Epidemiology of amyotrophic lateral sclerosis: an update of recent literature

SOD1 in ALS: Taking Stock in Pathogenic Mechanisms and the Role of Glial and Muscle Cells

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder characterized by the loss of motor neurons in the brain and spinal cord. While the exact causes of ALS are still unclear, the discovery that familial cases of ALS are related to mutations in the Cu/Zn superoxide dismutase (SOD1), a key antioxidant enzyme protecting cells from the deleterious effects of superoxide radicals, suggested that alterations in SOD1 functionality and/or aberrant SOD1 aggregation strongly contribute to ALS pathogenesis. A new scenario was opened in which, thanks to the generation of SOD1 related models, different mechanisms crucial for ALS progression were identified. These include excitotoxicity, oxidative stress, mitochondrial dysfunctions, and non-cell autonomous toxicity, also implicating altered Ca2+ metabolism. While most of the literature considers motor neurons as primary target of SOD1-mediated effects, here we mainly discuss the effects of SOD1 mutations in non-neuronal cells, such as glial and skeletal muscle cells, in ALS. Attention is given to the altered redox balance and Ca2+ homeostasis, two processes that are strictly related with each other. We also provide original data obtained in primary myocytes derived from hSOD1(G93A) transgenic mice, showing perturbed expression of Ca2+ transporters that may be responsible for altered mitochondrial Ca2+ fluxes. ALS-related SOD1 mutants are also responsible for early alterations of fundamental biological processes in skeletal myocytes that may impinge on skeletal muscle functions and the cross-talk between muscle cells and motor neurons during disease progression.

1,2-Dehydropyrrolizidine Alkaloids: Their Potential as a Dietary Cause of Sporadic Motor Neuron Diseases

Sporadic motor neuron diseases (MNDs), such as amyotrophic lateral sclerosis (ALS), can be caused by spontaneous genetic mutations. However, many sporadic cases of ALS and other debilitating neurodegenerative diseases (NDDs) are believed to be caused by environmental factors, subject to considerable debate and requiring intensive research. A common pathology associated with MND development involves progressive mitochondrial dysfunction and oxidative stress in motor neurons and glial cells of the central nervous system (CNS), leading to apoptosis. Consequent degeneration of skeletal and respiratory muscle cells can lead to death from respiratory failure. A significant number of MND cases present with cancers and liver and lung pathology. This Perspective explores the possibility that MNDs could be caused by intermittent, low-level dietary exposure to 1,2-dehydropyrrolizidine alkaloids (1,2-dehydroPAs) that are increasingly recognized as contaminants of many foods consumed throughout the world. Nontoxic, per se, 1,2-dehydroPAs are metabolized, by particular cytochrome P450 (CYP450) isoforms, to 6,7-dihydropyrrolizines that react with nucleophilic groups (-NH, -SH, -OH) on DNA, proteins, and other vital biochemicals, such as glutathione. Many factors, including aging, gender, smoking, and alcohol consumption, influence CYP450 isoform activity in a range of tissues, including glial cells and neurons of the CNS. Activation of 1,2-dehydroPAs in CNS cells can be expected to cause gene mutations and oxidative stress, potentially leading to the development of MNDs and other NDDs. While relatively high dietary exposure to 1,2-dehydroPAs causes hepatic sinusoidal obstruction syndrome, pulmonary venoocclusive disease, neurotoxicity, and diverse cancers, this Perspective suggests that, at current intermittent, low levels of dietary exposure, neurotoxicity could become the primary pathology that develops over time in susceptible individuals, along with a tendency for some of them to also display liver and lung pathology and diverse cancers co-occurring with some MND/NDD cases. Targeted research is recommended to investigate this proposal.

Inter-Species Rescue of Mutant Phenotype-The Standard for Genetic Analysis of Human Genetic Disorders in Drosophila melanogaster Model

Drosophila melanogaster (the fruit fly) is arguably a superstar of genetics, an astonishing versatile experimental model which fueled no less than six Nobel prizes in medicine. Nowadays, an evolving research endeavor is to simulate and investigate human genetic diseases in the powerful D. melanogaster platform. Such a translational experimental strategy is expected to allow scientists not only to understand the molecular mechanisms of the respective disorders but also to alleviate or even cure them. In this regard, functional gene orthology should be initially confirmed in vivo by transferring human or vertebrate orthologous transgenes in specific mutant backgrounds of D. melanogaster. If such a transgene rescues, at least partially, the mutant phenotype, then it qualifies as a strong candidate for modeling the respective genetic disorder in the fruit fly. Herein, we review various examples of inter-species rescue of relevant mutant phenotypes of the fruit fly and discuss how these results recommend several human genes as candidates to study and validate genetic variants associated with human diseases. We also consider that a wider implementation of this evolutionist exploratory approach as a standard for the medicine of genetic disorders would allow this particular field of human health to advance at a faster pace.

Comprehensive Research on Past and Future Therapeutic Strategies Devoted to Treatment of Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a rapidly debilitating fatal neurodegenerative disorder, causing muscle atrophy and weakness, which leads to paralysis and eventual death. ALS has a multifaceted nature affected by many pathological mechanisms, including oxidative stress (also via protein aggregation), mitochondrial dysfunction, glutamate-induced excitotoxicity, apoptosis, neuroinflammation, axonal degeneration, skeletal muscle deterioration and viruses. This complexity is a major obstacle in defeating ALS. At present, riluzole and edaravone are the only drugs that have passed clinical trials for the treatment of ALS, notwithstanding that they showed modest benefits in a limited population of ALS. A dextromethorphan hydrobromide and quinidine sulfate combination was also approved to treat pseudobulbar affect (PBA) in the course of ALS. Globally, there is a struggle to prevent or alleviate the symptoms of this neurodegenerative disease, including implementation of antisense oligonucleotides (ASOs), induced pluripotent stem cells (iPSCs), CRISPR-9/Cas technique, non-invasive brain stimulation (NIBS) or ALS-on-a-chip technology. Additionally, researchers have synthesized and screened new compounds to be effective in ALS beyond the drug repurposing strategy. Despite all these efforts, ALS treatment is largely limited to palliative care, and there is a strong need for new therapeutics to be developed. This review focuses on and discusses which therapeutic strategies have been followed so far and what can be done in the future for the treatment of ALS.

Reflections of family caregivers and health professionals on the everyday challenges of caring for persons with amyotrophic lateral sclerosis and cognitive impairments: a qualitative study

Aims and objectives:

To explore reflections of family caregivers and health professionals regarding the challenges involved in caring for persons with amyotrophic lateral sclerosis and cognitive and/or behavioral impairments (PALS/CIs).

Background:

Family caregivers of PALS/CIs are highly burdened and at great risk of psychological sequela. Professionals working with these families can be negatively affected on their well-being and are at risk of burnout.

Design:

The design was a qualitative interview study.

Methods:

One focus group and 10 individual semi-structured interviews were conducted with seven family caregivers and nine professionals after the death of a PALS/CIs. The analysis was guided by the interpretive description methodology and the theory of sense of coherence. This study adheres to the COREQ guidelines and the ICMJE recommendations.

Results:

The family caregivers’ challenges regarding coping with everyday needs related to the sick person were associated with ‘Accepting that nothing else matters’, ‘Adjusting to new roles while balancing’, and ‘Realizing different values in relationships’; whereas the professionals’ challenges were related to ‘Collaboration a balancing act’, ‘Working in a home of sorrow’, and ‘Coordinating threads to tie’.

Conclusion:

Family caregivers found coping with the complexity of the diseases a challenge, and their everyday life needed constant adjustment to new roles, coping with inappropriate behavior, and navigating through the progression of the diseases of their sick relatives while collaborating with numerous professionals. The professionals struggled with coordinating and collaborating with the families and with other colleagues due to the severeness and complexity of diseases.

Relevance to clinical practice:

Findings point to the importance of relationships for caregivers and professionals and a need to provide support through an online palliative rehabilitation program that encompass coping strategies in relation to the diseases.

Trial registration details:

Id no. NCT 04638608.

Emerging Roles for Phase Separation of RNA-Binding Proteins in Cellular Pathology of ALS

Liquid-liquid phase separation (LLPS) is emerging as a major principle for the mesoscale organization of proteins, RNAs, and membrane-bound organelles into biomolecular condensates. These condensates allow for rapid cellular responses to changes in metabolic activities and signaling. Nowhere is this regulation more important than in neurons and glia, where cellular physiology occurs simultaneously on a range of time- and length-scales. In a number of neurodegenerative diseases, such as Amyotrophic Lateral Sclerosis (ALS), misregulation of biomolecular condensates leads to the formation of insoluble aggregates-a pathological hallmark of both sporadic and familial ALS. Here, we summarize how the emerging knowledge about the LLPS of ALS-related proteins corroborates with their aggregation. Understanding the mechanisms that lead to protein aggregation in ALS and how cells respond to these aggregates promises to open new directions for drug development.

Previous psychiatric disorders in the multistep hypothesis of amyotrophic lateral sclerosis: a South Korean population study

Objective: There is accumulating evidence about an association between amyotrophic lateral sclerosis (ALS) and psychiatric disorders. We aimed to investigate the prevalence of previous psychiatric disorders before ALS onset and evaluate the contribution of psychiatric disorders to the number of steps toward developing ALS.Methods: We analyzed the National Health Insurance claims data from 2011 to 2017 and calculated the incidence of ALS. We created a multistep model using the linear least squares method with regression of the log incidence against the log age.Results: The mean annual incidence of ALS was 0.95/100,000 and frequency of familial ALS (fALS) was 5.89%. The proportions of patients who had psychiatric disorders before ALS diagnosis were 36.8% and 47.0% in fALS and sporadic ALS (sALS), respectively (p = 0.009). In both fALS and sALS, depressive disorders and anxiety and stress disorders were relatively frequent, whereas psychotic disorders and bipolar disorders were rare. Further, the slope estimates for regression analyses were 3.50 (R² = 0.94) and 3.56 (R² = 0.99) for fALS and sALS, respectively, suggesting a 4-5-step process to ALS onset. However, slope estimates did not differ between sALS patients with pre-symptomatic psychiatric disorders and those without.Conclusions: The incidence of ALS is relatively low in Korea and fewer steps are required to develop ALS compared to Western populations (all 6 steps). Although the prevalence of previous depression or anxiety is seemingly high, the multistep model provides no evidence that these conditions modify the risk of developing ALS in our cohort.

Central nervous system organoids for modeling neurodegenerative diseases

Recent advances in induced pluripotent stem cell (iPSC) technology have allowed researchers to generate neurodegenerative disease-specific iPSCs and use the cells to derive a variety of relevant cell populations for laboratory modeling and drug testing. Nevertheless, these efforts have faced challenges related to immaturity and lack of complex developmental niches in the derived cell populations, limiting the utility of these in vitro models of neurodegenerative disease. Such limitations may be overcome by using human iPSC technology to generate three-dimensional (3D) brain organoids, which better recapitulate in vivo tissue architecture than traditional neuronal cultures to provide more complex and representative disease models and drug testing systems. In this review, we focus on the application of pluripotent stem cell-derived central nervous system (CNS) organoids to model neurodegenerative diseases. We first summarize recent progress in generating and characterizing various CNS organoids from pluripotent stem cells. We then review the application of CNS organoids for modeling several different human neurodegenerative diseases. We also describe several novel pathological mechanisms and drugs that were studied using patient iPSC-derived CNS organoids. Finally, we discuss remaining challenges and emerging opportunities for the use of 3D brain organoids for in vitro modeling of CNS development and neurodegeneration.

Protein Arginine Methyltransferases in Neuromuscular Function and Diseases

Neuromuscular diseases (NMDs) are characterized by progressive loss of muscle mass and strength that leads to impaired body movement. It not only severely diminishes the quality of life of the patients, but also subjects them to increased risk of secondary medical conditions such as fall-induced injuries and various chronic diseases. However, no effective treatment is currently available to prevent or reverse the disease progression. Protein arginine methyltransferases (PRMTs) are emerging as a potential therapeutic target for diverse diseases, such as cancer and cardiovascular diseases. Their expression levels are altered in the patients and molecular mechanisms underlying the association between PRMTs and the diseases are being investigated. PRMTs have been shown to regulate development, homeostasis, and regeneration of both muscle and neurons, and their association to NMDs are emerging as well. Through inhibition of PRMT activities, a few studies have reported suppression of cytotoxic phenotypes observed in NMDs. Here, we review our current understanding of PRMTs' involvement in the pathophysiology of NMDs and potential therapeutic strategies targeting PRMTs to address the unmet medical need.

High incidence of amyotrophic lateral sclerosis in the Faroe Islands 2010-2020

The Faroese population isolate harbors epidemiological and genetic characteristics that likely differ from outbred populations. This population-based register study found that the Faroese 2010-2020 crude incidence of amyotrophic lateral sclerosis (ALS) was 4.9/100,000 person-years (95% confidence interval [CI], 3.3-7.0) and the age- and sex-standardized incidence (US 2010 Census Population) was 4.1/100,000 person-years (95% CI, 2.7-6.0), which is a 68% increase from the 1987-2009 estimate. The 2020 crude prevalence was 9.5/100,000 (95% CI, 3.0-19.6) in a population of 52,912 inhabitants. Incidence and prevalence estimates of ALS in the Faroes are high and further research is warranted to uncover the genetic or environmental determinants of ALS in this population.

Altered Blood-Brain Barrier and Blood-Spinal Cord Barrier Dynamics in Amyotrophic Lateral Sclerosis: Impact on Medication Efficacy and Safety

The access of drugs into the central nervous system (CNS) is regulated by the blood-brain barrier (BBB) and blood-spinal cord barrier (BSCB). A large body of evidence supports perturbation of these barriers in neurodegenerative diseases, including Alzheimer's disease and Parkinson's disease. Modifications to the BBB and BSCB are also reported in amyotrophic lateral sclerosis (ALS), albeit these modifications have received less attention relative to those in other neurodegenerative diseases. Such alterations to the BBB and BSCB have the potential to impact on CNS exposure of drugs in ALS, modulating the effectiveness of drugs intended to reach the brain and the toxicity of drugs that are not intended to reach the brain. Given the clinical importance of these phenomena, this review will summarise reported modifications to the BBB and BSCB in ALS, discuss their impact on CNS drug exposure and suggest further research directions so as to optimise medicine use in people with ALS.

Organ on a Chip: A Novel in vitro Biomimetic Strategy in Amyotrophic Lateral Sclerosis (ALS) Modeling

Amyotrophic lateral sclerosis is a pernicious neurodegenerative disorder that is associated with the progressive degeneration of motor neurons, the disruption of impulse transmission from motor neurons to muscle cells, and the development of mobility impairments. Clinically, muscle paralysis can spread to other parts of the body. Hence it may have adverse effects on swallowing, speaking, and even breathing, which serves as major problems facing these patients. According to the available evidence, no definite treatment has been found for amyotrophic lateral sclerosis (ALS) that results in a significant outcome, although some pharmacological and non-pharmacological treatments are currently applied that are accompanied by some positive effects. In other words, available therapies are only used to relieve symptoms without any significant treatment effects that highlight the importance of seeking more novel therapies. Unfortunately, the process of discovering new drugs with high therapeutic potential for ALS treatment is fraught with challenges. The lack of a broad view of the disease process from early to late-stage and insufficiency of preclinical studies for providing validated results prior to conducting clinical trials are other reasons for the ALS drug discovery failure. However, increasing the combined application of different fields of regenerative medicine, especially tissue engineering and stem cell therapy can be considered as a step forward to develop more novel technologies. For instance, organ on a chip is one of these technologies that can provide a platform to promote a comprehensive understanding of neuromuscular junction biology and screen candidate drugs for ALS in combination with pluripotent stem cells (PSCs). The structure of this technology is based on the use of essential components such as iPSC- derived motor neurons and iPSC-derived skeletal muscle cells on a single miniaturized chip for ALS modeling. Accordingly, an organ on a chip not only can mimic ALS complexities but also can be considered as a more cost-effective and time-saving disease modeling platform in comparison with others. Hence, it can be concluded that lab on a chip can make a major contribution as a biomimetic micro-physiological system in the treatment of neurodegenerative disorders such as ALS.

How Molecular Topology Can Help in Amyotrophic Lateral Sclerosis (ALS) Drug Development: A Revolutionary Paradigm for a Merciless Disease

Even if amyotrophic lateral sclerosis is still considered an orphan disease to date, its prevalence among the population is growing fast. Despite the efforts made by researchers and pharmaceutical companies, the cryptic information related to the biological and physiological onset mechanisms, as well as the complexity in identifying specific pharmacological targets, make it almost impossible to find effective treatments. Furthermore, because of complex ethical and economic aspects, it is usually hard to find all the necessary resources when searching for drugs for new orphan diseases. In this context, computational methods, based either on receptors or ligands, share the capability to improve the success rate when searching and selecting potential candidates for further experimentation and, consequently, reduce the number of resources and time taken when delivering a new drug to the market. In the present work, a computational strategy based on Molecular Topology, a mathematical paradigm capable of relating the chemical structure of a molecule to a specific biological or pharmacological property by means of numbers, is presented. The result was the creation of a reliable and accessible tool to help during the early in silico stages in the identification and repositioning of potential hits for ALS treatment, which can also apply to other orphan diseases. Considering that further computational and experimental results will be required for the final identification of viable hits, three linear discriminant equations combined with molecular docking simulations on specific proteins involved in ALS are reported, along with virtual screening of the Drugbank database as a practical example. In this particular case, as reported, a clinical trial has been already started for one of the drugs proposed in the present study.

Proteinopathies as Hallmarks of Impaired Gene Expression, Proteostasis and Mitochondrial Function in Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a fatal adult-onset neurodegenerative disease characterized by progressive degeneration of upper and lower motor neurons. As with the majority of neurodegenerative diseases, the pathological hallmarks of ALS involve proteinopathies which lead to the formation of various polyubiquitylated protein aggregates in neurons and glia. ALS is a highly heterogeneous disease, with both familial and sporadic forms arising from the convergence of multiple disease mechanisms, many of which remain elusive. There has been considerable research effort invested into exploring these disease mechanisms and in recent years dysregulation of RNA metabolism and mitochondrial function have emerged as of crucial importance to the onset and development of ALS proteinopathies. Widespread alterations of the RNA metabolism and post-translational processing of proteins lead to the disruption of multiple biological pathways. Abnormal mitochondrial structure, impaired ATP production, dysregulation of energy metabolism and calcium homeostasis as well as apoptosis have been implicated in the neurodegenerative process. Dysfunctional mitochondria further accumulate in ALS motor neurons and reflect a wider failure of cellular quality control systems, including mitophagy and other autophagic processes. Here, we review the evidence for RNA and mitochondrial dysfunction as some of the earliest critical pathophysiological events leading to the development of ALS proteinopathies, explore their relative pathological contributions and their points of convergence with other key disease mechanisms. This review will focus primarily on mutations in genes causing four major types of ALS (C9ORF72, SOD1, TARDBP/TDP-43, and FUS) and in protein homeostasis genes (SQSTM1, OPTN, VCP, and UBQLN2) as well as sporadic forms of the disease. Finally, we will look to the future of ALS research and how an improved understanding of central mechanisms underpinning proteinopathies might inform research directions and have implications for the development of novel therapeutic approaches.

Functional ambulation decline and factors associated in amyotrophic lateral sclerosis

Abstract Introduction: Amyotrophic lateral sclerosis (ALS) is a disabling neurodegenerative disease, which compromises locomotion and functional independence. As the goal of physical therapy is to maintain the individual's locomotion capacity and independence as long as possible, it is necessary to gain a better understanding of the possible factors associated with the loss of this capacity. Objective: To evaluate functional ambulation in patients with ALS and possible factors associated with its decline. Methods: A cross-sectional study was conducted with sporadic ALS patients. Demographic and clinical/functional aspects were evaluated. ALS Functional Rating Scale-Revised (ALSFRS-R), Functional Ambulation Category, Medical Research Council scale and Fatigue Severity Scale were used. Descriptive and comparative analyses were conducted of the groups capable and incapable of functional ambulation. Binary logistic regression (stepwise forward method) was performed to determine potential factors associated with the loss of functional ambulation. Results: Among the 55 patients (mean age: 56.9 ± 11.2 years), 74.5% were able to walk functionally. Differences were found between groups regarding time of diagnosis, number of falls, pain, use of noninvasive ventilation, gastrostomy, ability to turn in bed, mobility aids, home adaptations, functional performance, muscle strength and fatigue. The possible predictors of walking disability were overall muscle strength (OR = 0.837; p = 0.003) and fatigue (OR =1.653; p = 0.034). Conclusion: Muscle strength and fatigue are associated with the decline in ambulation capacity in patients with ALS. In view of the complexity of elements involved in walking, further studies are needed to investigate the influence of these aspects in this population.

Cardiovascular comorbidities in amyotrophic lateral sclerosis: A systematic review

OBJECTIVE

To summarize the prevalence of the cardiovascular comorbidities in patients with amyotrophic lateral sclerosis (ALS) and explore the impacts of cardiovascular diseases on ALS.

METHODS

PubMed, EMBASE, OVID and Web of Science were searched systematically until July 2021 for studies on the prevalence of cardiovascular diseases among ALS patients or quantitatively investigating the effects of cardiovascular comorbidities on incidence, progression or survival of ALS. We conducted a fixed-effects or random-effects meta-analysis to calculate the summary rate or ORs (odds ratios) with 95 %CIs (confidence intervals).

RESULTS

The comorbidity of hypertension in France (56.9%) was the highest, followed by Portugal (48%). Only 15% of Chinese ALS patients suffered from hypertension. A quarter of ALS patients in America had coronary heart disease while only 4-5% of patients with ALS in Australia or the Netherlands suffered from coronary heart disease. There was significant relationship between hypertension and survival of ALS (OR: 1.04, 95%CI: 1.01, 1.07). Coronary heart disease was considerably related to ALS onset (OR: 1.19, 95%CI: 1.14, 1.24) and heart failure could noticeably accelerate the progression rate of ALS (OR: 6.33, 95%CI: 1.55, 24.84).

CONCLUSIONS

Cardiovascular comorbidities in ALS patients varied significantly with different regions. Hypertension could reduce the survival of ALS so the intensive treatment of chronic hypertension should be recommended to ALS patients in clinical practice. Coronary heart disease could increase the risk of ALS and heart failure was a negative prognostic factor for ALS, which deserved more attention of clinicians.

Hydrogen Peroxide and Amyotrophic Lateral Sclerosis: From Biochemistry to Pathophysiology

Free radicals are unstable chemical reactive species produced during Redox dyshomeostasis (RDH) inside living cells and are implicated in the pathogenesis of various neurodegenerative diseases. One of the most complicated and life-threatening motor neurodegenerative diseases (MND) is amyotrophic lateral sclerosis (ALS) because of the poor understanding of its pathophysiology and absence of an effective treatment for its cure. During the last 25 years, researchers around the globe have focused their interest on copper/zinc superoxide dismutase (Cu/Zn SOD, SOD1) protein after the landmark discovery of mutant SOD1 (mSOD1) gene as a risk factor for ALS. Substantial evidence suggests that toxic gain of function due to redox disturbance caused by reactive oxygen species (ROS) changes the biophysical properties of native SOD1 protein thus, instigating its fibrillization and misfolding. These abnormal misfolding aggregates or inclusions of SOD1 play a role in the pathogenesis of both forms of ALS, i.e., Sporadic ALS (sALS) and familial ALS (fALS). However, what leads to a decrease in the stability and misfolding of SOD1 is still in question and our scientific knowledge is scarce. A large number of studies have been conducted in this area to explore the biochemical mechanistic pathway of SOD1 aggregation. Several studies, over the past two decades, have shown that the SOD1-catalyzed biochemical reaction product hydrogen peroxide (H₂O₂) at a pathological concentration act as a substrate to trigger the misfolding trajectories and toxicity of SOD1 in the pathogenesis of ALS. These toxic aggregates of SOD1 also cause aberrant localization of TAR-DNA binding protein 43 (TDP-43), which is characteristic of neuronal cytoplasmic inclusions (NCI) found in ALS. Here in this review, we present the evidence implicating the pivotal role of H₂O₂ in modulating the toxicity of SOD1 in the pathophysiology of the incurable and highly complex disease ALS. Also, highlighting the role of H₂O₂ in ALS, we believe will encourage scientists to target pathological concentrations of H₂O₂ thereby halting the misfolding of SOD1.

Genetic architecture of motor neuron diseases

Motor neuron diseases (MNDs) are rare and frequently fatal neurological disorders in which motor neurons within the brainstem and spinal cord regions slowly die. MNDs are primarily caused by genetic mutations, and > 100 different mutant genes in humans have been discovered thus far. Given the fact that many more MND-related genes have yet to be discovered, the growing body of genetic evidence has offered new insights into the diverse cellular and molecular mechanisms involved in the aetiology and pathogenesis of MNDs. This search may aid in the selection of potential candidate genes for future investigation and, eventually, may open the door to novel interventions to slow down disease progression. In this review paper, we have summarized detailed existing research findings of different MNDs, such as amyotrophic lateral sclerosis (ALS), spinal muscular atrophy (SMA), spinal bulbar muscle atrophy (SBMA) and hereditary spastic paraplegia (HSP) in relation to their complex genetic architecture.

Drosophila as a model to study autophagy in neurodegenerative diseases and digestive tract

Autophagy regulates cellular homeostasis by degrading and recycling cytosolic components and damaged organelles. Disruption of autophagic flux has been shown to induce or facilitate neurodegeneration and accumulation of autophagic vesicles is overt in neurodegenerative diseases. The fruit fly Drosophila has been used as a model system to identify new factors that regulate physiology and disease. Here we provide a historical perspective of how the fly models have offered mechanistic evidence to understand the role of autophagy in neurodegenerative diseases including Alzheimer's disease, Parkinson's disease, Charcot-Marie-Tooth neuropathy, and polyglutamine disorders. Autophagy also plays a pivotal role in maintaining tissue homeostasis and protecting organism health. The gastrointestinal tract regulates organism health by modulating food intake, energy balance, and immunity. Growing evidence is strengthening the link between autophagy and digestive tract health in recent years. Here, we also discuss how the fly models have advanced the understanding of digestive physiology regulated by autophagy.

Traditional East Asian Herbal Medicine for Amyotrophic Lateral Sclerosis: A Scoping Review

This study aimed to analyze and summarize the existing evidence regarding herbal medicine treatments for amyotrophic lateral sclerosis (ALS). Studies on herbal medicine treatment in patients with ALS were searched within English, Chinese, Japanese, and Korean databases up to July 31, 2021. In the selected studies, we collected the following information: the first author, year of publication, country, language, study methodology, sample size, demographic characteristics of the study participants, disease duration, diagnostic criteria, treatment method, treatment periods, evaluation tools, results, and side effects. The organized data were classified and analyzed narratively. This study included 59 studies. The first clinical study on the effect of herbal medicine was published in 1995; moreover, most studies were conducted in China. Among the 59 selected studies, 47.5% were observational studies, including case reports and case series. Moreover, there was one meta-analysis. The El Escorial criteria were the most commonly used diagnostic criterion for ALS; moreover, the ALS functional rating scale was the most common evaluation tool. Buzhongyiqitang, Sijunzitangjiawei, and Jianpiyifeitang were the most commonly used herbal medicines, with anti-inflammatory, protein aggregation, and anti-oxidant effects. There remain evidence of gaps in the effectiveness of herbal medicine for ALS. To allow effective treatment of patients with ALS using herbal medicine, large-scale and rigorously designed high-quality clinical studies should be performed.

MN-166 (ibudilast) in amyotrophic lateral sclerosis in a Phase IIb/III study: COMBAT-ALS study design

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease with motor neuron loss as a defining feature. Despite significant effort, therapeutic breakthroughs have been modest. MN-166 (ibudilast) has demonstrated neuroprotective action by various mechanisms: inhibition of proinflammatory cytokines and macrophage migration inhibitory factor, phosphodiesterase inhibition, and attenuation of glial cell activation in models of ALS. Early-phase studies suggest that MN-166 may improve survival outcomes and slow disease progression in patients with ALS. This article describes the rationale and design of COMBAT-ALS, an ongoing randomized, double-blind, placebo-controlled, multicenter Phase IIb/III study in ALS. This study is designed to evaluate the pharmacokinetics, safety and tolerability and assess the efficacy of MN-166 on function, muscle strength, quality of life and survival in ALS.

Trends in survival of ALS from a population-based registry

Objective: To assess survival of ALS patients in general and in selected demographic and clinical subgroups comparing two periods (1998-2000 vs. 2008-2010). Methods: Newly diagnosed adults resident of Lombardy, Northern Italy from a population-based registry were included. Data were collected on age at diagnosis, sex, site of onset, diagnostic delay, and El-Escorial diagnostic category. Patients were followed until death or last observation. Survival was evaluated using Kaplan-Meier curves and Cox's proportional hazards models. Results: In 2008-2010 (267 patients), median survival was 2.4 years and 1-year, 2-year, 3-year and 5-year survival rates were 79%, 56%, 41% and 24%. Longer survival was associated with male sex, younger age, spinal onset, and longer diagnostic delay. Multivariable analysis confirmed higher death in 65-69yr (HR 2.8; 95% CI 1.4-5.6), 70-74yr (HR 3.2; 95% CI 1.6-6.3) and 75 + yr (HR 6.9; 95% CI 3.5-13.8) categories, compared to ≤49yr, in females (HR 1.4; 95% CI 1.02-1.8), compared to males, and in patients diagnosed after 6-12 months (HR 1.9; 95% CI 1.4-2.7), compared with longer diagnostic delay. In 1998-2000 (235 patients), median survival was 2.2 years. The 1-year, 2-year, 3-year and 5-year survival rates were 77%, 53%, 38% and 20%. When adjusting for demographic and clinical variables, the HR for death in 2008-2010 versus 1998-2000 was 0.80 (95% CI 0.66-0.98). A significant increase of survival in 2008-2010 was found only in patients aged 50-59yr and 70-74yr at diagnosis. Conclusions: Survival of ALS has increased over time in the last decades, especially in middle aged and elderly patients. The benefits of comprehensive care in selected age groups might explain our findings.

Epidemiology and survival trends of motor neurone disease in Northern Ireland from 2015 to 2019

BACKGROUND AND PURPOSE

This study evaluates the incidence, prevalence and survival trends of motor neurone disease (MND) in Northern Ireland from 2015 to 2019.

METHODS

A capture-recapture analysis was performed using five independent data sources. Incidence and prevalence rates were standardized to the European Standard Population. Survival outcomes were analysed using Kaplan-Meier curves and Cox regression analysis.

RESULTS

Amongst 254 total cases of MND, capture-recapture analysis estimated three missing cases (case ascertainment 98.8%). Age standardized incidence of captured cases was 3.12 per 100,000 (2.73, 3.50) and standardized prevalence ranged from 9.45 to 6.49 per 100,000 from 2015 to 2019. Standardized incidence and prevalence rates in 2006 were 1.4 and 3.3 per 100,000 respectively. Of identified cases, 133 (52.4%) were male; 94.5% had amyotrophic lateral sclerosis; median age of onset was 67 years; median time to diagnosis was 12 months (95% confidence interval 11.2, 12.8); survival from diagnosis was 12 months (95% confidence interval 10.6, 15.4); 25 (9.8%) reported a family history of MND or frontotemporal dementia; and a known MND-associated genetic mutation was identified in 7.9% of total cases, of which the most common was C9orf72 (5.7% of all patients). Factors associated with improved survival were younger age at onset, longer time to diagnosis, attendance at regional MND clinic, and initial neurology presentation as outpatient (all p < 0.001).

CONCLUSION

The incidence and prevalence of MND in Northern Ireland has increased over the last 10 years, in line with increasing rates reported from other European countries. Improved survival was associated with younger age at onset, longer time to diagnosis, attendance at a regional MND clinic and outpatient presentation to a Neurology Department.

Glia: A major player in glutamate-GABA dysregulation-mediated neurodegeneration

The imbalance between glutamate and γ-aminobutyric acid (GABA) results in the loss of synaptic strength leading to neurodegeneration. The dogma on the field considered neurons as the main players in this excitation-inhibition (E/I) balance. However, current strategies focusing only on neurons have failed to completely understand this condition, bringing up the importance of glia as an alternative modulator for neuroinflammation as glia alter the activity of neurons and is a source of both neurotrophic and neurotoxic factors. This review's primary goal is to illustrate the role of glia over E/I balance in the central nervous system and its interaction with neurons. Rather than focusing only on the neuronal targets, we take a deeper look at glial receptors and proteins that could also be explored as drug targets, as they are early responders to neurotoxic insults. This review summarizes the neuron-glia interaction concerning GABA and glutamate, possible targets, and its involvement in the E/I imbalance in neurodegenerative diseases like Alzheimer's disease, Parkinson's disease, Huntington's disease, and multiple sclerosis.

Assessing the Causal Role of Selenium in Amyotrophic Lateral Sclerosis: A Mendelian Randomization Study

Objectives: The relation between selenium overexposure and increased risk of amyotrophic lateral sclerosis (ALS) has been subject to considerable interest. Epidemiologic studies have reported suggestive associations between selenium and ALS, although the causal inference between selenium and ALS remains to be established.

Methods: We conducted a two-sample Mendelian randomization (MR) analysis to analyze the causal role of selenium on ALS risk. Variants associated with selenium levels were obtained from the GWAS meta-analysis of circulating selenium levels (n = 5,477) and toenail selenium levels (n = 4,162) in the European population. Outcome data were from the largest ALS GWAS dataset with 20,806 ALS cases and 59,804 controls in the European population. Inverse variance weighted (IVW) method was used as the main analysis, with an array of sensitivity analyses performed to detect potential violations of MR assumptions.

Results: Inverse variance weighted (IVW) analysis indicated no evidence of a causal role for selenium levels in ALS development (odds ratio (OR) = 1.02, 95% confidence interval (CI) = 0.96–1.08). Similar results were observed for the sensitivity analyses (OR = 1.00, 95% CI = 0.95–1.07 for weighted median; OR = 1.07, 95% CI = 0.87–1.32 for MR-Egger), with no pleiotropy detected.

Conclusions: Although selenium was found associated with ALS according to earlier epidemiologic studies, current evidence based on the population of European ancestry does not support the causal effect of selenium on ALS risk.

Cannabis, a Miracle Drug with Polyvalent Therapeutic Utility: Preclinical and Clinical-Based Evidence

Cannabis sativa L. is an annual herbaceous dioecious plant which was first cultivated by agricultural human societies in Asia. Over the period of time, various parts of the plant like leaf, flower, and seed were used for recreational as well as therapeutic purposes. The main chemical components of Cannabis sativa are termed as cannabinoids, among them the key psychoactive constituent is Δ-9-tetrahydrocannabinol and cannabidiol (CBD) as active nonpsychotic constituent. Upon doing extensive literature review, it was found that cannabis has been widely studied for a number of disorders. Very recently, a pure CBD formulation, named Epidiolex, got a green flag from both United States Food and Drug Administration and Drug Enforcement Administration for 2 rare types of epilepsies. This laid a milestone in medical cannabis research. This review intends to give a basic and extensive assessment, from past till present, of the ethnological, plant, chemical, pharmacological, and legal aspects of C. sativa. Further, this review contemplates the evidence the studies obtained of cannabis components on Alzheimer's, Parkinson's, amyotrophic lateral sclerosis, multiple sclerosis, emesis, epilepsy, chronic pain, and cancer as a cytotoxic agent as well as a palliative therapy. The assessment in this study was done by reviewing in extensive details from studies on historical importance, ethnopharmacological aspects, and legal grounds of C. sativa from extensive literature available on the scientific databases, with a vision for elevating further pharmaceutical research to investigate its total potential as a therapeutic agent.

Exploring Aromatic Medicinal Compounds for the Treatment of Amyotrophic Lateral Sclerosis

Purpose: Amyotrophic lateral sclerosis (ALS) is a lethal neurodegenerative condition, in which motor neurons start to degenerate due to the accumulation of protein aggregates in the neuron cytoplasm. The formation of aggregates causes neurotoxicity, facilitated by the N-terminal domain (NTD) of the transactive response DNA-binding protein-43 (TDP-43). Therapies used to treat ALS manage secondary symptoms, but do not stop the activity of the rogue NTD domain of TDP-43. Therefore, new drug candidates should be designed to deal efficiently with this disease by inhibiting the domains involved in the development of ALS. This study determined the chemical affinity of aromatic medicinal compounds with NTD. Screening of 1323 medicinal compounds was conducted with PYRX 0.9 software against NTD. Compounds obtained from this analysis were further used to predict absorption, distribution, metabolism, excretion, and toxic (ADMET) properties and their effect on major gene targets of ALS. Results: From 1300 + compounds, acetovanillone showed binding affinity for NTD and had good ADMET and drug likeness attributes. This compound reduced the expression of CXCL2, NOP56, and SOD1 genes implicated in ALS pathogenesis. Conclusion: These results concluded that acetovanillone is a candidate drug for in vitro and clinical studies into the exploitation of drugs within ALS therapeutics.

Gut microbiome and amyotrophic lateral sclerosis: A systematic review of current evidence

Amyotrophic lateral sclerosis (ALS), characterized by a loss of motor neurons in the brain and spinal cord, is a relatively rare but currently incurable neurodegenerative disease. The global incidence of ALS is estimated as 1.75 per 100,000 person-years and the global prevalence is estimated as 4.1-8.4 per 100,000 individuals. Contributions from outside the central nervous system to the etiology of ALS have been increasingly recognized. Gut microbiome is one of the most quickly growing fields of research for ALS. In this article, we performed a comprehensive review of the results from existing animal and human studies, to provide an up-to-date summary of the current research on gut microbiome and ALS. In brief, we found relatively consistent results from animal studies, suggesting an altered gut microbiome composition in experimental ALS. Publication bias might however be a concern. Findings from human studies are largely inconclusive. A few animal and human studies demonstrated the usefulness of intervention with microbial-derived metabolites in modulating the disease progression of ALS. We discussed potential methodological concerns in these studies, including study design, statistical power, handling process of biospecimens and sequencing data, as well as statistical methods and interpretation of results. Finally, we made a few proposals for continued microbiome research in ALS, with the aim to provide valid, reproducible, and translatable findings.

Geographical clusters of amyotrophic lateral sclerosis and the Bradford Hill criteria

With the aim of shedding further light on the role of environmental factors in amyotrophic lateral sclerosis (ALS) etiology, we hereby conducted a historical narrative review to critically appraise the published reports on ALS geographical clusters using the modern interpretation of the Bradford Hill criteria for causation. Our research hypothesis was that the more criteria were met, the greater was the evidence supporting a causal association. We found that cluster studies that met the greatest number of Bradford's Hill criteria regarded the non-protein amino acid β-N-methylamino-L-alanine (L-BMAA) and exposure to metals and minerals, but the evidence for causation was at best moderate and was poor for other environmental factors. This defective picture might be attributed not only to the methodological approach adopted by published studies, but also to the inherent difficulties in the application of Bradford Hill criteria, due to the complexity of the disease phenotype and the underlying pathogenic mechanisms.

Alternative platelet activation pathways and their role in neurodegenerative diseases

PURPOSE OF THE REVIEW

The study of platelets in the context of neurodegenerative diseases is intensifying, and increasing evidence suggests that platelets may play an important role in the pathogenesis of neurodegenerative disorders. Therefore, we aim to provide a comprehensive overview of the role of platelets and their diverse activation pathways in the development of these diseases.

RECENT FINDINGS

Platelets participate in synaptic plasticity, learning, memory, and platelets activated by exercise promote neuronal differentiation in several brain regions. Platelets also contribute to the immune response by modulating their surface protein profile and releasing pro- and anti-inflammatory mediators. In Alzheimer's disease, increased levels of platelet amyloid precursor protein raise the production of amyloid-beta peptides promoting platelet activation, triggering at the same time amyloid-beta fibrillation. In Parkinson's disease, increased platelet α-synuclein is associated with elevated ROS production and mitochondrial dysfunction.

SUMMARY

In this review, we revise different platelet activation pathways, those classically involved in hemostasis and wound healing, and alternative activation pathways recently described in the context of neurodegenerative diseases, especially in Alzheimer's disease.

All Roads Lead to Rome: Different Molecular Players Converge to Common Toxic Pathways in Neurodegeneration

Multiple neurodegenerative diseases (NDDs) such as Alzheimer’s disease (AD), Parkinson’s disease (PD), amyotrophic lateral sclerosis (ALS) and Huntington’s disease (HD) are being suggested to have common cellular and molecular pathological mechanisms, characterized mainly by protein misfolding and aggregation. These large inclusions, most likely, represent an end stage of a molecular cascade; however, the soluble misfolded proteins, which take part in earlier steps of this cascade, are the more toxic players. These pathological proteins, which characterize each specific disease, lead to the selective vulnerability of different neurons, likely resulting from a combination of different intracellular mechanisms, including mitochondrial dysfunction, ER stress, proteasome inhibition, excitotoxicity, oxidative damage, defects in nucleocytoplasmic transport, defective axonal transport and neuroinflammation. Damage within these neurons is enhanced by damage from the nonneuronal cells, via inflammatory processes that accelerate the progression of these diseases. In this review, while acknowledging the hallmark proteins which characterize the most common NDDs; we place specific focus on the common overlapping mechanisms leading to disease pathology despite these different molecular players and discuss how this convergence may occur, with the ultimate hope that therapies effective in one disease may successfully translate to another.

Sequencing of neurofilament genes identified NEFH Ser787Arg as a novel risk variant of sporadic amyotrophic lateral sclerosis in Chinese subjects

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease with neuronal cell inclusions composed of neurofilaments and other abnormal aggregative proteins as pathological hallmarks. Approximately 90% of patients have sporadic cases (sALS), and at least 4 genes, i.e. C9orf72, SOD1, FUS and TARDBP, have been identified as the main causative genes, while many others have been proposed as potential risk genes. However, these mutations could explain only ~ 10% of sALS cases. The neurofilament polypeptides encoded by NEFH, NEFM, and NEFL are promising protein biomarkers for ALS and other degenerative diseases. However, whether the genetic variants of these genes were associated with ALS remain ambiguous.

METHODS

Here, we used PCR-Sanger to sequence the exons of these three genes in a cohort of 371 sALS patients and 711 healthy controls (Phase I) and validated the risk variant in another 300 sALS patients and 1076 controls (Phase II).

RESULTS

A total of 92 variants were identified, including 36 rare heterozygous variants in NEFH, 27 in NEFM, and 16 in NEFL, and only rs568759161 (p.Ser787Arg) in NEFH reached nominal statistical power (P = 0.02 at Phase I, P = 0.009 at Phase II) in the case-control comparison. Together, the Phase I and II studies showed the significantly higher frequency of the variant in cases (9/1342, 0.67%) than in controls (2/3574, 0.07%) (OR 12.06; 95% CI 2.60-55.88; P = 0.0003). No variants passed multiple testing in the discovery cohort, but rs568759161 was associated with ALS in a replication cohort.

CONCLUSIONS

Our results confirmed that NEFH Ser787Arg is a novel sALS risk variant in Chinese subjects, but NEFM and NEFL were not associated with sALS. These data may have implications for genetic counselling and for understanding the pathogenesis of sALS.

Current Concepts on Genetic Aspects of Mitochondrial Dysfunction in Amyotrophic Lateral Sclerosis

Amyotrophic Lateral Sclerosis (ALS), neurodegenerative motor neuron disorder is characterized as multisystem disease with important contribution of genetic factors. The etiopahogenesis of ALS is not fully elucidate, but the dominant theory at present relates to RNA processing, as well as protein aggregation and miss-folding, oxidative stress, glutamate excitotoxicity, inflammation and epigenetic dysregulation. Additionally, as mitochondria plays a leading role in cellular homeostasis maintenance, a rising amount of evidence indicates mitochondrial dysfunction as a substantial contributor to disease onset and progression. The aim of this review is to summarize most relevant findings that link genetic factors in ALS pathogenesis with different mechanisms with mitochondrial involvement (respiratory chain, OXPHOS control, calcium buffering, axonal transport, inflammation, mitophagy, etc.). We highlight the importance of a widening perspective for better understanding overlapping pathophysiological pathways in ALS and neurodegeneration in general. Finally, current and potentially novel therapies, especially gene specific therapies, targeting mitochondrial dysfunction are discussed briefly.

Fly for ALS: Drosophila modeling on the route to amyotrophic lateral sclerosis modifiers

Amyotrophic lateral sclerosis (ALS) is a rare, devastating disease, causing movement impairment, respiratory failure and ultimate death. A plethora of genetic, cellular and molecular mechanisms are involved in ALS signature, although the initiating causes and progressive pathological events are far from being understood. Drosophila research has produced seminal discoveries for more than a century and has been successfully used in the past 25 years to untangle the process of ALS pathogenesis, and recognize potential markers and novel strategies for therapeutic solutions. This review will provide an updated view of several ALS modifiers validated in C9ORF72, SOD1, FUS, TDP-43 and Ataxin-2 Drosophila models. We will discuss basic and preclinical findings, illustrating recent developments and novel breakthroughs, also depicting unsettled challenges and limitations in the Drosophila-ALS field. We intend to stimulate a renewed debate on Drosophila as a screening route to identify more successful disease modifiers and neuroprotective agents.

The rs2619566, rs10260404, and rs79609816 Polymorphisms Are Associated With Sporadic Amyotrophic Lateral Sclerosis in Individuals of Han Ancestry From Mainland China

The pathogenesis of sporadic amyotrophic lateral sclerosis (sALS) remains unknown; however, recent research suggests that genetic factors may play an important role. This study aimed at investigating possible genetic risk factors for the pathogenesis of sALS. In our previous study, we conducted a genome-wide association study (GWAS) in 250 sALS patients and 250 control participants of Han ancestry from mainland China (HACM) and retrospectively analyzed the previously reported candidate loci related with sALS including our GWAS investigated results. In this study, twenty-seven candidate loci that were most likely associated with sALS were selected for further analysis in an independent case/control population of 239 sALS patients and 261 control subjects of HACM ethnicity using sequenom massARRAY methodology and DNA sequencing. We discovered that the polymorphism rs2619566 located within the contactin-4 (CNTN4) gene, rs10260404 in the dipeptidyl-peptidase 6 (DPP6) gene, and rs79609816 in the inositol polyphosphate-5-phosphatase B (INPP5B) gene were strongly associated with sALS in subjects of HACM ethnicity. Subjects harboring the minor C allele of rs2619566 and the minor T allele of rs79609816 exhibited an increased risk for sALS development, while carriers of the minor C allele of rs10260404 showed a decreased risk of sALS development compared to the subjects of other genotypes. The polymorphisms of rs2619566, rs10260404, and rs79609816 may change or affect the splicing, transcription, and translation of CNTN4, DPP6, and INPP5B genes and may play roles in the pathogenesis of sALS roles in the pathogenesis of sALS.

Amyotrophic lateral sclerosis (ALS) among immigrant groups and Swedish-born individuals: a cohort study of all adults 18 years of age and older in Sweden

Background

There is a lack of studies of amyotrophic lateral sclerosis (ALS) in immigrants.

Objective

The objective is to study the association between country of birth and incident ALS in first-generation immigrants versus Swedish-born individuals, and in second-generation immigrants versus native Swedes.

Methods

Study populations included all adults aged 18 years and older in Sweden, in the first-generation study 6,128,698 individuals (2,975,141 men, 3,153,557 women) with 5,344 ALS cases (3017 men, 2327 women), and in the second-generation study 4,588,845 individuals (2,346,855 men and 2,241,990 women) with 3,420 cases (2027 men and 1393 women). ALS was defined as having at least one registered diagnosis of ALS in the National Patient Register 1998–2017. The incidence of ALS in different first-generation immigrant groups versus Swedish-born individuals was assessed by Cox regression, expressed as hazard ratios (HRs) with 95% confidence intervals (CI). The models were stratified by sex and adjusted for age, geographical residence in Sweden, educational level, marital status, and neighbourhood socioeconomic status.

Results

After adjusting for potential confounders, the HRs were lower in foreign-born men, 0.71 (95% CI 0.63–0.81), and women, 0.80 (95% CI 0.70–0.92). The ALS risk was lower among men and women from most Western countries (Europe outside Nordic countries, and North America), and from other regions of the world (Africa, Asia, and Latin America). Among men and women with foreign-born parents, the risk of ALS did not differ significantly from native Swedes.

Significance

In general, the risk of ALS was lower in first-generation men and women but did not differ in second-generation individuals.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00415-021-10765-6.

Therapeutic Potential of Polyphenols in Amyotrophic Lateral Sclerosis and Frontotemporal Dementia

Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are severe neurodegenerative disorders that belong to a common disease spectrum. The molecular and cellular aetiology of the spectrum is a highly complex encompassing dysfunction in many processes, including mitochondrial dysfunction and oxidative stress. There is a paucity of treatment options aside from therapies with subtle effects on the post diagnostic lifespan and symptom management. This presents great interest and necessity for the discovery and development of new compounds and therapies with beneficial effects on the disease. Polyphenols are secondary metabolites found in plant-based foods and are well known for their antioxidant activity. Recent research suggests that they also have a diverse array of neuroprotective functions that could lead to better treatments for neurodegenerative diseases. We present an overview of the effects of various polyphenols in cell line and animal models of ALS/FTD. Furthermore, possible mechanisms behind actions of the most researched compounds (resveratrol, curcumin and green tea catechins) are discussed.

The molecular and cellular basis of copper dysregulation and its relationship with human pathologies

Copper (Cu) is an essential micronutrient required for the activity of redox-active enzymes involved in critical metabolic reactions, signaling pathways, and biological functions. Transporters and chaperones control Cu ion levels and bioavailability to ensure proper subcellular and systemic Cu distribution. Intensive research has focused on understanding how mammalian cells maintain Cu homeostasis, and how molecular signals coordinate Cu acquisition and storage within organs. In humans, mutations of genes that regulate Cu homeostasis or facilitate interactions with Cu ions lead to numerous pathologic conditions. Malfunctions of the Cu⁺ -transporting ATPases ATP7A and ATP7B cause Menkes disease and Wilson disease, respectively. Additionally, defects in the mitochondrial and cellular distributions and homeostasis of Cu lead to severe neurodegenerative conditions, mitochondrial myopathies, and metabolic diseases. Cu has a dual nature in carcinogenesis as a promotor of tumor growth and an inducer of redox stress in cancer cells. Cu also plays role in cancer treatment as a component of drugs and a regulator of drug sensitivity and uptake. In this review, we provide an overview of the current knowledge of Cu metabolism and transport and its relation to various human pathologies.

A perspective on therapies for amyotrophic lateral sclerosis: can disease progression be curbed?

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease involving both upper and lower motor neurons, leading to paralysis and eventually death. Symptomatic treatments such as inhibition of salivation, alleviation of muscle cramps, and relief of spasticity and pain still play an important role in enhancing the quality of life. To date, riluzole and edaravone are the only two drugs approved by the Food and Drug Administration for the treatment of ALS in a few countries. While there is adequate consensus on the modest efficacy of riluzole, there are still open questions concerning the efficacy of edaravone in slowing the disease progression. Therefore, identification of novel therapeutic strategies is urgently needed. Impaired autophagic process plays a critical role in ALS pathogenesis. In this review, we focus on therapies modulating autophagy in the context of ALS. Furthermore, stem cell therapies, gene therapies, and newly-developed biomaterials have great potentials in alleviating neurodegeneration, which might halt the disease progression. In this review, we will summarize the current and prospective therapies for ALS.

Communication About End of Life for Patients Living With Amyotrophic Lateral Sclerosis: A Scoping Review of the Empirical Evidence

Background: Communication about end of life, including advance care planning, life-sustaining therapies, palliative care, and end-of-life options, is critical for the clinical management of amyotrophic lateral sclerosis patients. The empirical evidence base for this communication has not been systematically examined. Objective: To support evidence-based communication guidance by (1) analyzing the scope and nature of research on health communication about end of life for amyotrophic lateral sclerosis; and (2) summarizing resultant recommendations. Methods: A scoping review of empirical literature was conducted following recommended practices. Fifteen health-related and three legal databases were searched; 296 articles were screened for inclusion/exclusion criteria; and quantitative data extraction and analysis was conducted on 211 articles with qualitative analysis on a subset of 110 articles that focused primarily on health communication. Analyses summarized article characteristics, themes, and recommendations. Results: Analysis indicated a multidisciplinary but limited evidence base. Most reviewed articles addressed end-of-life communication as a peripheral focus of investigation. Generic communication skills are important; however, substantive and sufficient disease-related information, including symptom management and assistive devices, is critical to discussions about end of life. Few articles discussed communication about specific end-of-life options. Communication recommendations in analyzed articles draw attention to communication processes, style and content but lack the systematized guidance needed for clinical practice. Conclusions: This review of primary research articles highlights the limited evidence-base and consequent need for systematic, empirical investigation to inform effective communication about end of life for those with amyotrophic lateral sclerosis. This will provide a foundation for actionable, evidence-based communication guidelines about end of life. Implications for research, policy, and practice are discussed.

ALS incidence and population aging in Northern Italy

Objective: Data on and increase of the incidence of amyotrophic lateral sclerosis (ALS) are conflicting and reflect the use of differing populations and designs. We investigated the incidence of ALS using data from a large population-based registry (SLALOM) in two three-year periods using the same diagnostic criteria and equal methods of case ascertainment. Methods: The registry is based in Lombardy, a 10 million population area of Northern Italy. Using different sources of cases (hospital discharge and ambulatory records, regional claims and prescription records) from nine Lombardy provinces (population, 5,485,163), all patients with newly diagnosed ALS during the periods 1998-2000 and 2008-2010 were included. Results: A total of 235 and 440 newly diagnosed patients were traced during the two study periods. The corresponding incidence rates were, respectively, 1.61 and 2.72 per 100,000 person-years. Data varied with age, sex and province by a significant increase was found only in men aged 65 through 74 years. Conclusions: Based on our findings, the increased incidence of ALS with time is real and can be largely interpreted as a reflection of the advancing age of the general population.

Interplay between immunity and amyotrophic lateral sclerosis: Clinical impact

Amyotrophic lateral sclerosis (ALS) is a debilitating and rapidly fatal neurodegenerative disease. Despite decades of research and many new insights into disease biology over the 150 years since the disease was first described, causative pathogenic mechanisms in ALS remain poorly understood, especially in sporadic cases. Our understanding of the role of the immune system in ALS pathophysiology, however, is rapidly expanding. The aim of this manuscript is to summarize the recent advances regarding the immune system involvement in ALS, with particular attention to clinical translation. We focus on the potential pathophysiologic mechanism of the immune system in ALS, discussing local and systemic factors (blood, cerebrospinal fluid, and microbiota) that influence ALS onset and progression in animal models and people. We also explore the potential of Positron Emission Tomography to detect neuroinflammation in vivo, and discuss ongoing clinical trials of therapies targeting the immune system. With validation in human patients, new evidence in this emerging field will serve to identify novel therapeutic targets and provide realistic hope for personalized treatment strategies.

Recruitment of population-based controls for ALS cases from the National ALS Registry

Objective: In 2010, the United States Agency for Toxic Substances and Disease Registry (ATSDR) created the National ALS Registry (Registry) to examine the epidemiology of ALS and potential risk factors. We are currently recruiting population-based controls for an epidemiologic case-control study to examine ALS environmental risk factors using this Registry. To date, we have recruited 181 non-diseased, population-based controls for comparison to Registry cases (n = 280). Here we report our recruitment methods for controls and the associated response rates and costs. Methods: Eligible ALS cases had complete risk factor survey data, DNA analysis, and blood concentrations of persistent organic pollutants (POPs). Age, sex, and county-matched controls were identified from commercial/consumer databases using a targeted landline phone sample. Eligible controls were consented, surveyed, and mailed the POPs' blood analysis consent form. Once consented, phlebotomy was scheduled. Results: We mailed 3760 recruitment letters for 181 potential case-matches across 42 states between 9/2018 and 3/2020. After making phone contact and determining eligibility, 146 controls agreed to participate (response rate = 11.4%, cooperation rate = 22.8%). To date, 127 controls completed the survey and bloodwork. Though controls were matched to cases on age, sex, and county, unmatched characteristics (e.g. smoking) did not differ statistically. Interviewing and incentive costs are estimated at $211.85 per complete participation. Conclusions: Recruiting matched population-based controls for comparison to cases from the Registry for a study involving completion of a detailed survey and blood specimen provision is relatively feasible and cost effective. This recruitment method could be useful for case-control studies of other rare disorders.

Hypoxia-Inducible Factor (HIF) in Ischemic Stroke and Neurodegenerative Disease

Hypoxia is one of the most common pathological conditions, which can be induced by multiple events, including ischemic injury, trauma, inflammation, tumors, etc. The body's adaptation to hypoxia is a highly important phenomenon in both health and disease. Most cellular responses to hypoxia are associated with a family of transcription factors called hypoxia-inducible factors (HIFs), which induce the expression of a wide range of genes that help cells adapt to a hypoxic environment. Basic mechanisms of adaptation to hypoxia, and particularly HIF functions, have being extensively studied over recent decades, leading to the 2019 Nobel Prize in Physiology or Medicine. Based on their pivotal physiological importance, HIFs are attracting increasing attention as a new potential target for treating a large number of hypoxia-associated diseases. Most of the experimental work related to HIFs has focused on roles in the liver and kidney. However, increasing evidence clearly demonstrates that HIF-based responses represent an universal adaptation mechanism in all tissue types, including the central nervous system (CNS). In the CNS, HIFs are critically involved in the regulation of neurogenesis, nerve cell differentiation, and neuronal apoptosis. In this mini-review, we provide an overview of the complex role of HIF-1 in the adaptation of neurons and glia cells to hypoxia, with a focus on its potential involvement into various neuronal pathologies and on its possible role as a novel therapeutic target.

National registry for amyotrophic lateral sclerosis: a systematic review for structuring population registries of motor neuron diseases

BACKGROUND

This article comprises a systematic review of the literature that aims at researching and analyzing the frequently applied guidelines for structuring national databases of epidemiological surveillance for motor neuron diseases, especially Amyotrophic Lateral Sclerosis (ALS).

METHODS

We searched for articles published from January 2015 to September 2019 on online databases as PubMed - U.S. National Institutes of Health's National Library of Medicine, Scopus, Science Direct, and Springer. Subsequently, we analyzed studies that considered risk factors, demographic data, and other strategic data for directing techno-scientific research, calibrating public health policies, and supporting decision-making by managers through a systemic panorama of ALS.

RESULTS

2850 studies were identified. 2400 were discarded for not satisfying the inclusion criteria, and 435 being duplicated or published in books or conferences. Hence, 15 articles were elected. By applying quality criteria, we then selected six studies to compose this review. Such researches featured registries from the American (3), European (2), and Oceania (1) continent. All the studies specified the methods for data capture and the patients' recruitment process for the registers.

DISCUSSIONS

From the analysis of the selected papers and reported models, it is noticeable that most studies focused on the prospect of obtaining data to characterize research on epidemiological studies. Demographic data (ID01) are present in all the registries, representing the main collected data category. Furthermore, the general health history (ID02) is present in 50% of the registries analyzed. Characteristics such as access control, confidentiality and data curation. We observed that 50% of the registries comprise a patient-focused web-based self-report system.

CONCLUSION

The development of robust, interoperable, and secure electronic registries that generate value for research and patients presents itself as a solution and a challenge. This systematic review demonstrated the success of a population register requires actions with well-defined development methods, as well as the involvement of various actors of civil society.

Lysosome dysfunction as a cause of neurodegenerative diseases: Lessons from frontotemporal dementia and amyotrophic lateral sclerosis

Frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) are fatal neurodegenerative disorders that are thought to exist on a clinical and pathological spectrum. FTD and ALS are linked by shared genetic causes (e.g. C9orf72 hexanucleotide repeat expansions) and neuropathology, such as inclusions of ubiquitinated, misfolded proteins (e.g. TAR DNA-binding protein 43; TDP-43) in the CNS. Furthermore, some genes that cause FTD or ALS when mutated encode proteins that localize to the lysosome or modulate endosome-lysosome function, including lysosomal fusion, cargo trafficking, lysosomal acidification, autophagy, or TFEB activity. In this review, we summarize evidence that lysosomal dysfunction, caused by genetic mutations (e.g. C9orf72, GRN, MAPT, TMEM106B) or toxic-gain of function (e.g. aggregation of TDP-43 or tau), is an important pathogenic disease mechanism in FTD and ALS. Further studies into the normal function of many of these proteins are required and will help uncover the mechanisms that cause lysosomal dysfunction in FTD and ALS. Mutations or polymorphisms in genes that encode proteins important for endosome-lysosome function also occur in other age-dependent neurodegenerative diseases, including Alzheimer's (e.g. APOE, PSEN1, APP) and Parkinson's (e.g. GBA, LRRK2, ATP13A2) disease. A more complete understanding of the common and unique features of lysosome dysfunction across the spectrum of neurodegeneration will help guide the development of therapies for these devastating diseases.

Do Generic Preference-Based Measures Accurately Capture Areas of Health-Related Quality of Life Important to Individuals with Amyotrophic Lateral Sclerosis: A Content Validation Study

Objective

The objectives of this study were to 1) assess the content validity of generic preference-based measures (GPBMs), and (2) examine the convergent validity of the EuroQol 5 Dimension 5 Level (EQ-5D-5L), against the Patient Generated Index (PGI) in Amyotrophic Lateral Sclerosis (ALS).

Methods

Participants were recruited from 3 clinical sites across Canada. The PGI, EQ-5D-5L and Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised (ALSFRS-R) were administered through an online or hardcopy survey and scores compared for convergent validation. Domains nominated by participants as important to their health-related quality of life were generated using the PGI, classified using the International Classification of Functioning, Disability and Health (ICF) and mapped onto GPBMs to determine content coverage.

Results

Fifty-two participants (N=28 female; 61.3 ± 11.6 mean age ± standard deviation (SD); 3.5 ± 2.9 mean ± SD years since diagnosis) completed this study. The top three ICF domains identified by participants were recreation and leisure, lower limb mobility, and interpersonal relationships. The Quality of Well-Being Self-Administered (QWB-SA) scale had the highest content coverage (87%) and the Health Utilities Index 3 (HUI3) had the lowest (33%). Two domains were covered by all GPBMs and no GPBM included all domains identified as important by participants. A moderate correlation coefficient of 0.52 between the PGI and EQ-5D-5L was found.

Conclusion

The majority of GPBMs covered only approximately half of the domains important to individuals with ALS suggesting the need for an ALS specific preference-based measure to better reflect the health-related quality of life of this population.

An amyotrophic lateral sclerosis hot spot in the French Alps associated with genotoxic fungi

Between 1990 and 2018, 14 cases of amyotrophic lateral sclerosis (ALS) were diagnosed in residents of, and in visitors with second homes to, a mountainous hamlet in the French Alps. Systematic investigation revealed a socio-professional network that connected ALS cases. Genetic risk factors for ALS were excluded. Several known environmental factors were scrutinized and eliminated, notably lead and other chemical contaminants in soil, water or home-grown vegetation used for food, radon and electromagnetic fields. Some lifestyle-related behavioral risk factors were identified: Prior to clinical onset of motor neuron disease, some patients had a high degree of athleticism and smoked tobacco. Recent investigations on site, based on a new hypothesis, showed that all patients had ingested wild mushrooms, notably poisonous False Morels. Half of the ALS cohort reported acute illness following Gyromitra gigas mushroom consumption. This finding supports the hypothesis that genotoxins of fungal origin may induce motor neuron degeneration.