Fused in sarcoma (FUS) is an RNA binding protein involved in DNA repair and RNA metabolism, including mRNA transcription, splicing, transport and translation. FUS is genetically and pathologically associated with rare and aggressive forms of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). To explore the mechanisms by which pathogenic mutations in FUS cause neurodegeneration in ALS-FUS, we generated a series of FUS knock-in mouse lines that express the equivalent of the ALS-associated mutant proteins FUSP525L and FUSΔEX14 at physiological levels from the FUS locus. We demonstrate that heterozygous mutant FUS mice show progressive, age-dependent loss of vulnerable subpopulations of spinal motor neurons. While ALS-associated mutations in FUS lead to partial loss of function, we provide genetic evidence that the motor neuron phenotype observed is a consequence of a dose-dependent gain of function, associated with the insolubility of FUS and related RNA binding proteins (RBPs). Furthermore, we show that motor neuron degeneration is driven by cell autonomous mechanisms, associated with mutant FUS-independent inflammatory changes. In this faithful mouse model of ALS-FUS, we demonstrate that an antisense oligonucleotide (ASO) targeting the FUS transcript (ION363) results in the efficient silencing of both wild type and mutant FUS alleles, and that postnatal reduction of FUS protein levels in the brain and spinal cord delays disease onset in this mouse model of ALS-FUS. In a first-in-human trial of ION363, we demonstrate that repeated, intrathecal injections of this candidate therapeutic in an ALS patient with a FUSP525L mutation leads to the efficient silencing of both wild type and mutant FUS in the central nervous system, and a reduction in the burden of FUS aggregates that are a pathological hallmark of ALS-FUS. In mouse genetic and human clinical studies, we provide evidence in support of a therapeutic strategy by which silencing of the FUS gene may be used to prevent or delay disease onset in pre-symptomatic carriers of pathogenic FUS mutations, or to slow disease progression in symptomatic ALS- and FTD-FUS patients. In addition, we use this newly generated model to investigate the role of potential modifiers of FUS toxicity, including hnRNP U and UPF1, and study the role of chronic neuroinflammation in the disease progression that could lead to the development of novel therapeutics to provide immediate clinical benefit to patients with ALS-FUS.

Bakgrund: I Sverige insjuknar cirka 220–250 personer av Amyotrofisk Lateralskleros (ALS) per år. Sjukdomen innebär att nervceller som styr skelettmusklerna förtvinar och slutligen dör vilket leder till svåra symtom. Idag finns inget botemedel utan insatserna riktas till symtomlindring och livslängden är cirka två till tre år. Sjuksköterskor som vårdar personer med ALS upplevde svårigheter att balansera både den sjukes och anhörigas vilja/upplevelser samtidigt.   Syfte: Att beskriva upplevelser om hur det är att vara anhörig till personer som lever med Amyotrofisk lateralskleros (ALS). Metod: En deskriptiv litteraturstudie bestående av 14 vetenskapliga artiklar med kvalitativ ansats som söktes i databasen Medline via PubMed. Huvudresultat: Känslor som maktlöshet och sorg uppstod hos de anhöriga samt en känsla av att vara fängslad till personen med ALS och hemmet. Anhöriga genomgick en livsomställning och hittade olika hanteringsstrategier för att klara av situationen. Förändrade roller i familjen medförde starkare och svagare familjerelationer samtidigt som kärleken blev mer komplex. Anhöriga fick en negativ bild av vården och lyfte bristen på information, istället verkade stödet från det sociala nätverket vara mer betydelsefullt.  Slutsats: Anhöriga till personer med ALS kände sig maktlösa och sorgsna men dem hittade hanteringsstrategier som underlättade vardagen. Anhöriga sökte stöd inom det sociala nätverket då vården ofta var en besvikelse. Dem lyfte ett behov av bättre informationshantering från vården och önskade att den skulle vara familjecentrerad. Denna litteraturstudie kan komma att bidra till ett ökat perspektiv hos anhöriga, personer med ALS och vården. / Background: 220–250 people get diagnosed with Amyotrophic Lateral Sclerosis (ALS) every year in Sweden. The disease entails that the nerve cells controlling skeletal muscles degenerate and die creating severe symptoms. Today, there is no cure, so the resources focus on symptom-management, the average lifespan after diagnosis is two to three years. Nurses caring for people with ALS struggled with balancing the will/experience of the person with ALS and the close relatives concurrently.  Aim: Describe experiences of being a close relative to people living with Amyotrophic Lateral Sclerosis. Method: Descriptive literature study based on 14 scientific articles with qualitative approach searched on the database Medline via PubMed. Main results: Emotions such as feeling powerless and grief was identified, they felt imprisoned to the person with ALS and their home. Close relatives went through life-changing events and found coping strategies. Changed family roles created stronger and weaker family relationships and love got complex. Close relatives got a negative picture of the health-system and highlighted the lack of information, instead they valued the support from their social networks. Conclusion: Close relatives to people with ALS felt powerless and grief but found coping strategies that eased their situation. Close relatives soughed support within the social network since the health-system disappointed. They highlighted needs for better information management from the health-system and whished for it to be family-focused. This literature study may create wider perspectives among close relatives, people with ALS and the health-system.

Ataxin-2 is an RNA-binding protein that is involved in many crucial cellular processes such as R-loop regulation, mRNA stability, TOR signaling regulation, and stress granule formation. Ataxin-2 is highly conserved, found in organisms ranging from Saccharomyces cerevisiae to Caenorhabditis elegans and Homo sapiens. Recently, ataxin-2 has been linked to the neurodegenerative disease Amyotrophic Lateral Sclerosis (ALS). ALS is a fatal disease that causes loss of motor neurons. In addition to ataxin-2 interacting with known ALS risk factor proteins, research into the relationship between ataxin-2 and ALS shows that polyglutamine expansions in ataxin-2 are gain-of-function mutations that lead to overactivity of ataxin-2 and probable neurodegeneration. In fact, targeting ataxin-2 using gene silencing techniques dramatically slows the progression of ALS in both mice and man.The Grose laboratory has characterized a serine-threonine kinase, PAS kinase as upstream kinase and putative activator of ataxin-2. We hypothesize that knockdown of PAS kinase could, therefore, have similar effects to directly downregulating ataxin-2 and its cellular functions. Characterization of Ataxin-2 has revealed that its gain or loss of function lead to distinct cellular phenotypes. One study concluded that lowering ataxin-2 levels reduced the size and number of stress granules in mammalian cells, which was observed through microscopy. Another study found that activation and overexpression of ataxin-2 lead to reduced mTOR levels because of its sequestration to stress granules. Lastly, preliminary data obtained by the Grose laboratory suggests that yeast deficient in Pbp1 (the yeast homologue of ataxin-2) have altered cell cycles.This project describes the cellular readouts used to determine if PAS kinase downregulation confers the same cellular phenotypes as ataxin-2 downregulation. First, we found that PAS kinase does influence ataxin-2 abundance in mammalian cells. Using yeast as a model, we found that Pbp1 influences the cell cycle through its binding partners, causing a reduction in the percentage of cells in the G2 phase compared to the G1 phase. PAS kinase conferred an opposite change, most likely due to the activity of other PAS kinase substrates. Additionally, we found that Pbp1 deficiency is synthetically lethal when in conjunction with deficiency of any one of its cell cycle-related binding partners. The cellular changes cause by Pbp1 deficiency highlight not only the importance of ataxin-2 in the cell, but also the importance of understanding the effects of downregulation of ataxin-2.

Bakgrund Amyotrofisk lateralskleros är en dödlig sjukdom som påverkar såväl den drabbade som anhöriga. Anhöriga har en betydande roll då de ofta vårdar den närstående i hemmet, och på grund av sjukdomens progression kan det bli en omfattande livsförändring. Sjuksköterskor ska utgå ifrån ett palliativt personcentrerat förhållningssätt där anhöriga behöver praktiskt och emotionellt stöd. En anhörig som vårdar en person med långvarig sjukdom ska erbjudas stöd för att minska belastning och förbättra livssituationen. Syfte Syftet var att beskriva anhörigas erfarenheter av att ge stöd till en person med Amyotrofisk lateralskleros. Metod En litteraturöversikt med elva vetenskapliga artiklar användes. Artiklarna hämtades från databaserna Cinahl Complete och PubMed. Artiklarna analyserades med stöd av Fribergs analysmodell. Resultat Tre teman identifierades i resultatet: (1) Inre känslor, (2) Förändringar inom familjen och (3) Hälso- och sjukvårdspersonalens påverkan. Två underteman framkom: Förändrade familjerelationer och Förändrade roller. Sammanfattning Litteraturöversikten visade att det fanns ett behov av information och stöd från sjukvården och övriga anhöriga. Att vara anhörigvårdare medförde en känslomässig påverkan på grund av hög belastning och ansvarskänslor. Sjukdomen bidrog till förändringar inom familjen så som förändrade familjerelationer och nya roller och anhörigvårdare upplevde olika utmaningar som att bibehålla en normal vardag och åsidosätta sina egna behov. / Background Amyotrophic lateral sclerosis is a deadly disease that affects both the person affected by illness and their relatives. Relatives have a significant role as they often provide care for the person at home, and due to the progression of the disease there can be an extensive life change. Nurses shall focus on a palliative person-centered care where relatives need practical and emotional support. A relative who cares for a person with a long-term illness must be offered support to reduce the burden and improve the living situation. Aim The aim was to describe relatives’ experiences of providing support to a person with Amyotrophic Lateral Sclerosis Method Literatur review with eleven scientific articles were used. The articles were retrieved from the databases Cinahl Complete and PubMed. Friberg’s analysis model were used to analyze the articles. Results Three themes were identified in the result: (1) Inner feelings, (2) Changes within the family and (3) The impact of health care professionals. Two sub-themes emerged: Changed family relationships and Changed roles. Summary The literature review showed that there was a need of information and support from the healthcare system and other relatives. Family caregivers experienced an emotional impact due to high workload and feelings of responsibility. The disease contributed to changes such as changing family relationships and new roles, and family caregivers experienced various challenges such as maintaining a normal everyday life and overriding their own needs.

No description available.

No description available.

Circular RNAs (circRNAs) are a type of long noncoding RNA that are highly abundant and highly conserved throughout evolution and exhibit differential expression patterns in various tissue types in multiple diseases, including amyotrophic lateral sclerosis (ALS). The most well-known function of circRNAs is their ability to act as microRNA (miRNA) sponges. This entails circRNA binding to miRNA, which would otherwise target and degrade messenger RNA, thus affecting gene expression. This study analyzed ALS patient samples from three spinal cord regions to investigate circular transcriptome perturbation and circular RNA–microRNA–mRNA interactions. Using stringent statistical parameters, we identified 92 differentially expressed circRNAs across the spinal cord tissues with the aim of identifying specific circRNAs with biomarker potential. We also found evidence for differential expression of 37 linear RNAs possibly due to miRNA sequestration by circRNAs, thus revealing their potential as novel biomarkers and therapeutic candidates for ALS.

Aggregations of fused in sarcoma (FUS), a multifunctional RNA processing protein, define a pathological subtype of both frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS), whilst mutations in the FUS gene are causative for ALS. To model the impact of FUS mutations, expression vectors containing the entire genomic sequence of FUS, up and downstream regions, and native promoter sequences have been generated. The constructs have been tagged with an mCherry fluorescent tag, and three separate pathological mutations (R244C, R521C, and P525L) have been separately inserted. Transgenic mice have been generated using the WT and P525L FUS vectors to provide a highly physiological model of FUS in disease. Within transfected HEK293 cells, insertion of the P525L and R521C FUS mutations leads to relocalisation of FUS from the nucleus to the cytoplasm. R521C and P525L mutant FUS incorporates into cytoplasmic aggregations of untranslated mRNA and RNA binding proteins known as stress granules. The strong relocalisation seen with P525L-FUS is associated with a gain of cytotoxicity. Reversal of this cytoplasmic relocalisation by demethylation of FUS rescues this cytotoxicity, suggesting a toxic gain of cytoplasmic function in the majority of FUS mutations. By contrast, insertion of the R244C mutation leads to neither relocalisation, stress granule association, nor cytotoxicity. Notably the R244C mutation, located away from the nuclear localization domain in which the majority of FUS mutations are found, leads to the presence of smaller FUS fragments in western blot analyses. These fragments appear not to be due to splicing defects in FUS but rather are due to post-translational modifications or aberrant protein cleavage. These data suggest an alternative pathway for FUS toxicity based upon a nuclear loss of function.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterised clinically by rapidly progressive paralysis leading ultimately to death from respiratory failure. There is no cure for ALS and no definitive explanation for the onset and rapid progression of motor neuron degeneration. Genetics is a known risk factor for a portion of familial cases. However, the role of genetics in the commoner sporadic form of the disease is poorly understood, although numerous genes have been implicated. The primary aim of this thesis project is to uncover the genetic causes that underlie ALS. To accomplish this goal, the main focus of this thesis is to perform genome-wide association analysis of sporadic ALS using high density SNP arrays. This thesis describes the first and the largest genome-wide association studies of ALS to date. Results demonstrate that there is no single large effect susceptibility variant underlying a large proportion of ALS, such as ApoE in Alzheimer’s disease. However, the genotyping data has been made publically available and the digital nature of this data means that it is a resource that can grow with future studies. Beyond genome-wide association, this thesis describes work using linkage, haplotype and sequence analysis to investigate the genetic overlap between ALS and frontotemporal dementia. Lastly, this thesis presents a novel method for linkage analysis using high throughput SNP arrays. Ultimately, it is hoped that by uncovering the genes that cause ALS, such knowledge will shed light on the pathogenic mechanisms underlying motor neuron degeneration and potentially lead to new rational therapies effective in slowing or even halting disease progression.

TDP-43 est une protéine multifonctionnelle possédant des rôles dans la transcription, l'épissage des pré-ARNm, la stabilité et le transport des ARNm. TDP-43 interagit avec d'autres hnRNP, incluant hnRNP A2, via son extrémité C-terminale. Plusieurs membres de la famille des hnRNP étant impliqués dans la réponse au stress cellulaire, alors nous avons émis l’hypothèse que TDP-43 pouvait y participer aussi. Nos résultats démontrent que TDP-43 et hnRNP A2 sont localisés au niveau des granules de stress, à la suite d’un stress oxydatif, d’un choc thermique, et lors de l’exposition à la thapsigargine. TDP-43 contribue à la fois à l'assemblage et au maintien des granules de stress en réponse au stress oxydatif. TDP-43 régule aussi de façon différentielle les composants clés des granules de stress, notamment TIA-1 et G3BP. L'agrégation contrôlée de TIA-1 est perturbée en l'absence de TDP-43. En outre, TDP-43 régule le niveau d`ARNm de G3BP, un facteur de granule de stress de nucléation. La mutation associée à la sclérose latérale amyotrophique, TDP-43R361S, compromet la formation de granules de stress. Ainsi, la fonction cellulaire de TDP-43 s'étend au-delà de l’épissage; TDP-43 est aussi un composant de la réponse cellulaire au stress central et un acteur actif dans le stockage des ARNs. / TDP-43 is a multifunctional protein with roles in transcription, pre-mRNA splicing, mRNA stability and transport. TDP-43 interacts with other hnRNPs, including hnRNP A2, via its C-terminus and several hnRNP family members are involved in the cellular stress response. This relationship led us to investigate the role of TDP-43 in cellular stress. Our results demonstrate that TDP-43 and hnRNP A2 are localized to stress granules, following oxidative stress, heat shock, and exposure to thapsigargin. TDP-43 contributes to both the assembly and maintenance of stress granules in response to oxidative stress and differentially regulates key stress granules components including TIA-1 and G3BP. The controlled aggregation of TIA-1 is disrupted in the absence of TDP-43. In addition, TDP-43 regulates G3BP mRNA levels, a stress granule nucleating factor. A mutation associated with amyotrophic lateral sclerosis, TDP-43R361S, compromises stress granule formation. Thus, the cellular function of TDP-43 extends beyond splicing and places TDP-43 as a participant of the central cellular response to stress and an active player in RNA storage.