7, we have previously demonstrated that multiple factors govern this pathogens adherence to HeLa cells (39). One of these factors is CadA, a lysine decarboxylase, and this protein has been proposed to negatively regulate virulence in several enteric pathogens. In the case of EHEC strains, CadA modulates expression of the intimin, an outer membrane adhesin involved in pathogenesis. Here, we experimentally inactivated cadA in O157:H7 strain 86-24 to investigate the role of this gene in EHEC adhesion to tissue culture monolayers, global gene expression patterns, and colonization of the infant rabbit intestine. As expected, the cadA mutant did not possess lysine decarboxylation activity and was hyper-adherent to tissue-culture cells. Adherence of the cadA mutant was nearly 2-fold greater than that of the wt and complementation of the cadA defect reduced adherence back to wt levels. Furthermore, the cadA mutant affected the expression of intimin protein. Disruption of the eae gene (encoding the intimin protein) in the cadA mutant significantly reduced its adherence to tissue-culture cells. However, adherence of the cadA eae double mutant was greater than that of an 86-24 eae mutant, suggesting that the enhanced adherence of the cadA mutant is not entirely attributable to enhanced expression of intimin in this background. Gene array analysis revealed that the cadA mutation significantly altered EHEC gene expression patterns; expression of 1332 genes was down-regulated and 132 genes up-regulated in the mutant compared to the wild type strain. Interestingly, the gene expression variation shows an EHEC-biased gene alteration including intergenic regions. Two putative adhesins: flagella and F9 fimbriae were up-regulated in the cadA mutant, suggestive of their association with adherence in absence of the Cad regulatory mechanism. Remarkably, in the infant rabbit model, the cadA mutant out-competed the wild type strain in the ileum but not in the cecum or mid-colon, raising the possibility that CadA negatively regulates EHEC pathogenicity in a tissue-specific fashion.
Publication Title
CadA negatively regulates Escherichia coli O157:H7 adherence and intestinal colonization.
Sample Metadata Fields
No sample metadata fields
View Samples- Saccharomyces cerevisiae
- 1 Downloadable Sample
- Affymetrix Yeast Genome S98 Array (ygs98)
Description
Zinc is indispensable for the catalytic activity and structural stability of many proteins, and its deficiency can have severe consequences for microbial growth in natural and industrial environments. For example, Zn depletion in wort negatively affects beer fermentation and quality. Several studies have investigated yeast adaptation to low Zn supply, but were all performed in batch cultures, where specific growth rate depends on Zn availability. The transcriptional responses to growth-rate and Zn availability are then intertwined, which obscures result interpretation. In the present study, transcriptional responses of Saccharomyces cerevisiae to Zn availability were investigated at a fixed specific growth rate under Zn limitation and excess in chemostat culture. To investigate the context-dependency of this transcriptional response, yeast was grown under several chemostat regimes resulting in various carbon (glucose), nitrogen (ammonium) and oxygen supplies. A robust set of genes that responded consistently to Zn limitation was identified and enabled the definition of a Zn-specific Zap1 regulon comprising of 26 genes and characterized by a broader ZRE consensus (MHHAACCBYNMRGGT) than so far described. Most surprising was the Zn-dependent regulation of genes involved in storage carbohydrate metabolism. Their concerted down-regulation was physiologically relevant as revealed by a substantial decrease in glycogen and trehalose cellular content under Zn limitation. An unexpectedly large amount of genes were synergistically or antagonistically regulated by oxygen and Zn availability. This combinatorial regulation suggested a more prominent involvement of Zn in mitochondrial biogenesis and function than hitherto identified
Publication Title
Physiological and transcriptional responses of Saccharomyces cerevisiae to zinc limitation in chemostat cultures.
Sample Metadata Fields
No sample metadata fields
View Samples- Saccharomyces cerevisiae
- 5 Downloadable Samples
- Affymetrix Yeast Genome S98 Array (ygs98)
Description
Zinc is indispensable for the catalytic activity and structural stability of many proteins, and its deficiency can have severe consequences for microbial growth in natural and industrial environments. For example, Zn depletion in wort negatively affects beer fermentation and quality. Several studies have investigated yeast adaptation to low Zn supply, but were all performed in batch cultures, where specific growth rate depends on Zn availability. The transcriptional responses to growth-rate and Zn availability are then intertwined, which obscures result interpretation. In the present study, transcriptional responses of Saccharomyces cerevisiae to Zn availability were investigated at a fixed specific growth rate under Zn limitation and excess in chemostat culture. To investigate the context-dependency of this transcriptional response, yeast was grown under several chemostat regimes resulting in various carbon (glucose), nitrogen (ammonium) and oxygen supplies. A robust set of genes that responded consistently to Zn limitation was identified and enabled the definition of a Zn-specific Zap1 regulon comprising of 26 genes and characterized by a broader ZRE consensus (MHHAACCBYNMRGGT) than so far described. Most surprising was the Zn-dependent regulation of genes involved in storage carbohydrate metabolism. Their concerted down-regulation was physiologically relevant as revealed by a substantial decrease in glycogen and trehalose cellular content under Zn limitation. An unexpectedly large amount of genes were synergistically or antagonistically regulated by oxygen and Zn availability. This combinatorial regulation suggested a more prominent involvement of Zn in mitochondrial biogenesis and function than hitherto identified.
Publication Title
Physiological and transcriptional responses of Saccharomyces cerevisiae to zinc limitation in chemostat cultures.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 4 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Efficient processing of target antigens by the ubiquitin-proteasome-system (UPS) is essential for treatment of cancers by T cell therapies. However, immune escape due to impaired expression of IFN--inducible components of the antigen presentation machinery and consequent inefficient processing of HLA-dependent tumor epitopes can be one important reason for failure of such therapies. Here, we show that repeated short-term co-cultures of Melan-A/MART-1 tumor antigen-expressing melanoma cells with Melan-A/MART-1 (26-35)-specific CTL led to the generation of clones resistant to CTL-mediated cell death. To determine which of the UPS components and its associated pathways was responsible for CTL escape; three UKRV-Mel-15a clones were subjected to microarray gene expression analysis.
Publication Title
Exposure to Melan-A/MART-126-35 tumor epitope specific CD8(+)T cells reveals immune escape by affecting the ubiquitin-proteasome system (UPS).
Sample Metadata Fields
Specimen part
View Samples- Saccharomyces cerevisiae
- 3 Downloadable Samples
- Affymetrix Yeast Genome S98 Array (ygs98)
Description
Zinc is indispensable for the catalytic activity and structural stability of many proteins, and its deficiency can have severe consequences for microbial growth in natural and industrial environments. For example, Zn depletion in wort negatively affects beer fermentation and quality. Several studies have investigated yeast adaptation to low Zn supply, but were all performed in batch cultures, where specific growth rate depends on Zn availability. The transcriptional responses to growth-rate and Zn availability are then intertwined, which obscures result interpretation. In the present study, transcriptional responses of Saccharomyces cerevisiae to Zn availability were investigated at a fixed specific growth rate under Zn limitation and excess in chemostat culture. To investigate the context-dependency of this transcriptional response, yeast was grown under several chemostat regimes resulting in various carbon (glucose), nitrogen (ammonium) and oxygen supplies. A robust set of genes that responded consistently to Zn limitation was identified and enabled the definition of a Zn-specific Zap1 regulon comprising of 26 genes and characterized by a broader ZRE consensus (MHHAACCBYNMRGGT) than so far described. Most surprising was the Zn-dependent regulation of genes involved in storage carbohydrate metabolism. Their concerted down-regulation was physiologically relevant as revealed by a substantial decrease in glycogen and trehalose cellular content under Zn limitation. An unexpectedly large amount of genes were synergistically or antagonistically regulated by oxygen and Zn availability. This combinatorial regulation suggested a more prominent involvement of Zn in mitochondrial biogenesis and function than hitherto identified
Publication Title
Physiological and transcriptional responses of Saccharomyces cerevisiae to zinc limitation in chemostat cultures.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 12 Downloadable Samples
- Affymetrix Human Genome U133A 2.0 Array (hgu133a2)
Description
Human epidermal keratinocytes were treated with 25 ng.ml EphB2 or EFNA4, both as-Fc conjugates (Sigma).
Publication Title
Eph-2B, acting as an extracellular ligand, induces differentiation markers in epidermal keratinocytes.
Sample Metadata Fields
Time
View Samples- Mus musculus
- 8 Downloadable Samples
Illumina HiSeq 2500
Description
Background: Skeletal muscle constitutes a significant portion of total body mass and is a major regulator of systemic metabolism as it serves as the major site for glucose disposal and the main reservoir for amino acids. With aging, cachexia, starvation, and myositis, there is a preferential loss of fast glycolytic muscle fibers. We previously reported a mouse model in which a constitutively-active Akt transgene is induced to express in a subset of muscle groups leading to the hypertrophy of type IIb myofibers with an accompanying increase in strength. This muscle growth protects mice in various cardio-metabolic disease models, but little is known about the underlying cellular and molecular mechanisms by which fast-twitch muscle impacts disease processes and regulates distant tissues. Purpose: In the present study, poly(A)+ tail mRNA-seq was performed to characterize the transcriptome of the hypertrophic gastrocnemius muscle from Akt1-transgenic mice. Results: Pathway analysis for the 3,481 differentially expressed genes in muscle identified enriched signaling pathways involving growth, cell cycle regulation, and inflammation. Combined metabolomics and transcriptomic analyses revealed that Akt1-induced muscle growth mediated a metabolic shift involving reductions in glycolysis and oxidative phosphorylation, but enhanced pentose phosphate pathway activation and increased branch chain amino acid accumulation. Signal peptide prediction analysis revealed 241 differentially expressed in muscle transcripts that potentially encode secreted proteins. A number of these secreted factors have signaling properties that are consistent with the myogenic, metabolic and cardiovascular-protective properties that have previously been associated with type IIb muscle growth. Conclusions: These data reveal that enhanced Akt signaling promotes the activation of the pentose phosphate and the accumulation of branched amino acids that are important for the production of nucleic acids and proteins. Numerous known and novel transcripts potentially encoding muscle secreted proteins were identified, indicating the importance of fast-twitch muscle in inter-tissue communication. Overall design: mRNA profiles of adult muscle growth from four muscle-specific conditional Akt transgenic (DTG) and four littermate control mice (1256[3Emut]Mck-rtTA) were generated by deep sequencing using Illumina HiSeq.
Publication Title
RNA-seq and metabolomic analyses of Akt1-mediated muscle growth reveals regulation of regenerative pathways and changes in the muscle secretome.
Sample Metadata Fields
Age, Specimen part, Cell line, Subject
View Samples- Homo sapiens
- 6 Downloadable Samples
- Affymetrix Human Genome U133A 2.0 Array (hgu133a2)
Description
Both ephrins and their receptors are membrane bound, restricting their interactions to the sites of direct cell-to-cell interfaces. They are widely expressed, often co-expressed and regulate developmental processes, cell adhesion, motility, survival, proliferation, and differentiation. Both tumor suppressor and oncogene activities are ascribed to EFNs and Ephs in various contexts. A major conundrum regarding the EFN/Eph system concerns their large number and functional redundancy, given the promiscuous cross-activation of ligands and receptors and the overlapping intracellular signaling pathways. To address this issue, we treated human epidermal keratinocytes with 5 EFNAs individually and defined the transcriptional responses in the cells. We found that a large set of genes is coregulated by all EFNAs. However, while the responses to EFNA3, EFNA 4 and EFNA 5 are identical, the responses to EFNA1 and EFNA2 are characteristic and distinctive. All EFNAs induce epidermal differentiation markers and suppress cell adhesion genes, especially integrins. Ontological analysis shows that all EFNAs induce cornification and keratin genes, while suppressing wound-healing associated, signaling, receptor and ECM associated genes. Transcriptional targets of AP1 are selectively suppressed by EFNAs. EFNA1 and EFNA2, but not the EFNA3, EFNA4, EFNA5 cluster, regulate the members of the ubiquitin-associated proteolysis genes. EFNA1 specifically induces collagen production. Our results demonstrate that the EFN-Eph interactions in the epidermis, while promiscuous, are not redundant but specific. This suggests that different members of the EFN/Eph system have specific, clearly demarcated functions.
Publication Title
Specific and shared targets of ephrin A signaling in epidermal keratinocytes.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 7 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
TDP-43 is an RNA/DNA-binding protein implicated in transcriptional repression and mRNA processing. Inclusions of TDP-43 are hallmarks of frontotemporal dementias and amyotrophic lateral sclerosis. Besides aggregation of TDP-43, loss of nuclear localization is observed in disease. To identify relevant targets of TDP-43, we performed an expression profiling study. Thereby, histone deacetylase 6 (HDAC6) downregulation was discovered upon TDP-43 silencing on mRNA and protein level in human embryonic kidney HEK293E and neuronal SH-SY5Y cells. This was accompanied by accumulation of the major HDAC6 substrate, acetyl-tubulin. Expression of wild-type but neither RNA-binding- nor nuclear-localization-deficient TDP-43 restored HDAC6 expression. Moreover, TDP-43 bound specifically to HDAC6 mRNA arguing for a direct functional interaction. Importantly, in vivo validation in TDP-43 knockout Drosophila melanogaster also showed HDAC6 mRNA decrease. HDAC6 is necessary for protein aggregate formation and degradation. Indeed, downregulation of HDAC6 reduced aggregate formation and increased cytotoxicity of expanded poly-glutamine ataxin-3 in TDP-43 silenced cells. This was completely restored by co-transfection with HDAC6. In conclusion, loss of functional TDP-43 causes HDAC6 downregulation and might thereby contribute to pathogenesis.
Publication Title
Knockdown of transactive response DNA-binding protein (TDP-43) downregulates histone deacetylase 6.
Sample Metadata Fields
Cell line
View Samples- Mus musculus
- 24 Downloadable Samples
- Affymetrix Murine Genome U74A Version 2 Array (mgu74av2)
Description
Attainment of a brown adipocyte cell phenotype in white adipocytes, with their abundant mitochondria and increased energy expenditure potential, is a legitimate strategy for combating obesity. The unique transcriptional regulators of the primary brown adipocyte phenotype are unknown, limiting our ability to promote brown adipogenesis over white. In the present work, we used microarray analysis strategies to study primary preadipocytes, and we made the striking discovery that brown preadipocytes demonstrate a myogenic transcriptional signature, whereas both brown and white primary preadipocytes demonstrate signatures distinct from those found in immortalized adipogenic models. We found a plausible SIRT1-related transcriptional signature during brown adipocyte differentiation that may contribute to silencing the myogenic signature. In contrast to brown preadipocytes or skeletal muscle cells, white preadipocytes express Tcf21, a transcription factor that has been shown to suppress myogenesis and nuclear receptor activity. In addition, we identified a number of developmental genes that are differentially expressed between brown and white preadipocytes and that have recently been implicated in human obesity. The interlinkage between the myocyte and the brown preadipocyte confirms the distinct origin for brown versus white adipose tissue and also represents a plausible explanation as to why brown adipocytes ultimately specialize in lipid catabolism rather than storage, much like oxidative skeletal muscle tissue.
Publication Title
Myogenic gene expression signature establishes that brown and white adipocytes originate from distinct cell lineages.
Sample Metadata Fields
No sample metadata fields
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