Stem Cell-Derived Cranial and Spinal Motor Neurons Reveal Proteostatic Differences between ALS Resistant and Sensitive Motor Neurons

An, Disi; Fujiki, Ryosuke; Smerdon, John W.; Iannitelli, Dylan E.; Wanaselja, Elizabeth K; Yagudayeva, Ilona; Lee, Joun Y.; Maity, Shuvadeep; Vogel, Christine; Wichterle, Hynek; Engle, Elizabeth C.; Mazzoni, Esteban O.

doi:10.2139/ssrn.3246042

Cited by 7 publications

(12 citation statements)

References 59 publications

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“…iCrMNs and iSpMNs modeled the differential sensitivity to ALS-related proteotoxic stress and displayed differential cellular phenotypes associated with ALS progression, such as TDP43 aggregation and mislocalization. We also revealed iCrMN-specific reliance on proteasome function to resist ALS-like stress, supporting our previous finding in mouse ESC-derived MNs 7 . For the first time, we found that iCrMNs and iSpMNs differ in the number and the sets of genes with altered splicing after MG132 induced TDP43 nuclear depletion and in response to ALS-inducing TDP43 mutation.…”

Section: Introductionsupporting

confidence: 91%

“…ALS-sensitive spinal motor neurons are under proteostasis stress during ALS progression 11,45 . Following observations in mouse motor neurons, we hypothesized that under generalized proteotoxic stress, the superior ability of iCrMNs to maintain proteostasis would result in increased survival when compared to iSpMNs 7 . Thus, we compared the survival of iCrMNs and iSpMNs when treated with two well-described proteostatic stressors, cyclopiazonic acid (CPA) and tunicamycin (TM) 46,47 .…”

Section: Resultsmentioning

confidence: 99%

“…The similar response of iCrMNs and iSpMNs to CPA treatment between the VAChT-tdT and TDP43 M337V lines indicated that the TDP43 mutant background allows for motor neuron fate differentiation which maintains differentially susceptibility to stress within the timescale of the experiment. Similar to in vivo conditions or in vitro directed differentiation, direct programming of motor neurons carrying ALS-inducing mutations initially generates a stress-sensitive population 7 . Together, these results reflect the ability of directly programmed and patterned iCrMNs and iSpMNs to model in vitro the differential sensitivity to ALS observed in in vivo models and patients.…”

Section: Resultsmentioning

confidence: 99%

“…The selective resistance of CrMNs compared to SpMNs has been found in a mouse model of ALS expressing human SOD1 G93A and in mouse ESC derived in vitro models of oculomotor/CrMN and SpMN differential sensitivity to ALS 5–7 . Our recent work uncovered a superior ability of mouse ESC-derived CrMNs to maintain proteostasis compared to SpMNs, possibly owing to higher protein expression of catalytic proteasome subunits and higher proteasome activity 7 .…”

Section: Introductionmentioning

confidence: 92%

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ALS sensitive spinal motor neurons enter a degenerative downward spiral of impaired splicing and proteostasis

Iannitelli

Tan

Nguyen

et al. 2022

Preprint

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Despite clear therapeutic potential, the mechanisms that confer differential neuronal sensitivity are not well understood. During Amyotrophic Lateral Sclerosis (ALS), sensitive spinal motor neurons (SpMN) die while a subset of rostral cranial motor neurons (CrMN) survive. In this work, we optimized a protocol to differentiate CrMNs and SpMNs from human induced pluripotent stem cells (iPSCs) by direct programming and positional patterning. Human iCrMNs are more resistant than iSpMNs to proteotoxic stress and rely on the proteasome to maintain proteostasis. iCrMNs better prevent mislocalization of TDP43 from the nucleus, a hallmark of ALS progression. iSpMNs contain more splicing defects than iCrMNs in response to ALS-related stress with genes involved in splicing and proteostasis maintenance. Therefore, iCrMNs resist ALS at two levels, preventing protein accumulation and reducing splicing defects in response to TDP43 nuclear depletion. Thus, ALS-sensitive iSpMNs appear to enter a downward spiral compromising their ability to maintain proteostasis and splicing.

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Section: Introductionsupporting

confidence: 91%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 92%

See 2 more Smart Citations

ALS sensitive spinal motor neurons enter a degenerative downward spiral of impaired splicing and proteostasis

Iannitelli

Tan

Nguyen

et al. 2022

Preprint

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“…Both EOMs and bulbar muscles are muscles innervated by the cranial motor neurons, whereas limb muscles are controlled by spinal motor neurons. A study has revealed that stem cell–derived cranial neurons have a higher level of proteasome activity than spinal motor neurons, hinting that intrinsic characteristics vary between cranial and spinal motor neurons (22). Therefore, it is likely that a more similarity of NMJ and muscle fiber phenotypes may exist in between ocular and bulbar muscles than in between ocular and limb muscles, which in turn results in a higher frequency of ocular weakness in bulbar onset MG than in nonbulbar onset MG.…”

Section: Discussionmentioning

confidence: 99%

Involvement of Ocular Muscles in Patients With Myasthenia Gravis With Nonocular Onset

Lei

Fan²,

Su³

et al. 2021

Journal of Neuro-Ophthalmology

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Background:Myasthenia gravis (MG) is an autoimmune disorder involving neuromuscular junctions and more than half of MG patients manifested with extraocular muscle weakness initially. In the remained patients, ocular weakness may occur later in the course of the disease. However, little data are available about ocular involvement in such patients. Therefore, the study aims to investigate ocular weakness in MG patients with nonocular onset and evaluate the associated factors influencing it.Methods:In our monocentric retrospective study, 54 adult-onset patients with MG with nonocular onset were included and were followed up for at least 2 years from the onset. The primary outcome was the occurrence of ptosis, diplopia, or both. Kaplan–Meier analysis was performed to estimate the time to the ocular weakness, and log-rank tests were used to analyze the association between clinical characteristics and ocular weakness. Multivariate Cox proportional hazards regression models were used to identify factors associated with ocular involvement.Results:A total of 47 (87.0%) patients developed ocular weakness during the study period. The median time to ocular weakness was 6.0 months. Time to the ocular involvement was earlier in patients with bulbar onset (P = 0.007), whereas patients receiving pyridostigmine monotherapy and immunomodulatory therapy had a longer median time of ocular weakness (P < 0.0001). No significant difference was noted between ocular weakness and age of onset, gender, and thymoma. The Cox analysis showed that bulbar onset was a risk factor of ocular weakness (adjusted hazard ratio [HR] 2.65, 95% confidence interval [CI] 1.41–4.99), whereas pyridostigmine monotherapy (adjusted HR 0.28, 95% CI 0.13–0.60) and immunotherapy (adjusted HR 0.09, 95% CI 0.04–0.22) were protective factors.Conclusions:Eighty-seven percent of patients with MG with nonocular onset developed ocular weakness. Bulbar onset was an independent risk factor for ocular involvement, whereas pyridostigmine and immunotherapy were protective factors.

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Mouse embryonic stem cell‐derived motor neurons are susceptible to ferroptosis

et al. 2023

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Ferroptosis is a regulated form of cell death driven by the lethal accumulation of lipid peroxides in cell membranes. Several regulators of ferroptosis have been identified using cancer cell lines. However, the cellular pathways of ferroptosis in neurons remain poorly characterized. In this study, we used a mouse embryonic stem cell‐derived motor neuron model to investigate how motor neurons respond to ferroptosis inducers. Pharmacological and genetic inhibition of glutathione peroxidase 4 (GPx4) induced ferroptosis in motor neurons, while system xc− inhibition by erastin had no effect. RNA‐seq analysis showed that the expression levels of several genes were altered during RSL3‐induced ferroptosis. Subsequent bioinformatic analysis revealed alterations in several biological pathways during ferroptosis, including synaptogenesis and calcium signaling. Finally, we found that edaravone, an FDA‐approved drug for treating amyotrophic lateral sclerosis (ALS) disease, rescued motor neurons from RSL3‐induced ferroptosis. Our data highlight the crucial role of GPx4 in ferroptosis regulation and demonstrate that stem cell‐derived motor neuron culture is a valuable model to study ferroptosis at the single‐cell level in a neuronal context.

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Stem Cell-Derived Cranial and Spinal Motor Neurons Reveal Proteostatic Differences between ALS Resistant and Sensitive Motor Neurons

Cited by 7 publications

References 59 publications

ALS sensitive spinal motor neurons enter a degenerative downward spiral of impaired splicing and proteostasis

ALS sensitive spinal motor neurons enter a degenerative downward spiral of impaired splicing and proteostasis

Involvement of Ocular Muscles in Patients With Myasthenia Gravis With Nonocular Onset

Mouse embryonic stem cell‐derived motor neurons are susceptible to ferroptosis

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