scholarly journals Human Motor Neuron Progenitor Transplantation Leads to Endogenous Neuronal Sparing in 3 Models of Motor Neuron Loss

2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
Tanya J. Wyatt ◽  
Sharyn L. Rossi ◽  
Monica M. Siegenthaler ◽  
Jennifer Frame ◽  
Rockelle Robles ◽  
...  
Keyword(s):  
Animal Models ◽  
Motor Neuron ◽  
Motor Neurons ◽  
Embryonic Stem ◽  
Active Growth ◽  
Neuron Loss ◽  
Cord Injury ◽  
Human Motor ◽  
Motor Neuron Loss

Motor neuron loss is characteristic of many neurodegenerative disorders and results in rapid loss of muscle control, paralysis, and eventual death in severe cases. In order to investigate the neurotrophic effects of a motor neuron lineage graft, we transplanted human embryonic stem cell-derived motor neuron progenitors (hMNPs) and examined their histopathological effect in three animal models of motor neuron loss. Specifically, we transplanted hMNPs into rodent models of SMA (Δ7SMN), ALS (SOD1 G93A), and spinal cord injury (SCI). The transplanted cells survived and differentiated in all models. In addition, we have also found that hMNPs secrete physiologically active growth factorsin vivo, including NGF and NT-3, which significantly enhanced the number of spared endogenous neurons in all three animal models. The ability to maintain dying motor neurons by delivering motor neuron-specific neurotrophic support represents a powerful treatment strategy for diseases characterized by motor neuron loss.

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 Modeling motor neuron resilience in ALS using stem cells

2018 ◽  
Author(s):  
Ilary Allodi ◽  
Jik Nijssen ◽  
Julio Aguila Benitez ◽  
Christoph Schweingruber ◽  
Andrea Fuchs ◽  
...  
Keyword(s):  
Stem Cells ◽  
Motor Neuron ◽  
Motor Neurons ◽  
Embryonic Stem ◽  
Spinal Motor Neurons ◽  
Neuronal Progenitors ◽  
Oculomotor Neurons ◽  
Bona Fide

SUMMARYOculomotor neurons, which regulate eye movement, are resilient to degeneration in the lethal motor neuron disease amyotrophic lateral sclerosis (ALS). It would be highly advantageous if motor neuron resilience could be modeled in vitro. Towards this goal, we generated a high proportion of oculomotor neurons from mouse embryonic stem cells through temporal overexpression of Phox2a in neuronal progenitors. We demonstrate, using electrophysiology, immunocytochemistry and RNA sequencing, that in vitro generated neurons are bona fide oculomotor neurons based on their cellular properties and similarity to their in vivo counterpart in rodent and man. We also show that in vitro generated oculomotor neurons display a robust activation of survival-promoting Akt signaling and are more resilient to the ALS-like toxicity of kainic acid than spinal motor neurons. Thus, we can generate bona fide oculomotor neurons in vitro which display a resilience similar to that seen in vivo.

Degenerating compartment and functioning compartment of motor neurons in ALS: Possible process of motor neuron loss

Neurology ◽  
1983 ◽  
Vol 33 (5) ◽  
pp. 654-654 ◽  
Author(s):  
G. Sobue ◽  
K. Sahashi ◽  
A. Takahashi ◽  
Y. Matsuoka ◽  
T. Muroga ◽  
...  
Keyword(s):  
Motor Neuron ◽  
Motor Neurons ◽  
Neuron Loss ◽  
Motor Neuron Loss

Lasting paraplegia caused by loss of lumbar spinal cord interneurons in rats: no direct correlation with motor neuron loss

2000 ◽  
Vol 93 (2) ◽  
pp. 266-275 ◽  
Author(s):  
Bassam Hadi ◽  
Y. Ping Zhang ◽  
Darlene A. Burke ◽  
Christopher B. Shields ◽  
David S. K. Magnuson
Keyword(s):  
Spinal Cord ◽  
Locomotor Activity ◽  
Motor Neuron ◽  
Motor Neurons ◽  
Lumbar Spinal Cord ◽  
Neuron Loss ◽  
Content Type ◽  
Motor Neuron Loss ◽  
Lumbar Spinal ◽  
Fine Print

Object. The aims of this study were to investigate further the role played by lumbar spinal cord interneurons in the generation of locomotor activity and to develop a model of spinal cord injury suitable for testing neuron replacement strategies. Methods. Adult rats received intraspinal injections of kainic acid (KA). Locomotion was assessed weekly for 4 weeks by using the Basso, Beattie, and Bresnahan (BBB) 21-point locomotor scale, and transcranial magnetic motor evoked potentials (MMEPs) were recorded in gastrocnemius and quadriceps muscles at 1 and 4 weeks. No changes in transcranial MMEP latency were noted following KA injection, indicating that the descending motor pathways responsible for these responses, including the alpha motor neurons, were not compromised. Rats in which KA injections included much of the L-2 segment (10 animals) showed severe locomotor deficits, with a mean BBB score of 4.5 ± 3.6 (± standard deviation). Rats that received lesions rostral to the L-2 segment (four animals) were able to locomote and had a mean BBB score of 14.6 ± 2.6. Three rats that received only one injection bilaterally centered at L-2 (three animals) had a mean BBB score of 3.2 ± 2. Histological examination revealed variable loss of motor neurons limited to the injection site. There was no correlation between motor neuron loss and BBB score. Conclusions. Interneuron loss centered on the L-2 segment induces lasting paraplegia independent of motor neuron loss and white matter damage, supporting earlier suggestions that circuitry critical to the generator of locomotor activity (the central pattern generator) resides in this area. This injury model may prove ideal for studies of neuron replacement strategies.

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 ALS mice carrying pathological mutant TDP-43, but not mutant FUS, display axonal transport defects in vivo

2018 ◽  
Author(s):  
James N. Sleigh ◽  
Andrew P. Tosolini ◽  
David Gordon ◽  
Anny Devoy ◽  
Pietro Fratta ◽  
...  
Keyword(s):  
Motor Neuron ◽  
Axonal Transport ◽  
Rna Processing ◽  
Motor Symptom ◽  
Neuronal Process ◽  
Neuron Loss ◽  
Disease Spectrum ◽  
Motor Neuron Loss ◽  
Lateral Sclerosis

AbstractAmyotrophic lateral sclerosis (ALS) is a fatal, progressive neurodegenerative disease resulting from a complex interplay between genetics and environment. Impairments in the basic neuronal process of axonal transport have been identified in several ALS models. However, in vivo evidence of early/pre-symptomatic deficiencies in neuronal cargo trafficking remains limited, thus the pathogenic importance of axonal transport to the ALS disease spectrum remains to be fully resolved. We therefore analysed the in vivo dynamics of retrogradely transported, neurotrophin-containing signalling endosomes in motor neuron axons of two new mouse models of ALS that have mutations in different RNA processing genes (Tardbp and Fus). TDP-43M337V mice, which show neuromuscular pathology but no overt motor neuron loss, displayed in vivo perturbations in axonal transport that manifested between 1.5 and 3 months and preceded motor symptom onset. In contrast, signalling endosome transport remained largely unaffected in mutant FusΔ14/+ mice, despite 20% motor neuron loss. These findings indicate that deficiencies in retrograde neurotrophin signalling and axonal transport are not common to all ALS-linked genes, and that there are inherent and mechanistic distinctions in the pathogenesis of ALS caused by mutations in different RNA processing genes.

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 Loss of BICD2 in muscle drives motor neuron loss in a developmental form of spinal muscular atrophy

2019 ◽  
Author(s):  
AM Rossor ◽  
JN Sleigh ◽  
M Groves ◽  
F Muntoni ◽  
MM Reilly ◽  
...  
Keyword(s):  
Spinal Muscular Atrophy ◽  
Motor Neuron ◽  
Motor Neurons ◽  
Secretory Pathway ◽  
Muscular Atrophy ◽  
Adaptor Protein ◽  
Small Gtpase ◽  
Missense Mutations ◽  
Neuron Loss ◽  
Motor Neuron Loss

AbstractBICD2 is a key component of the dynein/dynactin motor complex. Autosomal dominant mutations in BICD2 cause Spinal Muscular Atrophy Lower Extremity Predominant 2 (SMALED2), a developmental disease of motor neurons. In this study we sought to examine the motor neuron phenotype of conditional Bicd2−/− mice. Bicd2−/− mice show a significant reduction in the number of motor axons of the L4 ventral root compared to wild type mice. Muscle-specific knockout of Bicd2, but not motor neuron-specific Bicd2 loss, results in a reduction in L4 ventral axons comparable to global Bicd2−/− mice. Rab6, a small GTPase required for the sorting of secretory vesicles from the TGN to the plasma membrane is a major binding partner of BICD2. We therefore examined the secretory pathway in SMALED2 patient fibroblasts and demonstrated impaired flow of constitutive secretory cargoes. Together, these data indicate that BICD2 loss from muscles is a major driver of non-cell autonomous pathology with important implications for future therapeutic approaches to SMALED2.SummaryMissense mutations in the cargo adaptor protein BICD2 cause SMALED2, a developmental disease of motor neurons. In this study, the authors show that BICD2 mutations cause motor neuron loss by a non-cell autonomous mechanism determining a disabling impairment of muscle function.

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