Several studies indicate that SMN-containing mRNP complexes could be involved in the axonal localization of a large number of mRNAs. We have used murine motor neuron-like NSC-34 cells and RNA Immuno-Precipitation experiments coupled to microarray analyses to perform a genome-wide analysis of RNA species present in mRNP complexes containing the full length SMN protein (flSMN). In situ hybridization and immuno-fluorescence experiments performed on several candidates indicate that these mRNAs colocalize with the SMN protein in neurites and axons of differentiated NSC-34 cells. Moreover, they localize in cell processes in a SMN-dependent manner. Thus, low SMN levels might result in localization deficiencies of mRNAs required for axonogenesis.
Genome-wide identification of mRNAs associated with the protein SMN whose depletion decreases their axonal localization.
Specimen part, Cell line
View SamplesThe aim of this study was to analyze the influence of PADMA28 ethanolic extracts on HepG2 gene expression. PADMA28 (Swissmedic Nr. 58436) is an Indo-Tibetan polyherbal preparation used for the treatment of symptoms associated with circulatory disorders.
Pathway-focused bioassays and transcriptome analysis contribute to a better activity monitoring of complex herbal remedies.
Cell line, Treatment
View SamplesA549 cells were grown at air liquid interphase (ALI) and exposed to airborne formaldehyde for three days. An exposure platform was developed for this purpose, which provided the volatile analyte in a humidified atmosphere. The platform was composed of a reference and an exposure chamber.
Cellular reactions to long-term volatile organic compound (VOC) exposures.
Cell line
View SamplesOur goal was to demonstrate the similarity between the original keratinocytes and iPSC-derived keratinocytes from the same individual
Induced pluripotent stem cells from human revertant keratinocytes for the treatment of epidermolysis bullosa.
Specimen part
View Samplesexpression analysis from a genetically engineered mouse model of osteosarcoma
Conditional mouse osteosarcoma, dependent on p53 loss and potentiated by loss of Rb, mimics the human disease.
No sample metadata fields
View SamplesThere is a critical need in cancer therapeutics to identify targeted therapies that will improve outcomes and decrease toxicities compared to conventional, cytotoxic chemotherapy. Ewing sarcoma is a highly aggressive bone and soft tissue cancer that is caused by the EWS-FLI1 fusion protein. Although EWS-FLI1 is specific for cancer cells, and required for tumorigenesis, directly targeting this transcription factor has proven challenging. Consequently, targeting unique dependencies or key downstream mediators of EWS-FLI1 represent important alternative strategies. We used gene expression data derived from a genetically defined model of Ewing sarcoma to interrogate the Connectivity Map and identify a class of drugs, iron chelators, that downregulate a significant number of EWS-FLI1 target genes. We then identified ribonucleotide reductase M2 (RRM2), the iron-dependent subunit of ribonucleotide reductase (RNR), as one mediator of iron chelator toxicity in Ewing sarcoma cells. Inhibition of RNR in Ewing sarcoma cells led to apoptosis and cell death in vitro and attenuated tumor growth in vivo in a xenograft model. Additionally, we discovered that the sensitivity of Ewing sarcoma cells to inhibition or suppression of RNR is mediated, in part, by high levels of SLFN11, a protein that sensitizes cells to DNA damage. This work demonstrates a unique dependency of Ewing sarcoma cells on RNR and supports further exploration of clinically used inhibitors of RNR as a therapeutic approach in treating this cancer.
Gene expression signature based screening identifies ribonucleotide reductase as a candidate therapeutic target in Ewing sarcoma.
Specimen part, Cell line, Treatment
View SamplesExperiments performed over the past three decades have shown that nucleosomes are transcriptional repressors. In Saccharomyces cerevisiae, depletion of histone H4 results in the genome-wide transcriptional de-repression of hundreds genes. The mechanism of de-repression is hypothesized to be rooted directly in chromatin changes. To test this, we reproduced classical H4 depletion experiments by conditional repression of all histone H3 transcription, which depletes the supply of nucleosomes in vivo. RNA-seq results were consistent with the earlier studies, but much more sensitive, revealing nearly 2500 de-repressed genes. Changes in chromatin organization were determined by MNase-seq. Nucleosomes that were preferentially retained occurred in regions of high DNA-encoded nucleosome affinity, and were marked with H3K36me2, which is linked to transcription elongation. Nucleosomes harboring acetyl marks or that contained the variant histone H2A.z were preferentially lost. Genes that were de-repressed lost or rearranged nucleosomes at their promoter, but not in the gene body. Therefore, a combination of DNA-encoded nucleosome stability and nucleosome composition dictates which nucleosomes will be lost under conditions of limiting histone protein. This, in turn, governs which genes will experience a loss of regulatory fidelity. Overall design: MNase-seq experiments consist of three wildtype (1 single-end and 2 paired-end) and four mutant (DCB200.1/H3 shutoff; 2 single-end, 2 paired-end) replicates. Each replicate contains two timepoints reflecting chromatin immediately after ("O hours") and 3 hours after transition to media containing dextrose. RNA-seq data includes three replicates from wildtype or H3 depleted cells after 3 hours in media containing dextrose.
In vivo effects of histone H3 depletion on nucleosome occupancy and position in Saccharomyces cerevisiae.
Cell line, Subject, Time
View SamplesHuntington disease (HD) is associated with increased nuclear accumulation of the repressor element-1 silencing transcription factor (REST) which govens a huge gene network. An alternative REST splicing event (E3) eliminates a motif essential for nuclear targeting of REST.
Modulation of nuclear REST by alternative splicing: a potential therapeutic target for Huntington's disease.
Cell line, Treatment
View SamplesMechanical overload in the heart induces pathological remodeling that typcially leads to heart failure. We sought to build an in vitro model of heart failure by applying cyclic stretch to engineered isotropic (iso) and anisotropic (aniso) NRVM tissues.
Recapitulating maladaptive, multiscale remodeling of failing myocardium on a chip.
Specimen part
View SamplesInteraction of hematopoietic progenitors with the thymic stromal microenvironment induces them to proliferate, adopt the T cell fate, and asymmetrically diverge into multiple T lineages. Progenitors at various developmental stages are stratified among different regions of the thymus, implying that the corresponding microenvironments differ from one another, and provide unique sets of signals to progenitors migrating between them. The nature of these differences remains undefined. Here we use novel physical and computational approaches to characterize these stromal subregions, distinguishing gene expression in microdissected tissues from that of their lymphoid constituents. Using this approach, we comprehensively map gene expression in functionally distinct stromal microenvironments, and identify clusters of genes that define each region. Quite unexpectedly, we find that the central cortex lacks distinctive features of its own, and instead appears to function by sequestering unique microenvironments found at the cortical extremities, and modulating the relative proximity of progenitors moving between them.
Spatial mapping of thymic stromal microenvironments reveals unique features influencing T lymphoid differentiation.
Specimen part
View Samples