Amyotrophic lateral sclerosis: a clinical review

Blood diagnostic and prognostic biomarkers in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis is a devastating neurodegenerative disease for which the current treatment approaches remain severely limited. The principal pathological alterations of the disease include the selective degeneration of motor neurons in the brain, brainstem, and spinal cord, as well as abnormal protein deposition in the cytoplasm of neurons and glial cells. The biological markers under extensive scrutiny are predominantly located in the cerebrospinal fluid, blood, and even urine. Among these biomarkers, neurofilament proteins and glial fibrillary acidic protein most accurately reflect the pathologic changes in the central nervous system, while creatinine and creatine kinase mainly indicate pathological alterations in the peripheral nerves and muscles. Neurofilament light chain levels serve as an indicator of neuronal axonal injury that remain stable throughout disease progression and are a promising diagnostic and prognostic biomarker with high specificity and sensitivity. However, there are challenges in using neurofilament light chain to differentiate amyotrophic lateral sclerosis from other central nervous system diseases with axonal injury. Glial fibrillary acidic protein predominantly reflects the degree of neuronal demyelination and is linked to non-motor symptoms of amyotrophic lateral sclerosis such as cognitive impairment, oxygen saturation, and the glomerular filtration rate. TAR DNA-binding protein 43, a pathological protein associated with amyotrophic lateral sclerosis, is emerging as a promising biomarker, particularly with advancements in exosome-related research. Evidence is currently lacking for the value of creatinine and creatine kinase as diagnostic markers; however, they show potential in predicting disease prognosis. Despite the vigorous progress made in the identification of amyotrophic lateral sclerosis biomarkers in recent years, the quest for definitive diagnostic and prognostic biomarkers remains a formidable challenge. This review summarizes the latest research achievements concerning blood biomarkers in amyotrophic lateral sclerosis that can provide a more direct basis for the differential diagnosis and prognostic assessment of the disease beyond a reliance on clinical manifestations and electromyography findings.

Improving mitochondria-associated endoplasmic reticulum membranes integrity as converging therapeutic strategy for rare neurodegenerative diseases and cancer

Membrane contact sites harbor a distinct set of proteins with varying biological functions, thereby emerging as hubs for localized signaling nanodomains underlying adequate cell function. Here, we will focus on mitochondria-associated endoplasmic reticulum membranes (MAMs), which serve as hotspots for Ca2+ signaling, redox regulation, lipid exchange, mitochondrial quality and unfolded protein response pathway. A network of MAM-resident proteins contributes to the structural integrity and adequate function of MAMs. Beyond endoplasmic reticulum (ER)-mitochondrial tethering proteins, MAMs contain several multi-protein complexes that mediate the transfer of or are influenced by Ca2+, reactive oxygen species and lipids. Particularly, IP3 receptors, intracellular Ca2+-release channels, and Sigma-1 receptors (S1Rs), ligand-operated chaperones, serve as important platforms that recruit different accessory proteins and intersect with these local signaling processes. Furthermore, many of these proteins are directly implicated in pathophysiological conditions, where their dysregulation or mutation is not only causing diseases such as cancer and neurodegeneration, but also rare genetic diseases, for example familial Parkinson's disease (PINK1, Parkin, DJ-1), familial Amyotrophic lateral sclerosis (TDP43), Wolfram syndrome1/2 (WFS1 and CISD2), Harel-Yoon syndrome (ATAD3A). In this review, we will discuss the current state-of-the-art regarding the molecular components, protein platforms and signaling networks underlying MAM integrity and function in cell function and how their dysregulation impacts MAMs, thereby driving pathogenesis and/or impacting disease burden. We will highlight how these insights can generate novel, potentially therapeutically relevant, strategies to tackle disease outcomes by improving the integrity of MAMs and the signaling processes occurring at these membrane contact sites.

Investigating the Interplay Between the Nrf2/Keap1/HO-1/SIRT-1 Pathway and the p75NTR/PI3K/Akt/MAPK Cascade in Neurological Disorders: Mechanistic Insights and Therapeutic Innovations

Neurological illnesses are debilitating diseases that affect brain function and balance. Due to their complicated aetiologies and progressive nature, neurodegenerative and neuropsychiatric illnesses are difficult to treat. These incurable conditions damage brain functions like mobility, cognition, and emotional regulation, but medication, gene therapy, and physical therapy can manage symptoms. Disruptions in cellular signalling pathways, especially those involving oxidative stress response, memory processing, and neurotransmitter modulation, contribute to these illnesses. This review stresses the interplay between key signalling pathways involved in neurological diseases, such as the Nrf2/Keap1/HO-1/SIRT-1 axis and the p75NTR/PI3K/Akt/MAPK cascade. To protect neurons from oxidative damage and death, the Nrf2 transcription factor promotes antioxidant enzyme production. The Keap1 protein releases Nrf2 during oxidative stress for nuclear translocation and gene activation. The review also discusses how neurotrophin signalling through the p75 neurotrophin receptor (p75NTR) determines cell destiny, whether pro-survival or apoptotic. The article highlights emerging treatment approaches targeting these signalling pathways by mapping these connections. Continued research into these molecular pathways may lead to new neurological disease treatments that restore cellular function and neuronal survival. In addition to enhanced delivery technologies, specific modulators and combination therapies should be developed to fine-tune signalling responses. Understanding these crosstalk dynamics is crucial to strengthening neurological illness treatment options and quality of life.

Glutamatergic dysfunction in neurodegenerative diseases focusing on Parkinson's disease: Role of glutamate modulators

Parkinson's disease (PD) is a prevalent neurodegenerative disorder resulting from the degeneration of dopamenergic neurons in the substantia nigra pars compacta (SNpc). Research has predominantly centered on understanding the dysfunction of dopaminergic neurotransmission in PD. Recently, more studies discussed the potential role of other neurotransmitters in PD neuropathology. One of the most important non-dopaminergic neurotransmitters involved in the pathogenesis of PD is glutamate, which is widely involved in glutamatergic neurotransmission in different brain regions, including SNpc. The development and progression of PD neuropathology and levodopa-induced dyskinesias (LID) are associated with glutamate neurotoxicity. Therefore, this review seeks to explore the possible involvement of glutamatergic signaling in PD development and assess the therapeutic potential of glutamate receptor antagonists in treating the disorder.

Exploring CSF biomarkers in amyotrophic lateral sclerosis: Highlighting the significance of TDP-43

PURPOSE

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by the existence of the TAR DNA-binding protein 43 (TDP-43) aggregates in motor neurons. This study investigated specific cerebrospinal fluid (CSF) biomarkers, including TDP-43, as diagnostic or prognostic biomarkers for ALS.

METHODS

The study included a hospital-based cohort of sporadic ALS patients (N = 30) and age-matched controls (N = 19). Using immunomagnetic reduction technology, CSF levels of TDP-43, neurofilament light chain (NfL), phosphorylated tau 181 (p-tau181), and total tau (t-tau) were assessed. Plasma levels of TDP-43 were also measured. The association of the different biomarkers with disease severity was investigated using ALS Functional Rating Scale-Revised (ALSFRS-R) scores, forced vital capacity (FVC), and compound muscle action potential (CMAP) amplitudes. The rate of disease progression was evaluated by measuring decline in ALSFRS-R over time.

RESULTS

ALS patients had higher CSF NfL and lower ratio of p-tau181/t-tau than control subjects. No significant difference between groups was observed in CSF TDP-43. In ALS patients, CSF levels of any biomarker, including TDP-43, were not associated with ALSFRS-R scores, FVC, or mean CMAP amplitudes. However, CSF TDP-43 positively correlated with the rate of decline in ALSFRS-R (p = 0.042). ALS patients with high CSF TDP-43 levels (>5 pg/mL) showed larger decline in ALSFRS-R (14.0 ± 11.90 vs. 8.8 ± 5.48 per year; p = 0.045) than those with lower TDP-43. Plasma TDP-43 levels did not correlate with CSF TDP-43 or any clinical parameter.

CONCLUSION

CSF TDP-43 is associated with the rate of disease progression and may be a prognostic biomarker in patients with sporadic ALS.

Power wheelchair users with ALS: Impact of an alerting system on complications with prolonged sitting and power feature utilization

An interventional technology called Virtual Seating Coach (VSC) provided alerts via an app to perform pressure redistribution using power wheelchair seat functions. The objective was whether alerts can contribute to more function utilization and thereby reduce pressure injuries and pain. Thirty-nine individuals with Amyotrophic Lateral Sclerosis (ALS) participated, 14 consented to use VSC, and 25 controls. The duration of the study was 27 months, with follow-up at 1 month or 3 months. Due to multiple technological and disease-related difficulties, three of those consented for the VSC received alerts once per hour to move into prescribed positions for one minute. These participants were able to use the VSC through the study end, and two of the three adhered to performing pressure redistribution after receiving alerts. The three using the VSC did not report pressure injuries; 12 of 21 controls reported development of a pressure injury. Furthermore, those using VSC noted a decrease in pain; most controls showed an increase during the same time period. The study thus highlighted the potential for such alerting technology while at the same time revealing many limitations due to disease progression and diminishing access to wheelchair controls.

Clinical assessment and interpretation of dysarthria in ALS using attention based deep learning AI models

Speech dysarthria is a key symptom of neurological conditions like ALS, yet existing AI models designed to analyze it from audio signal rely on handcrafted features with limited inference performance. Deep learning approaches improve accuracy but lack interpretability. We propose an attention-based deep learning AI model to assess dysarthria severity based on listener effort ratings. Using 2,102 recordings from 125 participants, rated by three speech-language pathologists on a 100-point scale, we trained models directly from recordings collected remotely. Our best model achieved R2 of 0.92 and RMSE of 6.78. Attention-based interpretability identified key phonemes, such as vowel sounds influenced by 'r' (e.g., "car," "more"), and isolated inspiration sounds as markers of speech deterioration. This model enhances precision in dysarthria assessment while maintaining clinical interpretability. By improving sensitivity to subtle speech changes, it offers a valuable tool for research and patient care in ALS and other neurological disorders.

Histone Deacetylase 6 Brain PET in Amyotrophic Lateral Sclerosis-Frontotemporal Spectrum Disorder

OBJECTIVE

[18F]EKZ-001 is a positron emission tomography (PET) tracer targeting histone deacetylase 6 (HDAC6), an enzyme responsible for intracellular transport and clearance of misfolded proteins. HDAC6 modulation is a promising treatment strategy in neurodegenerative disorders, including amyotrophic lateral sclerosis (ALS). Apart from motor symptoms, people with ALS (pwALS) can show a variable degree of cognitive impairment as part of the ALS-frontotemporal spectrum disorder (ALS-FTSD). This work assessed [18F]EKZ-001 binding in pwALS with variable involvement of FTSD.

METHODS

Twenty-four pwALS (13M/11F, 61 ± 10 years) and 12 healthy controls (HC) (6M/6F, 58 ± 3 years) were included. Thirteen pwALS were cognitively normal (ALS-CN), and eleven pwALS presented with FTSD (ALS-FTSD) ranging from mild cognitive or behavioral impairment to FTD, according to their performance on the Edinburgh cognitive and behavioral ALS screen (ECAS). All subjects underwent dynamic PET-MR imaging with arterial sampling, and regional distribution volumes (VT) were calculated using a Logan graphical analysis.

RESULTS

[18F]EKZ-001 VT was significantly lower in pwALS compared to HC. For ALS-CN, the largest reduction was found in the brainstem. For ALS-FTSD, reductions were more widespread in both gray and white matter. No differences in VT were found between pwALS with and without a C9orf72 mutation. [18F]EKZ-001 VT was not correlated with ECAS scores, age, or disease duration.

INTERPRETATION

[18F]EKZ-001 binding is lower throughout the brain in pwALS compared to HC. This may be related to a compensatory mechanism to repair intracellular transport defects in ALS or to reduced HDAC6 enzyme availability for [18F]EKZ-001 binding due to sequestration of HDAC6 within protein aggregates.

Aggregates associated with amyotrophic lateral sclerosis sequester the actin-binding protein profilin 2

Amyotrophic Lateral Sclerosis (ALS) is a devastating neurodegenerative disease characterized by the degeneration of upper and lower motoneurons. The four most frequently mutated genes causing familial ALS (fALS) are C9orf72, FUS, SOD1, and TARDBP. Some of the related wild-type proteins comprise intrinsically disordered regions (IDRs) which favor their assembly in liquid droplets-the biophysical mechanism behind the formation of physiological granules such as stress granules (SGs). SGs assemble and dissolve dependent on the cellular condition. However, it has been suggested that transition from reversible SGs to irreversible aggregates contributes to the toxic properties of ALS-related mutated proteins. Sequestration of additional proteins within these aggregates may then result in downstream toxicity. While the exact downstream mechanisms remain elusive, rare ALS-causing mutations in the actin binding protein profilin 1 suggest an involvement of the actin cytoskeleton. Here, we hypothesize that profilin isoforms become sequestered in aggregates of ALS-associated proteins which induce subsequent dysregulation of the actin cytoskeleton. Interestingly, localization of neuronal profilin 2 in SGs was more pronounced compared with the ubiquitously expressed profilin 1. Accordingly, FUS and C9orf72 aggregates prominently sequestered profilin 2 but not profilin 1. Moreover, we observed a distinct sequestration of profilin 2 and G-actin to C9orf72 aggregates in different cellular models. On the functional level, we identified dysregulated actin dynamics in cells with profilin 2-sequestering aggregates. In summary, our results suggest a more common involvement of profilins in ALS pathomechanisms than indicated from the rarely occurring profilin mutations.

Synaptic defects in adult drosophila motor neurons in a model of amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that primarily affects motor neurons in the brain and spinal cord. Like other neurodegenerative diseases, defects in synaptic integrity are among the earliest hallmarks of ALS. However, the specific impairments to synaptic integrity remain unclear. To better understand synaptic defects in ALS, we expressed either wild-type or mutant Fused in Sarcoma (FUS), an RNA binding protein that is often mis-localized in ALS, in adult motor neurons. Using optogenetic stimulation of the motor neurons innervating the Ventral Abdominal Muscles (VAMs), we found that expression of mutant FUS disrupted the functional integrity of these synapses. This functional deficit was followed by disruption of synaptic gross morphology, localization of pre- and post-synaptic proteins, and cytoskeleton integrity. We found similar synaptic defects using the motor neurons innervating the Dorsal Longitudinal Muscles (DLMs), where expression of mutant FUS resulted in a progressive loss of flight ability along with disruption of active zone distribution. Our findings uncover defects in synaptic function that precede changes in synaptic structure, suggesting that synaptic function is more sensitive to this ALS model. Highlighting the earliest synaptic defects in this disease model should help to identify strategies for preventing later stages of disease progression.

Respiratory function, survival, and NIV prevalence over time in ALS - a PRECISION ALS study

INTRODUCTION

Respiratory function typically deteriorates as ALS progresses and is associated with shorter survival. This study aims to describe respiratory function and the prevalence of noninvasive ventilation (NIV) along the disease trajectory using prospective data from the PRECISION ALS project.

METHODS

We included 3449 ALS patients from six European population-based cohorts. All had comparable assessments of vital capacity, percent predicted (VC%) (58.1% had multiple assessments) and 56% had assessments of the revised ALS Functional Rating Scale (ALSFRS-R). The data were analyzed in relation to survival, NIV, and genetic status (C9orf72, SOD1, FUS, and TARDBP).

RESULTS

In those with a survival time of 1-4 years from diagnosis, the median VC% declined from 91 to 97% at the first assessment to 47-50% at the last assessment 6 months before death. In those with longitudinal assessments, the median VC% declined an average of 24 percentage points per year. Over time, there was an increase in respiratory symptoms relative to general functional impairment, as measured by the ALSFRS-R, and VC% was strongly associated with shorter survival. The confirmed prevalence of NIV was approximately 3%, 15%, and 25% in patients with a VC% of >80, 50-80, and <50, respectively.

CONCLUSION

There was a trend of worsening respiratory function over time and an increase in respiratory symptoms relative to general functional impairment. Survival was strongly associated with respiratory function. In those with impaired respiratory function, there was significant variation in the introduction of NIV.

Pathological Aging of Patients With Amyotrophic Lateral Sclerosis: A Preliminary Longitudinal Study

OBJECTIVE

This longitudinal study investigated pathological brain aging in amyotrophic lateral sclerosis (ALS) by evaluating disparities between chronological age and deep learning-derived brain structure age (BSA) and exploring associations with cognitive and functional decline.

METHODS

Ten limb-onset ALS patients (seven males) and 10 demographically matched healthy controls (HCs) underwent structural magnetic resonance imaging (sMRI) and cognitive assessments at baseline and follow-up. The BSA was estimated using the validated volBrain platform. Cognitive domains (language, verbal fluency, executive function, memory, and visuospatial skills) and global cognition (Persian adaptive Edinburgh Cognitive and Behavioral ALS Screen [ECAS] total score) were assessed along with functional status (ALSFRS-R).

RESULTS

ALS patients exhibited significant BSA-chronological age disparities at baseline (Δ = +7.31 years, p = 0.009) and follow-up (Δ = +8.39 years, p = 0.003), with accelerated BSA progression over time (p = 0.004). The HCs showed no such disparities (p = 0.931). Longitudinal BSA increases were correlated with executive function decline (r = -0.651, p = 0.042). Higher education predicted preserved language (r = 0.831, p = 0.003) and verbal fluency (r = 0.738, p = 0.015). ALSFRS-R decline paralleled visuospatial (r = 0.642, p = 0.045) and global cognitive deterioration (r = 0.667, p = 0.035).

CONCLUSIONS

ALS is characterized by accelerated structural brain aging that progresses independently of chronological age and is correlated with executive dysfunction. Education may mitigate cognitive decline, while motor functional deterioration aligns with visuospatial and global cognitive impairments. BSA has emerged as a potential biomarker for tracking pathological aging trajectories in ALS, warranting validation using larger cohorts.

Characteristics of Patients With Amyotrophic Lateral Sclerosis Followed by a Home Palliative Care Team

BackgroundInformation about patients with amyothrophic lateral sclerosis (ALS) followed at home is limited.ObjectivesTo assess patients's characteristics at admission to a home palliative care program based on a multidisciplinary team, and the temporal course along the trajectory of ALS disease.DesignRetrospective. Setting/subjects: Charts of a consecutive number of ALS patients who were referred to a specialistic home palliative care were reviewed.MeasurementGeneral data, referral, start of home palliative care, use of ventilator support and nutritional support, were recorded. The existence of advance directives and shared care planning was also collected.Results82 patients were examined; 31 patients died before the term of the study and 51 patients were still living. No patient anticipately expressed their will regarding their treatments. However, a certain number of patients shared a care planning with ALS team, generally after starting home care. Most patients did not have ventilatory support at the beginning of home care assistance, but progressively received ventilatory support by NIV or MV, particularly those who were still living. NIV at start of home care was negatively correlated to frontotemporal dementia. (P = 0.015), and directly correlated to referral from hospital and GP (P = 0.031) and awareness of disease (P = 0.034). Gastrostomy at start of home care was positively correlated to referral from hospital (P = 0.046). Gastrostomy during home care was correlated to bulbar SLA (P = 0.017). The use of NIV during home care was positively correlated to shared care planning (P = 0.001).ConclusionThe continuous presence of a multi-specialist team may provide timely intervention, guarantee and trust on the part of the patient and family members.

MicroRNA signature of lymphoblasts from amyotrophic lateral sclerosis patients as potential clinical biomarkers

MicroRNAs (miRNAs) are a class of small, non-coding RNAs involved in different cellular functions that have emerged as key regulators of neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS). ALS is a fatal disease that lacks of not only effective treatments, but also presents delays in its diagnosis, since reliable clinical biomarkers are unavailable. In recent years, advancements in high-throughput sequencing strategies have led to the identification of novel ALS biomarkers, facilitating earlier diagnosis and assessment of treatment efficacy. Since immortalized lymphocytes obtained from peripheral blood are a suitable model to study pathological features of ALS, we employed these samples with the aim of characterize the dysregulated miRNAs in ALS patients. Next-generation sequencing (NGS) was utilized in order to analyze the expression profiles of miRNAs in immortalized lymphocytes from healthy controls, sporadic ALS (sALS), and familial ALS with mutations in superoxide dismutase 1 (SOD1-ALS). The screening analysis of the NGS data identified a set of dysregulated miRNAs, of which nine candidates were selected for qRT-PCR validation, identifying for the first time the possible importance of hsa-miR-6821-5p as a potential ALS biomarker. Furthermore, the up-regulated miRNAs identified are predicted to have direct or indirect interactions with genes closely related to ALS, such as SIGMAR1, HNRNPA1 and TARDBP. Additionally, by Metascape enrichment analysis, we found the VEGFA/VEGFR2 signaling pathway, previously implicated in neuroprotective effects in ALS, as a candidate pathway for further analyses.

Association among blood pressure, antihypertensive drugs, and amyotrophic lateral sclerosis

BACKGROUND

 Amyotrophic lateral sclerosis (ALS) is a fatal and incurable neurodegenerative disease. The impacts of antihypertensive drugs and blood pressure (BP) on ALS are currently debatable.

OBJECTIVE

 To evaluate the causal relationship involving antihypertensive drugs, BP, and ALS through a Mendelian randomization (MR) analysis.

METHODS

 The causal relationship between BP and ALS was evaluated by a bidirectional two-sample MR analysis. Then, a sensitivity analysis was performed using a secondary BP genome-wide association study. The drug-target MR was employed to evaluate the impact of antihypertensive drugs on ALS. Furthermore, we used cis-expression quantitative trait loci (cis-eQTLs) data from brain tissue and blood to validate the positive results by a summary-based MR method.

RESULTS

 We found that an increment in systolic BP (SBP) could elevate the risk of ALS (inverse-variance weighted [IVW] odds ratio [OR] = 1.003; 95% confidence interval [95%CI]: 1.001-1.006; per 10-mmHg increment) and ALS might be protected by angiotensin-converting enzyme inhibitors (ACEIs; OR = 0.970; 95%CI: 0.956-0.984; p = 1.96 × 10-5; per 10-mmHg decrement). A causal relationship was not observed between diastolic BP and other antihypertensive drugs in ALS.

CONCLUSION

 In the present study, genetic support for elevated SBP serves as a risk factor for ALS. Besides, ACEIs hold promise as a candidate for ALS.

Lower Circulating Gas6 Levels Are Associated with Bulbar Phenotype and Faster Disease Progression in Amyotrophic Lateral Sclerosis Patients

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder that primarily affects the motor neurons in the brain and spinal cord. While the exact cause of ALS is not fully understood, a combination of genetic and environmental factors is believed to contribute to its development. Growth arrest-specific 6 (Gas6), a vitamin K-dependent protein, has been recognized to enhance oligodendrocytes and neurons' survival and is associated with different kinds of (neuro)inflammatory conditions. Therefore, we aimed to determine a possible implication of Gas6 in ALS phenotype and progression by evaluating the value of circulating Gas6 and its soluble receptors (sAxl, sMer, sTyro-3) in ALS patients. We conducted a prospective observational study including 65 ALS patients and measured the circulating serum levels of Gas6, sAxl, sMer, soluble Tyro-3 (sTyro-3), and neurofilaments (NfLs). In our ALS cohort, lower serum levels of Gas6 and concomitantly higher levels of NfLs were associated with a more aggressive disease, expressed with bulbar phenotype (p-value for Gas6 = 0.03) and faster progression (p-value for Gas6 = 0.03). Also, serum Gas6 was able to distinguish (area under the curve, cut-off 13.70 ng/mL, sensitivity 69.57%, specificity 72.72%) between fast and slow progressors. Due to its neuroprotective properties, our data suggest that Gas6 could be an intriguing biomarker in ALS patients.

Characterization, epidemiology, and factors associated with evolution and survival in patients with amyotrophic lateral sclerosis in southeastern Spain, 2008-2021: a population-based study

OBJECTIVE

To describe the epidemiology, characteristics, and factors associated with the evolution and survival in patients with amyotrophic lateral sclerosis (ALS) in a region of southeastern Spain.

METHODS

An observational study was carried out in people with a diagnosis of ALS in the period 2008-2021 who were registered in the Information System of Rare Diseases of the Region of Murcia (SIER). We calculated crude and standardized incidence rate (SIR) using European Standard Population of 2013 and point prevalence. The Kaplan-Meier method and the log-rank test were used to estimate and compare survival curves.

RESULTS

We identified 374 cases. The mean age at diagnosis was 66.5 ± 11.7 and 50.3% persons were spinal onset. Mean time from the onset of symptoms to diagnosis was 0.9 ± 1.0 years. The global SIR was 1.95/100,000 person-years (95%CI: 1.77-2.12), which was higher in men (ratio 1.34), and the point prevalence in 2021 was 4.57 per 100,000 (95% CI: 4.46-4.68). There were 297 deaths with a mean age of 69.8 ± 10.8. The median survival from clinical onset was 2 years (95%CI: 1.0-3.0). Factors associated with lower survival were bulbar onset (p < 0.001), older age at the onset of symptoms (p < 0.001), and the absence of riluzole treatment (p = 0.003).

CONCLUSIONS

This study is one of few to evaluate the epidemiological, characteristics, and prognostic factors of ALS in Spain, with findings similar to previous population studies. The use of population-based registries offers reliable information on the magnitude, or evolution in these patients.

Proteomics Analysis of the TDP-43 Interactome in Cellular Models of ALS Pathogenesis

Cytoplasmic aggregation and nuclear depletion of TAR DNA-binding protein 43 (TDP-43) is a hallmark pathology of several neurodegenerative diseases including amyotrophic lateral sclerosis (ALS), frontotemporal lobar degeneration (FTLD) and limbic-predominant age-related TDP-43 encephalopathy (LATE). However, the protein interactome of TDP-43 remains incompletely defined. In this study, we aimed to identify putative TDP-43 protein partners within the nucleus and the cytoplasm and with different disease models of TDP-43 by comparing TDP-43 interaction partners in three different cell lines. We verified the levels of interaction of protein partners under stress conditions as well as after introducing TDP-43 variants containing ALS missense mutations (G294V and A315T). Overall, we identified 58 putative wild-type TDP-43 interactors, including novel binding partners responsible for RNA metabolism and splicing. Oxidative stress exposure broadly led to changes in TDP-43WT interactions with proteins involved in mRNA metabolism, suggesting a dysregulation of the transcriptional machinery early in disease. Conversely, although G294V and A315T mutations are both located in the C-terminal domain of TDP-43, both mutants presented different interactome profiles with most interaction partners involved in translational and transcriptional machinery. Overall, by correlating different cell lines and disease-simulating interventions, we provide a list of high-confidence TDP-43 interaction partners, including novel and previously reported proteins. Understanding pathological changes to TDP-43 and its specific interaction partners in different models of stress is critical to better understand TDP-43 proteinopathies and provide novel potential therapeutic targets and biomarkers.

The burden of upper motor neuron involvement is correlated with the bilateral limb involvement interval in patients with amyotrophic lateral sclerosis: a retrospective observational study

JOURNAL/nrgr/04.03/01300535-202505000-00032/figure1/v/2024-07-28T173839Z/r/image-tiff Amyotrophic lateral sclerosis is a rare neurodegenerative disease characterized by the involvement of both upper and lower motor neurons. Early bilateral limb involvement significantly affects patients' daily lives and may lead them to be confined to bed. However, the effect of upper and lower motor neuron impairment and other risk factors on bilateral limb involvement is unclear. To address this issue, we retrospectively collected data from 586 amyotrophic lateral sclerosis patients with limb onset diagnosed at Peking University Third Hospital between January 2020 and May 2022. A univariate analysis revealed no significant differences in the time intervals of spread in different directions between individuals with upper motor neuron-dominant amyotrophic lateral sclerosis and those with classic amyotrophic lateral sclerosis. We used causal directed acyclic graphs for risk factor determination and Cox proportional hazards models to investigate the association between the duration of bilateral limb involvement and clinical baseline characteristics in amyotrophic lateral sclerosis patients. Multiple factor analyses revealed that higher upper motor neuron scores (hazard ratio [HR] = 1.05, 95% confidence interval [CI] = 1.01-1.09, P = 0.018), onset in the left limb (HR = 0.72, 95% CI = 0.58-0.89, P = 0.002), and a horizontal pattern of progression (HR = 0.46, 95% CI = 0.37-0.58, P < 0.001) were risk factors for a shorter interval until bilateral limb involvement. The results demonstrated that a greater degree of upper motor neuron involvement might cause contralateral limb involvement to progress more quickly in limb-onset amyotrophic lateral sclerosis patients. These findings may improve the management of amyotrophic lateral sclerosis patients with limb onset and the prediction of patient prognosis.

Metabolic dysregulation in amyotrophic lateral sclerosis: insights from 1H NMR-based metabolomics in a tertiary care center in India

Amyotrophic Lateral Sclerosis (ALS) is a progressive neurodegenerative disorder characterized by motor neuron loss, leading to severe physical impairment and mortality. Despite available treatments like Riluzole and Edaravone, their limited efficacy highlights the need for improved understanding of ALS pathology. This study has explored metabolic alterations in North Indian ALS patients using 1H Nuclear Magnetic Resonance (NMR)-based metabolomics. A case-control study, involving 45 ALS patients and 30 healthy controls (HCs) was performed. Serum samples were analyzed using 600-MHz NMR spectrometer, revealing significant metabolic differences between ALS and HC groups. Multivariate analyses identified nine dysregulated metabolites-pyruvate, glutamine, histidine, isoleucine, leucine, imidazole, arginine, creatinine, and choline-with ROC analysis showing isoleucine as a promising biomarker (AUC 83%). Pathway enrichment analysis highlighted disruptions in key metabolic pathways, including the Glucose-Alanine Cycle, Urea Cycle, Ammonia Recycling, and the Warburg Effect, suggesting potential links to neuroinflammatory and mitochondrial dysfunction in ALS pathogenesis. This pilot study provides insight into ALS-specific metabolic alterations in Indian cohort and demonstrates the potential of these metabolites as diagnostic biomarkers. Our findings identify potential biomarkers that require validation in larger, multi-centric cohorts to support diagnosis, prognosis, and improved management of ALS.

Discovering Novel Biomarkers and Potential Therapeutic Targets of Amyotrophic Lateral Sclerosis Through Integrated Machine Learning and Gene Expression Profiling

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder that has multiple factors that make its molecular pathogenesis difficult to understand and its diagnosis and treatment during the early stages difficult to determine. Discovering novel biomarkers in ALS for diagnostic and therapeutic potential has become important. Consequently, bioinformatics and machine learning algorithms are useful for identifying differentially expressed genes (DEGs) and potential biomarkers, as well as understanding the molecular mechanisms and intricacies of diseases such as ALS. To achieve the aim of the present study, six datasets obtained from the Gene Expression Omnibus (GEO) were utilized and analyzed using an integrative bioinformatics and machine learning approach. Log transformation was done during data preprocessing, RMA normalization was performed, and the batch effect was corrected. Differential expression analysis identified 206 DEGs that were significantly associated with different biological processes, including muscle function, energy metabolism, and mitochondrial membrane activity. Functional enrichment analysis highlighted pathways, including those related to prion disease, Parkinson's disease, and ATP synthesis via chemiosmotic coupling. We employed a multi-step machine learning framework incorporating random forest, LASSO regression, and SVM-RFE to identify robust biomarkers. This approach identified three key genes, CHRNA1, DLG5, and PLA2G4C, which could be explored as promising biomarkers for ALS after further validation. The internal validation, including principal component analysis (PCA) and ROC-AUC analysis, demonstrated strong diagnostic potential of these hub genes, achieving an AUC of 0.96. This work highlights the utility of bioinformatics and machine learning in identifying key genes as biomarkers for diagnostic and therapeutic potential in ALS.

Unraveling the role of CGRP in neurological diseases: a comprehensive exploration to pathological mechanisms and therapeutic implications

Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), Multiple sclerosis (MS), Amyotrophic lateral sclerosis (ALS), and Spinal muscular atrophy (SMA) are neurodegenerative diseases (NDDs) characterized by progressive neuronal degeneration. Recent studies provide compelling information regarding the contribution of Calcitonin Gene-Related Peptide (CGRP), a potent neuropeptide, in regulating neuroinflammation, vasodilation, and neuronal survival in these disorders. This review systematically delves into the multidimensional aspects of CGRP as both a neuroprotective agent and a neurotoxic factor in NDDs. The neuroprotective effects of CGRP include suppression of inflammation, regulation of intracellular signaling pathways, and promotion of neuronal growth and survival. However, under pathological conditions, its overexpression or dysregulation is associated with oxidative stress, excitotoxicity, and neuronal death. The therapeutic use of CGRP and its receptor antagonists in migraine provides substantial evidence for CGRP's therapeutic potential, which can be further explored for the management of NDDs. However, since the bidirectional nature of CGRP effects is evident, it is crucial to gain an accurate insight into its mechanisms to target only the neuropeptide's beneficial effects while completely avoiding the undesired consequences. Further studies should focus on understanding the context-dependent activity of CGRP in the hope of designing targeted therapy for NDDs, which could gradually transform the current pharmacological management of NDDs.

Muscle strengthening in individuals with Amyotrophic Lateral Sclerosis: a systematic review with meta-analyses

Despite the observed benefits of properly prescribed exercises for people with Amyotrophic Lateral Sclerosis (ALS), the scarcity of studies and lack of consensus on the effects of muscle-strengthening exercises on this population has a negative impact on their rehabilitation. This study aimed to evaluate the effects of muscle-strengthening interventions in individuals with ALS. This systematic review of intervention studies included clinical trials that performed non-respiratory muscle strengthening in people with ALS compared to non-strengthening interventions, usual care, or placebo. Such studies were obtained from the MEDLINE, EMBASE, Cochrane Library, SPORTDiscus, and Physiotherapy Evidence Database databases, with no language or publication date restrictions. The outcomes considered were peripheral muscle strength, functionality, fatigue, and adverse events. The Physiotherapy Evidence Database scale was used to analyze the risk of bias, while the Grading of Recommendations Assessment, Development and Evaluation system was used to evaluate the quality of the evidence. Searches were conducted in October 2023 and eight studies were included, totaling 296 individuals. Seven of the eight studies showed superiority of the experimental intervention over the control, but this was not supported in the meta-analyses. Small sample size and high heterogeneity in the primary studies contributed significantly to the low quality of the evidence. There was no evidence of the superiority of interventions for muscle strengthening compared to interventions not aimed at strengthening, usual care, or placebo in terms of the outcomes analyzed immediately after the intervention. The quality of the evidence ranged from low to very low. Five of the studies evaluated adverse events, without reporting serious events. Interventions for muscle strengthening did not prove to be more effective when compared to the control group in the short term nor seem to produce serious adverse events. The low quality of the evidence indicates the need for studies with greater methodological rigor in this population, to more assertively assess the impacts of this intervention over the short, medium, and long term.

Brain Metabolite Profiles are Associated with Selective Neuronal Vulnerability and Underlying Mechanisms in Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a lethal neurological syndrome accompanied by selective degeneration of somatic motor neurons and neurochemistry alterations. Nevertheless, eye movement's nuclei are relatively spared from ALS damage. This survey was to probe metabolite changes in the primary motor cortex (PMC) and interstitial nucleus of Cajal (INC) of ALS patients using proton magnetic resonance spectroscopy (1H-MRS). In this case-control study, 20 patients with ALS and 20 healthy controls underwent 1.5 T MRI and multivoxel 1H-MRS. 1H-MRS spectra to determine metabolite profiles including tNAA, mIns, tCr, tCho, and also tNAA/tCr, tNAA/tCho, and mIns/tNAA metabolite ratios from the PMC and INC were quantified via a point resolved spectroscopy pulse (PRESS) sequence in two groups. Further, the associations between 1H-MRS markers with forced vital capacity (FVC), ALS functional rating scale (ALSFRS-R), and disease progression rate (ΔFS) were investigated. In the PMC, tNAA and tNAA/tCr were significantly lower in ALS patients than the healthy controls, but mIns and mIns/tNAA were significantly greater in these patients (p < 0.05). In the INC, tCho and mIns concentrations, and mIns/tNAA ratio were significantly increased (p < 0.05) in ALS patients, while tNAA and tNAA/tCr ratio did not show significant discriminations between the two groups (p > 0.05). The PMC tNAA/Cr ratio is associated with ALSFRS-R (p = 0.001, r = 0.71), FVC (p = 0.03, r = 0.58), and ΔFS (p = 0.01, r = -0.33). The mIns/tNAA ratio in PMC is also associated with ΔFS (p = 0.02, r = 0.41). In the INC, tCho concentrations (p = 0.04, r = -0.54) and mIns/tNAA ratio (p = 0.02, r = -0.38) were negatively associated with ALSFRS-R and positively correlated with ΔFS (p = 0.01, r = 0.33) and (p = 0.001, r = 0.61), respectively. The study suggests that neurochemistry changes in ALS patients' brains are linked to selective neuronal vulnerability and the underlying pathophysiology of the disease.

Characterization of human healthy i3 lower motor neurons exposed to CSF from ALS patients stratified by UNC13A and C9ORF72 genotype

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease affecting upper and lower motor neurons. Neurodegeneration in ALS might be driven by proteotoxicity or neuroinflammation, which have also been proposed to be promoted by toxic components of the cerebrospinal fluid (CSF). We investigated the possible toxicity of ALS CSF on healthy induced pluripotent stem cells (iPSC)-derived integrated, inducible, and isogenic lower motor neurons (i3LMNs). CSFs were obtained from ALS patients homozygous for the risk UNC13A rs12608932 single nucleotide polymorphism (CC) and for the corresponding major allele (AA), ALS patients with C9ORF72 hexanucleotide repeat expansion, and individuals affected by normal pressure hydrocephalus as non-disease controls (ND). A chronic and low-dose sodium arsenite (ARS) treatment was used as positive control of oxidative stress. We found that 10 % ALS CSF treatment for 48 h was not sufficient to induce significant alterations in viability, autophagic flux, axonal degeneration, DNA damage, and Golgi apparatus integrity in healthy i3LMNs, in contrast to ARS treatment. Only UNC13A CC CSF significantly increased protein aggregation and Golgi apparatus fragments dimension. RNA-sequencing revealed that all ALS and ND CSFs induced expression changes of few genes, while chronic ARS deregulated the expression of thousands of genes, mostly involved in inflammation and synapse biology. In this work, we demonstrated that in our experimental settings only CSF from UNC13A CC patients induced some ALS-associated pathological features in healthy i3LMNs. Further studies will be required to elucidate the mechanistic link between the risk UNC13A genotype and CSF composition and toxicity.

Single-cell transcriptomic and functional studies identify glial state changes and a role for inflammatory RIPK1 signaling in ALS pathogenesis

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease characterized by motor neuron loss. Microglia and astrocyte-driven neuroinflammation is prominent in ALS, but the cell state dynamics and pathways driving disease remain unclear. We performed single-nucleus RNA sequencing of ALS spinal cords and identified altered glial cell states, including increased expression of inflammatory and glial activation markers. Many of these signals converged on the inflammation and cell death regulator receptor-interacting protein kinase 1 (RIPK1) and the necroptotic cell death pathway. In superoxide dismutase 1 (SOD1)G93A mice, blocking RIPK1 kinase activity delayed symptom onset and motor impairment and modulated glial responses. We used human induced pluripotent stem cell (iPSC)-derived motor neuron, astrocyte, and microglia tri-cultures to identify potential biomarkers that are secreted upon RIPK1 activation in vitro and modulated by RIPK1 inhibition in the cerebrospinal fluid (CSF) of people with ALS. These data reveal ALS-enriched glial populations associated with inflammation and suggest a deleterious role for neuroinflammatory signaling in ALS pathogenesis.

Nutrition and Survival of 150 Endoscopic Gastrostomy-Fed Patients with Amyotrophic Lateral Sclerosis

Background/Objectives: Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder affecting motor neurons in the brain and spinal cord, leading to muscle weakness, atrophy, and paralysis. Treatment focuses on symptom management, using medication, physiotherapy, and nutritional support. In this context, endoscopic gastrostomy (PEG) can provide adequate feeding, hopefully improving nutrition and preventing complications. Methods: We studied ALS patients undergoing PEG over three months post-procedure, using anthropometry ((BMI)-body mass index; (MUAC)-mid-upper arm circumference; (TSF)-tricipital skinfold; (MAMC)-mid-arm muscle circumference) and laboratory data (Albumin; Transferrin; total cholesterol and hemoglobin), evaluating survival, complications, and nutritional/clinical status. Statistical analysis included Kaplan-Meier survival estimation and Cox regression to assess nutritional markers associated with survival. Results: 150 ALS patients underwent gastrostomy, mostly older adults (mean age: 66.1 years; median: 67). Mean survival was 527 [95% CI: 432-622] days, median 318 [95% CI: 236-400]. ALS bulbar subtype, MUAC and MAMC positively impacted PEG-feeding survival time (p < 0.05, Wald test). During the first three months of PEG feeding, each unit increase (cm) in MUAC and MAMC lowered death risk by 10% and 11%, respectively, highlighting the importance of nutrition care for survival. The bulbar subtype showed higher PEG feeding survival, with a 55.3% lower death hazard than the spinal subtype. There were no major PEG complications. Conclusions: ALS patients present a high risk of malnutrition. Patients that improved MAMC and MUAC in the first three PEG-fed months presented longer survival. Early PEG nutrition, even when some oral feeding is still possible, may reinforce the preventative role of enteral feeding in maintaining nutrition and potentially improving survival.

Toward brain-computer interface speller with movement-related cortical potentials as control signals

Brain Computer Interface spellers offer a promising alternative for individuals with Amyotrophic Lateral Sclerosis (ALS) by facilitating communication without relying on muscle activity. This study assessed the feasibility of using movement related cortical potentials (MRCPs) as a control signal for a Brain-Computer Interface speller in an offline setting. Unlike motor imagery-based BCIs, this study focused on executed movements. Fifteen healthy subjects performed three spelling tasks that involved choosing specific letters displayed on a computer screen by performing a ballistic dorsiflexion of the dominant foot. Electroencephalographic signals were recorded from 10 sites centered around Cz. Three conditions were tested to evaluate MRCP performance under varying task demands: a control condition using repeated selections of the letter "O" to isolate movement-related brain activity; a phrase spelling condition with structured text ("HELLO IM FINE") to simulate a meaningful spelling task with moderate cognitive load; and a random condition using a randomized sequence of letters to introduce higher task complexity by removing linguistic or semantic context. The success rate, defined as the presence of an MRCP, was manually determined. It was approximately 69% for both the control and phrase conditions, with a slight decrease in the random condition, likely due to increased task complexity. Significant differences in MRCP features were observed between conditions with Laplacian filtering, whereas no significant differences were found in single-site Cz recordings. These results contribute to the development of MRCP-based BCI spellers by demonstrating their feasibility in a spelling task. However, further research is required to implement and validate real-time applications.

Association of glymphatic system disturbance with neural dysfunction in amyotrophic lateral sclerosis

Background

Formation and aggregation of pathological proteins in the brain constitutes a critical hallmark of amyotrophic lateral sclerosis (ALS). However, the role of the glymphatic system in the clearance of pathological proteins in ALS remains unclear. The purpose of this cross-sectional study was to evaluate glymphatic system disturbance in ALS and its relation to neural function.

Methods

This study included 38 healthy controls (HCs) and 30 patients with ALS who underwent diffusion tensor imaging (DTI) and resting-state functional magnetic resonance imaging (rs-fMRI). The disease severity, duration, and progression rate of ALS were recorded. Glymphatic system function was indirectly evaluated by DTI analysis along the perivascular space (ALPS) surrounding the deep medullary vein. Neural activity was examined in sensorimotor-related brain areas by measuring amplitude of low-frequency fluctuation (ALFF) based on rs-fMRI. A two-sample t-test or Mann-Whitney test was used to examine between-group differences in ALPS, diffusivities measured along the x-, y-, and z-axis in the association (Dxx_association, Dyy_association, Dzz_association) and projection (Dxx_projection, Dyy_projection, Dzz_projection) fiber areas, and ALFF indices. The associations between ALPS, diffusivities, ALFF, and clinical assessments were determined via Spearman correlation analysis, and diagnostic performance was evaluated with receiver operating characteristic curve analysis.

Results

Patients with ALS exhibited significantly decreased ALPS and increased diffusivities (Dyy_association and Dyy_projection) as compared to HCs (all P values <0.05). Patients with ALS showed decreased ALFF in sensorimotor-related regions, including the bilateral primary motor and somatosensory areas (all P values <0.001) and left supplementary motor area (P=0.031). ALPS and diffusivities were correlated with ALFF in the sensorimotor-motor regions (all P values <0.05), and ALPS and ALFF correlated with disease severity and duration (all P values <0.05). ALPS, diffusivities, and ALFF showed moderate ability to diagnose ALS.

Conclusions

The glymphatic system function was impaired in ALS. This may contribute to spontaneous neural activity disturbance and could represent a mechanism for the development of sensorimotor deficits frequently observed in patients with ALS.

Glycosphingolipids in neurodegeneration - Molecular mechanisms, cellular roles, and therapeutic perspectives

Neurodegenerative diseases, including Alzheimer's (AD), Parkinson's (PD), Huntington's (HD), and amyotrophic lateral sclerosis (ALS), are characterized by progressive neuronal loss and pose significant global health challenges. Glycosphingolipids (GSLs), critical components of neuronal membranes, regulate signal transduction, membrane organization, neuroinflammation, and lipid raft functionality. This review explores GSL roles in neural development, differentiation, and neurogenesis, along with their dysregulation in neurodegenerative diseases. Aberrations in GSL metabolism drive key pathological features such as protein aggregation, neuroinflammation, and impaired signaling. Specific GSLs, such as GM1, GD3, and GM3, influence amyloid-beta aggregation in AD, α-synuclein stability in PD, and mutant huntingtin toxicity in HD. Therapeutic strategies targeting GSL metabolism, such as GM1 supplementation and enzyme modulation, have demonstrated potential to mitigate disease progression. Further studies using advanced lipidomics and glycomics may support biomarker identification and therapeutic advancements. This work aims to highlight the translational potential of GSL research for diagnosing and managing devastating neurodegenerative conditions.

Amyotrophic lateral sclerosis in Argentina: unveiling the burden of treatment through patient and caregiver perspectives

PURPOSE

To examine the burden of treatment (BoT) experienced by people with Amyotrophic Lateral Sclerosis (ALS) in Argentina.

METHODS

Qualitative methodological design based on semi-structured interviews. Nineteen semi-structured interviews were conducted (PwALS = 7, informal caregivers= 12). The interview guides were designed based on the literature and BoT theory. Data were analysed following a framework analysis approach.

RESULTS

The research highlighted the arduous journey toward obtaining a diagnosis, marked by delays influenced by healthcare system inefficiencies, lack of disease awareness and pandemic-related anxiety. Receiving the diagnosis was a destabilising experience, triggering the need to reframe self-identity, a new reality. As the disease progressed, patients encountered significant challenges in their daily activities and basic tasks, affecting their ability to work, communicate, and manage personal care. The burden extended beyond the patients to their primary caregivers. Access to specialised care, bureaucratic complexities in securing treatment, and the financial impact of managing the disease posed substantial challenges.

CONCLUSION

The findings offer valuable insights into the experiences of PwALS and their caregivers in Argentina. They underscore the need for increased disease awareness, improved access to specialised care, and enhanced support networks to alleviate the burdens PwALS and their families face.

Associations of dietary factors with amyotrophic lateral sclerosis: A Mendelian randomization study

BACKGROUND

An inconsistent yet notable relationship between dietary habits and the risk of amyotrophic lateral sclerosis (ALS) has been previously established, with the causative nature of this relationship remaining uncertain. This study aims to explore the causal connections at a genetic level.

METHODS

A two-sample Mendelian Randomization (MR) based analysis was conducted utilizing a comprehensive, publicly assessable Genome-wide association study (GWAS) database. Fourteen dietary variables were examined as potential exposure factors, and the ALS outcome data was statistically analyzed. The inverse-variance weighted (IVW) approach was used as the primary analytical method, supplemented by sensitivity analyses to assess the reliability of our findings.

RESULTS

Our analysis identified significant protective effects against ALS from increased intake of water (fixed-effects IVW: OR = 0.700, 95 % CI: 0.524-0.935, P = 0.016), fresh fruit (random-effects IVW: OR = 0.561, 95 % CI: 0.361-0.871, P = 0.010), and cooked vegetable (fixed-effects IVW: OR = 0.200, 95 % CI: 0.090-0.445, P = 0.000). No significant associations were found for the other 11 dietary factors examined.

CONCLUSION

The study highlights the protective association of cooked vegetables and fresh fruit intake with ALS risk reduction. Additionally, an intriguing association between water intake and ALS was observed, warranting further investigation to elucidate the underlying mechanisms.

NERP-1 modifications in amyotrophic lateral sclerosis

VGF peptides, such as NERPs (neuroendocrine regulatory peptides 1 and 2), are derived from amino acids 282-306 and 313-350, respectively, of the human proVGF, which is produced in spinal cord motor neurons. Although certain VGF-derived peptides are changed in ALS, less is known about NERPs. Possible modulations of NERPs and additional VGF peptides (NAPP and TPGH) were investigated using specific antibodies through competitive ELISA in the plasma of ALS patients (at both the initial and advanced phases; n = 46 each vs. 46 controls). As additional controls, naïve PD patients were also enrolled (n = 19 vs. 18 controls) while the potential VGF peptide role in oxidative stress was investigated using a motoneuron-like cell line (NSC34) stressed with sodium arsenate (SA). Western blot (WB) and sephadex chromatography (SC) were used to identify the molecular weight (MW) forms recognized by the VGF antibodies. Exclusively NERP-1 immunoreactivity was changed (elevated) in all plasma samples of ALS patients (compared to controls). Therefore, the NERP-1 antibody was the sole antibody used in ELISA with PD samples and NSC-34 cells. No alterations were seen in PD samples (vs. controls) while NERP-1 immunoreactivity decreased within SA-treated cells but increased in their culture medium. The viability test performed by adding NERP-1 to the stressed cells showed no protective effect. Using WB and SC, we revealed NERP-1 antibody reactivity against various MW forms, including those compatible with the NERP-1 peptide and/or proVGF. NERP-1 is suggested as a possible ALS blood biomarker.

Drug repurposing in amyotrophic lateral sclerosis (ALS)

INTRODUCTION

Identifying treatments that can alter the natural history of amyotrophic lateral sclerosis (ALS) is challenging. For years, drug discovery in ALS has relied upon traditional approaches with limited success. Drug repurposing, where clinically approved drugs are reevaluated for other indications, offers an alternative strategy that overcomes some of the challenges associated with de novo drug discovery.

AREAS COVERED

In this review, the authors discuss the challenge of drug discovery in ALS and examine the potential of drug repurposing for the identification of new effective treatments. The authors consider a range of approaches, from screening in experimental models to computational approaches, and outline some general principles for preclinical and clinical research to help bridge the translational gap. Literature was reviewed from original publications, press releases and clinical trials.

EXPERT OPINION

Despite remaining challenges, drug repurposing offers the opportunity to improve therapeutic options for ALS patients. Nevertheless, stringent preclinical research will be necessary to identify the most promising compounds together with innovative experimental medicine studies to bridge the translational gap. The authors further highlight the importance of combining expertise across academia, industry and wider stakeholders, which will be key in the successful delivery of repurposed therapies to the clinic.

Scientific plurality and amyotrophic lateral sclerosis (ALS): A philosophical and historical perspective on Charcot's texts

The history of amyotrophic lateral sclerosis (ALS)-also known as Charcot's disease, Lou Gehrig's disease, and motor neuron disease (MND)-freezes the texts of the scientist and physician Jean-Martin Charcot in a hagiographic narrative describing a brilliant discovery, based on the anatomo-clinical method. This narrative is often used by biologists and physicians as a reference point. This article shows that the use of the hagiographic register faces limitations. In particular, it obscures points of interest from Charcot's texts on ALS, such as the epistemological and ontological implications of scientific plurality in medicine. Although Charcot recognized the importance of scientific plurality in medicine, he prioritized the approaches and conferred the most important epistemic authority on clinical and pathological observations. In his view, animal modeling remains secondary to the understanding of disease. The concept of ALS and its diagnostic operability are the result of symptoms and lesions. By studying the past, we can highlight the specific features of the present. Today, although the ALS concept retains its diagnostic and clinical relevance, it is increasingly called into question in etiological and mechanistic research. Despite these differences, Charcot's reflections are a reminder of the importance of theoretical thinking on scientific plurality, all the more so today in the context of ALS research, in which combining different approaches is increasingly valued to understand the phenotypic and genetic heterogeneity of ALS.

Enhanced Acute Muscle Activation in ALS Patients Following Liposomal Curcumin, Resveratrol, and Dutasteride Administration

Introduction: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by loss of electrical activity and motor control at the muscular level. Therapeutic alternatives, such as the polyphenolic antioxidants curcumin and resveratrol in liposome form, or the drug dutasteride, could be effective for muscular activity. Objective: To measure the acute change in electrical muscle activation after administration of a combination of curcumin in liposomal form, resveratrol, and dutasteride in patients with ALS. Materials and methods: Patients with bulbar and spinal ALS were selected and randomly distributed into an intervention group (IG), which received an oral combination of curcumin in liposomal form/resveratrol® and dutasteride for 2 months, and a control group (CG), which received a placebo. Electrical activity to determine basal muscle activation and fasciculations was measured before and after the intervention using surface electromyography of the biceps brachii (BB), triceps brachii (TB), rectus femoris (RF), and tibialis anterior (TA). Within comparisons of pre and post-muscular variations in each group were conducted. Results: Electrical basal activity increased only for the IG in the right (p = 0.05; g = -0.45) and left (p = 0.004; g = -0.74) hemibody muscles and also presented less variation among them after treatment in the IG. For fasciculations, there was an increase in the total activation of the upper muscles in the IG (p = 0.017; g = -0.86) and for the lower muscles in the CG (p = 0.037; g = -0.68). The pattern of muscle activation remained constant in the IG but experienced variations in the CG.

Dysfunctional Mitochondria Characterize Amyotrophic Lateral Sclerosis Patients' Cells Carrying the p.G376D TARDBP Pathogenetic Substitution

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease caused by the degeneration of upper and lower motor neurons in the brain, brainstem and spinal cord. About 10% of familial ALS cases are linked to pathogenetic substitution in TARDBP, the gene encoding the TDP-43 protein. A novel rare causative variant in TARDBP (p.G376D) was recently reported in ALS patients. It leads to TDP-43 cytoplasmic mislocalization, increased oxidative stress and reduced cell viability. However, functional studies on the effects of this molecular defect have not yet been carried out. Mitochondria are highly dynamic organelles, and their deregulation has emerged as a key factor in many diseases, among which is ALS. Therefore, this study aimed at determining the impact of this causative variant on mitochondria. In cellular models expressing TDP-43G376D and in fibroblasts derived from patients carrying this molecular defect, we observed alterations of mitochondrial functionality. We demonstrated increased localization of the mutated protein to mitochondria and a reduced abundance of subunits of complex I and complex II of the mitochondrial respiratory chain, associated with a decrease in mitochondrial membrane potential, in cellular respiration and in cytochrome C oxidase (COX) activity. Moreover, ALS cells showed increased mitochondrial fragmentation and reduced abundance of antioxidant enzymes causing increased oxidative stress. These results expand our knowledge about the molecular mechanisms underlying ALS pathogenesis associated with TDP-43 p.G376D and could help to identify new therapeutic strategies to counteract this disease.

Targeting senescence in Amyotrophic Lateral Sclerosis: senolytic treatment improves neuromuscular function and preserves cortical excitability in a TDP-43Q331K mouse model

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder marked by progressive motor neuron degeneration in the primary motor cortex (PMC) and spinal cord. Aging is a key factor in ALS onset and progression, with evidence suggesting that biological aging-a process involving cellular decline- far outpaces chronological aging in ALS. This promotes senescent cell accumulation-marked by irreversible cell-cycle arrest, impaired apoptosis, and chronic inflammation-disrupting tissue homeostasis and impairing neuronal support functions. Thus, targeting senescence presents a novel therapeutic strategy for ALS. Here, we investigated the senolytic combination Dasatinib and Quercetin (D&Q) in TDP-43Q331K ALS mice. D&Q improved neuromuscular function and reduced plasma neurofilament light chain, a biomarker of axonal damage. The most pronounced improvement was the improved cortical excitability, accompanied by reductions in senescence and TDP-43 in the PMC. These findings highlight the potential of senolytics to mitigate ALS-related dysfunction, supporting their viability as a therapeutic strategy.

Molecular mechanisms and biomarkers in neurodegenerative disorders: a comprehensive review

Neurodegenerative disorders, including Alzheimer's disease (AD), Parkinson's disease (PD), Amyotrophic Lateral Sclerosis (ALS), and Huntington's disease (HD), are significant global health challenges, owing to their profound impact on cognitive, motor, and behavioral functions. The etiology and progression of these disorders are influenced by a complex interplay of environmental factors and genetic predispositions with specific genetic markers, such as mutations in the APOE and HTT genes, which play pivotal roles. Current therapeutic interventions predominantly focus on symptom management; however, emerging strategies, including gene therapies, anti-amyloid agents, and neuroprotective approaches, are designed to directly target the underlying disease mechanisms. Advances in biomarker discovery and imaging methodologies have emerged as essential tools for early diagnosis and monitoring of therapeutic efficacy in these disorders. In the context of AD, cerebrospinal fluid (CSF) amyloid-beta (Aβ) and tau levels, along with positron emission tomography (PET) imaging, are well-established biomarkers. Similarly, CSF alpha-synuclein and dopamine transporter (DAT) imaging have been employed as diagnostic tools for PD. Moreover, emerging biomarkers, such as blood-based tau and the Aβ42/40 ratio for AD, as well as the neurofilament light chain (NfL) for ALS and PD, hold promise for enhancing early diagnostic accuracy and facilitating the longitudinal assessment of disease progression. This study comprehensively examined the molecular mechanisms underlying these neurodegenerative disorders, focusing on amyloid-beta plaque deposition and tau protein aggregation in AD, alpha-synuclein misfolding in PD, and aberrant protein aggregation in ALS and HD, thereby contributing to a deeper understanding of the pathophysiological basis of these disorders.

Targeting TDP-43 Proteinopathy in hiPSC-Derived Mutated hNPCs with Mitoxantrone Drugs and miRNAs

Background/Objectives: TDP-43 mutation-driven Amyotrophic Lateral Sclerosis (ALS) motor neuron disease is one of the most prominent forms (approximately 97%) in cases of sporadic ALS. Dysfunctional autophagy and lysosomal function are the prime mechanisms behind ALS. Mitoxantrone (Mito), a synthetic doxorubicin analog, is an inhibitor of DNA and RNA synthesis/repair via intercalating with nitrogenous bases and inhibiting topoisomerase II. The therapeutic potential of miRNAs associated with disease conditions has also been reported. This study explores the therapeutic potential of Mito along with miRNAs against mutated TDP-43 protein-induced proteinopathy in human-induced pluripotent stem cell (hiPSC)-derived human neural progenitor cells (hNPCs). Methods: HiPSCs mutated for TDP-43 were differentiated into hNPCs and used to explore the therapeutic potential of Mito at a concentration of 1 μM for 24 h (the identified non-cytotoxic dose). The therapeutic effects of Mito on miRNA expression and various cellular parameters such as mitochondrial dynamics, autophagy, and stress granules were assessed using the high-throughput Open Array technique, immunocytochemistry, flow cytometry, immunoblotting, and mitochondrial bioenergetic assay. Results: Mutated TDP-43 protein accumulation causes stress granule formation (G3BP1), mitochondrial bioenergetic dysfunction, SOD1 accumulation, hyperactivated autophagy, and ER stress in hNPCs. The mutated hNPCs also show dysregulation in six miRNAs (miR-543, miR-34a, miR-200c, miR-22, miR-29b, and miR-29c) in mutated hNPCs. A significant restoration of TDP-43 mutation-induced alterations could be witnessed upon the exposure of mutated hNPCs to Mito. Conclusions: Our study indicates that miR-543, miR-29b, miR-22, miR-200c, and miR-34a have antisense therapeutic potential alone and in combination with Mitoxantrone.

VGF and Its Derived Peptides in Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by a progressive degeneration in the neurons of the frontal cortex, spinal cord, and brainstem, altering the correct release of neurotransmitters. The disease affects every muscle in the body and could cause death three to five years after symptoms first occur. There is currently no efficient treatment to stop the disease's progression. The lack of identification of potential therapeutic strategies is a consequence of the delayed diagnosis due to the absence of accurate ALS early biomarkers. Indeed, neurotransmitters altered in ALS are not measurable in body fluids at quantities that allow for testing, making their use as diagnostic tools a challenge. Contrarily, neuroproteins and neuropeptides are chemical messengers produced and released by neurons, and most of them have the potential to enter bodily fluids. To find out new possible ALS biomarkers, the research of neuropeptides and proteins is intensified using mass spectrometry and biochemical-based assays. Neuropeptides derived from the proVGF precursor protein act as signaling molecules within neurons. ProVGF and its derived peptides are expressed in the nervous and endocrine systems but are also widely distributed in body fluids such as blood, urine, and cerebrospinal fluid, making them viable options as disease biomarkers. To highlight the proVGF and its derived peptides' major roles as ALS diagnostic biomarkers, this review provides an overview of the VGF peptide alterations in spinal cord and body fluids and outlines the limitations of the reported investigations.

Lysosomal Dysfunction in Amyotrophic Lateral Sclerosis: A Familial Case Linked to the p.G376D TARDBP Mutation

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease affecting motor neurons. Consequent to the loss of these cells, neuromuscular functions decline, causing progressive weakness, muscle wasting, and paralysis, leading to death in 2 to 5 years. More than 90% of ALS cases are sporadic, while the remaining 10% of cases are familial, due to mutations in 40 different genes. One of the most common genes to be mutated in ALS is TARDBP (transactive response DNA binding protein 43), which encodes TDP-43 (TAR DNA-binding protein 43). A mutation in exon 6 of TARDBP causes the aminoacidic substitution G376D in the C-terminal region of TDP-43, leading to its cytoplasmic mislocalization and aggregation. In fibroblasts derived from patients carrying this mutation, we found a strong increase in lysosome number, with overexpression and higher nuclear translocation of the transcription factor TFEB. In contrast, lysosomal functionality was deeply compromised. Interestingly, lysosomal activity was unaffected at an early stage of the disease, worsening in more advanced stages. Moreover, we observed the same pathological phenotype in iPSC (induced pluripotent stem cells)-derived patient motor neurons carrying the G376D mutation. Therefore, this mutation compromises the functionality of lysosomes, possibly contributing to neurodegeneration.

Extracellular Vesicles from Regenerating Skeletal Muscle Mitigate Muscle Atrophy in an Amyotrophic Lateral Sclerosis Mouse Model

Amyotrophic lateral sclerosis (ALS) is a devastating neuromuscular disease characterized by progressive motor neuron degeneration and muscle atrophy, with no effective treatments available. Chronic inflammation, which impairs muscle regeneration and promotes proteolysis, is a key contributor to ALS-related muscle atrophy and a promising therapeutic target. Here, we applied extracellular vesicles (EVs) derived from regenerating skeletal muscles 14 days post-acute injury (CTXD14SkM-EVs), which possess a unique anti-inflammatory profile, to target muscle defects in ALS. We found that CTXD14SkM-EVs enhanced myoblast differentiation and fusion in a cellular muscle-wasting model induced by pro-inflammatory cytokine tumor necrosis factor alpha. Intramuscular administration of these EVs into an ALS mouse model mitigated muscle atrophy by promoting muscle regeneration, shifting macrophage polarization from pro-inflammatory M1 to anti-inflammatory M2 state, and suppressing the aberrant Nuclear Factor Kappa B (NF-κB) signaling, a key driver of muscle protein degradation. These results underscore the therapeutic potential of regenerating muscle-derived EVs for combating muscle atrophy in ALS.

Improved Pharyngeal Contraction and Oral Intake Status After Modified Central-Part Laryngectomy for Late-Stage ALS

OBJECTIVE

To investigate the effects of modified central-part laryngectomy with pharyngeal space reduction (CPL-PR) on patients with weak deglutitive pharyngeal contraction, as seen in late-stage amyotrophic lateral sclerosis (ALS).

STUDY DESIGN

Retrospective case series.

SETTING

Single-institution academic center.

METHODS

Patients with late-stage ALS confined at The University of Tokyo Hospital between 2019 and March 2024 in whom CPL-PR had been performed were identified. Patients who had undergone simultaneous pharyngeal flap surgery or had no preoperative high-resolution manofluorography done were excluded. Preoperatively, penetration-aspiration scale (PAS) scores were determined via videofluoroscopic swallowing study. Functional oral intake scale (FOIS) scores and high-resolution manometric parameters were measured and compared preoperatively and postoperatively.

RESULTS

Eighteen patients were identified with a median age of 66.5 (interquartile range [IQR]: 58.0-74.8). The median preoperative PAS score was 7.5 (IQR: 5.5-8.0), indicating severe dysphagia. There was significant improvement in oral intake status with FOIS scores increasing from 1 (IQR: 1-1) to 3 (IQR: 2-3) at 3 months postoperatively (P = .0002). Significant increases in velopharyngeal closure integral (P = .024) and mesohypopharyngeal contractile integral (P = .0001) were observed. Upper esophageal sphincter (UES) resting pressure was reduced (P = .0002), and UES relaxation time was prolonged during swallowing (P < .0001).

CONCLUSION

There were tangible improvements in pharyngeal contraction, UES bolus passage, and oral intake status following CPL-PR, which contribute to regaining oral intake in late-stage ALS. CPL-PR is an option for patients requiring tracheostomy who wish to prevent aspiration and regain their ability to take food orally.

Image-Guided Monitoring of Mitochondria and Blood-Brain Barrier Dysfunction in Amyotrophic Lateral Sclerosis Mice

Early detection of amyotrophic lateral sclerosis (ALS) progression is critical for improving disease management and therapeutic outcomes. However, the clinical heterogeneity and variability in ALS symptoms often lead to delayed diagnosis and suboptimal therapeutic interventions. Since mitochondrial dysfunction is a hallmark of ALS, we hypothesized that monitoring mitochondrial function could serve as a reliable strategy for early diagnosis and therapeutic monitoring of ALS. To address this, we synthesized and characterized 2 novel near-infrared fluorophores, ALS04 and ALS05, designed to target mitochondria and lysosomes. Their physicochemical properties, serum protein binding, fluorescence characteristics, photostability, and pharmacokinetics were systematically evaluated. We found that benzothiazole-based fluorophores exhibit excellent mitochondrial targeting, optimal optical properties, biocompatibility, and favorable biodistribution in vivo. Interestingly, ALS04 showed superior mitochondrial accumulation compared to ALS05, despite their similar physicochemical properties. This enhanced accumulation can be attributed to the lower molecular weight and higher lipophilicity of ALS04. Real-time fluorescence imaging revealed a substantial reduction in ALS04 signals in mitochondrial-rich tissues such as brown fat, highlighting its potential for monitoring mitochondrial dysfunction in early-stage ALS. Furthermore, the detection of ALS04 in the mouse brain suggests its ability to monitor blood-brain barrier hyperpermeability, another key feature of ALS pathology. These findings establish ALS04 as a promising noninvasive imaging tool for monitoring biomarkers associated with ALS progression. Its ability to detect early-stage pathophysiological changes in an ALS mouse model highlights its potential for advancing our understanding of ALS mechanisms and facilitating the identification of novel therapeutic targets.

Exosomes as Biomarkers and Therapeutic Agents in Neurodegenerative Diseases: Current Insights and Future Directions

Neurodegenerative diseases (NDs) like Alzheimer's, Parkinson's, and ALS rank among the most challenging global health issues, marked by substantial obstacles in early diagnosis and effective treatment. Current diagnostic techniques frequently demonstrate inadequate sensitivity and specificity, whilst conventional treatment strategies encounter challenges related to restricted bioavailability and insufficient blood-brain barrier (BBB) permeability. Recently, exosomes-nanoscale vesicles packed with proteins, RNAs, and lipids-have emerged as promising agents with the potential to reshape diagnostic and therapeutic approaches to these diseases. Unlike conventional drug carriers, they naturally traverse the BBB and can deliver bioactive molecules to affected neural cells. Their molecular cargo can influence cell signaling, reduce neuroinflammation, and potentially slow neurodegenerative progression. Moreover, exosomes serve as non-invasive biomarkers, enabling early and precise diagnosis while allowing real-time disease monitoring. Additionally, engineered exosomes, loaded with therapeutic molecules, enhance this capability by targeting diseased neurons and overcoming conventional treatment barriers. By offering enhanced specificity, reduced immunogenicity, and an ability to bypass physiological limitations, exosome-based strategies present a transformative advantage over existing diagnostic and therapeutic approaches. This review examines the multifaceted role of exosomes in NDDs, emphasizing their diagnostic capabilities, intrinsic therapeutic functions, and transformative potential as advanced treatment vehicles.

A molecular systems architecture of neuromuscular junction in amyotrophic lateral sclerosis

A molecular systems architecture is presented for the neuromuscular junction (NMJ) in order to provide a framework for organizing complexity of biomolecular interactions in amyotrophic lateral sclerosis (ALS) using a systematic literature review process. ALS is a fatal motor neuron disease characterized by progressive degeneration of the upper and lower motor neurons that supply voluntary muscles. The neuromuscular junction contains cells such as upper and lower motor neurons, skeletal muscle cells, astrocytes, microglia, Schwann cells, and endothelial cells, which are implicated in pathogenesis of ALS. This molecular systems architecture provides a multi-layered understanding of the intra- and inter-cellular interactions in the ALS neuromuscular junction microenvironment, and may be utilized for target identification, discovery of single and combination therapeutics, and clinical strategies to treat ALS.

Intercellular communication via exosomes: A new paradigm in the pathophysiology of neurodegenerative disorders

Neurodegenerative disorders are one of the leading causes of death and disability and pose a great economic burden on healthcare systems. Generally, these neurodegenerative disorders have a progressive deterioration in neural function and structure, and deposition of misfolded proteins commonly occurs, such as amyloid-β in AD and α-synuclein in PD. However, there exists a special class of exosomes, which acts like a transmitter and enhances communication between cells. The present review discusses the significant role of exosomes in neurodegenerative diseases, with a focus on Amyotrophic lateral Sclerosis (ALS), AD, PD, and Huntington's disease (HD). In this review, the biogenesis of exosomes is discussed from multivesicular bodies and onwards to their release into the extracellular environment. The present review focuses on recent data concerning the possible use of modified exosomes as ND therapy. Indeed, future work is needed to explain the processes driving exosome biogenesis and cargo selection, while opening new routes by the use of exosome-based therapeutics in neurodegenerative disease diagnosis and treatment.

The phenotyping dilemma in VRK1-related motor neuron disease: a Turkish family with young-onset amyotrophic lateral sclerosis caused by a novel mutation

Objective: Vaccinia-related kinase 1 (VRK1)-related disease is an extremely rare autosomal recessive disorder primarily affecting the peripheral and/or central nervous system. In this report, we describe the genetic and clinical features of two siblings from a Turkish family presenting with an amyotrophic lateral sclerosis (ALS) phenotype due to a novel homozygous VRK1 mutation, and discuss the broad phenotypic spectrum associated with pathogenic variants in this gene. Methods: We analyzed the demographic data, clinical histories, neurological examinations, laboratory findings, and genetic results of 53 patients, including our cases, derived from 27 different reports. Results: Whole-exome sequencing identified a novel homozygous missense mutation, c.700A > G (p.Asn234Asp), in the VRK1 gene in two affected siblings. The characteristic features of the ALS phenotype included a recessive inheritance pattern, motor deficits with onset in the lower limbs, pyramidal tract signs, and a muscle magnetic resonance imaging (MRI) pattern demonstrating preferential involvement of the posterior compartments of the leg and thigh. The most common phenotypes associated with VRK1 mutations were ALS (18/53, 34%) and distal hereditary motor neuropathy (dHMN) (14/53, 26.4%), followed by pontocerebellar hypoplasia type 1 (7/53, 13.2%), hereditary motor and sensory neuropathy (5/53, 9.4%), autosomal recessive primary microcephaly with brain malformations (4/53, 7.5%), and spastic paraplegia (2/53, 3.8%). The ALS phenotype exhibited a significantly earlier mean age of onset compared to the dHMN phenotype (p = 0.015; 15.3 ± 11.5 and 27 ± 15.5 years, respectively). Conclusion: Our findings highlight the importance of investigating VRK1 mutations in patients with young-onset familial ALS. Furthermore, this report provides a systematic classification of the phenotype definitions associated with VRK1 mutations.