Does ALS-FUS without FUS mutation represent ALS-FET? Report of three cases.
Ontology highlight
ABSTRACT:
SUBMITTER: Borrego-Ecija S
PROVIDER: S-EPMC7380051 | biostudies-literature | 2019 Jun
REPOSITORIES: biostudies-literature
Publications
Does ALS-FUS without FUS mutation represent ALS-FET? Report of three cases.
Borrego-Écija S S Cortés-Vicente E E Cervera-Carles L L Clarimón J J Gámez J J Batlle J J Ricken G G Molina-Porcel L L Aldecoa I I Sánchez-Valle R R Rojas-García R R Gelpi E E
Neuropathology and applied neurobiology 20181120 4
Similar Datasets
Project description:Through the generation of humanized FUS mice expressing full-length human FUS, we identify that when expressed at near endogenous murine FUS levels, both wild-type and ALS-causing and frontotemporal dementia (FTD)-causing mutations complement the essential function(s) of murine FUS. Replacement of murine FUS with mutant, but not wild-type, human FUS causes stress-mediated induction of chaperones, decreased expression of ion channels and transporters essential for synaptic function, and reduced synaptic activity without loss of nuclear FUS or its cytoplasmic aggregation. Most strikingly, accumulation of mutant human FUS is shown to activate an integrated stress response and to inhibit local, intra-axonal protein synthesis in hippocampal neurons and sciatic nerves. Collectively, our evidence demonstrates that human ALS/FTD-linked mutations in FUS induce a gain of toxicity that includes stress-mediated suppression in intra-axonal translation, synaptic dysfunction, and progressive age-dependent motor and cognitive disease without cytoplasmic aggregation, altered nuclear localization, or aberrant splicing of FUS-bound pre-mRNAs. VIDEO ABSTRACT.
| S-EPMC6277851 | biostudies-literature
Project description:IntroductionMutations in the FUS gene have been shown to be a rare cause of amyotrophic lateral sclerosis (ALS-FUS) and whilst well documented clinically and genetically there have been relatively few neuropathological studies.Recent work suggested a possible correlation between pathological features such as frequency of basophilic inclusions in neurons and rate of clinical decline, other studies have revealed a discrepancy between the upper motor neuron features detected clinically and the associated pathology. The purpose of this study was to describe the pathological features associated with more recently discovered FUS mutations and reinvestigate those with well recognised mutations in an attempt to correlate the pathology with mutation and/or clinical phenotype. The brains and spinal cords of seven cases of ALS-FUS were examined neuropathologically, including cases with the newly described p.K510E mutation and a case with both a known p.P525L mutation in the FUS gene and a truncating p.Y374X mutation in the TARDBP gene.ResultsThe neuropathology in all cases revealed basophilic and FUS inclusions in the cord. The density and type of inclusions varied markedly between cases, but did not allow a clear correlation with clinical progression. Only one case showed significant motor cortical pathology despite the upper motor neuron clinical features being evident in 4 patients. The case with both a FUS and TARDBP mutation revealed FUS positive inclusions but no TDP-43 pathology. Instead there were unusual p62 positive, FUS negative neuronal and glial inclusions as well as dot-like neurites.ConclusionsThe study confirms cases of ALS-FUS to be mainly a lower motor neuron disease and to have pathology that does not appear to neatly correlate with clinical features or genetics. Furthermore, the case with both a FUS and TARDBP mutation reveals an intriguing pathological profile which at least in part involves a very unusual staining pattern for the ubiquitin-binding protein p62.
| S-EPMC4600255 | biostudies-literature
Project description: Not available
| S-EPMC8011883 | biostudies-literature
Project description:Autosomal dominant mutations of the RNA/DNA binding protein FUS are linked to familial amyotrophic lateral sclerosis (FALS); however, it is not clear how FUS mutations cause neurodegeneration. Using transgenic mice expressing a common FALS-associated FUS mutation (FUS-R521C mice), we found that mutant FUS proteins formed a stable complex with WT FUS proteins and interfered with the normal interactions between FUS and histone deacetylase 1 (HDAC1). Consequently, FUS-R521C mice exhibited evidence of DNA damage as well as profound dendritic and synaptic phenotypes in brain and spinal cord. To provide insights into these defects, we screened neural genes for nucleotide oxidation and identified brain-derived neurotrophic factor (Bdnf) as a target of FUS-R521C-associated DNA damage and RNA splicing defects in mice. Compared with WT FUS, mutant FUS-R521C proteins formed a more stable complex with Bdnf RNA in electrophoretic mobility shift assays. Stabilization of the FUS/Bdnf RNA complex contributed to Bdnf splicing defects and impaired BDNF signaling through receptor TrkB. Exogenous BDNF only partially restored dendrite phenotype in FUS-R521C neurons, suggesting that BDNF-independent mechanisms may contribute to the defects in these neurons. Indeed, RNA-seq analyses of FUS-R521C spinal cords revealed additional transcription and splicing defects in genes that regulate dendritic growth and synaptic functions. Together, our results provide insight into how gain-of-function FUS mutations affect critical neuronal functions.
| S-EPMC3938263 | biostudies-literature
Project description:Stress granules (SG) are part of a cellular protection mechanism where untranslated messenger RNAs and RNA-binding proteins are stored upon conditions of cellular stress. Compositional variations due to qualitative or quantitative protein changes can disrupt their functionality and alter their structure. This is the case of different forms of amyotrophic lateral sclerosis (ALS) where a causative link has been proposed between the cytoplasmic de-localization of mutant proteins, such as FUS (Fused in Sarcoma), and the formation of cytotoxic inclusions. Here, we describe the SG transcriptome in neuroblastoma cells and define several features for RNA recruitment in these condensates. We demonstrate that SG dynamics and RNA content are strongly modified by the incorporation of mutant FUS, switching to a more unstructured, AU-rich SG transcriptome. Moreover, we show that mutant FUS, together with its protein interactors and their target RNAs, are responsible for the reshaping of the mutant SG transcriptome with alterations that can be linked to neurodegeneration. Our data describe the molecular differences between physiological and pathological SG in ALS-FUS conditions, showing how FUS mutations impact the RNA and protein composition of these condensates.
| S-EPMC11602144 | biostudies-literature
Project description:Through the generation of humanized FUS mice expressing full length human FUS, we identify that when expressed at near endogenous murine FUS levels both wild-type or ALS- and frontotemporal dementia (FTD)-causing mutations complement the essential function(s) of murine FUS. Replacement of murine FUS with mutant, but not wild-type, human FUS causes stress-mediated induction of chaperones, decreased expression of ion channels/transporters essential for synaptic function, and reduced synaptic activity, without loss of nuclear FUS or its cytoplasmic aggregation. Most strikingly, accumulation of mutant human FUS is shown to activate an integrated stress response and inhibit local, intra-axonal protein synthesis in hippocampal neurons and sciatic nerves. Collectively, our evidence demonstrates that human ALS/FTD-linked mutations in FUS induce a gain-of-toxicity that includes stress-mediated suppression in intra-axonal translation, synaptic dysfunction, and progressive, age-dependent motor and cognitive disease without cytoplasmic aggregation, altered nuclear localization, or aberrant splicing of FUS-bound pre-mRNAs. Methods: RNA from mouse spinal cords of 18-month-old mFUS-/-/hgFUS (WT, R521C or R521H) and their Non-Tg control littermates was extracted with TRIzol. RNA quality was measured using the Agilent Bioanalyzer system and processed using the Illumina TruSeq Stranded mRNA Sample Preparation Kit according to manufacturer’s protocols. mRNA profiles were generated by deep sequencing, with n≥3 biological replicates per group. Results: We mapped on average 15 million non-redundant reads per sample. Fastq files were aligned to mouse reference genome (mm9 UCSC Genome Browser) using TopHat workfow and the transcript abundance for each annotated protein-coding gene [as fragments per kilobase of transcript per million mapped reads (FPKM)] was estimated by Cufflinks. 13,468 genes which expressed FPKM>=1 were kept for downstream analyses. RNA profiles from normal (Non-Tg) and humanized hgFUSWT mice were almost undistinguishable. Both humanized mutant FUS lines had highly distinct RNA profiles [determined with unsupervised hierarchical clustering and principal component analysis (PCA)], with 709 down and 348 up-regulated genes relative to age-matched Non-Tg or humanized hgFUSWT littermates (P<0.05). These changes uncovered FUS mutant dependent altered pathways that may contribute to ALS/FTD-linked mutant FUS-mediated toxicity. The validation by RT-QPCR of altered expression of 20 genes is shown in Figure 5.
2018-12-26 | GSE120247 | GEO
Project description:Allgrove syndrome (AS) is an autosomal recessive congenital disease, caused by mutations in the AAAS gene, and is characterized by the triad of Addison's disease, achalasia and alacrima. The present study describes three newly diagnosed cases of AS, in which genetic analysis of the AAAS gene was used to identify AAAS gene mutations, to enhance the understanding of the pathogenesis and clinical manifestations of AS in the Chinese population. Two of the cases exhibited homozygous mutations of c.771delG (p.Arg258GlyfsX33) in exon 8 and one case exhibited a homozygous mutation of c.1366C>T (p.Q456X) in exon 15. A review of the current literature suggests that the AAAS c.771delG mutation has only been reported in the Chinese population. Genetic analysis of the AAAS gene in Chinese AS patients at a young age may facilitate an earlier diagnosis and the timely initiation of the appropriate treatment, ultimately improving the patient outcome.
| S-EPMC4578041 | biostudies-literature
Project description:ObjectivesInfantile neuroaxonal degeneration (INAD) is a rare subgroup of neurodegeneration with brain iron accumulation (NBIA) disorders. This progressive disorder may develop during the early years of life. Affected individuals mostly manifest developmental delay and/or psychomotor regression as well as other neurological deficits. In the present study, we discussed 3 INAD patients diagnosed before the age of 10 by using Whole-Exome Sequencing (WES).Materials and methodsWe evaluated 3 pediatric patients with clinical phenotypes of INAD who underwent WES. Sanger sequencing was performed for co-segregation analysis of the variants in the families. An in-silico study was conducted for identification of the molecular function of the identified genetic variants in the PLA2G6 gene.ResultsWe detected three novel genetic variants in the PLA2G6 gene including a homozygous missense (NM_003560.2; c.1949T>C; p.Phe650Ser), a splicing (NM_001349864; c.1266-1G>A) and a frameshift variant (NM_003560.4; c.1547_1548dupCG; p.Gly517ArgfsTer29). Since the variants were not previously reported in literature or population databases, we performed in-silico studies for these variants and demonstrated their potential pathogenicity.ConclusionThe current study reports novel genetic variants in the PLA2G6 gene in the Iranian population, emphasizing the importance of high-throughput genetic testing in rare diseases.
| S-EPMC8751752 | biostudies-literature
Project description:Deregulation of RNA metabolism has emerged as one of the key events leading to the degeneration of motor neurons (MNs) in Amyotrophic Lateral Sclerosis (ALS) disease. Indeed, mutations on RNA-binding proteins (RBPs) or on proteins involved in aspects of RNA metabolism account for the majority of familiar forms of ALS. In particular, the impact of the ALS-linked mutations of the RBP FUS on many aspects of RNA-related processes has been vastly investigated. FUS plays a pivotal role in splicing regulation and its mutations severely alter the exon composition of transcripts coding for proteins involved in neurogenesis, axon guidance, and synaptic activity. In this study, by using in vitro-derived human MNs, we investigate the effect of the P525L FUS mutation on non-canonical splicing events that leads to the formation of circular RNAs (circRNAs). We observed altered levels of circRNAs in FUSP525L MNs and a preferential binding of the mutant protein to introns flanking downregulated circRNAs and containing inverted Alu repeats. For a subset of circRNAs, FUSP525L also impacts their nuclear/cytoplasmic partitioning, confirming its involvement in different processes of RNA metabolism. Finally, we assess the potential of cytoplasmic circRNAs to act as miRNA sponges, with possible implications in ALS pathogenesis.
| S-EPMC9968238 | biostudies-literature
Project description:Mutations in the Cu/Zn superoxide dismutase (SOD1), transactive response (TAR)-DNA binding protein (TARDBP) and fused in sarcoma (FUS) genes account for approximately 1 third of familial amyotrophic lateral sclerosis (ALS) cases. Mutations in these genes have been found in 1% to 2% of apparently sporadic cases. We present the first case of an ALS patient carrying a de novo missense mutation of the FUS gene (c.1561C>T, p.R521C). This report highlights the importance of screening ALS patients, both familial and sporadic, for FUS mutations and also suggests that de novo mutations is a relevant mechanism underlying sporadic neurodegenerative disease.
| S-EPMC2972379 | biostudies-literature