Drosophila melanogaster
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA137367 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Recent evidence supports a role for RNA as a common pathogenic agent in both the “polyglutamine” and “untranslated” dominant expanded repeat disorders. One feature of all repeat sequences currently associated with disease is their predicted ability to form a hairpin secondary structure at the RNA level. In order to investigate mechanisms by which hairpin forming repeat RNAs could induce neurodegeneration, we have looked for alterations in gene transcripts as hallmarks of the cellular response to toxic hairpin repeat RNAs. Three disease associated repeat sequences - CAG, CUG and AUUCU - were specifically expressed in the neurons of Drosophila and resultant common, early, transcriptional changes assessed by microarray analyses. Transcripts that encode several components of the Akt/Gsk3-β signalling pathway were altered as a consequence of expression of these repeat RNAs, indicating that this pathway is a component of the neuronal response to these pathogenic RNAs and may represent an important common therapeutic target in this class of diseases.
2011-04-28 | GSE27178 | GEO
Project description:Recent evidence supports a role for RNA as a common pathogenic agent in both the “polyglutamine” and “untranslated” dominant expanded repeat disorders. One feature of all repeat sequences currently associated with disease is their predicted ability to form a hairpin secondary structure at the RNA level. In order to investigate mechanisms by which hairpin forming repeat RNAs could induce neurodegeneration, we have looked for alterations in gene transcripts as hallmarks of the cellular response to toxic hairpin repeat RNAs. Three disease associated repeat sequences - CAG, CUG and AUUCU - were specifically expressed in the neurons of Drosophila and resultant common, early, transcriptional changes assessed by microarray analyses. Transcripts that encode several components of the Akt/Gsk3-β signalling pathway were altered as a consequence of expression of these repeat RNAs, indicating that this pathway is a component of the neuronal response to these pathogenic RNAs and may represent an important common therapeutic target in this class of diseases. The heads from newly eclosed Male Drosophila were used for RNA extraction and profiling on Affymetrix Drosophile Genome 2.0 microarrays. Twenty samples were analysed, representing control and experimental lines. Two independently derived control lines were used in each exeriment, totaling 4 samples. The tri-nucleotide repeats (CAG, CUG, CAA) were represented by three independently derived two transgene insertion lines each in one experiment and two independent four transgene insertion lines each in a second experiment, totaling 15 samples. A single four transgene insertion line was analysed for AUUCU. Candidates were selected from the pool of transcripts which showed a ‘present’ call in either all independent lines for a particular repeat sequence, or in all samples for the elav- GAL4/+ control in that experiment. Where possible, T-tests were performed on raw values to determine samples that showed a significant difference with a P-value < 0.05.
2011-04-28 | E-GEOD-27178 | biostudies-arrayexpress
Project description:This study examined the effects of antisense oligonucleotides (ASOs) on the muscle transcriptome in a transgenic mouse model of myotonic dystrophy. Two ASOs were tested in HSALR transgenic mice. Both of the ASOs targeted mRNA from a human skeletal actin (hACTA1) transgene. This transgene contains an expanded CTG repeat in the 3’ untranslated region (UTR) (Mankodi et al “Myotonic dystrophy in transgenic mice expressing an expanded CUG repeat” Science 2000; 289:1769-72). ASO 445235 targeted the hACTA1 transcript in the 3’ UTR, downstream from the expanded repeat. ASO 190401 targeted the hACTA1 transcript in the coding region. The HSALR mice received 4 weeks of biweekly subcutaneous injections of vehicle (saline), ASO 190401, or ASO 445236 (n = 4 per group), at a dose of 25 mg/kg per injection. Wild-type mice of the same strain background received saline injections (n = 4). One week after the final injection, quadriceps muscle was harvested for RNA analysis.
2012-06-28 | GSE38962 | GEO
Project description:This study examined the effects of antisense oligonucleotides (ASOs) on the muscle transcriptome in a transgenic mouse model of myotonic dystrophy. Two ASOs were tested in HSALR transgenic mice. Both of the ASOs targeted mRNA from a human skeletal actin (hACTA1) transgene. This transgene contains an expanded CTG repeat in the 3M-bM-^@M-^Y untranslated region (UTR) (Mankodi et al M-bM-^@M-^\Myotonic dystrophy in transgenic mice expressing an expanded CUG repeatM-bM-^@M-^] Science 2000; 289:1769-72). ASO 445235 targeted the hACTA1 transcript in the 3M-bM-^@M-^Y UTR, downstream from the expanded repeat. ASO 190401 targeted the hACTA1 transcript in the coding region. The HSALR mice received 4 weeks of biweekly subcutaneous injections of vehicle (saline), ASO 190401, or ASO 445236 (n = 4 per group), at a dose of 25 mg/kg per injection. Wild-type mice of the same strain background received saline injections (n = 4). One week after the final injection, quadriceps muscle was harvested for RNA analysis. Four conditions, four arrays per condition, to compare WT and HSALR trangenic mice without treatment (saline) and to examine the effect of two oligos (vs. saline) in the HSALR transgenic mice.
2012-06-27 | E-GEOD-38962 | biostudies-arrayexpress
Project description:Expanded CAG/CTG repeats underlie thirteen neurological disorders, including myotonic dystrophy type 1 (DM1) and Huntington’s disease (HD). Upon expansion, CAG/CTG repeat loci acquire heterochromatic characteristics. This observation raises the hypothesis that repeat expansion provokes changes to higher-order chromatin conformation and thereby affects both gene expression in cis and the genetic instability of the repeat tract. Here we tested this hypothesis directly by performing 4C sequencing at the DMPK and HTT loci from DM1 and HD patient-derived cells. Surprisingly, chromatin contacts remain unchanged upon repeat expansion at both loci. This was true for expanded alleles with different DNA methylation levels and CTCF binding. Repeat tract sizes ranging from 15 to 1,700 repeats displayed strikingly similar chromatin interaction profiles. Moreover, the ectopic insertion of an expanded CAG repeat tract did not change the three-dimensional chromatin conformation of the surrounding genomic region. Our findings argue that extensive changes in heterochromatic properties are not enough to alter chromatin conformation at expanded CAG/CTG repeat loci. We conclude that 3D chromatin conformation is unlikely to drive repeat expansions or changes in gene expression in expanded CAG/CTG repeat disorders.
2020-04-07 | GSE148176 | GEO
Project description:Expanded CAG/CTG repeats underlie thirteen neurological disorders, including myotonic dystrophy type 1 (DM1) and Huntington’s disease (HD). Upon expansion, CAG/CTG repeat loci acquire heterochromatic characteristics. This observation raises the hypothesis that repeat expansion provokes changes to higher-order chromatin conformation and thereby affects both gene expression in cis and the genetic instability of the repeat tract. Here we tested this hypothesis directly by performing 4C sequencing at the DMPK and HTT loci from DM1 and HD patient-derived cells. Surprisingly, chromatin contacts remain unchanged upon repeat expansion at both loci. This was true for expanded alleles with different DNA methylation levels and CTCF binding. Repeat tract sizes ranging from 15 to 1,700 repeats displayed strikingly similar chromatin interaction profiles. Moreover, the ectopic insertion of an expanded CAG repeat tract did not change the three-dimensional chromatin conformation of the surrounding genomic region. Our findings argue that extensive changes in heterochromatic properties are not enough to alter chromatin conformation at expanded CAG/CTG repeat loci. We conclude that 3D chromatin conformation is unlikely to drive repeat expansions or changes in gene expression in expanded CAG/CTG repeat disorders. This SuperSeries is composed of the SubSeries listed below.
2020-04-07 | GSE148185 | GEO
Project description:Spinocerebellar ataxia type 3 (SCA3) is one of the polyglutamine (polyQ) diseases, which are caused by a CAG repeat expansion within the coding region of the associated genes. The CAG repeat specifies glutamine, and the expanded polyQ domain with mutation confers dominant toxicity on the protein. Traditionally, studies have focused on protein toxicity in polyQ disease mechanisms. Recent findings, however, demonstrate that the CAG repeat RNA, which encodes the toxic polyQ protein, also contributes to the disease in Drosophila. To provide insight into the nature of the RNA toxicity, we extracted brain-enriched RNA from flies expressing a toxic CAG repeat mRNA (CAG100) and a non-toxic interrupted CAA/G mRNA repeat (CAA/G105) for microarray analysis. This approach identified a set of genes that are differentially expressed specifically in CAG100 flies. Four independent replicates of flies expressing CAG0, CAG100, or CAA/G105 by elav-GAL4 were collected at 3 days. The transgenes are DsRed with either (CAG0) no CAG repeat in the 3'UTR, (CAG100) a CAG repeat of 100 CAGs in the 3'UTR, or (CAA/G105) an interrupted CAA CAG repeat in the 3'UTR (ref: Li et al., Nature 453:1107) The transgenes were adjusted to match in mRNA expression such that CAG0 flies had one copy of the transgene, CAG100 flies had 5 copies, and CAA/G105 had two copies. Fly brain tissue (about 20 brains per sample, dissected from head capsule, eyes, lamina and outer medulla removed) was dissected in cold phosphate buffered saline (PBS) and stored in Trizol reagent (Invitrogen Corporation, Carlsbad, CA) at -80Ë?C. Total brain RNA was extracted and purified using TRIzol reagent (Invitrogen) and the RNeasy Mini system (Qiagen), and treated with RNase-free DNase I (Qiagen). To define genes whose expression is altered in response to a toxic CAG repeat RNA, we compared CAG100 flies with age-matched flies expressing CAG0. To exclude transcriptional changes in response to a non-toxic trinucleotide repeat, a second gene list was generated by comparing CAA/G105 flies with age-matched CAG0 flies.
2011-11-22 | E-GEOD-31875 | biostudies-arrayexpress
Project description:Spinocerebellar ataxia type 3 (SCA3) is one of the polyglutamine (polyQ) diseases, which are caused by a CAG repeat expansion within the coding region of the associated genes. The CAG repeat specifies glutamine, and the expanded polyQ domain with mutation confers dominant toxicity on the protein. Traditionally, studies have focused on protein toxicity in polyQ disease mechanisms. Recent findings, however, demonstrate that the CAG repeat RNA, which encodes the toxic polyQ protein, also contributes to the disease in Drosophila. To provide insight into the nature of the RNA toxicity, we extracted brain-enriched RNA from flies expressing a toxic CAG repeat mRNA (CAG100) and a non-toxic interrupted CAA/G mRNA repeat (CAA/G105) for microarray analysis. This approach identified a set of genes that are differentially expressed specifically in CAG100 flies.
2011-11-22 | GSE31875 | GEO
Project description:Identification of repeat-associated non-AUG (RAN) translation in trinucleotide (CAG) repeat diseases leads to an emerging concept that CAG repeat diseases are caused by non-polyglutamine products. Nonetheless, the exact contribution of RAN translation to the pathogenesis of CAG repeat diseases remains elusive. Via CRISPR/Cas9-mediated genome editing, we established new knock-in mouse models that harbor expanded CAG repeats in the mouse huntingtin gene, which express RAN translated products or polyglutamine products respectively. Here we report that RAN translation is not detected in the knock-in mouse models, and that only the expanded polyglutamine products can cause neuropathology and behavioral phenotypes. Therefore, polyglutamine products, rather than RAN translated products, play a major role in the pathogenesis of CAG repeat diseases.
2020-02-03 | GSE142603 | GEO
Project description:Myotonic dystrophy type 1 (DM1) is the most common form of adult-onset muscular dystrophy and is caused by an repeat expansion [r(CUG)exp] located in the 3' untranslated region of the DMPK gene. Symptoms include skeletal and cardiac muscle dysfunction and fibrosis. In DM1, there is a lack of established biomarkers in routine clinical practice. Thus, we aimed to identify a blood biomarker with relevance for DM1-pathophysiology and clinical presentation.
2023-05-02 | PXD024107 | Pride