Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 4.612
Filtrar
1.
Adv Exp Med Biol ; 1158: 71-82, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31452136

RESUMO

Proteins oxidation by reactive species is implicated in the aetiology or progression of a panoply of disorders and diseases such as neurodegenerative disorders. It is becoming increasingly evident that redox imbalance in the brain mediates neurodegeneration. Free radicals, as reactive species of oxygen (ROS) but also reactive nitrogen species (RNS) and reactive sulfur species (RSS), are generated in vivo from several sources. Within the cell the mitochondria represent the main source of ROS and mitochondrial dysfunction is both the major contributor to oxidative stress (OS) as well its major consequence.To date there are no doubts that a condition of OS added to other factors as mitochondrial damage in mtDNA or mitochondrial respiratory chain, may contribute to trigger or amplify mechanisms leading to neurodegenerative disorders.In this chapter, we aim at illustrate the molecular interplay occurring between mitochondria and OS focusing on Amyotrophic Lateral Sclerosis, describing a phenotypic reprogramming mechanism of mitochondria in complex neurological disorder.


Assuntos
Esclerose Amiotrófica Lateral , Mitocôndrias , Estresse Oxidativo , Esclerose Amiotrófica Lateral/genética , Esclerose Amiotrófica Lateral/fisiopatologia , DNA Mitocondrial/genética , Humanos , Mitocôndrias/patologia , Espécies Reativas de Nitrogênio , Espécies Reativas de Oxigênio/metabolismo
2.
Yakugaku Zasshi ; 139(7): 1015-1019, 2019.
Artigo em Japonês | MEDLINE | ID: mdl-31257248

RESUMO

Amyotrophic lateral sclerosis (ALS) is a lethal neurodegenerative disease that is characterized by the loss of motor neurons, which results in progressive muscle atrophy. The pathology spreads from the initial site of onset to contiguous anatomic regions. Mutations in the gene encoding Cu/Zn-superoxide dismutase (SOD1) have been identified in a dominantly inherited form of ALS (ALS-SOD1). A major hallmark of ALS-SOD1 is the abnormal accumulation of conformationally aberrant SOD1 protein (i.e., misfolded SOD1) within motor neurons. Emerging experimental evidence has suggested that misfolded proteins associated with neurodegenerative diseases exhibit prion-like properties, i.e., misfolded proteins act as conformational templates that convert normal proteins into a pathogenic form. Possibly as a result of this prion-like self-propagation property, misfolded forms of pathological proteins are considered to accumulate in the central nervous system and cause neurodegeneration. In this article, we review recent evidence for the role of prion-like mechanisms in ALS-SOD1. In particular, we discuss the propensity of misfolded SOD1 to act as a pathological seed, spread between cells, and propagate neuroanatomically.


Assuntos
Esclerose Amiotrófica Lateral/genética , Superóxido Dismutase-1/genética , Humanos , Neurônios Motores/metabolismo , Mutação , Príons , Agregação Patológica de Proteínas , Dobramento de Proteína , Superóxido Dismutase-1/metabolismo
3.
Intern Med ; 58(13): 1851-1858, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31257275

RESUMO

Objective Amyotrophic lateral sclerosis (ALS) is an adult-onset neurodegenerative disease characterized by the progressive loss of the upper and lower motor neurons that progresses to paralysis of almost all skeletal muscles of the extremities, bulbar, and respiratory system. Although most ALS cases are sporadic, about 10% are dominantly inherited. We herein report an atypical phenotype of familial ALS (fALS). To elucidate the phenotype-genotype correlation of this atypical phenotype of fALS, clinical and genetic investigations were performed. Methods and Patients Five sibling patients (three men, two women) from a Japanese family and one healthy sibling (a woman) were clinically interviewed and examined. Genetic analyses, including genome-wide linkage analyses and whole-exome sequencing, were performed using genomic DNA extracted from the peripheral blood samples of these siblings. Results The clinical features of fALS are characterized by slow progression (mean duration of the disease±standard deviation [SD]: 19.6±3.9 years) and lower extremities-predominant late-onset muscular weakness (mean onset of muscular weakness±SD: 52.8±2.6 years). Genetic analyses revealed novel heterozygous missense mutations of c.2668C>T, p.R890C in the PLEC gene and c.421G>C, p.V141L in the ST3GAL6 gene in all affected siblings. Conclusion A new atypical fALS family with a benign clinical course is herein reported. We identified two candidate gene mutations of PLEC and ST3GAL6 linked to this phenotype.


Assuntos
Esclerose Amiotrófica Lateral/genética , Esclerose Amiotrófica Lateral/mortalidade , Predisposição Genética para Doença , Neurônios Motores/fisiologia , Debilidade Muscular/fisiopatologia , Doenças Neurodegenerativas/genética , Doenças Neurodegenerativas/fisiopatologia , Idoso , Idoso de 80 Anos ou mais , Esclerose Amiotrófica Lateral/fisiopatologia , Grupo com Ancestrais do Continente Asiático , Evolução Fatal , Feminino , Genótipo , Humanos , Extremidade Inferior/fisiopatologia , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/fisiopatologia , Mutação , Doenças Neurodegenerativas/mortalidade , Fenótipo
4.
Nat Commun ; 10(1): 2906, 2019 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-31266945

RESUMO

A GGGGCC hexanucleotide repeat expansion in intron 1 of chromosome 9 open reading frame 72 (C9ORF72) gene is the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia. Repeat-associated non-ATG translation of dipeptide repeat proteins (DPRs) contributes to the neuropathological features of c9FTD/ALS. Among the five DPRs, arginine-rich poly-PR are reported to be the most toxic. Here, we generate a transgenic mouse line that expresses poly-PR (GFP-PR28) specifically in neurons. GFP-PR28 homozygous mice show decreased survival time, while the heterozygous mice show motor imbalance, decreased brain weight, loss of Purkinje cells and lower motor neurons, and inflammation in the cerebellum and spinal cord. Transcriptional analysis shows that in the cerebellum, GFP-PR28 heterozygous mice show differential expression of genes related to synaptic transmission. Our findings show that GFP-PR28 transgenic mice partly model neuropathological features of c9FTD/ALS, and show a role for poly-PR in neurodegeneration.


Assuntos
Esclerose Amiotrófica Lateral/fisiopatologia , Proteína C9orf72/genética , Dipeptídeos/genética , Modelos Animais de Doenças , Esclerose Amiotrófica Lateral/genética , Esclerose Amiotrófica Lateral/metabolismo , Animais , Proteína C9orf72/metabolismo , Dipeptídeos/metabolismo , Dipeptídeos/toxicidade , Feminino , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Atividade Motora
5.
Eur Biophys J ; 48(5): 475-484, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31243482

RESUMO

Pathological mechanisms in amyotrophic lateral sclerosis (ALS), a fatal neurodegenerative disease, are still poorly understood. One subset of familial ALS cases is caused by mutations in the metallo-enzyme copper-zinc superoxide dismutase (SOD1), increasing the susceptibility of the SOD1 protein to form insoluble intracellular aggregates. Here, we employed synchrotron radiation-based Fourier transform infrared spectroscopy and microscopy to investigate brainstem cross-sections from the transgenic hSOD1 G93A rat model of ALS that overexpresses human-mutated SOD1. We compared the biomacromolecular organic composition in brainstem tissue cross-sections of ALS rats and their non-transgenic littermates (NTg). We demonstrate that the proteins and especially their antiparallel ß-sheet structure significantly differed in all three regions: the facial nucleus (FN), the gigantocellular reticular nucleus (GRN) and the trigeminal motor nucleus (TMN) in the brainstem tissue of ALS rats. The protein levels varied between different brainstem areas, with the highest concentration observed in the region of the FN in the brainstem tissue of NTg animals. Furthermore, the concentration of lipids and esters was significantly decreased in the TMN and FN of ALS animals. A similar pattern was detected for choline and phosphate assigned to nucleic acids with the highest concentrations in the FN of NTg animals. The spectroscopic analysis showed significant differences in phosphates, amide and lipid structure in the FN of NTg animals in comparison with the same area of ALS rats. These results show that the hG93A SOD1 mutation causes metabolic cellular changes and point to a link between bioorganic composition and hallmarks of protein aggregation.


Assuntos
Esclerose Amiotrófica Lateral/diagnóstico por imagem , Tronco Encefálico/diagnóstico por imagem , Microscopia/instrumentação , Mutação , Espectroscopia de Infravermelho com Transformada de Fourier , Superóxido Dismutase-1/genética , Síncrotrons , Esclerose Amiotrófica Lateral/genética , Esclerose Amiotrófica Lateral/metabolismo , Animais , Tronco Encefálico/metabolismo , Modelos Animais de Doenças , Humanos , Camundongos Transgênicos , Ratos
6.
Biochemistry (Mosc) ; 84(3): 299-309, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31221068

RESUMO

Patient-specific induced pluripotent stem cells (iPSCs) capable of differentiation into required cell type are a promising model for studying various pathological processes and development of new therapeutic approaches. However, no conventional strategies for using iPSCs in disease research have been established yet. Genetically encoded biosensors can be used for monitoring messenger molecules, metabolites, and enzyme activity in real time with the following conversion of the registered signals in quantitative data, thus allowing evaluation of the impact of certain molecules on pathology development. In this article, we describe the development of a universal cell-based platform for studying pathological processes associated with amyotrophic lateral sclerosis. For this purpose, we have created a series of plasmid constructs for monitoring endoplasmic reticulum stress, oxidative stress, apoptosis, and Ca2+-dependent hyperexcitability and generated transgenic iPSC line carrying mutation in the superoxide dismutase 1 gene (SOD1) and healthy control cell line. Both cell lines have specific transactivator sequence required for doxycycline-controlled transcriptional activation and can be used for a single-step biosensor insertion.


Assuntos
Esclerose Amiotrófica Lateral/genética , Esclerose Amiotrófica Lateral/patologia , Técnicas Biossensoriais/métodos , Células-Tronco Pluripotentes Induzidas/metabolismo , Apoptose , Cálcio/metabolismo , Diferenciação Celular , Células Cultivadas , Estresse do Retículo Endoplasmático , Humanos , Células-Tronco Pluripotentes Induzidas/patologia , Mutação , Estresse Oxidativo , Superóxido Dismutase-1/genética , Superóxido Dismutase-1/metabolismo
7.
Nat Neurosci ; 22(6): 851-862, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31086314

RESUMO

The GGGGCC repeat expansion in C9ORF72 is the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). However, it is not known which dysregulated molecular pathways are primarily responsible for disease initiation or progression. We established an inducible mouse model of poly(GR) toxicity in which (GR)80 gradually accumulates in cortical excitatory neurons. Low-level poly(GR) expression induced FTD/ALS-associated synaptic dysfunction and behavioral abnormalities, as well as age-dependent neuronal cell loss, microgliosis and DNA damage, probably caused in part by early defects in mitochondrial function. Poly(GR) bound preferentially to the mitochondrial complex V component ATP5A1 and enhanced its ubiquitination and degradation, consistent with reduced ATP5A1 protein level in both (GR)80 mouse neurons and patient brains. Moreover, inducing ectopic Atp5a1 expression in poly(GR)-expressing neurons or reducing poly(GR) level in adult mice after disease onset rescued poly(GR)-induced neurotoxicity. Thus, poly(GR)-induced mitochondrial defects are a major driver of disease initiation in C9ORF72-related ALS/FTD.


Assuntos
Esclerose Amiotrófica Lateral/fisiopatologia , Proteína C9orf72/genética , Demência Frontotemporal/fisiopatologia , Mitocôndrias/patologia , ATPases Mitocondriais Próton-Translocadoras/metabolismo , Esclerose Amiotrófica Lateral/genética , Animais , Encéfalo/metabolismo , Expansão das Repetições de DNA , Modelos Animais de Doenças , Demência Frontotemporal/genética , Humanos , Camundongos , Camundongos Transgênicos , Neurônios/metabolismo
8.
RNA ; 25(8): 935-947, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31048495

RESUMO

Some neurological disorders, including amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), fragile X syndrome, Huntington's disease, myotonic dystrophy, and various ataxias, can be caused by expansions of short nucleic acid sequence repeats in specific genes. A possible disease mechanism involves the transcribed repeat RNA binding an RNA-binding protein (RBP), resulting in its sequestration and thus dysfunction. Polycomb repressive complex 2 (PRC2), the histone methyltransferase that deposits the H3K27me3 mark of epigenetically silenced chromatin, binds G-rich RNAs and has especially high affinity for G-quadruplex (G-Q) structures. Here, we find that PRC2 target genes are derepressed and the RNA binding subunit EZH2 largely insoluble in postmortem brain samples from ALS/FTD patients with C9ORF72 (C9) repeat expansions, leading to the hypothesis that the (G4C2)n repeat RNA might be sequestering PRC2. Contrary to this expectation, we found that C9 repeat RNAs (n = 6 or 10) bind weakly to purified PRC2, and studies with the G-Q specific BG4 antibody and circular dichroism studies both indicated that these C9 RNAs have little propensity to form G-Qs in vitro. Several GC-rich triplet-repeat expansion RNAs also have low affinity for PRC2 and do not appreciably form G-Qs in vitro. The results are consistent with these sequences forming hairpin structures that outcompete G-Q folding when the repeat length is sufficiently large. We suggest that binding of PRC2 to these GC-rich RNAs is fundamentally weak but may be modulated in vivo by protein factors that affect secondary structure, such as helicases and other RBPs.


Assuntos
Esclerose Amiotrófica Lateral/genética , Proteína C9orf72/química , Proteína C9orf72/genética , Demência Frontotemporal/genética , Complexo Repressor Polycomb 2/metabolismo , Repetições de Trinucleotídeos , Esclerose Amiotrófica Lateral/metabolismo , Autopsia , Dicroísmo Circular , Proteína Potenciadora do Homólogo 2 de Zeste/química , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Epigênese Genética , Demência Frontotemporal/metabolismo , Quadruplex G , Humanos , Complexo Repressor Polycomb 2/química , Solubilidade
9.
Nat Commun ; 10(1): 2006, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-31043593

RESUMO

Subcellular membrane-less organelles consist of proteins with low complexity domains. Many of them, such as hnRNPA1, can assemble into both a polydisperse liquid phase and an ordered solid phase of amyloid fibril. The former mirrors biological granule assembly, while the latter is usually associated with neurodegenerative disease. Here, we observe a reversible amyloid formation of hnRNPA1 that synchronizes with liquid-liquid phase separation, regulates the fluidity and mobility of the liquid-like droplets, and facilitates the recruitment of hnRNPA1 into stress granules. We identify the reversible amyloid-forming cores of hnRNPA1 (named hnRACs). The atomic structures of hnRACs reveal a distinct feature of stacking Asp residues, which contributes to fibril reversibility and explains the irreversible pathological fibril formation caused by the Asp mutations identified in familial ALS. Our work characterizes the structural diversity and heterogeneity of reversible amyloid fibrils and illuminates the biological function of reversible amyloid formation in protein phase separation.


Assuntos
Amiloide/ultraestrutura , Grânulos Citoplasmáticos/metabolismo , Ribonucleoproteína Nuclear Heterogênea A1/ultraestrutura , Amiloide/genética , Amiloide/metabolismo , Esclerose Amiotrófica Lateral/genética , Esclerose Amiotrófica Lateral/patologia , Asparagina/genética , Asparagina/metabolismo , Grânulos Citoplasmáticos/ultraestrutura , Células HeLa , Ribonucleoproteína Nuclear Heterogênea A1/genética , Ribonucleoproteína Nuclear Heterogênea A1/isolamento & purificação , Ribonucleoproteína Nuclear Heterogênea A1/metabolismo , Humanos , Microscopia Eletrônica de Transmissão , Modelos Moleculares , Mutação , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/ultraestrutura , Difração de Raios X
10.
BMC Bioinformatics ; 20(1): 213, 2019 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-31029080

RESUMO

BACKGROUND: Next Generation Sequencing (NGS) is a commonly used technology for studying the genetic basis of biological processes and it underpins the aspirations of precision medicine. However, there are significant challenges when dealing with NGS data. Firstly, a huge number of bioinformatics tools for a wide range of uses exist, therefore it is challenging to design an analysis pipeline. Secondly, NGS analysis is computationally intensive, requiring expensive infrastructure, and many medical and research centres do not have adequate high performance computing facilities and cloud computing is not always an option due to privacy and ownership issues. Finally, the interpretation of the results is not trivial and most available pipelines lack the utilities to favour this crucial step. RESULTS: We have therefore developed a fast and efficient bioinformatics pipeline that allows for the analysis of DNA sequencing data, while requiring little computational effort and memory usage. DNAscan can analyse a whole exome sequencing sample in 1 h and a 40x whole genome sequencing sample in 13 h, on a midrange computer. The pipeline can look for single nucleotide variants, small indels, structural variants, repeat expansions and viral genetic material (or any other organism). Its results are annotated using a customisable variety of databases and are available for an on-the-fly visualisation with a local deployment of the gene.iobio platform. DNAscan is implemented in Python. Its code and documentation are available on GitHub: https://github.com/KHP-Informatics/DNAscan . Instructions for an easy and fast deployment with Docker and Singularity are also provided on GitHub. CONCLUSIONS: DNAscan is an extremely fast and computationally efficient pipeline for analysis, visualization and interpretation of NGS data. It is designed to provide a powerful and easy-to-use tool for applications in biomedical research and diagnostic medicine, at minimal computational cost. Its comprehensive approach will maximise the potential audience of users, bringing such analyses within the reach of non-specialist laboratories, and those from centres with limited funding available.


Assuntos
Biologia Computacional/métodos , Sequenciamento de Nucleotídeos em Larga Escala , Interface Usuário-Computador , Esclerose Amiotrófica Lateral/genética , Esclerose Amiotrófica Lateral/patologia , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Bacteriano/metabolismo , Bases de Dados Factuais , HIV-1/genética , Humanos , Mutação INDEL , Polimorfismo de Nucleotídeo Único , RNA Viral/química , RNA Viral/genética , RNA Viral/metabolismo , Sequenciamento Completo do Genoma
11.
Mol Cell ; 74(4): 713-728.e6, 2019 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-30981631

RESUMO

Repeat expansion in the C9orf72 gene is the most common cause of the neurodegenerative disorder amyotrophic lateral sclerosis (C9-ALS) and is linked to the unconventional translation of five dipeptide-repeat polypeptides (DPRs). The two enriched in arginine, poly(GR) and poly(PR), infiltrate liquid-like nucleoli, co-localize with the nucleolar protein nucleophosmin (NPM1), and alter the phase separation behavior of NPM1 in vitro. Here, we show that poly(PR) DPRs bind tightly to a long acidic tract within the intrinsically disordered region of NPM1, altering its phase separation with nucleolar partners to the extreme of forming large, soluble complexes that cause droplet dissolution in vitro. In cells, poly(PR) DPRs disperse NPM1 from nucleoli and entrap rRNA in static condensates in a DPR-length-dependent manner. We propose that R-rich DPR toxicity involves disrupting the role of phase separation by NPM1 in organizing ribosomal proteins and RNAs within the nucleolus.


Assuntos
Esclerose Amiotrófica Lateral/genética , Proteína C9orf72/genética , Proteínas Nucleares/genética , Sequências Repetitivas de Aminoácidos/genética , Esclerose Amiotrófica Lateral/patologia , Arginina/genética , Nucléolo Celular/química , Nucléolo Celular/genética , Dipeptídeos/genética , Humanos , Peptídeos/genética , Poli A/genética , RNA Ribossômico/genética
12.
Methods Mol Biol ; 1958: 237-261, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30945222

RESUMO

Proteins with prion-like behavior are attracting an increasing interest, since accumulating evidences indicate that they play relevant roles both in health and disease. The self-assembly of these proteins into insoluble aggregates is associated with severe neuropathological processes such as amyotrophic lateral sclerosis (ALS). However, in normal conditions, they are known to accomplish a wide range of functional roles. The conformational duality of prion-like proteins is often encoded in specific protein regions, named prion-like domains (PrLDs). PrLDs are usually long and disordered regions of low complexity. We have shown that PrLDs might contain soft-amyloid cores that contribute significantly to trigger their aggregation, as well as to support their propagation. Further exploration of the role of these sequences in the conformational conversion of prion-like proteins might provide novel insights into the mechanism of action and regulation of these polypeptides, enabling the future development of therapeutic strategies. Here, we describe a set of methodologies aimed to identify and characterize these short amyloid stretches in a protein or proteome of interest, ranging from in silico detection to in vitro and in vivo evaluation and validation.


Assuntos
Biologia Molecular/métodos , Proteínas Priônicas/química , Príons/química , Sequência de Aminoácidos/genética , Amiloide/química , Amiloide/genética , Esclerose Amiotrófica Lateral/genética , Esclerose Amiotrófica Lateral/patologia , Proteínas Ligadas por GPI/química , Proteínas Ligadas por GPI/genética , Humanos , Proteínas Priônicas/genética , Príons/genética , Agregados Proteicos/genética , Domínios Proteicos/genética , Proteoma/química , Proteoma/genética
13.
Cell Mol Life Sci ; 76(11): 2043-2058, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30980111

RESUMO

MicroRNAs are small endogenous RNAs that pair and bind to sites on mRNAs to direct post-transcriptional repression. However, there is a possibility that microRNAs directly influence protein structure and activity, and this influence can be termed post-translational riboregulation. This conceptual review explores the literature on neurodegenerative disorders. Research on the association between neurodegeneration and RNA-repeat toxicity provides data that support a protein-RNA recognition code. For example, this code explains why hnRNP H and SFPQ proteins, which are involved in amyotrophic lateral sclerosis, are sequestered by the (GGGGCC)n repeat sequence. Similarly, it explains why MNBL proteins and (CTG)n repeats in RNA, which are involved in myotonic dystrophy, are sequestered into RNA foci. Using this code, proteins involved in diseases can be identified. A simple protein BLAST search of the human genome for amino acid repeats that correspond to the nucleotide repeats reveals new proteins among already known proteins that are involved in diseases. For example, the (CAG)n repeat sequence, when transcribed into possible peptide sequences, leads to the identification of PTCD3, Rem2, MESP2, SYPL2, WDR33, COL23A1, and others. After confirming this approach on RNA repeats, in the next step, the code was used in the opposite manner. Proteins that are involved in diseases were compared with microRNAs involved in those diseases. For example, a reasonable correspondence of microRNA 9 and 107 with amyloid-ß-peptide (Aß42) was identified. In the last step, a miRBase search for micro-nucleotides, obtained by transcription of a prion amino acid sequence, revealed new microRNAs and microRNAs that have previously been identified as involved in prion diseases. This concept provides a useful key for designing RNA or peptide probes.


Assuntos
Código Genético , MicroRNAs/metabolismo , Repetições de Microssatélites , Processamento de Proteína Pós-Traducional , RNA Mensageiro/metabolismo , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Esclerose Amiotrófica Lateral/genética , Esclerose Amiotrófica Lateral/metabolismo , Esclerose Amiotrófica Lateral/patologia , Sítios de Ligação , Genoma Humano , Ribonucleoproteínas Nucleares Heterogêneas Grupo F-H/genética , Ribonucleoproteínas Nucleares Heterogêneas Grupo F-H/metabolismo , Humanos , Doença de Huntington/genética , Doença de Huntington/metabolismo , Doença de Huntington/patologia , MicroRNAs/genética , Distrofia Miotônica/genética , Distrofia Miotônica/metabolismo , Distrofia Miotônica/patologia , Fator de Processamento Associado a PTB/genética , Fator de Processamento Associado a PTB/metabolismo , Doença de Parkinson/genética , Doença de Parkinson/metabolismo , Doença de Parkinson/patologia , Doenças Priônicas/genética , Doenças Priônicas/metabolismo , Doenças Priônicas/patologia , Ligação Proteica , RNA Mensageiro/genética
14.
Science ; 364(6435): 89-93, 2019 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-30948552

RESUMO

Paralysis occurring in amyotrophic lateral sclerosis (ALS) results from denervation of skeletal muscle as a consequence of motor neuron degeneration. Interactions between motor neurons and glia contribute to motor neuron loss, but the spatiotemporal ordering of molecular events that drive these processes in intact spinal tissue remains poorly understood. Here, we use spatial transcriptomics to obtain gene expression measurements of mouse spinal cords over the course of disease, as well as of postmortem tissue from ALS patients, to characterize the underlying molecular mechanisms in ALS. We identify pathway dynamics, distinguish regional differences between microglia and astrocyte populations at early time points, and discern perturbations in several transcriptional pathways shared between murine models of ALS and human postmortem spinal cords.


Assuntos
Esclerose Amiotrófica Lateral/genética , Expressão Gênica , Neurônios Motores/metabolismo , Medula Espinal/metabolismo , Esclerose Amiotrófica Lateral/patologia , Animais , Astrócitos/metabolismo , Astrócitos/patologia , Modelos Animais de Doenças , Perfilação da Expressão Gênica , Humanos , Camundongos , Microglia/metabolismo , Microglia/patologia , Neurônios Motores/patologia , Músculo Esquelético/patologia , Músculo Esquelético/fisiopatologia , Degeneração Neural/genética , Degeneração Neural/fisiopatologia , Neuroglia/metabolismo , Neuroglia/patologia , Mudanças Depois da Morte , Análise Espaço-Temporal , Medula Espinal/patologia , Transcriptoma
15.
Molecules ; 24(8)2019 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-31022909

RESUMO

Fused in sarcoma (FUS) is a DNA/RNA binding protein that is involved in RNA metabolism and DNA repair. Numerous reports have demonstrated by pathological and genetic analysis that FUS is associated with a variety of neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS), frontotemporal lobar degeneration (FTLD), and polyglutamine diseases. Traditionally, the fibrillar aggregation of FUS was considered to be the cause of those diseases, especially via its prion-like domains (PrLDs), which are rich in glutamine and asparagine residues. Lately, a nonfibrillar self-assembling phenomenon, liquid-liquid phase separation (LLPS), was observed in FUS, and studies of its functions, mechanism, and mutual transformation with pathogenic amyloid have been emerging. This review summarizes recent studies on FUS self-assembling, including both aggregation and LLPS as well as their relationship with the pathology of ALS, FTLD, and other neurodegenerative diseases.


Assuntos
Doenças Neurodegenerativas/genética , Agregação Patológica de Proteínas/genética , Proteína FUS de Ligação a RNA/química , Esclerose Amiotrófica Lateral/genética , Esclerose Amiotrófica Lateral/patologia , Asparagina/química , Asparagina/genética , Degeneração Lobar Frontotemporal/genética , Degeneração Lobar Frontotemporal/patologia , Proteínas Ligadas por GPI/química , Proteínas Ligadas por GPI/genética , Humanos , Doenças Neurodegenerativas/patologia , Peptídeos/química , Peptídeos/genética , Príons/química , Príons/genética , Agregação Patológica de Proteínas/patologia , Domínios Proteicos/genética , Proteína FUS de Ligação a RNA/genética
16.
Neuron ; 101(6): 1057-1069, 2019 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-30897357

RESUMO

Amyotrophic lateral sclerosis (ALS) is an aggressive neurodegenerative disorder that orchestrates an attack on the motor nervous system that is unrelenting. Recent discoveries into the pathogenic consequences of repeat expansions in C9ORF72, which are the most common genetic cause of ALS, combined with the identification of new genetic mutations are providing novel insight into the underlying mechanism(s) that cause ALS. In particular, the myriad of functions linked to ALS-associated genes have collectively implicated four main pathways in disease pathogenesis, including RNA metabolism and translational biology; protein quality control; cytoskeletal integrity and trafficking; and mitochondrial function and transport. Through the identification of common disease mechanisms on which multiple ALS genes converge, key targets for potential therapeutic intervention are highlighted.


Assuntos
Esclerose Amiotrófica Lateral/genética , Proteína C9orf72/genética , Citoesqueleto/metabolismo , Proteínas de Ligação a DNA/genética , Mitocôndrias/metabolismo , RNA/metabolismo , Superóxido Dismutase-1/genética , Esclerose Amiotrófica Lateral/metabolismo , Grânulos Citoplasmáticos/metabolismo , Expansão das Repetições de DNA , Proteínas de Ligação a DNA/metabolismo , Humanos , Transporte Proteico/genética , Proteínas Serina-Treonina Quinases/genética , Proteína FUS de Ligação a RNA/genética , Estresse Fisiológico , Superóxido Dismutase-1/metabolismo , Fator de Transcrição TFIIIA/genética , Fator de Transcrição TFIIIA/metabolismo , Resposta a Proteínas não Dobradas , Proteína com Valosina/genética
17.
Mol Neurodegener ; 14(1): 14, 2019 03 27.
Artigo em Inglês | MEDLINE | ID: mdl-30917850

RESUMO

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is a multifactorial fatal motoneuron disease without a cure. Ten percent of ALS cases can be pointed to a clear genetic cause, while the remaining 90% is classified as sporadic. Our study was aimed to uncover new connections within the ALS network through a bioinformatic approach, by which we identified C13orf18, recently named Pacer, as a new component of the autophagic machinery and potentially involved in ALS pathogenesis. METHODS: Initially, we identified Pacer using a network-based bioinformatic analysis. Expression of Pacer was then investigated in vivo using spinal cord tissue from two ALS mouse models (SOD1G93A and TDP43A315T) and sporadic ALS patients. Mechanistic studies were performed in cell culture using the mouse motoneuron cell line NSC34. Loss of function of Pacer was achieved by knockdown using short-hairpin constructs. The effect of Pacer repression was investigated in the context of autophagy, SOD1 aggregation, and neuronal death. RESULTS: Using an unbiased network-based approach, we integrated all available ALS data to identify new functional interactions involved in ALS pathogenesis. We found that Pacer associates to an ALS-specific subnetwork composed of components of the autophagy pathway, one of the main cellular processes affected in the disease. Interestingly, we found that Pacer levels are significantly reduced in spinal cord tissue from sporadic ALS patients and in tissues from two ALS mouse models. In vitro, Pacer deficiency lead to impaired autophagy and accumulation of ALS-associated protein aggregates, which correlated with the induction of cell death. CONCLUSIONS: This study, therefore, identifies Pacer as a new regulator of proteostasis associated with ALS pathology.


Assuntos
Esclerose Amiotrófica Lateral/metabolismo , Esclerose Amiotrófica Lateral/patologia , Autofagia/efeitos dos fármacos , Proteínas de Ligação a DNA/metabolismo , Neurônios Motores/metabolismo , Esclerose Amiotrófica Lateral/genética , Animais , Modelos Animais de Doenças , Humanos , Camundongos Transgênicos , Medula Espinal/metabolismo , Medula Espinal/patologia , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo
19.
Nucleic Acids Res ; 47(5): 2487-2505, 2019 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-30759234

RESUMO

TDP-43 regulates cellular levels of Cajal bodies (CBs) that provide platforms for the assembly and RNA modifications of small nuclear ribonucleoproteins (snRNPs) involved in pre-mRNA splicing. Alterations in these snRNPs may be linked to pathogenesis of amyotrophic lateral sclerosis. However, specific roles for TDP-43 in CBs remain unknown. Here, we demonstrate that TDP-43 regulates the CB localization of four UG-rich motif-bearing C/D-box-containing small Cajal body-specific RNAs (C/D scaRNAs; i.e. scaRNA2, 7, 9 and 28) through the direct binding to these scaRNAs. TDP-43 enhances binding of a CB-localizing protein, WD40-repeat protein 79 (WDR79), to a subpopulation of scaRNA2 and scaRNA28; the remaining population of the four C/D scaRNAs was localized to CB-like structures even with WDR79 depletion. Depletion of TDP-43, in contrast, shifted the localization of these C/D scaRNAs, mainly into the nucleolus, as well as destabilizing scaRNA2, and reduced the site-specific 2'-O-methylation of U1 and U2 snRNAs, including at 70A in U1 snRNA and, 19G, 25G, 47U and 61C in U2 snRNA. Collectively, we suggest that TDP-43 and WDR79 have separate roles in determining CB localization of subsets of C/D and H/ACA scaRNAs.


Assuntos
Esclerose Amiotrófica Lateral/genética , Corpos Enovelados/genética , Proteínas de Ligação a DNA/genética , Proteínas/genética , Esclerose Amiotrófica Lateral/patologia , Nucléolo Celular/genética , Corpos Enovelados/metabolismo , Citidina/análogos & derivados , Citidina/genética , Células HeLa , Humanos , RNA Guia/genética , RNA Nuclear Pequeno/genética , Ribonucleoproteínas Nucleares Pequenas/genética
20.
Muscle Nerve ; 59(5): 567-576, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30734322

RESUMO

INTRODUCTION: We sought to identify patients with amyotrophic lateral sclerosis (ALS) who displayed suspected peripheral nervous system (PNS) inflammation to compare them to those with suspected PNS degeneration. METHODS: We measured sonographic median and ulnar nerve cross-sectional area (CSA) and cerebrospinal fluid albumin/serum albumin ratio (Qalb ) in patients with ALS to classify them as having suspected PNS degeneration (small CSA/low Qalb ) or inflammation (larger CSA/high Qalb ). RESULTS: Fifty-seven percent of patients had suspected PNS degeneration, 21% had suspected PNS inflammation, and 21% displayed suspected "normal PNS state." Suspected PNS degeneration was related to classic ALS, shorter disease duration, and a smaller hypoechoic nerve area. Suspected PNS inflammation was associated with men, longer disease duration, and a larger hypoechoic nerve area and was the dominant finding in superoxide dismutase 1 mutation carriers. DISCUSSION: Our simple approach might aid in the in vivo differentiation of supposed ALS subtypes, those with suspected PNS degeneration vs. inflammation, for stratification in clinical trials. Muscle Nerve 59:567-567, 2019.


Assuntos
Esclerose Amiotrófica Lateral/diagnóstico por imagem , Nervo Mediano/diagnóstico por imagem , Nervo Ulnar/diagnóstico por imagem , Idoso , Albuminas/líquido cefalorraquidiano , Esclerose Amiotrófica Lateral/genética , Esclerose Amiotrófica Lateral/imunologia , Feminino , Humanos , Inflamação/diagnóstico por imagem , Masculino , Nervo Mediano/patologia , Pessoa de Meia-Idade , Mutação , Tamanho do Órgão , Sistema Nervoso Periférico/diagnóstico por imagem , Sistema Nervoso Periférico/imunologia , Curva ROC , Albumina Sérica , Superóxido Dismutase-1/genética , Nervo Ulnar/patologia , Ultrassonografia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA