AbstractAmyotrophic Lateral Sclerosis Patients Research Articles

Physical activity as an exogenous risk factor for amyotrophic lateral sclerosis: a review of the evidence.

Amyotrophic lateral sclerosis (ALS) is a rapidly progressive and fatal neurodegenerative disorder. The only established epidemiological risk factors for ALS are male sex and increasing age. The role of physical activity has been debated as an environmental risk factor. Over the last decade multiple studies have attempted to delineate the architecture of ALS. These have not yet established definite risk factors, often due to low-powered studies, lack of focus on at-risk genotypes and sub-optimal methodology. We have conducted a review of all the studies published between 2009 and December 2021. The free text search terms were [(motor neuron disease) OR (MND) OR (Amyotrophic Lateral Sclerosis) OR (ALS)] AND [(Exercise) or (Physical Activity) or (PA) or (sport)]. We identified common themes, for example soccer, head injury and the physiological mechanisms that differ in ALS patients. We have analysed the relevant, available studies (n = 93), highlighting the underlying reasons for any reported discrepancies. Overall, we have found that the more highly powered studies using validated exposure methodologies, linked strenuous, anaerobic physical activity as a risk factor for ALS. Future large-scale studies focusing on specific at-risk genotypes and physical activity should be conducted to confirm this finding. This will strengthen the evidence already surrounding strenuous physical activity as an environmental risk factor for ALS and allow advice to be given to at-risk family members. Increasing our understanding of the genetic-environmental interactions in the pathophysiology of ALS will allow for the possibility of developing preventative therapeutic approaches.

Heat shock protein Grp78/BiP/HspA5 binds directly to TDP-43 and mitigates toxicity associated with disease pathology

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with no cure or effective treatment in which TAR DNA Binding Protein of 43 kDa (TDP-43) abnormally accumulates into misfolded protein aggregates in affected neurons. It is widely accepted that protein misfolding and aggregation promotes proteotoxic stress. The molecular chaperones are a primary line of defense against proteotoxic stress, and there has been long-standing interest in understanding the relationship between chaperones and aggregated protein in ALS. Of particular interest are the heat shock protein of 70 kDa (Hsp70) family of chaperones. However, defining which of the 13 human Hsp70 isoforms is critical for ALS has presented many challenges. To gain insight into the specific Hsp70 that modulates TDP-43, we investigated the relationship between TDP-43 and the Hsp70s using proximity-dependent biotin identification (BioID) and discovered several Hsp70 isoforms associated with TDP-43 in the nucleus, raising the possibility of an interaction with native TDP-43. We further found that HspA5 bound specifically to the RNA-binding domain of TDP-43 using recombinantly expressed proteins. Moreover, in a Drosophila strain that mimics ALS upon TDP-43 expression, the mRNA levels of the HspA5 homologue (Hsc70.3) were significantly increased. Similarly we observed upregulation of HspA5 in prefrontal cortex neurons from human ALS patients. Finally, overexpression of HspA5 in Drosophila rescued TDP-43-induced toxicity, suggesting that upregulation of HspA5 may have a compensatory role in ALS pathobiology.

Targeted Screening of the C9orf72 Gene in Bulgarian Amyotrophic Lateral Sclerosis Patients

Abstract Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease, characterized by progressive degeneration of the upper and lower motor neurons, leading to muscle weakness, hypotrophy, swallowing and respiratory failure. The cause of ALS is not yet fully elucidated, but there are 35 associated genes and 2 gene loci with an unidentified gene. The most common are C9orf72, SOD1, TARDBP and FUS found in approximately 10% of patients. Variants in the C9orf72 gene are the main cause of fALS – 25-40% of cases (and a small percentage of sALS). The goal of the present study was to evaluate the significance of the C9orf72 hexanucleotide repeat expansion in Bulgarian patients with ALS, through the means of in house and triplet repeat-primed PCR assay (TP-PCR). From 171 patients diagnosed with ALS and included in the current study, we have identified the repeat expansion with more than 145 GGGGCC repeats in 7 (4,1%). Short expansions or borderline values (24 to 30 repeats) were not detected. Due to absence of sufficient data, we have established an ALS-focused research for the association of the C9orf72 gene in clinically well-characterized Bulgarian ALS patients. Published data show variable percentage ratios for genetically verified cases (4-40%), which is mainly due to small sample counts and sALS-fALS ratios. Our patients’ group also contains sALS and fALS cases, which explains the low percentage of genetic verification. The obtained results enrich the worldwide database and shed light onto genetically characterized Bulgarian ALS patients. Affected patients and their families can receive adequate medical-genetic consultation and prenatal diagnostic testing.

Cortical Hyperexcitability in the Driver’s Seat in ALS

Amyotrophic lateral sclerosis (ALS) is a fatal disease characterized by the degeneration of cortical and spinal motor neurons. With no effective treatment available to date, patients face progressive paralysis and eventually succumb to the disease due to respiratory failure within only a few years. Recent research has revealed the multifaceted nature of the mechanisms and cell types involved in motor neuron degeneration, thereby opening up new therapeutic avenues. Intriguingly, two key features present in both ALS patients and rodent models of the disease are cortical hyperexcitability and hyperconnectivity, the mechanisms of which are still not fully understood. We here recapitulate current findings arguing for cell autonomous and non-cell autonomous mechanisms causing cortical excitation and inhibition imbalance, which is involved in the degeneration of motor neurons in ALS. Moreover, we will highlight recent evidence that strongly indicates a cardinal role for the motor cortex as a main driver and source of the disease, thus arguing for a corticofugal trajectory of the pathology.

Safety and Efficacy of Allogeneic Adipose Tissue Mesenchymal Stromal Cells in Amyotrophic Lateral Sclerosis Patients, Single-Center, Prospective, Open-Label, Single-Arm Clinical Trial, Long-Term Follow-up.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder with very limited treatment options. Stem cells have been raised as a new treatment modality for these patients. We have designed a single-center, prospective, open-label, and single arm clinical trial to assess the safety, feasibility, and rather efficacy of administrating allogeneic adipose-derived mesenchymal stromal cells (Ad-MSCs) in ALS patients. We enrolled 17 patients with confirmed ALS diagnosis with ALS Functional Rating Scale-Revised (ALSFRS-R) ≥24 and predicted forced vital capacity (FVC) ≥40%. Allogeneic Ad-MSCs were transplanted intravenously for all patients. Follow-ups were done at 24 hours, 2, 4, 6, and 12 months after cell infusion by checking adverse events, laboratory tests, and clinically by ALSFRS-R and FVC. Patients were also followed five years later and ALSFRS-R score was recorded in the survived individuals. There was no report of severe adverse events related to cell infusion. Two patients experienced dyspnea and chest pain 36 and 65 days after cell infusion due to pulmonary emboli. The progressive decrease in ALSFRS-R and FVC levels was recorded and three patients died in the first year. During five years follow up, despite a notable decrease in functional scores, 5 patients survived. Intravenous (IV) infusion of allogeneic Ad-MSCs in ALS patients is safe and feasible. The survival rate of the patients is more than IV autologous MSCs (Registration number: IRCT20080728001031N26).

Novel chemical inhibitor against SOD1 misfolding and aggregation protects neuron-loss and ameliorates disease symptoms in ALS mouse model

Amyotrophic Lateral Sclerosis (ALS) is a fatal neurodegenerative disease characterized by selective death of motor neurons. Mutations in Cu, Zn-superoxide dismutase (SOD1) causing the gain of its toxic property are the major culprit of familial ALS (fALS). The abnormal SOD1 aggregation in the motor neurons has been suggested as the major pathological hallmark of ALS patients. However, the development of pharmacological interventions against SOD1 still needs further investigation. In this study, using ELISA-based chemical screening with wild and mutant SOD1 proteins, we screened a new small molecule, PRG-A01, which could block the misfolding/aggregation of SOD1 or TDP-43. The drug rescued the cell death induced by mutant SOD1 in human neuroblastoma cell line. Administration of PRG-A01 into the ALS model mouse resulted in significant improvement of muscle strength, motor neuron viability and mobility with extended lifespan. These results suggest that SOD1 misfolding/aggregation is a potent therapeutic target for SOD1 related ALS.

Influence of a clinical trial in the decision-making processes of patients with amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is an incurable neurological disease, and patients diagnosed with ALS have a survival time of 2-5years without life-sustaining therapy. Decision-making processes for the acceptance or decline of percutaneous endoscopic gastrostomy (PEG) and tracheostomy with invasive ventilation (TIV) therapy are complex and multifaceted. In this study, we examined whether participation or no participation in clinical trials of ALS had an influence on the decision-making processes of ALS patients. Fifty-seven consecutive ALS participants were recruited. Two participants did not wish to participate in any clinical trials, and Twenty-two participants were enrolled in clinical trials. Twenty-three participants wished to participate but could not be enrolled in any of the clinical trials because they exceeded the number of participants in these trials or they met the exclusion criteria. At baseline, there was no significant difference in the preference rates for PEG and TIV between the participant and non-participant groups, but after the double-blind period/6months, both preference rates were significantly higher in the non-participant group than in the participant group. Notably, the rate of preferred TIV in the participant group drastically decreased after the double-blind period. A single regression analysis revealed that participation in clinical trials had a strong influence on the change of TIV preference for 6months. Participation in a clinical trial decreases the willingness to prolong life after the clinical trial. The present results are meaningful when designing clinical trials and discussing life-sustaining treatments with ALS patients.

γ' Fibrinogen as a Predictor of Survival in Amyotrophic Lateral Sclerosis.

Amyotrophic lateral sclerosis (ALS) is an aggressive neurodegenerative disorder related to neuroinflammation that is associated with increased risk of thrombosis. We aimed to evaluate γ' fibrinogen plasma level (an in vivo variant of fibrinogen) as a biomarker in ALS, and to test its role as a predictor of disease progression and survival. Sixty-seven consecutive patients with ALS were followed and the results were compared with those from 82 healthy blood donors. Patients were clinically evaluated at the time of blood sampling and on follow-up (every 3 months for the beginning of the follow-up until death) by applying the revised ALS Functional Rating Scale. Human plasma γ' fibrinogen concentration was quantified using a specific two-site sandwich kit enzyme-linked immunosorbent assay. We found, for the first time, a positive association between γ' fibrinogen concentration and survival in ALS patients: patients with higher γ' fibrinogen plasma levels survived longer, and this finding was not influenced by confounders such as age, gender, respiratory impairment, or functionality (ALSFRS-R score). Since increased levels have a positive impact on outcome, this novel biomarker should be further investigated in ALS.

Mitochondrial genome variations are associated with amyotrophic lateral sclerosis in patients from mainland China.

Amyotrophic lateral sclerosis (ALS) is a late-onset neurodegenerative disorder. Mitochondrial dysfunction is involved in the complex pathophysiology of ALS; however, the role of mitochondrial DNA (mtDNA) variants in ALS is poorly understood. We aimed to elucidate the role of mtDNA variants in the pathogenesis of ALS. The mitochondrial haplogroups of 585 ALS patients and 371 healthy controls were determined; 38 ALS patients and 42 controls underwent long-range polymerase chain reaction combined with next-generation sequencing technology to analyze whole mitochondrial genome variants. A higher percentage of variants accumulated in ALS patients than in controls. Analysis of coding region variations that were further stratified by mtDNA genes revealed that nonsynonymous variants were more vulnerable in ALS patients than in controls, particularly in the ND4L, ND5, and ATP8 genes. Moreover, pathogenic nonsynonymous variants tended to over-represent in ALS patients. Unsurprisingly, nonsynonymous variants were not related to the phenotype. Haplogroup analysis did not found evidence of association between haplogroups with the risk of ALS, however, patients belonging to haplogroup Y and M7c were prone to develop later onset of ALS. This is the first study to profile mtDNA variants in ALS patients from mainland China. Our results suggest that an increase in the number of nonsynonymous variants is linked to the pathogenesis of ALS. Moreover, haplogroup Y and M7c may modulate the clinical expression of ALS. Our findings provide independent, albeit limited, evidence for the role of mtDNA in the pathogenesis of ALS.

Mutation Screening of the GLE1 Gene in a Large Chinese Cohort of Amyotrophic Lateral Sclerosis Patients.

Amyotrophic lateral sclerosis (ALS) is a fatal progressive neurodegenerative disease involving the upper and lower motor neurons of the spinal cord, brainstem, and cerebral cortex. At least 30 genes have been implicated in familial ALS (fALS) and sporadic ALS (sALS). Kaneb et al. (2015) first carried out a large-scale sequencing study in ALS patients and identified two loss-of-function (LOF) variants in the GLE1 gene. The LOF mutation-induced disruption of RNA metabolism through the haploinsufficiency mechanism is implicated in ALS pathogenesis. A total of 628 ALS patients and 522 individuals without neurodegenerative disorders were enrolled in this study to explore the GLE1 gene contribution to ALS in the Chinese population. All 16 exons and the flanking intron of GLE1 were screened by Sanger sequencing. In total, we identified seven rare GLE1 coding variants, including one novel nonsense mutation and six rare missense mutations in 628 ALS patients. The frequency of GLE1 LOF mutations was 0.16% (1/628) among Chinese sALS patients, implying that it is an uncommon genetic determinant of ALS in Chinese patients. Additionally, the rare missense variants in the hCG1-binding domain of GLE1 impairing the distribution of the hGle1B isoform at the nuclear pore complex (NPC) region may be involved in the pathogenesis of ALS.

Continuing Non-Invasive Ventilation During Amyotrophic Lateral Sclerosis-Related Hospice Care Is Medically, Administratively, and Financially Feasible.

Amyotrophic Lateral Sclerosis (ALS) is a terminal neuromuscular disease with patients dying within 3-5 years of diagnosis. Most patients choose to forego invasive life sustaining measures. Timing of hospice referral can be challenging given the advancement of non-invasive ventilation (NIV) technology. To describe the characteristics of patients enrolled in hospice from an ALS clinic at 1 academic medical center and to perform a cost analysis for patients who remained on ventilator support. Retrospective cross-sectional study of patients enrolled in hospice over a 2-year period. Clinical characteristics included ALS Functional Rating Scale Revised (ALSFRS-R) score, Forced Vital Capacity (FVC), use of NIV and mechanical insufflation-exsufflation (MIE), riluzole use, and length of stay in hospice. A cost analysis was performed for patients enrolled in Duke Home Care and Hospice. 85 of 104 patients who died were enrolled in hospice. Median days enrolled in hospice was 84. Patients who continued on NIV had similar hospice length of stay as those on no respiratory support (88 versus 80 days, p = 0.83). Bulbar patients had a trend toward shorter length of stay in hospice than limb onset patients (71 versus 101 days, p = 0.49). Cost analysis showed that hospice maintained a mean net operating revenue of $3234.50 per patient who continued on NIV. Hospice referrals for ALS patients on NIV can be challenging. This study shows that even with continued NIV use, most ALS patients die within the expected 6 months on home hospice, and care remains cost effective for hospice agencies.

Humoral Influence of Repeated Lineage-Negative Stem/Progenitor Cell Administration on Articulatory Functions in ALS Patients.

Amyotrophic lateral sclerosis (ALS) remains a fatal, neurodegenerative disease frequently leading to dysarthria and impaired swallowing. Better understanding of ALS pathophysiology is prompting the use of humoral cell therapies. Hence, a repeated cellular therapy was applied to ALS patients as an attempt to prevent speech deterioration. Autologous bone marrow-derived lineage-negative (Lin−) cells were intrathecally administered three times at six-week intervals to 42 sporadic ALS patients. Patients were examined for articulatory functions using subjective (VHI) and objective (FDA) scales. Selected trophic, proinflammatory factors and expression profiles of miRNA were measured in cerebrospinal fluid (CSF) and plasma by multiplex Luminex and q-PCR in different timepoints. Of the 42 patients who received the Lin− cells, 6 showed improvement in articulatory functions, 27 remained stable, and 9 deteriorated after 18 weeks of therapy according to FDA scale. Clinical improvement was particularly evident by the 7th day of each cell application and concerned better cough and swallow reflex, soft palate, laryngeal time, pitch, and volume. These results correlated with significant changes in the concentration of various trophic and proinflammatory factors and miRNA expression profiles. A multiple application of Lin− cells proved to be safe and feasible. The repeated procedure can potentate a humoral effect and prevent speech deterioration. A short-lasting trophic effect of each Lin− cells administration was observed on local and systemic level. However, further in-depth studies are necessary to sustain the beneficial effect.

Utility of phrenic nerve ultrasound in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder affecting the upper and lower motor neurons causing progressive weakness. It eventually involves the diaphragm which leads to respiratory paralysis and subsequently death. Phrenic nerve (PN) conduction studies and diaphragm ultrasound has been studied and correlated with pulmonary function tests in ALS patients. However, PN ultrasonography has not been employed in ALS. This study aims to sonographically evaluate the morphologic appearance of the PN of ALS patients. Thirty-eight ALS patients and 28 normal controls referred to the neurophysiology laboratory of two institutions were retrospectively included in the study. Baseline demographic and clinical variables such as disease duration, ALS Functional Rating Scale-Revised score, and ALS region of onset were collected. Ultrasound was used to evaluate the PN cross-sectional area (CSA) of ALS and control subjects. The mean PN CSA of ALS patients were 1.08 ± 0.39 mm on the right and 1.02 ± 0.34 mm on the left. The PN CSA of ALS patients were significantly decreased compared to controls (p value < 0.00001). The PN CSA of ALS patients was not correlated to any of the demographic and clinical parameters tested. This study demonstrates that ALS patients have a smaller PN size compared to controls using ultrasonography.

Therapeutic benefit of Muse cells in a mouse model of amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by progressive motor neuron loss. Muse cells are endogenous reparative pluripotent-like stem cells distributed in various tissues. They can selectively home to damaged sites after intravenous injection by sensing sphingosine-1-phosphate produced by damaged cells, then exert pleiotropic effects, including tissue protection and spontaneous differentiation into tissue-constituent cells. In G93A-transgenic ALS mice, intravenous injection of 5.0 × 104 cells revealed successful homing of human-Muse cells to the lumbar spinal cords, mainly at the pia-mater and underneath white matter, and exhibited glia-like morphology and GFAP expression. In contrast, such homing or differentiation were not recognized in human mesenchymal stem cells but were instead distributed mainly in the lung. Relative to the vehicle groups, the Muse group significantly improved scores in the rotarod, hanging-wire and muscle strength of lower limbs, recovered the number of motor neurons, and alleviated denervation and myofiber atrophy in lower limb muscles. These results suggest that Muse cells homed in a lesion site-dependent manner and protected the spinal cord against motor neuron death. Muse cells might also be a promising cell source for the treatment of ALS patients.

Role and therapeutic potential of liquid-liquid phase separation in amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is a late-onset neurodegenerative disease selectively affecting motor neurons, leading to progressive paralysis. Although most cases are sporadic, ∼10% are familial. Similar proteins are found in aggregates in sporadic and familial ALS, and over the last decade, research has been focused on the underlying nature of this common pathology. Notably, TDP-43 inclusions are found in almost all ALS patients, while FUS inclusions have been reported in some familial ALS patients. Both TDP-43 and FUS possess ‘low-complexity domains’ (LCDs) and are considered as ‘intrinsically disordered proteins’, which form liquid droplets in vitro due to the weak interactions caused by the LCDs. Dysfunctional ‘liquid–liquid phase separation’ (LLPS) emerged as a new mechanism linking ALS-related proteins to pathogenesis. Here, we review the current state of knowledge on ALS-related gene products associated with a proteinopathy and discuss their status as LLPS proteins. In addition, we highlight the therapeutic potential of targeting LLPS for treating ALS.

The alteration of gut microbiome and metabolism in amyotrophic lateral sclerosis patients

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease accompanied with severe paralysis or even death, while the pathogenesis of ALS is still unclear and no effective therapy exists. The accumulating evidence has indicated the association between gut microbiota and various neurological diseases. Thus, to explore the potential role of gut microbiome in ALS, 20 patients diagnosed with probable or definite ALS and 20 healthy controls were enrolled and their fecal excrements were collected. The analysis of fecal community diversity with 16S rDNA sequencing showed an obvious change in microbial structure of ALS patients, where Bacteroidetes at the phylum level and several microbes at the genus level were up-regulated, while Firmicutes at the phylum level and Megamonas at the genus level were down-regulated compared to healthy controls. Additionally, decreased gene function associated with metabolic pathways was observed in ALS patients. The metagenomics further demonstrated the discrepancies in microflora at the species level and relevant metabolites thereof were also revealed when combined with metabolomics. In conclusion, the altered composition of the gut microbiota and metabolic products in ALS patients provided deeper insights into the pathogenesis of ALS, and these biomarkers might be established as potential therapeutic targets which deserve further exploration.

Phenotypic and genotypic features of patients diagnosed with ALS in the city of Sakarya, Turkey

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease leading to motor neuron damage. In this study, the clinical, demographic, and genetic features of ALS patients in the city of Sakarya, Turkey, were investigated. Patients with an established diagnosis of ALS according to the Awaji criteria were included. Age, sex, age at onset of ALS, initial complaints, consanguineous marriage, and genetic features were retrospectively investigated. Conventional genetic analysis and NGS were used for molecular evaluation of patients. A total of 55 probands (10 familial, 45 sporadic) in whom ALS was suspected due to their phenotypic features were included. Thirty-two patients were male (58.2%), and 23 were female (41.8%); their mean ages were 62.65 ± 13years. The mean age of onset for 37 familial patients from 10 families was 49.9years. Two cases had juvenile-onset. Fourteen (25.5%) bulbar-onset versus 40 (72.7%) limb-onset patients were detected; one patient had both. Six (10.9%) patients showed marked frontotemporal dementia. Twenty-nine (52.7%) patients died during the follow-up period. Genetic analysis identified causative variants in eleven cases, carrying variants in six different ALS genes (C9orf72, SOD1, VCP, SPG11, TBK1, and SH3TC2). Genetic investigations have revealed more than 40 genes to be involved in the pathogenesis of ALS. Our relatively small study cohort restricted to one province of Turkey, however, prone to migration, consists of 10/55 familial ALS cases, which harbor two rare (SH3TC2-p.Met523Thr and TBK1-p.Glu643del) and two novel (SPG11-p.Lys656Valfs*11 and VCP-p.Arg191Pro) mutations contributing to the literature.

A Study of Gene Expression Changes in Human Spinal and Oculomotor Neurons; Identifying Potential Links to Sporadic ALS.

Amyotrophic Lateral Sclerosis (ALS) is a neurodegenerative disease that causes compromised function of motor neurons and neuronal death. However, oculomotor neurons are largely spared from disease symptoms. The underlying causes for sporadic ALS as well as for the resistance of oculomotor neurons to disease symptoms remain poorly understood. In this bioinformatic-analysis, we compared the gene expression profiles of spinal and oculomotor tissue samples from control individuals and sporadic ALS patients. We show that the genes GAD2 and GABRE (involved in GABA signaling), and CALB1 (involved in intracellular Ca2+ ion buffering) are downregulated in the spinal tissues of ALS patients, but their endogenous levels are higher in oculomotor tissues relative to the spinal tissues. Our results suggest that the downregulation of these genes and processes in spinal tissues are related to sporadic ALS disease progression and their upregulation in oculomotor neurons confer upon them resistance to ALS symptoms. These results build upon prevailing models of excitotoxicity that are relevant to sporadic ALS disease progression and point out unique opportunities for better understanding the progression of neurodegenerative properties associated with sporadic ALS.

Immunosuppressive Functions of M2 Macrophages Derived from iPSCs of ALS Patients

Amyotrophic lateral sclerosis (ALS), an adult-onset neurodegenerative disease, is a systemic inflammatory disorder that augments disease burden and rates of disease progression, and is pathologically characterized by activated leukocytes. Activated macrophages are members of this family and can be simplistically separated into M1 and M2 cells. M2 macrophages (M2) have been shown to provide therapeutic benefits in mouse models of diabetes and Adriamycin nephrosis by suppressing the pro-inflammatory state. However, the suppressive functions of M2 have not been investigated in ALS, nor have M2 derived from human iPSCs (Induced Pluripotent Stem Cells) been studied for their immunosuppressive potential. In this study, human iPSCs from ALS patients with C9orf72 (C9) mutation or from sporadic ALS patients were differentiated into M2 macrophages, which suppressed activation of pro-inflammatory M1 macrophages as-well-as proliferation of pro-inflammatory CD4+CD25- T lymphocytes (Teffs) of ALS patients. These M2 macrophages also converted ALS Teffs into CD4+CD25+Foxp3+ regulatory T cells (Tregs), and rescued ALS patients’ Tregs from the loss of functional markers CD25 and Foxp3. Furthermore, the ALS Tregs induced or rescued by iPSC-derived M2 cells had strong suppressive functions. Without influence of C9 mutation or disease insult, immunomodulatory effects of ALS iPSC-derived M2 cells behaved similarly to control iPSC-derived M2 cells. This study demonstrates that M2 cells differentiated from ALS patients’ iPSCs have immunosuppressive functions and boost ALS Tregs, and may serve as a candidate for immune-cell-based therapy to mitigate the systemic inflammation occurring in patients with ALS.

A rare CACNA1H variant associated with amyotrophic lateral sclerosis causes complete loss of Cav3.2\u2009T-type channel activity

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder characterized by the progressive loss of cortical, brain stem and spinal motor neurons that leads to muscle weakness and death. A previous study implicated CACNA1H encoding for Cav3.2 calcium channels as a susceptibility gene in ALS. In the present study, two heterozygous CACNA1H variants were identified by whole genome sequencing in a small cohort of ALS patients. These variants were functionally characterized using patch clamp electrophysiology, biochemistry assays, and molecular modeling. A previously unreported c.454GTAC > G variant produced an inframe deletion of a highly conserved isoleucine residue in Cav3.2 (p.ΔI153) and caused a complete loss-of-function of the channel, with an additional dominant-negative effect on the wild-type channel when expressed in trans. In contrast, the c.3629C > T variant caused a missense substitution of a proline with a leucine (p.P1210L) and produced a comparatively mild alteration of Cav3.2 channel activity. The newly identified ΔI153 variant is the first to be reported to cause a complete loss of Cav3.2 channel function. These findings add to the notion that loss-of-function of Cav3.2 channels associated with rare CACNA1H variants may be risk factors in the complex etiology of ALS.