Photoreceptor damage in adult mammals results in permanent cell loss and glial scarring in the retina. In contrast, adult zebrafish can regenerate photoreceptors following injury. By using a stable transgenic line in which GFP is driven by the cis-regulatory sequences of a glial specific marker gfap, Tg(gfap:GFP)mi2002, previous studies showed that Mller glia, the radial glial cells in the retina, proliferate after photoreceptor loss and give rise to neuronal progenitors that eventually differentiate into regenerated photoreceptors. To identify the molecular mechanisms that initiate this regenerative response, Mller glia were isolated from Tg(gfap:GFP)mi2002 fish during the early stages of regeneration after light lesion and gene expression profiles were generated by microarray analyses.
Genetic evidence for shared mechanisms of epimorphic regeneration in zebrafish.
No sample metadata fields
View SamplesActivation of the MLL-ENL-ERtm oncogene initiates aberrant proliferation of myeloid progenitors. Here, we show induction of a fail-safe mechanism mediated by the DNA damage response (DDR) machinery that results in activation of the ATR/ATM-Chk1/Chk2-p53/p21 checkpoint and cellular senescence at early stages of cellular transformation caused by a regulatable MLL-ENL-ERtm in mice. Furthermore, we identified the transcription program underlying this intrinsic anti-cancer barrier, and DDR-induced inflammatory regulators that fine-tune the signaling towards senescence, thereby modulating the fate of MLL-ENL-immortalized cells in a tissue-environment-dependent manner. Our results indicate that DDR is a rate-limiting event for acquisition of stem cell-like properties in MLL-ENL-ERtm-mediated transformation, as experimental inhibition of the barrier accelerated the transition to immature cell states and acute leukemia development.
DNA damage response and inflammatory signaling limit the MLL-ENL-induced leukemogenesis in vivo.
Specimen part, Disease stage
View SamplesWe employed next generation sequencing to examine whether knocking down the steroid receptor RNA activator (SRA) gene significantly affect the expression levels of certain genes in MCF-7 cells. MCF-7 cells were transfected with either a pool of four non-target control siRNAs or a pool of four SRA siRNAs for 32 hrs. 157 million reads were generated from triplicate samples of the control group; 151 million reads were generated from triplicate samples of the SRA knockdown group. Six genes were identified as significantly changed in the expression levels with the cutoff of q value = 0.05, fold change = 0.5 or = 2, and reads per kilobase per million mapped reads (RPKM) = 1. However, except for SRA itself, the other five genes were shown by real-time PCR to be only affected by one siRNA in the SRA siRNA pool. Further analysis of this dataset with different cuttoff setting may reveal true SRA-regulated genes in MCF-7. Overall design: MCF-7 cells were cultured in high glucose DMEM with 10% fetal bovine serum, 2 mM Glutamax-1, 100 units/ml penicillin and 100 µg/ml streptomycin. ON-TARGETplus SMARTpool for human SRA (Thermo Scientific, L-027192-00-0005) was used to knockdown SRA (siSRA) and ON-TARGETplus Non-targeting Pool Thermo Scientific, D-001810-10-05) was used as a negative control (siCtrl). A total of 25 nM siRNA was transfected in 6-well dishes using Lipofectamine™ RNAiMAX Reagent (Life Technologies, Invitrogen) following the manufacturer’s recommendations. Polyadenylated RNA was purified from the cells 32 hrs after transfection. cDNA libraries were prepared and double-stranded cDNA was fragmented using DNase I according to Illumina specifications, prior to adaptor ligation. Sequencing libraries were amplified and sequenced using an Illumina HiSeq 2000 sequencer.
Structure and function of steroid receptor RNA activator protein, the proposed partner of SRA noncoding RNA.
No sample metadata fields
View SamplesThe perception that soy food products and dietary supplements will have beneficial effects on heart health has led to a massive consumer market. However, we have previously noted that diet has a profound effect on disease progression in a genetic model of hypertrophic cardiomyopathy (HCM). In this model, a soy-based diet negatively impacts cardiac function in male mice.
Remodeling the cardiac transcriptional landscape with diet.
Sex, Specimen part
View SamplesHuman strabismic extraocular muscles (EOMs) differ from normal EOMs in structural and functional properties, but the gene expression profile of these two types of human EOM has not been examined. Differences in gene expression may inform about causes and effects of the strabismic condition in humans. Our samples are from human strabismic patients undergoing corrective surgery, and from human organ donors with no history of EOM disease.
Differences in gene expression between strabismic and normal human extraocular muscles.
Sex, Specimen part
View SamplesWe sought to determine the genes regulated by the Drosophila Hox protein AbdA in a homogenous cell system. S2-DRSC cells that have no Hox expression were stably transfected with HA-tagged AbdA under the control of a metallothionein promoter. Overall design: S2-DRSC cells are stably transfected with HA-tagged AbdA (S2-DRSC:AbdA). S2 and S2-AbdA cells are analysed for gene expression in the absence (S2-DRSC) and presence (S2-DRSC-HA::AbdA) of AbdA
Human ZKSCAN3 and Drosophila M1BP are functionally homologous transcription factors in autophagy regulation.
Cell line, Treatment, Subject
View SamplesUnderstanding the physiological relevance of structures in mammalian mRNAs remains elusive, especially considering the global unfolding of mRNA structures in eukaryotic organisms recently examined, as well as the decade-long observation that mRNAs generally seem no more likely than random sequences to be stably folded. Here we show that RNA secondary structures, mostly weak and close-to-random, facilitate the 3'-end processing of thousands of human mRNAs by juxtaposing poly(A) signals (PASs) and cleavage sites that are otherwise too far apart. Folding of these 3'-end structures also enhances mRNA stability. Global structure probing shows that 3'-end regions are indeed folded in cells despite substantial unfolding of PAS-upstream regions. Analyses of thousands of ectopically expressed variants prove that folding both enhances processing and increases stability. Mutagenesis of a genomic locus further implicates structure-controlled processing in regulating neighboring gene expression. These results reveal widespread roles for RNA structure in mammalian mRNA biogenesis and metabolism. Overall design: This series includes 8 samples designed to measure the efficiency of 3'' end processing from a reporter library expressed in HEK293T cells and HeLa cells, in steady state or in nascent RNAs (by 4sU labeling and capture).
Widespread Influence of 3'-End Structures on Mammalian mRNA Processing and Stability.
Cell line, Subject
View SamplesSmall endogenous C. elegans RNAs from L4 and young adult worms were prepared for sequencing using a protocol derived from Batista et al., (2008) and Lau et al. (2001). The small-RNA libraries were constructed using a method that does not require a 5' monophosphate (called 5' monophosphate-independent method, Ambros et al., 2003) to profile secondary siRNAs that have 5' triphosphorylated G. All preprocessed small-RNA reads were mapped to genome (ce6), allowing no mismatches. After excluding miRNAs, 21U RNAs, rRNAs, and other structural ncRNAs, the remaining reads were classified as 22G RNAs, 26G RNAs, and other siRNAs, based on their length and 5' terminal nucleotide. Overall design: Small-RNA libraries were sequenced in L4 and young adult stages in C.elegans.
Long noncoding RNAs in C. elegans.
Cell line, Subject
View SamplesA soy diet worsens the progression of an inherited form of hypertrophic cardiomyopathy (HCM) in male mice when compared to casein-fed mice. Females are largely resistant to this diet effect and better preserve cardiac function. We hypothesized that the abundant phytoestrogens found in soy are mainly responsible for this diet-dependent phenotype. Indeed, feeding male mice a phytoestrogen-supplemented casein-based diet can recapitulate the negative outcome seen when male mice are fed a standard soy-based diet.
Estrogenic compounds are not always cardioprotective and can be lethal in males with genetic heart disease.
Sex, Specimen part
View SamplesThe development of CRISPR-Cas systems for targeting DNA and RNA in diverse organisms has transformed biotechnology and biological research. Moreover, the CRISPR revolution has highlighted bacterial adaptive immune systems as a rich and largely unexplored frontier for discovery of new genome engineering technologies. In particular, the class 2 CRISPR-Cas systems, which use single RNA-guided DNA-targeting nucleases such as Cas9, have been widely applied for targeting DNA sequences in eukaryotic genomes. Here, we report DNA-targeting and transcriptional control with class I CRISPR-Cas systems. Specifically, we repurpose the effector complex from type I variants of class 1 CRISPR-Cas systems, the most prevalent CRISPR loci in nature, that target DNA via a multi-component RNA-guided complex termed Cascade. We validate Cascade expression, complex formation, and nuclear localization in human cells and demonstrate programmable CRISPR RNA (crRNA)-mediated targeting of specific loci in the human genome. By tethering transactivation domains to Cascade, we modulate the expression of targeted chromosomal genes in both human cells and plants. This study expands the toolbox for engineering eukaryotic genomes and establishes Cascade as a novel CRISPR-based technology for targeted eukaryotic gene regulation. Overall design: Examination of transcriptome-wide changes in gene expression with Cascade-mediated activation of endogenous genes.
Targeted transcriptional modulation with type I CRISPR-Cas systems in human cells.
Specimen part, Cell line, Subject
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