RESUMO
INTRODUCTION: Although symptomatic manifestations in encephalitis vary, they typically include seizures, memory deficit(s), and altered consciousness. Psychosis also occurs as an initial manifestation. In clinical practice, clinicians often encounter the question of whether first-episode psychosis (FEP) originates from encephalitis itself or if encephalitis presenting with FEP develops concurrently. The prognosis of FEP among patients with overall encephalitis, including autoimmune encephalitis, remains uncertain. METHODS: We examined a prognostic factor in patients with encephalitis who had both FEP and CSF pleocytosis. A total of 36 patients who presented with FEP were enrolled. A score of ≥3 and ≤2 on the modified Rankin scale were defined as poor and good outcomes, respectively. A total of 13 independent variables were analyzed by the multivariate logistic regression analysis. RESULTS: Significant variables on univariate logistic regression analysis included female sex (OR 5.571, 95% CI: 1.297-23.934; p = 0.021) and the use of mechanical ventilation during the acute stage (OR 7.286, 95% CI: 1.508-35.211; p = 0.013). On multivariate logistic regression analysis, the use of mechanical ventilation during the acute stage (OR 5.446, 95% CI: 1.044-28.615; p = 0.044) was significantly associated with poor outcomes. CONCLUSIONS: The use of mechanical ventilation is a poor prognostic factor of subacute encephalitis with FEP, and female sex may be a risk factor for unfavorable development of the disease.
Assuntos
Encefalite , Doença de Hashimoto , Transtornos Psicóticos , Humanos , Feminino , Prognóstico , Doença de Hashimoto/complicações , Encefalite/complicações , Transtornos Psicóticos/etiologia , Fatores de RiscoRESUMO
Chronic graft-versus-host disease (cGVHD) is the most important complication resulting in the death of bone marrow transplantation (BMT) survivors. It is also a relatively rare cause of inflammatory myopathy (IM). We report the case of a 46-year-old woman who developed severe cGVHD-related IM after BMT for myelodysplastic syndrome. She presented with severe muscle pain and weakness with cGVHD-related symptoms in other organs. Myopathological analysis showed moderate cell infiltration with remarkable necrotic and regenerative fibers. Sarcoplasm and capillaries expressed C5b9 and myxovirus resistance protein 1. Non-necrotic fibers in perifascicular regions expressed MHC-II. Steroid therapy did not sufficiently control cGVHD-related IM, and the patient was concurrently treated with an immunosuppressant. Our findings show that IM is a key manifestation of cGVHD and that the expression of interferon-inducible proteins in muscle pathology is useful for identifying cGVHD-related IM.
Assuntos
Doença Enxerto-Hospedeiro , Transplante de Células-Tronco Hematopoéticas , Miosite , Transplante de Medula Óssea/efeitos adversos , Doença Crônica , Feminino , Doença Enxerto-Hospedeiro/complicações , Doença Enxerto-Hospedeiro/patologia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Humanos , Pessoa de Meia-Idade , Miosite/complicaçõesRESUMO
BACKGROUND: Freezing of gait (FOG) has been linked to increased numbers of steps taken while walking. We tested the hypothesis that an increased number of steps associated with FOG might predict the exacerbation of the severity of Parkinson's disease (PD). METHODS: We prospectively studied 26 patients. Clinical assessments were performed and balance was evaluated in 30 patients with Hoehn-Yahr stage III PD 6 years previously. Gait parameters were analyzed with the use of an originally designed, suddenly narrowed path. PD-related independent variables, balance investigation-related variables, and gait-independent-related variables were analyzed by multiple logistic regression analysis. RESULTS: The Hoehn-Yahr stage increased in 14 patients and was unchanged in 12 patients. The 36-item Short-Form Health Survey score (OR 1.079, p = 0.041, 95% CI 1.003-1.161) and the number of steps on the suddenly narrow path (OR 1.605, p = 0.047, 95% CI 1.006-2.56) were related to an increase in the Hoehn-Yahr stage. The number of steps was significantly higher on the suddenly narrowed path (11.3 ± 3.6) than on a straightly narrowed path (10.1 ± 3.2) at the time of final follow-up in the 26 patients (p < 0.001). CONCLUSIONS: An increased number of steps associated with FOG, which was elicited by the suddenly narrowed path, might be one predictor of an upgrade of stage in patients with Hoehn-Yahr stage III PD.
Assuntos
Transtornos Neurológicos da Marcha/etiologia , Doença de Parkinson/complicações , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , CaminhadaRESUMO
Danon disease, an X-linked dominant cardioskeletal myopathy, is caused by primary deficiency of lysosome-associated membrane protein-2 (LAMP-2). To clarify the clinicopathological features and management, we performed the first nationwide, questionnaire-based survey on Danon disease in Japan. A total of 39 patients (17 males, 22 females) from 20 families were identified in the analysis. All patients had cardiomyopathy. Of the 21 patients who died, 20 (95%) died of cardiac failure or sudden cardiac arrest. Most patients had hypertrophic cardiomyopathy. Wolfâ»Parkinsonâ»White syndrome was present at a comparatively high incidence (54% in males, 22% in females). Only one female patient received a heart transplant, which is the most effective therapy. Histopathologically, all male patients showed autophagic vacuoles with sarcolemmal features in muscle. Half of the probands showed de novo mutations. Male patients showed completely absent LAMP-2 expression in muscle. In contrast, female patients showed decreased LAMP-2 expression, which is suggested to reflect LAMP-2 haploinsufficiency due to a heterozygous null mutation. In conclusion, Danon disease is an extremely rare muscular disorder in Japan. Cardiomyopathy is the most significant prognostic factor and the main cause of death. Our findings suggest that the present survey can extend our understanding of the clinical features of this rare disease.
Assuntos
Cardiomiopatias/genética , Doença de Depósito de Glicogênio Tipo IIb/genética , Proteína 2 de Membrana Associada ao Lisossomo/genética , Músculo Esquelético/metabolismo , Cardiomiopatias/epidemiologia , Cardiomiopatias/patologia , Feminino , Regulação da Expressão Gênica , Doença de Depósito de Glicogênio Tipo IIb/epidemiologia , Doença de Depósito de Glicogênio Tipo IIb/patologia , Humanos , Japão/epidemiologia , Masculino , Músculo Esquelético/patologia , Caracteres Sexuais , Inquéritos e QuestionáriosRESUMO
BACKGROUND: Recently, we evaluated factors responsible for falling, including walking speed evaluated with the use of originally designed, suddenly narrowed paths, in patients with Hoehn-Yahr stage III PD. We prospectively studied the same cohort of patients with PD who were followed up for 2 years, to determine predictors of future falls. METHODS: We performed clinical assessments and evaluated balance in 26 patients. A total of 19 variables including PD-related independent variables, balance investigation-related independent variables and gait independent-related variables were evaluated. RESULTS: The Frontal Assessment Battery (FAB) score (p = 0.002), Tinetti balance (p = 0.009), and gait velocity (p = 0.001) were higher in fallers than in non-fallers. On multiple logistic regression analysis, the FAB score was related to falling (odds ratio = 3.328, p = 0.033, 95% confidence interval = 1.104-10.03). On the FAB, the scores of 'inhibitory control' and 'sensitivity to interference' were significantly lower in fallers than in non-fallers. CONCLUSIONS: The use of the originally designed, suddenly narrowed path was the primary reason for demonstrating for the first time that a low FAB score is a risk factor for future falls. Calculation of the FAB score may be useful for predicting the risk of future falls.
Assuntos
Acidentes por Quedas , Exame Neurológico/métodos , Doença de Parkinson/complicações , Equilíbrio Postural/fisiologia , Acidentes por Quedas/prevenção & controle , Idoso , Feminino , Humanos , Masculino , Fatores de RiscoRESUMO
BACKGROUND: Postoperative respiratory insufficiency (PRI) in myasthenia gravis (MG) often occurs within several days after thymectomy and remains problematic. In limited studies reporting that preoperative steroids prevented PRI in patients with MG, high doses of steroids were used and detailed information on the use of steroids is limited. Because high-dose steroids significantly increase the risk of adverse effects, we studied 37 patients with generalized MG to investigate whether low-dose steroids might prevent PRI. METHODS: The low-dose steroids were started orally, and the dose was gradually increased to the maximum level (30 mg/day). Immediately before thymectomy, patients received the maximum dose of oral steroids daily. PRI was defined as the development of restrictive dysfunction requiring mechanical ventilation within 3 days after thymectomy and total postoperative mechanical ventilation support time of >24 h. RESULTS: The rate of PRI in the low-dose steroid use group was significantly lower than that in the no-steroid use group. The postoperative stay in the intensive care unit was shorter in the steroid use group. CONCLUSIONS: Extended thymectomy is a well-accepted surgical treatment for selected patients with MG. However, PRI remains problematic. Our results suggest that not only preoperative high-dose steroid treatment, but also low-dose steroid treatment can prevent PRI.
Assuntos
Complicações Pós-Operatórias/prevenção & controle , Insuficiência Respiratória/etiologia , Insuficiência Respiratória/prevenção & controle , Esteroides/administração & dosagem , Timectomia/efeitos adversos , Administração Oral , Adulto , Idoso , Humanos , Pessoa de Meia-Idade , Miastenia Gravis/tratamento farmacológico , Miastenia Gravis/cirurgia , Estudos Prospectivos , Estudos RetrospectivosRESUMO
BACKGROUND: Accumulating evidence indicates an association of Alzheimer's disease (AD) with the metabolic syndrome (MetS), characterized by visceral fat accumulation with insulin resistance and altered secretion of adipocytokines such as adiponectin and leptin. The renin-angiotensin system (RAS) regulates blood pressure and insulin resistance. Recent studies suggest that the RAS plays crucial roles in cognitive functions and that adipocytokines exert neuroprotective activity in the brain. We investigated whether RAS blockers (RASB) affect adipocytokines and cognitive function in patients with AD. METHODS: We studied 78 patients with a diagnosis of probable AD according to the Diagnostic and Statistical Manual of Mental Disorders, 4th edition and 106 nondemented control subjects who visited our clinic with a main complaint of headache or dizziness. We examined retrospectively the effects of RASB on adipocytokines and cognitive decline in patients with AD who were divided into three groups: hypertension treated with RASB (HT-RASB; n = 17), hypertension treated with other antihypertensive drugs (HT-other; n = 34), and no hypertension (non-HT; n = 27). RESULTS: The HT-RASB group had a significantly higher serum leptin level and a relatively larger visceral fat area than the other groups, because of the bias toward patients with MetS in this group. The HT-RASB group also had a significantly lower immunoreactive insulin level, a relatively low homeostasis model assessment as an index of insulin resistance, and a relatively high serum adiponectin level among the three groups. Cognitive decline, estimated on the basis of the mean annual decline using the Hasegawa Dementia Scale score was significantly low in the HT-RASB group. CONCLUSION: Treatment with RASB might modulate serum adipocytokines and glucose homeostasis, potentially slowing cognitive decline in patients with AD.
Assuntos
Adipocinas/sangue , Doença de Alzheimer/complicações , Doença de Alzheimer/tratamento farmacológico , Anti-Hipertensivos/uso terapêutico , Síndrome Metabólica/complicações , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/sangue , Feminino , Humanos , Hipertensão/complicações , Hipertensão/tratamento farmacológico , Hipertensão/epidemiologia , Masculino , Síndrome Metabólica/epidemiologia , Pessoa de Meia-Idade , Prevalência , Sistema Renina-Angiotensina/efeitos dos fármacos , Estudos RetrospectivosRESUMO
Recently, we studied fallers and non-fallers with Hoehn-Yahr stage III Parkinson's disease (PD) using a path that suddenly narrowed, which we originally designed and produced. A risk of future falls was suggested to be related to slow gait with freezing (SGF) elicited by a fear of falling before arrival at a narrowed entrance or while walking on a narrow path, as well as to the Unified Parkinson's Disease Rating Scale part II score, associated with SGF. In the same study, we had faller patients walk on a path that narrowed in a straight-line fashion to determine whether SGF could be improved. In one patient, who showed a unique paradoxical gait, SGF resolved. We describe this patient in the hope that our experience will provide potential clues to effective ways to prevent future falls in patients with Hoehn-Yahr stage III PD. To prevent gait instability elicited by fear of falling in patients with Hoehn-Yahr stage III PD, it might be useful to remove narrowed entrances.
Assuntos
Transtornos Neurológicos da Marcha/etiologia , Doença de Parkinson/fisiopatologia , Acidentes por Quedas/prevenção & controle , Idoso , Medo/fisiologia , Feminino , Humanos , Exame Neurológico/métodos , Doença de Parkinson/complicações , Risco , Índice de Gravidade de DoençaRESUMO
There has been limited research on encephalitis/encephalopathy, which is a less common coronavirus disease 2019 (COVID-19) neurological complication. The differentiation between stroke and encephalopathy with stroke mimickers is challenging in patients with COVID-19. Here, we describe a case of COVID-19-related encephalopathy mimicking stroke that was successfully treated with high-dose steroid pulse therapy. The patient suddenly experienced language disturbance with a left facial droop and symmetric numbness in his upper limbs. Magnetic resonance imaging (MRI) scans revealed hyperintensities in both the white matter and splenium. No pneumonia was observed. MRI abnormalities and neurological symptoms resolved after steroid pulse therapy and administration of remdesivir. High-dose steroid pulse treatment (for 3 days) might alleviate COVID-19-related encephalopathy.
RESUMO
The patient, a 50-year-old woman, presented with fever and diarrhea in early July, X. One week later, she noticed muscle weakness in both lower extremities, which upon examination was found to be dominant in the distal muscles, with associated loss of tendon reflexes. We diagnosed the case as Guillain-Barré syndrome. After admission, the patient experienced decreased oxygenation, and a chest X-ray indicated elevation of the left hemidiaphragm. The phrenic nerve conduction studies revealed laterality of the amplitude of compound muscle action potential, and diaphragmatic ultrasonographic examination revealed decreased left diaphragmatic wall motion. We diagnosed the patient with unilateral diaphragmatic nerve palsy and initiated intravenous immunoglobulin and methylprednisolone treatment. After 2 weeks, the patient demonstrated good clinical recovery, increased diaphragmatic nerve amplitude, and improved diaphragmatic movement. We evaluated the longitudinal clinical course of unilateral diaphragmatic nerve palsy in the patient using nerve conduction tests and diaphragmatic echocardiography. The longitudinal evaluation allowed us to assess the pathological condition more sensitively so that the prognosis could be predicted accurately.
Assuntos
Síndrome de Guillain-Barré , Imunoglobulinas Intravenosas , Feminino , Humanos , Pessoa de Meia-Idade , Imunoglobulinas Intravenosas/uso terapêutico , Síndrome de Guillain-Barré/complicações , Síndrome de Guillain-Barré/diagnóstico , Síndrome de Guillain-Barré/tratamento farmacológico , Paralisia/complicações , Nervo Frênico , MetilprednisolonaRESUMO
False windows can display a variety of outdoor scenery in rooms without real windows. We aimed to assess the effects of three different hospital beds on the change in the frontal assessment battery scores in patients aged ≥ 20-year-old admitted in our neurological ward. We included 24 patients on the window side, 12 patients on the aisle side with a false window, and 12 patients on the aisle side without a false window. There were no statistical differences in the change of cognitive function among the three hospital beds. Only the length of hospital stay was a significant associated factor.
RESUMO
Postural imbalance, abnormal axial posture, and axial rigidity are the characteristic features of Parkinson's disease (PD), and they are referred to as axial symptoms. The symptoms are difficult to manage since they are often resistant to both L-DOPA and deep brain stimulation. Hence, other treatments that can improve Parkinsonian axial symptoms without adverse effects are required. Vestibular dysfunction occurs in PD since neuropathological changes and reflex abnormalities are involved in the vestibular nucleus complex. Galvanic vestibular stimulation (GVS), which activates the vestibular system, is a noninvasive method. This review aimed to assess the clinical effect of GVS on axial symptoms in PD. To date, studies on the effects of GVS on postural instability, anterior bending posture, lateral bending posture, and trunk rigidity and akinesia in PD had yielded interesting data, and none of the patients presented with severe adverse events, and the others had mild reactions. GVS indicated a possible novel therapy. However, most included a small number of patients, and the sample sizes were not similar in some studies that included controls. In addition, there was only one randomized controlled clinical trial, and it did not perform an objective evaluation of axial symptoms. In this type of research, vestibular contributions to balance should be distinguished from others such as proprioceptive inputs or nonmotor symptoms of PD.
RESUMO
Proline:arginine (PR) poly-dipeptides from the GGGGCC repeat expansion in C9orf72 have cytotoxicity and bind intermediate filaments (IFs). However, it remains unknown how PR poly-dipeptides affect cytoskeletal organization and focal adhesion (FA) formation. Here, we show that changes to the cytoskeleton and FA by PR poly-dipeptides result in the alteration of cell stiffness and mechanical stress response. PR poly-dipeptides increased the junctions and branches of the IF network and increased cell stiffness. They also changed the distribution of actin filaments and increased the size of FA and intracellular calcium concentration. PR poly-dipeptides or an inhibitor of IF organization prevented cell detachment. Furthermore, PR poly-dipeptides induced upregulation of mechanical stress response factors and led to a maladaptive response to cyclic stretch. These results suggest that the effects of PR poly-dipeptides on mechanical properties and mechanical stress response may serve as a pathogenesis of C9orf72-related neurodegeneration.
RESUMO
Spinocerebellar ataxia type 14 (SCA14) is an autosomal dominant disease caused by mutations in the gene encoding protein kinase C gamma (PKC gamma). We report an SCA14 family with a novel deletion of a termination-codon-containing region, resulting in a missense change and a C-terminal 13-amino-acid extension with increased kinase activity. Notably, one patient with a severe phenotype is the first homozygote for the mutation causing SCA14. We show the novel molecular consequences of increased kinase activities of mutants: aprataxin (APTX), a DNA repair protein causative for autosomal recessive ataxia, was found to be a preferential substrate of mutant PKC gamma, and phosphorylation inhibited its nuclear entry. The phosphorylated residue was Thr111, located adjacent to the nuclear localization signal, and disturbed interactions with importin alpha, a nuclear import adaptor. Decreased nuclear APTX increased oxidative stress-induced DNA damage and cell death. Phosphorylation-resistant APTX, kinase inhibitors, and antioxidants may be therapeutic options for SCA14.
Assuntos
Núcleo Celular/metabolismo , Proteínas de Ligação a DNA/metabolismo , Regulação para Baixo , Proteínas Nucleares/metabolismo , Proteína Quinase C/metabolismo , Ataxias Espinocerebelares/metabolismo , Transporte Ativo do Núcleo Celular , Idoso de 80 Anos ou mais , Sequência de Aminoácidos , Sequência de Bases , Linhagem Celular , Núcleo Celular/química , Núcleo Celular/genética , Dano ao DNA , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Mutação de Sentido Incorreto , Proteínas Nucleares/química , Proteínas Nucleares/genética , Linhagem , Fosforilação , Proteína Quinase C/química , Proteína Quinase C/genética , Transporte Proteico , Ataxias Espinocerebelares/genética , Adulto JovemRESUMO
BACKGROUND: It is difficult to predict the risk of falling, especially in patients with good motor ability, and the mechanisms underlying the relation between gait patterns and falling in Parkinson's disease (PD) remain unclear. We investigated factors related to falling, including walking speed and time, in patients with Hoehn-Yahr stage III PD. METHODS: We performed clinical assessments and evaluated balance in 30 patients with PD. Information on falling was obtained from questionnaires and personal interviews. Gait patterns were analyzed with the use of an originally designed, suddenly narrowed path. RESULTS: Gait velocity was slower in fallers than in non-fallers (p = 0.047). Unified Parkinson's Disease Rating Scale part II (UPDRS part II) score, fear of falling, and gait velocity were significantly related to falling on analysis with a single logistic model. When a multiple logistic model was used, the UPDRS part II score was significantly related to falling (OR: 1.48, p = 0.037, 95% CI: 1.02-2.16). CONCLUSIONS: Patients with Hoehn-Yahr stage III PD showed slow gait velocity attributed to fear of falling before arrival at a narrowed entrance or while walking on a narrowed path. The UPDRS part II score is significantly related to the risk of future falls.
Assuntos
Acidentes por Quedas , Transtornos Neurológicos da Marcha/etiologia , Doença de Parkinson/complicações , Idoso , Antiparkinsonianos/uso terapêutico , Feminino , Seguimentos , Humanos , Levodopa/uso terapêutico , Modelos Logísticos , Masculino , Entrevista Psiquiátrica Padronizada , Pessoa de Meia-Idade , Exame Neurológico , Testes Neuropsicológicos , Doença de Parkinson/tratamento farmacológico , Inquéritos e Questionários , Gravação em VídeoRESUMO
We describe an adult with Rasmussen's encephalitis associated with widespread decreased accumulation of tracer on 123-I iomazenil (IMZ) SPECT. The patient had a form of epilepsia partialis continua and neurological deterioration associated with hemiatrophy. Cranial MRI showed cerebral atrophy in the left frontal, parietal, and temporal lobes, without abnormal intensity. Delayed IMZ SPECT showed widespread decreased accumulation of tracer in the left temporal and frontal regions. An early scan showed mildly decreased accumulation in the left temporal and frontal regions. Three-dimensional stereotactic surface projection (3D-SSP) analysis showed that the decreased regions on delayed IMZ images were slightly larger as compared with the previous IMZ study performed. Some regions without decreased accumulation of tracer on Tc-ECD or early IMZ images showed decreased accumulation on delayed IMZ images. This case study suggests that benzodiazepine receptors may be reduced in the affected hemisphere of patients with Rasmussen's encephalitis.
Assuntos
Encéfalo/metabolismo , Encefalite/metabolismo , Epilepsia Parcial Contínua/metabolismo , Receptores de GABA-A/metabolismo , Adulto , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico , Encefalite/diagnóstico por imagem , Epilepsia Parcial Contínua/diagnóstico por imagem , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Tomografia Computadorizada de Emissão de Fóton ÚnicoRESUMO
Background: Sleep disorders are one of the most frequent non-motor symptoms of Parkinson's disease (PD), and the efficacy of dopaminergic agents remains controversial. Clinical randomized control trials for the treatment of sleep disorders in PD are limited. Zonisamide (1,2-benzisoxazole-3-methanesulfonamide) improved motor symptoms and wearing-off in patients with PD. Patients with PD were reported to have dream-enacting behavior that was resolved after treatment with zonisamide. This study aimed to verify the safety and efficacy of zonisamide for sleep disorders and rapid eye movement (REM) sleep behavioral disorders using a mobile two-channel electroencephalography (EEG)/electrooculography (EOG) recording system. Methods and Analysis: The present study is a randomized placebo-controlled trial to determine the efficacy of zonisamide for sleep disorders in patients with PD. This study was designed to be single-blind, but the subject allocation is randomized by an independent allocation manager via computer-generated block randomization. The subjects in the treatment group took zonisamide (25 mg per day) before bedtime for 28 days. The sleep index is analyzed using a portable EEG/EOG recording system collected on two consecutive nights within 7 days prior to the intervention and reobtained on one night within 2 days after the 28-day administration of zonisamide. The amount of change in sleep efficiency before and after the 28-day administration will be compared between the zonisamide treatment group and placebo group concerning the primary endpoint. As for the secondary endpoint, the change in the ratio of other sleep parameters, including REM sleep without atonia, or sleep architecture will be evaluated. Ethics and Dissemination: The protocol was approved by the Nara Medical University Certified Review Board (CRB5200002). The trial was notified and registered with the Japan Registry of Clinical Trials (jRCTs051200160). Written informed consent will be obtained from every participant using informed consent approved by the CRB. The results of this trial will be disseminated through peer-reviewed scientific journals.
RESUMO
Ischemic stroke is one of the most common neurological diseases. However, the impact of ischemic stroke on human cerebral tissue remains largely unknown due to a lack of ischemic human brain samples. In this study, we applied cerebral organoids derived from human induced pluripotent stem cells to evaluate the effect of oxygen-glucose deprivation/reoxygenation (OGD/R). Pathway analysis showed the relationships between vitamin digestion and absorption, fat digestion and absorption, peroxisome proliferator-activated receptor (PPAR) signaling pathway, and complement and coagulation cascades. Combinational verification with transcriptome and gene expression analysis of different cell types revealed fatty acids-related PPAR signaling pathway and pyruvate kinase isoform M2 (PKM2) as key markers of neuronal cells in response to OGD/R. These findings suggest that, although there remain some limitations to be improved, our ischemic stroke model using human cerebral organoids would be a potentially useful tool when combined with other conventional two-dimensional (2D) mono-culture systems.
RESUMO
Nuclear import receptors (NIRs) not only transport RNA-binding proteins (RBPs) but also modify phase transitions of RBPs by recognizing nuclear localization signals (NLSs). Toxic arginine-rich poly-dipeptides from C9orf72 interact with NIRs and cause nucleocytoplasmic transport deficit. However, the molecular basis for the toxicity of arginine-rich poly-dipeptides toward NIRs function as phase modifiers of RBPs remains unidentified. Here we show that arginine-rich poly-dipeptides impede the ability of NIRs to modify phase transitions of RBPs. Isothermal titration calorimetry and size-exclusion chromatography revealed that proline:arginine (PR) poly-dipeptides tightly bind karyopherin-ß2 (Kapß2) at 1:1 ratio. The nuclear magnetic resonances of Kapß2 perturbed by PR poly-dipeptides partially overlapped with those perturbed by the designed NLS peptide, suggesting that PR poly-dipeptides target the NLS binding site of Kapß2. The findings offer mechanistic insights into how phase transitions of RBPs are disabled in C9orf72-related neurodegeneration.
Assuntos
Transporte Ativo do Núcleo Celular/genética , Proteína C9orf72/química , Peptídeos/química , beta Carioferinas/química , Sítios de Ligação , Proteína C9orf72/genética , Proteína C9orf72/metabolismo , Clonagem Molecular , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Expressão Gênica , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Células HeLa , Humanos , Modelos Moleculares , Sinais de Localização Nuclear/genética , Sinais de Localização Nuclear/metabolismo , Peptídeos/genética , Peptídeos/metabolismo , Transição de Fase , Ligação Proteica , Conformação Proteica , Domínios e Motivos de Interação entre Proteínas , Proteína FUS de Ligação a RNA/genética , Proteína FUS de Ligação a RNA/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , beta Carioferinas/antagonistas & inibidores , beta Carioferinas/genética , beta Carioferinas/metabolismoRESUMO
Intranuclear events due to mutations in the Parkin gene remain elusive in autosomal recessive juvenile parkinsonism (ARJP). We identified a mutant PARKIN protein in fibroblast cultures from a pair of siblings with ARJP who were homozygous for the exon 4-deleted Parkin gene. Disease was mild in one patient and debilitating in the other. The detected mutant, encoded by a transcript lacking exon 3 as well as exon 4, is an in-frame deletion that removes 121 aa, resulting in a 344-aa protein (PaDel3,4). Cell culture and transfection studies revealed negative correlations between expression levels of PaDel3,4 and those of cell cycle proteins, including cyclin E, CDK2, ppRb, and E2F-1, and demonstrated that GFP-PaDel3,4 entered nucleus and ubiquitinated cyclin E as a part of SCF(hSel-10) ligase complex in the patient cells. In addition, nuclear localization signal-tagged PaDel3,4 expressed in the transfected patient cells most effectively ubiquitinated cyclin E and reduced DNA damage, protecting cells from oxidative stress. Antisense-oligonucleotide treatment promoted skipping of exon 3 and thus generated PaDel3,4, increasing cell survival. Collectively, we propose that naturally- and experimentally-induced exon skipping at least partly restores the mutant Parkin gene deficit, providing a molecular basis for the development of therapeutic exon skipping.