Alcoholism is a complex disorder determined by interactions between genetic and environmental risk factors. Drosophila represents a powerful model system to dissect the genetic architecture of alcohol sensitivity, as large numbers of flies can readily be reared in defined genetic backgrounds and under controlled environmental conditions. Furthermore, flies exposed to ethanol undergo physiological and behavioral changes that resemble human alcohol intoxication, including loss of postural control, sedation, and development of tolerance.
Phenotypic and transcriptional response to selection for alcohol sensitivity in Drosophila melanogaster.
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View SamplesHepatic iron overload is a risk factor for progression of hepatocellular carcinoma (HCC), although the molecular mechanisms underlying this association have remained unclear. We now show that the iron-sensing ubiquitin ligase FBXL5 is previously unrecognized oncosuppressor in liver carcinogenesis in mice. Hepatocellular iron overload evoked by FBXL5 ablation gives rise to oxidative stress, tissue damage, inflammation and compensatory proliferation in hepatocytes and to consequent promotion of liver carcinogenesis induced by exposure to a chemical carcinogen. The tumor-promoting effect of FBXL5 deficiency in the liver is also operative in a model of virus-induced HCC. FBXL5-deficient mice thus constitute the first genetically engineered mouse model of liver carcinogenesis induced by iron overload. Dysregulation of FBXL5-mediated cellular iron homeostasis was also found to be associated with poor prognosis in human HCC, implicating FBXL5 plays a significant role in defense against hepatocarcinogenesis. Overall design: Total RNA was extracted from the nontumor and tumor tissue of an Alb-Cre/Fbxl5F/F male mouse (nontumor, n = 5; tumor, n = 5) or two littermate control Fbxl5F/F mice (nontumor, n = 6; tumor, n = 6) at 45 weeks of age.
Disruption of FBXL5-mediated cellular iron homeostasis promotes liver carcinogenesis.
Specimen part, Cell line, Subject
View SamplesA chromosomal translocation fusion gene product EWS-WT1 is the defining genetic event in Desmoplastic Small Round Cell Tumor (DSRCT), a rare but aggressive tumor with a high rate of mortality. EWS-WT1 oncogene acts as an aberrant transcription factor that drives tumorigenesis, but the mechanism by which EWS-WT1 causes tumorigenesis is not well understood. To delineate the oncogenic mechanisms, we generated the EWS-WT1 fusion in the mouse using a gene targeting (knock-in) approach, enabling physiologic expression of EWS-WT1 under the native Ews promoter. We derived mouse embryonic fibroblasts (MEFs) and performed genome-wide expression profiling to identify transcripts directly regulated by EWS-WT1. Remarkably, expression of EWS-WT1 led to a dramatic induction of many neuronal genes. Notably, a neural reprogramming factor, ASCL1 (achaete-scute complex-like 1), was highly induced by EWS-WT1 in MEFs and in primary DSRCT. Further analysis demonstrated that EWS-WT1 directly binds to the proximal promoter region of ASCL1 and activates its transcription through multiple WT1-responsive elements. Depletion of EWS-WT1 in a DSRCT cell line resulted in severe reduction in ASCL1 expression and cell viability. Remarkably, when stimulated with neuronal induction media, cells expressing EWS-WT1 expressed neural markers and generated neurite-like projections. These results demonstrate for the first time that EWS-WT1 activates neural gene expression and is capable of directing partial neuronal differentiation, likely via ASCL1. These findings suggest that stimulating DSRCT tumor cells with biological or chemical agents that promote neural differentiation might be a useful approach to develop novel therapeutics against this incurable disease.
EWS-WT1 oncoprotein activates neuronal reprogramming factor ASCL1 and promotes neural differentiation.
Specimen part, Time
View SamplesGlobal expression analysis of neural crest-like skin-derived precursors (SKPs) and Sox2-positive follicle dermal cells that SKPs originate from.
SKPs derive from hair follicle precursors and exhibit properties of adult dermal stem cells.
Specimen part
View SamplesGene expressions relate to the pathogenesis of periodontitis and have a crucial role in local tissue destruction and susceptibility to the disease. The aims of the present study were to explore comprehensive gene expressions/transcriptomes in periodontitis-affected gingival tissues, and to identify specific biological processes.
Altered gene expression in leukocyte transendothelial migration and cell communication pathways in periodontitis-affected gingival tissues.
Sex, Specimen part
View SamplesIn spite of the many recent developments in the field of vector sialomics, the salivary glands of larvalmosquitoes have been largely unexplored. We used whole-transcriptome microarray analysis to create a gene-expression profile of the salivary gland tissue of fourth-instar Anopheles gambiae larvae, and compare it to the gene-expression profile of a matching group of whole larvae. We identified a total of 221 probes with expression values that were (a) significantly enriched in the salivary glands, and (b)sufficiently annotated as to allow the prediction of the presence/absence of signal peptides in their corresponding gene products. Based on available annotation of the protein sequences associated with these probes, we propose that the main roles of larval salivary secretions include: (a) immune response, (b) mouthpart lubrication, (c) nutrient metabolism, and (d) xenobiotic detoxification. Other highlights of the study include the cloning of a transcript encoding a previously unknown salivary defensin (AgDef5), the confirmation of mucus secretion by the larval salivary glands, and the first report of salivary lipocalins in the Culicidae.
The salivary transcriptome of Anopheles gambiae (Diptera: Culicidae) larvae: A microarray-based analysis.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Identification of mRNAs bound and regulated by human LIN28 proteins and molecular requirements for RNA recognition.
Cell line
View SamplesHuman LIN28A and B are RNA-binding proteins (RBPs) conserved in animals with important roles during development and stem cell reprogramming. We used Photoactivatable-Ribonucleoside-Enhanced Crosslinking and Immunoprecipitation (PAR-CLIP) in HEK293 cells and identified a largely overlapping set of ~3,000 mRNAs at ~9,500 sites located in the 3UTR and CDS. In vitro and in vivo, LIN28 preferentially bound single-stranded RNA containing a uridine-rich element and one or more flanking guanosines, and appeared to be able to disrupt base-pairing to access these elements when embedded in predicted secondary structure. In HEK293 cells, LIN28 protein binding mildly stabilized target mRNAs and increased protein abundance. The top targets were its own mRNAs and those of other RBPs and cell-cycle regulators. Alteration of LIN28 protein levels also negatively regulated the abundance of some, but not all let-7 miRNA family members, indicating sequence-specific binding of let-7 precursors to LIN28 proteins and competition with cytoplasmic miRNA biogenesis factors.
Identification of mRNAs bound and regulated by human LIN28 proteins and molecular requirements for RNA recognition.
Cell line
View SamplesHuman LIN28A and B are RNA-binding proteins (RBPs) conserved in animals with important roles during development and stem cell reprogramming. We used Photoactivatable-Ribonucleoside-Enhanced Crosslinking and Immunoprecipitation (PAR-CLIP) in HEK293 cells and identified a largely overlapping set of ~3,000 mRNAs at ~9,500 sites located in the 3’UTR and CDS. In vitro and in vivo, LIN28 preferentially bound single-stranded RNA containing a uridine-rich element and one or more flanking guanosines, and appeared to be able to disrupt base-pairing to access these elements when embedded in predicted secondary structure. In HEK293 cells, LIN28 protein binding mildly stabilized target mRNAs and increased protein abundance. The top targets were its own mRNAs and those of other RBPs and cell-cycle regulators. Alteration of LIN28 protein levels also negatively regulated the abundance of some, but not all let-7 miRNA family members, indicating sequence-specific binding of let-7 precursors to LIN28 proteins and competition with cytoplasmic miRNA biogenesis factors. Overall design: To assess whether miRNAs are regulated by LIN28B we analyzed the miRNA levels of LIN28B overexpressing and LIN28B-depleted cells using small RNA cDNA library sequencing. The RBP LIN28B was depleted by siRNAs and the expression levels was compared to mock-transfected HEK293 cells.
Identification of mRNAs bound and regulated by human LIN28 proteins and molecular requirements for RNA recognition.
Cell line, Subject
View SamplesHuman LIN28A and B are RNA-binding proteins (RBPs) conserved in animals with important roles during development and stem cell reprogramming. We used Photoactivatable-Ribonucleoside-Enhanced Crosslinking and Immunoprecipitation (PAR-CLIP) in HEK293 cells and identified a largely overlapping set of ~3,000 mRNAs at ~9,500 sites located in the 3’UTR and CDS. In vitro and in vivo, LIN28 preferentially bound single-stranded RNA containing a uridine-rich element and one or more flanking guanosines, and appeared to be able to disrupt base-pairing to access these elements when embedded in predicted secondary structure. In HEK293 cells, LIN28 protein binding mildly stabilized target mRNAs and increased protein abundance. The top targets were its own mRNAs and those of other RBPs and cell-cycle regulators. Alteration of LIN28 protein levels also negatively regulated the abundance of some, but not all let-7 miRNA family members, indicating sequence-specific binding of let-7 precursors to LIN28 proteins and competition with cytoplasmic miRNA biogenesis factors. Overall design: LIN28 protein PAR-CLIP
Identification of mRNAs bound and regulated by human LIN28 proteins and molecular requirements for RNA recognition.
Subject
View Samples