Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

An aberrant cytoplasmic intron retention programme is a blueprint for ALS-related RBP mislocalization

ABSTRACT: We recently described aberrant cytoplasmic SFPQ intron-retaining transcripts (IRTs) and concurrent SFPQ protein mislocalization as a new hallmark of amyotrophic lateral sclerosis (ALS). However the generalizability and potential roles of cytoplasmic IRTs in health and disease remain unclear. Here, using time-resolved deep-sequencing of nuclear and cytoplasmic fractions of hiPSCs undergoing motor neurogenesis, we reveal that ALS-causing VCP gene mutations lead to compartment-specific aberrant accumulation of IRTs. Specifically, we identify >100 IRTs with increased cytoplasmic (but not nuclear) abundance in ALS samples. Furthermore, these aberrant cytoplasmic IRTs possess sequence-specific attributes and differential predicted binding affinity to RNA binding proteins (RBPs). Remarkably, TDP-43, SFPQ and FUS - RBPs known for nuclear-to-cytoplasmic mislocalization in ALS - avidly and specifically bind to this aberrant cytoplasmic pool of IRTs, as opposed to any individual IRT. Our data are therefore consistent with a novel role for cytoplasmic IRTs in regulating compartment-specific protein abundance. This study provides new molecular insight into potential pathomechanisms underlying ALS and highlights aberrant cytoplasmic IRTs as potential therapeutic targets.

ORGANISM(S): Homo sapiens

PROVIDER: GSE152983 | GEO | 2020/12/31

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

FUS pathology in ALS is linked to alterations in multiple ALS-associated proteins and rescued by drugs stimulating autophagy

Project description:Unraveling the mechanistic link connecting the multiple RNA-binding proteins (RBPs) associated with amyotrophic lateral sclerosis (ALS) is critical for identifying novel therapeutics. Mutations in the RBP FUS cause the third most common genetic form of ALS. Here, we show that motor neurons (MNs) of FUS-ALS patients manifest heterogeneous levels of cytoplasmic FUS. Using neurons differentiated from induced pluripotent stem cells (iPSCs) carrying a FUS-eGFP reporter, we demonstrate that pronounced cytoplasmic FUS mislocalization is linked to aberrant protein degradation. We also show that the P525L FUS mutation reduces the interaction of FUS with RBPs, including hnRNPA1, hnRNPA2B1, EWSR1, and TAF15, facilitating FUS aggregation. Additionally, RBP levels are decreased, inducing neurodegeneration. We use patient spinal cord to demonstrate that MNs containing aggregated FUS have reduced RBP content compared to MNs lacking FUS aggregates. Finally, we demonstrate that small molecules inducing autophagy, including PQR309, a brain penetrant compound in clinical trials, restore proteostasis.

2019-03-26 | PXD010966 | Pride

An aberrant cytoplasmic intron retention programme is a blueprint for ALS-related RBP mislocalization

Project description:An aberrant cytoplasmic intron retention programme is a blueprint for ALS-related RBP mislocalization

| PRJNA641118 | ENA

Cytoplasmic accumulation of FUS triggers early behavioral alterations linked to cortical neuronal hyperactivity and defects in inhibitory synapses

Project description:Purpose: Next-generation sequencing (NGS) has revolutionized systems-based analysis of cellular pathways. The goals of this study are to compare NGS-derived frontal cortex transcriptome profiling (RNA-seq) from control and a mouse of ALS-FUS. Gene mutations causing cytoplasmic mislocalization of the RNA-binding protein FUS, lead to severe forms of amyotrophic lateral sclerosis (ALS). Cytoplasmic accumulation of FUS is also observed in other diseases, with unknown consequences. Here, we show that cytoplasmic mislocalization of FUS drives behavioral abnormalities in knock-in mice, including locomotor hyperactivity and alterations in social interactions, in the absence of widespread neuronal loss. Mechanistically, we identified a profound increase in neuronal activity in the frontal cortex of Fus knock-in mice in vivo. Importantly, RNAseq analysis suggested involvement of defects in inhibitory neurons, that was confirmed by ultrastructural and morphological defects of inhibitory synapses and increased synaptosomal levels of mRNAs involved in inhibitory neurotransmission. Thus, cytoplasmic FUS triggers inhibitory synaptic deficits, leading to increased neuronal activity and behavioral phenotypes. FUS mislocalization may trigger deleterious phenotypes beyond motor neuron impairment in ALS, but also in other neurodegenerative diseases with FUS mislocalization.

2021-02-12 | GSE166615 | GEO

Abberant neuronal Wnt activation causes defective TDP43 localization

Project description:Conserved neuropathologies across multiple neurodegenerative diseases have identified shared causal pathways for neurodegeneration. One pathway involves the RNA-binding protein TDP-43, whose nuclear exclusion and cytoplasmic accumulation are established drivers of neurodegeneration. TDP-43 mislocalization is attributed to defective nucleocytoplasmic transport (NCT), but the underlying mechanisms are unclear. The vertebrate-specific six-transmembrane enzyme, Glycerophosphodiester phosphodiesterase 2 (GDE2 or GDPD5), cleaves the glycosylphosphatidylinositol (GPI)-anchor that tethers some proteins to the membrane. Here, we show that loss of GDE2 leads to aberrant sustained activation of canonical Wnt signaling in adult neurons, which is sufficient to cause NCT and nuclear pore abnormalities and the nuclear exclusion of TDP-43. GDE2 disruption coincides with TDP-43 nuclear exclusion in postmortem tissue from patients with Amyotrophic Lateral Sclerosis (ALS), and neuronal Wnt signaling is erroneously activated in Drosophila and induced human spinal neuronal (iSN) models of ALS. Wnt knockdown in Drosophila ALS models mitigates cell death, while pharmacological inhibition of Wnt activation in iSNs from ALS patients rescues mRNA levels of known TDP-43 splicing targets. Our study identifies GDE2 as a critical regulator of Wnt signaling in adult neurons and highlights Wnt pathway activation as a previously unappreciated mechanism contributing to NCT and TDP-43 abnormalities in disease.

2024-09-27 | GSE246462 | GEO

Toxic gain of function from mutant FUS protein is crucial to trigger cell autonomous motor neuron loss

Project description:FUS is an RNA-binding protein involved in amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Cytoplasmic FUS-containing aggregates are often associated with concomitant loss of nuclear FUS. Whether loss of nuclear FUS function, gain of a cytoplasmic function, or a combination of both lead to neurodegeneration remains elusive. To address this question, we generated knock-in mice expressing mislocalized cytoplasmic FUS and complete FUS knock-out mice. Both mouse models display similar perinatal lethality with respiratory insufficiency, reduced body weight and length, and largely similar alterations in gene expression and mRNA splicing patterns, indicating that mislocalized FUS results in loss of its normal function. However, FUS knock-in mice, but not FUS knock-out mice, display reduced motor neuron numbers at birth, associated with enhanced motor neuron apoptosis, which can be rescued by cell-specific CRE-mediated expression of wild-type FUS within motor neurons. Together, our findings indicate that cytoplasmic FUS mislocalization not only leads to nuclear loss of function, but also triggers motor neuron death through a toxic gain of function within motor neurons.

2016-03-14 | GSE78730 | GEO

Inhibition of RNA splicing triggers CHMP7 nuclear entry, impacting TDP-43 function and leading to the onset of ALS cellular phenotypes

Project description:Amyotrophic lateral sclerosis (ALS) is linked to the reduction of certain nucleoporins in neurons. Increased nuclear localization of charged multivesicular body protein 7 (CHMP7), a protein involved in nuclear pore surveillance, has been identified as a key factor damaging nuclear pores and disrupting transport. Using CRISPR-based microRaft, followed by gRNA identification (CRaft-ID), we discovered 55 RNA-binding proteins (RBPs) that influence CHMP7 localization, including SmD1, a survival of motor neuron (SMN) complex component. Immunoprecipitation-mass spectrometry (IP-MS) and enhanced crosslinking and immunoprecipitation (CLIP) analyses revealed CHMP7’s interactions with SmD1, small nuclear RNAs, and splicing factor mRNAs in motor neurons (MNs). ALS induced pluripotent stem cell (iPSC)-MNs show reduced SmD1 expression, and inhibiting SmD1/SMN complex increased CHMP7 nuclear localization. Crucially, overexpressing SmD1 in ALS iPSC-MNs restored CHMP7’s cytoplasmic localization and corrected STMN2 splicing. Our findings suggest that early ALS pathogenesis is driven by SMN complex dysregulation.

2024-01-24 | MSV000093914 | MassIVE

Disruption of nuclear speckle integrity dysregulates RNA splicing in C9ORF72-FTD/ALS

Project description:Dysregulation of RNA processing contributes to neurodegenerative diseases, especially amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Expansion of an intronic (GGGGCC)n repeat within the C9ORF72 gene is the most common cause of both FTD and ALS (C9-FTD/ALS), characterized with aberrant repeat RNA foci in the nucleus and noncanonical translation-produced dipeptide repeat (DPR) protein inclusions in the cytoplasm. Here we elucidate that the (GGGGCC)n repeat RNA co-localizes with nuclear speckles and alters their phase separation properties and granule dynamics. Moreover, the essential nuclear speckle scaffold protein SRRM2 is sequestered into the poly-GR cytoplasmic inclusions in C9-FTD/ALS mouse model and patient postmortem tissues, exacerbating the nuclear speckle dysfunction. Impaired nuclear speckle integrity induces global exon-skipping and intron retention in human iPSC-derived neurons. Similar alternative splicing changes can be found in patient postmortem tissues. This work identified novel molecular mechanism of global RNA splicing defects by impaired nuclear speckle function in C9-FTD/ALS and revealed novel potential biomarkers or therapeutic targets.

2024-08-23 | GSE248404 | GEO

Mislocalization of pathogenic RBM20 variants in dilated cardiomyopathy is caused by loss-of-interaction with Transportin-3

Project description:Severe forms of dilated cardiomyopathy (DCM) are associated with point mutations in the alternative splicing regulator RBM20 that are frequently located in the arginine/serine-rich domain (RS-domain). Such mutations can cause defective splicing and cytoplasmic mislocalization, which leads to the formation of detrimental cytoplasmic granules. Successful development of personalized therapies requires identifying the direct mechanisms of pathogenic RBM20 variants. Here, we decipher the molecular mechanism of RBM20 mislocalization and its specific role in DCM pathogenesis. We demonstrate that mislocalized RBM20 variants retain their splice regulatory activity, which reveals that aberrant cellular localization drives the pathological phenotype. A genome-wide CRISPR knock-out screen combined with image-enabled cell sorting identified Transportin-3 (TNPO3) as the main nuclear importer of RBM20. We show that the direct RBM20-TNPO3 interaction involves the RS-domain, disrupted by pathogenic variants. Re-localization of pathogenic RBM20 variants to the nucleus restores alternative splicing and dissolves cytoplasmic granules in cell culture and animal models. These findings provide proof-of-principle for developing therapeutic strategies to restore RBM20’s nuclear localization in RBM20-DCM patients.

2023-06-19 | PXD038790 | Pride

Axonal TDP-43 Drives NMJ Disruption through Inhibition of Local Protein Synthesis

Project description:Mislocalization of the predominantly nuclear RNA/DNA binding protein, TDP-43, occurs in motor neurons of ~95% of ALS patients, but the contribution of axonal TDP-43 to this fatal neurodegenerative disease is unclear. Here, we find TDP-43 accumulation in the axons of intra-muscular nerves from ALS patients, and in motor neurons and neuromuscular junctions(NMJs) of a mouse model with TDP-43 mislocalization. This leads to the formation of G3BP1- and TDP-43-positive RNA-granules in motor neuron axons, and to inhibition of local protein synthesis in axons and NMJs. Specifically, the axonal and synaptic levels of nuclear-encoded mitochondria proteins are reduced. Clearance of axonal TDP-43 restored local translation of the nuclear-encoded mitochondrial proteins and rescued TDP-43-derived axonal and NMJ toxicity. These findings suggest that targeting TDP-43 axonal gain of function may mediata therapeutic effect in ALS.

2021-11-04 | PXD021876 | Pride

A TDP-43 acetylation-mimic mutation that disrupts RNA-binding drives FTLD-like neurodegeneration in a mouse model of sporadic TDP-43 proteinopathy

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