scholarly journals Microglia influence neurofilament deposition in ALS iPSC-derived motor neurons

2022 ◽  
Author(s):  
Reilly L Allison ◽  
Jacob W Adelman ◽  
Jenica Abrudan ◽  
Raul A Urrutia ◽  
Michael T Zimmermann ◽  
...  
Keyword(s):  
Motor Neuron ◽  
Conditioned Medium ◽  
Motor Neurons ◽  
Neuron Loss ◽  
Secreted Factors ◽  
Sporadic Als ◽  
Motor Neuron Loss ◽  
Induced Pluripotent ◽  
Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease in which upper and lower motor neuron loss is the primary phenotype, leading to muscle weakness and wasting, respiratory failure, and death. Although a portion of ALS cases are linked to one of over 50 unique genes, the vast majority of cases are sporadic in nature. However, the mechanisms underlying the motor neuron loss in either familial or sporadic ALS are not entirely clear. Here we used induced pluripotent stem cells derived from a set of identical twin brothers discordant for ALS to assess the role of astrocytes and microglia on the expression and accumulation of neurofilament proteins in motor neurons. We found that motor neurons derived from the affected twin exhibited increased transcript levels of all three neurofilament isoforms and increased expression of phosphorylated neurofilament puncta. We further found that treatment of the motor neurons with astrocyte conditioned medium and microglial conditioned medium significantly impacted neurofilament deposition. Together, these data suggest that glial-secreted factors can alter neurofilament pathology in ALS iPSC-derived motor neurons.

scholarly journals The Src/c-Abl pathway is a potential therapeutic target in amyotrophic lateral sclerosis

2017 ◽  
Vol 9 (391) ◽  
pp. eaaf3962 ◽  
Author(s):  
Keiko Imamura ◽  
Yuishin Izumi ◽  
Akira Watanabe ◽  
Kayoko Tsukita ◽  
Knut Woltjen ◽  
...  
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Motor Neuron ◽  
Motor Neurons ◽  
New Drugs ◽  
Small Interfering Rnas ◽  
Altered Expression ◽  
Sporadic Als ◽  
Induced Pluripotent ◽  
Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS), a fatal disease causing progressive loss of motor neurons, still has no effective treatment. We developed a phenotypic screen to repurpose existing drugs using ALS motor neuron survival as readout. Motor neurons were generated from induced pluripotent stem cells (iPSCs) derived from an ALS patient with a mutation in superoxide dismutase 1 (SOD1). Results of the screen showed that more than half of the hits targeted the Src/c-Abl signaling pathway. Src/c-Abl inhibitors increased survival of ALS iPSC-derived motor neurons in vitro. Knockdown of Src or c-Abl with small interfering RNAs (siRNAs) also rescued ALS motor neuron degeneration. One of the hits, bosutinib, boosted autophagy, reduced the amount of misfolded mutant SOD1 protein, and attenuated altered expression of mitochondrial genes. Bosutinib also increased survival in vitro of ALS iPSC-derived motor neurons from patients with sporadic ALS or other forms of familial ALS caused by mutations in TAR DNA binding protein (TDP-43) or repeat expansions in C9orf72. Furthermore, bosutinib treatment modestly extended survival of a mouse model of ALS with an SOD1 mutation, suggesting that Src/c-Abl may be a potentially useful target for developing new drugs to treat ALS.

scholarly journals Motor Neuron Generation from iPSCs from Identical Twins Discordant for Amyotrophic Lateral Sclerosis

Cells ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 571 ◽  
Author(s):  
Emily R. Seminary ◽  
Stephanie Santarriaga ◽  
Lynn Wheeler ◽  
Marie Mejaki ◽  
Jenica Abrudan ◽  
...  
Keyword(s):  
Stem Cells ◽  
Amyotrophic Lateral Sclerosis ◽  
Motor Neuron ◽  
Induced Pluripotent Stem Cells ◽  
Motor Neurons ◽  
Pluripotent Stem Cells ◽  
Identical Twins ◽  
Sporadic Als ◽  
Induced Pluripotent ◽  
Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a complex neurodegenerative disorder characterized by the loss of the upper and lower motor neurons. Approximately 10% of cases are caused by specific mutations in known genes, with the remaining cases having no known genetic link. As such, sporadic cases have been more difficult to model experimentally. Here, we describe the generation and differentiation of ALS induced pluripotent stem cells reprogrammed from discordant identical twins. Whole genome sequencing revealed no relevant mutations in known ALS-causing genes that differ between the twins. As protein aggregation is found in all ALS patients and is thought to contribute to motor neuron death, we sought to characterize the aggregation phenotype of the sporadic ALS induced pluripotent stem cells (iPSCs). Motor neurons from both twins had high levels of insoluble proteins that commonly aggregate in ALS that did not robustly change in response to exogenous glutamate. In contrast, established genetic ALS iPSC lines demonstrated insolubility in a protein- and genotype-dependent manner. Moreover, whereas the genetic ALS lines failed to induce autophagy after glutamate stress, motor neurons from both twins and independent controls did activate this protective pathway. Together, these data indicate that our unique model of sporadic ALS may provide key insights into disease pathology and highlight potential differences between sporadic and familial ALS.

scholarly journals Viral mediated knockdown of GATA6 in SMA iPSC-derived astrocytes prevents motor neuron loss and microglial activation

2021 ◽  
Author(s):  
Reilly L Allison ◽  
Emily Welby ◽  
Guzal Khayrullina ◽  
Barrington G Burnett ◽  
Allison D Ebert
Keyword(s):  
Spinal Cord ◽  
Motor Neuron ◽  
Motor Neurons ◽  
Muscular Atrophy ◽  
Genetic Disorder ◽  
Neuron Loss ◽  
Microglial Phagocytosis ◽  
Lentiviral Infection ◽  
Motor Neuron Loss ◽  
Induced Pluripotent

Spinal muscular atrophy (SMA), a pediatric genetic disorder, is characterized by the profound loss of spinal cord motor neurons and subsequent muscle atrophy and death. Although the mechanisms underlying motor neuron loss are not entirely clear, data from our work and others support the idea that glial cells contribute to disease pathology. GATA6, a transcription factor that we have previously shown to be upregulated in SMA astrocytes, is negatively regulated by SMN and can increase the expression of the inflammatory regulator NFκB. In this study, we identified upregulated GATA6 as a contributor to increased activation, pro-inflammatory ligand production, and neurotoxicity in spinal-cord patterned astrocytes differentiated from SMA patient induced pluripotent stem cells. Reducing GATA6 expression in SMA astrocytes via lentiviral infection ameliorated these effects to healthy control levels. Additionally, we found that SMA astrocytes contribute to SMA microglial phagocytosis, which was again decreased by lentiviral-mediated knockdown of GATA6. Together these data identify a role of GATA6 in SMA astrocyte pathology and further highlight glia as important targets of therapeutic intervention in SMA.

scholarly journals Bisperoxovanadium promotes motor neuron survival and neuromuscular innervation in amyotrophic lateral sclerosis

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Junmei Wang ◽  
Lydia Tierney ◽  
Ranjeet Mann ◽  
Thomas Lonsway ◽  
Chandler L. Walker
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Motor Neuron ◽  
Lumbar Spinal Cord ◽  
Therapeutic Effects ◽  
Spinal Cord Tissue ◽  
Neuron Loss ◽  
Neuroprotective Therapy ◽  
Motor Neuron Loss ◽  
Lateral Sclerosis

AbstractAmyotrophic lateral sclerosis (ALS) is the most common motor neuron (MN) disease, with no present cure. The progressive loss of MNs is the hallmark of ALS. We have previously shown the therapeutic effects of the phosphatase and tensin homolog (PTEN) inhibitor, potassium bisperoxo (picolinato) vanadium (bpV[pic]), in models of neurological injury and demonstrated significant neuroprotective effects on MN survival. However, accumulating evidence suggests PTEN is detrimental for MN survival in ALS. Therefore, we hypothesized that treating the mutant superoxide dismutase 1 G93A (mSOD1G93A) mouse model of ALS during motor neuron degeneration and an in vitro model of mSOD1G93A motor neuron injury with bpV(pic) would prevent motor neuron loss. To test our hypothesis, we treated mSOD1G93A mice intraperitoneally daily with 400 μg/kg bpV(pic) from 70 to 90 days of age. Immunolabeled MNs and microglial reactivity were analyzed in lumbar spinal cord tissue, and bpV(pic) treatment significantly ameliorated ventral horn motor neuron loss in mSOD1G93A mice (p = 0.003) while not significantly altering microglial reactivity (p = 0.701). Treatment with bpV(pic) also significantly increased neuromuscular innervation (p = 0.018) but did not affect muscle atrophy. We also cultured motor neuron-like NSC-34 cells transfected with a plasmid to overexpress mutant SOD1G93A and starved them in serum-free medium for 24 h with and without bpV(pic) and downstream inhibitor of Akt signaling, LY294002. In vitro, bpV(pic) improved neuronal viability, and Akt inhibition reversed this protective effect (p < 0.05). In conclusion, our study indicates systemic bpV(pic) treatment could be a valuable neuroprotective therapy for ALS.

scholarly journals Gamma motor neurons survive and exacerbate alpha motor neuron degeneration in ALS

2016 ◽  
Vol 113 (51) ◽  
pp. E8316-E8325 ◽  
Author(s):  
Melanie Lalancette-Hebert ◽  
Aarti Sharma ◽  
Alexander K. Lyashchenko ◽  
Neil A. Shneider
Keyword(s):  
Motor Neuron ◽  
Mouse Models ◽  
Motor Neurons ◽  
Muscle Spindles ◽  
Excitatory Input ◽  
Synaptic Excitation ◽  
Fused In Sarcoma ◽  
Alpha Motor Neuron ◽  
Lateral Sclerosis

The molecular and cellular basis of selective motor neuron (MN) vulnerability in amyotrophic lateral sclerosis (ALS) is not known. In genetically distinct mouse models of familial ALS expressing mutant superoxide dismutase-1 (SOD1), TAR DNA-binding protein 43 (TDP-43), and fused in sarcoma (FUS), we demonstrate selective degeneration of alpha MNs (α-MNs) and complete sparing of gamma MNs (γ-MNs), which selectively innervate muscle spindles. Resistant γ-MNs are distinct from vulnerable α-MNs in that they lack synaptic contacts from primary afferent (IA) fibers. Elimination of these synapses protects α-MNs in the SOD1 mutant, implicating this excitatory input in MN degeneration. Moreover, reduced IAactivation by targeted reduction of γ-MNs in SOD1G93Amutants delays symptom onset and prolongs lifespan, demonstrating a pathogenic role of surviving γ-MNs in ALS. This study establishes the resistance of γ-MNs as a general feature of ALS mouse models and demonstrates that synaptic excitation of MNs within a complex circuit is an important determinant of relative vulnerability in ALS.

Longitudinal study of functional spinal alpha motor neuron loss in amyotrophic lateral sclerosis

2002 ◽  
Vol 25 (4) ◽  
pp. 520-526 ◽  
Author(s):  
K. Arasaki ◽  
Y. Kato ◽  
A. Hyodo ◽  
R. Ushijima ◽  
M. Tamaki
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Longitudinal Study ◽  
Motor Neuron ◽  
Neuron Loss ◽  
Motor Neuron Loss ◽  
Alpha Motor Neuron ◽  
Lateral Sclerosis

scholarly journals Diaphragm muscle function following midcervical contusion injury in rats

2019 ◽  
Vol 126 (1) ◽  
pp. 221-230 ◽  
Author(s):  
Obaid U. Khurram ◽  
Matthew J. Fogarty ◽  
Sabhya Rana ◽  
Pangdra Vang ◽  
Gary C. Sieck ◽  
...  
Keyword(s):  
Motor Neuron ◽  
Motor Neurons ◽  
Force Generation ◽  
Diaphragm Muscle ◽  
Neuron Loss ◽  
Motor Behaviors ◽  
Contusion Injury ◽  
Motor Neuron Loss ◽  
The Impact ◽  
Over Time

Midcervical spinal cord contusion injury results in tissue damage, disruption of spinal pathways, and motor neuron loss. Unilateral C4 contusion results in loss of 40%–50% of phrenic motor neurons ipsilateral to the injury (~25% of the total phrenic motor neuron pool). Over time after unilateral C4 contusion injury, diaphragm muscle (DIAm) electromyogram activity increases both contralateral and ipsilateral to the side of injury in rats, suggesting compensation because of increased activation of the surviving motor neurons. However, the impact of contusion injury on DIAm force generation is less clear. Transdiaphragmatic pressure (Pdi) was measured across motor behaviors over time after unilateral C4 contusion injury in adult male Sprague-Dawley rats. Maximum Pdi (Pdimax) was elicited by bilateral phrenic nerve stimulation at 7 days postinjury. We hypothesized that Pdimax is reduced following unilateral C4 contusion injury, whereas ventilatory behaviors of the DIAm are unimpaired. In support of our hypothesis, Pdimax was reduced by ~25% after unilateral C4 contusion, consistent with the extent of phrenic motor neuron loss following contusion injury. One day after contusion injury, the Pdi amplitude during airway occlusion was reduced from ~30 to ~20 cmH2O, but this reduction was completely reversed by 7 days postinjury. Ventilatory behaviors (~10 cmH2O), DIAm-specific force, and muscle fiber cross-sectional area did not differ between the laminectomy and contusion groups. These results indicate that the large reserve capacity for DIAm force generation allows for higher-force motor behaviors to be accomplished despite motor neuron loss, likely reflecting changes in motor unit recruitment. NEW & NOTEWORTHY Respiratory muscles such as the diaphragm generate the pressures necessary to accomplish a variety of motor behaviors ranging from ventilation to near-maximal expulsive behaviors. However, the impact of contusion injury on diaphragm pressure generation across behaviors is not clear. The present study shows that contusion injury impairs maximal pressure generation while preserving the ability of the diaphragm to accomplish lower-force motor behaviors, likely reflecting changes in diaphragm motor unit recruitment.

scholarly journals Genome Wide Analysis Points towards Subtype-Specific Diseases in Different Genetic Forms of Amyotrophic Lateral Sclerosis

2020 ◽  
Vol 21 (18) ◽  
pp. 6938
Author(s):  
Banaja P. Dash ◽  
Marcel Naumann ◽  
Jared Sterneckert ◽  
Andreas Hermann
Keyword(s):  
Motor Neurons ◽  
Individualized Medicine ◽  
Induced Pluripotent Stem Cell ◽  
Kegg Pathways ◽  
Amyotropic Lateral Sclerosis ◽  
Sporadic Als ◽  
Apparent Death ◽  
Induced Pluripotent ◽  
Simplex Virus ◽  
Lateral Sclerosis

Amyotropic lateral sclerosis (ALS) is a lethally progressive and irreversible neurodegenerative disease marked by apparent death of motor neurons present in the spinal cord, brain stem and motor cortex. While more and more gene mutants being established for genetic ALS, the vast majority suffer from sporadic ALS (>90%). It has been challenging, thus, to model sporadic ALS which is one reason why the underlying pathophysiology remains elusive and has stalled the development of therapeutic strategies of this progressive motor neuron disease. To further unravel these pathological signaling pathways, human induced pluripotent stem cell (hiPSCs)-derived motor neurons (MNs) from FUS- and SOD1 ALS patients and healthy controls were systematically compared to independent published datasets. Here through this study we created a gene profile of ALS by analyzing the DEGs, the Kyoto encyclopedia of Genes and Genomes (KEGG) pathways, the interactome and the transcription factor profiles (TF) that would identify altered molecular/functional signatures and their interactions at both transcriptional (mRNAs) and translational levels (hub proteins and TFs). Our findings suggest that FUS and SOD1 may develop from dysregulation in several unique pathways and herpes simplex virus (HSV) infection was among the topmost predominant cellular pathways connected to FUS and not to SOD1. In contrast, SOD1 is mainly characterized by alterations in the metabolic pathways and alterations in the neuroactive-ligand–receptor interactions. This suggests that different genetic ALS forms are singular diseases rather than part of a common spectrum. This is important for patient stratification clearly pointing towards the need for individualized medicine approaches in ALS.

scholarly journals Spatiotemporal dynamics of molecular pathology in amyotrophic lateral sclerosis

Science ◽  
2019 ◽  
Vol 364 (6435) ◽  
pp. 89-93 ◽  
Author(s):  
Silas Maniatis ◽  
Tarmo Äijö ◽  
Sanja Vickovic ◽  
Catherine Braine ◽  
Kristy Kang ◽  
...  
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Motor Neuron ◽  
Motor Neurons ◽  
Molecular Mechanisms ◽  
Early Time ◽  
Course Of Disease ◽  
Molecular Events ◽  
Motor Neuron Loss ◽  
Als Patients ◽  
Lateral Sclerosis

Paralysis occurring in amyotrophic lateral sclerosis (ALS) results from denervation of skeletal muscle as a consequence of motor neuron degeneration. Interactions between motor neurons and glia contribute to motor neuron loss, but the spatiotemporal ordering of molecular events that drive these processes in intact spinal tissue remains poorly understood. Here, we use spatial transcriptomics to obtain gene expression measurements of mouse spinal cords over the course of disease, as well as of postmortem tissue from ALS patients, to characterize the underlying molecular mechanisms in ALS. We identify pathway dynamics, distinguish regional differences between microglia and astrocyte populations at early time points, and discern perturbations in several transcriptional pathways shared between murine models of ALS and human postmortem spinal cords.

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