Lateral Sclerosis Research Articles

Amyotrophic Lateral Sclerosis: Insights and New Prospects in Disease Pathophysiology, Biomarkers and Therapies.

Amyotrophic Lateral Sclerosis (ALS) is a severe neurodegenerative disorder marked by the gradual loss of motor neurons, leading to significant disability and eventual death. Despite ongoing research, there are still limited treatment options, underscoring the need for a deeper understanding of the disease's complex mechanisms and the identification of new therapeutic targets. This review provides a thorough examination of ALS, covering its epidemiology, pathology, and clinical features. It investigates the key molecular mechanisms, such as protein aggregation, neuroinflammation, oxidative stress, and excitotoxicity that contribute to motor neuron degeneration. The role of biomarkers is highlighted for their importance in early diagnosis and disease monitoring. Additionally, the review explores emerging therapeutic approaches, including inhibitors of protein aggregation, neuroinflammation modulators, antioxidant therapies, gene therapy, and stem cell-based treatments. The advantages and challenges of these strategies are discussed, with an emphasis on the potential for precision medicine to tailor treatments to individual patient needs. Overall, this review aims to provide a comprehensive overview of the current state of ALS research and suggest future directions for developing effective therapies.

Severe dynein dysfunction in cholinergic neurons exacerbates ALS-like phenotypes in a new mouse model

Cytoplasmic dynein 1, a motor protein essential for retrograde axonal transport, is increasingly implicated in the pathogenesis of neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS). In this study, we developed a novel mouse model that combines the Legs at odd angles (Loa, F580Y) point mutation in the dynein heavy chain with a cholinergic neuron-specific knockout of the dynein heavy chain. This model, for the first time, allows us to investigate the impact of Loa allele exclusivity in these neurons into adulthood. Our findings reveal that this selective increase in dynein dysfunction exacerbated the phenotypes observed in heterozygous Loa mice including pre-wean survival, reduced body weight and grip strength. Additionally, it induced ALS-like pathology in neuromuscular junctions (NMJs) not seen in heterozygous Loa mice. Notably, we also found a previously unobserved significant increase in neurons displaying TDP-43 puncta in both Loa mutants, suggesting early TDP-43 mislocalisation – a hallmark of ALS. The novel model also exhibited a concurrent rise in p62 puncta that did not co-localise with TDP-43, indicating broader impairments in autophagic clearance mechanisms. Overall, this new model underscores the fact that dynein impairment alone can induce ALS-like pathology and provides a valuable platform to further explore the role of dynein in ALS.

A DISEASE-BASED PERSPECTIVE OF THE RELATIONSHIP BETWEEN NEUROINFLAMMATION AND IMPAIRED GLUCOSE METABOLISM

Neuroinflammation is a significant contributor to the pathogenesis of several central nervous system disorders including Alzheimer's Disease, Parkinson's Disease, Huntington's Disease, and amyotrophic lateral sclerosis. Neuroinflammation is the immune response of the central nervous system against central or peripheral abnormalities disturbed by foreign agents, molecules, metabolic activities, or various diseases. Astrocytes and microglia activation are the main activators of neuroinflammation. The polarization changes of these defender cells have some key roles in bodily metabolism as much as neuronal behavior. The blood-brain barrier is known as the first defender of brain parenchyma. Neuroinflammation disrupts blood-brain barrier integrity and may cause blood-brain barrier breakdown. Glucose is the main energy source of brain and glucose uptake is achieved through the blood-brain barrier. Altered glucose metabolism may have detrimental effects on brain functions and may cause brain disorders. Also, it has been suggested that neuroinflammation may have crucial roles in glucose metabolism. The distribution of the blood-brain barrier in vascular endothelial cells of neurons, astrocytes, and microglia contributes to the transport of glucose to the cells of brain. Microglia and astrocyte polarization are suggested as the two main underlying mechanisms in neuroinflammation. It’s obviously determined that neuroinflammation-caused neurodegenerative diseases are tightly linked with the brain insulin resistance and disrupted cerebral and peripheral glucose metabolism. However, there is lacking knowledge about glucose metabolism deficiencies and microglia/astrocyte polarization. Herein this review, we summarized the neuroinflammation and glucose metabolism with the most common neurological diseases and the possible effects of microglia/astrocyte polarization on glucose metabolism.

The gut microbiota-brain axis role in neurodegenerative diseases and implications according to the sex

Recent advancements in neurodegenerative research have embraced a multisystemic approach, emphasizing the role of the gut microbiota and its interactions with various systems, including the central nervous system. This review explores the interactions between the gut-brain axis and neurological illnesses associated with ageing, with a particular focus on the potential influence of sex. Despite increased life expectancy, the chronological ceiling of human well-being remains unchanged, implying that conditions such as dementia and Parkinson's disease will continue to affect individuals for extended periods as lifespans increase. Understanding the microbiota-gut-brain axis in relation to neurodegenerative diseases may pave the way for novel therapeutic approaches. Additionally, emerging research suggests that sex-related variations in gut microbiota and the influence of sex hormones may impact the manifestation of several neurodegenerative conditions, including those related to mental health. This review updates the current knowledge on age-related neurodegenerative diseases, such as dementia, Alzheimer's disease, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis, and dementia with Lewy bodies. Future research should focus on exploring microbial therapeutics for the treatment and prevention of age-related neurodegenerative disorders, as well as gender-specific variations in gut microbiota. In this context, the EU-funded project MEMOIR will investigate the impact of a healthy diet on gut microbiota and the progression of Mild Cognitive Impairment.

Stem Cell Interventions in Neurology: From Bench to Bedside.

Stem cell therapies are progressively redefining the treatment landscape for a spectrum of neurological and age-related disorders. This review discusses the molecular and functional attributes of stem cells, emphasizing the roles of neural stem cells and mesenchymal stem cells in the context of neurological diseases such as stroke, multiple sclerosis, amyotrophic lateral sclerosis, traumatic brain injury, Parkinson's disease, and Alzheimer's disease. The review also explores the potential of stem cells in addressing the aging process. The paper analyzes stem cells' intrinsic properties of self-renewal, differentiation, and paracrine effects, alongside the importance of laboratory-modified stem cells like induced pluripotent stem cells and transgenic stem cells. Insights into disease-specific stem cell treatments are offered, reviewing both successes and challenges in the field. This includes the translational difficulties from rodent studies to human trials. The review concludes by acknowledging the uncharted territories that warrant further investigation, emphasizing the potential roles of stem cell-derived exosomes and indole-related molecules, and aiming at providing a basic understanding of stem cell therapies.

Phenotype and Genotype of Children with ALS2 gene-Related Disorder.

The Alsin Rho Guanine Nucleotide Exchange Factor (ALS2) gene encodes a protein alsin that functions as a guanine nucleotide exchange factor. The variations in ALS2 gene leads to degeneration of upper motor neurons of the corticospinal tract. The phenotypes resulting from variants in ALS2 gene are infantile-onset ascending hereditary spastic paralysis (IAHSP, OMIM # 607225), juvenile primary lateral sclerosis (JPLS, OMIM # 606353), and juvenile amyotrophic lateral sclerosis (JALS, OMIM # 205100). Our study objectives were to describe the clinical phenotype and genotype of children with an established diagnosis of ALS2 gene-related disorder. The clinical details, laboratory data, and genotype findings of children with an established diagnosis of ALS2 gene-related disorder were collected from the hospital electronic database after obtaining institutional review board approval. One family with three affected siblings, a second family with a proband and an affected fetus, and a third family with two affected siblings with ALS2 gene variants were identified. IAHSP was diagnosed in all of our patients with variants in ALS2 gene. The clinical findings observed in our patients were insidious onset progressive spastic paraparesis, contractures, and dysarthria. Nonsense variants were observed in four patients while frameshift variant was observed in one family. Novel variants in ALS2 gene were identified in two unrelated families. ALS2 mutation results in rare neurodegenerative disorders with the clinical spectrum encompassing IAHSP, JPLS, and JALS disorders. In view of allelic heterogeneity described in the literature, more research studies are needed for establishing genotype-phenotype correlation in patients with ALS2 gene-related disorder.

Divergent and Convergent TMEM106B Pathology in Murine Models of Neurodegeneration and Human Disease.

TMEM106B is a lysosomal/late endosome protein that is a potent genetic modifier of multiple neurodegenerative diseases as well as general aging. Recently, TMEM106B was shown to form insoluble aggregates in postmortem human brain tissue, drawing attention to TMEM106B pathology and the potential role of TMEM106B aggregation in disease. In the context of neurodegenerative diseases, TMEM106B has been studied in vivo using animal models of neurodegeneration, but these studies rely on overexpression or knockdown approaches. To date, endogenous TMEM106B pathology and its relationship to known canonical pathology in animal models has not been reported. Here, we analyze histological patterns of TMEM106B in murine models of C9ORF72 -related amyotrophic lateral sclerosis and frontotemporal dementia (C9-ALS/FTD), SOD1-related ALS, and tauopathy and compare these to postmortem human tissue from patients with C9-ALS/FTD, Alzheimer's disease (AD), and AD with limbic-predominant age-related TDP-43 encephalopathy (AD/LATE). We show that there are significant differences between TMEM106B pathology in mouse models and human patient tissue. Importantly, we also identified convergent evidence from both murine models and human patients that links TMEM106B pathology to TDP-43 nuclear clearance specifically in C9-ALS. Similarly, we find a relationship at the cellular level between TMEM106B pathology and phosphorylated Tau burden in Alzheimer's disease. By characterizing endogenous TMEM106B pathology in both mice and human postmortem tissue, our work reveals considerations that must be taken into account when analyzing data from in vivo mouse studies and elucidates new insights supporting the involvement of TMEM106B in the pathogenesis and progression of multiple neurodegenerative diseases.

Chitosan, Methyl Jasmonate, and Silicon Induce Resistance to Angular Leaf Spot in Common Bean, Caused by Pseudocercospora griseola, with Expression of Defense-Related Genes and Enzyme Activities

This study assessed the efficacy of chitosan, methyl jasmonate, and silicon in the reduction of disease severity and the induction of defense responses in common bean plants against angular leaf spot caused by Pseudocercospora griseola. The expression level of several pathogenesis-related (PR) proteins, PR1, PR2 (β-1,3-glucanase), and PR3 (chitinase), and defense-related enzymes, phenylalanine ammonia-lyase, peroxidase, and lipoxygenase, was analyzed at different time points in common bean plants after different treatments. Elicitor treatments significantly reduced disease severity 21 days after inoculation, with silicon at a 2 mM concentration proving most effective with 38.93% disease control, followed by 1 mM MeJA and 2% chitosan, respectively. Treatments with chitosan, methyl jasmonate, and silicon, regardless of pathogen infection, significantly elevated PR1, PR2, and PR3 gene expressions at 48 h after inoculation (hpi). PAL and POD activities were similarly increased following elicitor treatments and pathogen infection, especially at 48 hpi. Chemical elicitors applied post-inoculation induced PR proteins, PAL, and POD enzyme activities at 48 hpi, while LOX activity exhibited a variable fluctuation with treatments. These findings suggested that chemical elicitors, especially silicon, were effective in reducing ALS disease severity in common beans, with improved resistance associated with the expression of pathogen-responsive genes. This study is the first to analyze the expression profiles of defense-related genes in common beans treated with chemical elicitors prior to P. griseola infection.

Perceived Pain in People Living with Amyotrophic Lateral Sclerosis-A Scoping Review.

(1) Background: Pain is a common symptom in patients with Amyotrophic Lateral Sclerosis (ALS). There are no evidence-based pharmacological treatments for pain in ALS; recommendations are based on guidelines for chronic non-oncological pain and clinical experience. The aim is to map the literature on how people with ALS experience pain, and how this affects their daily activities and social relationships. (2) Methods: This scoping review included studies concerning patients with spinal/bulbar ALS aged ≥ 18 years who experience pain, focusing on perception, characteristics, treatment, and impact on quality of life. Temporal and linguistic criteria were applied when searching the MEDLINE, CINAHL, and SCOPUS databases. (3) Results: The management of pain in these patients is complex and involves the use of anti-inflammatory drugs, analgesics, and opioids. Pain is associated with other conditions such as depression and anxiety, which contribute to a deterioration in the quality of life. Moreover, pain may also negatively influence patient compliance with prescribed treatment regimens and the quality of care they perceive themselves to be receiving. (4) Conclusions: It is of the most importance to identify effective ways to assess and treat this issue, with health care professionals taking an active role in this process.

Nerve ultrasound in amyotrophic lateral sclerosis: systematic review and meta-analysis

Background/ AimAmyotrophic lateral sclerosis (ALS) is a neurodegenerative disease affecting upper and lower motor neurons, causing progressive atrophy of muscles, hypertonia, and paralysis. This study aimed to evaluate the current evidence and effectiveness of ultrasound in investigating nerve cross-sectional area (CSA) of peripheral nerves, vagus and cervical roots in those with ALS compared with healthy controls and to pool the CSA measurements.MethodsA systematic search was conducted on Cochrane, Clarivate Web of Science, PubMed, Scopus, and Embase for the mesh terms nerve, ultrasonography, and amyotrophic lateral sclerosis. A quality assessment was performed using the New-Ottawa scale. In addition, a double-arm meta-analysis using Review Manager 5 software version 5.4 was performed.ResultsFrom the seventeen studies included in this review, the overall mean difference showed that individuals with ALS had a significantly smaller CSA in comparison to healthy controls for median, ulnar, C6 root, and phrenic nerves. However, no significant difference in the CSA was found in radial, vagal, sural, and tibial nerves.DiscussionThis study confirmed results of some of the included studies regards the anatomic sites, where nerve atrophy in ALS could be detected to potentially support the diagnosis of ALS. However, we recommend further large, prospective studies to assess the diagnostic value of these anatomical sites for the diagnosis of ALS.ConclusionsOur findings confirmed specific anatomic sites to differentiate ALS patients from healthy controls through ultrasound. However, these findings cannot be used to confirm the ALS diagnosis, but rather assist in differentiating it from other diagnoses.Trial registrationRetrospectively registered on July 30th 2024 in PROSPERO (PROSPERO (york.ac.uk)) with ID574702.Graphical abstract

The Emerging Role of Phosphodiesterase 5 Inhibition in Neurological Disorders: The State of the Art.

Growing evidence suggests that neuroinflammation is not just a consequence of neurodegeneration in pathologies such as Alzheimer's disease, Parkinson's disease, Huntington's disease or Amyotrophic lateral sclerosis, but it is rather a determinant factor, which plays a pivotal role in the onset and progression of these disorders. Neuroinflammation can affect cells and processes in the central nervous system (CNS) as well as immune cells, and might precede protein aggregation, which is a hallmark of the neurodegenerative process. Standard treatment methods are far from being able to counteract inflammation and delay neurodegeneration. Remarkably, phosphodiesterase 5 inhibitors (PDE5is), which represent potent vasoactive drugs used as a first-line treatment for erectile dysfunction (ED), display important anti-inflammatory effects through cyclic guanosine monophosphate (cGMP) level stabilization. Since PDE5 hydrolyzes cGMP, several studies positioned PDE5 as a therapeutic target, and more specifically, PDE5is as potential alternative strategies for the treatment of a variety of neurological disorders. Indeed, PDE5is can limit neuroinflammation and enhance synaptic plasticity, with beneficial effects on cognitive function and memory. The aim of this review is to provide an overview of some of the main processes underlying neuroinflammation and neurodegeneration which may be potential targets for PDE5is, focusing on sildenafil, the most extensively studied. Current strategies using PDEis for the treatment of neurodegenerative diseases will be summarized.

Systemic Innate Immune System Restoration as a Therapeutic Approach for Neurodegenerative Disease: Effects of NP001 on Amyotrophic Lateral Sclerosis (ALS) Progression.

Amyotrophic lateral sclerosis (ALS) is a diagnosis that incorporates a heterogeneous set of neurodegenerative processes into a single progressive and uniformly fatal disease making the development of a uniformly applicable therapeutic difficult. Recent multinational ALS natural history incidence studies have identified systemic chronic activation of the innate immune system as a major risk factor for developing ALS. Persistent immune activation in patients with ALS leads to loss of muscle and lowering of serum creatinine. The goal of the current study was to test whether the slowing of nerve and muscle destruction in NP001-treated ALS patients compared with controls in phase 2 studies would lead to extension of survival. Phase 2 clinical studies with NP001, an intravenously administered form of the innate immune system regulator NaClO2, are now reporting long-term survival benefits for drug recipients vs. placebo controls after only six months of intermittent treatment. As a prodrug, NP001 is converted by macrophages to taurine chloramine, a long-lived regulator of inflammation. We performed a pooled analysis of all patients who had completed the studies in two six-month NP001 phase 2 trials. Changes in respiratory vital capacity and the muscle mass product, creatinine, defined treated patients who, compared to placebo, had up to a year of extended survival. The observed longer survival in ALS patients with the greatest inflammation-associated muscle loss provides further evidence that ALS is a disease of ongoing innate immune dysfunction and that NP001 is a disease-modifying drug with sustained clinical activity.

Preservation of masseter muscle until the end stage in the SOD1G93A mouse model for ALS

Amyotrophic lateral sclerosis (ALS) progressively impairs motor neurons, leading to muscle weakness and loss of voluntary muscle control. This study compared the effects of SOD1 mutation on masticatory and limb muscles from disease onset to death in ALS model mice. Notably, limb muscles begin to atrophy soon after ALS-like phenotype appear, whereas masticatory muscles maintain their volume and function in later stages. Our analysis showed that, unlike limb muscles, masticatory muscles retain their normal structure and cell makeup throughout most of the disease course. We found an increase in the number of muscle satellite cells (SCs), which are essential for muscle repair, in masticatory muscles. In addition, we observed no reduction in the number of muscle nuclei and no muscle fibre-type switching in masticatory muscles. This indicates that masticatory muscles have a higher resistance to ALS-related damage than limb muscles, likely because of differences in cell composition and repair mechanisms. Understanding why masticatory muscles are less affected by ALS could lead to the development of new treatments. This study highlights the importance of studying different muscle groups in ALS to clarify disease aetiology and mechanisms.

Synaptic dynamics linked to widespread elevation of H-reflex before peripheral denervation in amyotrophic lateral sclerosis.

Changes in Hoffmann reflex (H-reflex) exhibit heterogeneity among patients with amyotrophic lateral sclerosis (ALS), likely due to phenotype diversity. Current knowledge primarily focuses on soleus H-reflex, which may demonstrate an initial increase before subsequent decline throughout the disease course. The main objective was to investigate other muscles, to determine whether H-reflex changes could be associated with patient phenotype (onset site, functional disabilities). Additional experiments were performed to elucidate the neurophysiological mechanisms underlying H-reflex modifications. In age- and sex-matched groups of controls and patients, we compared H-reflex recruitment curves in soleus, quadriceps, and forearm flexors. Additionally, we examined H-reflex and motor evoked potential (MEP) recruitment curves in quadriceps. Last, to assess potential changes in monosynaptic excitatory post-synaptic potentials (EPSPs) of both peripheral and cortical origins, we analyzed peri-stimulus time histograms (PSTH) and peristimulus frequencygrams (PSF) of single motor units, along with H-reflex occurrence after paired pulse stimuli. The ratio between maximal amplitudes of H-reflex and direct motor response increased in all muscles, irrespective of disease onset, and was found positively correlated with exaggerated osteotendinous reflexes and spasticity, but depressed in patients on-riluzole. This finding was accompanied by a reduction in MEP size and no changes in PSTH, PSF, and paired-pulse H-reflex probability. It is speculated that spinal interneurons may compensate for potential depression of monosynaptic EPSPs in ALS. From a clinical perspective, while the added value of H-reflex to osteotendinous reflex evaluation may be limited, it can serve as a valuable quantitative biomarker of pyramidal dysfunction in clinical trials.

The Effectiveness of NP001 on the Long-Term Survival of Patients with Amyotrophic Lateral Sclerosis.

The aim of this study was to estimate the effect of a 6 months' treatment course of the innate immune modulator NP001 (a pH-adjusted intravenous formulation of purified sodium chlorite), on disease progression, as measured by overall survival (OS) in patients with amyotrophic lateral sclerosis. Blinded survival data were retrospectively collected for 268 of the 273 patients who had participated in two phase 2 placebo-controlled clinical trials of NP001 (ClinicalTrials.gov: NCT01281631 and NCT02794857) and received at least one dose of either 1 mg/kg or 2 mg/kg of NP001 as chlorite based on actual body weight, or placebo. Kaplan-Meier methods were used on the intent-to-treat population to estimate survival probabilities. In the overall population, the median OS was 4.8 months (2.7 years [95% CI: 2.3, 3.5] in the 2 mg/kg NP001group and 2.3 years [95% CI: 1.8, 2.9] in the placebo group). Hazard ratio (HR): 0.77 (95% CI: 0.57, 1.03), p = 0.073. Among patients aged ≤ 65 years, the median OS for the 2 mg/kg NP001 group was 10.8 months (3.3 years [95% CI: 2.4, 3.8] in the 2 mg/kg NP001 group and 2.4 years [95% CI: 1.7, 3.3] in the placebo group). HR: 0.69 (95% CI: 0.50, 0.95). No differences were observed in the 1 mg/kg NP001 group or in patients aged > 65 years. The findings from this study suggest that a 6 months' treatment course of NP001 resulted in a 4.8-month increase in overall survival in patients with ALS. The findings from this study indicate that targeting inflammation associated with the innate immune system may provide a pathway for new therapeutic options for the treatment of ALS.

Clinical usefulness of the Verbal Fluency Index (VFI) in amyotrophic lateral sclerosis.

This study aimed at assessing the clinical utility of the Verbal Fluency Index (VFI) over a classical phonemic verbal fluency test in Italian-speaking amyotrophic lateral sclerosis (ALS) patients. N = 343 non-demented ALS patients and N = 226 healthy controls (HCs) were administered the Verbal fluency - S task from the Edinburgh Cognitive and Behavioural ALS Screen (ECAS). The associations between the number of words produced (NoW), the time to read words aloud (TRW) and the VFI (computed as [(60"-TRW)/NoW]) on one hand and both bulbar/respiratory scores from the ALS Functional Rating Scale - Revised (ALSFRS-R) and the ECAS-Executive on the other were tested. Italian norms for the NoW and the VFI were derived in HCs via the Equivalent Score method. Patients were classified based on their impaired/unimpaired performances on the NoW and the VFI (NoW-VFI-; NoW-VFI+; NoW + VFI-; NoW + VFI+), with these groups being compared on ECAS-Executive scores. The VFI, but neither the NoW nor the TRW, were related to ALSFRS-Bulbar/-Respiratory scores; VFI and NoW measures, but not the TRW, were related to the ECAS-Executive (p < .001). The NoW slightly overestimated the number of executively impaired patients when compared to the VFI (31.1% vs. 26.8%, respectively). Patients with a defective VFI score - regardless of whether they presented or not with a below-cutoff NoW - reported worse ECAS-Executive scores than NoW + VFI + ones. The present reports support the use of the Italian VFI as a mean to validly assess ALS patients' executive status by limiting the effect of motor disabilities that might undermine their speech rate.

The spectrum of behavioral disorders in amyotrophic lateral sclerosis: current view.

Behavioral disorders, with an average prevalence of 30-60% are important non-motor symptoms in amyotrophic lateral sclerosis (ALS) that have a negative impact on prognosis, management and quality of life, yet the underlying neurobiology is poorly understood. Among people with ALS, apathy, fatigue, anxiety, irritability and other behavioral symptoms are the most prominent, although less frequent than cognitive impairment. The present review explores the current understanding of behavioral changes in ALS with particular emphasis on our current knowledge about their structural and functional brain correlates, substantiating a multisystem degeneration with particular dysfunction of frontal-subcortical circuits and dysfunction of fronto-striatal, frontotemporal and other essential brain systems. The natural history of behavioral dysfunctions in ALS and their relationship to frontotemporal lobe degeneration (FTLD) are not fully understood, although they form a clinical continuum, suggesting a differential vulnerability of non-motor brain networks, ALS being considered a brain network disorder. An assessment of risks or the early detection of brain connectivity signatures before structural changes may be helpful in investigating the pathophysiological mechanisms of behavioral impairment in ALS. Treatment of both ALS and co-morbid behavioral disorders is a multidisciplinary task, but whereas no causal or disease-modifying therapies for ALS are available, symptomatic treatment of a variety of behavioral symptoms plays a pivotal role in patient care, although the management of behavioral symptoms in clinical care still remains limited.

Exercise, disease state and sex influence the beneficial effects of Fn14-depletion on survival and muscle pathology in the SOD1G93A amyotrophic lateral sclerosis (ALS) mouse model

BackgroundAmyotrophic lateral sclerosis (ALS) is a devastating and incurable neurodegenerative disease. Accumulating evidence strongly suggests that intrinsic muscle defects exist and contribute to disease progression, including imbalances in whole-body metabolic homeostasis. We have previously reported that tumour necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK) and fibroblast growth factor inducible 14 (Fn14) are significantly upregulated in skeletal muscle of the SOD1G93A ALS mouse model. While antagonising TWEAK did not impact survival, we did observe positive effects in skeletal muscle. Given that Fn14 has been proposed as the main effector of the TWEAK/Fn14 activity and that Fn14 can act independently from TWEAK in muscle, we suggest that manipulating Fn14 instead of TWEAK in the SOD1G93A ALS mice could lead to differential and potentially improved benefits.MethodsWe thus investigated the contribution of Fn14 to disease phenotypes in the SOD1G93A ALS mice. To do so, Fn14 knockout mice (Fn14−/−) were crossed onto the SOD1G93A background to generate SOD1G93A;Fn14−/− mice. Investigations were performed on both unexercised and exercised (rotarod and/or grid test) animals (wild type (WT), Fn14−/−, SOD1G93A and SOD1G93A;Fn14−/−).ResultsHere, we firstly confirm that the TWEAK/Fn14 pathway is dysregulated in skeletal muscle of SOD1G93A mice. We then show that Fn14-depleted SOD1G93A mice display increased lifespan, myofiber size, neuromuscular junction endplate area as well as altered expression of known molecular effectors of the TWEAK/Fn14 pathway, without an impact on motor function. Importantly, we also observe a complex interaction between exercise (rotarod and grid test), genotype, disease state and sex that influences the overall effects of Fn14 deletion on survival, expression of known molecular effectors of the TWEAK/Fn14 pathway, expression of myosin heavy chain isoforms and myofiber size.ConclusionsOur study provides further insights on the different roles of the TWEAK/Fn14 pathway in pathological skeletal muscle and how they can be influenced by age, disease, sex and exercise. This is particularly relevant in the ALS field, where combinatorial therapies that include exercise regimens are currently being explored. As such, a better understanding and consideration of the interactions between treatments, muscle metabolism, sex and exercise will be of importance in future studies.

Proteome Aggregation in Cells Derived from Amyotrophic Lateral Sclerosis Patients for Personalized Drug Evaluation.

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder that currently lacks effective therapy. Given the heterogeneity of clinical and molecular profiles of ALS patients, personalized diagnostics and pathological characterization represent a powerful strategy to optimize patient stratification, thereby enabling personalized treatment. Immortalized lymphocytes from sporadic and genetic ALS patients recapitulate some pathological hallmarks of the disease, facilitating the fundamental task of drug screening. However, the molecular aggregation of ALS has not been characterized in this patient-derived cellular model. Indeed, protein aggregation is one of the most prominent features of neurodegenerative diseases, and therefore, models to test drugs against personalized pathological aggregation could help discover improved therapies. With this work, we aimed to characterize the aggregation profile of ALS immortalized lymphocytes and test several drug candidates with different mechanisms of action. In addition, we have evaluated the molecular aggregation in motor neurons derived from two hiPSC cell lines corresponding to ALS patients with different mutations in TARDBP. The results provide valuable insight into the different characterization of sporadic and genetic ALS patients' immortalized lymphocytes, their differential response to drug treatment, and the usefulness of proteome homeostasis characterization in patients' cells.

An Effective DNA Methylation Biomarker Screening Mechanism for Amyotrophic Lateral Sclerosis (ALS) Based on Comorbidities and Gene Function Analysis.

This study used epigenomic methylation differential expression analysis to identify primary biomarkers in patients with amyotrophic lateral sclerosis (ALS). We combined electronic medical record datasets from MIMIC-IV (United States) and NHIRD (Taiwan) to explore ALS comorbidities in depth and discover any comorbidity-related biomarkers. We also applied word2vec to these two clinical diagnostic medical databases to measure similarities between ALS and other similar diseases and evaluated the statistical assessment of the odds ratio to discover significant comorbidities for ALS subjects. Important and representative DNA methylation biomarker candidates could be effectively selected by cross-comparing similar diseases to ALS, comorbidity-related genes, and differentially expressed methylation loci for ALS subjects. The screened epigenomic and comorbidity-related biomarkers were clustered based on their genetic functions. The candidate DNA methylation biomarkers associated with ALS were comprehensively discovered. Gene ontology annotations were then applied to analyze and cluster the candidate biomarkers into three different groups based on gene function annotations. The results showed that a potential testing kit for ALS detection can be composed of SOD3, CACNA1H, and ERBB4 for effective early screening of ALS using blood samples. By developing an effective DNA methylation biomarker screening mechanism, early detection and prophylactic treatment of high-risk ALS patients can be achieved.