C9orf72 Intermediate Repeats are Associated with Corticobasal Degeneration, Increased C9orf72 Expression and Disruption of Autophagy
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ABSTRACT:
PROVIDER: PRJNA551119 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR9602170_1.fastq.gz | Fastqsanger.gz | |||
| SRR9602170_2.fastq.gz | Fastqsanger.gz | |||
| SRR9602171_1.fastq.gz | Fastqsanger.gz | |||
| SRR9602171_2.fastq.gz | Fastqsanger.gz | |||
| SRR9602172_1.fastq.gz | Fastqsanger.gz |
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Project description:Microsatellite repeat expansion disease loci can exhibit pleiotropic clinical and biological effects depending on repeat length. Large expansions in C9orf72 (100s-1000s of units) are the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal degeneration (FTD). However, whether intermediate expansions also contribute to neurodegenerative disease is not well understood. Several studies have identified intermediate repeats in Parkinson’s disease patients, but the association was not found in autopsy confirmed cases. We hypothesized that intermediate C9orf72 repeats are a genetic risk factor for corticobasal degeneration (CBD), a neurodegenerative disease that can be clinically similar to Parkinson’s but has distinct tau protein pathology. Indeed, intermediate C9orf72 repeats were significantly enriched in autopsy-proven CBD (n=354 cases, odds ratio=3.59, p-value=0.00024). While large C9orf72 repeat expansions are known to decrease C9orf72 expression, intermediate C9orf72 repeats result in increased C9orf72 expression in human brain tissue and CRISPR/cas9 knockin iPSC derived neural progenitor cells. In contrast to cases of FTD/ALS with large C9orf72 expansions, CBD with intermediate C9orf72 repeats was not associated with pathologic RNA foci or dipeptide repeat protein aggregates. Knock-in cells with intermediate repeats exhibit numerous changes in gene expression pathways relating to vesicle trafficking and autophagy. Additionally, overexpression of C9orf72 without the repeat expansion leads to defects in autophagy under nutrient starvation conditions. These results raise the possibility that therapeutic strategies to reduce C9orf72 expression may be beneficial for the treatment of CBD.
2019-09-17 | GSE133323 | GEO
Project description:Microsatellite repeat expansion disease loci can exhibit pleiotropic clinical and biological effects depending on repeat length. Large expansions in C9orf72 (100s-1000s of units) are the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal degeneration (FTD). However, whether intermediate expansions also contribute to neurodegenerative disease is not well understood. Several studies have identified intermediate repeats in Parkinson's disease patients, but the association was not found in autopsy-confirmed cases. We hypothesized that intermediate C9orf72 repeats are a genetic risk factor for corticobasal degeneration (CBD), a neurodegenerative disease that can be clinically similar to Parkinson's but has distinct tau protein pathology. Indeed, intermediate C9orf72 repeats were significantly enriched in autopsy-proven CBD (n = 354 cases, odds ratio = 3.59, p = 0.00024). While large C9orf72 repeat expansions are known to decrease C9orf72 expression, intermediate C9orf72 repeats result in increased C9orf72 expression in human brain tissue and CRISPR/cas9 knockin iPSC-derived neural progenitor cells. In contrast to cases of FTD/ALS with large C9orf72 expansions, CBD with intermediate C9orf72 repeats was not associated with pathologic RNA foci or dipeptide repeat protein aggregates. Knock-in cells with intermediate repeats exhibit numerous changes in gene expression pathways relating to vesicle trafficking and autophagy. Additionally, overexpression of C9orf72 without the repeat expansion leads to defects in autophagy under nutrient starvation conditions. These results raise the possibility that therapeutic strategies to reduce C9orf72 expression may be beneficial for the treatment of CBD.
| S-EPMC6802287 | biostudies-literature
Project description:Repeat expansions in the C9orf72 gene are a common cause of amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD), two devastating neurodegenerative disorders. One of the proposed mechanisms of GGGGCC repeat expansion is their translation to produce unnatural dipeptide repeat (DPR) proteins that accumulate in aggregates and contribute to the pathology. There are 5 different DPRs poly(GA), poly(GR), poly(PR), poly(PA), poly(GP) which are neurotoxic in vitro. In our study, we identified the interactome of all five DPR proteins, consisting of 125 repeats, overexpressed in HEK293T cells using BioID2 proximity labeling. We identified 140 interacting partners for polyGR, 130 for polyGA, 138 for polyPR, 62 for polyPA, and 38 for polyGP. Gene ontology enrichment analysis of proteomic data identified interaction candidates involved in protein translation, signal transduction pathways, protein catabolic processes, amide metabolic processes, and RNA-binding. Through further analyses, we evaluated the interaction between polyGA and Valosin-containing protein (VCP) in HEK293T cells as well as in brains of C9orf72 patients. Furthermore, we are showing that polyGA sequester VCP in polyGA aggregates and hinders its function. Additionally, we analyzed the effect of decreased level of VCP on autophagic markers p62 and LC3.
2022-05-19 | PXD024120 | Pride
Project description:Noncoding expansions of a hexanucleotide repeat (GGGGCC) in the C9orf72 gene are the most common cause of familial amyotrophic lateral sclerosis and frontotemporal dementia. Here we report transgenic mice carrying a bacterial artificial chromosome (BAC) containing the full human C9orf72 gene with either a normal allele (15 repeats) or disease-associated expansion (~100â??1,000 repeats; C9-BACexp). C9-BACexp mice displayed pathologic features seen in C9orf72 expansion patients, including widespread RNA foci and repeat-associated non-ATG (RAN) translated dipeptides, which were suppressed by antisense oligonucleotides targeting human C9orf72. Nucleolin distribution was altered, supporting that either C9orf72 transcripts or RAN dipeptides promote nucleolar dysfunction. Despite early and widespread production of RNA foci and RAN dipeptides in C9-BACexp mice, behavioral abnormalities and neurodegeneration were not observed even at advanced ages, supporting the hypothesis that RNA foci and RAN dipeptides occur presymptomatically and are not sufficient to drive neurodegeneration in mice at levels seen in patients. To compare the RNA Seq profiles from the cortex and spinal cord of transgenic mice expressing unexpanded human C9orf72 (F08, n=4), expanded human C9orf72 (F112, n=3/4), and nontransgenic controls (n=4).
2016-02-10 | E-GEOD-77720 | biostudies-arrayexpress
Project description:N6-methyladenosine (m6A) is the most prevalent internal mRNA modification and regulates RNA metabolism. Repeat expansion in C9ORF72 is the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal degeneration (FTD). Here, we showed that m6A is downregulated in C9ORF72-ALS/FTD patient-derived iPSC-differentiated neurons and postmortem brain tissues. The global m6A hypomethylation leads to transcriptome-wide mRNA stabilization and upregulated gene expression, especially ones involved in synaptic activity and neuronal functions. The m6A modification in the C9ORF72 intron sequence preceding the expanded repeats enhances RNA degradation via the nuclear reader YTHDC1. The m6A reduction leads to increased accumulation of repeat RNA and poly-dipeptides. Moreover, the antisense RNA can also be regulated by m6A. Elevating m6A level significantly reduces both sense and antisense repeat RNA and poly-dipeptides, rescues global mRNA homeostasis, and improves survival of C9ORF72-ALS/FTD patient neurons.
2023-06-09 | GSE203580 | GEO
Project description:N6-methyladenosine (m6A) is the most prevalent internal mRNA modification and regulates RNA metabolism. Repeat expansion in C9ORF72 is the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal degeneration (FTD). Here, we showed that m6A is downregulated in C9ORF72-ALS/FTD patient-derived iPSC-differentiated neurons and postmortem brain tissues. The global m6A hypomethylation leads to transcriptome-wide mRNA stabilization and upregulated gene expression, especially ones involved in synaptic activity and neuronal functions. The m6A modification in the C9ORF72 intron sequence preceding the expanded repeats enhances RNA degradation via the nuclear reader YTHDC1. The m6A reduction leads to increased accumulation of repeat RNA and poly-dipeptides. Moreover, the antisense RNA can also be regulated by m6A. Elevating m6A level significantly reduces both sense and antisense repeat RNA and poly-dipeptides, rescues global mRNA homeostasis, and improves survival of C9ORF72-ALS/FTD patient neurons.
2023-06-09 | GSE203579 | GEO
Project description:N6-methyladenosine (m6A) is the most prevalent internal mRNA modification and regulates RNA metabolism. Repeat expansion in C9ORF72 is the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal degeneration (FTD). Here, we showed that m6A is downregulated in C9ORF72-ALS/FTD patient-derived iPSC-differentiated neurons and postmortem brain tissues. The global m6A hypomethylation leads to transcriptome-wide mRNA stabilization and upregulated gene expression, especially ones involved in synaptic activity and neuronal functions. The m6A modification in the C9ORF72 intron sequence preceding the expanded repeats enhances RNA degradation via the nuclear reader YTHDC1. The m6A reduction leads to increased accumulation of repeat RNA and poly-dipeptides. Moreover, the antisense RNA can also be regulated by m6A. Elevating m6A level significantly reduces both sense and antisense repeat RNA and poly-dipeptides, rescues global mRNA homeostasis, and improves survival of C9ORF72-ALS/FTD patient neurons.
2023-06-09 | GSE203578 | GEO
Project description:Compelling evidence indicates that defects in nucleocytoplasmic transport contribute to the pathogenesis of amyotrophic lateral sclerosis (ALS). In particular, hexanucleotide (G4C2) repeat expansions in C9orf72, the most common cause of genetic ALS, have a widespread impact on the transport machinery that regulates the nucleocytoplasmic distribution of proteins and RNAs, thereby affecting their functions. We have previously reported that the expression of G4C2 hexanucleotide repeats in cultured human and mouse cells caused a marked accumulation of poly(A) mRNAs in cell nuclei, suggesting that mRNA trafficking is impaired by expanded C9orf72-ALS repeats. To further characterize the process, in this work we set out to systematically identify the specific mRNAs that are altered in their nucleocytoplasmic distribution in the presence of C9orf72-ALS repeats. Results from RNAseq profiling of nuclear and cytoplasmic RNA fractions obtained from cells expressing G4C231 repeats show a significant accumulation of mRNAs in the nuclei of G4C231 cells, further suggesting that nuclear retention of mRNAs is a major effect of C9orf72 expanded repeats expression. Interestingly, pathway analysis shows that mRNAs involved in ER-to-Golgi trafficking are particularly enriched among the identified mRNAs. Most importantly, functional studies in cultured cells and Drosophila indicate that the membrane trafficking route regulated by ARFGAP1, a GTPase-activating protein that associates with Golgi, is specifically affected by expanded C9orf72 repeats, as well as by C9orf72-related dipeptide repeat proteins (C9-DPRs), pointing to ER-to-Golgi vesicle-mediated transport as a target of C9orf72 toxicity.
2023-08-21 | GSE235448 | GEO
Project description:In this study we investigated the role of SRSF1 in mitigating locomotor defect in C9ORF72-ALS/FTD Drosophila lines. We analysed the transcriptomes of Drosophila heads from the same lines: (i) control flies expressing 3 G4C2 repeats and a luciferase-RNAi control (G4C2x3 + C-RNAi); (ii) C9ORF72-ALS/FTD model expressing 36 G4C2 repeats and the RNAi control (G4C2x36 + C-RNAi); (iii) C9ORF72-ALS/FTD-neuroprotected flies expressing 36 G4C2 repeats and the disrupted SRSF1 allele (G4C2x36 + ΔSRSF1). RNA samples were profiled using Drosophila 3' IVT gene expression Affymetrix microarrays prior to qRT-PCR validation of the SRSF1 depletion in neuroprotected flies. This study is part of a larger study that investigates the mitigating role of SRSF1 at whole-genome level to detect transcriptomal alterations and neuronal hyperexcitability in C9ORF72-linked amyotrophic lateral sclerosis.
2021-07-21 | GSE138592 | GEO
Project description:Noncoding expansions of a hexanucleotide repeat (GGGGCC) in the C9orf72 gene are the most common cause of familial amyotrophic lateral sclerosis and frontotemporal dementia. Here we report transgenic mice carrying a bacterial artificial chromosome (BAC) containing the full human C9orf72 gene with either a normal allele (15 repeats) or disease-associated expansion (~100–1,000 repeats; C9-BACexp). C9-BACexp mice displayed pathologic features seen in C9orf72 expansion patients, including widespread RNA foci and repeat-associated non-ATG (RAN) translated dipeptides, which were suppressed by antisense oligonucleotides targeting human C9orf72. Nucleolin distribution was altered, supporting that either C9orf72 transcripts or RAN dipeptides promote nucleolar dysfunction. Despite early and widespread production of RNA foci and RAN dipeptides in C9-BACexp mice, behavioral abnormalities and neurodegeneration were not observed even at advanced ages, supporting the hypothesis that RNA foci and RAN dipeptides occur presymptomatically and are not sufficient to drive neurodegeneration in mice at levels seen in patients.
2016-02-10 | GSE77720 | GEO