Familiar Amyotrophic Lateral Sclerosis Research Articles

Familiar Amyotrophic Lateral Sclerosis Linked to SOD1 and VAPB Genes

Familiar Amyotrophic Lateral Sclerosis Linked to SOD1 and VAPB Genes

Association between rare UBQLN2 variants and amyotrophic lateral sclerosis in Chinese population

Objective: To explore the association between rare UBQLN2 variants and amyotrophic lateral sclerosis (ALS) in Chinese population, and the characteristic of phenotypes of their carriers. Methods: A total of 166 ALS patients who visited Department of Neurology of Peking University Third Hospital between January 2018 and July 2020 were recruited. The next-generation sequencing was performed to screen possible pathogenic rare variants of UBQLN2. Meanwhile, control individuals were obtained from 1000 Genome Project (2 504 samples) and an in-house whole-exome sequencing database (1 812 samples), separately. The sequence kernel association test (SKAT) and the SKAT-optimal test (SKAT-O) were used to identify the association between UBQLN2 rare variants and ALS. The clinical characteristics of rare variant carriers were analyzed. Results: A total of 33 familiar ALS and 133 sporadic ALS of Chinese ancestry were enrolled. Of the 166 ALS patients, 12.7% had bulbar-onset, 85.5% had limb-onset, and 5 cases were ALS with frontotemporal dementia (3.0%). The male-to-female ratio was 1.68∶1, with a mean age at symptom onset of (43.8±12.2) years. Three possible pathogenic rare variants of UBQLN2 were detected, including c.128A>G (p.Lys43Arg), c.142G>T (p.Val48Leu) and c.1451T>G (p.Val484Gly), and all of them were novel missense mutations. Compared with 1000 Genome Project, SKAT and SKAT-O showed a P value of 2.49×10-6 and 9.22×10-7, respectively. While compared with the in-house database, SKAT and SKAT-O revealed a P value of 1.42×10-3 and 1.10×10-3, respectively. Patients who carried rare UBQLN2 variants were with a higher rate of bulbar-onset (2/3 vs 19/163, P=0.042). Conclusion: Rare variants of UBQLN2 are associated with ALS in Chinese population, and mutation of UBQLN2 may be relevant to bulbar-onset.

Speech intelligibility in people with Amyotrophic Lateral Sclerosis (ALS).

To evaluate speech intelligibility and dysarthria, correlated to the functional assessment of Amyotrophic Lateral Sclerosis (ALS). Quantitative-descriptive study approved by REC under No. CAAE 62912416.4.0000.5404, comprised of 19 individuals with sporadic or familiar ALS. Data were collected using the Dysarthria Protocol and the Revised Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS-Re). We used visual analogue scale (VAS) to assess speech intelligibility and summary measures; and Spearman's coefficients of correlation for the instruments with significance level of 5%. Speech intelligibility is compromised (41.37±39.73) in varied degrees with positive correlation with the general degree of dysarthria (p=<.0001), and with all the analyzed speech parameters, indicating impact on the speech deterioration of the studied group. There is negative correlation between speech intelligibility and the results of the bulbar sections - speech and deglutition (p=0.0166), arm - activities with the upper limb (p=0.0064) and leg - activities with the lower limb (p=0.0391). Breathing (p=0.0178), phonation (p=0.0334) and resonance (p=0.0053) parameters showed a negative correlation with the item "speech" of the ALSFRS-Re. Results show impaired speech intelligibility and dysarthria, and evidence breathing, phonation and resonance as important markers of the disease progression. A thorough and early evaluation of the oral motor production allows for a better management of alterations in ALS.

Motor neuron degeneration, severe myopathy and TDP-43 increase in a transgenic pig model of SOD1-linked familiar ALS

Amyotrophic Lateral Sclerosis (ALS) is a neural disorder gradually leading to paralysis of the whole body. Alterations in superoxide dismutase SOD1 gene have been linked with several variants of familial ALS. Here, we investigated a transgenic (Tg) cloned swine model expressing the human pathological hSOD1G93A allele. As in patients, these Tg pigs transmitted the disease to the progeny with an autosomal dominant trait and showed ALS onset from about 27 months of age. Post mortem analysis revealed motor neuron (MN) degeneration, gliosis and hSOD1 protein aggregates in brainstem and spinal cord. Severe skeletal muscle pathology including necrosis and inflammation was observed at the end stage, as well. Remarkably, as in human patients, these Tg pigs showed a quite long presymptomatic phase in which gradually increasing amounts of TDP-43 were detected in peripheral blood mononuclear cells. Thus, this transgenic swine model opens the unique opportunity to investigate ALS biomarkers even before disease onset other than testing novel drugs and possible medical devices.

Molecular Taxonomy of Sporadic Amyotrophic Lateral Sclerosis Using Disease-Associated Genes

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by selective loss of upper and lower motor neurons. Despite intensive research, the origin and progression of ALS remain largely unknown, suggesting that the traditional clinical diagnosis and treatment strategies might not be adequate to completely capture the molecular complexity underlying the disease. In our previous work, comprehensive genomic profiling of 41 motor cortex samples enabled to discriminate control from sporadic ALS patients and segregated these latter into two distinct subgroups, each associated with different deregulated genes and pathways. Interestingly, some deregulated genes in sporadic ALS were previously associated with familiar ALS, indicating shared pathogenic mechanisms between the two forms of disease. In this, we performed cluster analysis on the same whole-genome expression profiles using a restricted (203) subset of genes extensively implicated in monogenic forms of ALS. Surprisingly, this short and unbiased gene list was sufficiently representative to allow the accurate separation of SALS patients from controls and the stratification of SALS patients into two molecularly distinct subgroups. Overall, our findings support the existence of a molecular taxonomy for ALS and represent a further step toward the establishment of a molecular-based diagnosis and patient-tailored therapies.

Epigenetic Mechanisms of Gene Regulation in Amyotrophic Lateral Sclerosis.

Despite being clinically described 150 years ago, the mechanisms underlying amyotrophic lateral sclerosis (ALS) pathogenesis have not yet been fully understood. Studies in both animal models of ALS and human patients reveal a plethora of alterations such as increased glutamate-mediated excitotoxicity, redox stress, increased apoptosis, defective axonal transport, protein-misfolding events, mitochondrial impairment and sustained unregulated immune responses. Regardless of being sporadic or familiar ALS, the final outcome at the cellular level is the death of upper and lower motor neurons, and once diagnosed, ALS is typically lethal within the next 5 years. There are neither clear biomarkers nor therapeutic or disease-modifying treatments for ALS.Accumulating evidence supports the concept that epigenetic-driven modifications, including altered chromatin remodelling events, RNA editing and non-coding RNA molecules, might shed light into the pathogenic mechanisms underlying sporadic/familiar ALS onset and/or severity to facilitate the identification of effective therapies, early diagnosis and potentially early-stage therapeutic interventions to increase the survival outcome of ALS patients.

Anti-Sulfoglucuronosyl Paragloboside Antibody: A Potential Serologic Marker of Amyotrophic Lateral Sclerosis.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by progressive degeneration of upper and lower motor neurons. Although the etiology of ALS is obscure, genetic studies of familiar ALS suggest a multifactorial etiology for this condition. Similarly, there probably are multiple causes for sporadic ALS. Autoimmune-mediated motor neuron dysfunction is one proposed etiology for sporadic ALS. In the present study, anti-glycolipid antibodies including GM1, GD1b, GD3, and sulfoglucuronosyl paragloboside (SGPG) were investigated in the sera of a large number of patient samples, including 113 ALS patients and 50 healthy controls, by means of enzyme-linked immunosorbent assay with affinity parametric complex criterion evaluation and thin-layer chromatography immunooverlay (immuno-TLC). Anti-SGPG antibodies were found in the sera of 13.3% ALS patients (15 out of 113). The highest titer reached 1:1600. The presence of anti-SGPG antibodies in the serum samples was also confirmed by immuno-TLC. Importantly, a multiple logistic regression analysis showed that the presence of anti-SGPG antibody was positively correlated with age (p < .01) and negatively correlated with ALS Functional Rating Scale score (p < .05). Moreover, the localization of SGPG-immunoreactivity on the motor neurons of rat spinal cord and a mouse motor neuronal cell line, NSC-34 was observed by an immunofluorescence method. These data suggest that SGPG could represent a specific pathogenic antigen in those ALS patients. The presence of anti-SGPG antibodies in the serum of ALS patients should represent a diagnostic biomarker of ALS, and it could reflect the severity of the disease.

Molecular classification of amyotrophic lateral sclerosis by unsupervised clustering of gene expression in motor cortex

Amyotrophic lateral sclerosis (ALS) is a rapidly progressive and ultimately fatal neurodegenerative disease, caused by the loss of motor neurons in the brain and spinal cord. Although 10% of ALS cases are familial (FALS), the majority are sporadic (SALS) and probably associated to a multifactorial etiology. Currently there is no cure or prevention for ALS. A prerequisite to formulating therapeutic strategies is gaining understanding of its etio-pathogenic mechanisms. In this study we analyzed whole-genome expression profiles of 41 motor cortex samples of control (10) and sporadic ALS (31) patients. Unsupervised hierarchical clustering was able to separate control from SALS patients. In addition, SALS patients were subdivided in two different groups that were associated to different deregulated pathways and genes, some of which were previously associated to familiar ALS. These experiments are the first to highlight the genomic heterogeneity of sporadic ALS and reveal new clues to its pathogenesis and potential therapeutic targets.

Early presymptomatic cholinergic dysfunction in a murine model of amyotrophic lateral sclerosis

Sporadic and familiar amyotrophic lateral sclerosis (ALS) cases presented lower cholinergic activity than in healthy individuals in their still preserved spinal motoneurons (MNs) suggesting that cholinergic reduction might occur before MN death. To unravel how and when cholinergic function is compromised, we have analyzed the spatiotemporal expression of choline acetyltransferase (ChAT) from early presymptomatic stages of the SOD1G93A ALS mouse model by confocal immunohistochemistry. The analysis showed an early reduction in ChAT content in soma and presynaptic boutons apposed onto MNs (to 76%) as well as in cholinergic interneurons in the lumbar spinal cord of the 30-day-old SOD1G93A mice. Cholinergic synaptic stripping occurred simultaneously to the presence of abundant surrounding major histocompatibility complex II (MHC-II)-positive microglia and the accumulation of nuclear Tdp-43 and the appearance of mild oxidative stress within MNs. Besides, there was a loss of neuronal MHC-I expression, which is necessary for balanced synaptic stripping after axotomy. These events occurred before the selective raise of markers of denervation such as ATF3. By the same time, alterations in postsynaptic cholinergic-related structures were also revealed with a loss of the presence of sigma-1 receptor, a Ca2+ buffering chaperone in the postsynaptic cisternae. By 2 months of age, ChAT seemed to accumulate in the soma of MNs, and thus efferences toward Renshaw interneurons were drastically diminished. In conclusion, cholinergic dysfunction in the local circuitry of the spinal cord may be one of the earliest events in ALS etiopathogenesis.

P4. A patient with familiar Amyotrophic Lateral Sclerosis (ALS) carrying the C9orf72 repeat expansion: Clinical picture and review of literature

Amyotrophic Lateral Sclerosis (ALS) is a progressive neurodegenerative disorder of upper and lower motor neuron disorder and is associated with frontotemporal dementia in about 14% of cases. Recently identified C9orf72 expansion in familiar and apparently sporadic cases of ALS seems to present a peculiar and recognisable phenotype. We describe a case of 50-years old patient who developed rapidly progressive spastic paraparesis, followed by appearance of generalized symptoms and signs of the first and second motor neuron disorder, fulfilling clinical and electrophysiological diagnostic criteria of ALS. The cerebral MRI showed marked hyperintensity of pyramidal tracts. In the following months cognitive, especially executive changes appeared. The clinical course was extremely rapid, with consecutively bulbar and respiratory involvement within 6 month after onset. The patient refused both non invasive and invasive ventilation and percutaneous gastrostomy and died 1 year after diagnosis. As in family history his father died at the age of 60 from define ALS after 2 years since onset, an extensive genetic testing for familiar ALS forms has been performed. Mutation in Superoxide Dismutase 1 (SOD 1) gene was firstly excluded. Mutations in Angiogenin gene (ANG), Fused In Sarcoma gene (FUS), Tar DNA binding Protein (TARDPB) gene and optineurin (OPTN) gene were also excluded. However the patient carried C9orf72 hexanucleotide repeat expansion. The expansion of C9orf72 has been recently described in patients from different geographical regions. The clinical picture is not homogeneous but patients share some common characteristic as younger age at onset, autosomal dominant inheritance, rapid progression and presence of cognitive and behavioural changes similar to frontotemporal dementia. The radiological picture may show, together with pyramidal tracts hyperintensity, also grey matter volume loss.

Mitochondria and ALS: Implications from novel genes and pathways

Evidence from patients with sporadic and familiar amyotrophic lateral sclerosis (ALS) and from models based on the overexpression of mutant SOD1 found in a small subset of patients, clearly point to mitochondrial damage as a relevant facet of this neurodegenerative condition. In this mini-review we provide a brief update on the subject in the light of newly discovered genes (such as TDP-43 and FUS/TLS) associated to familial ALS and of a deeper knowledge of the mechanisms of derangement of mitochondria. This article is part of a Special Issue entitled 'Mitochondrial function and dysfunction in neurodegeneration'.

Differences in Motor Unit Loss and Axonal Regeneration Rate between Sporadic and Familiar Amyotrophic Lateral Sclerosis: An Undervalued Field of Research?

Amyotrophic Lateral Sclerosis (ALS) is a clinically and genetically heterogeneous, late-onset, neurodegenerative disorder of the motor system [1]. Five to ten percent of cases are familial and about 20% of these cases have point mutations in the Cu/Zn superoxide dismutase 1 (SOD-1) gene. Since its discovery, mutations in Cu/Zn superoxide dismutase (SOD-1) have stimulated a huge amount of interest [2], but the pathogenic mechanisms underlying disease’s induction in familiar cases are still elusive. The most accepted hypothesis is that familiar ALS, SOD-1 positive could be caused by a neuronal damage, due to a gradual accumulation of a toxic product SOD-1 this cumulative damage leads to a disruption of the cytoskeleton and organelle trafficking within motor neuron dendrites. Aggregates do not exclusively occur in neurons, but also in glial cells, raising the question of whether mutant SOD-1 expression in neurons is sufficient per se to induce pyramidal degeneration and sustain disease evolution over time [3]. The familial form is clinically indistinguishable from the sporadic one and to date only few studies have tried to highlight electromyographic differences between sporadic and familiar ALS forms.

Differential Motor Neuron Impairment and Axonal Regeneration in Sporadic and Familiar Amyotrophic Lateral Sclerosis with SOD-1 Mutations: Lessons from Neurophysiology

Amyotrophic Lateral Sclerosis (ALS) is a degenerative disorder of the motor system. About 10% of cases are familial and 20% of these families have point mutations in the Cu/Zn superoxide dismutase 1 (SOD-1) gene. SOD-1 catalyses the superoxide radical (O−2) into hydrogen peroxide and molecular oxygen. The clinical neurophysiology in ALS plays a fundamental role in differential diagnosis between the familial and sporadic forms and in the assessment of its severity and progression. Sixty ALS patients (34 males; 26 females) were enrolled in the study and examined basally (T0) and every 4 months (T1, T2, and T3). Fifteen of these patients are SOD-1 symptomatic mutation carriers (nine males, six females). We used Macro-EMG and Motor Unit Number Estimation (MUNE) in order to evaluate the neuronal loss and the re-innervation process at the onset of disease and during follow-up period. Results and Discussion: SOD-1 mutation carriers have a higher number of motor units at the moment of diagnosis when compared with the sporadic form, despite a more dramatic drop in later stages. Moreover, in familiar SOD-1 ALS there is not a specific time interval in which the axonal regeneration can balance the neuronal damage. Taken together, these results strengthen the idea of a different pathogenetic mechanism at the base of sALS and fALS.

Screening of mutations in &lt;I&gt;SOD1&lt;/I&gt; gene and analysis of geno-type-phenotype correlation in Chinese patients with amyotrophic lateral sclerosis

In this study, we screened for the Cu/Zn superoxide dismutase (SOD1) mutations in 8 probands who had been clinically diagnosed with familiar amyotrophic lateral sclerosis (FALS) using PCR and direct sequencing. Two known mutations were detected in the three probands. Two probands carried the same Cys111Tyr (c.332G > A) mutation in exon 4, and others carried Gly147Asp (c.440G > A) mutation in exon 5. These two mutations were first reported in the Chinese ALS patients. After reviewing all clinical data of these three pedigrees, we found that Cys111Tyr led to a relatively mild phenotype and Gly147Asp displayed a rapidly progression, which needs to be confirmed by further study in more ALS patients. In conclusion, this study extends the spectrum of SOD1 mutations in the Chinese FALS patients and facilitates to investigate characteristics and distribution of SOD1 mutations in the Chinese population.

In vivo imaging reveals rapid morphological reactions of astrocytes towards focal lesions in an ALS mouse model

Pathophysiology of the motoneuron disease amyotrophic lateral sclerosis (ALS) is non-cell-autonomous. In mouse models of familiar ALS, neurotoxicity is derived not only from mutant motor neurons but also from mutant neighbouring glial cells. In vivo imaging by two-photon laser-scanning microscopy was used to study rapid morphological reactions of astroglial cells towards laser-induced axonal transection in ALS-linked transgenic SOD1G93A mice. In the affected lateral spinal cord, mutated astroglial cells extended branches towards injured axons within a time frame of minutes to hours post lesion while in control animals astrocytes lack any rapid morphological alteration within the studied time frame. This suggests that astrocytes partially contribute to the rapid response of non-neuronal cells to acute axonal lesions in ALS mice.

Familiar amyotrophic lateral sclerosis (FALS)-linked SOD1 mutation accelerates neuronal cell death by activating cleavage of caspase-4 under ER stress in an in vitro model of FALS

Recently, endoplasmic reticulum (ER) dysfunction has been implicated in the pathogenesis of familial amyotrophic lateral sclerosis (FALS). Although up-regulation of caspase-12 has been reported in G93A SOD1 transgenic mice, it is controversial whether similar mechanisms operate in human FALS. We found that ER stress in cells stably expressing L84V SOD1 induces neuronal cell death and accelerates cleavage of caspase-4. We also detected oligomer formation of L84V SOD1 in L84V SOD1-expressing human neuroblastoma cells. These findings show that ER stress in L84V SOD1-expressing human cells causes the aggregation and inclusion bodies of L84V SOD1 to induce neuronal death through the accelerated cleavage of caspase-4.

Molecular Dynamics Simulations of the Enzyme Cu, Zn Superoxide Dismutase

The enzyme Cu, Zn superoxide dismutase (Cu,Zn-SOD) is a ubiquitous oxireductase, which is responsible for the cellular defense against oxidative stress caused by the high toxicity of the superoxide radical, and has been also linked to some cases of familiar amyotrophic lateral sclerosis. In the present study a set of molecular mechanics parameters for the active site of Cu,Zn-SOD has been derived. Afterward, an extensive molecular dynamics simulation has been carried out in an aqueous environment. The obtained results shed a further light on the structural flexibility of the backbone, where the active site is nested, and the solvation shell occupancy. The relatively small backbone deviation, shown by a root-mean-square deviation below 1.0 A, confirms the accuracy of the parameters. The solvent shell analysis has shown that the first solvation shell is located at about 5 A from the copper ion, generating an empty cavity with enough space to accommodate the superoxide radical. The low residence time means that a high permutation rate of water molecules in both solvation shells is consistent with the efficiency of this catalytic mechanism. Hybrid studies using ONIOM methodologies can now be done to evaluate the mechanistic implications of the explicit inclusion of the whole system.

Liquid chromatographic assay for riluzole in mouse plasma and central nervous system tissues

An isocratic, reversed-phase high-performance liquid chromatographic procedure (HPLC) was developed for determination of the neuroprotective agent riluzole in mice plasma, brain and spinal cord. The procedure is based on isolation of the compound and the internal standard from plasma and central nervous system tissues using a Bakerbond spe™ C8 cartridge, with satisfactory recovery and specificity. Separation was on a C18 column, coupled with an UV detector at 263 nm. The assay was linear over a wide range, with a lower limit of quantification of 100 ng ml −1 or g −1 using 0.1 ml of plasma and about 100 mg of brain tissue. The precision and accuracy were within the acceptable limits for an HPLC assay. The method is currently used to support pharmacological studies of the activity of riluzole when given in combination with other potential neuroprotective agents in an animal model of familiar amyotrophic lateral sclerosis (SOD1-G93A transgenic mice).