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1.
bioRxiv ; 2023 Dec 21.
Article in English | MEDLINE | ID: mdl-38187633

ABSTRACT

Matriglycan (-1,3-ß-glucuronic acid-1,3-α-xylose-) is a polysaccharide that is synthesized on α-dystroglycan, where it functions as a high-affinity glycan receptor for extracellular proteins, such as laminin, perlecan and agrin, thus anchoring the plasma membrane to the extracellular matrix. This biological activity is closely associated with the size of matriglycan. Using high-resolution mass spectrometry and site-specific mutant mice, we show for the first time that matriglycan on the T317/T319 and T379 sites of α-dystroglycan are not identical. T379-linked matriglycan is shorter than the previously characterized T317/T319-linked matriglycan, although it maintains its laminin binding capacity. Transgenic mice with only the shorter T379-linked matriglycan exhibited mild embryonic lethality, but those that survived were healthy. The shorter T379-linked matriglycan exists in multiple tissues and maintains neuromuscular function in adult mice. In addition, the genetic transfer of α-dystroglycan carrying just the short matriglycan restored grip strength and protected skeletal muscle from eccentric contraction-induced damage in muscle-specific dystroglycan knock-out mice. Due to the effects that matriglycan imparts on the extracellular proteome and its ability to modulate cell-matrix interactions, our work suggests that differential regulation of matriglycan length in various tissues optimizes the extracellular environment for unique cell types.

2.
Genet Med ; 24(12): 2453-2463, 2022 12.
Article in English | MEDLINE | ID: mdl-36305856

ABSTRACT

PURPOSE: Cerebellar hypoplasia and atrophy (CBHA) in children is an extremely heterogeneous group of disorders, but few comprehensive genetic studies have been reported. Comprehensive genetic analysis of CBHA patients may help differentiating atrophy and hypoplasia and potentially improve their prognostic aspects. METHODS: Patients with CBHA in 176 families were genetically examined using exome sequencing. Patients with disease-causing variants were clinically evaluated. RESULTS: Disease-causing variants were identified in 96 of the 176 families (54.5%). After excluding 6 families, 48 patients from 42 families were categorized as having syndromic associations with CBHA, whereas the remaining 51 patients from 48 families had isolated CBHA. In 51 patients, 26 aberrant genes were identified, of which, 20 (76.9%) caused disease in 1 family each. The most prevalent genes were CACNA1A, ITPR1, and KIF1A. Of the 26 aberrant genes, 21 and 1 were functionally annotated to atrophy and hypoplasia, respectively. CBHA+S was more clinically severe than CBHA-S. Notably, ARG1 and FOLR1 variants were identified in 2 families, leading to medical treatments. CONCLUSION: A wide genetic and clinical diversity of CBHA was revealed through exome sequencing in this cohort, which highlights the importance of comprehensive genetic analyses. Furthermore, molecular-based treatment was available for 2 families.


Subject(s)
Exome , Nervous System Malformations , Child , Humans , Exome/genetics , Mutation , Nervous System Malformations/genetics , Atrophy/genetics , Folate Receptor 1/genetics , Kinesins
3.
Sci Rep ; 12(1): 14589, 2022 08 26.
Article in English | MEDLINE | ID: mdl-36028527

ABSTRACT

Recently, whole-exome sequencing (WES) has been used for genetic diagnoses of patients who remain otherwise undiagnosed. WES was performed in 177 Japanese patients with undiagnosed conditions who were referred to the Tokai regional branch of the Initiative on Rare and Undiagnosed Diseases (IRUD) (TOKAI-IRUD). This study included only patients who had not previously received genome-wide testing. Review meetings with specialists in various medical fields were held to evaluate the genetic diagnosis in each case, which was based on the guidelines of the American College of Medical Genetics and Genomics. WES identified diagnostic single-nucleotide variants in 66 patients and copy number variants (CNVs) in 11 patients. Additionally, a patient was diagnosed with Angelman syndrome with a complex clinical phenotype upon detection of a paternally derived uniparental disomy (UPD) [upd(15)pat] wherein the patient carried a homozygous DUOX2 p.E520D variant in the UPD region. Functional analysis confirmed that this DUOX2 variant was a loss-of-function missense substitution and the primary cause of congenital hypothyroidism. A significantly higher proportion of genetic diagnoses was achieved compared to previous reports (44%, 78/177 vs. 24-35%, respectively), probably due to detailed discussions and the higher rate of CNV detection.


Subject(s)
Exome , Undiagnosed Diseases , DNA Copy Number Variations , Dual Oxidases , Homozygote , Humans , Rare Diseases , Uniparental Disomy , Exome Sequencing
4.
Sci Adv ; 8(21): eabn0379, 2022 05 27.
Article in English | MEDLINE | ID: mdl-35613260

ABSTRACT

Muscular dystrophy is a progressive and ultimately lethal neuromuscular disease. Although gene editing and gene transfer hold great promise as therapies when administered before the onset of severe clinical symptoms, it is unclear whether these strategies can restore muscle function and improve survival in the late stages of muscular dystrophy. Largemyd/Largemyd (myd) mice lack expression of like-acetylglucosaminyltransferase-1 (Large1) and exhibit severe muscle pathophysiology, impaired mobility, and a markedly reduced life span. Here, we show that systemic delivery of AAV2/9 CMV Large1 (AAVLarge1) in >34-week-old myd mice with advanced disease restores matriglycan expression on dystroglycan, attenuates skeletal muscle pathophysiology, improves motor and respiratory function, and normalizes systemic metabolism, which collectively and markedly extends survival. Our results in a mouse model of muscular dystrophy demonstrate that skeletal muscle function can be restored, illustrating its remarkable plasticity, and that survival can be greatly improved even after the onset of severe muscle pathophysiology.


Subject(s)
Muscular Dystrophies , N-Acetylglucosaminyltransferases , Animals , Dystroglycans/metabolism , Gene Transfer Techniques , Glycosylation , Mice , Muscle, Skeletal/metabolism , Muscular Dystrophies/genetics , Muscular Dystrophies/metabolism , Muscular Dystrophies/therapy , Musculoskeletal Physiological Phenomena , N-Acetylglucosaminyltransferases/genetics
5.
Brain Sci ; 11(7)2021 Jun 22.
Article in English | MEDLINE | ID: mdl-34206592

ABSTRACT

Neonatal thalamic hemorrhage is a strong risk factor for developing encephalopathy with continuous spikes and waves during sleep (ECSWS), even when not accompanied by widespread cortical destruction. The efficacy and indication of resective epilepsy surgery in such patients has not yet been reported. A 4-year-old boy was diagnosed with ECSWS based on strong epileptiform activation during sleep and neurocognitive deterioration. He had a history of left thalamic hemorrhage related to a straight sinus thrombosis during the newborn period. He presented with daily absence seizures that were refractory to medical treatment. At age 5, he underwent intracranial electroencephalogram (EEG) recording using depth and subdural strip electrodes placed in the left thalamus and over bilateral cortex, respectively. Interictal and ictal epileptiform discharges were observed in the thalamus, always preceded by discharges in the left or right parietal lobe. Left hemispherotomy successfully normalized the EEG of his unaffected hemisphere and extinguished his seizures. This is the first case report documenting resective epilepsy surgery in a patient with ECSWS due to neonatal thalamic injury without widespread cerebral destruction. Based on intracranial EEG findings, his injured thalamus did not directly generate the EEG abnormalities or absence seizures on its own. Patients with ipsilateral neonatal thalamic injury and even mild lateralized cortical changes may be candidates for resective or disconnective surgery for ECSWS.

6.
Orphanet J Rare Dis ; 16(1): 284, 2021 06 24.
Article in English | MEDLINE | ID: mdl-34167565

ABSTRACT

BACKGROUND: Collagen VI-related dystrophy spans a clinical continuum from severe Ullrich congenital muscular dystrophy to milder Bethlem myopathy. This disease is caused by causative variants in COL6A1, COL6A2, or COL6A3. Most reported causative variants are de novo; therefore, to identify possible associated causative variants, comprehensive large cohort studies are required for different ethnicities. METHODS: We retrospectively reviewed clinical information, muscle histology, and genetic analyses from 147 Japanese patients representing 130 families, whose samples were sent for diagnosis to the National Center of Neurology and Psychiatry between July 1979 and January 2020. Genetic analyses were conducted by gene-based resequencing, targeted panel resequencing, and whole exome sequencing, in combination with cDNA analysis. RESULTS: Of a total of 130 families with 1-5 members with collagen VI-related dystrophy, 120 had mono-allelic and 10 had bi-allelic variants in COL6A1, COL6A2, or COL6A3. Among them, 60 variants were in COL6A1, 57 in COL6A2, and 23 in COL6A3, including 37 novel variants. Mono-allelic variants were classified into four groups: missense (69, 58%), splicing (40, 33%), small in-frame deletion (7, 6%), and large genomic deletion (4, 3%). Variants in the triple helical domains accounted for 88% (105/120) of all mono-allelic variants. CONCLUSIONS: We report the causative variant profile of a large set of Japanese cases of collagen VI-related dystrophy. This dataset can be used as a reference to support genetic diagnosis and variant-specific treatment.


Subject(s)
Collagen Type VI , Muscular Dystrophies , Collagen Type VI/genetics , Humans , Japan , Muscular Dystrophies/genetics , Mutation , Retrospective Studies , Sequence Deletion
7.
Elife ; 92020 09 25.
Article in English | MEDLINE | ID: mdl-32975514

ABSTRACT

Matriglycan [-GlcA-ß1,3-Xyl-α1,3-]n serves as a scaffold in many tissues for extracellular matrix proteins containing laminin-G domains including laminin, agrin, and perlecan. Like-acetyl-glucosaminyltransferase 1 (LARGE1) synthesizes and extends matriglycan on α-dystroglycan (α-DG) during skeletal muscle differentiation and regeneration; however, the mechanisms which regulate matriglycan elongation are unknown. Here, we show that Protein O-Mannose Kinase (POMK), which phosphorylates mannose of core M3 (GalNAc-ß1,3-GlcNAc-ß1,4-Man) preceding matriglycan synthesis, is required for LARGE1-mediated generation of full-length matriglycan on α-DG (~150 kDa). In the absence of Pomk gene expression in mouse skeletal muscle, LARGE1 synthesizes a very short matriglycan resulting in a ~ 90 kDa α-DG which binds laminin but cannot prevent eccentric contraction-induced force loss or muscle pathology. Solution NMR spectroscopy studies demonstrate that LARGE1 directly interacts with core M3 and binds preferentially to the phosphorylated form. Collectively, our study demonstrates that phosphorylation of core M3 by POMK enables LARGE1 to elongate matriglycan on α-DG, thereby preventing muscular dystrophy.


Subject(s)
Dystroglycans/metabolism , Gene Expression , Muscle, Skeletal/physiology , N-Acetylglucosaminyltransferases/genetics , Protein Kinases/genetics , Animals , Male , Mannose/chemistry , Mice , N-Acetylglucosaminyltransferases/metabolism , Phosphorylation , Protein Kinases/metabolism
8.
Skelet Muscle ; 9(1): 11, 2019 05 04.
Article in English | MEDLINE | ID: mdl-31054580

ABSTRACT

BACKGROUND: α-Dystroglycan is the highly glycosylated component of the dystrophin-glycoprotein complex (DGC) that binds with high-affinity to extracellular matrix (ECM) proteins containing laminin-G-like (LG) domains via a unique heteropolysaccharide [-GlcA-beta1,3-Xyl-alpha1,3-]n called matriglycan. Changes in expression of components of the DGC or in the O-glycosylation of α-dystroglycan result in muscular dystrophy but are also observed in certain cancers. In mice, the loss of either of two DGC proteins, dystrophin or α-sarcoglycan, is associated with a high incidence of rhabdomyosarcoma (RMS). In addition, glycosylation of α-dystroglycan is aberrant in a small cohort of human patients with RMS. Since both the glycosylation of α-dystroglycan and its function as an ECM receptor require over 18 post-translational processing enzymes, we hypothesized that understanding its role in the pathogenesis of RMS requires a complete analysis of the expression of dystroglycan-modifying enzymes and the characterization of α-dystroglycan glycosylation in the context of RMS. METHODS: A series of cell lines and biopsy samples from human and mouse RMS were analyzed for the glycosylation status of α-dystroglycan and for expression of the genes encoding the responsible enzymes, in particular those required for the addition of matriglycan. Furthermore, the glycosyltransferase LARGE1 was ectopically expressed in RMS cells to determine its effects on matriglycan modifications and the ability of α-dystroglycan to function as a laminin receptor. RESULTS: Immunohistochemistry and immunoblotting of a collection of primary RMS tumors show that although α-dystroglycan is consistently expressed and glycosylated in these tumors, α-dystroglycan lacks matriglycan and the ability to bind laminin. Similarly, in a series of cell lines derived from human and mouse RMS, α-dystroglycan lacks matriglycan modification and the ability to bind laminin. RNAseq data from RMS cell lines was analyzed for expression of the genes known to be involved in α-dystroglycan glycosylation, which revealed that, for most cell lines, the lack of matriglycan can be attributed to the downregulation of the dystroglycan-modifying enzyme LARGE1. Ectopic expression of LARGE1 in these cell cultures restored matriglycan to levels comparable to those in muscle and restored high-affinity laminin binding to α-dystroglycan. CONCLUSIONS: Collectively, our findings demonstrate that a lack of matriglycan on α-dystroglycan is a common feature in RMS due to the downregulation of LARGE1, and that ectopic expression of LARGE1 can restore matriglycan modifications and the ability of α-dystroglycan to function as an ECM receptor.


Subject(s)
Dystroglycans/metabolism , Laminin/metabolism , N-Acetylglucosaminyltransferases/metabolism , Rhabdomyosarcoma/metabolism , Animals , Cell Line, Tumor , Glycosylation , Humans , Mice , N-Acetylglucosaminyltransferases/genetics , Protein Processing, Post-Translational , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Rhabdomyosarcoma/genetics , Rhabdomyosarcoma, Alveolar/genetics , Rhabdomyosarcoma, Alveolar/metabolism , Rhabdomyosarcoma, Embryonal/genetics , Rhabdomyosarcoma, Embryonal/metabolism
9.
eNeuro ; 4(2)2017.
Article in English | MEDLINE | ID: mdl-28374014

ABSTRACT

Age-associated neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, and the polyglutamine (polyQ) diseases, are becoming prevalent as a consequence of elongation of the human lifespan. Although various rodent models have been developed to study and overcome these diseases, they have limitations in their translational research utility owing to differences from humans in brain structure and function and in drug metabolism. Here, we generated a transgenic marmoset model of the polyQ diseases, showing progressive neurological symptoms including motor impairment. Seven transgenic marmosets were produced by lentiviral introduction of the human ataxin 3 gene with 120 CAG repeats encoding an expanded polyQ stretch. Although all offspring showed no neurological symptoms at birth, three marmosets with higher transgene expression developed neurological symptoms of varying degrees at 3-4 months after birth, followed by gradual decreases in body weight gain, spontaneous activity, and grip strength, indicating time-dependent disease progression. Pathological examinations revealed neurodegeneration and intranuclear polyQ protein inclusions accompanied by gliosis, which recapitulate the neuropathological features of polyQ disease patients. Consistent with neuronal loss in the cerebellum, brain MRI analyses in one living symptomatic marmoset detected enlargement of the fourth ventricle, which suggests cerebellar atrophy. Notably, successful germline transgene transmission was confirmed in the second-generation offspring derived from the symptomatic transgenic marmoset gamete. Because the accumulation of abnormal proteins is a shared pathomechanism among various neurodegenerative diseases, we suggest that this new marmoset model will contribute toward elucidating the pathomechanisms of and developing clinically applicable therapies for neurodegenerative diseases.


Subject(s)
Animals, Genetically Modified , Callithrix , Disease Models, Animal , Neurodegenerative Diseases , Peptides , Aging/pathology , Aging/physiology , Animals , Ataxin-3/genetics , Ataxin-3/metabolism , Brain/diagnostic imaging , Brain/metabolism , Brain/pathology , Cell Line , Disease Progression , Ear , Fibroblasts/metabolism , Fibroblasts/pathology , Genetic Vectors , Humans , Lentivirus/genetics , Male , Motor Activity/physiology , Muscle, Skeletal/metabolism , Muscle, Skeletal/pathology , Neurodegenerative Diseases/diagnostic imaging , Neurodegenerative Diseases/metabolism , Neurodegenerative Diseases/pathology , Peptides/metabolism , Phenotype , Repressor Proteins/genetics , Repressor Proteins/metabolism , Trinucleotide Repeat Expansion
10.
J Hum Genet ; 62(2): 159-166, 2017 Feb.
Article in English | MEDLINE | ID: mdl-27829678

ABSTRACT

GNE myopathy is an autosomal recessive distal myopathy caused by loss-of-function mutations in the GNE gene, which encodes UDP-GlcNAc 2-epimerase/ManNAc kinase (GNE), a key enzyme in sialic-acid biosynthesis. By comprehensive screening of manifesting patients using a fine-mapped targeted next-generation sequencing (NGS), we identified copy number variations (CNVs) in 13 patients from 11 unrelated families. The nine unique CNVs largely vary in size from 0.3 to 72 kb. Over half of the cases carry different deletions spanning merely exon 2, which contains the 5' untranslated region (5'UTR) of the muscle major transcript hGNE1. Of most unique CNVs, either the telomeric or the centromeric breakpoint locates within intron 2, indicating rearrangement hotspots. Haplotype analysis suggested the existence of a founder allele with exon 2 deletion. The breakpoints for all CNVs were determined by long-range PCR and sequencing. All of the breakpoints of gross deletion/duplications reside within directly oriented pairs of Alu repeats. The results of this study firstly widen the spectra of mutations to CNVs encompassing 5'UTR, underscoring the pivotal role of the hGNE1 transcript. Alu-mediated non-recurrent CNVs may have been overlooked in a wide variety of recessive phenotypes, especially in those associated with genomic Alu-rich genes such as GNE.


Subject(s)
5' Untranslated Regions/genetics , DNA Copy Number Variations/genetics , Distal Myopathies/genetics , Multienzyme Complexes/genetics , Adult , Base Sequence , Female , Genetic Predisposition to Disease , Genetic Testing , Genome/genetics , Genome-Wide Association Study , Haplotypes/genetics , Humans , Male , Mutation, Missense/genetics , Polymerase Chain Reaction , Sequence Analysis, DNA , Sequence Deletion/genetics , Young Adult
11.
Neurology ; 86(3): 211-7, 2016 Jan 19.
Article in English | MEDLINE | ID: mdl-26683644

ABSTRACT

OBJECTIVE: To clarify whether there is any association between inclusion body myositis (IBM) and hepatitis C virus (HCV) infection. METHODS: We assessed the prevalence of HCV infection in 114 patients with IBM whose muscle biopsies were analyzed pathologically for diagnostic purpose from 2002 to 2012 and in 44 age-matched patients with polymyositis diagnosed in the same period as a control by administering a questionnaire survey to the physicians in charge. We also compared clinicopathologic features including the duration from onset to development of representative symptoms of IBM and the extent of representative pathologic changes between patients with IBM with and without HCV infection. RESULTS: A significantly higher number of patients with IBM (28%) had anti-HCV antibodies as compared with patients with polymyositis (4.5%; odds ratio 8.2, 95% confidence interval 1.9-36) and the general Japanese population in their 60s (3.4%). Furthermore, between patients with IBM with and without HCV infection, we did not find any significant difference in the clinicopathologic features, indicating that the 2 groups have essentially the same disease regardless of HCV infection. CONCLUSION: Our results provide the statistical evidence for an association between IBM and HCV infection, suggesting a possible pathomechanistic link between the 2 conditions.


Subject(s)
Hepatitis C Antibodies/analysis , Hepatitis C/virology , Myositis, Inclusion Body/virology , Polymyositis/virology , Aged , Case-Control Studies , Comorbidity , Female , Hepatitis C/epidemiology , Hepatitis C/pathology , Humans , Japan/epidemiology , Male , Middle Aged , Myositis, Inclusion Body/epidemiology , Myositis, Inclusion Body/pathology , Polymyositis/epidemiology , Polymyositis/pathology , Prevalence
12.
J Neurol Neurosurg Psychiatry ; 86(3): 280-7, 2015 Mar.
Article in English | MEDLINE | ID: mdl-24938411

ABSTRACT

Collagen VI is widely distributed throughout extracellular matrices (ECMs) in various tissues. In skeletal muscle, collagen VI is particularly concentrated in and adjacent to basement membranes of myofibers. Ullrich congenital muscular dystrophy (UCMD) is caused by mutations in either COL6A1, COL6A2 or COL6A3 gene, thereby leading to collagen VI deficiency in the ECM. It is known to occur through either recessive or dominant genetic mechanism, the latter most typically by de novo mutations. UCMD is well defined by the clinicopathological hallmarks including distal hyperlaxity, proximal joint contractures, protruding calcanei, scoliosis and respiratory insufficiency. Recent reports have depicted the robust natural history of UCMD; that is, loss of ambulation by early teenage years, rapid decline in respiratory function by 10 years of age and early-onset, rapidly progressive scoliosis. Muscle pathology is characterised by prominent interstitial fibrosis disproportionate to the relative paucity of necrotic and regenerating fibres. To date, treatment for patients is supportive for symptoms such as joint contractures, respiratory failure and scoliosis. There have been clinical trials based on the theory of mitochondrion-mediated myofiber apoptosis or impaired autophagy. Furthermore, the fact that collagen VI producing cells in skeletal muscle are interstitial mesenchymal cells can support proof of concept for stem cell-based therapy.


Subject(s)
Muscular Dystrophies/diagnosis , Muscular Dystrophies/pathology , Sclerosis/diagnosis , Sclerosis/pathology , Adolescent , Child , Child, Preschool , Collagen Type VI/genetics , DNA Mutational Analysis , Disease Progression , Genes, Dominant/genetics , Genes, Recessive/genetics , Humans , Infant , Infant, Newborn , Mobility Limitation , Muscle, Skeletal/pathology , Muscular Dystrophies/genetics , Neurologic Examination , Phenotype , Sclerosis/genetics
13.
Pediatr Neurol ; 51(5): 726-9, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25193411

ABSTRACT

BACKGROUND: Spastic paraplegia 3A typically manifests in childhood as an uncomplicated form of hereditary spastic paraplegia with slow progression. Most affected individuals present with spasticity and weakness in the legs before the end of the first decade. PATIENT: We describe a 12-year-old boy with neonatal onset of extremely severe complicated spastic paraplegia 3A associated with a de novo c.1226G>A (p.G409D) mutation in ATL1, a gene which encodes atlatsin GTPase 1. He manifested general hypertonia and hypokinesia since the neonatal period and was initially diagnosed with cerebral palsy. He was never able to move without assistance because of severe spastic quadriplegia with distal dominant muscle weakness. He also developed with pseudobulbar palsy; his speech, chewing, and swallowing were severely impaired. Electrophysiological studies revealed severe diffuse axonal neuropathy. CONCLUSIONS: Extremely severe complicated spastic paraplegia 3A can be caused by mutations in the linker or three-helix bundle of atlastin 1.


Subject(s)
Adolescent , Child , Female , GTP-Binding Proteins/genetics , Humans , Male , Membrane Proteins/genetics , Mutation/genetics , Neural Conduction/genetics , Paraplegia/diagnosis , Paraplegia/genetics , Paraplegia/physiopathology , Spastic Paraplegia, Hereditary/diagnosis , Spastic Paraplegia, Hereditary/genetics , Spastic Paraplegia, Hereditary/physiopathology
14.
Brain ; 137(Pt 10): 2670-9, 2014 Oct.
Article in English | MEDLINE | ID: mdl-25062695

ABSTRACT

Patients with GNE myopathy, a progressive and debilitating disease caused by a genetic defect in sialic acid biosynthesis, rely on supportive care and eventually become wheelchair-bound. To elucidate whether GNE myopathy is treatable at a progressive stage of the disease, we examined the efficacy of sialic acid supplementation on symptomatic old GNE myopathy mice that have ongoing, active muscle degeneration. We examined the therapeutic effect of a less metabolized sialic acid compound (6'-sialyllactose) or free sialic acid (N-acetylneuraminic acid) by oral, continuous administration to 50-week-old GNE myopathy mice for 30 weeks. To evaluate effects on their motor performance in living mice, spontaneous locomotion activity on a running wheel was measured chronologically at 50, 65, 72 and 80 weeks of age. The size, force production, and pathology of isolated gastrocnemius muscle were analysed at the end point. Sialic acid level in skeletal muscle was also measured. Spontaneous locomotion activity was recovered in 6'-sialyllactose-treated mice, while NeuAc-treated mice slowed the disease progression. Treatment with 6'-sialyllactose led to marked restoration of hyposialylation in muscle and consequently to robust improvement in the muscle size, contractile parameters, and pathology as compared to NeuAc. This is due to the fact that 6'-sialyllactose is longer working as it is further metabolized to free sialic acid after initial absorption. 6'-sialyllactose ameliorated muscle atrophy and degeneration in symptomatic GNE myopathy mice. Our results provide evidence that GNE myopathy can be treated even at a progressive stage and 6'-sialyllactose has more remarkable advantage than free sialic acid, providing a conceptual proof for clinical use in patients.


Subject(s)
Distal Myopathies/drug therapy , Lactose/analogs & derivatives , Aging/pathology , Amyloid beta-Peptides/metabolism , Animals , Body Weight/drug effects , Cells, Cultured , Creatine Kinase/metabolism , Disease Models, Animal , Distal Myopathies/pathology , Enzyme-Linked Immunosorbent Assay , Hexosamines/therapeutic use , Lactose/adverse effects , Lactose/pharmacokinetics , Lactose/therapeutic use , Mice , Muscle Contraction/physiology , Muscle, Skeletal/pathology , Mutation/genetics , Myoblasts/drug effects , Myoblasts/metabolism , N-Acetylneuraminic Acid/metabolism , N-Acetylneuraminic Acid/therapeutic use , Peptide Fragments/metabolism , Phenotype
15.
J Neuroimmunol ; 274(1-2): 202-8, 2014 Sep 15.
Article in English | MEDLINE | ID: mdl-25064497

ABSTRACT

Of 207 adult patients with idiopathic inflammatory myopathies, detection of autoantibodies by RNA immunoprecipitation showed that 99 patients (48%) were antibody-positive. We divided these 99 into five subgroups: anti-signal recognition particle (SRP), anti-aminoacyl transfer RNA synthetase, anti-Ku, anti-U1RNP, and anti-SSA/B. Younger age at onset, severe weakness, muscle atrophy, elevated creatine kinase, and necrosis in muscle fibers without inflammatory cell infiltration were found significantly more frequently among the patients with anti-SRP antibodies (n=41) compared to the antibody-negative patients (n=108). Autoantibody detection by RNA immunoprecipitation can provide useful information associated with clinical and histological findings.


Subject(s)
Autoantibodies/immunology , Chromatin Immunoprecipitation/methods , Myelitis, Transverse/immunology , Myositis/immunology , Adult , Aged , Female , Humans , Male , Middle Aged , Muscular Atrophy/immunology , Muscular Atrophy/pathology , Myelitis, Transverse/pathology , Myositis/pathology , RNA , Signal Recognition Particle/immunology
17.
J Neurol Neurosurg Psychiatry ; 84(9): 982-8, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23572247

ABSTRACT

OBJECTIVE: To characterise the natural history of Ullrich congenital muscular dystrophy (UCMD). PATIENTS AND METHODS: Questionnaire-based nationwide survey to all 5442 certified paediatric and adult neurologists in Japan was conducted from October 2010 to February 2011. We enrolled the 33 patients (age at assessment, 11 ± 6.6 years) who were reported to have collagen VI deficiency on immunohistochemistry in muscle biopsies. We analysed the development, clinical manifestations, Cobb angle and %vital capacity (%VC) in spirogram. RESULTS: Cobb angle over 30° was noted at age 9.9 ± 5.3 years (n=17). The maximum progression rate was 16.2 ± 10°/year (n=13). %VC was decreased exponentially with age, resulting in severe respiratory dysfunction before pubescence. Scoliosis surgery was performed in 3 patients at ages 5 years, 9 years and 10 years. Postoperative %VC was relatively well maintained in the youngest patient. Non-invasive ventilation was initiated at age 11.2 ± 3.6 years (n=13). Twenty-five (81%) of 31 patients walked independently by age 1.7 ± 0.5 years but lost this ability by age 8.8 ± 2.9 years (n=11). Six patients never walked independently. CONCLUSIONS: The natural history of scoliosis, respiratory function and walking ability in UCMD patients were characterised. Although the age of onset varied, scoliosis, as well as restrictive respiratory dysfunction, progressed rapidly within years, once they appeared.


Subject(s)
Muscular Dystrophies/pathology , Respiratory Tract Diseases/pathology , Sclerosis/pathology , Scoliosis/pathology , Adolescent , Adult , Age of Onset , Biopsy , Child , Child, Preschool , Collagen/genetics , DNA/genetics , Disease Progression , Female , Humans , Immunohistochemistry , Infant , Japan/epidemiology , Kaplan-Meier Estimate , Male , Muscle, Skeletal/pathology , Muscular Dystrophies/epidemiology , Muscular Dystrophies/genetics , Neck , Posture , Respiratory Tract Diseases/genetics , Sclerosis/epidemiology , Sclerosis/genetics , Scoliosis/genetics , Scoliosis/surgery , Survival Analysis , Treatment Outcome , Vital Capacity , Young Adult
18.
Pediatr Neurol ; 48(1): 59-62, 2013 Jan.
Article in English | MEDLINE | ID: mdl-23290023

ABSTRACT

We describe a boy aged 2 years and 11 months with congenital hypomyelinating neuropathy attributable to a de novo heterozygous missense mutation of c.181 G>A (p.Asp61Asn) in the myelin protein zero gene. A nerve conduction study indicated markedly reduced motor conduction velocities in the upper and lower extremities. Stimuli of up to 50-100 mA were necessary for nerve activation, suggesting diseased nerves with greatly decreased excitability. A sural nerve biopsy revealed a marked loss of large myelinated fibers, the absence of myelin breakdown products, occasional basal lamina onion-bulb formations, and tomacula-like structures. The p.Asp61Asn mutation is novel in congenital hypomyelinating neuropathy, but was previously reported in a patient with Charcot-Marie-Tooth disease type 1.


Subject(s)
Asparagine/genetics , Aspartic Acid/genetics , Charcot-Marie-Tooth Disease/genetics , Myelin P0 Protein/genetics , Charcot-Marie-Tooth Disease/pathology , Child, Preschool , Humans , Male , Sural Nerve/pathology , Sural Nerve/ultrastructure
19.
Brain Dev ; 35(2): 165-71, 2013 Feb.
Article in English | MEDLINE | ID: mdl-22512990

ABSTRACT

We examined the specific nerve conduction deficits distinguishing spinal muscular atrophy (SMA) subtypes I and II. Five SMA I patients (age, 0.2-1.1 years) and 10 SMA II patients (age, 1.0-2.8 years) were examined. Patients were compared to age-matched controls for motor and sensory conduction velocity (MCV and SCV) changes, compound muscle and sensory nerve action potential amplitudes (CMAP and SNAP), and F-wave occurrence (FO). Slower MCVs were found in three of five SMA I patients; all five exhibited markedly decreased CMAP amplitudes. Tibial nerve CMAP amplitudes significantly reduced in SMA II patients (p<0.01). Slower SCVs and decreased SNAP amplitudes were observed in three of five SMA I patients but not in SMA II patients. Although FOs were reduced in both extremities of SMA I patients, the reduction was prominent in the tibial nerve of SMA II patients (p=0.031). Loss of motor units may be widespread in the early stage of SMA I, while specific to the legs in young SMA II patients. SMA I showed sensory nerve degeneration, especially of large myelinated fibers. SMA II showed no sensory nerve abnormalities.


Subject(s)
Peripheral Nerves/physiopathology , Spinal Muscular Atrophies of Childhood/physiopathology , Action Potentials/physiology , Axons/physiology , Child, Preschool , Data Interpretation, Statistical , Electric Stimulation , Female , Humans , Infant , Leg/innervation , Male , Median Nerve/physiopathology , Motor Neurons/physiology , Neural Conduction/physiology , Neuronal Apoptosis-Inhibitory Protein/genetics , Retrospective Studies , Sensory Receptor Cells/physiology , Sural Nerve/physiopathology , Survival of Motor Neuron 1 Protein/genetics , Tibial Nerve/physiopathology , Ulnar Nerve/physiopathology
20.
Epilepsy Behav ; 22(4): 697-704, 2011 Dec.
Article in English | MEDLINE | ID: mdl-21978470

ABSTRACT

To evaluate the effect of corpus callosotomy (CC) on attention deficit and behavioral problems in pediatric patients with intractable epilepsy, we retrospectively investigated sequential patients who had undergone CC to control seizures. Between August 2005 and April 2010, a total of 15 patients aged between 3.1 and 17.9 years underwent CC at our institute. All the patients experienced either drop attacks or head nodding, which were considered to be therapeutic targets of CC. A standardized instrument, the Child Behavior Checklist (CBCL), was used to assess behavioral and emotional problems before and after surgery. On postoperative EEGs, 8 (53%) showed improvement and 7 (47%) showed no change in epileptiform discharges. The Attention Problems scale and total score on the CBCL significantly improved in patients whose postoperative EEGs showed improvement. In addition to amelioration of target seizures, CC can improve attention impairments in association with improvement in the postoperative EEG.


Subject(s)
Attention Deficit Disorder with Hyperactivity/etiology , Attention Deficit Disorder with Hyperactivity/surgery , Child Behavior Disorders/etiology , Child Behavior Disorders/surgery , Corpus Callosum/surgery , Epilepsy/complications , Adolescent , Checklist , Child , Child, Preschool , Corpus Callosum/physiology , Developmental Disabilities/etiology , Developmental Disabilities/surgery , Electroencephalography , Epilepsy/pathology , Epilepsy/surgery , Female , Humans , Linear Models , Male , Retrospective Studies , Treatment Outcome
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