RESUMO
Amyotrophic lateral sclerosis (ALS) is a paralytic and usually fatal disorder caused by motor-neuron degeneration in the brain and spinal cord. Most cases of ALS are sporadic but about 5-10% are familial. Mutations in superoxide dismutase 1 (SOD1), TAR DNA-binding protein (TARDBP, also known as TDP43) and fused in sarcoma (FUS, also known as translocated in liposarcoma (TLS)) account for approximately 30% of classic familial ALS. Mutations in several other genes have also been reported as rare causes of ALS or ALS-like syndromes. The causes of the remaining cases of familial ALS and of the vast majority of sporadic ALS are unknown. Despite extensive studies of previously identified ALS-causing genes, the pathogenic mechanism underlying motor-neuron degeneration in ALS remains largely obscure. Dementia, usually of the frontotemporal lobar type, may occur in some ALS cases. It is unclear whether ALS and dementia share common aetiology and pathogenesis in ALS/dementia. Here we show that mutations in UBQLN2, which encodes the ubiquitin-like protein ubiquilin 2, cause dominantly inherited, chromosome-X-linked ALS and ALS/dementia. We describe novel ubiquilin 2 pathology in the spinal cords of ALS cases and in the brains of ALS/dementia cases with or without UBQLN2 mutations. Ubiquilin 2 is a member of the ubiquilin family, which regulates the degradation of ubiquitinated proteins. Functional analysis showed that mutations in UBQLN2 lead to an impairment of protein degradation. Therefore, our findings link abnormalities in ubiquilin 2 to defects in the protein degradation pathway, abnormal protein aggregation and neurodegeneration, indicating a common pathogenic mechanism that can be exploited for therapeutic intervention.
Assuntos
Esclerose Lateral Amiotrófica/genética , Proteínas de Ciclo Celular/genética , Demência/complicações , Demência/genética , Genes Dominantes/genética , Genes Ligados ao Cromossomo X/genética , Mutação/genética , Ubiquitinas/genética , Proteínas Adaptadoras de Transdução de Sinal , Adulto , Idade de Início , Envelhecimento , Sequência de Aminoácidos , Esclerose Lateral Amiotrófica/complicações , Esclerose Lateral Amiotrófica/patologia , Proteínas Relacionadas à Autofagia , Sequência de Bases , Proteínas de Ciclo Celular/análise , Linhagem Celular , Criança , Proteínas de Ligação a DNA/metabolismo , Demência/patologia , Feminino , Hipocampo/metabolismo , Humanos , Masculino , Dados de Sequência Molecular , Linhagem , Complexo de Endopeptidases do Proteassoma/metabolismo , Medula Espinal/metabolismo , Ubiquitina/metabolismo , Ubiquitinas/análiseRESUMO
OBJECTIVE: To determine the validity of the 6-minute walk test (6MWT) as an outcome measure to evaluate walking capacity in ambulatory patients with amyotrophic lateral sclerosis (ALS). DESIGN: Observational study. SETTING: Multidisciplinary ALS clinic at an academic medical center. PARTICIPANTS: Patients with ALS (N=186) who ambulate without (stage I) or with (stage II) an assistive device. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: Walking distance obtained from the 6MWT. RESULTS: Participants performed the 6MWT, 25-foot walk test (25FWT), Timed Up and Go (TUG) test, lower extremity maximum voluntary isometric contraction (MVIC), ALS Functional Rating Scale-Revised (ALSFRS-R), and forced vital capacity (FVC). Walking capacity was reduced to 66% predicted of healthy subjects (75.2%±22% in stage I; 42.6%±22% in stage II). The 6MWT correlated with all other outcome measures in ambulatory patients with ALS (25FWT: r=-.74, P≤.0001; TUG test: r=-.80, P≤.0001; MVIC: r=.64, P≤.0001; percent predicted FVC: r=.25, P≤.0007; ALSFRS-R: r=.52, P≤.0001; ALSFRS-R gross motor subscore: r=.71, P≤.0001). When ambulatory patients with ALS were stratified by stage of ambulation, the 6MWT was associated with all other outcome measures in stage I (25FWT: r=-.56, P≤.0001; TUG test: r=-.66, P≤.0001; MVIC: r=.51, P≤.0001; percent predicted FVC: r=.40, P≤.02; ALSFRS-R: r=.52, P≤.0001; ALSFRS-R gross motor subscore: r=.61, P≤.0001). In stage II, the 6MWT correlated with the 25FWT (r=-.83, P≤.0001), TUG test (r=-.77, P≤.0001), MVIC (r=.47, P≤.0001), and ALSFRS gross motor subscore (r=.61, P≤.0001), but not with percent predicted FVC (r=.09, P≤.513) or ALSFRS-R (r=.21, P≤.141). CONCLUSIONS: The 6MWT is a valid measure of walking capacity of ambulatory patients with ALS that is associated with measures of lower extremity muscle strength and function in both stages of ambulation. The discordance between the 6MWT with the ALSFRS-R and percent predicted FVC in stage II ambulatory patients with ALS indicates that the 6MWT is an independent measure of ambulatory function in both stages of ambulation. The 6MWT may provide a quantitative, simple, and inexpensive outcome measure of walking capacity for early stage clinical trials in ambulatory patients with ALS.
Assuntos
Esclerose Lateral Amiotrófica/reabilitação , Modalidades de Fisioterapia/normas , Capacidade Vital/fisiologia , Caminhada/fisiologia , Centros Médicos Acadêmicos , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Força Muscular/fisiologia , Equilíbrio Postural , Reprodutibilidade dos Testes , Velocidade de CaminhadaRESUMO
BACKGROUND: Sporadic Amyotrophic Lateral Sclerosis (sALS) is a devastating, complex disease of unknown etiology. We studied this disease with microarray technology to capture as much biological complexity as possible. The Affymetrix-focused BaFL pipeline takes into account problems with probes that arise from physical and biological properties, so we adapted it to handle the long-oligonucleotide probes on our arrays (hence LO-BaFL). The revised method was tested against a validated array experiment and then used in a meta-analysis of peripheral white blood cells from healthy control samples in two experiments. We predicted differentially expressed (DE) genes in our sALS data, combining the results obtained using the TM4 suite of tools with those from the LO-BaFL method. Those predictions were tested using qRT-PCR assays. RESULTS: LO-BaFL filtering and DE testing accurately predicted previously validated DE genes in a published experiment on coronary artery disease (CAD). Filtering healthy control data from the sALS and CAD studies with LO-BaFL resulted in highly correlated expression levels across many genes. After bioinformatics analysis, twelve genes from the sALS DE gene list were selected for independent testing using qRT-PCR assays. High-quality RNA from six healthy Control and six sALS samples yielded the predicted differential expression for 7 genes: TARDBP, SKIV2L2, C12orf35, DYNLT1, ACTG1, B2M, and ILKAP. Four of the seven have been previously described in sALS studies, while ACTG1, B2M and ILKAP appear in the context of this disease for the first time. Supplementary material can be accessed at: http://webpages.uncc.edu/~cbaciu/LO-BaFL/supplementary_data.html. CONCLUSION: LO-BaFL predicts DE results that are broadly similar to those of other methods. The small healthy control cohort in the sALS study is a reasonable foundation for predicting DE genes. Modifying the BaFL pipeline allowed us to remove noise and systematic errors, improving the power of this study, which had a small sample size. Each bioinformatics approach revealed DE genes not predicted by the other; subsequent PCR assays confirmed seven of twelve candidates, a relatively high success rate.
Assuntos
Esclerose Lateral Amiotrófica/genética , Perfilação da Expressão Gênica/estatística & dados numéricos , Análise de Sequência com Séries de Oligonucleotídeos/estatística & dados numéricos , Software , Interpretação Estatística de Dados , Humanos , Leucócitos/metabolismo , Análise em Microsséries/métodosRESUMO
Mitochondrial dysfunctions contribute to neurodegeneration, the locations of which vary among neurodegenerative diseases. To begin to understand what mechanisms may underlie higher vulnerability of the spinal cord motor neurons in amyotrophic lateral sclerosis, compared with brain mitochondria, we studied three major functions of rat brain mitochondria (BM) and spinal cord mitochondria (SCM) mitochondria: oxidative phosphorylation, Ca(2+) sequestration, and production of reactive oxygen species (ROS), using a new metabolic paradigm (Panov et al., J. Biol. Chem. 284: 14448-14456, 2009). We present data that SCM share some unique metabolic properties of the BM. However, SCM also have several distinctions from the BM: 1) With the exception of succinate, SCM show significantly lower rates of respiration with all substrates studied; 2) immunoblotting analysis showed that this may be due to 30-40% lower contents of respiratory enzymes and porin; 3) compared with BM, SCM sequestered 40-50% less Ca(2+), and the total tissue calcium content was 8 times higher in the spinal cord; 4) normalization for mitochondria from 1 g of tissue showed that BM can sequester several times more Ca(2+) than was available in the brain tissue, whereas SCM had the capacity to sequester only 10-20% of the total tissue Ca(2+); and 5) with succinate and succinate-containing substrate mixtures, SCM showed significantly higher state 4 respiration than BM and generated more ROS associated with the reverse electron transport. We conclude that SCM have an intrinsically higher risk of oxidative damage and overload with calcium than BM, and thus spinal cord may be more vulnerable under some pathologic conditions. (250).
Assuntos
Encéfalo/metabolismo , Encéfalo/patologia , Mitocôndrias/metabolismo , Medula Espinal/metabolismo , Medula Espinal/patologia , Animais , Apoptose/fisiologia , Cálcio/metabolismo , Respiração Celular/fisiologia , Glutamatos/metabolismo , Malatos/metabolismo , Masculino , Modelos Animais , Neurônios/metabolismo , Neurônios/patologia , Piruvatos/metabolismo , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismoRESUMO
OBJECTIVE: To evaluate safety, dose response, and preliminary efficacy of reldesemtiv over 12 weeks in patients with amyotrophic lateral sclerosis (ALS). Methods: Patients (≤2 years since diagnosis) with slow upright vital capacity (SVC) of ≥60% were randomized 1:1:1:1 to reldesemtiv 150, 300, or 450 mg twice daily (bid) or placebo; active treatment was 12 weeks with 4-week follow-up. Primary endpoint was change in percent predicted SVC at 12 weeks; secondary measures included ALS Functional Rating Scale-Revised (ALSFRS-R) and muscle strength mega-score. Results: Patients (N = 458) were enrolled; 85% completed 12-week treatment. The primary analysis failed to reach statistical significance (p = 0.11); secondary endpoints showed no statistically significant effects (ALSFRS-R, p = 0.09; muscle strength mega-score, p = 0.31). Post hoc analyses pooling all active reldesemtiv-treated patients compared against placebo showed trends toward benefit in all endpoints (progression rate for SVC, ALSFRS-R, and muscle strength mega-score (nominal p values of 0.10, 0.01 and 0.20 respectively)). Reldesemtiv was well tolerated, with nausea and fatigue being the most common side effects. A dose-dependent decrease in estimated glomerular filtration rate was noted, and transaminase elevations were seen in approximately 5% of patients. Both hepatic and renal abnormalities trended toward resolution after study drug discontinuation. Conclusions: Although the primary efficacy analysis did not demonstrate statistical significance, there were trends favoring reldesemtiv for all three endpoints, with effect sizes generally regarded as clinically important. Tolerability was good; modest hepatic and renal abnormalities were reversible. The impact of reldesemtiv on patients with ALS should be assessed in a pivotal Phase 3 trial. (ClinicalTrials.gov Identifier: NCT03160898).
Assuntos
Esclerose Lateral Amiotrófica , Esclerose Lateral Amiotrófica/tratamento farmacológico , Método Duplo-Cego , Humanos , Força MuscularRESUMO
The cluster of neurodegenerative disorders in the western Pacific termed amyotrophic lateral sclerosis-parkinsonism dementia complex (ALS-PDC) has been repeatedly linked to the use of seeds of various species of cycad. Identification and chemical synthesis of the most toxic compounds in the washed cycad seeds, a variant phytosteryl glucosides, and even more toxic cholesterol ß-D-glucoside (CG), which is produced by the human parasite Helicobacter pylori, provide a possibility to study in vitro the mechanisms of toxicity of these compounds. We studied in detail the effects of CG on the respiratory activities and generation of reactive oxygen species (ROS) by nonsynaptic brain and heart mitochondria oxidizing various substrates. The stimulatory effects of CG on respiration and ROS generation showed strong substrate dependence, suggesting involvement of succinate dehydrogenase (complex II). Maximal effects on ROS production were observed with 1 µmol CG/1 mg mitochondria. At this concentration the cycad toxins ß-sitosterol-ß-D-glucoside and stigmasterol-ß-D-glucoside had effects on respiration and ROS production similar to CG. However, poor solubility precluded full concentration analysis of these toxins. Cholesterol, stigmasterol and ß-sitosterol had no effect on mitochondrial functions studied at concentrations up to 100 µmol/mg protein. Our results suggest that CG may influence mitochondrial functions through changes in the packing of the bulk membrane lipids, as was shown earlier by Deliconstantinos et al. (Biochem Cell Biol 67:16-24, 1989). The neurotoxic effects of phytosteryl glucosides and CG may be associated with increased oxidative damage of neurons. Unlike heart mitochondria, in activated neurons mitochondria specifically increase ROS production associated with succinate oxidation (Panov et al., J Biol Chem 284:14448-14456, 2009).
Assuntos
Encéfalo/metabolismo , Colesterol/farmacologia , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Animais , Respiração Celular/efeitos dos fármacos , Colesterol/análogos & derivados , Dimetil Sulfóxido/farmacologia , Glucosídeos/farmacologia , Peróxido de Hidrogênio/metabolismo , Técnicas In Vitro , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Sitosteroides/farmacologia , Estigmasterol/análogos & derivados , Estigmasterol/farmacologiaRESUMO
OBJECTIVES: To determine the feasibility, tolerability, safety, and exercise treatment-effect size of repetitive rhythmic exercise mediated by supported treadmill ambulation training (STAT) for patients with amyotrophic lateral sclerosis (ALS). DESIGN: Interventional with repeated-measures design. SETTING: Multidisciplinary ALS clinic at academic medical center. PARTICIPANTS: Convenience sample of patients with ALS (N=9) who were ambulatory with assistive devices (Sinaki-Mulder stages II-III). INTERVENTIONS: Repetitive rhythmic exercise-STAT (30min total; 5min of exercise intercalated with 5min of rest) performed 3 times a week for 8 weeks. MAIN OUTCOME MEASURE: ALS Functional Rating Scale-Revised (ALSFRS-R), percentage of predicted vital capacity (VC), total lower-extremities manual muscle test (MMT), rate of perceived exertion (RPE), Fatigue Severity Scale (FSS), and maximum voluntary isometric contraction (MVIC) in 10 lower and 10 upper extremities. Gait performance, which included walking distance, speed, steps, and stride length, was evaluated during treadmill and ground 6-minute walk tests (6MWTs) and 25-foot walk test (25FWT). RESULTS: Feasibility issues decreased screened participants by 4 patients (31%). Nine patients were enrolled, but 6 patients (67%) completed the study and 3 (23% of original cohort; 33% of enrolled cohort) could not complete the exercise intervention because of non-ALS-related medical problems. Tolerability of the intervention measures during the treadmill 6MWT showed improvement in RPE (P≤.05) and FSS score (P≥.05). Safety measures (ALSFRS-R, VC, MMT) showed no decrease and showed statistical improvement in ALSFRS-R score (P≤.05) during the study interval. Exercise treatment-effect size showed variable improvements. Gait speed, distance, and stride length during the treadmill 6MWT improved significantly (P≤.05) after 4 weeks and improvements were maintained after 8 weeks compared with baseline. Walking distance during the ground 6MWT increased significantly after 4 weeks and was maintained after 8 weeks compared with baseline (P≤.05). Walking speed during the 25FWT and lower-extremity MVIC improved, but were not statistically significant. CONCLUSIONS: Repetitive rhythmic exercise-STAT is feasible, tolerated, and safe for patients with ALS. Repetitive rhythmic exercise-STAT treatment-effect size across a number of ALS-related measures was consistent with improved work capacity and gait function in patients with ALS who are dependent on assistive devices for ambulation. Repetitive rhythmic exercise-STAT should be evaluated further in larger studies to determine the stability of this improved function in relation to the rate of progression of the underlying ALS.
Assuntos
Esclerose Lateral Amiotrófica/reabilitação , Terapia por Exercício/métodos , Atividades Cotidianas , Adulto , Idoso , Esclerose Lateral Amiotrófica/fisiopatologia , Análise de Variância , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Desempenho Psicomotor , Resultado do Tratamento , CaminhadaRESUMO
OBJECTIVE: Evaluate the safety and tolerability of resistance and endurance exercise in ALS participants as measured by their ability to complete this six-month study. METHODS: Participants were randomized to Resistance, Endurance, or Stretching/Range of Motion (SROM the exercise regimen prescribed for most ALS patients) exercises. All exercises were performed at home with an individualized regimen designed by a physical therapist trained in ALS management. Primary outcome measures were tolerability of the exercises at 24 weeks defined by 50% of participants completing at least 50% of the prescribed exercise regimen. Secondary outcome measures included the ALSFRS-R, pulmonary FVC, and other measures of ALS function. RESULTS: At 12 and 24 weeks, all three exercise regimens were tolerated according to our pre-specified criteria. Compliance to the prescribed exercise regimen was the highest in the resistance and SROM arms of the study. All three forms of exercise were considered safe as there were no differences in the rates of disease progression among groups. There were no differences in the secondary outcome measures and feasibility for evaluating these measures was successful. In a post-hoc analysis, there was a trend towards fewer falls in the Resistance and Endurance groups. CONCLUSIONS: This study demonstrates that SROM, resistance, and endurance exercise are all safe to be performed with the specified regimen without any worsening of outcomes as related to ALS function. All three forms of exercise were tolerated with resistance and SROM exercises showing the highest compliance over the 24 week-period.
Assuntos
Esclerose Lateral Amiotrófica/fisiopatologia , Esclerose Lateral Amiotrófica/reabilitação , Terapia por Exercício/métodos , Resistência Física/fisiologia , Idoso , Progressão da Doença , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde , Consumo de Oxigênio/fisiologia , Cooperação do Paciente , Estudos Retrospectivos , Escala Visual AnalógicaRESUMO
OBJECTIVE: The aim of this Symposium was to develop a consensus based, bulbar assessment protocol for implementation within NEALS clinics. METHODS: A one-day symposium, held in April 2017, was organized into Speech and Swallowing sections to establish summary recommendations for the assessment of bulbar dysfunction within each group. RESULTS: Summary recommendations included speech referrals and AAC evaluations at initial visit, CNS-BFS, maximum sustained phonation, and speaking rate. Dysarthria evaluation included the speech subsystem involvement of respiration, phonation, resonance, and articulation. Specific recommendations for swallowing were established for each of the following domains: dietary/oral intake, airway defense physiologic capacity, swallow safety screen, patient-reported swallow-related outcomes, oral sensorimotor exam, and pulmonary function. Practice parameters focused upon patient education and unresolved questions included the use of videofluoscopy, monitoring diet progression, and swallow safety screening. CONCLUSIONS: The working goal is to establish a clinical bulbar protocol, designed to be incorporated within ALS clinics and ultimately to formulate a best practice set of bulbar ALS guidelines, available for implementation throughout the international ALS community.
Assuntos
Esclerose Lateral Amiotrófica/complicações , Transtornos de Deglutição/diagnóstico , Transtornos de Deglutição/etiologia , Disartria/diagnóstico , Disartria/etiologia , Distúrbios da Fala/etiologia , Progressão da Doença , Feminino , Humanos , Masculino , Estudos Retrospectivos , Índice de Gravidade de Doença , Distúrbios da Fala/diagnósticoRESUMO
Uncontrollable episodes of emotional expression occur in a variety of neurological conditions. This emotional disinhibition syndrome is characterized by episodes of crying or laughing that are unrelated to or out of proportion to the eliciting stimulus. This syndrome is common among patients with amyotrophic lateral sclerosis, multiple sclerosis, stroke, and traumatic brain injury and a variety of terms and definitions have been used to describe it. The confusing nomenclature has been a barrier to understanding, diagnosis, and treatment of this disorder. The authors propose a unifying term, involuntary emotional expression disorder (IEED), and provide diagnostic criteria for this disorder.
Assuntos
Depressão/diagnóstico , Depressão/psicologia , Emoções Manifestas , Volição , Choro , Diagnóstico Diferencial , Humanos , EstereotipagemRESUMO
Amyotrophic lateral sclerosis (ALS) is one of the most rapidly progressive neurodegenerative diseases of unknown cause. Riluzole is the only drug that slows disease progression. More than 50 randomised controlled trials (RCTs) of proposed disease-modifying drugs have failed to show positive results in the past half-century. In the past decade, at least 18 drugs have been tested in large phase 2 or 3 RCTs, including lithium, which was tested in several RCTs. Potential reasons for the negative results can be classified into three categories: first, issues regarding trial rationale and preclinical study results; second, pharmacological issues; and third, clinical trial design and methodology issues. Clinical trials for stem cell therapy and RCTs targeting pharmacological or non-pharmacological symptomatic treatment in ALS are examples of areas that need novel design strategies. Only through critical analyses of the failed trials can new and important suggestions be identified for the future success of clinical trials in ALS.
Assuntos
Esclerose Lateral Amiotrófica/terapia , Fármacos Neuroprotetores/uso terapêutico , Ensaios Clínicos Controlados Aleatórios como Assunto/normas , Riluzol/uso terapêutico , Transplante de Células-Tronco/normas , Esclerose Lateral Amiotrófica/diagnóstico , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto/tendências , Transplante de Células-Tronco/tendênciasRESUMO
Our objective was to compare the phase II and phase III (EMPOWER) studies of dexpramipexole in ALS and evaluate potential EMPOWER responder subgroups and biomarkers based on significant inter-study population differences. In a post hoc analysis, we compared the baseline population characteristics of both dexpramipexole studies and analyzed EMPOWER efficacy outcomes and laboratory measures in subgroups defined by significant inter-study differences. Results showed that, compared with phase II, the proportion of El Escorial criteria (EEC) definite participants decreased (p = 0.005), riluzole use increased (p = 0.002), and mean symptom duration increased (p = 0.037) significantly in EMPOWER. Baseline creatinine (p < 0.001) and on-study creatinine change (p < 0.001) correlated significantly with ALSFRS-R in EMPOWER. In the EMPOWER subgroup defined by EEC-definite ALS, riluzole use, and < median symptom duration (15.3 months), dexpramipexole-treated participants had reduced ALSFRS-R slope decline (p = 0.015), decreased mortality (p = 0.011), and reduced creatinine loss (p = 0.003). In conclusion, significant differences existed between the phase II and EMPOWER study populations in ALS clinical trials of dexpramipexole. In a post hoc analysis of EMPOWER subgroups defined by these differences, potential clinical benefits of dexpramipexole were identified in the subgroup of riluzole-treated, short-symptom duration, EEC-definite ALS participants. Creatinine loss correlated with disease progression and was reduced in dexpramipexole-treated participants, suggesting it as a candidate biomarker.
Assuntos
Antagonistas Adrenérgicos beta/uso terapêutico , Esclerose Lateral Amiotrófica/tratamento farmacológico , Esclerose Lateral Amiotrófica/metabolismo , Creatinina/metabolismo , Propranolol/uso terapêutico , Ensaios Clínicos Fase II como Assunto , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Fármacos Neuroprotetores/uso terapêutico , Riluzol/uso terapêutico , Índice de Gravidade de Doença , Resultado do TratamentoRESUMO
Two decades after the discovery that 20% of familial amyotrophic lateral sclerosis (ALS) cases were linked to mutations in the superoxide dismutase-1 (SOD1) gene, a substantial proportion of the remainder of cases of familial ALS have now been traced to an expansion of the intronic hexanucleotide repeat sequence in C9orf72. This breakthrough provides an opportunity to re-evaluate longstanding concepts regarding the cause and natural history of ALS, coming soon after the pathological unification of ALS with frontotemporal dementia through a shared pathological signature of cytoplasmic inclusions of the ubiquitinated protein TDP-43. However, with profound clinical, prognostic, neuropathological, and now genetic heterogeneity, the concept of ALS as one disease appears increasingly untenable. This background calls for the development of a more sophisticated taxonomy, and an appreciation of ALS as the breakdown of a wider network rather than a discrete vulnerable population of specialised motor neurons. Identification of C9orf72 repeat expansions in patients without a family history of ALS challenges the traditional division between familial and sporadic disease. By contrast, the 90% of apparently sporadic cases and incomplete penetrance of several genes linked to familial cases suggest that at least some forms of ALS arise from the interplay of multiple genes, poorly understood developmental, environmental, and age-related factors, as well as stochastic events.
Assuntos
Esclerose Lateral Amiotrófica , Esclerose Lateral Amiotrófica/etiologia , Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/fisiopatologia , Animais , HumanosRESUMO
BACKGROUND: Sporadic amyotrophic lateral sclerosis (sALS) is a motor neuron disease with poorly understood etiology. Results of gene expression profiling studies of whole blood from ALS patients have not been validated and are difficult to relate to ALS pathogenesis because gene expression profiles depend on the relative abundance of the different cell types present in whole blood. We conducted microarray analyses using Agilent Human Whole Genome 4 × 44k Arrays on a more homogeneous cell population, namely purified peripheral blood lymphocytes (PBLs), from ALS patients and healthy controls to identify molecular signatures possibly relevant to ALS pathogenesis. METHODS: Differentially expressed genes were determined by LIMMA (Linear Models for MicroArray) and SAM (Significance Analysis of Microarrays) analyses. The SAFE (Significance Analysis of Function and Expression) procedure was used to identify molecular pathway perturbations. Proteasome inhibition assays were conducted on cultured peripheral blood mononuclear cells (PBMCs) from ALS patients to confirm alteration of the Ubiquitin/Proteasome System (UPS). RESULTS: For the first time, using SAFE in a global gene ontology analysis (gene set size 5-100), we show significant perturbation of the KEGG (Kyoto Encyclopedia of Genes and Genomes) ALS pathway of motor neuron degeneration in PBLs from ALS patients. This was the only KEGG disease pathway significantly upregulated among 25, and contributing genes, including SOD1, represented 54% of the encoded proteins or protein complexes of the KEGG ALS pathway. Further SAFE analysis, including gene set sizes >100, showed that only neurodegenerative diseases (4 out of 34 disease pathways) including ALS were significantly upregulated. Changes in UBR2 expression correlated inversely with time since onset of disease and directly with ALSFRS-R, implying that UBR2 was increased early in the course of ALS. Cultured PBMCs from ALS patients accumulated more ubiquitinated proteins than PBMCs from healthy controls in a serum-dependent manner confirming changes in this pathway. CONCLUSIONS: Our study indicates that PBLs from sALS patients are strong responders to systemic signals or local signals acquired by cell trafficking, representing changes in gene expression similar to those present in brain and spinal cord of sALS patients. PBLs may provide a useful means to study ALS pathogenesis.
Assuntos
Esclerose Lateral Amiotrófica/genética , Perfilação da Expressão Gênica/métodos , Leucócitos Mononucleares/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Idoso , Esclerose Lateral Amiotrófica/sangue , Esclerose Lateral Amiotrófica/enzimologia , Estudos de Casos e Controles , Separação Celular , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Técnicas de Amplificação de Ácido Nucleico , Inibidores de Proteases/farmacologia , Complexo de Endopeptidases do Proteassoma/metabolismo , Inibidores de Proteassoma , RNA Mensageiro/genética , RNA Mensageiro/isolamento & purificação , Ubiquitina/metabolismoRESUMO
Although [(18)F]fluoro-L: -dopa [FDOPA] positron emission tomography (PET) has been used as a surrogate outcome measure in Parkinson's disease therapeutic trials, this biomarker has not been proven to reflect clinical status longitudinally. We completed a retrospective analysis of relationships between computerized sampling of motor performance, FDOPA PET, and clinical outcome scales, repeated over 4 years, in 26 Parkinson's disease (PD) patients and 11 healthy controls. Mixed effects analyses showed that movement time and tongue strength best differentiated PD from control subjects. In the treated PD cohort, motor performance measures changed gradually in contrast to a steady decline in striatal FDOPA uptake. Prolonged reaction and movement time were related to lower caudate nucleus FDOPA uptake, and abnormalities in hand fine force control were related to mean striatal FDOPA uptake. These findings provide evidence that regional loss of nigrostriatal inputs to frontostriatal networks affects specific aspects of motor function.
Assuntos
Corpo Estriado/diagnóstico por imagem , Corpo Estriado/metabolismo , Di-Hidroxifenilalanina/análogos & derivados , Doença de Parkinson/diagnóstico por imagem , Doença de Parkinson/metabolismo , Desempenho Psicomotor/fisiologia , Compostos Radiofarmacêuticos , Idoso , Envelhecimento/fisiologia , Antiparkinsonianos/uso terapêutico , Carbidopa/uso terapêutico , Núcleo Caudado/diagnóstico por imagem , Núcleo Caudado/metabolismo , Di-Hidroxifenilalanina/farmacocinética , Feminino , Força da Mão/fisiologia , Humanos , Contração Isométrica/fisiologia , Levodopa/uso terapêutico , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Força Muscular/fisiologia , Testes Neuropsicológicos , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos/farmacocinética , Tempo de Reação/fisiologia , Estudos Retrospectivos , Caracteres Sexuais , Língua/fisiologiaRESUMO
OBJECTIVE: A number of neuromuscular conditions may lead to a dropped head syndrome (DHS), with some patients developing a late onset noninflammatory myopathy affecting only, or predominantly, neck extensor muscles (NEM). The cause, pathogenesis, and nosological classification of this condition are unclear. To further investigate this condition, the authors evaluated the clinical, electrodiagnostic and pathologic findings in seven patients with a myopathic DHS. DESIGN: Analysis of clinical data, electrodiagnostic studies, and muscle biopsies of seven patients, including one set of identical twins, who developed a very late onset myopathy with severe NEM weakness. RESULTS: Age of onset was 61-79 yrs, with the pair of identical twins developing NEM weakness within 1 yr of each other (ages 63 and 64, respectively). Seven patients developed weakness (six slight weakness and one more severe) in muscles other than NEM. The group was characterized by the electromyography (EMG) showing a "myopathic" pattern in cervical paraspinal muscles (7/7), muscle biopsies with nonspecific myopathic changes on histologic stains (7/7), marked abnormalities in NADH dehydrogenase-reacted sections (6/7), desmin-positive sarcoplasmic deposits (1/7), low carnitine levels by biochemical assays (2/7), and mitochondrial changes (3/7). CONCLUSIONS: Myopathic DHS encompasses a wide spectrum of conditions that strongly affect NEM; however, as documented in the monozygotic twins, some patients may suffer from a distinct, genetically determined form of late-onset restricted myopathy leading clinically to DHS.