Inhibition of nonsense-mediated decay in TDP-43 deficient neurons reveals novel cryptic exons
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE307054 | GEO | 2025/09/02
REPOSITORIES: GEO
Similar Datasets
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:Eukaryotic cells express a large number of transcripts from a single gene due to alternative splicing. Despite hundreds of thousands of splice isoforms being annotated in databases, it has been reported that the current exon catalogs remain incomplete. At the same time, introns of human protein-coding genes contain a large number of evolutionarily conserved elements with unknown function. Here, we explore the possibility that some of them represent cryptic exons that are expressed in rare conditions. We identified a group of cryptic exons that are similar to the annotated exons in terms of evolutionary conservation and RNA-seq read coverage in the GTEx dataset. Most of them were poison, i.e. generated an NMD isoform upon inclusion, and many showed signs of tissue-specific and cancer-specific expression and regulation. We performed RNA-seq in A549 cell line treated with cycloheximide to inactivate NMD, and confirmed using qPCR that seven of eight exons tested are, indeed, expressed. This study shows that introns of human protein-coding genes contain cryptic poison exons, which reside in conserved intronic regions and remain not fully annotated due to insufficient representation in RNA-seq libraries.
2024-11-20 | GSE270310 | 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:Nuclear depletion and cytoplasmic aggregation of the RNA-binding protein TDP-43 is the hallmark of ALS, occurring in over 97% of cases. A key consequence of TDP-43 nuclear loss is the de-repression of cryptic exons. Whilst TDP-43 regulated cryptic splicing is increasingly well catalogued, cryptic alternative polyadenylation (APA) events, which define the 3’ end of last exons, have been largely overlooked, especially when not associated with novel upstream splice junctions. We developed a bioinformatic pipeline to reliably identify distinct APA event types: alternative last exons (ALE), 3’UTR extensions (3’Ext) and ‘ composite ’ intronic polyadenylation (IPA) events. We identified novel neuronal cryptic APA sites induced by TDP-43 loss of function by systematically applying our pipeline to a compendium of publicly available and in house datasets. We find that TDP-43 binding sites and target motifs are enriched at these cryptic events and that TDP-43 can have both repressive and enhancing action on APA. Importantly, all categories of cryptic APA can also be identified in ALS and FTD post mortem brain regions with TDP-43 proteinopathy underlining their potential disease relevance. RNA-seq and Ribo-seq analyses indicate that distinct cryptic APA categories have different downstream effects on transcript and translation. Intriguingly, cryptic 3’Exts occur in multiple transcription factors, such as ELK1 , SIX3, and TLX1, and lead to an increase in RNA stability. 3’Exts are localised to the cytoplasm and neurites and translated leading to an increase in wild-type protein levels. In summary, we demonstrate that TDP-43 nuclear depletion induces a novel category of cryptic RNA processing events and we expand the palette of TDP-43 loss consequences by showing this can also lead to an increase in normal protein translation.
2025-05-30 | GSE296713 | GEO
Project description:Nuclear depletion and cytoplasmic aggregation of the RNA-binding protein TDP-43 is the hallmark of ALS, occurring in over 97% of cases. A key consequence of TDP-43 nuclear loss is the de-repression of cryptic exons. Whilst TDP-43 regulated cryptic splicing is increasingly well catalogued, cryptic alternative polyadenylation (APA) events, which define the 3’ end of last exons, have been largely overlooked, especially when not associated with novel upstream splice junctions. We developed a bioinformatic pipeline to reliably identify distinct APA event types: alternative last exons (ALE), 3’UTR extensions (3’Ext) and ‘ composite ’ intronic polyadenylation (IPA) events. We identified novel neuronal cryptic APA sites induced by TDP-43 loss of function by systematically applying our pipeline to a compendium of publicly available and in house datasets. We find that TDP-43 binding sites and target motifs are enriched at these cryptic events and that TDP-43 can have both repressive and enhancing action on APA. Importantly, all categories of cryptic APA can also be identified in ALS and FTD post mortem brain regions with TDP-43 proteinopathy underlining their potential disease relevance. RNA-seq and Ribo-seq analyses indicate that distinct cryptic APA categories have different downstream effects on transcript and translation. Intriguingly, cryptic 3’Exts occur in multiple transcription factors, such as ELK1 , SIX3, and TLX1, and lead to an increase in RNA stability. 3’Exts are localised to the cytoplasm and neurites and translated leading to an increase in wild-type protein levels. In summary, we demonstrate that TDP-43 nuclear depletion induces a novel category of cryptic RNA processing events and we expand the palette of TDP-43 loss consequences by showing this can also lead to an increase in normal protein translation.
2025-05-30 | GSE296716 | GEO
Project description:Nuclear depletion and cytoplasmic aggregation of the RNA-binding protein TDP-43 is the hallmark of ALS, occurring in over 97% of cases. A key consequence of TDP-43 nuclear loss is the de-repression of cryptic exons. Whilst TDP-43 regulated cryptic splicing is increasingly well catalogued, cryptic alternative polyadenylation (APA) events, which define the 3’ end of last exons, have been largely overlooked, especially when not associated with novel upstream splice junctions. We developed a bioinformatic pipeline to reliably identify distinct APA event types: alternative last exons (ALE), 3’UTR extensions (3’Ext) and ‘ composite ’ intronic polyadenylation (IPA) events. We identified novel neuronal cryptic APA sites induced by TDP-43 loss of function by systematically applying our pipeline to a compendium of publicly available and in house datasets. We find that TDP-43 binding sites and target motifs are enriched at these cryptic events and that TDP-43 can have both repressive and enhancing action on APA. Importantly, all categories of cryptic APA can also be identified in ALS and FTD post mortem brain regions with TDP-43 proteinopathy underlining their potential disease relevance. RNA-seq and Ribo-seq analyses indicate that distinct cryptic APA categories have different downstream effects on transcript and translation. Intriguingly, cryptic 3’Exts occur in multiple transcription factors, such as ELK1 , SIX3, and TLX1, and lead to an increase in RNA stability. 3’Exts are localised to the cytoplasm and neurites and translated leading to an increase in wild-type protein levels. In summary, we demonstrate that TDP-43 nuclear depletion induces a novel category of cryptic RNA processing events and we expand the palette of TDP-43 loss consequences by showing this can also lead to an increase in normal protein translation.
2025-05-30 | GSE296714 | GEO
Project description:Nuclear depletion and cytoplasmic aggregation of the RNA-binding protein TDP-43 is the hallmark of ALS, occurring in over 97% of cases. A key consequence of TDP-43 nuclear loss is the de-repression of cryptic exons. Whilst TDP-43 regulated cryptic splicing is increasingly well catalogued, cryptic alternative polyadenylation (APA) events, which define the 3’ end of last exons, have been largely overlooked, especially when not associated with novel upstream splice junctions. We developed a bioinformatic pipeline to reliably identify distinct APA event types: alternative last exons (ALE), 3’UTR extensions (3’Ext) and ‘ composite ’ intronic polyadenylation (IPA) events. We identified novel neuronal cryptic APA sites induced by TDP-43 loss of function by systematically applying our pipeline to a compendium of publicly available and in house datasets. We find that TDP-43 binding sites and target motifs are enriched at these cryptic events and that TDP-43 can have both repressive and enhancing action on APA. Importantly, all categories of cryptic APA can also be identified in ALS and FTD post mortem brain regions with TDP-43 proteinopathy underlining their potential disease relevance. RNA-seq and Ribo-seq analyses indicate that distinct cryptic APA categories have different downstream effects on transcript and translation. Intriguingly, cryptic 3’Exts occur in multiple transcription factors, such as ELK1 , SIX3, and TLX1, and lead to an increase in RNA stability. 3’Exts are localised to the cytoplasm and neurites and translated leading to an increase in wild-type protein levels. In summary, we demonstrate that TDP-43 nuclear depletion induces a novel category of cryptic RNA processing events and we expand the palette of TDP-43 loss consequences by showing this can also lead to an increase in normal protein translation.
2025-05-30 | GSE296711 | GEO
Project description:Nuclear depletion and cytoplasmic aggregation of the RNA-binding protein TDP-43 is the hallmark of ALS, occurring in over 97% of cases. A key consequence of TDP-43 nuclear loss is the de-repression of cryptic exons. Whilst TDP-43 regulated cryptic splicing is increasingly well catalogued, cryptic alternative polyadenylation (APA) events, which define the 3’ end of last exons, have been largely overlooked, especially when not associated with novel upstream splice junctions. We developed a bioinformatic pipeline to reliably identify distinct APA event types: alternative last exons (ALE), 3’UTR extensions (3’Ext) and ‘ composite ’ intronic polyadenylation (IPA) events. We identified novel neuronal cryptic APA sites induced by TDP-43 loss of function by systematically applying our pipeline to a compendium of publicly available and in house datasets. We find that TDP-43 binding sites and target motifs are enriched at these cryptic events and that TDP-43 can have both repressive and enhancing action on APA. Importantly, all categories of cryptic APA can also be identified in ALS and FTD post mortem brain regions with TDP-43 proteinopathy underlining their potential disease relevance. RNA-seq and Ribo-seq analyses indicate that distinct cryptic APA categories have different downstream effects on transcript and translation. Intriguingly, cryptic 3’Exts occur in multiple transcription factors, such as ELK1 , SIX3, and TLX1, and lead to an increase in RNA stability. 3’Exts are localised to the cytoplasm and neurites and translated leading to an increase in wild-type protein levels. In summary, we demonstrate that TDP-43 nuclear depletion induces a novel category of cryptic RNA processing events and we expand the palette of TDP-43 loss consequences by showing this can also lead to an increase in normal protein translation.
2025-05-30 | GSE296710 | GEO
Project description:Nuclear depletion and cytoplasmic aggregation of the RNA-binding protein TDP-43 is the hallmark of ALS, occurring in over 97% of cases. A key consequence of TDP-43 nuclear loss is the de-repression of cryptic exons. Whilst TDP-43 regulated cryptic splicing is increasingly well catalogued, cryptic alternative polyadenylation (APA) events, which define the 3’ end of last exons, have been largely overlooked, especially when not associated with novel upstream splice junctions. We developed a bioinformatic pipeline to reliably identify distinct APA event types: alternative last exons (ALE), 3’UTR extensions (3’Ext) and ‘ composite ’ intronic polyadenylation (IPA) events. We identified novel neuronal cryptic APA sites induced by TDP-43 loss of function by systematically applying our pipeline to a compendium of publicly available and in house datasets. We find that TDP-43 binding sites and target motifs are enriched at these cryptic events and that TDP-43 can have both repressive and enhancing action on APA. Importantly, all categories of cryptic APA can also be identified in ALS and FTD post mortem brain regions with TDP-43 proteinopathy underlining their potential disease relevance. RNA-seq and Ribo-seq analyses indicate that distinct cryptic APA categories have different downstream effects on transcript and translation. Intriguingly, cryptic 3’Exts occur in multiple transcription factors, such as ELK1 , SIX3, and TLX1, and lead to an increase in RNA stability. 3’Exts are localised to the cytoplasm and neurites and translated leading to an increase in wild-type protein levels. In summary, we demonstrate that TDP-43 nuclear depletion induces a novel category of cryptic RNA processing events and we expand the palette of TDP-43 loss consequences by showing this can also lead to an increase in normal protein translation.
2025-05-30 | GSE296712 | GEO
Project description:Splicing misregulation, such as the inclusion of previously unknown cryptic exons, is implicated in numerous diseases. Recent methods have increased accurate and efficient detection of such splicing alterations occurring in disease phenotypes. However, the quantification and differential analyses of non-canonical splicing alterations remains focused at a splice event level, thus preventing a complete view of the effects on the downstream transcriptomic landscape. Here, we present a novel and integrated pipeline, SpliCeAT, that (1) detects and quantifies differential non-canonical splicing events from short-read bulk RNA-seq data, (2) augments the canonical transcriptome with novel transcripts containing these non-canonical splicing events, and (3) performs transcript-level differential analysis to identify and quantify aberrant cryptic exon-containing transcripts based on this augmented transcriptome. Using TDP-43, an ALS/FTD-associated RNA-binding protein as an example, we identified and catalogued aberrant splicing events in embryonic mouse brains. The accuracy of our integrated pipeline was further confirmed and validated with long-read isoform sequencing. Furthermore, by comparing neuronal TDP-43 knockouts in mice with a publicly available human dataset with TDP-43 pathology, we identified and validated 4 common genes, namely, Kalrn/KALRN, Poldip3/POLDIP3, Rnf144a/RNF144A, and Unc13a/UNC13A, with cryptic exons. In summary, our integrated pipeline, novel splice events are identified, incorporated and quantified at the transcript level, thereby enabling more complete transcriptome profiling of well-annotated genomes in in the case of pathological splicing misregulation.
2025-02-02 | GSE288457 | GEO