Muscle Exosome-Derived miR-126 Regulates Local Synthesis of TDP-43 and NMJ Integrity in ALS
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PROVIDER: PRJNA1210537 | ENA |
REPOSITORIES: ENA
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Project description:Amyotrophic lateral sclerosis (ALS) is characterized by neuromuscular junction (NMJ) disruption and neurodegeneration. Recent findings highlight a pivotal role for TDP-43 in forming axonal pathological condensates and facilitating NMJ disruption through inhibition of local protein synthesis. However, the mechanisms which drive local TDP-43 accumulation remain unknown. Here we identify TDP-43 axonal accumulation in peripheral nerves of SOD1 patients and mice stemming from its aberrant local synthesis. This is a non-cell-autonomous process driven by muscle-derived miR-126a-5p exosomes. Inhibiting muscle secretion of miR-126a-5p prompts pre-synaptic TDP-43 synthesis and accumulation that disrupts axonal translation and causes NMJ degeneration. Introducing miR-126 to SOD1G93A mice, primary co-cultures, and human iPSC-derived co-cultures with ALS mutations exhibits neuroprotective effects and delays motor decline. These findings identify a transcellular communication axis between muscles and motor neurons that regulates axonal local synthesis and NMJ maintenance offering insights into ALS onset and progression.
2025-07-15 | GSE286913 | GEO
Project description:This SuperSeries is composed of the following subset Series: GSE40649: Divergent roles of ALS-linked proteins FUS/TLS and TDP-43 intersect in processing long pre-mRNAs (microarray) GSE40651: Divergent roles of ALS-linked proteins FUS/TLS and TDP-43 intersect in processing long pre-mRNAs (CLIP-Seq) GSE40652: Divergent roles of ALS-linked proteins FUS/TLS and TDP-43 intersect in processing long pre-mRNAs (RNA-Seq) Refer to individual Series
2012-09-30 | E-GEOD-40653 | biostudies-arrayexpress
Project description:Amyotrophic lateral sclerosis is the most common and fatal motor neuron disease. Approximately 90% of ALS patients exhibit pathology of the master RNA regulator, Transactive Response DNA Binding protein (TDP-43). Despite the prevalence TDP-43 pathology in ALS motor neurons, recent findings suggest immune dysfunction is a determinant of disease progression in patients. Whether TDP-43 aggregates elicit immune responses remains underexplored. In this study, we demonstrate that TDP-43 aggregates are internalized by antigen presenting cell populations, cause vesicle rupture, and drive innate and adaptive immune cell activation by way of antigen presentation. Using a multiplex imaging platform, we observed enrichment of activated microglia/macrophages in ALS white matter that correlated with phosphorylated TDP-43 accumulation, CD8 T-cell infiltration, and major histocompatibility complex expression. Taken together, this study sheds light on a novel cellular response to TDP43 aggregates through an immunological lens.
2025-04-07 | GSE293662 | GEO
Project description:Recent studies exploring the underlying pathomechanisms of amyotrophic lateral sclerosis (ALS), a fatal motor neuron disorder, have focused on biomolecular condensates, such as stress granules (SGs) and TDP-43 condensates. Our comprehension of the physicochemical processes that control the behavior of these condensates is still evolving. In this work, we reveal an unexpected function for YAP, a central component of the Hippo pathway, in regulating the dynamic behavior of SGs and TDP-43 condensates, a role that is independent of its transcriptional activity in Hippo pathway. We found that YAP can directly bind to the TB domain of TDP-43 through its N-terminal domain. This interaction promotes the homotypic multimerization and phase separation of TDP-43, while inhibiting its hyper- phosphorylation and solidification under stress conditions. Remarkably, YAP, whose mRNA level is reduced in ALS patients, is found to co-localize with pathological pTDP-43 aggregates in the cytoplasmic foci of ALS patient brains. Additionally, elevating YAP/Yorkie expression substantially reduces neurotoxicity in a TDP-43 transgenic fly model of ALS. Our findings highlight an unexpected chaperone-like role of YAP in managing ALS-associated biomolecular condensates, presenting significant implications for potential ALS treatments.
2024-02-24 | PXD050122 |
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
Project description:The pathological hallmark of amyotrophic lateral sclerosis (ALS) is the presence of cytoplasmic inclusions, containing C-terminal fragments of the protein TDP-43. Here, we tested the hypothesis that highly sensitive mass spectrometry with parallel reaction monitoring (MS-PRM) can generate a high-resolution map of pathological TDP-43 peptide ratios to form the basis for quantitation of abnormal C-terminal TDP-43 fragment enrichment. Human cortex and spinal cord, microscopically staged for the presence of phosphoTDP-43, p-tau, alpha-synuclein and beta-amyloid pathology, were biochemically fractionated and analysed by immunoblot and MS for detection of full-length and truncated (disease-specific) TDP-43 peptides. This informed synthesis of heavy isotope-labelled peptides for the absolute quantification of TDP-43 by MS-PRM across 16 ALS, 8 Parkinson’s and 8 Alzheimer’s disease and 8 aged control cases. We confirmed by immunoblot the previously described enrichment of pathological C-terminal fragments in ALS-TDP urea fractions. Subsequent MS analysis resolved specific TDP-43 N- and C-terminal peptides, including a novel N-terminal truncation site-specific peptide. Absolute quantification of peptides by MS-PRM showed an increased C:N-terminal TDP-43 peptide ratio in ALS-TDP brain compared to normal and disease controls. A C:N-terminal ratio >1.5 discriminated ALS from controls with a sensitivity of 100% (CI 79.6-100) and specificity of 100% (CI 68-100), and from Parkinson’s and Alzheimer’s disease with a sensitivity of 93% (CI 70-100) and specificity of 100% (CI 68-100). N-terminal Truncation site-specific peptides were increased in ALS in line with C-terminal fragment enrichment, but also found in a proportion of Alzheimer cases with normal C:N-terminal ratio but coexistent TDP-43 pathology. In conclusion this is a novel, sensitive and specific method to quantify the enrichment of pathological TDP-43 fragments in human brain, which could form the basis for an antibody-free assay. Our methodology has the potential to help clarify if specific pathological TDP-43 peptide signatures are associated with primary or secondary TDP-43 proteinopathies.
2020-12-17 | PXD022186 | Pride
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:When mutant superoxide dismutase 1 (SOD1) was first linked to amyotrophic lateral sclerosis (ALS), it was thought that ALS is a disease of oxidative stress, but this idea has taken a back seat since the discovery of multiple ALS-linked genes involved in RNA processing and proteostasis. Strikingly, a hallmark of both familial and sporadic ALS is the aggregation of the essential DNA/RNA binding protein TDP-43, which is thought to cause simultaneous loss-of-nuclear function and gain-of-cytoplasmic toxicity. A central unanswered question is what triggers ALS in adult followed by rapid and irreversible progression? Here we report that neuronal cells are particularly prone to oxidative stress to trigger TDP-43 aggregation, which in turn sponges a large subset of microRNAs and proteins, resulting in global mitochondrial imbalance that further elevates the oxidative stress. We propose that this ferocious cycle may underlie ALS onset and progression with oxidative stress as a key disease-driving event.
2020-10-12 | GSE126801 | 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 fibroblasts grown from neurologically healthy controls (n=6) and 3 groups of patients with ALS: 1) sporadic cases (n=6); 2) cases due to mutations of SOD1 (n=4); 3) cases due to mutations of TARDBP (n=3). The three ALS groups were compared to the controls.
2014-06-01 | E-GEOD-33855 | biostudies-arrayexpress
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 lower motor neurons obtained by laser capture microdissection from autopsy material from neurologically healthy controls (n=6) and cases of sporadic ALS (n=3) and ALS due to C9ORF72 mutations (n=3).
2014-06-01 | E-GEOD-56500 | biostudies-arrayexpress