Chapter 13 Amyotrophic lateral sclerosis

An Exploratory Trial of EPI-589 in Amyotrophic Lateral Sclerosis (EPIC-ALS): Protocol for a Multicenter, Open-Labeled, 24-Week, Single-Group Study

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder, with its currently approved drugs, including riluzole and edaravone, showing limited therapeutic effects. Therefore, safe and effective drugs are urgently necessary. EPI-589 is an orally available, small-molecule, novel redox-active agent characterized by highly potent protective effects against oxidative stress with high blood-brain barrier permeability. Given the apparent oxidative stress and mitochondrial dysfunction involvement in the pathogenesis of ALS, EPI-589 may hold promise as a therapeutic agent.

OBJECTIVE

This protocol aims to describe the design and rationale for the EPI-589 Early Phase 2 Investigator-Initiated Clinical Trial for ALS (EPIC-ALS).

METHODS

EPIC-ALS is an explorative, open-labeled, single-arm trial that evaluates the safety and tolerability of EPI-589 in patients with ALS. This trial consists of 12-week run-in, 24-week treatment, and 4-week follow-up periods. Patients will receive 500 mg of EPI-589 3 times daily over the 24-week treatment period. Clinical assessments include the mean monthly change of Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised total score. The biomarkers are selected to analyze the effect on oxidative stress and neuronal damage. The plasma biomarkers are 8-hydroxy-2'-deoxyguanosine (8-OHdG), 3-nitrotyrosine (3-NT), neurofilament light chain (NfL), phosphorylated neurofilament heavy chain (pNfH), homocysteine, and creatinine. The cerebrospinal fluid biomarkers are 8-OHdG, 3-NT, NfL, pNfH, and ornithine. The magnetic resonance biomarkers are fractional anisotropy in the corticospinal tract and N-acetylaspartate in the primary motor area.

RESULTS

This trial began data collection in September 2021 and is expected to be completed in October 2023.

CONCLUSIONS

This study can provide useful data to understand the characteristics of EPI-589.

TRIAL REGISTRATION

Japan Primary Registries Network jRCT2061210031; tinyurl.com/2p84emu6.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/42032.

Young-onset Amyotrophic Lateral Sclerosis with Rare Skin Manifestation: Case Report and Literature Review

Amyotrophic lateral sclerosis (ALS) is one of the most common motor neuron diseases (MND), which presents as muscle weakness, atrophy, spasticity, and, in extreme cases, may result in death due to respiratory failure. ALS has been reported with dermatological conditions such as bullous pemphigoid and decreased collagen. Hyperpigmentation usually occurs due to underlying adrenal or metabolic disorder, but no case of hyperpigmentation has been associated with MND. We report a case of a 25-year-old man who presented with signs of young-onset ALS (progressive weakness of both upper limbs) with hyperpigmentation of limbs. The patient did not have any other underlying etiology, which could have led to the development of hyperpigmentation Biopsy was negative for polymyositis and dermatomyositis. The patient was counseled about the nature of the disease and was advised regular follow-ups.

Functional limitation of the masticatory system in patients with bulbar involvement in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) with bulbar dysfunction affects the motor neurons responsible for controlling the muscles in the jaw, face, soft palate, pharynx, larynx and tongue. This cross-sectional study aimed to determine the functional limitation of the jaw in patients with ALS and bulbar dysfunction who had upper motor neuron (UMN), lower motor neuron (LMN) or balanced involvement. One hundred and fifty-three patients with ALS and 23 controls were included. All participants answered using the 8-item Jaw Functional Limitation Scale (JFLS-8). Patients with ALS were grouped by neurologic examination as follows: non-bulbar ALS, bulbar UMN-predominant ALS; bulbar LMN-predominant ALS; and bulbar balanced (UMN + LMN) ALS. Jaw limitation between the different groups was compared using the Kruskal-Wallis test. Patients with non-bulbar ALS had similar mandibular limitations to healthy participants. Only patients with balanced UMN and LMN bulbar manifestations reported greater difficulties in chewing soft food or in jaw mobility compared to the non-bulbar ALS group. Patients with bulbar involvement also had greater difficulties in chewing tough food or chicken and in swallowing and talking compared to the non-bulbar group, regardless of whether UMN or LMN predominant. No significant differences were found between the groups in smiling and yawning difficulties. Bulbar involvement in patients with ALS is associated with functional limitation of the masticatory system. However, balanced bulbar UMN and LMN involvement is associated with the worst impairments in chewing soft food and in opening the jaw widely.

Preoperative parameters and their prognostic value in amyotrophic lateral sclerosis patients undergoing implantation of a diaphragm pacing stimulation system

Introduction:

Amyotrophic lateral sclerosis (ALS) is a progressive neuromuscular disease with devastating and fatal respiratory complications. Diaphragm pacing stimulation (DPS) is a treatment option in diaphragm insufficient ALS patients. Ventilatory insufficiency depending on diaphragmatic failure is treated by the present study aimed to investigate prognostic value of preoperative clinical and functional characteristics of ALS patients undergoing implantation of a DPS system and to determine appropriate indications for the DPS system.

Methods:

The study included 34 ALS patients implanted with DPS system. All patients underwent multidisciplinary and laboratory evaluations before the surgery. The laboratory examinations included pulmonary function tests and arterial blood gas analysis. Survival rates were recorded in a 2-year follow-up after the surgery.

Results:

Twenty-eight of 34 patients with ALS survived after a 2-year follow-up. These patients were younger than those who died and had the disease for a longer time; however, the differences were not significant. Both right and left hemidiaghragms were thicker in the survived patients (P < 0.0001 for each). Pulmonary function tests revealed no significant differences between the patients who survived. Arterial blood gas analysis demonstrated lower partial pressure of carbon dioxide in the survived patients (P = 0.025).

Conclusions:

DPS implantation was more efficacious in ALS patients with mild respiratory failure and thicker diaphragm. Predictors of long-term effectiveness of DPS system are needed to be addressed by large-scale studies.

Imbalance of mitochondrial dynamics in Drosophila models of amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is the most common neurodegenerative disease, characterized by progressive and selective loss of motor neurons in the brain and spinal cord. DNA/RNA-binding proteins such as TDP-43, FUS, and TAF15 have been linked with the sporadic and familial forms of ALS. However, the exact pathogenic mechanism of ALS is still unknown. Recently, we found that ALS-causing genes such as TDP-43, FUS, and TAF15 genetically interact with mitochondrial dynamics regulatory genes. In this study, we show that mitochondrial fission was highly enhanced in muscles and motor neurons of TDP-43, FUS, and TAF15-induced fly models of ALS. Furthermore, the mitochondrial fission defects were rescued by co-expression of mitochondrial dynamics regulatory genes such as Marf, Opa1, and the dominant negative mutant form of Drp1. Moreover, we found that the expression level of Marf was decreased in ALS-induced flies. These results indicate that the imbalance of mitochondrial dynamics caused by instability of Marf is linked to the pathogenesis of TDP-43, FUS, and TAF15-associated ALS.

Chronic administration of AMD3100 increases survival and alleviates pathology in SOD1(G93A) mice model of ALS

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a progressive fatal neurodegenerative disease, involving both upper and lower motor neurons. The disease is induced by multifactorial pathologies, and as such, it requires a multifaceted therapeutic approach. CXCR4, a chemokine receptor widely expressed in neurons and glial cells and its ligand, CXCL12, also known as stromal-cell-derived factor (SDF1), modulate both neuronal function and apoptosis by glutamate release signaling as well as hematopoietic stem and progenitor cells (HSPCs) migration into the blood and their homing towards injured sites. Inhibition approaches towards the CXCR4/CXCL12 signaling may result in preventing neuronal apoptosis and alter the HSPCs migration and homing. Such inhibition can be achieved by means of treatment with AMD3100, an antagonist of the chemokine receptor CXCR4.

METHODS

We chronically treated male and female transgenic mice model of ALS, SOD1(G93A) mice, with AMD3100. Mice body weight and motor function, evaluated by Rotarod test, were recorded once a week. The most effective treatment regimen was repeated for biochemical and histological analyses in female mice.

RESULTS

We found that chronic administration of AMD3100 to SOD1(G93A) mice led to significant extension in mice lifespan and improved motor function and weight loss. In addition, the treatment significantly improved microglial pathology and decreased proinflammatory cytokines in spinal cords of treated female mice. Furthermore, AMD3100 treatment decreased blood-spinal cord barrier (BSCB) permeability by increasing tight junction proteins levels and increased the motor neurons count in the lamina X area of the spinal cord, where adult stem cells are formed.

CONCLUSIONS

These data, relevant to the corresponding disease mechanism in human ALS, suggest that blocking CXCR4 by the small molecule, AMD3100, may provide a novel candidate for ALS therapy with an increased safety.

Early and gender-specific differences in spinal cord mitochondrial function and oxidative stress markers in a mouse model of ALS

Introduction

Amyotrophic lateral sclerosis (ALS) is a motor neuron disease with a gender bias towards major prevalence in male individuals. Several data suggest the involvement of oxidative stress and mitochondrial dysfunction in its pathogenesis, though differences between genders have not been evaluated. For this reason, we analysed features of mitochondrial oxidative metabolism, as well as mitochondrial chain complex enzyme activities and protein expression, lipid profile, and protein oxidative stress markers, in the Cu,Zn superoxide dismutase with the G93A mutation (hSOD1-G93A)- transgenic mice and Neuro2A(N2A) cells overexpressing hSOD1-G93A.

Results and Conclusions

Our results show that overexpression of hSOD1-G93A in transgenic mice decreased efficiency of mitochondrial oxidative phosphorylation, located at complex I, revealing a temporal delay in females with respect to males associated with a parallel increase in selected markers of protein oxidative damage. Further, females exhibit a fatty acid profile with higher levels of docosahexaenoic acid at 30 days. Mechanistic studies showed that hSOD1-G93A overexpression in N2A cells reduced complex I function, a defect prevented by 17β-estradiol pretreatment. In conclusion, ALS-associated SOD1 mutation leads to delayed mitochondrial dysfunction in female mice in comparison with males, in part attributable to the higher oestrogen levels of the former. This study is important in the effort to further understanding of whether different degrees of spinal cord mitochondrial dysfunction could be disease modifiers in ALS.

Electronic supplementary material

The online version of this article (doi:10.1186/s40478-015-0271-6) contains supplementary material, which is available to authorized users.

Mutant SOD1 Increases APP Expression and Phosphorylation in Cellular and Animal Models of ALS

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease and it is the most common adult onset neurodegenerative disorder affecting motor neurons. There is currently no effective treatment for ALS and our understanding of the pathological mechanism is still far away from prevention and/or treatment of this devastating disease. Amyloid precursor protein (APP) is a transmembrane protein that undergoes processing either by β-secretase or α-secretase, followed by γ-secretase. In the present study, we show that APP levels, and aberrant phosphorylation, which is associated with enhanced β-secretase cleavage, are increased in SOD1^G93A ALS mouse model. Fluorescence resonance energy transfer (FRET) analysis suggests a close interaction between SOD1 and APP at hippocampal synapses. Notably, SOD1^G93A mutation induces APP-SOD1 conformational changes, indicating a crosstalk between these two signaling proteins. Inhibition of APP processing via monoclonal antibody called BBS that blocks APP β-secretase cleavage site, resulted in reduction of mutant SOD1^G93A levels in animal and cellular models of ALS, significantly prolonged life span of SOD1^G93A mice and diminished inflammation. Beyond its effect on toxic mutant SOD1^G93A, BBS treatment resulted in a reduction in the levels of APP, its processing product soluble APPβ and pro-apoptotic p53. This study demonstrates that APP and its processing products contribute to ALS pathology through several different pathways; thus BBS antibody could be a promising neuroprotective strategy for treatment of this disease.

Mitochondrial dynamic abnormalities in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is the most common motor neuron disease characterized by progressive loss of motor neurons in the brainstem and spinal cord. Currently, there is no cure or effective treatment for ALS and the cause of disease is unknown in the majority of ALS cases. Neuronal mitochondria dysfunction is one of the earliest features of ALS. Mitochondria are highly dynamic organelles that undergo continuous fission, fusion, trafficking and turnover, all of which contribute to the maintenance of mitochondrial function. Abnormal mitochondrial dynamics have been repeatedly reported in ALS and increasing evidence suggests altered mitochondrial dynamics as possible pathomechanisms underlying mitochondrial dysfunction in ALS. Here, we provide an overview of mitochondrial dysfunction and dynamic abnormalities observed in ALS, and discuss the possibility of targeting mitochondrial dynamics as a novel therapeutic approach for ALS.

Peripheral nerve ultrasound in amyotrophic lateral sclerosis phenotypes

INTRODUCTION

In this study we sought to determine the cross-sectional area (CSA) of peripheral nerves in patients with distinct subtypes of amyotrophic lateral sclerosis (ALS).

METHODS

Ulnar and median nerve ultrasound was performed in 78 ALS patients [classic, n = 21; upper motor neuron dominant (UMND), n = 14; lower motor neuron dominant (LMND), n = 20; bulbar, n = 15; primary lateral sclerosis (PLS), n = 8] and 18 matched healthy controls.

RESULTS

Compared with controls, ALS patients had significant, distally pronounced reductions of ulnar CSA (forearm/wrist level) across all disease groups, except for PLS. Median nerve CSA (forearm/wrist level) did not differ between controls and ALS.

CONCLUSION

Ulnar nerve ultrasound in ALS subgroups revealed significant differences in distal CSA values, which suggests it has value as a marker of LMN involvement. Its potential was particularly evident in the UMND and PLS groups, which can be hard to separate clinically, yet their accurate separation has major prognostic implications.

Discrimination of spinal and bulbar muscular atrophy from amyotrophic lateral sclerosis using sensory nerve action potentials

INTRODUCTION

Spinal and bulbar muscular atrophy (SBMA) and amyotrophic lateral sclerosis (ALS) are motor neuron diseases. Sensory impairment is sometimes observed, and electrophysiological involvement has been described in the sensory nerves of SBMA patients. We hypothesized that a sensory nerve conduction study (NCS) could be used to discriminate SBMA from ALS.

METHODS

We compared the results from NCSs in a total of 120 SBMA cases confirmed by genetic analysis, 188 ALS cases, and 50 normal subjects.

RESULTS

Sensory nerve action potential (SNAP) amplitudes of the SBMA group were significantly lower than in the ALS and control groups. In addition, receiver-operating characteristic curve analysis for SNAP amplitude showed that a cut-off value of 13.8 μV for median, 10.7 μV for ulnar, and 9.9 μV for sural nerve best discriminated SBMA from ALS.

CONCLUSIONS

The specific decrease of SNAP amplitude in SBMA provides another useful tool for the differential diagnosis of motor neuron diseases.

Inhibition of amyloid precursor protein beta-secretase cleavage site affects survival and motor functions of amyotrophic lateral sclerosis transgenic mice

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease defined by motor neuron loss. Recent studies have reported an increase in amyloid precursor protein (APP) levels and in its cleavage products in ALS patients indicating their possible involvement in this disease. APP is a transmembrane protein processed either by β-secretase or α-secretase followed by γ-secretase. The APP cleavage products--soluble APP-β (sAPPβ), amyloidogenic Aβ, and amino-terminal fragment N-APP--mediate a reduction in synaptic transmission, synaptic loss, neurite retraction and, ultimately, programmed cell death.

OBJECTIVE

To elucidate the role of APP cleavage products in the pathology of ALS.

METHODS

ALS mouse models that express mutant superoxide dismutase 1 were treated intraventricularly with a monoclonal antibody that blocks the β-secretase cleavage site on APP. Levels of the APP cleavage product called sAPPβ, motor functions and survival were assessed.

RESULTS

Inhibition of APP cleavage at a presymptomatic stage resulted in a decrease in the levels of sAPPβ, delay of disease onset and deterioration while at the symptomatic stage there was almost no beneficial effect.

CONCLUSION

APP cleavage products might contribute to the degeneration in ALS, and early inhibition of the APP process may ameliorate disease progression.

Cellular and molecular biology of optineurin

Optineurin is a gene linked to glaucoma, amyotrophic lateral sclerosis, other neurodegenerative diseases, and Paget's disease of bone. This review describes the characteristics of optineurin and summarizes the cellular and molecular biology investigations conducted so far on optineurin. Data from a number of laboratories indicate that optineurin is a cytosolic protein containing 577 amino acid residues. Interacting with proteins such as myosin VI, Rab8, huntingtin, transferrin receptor, and TANK-binding kinase 1, optineurin is involved in basic cellular functions including protein trafficking, maintenance of the Golgi apparatus, as well as NF-κB pathway, antiviral, and antibacteria signaling. Mutation or alteration of homeostasis of optineurin (such as overexpression or knockdown) results in adverse consequences in the cells, leading to the development of neurodegenerative diseases including glaucoma.

Amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterised by progressive muscular paralysis reflecting degeneration of motor neurones in the primary motor cortex, corticospinal tracts, brainstem and spinal cord. Incidence (average 1.89 per 100,000/year) and prevalence (average 5.2 per 100,000) are relatively uniform in Western countries, although foci of higher frequency occur in the Western Pacific. The mean age of onset for sporadic ALS is about 60 years. Overall, there is a slight male prevalence (M:F ratio approximately 1.5:1). Approximately two thirds of patients with typical ALS have a spinal form of the disease (limb onset) and present with symptoms related to focal muscle weakness and wasting, where the symptoms may start either distally or proximally in the upper and lower limbs. Gradually, spasticity may develop in the weakened atrophic limbs, affecting manual dexterity and gait. Patients with bulbar onset ALS usually present with dysarthria and dysphagia for solid or liquids, and limbs symptoms can develop almost simultaneously with bulbar symptoms, and in the vast majority of cases will occur within 1-2 years. Paralysis is progressive and leads to death due to respiratory failure within 2-3 years for bulbar onset cases and 3-5 years for limb onset ALS cases. Most ALS cases are sporadic but 5-10% of cases are familial, and of these 20% have a mutation of the SOD1 gene and about 2-5% have mutations of the TARDBP (TDP-43) gene. Two percent of apparently sporadic patients have SOD1 mutations, and TARDBP mutations also occur in sporadic cases. The diagnosis is based on clinical history, examination, electromyography, and exclusion of 'ALS-mimics' (e.g. cervical spondylotic myelopathies, multifocal motor neuropathy, Kennedy's disease) by appropriate investigations. The pathological hallmarks comprise loss of motor neurones with intraneuronal ubiquitin-immunoreactive inclusions in upper motor neurones and TDP-43 immunoreactive inclusions in degenerating lower motor neurones. Signs of upper motor neurone and lower motor neurone damage not explained by any other disease process are suggestive of ALS. The management of ALS is supportive, palliative, and multidisciplinary. Non-invasive ventilation prolongs survival and improves quality of life. Riluzole is the only drug that has been shown to extend survival.