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E-MEXP-580
Saccharomyces cerevisiae
18 Downloadable Samples
Affymetrix Yeast Genome S98 Array (ygs98)
Description
Nitric oxide and NO-derived species (RNS) are defense molecules with broad antimicrobial activity. Micro-organisms have developed strategies to sense RNS and counteract their damaging effects. We used Saccharomyces cerevisiae, harbouring a deletion of YHB1 that encodes the main NO scavenger enzyme, to study consequences of RNS exposure on whole genome transcriptional response. The expression of >700 genes was altered on RNS treatment. No major role for ROS-scavenging enzymes was found, and the respiratory chain, the main site of ROS production, had only minor involvement in the RNS-induced stress. The changes were generally transient and also found after treatment with the respiratory inhibitor myxothiazol. 117 genes however showed a persistent response which was not observed after myxothiazol treatment. Of these, genes of the glutathione and DNA repair systems, iron homeostasis and transport were found up-regulated. Severe repression of genes of respiratory chain enzymes was observed. Many of these genes are known to be regulated by the transcription factor Hap1p suggesting that RNS might interfere with Hap1p activity. We showed also that Msn2/4p and Yap1p, key regulators of the response to, respectively, general stress and oxidative stress, played a role in mediating the RNS-induced response.
Publication Title
Transcriptional response to nitrosative stress in Saccharomyces cerevisiae.
Sample Metadata Fields
Compound, Time
View Samples- Saccharomyces cerevisiae
- 29 Downloadable Samples
- Affymetrix Yeast Genome S98 Array (ygs98)
Description
The mitochondrial respiratory chain is composed of lipoprotein complexes imbedded in the inner mitochondrial membrane. This chain of enzymes transfers electrons from NADH and FADH2, provided from divers metabolic pathways, to oxygen. It couples the transfer of electrons to the translocation of protons across the membrane. Several clinical syndromes have been associated with respiratory dysfunction caused by mitochondrial or nuclear mutations. A number of mutations in the mitochondrial genes encoding for cytochrome b (CYTB) and cytochrome oxidase (COX 1, 2 and 3) have been linked with diseases. We are using yeast mutants to characterize the deleterious effect of mutations reported in patients on the assembly and catalytic properties of the affected enzymes, and to study the impact of mutations in nuclear genes, such as OXA1, encoding for factors required for the assembly of the respiratory complexes. In this work, we monitored the effects of the mutations causing respiratory defect on the whole genome expression. We compared the change in gene expression in rho0 cells (with a complete deletion of the mitochondrial genome, and by consequence without respiratory chain), in cells with either a single defective enzyme or several, and in cells after prolonged treatment with the bc1 inhibitors myxothiazol or antimycin. The impact of the mutations on the respiratory function ranged from mild to severe. The expression of approx. 350 genes was changed in at least one mutant. Cluster analysis was performed using the Cluster program (Eisen, 1998, PNAS 95:14863). Four groups of genes were studied in more details: Group A, the most repressed genes; Group B, the most over-expressed genes; Group C, genes more repressed in rho0 and Doxa1 cells; and Group D, genes more over-expressed in Doxa1.
Publication Title
Multiple defects in the respiratory chain lead to the repression of genes encoding components of the respiratory chain and TCA cycle enzymes.
Sample Metadata Fields
Compound
View Samples- Mus musculus
- 11 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
Primary murine fetal liver cells were freshly isolated from day e14.5 livers and then sorted for successive differentiation stages by Ter119 and CD71 surface expression (ranging from double-negative CFU-Es to Ter-119 positive enucleated erythrocytes) [Zhang, et al. Blood. 2003 Dec 1; 102(12):3938-46]. RNA isolated from each freshly isolated, stage-sorted population was reverse-transcribed, labelled, and then hybridized onto 3' oligo Affymetrix arrays. Important erythroid specific genes as well as the proteins that regulate them were elucidated through this profiling based on coexpression and differential expression patterns as well as by extracting specific GO categories of genes (such as DNA-binding proteins).
Publication Title
Homeodomain-interacting protein kinase 2 plays an important role in normal terminal erythroid differentiation.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 51 Downloadable Samples
- Affymetrix Human Genome U133A Array (hgu133a)
Description
This study was performed with an overall aim to compare gene expression prolife in human sarcoma cell lines and in primary untransformed cells.
Publication Title
No associated publication
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 47 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Cellular senescence is a program of irreversible cell cycle arrest that normal cells undergo in response to progressive shortening of telomeres, changes in telomeric structure, oncogene activation or oxidative stress. The underlying signalling pathways, potentially of major clinicopathological relevance, are unknown. A major stumbling block to studying senescence has been the absence of suitable model systems because of the asynchrony of this process in heterogeneous cell populations. To simplify this process many investigators study oncogene-induced senescence due to expression of activated oncogenes where senescence occurs prematurely without telomere attrition and can be induced acutely in a variety of cell types. We have taken a different approach by making use of the finding that reconstitution of telomerase activity by introduction of the catalytic subunit of human telomerase alone is incapable of immortalising all human somatic cells, but inactivation of the p16-pRB and p53-p21 pathways are required in addition. The ability of SV40 large T antigen to inactivate the p16-pRB and p53-p21 pathways has enabled us to use a thermolabile mutant of LT antigen, in conjunction with hTERT, to develop conditionally immortalised human (HMF3A) fibroblasts that are immortal but undergo an irreversible growth arrest when the thermolabile LT antigen is inactivated leading to activation of pRB and p53. When these cells cease dividing, senescence-associated- b-galactosidase activity is induced and the growth-arrested cells have morphological features and express genes in common with senescent cells. Since these cells growth arrest in a synchronous manner they are an excellent starting point for dissecting the pathways that underlie cellular senescence and act downstream of p16-pRB and p53-p21 pathways. We have combined genome-wide expression profiling with genetic complementation to undertake identification of genes that are differentially expressed when these conditionally immortalised human fibroblasts undergo senescence upon activation of the p16-pRB and p53-p21 tumour suppressor pathways.
Publication Title
Activation of nuclear factor-kappa B signalling promotes cellular senescence.
Sample Metadata Fields
Cell line, Treatment
View Samples- Homo sapiens
- 36 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
KSHV-encoded miRNAs target MAF to induce endothelial cell reprogramming.
Sample Metadata Fields
Sex, Specimen part
View Samples- Homo sapiens
- 34 Downloadable Samples
- Affymetrix Human Gene 1.0 ST Array (hugene10st)
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
No associated publication
Sample Metadata Fields
Cell line
View Samples- Mus musculus
- 29 Downloadable Samples
- Affymetrix Mouse Genome 430A 2.0 Array (mouse430a2)
Description
PD is the second most common neurodegenerative disease worldwide with growing prevalence. MPTP is a neurotoxin which causes the appearance of Parkinson's disease (PD) pathology. The involvement of the cholinergic system in PD has been identified decades ago and anti-cholinergic drugs were upon the first drugs used for symptomatic treatment of PD. Of note, MPTP intoxication is a model of choice for symptomatic neuroprotective therapies since it have been quite predictive. Mice were exposed to the dopaminergic neurotoxin 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP), with or without the protective acetylcholinesterase (AChE-R) variant. Transgenic AChE-S (the synaptic variant), AChE-R (the shorter, protective variant) and FVB/N control mice were included in this study. Two brain regions were examined: the pre-frontal cortex (PFC) and the striatal caudate-putamen (CPu). Each condition (i.e brain region and transgenic variant) was examined on both naive and MPTP-exposed mice.
Publication Title
Meta-analysis of genetic and environmental Parkinson's disease models reveals a common role of mitochondrial protection pathways.
Sample Metadata Fields
Specimen part, Treatment
View Samples- Homo sapiens
- 26 Downloadable Samples
- Affymetrix Human Exon 1.0 ST Array [probe set (exon) version (huex10st)
Description
Sub-thalamic deep brain stimulation (DBS) reversibly modulates Parkinsons disease (PD) motor symptoms, providing an unusual opportunity to compare leukocyte transcripts in the same subjects before and after neurosurgery and after disconnecting the stimulus (ON-and OFF-stimulus). Here, we report rapid stimulus-induced and largely reversible changes in PD leukocyte transcripts, which were larger in scope than the disease-induced changes. These transcript changes classified advanced pre- from post-surgery PD patients and discriminated patients from controls. Moreover, the extent of changes correlated with the neurological efficacy of the DBS neurosurgery, and covered both regulatory pathways and individual transcript changes, e.g. SNCA, PARK7 and the splicing factor SFRS1. Following 1 hour OFF-stimulus, these changes were largely reversed. We extracted from these differences a modified transcripts signature which discriminated controls from advanced PD patients, pre- from post-surgery and ON-from OFF-stimulus conditions. A further gene-list independent analysis detected reversed pathways. Our findings suggest future uses of this approach and the discovered molecular signature for early diagnostics of PD and for identifying novel targets for therapeutic intervention in this and other DBS-treatable neurological diseases.
Publication Title
Deep brain stimulation induces rapidly reversible transcript changes in Parkinson's leucocytes.
Sample Metadata Fields
Sex, Specimen part, Disease stage
View Samples- Mus musculus
- 25 Downloadable Samples
- Affymetrix Mouse Gene 2.0 ST Array (mogene20st)
Description
Administration of G-CSF mobilizes a unique population of CD11b+Ly6C+CD34+mature monocytes that can inhibit GVHD in murine models of BMT via an iNOS-dependent mechanism. The transcriptional profiles of flow sorted lineage-CD11b+CD34+ cells from G-CSF treated mice were compared with conventional splenic Ly6C+ and Ly6C- monocytes, progenitor cells and cultured myeloid-derived suppressor cells. Further comparisons were made with lineage-CD11b+CD34+ cells from G-CSF treated mice that had been grown in culture or that were derived from iNOS ko mice.
Publication Title
No associated publication
Sample Metadata Fields
Specimen part
View Samples