scholarly journals Disease modeling with human neurons reveals LMNB1 dysregulation underlying DYT1 dystonia

2020 ◽  
Author(s):  
Baojin Ding ◽  
Yu Tang ◽  
Shuaipeng Ma ◽  
Masuma Akter ◽  
Meng-Lu Liu ◽  
...  
Keyword(s):  
Animal Models ◽  
Motor Neurons ◽  
Molecular Mechanisms ◽  
Disease Modeling ◽  
Nuclear Lamina ◽  
Nucleocytoplasmic Transport ◽  
Heterozygous Mutation ◽  
Human Patient ◽  
Dyt1 Dystonia ◽  
Human Neurons

AbstractDYT1 dystonia is a hereditary neurological disease caused by a heterozygous mutation in torsin A (TOR1A). While animal models provide insights into disease mechanisms, significant species-dependent differences exist since mice with the identical heterozygous mutation fail to show pathology. Here, we model DYT1 by using human patient-derived motor neurons. These neurons with the heterozygous TOR1A mutation show markedly thickened nuclear lamina, disrupted nuclear morphology, and impaired nucleocytoplasmic transport, whereas they lack the perinuclear “blebs” that are often observed in animal models. Importantly, we further uncover that the nuclear lamina protein LMNB1 is specifically dysregulated in expression and subcellular localization. LMNB1 downregulation can largely ameliorate all the cellular defects in DYT1 motor neurons. These results reveal the value of disease modeling with human neurons and provide novel molecular mechanisms underlying DYT1 dystonia and potentially other neurological diseases with impaired nucleocytoplasmic transport.

scholarly journals A streamlined CRISPR workflow to introduce mutations and generate isogenic iPSCs for modeling amyotrophic lateral sclerosis

2021 ◽  
Author(s):  
Eric Deneault ◽  
Mathilde Chaineau ◽  
Maria Jose Castellanos-Montiel ◽  
Anna Kristyna Franco Flores ◽  
Ghazal Haghi ◽  
...  
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Motor Neurons ◽  
Molecular Mechanisms ◽  
Neurodegenerative Disorder ◽  
Control Line ◽  
Human Neurons ◽  
Recent Developments ◽  
Induced Pluripotent ◽  
Specific Contribution ◽  
Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) represents a complex neurodegenerative disorder with significant genetic heterogeneity. To date, both the genetic etiology and the underlying molecular mechanisms driving this disease remain poorly understood, although in recent years a number of studies have highlighted a number of genetic mutations causative for ALS. With these mutations pointing to potential pathways that may be affected within individuals with ALS, having the ability to generate human neurons and other disease relevant cells containing these mutations becomes even more critical if new therapies are to emerge. Recent developments with the advent of induced pluripotent stem cells (iPSCs) and clustered regularly interspaced short palindromic repeats (CRISPR) gene editing fields gave us the tools to introduce or correct a specific mutation at any site within the genome of an iPSC, and thus model the specific contribution of risk mutations. In this study we describe a rapid and efficient way to either introduce a mutation into a control line, or to correct a mutation, generating an isogenic control line from patient-derived iPSCs with a given mutation. The mutations introduced were the G93A mutation into SOD1 or H517Q into FUS, and the mutation corrected was a patient iPSC line with I114T in SOD1. A combination of small molecules and growth factors were used to guide a stepwise differentiation of the edited cells into motor neurons in order to demonstrate that disease-relevant cells could be generated for downstream applications. Through a combination of iPSCs and CRISPR editing, the cells generated here will provide fundamental insights into the molecular mechanisms underlying neuron degeneration in ALS.

scholarly journals Defective Oligodendroglial Lineage and Demyelination in Amyotrophic Lateral Sclerosis

2021 ◽  
Vol 22 (7) ◽  
pp. 3426
Author(s):  
Elisabeth Traiffort ◽  
Séverine Morisset-Lopez ◽  
Mireille Moussaed ◽  
Amina Zahaf
Keyword(s):  
Skeletal Muscle ◽  
Amyotrophic Lateral Sclerosis ◽  
Animal Models ◽  
Glial Cells ◽  
Motor Neurons ◽  
Molecular Mechanisms ◽  
Axonal Injury ◽  
Protein Aggregates ◽  
Present Review ◽  
Lateral Sclerosis

Motor neurons and their axons reaching the skeletal muscle have long been considered as the best characterized targets of the degenerative process observed in amyotrophic lateral sclerosis (ALS). However, the involvement of glial cells was also more recently reported. Although oligodendrocytes have been underestimated for a longer time than other cells, they are presently considered as critically involved in axonal injury and also conversely constitute a target for the toxic effects of the degenerative neurons. In the present review, we highlight the recent advances regarding oligodendroglial cell involvement in the pathogenesis of ALS. First, we present the oligodendroglial cells, the process of myelination, and the tight relationship between axons and myelin. The histological abnormalities observed in ALS and animal models of the disease are described, including myelin defects and oligodendroglial accumulation of pathological protein aggregates. Then, we present data that establish the existence of dysfunctional and degenerating oligodendroglial cells, the chain of events resulting in oligodendrocyte degeneration, and the most recent molecular mechanisms supporting oligodendrocyte death and dysfunction. Finally, we review the arguments in support of the primary versus secondary involvement of oligodendrocytes in the disease and discuss the therapeutic perspectives related to oligodendrocyte implication in ALS pathogenesis.

scholarly journals Animal Models of CMT2A: State-of-art and Therapeutic Implications

2020 ◽  
Vol 57 (12) ◽  
pp. 5121-5129
Author(s):  
Roberta De Gioia ◽  
Gaia Citterio ◽  
Elena Abati ◽  
Monica Nizzardo ◽  
Nereo Bresolin ◽  
...  
Keyword(s):  
Animal Models ◽  
Molecular Mechanisms ◽  
Disease Modeling ◽  
Neuronal Degeneration ◽  
Axonal Neuropathy ◽  
Gene Mutations ◽  
Transgenic Animal ◽  
Mitofusin 2 ◽  
Therapeutic Implications

Abstract Charcot–Marie–Tooth disease type 2A (CMT2A), arising from mitofusin 2 (MFN2) gene mutations, is the most common inherited axonal neuropathy affecting motor and sensory neurons. The cellular and molecular mechanisms by which MFN2 mutations determine neuronal degeneration are largely unclear. No effective treatment exists for CMT2A, which has a high degree of genetic/phenotypic heterogeneity. The identification of mutations in MFN2 has allowed the generation of diverse transgenic animal models, but to date, their ability to recapitulate the CMT2A phenotype is limited, precluding elucidation of its pathogenesis and discovery of therapeutic strategies. This review will critically present recent progress in in vivo CMT2A disease modeling, discoveries, drawbacks and limitations, current challenges, and key reflections to advance the field towards developing effective therapies for these patients.

scholarly journals Disease modeling with human neurons reveals LMNB1 dysregulation underlying DYT1 dystonia

2021 ◽  
pp. JN-RM-2507-20
Author(s):  
Baojin Ding ◽  
Yu Tang ◽  
Shuaipeng Ma ◽  
Masuma Akter ◽  
Meng-Lu Liu ◽  
...  
Keyword(s):  
Disease Modeling ◽  
Dyt1 Dystonia ◽  
Human Neurons

scholarly journals A Step-by-Step Refined Strategy for Highly Efficient Generation of Neural Progenitors and Motor Neurons from Human Pluripotent Stem Cells

Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 3087
Author(s):  
Jie Ren ◽  
Chaoyi Li ◽  
Mengfei Zhang ◽  
Huakun Wang ◽  
Yali Xie ◽  
...  
Keyword(s):  
Stem Cells ◽  
Transcription Factors ◽  
Motor Neurons ◽  
Neural Development ◽  
Pluripotent Stem Cells ◽  
Disease Modeling ◽  
Human Pluripotent Stem Cells ◽  
Highly Efficient ◽  
Efficient Generation ◽  
Human Neurons

Limited access to human neurons, especially motor neurons (MNs), was a major challenge for studying neurobiology and neurological diseases. Human pluripotent stem cells (hPSCs) could be induced as neural progenitor cells (NPCs) and further multiple neural subtypes, which provide excellent cellular sources for studying neural development, cell therapy, disease modeling and drug screening. It is thus important to establish robust and highly efficient methods of neural differentiation. Enormous efforts have been dedicated to dissecting key signalings during neural commitment and accordingly establishing reliable differentiation protocols. In this study, we refined a step-by-step strategy for rapid differentiation of hPSCs towards NPCs within merely 18 days, combining the adherent and neurosphere-floating methods, as well as highly efficient generation (~90%) of MNs from NPCs by introducing refined sets of transcription factors for around 21 days. This strategy made use of, and compared, retinoic acid (RA) induction and dual-SMAD pathway inhibition, respectively, for neural induction. Both methods could give rise to highly efficient and complete generation of preservable NPCs, but with different regional identities. Given that the generated NPCs can be differentiated into the majority of excitatory and inhibitory neurons, but hardly MNs, we thus further differentiate NPCs towards MNs by overexpressing refined sets of transcription factors, especially by adding human SOX11, whilst improving a series of differentiation conditions to yield mature MNs for good modeling of motor neuron diseases. We thus refined a detailed step-by-step strategy for inducing hPSCs towards long-term preservable NPCs, and further specified MNs based on the NPC platform.

scholarly journals Edaravone activates the GDNF/RET neurotrophic signaling pathway and protects mRNA-induced motor neurons from iPS cells

2022 ◽  
Vol 17 (1) ◽  
Author(s):  
Qian Li ◽  
Yi Feng ◽  
Yingchao Xue ◽  
Xiping Zhan ◽  
Yi Fu ◽  
...  
Keyword(s):  
Neurodegenerative Diseases ◽  
Clinical Efficacy ◽  
Motor Neurons ◽  
Molecular Mechanisms ◽  
Disease Modeling ◽  
Neuroprotective Effect ◽  
Combined Treatment ◽  
Ips Cells ◽  
Transcriptomic Analysis ◽  
Neurotrophic Signaling

Abstract Background Spinal cord motor neurons (MNs) from human iPS cells (iPSCs) have wide applications in disease modeling and therapeutic development for amyotrophic lateral sclerosis (ALS) and other MN-associated neurodegenerative diseases. We need highly efficient MN differentiation strategies for generating iPSC-derived disease models that closely recapitulate the genetic and phenotypic complexity of ALS. An important application of these models is to understand molecular mechanisms of action of FDA-approved ALS drugs that only show modest clinical efficacy. Novel mechanistic insights will help us design optimal therapeutic strategies together with predictive biomarkers to achieve better efficacy. Methods We induce efficient MN differentiation from iPSCs in 4 days using synthetic mRNAs coding two transcription factors (Ngn2 and Olig2) with phosphosite modification. These MNs after extensive characterization were applied in electrophysiological and neurotoxicity assays as well as transcriptomic analysis, to study the neuroprotective effect and molecular mechanisms of edaravone, an FDA-approved drug for ALS, for improving its clinical efficacy. Results We generate highly pure and functional mRNA-induced MNs (miMNs) from control and ALS iPSCs, as well as embryonic stem cells. Edaravone alleviates H2O2-induced neurotoxicity and electrophysiological dysfunction in miMNs, demonstrating its neuroprotective effect that was also found in the glutamate-induced miMN neurotoxicity model. Guided by the transcriptomic analysis, we show a previously unrecognized effect of edaravone to induce the GDNF receptor RET and the GDNF/RET neurotrophic signaling in vitro and in vivo, suggesting a clinically translatable strategy to activate this key neuroprotective signaling. Notably, edaravone can replace required neurotrophic factors (BDNF and GDNF) to support long-term miMN survival and maturation, further supporting the neurotrophic function of edaravone-activated signaling. Furthermore, we show that edaravone and GDNF combined treatment more effectively protects miMNs from H2O2-induced neurotoxicity than single treatment, suggesting a potential combination strategy for ALS treatment. Conclusions This study provides methodology to facilitate iPSC differentiation and disease modeling. Our discoveries will facilitate the development of optimal edaravone-based therapies for ALS and potentially other neurodegenerative diseases. Graphical abstract

scholarly journals Edaravone activates the GDNF/RET neurotrophic signaling pathway and protects mRNA-induced motor neurons from iPS cells.

2021 ◽  
Author(s):  
Qian Li ◽  
Yi Feng ◽  
Yingchao Xue ◽  
Xiping Zhan ◽  
Yi Fu ◽  
...  
Keyword(s):  
Neurodegenerative Diseases ◽  
Clinical Efficacy ◽  
Motor Neurons ◽  
Molecular Mechanisms ◽  
Disease Modeling ◽  
Neuroprotective Effect ◽  
Combined Treatment ◽  
Ips Cells ◽  
Transcriptomic Analysis ◽  
Neurotrophic Signaling

Background: Spinal cord motor neurons (MNs) from human iPS cells (iPSCs) have wide applications in disease modeling and therapeutic development for amyotrophic lateral sclerosis (ALS) and other MN-associated neurodegenerative diseases. We need highly efficient MN differentiation strategies for generating iPSC-derived disease models that closely recapitulate the genetic and phenotypic complexity of ALS. An important application of these models is to understand molecular mechanisms of action of FDA-approved ALS drugs that only show modest clinical efficacy. Novel mechanistic insights will help us design optimal therapeutic strategies together with predictive biomarkers to achieve better efficacy. Methods: We induce efficient MN differentiation from iPSCs in 4 days using synthetic mRNAs coding two transcription factors (Ngn2 and Olig2) with phosphosite modification. These MNs after extensive characterization were applied in electrophysiological and neurotoxicity assays as well as transcriptomic analysis, to study the neuroprotective effect and molecular mechanisms of edaravone, an FDA-approved drug for ALS, for improving its clinical efficacy. Results: We generate highly pure and functional mRNA-induced MNs (miMNs) from normal and ALS iPSCs, as well as embryonic stem cells. Edaravone alleviates H2O2-induced neurotoxicity and electrophysiological dysfunction in miMNs, demonstrating its neuroprotective effect. Guided by the transcriptomic analysis, we show a previously unrecognized effect of edaravone to induce the GDNF receptor RET and the GDNF/RET neurotrophic signaling in vitro and in vivo, suggesting a clinically translatable strategy to activate this key neuroprotective signaling. Notably, edaravone can replace required neurotrophic factors (BDNF and GDNF) to support long-term miMN survival and maturation, further supporting the neurotrophic function of edaravone-activated signaling. Furthermore, we show that edaravone and GDNF combined treatment more effectively protects miMNs from H2O2-induced neurotoxicity than single treatment, suggesting a potential combination strategy for ALS treatment. Conclusions: This study provides methodology to facilitate iPSC differentiation and disease modeling. Our discoveries will facilitate the development of optimal edaravone-based therapies for ALS and potentially other neurodegenerative diseases.

Structure, assembly and interactions of the nuclear lamina and the nuclear pore complex

1992 ◽  
Vol 50 (1) ◽  
pp. 490-491
Author(s):  
N. Panté ◽  
M. Jarnik ◽  
E. Heitlinger ◽  
U. Aebi
Keyword(s):  
Nuclear Pore Complex ◽  
Divalent Cations ◽  
Nuclear Lamina ◽  
Dynamic Structure ◽  
Nucleocytoplasmic Transport ◽  
Nuclear Pore ◽  
Cytoplasmic Filaments ◽  
Radial Spokes ◽  
Nuclear Ring ◽  
Central Plug

The nuclear pore complex (NPC) is a ∼120 MD supramolecular machine implicated in nucleocytoplasmic transport, that is embedded in the double-membraned nuclear envelope (NE). The basic framework of the ∼120 nm diameter NPC consists of a 32 MD cytoplasmic ring, a 66 MD ‘plug-spoke’ assembly, and a 21 MD nuclear ring. The ‘central plug’ seen in en face views of the NPC reveals a rather variable appearance indicating that it is a dynamic structure. Projecting from the cytoplasmic ring are 8 short, twisted filaments (Fig. 1a), whereas the nuclear ring is topped with a ‘fishtrap’ made of 8 thin filaments that join distally to form a fragile, 30-50 nm distal diameter ring centered above the NPC proper (Fig. 1b). While the cytoplasmic filaments are sensitive to proteases, they as well as the nuclear fishtraps are resistant to RNase treatment. Removal of divalent cations destabilizes the distal rings and thereby opens the fishtraps, addition causes them to reform. Protruding from the tips of the radial spokes into perinuclear space are ‘knobs’ that might represent the large lumenal domain of gp210, a membrane-spanning glycoprotein (Fig. 1c) which, in turn, may play a topogenic role in membrane folding and/or act as a membrane-anchoring site for the NPC. The lectin wheat germ agglutinin (WGA) which is known to recognize the ‘nucleoporins’, a family of glycoproteins having O-linked N-acetyl-glucosamine, is found in two locations on the NPC (Fig. 1. d-f): (i) whereas the cytoplasmic filaments appear unlabelled (Fig. 1d&e), WGA-gold labels sites between the central plug and the cytoplasmic ring (Fig. le; i.e., at a radius of 25-35 nm), and (ii) it decorates the distal ring of the nuclear fishtraps (Fig. 1, d&f; arrowheads).

scholarly journals Molecular mechanisms of Zika virus teratogenesis from animal studies: a systematic review protocol

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Gabriela Elis Wachholz ◽  
Julia do Amaral Gomes ◽  
Juliano André Boquett ◽  
Fernanda Sales Luiz Vianna ◽  
Lavínia Schuler-Faccini ◽  
...  
Keyword(s):  
Systematic Review ◽  
Animal Models ◽  
Zika Virus ◽  
Methodological Quality ◽  
Molecular Mechanisms ◽  
Grey Literature ◽  
Standard Form ◽  
Teratogenic Effect ◽  
Control Group

Abstract Background Due to the diversity of studies in animal models reporting that molecular mechanisms are involved in the teratogenic effect of the Zika virus (ZIKV), the objective of the present study is to evaluate the methodological quality of these studies, as well as to demonstrate which genes and which molecular pathways are affected by ZIKV in different animal models. Methods This search will be performed in four databases: PubMed/MEDLINE, EMBASE, Web of Science, and Scopus, as well as in the grey literature. The studies selection process will be reported through the PRISMA Statement diagram model. All studies describing the molecular mechanisms possibly involved in the development of malformations caused by embryonic/fetal ZIKV exposure in animal models with an appropriate control group and methodology will be included (including, for instance, randomized and non-randomized studies). All animals used as experimental models for ZIKV teratogenesis may be included as long as exposure to the virus occurred during the embryonic/fetal period. From the selected studies, data will be extracted using a previously prepared standard form. Bias risk evaluation will be conducted following the SYRCLE’s Risk of Bias tool. All data obtained will be tabulated and organized by outcomes (morphological and molecular). Discussion With the proposed systematic review, we expect to present results about the methodological quality of the published studies with animal models that investigated the molecular mechanisms involved in the teratogenic effect of ZIKV, as well as to show the studies with greater reliability. Systematic review registration PROSPERO CRD42019157316

scholarly journals Emerging hiPSC Models for Drug Discovery in Neurodegenerative Diseases

2021 ◽  
Vol 22 (15) ◽  
pp. 8196
Author(s):  
Dorit Trudler ◽  
Swagata Ghatak ◽  
Stuart A. Lipton
Keyword(s):  
Drug Discovery ◽  
Animal Models ◽  
Neurodegenerative Diseases ◽  
Disease Modeling ◽  
Induced Pluripotent Stem Cell ◽  
Neural Function ◽  
Neural Cells ◽  
Human Samples ◽  
Healthy Donors ◽  
Induced Pluripotent

Neurodegenerative diseases affect millions of people worldwide and are characterized by the chronic and progressive deterioration of neural function. Neurodegenerative diseases, such as Alzheimer’s disease (AD), Parkinson’s disease (PD), amyotrophic lateral sclerosis (ALS), and Huntington’s disease (HD), represent a huge social and economic burden due to increasing prevalence in our aging society, severity of symptoms, and lack of effective disease-modifying therapies. This lack of effective treatments is partly due to a lack of reliable models. Modeling neurodegenerative diseases is difficult because of poor access to human samples (restricted in general to postmortem tissue) and limited knowledge of disease mechanisms in a human context. Animal models play an instrumental role in understanding these diseases but fail to comprehensively represent the full extent of disease due to critical differences between humans and other mammals. The advent of human-induced pluripotent stem cell (hiPSC) technology presents an advantageous system that complements animal models of neurodegenerative diseases. Coupled with advances in gene-editing technologies, hiPSC-derived neural cells from patients and healthy donors now allow disease modeling using human samples that can be used for drug discovery.

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