Salmonella enterica is a Gram-negative bacterium that causes gastroenteritis, bacteremia and typhoid fever in several animal species including humans. Its virulence is greatly dependent on two type III secretion systems (T3SSs), encoded in pathogenicity islands 1 (SPI1) and 2 (SPI2), respectively. These systems translocate proteins called effectors into eukaryotic host cell. Effectors interfere with certain host signal transduction pathways to allow the internalization of pathogens and their survival and proliferation inside vacuoles. SteA is one of the few Salmonella effectors that are substrates of both T3SSs. Nothing is known about the function of this protein inside the host cells. Here, we used gene arrays and bioinformatics analysis to study the genetic response of human epithelial cells to SteA. We found that constitutive synthesis of SteA in epithelial cells leads to induction of genes related to extracellular matrix organization and regulation of cell proliferation and serine/threonine kinase signaling pathways. SteA also represses genes related to immune processes and regulation of purine nucleotide synthesis and pathway-restricted SMAD protein phosphorylation. Consisted with this analysis a cell biology approach revealed that epithelial cells expressing steA show altered cell morphology, reduction of cytotoxicity, cell-cell adhesion and migration capability, and increase in endocytosis.
Global impact of Salmonella type III secretion effector SteA on host cells.
Cell line
View SamplesUntreated HIV-1 infection progresses through acute and asymptomatic stages to AIDS. While each of the three stages has well-known clinical, virologic and immunological characteristics, much less is known of the molecular mechanisms underlying each stage. Here we report lymphatic tissue microarray analyses revealing for the first time stage-specific patterns of gene expression during HIV-1 infection. We show that while there is a common set of key genes with altered expression throughout all stages, each stage has a unique gene-expression signature. The acute stage is most notably characterized by increased expression of hundreds of genes involved in immune activation, innate immune defenses (e.g.MDA-5, TLR-7 and -8, PKR, APOBEC3B, 3F, 3G), adaptive immunity, and in the pro-apoptotic Fas-Fas-L pathway. Yet, quite strikingly, the expression of nearly all acute-stage genes return to baseline levels in the asymptomatic stage, accompanying partial control of infection. In the AIDS stage, decreased expression of numerous genes involved in T cell signaling identifies genes contributing to T cell dysfunction. These common and stage-specific, gene-expression signatures provide new insights into the molecular mechanisms underlying the host response and the slow, natural course of HIV-1 infection.
Microarray analysis of lymphatic tissue reveals stage-specific, gene expression signatures in HIV-1 infection.
Sex, Age, Specimen part, Disease, Disease stage, Race, Subject
View SamplesThis project is based on the hygiene hypothesis that exposure to TB provides a protective mechanism against asthma through specific cytokines and the balance of Th1, Th2 cells. Additionally, expression changes are examined in patients with and without atopy in combination with asthma and PPD status. Expression levels were evaluated in CD4+ cells isolated from peripheral blood of 30 patients. Each patient was evaluated on the entire U133 Affymetrix GeneChip set.
A module-based analytical strategy to identify novel disease-associated genes shows an inhibitory role for interleukin 7 Receptor in allergic inflammation.
No sample metadata fields
View SamplesComparison of the transcriptome of human kideny cancer cells either wild-type for FH or FH-deficient. The UOK262 cells were isolated from mediastinum metastasis of a HLRCC patient (Yang et al. Cancer Genetics and Cytogenetics, Volume 196, Issue 1, 1 January 2010, Pages 45–55). FH function was restored in the UOK262 by re-expressing the FH transcript from an exogenous plasmid. Overall design: Examination of gene transciption in 2 cell types.
Fumarate is an epigenetic modifier that elicits epithelial-to-mesenchymal transition.
No sample metadata fields
View SamplesComparison of the transcriptome of immortalised mouse kidney epithelial cells either wt for Fh1 or Fh1-deficient. The cells were isolated from kidneys of P5 mouse(see Frezza et al, Nature 2011). Briefly, Fh1_fl (flox) are wt for Fh1 (floxed cassette not excised), clone 1 and clone 19 are two different Fh1-deificent clones (floxed cassette excised) and Rec are clone 19 with reconstituted Fh1 expression from exogenous plasmid. Overall design: Examination of gene transciption in 4 cell types.
Fumarate is an epigenetic modifier that elicits epithelial-to-mesenchymal transition.
Specimen part, Cell line, Subject
View SamplesAnalysis of gene-expression profiles by microarrays can be very useful to characterize new potential candidate genes, key regulatory networks, and to define phenotypes or molecular signatures to improve the diagnosis or classification of the disease. We have used this approach in the study of one of the major causes of allergic diseases in Mediterranean countries, the olive pollen response, in order to find differential molecular markers among five clinical groups, Non-allergic, Asymptomatic, Allergic but not to olive pollen, Non-treated, olive pollen allergic patients and Olive pollen allergic patients (under specific-immunotherapy). The results of gene-expression by principal components analysis (PCA) clearly showed five clusters of samples that correlated with the five clinical groups. Analysis of differential gene-expression by multiple testing, and functional analysis by KEGG and Gene-Ontology revealed differential genes and pathways among the 5 clinical groups.
Differential gene-expression analysis defines a molecular pattern related to olive pollen allergy.
No sample metadata fields
View SamplesThe association between hyper-inflammatory states and numerous diseases is widely recognized, but our understanding of the molecular strategies that have evolved to prevent uncontrolled activation of inflammatory responses remains incomplete. Here, we report a critical, non-transcriptional role of GPS2 as a guardian against hyperstimulation of TNFA-induced gene program. GPS2 cytoplasmic actions are required to specifically modulate RIP1 ubiquitylation and JNK activation by inhibiting TRAF2/Ubc13 enzymatic activity. In vivo relevance of GPS2 anti-inflammatory role is confirmed by inhibition of TNFA target genes in macrophages and by improved insulin signaling in the adipose tissue of aP2-GPS2 transgenic mice. As the non-transcriptional role is complemented by GPS2 functioning as positive and negative cofactor for nuclear receptors, in vivo overexpression also results in elevated circulating level of resistin and development of hepatic steatosis. Together, these studies define GPS2 as a molecular guardian required for precise control of inflammatory responses involved in immunity and homeostasis. Overall design: RNA-sequencing of polyA selected RNA molecules in 293T cells and ChIP-seq of GPS2, TBL1, and NCOR.
A protective strategy against hyperinflammatory responses requiring the nontranscriptional actions of GPS2.
No sample metadata fields
View SamplesMyotonic Dystrophy Type-2 (DM2) is an autosomal dominant disease caused by the expansion of a CCTG tetraplet repeat. It is a multisystemic disorder, affecting skeletal muscles, the heart, the eye, the central nervous system and the endocrine system.
Genome wide identification of aberrant alternative splicing events in myotonic dystrophy type 2.
Sex, Age, Specimen part, Disease, Disease stage
View SamplesThymic lymphomas develop spontaneously in LN3 mice. As for T-ALL in general, ex vivo LN3 lymphoma cells require stromal support to remain viable in culture. We found that primary stromal cells from thymic lymphomas, but not from wild-type thymi, support ex vivo lymphoma survival. By FACS sorting stromal populations, we identified dendritic cells in the tumor microenvironment as the cells capable of supporting lymphoma survival.
Endogenous dendritic cells from the tumor microenvironment support T-ALL growth via IGF1R activation.
Sex, Age, Specimen part, Disease, Disease stage
View SamplesTumor cells exhibit aberrant metabolism characterized by high glycolysis even in the presence of oxygen. This metabolic reprogramming, known as the Warburg effect, provides tumor cells with the substrates and redox potential required for the generation of biomass. Here, we show that the mitochondrial NAD-dependent deacetylase SIRT3 is a crucial regulator of the Warburg effect. SIRT3 loss promotes a metabolic profile consistent with high glycolysis required for anabolic processes in vivo and in vitro. Mechanistically, SIRT3 mediates metabolic reprogramming independently of mitochondrial oxidative metabolism and through HIF1a, a transcription factor that controls expression of key glycolytic enzymes. SIRT3 loss increases reactive oxygen species production, resulting in enhanced HIF1a stabilization. Strikingly, SIRT3 is deleted in 40% of human breast cancers, and its loss correlates with the upregulation of HIF1a target genes. Finally, we find that SIRT3 overexpression directly represses the Warburg effect in breast cancer cells. In sum, we identify SIRT3 as a regulator of HIF1a and a suppressor of the Warburg effect.
SIRT3 opposes reprogramming of cancer cell metabolism through HIF1α destabilization.
Specimen part
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