TDP-43 represses a cryptic exon in Schwann cells to ensure rapid saltatory conduction
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA662527 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR12616323_1.fastq.gz | Fastqsanger.gz | |||
| SRR12616323_2.fastq.gz | Fastqsanger.gz | |||
| SRR12616324_1.fastq.gz | Fastqsanger.gz | |||
| SRR12616324_2.fastq.gz | Fastqsanger.gz | |||
| SRR12616325_1.fastq.gz | Fastqsanger.gz |
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Similar Datasets
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:TDP-43 is extensively studied in neurons in physiological and pathological contexts. However, emerging evidence indicates that glial cells are also reliant on TDP-43 function. We demonstrate that deletion of TDP-43 in Schwann cells results in a dramatic delay in peripheral nerve conduction causing significant motor deficits in mice, which is directly attributed to the absence of paranodal axoglial junctions. By contrast, paranodes in the central nervous system are unaltered in oligodendrocytes lacking TDP-43. Mechanistically, TDP-43 binds directly to Neurofascin mRNA, encoding the cell adhesion molecule essential for paranode assembly and maintenance. Loss of TDP-43 triggers the retention of a previously unidentified cryptic exon, which targets Neurofascin mRNA for nonsense-mediated decay. Thus, TDP-43 is required for neurofascin expression, proper assembly and maintenance of paranodes, and rapid saltatory conduction. Our findings provide a framework and mechanism for how Schwann cell-autonomous dysfunction in nerve conduction is directly caused by TDP-43 loss-of-function.
| S-EPMC7946431 | biostudies-literature
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:TDP-43 represses cryptic exon inclusion in FTD/ALS gene UNC13A
| PRJNA758574 | ENA
Project description:A hallmark pathological feature of the neurodegenerative diseases amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) is the depletion of RNA-binding protein TDP-43 from the nucleus of neurons in the brain and spinal cord1. A major function of TDP-43 is as a repressor of cryptic exon inclusion during RNA splicing2-4. Single nucleotide polymorphisms in UNC13A are among the strongest hits associated with FTD and ALS in human genome-wide association studies5,6, but how those variants increase risk for disease is unknown. Here we show that TDP-43 represses a cryptic exon-splicing event in UNC13A. Loss of TDP-43 from the nucleus in human brain, neuronal cell lines and motor neurons derived from induced pluripotent stem cells resulted in the inclusion of a cryptic exon in UNC13A mRNA and reduced UNC13A protein expression. The top variants associated with FTD or ALS risk in humans are located in the intron harbouring the cryptic exon, and we show that they increase UNC13A cryptic exon splicing in the face of TDP-43 dysfunction. Together, our data provide a direct functional link between one of the strongest genetic risk factors for FTD and ALS (UNC13A genetic variants), and loss of TDP-43 function.
| S-EPMC8891019 | biostudies-literature
Project description:Abnormal accumulation of TDP-43 into cytoplasmic or nuclear inclusions with accompanying nuclear clearance, a common pathology initially identified in amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), has also been found in Alzheimer' disease (AD). TDP-43 serves as a splicing repressor of nonconserved cryptic exons and that such function is compromised in brains of ALS and FTD patients, suggesting that nuclear clearance of TDP-43 underlies its inability to repress cryptic exons. However, whether TDP-43 cytoplasmic aggregates are a prerequisite for the incorporation of cryptic exons is not known. Here, we assessed hippocampal tissues from 34 human postmortem brains including cases with confirmed diagnosis of AD neuropathologic changes along with age-matched controls. We found that cryptic exon incorporation occurred in all AD cases exhibiting TDP-43 pathology. Furthermore, incorporation of cryptic exons was observed in the hippocampus when TDP-43 inclusions was restricted only to the amygdala, the earliest stage of TDP-43 progression. Importantly, cryptic exon incorporation could be detected in AD brains lacking TDP-43 inclusion but exhibiting nuclear clearance of TDP-43. These data supports the notion that the functional consequence of nuclear depletion of TDP-43 as determined by cryptic exon incorporation likely occurs as an early event of TDP-43 proteinopathy and may have greater contribution to the pathogenesis of AD than currently appreciated. Early detection and effective repression of cryptic exons in AD patients may offer important diagnostic and therapeutic implications for this devastating illness of the elderly.
| S-EPMC5444385 | biostudies-literature
Project description:Proper development of the specialized cardiac conduction system is crucial for function of the mature heart. Tools for isolation and in-vivo study of the conduction system are limited. The goal of this study was to identify pathways important for conduction system development. We generated a BAC transgenic mouse line, minKGFP, that marks the conduction system during embryogenesis and in adulthood. GFP is expressed in this line at high levels in conduction system myocardium (minkGFP high) and low levels in chamber myocardium (minKGFP low). We used this mouse line to isolate E10.5 conduction system cells, and performed transcriptional profiling on these cells to identify pathways with potential roles in specification of the developing cardiac conduction system.
2015-08-19 | GSE36136 | GEO
Project description:Arrhythmias are a hallmark of myocardial infarction (MI) and increase patient mortality. The cardiac conduction system is implicated in arrhythmias, but how it is altered following MI is poorly understood. We demonstrate complete conduction system restoration during neonatal mouse heart regeneration, versus pathological remodelling at non-regenerative stages. Tissue-cleared whole-organ imaging identified disorganised bundling of conduction fibres after MI, global His/Purkinje disruption and regional loss of connexin-40. Single-cell RNA-sequencing revealed that Purkinje cells undergo specific molecular changes to regenerate the network, versus sustained aberrant electrical alterations during fibrotic repair. This manifested functionally as transition from normal rhythm to pathological conduction delay beyond the regenerative window. Modelling the non-regenerative phenotype in the infarcted human heart implicated these changes as causative for bundle branch block and ventricular dyssynchrony, as observed in patients. These findings elucidate the mechanisms underpinning conduction system regeneration versus repair and reveal the consequences of MI-induced damage for clinical arrhythmogenesis.
2024-10-31 | GSE245872 | GEO
Project description:ALS/FTD GWAS risk variant rs12973192 promotes severe cryptic splicing of the UNC13A transcript upon TDP-43 depletion
| PRJEB42763 | ENA
Project description:MicroRNAs (miRNAs) play important roles in a wide range of cellular processes. Aberrant regulation of miRNA genes contributes to human diseases, including cancer. The TAR DNA binding protein 43 (TDP-43), a DNA/RNA binding protein associated with neurodegeneration, is involved in miRNA biogenesis. Here, we systematically examined miRNAs whose expression levels are regulated by TDP-43 using RNA-Seq coupled with siRNA-mediated knockdown approach. TDP-43 knocking down affected the expression of a number of miRNAs. Alterations in isomiR patterns and miRNA arm selection after TDP-43 knockdown suggest a role of TDP-43 in miRNA editing. We examined correlation of selected TDP-43 associated miRNAs and their candidate target genes in human cancers. Our data reveal highly complex roles of TDP-43 in regulating different miRNAs and their target genes. Our results suggest that TDP-43 may promote migration of lung cancer cells by regulating miR-423-3p expression. On the other hand, TDP-43 increases miR-500a-3p expression and binds to the mature miR-500a-3p sequence. Low expression of miR-500a-3p was associated with poor survival of lung cancer patients, suggesting that TDP-43 may have a suppressive role in cancer by regulating miR-500a-3p. Our experiments reveal that cancer-associated genes LIF and PAPPA may be targets of miR-500a-3p. Together with other studies, our work suggests that TDP-43-regulated miRNAs may play multi-facet roles in the pathogenesis of cancer. small RNA seq in SH-SY-5Y, SNB-19 and HT22 (TDP-43 siRNA VS Control siRNA)
2016-08-02 | E-GEOD-85065 | biostudies-arrayexpress