Animal models are essential for investigating the pathogenesis and developing the treatment of human diseases. Identification of genetic mutations responsible for neurodegenerative diseases has enabled the creation of a large number of small animal models that mimic genetic defects found in the affected individuals. Of the current animal models, rodents with genetic modifications are the most commonly used animal models and provided important insights into pathogenesis. However, most of genetically modified rodent models lack overt neurodegeneration, imposing challenges and obstacles in utilizing them to rigorously test the therapeutic effects on neurodegeneration. Recent studies that used CRISPR/Cas9-targeted large animal (pigs and monkeys) have uncovered important pathological events that resemble neurodegeneration in the patient's brain but could not be produced in small animal models. Here we highlight the unique nature of large animals to model neurodegenerative diseases as well as the limitations and challenges in establishing large animal models of neurodegenerative diseases, with focus on Huntington disease, Amyotrophic lateral sclerosis, and Parkinson diseases. We also discuss how to use the important pathogenic insights from large animal models to make rodent models more capable of recapitulating important pathological features of neurodegenerative diseases.
Amyotrophic Lateral Sclerosis/genetics* ; Animals ; Brain/pathology* ; Disease Models, Animal ; Gene Editing ; Neurodegenerative Diseases/pathology* ; Swine

Amyotrophic lateral sclerosis (ALS) is a progressive motor neuron degenerative disease that clinically manifests both upper and lower motor neuron signs. However, it is unknown where and how the motor neuron degeneration begins, and conflicting hypotheses have been suggested. Recent advanced radiological techniques enable us to look into ALS neuropathology in vivo. Herein, we report a case with upper motor neuron-predominant ALS in whom the results of brain magnetic resonance imaging (MRI) and myelin water fraction MRI suggest axonal degeneration.
Amyotrophic Lateral Sclerosis* ; Axons ; Brain ; Magnetic Resonance Imaging* ; Motor Neurons ; Myelin Sheath* ; Neuropathology ; Pathology ; Water*

Amyotrophic Lateral Sclerosis ; pathology ; physiopathology ; Female ; Frontotemporal Dementia ; pathology ; physiopathology ; Humans ; Male ; Middle Aged ; Psychotic Disorders ; pathology ; physiopathology

Aged ; Agraphia ; etiology ; Amyotrophic Lateral Sclerosis ; complications ; pathology ; Female ; Frontotemporal Lobar Degeneration ; complications ; pathology ; Humans ; Magnetic Resonance Imaging

Amyotrophic lateral sclerosis (ALS) is the most common motor neuron disease. At present, no definite ALS biomarkers are available. In this study, exosomes from the plasma of patients with ALS and healthy controls were extracted, and differentially expressed exosomal proteins were compared. Among them, the expression of exosomal coronin-1a (CORO1A) was 5.3-fold higher than that in the controls. CORO1A increased with disease progression at a certain proportion in the plasma of patients with ALS and in the spinal cord of ALS mice. CORO1A was also overexpressed in NSC-34 motor neuron-like cells, and apoptosis, oxidative stress, and autophagic protein expression were evaluated. CORO1A overexpression resulted in increased apoptosis and oxidative stress, overactivated autophagy, and hindered the formation of autolysosomes. Moreover, CORO1A activated Ca²⁺-dependent phosphatase calcineurin, thereby blocking the fusion of autophagosomes and lysosomes. The inhibition of calcineurin activation by cyclosporin A reversed the damaged autolysosomes. In conclusion, the role of CORO1A in ALS pathogenesis was discovered, potentially affecting the disease onset and progression by blocking autophagic flux. Therefore, CORO1A might be a potential biomarker and therapeutic target for ALS.
Mice ; Animals ; Amyotrophic Lateral Sclerosis/pathology* ; Calcineurin/metabolism* ; Motor Neurons/pathology* ; Microfilament Proteins/metabolism* ; Cytoskeletal Proteins/metabolism*

ALS is a fatal adult-onset motor neuron disease. Motor neurons in the cortex, brain stem and spinal cord gradually degenerate in ALS patients, and most ALS patients die within 3~5 years of disease onset due to respiratory failure. The major pathological hallmark of ALS is abnormal accumulation of protein inclusions containing TDP-43, FUS or SOD1 protein. Moreover, the focality of clinical onset and regional spreading of neurodegeneration are typical features of ALS. These clinical data indicate that neurodegeneration in ALS is an orderly propagating process, which seems to share the signature of a seeded self-propagation with pathogenic prion proteins. In vitro and cell line experimental evidence suggests that SOD1, TDP-43 and FUS form insoluble fibrillar aggregates. Notably, these protein fibrillar aggregates can act as seeds to trigger the aggregation of native counterparts. Collectively, a self-propagation mechanism similar to prion replication and spreading may underlie the pathology of ALS. In this review, we will briefly summarize recent evidence to support the prion-like properties of major ALS-associated proteins and discuss the possible therapeutic strategies for ALS based on a prion-like mechanism.
Amyotrophic Lateral Sclerosis* ; Brain Stem ; Cell Line ; Humans ; Motor Neuron Disease ; Motor Neurons ; Pathology ; Prions ; Respiratory Insufficiency ; Spinal Cord

BACKGROUND AND PURPOSE: Involvement of the corpus callosum (CC) is reported to be a consistent feature of amyotrophic lateral sclerosis (ALS). We examined the CC pathology using diffusion tensor tractography analysis to identify precisely which fiber bundles are involved in ALS. METHODS: Diffusion tensor imaging was performed in 14 sporadic ALS patients and 16 age-matched healthy controls. Whole brain tractography was performed using the multiple-region of interest (ROI) approach, and CC fiber bundles were extracted in two ways based on functional and structural relevance: (i) cortical ROI selection based on Brodmann areas (BAs), and (ii) the sulcal-gyral pattern of cortical gray matter using FreeSurfer software, respectively. RESULTS: The mean fractional anisotropy (FA) values of the CC fibers interconnecting the primary motor (BA4), supplementary motor (BA6), and dorsolateral prefrontal cortex (BA9/46) were significantly lower in ALS patients than in controls, whereas those of the primary sensory cortex (BA1, BA2, BA3), Broca's area (BA44/45), and the orbitofrontal cortex (BA11/47) did not differ significantly between the two groups. The FreeSurfer ROI approach revealed a very similar pattern of abnormalities. In addition, a significant correlation was found between the mean FA value of the CC fibers interconnecting the primary motor area and disease severity, as assessed using the revised Amyotrophic Lateral Sclerosis Functional Rating Scale, and the clinical extent of upper motor neuron signs. CONCLUSIONS: Our findings suggest that there is some degree of selectivity or a gradient in the CC pathology in ALS. The CC fibers interconnecting the primary motor and dorsolateral prefrontal cortices may be preferentially involved in ALS.
Amyotrophic Lateral Sclerosis* ; Anisotropy ; Brain ; Corpus Callosum* ; Diffusion Tensor Imaging ; Diffusion* ; Humans ; Motor Neuron Disease ; Motor Neurons ; Pathology ; Prefrontal Cortex

BACKGROUNDIn amyotrophic lateral sclerosis (ALS), repeater F waves are increased. Accurate assessment of repeater F waves requires an adequate sample size.

METHODSWe studied the F waves of left ulnar nerves in ALS patients. Based on the presence or absence of pyramidal signs in the left upper limb, the ALS patients were divided into two groups: One group with pyramidal signs designated as P group and the other without pyramidal signs designated as NP group. The Index repeating neurons (RN) and Index repeater F waves (Freps) were compared among the P, NP and control groups following 20 and 100 stimuli respectively. For each group, the Index RN and Index Freps obtained from 20 and 100 stimuli were compared.

RESULTSIn the P group, the Index RN (P = 0.004) and Index Freps (P = 0.001) obtained from 100 stimuli were significantly higher than from 20 stimuli. For F waves obtained from 20 stimuli, no significant differences were identified between the P and NP groups for Index RN (P = 0.052) and Index Freps (P = 0.079); The Index RN (P < 0.001) and Index Freps (P < 0.001) of the P group were significantly higher than the control group; The Index RN (P = 0.002) of the NP group was significantly higher than the control group. For F waves obtained from 100 stimuli, the Index RN (P < 0.001) and Index Freps (P < 0.001) of the P group were significantly higher than the NP group; The Index RN (P < 0.001) and Index Freps (P < 0.001) of the P and NP groups were significantly higher than the control group.

CONCLUSIONSIncreased repeater F waves reflect increased excitability of motor neuron pool and indicate upper motor neuron dysfunction in ALS. For an accurate evaluation of repeater F waves in ALS patients especially those with moderate to severe muscle atrophy, 100 stimuli would be required.

Adult ; Amyotrophic Lateral Sclerosis ; pathology ; physiopathology ; Female ; Humans ; Male ; Middle Aged ; Motor Neurons ; physiology ; Neural Conduction ; physiology ; Sample Size

BACKGROUND AND PURPOSE: Disruption of nucleoporins has been reported in the motor neurons of patients with sporadic amyotrophic lateral sclerosis (sALS). However, the precise changes in the morphology of nucleoporins associated with the pathology of the 43-kDa TAR DNA-binding protein (TDP-43) in the disease process remain unknown. We investigated the expression of nucleoporins that constitute the nuclear pore complex (NPC) in spinal motor neurons that exhibit sALS in relation to TDP-43 pathology, which is a reliable neuropathological hallmark of sALS. METHODS: Paraffin-embedded sections of the lumbar spinal cord were obtained for immunofluorescence analysis from seven control subjects and six sALS patients. Anti-TDP-43 antibody, anti-nucleoporin p62 (NUP62) antibody, and anti-karyopherin beta 1 (KPNB1) antibody were applied as primary antibodies, and then visualized using appropriate secondary antibodies. The sections were then examined under a fluorescence microscope. RESULTS: NUP62 and KPNB1 immunoreactivity appeared as a smooth round rim bordering the nuclear margin in normal spinal motor neurons that exhibited nuclear TDP-43 immunoreactivity. sALS spinal motor neurons with apparent TDP-43 mislocalization demonstrated irregular, disrupted nuclear staining for NUP62 or KPNB1. Some atrophic sALS spinal motor neurons with TDP-43 mislocalization presented no NUP62 immunoreactivity. CONCLUSIONS: Our findings suggest a close relationship between NPC alterations and TDP-43 pathology in the degenerative process of the motor neurons of sALS patients.
Amyotrophic Lateral Sclerosis* ; Antibodies ; Fluorescence ; Fluorescent Antibody Technique ; Humans ; Motor Neurons* ; Nuclear Pore ; Nuclear Pore Complex Proteins* ; Pathology ; Spinal Cord

BACKGROUND: It is important to determine prognostic factors for the outcome of amyotrophic lateral sclerosis (ALS) at an early stage. The time taken for symptoms to spread from spinal or bulbar regions to both (time to generalization; TTG) is considered a strong predictor of survival; however, this has rarely been studied in Asian populations. The aim of this retrospective study was to evaluate potential factors affecting prognosis in Chinese patients with sporadic ALS, with a focus on the association between TTG and overall survival. METHODS: Seventy-one patients with sporadic ALS who were hospitalized at Chinese PLA General Hospital from 2009 to 2016 were followed up until December 2017. Survival analysis was performed using univariate Kaplan-Meier log-rank and multivariate Cox proportional hazards models. The clinical data of the patients were recorded and analyzed. Variables studied were age at symptom onset, sex, site of symptom onset, diagnostic latency, TTG, diagnostic category, ALS Functional Rating Scale-revised score, percent predicted forced vital capacity (FVC%), and disease progression rate (DPR) at diagnosis. RESULTS: The mean age at onset was 54 (SD = 10.2) years, and the median survival time from symptom onset was 41 months (95% confidence interval: 34-47). By univariate analysis, factors independently affecting survival were age at symptom onset (Log rank = 15.652, P < 0.0001), TTG (Log rank = 14.728, P < 0.0001), diagnostic latency (Log rank = 11.997, P = 0.001), and DPR (Log rank = 6.50, P = 0.011). In the Cox multivariate model, TTG had the strongest impact on survival time (hazard ratio = 0.926, P = 0.01). CONCLUSIONS TTG can be used as an effective indicator of prognosis in patients with sporadic ALS.
Adult ; Amyotrophic Lateral Sclerosis ; pathology ; Disease Progression ; Female ; Humans ; Male ; Middle Aged ; Prognosis ; Proportional Hazards Models ; Retrospective Studies