PARP Expression Is Increased in Astrocytes but Decreased in Motor Neurons in the Spinal Cord of Sporadic ALS Patients

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.

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Astrocytes from familial and sporadic ALS patients are toxic to motor neurons

Nature Biotechnology ◽

10.1038/nbt.1957 ◽

2011 ◽

Vol 29 (9) ◽

pp. 824-828 ◽

Cited By ~ 463

Author(s):

Amanda M Haidet-Phillips ◽

Mark E Hester ◽

Carlos J Miranda ◽

Kathrin Meyer ◽

Lyndsey Braun ◽

...

Keyword(s):

Motor Neurons ◽

Sporadic Als ◽

Als Patients

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Testing of the therapeutic efficacy and safety of AMPA receptor RNA aptamers in an ALS mouse model

Life Science Alliance ◽

10.26508/lsa.202101193 ◽

2022 ◽

Vol 5 (4) ◽

pp. e202101193

Author(s):

Megumi Akamatsu ◽

Takenari Yamashita ◽

Sayaka Teramoto ◽

Zhen Huang ◽

Janet Lynch ◽

...

Keyword(s):

Ampa Receptor ◽

Motor Neurons ◽

Ampa Receptors ◽

Motor Dysfunction ◽

Rna Aptamers ◽

Sporadic Amyotrophic Lateral Sclerosis ◽

Efficacy And Safety ◽

Intracerebroventricular Infusion ◽

Sporadic Als ◽

Als Patients

In motor neurons of sporadic amyotrophic lateral sclerosis (ALS) patients, the RNA editing at the glutamine/arginine site of the GluA2 subunit of α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors is defective or incomplete. As a result, AMPA receptors containing the abnormally expressed, unedited isoform of GluA2 are highly Ca2+-permeable, and are responsible for mediating abnormal Ca2+ influx, thereby triggering motor neuron degeneration and cell death. Thus, blocking the AMPA receptor–mediated, abnormal Ca2+ influx is a potential therapeutic strategy for treatment of sporadic ALS. Here, we report a study of the efficacy and safety of two RNA aptamers targeting AMPA receptors on the ALS phenotype of AR2 mice. A 12-wk continuous, intracerebroventricular infusion of aptamers to AR2 mice reduced the progression of motor dysfunction, normalized TDP-43 mislocalization, and prevented death of motor neurons. Our results demonstrate that the use of AMPA receptor aptamers as a novel class of AMPA receptor antagonists is a promising strategy for developing an ALS treatment approach.

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Muscle cells of sporadic ALS patients secrete neurotoxic vesicles

10.1101/2021.03.11.21252078 ◽

2021 ◽

Author(s):

Laura Le Gall ◽

William J Duddy ◽

Cecile Martinat ◽

Virginie Mariot ◽

Owen Connolly ◽

...

Keyword(s):

Electron Microscopy ◽

Stem Cells ◽

Extracellular Vesicles ◽

Motor Neurons ◽

Rna Processing ◽

Healthy Human ◽

Muscle Stem Cells ◽

Sporadic Als ◽

Als Patients ◽

Muscle Biopsies

AbstractBackgroundThe cause of the motor neuron (MN) death that drives terminal pathology in Amyotrophic Lateral Sclerosis (ALS) remains unknown, and it is thought that the cellular environment of the MN may play a key role in MN survival. Several lines of evidence implicate vesicles in ALS, including that extracellular vesicles may carry toxic elements from astrocytes towards motor neurons, and that pathological proteins have been identified in circulating extracellular vesicles of sporadic ALS patients. Since MN degeneration at the neuromuscular junction is a feature of ALS, and muscle is a vesicle-secretory tissue, we hypothesized that muscle vesicles may be involved in ALS pathology.MethodsSporadic ALS patients were confirmed to be ALS according to El Escorial criteria, were genotyped to test for classic gene mutations associated with ALS, and physical function was assessed using the ALSFRS-R score. Muscle biopsies of either mildly affected deltoids of ALS patients (n=27) or deltoids of aged-matched healthy subjects (n=30) were used for extraction of muscle stem cells, to perform immunohistology, or for electron microscopy. Muscle stem cells were characterized by immunostaining, RTqPCR and transcriptomic analysis. Secreted muscle vesicles were characterized by proteomic analysis, Western blot, NanoSight, and electron microscopy. The effects of muscle vesicles isolated from the culture medium of ALS and healthy myotubes were tested on healthy human-derived iPSC motor neurons and on healthy human myotubes, with untreated cells used as controls.ResultsAn accumulation of multivesicular bodies was observed in muscle biopsies of sporadic ALS patients by immunostaining and electron microscopy. Study of muscle biopsies and biopsy-derived denervation-naïve differentiated muscle stem cells (myotubes) revealed a consistent disease signature in ALS myotubes, including intracellular accumulation of exosome-like vesicles and disruption of RNA-processing. Compared to vesicles from healthy control myotubes, when administered to healthy motor neurons the vesicles of ALS myotubes induced shortened, less branched neurites, cell death, and disrupted localization of RNA and RNA-processing proteins. The RNA-processing protein FUS and a majority of its binding partners were present in ALS muscle vesicles, and toxicity was dependent on the expression level of FUS in recipient cells. Toxicity to recipient motor neurons was abolished by anti-CD63 immuno-blocking of vesicle uptake.ConclusionALS muscle vesicles are shown to be toxic to motor neurons, which establishes the skeletal muscle as a potential source of vesicle-mediated toxicity in ALS.One Sentence SummaryMuscle cells of ALS patients secrete vesicles that are toxic to motor neurons

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Motor neuron disease-associated loss of nuclear TDP-43 is linked to DNA double-strand break repair defects

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1818415116 ◽

2019 ◽

Vol 116 (10) ◽

pp. 4696-4705 ◽

Cited By ~ 54

Author(s):

Joy Mitra ◽

Erika N. Guerrero ◽

Pavana M. Hegde ◽

Nicole F. Liachko ◽

Haibo Wang ◽

...

Keyword(s):

Dna Binding ◽

Motor Neuron ◽

Motor Neuron Disease ◽

Motor Neurons ◽

Strand Break ◽

Double Strand Break ◽

Dsb Repair ◽

Dna Double Strand Break ◽

Sporadic Als ◽

Als Patients

Genome damage and their defective repair have been etiologically linked to degenerating neurons in many subtypes of amyotrophic lateral sclerosis (ALS) patients; however, the specific mechanisms remain enigmatic. The majority of sporadic ALS patients feature abnormalities in the transactivation response DNA-binding protein of 43 kDa (TDP-43), whose nucleo-cytoplasmic mislocalization is characteristically observed in spinal motor neurons. While emerging evidence suggests involvement of other RNA/DNA binding proteins, like FUS in DNA damage response (DDR), the role of TDP-43 in DDR has not been investigated. Here, we report that TDP-43 is a critical component of the nonhomologous end joining (NHEJ)-mediated DNA double-strand break (DSB) repair pathway. TDP-43 is rapidly recruited at DSB sites to stably interact with DDR and NHEJ factors, specifically acting as a scaffold for the recruitment of break-sealing XRCC4-DNA ligase 4 complex at DSB sites in induced pluripotent stem cell-derived motor neurons. shRNA or CRISPR/Cas9-mediated conditional depletion of TDP-43 markedly increases accumulation of genomic DSBs by impairing NHEJ repair, and thereby, sensitizing neurons to DSB stress. Finally, TDP-43 pathology strongly correlates with DSB repair defects, and damage accumulation in the neuronal genomes of sporadic ALS patients and inCaenorhabditis elegansmutant with TDP-1 loss-of-function. Our findings thus link TDP-43 pathology to impaired DSB repair and persistent DDR signaling in motor neuron disease, and suggest that DSB repair-targeted therapies may ameliorate TDP-43 toxicity-induced genome instability in motor neuron disease.

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Motor neurons from ALS patients with mutations in C9ORF72 and SOD1 exhibit distinct transcriptional landscapes

Human Molecular Genetics ◽

10.1093/hmg/ddz104 ◽

2019 ◽

Vol 28 (16) ◽

pp. 2799-2810 ◽

Cited By ~ 2

Author(s):

Ching-On Wong ◽

Kartik Venkatachalam

Keyword(s):

Cell Adhesion ◽

Motor Neurons ◽

Induced Pluripotent Stem Cell ◽

Data Sets ◽

Spinal Motor Neurons ◽

Expression Of Genes ◽

Sporadic Als ◽

Elevated Expression ◽

Induced Pluripotent ◽

Als Patients

Abstract Amyotrophic lateral sclerosis (ALS) is a progressive motor neuron disease that culminates in paralysis and death. Here, we present our analyses of publicly available multiOMIC data sets generated using motor neurons from ALS patients and control cohorts. Functional annotation of differentially expressed genes in induced pluripotent stem cell (iPSC)-derived motor neurons generated from patients with mutations in C9ORF72 (C9-ALS) suggests elevated expression of genes that pertain to extracellular matrix (ECM) and cell adhesion, inflammation and TGFβ targets. On the other end of the continuum, we detected diminished expression of genes repressed by quiescence-promoting E2F4/DREAM complex. Proteins whose abundance was significantly altered in C9-ALS neurons faithfully recapitulated the transcriptional aberrations. Importantly, patterns of gene expression in spinal motor neurons dissected from C9-ALS or sporadic ALS patients were highly concordant with each other and with the C9-ALS iPSC neurons. In contrast, motor neurons from patients with mutations in SOD1 exhibited dramatically different signatures. Elevated expression of gene sets such as ECM and cell adhesion genes occurs in C9 and sporadic ALS but not SOD1-ALS. These analyses indicate that despite the similarities in outward manifestations, transcriptional and proteomic signatures in ALS motor neurons can vary significantly depending on the identity of the causal mutations.

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Glial Cells in Amyotrophic Lateral Sclerosis

Neurology Research International ◽

10.1155/2011/718987 ◽

2011 ◽

Vol 2011 ◽

pp. 1-7 ◽

Cited By ~ 62

Author(s):

Jurate Lasiene ◽

Koji Yamanaka

Keyword(s):

Amyotrophic Lateral Sclerosis ◽

Motor Neuron ◽

Glial Cells ◽

Motor Neurons ◽

Premature Death ◽

Active Role ◽

Sporadic Als ◽

Neuron Damage ◽

Als Patients ◽

Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is an adult motor neuron disease characterized by premature death of upper and lower motor neurons. Two percent of ALS cases are caused by the dominant mutations in the gene for superoxide dismutase 1 (SOD1) through a gain of toxic property of mutant protein. Genetic and chimeric mice studies using SOD1 models indicate that non-neuronal cells play important roles in neurodegeneration through non-cell autonomous mechanism. We review the contribution of each glial cell type in ALS pathology from studies of the rodent models and ALS patients. Astrogliosis and microgliosis are not only considerable hallmarks of the disease, but the intensity of microglial activation is correlated with severity of motor neuron damage in human ALS. The impaired astrocytic functions such as clearance of extracellular glutamate and release of neurotrophic factors are implicated in disease. Further, the damage within astrocytes and microglia is involved in accelerated disease progression. Finally, other glial cells such as NG2 cells, oligodendrocytes and Schwann cells are under the investigation to determine their contribution in ALS. Accumulating knowledge of active role of glial cells in the disease should be carefully applied to understanding of the sporadic ALS and development of therapy targeted for glial cells.

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Postmortem Cortex Samples Identify Distinct Molecular Subtypes of ALS: Retrotransposon Activation, Oxidative Stress, and Activated Glia

10.1101/574509 ◽

2019 ◽

Cited By ~ 1

Author(s):

Oliver H. Tam ◽

Nikolay V. Rozhkov ◽

Regina Shaw ◽

Duyang Kim ◽

Isabel Hubbard ◽

...

Keyword(s):

Motor Neurons ◽

Molecular Subtypes ◽

Machine Learning Algorithms ◽

Tissue Samples ◽

Proteotoxic Stress ◽

Sporadic Als ◽

History Of ◽

Als Patients ◽

Large Survey ◽

Lateral Sclerosis

SummaryAmyotrophic Lateral Sclerosis (ALS) is a fatal neurodegenerative disease characterized by the progressive loss of motor neurons. While several inherited pathogenic mutations have been identified as causative, the vast majority of cases are sporadic with no family history of disease. Thus, for the majority of ALS cases, a specific causal abnormality is not known and the disease may be a product of multiple inter-related pathways contributing to varying degrees in different ALS patients. Using unsupervised machine learning algorithms, we stratified the transcriptomes of 148 ALS decedent cortex tissue samples into three distinct and robust molecular subtypes. The largest cluster, identified in 61% of patient samples, displayed hallmarks of oxidative and proteotoxic stress. Another 20% of the ALS patient samples exhibited high levels of retrotransposon expression and other signatures of TDP-43 dysfunction. Finally, a third group showed predominant signatures of glial activation (19%). Together these results demonstrate that at least three distinct molecular signatures contribute to ALS disease. While multiple dysregulated components and pathways comprising these clusters have previously been implicated in ALS pathogenesis, unbiased analysis of this large survey demonstrated that sporadic ALS patient tissues can be segregated into distinct molecular subsets.

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Discrete mitochondrial aberrations in the spinal cord of sporadic ALS patients

Journal of Neuroscience Research ◽

10.1002/jnr.24249 ◽

2018 ◽

Vol 96 (8) ◽

pp. 1353-1366 ◽

Cited By ~ 4

Author(s):

Vedad Delic ◽

Crupa Kurien ◽

Josean Cruz ◽

Sandra Zivkovic ◽

Jennifer Barretta ◽

...

Keyword(s):

Spinal Cord ◽

Sporadic Als ◽

Als Patients

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CD34 Identifies a Subset of Proliferating Microglial Cells Associated with Degenerating Motor Neurons in ALS

International Journal of Molecular Sciences ◽

10.3390/ijms20163880 ◽

2019 ◽

Vol 20 (16) ◽

pp. 3880 ◽

Cited By ~ 2

Author(s):

Mariángeles Kovacs ◽

Emiliano Trias ◽

Valentina Varela ◽

Sofia Ibarburu ◽

Joseph S. Beckman ◽

...

Keyword(s):

Spinal Cord ◽

Motor Neurons ◽

Human Subjects ◽

Microglial Cells ◽

Lumbar Spinal Cord ◽

Reactive Microglia ◽

Sporadic Als ◽

Cd34 Cells ◽

Misfolded Sod1 ◽

Lumbar Spinal

Amyotrophic lateral sclerosis (ALS) is characterized by degeneration of upper and lower motor neurons accompanied by proliferation of reactive microglia in affected regions. However, it is unknown whether the hematopoietic marker CD34 can identify a subpopulation of proliferating microglial cells in the ALS degenerating spinal cord. Immunohistochemistry for CD34 and microglia markers was performed in lumbar spinal cords of ALS rats bearing the SOD1G93A mutation and autopsied ALS and control human subjects. Characterization of CD34-positive cells was also performed in primary cell cultures of the rat spinal cords. CD34 was expressed in a large number of cells that closely interacted with degenerating lumbar spinal cord motor neurons in symptomatic SOD1G93A rats, but not in controls. Most CD34+ cells co-expressed the myeloid marker CD11b, while only a subpopulation was stained for Iba1 or CD68. Notably, CD34+ cells actively proliferated and formed clusters adjacent to damaged motor neurons bearing misfolded SOD1. CD34+ cells were identified in the proximity of motor neurons in autopsied spinal cord from sporadic ALS subjects but not in controls. Cell culture of symptomatic SOD1G93A rat spinal cords yielded a large number of CD34+ cells exclusively in the non-adherent phase, which generated microglia after successive passaging. A yet unrecognized CD34+ cells, expressing or not the microglial marker Iba1, proliferate and accumulate adjacent to degenerating spinal motor neurons, representing an intriguing cell target for approaching ALS pathogenesis and therapeutics.

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