Administration of spermidine, a natural polyamine whose intracellular concentration declines during human ageing, markedly extends the lifespan of various model organisms including yeast, flies and worms. In ageing yeast, spermidine treatment triggeres epigenetic deacetylation of histone H3 through inhibition of histone acetyltransferases (HAT), leading to induction of autophagy and thereby suppressing oxidative stress and necrosis. In order to further characterize the effects by spermidine supplementation of aging yeast cultures and to understand how global histone deacetylation affects gene transcription during aging, Affymetrix-based microarray analyses of three day old as well as ten day old cultures with and without administration of spermidine was performed.
Induction of autophagy by spermidine promotes longevity.
Age, Compound, Time
View SamplesThis SuperSeries is composed of the SubSeries listed below.
VEGF blockade enhances the antitumor effect of BRAFV600E inhibition.
Cell line, Treatment
View SamplesIn this work we investigated the combined effects of the BRAF inhibition and of the VEGF blockade in a preclinical model of melanoma. The purpose of this dataset was to examine the transcriptional responses of a A375 xenograft model to PLX472 and bevacizumab, either as single agents or as combination therapy. We performed species-specific analysis of gene expression to discriminate the effects of the different therapeutic regimens on tumor cells (human) and stromal microenvironment (mouse). Here, Illumina Mouse BeadChips were used to profile the transcriptome after 12 days treatment. We reported that dispensing the dual treatment is more efficient than the single compounds and the occurrence of resistance by modifying the tumor genetic programs regulating myeloid cells recruitment and extracellular matrix remodeling.
VEGF blockade enhances the antitumor effect of BRAFV600E inhibition.
Cell line, Treatment
View SamplesIn this work we investigated the combined effects of the BRAF inhibition and of the VEGF blockade in a preclinical model of melanoma. The purpose of this dataset was to examine the transcriptional responses of a A375 xenograft model to PLX472 and bevacizumab, either as single agents or as combination therapy. We performed species-specific analysis of gene expression to discriminate the effects of the different therapeutic regimens on tumor cells (human) and stromal microenvironment (mouse). Here, Illumina Human BeadChips were used to profile the transcriptome after 12 days treatment. We reported that dispensing the dual treatment is more efficient than the single compounds and the occurrence of resistance by modifying the tumor genetic programs regulating myeloid cells recruitment and extracellular matrix remodeling.
VEGF blockade enhances the antitumor effect of BRAFV600E inhibition.
Cell line, Treatment
View SamplesEpigenetic events, including covalent post-translational modification of histones, have frequently been demonstrated to play critical roles in tumor development and progression. The transcriptional coactivator, p300/CBP, possesses both histone acetyltransferase (HAT) activity as well as scaffolding properties that directly influence transcriptional activation of targeted genes. We have used a recently reported small molecule inhibitor of p300 HAT activity, C646, to explore the specific contribution of p300/CBP HAT activity to tumor development and progression. We find that C646 inhibits the growth of lineage-specific tumor cell lines including human melanomas through direct transcriptional regulation of cell cycle regulatory proteins. Further evaluation of the p300 HAT transcriptome in human melanoma cells using comprehensive gene expression profiling reveals that p300 HAT activity globally promotes cell cycle progression, nucleosome assembly, and the DNA damage checkpoint through direct transcriptional regulatory mechanisms. Additionally, C646 promotes sensitivity to DNA damaging agents leading to enhanced apoptosis of melanoma cells following combination treatment with cisplatin. Together our data suggest that p300 HAT activity regulates critical growth regulatory pathways in tumors and may serve as a novel therapeutic target for melanoma and other malignancies by promoting cellular responses to DNA damaging agents.
Selective inhibition of p300 HAT blocks cell cycle progression, induces cellular senescence, and inhibits the DNA damage response in melanoma cells.
Cell line, Treatment, Time
View SamplesThe aim of this study was to identify genes expressed selectively in brown adipose tissue as compared to white adipose tissue from the same animals. This analysis provides a gene set that is brown and white adipose selective.
Transcriptional control of brown fat determination by PRDM16.
Sex, Specimen part
View SamplesLineage-specific transcription factors, which drive cellular identity during embryogenesis, have been shown to convert cell fate when express ectopically in heterologous cells. Herein, we screened the key molecular factors governing the dopaminergic neuronal specification during brain development for their ability to generate similar neurons directly from mouse and human fibroblasts. Remarkably, we found a minimal set of three factors Mash1, Nurr1 and Lmx1a/b able to elicit such cellular reprogramming. Molecular and transcriptome studies showed reprogrammed DA neurons to faithfully recapitulate gene expression of their brain homolog cells while lacking expression of other catecholaminergic neuronal types. Induced neurons showed spontaneous electrical activity organized in regular spikes consistent with the pacemaker activity featured by brain DA neurons. The three factors were able to elicit DA neuronal conversion in human fibroblasts from prenatal or adult fibroblasts of healthy donors and a Parkinsons disease patient. Generation of DA induced neurons from somatic cells might have significant implications in studies of neural development, disease in vitro modeling and cell replacement therapies.
Direct generation of functional dopaminergic neurons from mouse and human fibroblasts.
Specimen part
View SamplesXbp1 is a major transcription factor in the unfolded protein response. To uncover its function in DCs we generated a conditional KO for Xbp1 in dendritic cells. We here compare the expression of mRNAs in two different splenic DC subpopulations, CD8a and CD11b DCs in both WT and KO mice.
The unfolded-protein-response sensor IRE-1α regulates the function of CD8α+ dendritic cells.
Specimen part
View SamplesTyrosine phosphorylation is a hallmark for activation of Signal Transducer and Activator of Transcription (STAT) proteins, but their transcriptional activity also depends on other secondary modifications. Type I interferons (IFNs) can activate both the ISGF3 (STAT1:STAT2:IRF9) complex and STAT3, but with cell-specific, selective triggering of only the ISGF3 transcriptional program. Following a genome-wide RNAi screen, we identified the Sin3a complex as an important mediator of this STAT3 transcriptional repression. Sin3a directly interacts with the DNA-binding domain of STAT3 and alters its acetylation status. SIN3A silencing enhances recruitment of STAT3 and enhanceosome components to the SOCS3 promoter, resulting in histone hyperacetylation and enhanced transcription. Conversely, Sin3a is required for ISGF3-dependent gene transcription and for an efficient IFN-mediated antiviral protection against Influenza A and hepatitis C viruses. The Sin3a complex therefore acts as a context-dependent STAT1/3 transcriptional switch.
The Sin3a repressor complex is a master regulator of STAT transcriptional activity.
Cell line, Treatment
View SamplesTransplantation of GABAergic interneurons (INs) can sustain long-standing benefits in animal models of epilepsy and other neurological disorders. In a therapeutic perspective, a renewable source of functional GABAergic INs is needed. Here, we identified five factors (Foxg1, Sox2, Ascl1, Dlx5 and Lhx6) able to convert fibroblasts directly into induced GABAergic INs (iGABA-INs), displaying the molecular signature of telencephalic INs. The selected factors recapitulate in fibroblasts the activation of transcriptional networks required for the specification of GABAergic fate during telencephalon development. iGABA-INs exhibited progressively maturing firing patterns comparable to those of cortical INs, had synaptic currents and released GABA. Importantly, upon grafting in the hippocampus, iGABA-INs survived, matured and their optogenetic stimulation triggered GABAergic transmission and inhibited the activity of connected granule cells. The five factors also converted human cells into functional GABAergic neurons. These properties define iGABA-INs as a promising tool for disease modeling and cell-based therapeutic approaches. Overall design: Comparison of iGABA-INs transcriptional profile with those of starting fibroblasts and GAD67-GFP+ cortical interneurons.
Rapid Conversion of Fibroblasts into Functional Forebrain GABAergic Interneurons by Direct Genetic Reprogramming.
Specimen part, Cell line, Subject
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