scholarly journals Constitutively active SARM1 variants found in ALS patients induce neuropathy

2021 ◽  
Author(s):  
Joseph Bloom ◽  
Xianrong Mao ◽  
Amy Strickland ◽  
Yo Sasaki ◽  
Jeffrey Milbrandt ◽  
...  
Keyword(s):  
Intrathecal Injection ◽  
Motor Dysfunction ◽  
Single Amino Acid ◽  
Reference Allele ◽  
Naturally Occurring ◽  
Axon Loss ◽  
Als Patients ◽  
Multiple Patients ◽  
Lateral Sclerosis ◽  
Constitutively Active

In response to injury, neurons activate a program of organized axon self-destruction initiated by the NAD+ hydrolase SARM1. In healthy neurons SARM1 is autoinhibited, but single amino acid changes can abolish autoinhibition leading to constitutively-active SARM1 enzymes that promote degeneration when expressed in cultured neurons. To investigate whether naturally-occurring human variants might similarly disrupt SARM1 autoinhibition and potentially contribute to risk for neurodegenerative disease, we assayed the enzymatic activity of 29 rare SARM1 alleles identified among 8,507 amyotrophic lateral sclerosis (ALS) patients. Ten missense variants or small in-frame deletions exhibit constitutive NADase activity, including more than half of those that are unique to the ALS patients or that occur in multiple patients. Expression of these constitutively active ALS-associated SARM1 alleles in cultured dorsal root ganglion (DRG) neurons is pro-degenerative and cytotoxic. Intrathecal injection of an AAV expressing the common SARM1 reference allele is innocuous to mice, but a construct harboring SARM1V184G, the constitutively active variant found most frequently in the ALS patients, causes axon loss, motor dysfunction, and sustained neuroinflammation. These results implicate rare hypermorphic SARM1 alleles as candidate genetic risk factors for ALS and other neurodegenerative conditions.

scholarly journals Constitutively active SARM1 variants that induce neuropathy are enriched in ALS patients

2022 ◽  
Vol 17 (1) ◽  
Author(s):  
A. Joseph Bloom ◽  
Xianrong Mao ◽  
Amy Strickland ◽  
Yo Sasaki ◽  
Jeffrey Milbrandt ◽  
...  
Keyword(s):  
Intrathecal Injection ◽  
Motor Dysfunction ◽  
Single Amino Acid ◽  
Reference Allele ◽  
Axon Loss ◽  
Als Patients ◽  
Multiple Patients ◽  
Lateral Sclerosis ◽  
Constitutively Active

Abstract Background In response to injury, neurons activate a program of organized axon self-destruction initiated by the NAD+ hydrolase, SARM1. In healthy neurons SARM1 is autoinhibited, but single amino acid changes can abolish autoinhibition leading to constitutively active SARM1 enzymes that promote degeneration when expressed in cultured neurons. Methods To investigate whether naturally occurring human variants might disrupt SARM1 autoinhibition and potentially contribute to risk for neurodegenerative disease, we assayed the enzymatic activity of all 42 rare SARM1 alleles identified among 8507 amyotrophic lateral sclerosis (ALS) patients and 9671 controls. We then intrathecally injected mice with virus expressing SARM1 constructs to test the capacity of an ALS-associated constitutively active SARM1 variant to promote neurodegeneration in vivo. Results Twelve out of 42 SARM1 missense variants or small in-frame deletions assayed exhibit constitutive NADase activity, including more than half of those that are unique to the ALS patients or that occur in multiple patients. There is a > 5-fold enrichment of constitutively active variants among patients compared to controls. Expression of constitutively active ALS-associated SARM1 alleles in cultured dorsal root ganglion (DRG) neurons is pro-degenerative and cytotoxic. Intrathecal injection of an AAV expressing the common SARM1 reference allele is innocuous to mice, but a construct harboring SARM1V184G, the constitutively active variant found most frequently among the ALS patients, causes axon loss, motor dysfunction, and sustained neuroinflammation. Conclusions These results implicate rare hypermorphic SARM1 alleles as candidate genetic risk factors for ALS and other neurodegenerative conditions.

scholarly journals Serum naturally occurring anti-TDP-43 auto-antibodies are increased in amyotrophic lateral sclerosis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Elisa Conti ◽  
Gessica Sala ◽  
Susanna Diamanti ◽  
Marco Casati ◽  
Christian Lunetta ◽  
...  
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Serum Levels ◽  
The Other ◽  
Diagnostic Process ◽  
Healthy Controls ◽  
Naturally Occurring ◽  
Als Patients ◽  
First Time ◽  
Lateral Sclerosis

AbstractAmyotrophic Lateral Sclerosis (ALS) patients express significant clinical heterogeneity that often hinders a correct diagnostic definition. Intracellular deposition of TDP-43, a protein involved in RNA metabolism characterizes the pathology. Interestingly, this protein can be detected in serum, wherein cognate naturally-occurring auto-antibodies (anti-TDP-43 NAb) might be also present, albeit they have never been documented before. In this exploratory study, we quantified the levels of both anti-TDP-43 NAb and TDP-43 protein as putative accessible markers for improving the ALS diagnostic process by using ELISA in N = 70 ALS patients (N = 4 carrying TARDBP mutations), N = 40 age-comparable healthy controls (CTRL), N = 20 motor neuron disease mimics (MN-m), N = 20 Alzheimer’s disease (AD) and N = 15 frontotemporal lobar degeneration (FTLD) patients. Anti-TDP-43 NAb were found to be significantly increased in ALS patients compared to all the other groups (p < 0.001). On the other hand, the distribution of serum levels of TDP-43 protein was highly variable among the various groups. Levels were increased in ALS patients, albeit the highest values were detected in MN-m patients. NAb and protein serum levels failed to correlate. For the first time, we report that serum anti-TDP-43 NAb are detectable in human serum of both healthy controls and patients affected by a variety of neurodegenerative disorders; furthermore, their levels are increased in ALS patients, representing a potentially interesting trait core marker of this disease. Further studies are needed to clarify the exact role of the NAb. This information might be extremely useful for paving the way toward targeting TDP-43 by immunotherapy in ALS.

scholarly journals Looking backward to move forward: a meta-analysis of stem cell therapy in amyotrophic lateral sclerosis

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Cynthia Morata-Tarifa ◽  
Garikoitz Azkona ◽  
Jonathan Glass ◽  
Letizia Mazzini ◽  
Rosario Sanchez-Pernaute
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Mononuclear Cells ◽  
Meta Analysis ◽  
Intrathecal Injection ◽  
Current Evidence ◽  
Eligibility Criteria ◽  
Before And After ◽  
Als Patients ◽  
Positive Effect ◽  
Lateral Sclerosis

AbstractTransplantation of several types of stem cells (SC) for the treatment of amyotrophic lateral sclerosis (ALS) has been evaluated in numerous Phase I/II clinical trials with inconclusive results. Here, we conducted a meta-analysis to systematically assess the outcome of SC therapy trials which report the evolution of each patient before and after cell administration. In this way, we aimed to determine the effect of the SC intervention despite individual heterogeneity in disease progression. We identified 670 references by electronic search and 90 full-text studies were evaluated according to the eligibility criteria. Eleven studies were included comprising 220 cell-treated patients who received mesenchymal (M) SC (n = 152), neural (N) SC (n = 57), or mononuclear cells (MNC: CD34, CD117, and CD133 positive cells) (n = 11). Our analyses indicate that whereas intrathecal injection of mesenchymal stromal cells appears to have a transient positive effect on clinical progression, as measured by the ALS functional rating score, there was a worsening of respiratory function measured by forced vital capacity after all interventions. Based on current evidence, we conclude that optimal cell product and route of administration need to be determined in properly controlled preclinical models before further advancing into ALS patients. In addition, in-depth understanding of disease mechanisms in subsets of patients will help tailoring SC therapy to specific targets and increase the likelihood of improving outcomes.

Riluzole Exhibits No Therapeutic Efficacy on a Transgenic Rat model of Amyotrophic Lateral Sclerosis

2020 ◽  
Vol 17 (3) ◽  
pp. 275-285 ◽  
Author(s):  
Si Chen ◽  
Qiao Liao ◽  
Ke Lu ◽  
Jinxia Zhou ◽  
Cao Huang ◽  
...  
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Motor Neurons ◽  
Rat Model ◽  
Microglial Activation ◽  
Transgenic Rat ◽  
Intragastric Administration ◽  
Behavioral Deficits ◽  
Als Patients ◽  
Lateral Sclerosis ◽  
Transgenic Rat Model

Background: Amyotrophic lateral sclerosis (ALS) is a neurological disorder clinically characterized by motor system dysfunction, with intraneuronal accumulation of the TAR DNAbinding protein 43 (TDP-43) being a pathological hallmark. Riluzole is a primarily prescribed medicine for ALS patients, while its therapeutical efficacy appears limited. TDP-43 transgenic mice are existing animal models for mechanistic/translational research into ALS. Methods: We developed a transgenic rat model of ALS expressing a mutant human TDP-43 transgene (TDP-43M337V) and evaluated the therapeutic effect of Riluzole on this model. Relative to control, rats with TDP-43M337V expression promoted by the neurofilament heavy subunit (NEF) gene or specifically in motor neurons promoted by the choline acetyltransferase (ChAT) gene showed progressive worsening of mobility and grip strength, along with loss of motor neurons, microglial activation, and intraneuronal accumulation of TDP-43 and ubiquitin aggregations in the spinal cord. Results: Compared to vehicle control, intragastric administration of Riluzole (30 mg/kg/d) did not mitigate the behavioral deficits nor alter the neuropathologies in the transgenics. Conclusion: These findings indicate that transgenic rats recapitulate the basic neurological and neuropathological characteristics of human ALS, while Riluzole treatment can not halt the development of the behavioral and histopathological phenotypes in this new transgenic rodent model of ALS.

scholarly journals Lipidomics study of plasma from patients suggest that ALS and PLS are part of a continuum of motor neuron disorders

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Estela Area-Gomez ◽  
D. Larrea ◽  
T. Yun ◽  
Y. Xu ◽  
J. Hupf ◽  
...  
Keyword(s):  
Motor Neuron ◽  
Motor Neurons ◽  
Cell Structure ◽  
Disease Onset ◽  
Point Of View ◽  
Motor Dysfunction ◽  
Cellular Processes ◽  
Progressive Muscle Weakness ◽  
Human Pathology ◽  
Lateral Sclerosis

AbstractMotor neuron disorders (MND) include a group of pathologies that affect upper and/or lower motor neurons. Among them, amyotrophic lateral sclerosis (ALS) is characterized by progressive muscle weakness, with fatal outcomes only in a few years after diagnosis. On the other hand, primary lateral sclerosis (PLS), a more benign form of MND that only affects upper motor neurons, results in life-long progressive motor dysfunction. Although the outcomes are quite different, ALS and PLS present with similar symptoms at disease onset, to the degree that both disorders could be considered part of a continuum. These similarities and the lack of reliable biomarkers often result in delays in accurate diagnosis and/or treatment. In the nervous system, lipids exert a wide variety of functions, including roles in cell structure, synaptic transmission, and multiple metabolic processes. Thus, the study of the absolute and relative concentrations of a subset of lipids in human pathology can shed light into these cellular processes and unravel alterations in one or more pathways. In here, we report the lipid composition of longitudinal plasma samples from ALS and PLS patients initially, and after 2 years following enrollment in a clinical study. Our analysis revealed common aspects of these pathologies suggesting that, from the lipidomics point of view, PLS and ALS behave as part of a continuum of motor neuron disorders.

Plasma Creatinine Level Does Not Predict Respiratory Function in Amyotrophic Lateral Sclerosis

2021 ◽  
pp. 1-5
Author(s):  
João Morgadinho ◽  
Ana Catarina Pronto-Laborinho ◽  
Vasco A. Conceição ◽  
Marta Gromicho ◽  
Susana Pinto ◽  
...  
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Creatinine Level ◽  
Cox Regression ◽  
Functional Decline ◽  
Plasma Creatinine ◽  
Plasma Creatinine Level ◽  
Decline Rate ◽  
Respiratory Outcome ◽  
Als Patients ◽  
Lateral Sclerosis

In amyotrophic lateral sclerosis (ALS) lower plasma creatinine level has been associated with shorter survival and faster functional decline. It has not been clear if creatinine is associated with respiratory outcome. We analyzed retrospectively a population of unselected ALS patients. Multiple-regression and Cox-regression analyses were performed. We included 233 patients, mean age 62.8, mean disease duration of 18.6 months. At baseline, creatinine was significantly associated with ALSFRS-R, but not with its decline rate. No predictive value was disclosed for FVC, or their decline rate, or with survival. We did not confirm that creatinine is a marker of respiratory outcome.

Coping strategies among amyotrophic lateral sclerosis (ALS) patients: an integrative review

2021 ◽  
Author(s):  
Georgiana Soares Leandro ◽  
Mário Emílio Teixeira Dourado Júnior ◽  
Glauciane Costa Santana ◽  
Luan Samy Xavier Dantas
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Coping Strategies ◽  
Integrative Review ◽  
Als Patients ◽  
Lateral Sclerosis

scholarly journals Sterol auto-oxidation adversely affects human motor neuron viability and is a neuropathological feature of amyotrophic lateral sclerosis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
James C. Dodge ◽  
Jinlong Yu ◽  
S. Pablo Sardi ◽  
Lamya S. Shihabuddin
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Motor Neuron ◽  
Cholesterol Homeostasis ◽  
Cholesterol Oxidation ◽  
Therapeutic Approaches ◽  
Cellular Survival ◽  
Sporadic Als ◽  
Human Motor ◽  
Als Patients ◽  
Lateral Sclerosis

AbstractAberrant cholesterol homeostasis is implicated in the pathogenesis of amyotrophic lateral sclerosis (ALS), a fatal neuromuscular disease that is due to motor neuron (MN) death. Cellular toxicity from excess cholesterol is averted when it is enzymatically oxidized to oxysterols and bile acids (BAs) to promote its removal. In contrast, the auto oxidation of excess cholesterol is often detrimental to cellular survival. Although oxidized metabolites of cholesterol are altered in the blood and CSF of ALS patients, it is unknown if increased cholesterol oxidation occurs in the SC during ALS, and if exposure to oxidized cholesterol metabolites affects human MN viability. Here, we show that in the SOD1G93A mouse model of ALS that several oxysterols, BAs and auto oxidized sterols are increased in the lumbar SC, plasma, and feces during disease. Similar changes in cholesterol oxidation were found in the cervical SC of sporadic ALS patients. Notably, auto-oxidized sterols, but not oxysterols and BAs, were toxic to iPSC derived human MNs. Thus, increased cholesterol oxidation is a manifestation of ALS and non-regulated sterol oxidation likely contributes to MN death. Developing therapeutic approaches to restore cholesterol homeostasis in the SC may lead to a treatment for ALS.

scholarly journals Utility of Transcranial Magnetic Simulation in Studying Upper Motor Neuron Dysfunction in Amyotrophic Lateral Sclerosis

2021 ◽  
Vol 11 (7) ◽  
pp. 906
Author(s):  
Nimeshan Geevasinga ◽  
Mehdi Van den Bos ◽  
Parvathi Menon ◽  
Steve Vucic
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Motor Neurons ◽  
Cortical Excitability ◽  
Muscular Atrophy ◽  
Close Relationship ◽  
Bulbar Onset ◽  
Als Patients ◽  
Transcranial Magnetic Simulation ◽  
Cortical Dysfunction ◽  
Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is characterised by progressive dysfunction of the upper and lower motor neurons. The disease can evolve over time from focal limb or bulbar onset to involvement of other regions. There is some clinical heterogeneity in ALS with various phenotypes of the disease described, from primary lateral sclerosis, progressive muscular atrophy and flail arm/leg phenotypes. Whilst the majority of ALS patients are sporadic in nature, recent advances have highlighted genetic forms of the disease. Given the close relationship between ALS and frontotemporal dementia, the importance of cortical dysfunction has gained prominence. Transcranial magnetic stimulation (TMS) is a noninvasive neurophysiological tool to explore the function of the motor cortex and thereby cortical excitability. In this review, we highlight the utility of TMS and explore cortical excitability in ALS diagnosis, pathogenesis and insights gained from genetic and variant forms of the disease.

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