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1.
Nucleic Acids Res ; 49(W1): W193-W198, 2021 07 02.
Artículo en Inglés | MEDLINE | ID: mdl-34104972

RESUMEN

Exon skipping using antisense oligonucleotides (ASOs) has recently proven to be a powerful tool for mRNA splicing modulation. Several exon-skipping ASOs have been approved to treat genetic diseases worldwide. However, a significant challenge is the difficulty in selecting an optimal sequence for exon skipping. The efficacy of ASOs is often unpredictable, because of the numerous factors involved in exon skipping. To address this gap, we have developed a computational method using machine-learning algorithms that factors in many parameters as well as experimental data to design highly effective ASOs for exon skipping. eSkip-Finder (https://eskip-finder.org) is the first web-based resource for helping researchers identify effective exon skipping ASOs. eSkip-Finder features two sections: (i) a predictor of the exon skipping efficacy of novel ASOs and (ii) a database of exon skipping ASOs. The predictor facilitates rapid analysis of a given set of exon/intron sequences and ASO lengths to identify effective ASOs for exon skipping based on a machine learning model trained by experimental data. We confirmed that predictions correlated well with in vitro skipping efficacy of sequences that were not included in the training data. The database enables users to search for ASOs using queries such as gene name, species, and exon number.


Asunto(s)
Bases de Datos de Ácidos Nucleicos , Exones , Aprendizaje Automático , Oligonucleótidos Antisentido/química , Programas Informáticos , Internet , Intrones , Empalme del ARN , Análisis de Secuencia
2.
Int J Mol Sci ; 24(4)2023 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-36835433

RESUMEN

Amyotrophic lateral sclerosis (ALS) is a fatal late-onset motor neuron disease characterized by the loss of the upper and lower motor neurons. Our understanding of the molecular basis of ALS pathology remains elusive, complicating the development of efficient treatment. Gene-set analyses of genome-wide data have offered insight into the biological processes and pathways of complex diseases and can suggest new hypotheses regarding causal mechanisms. Our aim in this study was to identify and explore biological pathways and other gene sets having genomic association to ALS. Two cohorts of genomic data from the dbGaP repository were combined: (a) the largest available ALS individual-level genotype dataset (N = 12,319), and (b) a similarly sized control cohort (N = 13,210). Following comprehensive quality control pipelines, imputation and meta-analysis, we assembled a large European descent ALS-control cohort of 9244 ALS cases and 12,795 healthy controls represented by genetic variants of 19,242 genes. Multi-marker analysis of genomic annotation (MAGMA) gene-set analysis was applied to an extensive collection of 31,454 gene sets from the molecular signatures database (MSigDB). Statistically significant associations were observed for gene sets related to immune response, apoptosis, lipid metabolism, neuron differentiation, muscle cell function, synaptic plasticity and development. We also report novel interactions between gene sets, suggestive of mechanistic overlaps. A manual meta-categorization and enrichment mapping approach is used to explore the overlap of gene membership between significant gene sets, revealing a number of shared mechanisms.


Asunto(s)
Esclerosis Amiotrófica Lateral , Humanos , Esclerosis Amiotrófica Lateral/genética , Estudio de Asociación del Genoma Completo , Genotipo , Neuronas Motoras
3.
Eur J Neurol ; 29(3): 707-714, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-34748676

RESUMEN

BACKGROUND AND PURPOSE: This study evaluates the incidence, prevalence and survival trends of motor neurone disease (MND) in Northern Ireland from 2015 to 2019. METHODS: A capture-recapture analysis was performed using five independent data sources. Incidence and prevalence rates were standardized to the European Standard Population. Survival outcomes were analysed using Kaplan-Meier curves and Cox regression analysis. RESULTS: Amongst 254 total cases of MND, capture-recapture analysis estimated three missing cases (case ascertainment 98.8%). Age standardized incidence of captured cases was 3.12 per 100,000 (2.73, 3.50) and standardized prevalence ranged from 9.45 to 6.49 per 100,000 from 2015 to 2019. Standardized incidence and prevalence rates in 2006 were 1.4 and 3.3 per 100,000 respectively. Of identified cases, 133 (52.4%) were male; 94.5% had amyotrophic lateral sclerosis; median age of onset was 67 years; median time to diagnosis was 12 months (95% confidence interval 11.2, 12.8); survival from diagnosis was 12 months (95% confidence interval 10.6, 15.4); 25 (9.8%) reported a family history of MND or frontotemporal dementia; and a known MND-associated genetic mutation was identified in 7.9% of total cases, of which the most common was C9orf72 (5.7% of all patients). Factors associated with improved survival were younger age at onset, longer time to diagnosis, attendance at regional MND clinic, and initial neurology presentation as outpatient (all p < 0.001). CONCLUSION: The incidence and prevalence of MND in Northern Ireland has increased over the last 10 years, in line with increasing rates reported from other European countries. Improved survival was associated with younger age at onset, longer time to diagnosis, attendance at a regional MND clinic and outpatient presentation to a Neurology Department.


Asunto(s)
Esclerosis Amiotrófica Lateral , Enfermedad de la Neurona Motora , Anciano , Esclerosis Amiotrófica Lateral/diagnóstico , Esclerosis Amiotrófica Lateral/epidemiología , Humanos , Incidencia , Masculino , Enfermedad de la Neurona Motora/epidemiología , Irlanda del Norte/epidemiología , Prevalencia
4.
Int J Mol Sci ; 22(23)2021 Dec 02.
Artículo en Inglés | MEDLINE | ID: mdl-34884867

RESUMEN

Duchenne muscular dystrophy (DMD) is a lethal X-linked recessive disorder caused by mutations in the DMD gene and the subsequent lack of dystrophin protein. Recently, phosphorodiamidate morpholino oligomer (PMO)-antisense oligonucleotides (ASOs) targeting exon 51 or 53 to reestablish the DMD reading frame have received regulatory approval as commercially available drugs. However, their applicability and efficacy remain limited to particular patients. Large animal models and exon skipping evaluation are essential to facilitate ASO development together with a deeper understanding of dystrophinopathies. Using recombinant adeno-associated virus-mediated gene targeting and somatic cell nuclear transfer, we generated a Yucatan miniature pig model of DMD with an exon 52 deletion mutation equivalent to one of the most common mutations seen in patients. Exon 52-deleted mRNA expression and dystrophin deficiency were confirmed in the skeletal and cardiac muscles of DMD pigs. Accordingly, dystrophin-associated proteins failed to be recruited to the sarcolemma. The DMD pigs manifested early disease onset with severe bodywide skeletal muscle degeneration and with poor growth accompanied by a physical abnormality, but with no obvious cardiac phenotype. We also demonstrated that in primary DMD pig skeletal muscle cells, the genetically engineered exon-52 deleted pig DMD gene enables the evaluation of exon 51 or 53 skipping with PMO and its advanced technology, peptide-conjugated PMO. The results show that the DMD pigs developed here can be an appropriate large animal model for evaluating in vivo exon skipping efficacy.


Asunto(s)
Distrofina/genética , Exones , Músculo Esquelético/patología , Distrofia Muscular de Duchenne/genética , Animales , Animales Modificados Genéticamente , Dependovirus/genética , Modelos Animales de Enfermedad , Proteínas Asociadas a la Distrofina/genética , Proteínas Asociadas a la Distrofina/metabolismo , Femenino , Eliminación de Gen , Masculino , Fibras Musculares Esqueléticas/patología , Técnicas de Transferencia Nuclear , Oligonucleótidos Antisentido/genética , Sarcolema/metabolismo , Porcinos , Porcinos Enanos
5.
Mol Ther ; 27(11): 2005-2017, 2019 11 06.
Artículo en Inglés | MEDLINE | ID: mdl-31416775

RESUMEN

Mutations in the dystrophin (DMD) gene and consequent loss of dystrophin cause Duchenne muscular dystrophy (DMD). A promising therapy for DMD, single-exon skipping using antisense phosphorodiamidate morpholino oligomers (PMOs), currently confronts major issues in that an antisense drug induces the production of functionally undefined dystrophin and may not be similarly efficacious among patients with different mutations. Accordingly, the applicability of this approach is limited to out-of-frame mutations. Here, using an exon-skipping efficiency predictive tool, we designed three different PMO cocktail sets for exons 45-55 skipping aiming to produce a dystrophin variant with preserved functionality as seen in milder or asymptomatic individuals with an in-frame exons 45-55 deletion. Of them, the most effective set was composed of select PMOs that each efficiently skips an assigned exon in cell-based screening. These combinational PMOs fitted to different deletions of immortalized DMD patient muscle cells significantly induced exons 45-55 skipping with removing 3, 8, or 10 exons and dystrophin restoration as represented by western blotting. In vivo skipping of the maximum 11 human DMD exons was confirmed in humanized mice. The finding indicates that our PMO set can be used to create mutation-tailored cocktails for exons 45-55 skipping and treat over 65% of DMD patients carrying out-of-frame or in-frame deletions.


Asunto(s)
Empalme Alternativo , Distrofina/genética , Exones , Regulación de la Expresión Génica , Morfolinos/genética , Distrofia Muscular de Duchenne/genética , Mutación , Animales , Modelos Animales de Enfermedad , Humanos , Ratones , Ratones Transgénicos , Distrofia Muscular de Duchenne/diagnóstico , Fenotipo , Eliminación de Secuencia
6.
Hum Mol Genet ; 26(11): 1979-1991, 2017 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-28334824

RESUMEN

Repair of skeletal muscle after sarcolemmal damage involves dysferlin and dysferlin-interacting proteins such as annexins. Mice and patient lacking dysferlin exhibit chronic muscle inflammation and adipogenic replacement of the myofibers. Here, we show that similar to dysferlin, lack of annexin A2 (AnxA2) also results in poor myofiber repair and progressive muscle weakening with age. By longitudinal analysis of AnxA2-deficient muscle we find that poor myofiber repair due to the lack of AnxA2 does not result in chronic inflammation or adipogenic replacement of the myofibers. Further, deletion of AnxA2 in dysferlin deficient mice reduced muscle inflammation, adipogenic replacement of myofibers, and improved muscle function. These results identify multiple roles of AnxA2 in muscle repair, which includes facilitating myofiber repair, chronic muscle inflammation and adipogenic replacement of dysferlinopathic muscle. It also identifies inhibition of AnxA2-mediated inflammation as a novel therapeutic avenue for treating muscle loss in dysferlinopathy.


Asunto(s)
Anexina A2/metabolismo , Anexina A2/fisiología , Adipogénesis , Animales , Anexina A2/genética , Disferlina , Inflamación/metabolismo , Proteínas de la Membrana/metabolismo , Proteínas de la Membrana/fisiología , Ratones , Ratones Noqueados , Músculo Esquelético/metabolismo , Distrofia Muscular de Cinturas/metabolismo , Distrofia Muscular de Cinturas/terapia , Miofibrillas/fisiología , Sarcolema/metabolismo
7.
Mol Ther ; 25(11): 2561-2572, 2017 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-28865998

RESUMEN

Duchenne muscular dystrophy (DMD), the most common lethal genetic disorder, is caused by mutations in the dystrophin (DMD) gene. Exon skipping is a therapeutic approach that uses antisense oligonucleotides (AOs) to modulate splicing and restore the reading frame, leading to truncated, yet functional protein expression. In 2016, the US Food and Drug Administration (FDA) conditionally approved the first phosphorodiamidate morpholino oligomer (morpholino)-based AO drug, eteplirsen, developed for DMD exon 51 skipping. Eteplirsen remains controversial with insufficient evidence of its therapeutic effect in patients. We recently developed an in silico tool to design antisense morpholino sequences for exon skipping. Here, we designed morpholino AOs targeting DMD exon 51 using the in silico tool and quantitatively evaluated the effects in immortalized DMD muscle cells in vitro. To our surprise, most of the newly designed morpholinos induced exon 51 skipping more efficiently compared with the eteplirsen sequence. The efficacy of exon 51 skipping and rescue of dystrophin protein expression were increased by up to more than 12-fold and 7-fold, respectively, compared with the eteplirsen sequence. Significant in vivo efficacy of the most effective morpholino, determined in vitro, was confirmed in mice carrying the human DMD gene. These findings underscore the importance of AO sequence optimization for exon skipping.


Asunto(s)
Distrofina/genética , Terapia Genética/métodos , Morfolinos/genética , Distrofia Muscular de Duchenne/terapia , Oligonucleótidos Antisentido/genética , Recuperación de la Función , Animales , Modelos Animales de Enfermedad , Distrofina/metabolismo , Exones , Femenino , Expresión Génica , Humanos , Masculino , Ratones , Ratones Transgénicos , Morfolinos/metabolismo , Músculo Esquelético/metabolismo , Músculo Esquelético/patología , Distrofia Muscular de Duchenne/genética , Distrofia Muscular de Duchenne/metabolismo , Distrofia Muscular de Duchenne/patología , Mutación , Oligonucleótidos Antisentido/metabolismo , Empalme del ARN , Sistemas de Lectura
8.
Nucleic Acids Res ; 43(W1): W571-5, 2015 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-25883154

RESUMEN

Given a query list of genes or proteins, CellWhere produces an interactive graphical display that mimics the structure of a cell, showing the local interaction network organized into subcellular locations. This user-friendly tool helps in the formulation of mechanistic hypotheses by enabling the experimental biologist to explore simultaneously two elements of functional context: (i) protein subcellular localization and (ii) protein-protein interactions or gene functional associations. Subcellular localization terms are obtained from public sources (the Gene Ontology and UniProt-together containing several thousand such terms) then mapped onto a smaller number of CellWhere localizations. These localizations include all major cell compartments, but the user may modify the mapping as desired. Protein-protein interaction listings, and their associated evidence strength scores, are obtained from the Mentha interactome server, or power-users may upload a pre-made network produced using some other interactomics tool. The Cytoscape.js JavaScript library is used in producing the graphical display. Importantly, for a protein that has been observed at multiple subcellular locations, users may prioritize the visual display of locations that are of special relevance to their research domain. CellWhere is at http://cellwhere-myology.rhcloud.com.


Asunto(s)
Mapeo de Interacción de Proteínas , Proteínas/análisis , Programas Informáticos , Gráficos por Computador , Genes , Internet , Espacio Intracelular/química
9.
Cell Mol Life Sci ; 70(12): 2159-74, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23344255

RESUMEN

Duchenne muscular dystrophy results from loss of the protein dystrophin, which links the intracellular cytoskeletal network with the extracellular matrix, but deficiency in this function does not fully explain the onset or progression of the disease. While some intracellular events involved in the degeneration of dystrophin-deficient muscle fibers have been well characterized, changes in their secretory profile are undescribed. To analyze the secretome profile of mdx myotubes independently of myonecrosis, we labeled the proteins of mdx and wild-type myotubes with stable isotope-labeled amino acids (SILAC), finding marked enrichment of vesicular markers in the mdx secretome. These included the lysosomal-associated membrane protein, LAMP1, that co-localized in vesicles with an over-secreted cytoskeletal protein, myosin light chain 1. These LAMP1/MLC1-3-positive vesicles accumulated in the cytosol of mdx myotubes and were secreted into the culture medium in a range of abnormal densities. Restitution of dystrophin expression, by exon skipping, to some 30 % of the control value, partially normalized the secretome profile and the excess LAMP1 accumulation. Together, our results suggest that a lack of dystrophin leads to a general dysregulation of vesicle trafficking. We hypothesize that disturbance of the export of proteins through vesicles occurs before, and then concurrently with, the myonecrotic cascade and contributes chronically to the pathophysiology of DMD, thereby presenting us with a range of new potential therapeutic targets.


Asunto(s)
Distrofina/deficiencia , Proteínas de Membrana de los Lisosomas/metabolismo , Fibras Musculares Esqueléticas/patología , Distrofia Muscular de Duchenne/metabolismo , Vesículas Secretoras/metabolismo , Actinas/análisis , Aminoácidos/metabolismo , Animales , Western Blotting , Línea Celular , Cromatografía Liquida , Biología Computacional , Immunoblotting , Marcaje Isotópico , Masculino , Proteínas de la Membrana/metabolismo , Ratones , Microscopía Electrónica de Transmisión , Fibras Musculares Esqueléticas/metabolismo , Vesículas Secretoras/ultraestructura , Estadísticas no Paramétricas , Espectrometría de Masas en Tándem
10.
Stem Cells ; 30(10): 2212-20, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22865615

RESUMEN

Transplantation of myogenic stem cells possesses great potential for long-term repair of dystrophic muscle. However, a single donor muscle biopsy is unlikely to provide enough cells to effectively transplant the muscle mass of a patient affected by muscular dystrophy. Expansion of cells ex vivo using traditional culture techniques significantly reduces engraftment potential. We hypothesized that activation of Notch signaling during ex vivo expansion would maintain donor cell engraftment potential. In this study, we expanded freshly isolated canine muscle-derived cells on tissue culture plates coated with Delta-1(ext) -IgG to activate Notch signaling or with human IgG as a control. A model of canine-to-murine xenotransplantation was used to quantitatively compare canine muscle cell engraftment and determine whether engrafted donor cells could function as satellite cells in vivo. We show that Delta-1(ext) -IgG inhibited differentiation of canine muscle-derived cells and increased the level of genes normally expressed in myogenic precursors. Moreover, cells expanded on Delta-1(ext) -IgG resulted in a significant increase in the number of donor-derived fibers, as compared to cells expanded on human IgG, reaching engraftment levels similar to freshly isolated cells. Importantly, cells expanded on Delta-1(ext) -IgG engrafted to the recipient satellite cell niche and contributed to further regeneration. A similar strategy of expanding human muscle-derived cells on Notch ligand might facilitate engraftment and muscle regeneration for patients affected with muscular dystrophy.


Asunto(s)
Supervivencia de Injerto , Células Musculares/metabolismo , Músculo Esquelético/metabolismo , Receptores Notch/metabolismo , Células Madre/metabolismo , Animales , Comunicación Celular , Diferenciación Celular , Proliferación Celular , Células Cultivadas , Perros , Humanos , Inmunoglobulina G/farmacología , Ratones , Ratones SCID , Células Musculares/citología , Células Musculares/trasplante , Músculo Esquelético/citología , Regeneración , Transducción de Señal , Especificidad de la Especie , Trasplante de Células Madre , Células Madre/citología , Trasplante Heterólogo
11.
Life (Basel) ; 13(6)2023 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-37374084

RESUMEN

Neurofilament levels are elevated in many neurodegenerative diseases and have shown promise as diagnostic and prognostic biomarkers in Amyotrophic Lateral Sclerosis (ALS), the most common form of Motor Neuron Disease (MND). This study assesses serum neurofilament light (NFL) and neurofilament heavy (NFH) chain concentrations in patients with ALS, other variants of motor neuron disease such as Progressive Muscular Atrophy (PMA) and Primary Lateral Sclerosis (PLS), and a range of other neurological diseases. It aims to evaluate the use of NFL and NFH to differentiate these conditions and for the prognosis of MND disease progression. NFL and NFH levels were quantified using electrochemiluminescence immunoassays (ECLIA). Both were elevated in 47 patients with MND compared to 34 patients with other neurological diseases and 33 healthy controls. NFL was able to differentiate patients with MND from the other groups with a Receiver Operating Characteristic (ROC) curve area under the curve (AUC) of 0.90 (p < 0.001). NFL correlated with the rate of disease progression in MND (rho 0.758, p < 0.001) and with the ALS Functional Rating Scale (rho -0.335, p = 0.021). NFL levels were higher in patients with ALS compared to both PMA (p = 0.032) and PLS (p = 0.012) and were able to distinguish ALS from both PMA and PLS with a ROC curve AUC of 0.767 (p = 0.005). These findings support the use of serum NFL to help diagnose and differentiate types of MND, in addition to providing prognostic information to patients and their families.

12.
Cells ; 12(3)2023 01 21.
Artículo en Inglés | MEDLINE | ID: mdl-36766730

RESUMEN

Genes with similar expression patterns in a set of diverse samples may be considered coexpressed. Human Gene Coexpression Analysis 2.0 (HGCA2.0) is a webtool which studies the global coexpression landscape of human genes. The website is based on the hierarchical clustering of 55,431 Homo sapiens genes based on a large-scale coexpression analysis of 3500 GTEx bulk RNA-Seq samples of healthy individuals, which were selected as the best representative samples of each tissue type. HGCA2.0 presents subclades of coexpressed genes to a gene of interest, and performs various built-in gene term enrichment analyses on the coexpressed genes, including gene ontologies, biological pathways, protein families, and diseases, while also being unique in revealing enriched transcription factors driving coexpression. HGCA2.0 has been successful in identifying not only genes with ubiquitous expression patterns, but also tissue-specific genes. Benchmarking showed that HGCA2.0 belongs to the top performing coexpression webtools, as shown by STRING analysis. HGCA2.0 creates working hypotheses for the discovery of gene partners or common biological processes that can be experimentally validated. It offers a simple and intuitive website design and user interface, as well as an API endpoint.


Asunto(s)
Perfilación de la Expresión Génica , Redes Reguladoras de Genes , Genes , Humanos , RNA-Seq , Factores de Transcripción , Genes/genética , Genes/fisiología
13.
Exp Cell Res ; 317(14): 1979-93, 2011 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-21635888

RESUMEN

Research into muscle atrophy and hypertrophy is hampered by limitations of the available experimental models. Interpretation of in vivo experiments is confounded by the complexity of the environment while in vitro models are subject to the marked disparities between cultured myotubes and the mature myofibres of living tissues. Here we develop a method (PhAct) based on ex vivo maintenance of the isolated myofibre as a model of disuse atrophy, using standard microscopy equipment and widely available analysis software, to measure f-actin content per myofibre and per nucleus over two weeks of ex vivo maintenance. We characterize the 35% per week atrophy of the isolated myofibre in terms of early changes in gene expression and investigate the effects on loss of muscle mass of modulatory agents, including Myostatin and Follistatin. By tracing the incorporation of a nucleotide analogue we show that the observed atrophy is not associated with loss or replacement of myonuclei. Such a completely controlled investigation can be conducted with the myofibres of a single muscle. With this novel method we can distinguish those features and mechanisms of atrophy and hypertrophy that are intrinsic to the muscle fibre from those that include activities of other tissues and systemic agents.


Asunto(s)
Actinas/análisis , Fibras Musculares Esqueléticas/patología , Atrofia Muscular/patología , Programas Informáticos , Actinas/genética , Animales , Modelos Animales de Enfermedad , Perfilación de la Expresión Génica , Técnicas In Vitro , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Fibras Musculares Esqueléticas/metabolismo , Atrofia Muscular/genética , Atrofia Muscular/metabolismo , Análisis de Secuencia por Matrices de Oligonucleótidos , ARN Mensajero/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
14.
J Pers Med ; 12(11)2022 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-36422108

RESUMEN

The rapid increase in the number of genetic variants identified to be associated with Amyotrophic Lateral Sclerosis (ALS) through genome-wide association studies (GWAS) has created an emerging need to understand the functional pathways that are implicated in the pathology of ALS. Gene-set analysis (GSA) is a powerful method that can provide insight into the associated biological pathways, determining the joint effect of multiple genetic markers. The main contribution of this review is the collection of ALS GSA studies that employ GWAS or individual-based genotype data, investigating their methodology and results related to ALS-associated molecular pathways. Furthermore, the limitations in standard single-gene analyses are summarized, highlighting the power of gene-set analysis, and a brief overview of the statistical properties of gene-set analysis and related concepts is provided. The main aims of this review are to investigate the reproducibility of the collected studies and identify their strengths and limitations, in order to enhance the experimental design and therefore the quality of the results of future studies, deepening our understanding of this devastating disease.

15.
J Pers Med ; 12(11)2022 Nov 08.
Artículo en Inglés | MEDLINE | ID: mdl-36579600

RESUMEN

Amyotrophic lateral sclerosis is a disease affecting upper and lower motor neurons. Although motor neuron death is the core event of ALS pathology, it is increasingly recognized that other tissues and cell types are affected in the disease, making potentially major contributions to the occurrence and progression of pathology. We review here the known cellular and molecular characteristics of muscle tissue affected by ALS. Evidence of toxicity in skeletal muscle tissue is considered, including metabolic dysfunctions, impaired proteostasis, and deficits in muscle regeneration and RNA metabolism. The role of muscle as a secretory organ, and effects on the skeletal muscle secretome are also covered, including the increase in secretion of toxic factors or decrease in essential factors that have consequences for neuronal function and survival.

16.
Life (Basel) ; 13(1)2022 Dec 31.
Artículo en Inglés | MEDLINE | ID: mdl-36676070

RESUMEN

Amyotrophic Lateral Sclerosis is a progressive neurodegenerative disease and is the most common adult motor neuron disease. The disease pathogenesis is complex with the perturbation of multiple pathways proposed, including mitochondrial dysfunction, RNA processing, glutamate excitotoxicity, endoplasmic reticulum stress, protein homeostasis and endosomal transport/extracellular vesicle (EV) secretion. EVs are nanoscopic membrane-bound particles that are released from cells, involved in the intercellular communication of proteins, lipids and genetic material, and there is increasing evidence of their role in ALS. After discussing the biogenesis of EVs, we review their roles in the propagation of pathological proteins in ALS, such as TDP-43, SOD1 and FUS, and their contribution to disease pathology. We also discuss the ALS related genes which are involved in EV formation and vesicular trafficking, before considering the EV protein and RNA dysregulation found in ALS and how these have been investigated as potential biomarkers. Finally, we highlight the potential use of EVs as therapeutic agents in ALS, in particular EVs derived from mesenchymal stem cells and EVs as drug delivery vectors for potential treatment strategies.

17.
J Pers Med ; 12(9)2022 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-36143200

RESUMEN

Amyotrophic Lateral Sclerosis (ALS), Spinal Bulbar Muscular Atrophy (SBMA), and Spinal Muscular Atrophy (SMA) are motor neuron diseases (MNDs) characterised by progressive motor neuron degeneration, weakness and muscular atrophy. Lipid dysregulation is well recognised in each of these conditions and occurs prior to neurodegeneration. Several lipid markers have been shown to predict prognosis in ALS. Sphingolipids are complex lipids enriched in the central nervous system and are integral to key cellular functions including membrane stability and signalling pathways, as well as being mediators of neuroinflammation and neurodegeneration. This review highlights the metabolism of sphingomyelin (SM), the most abundant sphingolipid, and of its metabolite ceramide, and its role in the pathophysiology of neurodegeneration, focusing on MNDs. We also review published lipidomic studies in MNDs. In the 13 studies of patients with ALS, 12 demonstrated upregulation of multiple SM species and 6 demonstrated upregulation of ceramides. SM species also correlated with markers of clinical progression in five of six studies. These data highlight the potential use of SM and ceramide as biomarkers in ALS. Finally, we review potential therapeutic strategies for targeting sphingolipid metabolism in neurodegeneration.

18.
Cells ; 11(5)2022 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-35269468

RESUMEN

Extracellular vesicles can mediate communication between tissues, affecting the physiological conditions of recipient cells. They are increasingly investigated in Amyotrophic Lateral Sclerosis, the most common form of Motor Neurone Disease, as transporters of misfolded proteins including SOD1, FUS, TDP43, or other neurotoxic elements, such as the dipeptide repeats resulting from C9orf72 expansions. EVs are classified based on their biogenesis and size and can be separated by differential centrifugation. They include exosomes, released by the fusion of multivesicular bodies with the plasma membrane, and ectosomes, also known as microvesicles or microparticles, resulting from budding or pinching of the plasma membrane. In the current study, EVs were obtained from the myotube cell culture medium of ALS patients or healthy controls. EVs of two different sizes, separating at 20,000 or 100,000 g, were then compared in terms of their effects on recipient motor neurons, astrocytes, and myotubes. Compared to untreated cells, the smaller, exosome-like vesicles of ALS patients reduced the survival of motor neurons by 31% and of myotubes by 18%, decreased neurite length and branching, and increased the proportion of stellate astrocytes, whereas neither those of healthy subjects, nor larger EVs of ALS or healthy subjects, had such effects.


Asunto(s)
Esclerosis Amiotrófica Lateral , Exosomas , Vesículas Extracelulares , Síndromes de Neurotoxicidad , Esclerosis Amiotrófica Lateral/metabolismo , Exosomas/metabolismo , Vesículas Extracelulares/metabolismo , Humanos , Neuronas Motoras/metabolismo , Fibras Musculares Esqueléticas/metabolismo
19.
J Cachexia Sarcopenia Muscle ; 13(2): 1385-1402, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35194965

RESUMEN

BACKGROUND: The cause of the motor neuron (MN) death that drives terminal pathology in amyotrophic lateral sclerosis (ALS) remains unknown, and it is thought that the cellular environment of the MN may play a key role in MN survival. Several lines of evidence implicate vesicles in ALS, including that extracellular vesicles may carry toxic elements from astrocytes towards MNs, and that pathological proteins have been identified in circulating extracellular vesicles of sporadic ALS patients. Because MN degeneration at the neuromuscular junction is a feature of ALS, and muscle is a vesicle-secretory tissue, we hypothesized that muscle vesicles may be involved in ALS pathology. METHODS: Sporadic ALS patients were confirmed to be ALS according to El Escorial criteria and were genotyped to test for classic gene mutations associated with ALS, and physical function was assessed using the ALSFRS-R score. Muscle biopsies of either mildly affected deltoids of ALS patients (n = 27) or deltoids of aged-matched healthy subjects (n = 30) were used for extraction of muscle stem cells, to perform immunohistology, or for electron microscopy. Muscle stem cells were characterized by immunostaining, RT-qPCR, and transcriptomic analysis. Secreted muscle vesicles were characterized by proteomic analysis, Western blot, NanoSight, and electron microscopy. The effects of muscle vesicles isolated from the culture medium of ALS and healthy myotubes were tested on healthy human-derived iPSC MNs and on healthy human myotubes, with untreated cells used as controls. RESULTS: An accumulation of multivesicular bodies was observed in muscle biopsies of sporadic ALS patients by immunostaining and electron microscopy. Study of muscle biopsies and biopsy-derived denervation-naïve differentiated muscle stem cells (myotubes) revealed a consistent disease signature in ALS myotubes, including intracellular accumulation of exosome-like vesicles and disruption of RNA-processing. Compared with vesicles from healthy control myotubes, when administered to healthy MNs the vesicles of ALS myotubes induced shortened, less branched neurites, cell death, and disrupted localization of RNA and RNA-processing proteins. The RNA-processing protein FUS and a majority of its binding partners were present in ALS muscle vesicles, and toxicity was dependent on the expression level of FUS in recipient cells. Toxicity to recipient MNs was abolished by anti-CD63 immuno-blocking of vesicle uptake. CONCLUSIONS: ALS muscle vesicles are shown to be toxic to MNs, which establishes the skeletal muscle as a potential source of vesicle-mediated toxicity in ALS.


Asunto(s)
Esclerosis Amiotrófica Lateral , Células Madre Pluripotentes Inducidas , Anciano , Esclerosis Amiotrófica Lateral/genética , Humanos , Células Madre Pluripotentes Inducidas/metabolismo , Células Madre Pluripotentes Inducidas/patología , Neuronas Motoras/metabolismo , Células Musculares/metabolismo , Proteómica
20.
J Pers Med ; 11(5)2021 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-34065209

RESUMEN

The field of neuromuscular research has seen considerable recent advances in the molecular and cellular understanding of muscle biology, and the treatment of neuromuscular disease [...].

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