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1.
Am J Hum Genet ; 110(7): 1086-1097, 2023 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-37339631

RESUMO

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder characterized by the degeneration of motor neurons. Although repeat expansion in C9orf72 is its most common cause, the pathogenesis of ALS isn't fully clear. In this study, we show that repeat expansion in LRP12, a causative variant of oculopharyngodistal myopathy type 1 (OPDM1), is a cause of ALS. We identify CGG repeat expansion in LRP12 in five families and two simplex individuals. These ALS individuals (LRP12-ALS) have 61-100 repeats, which contrasts with most OPDM individuals with repeat expansion in LRP12 (LRP12-OPDM), who have 100-200 repeats. Phosphorylated TDP-43 is present in the cytoplasm of iPS cell-derived motor neurons (iPSMNs) in LRP12-ALS, a finding that reproduces the pathological hallmark of ALS. RNA foci are more prominent in muscle and iPSMNs in LRP12-ALS than in LRP12-OPDM. Muscleblind-like 1 aggregates are observed only in OPDM muscle. In conclusion, CGG repeat expansions in LRP12 cause ALS and OPDM, depending on the length of the repeat. Our findings provide insight into the repeat length-dependent switching of phenotypes.


Assuntos
Esclerose Lateral Amiotrófica , Distrofias Musculares , Doenças Neurodegenerativas , Humanos , Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/patologia , Neurônios Motores/patologia , Distrofias Musculares/genética , Doenças Neurodegenerativas/genética , Proteína C9orf72/genética , Expansão das Repetições de DNA , Proteína-1 Relacionada a Receptor de Lipoproteína de Baixa Densidade/genética
2.
BMC Immunol ; 25(1): 30, 2024 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-38734636

RESUMO

BACKGROUND: Immune-mediated necrotizing myopathy (IMNM) is an idiopathic inflammatory myopathy (IIM). Though patients with IMNM were not considered to show skin rash, several reports have showed atypical skin conditions in patients with anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) antibody-positive IMNM (HMGCR-IMNM). The incidence and phenotype of skin conditions in patients with HMGCR-IMNM are not fully known. RESULTS: Among the 100 IIM patients diagnosed from April 2015 through August 2022, 34 (34%) presented some form of skin condition, with 27 having typical skin rashes; this included 13 patients with dermatomyositis (DM), 8 with anti-synthetase syndrome (ASS), and 6 with IMNM. Meanwhile, 8 of 19 patients with HMGCR-IMNM (42%) presented atypical skin lesions, but no patients with other IIMs did (p < 0.001). Skin eruption with ash-like scales was observed in four HMGCR-IMNM patients, and non-scaly red patches and lumps in the other four patients; accordingly, their skin manifestations were considered as other dermal diseases except for IIM. However, skin and muscle biopsies revealed the atypical skin conditions of patients with HMGCR-IMNM to have the same pathological background, formed by Bcl-2-positive lymphocyte infiltrations. CONCLUSIONS: HMGCR-IMNM patients frequently have atypical skin conditions of the neck and back. Skin biopsy specimens from these lesions showed the same Bcl-2-positive lymphocytic infiltrations as muscle biopsy specimens regardless of the different gross dermal findings. Thus, such atypical skin conditions may be suggestive for HMGCR-IMNM.


Assuntos
Autoanticorpos , Hidroximetilglutaril-CoA Redutases , Miosite , Pele , Feminino , Humanos , Masculino , Autoanticorpos/imunologia , Autoanticorpos/sangue , Biópsia , Hidroximetilglutaril-CoA Redutases/imunologia , Doenças Musculares/imunologia , Doenças Musculares/diagnóstico , Miosite/imunologia , Miosite/diagnóstico , Pele/patologia , Pele/imunologia , Dermatopatias/imunologia , Dermatopatias/etiologia
3.
Biochem Biophys Res Commun ; 683: 149106, 2023 11 26.
Artigo em Inglês | MEDLINE | ID: mdl-37857162

RESUMO

Apolipoprotein E4 (APOE4), the strongest risk factor for late-onset Alzheimer's disease (AD), has been revealed to cause greater accumulation of extracellular amyloid ß (Aß) aggregates than does APOE3 in traditional transgenic mouse models of AD. However, concerns that the overexpression paradigm might have affected the phenotype remain. Amyloid precursor protein (APP)-knock-in (KI) mice, incorporating APP mutations associated with AD development, offer an alternative approach for overproducing pathogenic Aß without needing overexpression of APP. Here, we present the results of comprehensive analyses of pathological and biochemical traits in the brains of APP-KI mice harboring APP-associated familial AD mutations (APPNL-G-F/NL-G-F mice) crossed with human APOE-KI mice. Immunohistochemical and biochemical analyses revealed the APOE genotype-dependent increase in Aß pathology and glial activation, which was evident within 8 months in the mouse model. These results suggested that this mouse model may be valuable for investigating APOE pathobiology within a reasonable experimental time frame. Thus, this model can be considered in investigating the interaction between APOE and Aß in vivo, which may not be addressed appropriately by using other transgenic mouse models.


Assuntos
Doença de Alzheimer , Camundongos , Humanos , Animais , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Apolipoproteínas E/genética , Camundongos Transgênicos , Apolipoproteína E3/genética , Genótipo , Modelos Animais de Doenças
4.
J Hum Genet ; 68(2): 91-95, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36336708

RESUMO

Facioscapulohumeral dystrophy type1 (FSHD1) patients with a shortened D4Z4 repeat containing the DUX4 gene have a broad spectrum of clinical manifestations. In addition, high expression of DUX4 protein with an aberrant C terminus is frequently identified in B cell acute lymphoblastic leukemia. We investigated clinical manifestations in 31 FSHD1 patients and 30 non-affected individuals. Gastrointestinal cancers (gastric and colorectal cancers) increased after the age of 40 years and were more frequently observed in FSHD1 patients (n = 10) than in non-affected individuals (n = 2, p = 0.0217), though the incidence of cancers occurring in non-gastrointestinal tissues of FSHD1 patients was the same as that of non-affected individuals (p > 0.999). These comorbidities of FSHD1 patients were not associated with D4Z4 repeat number. Our results suggest that gastrointestinal cancers are among the extramuscular manifestations of adult FSHD1 patients, and do not depend on D4Z4 repeat number.


Assuntos
Neoplasias Gastrointestinais , Distrofia Muscular Facioescapuloumeral , Adulto , Humanos , Proteínas Cromossômicas não Histona/genética , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Distrofia Muscular Facioescapuloumeral/epidemiologia , Distrofia Muscular Facioescapuloumeral/genética , Distrofia Muscular Facioescapuloumeral/metabolismo , Neoplasias Gastrointestinais/epidemiologia , Neoplasias Gastrointestinais/genética
5.
Differentiation ; 123: 1-8, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34844057

RESUMO

Mutations in optineurin (OPTN) have been identified in a small proportion of sporadic and familial amyotrophic lateral sclerosis (ALS) cases. Recent evidences suggest that OPTN would be involved in not only the pathophysiological mechanisms of motor neuron death of ALS but also myofiber degeneration of sporadic inclusion body myositis. However, the detailed role of OPTN in muscle remains unclear. Initially, we showed that OPTN expression levels were significantly increased in the denervated muscles of mice, suggesting that OPTN may be involved in muscle homeostasis. To reveal the molecular role of OPTN in muscle atrophy, we used cultured C2C12 myotubes treated with tumor necrosis factor-like inducer of apoptosis (TWEAK) as an in vitro model of muscle atrophy. Our data showed that OPTN had no effect on the process of muscle atrophy in this model. On the other hand, we found that myogenic differentiation was affected by OPTN. Immunoblotting analysis showed that OPTN protein levels gradually decreased during C2C12 differentiation. Furthermore, OPTN knockdown inhibited C2C12 differentiation, accompanied by reduction of mRNA and protein expression levels of myogenin and MyoD. These findings suggested that OPTN may have a novel function in muscle homeostasis and play a role in the pathogenesis of neuromuscular diseases.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Animais , Diferenciação Celular/genética , Camundongos , Atrofia Muscular/patologia , Proteína MyoD/genética , Mioblastos/metabolismo , Miogenina/genética , Fator de Transcrição TFIIIA/genética , Fator de Transcrição TFIIIA/metabolismo
6.
Biochem Biophys Res Commun ; 627: 146-151, 2022 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-36037746

RESUMO

Extracellular vesicles (EVs) are particles released from most cell types delimited by a lipid bilayer. Small EVs (sEVs) are nanosized (<200 nm) and include exosomes. Brain-derived sEVs may provide a source for new biomarkers of brain status. CD9, CD63, and CD81 are major members of the tetraspanin family frequently used as sEV markers. However, according to a recent report, tetraspanins were not equally expressed in all sEVs, but rather show heterogeneity that reflects the expression levels in their secretory cells. We therefore investigated tetraspanin heterogeneity of sEVs in biofluids commonly used for clinical laboratory tests, and those in the brain. Expression levels and distributions of CD9, CD63 and CD81 on sEVs were determined in serum, plasma, and cerebrospinal fluid (CSF) samples collected from each healthy donor, and in post-mortem brain tissue samples. We found heterogeneous mixes of sEVs with various tetraspanin combinations among sEVs, and the predominant types and heterogeneous patterns of tetraspanins were specific to sample type. Hierarchical clustering revealed that brain sEVs were similar to those in the CSF, but different from those in peripheral blood. Our findings both provide basic information and contribute to the development of biomarkers for neurological and psychiatric disorders.


Assuntos
Exossomos , Vesículas Extracelulares , Biomarcadores/metabolismo , Encéfalo/metabolismo , Exossomos/metabolismo , Vesículas Extracelulares/metabolismo , Humanos , Tetraspanina 28/metabolismo , Tetraspanina 30/metabolismo , Tetraspaninas/metabolismo
7.
J Hum Genet ; 67(10): 595-599, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35760954

RESUMO

Spinocerebellar ataxia type 14 (SCA14) is an autosomal dominant SCA caused by variants of the PRKCG encoding protein kinase C gamma (PKCγ). Although the toxic gain-of-function mechanism is the main cause of SCA14, its molecular pathophysiology remains unclear. To elucidate the molecular pathogenesis of SCA14, we analyzed two families with the variants in PRKCG. Clinical symptoms and neurological findings of two Japanese families were evaluated by neurologists. Exome sequencing was performed using the BGI platform. GFP-tagged PRKCGs harboring the identified variants were transfected into the HeLa cells, and aggregation of PKCγ was analyzed using confocal laser microscopy. Solubility of PKCγ was evaluated by assessing the proportion of insoluble fraction present in1% Triton-X. Patients in family 1 presented with only cerebellar atrophy without ataxia; however, patients in family 2 exhibited cerebellar ataxia, dystonia, and more severe cerebellar atrophy than those in family 1. Exome sequencing identified two novel missense variants of PRKCG:c.171 G > C,p.W57C (family 1), and c.400 T > C,p.C134R (family 2). Both the mutant PKCγ aggregated in the cytoplasm. Although the solubility of PKCγ of the C134R variant was lower than that of the wild-type, PKCγ of W57C retained its solubility. In conclusion, we identified two novel variants of PRKCG. The difference in severity between the two families may be due to the difference in solubility changes observed between the two variants. Decreased solubility of the PKCγ may play an important role in the pathogenesis of SCA14.


Assuntos
Ataxia Cerebelar , Atrofia , Células HeLa , Humanos , Proteína Quinase C , Ataxias Espinocerebelares
8.
Neurobiol Dis ; 148: 105215, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33296728

RESUMO

We previously showed that optineurin (OPTN) mutations lead to the development of amyotrophic lateral sclerosis. The association between OPTN mutations and the pathogenesis of amyotrophic lateral sclerosis remains unclear. To investigate the mechanism underlying its pathogenesis, we generated Optn knockout mice. We evaluated histopathological observations of these mice and compared with those of OPTN- amyotrophic lateral sclerosis cases to investigate the mechanism underlying the pathogenesis of amyotrophic lateral sclerosis caused by OPTN mutations. The Optn (-/-) mice presented neuronal autophagic vacuoles immunopositive for charged multivesicular body protein 2b, one of the hallmarks of granulovacuolar degenerations, in the cytoplasm of spinal cord motor neurons at the age of 8 months and the OPTN- amyotrophic lateral sclerosis case with homozygous Q398X mutation. In addition, Optn (-/-) mice showed TAR-DNA binding protein 43/sequestosome1/p62 -positive cytoplasmic inclusions and the clearance of nuclear TAR-DNA binding protein 43. The axonal degeneration of the sciatic nerves was observed in Optn (-/-) mice. However, we could not observe significant differences in survival time, body weight, and motor functions, at 24 months. Our findings suggest that homozygous OPTN deletion or mutations might result in autophagic dysfunction and TAR-DNA binding protein 43 mislocalization, thereby leading to neurodegeneration of motor neurons. These findings indicate that the Optn (-/-) mice recapitulate both common and specific pathogenesis of amyotrophic lateral sclerosis associated with autophagic abnormalities. Optn (-/-) mice could serve as a mouse model for the development of therapeutic strategies.


Assuntos
Esclerose Lateral Amiotrófica/metabolismo , Autofagia/genética , Proteínas de Ciclo Celular/genética , Proteínas de Ligação a DNA/metabolismo , Hipocampo/metabolismo , Proteínas de Membrana Transportadoras/genética , Neocórtex/metabolismo , Medula Espinal/metabolismo , Vacúolos/metabolismo , Idoso de 80 Anos ou mais , Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/patologia , Esclerose Lateral Amiotrófica/fisiopatologia , Animais , Hipocampo/patologia , Humanos , Camundongos , Camundongos Knockout , Pessoa de Meia-Idade , Corpos Multivesiculares/metabolismo , Neocórtex/patologia , Medula Espinal/patologia , Vacúolos/patologia
9.
Curr Opin Rheumatol ; 33(6): 554-562, 2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-34456255

RESUMO

PURPOSE OF REVIEW: This review aims to describe clinical and pathological features, prognosis and treatment in patients with anti-HMGCR antibody positive immune-mediated necrotizing myopathy (HMGCR-IMNM) based on recent findings. RECENT FINDINGS: Using advances in diagnostic modalities that can confirm the presence of anti-HMGCR antibody, the clinical and pathological manifestations of HMGCR-IMNM were found to be broader than previously reported. Although only a small percentage of HMGCR-IMNM patients present with atypical manifestations, some of these patients show slow disease progression and clinical symptoms, which are similar to those of limb-girdle muscular dystrophies. Other atypical HMGCR-IMNM patients have skin conditions similar to dermatomyositis-like skin rush or dermatological presentations of Jessner-Kanoff disease or cutaneous lymphoma, whose pathological changes including CD8-positive and bcl-2-positive lymphocytic accumulations, similar to Jessner-Kanoff lymphocytic infiltration of skin or low-grade cutaneous lymphoma, which are observed in muscle and skin. SUMMARY: Anti-HMGCR autoantibodies define unique populations of IMNM patients. Recent studies have revealed that clinicopathological manifestations of HMGCR-IMNM, especially extramuscular symptoms and pathological manifestations, are more common than previously recognized.


Assuntos
Doenças Autoimunes , Doenças Musculares , Miosite , Autoanticorpos , Humanos , Hidroximetilglutaril-CoA Redutases , Músculo Esquelético , Doenças Musculares/diagnóstico , Miosite/diagnóstico , Necrose , Prognóstico
10.
J Hum Genet ; 66(10): 957-964, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33742109

RESUMO

Parkinson's disease (PD) is caused by a combination of genetic and environmental factors. Notably, genetic risk factors vary according to ethnicity and geographical regions, and few studies have analyzed the frequency of PD causative genes in Japanese patients. Therefore, we performed genetic analyses of Japanese patients with PD. We recruited 221 participants, including 26 patients with familial PD. Genetic risk factors were evaluated by target sequencing and gene dosage analysis. We detected the genetic risk factors in 58 cases (26.2%) and classified patients into three groups to clarify the differences in genetic risk factors by age at onset (AAO). The early-onset group (AAO < 50 years) included 18 cases (44.7%), who tended to have a larger number of genetic risk factors than the later-onset groups. Regarding the AAO for each causative gene, patients with PRKN variants were significantly younger at onset than those bearing LRRK2 variants. LRRK2 variants showed similar frequency in each AAO group. Of note, we identified two novel variants. Patients with early-onset PD have more genetic risk factors than patients with late-onset PD. In Japanese patients with PD, PRKN, and LRRK2 were the major PD-related genes. Particularly, LRRK2 was a common genetic factor in all age groups because of the presence of the Asian-specific variant such as LRRK2 p.G2385R. Accumulation of genetic and clinical data can contribute to the development of treatments for PD.


Assuntos
Predisposição Genética para Doença , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/genética , Doença de Parkinson/genética , Adulto , Idade de Início , Povo Asiático/genética , Feminino , Testes Genéticos , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/epidemiologia , Doença de Parkinson/patologia , Fatores de Risco
11.
BMC Neurol ; 21(1): 396, 2021 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-34641814

RESUMO

BACKGROUND: Both fragile X-associated tremor/ataxia syndrome (FXTAS) and late-onset neuronal intranuclear inclusion disease (NIID) show CGG/GGC trinucleotide repeat expansions. Differentiating these diseases are difficult because of the similarity in their clinical and radiological features. It is unclear that skin biopsy can distinguish NIID from FXTAS. We performed a skin biopsy in an FXTAS case with cognitive dysfunction and peripheral neuropathy without tremor, which was initially suspected to be NIID. CASE PRESENTATION: The patient underwent neurological assessment and examinations, including laboratory tests, electrophysiologic test, imaging, skin biopsy, and genetic test. A brain MRI showed hyperintensity lesions along the corticomedullary junction on diffusion-weighted imaging (DWI) in addition to middle cerebellar peduncle sign (MCP sign). We suspected NIID from the clinical picture and the radiological findings, and performed a skin biopsy. The skin biopsy specimen showed ubiquitin- and p62-positive intranuclear inclusions, suggesting NIID. However, a genetic analysis for NIID using repeat-primed polymerase chain reaction (RP-PCR) revealed no expansion detected in the Notch 2 N-terminal like C (NOTCH2NLC) gene. We then performed genetic analysis for FXTAS using RP-PCR, which revealed a repeat CGG/GGC expansion in the FMRP translational regulator 1 (FMR1) gene. The number of repeats was 83. We finally diagnosed the patient with FXTAS rather than NIID. CONCLUSIONS: For the differential diagnosis of FXTAS and NIID, a skin biopsy alone is insufficient; instead, genetic analysis, is essential. Further investigations in additional cases based on genetic analysis are needed to elucidate the clinical and pathological differences between FXTAS and NIID.


Assuntos
Corpos de Inclusão Intranuclear , Tremor , Ataxia , Biópsia , Proteína do X Frágil da Deficiência Intelectual , Síndrome do Cromossomo X Frágil , Humanos , Doenças Neurodegenerativas
12.
Neuropathology ; 41(1): 29-36, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33225515

RESUMO

UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase (GNE) is necessary for sialic acid biosynthesis. GNE myopathy is caused by a defect in GNE, and hyposialylation is a key factor in the pathomechanism of GNE myopathy. Although candidates for evaluating hyposialylation have been reported, it is difficult to measure them in routine clinical practice. Sialylation is necessary for synthesis of various glycoproteins, including Krebs von den Lungen-6 (KL-6)/mucin 1 (MUC1). Here we report that KL-6/MUC1 is decreased in GNE myopathy. We observed that KL-6 levels were decreased in the serum of patients with GNE myopathy, and that KL-6 and MUC1-C were also decreased in muscle biopsy specimens from these patients. An immunofluorescent study revealed that KL-6 and MUC1-C were not present in the sarcolemma but were, instead, localized in rimmed vacuoles in specimens from patients with GNE myopathy. KL-6 is already used to detect lung diseases in clinical practice, and this glycoprotein may be a novel candidate for evaluating hyposialylation in GNE myopathy.


Assuntos
Miopatias Distais/genética , Miopatias Distais/metabolismo , Mucina-1/metabolismo , Complexos Multienzimáticos/genética , Músculo Esquelético/metabolismo , Adulto , Idoso , Biomarcadores/sangue , Biomarcadores/metabolismo , Miopatias Distais/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mucina-1/sangue , Adulto Jovem
13.
Neuropathology ; 41(4): 266-272, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33942396

RESUMO

Immune-related adverse events (irAEs) commonly involve the gastrointestinal tract, endocrine glands, skin, and liver, and rarely the nervous system. The pathomechanism of irAEs in the nervous system is unclear, and so characterizing these severe toxic effects is a priority, even if irAEs are uncommon in the nervous system. Our patient presented subacute muscle weakness and dysesthesia with colitis as irAEs caused by pembrolizumab, one of the anti-programmed death-1 (PD-1) antibodies. Electromyography revealed abundant fibrillations and fasciculations of upper and lower extremities and severe reduction in motor unit potentials; however, antineutrophil cytoplasmic antibodies, rheumatoid factor, autoantibodies against Hu and Yo, and anti-ganglioside antibodies, such as GQ1b, were undetectable in the serum. Although he was treated with high-dose glucocorticoids, antibiotics, and a monoclonal anti-tumor necrosis factor alpha (TNFα) antibody, he developed colonic perforation. The total colorectal resection was performed, and the resected colon showed mucosal defect and perforation. He died of lung aspergillosis. Postmortem examination revealed CD8-positive lymphocyte infiltration around neurons of dorsal root ganglia. The sciatic nerve displayed the widening of myelin laminae and thinning of myelinated fibers but not a decrease in the density of myelinated nerve fibers. In the sural nerve, the density of myelinated fibers slightly decreased, and some fibers showed less densely myelinated laminae. Drug safety information, including previous randomized trials of anti-PD-1 and anti-cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) antibodies, showed that patients treated with anti-PD-1 antibodies appeared to have more frequent and severe peripheral neuropathies compared to those in patients who received anti-CTLA-4 antibodies (1.59% vs. 0.69%; Fisher exact test, P < 0.001; three severe events vs. zero severe events). The present results and drug safety information suggest that the pathomechanism of irAEs caused by anti-PD-1 antibodies is different from that by anti-CTLA-4 antibodies. The neurological irAEs might be clues to solving the pathomechanism of irAEs.


Assuntos
Doenças do Sistema Nervoso Periférico , Polirradiculoneuropatia , Anticorpos Monoclonais Humanizados/efeitos adversos , Humanos , Masculino , Receptor de Morte Celular Programada 1
14.
BMC Med Genet ; 21(1): 68, 2020 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-32234020

RESUMO

BACKGROUND: The TWNK gene encodes the twinkle protein, which is a mitochondrial helicase for DNA replication. The dominant TWNK variants cause progressive external ophthalmoplegia with mitochondrial DNA deletions, autosomal dominant 3, while the recessive variants cause mitochondrial DNA depletion syndrome 7 and Perrault syndrome 5. Perrault syndrome is characterized by sensorineural hearing loss in both males and females and gonadal dysfunction in females. Patients with Perrault syndrome may present early-onset cerebellar ataxia, whereas middle-age-onset cerebellar ataxia caused by TWNK variants is rare. CASE PRESENTATION: A Japanese female born to consanguineous parents presented hearing loss at age 48, a staggering gait at age 53, and numbness in her distal extremities at age 57. Neurological examination revealed sensorineural hearing loss, cerebellar ataxia, decreased deep tendon reflexes, and sensory disturbance in the distal extremities. Laboratory tests showed no abnormal findings other than a moderate elevation of pyruvate concentration levels. Brain magnetic resonance imaging revealed mild cerebellar atrophy. Using exome sequencing, we identified a homozygous TWNK variant (NM_021830: c.1358G>A, p.R453Q). CONCLUSIONS: TWNK variants could cause middle-age-onset cerebellar ataxia. Screening for TWNK variants should be considered in cases of cerebellar ataxia associated with deafness and/or peripheral neuropathy, even if the onset is not early.


Assuntos
Ataxia Cerebelar/genética , DNA Helicases/genética , Proteínas Mitocondriais/genética , Ataxia Cerebelar/complicações , Ataxia Cerebelar/diagnóstico , Consanguinidade , Feminino , Marcha Atáxica/complicações , Marcha Atáxica/diagnóstico , Marcha Atáxica/genética , Disgenesia Gonadal 46 XX/diagnóstico , Disgenesia Gonadal 46 XX/genética , Perda Auditiva/complicações , Perda Auditiva/diagnóstico , Perda Auditiva/genética , Perda Auditiva Neurossensorial/diagnóstico , Perda Auditiva Neurossensorial/genética , Homozigoto , Humanos , Japão , Transtornos de Início Tardio/diagnóstico , Transtornos de Início Tardio/genética , Pessoa de Meia-Idade , Mutação , Linhagem
15.
J Hum Genet ; 65(10): 917-920, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32451491

RESUMO

Primary familial brain calcification (PFBC) is a hereditary neurological disorder characterized by idiopathic calcification of the bilateral basal ganglia and other areas of the brain. MYORG has been identified as the first causative gene of autosomal recessive PFBC in Chinese families. There have been several reports of PFBC associated with MYORG (MYORG-PFBC) in individuals of Middle Eastern, European, and Latin American ancestry but to date, there have been no reported Japanese cases. We report the first Japanese case of MYORG-PFBC. The patient was a 43-year-old Japanese woman who experienced mild headaches and cerebellar ataxia including dysarthria. Computed tomography showed calcification in the cerebral white matter, basal ganglia, cerebellum, and brainstem. Using exome sequencing, we identified a homozygous variant in the MYORG gene (NM_020702.4: c.794C>T,p.Thr265Met). Our patient presented dysarthria and extensive calcification affecting the pons, which are specific features of MYORG-PFBC. We report clinical symptoms and imaging findings of a case with p.Thr265Met variant.


Assuntos
Encefalopatias/genética , Calcinose/genética , Glicosídeo Hidrolases/genética , Mutação de Sentido Incorreto , Mutação Puntual , Adulto , Substituição de Aminoácidos , Povo Asiático/genética , Encefalopatias/diagnóstico por imagem , Encefalopatias/patologia , Calcinose/diagnóstico por imagem , Calcinose/patologia , Ataxia Cerebelar/genética , Consanguinidade , Disartria/genética , Feminino , Glicosídeo Hidrolases/química , Cefaleia/genética , Homozigoto , Humanos , Japão , Linhagem , Sequenciamento do Exoma
16.
J Hum Genet ; 65(4): 363-369, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31907387

RESUMO

Spinocerebellar ataxia (SCA) is a genetically heterogeneous disease characterized by cerebellar ataxia. Many causative genes have been identified to date, the most common etiology being the abnormal expansion of repeat sequences, and the mutation of ion channel genes also play an important role in the development of SCA. Some of them encode calcium and potassium channels. However, due to limited reports about potassium genes in SCA, we screened 192 Japanese individuals with dominantly inherited SCA who had no abnormal repeat expansions of causative genes for potassium channel mutations (KCNC3 for SCA13 and KCND3 for SCA19/SCA22) by target sequencing. As a result, two variants were identified from two patients: c.1973G>A, p.R658Q and c.1018G>A, p.V340M for KCNC3, and no pathogenic variant was identified for KCND3. The newly identified p.V340M exists in the extracellular domain, and p.R658Q exists in the intracellular domain on the C-terminal side, although most of the reported KCNC3 mutations are present at the transmembrane site. Adult-onset and slowly progressive cerebellar ataxia are the main clinical features of SCA13 and SCA19 caused by potassium channel mutations, which was similar in our cases. SCA13 caused by KCNC3 mutations may present with deep sensory loss and cognitive impairment in addition to cerebellar ataxia. In this study, mild deep sensory loss was observed in one case. SCA caused by potassium channel gene mutations is extremely rare, and more cases should be accumulated in the future to elucidate its pathogenesis due to channel dysfunction.


Assuntos
Disfunção Cognitiva/genética , Mutação , Canais de Potássio/genética , Ataxias Espinocerebelares/genética , Adulto , Povo Asiático , Disfunção Cognitiva/diagnóstico por imagem , Feminino , Testes Genéticos , Humanos , Japão , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Ataxias Espinocerebelares/diagnóstico por imagem
17.
J Pathol ; 249(2): 182-192, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31056746

RESUMO

Mutations in the Matrin 3 (MATR3) gene have been identified as a cause of amyotrophic lateral sclerosis (ALS) or vocal cord and pharyngeal weakness with distal myopathy (VCPDM). This study investigated the mechanism by which mutant MATR3 causes multisystem proteinopathy (MSP) including ALS and VCPDM. We first analyzed the muscle pathology of C57BL/6 mice injected with adeno-associated viruses expressing human WT or mutant (S85C) MATR3. We next generated transgenic mice that overexpress mutant (S85C) MATR3, driven by the CMV early enhancer/chicken ß-actin promoter, and evaluated their clinicopathological features. Intramuscular injection of viruses expressing WT and mutant MATR3 induced similar myogenic changes, including smaller myofibers with internal nuclei, and upregulated p62 and LC3-II. Mutant MATR3 transgenic mice showed decreased body weight and lower motor activity. Muscle histology demonstrated myopathic changes including fiber-size variation, internal nuclei and rimmed vacuoles. Spinal cord histology showed a reduced number of motor neurons, and activation of microglia and astrocytes. Comprehensive proteomic analyses of muscle demonstrated upregulation of proteins related to chaperones, stress response, protein degradation, and nuclear function. Overexpression of WT and mutant MATR3 similarly caused myotoxicity, recapitulating the clinicopathological features of MSP. These models will be helpful for analyzing MSP pathogenesis and for understanding the function of MATR3. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.


Assuntos
Esclerose Lateral Amiotrófica/genética , Miopatias Distais/genética , Doenças da Laringe/genética , Músculo Esquelético/metabolismo , Mutação , Proteínas Associadas à Matriz Nuclear/genética , Doenças Faríngeas/genética , Proteínas de Ligação a RNA/genética , Medula Espinal/metabolismo , Esclerose Lateral Amiotrófica/metabolismo , Esclerose Lateral Amiotrófica/patologia , Esclerose Lateral Amiotrófica/fisiopatologia , Animais , Dependovirus/genética , Modelos Animais de Doenças , Miopatias Distais/metabolismo , Miopatias Distais/patologia , Miopatias Distais/fisiopatologia , Análise da Marcha , Técnicas de Transferência de Genes , Predisposição Genética para Doença , Humanos , Doenças da Laringe/metabolismo , Doenças da Laringe/patologia , Doenças da Laringe/fisiopatologia , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Proteínas Associadas aos Microtúbulos/metabolismo , Atividade Motora , Músculo Esquelético/patologia , Músculo Esquelético/fisiopatologia , Proteínas Associadas à Matriz Nuclear/metabolismo , Doenças Faríngeas/metabolismo , Doenças Faríngeas/patologia , Doenças Faríngeas/fisiopatologia , Proteínas de Ligação a RNA/metabolismo , Teste de Desempenho do Rota-Rod , Proteína Sequestossoma-1/metabolismo , Medula Espinal/patologia , Medula Espinal/fisiopatologia , Redução de Peso
18.
Lab Invest ; 99(11): 1728-1740, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-30894671

RESUMO

Oculopharyngeal muscular dystrophy (OPMD) is a late-onset disorder characterized by ptosis, dysphagia, and weakness of proximal limbs. OPMD is caused by the expansion of polyalanine in poly(A)-binding protein, nuclear 1 (PABPN1). Although mitochondrial abnormality has been proposed as the possible etiology, the molecular pathogenesis is still poorly understood. The aim of the study was to specify the mechanism by which expanded PABPN1 causes mitochondrial dysfunction in OPMD. We evaluated whether transgenic mouse model of OPMD, by expressing expanded PABPN1, indeed causes mitochondrial abnormality associated with muscle degeneration. We also investigated the mechanism by which expanded PABPN1 would cause mitochondrial dysfunction in the mouse and cell models of OPMD. Mitochondrial localization of PABPN1 was observed in the muscle fibers of patients with OPMD. Moreover, abnormal accumulation of PABPN1 on the inner membrane of mitochondria and reduced expression of OXPHOS complexes were detected in the muscle fibers of the transgenic mice expressing expanded human PABPN1 with a 13-alanine stretch. In cells expressing PABPN1 with a 10-alanine or 18-alanine stretch, both types of PABPN1 accumulated in the mitochondria and interacted with TIM23 mitochondrial protein import complex, but PABPN1 with 18-alanine stretch decreased the cell viability and aggresome formation. We proposed that the abnormal accumulation of expanded PABPN1 in mitochondria may be associated with mitochondrial abnormality in OPMD.


Assuntos
Mitocôndrias Musculares/metabolismo , Distrofia Muscular Oculofaríngea/genética , Distrofia Muscular Oculofaríngea/metabolismo , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , Proteína I de Ligação a Poli(A)/genética , Proteína I de Ligação a Poli(A)/metabolismo , Expansão das Repetições de Trinucleotídeos , Animais , Estudos de Casos e Controles , Sobrevivência Celular , Modelos Animais de Doenças , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Células HEK293 , Humanos , Camundongos , Camundongos Transgênicos , Microscopia Eletrônica de Transmissão , Mitocôndrias Musculares/patologia , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Proteínas do Complexo de Importação de Proteína Precursora Mitocondrial , Modelos Biológicos , Fibras Musculares Esqueléticas/metabolismo , Fibras Musculares Esqueléticas/patologia , Distrofia Muscular Oculofaríngea/patologia , Proteínas Mutantes/química , Fosforilação Oxidativa , Proteína I de Ligação a Poli(A)/química , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo
20.
Brain ; 139(Pt 12): 3170-3186, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27797808

RESUMO

Neuronal intranuclear inclusion disease (NIID) is a slowly progressive neurodegenerative disease characterized by eosinophilic hyaline intranuclear inclusions in the central and peripheral nervous system, and also in the visceral organs. NIID has been considered to be a heterogeneous disease because of the highly variable clinical manifestations, and ante-mortem diagnosis has been difficult. However, since we reported the usefulness of skin biopsy for the diagnosis of NIID, the number of NIID diagnoses has increased, in particular adult-onset NIID. In this study, we studied 57 cases of adult-onset NIID and described their clinical and pathological features. We analysed both NIID cases diagnosed by post-mortem dissection and by ante-mortem skin biopsy based on the presence of characteristic eosinophilic, hyaline and ubiquitin-positive intanuclear inclusion: 38 sporadic cases and 19 familial cases, from six families. In the sporadic NIID cases with onset age from 51 to 76, dementia was the most prominent initial symptom (94.7%) as designated 'dementia dominant group', followed by miosis, ataxia and unconsciousness. Muscle weakness and sensory disturbance were also observed. It was observed that, in familial NIID cases with onset age less than 40 years, muscle weakness was seen most frequently (100%), as designated 'limb weakness group', followed by sensory disturbance, miosis, bladder dysfunction, and dementia. In familial cases with more than 40 years of onset age, dementia was most prominent (100%). Elevated cerebrospinal fluid protein and abnormal nerve conduction were frequently observed in both sporadic and familial NIID cases. Head magnetic resonance imaging showed high intensity signal in corticomedullary junction in diffusion-weighted image in both sporadic and familial NIID cases, a strong clue to the diagnosis. All of the dementia dominant cases presented with this type of leukoencephalopathy on head magnetic resonance imaging. Both sporadic and familial NIID cases presented with a decline in Mini-Mental State Examination and Frontal Assessment Battery scores. Based on these clinicopathological features, we proposed a diagnosis flow chart of adult-onset NIID. Our study suggested that the prevalence rate of adult-onset NIID may be higher than previously thought, and that NIID may be underdiagnosed. We should take NIID into account for differential diagnosis of leukoencephalopathy and neuropathy.


Assuntos
Demência/etiologia , Debilidade Muscular/etiologia , Doenças Neurodegenerativas/patologia , Doenças Neurodegenerativas/fisiopatologia , Adolescente , Adulto , Idade de Início , Idoso , Feminino , Humanos , Corpos de Inclusão Intranuclear/patologia , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Doenças Neurodegenerativas/complicações , Linhagem , Adulto Jovem
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