(CA)n oligonucleotides correct RNA mis-splicing in TDP-43 pathology (II)
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE250255 | GEO | 2023/12/23
REPOSITORIES: GEO
Similar Datasets
Project description:The occurrence of extensive cryptic splicing following the depletion of nuclear TDP-43 results in impaired neuronal function and degeneration. Here, we show that oligonucleotides containing CA-repeat sequences can mimic TDP-43 pre-mRNA binding and broadly repress cryptic splicing events, reverse protein loss, and restore neuronal activity in TDP-43-depleted neurons. Our results indicate that (CA)n oligonucleotides are potential therapeutic agents to address global mis-splicing in TDP-43 proteinopathies.
2023-12-23 | GSE245513 | GEO
Project description:TDP-43 proteinopathies including frontotemporal lobar dementia (FTLD) and amyotrophic lateral sclerosis (ALS) are devastating neurodegenerative disorders characterized by aggregation and mislocalization of the nucleic-acid binding protein TDP-43 and subsequent neuronal dysfunction. Here, we developed an endogenous model of sporadic TDP-43 proteinopathy based on the principle that disease-associated TDP-43 acetylation at lysine 145 (K145) alters TDP-43 conformation, impairs its RNA-binding capacity, and induces downstream mis-regulation of target genes. Expression of aberrant acetylation-mimic TDP-43K145Q resulted in stress-induced phase-separated nuclear TDP-43 foci formation and loss-of-TDP-43-function in mouse primary neurons and human induced pluripotent stem cell (iPSC)-derived neurons. Aged mice harboring the single TDP-43K145Q mutation recapitulate several key hallmarks of neurodegenerative proteinopathies, including progressive TDP-43 phosphorylation and insolubility, cytoplasmic mis-localization, widespread transcriptomic and splicing alterations, and cognitive dysfunction. Our study supports a model in which aberrant TDP-43 acetylation drives neuronal dysfunction and cognitive decline through alternative splicing and transcription of genes important in synaptic plasticity and apoptosis, providing a new paradigm to interrogate FTLD disease mechanisms and uncover disease-modifying therapeutics.
2023-01-09 | GSE216294 | GEO
Project description:Through splicing analysis of a publicly available RNA-Seq dataset, we discovered TDP-43 represses a cryptic exon splicing event in UNC13A, a gene that had been associated with FTD/ALS through GWA studies. To confirm the sequences of the cryptic exons, we used shRNA to reduce TDP-43 levels in iPSC-derived motor neurons (iPSC-MNs) and by amplicon sequencing the RT-PCR product, we observed the insertion in cells with TDP-43 depletion but not in control shRNA-treated cells. Through sequence alignment, we verified the sequences of the cryptic exons.
2021-12-04 | GSE182976 | GEO
Project description:A pathological hallmark of amyotrophic lateral sclerosis and frontotemporal dementia is the aggregation of TDP-43. While extensive exploration into the function of TDP-43 has focused entirely in the central nervous system (CNS), the implications in physiology and pathology of the peripheral nervous system (PNS) have long been overlooked. Herein, we demonstrate that deletion of TDP-43 in Schwann cells results in a 50% reduction in peripheral nerve conduction velocity, without any obvious alterations to peripheral compact myelin. Compromised insulatory function of myelin was due to the complete loss of paranodal axoglial junctions flanking the nodes of Ranvier. By contrast, the paranodal junctions in the CNS oligodendrocytes are unaltered upon deletion of TDP-43. Mechanistically, TDP-43 binds directly to Nfasc mRNA, which encodes neurofascin, a key cell adhesion molecule essential for establishing paranodal junctions. TDP-43 binding sites overlap with a cryptic exon of Nfasc such that loss of TDP-43 leads to the retention of this cryptic exon with a premature stop codon, a prerequisite for nonsense-mediated decay. Thus, TDP-43 is required for the proper assembly of nodes of Ranvier that is essential for saltatory conduction by suppressing the cryptic exon in the Nfasc mRNA of the Schwann cells. Our findings indicate a direct involvement of TDP-43 in normal PNS function and suggest that PNS-autonomous dysfunction in saltatory conduction may contribute to TDP-43 proteinopathies.
2021-09-01 | GSE157714 | GEO
Project description:UNC13A contains a cryptic exon which is normally repressed by TDP-43. To better understand the mechanism by which TDP-43 represses this cryptic splicing, and how common SNPs (rs12973192(G) and rs12608932(C)) perturb this regulation, we transfected HEK293T cells with minigenes featuring UNC13A exons 20 and 21, and intron 20. We used two variants of the minigene: one with rs12973192(C) and rs12608932(G) (2x healthy) and the other with rs12973192(G) and rs12973192(C) (2x risk), then performed TDP-43 iCLIP on these cells. We used two replicates for each.
2022-03-24 | E-MTAB-10297 | biostudies-arrayexpress
Project description:Cellular responses to co-morbid tau and TDP-43 preceding neurodegeneration have not been characterized. In this study, we evaluate transcriptomic changes at time-points preceding frank neuronal loss using a C. elegans model of tau and TDP-43 co-expression. We find significant differential expression and exon usage in genes enriched in multiple pathways including lipid metabolism and lysosomal degradation. We note that tau related changes largely resemble tau/TDP-43 changes. We test loss-of-function mutations in a subset of tau and TDP-43 responsive genes, identifying new modifiers of neurotoxicity. Characterizing early cellular responses to tau and TDP-43 co-pathology is critical for understanding protective and pathogenic responses to mixed proteinopathies, and an important step in developing therapeutic strategies protecting against pathological tau and TDP-43 in AD.
2024-03-15 | GSE249339 | GEO
Project description:Aims: Loss of nuclear TDP-43 characterises sporadic and most familial forms of amyotrophic lateral sclerosis (ALS). TDP-43 (encoded by TARDBP) has multiple roles in RNA processing. We aimed to determine whether 1) RNA splicing dysregulation is present in lower motor neurons in ALS and in a motor neuron-like cell model, and 2) TARDBP mutations (mtTARDBP) are associated with aberrant RNA splicing using patient-derived fibroblasts. Methods: Affymetrix exon arrays were used to study mRNA expression and splicing in lower motor neurons obtained by laser capture microdissection of autopsy tissue from individuals with sporadic ALS and TDP-43 proteinopathy. Findings were confirmed by qRT-PCR and in NSC34 motor neuronal cells following shRNA-mediated TDP-43 depletion. Exon arrays and immunohistochemistry were used to study mRNA splicing and TDP-43 expression in fibroblasts from patients with mtTARDBP-associated, sporadic and mutant SOD1-associated ALS. Results: We found altered expression of spliceosome components in motor neurons and widespread aberrations of mRNA splicing that specifically affected genes involved in ribonucleotide binding. This was confirmed in TDP-43 depleted NSC34 cells. Fibroblasts with mtTARDBP showed loss of nuclear TDP-43 protein and demonstrated similar changes in splicing and gene expression, that were not present in fibroblasts from patients with sporadic or SOD1-related ALS. Conclusion: Loss of nuclear TDP-43 is associated with RNA processing abnormalities in ALS motor neurons, patient-derived cells with mtTARDBP, and following artificial TDP-43 depletion, suggesting that splicing dysregulation directly contributes to disease pathogenesis. Key functional pathways affected include those central to RNA metabolism. RNA was extracted from NSC34 motor neuronal cells depleted of TDP-43 by shRNA (n=4), treated with control shGFP (n=4), and treated with control shLuciferase (n=3).
2014-06-01 | E-GEOD-56503 | biostudies-arrayexpress
Project description:Cross-linking and immunoprecipitation coupled with high-throughput sequencing was used to identify binding sites within 6,304 genes as the brain RNA targets for TDP-43, an RNA binding protein which when mutated causes Amyotrophic Lateral Sclerosis (ALS). Use of massively parallel sequencing and splicing-sensitive junction arrays revealed that levels of 601 mRNAs are changed (including Fus/Tls, progranulin, and other transcripts encoding neurodegenerative disease-associated proteins) and 965 altered splicing events are detected (including in sortilin, the receptor for progranulin), following depletion of TDP-43 from adult brain with antisense oligonucleotides. RNAs whose levels are most depleted by reduction in TDP-43 are derived from genes with very long introns and which encode proteins involved in synaptic activity. Lastly, TDP-43 was found to auto-regulate its synthesis, in part by directly binding and enhancing splicing of an intron within the 3’ untranslated region of its own transcript, thereby triggering nonsense mediated RNA degradation. RNAseq in control and Tdp-43 knockdown mouse striatum
2011-03-03 | E-GEOD-27218 | biostudies-arrayexpress
Project description:In recent times, high throughput screening analyses have broadly defined the RNA cellular targets of TDP-43, a nuclear factor involved in neurodegeneration. A common outcome of all these studies is that changing the expression levels of this protein can alter the expression of several hundred RNAs within cells. What still remains to be clarified is which changes represent direct cellular targets of TDP-43 or just secondary variations due to the general role played by this protein in RNA metabolism. Using a HTS-based splicing junction analysis we have now identified 162 splicing events that are consistent with being directly controlled by TDP-43. Validation of the data, both in neuronal and non-neuronal cell lines demonstrated that TDP-43 substantially alters the levels of isoform expression in four genes potentially important for neuropathology: MADD/IG20, STAG2, FNIP1, and BRD8. Most importantly, for MADD/IG20 and STAG2 these changes could also be confirmed at the protein level. These alterations were also observed in a cellular model that successfully mimics TDP-43 loss of function effects following its aggregation. These novel splicing events may represent potential biomarkers to predict disease onset, progression, and to test the efficacy of novel therapeutic agents to recover TDP-43 functional properties. We have performed an HTS-based splicing junction analysis of a series of stable cell lines that lack TDP-43, overexpress this factor, or express an RNA-binding mutant, in order to find splicing events, potentially associated with neurodegenerativce diseases, regulated by this splicing factor. Samples were analyzed in triplicate from: The following samples were analyzed in triplicate: wild-type HEK-293 cells, siTDP43-treated HEK-293 cells, siTDP43-treated HEK-293 cells overexpressing a flagged-wildtype TDP-43, siTDP43-treated HEK-293 cells overexpressing a RNA-binding deficient mutant.
2015-08-11 | E-GEOD-67195 | biostudies-arrayexpress
Project description:The TDP-43 proteinopathies, which include amyotrophic lateral sclerosis and frontotemporal dementia, are a devastating group of neurodegenerative disorders that are characterized by the mislocalization and aggregation of TDP-43. Here we demonstrate that RNA-targeting CRISPR effector proteins, a programmable class of gene silencing agents that includes the Cas13 family of enzymes and Cas7-11, can be used to mitigate TDP-43 pathology when programmed to target ataxin-2, a modifier of TDP-43-associated toxicity. In addition to inhibiting the aggregation and transit of TDP-43 to stress granules, we find that the in vivo delivery of an ataxin-2-targeting Cas13 system to a mouse model of TDP-43 proteinopathy improved functional deficits, extended survival, and reduced the severity of neuropathological hallmarks. Further, we benchmark RNA-targeting CRISPR platforms against ataxin-2 and find that high-fidelity forms of Cas13 possess improved transcriptome-wide specificity compared to Cas7-11 and a first-generation effector. Our results demonstrate the potential of CRISPR technology for TDP-43 proteinopathies.
2023-09-28 | GSE244306 | GEO