Homo sapiens
Ontology highlight
ABSTRACT:
OTHER RELATED OMICS DATASETS IN: E-GEOD-5040
PROVIDER: PRJNA96673 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:The inherited neurodegenerative disease Friedreich’s ataxia (FRDA) is caused by hyperexpansion of GAA•TTC trinucleotide repeats within the first intron of the FXN gene, encoding the mitochondrial protein frataxin. Long GAA•TTC repeats causes heterochromatin-mediated silencing and loss of frataxin in affected individuals. We report the derivation of induced pluripotent stem cells (iPSCs) from FRDA patient fibroblasts through retroviral transduction of transcription factors. FXN gene repression is maintained in the iPSCs, as are the mRNA and miRNA global expression signatures reflecting the human disease. GAA•TTC repeats uniquely in FXN in the iPSCs exhibit repeat instability similar to patient families, where they expand and/or contract with discrete changes in length between generations. The mismatch repair enzyme Msh2, implicated in repeat instability in other triplet repeat diseases, is highly expressed in the iPSCs, occupies FXN intron 1, and shRNA silencing of Msh2 impedes repeat expansion, providing a possible molecular explanation for repeat expansion in FRDA.
2010-07-02 | GSE22651 | GEO
Project description:Expansion of triplex-forming GAA/TTC repeats in the first intron of FRDA gene is known to cause Friedreich’s ataxia. Besides FRDA, there are a number of other highly polymorphic GAA/TTC loci in the human genome where the size variations so far were considered to be a neutral event. Using yeast as a model system, we demonstrate that expanded GAA/TTC repeats represent a threat to eukaryotic genome integrity by triggering double-strand breaks and gross chromosomal rearrangements. The fragility potential strongly depends on the length of the track and orientation of the repeats relative to the replication origin which correlates with their propensity to adopt secondary structure and to block replication progression. We show that fragility is mediated by mismatch repair machinery and requires the MutS(beta) and endonuclease activity of MutL(alpha). We suggest that the mechanism of GAA/TTC-induced chromosome aberrations defined in yeast can also operate in human carriers with expanded tracks. Keywords: CGH-array
2008-05-14 | GSE11425 | GEO
Project description:Expansion of triplex-forming GAA/TTC repeats in the first intron of FRDA gene is known to cause Friedreich’s ataxia. Besides FRDA, there are a number of other highly polymorphic GAA/TTC loci in the human genome where the size variations so far were considered to be a neutral event. Using yeast as a model system, we demonstrate that expanded GAA/TTC repeats represent a threat to eukaryotic genome integrity by triggering double-strand breaks and gross chromosomal rearrangements. The fragility potential strongly depends on the length of the track and orientation of the repeats relative to the replication origin which correlates with their propensity to adopt secondary structure and to block replication progression. We show that fragility is mediated by mismatch repair machinery and requires the MutS(beta) and endonuclease activity of MutL(alpha). We suggest that the mechanism of GAA/TTC-induced chromosome aberrations defined in yeast can also operate in human carriers with expanded tracks. Keywords: CGH-array Genomic DNA from each of 15 strains was competitively hybridized to DNA from the parent diploid strain (Cy3/green). Gains of genomic segments in the survivors were detected as continuous regions of positive Log2 Red:Green ratios, while losses were detected as negative Log2 Red:Green ratios.
2008-05-14 | E-GEOD-11425 | biostudies-arrayexpress
Project description:Lymphoblast cells from a patient with Freidriech's Ataxia were incubated with pyrrole-imidazole polyamides targeted to the GAA triplet repeat in the intron 1. The polyamides were shown in cell culture to increase levels of endogenous frataxin mRNA. A normal sibling derived lymphoblast cell line was used as a control. Keywords: human lymphoblast cells
2006-06-14 | GSE5040 | GEO
Project description:Switching a paused RNA polymerase II into productive elongation is tightly-regulated, especially at genes involved in human development and disease. To exert control on this rate-limiting step, we designed sequence-specific synthetic transcription elongation factors (Syn-TEFs). These molecules are composed of programmable DNA-binding ligands flexibly tethered to a small molecule that binds a component of the transcription elongation machinery. The resultant bifunctional molecules convert constituent modules from broad-spectrum inhibitors of transcription into a gene-specific stimulator of transcriptional elongation. Here, we present Syn-TEF1, a molecule that actively facilitates transcription across repressive GAA repeats that silence frataxin expression in Friedreich’s ataxia, a debilitating and ultimately lethal neurodegenerative disease with no effective therapy.
2017-12-06 | GSE99402 | GEO
Project description:Switching a paused RNA polymerase II into productive elongation is tightly-regulated, especially at genes involved in human development and disease. To exert control on this rate-limiting step, we designed sequence-specific synthetic transcription elongation factors (Syn-TEFs). These molecules are composed of programmable DNA-binding ligands flexibly tethered to a small molecule that binds a component of the transcription elongation machinery. The resultant bifunctional molecules convert constituent modules from broad-spectrum inhibitors of transcription into a gene-specific stimulator of transcriptional elongation. Here, we present Syn-TEF1, a molecule that actively facilitates transcription across repressive GAA repeats that silence frataxin expression in Friedreich’s ataxia, a debilitating and ultimately lethal neurodegenerative disease with no effective therapy.
2017-12-06 | GSE99400 | GEO
Project description:Lymphoblast cells from a patient with Freidriech's Ataxia were incubated with pyrrole-imidazole polyamides targeted to the GAA triplet repeat in the intron 1. The polyamides were shown in cell culture to increase levels of endogenous frataxin mRNA. A normal sibling derived lymphoblast cell line was used as a control. Experiment Overall Design: Normal (GM15851) and patient (GM15850) cell lines were incubated in the presence of match polyamide FA1 at 1uM, 2uM or mismatch polyamide FA2 at 2uM for 7days prior to RNA purification and microarray analysis.
2008-06-13 | E-GEOD-5040 | biostudies-arrayexpress
Project description:In an 8-year-old girl of consanguineous Turkish parents, who developed ataxic gait and polyneuropathy at the age of 3 years, we identified a biallelic missense variant c.424C>T, p.R142W in Glypican 1 (GPC1) by using whole genome sequencing. Up to date, GPC1 has not been associated with a neuromuscular disorder and we hypothesized that this variant, which is predicted as deleterious (CADD score 26.4) may be causative for the disease. Using mass spectrometry-based proteomics, we investigated the interactome of the GPC1 missense variant. We identified 198 proteins interacting with GPC1, of which 16 were altered due to the missense variant. Differentially regulated proteins include members of the vacuolar ATPase (v-ATPase) and mammalian target of rapamycin complex 1 (mTORC1) complexes, whose mis-regulation could have a potential impact on disease severity in the patient. Importantly, these proteins are novel interaction partners of GPC1. At 11 years of age, the patient developed a cardiomyopathy and kyphoscoliosis and a Friedreich’s Ataxia (FRDA) was suspected. Indeed a 104 GAA-repeat expansion in the FXN gene was found. Given the unusually severe phenotype in a patient with FRDA carrying only 104 GAA-repeats, we currently assume that the disturbed function in GPC1 may exacerbate the disease phenotype.
2023-08-15 | PXD040023 | Pride
Project description:Friedreich’s Ataxia Induced Pluripotent Stem Cells Recapitulate GAA•TTC Triplet-Repeat Instability
| PRJNA128015 | ENA
Project description:Friedreich's ataxia (FRDA) is an autosomal-recessive neurodegenerative and cardiac disorder which occurs when transcription of the FXN gene is silenced due to an excessive expansion of GAA repeats into its first intron. Herein, we generate dorsal root ganglia organoids (DRGOs) by in vitro differentiation of human iPSCs. Bulk and single-cell RNA sequencing show that DRGOs present a close transcriptional signature with native DRGs and display the main peripheral sensory neuronal and glial cell subtypes. Furthermore, when co-cultured with human intrafusal muscle fibers, DRGO sensory neurons contact their peripheral targets and reconstitute the muscle spindle proprioceptive receptors. FRDA DRGOs recapitulate key molecular and cellular deficits of the disease that are extensively rescued only when the entire FXN intron 1 is removed and not with the excision of merely the expanded GAA tract. These results strongly suggest that removal of the repressed chromatin flanking the GAA tract might be necessary to obtain a complete rescue of FXN expression and fully revert the pathological hallmarks of FRDA DRG neurons.
2020-07-27 | GSE148212 | GEO