Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 23
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Nat Commun ; 12(1): 4908, 2021 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-34389711

RESUMO

C9ORF72 hexanucleotide GGGGCC repeat expansion is the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Repeat-containing RNA mediates toxicity through nuclear granules and dipeptide repeat (DPR) proteins produced by repeat-associated non-AUG translation. However, it remains unclear how the intron-localized repeats are exported and translated in the cytoplasm. We use single molecule imaging approach to examine the molecular identity and spatiotemporal dynamics of the repeat RNA. We demonstrate that the spliced intron with G-rich repeats is stabilized in a circular form due to defective lariat debranching. The spliced circular intron, instead of pre-mRNA, serves as the translation template. The NXF1-NXT1 pathway plays an important role in the nuclear export of the circular intron and modulates toxic DPR production. This study reveals an uncharacterized disease-causing RNA species mediated by repeat expansion and demonstrates the importance of RNA spatial localization to understand disease etiology.


Assuntos
Proteína C9orf72/genética , Núcleo Celular/metabolismo , Íntrons/genética , Biossíntese de Proteínas/genética , RNA/genética , Transporte Ativo do Núcleo Celular/genética , Esclerose Amiotrófica Lateral/genética , Esclerose Amiotrófica Lateral/metabolismo , Proteína C9orf72/metabolismo , Linhagem Celular Tumoral , Núcleo Celular/genética , Expansão das Repetições de DNA/genética , Dipeptídeos/genética , Dipeptídeos/metabolismo , Demência Frontotemporal/genética , Demência Frontotemporal/metabolismo , Predisposição Genética para Doença/genética , Células HEK293 , Humanos , Microscopia de Fluorescência , Proteínas de Transporte Nucleocitoplasmático/genética , Proteínas de Transporte Nucleocitoplasmático/metabolismo , RNA/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais/genética
2.
Neurology ; 95(1): e59-e69, 2020 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-32385188

RESUMO

OBJECTIVE: To identify preferred neurofilament assays and clinically validate serum neurofilament light (NfL) and phosphorylated neurofilament heavy (pNfH) as prognostic and potential pharmacodynamic biomarkers relevant to amyotrophic lateral sclerosis (ALS) therapy development. METHODS: In this prospective, multicenter, longitudinal observational study of patients with ALS (n = 229), primary lateral sclerosis (n = 20), and progressive muscular atrophy (n = 11), biological specimens were collected, processed, and stored according to strict standard operating procedures (SOPs). Neurofilament assays were performed in a blinded manner by independent contract research organizations. RESULTS: For serum NfL and pNfH measured using the Simoa assay, there were no missing data (i.e., technical replicates below the lower limit of detection were not encountered). For the Iron Horse and Euroimmun pNfH assays, such missingness was encountered in ∼4% and ∼10% of serum samples, respectively. Mean coefficients of variation for NfL in serum and CSF were both ∼3%. Mean coefficients of variation for pNfH in serum and CSF were ∼4%-5% and ∼2%-3%, respectively, in all assays. Baseline serum NfL concentration, but not pNfH, predicted the future Revised ALS Functional Rating Scale (ALSFRS-R) slope and survival. Incorporation of baseline serum NfL into mixed effects models of ALSFRS-R slopes yields an estimated sample size saving of ∼8%. Depending on the method used to estimate effect size, use of serum NfL (and perhaps pNfH) as pharmacodynamic biomarkers, instead of the ALSFRS-R slope, yields significantly larger sample size savings. CONCLUSIONS: Serum NfL may be considered a clinically validated prognostic biomarker for ALS. Serum NfL (and perhaps pNfH), quantified using the Simoa assay, has potential utility as a pharmacodynamic biomarker of treatment effect.


Assuntos
Esclerose Amiotrófica Lateral/sangue , Biomarcadores/sangue , Filamentos Intermediários/metabolismo , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico
3.
Cell Rep ; 29(5): 1164-1177.e5, 2019 10 29.
Artigo em Inglês | MEDLINE | ID: mdl-31665631

RESUMO

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by the progressive loss of motor neurons. While several pathogenic mutations have been identified, the vast majority of ALS cases have no family history of disease. Thus, for most ALS cases, the disease may be a product of multiple pathways contributing to varying degrees in each patient. Using machine learning algorithms, we stratify the transcriptomes of 148 ALS postmortem cortex samples into three distinct molecular subtypes. The largest cluster, identified in 61% of patient samples, displays hallmarks of oxidative and proteotoxic stress. Another 19% of the samples shows predominant signatures of glial activation. Finally, a third group (20%) exhibits high levels of retrotransposon expression and signatures of TARDBP/TDP-43 dysfunction. We further demonstrate that TDP-43 (1) directly binds a subset of retrotransposon transcripts and contributes to their silencing in vitro, and (2) pathological TDP-43 aggregation correlates with retrotransposon de-silencing in vivo.


Assuntos
Esclerose Amiotrófica Lateral/classificação , Esclerose Amiotrófica Lateral/patologia , Córtex Cerebral/patologia , Neuroglia/patologia , Estresse Oxidativo , Mudanças Depois da Morte , Retroelementos/genética , Esclerose Amiotrófica Lateral/genética , Biomarcadores/metabolismo , Linhagem Celular , Estudos de Coortes , Proteínas de Ligação a DNA/metabolismo , Regulação da Expressão Gênica , Inativação Gênica , Humanos , Estresse Oxidativo/genética , Ligação Proteica/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transdução de Sinais/genética
5.
Mob DNA ; 10: 32, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31372185

RESUMO

Transposable Elements (TEs) are mobile genetic elements whose sequences constitute nearly half of the human genome. Each TE copy can be present in hundreds to thousands of locations within the genome, complicating the genetic and genomic studies of these highly repetitive sequences. The recent development of better tools for evaluating TE derived sequences in genomic studies has enabled an increasing appreciation for the contribution of TEs to human development and disease. While some TEs have contributed novel and beneficial host functions, this review will summarize the evidence for detrimental TE activity in neurodegenerative disorders. Much of the evidence for pathogenicity implicates endogenous retroviruses (ERVs), a subset of TEs that entered the genome by retroviral infections of germline cells in our evolutionary ancestors and have since been passed down as a substantial fraction of the human genome. Human specific ERVs (HERVs) represent some of the youngest ERVs in the genome, and thus are presumed to retain greater function and resultant pathogenic potential.

6.
Mob DNA ; 9: 35, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30564290

RESUMO

Background: Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease involving loss of motor neurons and having no known cure and uncertain etiology. Several studies have drawn connections between altered retrotransposon expression and ALS. Certain features of the LINE-1 (L1) retrotransposon-encoded ORF1 protein (ORF1p) are analogous to those of neurodegeneration-associated RNA-binding proteins, including formation of cytoplasmic aggregates. In this study we explore these features and consider possible links between L1 expression and ALS. Results: We first considered factors that modulate aggregation and subcellular distribution of LINE-1 ORF1p, including nuclear localization. Changes to some ORF1p amino acid residues alter both retrotransposition efficiency and protein aggregation dynamics, and we found that one such polymorphism is present in endogenous L1s abundant in the human genome. We failed, however, to identify CRM1-mediated nuclear export signals in ORF1p nor strict involvement of cell cycle in endogenous ORF1p nuclear localization in human 2102Ep germline teratocarcinoma cells. Some proteins linked with ALS bind and colocalize with L1 ORF1p ribonucleoprotein particles in cytoplasmic RNA granules. Increased expression of several ALS-associated proteins, including TAR DNA Binding Protein (TDP-43), strongly limits cell culture retrotransposition, while some disease-related mutations modify these effects. Using quantitative reverse transcription PCR (RT-qPCR) of ALS tissues and reanalysis of publicly available RNA-Seq datasets, we asked if changes in expression of retrotransposons are associated with ALS. We found minimal altered expression in sporadic ALS tissues but confirmed a previous report of differential expression of many repeat subfamilies in C9orf72 gene-mutated ALS patients. Conclusions: Here we extended understanding of the subcellular localization dynamics of the aggregation-prone LINE-1 ORF1p RNA-binding protein. However, we failed to find compelling evidence for misregulation of LINE-1 retrotransposons in sporadic ALS nor a clear effect of ALS-associated TDP-43 protein on L1 expression. In sum, our study reveals that the interplay of active retrotransposons and the molecular features of ALS are more complex than anticipated. Thus, the potential consequences of altered retrotransposon activity for ALS and other neurodegenerative disorders are worthy of continued investigation.

7.
Mol Neurodegener ; 13(1): 39, 2018 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-30068350

RESUMO

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder. About 90% of ALS cases are without a known genetic cause. The human endogenous retrovirus multi-copy HERV-K(HML-2) group was recently reported to potentially contribute to neurodegeneration and disease pathogenesis in ALS because of transcriptional upregulation and toxic effects of HML-2 Envelope (Env) protein. Env and other proteins are encoded by some transcriptionally active HML-2 loci. However, more detailed information is required regarding which HML-2 loci are transcribed in ALS, which of their proteins are expressed, and differences between the disease and non-disease states. METHODS: For brain and spinal cord tissue samples from ALS patients and controls, we identified transcribed HML-2 loci by generating and mapping HML-2-specific cDNA sequences. We predicted expression of HML-2 env gene-derived proteins based on the observed cDNA sequences. Furthermore, we determined overall HML-2 transcript levels by RT-qPCR and investigated presence of HML-2 Env protein in ALS and control tissue samples by Western blotting. RESULTS: We identified 24 different transcribed HML-2 loci. Some of those loci are transcribed at relatively high levels. However, significant differences in HML-2 loci transcriptional activities were not seen when comparing ALS and controls. Likewise, overall HML-2 transcript levels, as determined by RT-qPCR, were not significantly different between ALS and controls. Indeed, we were unable to detect full-length HML-2 Env protein in ALS and control tissue samples despite reasonable sensitivity. Rather our analyses suggest that a number of HML-2 protein variants other than full-length Env may potentially be expressed in ALS patients. CONCLUSIONS: Our results expand and refine recent publications on HERV-K(HML-2) and ALS. Some of our results are in conflict with recent findings and call for further specific analyses. Our profiling of HML-2 transcription in ALS opens up the possibility that HML-2 proteins other than canonical full-length Env may have to be considered when studying the role of HML-2 in ALS disease.


Assuntos
Esclerose Amiotrófica Lateral/virologia , Retrovirus Endógenos , Proteínas de Membrana/biossíntese , Superantígenos/biossíntese , Perfilação da Expressão Gênica , Humanos , Provírus , Transcriptoma
8.
Sci Rep ; 7: 41141, 2017 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-28120938

RESUMO

Previously, we found that human Cu, Zn-superoxide dismutase (SOD1) is S-acylated (palmitoylated) in vitro and in amyotrophic lateral sclerosis (ALS) mouse models, and that S-acylation increased for ALS-causing SOD1 mutants relative to wild type. Here, we use the acyl resin-assisted capture (acyl-RAC) assay to demonstrate S-acylation of SOD1 in human post-mortem spinal cord homogenates from ALS and non-ALS subjects. Acyl-RAC further revealed that endogenous copper chaperone for SOD1 (CCS) is S-acylated in both human and mouse spinal cords, and in vitro in HEK293 cells. SOD1 and CCS formed a highly stable heterodimer in human spinal cord homogenates that was resistant to dissociation by boiling, denaturants, or reducing agents and was not observed in vitro unless both SOD1 and CCS were overexpressed. Cysteine mutations that attenuate SOD1 maturation prevented the SOD1-CCS heterodimer formation. The degree of S-acylation was highest for SOD1-CCS heterodimers, intermediate for CCS monomers, and lowest for SOD1 monomers. Given that S-acylation facilitates anchoring of soluble proteins to cell membranes, our findings suggest that S-acylation and membrane localization may play an important role in CCS-mediated SOD1 maturation. Furthermore, the highly stable S-acylated SOD1-CCS heterodimer may serve as a long-lived maturation intermediate in human spinal cord.


Assuntos
Esclerose Amiotrófica Lateral/metabolismo , Chaperonas Moleculares/metabolismo , Multimerização Proteica , Processamento de Proteína Pós-Traducional , Medula Espinal/metabolismo , Superóxido Dismutase-1/metabolismo , Acilação , Esclerose Amiotrófica Lateral/genética , Animais , Estudos de Casos e Controles , Células HEK293 , Humanos , Camundongos , Mutação , Ligação Proteica , Estabilidade Proteica , Superóxido Dismutase-1/genética
9.
Acta Neuropathol ; 132(6): 827-840, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27704280

RESUMO

Evidence of misfolded wild-type superoxide dismutase 1 (SOD1) has been detected in spinal cords of sporadic ALS (sALS) patients, suggesting an etiological relationship to SOD1-associated familial ALS (fALS). Given that there are currently a number of promising therapies under development that target SOD1, it is of critical importance to better understand the role of misfolded SOD1 in sALS. We previously demonstrated the permissiveness of the G85R-SOD1:YFP mouse model for MND induction following injection with tissue homogenates from paralyzed transgenic mice expressing SOD1 mutations. This prompted us to examine whether WT SOD1 can self-propagate misfolding of the G85R-SOD1:YFP protein akin to what has been observed with mutant SOD1. Using the G85R-SOD1:YFP mice, we demonstrate that misfolded conformers of recombinant WT SOD1, produced in vitro, induce MND with a distinct inclusion pathology. Furthermore, the distinct pathology remains upon successive passages in the G85R-SOD1:YFP mice, strongly supporting the notion for conformation-dependent templated propagation and SOD1 strains. To determine the presence of a similar misfolded WT SOD1 conformer in sALS tissue, we screened homogenates from patients diagnosed with sALS, fALS, and non-ALS disease in an organotypic spinal cord slice culture assay. Slice cultures from G85R-SOD1:YFP mice exposed to spinal homogenates from patients diagnosed with ALS caused by the A4V mutation in SOD1 developed robust inclusion pathology, whereas spinal homogenates from more than 30 sALS cases and various controls failed. These findings suggest that mutant SOD1 has prion-like attributes that do not extend to SOD1 in sALS tissues.


Assuntos
Esclerose Amiotrófica Lateral/genética , Superóxido Dismutase-1/genética , Amiloide/genética , Amiloide/metabolismo , Esclerose Amiotrófica Lateral/diagnóstico , Esclerose Amiotrófica Lateral/patologia , Análise de Variância , Animais , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Modelos Animais de Doenças , Humanos , Técnicas In Vitro , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Camundongos , Camundongos Transgênicos , Microscopia Eletrônica , Mutação/genética , Técnicas de Cultura de Órgãos , Dobramento de Proteína , Deficiências na Proteostase/diagnóstico , Deficiências na Proteostase/genética , Medula Espinal/metabolismo , Medula Espinal/patologia , Medula Espinal/ultraestrutura , Superóxido Dismutase-1/metabolismo
11.
J Neurosci ; 35(42): 14286-306, 2015 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-26490867

RESUMO

UNLABELLED: Misfolded proteins accumulate and aggregate in neurodegenerative disease. The existence of these deposits reflects a derangement in the protein homeostasis machinery. Using a candidate gene screen, we report that loss of RAD-23 protects against the toxicity of proteins known to aggregate in amyotrophic lateral sclerosis. Loss of RAD-23 suppresses the locomotor deficit of Caenorhabditis elegans engineered to express mutTDP-43 or mutSOD1 and also protects against aging and proteotoxic insults. Knockdown of RAD-23 is further neuroprotective against the toxicity of SOD1 and TDP-43 expression in mammalian neurons. Biochemical investigation indicates that RAD-23 modifies mutTDP-43 and mutSOD1 abundance, solubility, and turnover in association with altering the ubiquitination status of these substrates. In human amyotrophic lateral sclerosis spinal cord, we find that RAD-23 abundance is increased and RAD-23 is mislocalized within motor neurons. We propose a novel pathophysiological function for RAD-23 in the stabilization of mutated proteins that cause neurodegeneration. SIGNIFICANCE STATEMENT: In this work, we identify RAD-23, a component of the protein homeostasis network and nucleotide excision repair pathway, as a modifier of the toxicity of two disease-causing, misfolding-prone proteins, SOD1 and TDP-43. Reducing the abundance of RAD-23 accelerates the degradation of mutant SOD1 and TDP-43 and reduces the cellular content of the toxic species. The existence of endogenous proteins that act as "anti-chaperones" uncovers new and general targets for therapeutic intervention.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Doença dos Neurônios Motores/genética , Mutação/genética , Interferência de RNA/fisiologia , Animais , Animais Geneticamente Modificados , Animais Recém-Nascidos , Caenorhabditis elegans , Proteínas de Caenorhabditis elegans/genética , Células Cultivadas , Proteínas de Ligação a DNA/metabolismo , Modelos Animais de Doenças , Regulação da Expressão Gênica/genética , Genótipo , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Humanos , Masculino , Camundongos , Atividade Motora/genética , Fotodegradação , Ratos , Ratos Sprague-Dawley
12.
Nature ; 525(7567): 56-61, 2015 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-26308891

RESUMO

The hexanucleotide repeat expansion (HRE) GGGGCC (G4C2) in C9orf72 is the most common cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Recent studies support an HRE RNA gain-of-function mechanism of neurotoxicity, and we previously identified protein interactors for the G4C2 RNA including RanGAP1. A candidate-based genetic screen in Drosophila expressing 30 G4C2 repeats identified RanGAP (Drosophila orthologue of human RanGAP1), a key regulator of nucleocytoplasmic transport, as a potent suppressor of neurodegeneration. Enhancing nuclear import or suppressing nuclear export of proteins also suppresses neurodegeneration. RanGAP physically interacts with HRE RNA and is mislocalized in HRE-expressing flies, neurons from C9orf72 ALS patient-derived induced pluripotent stem cells (iPSC-derived neurons), and in C9orf72 ALS patient brain tissue. Nuclear import is impaired as a result of HRE expression in the fly model and in C9orf72 iPSC-derived neurons, and these deficits are rescued by small molecules and antisense oligonucleotides targeting the HRE G-quadruplexes. Nucleocytoplasmic transport defects may be a fundamental pathway for ALS and FTD that is amenable to pharmacotherapeutic intervention.


Assuntos
Transporte Ativo do Núcleo Celular/genética , Núcleo Celular/metabolismo , Expansão das Repetições de DNA/genética , Fases de Leitura Aberta/genética , Proteínas/genética , Esclerose Amiotrófica Lateral/genética , Esclerose Amiotrófica Lateral/patologia , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Proteína C9orf72 , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/citologia , Drosophila melanogaster/metabolismo , Feminino , Demência Frontotemporal/genética , Demência Frontotemporal/patologia , Quadruplex G , Proteínas Ativadoras de GTPase/metabolismo , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/metabolismo , Neurônios/metabolismo , Neurônios/patologia , Poro Nuclear/química , Poro Nuclear/metabolismo , Proteínas Nucleares/metabolismo , Oligonucleotídeos Antissenso/genética , RNA/genética , RNA/metabolismo
13.
Proc Natl Acad Sci U S A ; 110(51): E4968-77, 2013 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-24248382

RESUMO

The finding that a GGGGCC (G4C2) hexanucleotide repeat expansion in the chromosome 9 ORF 72 (C9ORF72) gene is a common cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) links ALS/FTD to a large group of unstable microsatellite diseases. Previously, we showed that microsatellite expansion mutations can be bidirectionally transcribed and that these mutations express unexpected proteins by a unique mechanism, repeat-associated non-ATG (RAN) translation. In this study, we show that C9ORF72 antisense transcripts are elevated in the brains of C9ORF72 expansion-positive [C9(+)] patients, and antisense GGCCCC (G2C4) repeat-expansion RNAs accumulate in nuclear foci in brain. Additionally, sense and antisense foci accumulate in blood and are potential biomarkers of the disease. Furthermore, we show that RAN translation occurs from both sense and antisense expansion transcripts, resulting in the expression of six RAN proteins (antisense: Pro-Arg, Pro-Ala, Gly-Pro; and sense: Gly-Ala, Gly-Arg, Gly-Pro). These proteins accumulate in cytoplasmic aggregates in affected brain regions, including the frontal and motor cortex, hippocampus, and spinal cord neurons, with some brain regions showing dramatic RAN protein accumulation and clustering. The finding that unique antisense G2C4 RNA foci and three unique antisense RAN proteins accumulate in patient tissues indicates that bidirectional transcription of expanded alleles is a fundamental pathologic feature of C9ORF72 ALS/FTD. Additionally, these findings suggest the need to test therapeutic strategies that target both sense and antisense RNAs and RAN proteins in C9ORF72 ALS/FTD, and to more broadly consider the role of antisense expression and RAN translation across microsatellite expansion diseases.


Assuntos
Esclerose Amiotrófica Lateral/metabolismo , Encéfalo/metabolismo , Demência Frontotemporal/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Proteínas/metabolismo , RNA Antissenso/biossíntese , Proteína ran de Ligação ao GTP/metabolismo , Esclerose Amiotrófica Lateral/genética , Esclerose Amiotrófica Lateral/patologia , Encéfalo/patologia , Proteína C9orf72 , Núcleo Celular/genética , Núcleo Celular/metabolismo , Núcleo Celular/patologia , Feminino , Demência Frontotemporal/genética , Demência Frontotemporal/patologia , Células HEK293 , Humanos , Masculino , Proteínas do Tecido Nervoso/genética , Proteínas/genética , RNA Antissenso/genética , Sequências Repetitivas de Ácido Nucleico , Proteína ran de Ligação ao GTP/genética
14.
Nat Neurosci ; 16(5): 571-9, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23542689

RESUMO

Oligodendrocytes associate with axons to establish myelin and provide metabolic support to neurons. In the spinal cord of amyotrophic lateral sclerosis (ALS) mice, oligodendrocytes downregulate transporters that transfer glycolytic substrates to neurons and oligodendrocyte progenitors (NG2(+) cells) exhibit enhanced proliferation and differentiation, although the cause of these changes in oligodendroglia is unknown. We found extensive degeneration of gray matter oligodendrocytes in the spinal cord of SOD1 (G93A) ALS mice prior to disease onset. Although new oligodendrocytes were formed, they failed to mature, resulting in progressive demyelination. Oligodendrocyte dysfunction was also prevalent in human ALS, as gray matter demyelination and reactive changes in NG2(+) cells were observed in motor cortex and spinal cord of ALS patients. Selective removal of mutant SOD1 from oligodendroglia substantially delayed disease onset and prolonged survival in ALS mice, suggesting that ALS-linked genes enhance the vulnerability of motor neurons and accelerate disease by directly impairing the function of oligodendrocytes.


Assuntos
Esclerose Amiotrófica Lateral/complicações , Esclerose Amiotrófica Lateral/patologia , Degeneração Neural/etiologia , Oligodendroglia/patologia , Regeneração/fisiologia , Animais , Animais Recém-Nascidos , Proliferação de Células , Células Cultivadas , Modelos Animais de Doenças , Lateralidade Funcional/genética , Humanos , Camundongos , Camundongos Transgênicos , Córtex Motor/patologia , Bainha de Mielina/metabolismo , Bainha de Mielina/patologia , Degeneração Neural/induzido quimicamente , Degeneração Neural/patologia , Fibras Nervosas Mielinizadas/patologia , Fibras Nervosas Mielinizadas/ultraestrutura , Proteínas do Tecido Nervoso/metabolismo , Oligodendroglia/efeitos dos fármacos , Oligodendroglia/ultraestrutura , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/genética , Regeneração/efeitos dos fármacos , Regeneração/genética , Medula Espinal/citologia , Medula Espinal/patologia , Análise de Sobrevida
15.
Lancet Neurol ; 12(5): 435-42, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23541756

RESUMO

BACKGROUND: Mutations in SOD1 cause 13% of familial amyotrophic lateral sclerosis. In the SOD1 Gly93Ala rat model of amyotrophic lateral sclerosis, the antisense oligonucleotide ISIS 333611 delivered to CSF decreased SOD1 mRNA and protein concentrations in spinal cord tissue and prolonged survival. We aimed to assess the safety, tolerability, and pharmacokinetics of ISIS 333611 after intrathecal administration in patients with SOD1-related familial amyotrophic lateral sclerosis. METHODS: In this randomised, placebo-controlled, phase 1 trial, we delivered ISIS 333611 by intrathecal infusion using an external pump over 11·5 h at increasing doses (0·15 mg, 0·50 mg, 1·50 mg, 3·00 mg) to four cohorts of eight patients with SOD1-positive amyotrophic lateral sclerosis (six patients assigned to ISIS 333611, two to placebo in each cohort). We did the randomisation with a web-based system, assigning patients in blocks of four. Patients and investigators were masked to treatment assignment. Participants were allowed to re-enrol in subsequent cohorts. Our primary objective was to assess the safety and tolerability of ISIS 333611. Assessments were done during infusion and over 28 days after infusion. This study was registered with Clinicaltrials.gov, number NCT01041222. FINDINGS: Seven of eight (88%) patients in the placebo group versus 20 of 24 (83%) in the ISIS 333611 group had adverse events. The most common events were post-lumbar puncture syndrome (3/8 [38%] vs 8/24 [33%]), back pain (4/8 [50%] vs 4/24 [17%]), and nausea (0/8 [0%] vs 3/24 [13%]). We recorded no dose-limiting toxic effects or any safety or tolerability concerns related to ISIS 333611. No serious adverse events occurred in patients given ISIS 333611. Re-enrolment and re-treatment were also well tolerated. INTERPRETATION: This trial is the first clinical study of intrathecal delivery of an antisense oligonucleotide. ISIS 333611 was well tolerated when administered as an intrathecal infusion. Antisense oligonucleotides delivered to the CNS might be a feasible treatment for neurological disorders. FUNDING: The ALS Association, Muscular Dystrophy Association, Isis Pharmaceuticals.


Assuntos
Esclerose Amiotrófica Lateral/tratamento farmacológico , Oligodesoxirribonucleotídeos Antissenso/uso terapêutico , Superóxido Dismutase/genética , Adulto , Esclerose Amiotrófica Lateral/genética , Método Duplo-Cego , Feminino , Humanos , Injeções Espinhais , Masculino , Pessoa de Meia-Idade , Oligodesoxirribonucleotídeos Antissenso/administração & dosagem , Superóxido Dismutase-1 , Resultado do Tratamento
16.
Mod Pathol ; 26(2): 166-70, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23222492

RESUMO

An outbreak of fungal infections has been identified in patients who received epidural injections of methylprednisolone acetate that was contaminated with environmental molds. In this report, we present the mycological and histopathological findings in an index case of Exserohilum meningitis and vasculitis in an immunocompetent patient, who received a cervical spine epidural steroid injection for chronic neck pain 1 week before the onset of fulminant meningitis with subsequent multiple brain and spinal cord infarcts. The fungus was recovered from two separate cerebrospinal fluid specimens collected before initiation of antifungal therapy and at autopsy on standard bacterial and fungal culture media. The mold was identified phenotypically as Exserohilum species. DNA sequencing targeting the internal transcribed spacer region and D1/D2 region of 28S ribosomal DNA enabled further speciation as E. rostratum. Gross examination at autopsy revealed moderate brain edema with bilateral uncal herniation and a ventriculostomy tract to the third ventricle. The brainstem, cerebellum, and right orbitofrontal cortex were soft and friable, along with hemorrhages in the cerebellar vermis and thalamus. Microscopic examination demonstrated numerous fungi with septate hyphae invading blood vessel walls and inducing acute necrotizing inflammation. The leptomeninges were diffusely infiltrated by mixed inflammatory cells along with scattered foci of fungal elements. This is the first report of iatrogenic E. rostratum meningitis in humans. This report describes the microbiological procedures and histopathological features for the identification of E. rostratum (a pigmented vascularly invasive fungi), the cause of a current nationwide outbreak of fatal fungal meningitis.


Assuntos
Ascomicetos/isolamento & purificação , Encéfalo/patologia , Injeções Epidurais/efeitos adversos , Meningite Fúngica/patologia , Medula Espinal/patologia , Encéfalo/microbiologia , Humanos , Meningite Fúngica/etiologia , Meningite Fúngica/microbiologia , Medula Espinal/microbiologia
17.
Muscle Nerve ; 45(5): 755-61, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22499107

RESUMO

INTRODUCTION: The diagnosis of amyloid myopathy is delayed when monoclonal gammopathies are not detected on initial testing and muscle biopsies are nondiagnostic, and the EMG and symptoms can mimic an inflammatory myopathy. METHODS: Case report of a patient presenting with severe progressive muscle weakness of unclear etiology despite an extensive workup including two nondiagnostic muscle biopsies. RESULTS: Directed by MRI, a third biopsy revealed amyloid angiopathy and noncongophilic kappa light chain deposition in scattered subsarcolemmal rings and perimysial regions. A serum free light chain (FLC) assay revealed a kappa monoclonal gammopathy, which was not detected by multiple immunofixations. CONCLUSIONS: The spectrum of immunoglobulin deposition in muscle is similar to other organs. It comprises a continuum that includes parenchymal amyloid deposition, amyloid angiopathy, and noncongophilic Light Chain Deposition Disease (LCDD). We recommend including the FLC assay in the routine investigation for monoclonal gammopathies. This case also highlights the value of MRI-guided muscle biopsy.


Assuntos
Cadeias Leves de Imunoglobulina/sangue , Músculo Esquelético/metabolismo , Paraproteinemias/sangue , Paraproteinemias/patologia , Adenosina Trifosfatases/metabolismo , Idoso , Amiloidose/sangue , Amiloidose/etiologia , Biópsia , Vermelho Congo , Humanos , Cadeias kappa de Imunoglobulina/metabolismo , Masculino , Músculo Esquelético/patologia , Paraproteinemias/complicações
19.
Biochem Biophys Res Commun ; 410(1): 81-6, 2011 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-21640709

RESUMO

The expression of endothelins (ETs) and ET-receptors is often upregulated in brain pathology. ET-1, a potent vasoconstrictor, also inhibits the expression of astrocyte glutamate transporters and is mitogenic for astrocytes, glioma cells, neurons, and brain capillary endothelia. We have previously shown that mechanical stress stimulates ET-1 production by adult rat astrocytes. We now show in adult astrocytes that ET-1 production is driven by calcium influx through stretch-activated ion channels (SACs) and the ET-1 production correlates with cell proliferation. Mechanical stimulation using biaxial stretch (<20%) of a rubber substrate increased ET-1 secretion, and 4 µM GsMTx-4 (a specific inhibitor of SACs) inhibited secretion by 30%. GsMTx-4 did not alter basal ET-1 levels in the absence of stretch. Decreasing the calcium influx by lowering extracellular calcium also inhibited stretch-induced ET-1 secretion without effecting ET-1 secretion in unstretched controls. Furthermore, inhibiting SACs with the less specific inhibitor streptomycin also inhibited stretch-induced ET-1 secretion. The data can be explained with a simple model in which ET-1 secretion depends on an internal Ca(2+) threshold. This coupling of mechanical stress to the astrocyte endothelin system through SACs has treatment implications, since all pathology deforms the surrounding parenchyma.


Assuntos
Astrócitos/metabolismo , Cálcio/metabolismo , Endotelina-1/metabolismo , Canais Iônicos/metabolismo , Estresse Mecânico , Animais , Proliferação de Células , Células Cultivadas , Peptídeos e Proteínas de Sinalização Intercelular , Canais Iônicos/antagonistas & inibidores , Peptídeos/farmacologia , Ratos , Venenos de Aranha/farmacologia
20.
Epileptic Disord ; 13(1): 99-101, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21393096

RESUMO

Electrodecremental status epilepticus is classically described in infants and children with severe refractory epilepsy, mental retardation, and structural brain abnormalities. We describe a 24-year-old woman who presented to the emergency department with prolonged tonic status epilepticus which evolved into stimulus-induced diffuse voltage attenuation (SIDVA) pattern in the setting of aseptic meningoencephalitis. There was no history of seizures or further events after recovery. This is the first report of a SIDVA pattern in an adult without a history of epilepsy.


Assuntos
Estado Epiléptico/diagnóstico , Anticonvulsivantes/uso terapêutico , Eletroencefalografia , Feminino , Humanos , Estado Epiléptico/tratamento farmacológico , Resultado do Tratamento , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...