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1.
PLoS One ; 19(8): e0306021, 2024.
Article in English | MEDLINE | ID: mdl-39088432

ABSTRACT

Sporadic inclusion body myositis (sIBM) is a muscle disease in older people and is characterized by inflammatory cell invasion into intact muscle fibers and rimmed vacuoles. The pathomechanism of sIBM is not fully elucidated yet, and controversy exists as to whether sIBM is a primary autoimmune disease or a degenerative muscle disease with secondary inflammation. Previously, we established a method of collecting CD56-positive myoblasts from human skeletal muscle biopsy samples. We hypothesized that the myoblasts derived from these patients are useful to see the cell-autonomous pathomechanism of sIBM. With these resources, myoblasts were differentiated into myotubes, and the expression profiles of cell-autonomous pathology of sIBM were analyzed. Myoblasts from three sIBM cases and six controls were differentiated into myotubes. In the RNA-sequencing analysis of these "myotube" samples, 104 differentially expressed genes (DEGs) were found to be significantly upregulated by more than twofold in sIBM, and 13 DEGs were downregulated by less than twofold. For muscle biopsy samples, a comparative analysis was conducted to determine the extent to which "biopsy" and "myotube" samples differed. Fifty-three DEGs were extracted of which 32 (60%) had opposite directions of expression change (e.g., increased in biopsy vs decreased in myotube). Apolipoprotein E (apoE) and transmembrane protein 8C (TMEM8C or MYMK) were commonly upregulated in muscle biopsies and myotubes from sIBM. ApoE and myogenin protein levels were upregulated in sIBM. Given that enrichment analysis also captured changes in muscle contraction and development, the triggering of muscle atrophy signaling and abnormal muscle differentiation via MYMK or myogenin may be involved in the pathogenesis of sIBM. The presence of DEGs in sIBM suggests that the myotubes formed from sIBM-derived myoblasts revealed the existence of muscle cell-autonomous degeneration in sIBM. The catalog of DEGs will be an important resource for future studies on the pathogenesis of sIBM focusing on primary muscle degeneration.


Subject(s)
Muscle Fibers, Skeletal , Myositis, Inclusion Body , Humans , Myositis, Inclusion Body/metabolism , Myositis, Inclusion Body/genetics , Myositis, Inclusion Body/pathology , Muscle Fibers, Skeletal/metabolism , Muscle Fibers, Skeletal/pathology , Cell Differentiation , Aged , Female , Male , Cells, Cultured , Transcriptome , Myoblasts/metabolism , Myoblasts/pathology , Biopsy , Gene Expression Profiling , Middle Aged
2.
Phys Rev E ; 109(6): L062201, 2024 Jun.
Article in English | MEDLINE | ID: mdl-39020885

ABSTRACT

It is demonstrated that quantum systems classically exhibiting strong and homogeneous chaos in a bounded region of the phase space can induce a global quantum diffusion. As an ideal model system, a small quantum chaos with finite Hilbert space dimension N weakly coupled with M additional degrees of freedom which is approximated by linear systems is proposed. By twinning the system the diffusion process in the additional modes can be numerically investigated without taking the unbounded diffusion space into account explicitly. Even though N is not very large, diffusion occurs in the additional modes as the coupling strength increases if M≥3. If N is large enough, a definite quantum transition to diffusion takes place through a critical subdiffusion characterized by an anomalous diffusion exponent.

3.
Phys Rev E ; 109(4-1): 044203, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38755861

ABSTRACT

Sawtooth structures are observed in tunneling probabilities with changing Planck's constant for a periodically perturbed rounded-rectangular potential with a sufficiently wide width for which instanton tunneling is substantially prohibited. The sawtooth structure is a manifestation of the essential nature of multiquanta absorption tunneling. Namely, the periodic perturbation creates an energy ladder of harmonic channels at E_{n}=E_{I}+nℏω, where E_{I} is an incident energy and ω is an angular frequency of the perturbation. The harmonic channel that absorbs the minimum amount of quanta of n=n[over ¯], such that V_{0}

4.
Cerebellum ; 23(4): 1498-1508, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38324175

ABSTRACT

Cerebellar ataxia, neuropathy, and vestibular areflexia syndrome (CANVAS) is an autosomal recessive multisystem neurologic disorder caused by biallelic intronic repeats in RFC1. Although the phenotype of CANVAS has been expanding via diagnostic case accumulation, there are scant pedigree analyses to reveal disease penetrance, intergenerational fluctuations in repeat length, or clinical phenomena (including heterozygous carriers). We identified biallelic RFC1 ACAGG expansions of 1000 ~ repeats in three affected siblings having sensorimotor neuronopathy with spinocerebellar atrophy initially presenting with painful muscle cramps and paroxysmal dry cough. They exhibit almost homogeneous clinical and histopathological features, indicating motor neuronopathy. Over 10 years of follow-up, painful intractable muscle cramps ascended from legs to trunks and hands, followed by amyotrophy and subsequent leg pyramidal signs. The disease course combined with the electrophysical and imagery data suggest initial and prolonged hyperexcitability and the ensuing spinal motor neuron loss, which may progress from the lumbar to the rostral anterior horns and later expand to the corticospinal tract. Genetically, heterozygous ACAGG expansions of similar length were transmitted in unaffected family members of three successive generations, and some of them experienced muscle cramps. Leukocyte telomere length assays revealed comparatively shorter telomeres in affected individuals. This comprehensive pedigree analysis demonstrated a non-anticipating ACAGG transmission and high penetrance of manifestations with a biallelic state, especially motor neuronopathy in which muscle cramps serve as a prodromal and disease progress marker. CANVAS and RFC1 spectrum disorder should be considered when diagnosing lower dominant motor neuron disease, idiopathic muscle cramps, or neuromuscular hyperexcitability syndromes.


Subject(s)
Muscle Cramp , Pedigree , Replication Protein C , Humans , Muscle Cramp/genetics , Male , Female , Replication Protein C/genetics , Adult , Middle Aged , Japan , Motor Neuron Disease/genetics , Bilateral Vestibulopathy/genetics , Spinocerebellar Ataxias/genetics , DNA Repeat Expansion/genetics , East Asian People
5.
Cerebellum ; 2024 Feb 29.
Article in English | MEDLINE | ID: mdl-38421477

ABSTRACT

This report describes an adult case of Poretti-Boltshauser syndrome (PTBHS) and with novel variants of LAMA1. A 65-year-old Japanese woman with cerebellar malformation identified during a medical checkup was referred to our hospital. Subsequently, neurological examination, brain imaging, and genetic investigation via whole-exome sequencing were performed. The patient presented with mild cerebellar ataxia and intellectual disability. Magnetic resonance imaging revealed cerebellar dysplasia and cysts and an absence of molar tooth sign. Genetic analysis revealed a novel homozygous variant of c.1711_1712del in LAMA1 (NM_005559.4). Most cases with PTBHS are reported in pediatric patients; however, our patient expressed a mild phenotype and was undiagnosed until her 60 s. These findings suggest that PTBHS should be considered in not only pediatric cerebellar dysplasia but also adult cerebellar ataxia with mild presentation.

6.
Ann Clin Transl Neurol ; 11(3): 577-592, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38158701

ABSTRACT

OBJECTIVE: Multisystem proteinopathy type 3 (MSP3) is an inherited, pleiotropic degenerative disorder caused by a mutation in heterogeneous nuclear ribonucleoprotein A1 (hnRNPA1), which can affect the muscle, bone, and/or nervous system. This study aimed to determine detailed histopathological features and transcriptomic profile of HNRNPA1-mutated skeletal muscles to reveal the core pathomechanism of hereditary inclusion body myopathy (hIBM), a predominant phenotype of MSP3. METHODS: Histopathological analyses and RNA sequencing of HNRNPA1-mutated skeletal muscles harboring a c.940G > A (p.D314N) mutation (NM_031157) were performed, and the results were compared with those of HNRNPA1-unlinked hIBM and control muscle tissues. RESULTS: RNA sequencing revealed aberrant alternative splicing events that predominantly occurred in myofibril components and mitochondrial respiratory complex. Enrichment analyses identified the nuclear pore complex (NPC) and nucleocytoplasmic transport as suppressed pathways. These two pathways were linked by the hub genes NUP50, NUP98, NUP153, NUP205, and RanBP2. In immunohistochemistry, these nucleoporin proteins (NUPs) were mislocalized to the cytoplasm and aggregated mostly with TAR DNA-binding protein 43 kDa and, to a lesser extent, with hnRNPA1. Based on ultrastructural observation, irregularly shaped myonuclei with deep invaginations were frequently observed in atrophic fibers, consistent with the disorganization of NPCs. Additionally, regarding the expression profiles of overall NUPs, reduced expression of NUP98, NUP153, and RanBP2 was shared with HNRNPA1-unlinked hIBMs. INTERPRETATION: The shared subset of altered NUPs in amyotrophic lateral sclerosis (ALS), as demonstrated in prior research, HNRNPA1-mutated, and HNRNPA1-unlinked hIBM muscle tissues may provide evidence regarding the underlying common nuclear pore pathology of hIBM, ALS, and MSP.


Subject(s)
Amyotrophic Lateral Sclerosis , Heterogeneous-Nuclear Ribonucleoprotein Group A-B , Muscular Diseases , Humans , Heterogeneous-Nuclear Ribonucleoprotein Group A-B/genetics , Heterogeneous-Nuclear Ribonucleoprotein Group A-B/metabolism , Amyotrophic Lateral Sclerosis/genetics , Nuclear Pore/metabolism , Nuclear Pore/pathology , Muscle, Skeletal/metabolism , Inclusion Bodies/metabolism , Inclusion Bodies/pathology , Muscular Diseases/metabolism , Nuclear Pore Complex Proteins/genetics , Nuclear Pore Complex Proteins/metabolism
7.
Mol Syndromol ; 14(6): 461-468, 2023 Dec.
Article in English | MEDLINE | ID: mdl-38108041

ABSTRACT

Introduction: DYT-KMT2B is a rare childhood-onset, hereditary movement disorder typically characterized by lower-limb dystonia and subsequently spreads into the craniocervical and laryngeal muscles. Recently, KMT2B-encoding lysine (K)-specific histone methyltransferase 2B was identified as the causative gene for DYT-KMT2B, also known as DYT28. In addition to the fact that many physicians do not have sufficient experience or knowledge of hereditary dystonia, the clinical features of DYT-KMT2B overlap with those of other hereditary dystonia, and limited clinical biomarkers make the diagnosis difficult. Methods: Histone proteins were purified from the oral mucosa of patients with de novo KMT2B mutation causing premature stop codon, and then trimethylated fourth lysine residue of histone H3 (H3K4me3) which was catalyzed by KMT2B was analyzed by immunoblotting with specific antibody. We further analyzed the significance of H3K4me3 in patients with DYT-KMT2B using publicly available datasets. Results: H3K4me3 histone mark was markedly lower in the patient than in the control group. Additionally, a reanalysis of publicly available datasets concerning DNA methylation also demonstrated that KMT2B remained inactive in DYT-KMT2B. Discussion: Although only one case was studied due to the rarity of the disease, the reduction of H3K4me3 in the patient's biological sample supports the dysfunction of KMT2B in DYT-KMT2B. Together with informatics approaches, our results suggest that KMT2B haploinsufficiency contributes to the DYT-KMT2B pathogenic process.

8.
Phys Rev E ; 107(6): L062201, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37464610

ABSTRACT

By using the kicked Harper model, the effect of dynamical perturbations to the localized and ballistic phases in quasiperiodic lattice systems is investigated. The transition from the localized phase to diffusive phase via a critical subdiffusion t^{α} (t is time) with 0<α<1 is observed. In addition, we confirm the existence of the transition from the ballistic phase to the diffusive phase via a critical superdiffusion with 1<α<2.

9.
Cureus ; 15(2): e34763, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36909070

ABSTRACT

Painful legs and moving toes syndrome (PLMTS) is a rare movement disorder characterized by spontaneous abnormal, involuntary toe movements and unilateral or bilateral lower extremity pain that predominantly affects women in middle age or later. The background etiology of PLMTS includes peripheral neuropathy, a history of trauma, and nerve root damage, but the cause of the disease is often undetermined. The pain usually occurs first and is often more distressing to the patient than abnormal toe movement. Spontaneous resolution is rare, and symptomatic therapies include the oral administration of anticonvulsants, antidepressants, and various pain relievers, as well as other therapeutic interventions, including botulinum toxin injection and epidural block, but their effectiveness is uncertain. We report a case of PMLTS in which low doses of pramipexole, a non-ergot dopamine agonist, dramatically improved both abnormal toe movement and leg pain, which are documented by videography.

10.
Case Rep Neurol ; 15(1): 41-47, 2023.
Article in English | MEDLINE | ID: mdl-36873620

ABSTRACT

Disturbance of smell is often accompanied with common neurodegenerative diseases such as Parkinson's and Alzheimer's diseases. In addition, patients with head trauma, intracranial tumors, and hydrocephalus can also develop olfactory dysfunction, and some of which can improve with treatment of the underlying disease. In clinical practice, few patients complain of smell disturbances, thus olfactory dysfunction is often overshadowed by visible motor symptoms. Herein, we report a case of late-onset idiopathic aqueductal stenosis, a rare form of adult-onset hydrocephalus in which olfactory dysfunction and gait disturbance was markedly improved after endoscopic ventriculostomy. This case report is expected to make more physicians aware that hydrocephalus can cause olfactory dysfunction and that it can be corrected postoperatively. Furthermore, in addition to motor and neuropsychological function, olfactory function test might be useful for functional assessment before and after surgical treatment of hydrocephalus.

11.
Intern Med ; 62(16): 2415-2418, 2023 Aug 15.
Article in English | MEDLINE | ID: mdl-36631088

ABSTRACT

Protein S deficiency causes spinal cord infarction in rare cases. We herein report the first case of severe cervicothoracic cord infarction in an adolescent with protein S deficiency. A 16-year-old boy presented with neck pain, four-limb paralysis, and numbness. Magnetic resonance imaging revealed spinal artery infarction in the C4 to Th4 area. Protein S antigen and activity were decreased. The patient was diagnosed with protein S deficiency-associated cervicothoracic cord infarction, which was treated with anticoagulation. Protein S deficiency should be considered as a potential cause of spinal cord infarction in young healthy patients and should be appropriately treated with anticoagulation.


Subject(s)
Ischemic Attack, Transient , Protein S Deficiency , Male , Humans , Adolescent , Spinal Cord/diagnostic imaging , Spinal Cord/pathology , Protein S Deficiency/complications , Protein S Deficiency/pathology , Infarction/complications , Infarction/diagnostic imaging , Magnetic Resonance Imaging/methods , Anticoagulants
12.
Tohoku J Exp Med ; 259(4): 293-300, 2023 Mar 24.
Article in English | MEDLINE | ID: mdl-36696983

ABSTRACT

Pseudobulbar palsy and bulbar palsy cause dysphagia in patients with amyotrophic lateral sclerosis (ALS). Dysphagia in patients with ALS not only increases the risk of aspiration and pneumonia but also leads to malnutrition and weight loss, which are poor prognostic factors. Gastrostomy is the preferred route of feeding and nutritional support in patients with dysphagia. However, there are no established standards to determine the ideal timing of gastrostomy for patients with ALS. Therefore, we used the videofluoroscopic dysphagia scale (VDS), which objectively quantifies swallowing function, in videofluoroscopic swallowing study (VFSS) to investigate whether this scale at diagnosis can be a useful predictor for the timing of gastrostomy. We retrospectively evaluated 22 patients with ALS who were diagnosed at our hospital. We assessed the VDS scores in all patients within 3 months of diagnosis. A decline in the ALS functional rating scale revised (ALSFRS-R) scores was used as an indicator of disease progression. As a result, we found that the VDS score of the pharyngeal phase and the total VDS score were significantly correlated with the ΔALSFRS-R scores. These scores were also associated with the existing indicators for the timing of gastrostomy, i.e., decreased body weight and percent-predicted forced vital capacity. We demonstrated the noninferiority of the VDS scores relative to the existing indicators. In addition, the VDS score of the pharyngeal phase was significantly correlated with the time from diagnosis to gastrostomy. The VDS score could estimate the timing of gastrostomy in patients with ALS with dysphagia at diagnosis.


Subject(s)
Amyotrophic Lateral Sclerosis , Deglutition Disorders , Humans , Deglutition Disorders/diagnosis , Deglutition Disorders/etiology , Amyotrophic Lateral Sclerosis/complications , Amyotrophic Lateral Sclerosis/diagnosis , Gastrostomy/adverse effects , Retrospective Studies , Deglutition
13.
Phys Rev E ; 108(6-1): 064210, 2023 Dec.
Article in English | MEDLINE | ID: mdl-38243542

ABSTRACT

The strong enhancement of tunneling couplings typically observed in tunneling splittings in the quantum map is investigated. We show that the transition from instanton to noninstanton tunneling, which is known to occur in tunneling splittings in the space of the inverse Planck constant, takes place in a parameter space as well. By applying the absorbing perturbation technique, we find that the enhancement invoked as a result of local avoided crossings and that originating from globally spread interactions over many states should be distinguished and that the latter is responsible for the strong and persistent enhancement. We also provide evidence showing that the coupling across the separatrix in phase space is crucial in explaining the behavior of tunneling splittings by performing the wave-function-based observation. In the light of these findings, we examine the validity of the resonance-assisted tunneling theory.

14.
Phys Rev E ; 105(5-1): 054201, 2022 May.
Article in English | MEDLINE | ID: mdl-35706293

ABSTRACT

Localization and delocalization of quantum diffusion in a time-continuous one-dimensional Anderson model perturbed by the quasiperiodic harmonic oscillations of M colors is investigated systematically, which has been partly reported by a preliminary Letter [H. S. Yamada and K. S. Ikeda, Phys. Rev. E 103, L040202 (2021)2470-004510.1103/PhysRevE.103.L040202]. We investigate in detail the localization-delocalization characteristics of the model with respect to three parameters: the disorder strength W, the perturbation strength ε, and the number of colors, M, which plays the similar role of spatial dimension. In particular, attention is focused on the presence of localization-delocalization transition (LDT) and its critical properties. For M≥3 the LDT exists and a normal diffusion is recovered above a critical strength ε, and the characteristics of diffusion dynamics mimic the diffusion process predicted for the stochastically perturbed Anderson model even though M is not large. These results are compared with the results of discrete-time quantum maps, i.e., the Anderson map and the standard map. Further, the features of delocalized dynamics are discussed in comparison with a limit model which has no static disordered part.

15.
Intern Med ; 61(11): 1761-1765, 2022.
Article in English | MEDLINE | ID: mdl-35650115

ABSTRACT

Cranial nerve palsy associated with coronavirus disease 2019 (COVID-19) is rare. We herein report the first Asian case of the immediate onset of isolated and unilateral abducens nerve palsy (ANP) accompanied with COVID-19 infection. A 25-year-old man developed diplopia one day after the COVID-19 symptom onset. Neurological examination revealed limitation of left eye abduction without ataxia and hyporeflexia. Negative anti-ganglioside antibody results and mild albuminocytological dissociation were noted. The patient was diagnosed with left ANP accompanied by COVID-19 infection. The ANP spontaneously recovered without treatment. ANP can develop during the early phase of COVID-19 infection and adversely affect patients' quality of life.


Subject(s)
Abducens Nerve Diseases , COVID-19 , Adult , Humans , Male , Abducens Nerve , Abducens Nerve Diseases/etiology , COVID-19/complications , Quality of Life
16.
Front Neurol ; 13: 845755, 2022.
Article in English | MEDLINE | ID: mdl-35299613

ABSTRACT

Myelin oligodendrocyte glycoprotein (MOG) antibody-associated disorder (MOGAD) is a newly identified autoimmune demyelinating disorder that is often associated with acute disseminated encephalomyelitis and usually occurs postinfection or postvaccination. Here we report a case of MOGAD after mRNA severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination. A previously healthy 68-year-old woman presented to our department with gradually worsening numbness on the right side of her face, which began 14 days after her second dose of an mRNA-1273 vaccination. The patient's brain MRI revealed a right cerebellar peduncle lesion with gadolinium enhancement, a typical finding of MOGAD. A neurological examination revealed paresthesia on her right V2 and V3 areas. Other neurological examinations were unremarkable. Laboratory workups were positive for serum MOG-IgG as assessed by live cell-based assays and the presence of oligoclonal bands in the cerebrospinal fluid (CSF). The patient's serum test results for cytoplasmic-antineutrophil cytoplasmic antibodies, perinuclear-cytoplasmic-antineutrophil cytoplasmic antibodies, GQ1b-antibodies, and aquaporin-4 antibodies (AQP4-IgG) were all negative. Tests for soluble interleukin (IL)-2 receptors in the serum, IL-6 in the CSF and skin pricks, and angiotensin converting enzyme tests were all unremarkable. The patient was diagnosed with MOGAD after receiving an mRNA SARS-CoV-2 vaccination. After two courses of intravenous methylprednisolone treatment, the patient's symptoms improved and her cerebellar peduncle lesion shrunk slightly without gadolinium enhancement. To date, there have only been two cases of monophasic MOGAD following SARS-CoV-2 vaccination, including both the ChAdOx1 nCOV-19 and mRNA-1273 vaccines, and the prognosis is generally similar to other typical MOGAD cases. Although the appearance of MOG antibodies is relatively rare in post-COVID-19-vaccine demyelinating diseases, MOGAD should be considered in patients with central nervous system (CNS) demyelinating diseases after receiving a SARS-CoV-2 vaccine.

17.
BMC Neurol ; 22(1): 94, 2022 Mar 16.
Article in English | MEDLINE | ID: mdl-35296264

ABSTRACT

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease that affects motor neurons selectively. In particular, weakness in respiratory and swallowing muscles occasionally causes aspiration pneumonia and choking, which can be lethal. Surgery to prevent aspiration, which separates the trachea and esophagus, can reduce the associated risks. Central-part laryngectomy (CPL) is a relatively minimally invasive surgery to prevent aspiration. No studies have been conducted on the long-term outcomes of surgery to prevent aspiration in patients with ALS. This case series aimed to determine the long-term outcomes of surgery to prevent aspiration and the use of a continuous low-pressure aspirator in patients with ALS by evaluating the frequency of intratracheal sputum suctions performed per day, intra- and postoperative complications, oral intake data, and satisfaction of patients and their primary caregiver to predict improvement in patients' quality of life (QOL). METHODS: We report a case series of six patients with ALS who underwent CPL along with tracheostomy to prevent aspiration between January 2015 and November 2018. We evaluated their pre- and postoperative status and administered questionnaires at the time of last admission to the patients and their primary caregivers. RESULTS: The mean follow-up period after CPL was 33.5 months. Aerophagia was a common postoperative complication. The use of a continuous low-pressure aspirator resulted in reduced frequency of intratracheal sputum suctions. All cases avoided aspiration pneumonia. Oral intake was continued for 2-4 years after the tracheostomy and CPL. The satisfaction levels of the patient and primary caregiver were high. CONCLUSION: Our case series suggests that the use of a continuous low-pressure aspirator in patients undergoing CPL improves oral intake and reduces the frequency of intratracheal sputum suctions, which improves the QOL of patients with ALS and their families and caregivers. CPL and continuous low-pressure aspiration should be considered as a management option for ALS with significant bulbar and respiratory muscle weakness/dysfunction.


Subject(s)
Amyotrophic Lateral Sclerosis , Neurodegenerative Diseases , Pneumonia, Aspiration , Amyotrophic Lateral Sclerosis/complications , Amyotrophic Lateral Sclerosis/surgery , Deglutition , Humans , Neurodegenerative Diseases/complications , Pneumonia, Aspiration/complications , Pneumonia, Aspiration/prevention & control , Quality of Life
18.
Clin Case Rep ; 10(2): e05276, 2022 Feb.
Article in English | MEDLINE | ID: mdl-35223001

ABSTRACT

Chronic renal failure and diabetes mellitus could also be risk factors of pseudoaneurysm of the internal carotid artery (ICA) due to malignant otitis externa (MOE). Although pseudoaneurysm of the ICA is a rarely encountered disease, it should always be taken into consideration when treating patients of MOE.

19.
Phys Rev E ; 103(4): L040202, 2021 Apr.
Article in English | MEDLINE | ID: mdl-34005878

ABSTRACT

A new type of delocalization induced by coherent harmonic perturbations in one-dimensional Anderson-localized disordered systems is investigated. With only a few M frequencies a normal diffusion is realized, but the transition to a localized state always occurs as the perturbation strength is weakened below a critical value. The nature of the transition qualitatively follows the Anderson transition (AT) if the number of degrees of freedom M+1 is regarded as the spatial dimension d. However, the critical dimension is found to be d=M+1=3 and is not d=M+1=2, which should naturally be expected by the one-parameter scaling hypothesis.

20.
Stem Cell Reports ; 16(6): 1527-1541, 2021 06 08.
Article in English | MEDLINE | ID: mdl-34048688

ABSTRACT

Amyotrophic lateral sclerosis (ALS) is an adult-onset incurable motor neuron (MN) disease. The reasons for selective MN vulnerability in ALS are unknown. Axonal pathology is among the earliest signs of ALS. We searched for novel modulatory genes in human MN axon shortening affected by TARDBP mutations. In transcriptome analysis of RNA present in the axon compartment of human-derived induced pluripotent stem cell (iPSC)-derived MNs, PHOX2B (paired-like homeobox protein 2B) showed lower expression in TARDBP mutant axons, which was consistent with axon qPCR and in situ hybridization. PHOX2B mRNA stability was reduced in TARDBP mutant MNs. Furthermore, PHOX2B knockdown reduced neurite length in human MNs. Finally, phox2b knockdown in zebrafish induced short spinal axons and impaired escape response. PHOX2B is known to be highly express in other types of neurons maintained after ALS progression. Collectively, TARDBP mutations induced loss of axonal resilience, which is an important ALS-related phenotype mediated by PHOX2B downregulation.


Subject(s)
Amyotrophic Lateral Sclerosis/metabolism , Axons/metabolism , DNA-Binding Proteins/metabolism , Homeodomain Proteins/metabolism , Induced Pluripotent Stem Cells/metabolism , Motor Neurons/metabolism , Transcription Factors/metabolism , Zebrafish/metabolism , Amyotrophic Lateral Sclerosis/genetics , Animals , DNA-Binding Proteins/genetics , Gene Expression Regulation , Gene Knockdown Techniques/methods , Homeodomain Proteins/genetics , Humans , Mutation , Phenotype , Transcription Factors/genetics , Transcriptome
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