The ability to regenerate or recover from injuries varies greatly not only between species but also between tissues and organs or developmental stages of the same species. The mechanisms behind these different regenerative capabilities are ultimately dependent on the control of genome activity, determined by a complex interplay of regulatory elements functioning at the level of chromatin. Resetting of gene expression patterns during injury responses is, thus, shaped by the coordinated action of genomic regions (enhancers, silencers) that integrate the activity of multiple sequence-specific DNA binding proteins (transcription factors and cofactors). Using genome- wide approaches to interrogate chromatin function here we identify the regulatory elements governing tissue recovery in Drosophila wing imaginal discs, which show a high regenerative capacity after genetically induced cell death. Our findings point to a global co-regulation of gene expression and provide evidence for Damage Responding Regulatory Elements (DRRE), some of which are novel whereas others are also used in other tissues or developmental stages. Overall design: We collected data at different time points (0, 15 and 25h) after apoptosis induction. These time periods were selected because they included the most important transcriptional responses to apoptosis, ranging from the earliest gene expression up to complete re-patterning. Discs kept at the same conditions without inducing cell death were used as controls.
Damage-responsive elements in <i>Drosophila</i> regeneration.
Specimen part, Subject
View SamplesSenescence is a cellular phenotype present in health and disease, characterized by a stable cell cycle arrest and an inflammatory response, denominated senescence-associated secretory phenotype (SASP). The SASP is important in influencing the behaviour of neighbouring cells and altering the microenvironment; yet, this role has been mainly attributed to soluble factors. Here, we show that both the soluble factors in addition to small extracellular vesicles (sEV) are capable of transmitting paracrine senescence to nearby cells. Analysis of individual cells internalizing sEV, using a Cre-reporter system, show a positive correlation between sEV uptake and senescence activation. Interestingly, we find an increase in the number of multivesicular bodies during senescence in vivo. sEV protein characterization by mass spectrometry (MS) followed by a functional siRNA screen identify the Interferon Induced Transmembrane Protein 3 (IFITM3) as partially responsible for transmitting senescence to normal cells. Altogether, we found that sEV contribute to paracrine senescence. Overall design: SASP related mRNA transcripts in HFFF2 treated with sEV from iRAS cells in comparison with HFFF2 treated with sEV from iC cells
Small Extracellular Vesicles Are Key Regulators of Non-cell Autonomous Intercellular Communication in Senescence via the Interferon Protein IFITM3.
Disease, Subject
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High-throughput sequencing analysis of the chromosome 7q32 deletion reveals IRF5 as a potential tumour suppressor in splenic marginal-zone lymphoma.
Specimen part, Disease, Disease stage
View SamplesUsing high-resolution genomic microarray analysis, a distinct genomic profile was defined in 114 samples from patients with splenic marginal zone lymphoma (SMZL). Notably, deletion or uniparental disomy of chromosome 7q were detected in 39% of SMZLs but in only 9 of 170 (5%) mature B-cell lymphomas (p<10-6). The presence of unmutated IgVH genes, genomic complexity, 17p13-P53 deletion and 8q gain including MYC gene, but not 7q deletion, were correlated with shorter overall survival. Extensive mapping analyses narrowed down the commonly deleted region to 2.7 Mb. in 7q32.1-q32.2 from SND1 to COPG2 genes. High-throughput sequencing analysis of the 7q32 deleted segment in SMZL cells did not identify bi-allelic deletions, insertions or clear pathogenic mutations, but detected six single nucleotide changes in IRF5 (n=2), TMEM209 (n=2), CALU (n=1) and ZC3HC1 (n=1). Comparative expression analysis found that IRF5, TMEM209 and CALU genes had down-regulated expression in lymphomas with 7q32 deletion vs. non-deleted tumors. Ectopic expression of IRF5 in marginal-zone lymphoma cells decreased cell proliferation and induced apoptosis. These results indicate that small deletions, insertions and/or point mutations inactivating genes within 7q32 are not common events in SMZL. Further studies are required to evaluate the putative role of IRF5 in SMZL pathogenesis.
High-throughput sequencing analysis of the chromosome 7q32 deletion reveals IRF5 as a potential tumour suppressor in splenic marginal-zone lymphoma.
Disease, Disease stage
View SamplesThe ability to form memories is a prerequisite for an organism’s behavioural adaptation to environmental changes. At the molecular level, the acquisition and maintenance of memory requires changes in chromatin modifications. In an effort to unravel the epigenetic network underlying both short- and long-term memory, we examined chromatin modification changes in two distinct mouse brain regions, two cell-types, and three time-points before and after contextual learning. Here we show that histone modifications predominantly change during memory acquisition and correlate surprisingly little with changes in gene expression. While long-lasting changes are almost exclusive to neurons, learning-related histone modification and DNA methylation changes occur also in non-neuronal cell types, suggesting a functional role for non-neuronal cells in epigenetic learning. Finally, our data provides evidence for a molecular framework of memory acquisition and maintenance, wherein DNA methylation could alter the expression and splicing of genes involved in functional plasticity and synaptic wiring. Overall design: We examined chromatin modification changes in two distinct mouse brain regions (CA1 and ACC), two cell-types (neurons, non-neurons), and three time-points before and after contextual learning (naive, 1h, 4w).
DNA methylation changes in plasticity genes accompany the formation and maintenance of memory.
Sex, Age, Cell line, Subject
View SamplesIxr1 is a transcriptional factor from Saccharomyces cerevisae with high affinity to cisplatin-DNA adducts through their two HMG-box DNA binding domains. Its transcriptional regulation is essential in the cytotoxicity caused by cisplatin, although the molecular mechanisms supporting this function are not understood. We present a transcriptome analysis discriminating between RNA changes induced by cisplatin which are dependent or independent of the Ixr1 function.
Ixr1 Regulates Ribosomal Gene Transcription and Yeast Response to Cisplatin.
No sample metadata fields
View SamplesSky1 is a Saccharomyces cerevisiae rich serine-arginine (SR) protein-specific kinase and its enzymatic activity is essential in the cytotoxicity caused by cisplatin, although the molecular mechanisms supporting this function are not understood. We present a transcriptome analysis discriminating between RNA changes induced by cisplatin which are dependent or independent of the Sky1 function.
Sky1 regulates the expression of sulfur metabolism genes in response to cisplatin.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Altered integrin expression patterns shown by microarray in human cutaneous melanoma.
Specimen part, Disease, Cell line
View SamplesMetastatic process is considered the predominant cause of melanoma-specific death, decreasing survival dramatically, and resulting in difficulties in the effective treatment. Large variety of molecular pathways associated with disease development and progression suggests that no individual molecular alteration is crucial in these processes per se.
Altered integrin expression patterns shown by microarray in human cutaneous melanoma.
Specimen part, Disease, Cell line
View SamplesEmbryonic stem cells are maintained in a self-renewing and pluripotent state by multiple regulatory pathways. Pluripotent-specific transcriptional networks are sequentially reactivated as somatic cells reprogram to achieve pluripotency. How epigenetic regulators modulate this process and contribute to somatic cell reprogramming is not clear. Here we perform a functional RNAi screen to identify the earliest epigenetic regulators required for reprogramming. We identify components of the SAGA histone acetyltransferase complex, in particular Gcn5, as critical regulators of reprogramming initiation. Furthermore, we show in mouse pluripotent stem cells that Gcn5 strongly associates with Myc and that upon initiation of somatic reprogramming, Gcn5 and Myc form a positive feed forward loop that activates a distinct alternative splicing network and the early acquisition of pluripotency-associated splicing events. These studies expose a Myc-SAGA pathway that drives expression of an essential alternative splicing regulatory network during somatic cell reprogramming. Overall design: Examination of expression level changes at D0 and D2 MEFs
Myc and SAGA rewire an alternative splicing network during early somatic cell reprogramming.
No sample metadata fields
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