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ABSTRACT:
PROVIDER: PRJNA579031 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Three-dimensional chromatin interactions remain stable upon CAG/CTG repeat expansion
| PRJNA623390 | ENA
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: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:The congenital form of myotonic dystrophy type 1 (cDM) is caused by large-scale expansion of a (CTG•CAG)n repeat in DMPK and DM1-AS. Production of toxic transcripts with long trinucleotide tracts from these genes results in impediment of myogenic differentiation capacity as cDM’s most prominent morpho-phenotypic hallmark. In the current in vitro study, we compared the early differentiation programs of isogenic cDM myoblasts with and without a (CTG)2600 repeat obtained by gene editing. We found that excision of the repeat restored the ability of cDM myoblasts to engage in myogenic fusion, preventing that the ensuing myotubes remained immature. Although the cDM-typical epigenetic status of the DM1 locus and the expression of genes therein were not altered upon removal of the repeat, analyses at the transcriptome and proteome level revealed that early abnormalities in the temporal expression of differentiation regulators, myogenic progression markers and alternative splicing patterns before and immediately after the onset of differentiation became normalized. Our observation that molecular and cellular features of cDM are reversible and can be corrected by repeat-directed genome editing in muscle progenitors is important information for future development of gene therapy for different forms of DM1.
2019-11-20 | PXD016056 | Pride
Project description:Recent data strongly suggest HTT CAG repeat expansion drives Huntington’s disease (HD) pathogenesis and that disease development is modulated by components of the DNA damage response (DDR) pathway. FAN1 has been identified as a major HD modifier which slows expansion of the HTT CAG repeat in several cell and animal HD models. Here we show dual FAN1 activities act to inhibit repeat expansion. A highly conserved SPYF motif in the FAN1 N-terminus is required for an MLH1 interaction, which slows expansion, with FAN1 nuclease activity also contributing towards repeat stabilisation. Our data supports a model where FAN1 binds MLH1, restricting its recruitment by MSH3 and the formation of the functional DNA mismatch repair (MMR) complex believed to promote CAG repeat expansion. FAN1 nuclease activity functions either concurrently or following MMR activity to maintain repeat stability. These data highlight a potential avenue for HD therapeutics in attenuating somatic expansion.
2022-02-16 | PXD023221 | Pride
Project description:In Huntington’s disease (HD), expanded HTT CAG repeat length correlates strongly with age at motor onset, indicating that it determines the rate of the disease process leading to diagnostic clinical manifestations. Similarly, in normal individuals, HTT CAG repeat length is correlated with biochemical differences that reveal it as a functional polymorphism. Here, we tested the hypothesis that gene expression signatures can capture continuous, length-dependent effects of the HTT CAG repeat. Using gene expression datasets for 107 HD and control lymphoblastoid cell lines, we constructed mathematical models in an iterative manner, based upon CAG correlated gene expression patterns in randomly chosen training samples, and tested their predictive power in test samples. Predicted CAG repeat lengths were significantly correlated with experimentally determined CAG repeat lengths, whereas models based upon randomly permuted CAGs were not at all predictive. Predictions from different batches of mRNA for the same cell lines were significantly correlated, implying that CAG length-correlated gene expression is reproducible. Notably, HTT expression was not itself correlated with HTT CAG repeat length. Taken together, these findings confirm the concept of a gene expression signature representing the continuous effect of HTT CAG length and not primarily dependent on the level of huntingtin expression. Such global and unbiased approaches, applied to additional cell types and tissues, may facilitate the discovery of therapies for HD by providing a comprehensive view of molecular changes triggered by HTT CAG repeat length for use in screening for and testing compounds that reverse effects of the HTT CAG expansion. To evaluate the continuous analytical approach as a strategy to discover the molecular consequences of the HTT CAG repeat, genome-wide gene expression datasets were generated from a panel of 107 human lymphoblastoid cell lines with HTT CAGs spanning the entire spectrum of allele sizes.
2013-05-03 | E-GEOD-34721 | biostudies-arrayexpress
Project description:In Huntington’s disease (HD), expanded HTT CAG repeat length correlates strongly with age at motor onset, indicating that it determines the rate of the disease process leading to diagnostic clinical manifestations. Similarly, in normal individuals, HTT CAG repeat length is correlated with biochemical differences that reveal it as a functional polymorphism. Here, we tested the hypothesis that gene expression signatures can capture continuous, length-dependent effects of the HTT CAG repeat. Using gene expression datasets for 107 HD and control lymphoblastoid cell lines, we constructed mathematical models in an iterative manner, based upon CAG correlated gene expression patterns in randomly chosen training samples, and tested their predictive power in test samples. Predicted CAG repeat lengths were significantly correlated with experimentally determined CAG repeat lengths, whereas models based upon randomly permuted CAGs were not at all predictive. Predictions from different batches of mRNA for the same cell lines were significantly correlated, implying that CAG length-correlated gene expression is reproducible. Notably, HTT expression was not itself correlated with HTT CAG repeat length. Taken together, these findings confirm the concept of a gene expression signature representing the continuous effect of HTT CAG length and not primarily dependent on the level of huntingtin expression. Such global and unbiased approaches, applied to additional cell types and tissues, may facilitate the discovery of therapies for HD by providing a comprehensive view of molecular changes triggered by HTT CAG repeat length for use in screening for and testing compounds that reverse effects of the HTT CAG expansion.
2013-05-03 | GSE34721 | GEO
Project description:CWG-cPIP targets CAG/CTG (CWG) triplet repeat DNA to inhibit the transcription in a repeat length-dependent manner. To investigate effects of CWG-cPIP on transcriptome defects in the brain of CUG300 mice, which we developed as a model of DM1, CWG-cPIP (83 ug/kg) was injected into mouse hippocampus. RNA sequencing analysis was performed using mouse hippocampus 10 days later.
2023-10-11 | GSE210838 | GEO
Project description:CWG-cPIP targets CAG/CTG (CWG) triplet repeat DNA to inhibit the transcription in a repeat length-dependent manner. To investigate effects of CWG-cPIP on alternative splicing defects in the brain of CUG300 mice, which we developed as a model of DM1, CWG-cPIP (83 ug/kg) was injected into mouse hippocampus. RNA sequencing analysis was performed using mouse hippocampus 10 days later.
2023-10-11 | GSE210837 | GEO
Project description:CWG-cPIP targets CAG/CTG (CWG) triplet repeat DNA to inhibit the transcription in a repeat length-dependent manner. To investigate off-target effects of CWG-cPIP on gene expression in cells, CWG-cPIP (1 μM) was treated to human fibroblasts. RNA sequencing analysis was performed using vehicle- or CWG-cPIP-treated human fibroblasts 7 days later, mixing with ERCC RNA spike-in controls.
2023-10-11 | GSE235810 | GEO