RESUMEN
Amyotrophic lateral sclerosis (ALS) is an adult-onset neurodegenerative disease leading to motor neuron loss. Currently mutations in > 40 genes have been linked to ALS, but the contribution of many genes and genetic mutations to the ALS pathogenic process remains poorly understood. Therefore, we first performed comparative interactome analyses of five recently discovered ALS-associated proteins (C21ORF2, KIF5A, NEK1, TBK1, and TUBA4A) which highlighted many novel binding partners, and both unique and shared interactors. The analysis further identified C21ORF2 as a strongly connected protein. The role of C21ORF2 in neurons and in the nervous system, and of ALS-associated C21ORF2 variants is largely unknown. Therefore, we combined human iPSC-derived motor neurons with other models and different molecular cell biological approaches to characterize the potential pathogenic effects of C21ORF2 mutations in ALS. First, our data show C21ORF2 expression in ALS-relevant mouse and human neurons, such as spinal and cortical motor neurons. Further, the prominent ALS-associated variant C21ORF2-V58L caused increased apoptosis in mouse neurons and movement defects in zebrafish embryos. iPSC-derived motor neurons from C21ORF2-V58L-ALS patients, but not isogenic controls, show increased apoptosis, and changes in DNA damage response, mitochondria and neuronal excitability. In addition, C21ORF2-V58L induced post-transcriptional downregulation of NEK1, an ALS-associated protein implicated in apoptosis and DDR. In all, our study defines the pathogenic molecular and cellular effects of ALS-associated C21ORF2 mutations and implicates impaired post-transcriptional regulation of NEK1 downstream of mutant C21ORF72 in ALS.
Asunto(s)
Esclerosis Amiotrófica Lateral , Células Madre Pluripotentes Inducidas , Mitocondrias , Neuronas Motoras , Quinasa 1 Relacionada con NIMA , Pez Cebra , Humanos , Esclerosis Amiotrófica Lateral/genética , Esclerosis Amiotrófica Lateral/metabolismo , Esclerosis Amiotrófica Lateral/patología , Quinasa 1 Relacionada con NIMA/genética , Quinasa 1 Relacionada con NIMA/metabolismo , Animales , Neuronas Motoras/metabolismo , Neuronas Motoras/patología , Células Madre Pluripotentes Inducidas/metabolismo , Ratones , Mitocondrias/metabolismo , Mitocondrias/patología , Reparación del ADN/genética , Daño del ADN , MutaciónRESUMEN
Spinal and bulbar muscular atrophy (SBMA), or Kennedy's disease (KD), is a rare hereditary neuromuscular disorder demonstrating commonalities with amyotrophic lateral sclerosis (ALS). The current study aimed to define functional and central nervous system abnormalities associated with SBMA pathology, their interaction, and to identify novel clinical markers for quantifying disease activity. 27 study participants (12 SBMA; 8 ALS; 7 Control) were recruited. SBMA patients underwent comprehensive motor and sensory functional assessments, and neurophysiological testing. All participants underwent whole-brain structural and diffusion MRI. SBMA patients demonstrated marked peripheral motor and sensory abnormalities across clinical assessments. Increased abnormalities on neurological examination were significantly associated with increased disease duration in SBMA patients (R2 = 0.85, p < 0.01). Widespread juxtacortical axonal degeneration of corticospinal white matter tracts were detected in SBMA patients (premotor; motor; somatosensory; p < 0.05), relative to controls. Increased axial diffusivity was significantly correlated with total neuropathy score in SBMA patients across left premotor (R2 = 0.59, p < 0.01), motor (R2 = 0.63, p < 0.01), and somatosensory (R2 = 0.61, p < 0.01) tracts. The present series has identified involvement of motor and sensory brain regions in SBMA, associated with disease duration and increasing severity of peripheral neuropathy. Quantification of annualized brain MRI together with Total Neuropathy Score may represent a novel approach for clinical monitoring.
Asunto(s)
Atrofia Bulboespinal Ligada al X , Humanos , Masculino , Persona de Mediana Edad , Femenino , Anciano , Atrofia Bulboespinal Ligada al X/fisiopatología , Atrofia Bulboespinal Ligada al X/patología , Adulto , Esclerosis Amiotrófica Lateral/fisiopatología , Esclerosis Amiotrófica Lateral/patología , Esclerosis Amiotrófica Lateral/diagnóstico por imagen , Encéfalo/diagnóstico por imagen , Encéfalo/patología , Encéfalo/fisiopatología , Imagen por Resonancia Magnética , Sustancia Blanca/diagnóstico por imagen , Sustancia Blanca/patología , Sustancia Blanca/fisiopatologíaRESUMEN
Hexanucleotide repeat expansion in the C9ORF72 gene is the most frequent inherited cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). The expansion results in multiple dipeptide repeat proteins, among which arginine-rich poly-GR proteins are highly toxic to neurons and decrease the rate of protein synthesis. We investigated whether the effect on protein synthesis contributes to neuronal dysfunction and degeneration. We found that the expression of poly-GR proteins inhibited global translation by perturbing translation elongation. In iPSC-differentiated neurons, the translation of transcripts with relatively slow elongation rates was further slowed, and stalled, by poly-GR. Elongation stalling increased ribosome collisions and induced a ribotoxic stress response (RSR) mediated by ZAKα that increased the phosphorylation of the kinase p38 and promoted cell death. Knockdown of ZAKα or pharmacological inhibition of p38 ameliorated poly-GR-induced toxicity and improved the survival of iPSC-derived neurons from patients with C9ORF72-ALS/FTD. Our findings suggest that targeting the RSR may be neuroprotective in patients with ALS/FTD caused by repeat expansion in C9ORF72.
Asunto(s)
Esclerosis Amiotrófica Lateral , Proteína C9orf72 , Expansión de las Repeticiones de ADN , Demencia Frontotemporal , Células Madre Pluripotentes Inducidas , Neuronas , Proteína C9orf72/genética , Proteína C9orf72/metabolismo , Esclerosis Amiotrófica Lateral/genética , Esclerosis Amiotrófica Lateral/metabolismo , Esclerosis Amiotrófica Lateral/patología , Humanos , Demencia Frontotemporal/genética , Demencia Frontotemporal/metabolismo , Demencia Frontotemporal/patología , Neuronas/metabolismo , Neuronas/patología , Células Madre Pluripotentes Inducidas/metabolismo , Expansión de las Repeticiones de ADN/genética , Extensión de la Cadena Peptídica de Translación , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/genética , Estrés Fisiológico/genética , Ribosomas/metabolismo , Ribosomas/genéticaRESUMEN
Amyotrophic lateral sclerosis (ALS) is a devastating paralytic disorder caused by the death of motoneurons. Several mutations in the KIF5A gene have been identified in patients with ALS. Some mutations affect the splicing sites of exon 27 leading to its deletion (Δ27 mutation). KIF5A Δ27 is aggregation-prone and pathogenic for motoneurons due to a toxic gain of function. Another mutation found to be enriched in ALS patients is a proline/leucine substitution at position 986 (P986L mutation). Bioinformatic analyses strongly suggest that this variant is benign. Our study aims to conduct functional studies in Drosophila to classify the KIF5A P986L variant. When expressed in motoneurons, KIF5A P986L does not modify the morphology of larval NMJ or the synaptic transmission. In addition, KIF5A P986L is uniformly distributed in axons and does not disturb mitochondria distribution. Locomotion at larval and adult stages is not affected by KIF5A P986L. Finally, both KIF5A WT and P986L expression in adult motoneurons extend median lifespan compared to control flies. Altogether, our data show that the KIF5A P986L variant is not pathogenic for motoneurons and may represent a hypomorphic allele, although it is not causative for ALS.
Asunto(s)
Esclerosis Amiotrófica Lateral , Cinesinas , Neuronas Motoras , Animales , Cinesinas/genética , Cinesinas/metabolismo , Neuronas Motoras/metabolismo , Neuronas Motoras/patología , Esclerosis Amiotrófica Lateral/genética , Esclerosis Amiotrófica Lateral/patología , Esclerosis Amiotrófica Lateral/metabolismo , Mutación , Humanos , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila , Unión Neuromuscular/metabolismo , Unión Neuromuscular/patología , Drosophila melanogaster/genética , Transmisión Sináptica/genética , Modelos Animales de Enfermedad , Axones/metabolismo , Axones/patología , Larva/genética , Larva/metabolismoRESUMEN
OBJECTIVES: This study aimed to clarify the relationship between 43-kDa TAR DNA-binding protein (TDP-43) pathology and spinal cord anterior horn motor neuron (AHMN) atrophy in sporadic amyotrophic lateral sclerosis (SALS). METHODS: Eight patients with SALS and 12 controls were included in this study. Formalin-fixed specimens of lumbar spinal cord samples were paraffin-embedded and sectioned at the level of the fourth lumbar spinal cord with a 4 µm thickness. Using a microscope, the long diameters of the neurons with nucleoli were measured in spinal AHMNs stained with an anti-SMI-32 antibody. AHMNs were divided into medial and lateral nuclei for statistical analysis. We also used previously reported data to measure the long diameter of AHMNs with initial TDP-43 pathology, in which TDP-43 was present both in the nucleus and cytoplasm. RESULTS: The long diameter of the lumbar spinal AHMNs in patients with SALS was smaller in the medial nucleus (42.54 ± 9.33 µm, n = 24) and the lateral nucleus (49.41 ± 13.86 µm, n = 129) than in controls (medial nucleus: 55.84 ± 13.49 µm, n = 85, p < 0.001; lateral nucleus: 62.39 ± 13.29 µm, n = 756, p < 0.001, Mann-Whitney U test). All 21 motor neurons with initial TDP-43 pathology were in the lateral nucleus, and their long diameter (67.60 ± 18.3 µm, p = 0.352) was not significantly different from that of controls. CONCLUSION: Motor neuron atrophy in SALS does not occur during the initial stages of TDP-43 pathology, and TDP-43 pathology is already advanced in the atrophied motor neurons.
Asunto(s)
Esclerosis Amiotrófica Lateral , Proteínas de Unión al ADN , Degeneración Nerviosa , Médula Espinal , Humanos , Esclerosis Amiotrófica Lateral/patología , Esclerosis Amiotrófica Lateral/metabolismo , Masculino , Femenino , Persona de Mediana Edad , Anciano , Proteínas de Unión al ADN/metabolismo , Médula Espinal/patología , Médula Espinal/metabolismo , Degeneración Nerviosa/patología , Células del Asta Anterior/patología , Neuronas Motoras/patología , Neuronas Motoras/metabolismoRESUMEN
Disease modeling of neuromuscular disorders, such as amyotrophic lateral sclerosis (ALS), is hindered by limited accessibility of affected cells. This problem can be overcome by generation of human induced pluripotent stem cells (hiPSC), which can be then differentiated into required cells. Here, we describe the detailed protocol of hiPSC establishment from peripheral blood mononuclear cells (PBMC) of two ALS patients with detected expansion of G4C2 (GGGGCC) repeats in the first intron of C9ORF72 gene, known to be linked with the most common form of familial ALS.Successful PBMC reprogramming with non-integrating Sendai vectors was confirmed by expression of pluripotency markers: OCT4, NANOG, SSEA4, and TRA-1-60 in obtained hiPSC and their ability to differentiate into cells of three germ layers.The generated ALS-patient-specific hiPSC create a possibility for deciphering molecular basis of this devastating neuromuscular disease.
Asunto(s)
Esclerosis Amiotrófica Lateral , Proteína C9orf72 , Diferenciación Celular , Células Madre Pluripotentes Inducidas , Leucocitos Mononucleares , Humanos , Esclerosis Amiotrófica Lateral/genética , Esclerosis Amiotrófica Lateral/patología , Proteína C9orf72/genética , Proteína C9orf72/metabolismo , Técnicas de Cultivo de Célula/métodos , Reprogramación Celular , Expansión de las Repeticiones de ADN , Células Madre Pluripotentes Inducidas/metabolismo , Células Madre Pluripotentes Inducidas/citología , Leucocitos Mononucleares/metabolismoRESUMEN
Amyotrophic lateral sclerosis (ALS) is characterized by degeneration of motor neurons in the central nervous system (CNS). Mutations in the metalloenzyme SOD1 are associated with inherited forms of ALS and cause a toxic gain of function thought to be mediated by dimer destabilization and misfolding. SOD1 binds two Cu and two Zn ions in its homodimeric form. We have applied native ambient mass spectrometry imaging to visualize the spatial distributions of intact metal-bound SOD1G93A complexes in SOD1G93A transgenic mouse spinal cord and brain sections and evaluated them against disease pathology. The molecular specificity of our approach reveals that metal-deficient SOD1G93A species are abundant in CNS structures correlating with ALS pathology whereas fully metalated SOD1G93A species are homogenously distributed. Monomer abundance did not correlate with pathology. We also show that the dimer-destabilizing post-translational modification, glutathionylation, has limited influence on the spatial distribution of SOD1 dimers.
Asunto(s)
Esclerosis Amiotrófica Lateral , Encéfalo , Espectrometría de Masas , Ratones Transgénicos , Médula Espinal , Superóxido Dismutasa-1 , Animales , Superóxido Dismutasa-1/genética , Superóxido Dismutasa-1/metabolismo , Superóxido Dismutasa-1/química , Esclerosis Amiotrófica Lateral/genética , Esclerosis Amiotrófica Lateral/metabolismo , Esclerosis Amiotrófica Lateral/patología , Ratones , Médula Espinal/metabolismo , Médula Espinal/patología , Espectrometría de Masas/métodos , Encéfalo/metabolismo , Encéfalo/diagnóstico por imagen , Encéfalo/patología , Cobre/metabolismo , Zinc/metabolismo , Humanos , Superóxido Dismutasa/metabolismo , Superóxido Dismutasa/genética , Superóxido Dismutasa/química , Mutación , Procesamiento Proteico-Postraduccional , Multimerización de Proteína , Modelos Animales de Enfermedad , MasculinoRESUMEN
The majority of severe early-onset and juvenile cases of amyotrophic lateral sclerosis (ALS) are caused by mutations in the FUS gene, resulting in rapid disease progression. Mutant FUS accumulates within stress granules (SGs), thereby affecting the dynamics of these ribonucleoprotein complexes. Here, we define the interactome of the severe mutant FUSP525L variant in human induced pluripotent stem cell (iPSC)-derived motor neurons. We find increased interaction of FUSP525L with the PARP1 enzyme, promoting poly-ADP-ribosylation (PARylation) and binding of FUS to histone H1.2. Inhibiting PARylation or reducing H1.2 levels alleviates mutant FUS aggregation, SG alterations, and apoptosis in human motor neurons. Conversely, elevated H1.2 levels exacerbate FUS-ALS phenotypes, driven by the internally disordered terminal domains of H1.2. In C. elegans models, knockdown of H1.2 and PARP1 orthologs also decreases FUSP525L aggregation and neurodegeneration, whereas H1.2 overexpression worsens ALS-related changes. Our findings indicate a link between PARylation, H1.2, and FUS with potential therapeutic implications.
Asunto(s)
Esclerosis Amiotrófica Lateral , Caenorhabditis elegans , Histonas , Mutación , Poli(ADP-Ribosa) Polimerasa-1 , Proteína FUS de Unión a ARN , Esclerosis Amiotrófica Lateral/genética , Esclerosis Amiotrófica Lateral/metabolismo , Esclerosis Amiotrófica Lateral/patología , Humanos , Histonas/metabolismo , Proteína FUS de Unión a ARN/metabolismo , Proteína FUS de Unión a ARN/genética , Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/genética , Animales , Mutación/genética , Poli(ADP-Ribosa) Polimerasa-1/metabolismo , Poli(ADP-Ribosa) Polimerasa-1/genética , Neuronas Motoras/metabolismo , Neuronas Motoras/patología , Poli ADP Ribosilación , Células Madre Pluripotentes Inducidas/metabolismo , Unión ProteicaRESUMEN
Amyotrophic lateral sclerosis (ALS) is a complex disease impacting motor neurons of the brain, brainstem, and spinal cord. Disease etiology is quite heterogeneous with over 40 genes causing the disease and a vast ~90% of patients having no prior family history. Astrocytes are major contributors to ALS, particularly through involvement in accelerating disease progression. Through study of genetic forms of disease including SOD1, TDP43, FUS, C9orf72, VCP, TBK1, and more recently patient-derived cells from sporadic individuals, many biological mechanisms have been identified to cause intrinsic or glial-mediated neurotoxicity to motor neurons. Overall, many of the normally supportive and beneficial roles that astrocytes contribute to neuronal health and survival instead switch to become deleterious and neurotoxic. While the exact pathways may differ based on disease-origin, altered astrocyte-neuron communication is a common feature of ALS. Within this chapter, distinct genetic forms are examined in detail, along with what is known from sporadic patient-derived cells. Overall, this chapter highlights the interplay between astrocytes and neurons in this complex disease and describes the key features underlying: astrocyte-mediated motor neuron toxicity, excitotoxicity, oxidative/nitrosative stress, protein dyshomeostasis, metabolic imbalance, inflammation, trophic factor withdrawal, blood-brain/blood-spinal cord barrier involvement, disease spreading, and the extracellular matrix/cell adhesion/TGF-ß signaling pathways.
Asunto(s)
Esclerosis Amiotrófica Lateral , Astrocitos , Comunicación Celular , Progresión de la Enfermedad , Neuronas Motoras , Esclerosis Amiotrófica Lateral/metabolismo , Esclerosis Amiotrófica Lateral/patología , Humanos , Astrocitos/metabolismo , Neuronas Motoras/metabolismo , Neuronas Motoras/patología , Comunicación Celular/fisiología , AnimalesRESUMEN
Neurodegenerative diseases are manifested by a progressive death of neural cells, resulting in the deterioration of central nervous system (CNS) functions, ultimately leading to specific behavioural and cognitive symptoms associated with affected brain regions. Several neurodegenerative disorders are caused by genetic variants or mutations, although the majority of cases are sporadic and linked to various environmental risk factors, with yet an unknown aetiology. Neuroglial changes are fundamental and often lead to the pathophysiology of neurodegenerative diseases. In particular, microglial cells, which are essential for maintaining CNS health, become compromised in their physiological functions with the exposure to environmental risk factors, genetic variants or mutations, as well as disease pathology. In this chapter, we cover the contribution of neuroglia, especially microglia, to several neurodegenerative diseases, including Nasu-Hakola disease, Parkinson's disease, amyotrophic lateral sclerosis, Alzheimer's disease, Huntington's disease, infectious disease-associated neurodegeneration, and metal-precipitated neurodegeneration. Future research perspectives for the field pertaining to the therapeutic targeting of microglia across these disease conditions are also discussed.
Asunto(s)
Microglía , Enfermedades Neurodegenerativas , Microglía/metabolismo , Microglía/patología , Humanos , Enfermedades Neurodegenerativas/metabolismo , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/patología , Esclerosis Amiotrófica Lateral/genética , Esclerosis Amiotrófica Lateral/metabolismo , Esclerosis Amiotrófica Lateral/patología , Esclerosis Amiotrófica Lateral/fisiopatología , Animales , Enfermedad de Parkinson/metabolismoRESUMEN
Intermediate-length repeat expansions in ATAXIN-2 (ATXN2) are the strongest genetic risk factor for amyotrophic lateral sclerosis (ALS). At the molecular level, ATXN2 intermediate expansions enhance TDP-43 toxicity and pathology. However, whether this triggers ALS pathogenesis at the cellular and functional level remains unknown. Here, we combine patient-derived and mouse models to dissect the effects of ATXN2 intermediate expansions in an ALS background. iPSC-derived motor neurons from ATXN2-ALS patients show altered stress granules, neurite damage and abnormal electrophysiological properties compared to healthy control and other familial ALS mutations. In TDP-43Tg-ALS mice, ATXN2-Q33 causes reduced motor function, NMJ alterations, neuron degeneration and altered in vitro stress granule dynamics. Furthermore, gene expression changes related to mitochondrial function and inflammatory response are detected and confirmed at the cellular level in mice and human neuron and organoid models. Together, these results define pathogenic defects underlying ATXN2-ALS and provide a framework for future research into ATXN2-dependent pathogenesis and therapy.
Asunto(s)
Esclerosis Amiotrófica Lateral , Ataxina-2 , Modelos Animales de Enfermedad , Células Madre Pluripotentes Inducidas , Ratones Transgénicos , Neuronas Motoras , Péptidos , Esclerosis Amiotrófica Lateral/genética , Esclerosis Amiotrófica Lateral/metabolismo , Esclerosis Amiotrófica Lateral/patología , Ataxina-2/genética , Ataxina-2/metabolismo , Humanos , Animales , Péptidos/metabolismo , Péptidos/genética , Ratones , Células Madre Pluripotentes Inducidas/metabolismo , Neuronas Motoras/metabolismo , Neuronas Motoras/patología , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Fenotipo , Masculino , Femenino , Mitocondrias/metabolismo , Neuritas/metabolismoRESUMEN
Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disorder characterized by progressive loss of motor neurons. The effective treatments for ALS remain elusive, necessitating exploration into novel preventive strategies. ALS pathogenesis is triggered by oxidative stress which results in neuroinflammation, exicitotoxicity and neuronal cell death. Nutritional mechanism for halting progression of neurodegeneration is through dietary compounds with antioxidants, anti-inflammatory or neuromodulating activity. Coffee is a widely consumed beverage made up of polyphenols, caffeine and other compounds with possible antioxidants and neuro-protective roles. It is important to say that various epidemiological studies have documented association between coffee intake and ALS. This chapter is aimed to present a comprehensive review of existing literature on coffee consumption and ALS, involving epidemiological studies, preclinical research, and its mechanism of actions in animal model of ALS. It highlights key findings regarding the potential neuroprotective properties of coffee constituents such as caffeine, polyphenols, and other bioactive compounds. Furthermore, it discusses possible pathways through which coffee may modulate ALS pathogenesis, including suppressing oxidative stress and neuroinflammation while boosting adenosine function via the adenosine receptor two on the motor neuron cells membrane in the spinal cord to enhance motor function via the corticospinal tract. Overall, this chapter underscores the significance of further research to unravel the specific mechanisms by which coffee exerts its neuroprotective effects in ALS, with the ultimate goal of identifying dietary strategies for ALS prevention and management.
Asunto(s)
Esclerosis Amiotrófica Lateral , Café , Esclerosis Amiotrófica Lateral/patología , Humanos , Animales , Fármacos Neuroprotectores/farmacología , Estrés Oxidativo/fisiología , Estrés Oxidativo/efectos de los fármacosRESUMEN
Amyotrophic lateral sclerosis (ALS) is a fatal disease that causes degeneration of motor neurons (MNs) and paralysis. ALS can be caused by mutations in the gene that encodes copper/zinc superoxide dismutase (SOD1). SOD1 is known mostly as a cytosolic antioxidant protein, but SOD1 is also in the nucleus of non-transgenic (tg) and human SOD1 (hSOD1) tg mouse MNs. SOD1's nuclear presence in different cell types and subnuclear compartmentations are unknown, as are the nuclear functions of SOD1. We examined hSOD1 nuclear localization and DNA damage in tg mice expressing mutated and wildtype variants of hSOD1 (hSOD1-G93A and hSOD1-wildtype). We also studied ALS patient-derived induced pluripotent stem (iPS) cells to determine the nuclear presence of SOD1 in undifferentiated and differentiated MNs. In hSOD1-G93A and hSOD1-wildtype tg mice, choline acetyltransferase (ChAT)-positive MNs had nuclear hSOD1, but while hSOD1-wildtype mouse MNs also had nuclear ChAT, hSOD1-G93A mouse MNs showed symptom-related loss of nuclear ChAT. The interneurons had preserved parvalbumin nuclear positivity in hSOD1-G93A mice. hSOD1-G93A was seen less commonly in spinal cord astrocytes and, notably, oligodendrocytes, but as the disease emerged, the oligodendrocytes had increased mutant hSOD1 nuclear presence. Brain and spinal cord subcellular fractionation identified mutant hSOD1 in soluble nuclear extracts of the brain and spinal cord, but mutant hSOD1 was concentrated in the chromatin nuclear extract only in the spinal cord. Nuclear extracts from mutant hSOD1 tg mouse spinal cords had altered protein nitration, footprinting peroxynitrite presence, and the intact nuclear extracts had strongly increased superoxide production as well as the active NADPH oxidase marker, p47phox. The comet assay showed that MNs from hSOD1-G93A mice progressively (6-14 weeks of age) accumulated DNA single-strand breaks. Ablation of the NCF1 gene, encoding p47phox, and pharmacological inhibition of NADPH oxidase with systemic treatment of apocynin (10 mg/kg, ip) extended the mean lifespan of hSOD1-G93A mice by about 25% and mitigated genomic DNA damage progression. In human postmortem CNS, SOD1 was found in the nucleus of neurons and glia; nuclear SOD1 was increased in degenerating neurons in ALS cases and formed inclusions. Human iPS cells had nuclear SOD1 during directed differentiation to MNs, but mutant SOD1-expressing cells failed to establish wildtype MN nuclear SOD1 levels. We conclude that SOD1 has a prominent nuclear presence in the central nervous system, perhaps adopting aberrant contexts to participate in ALS pathobiology.
Asunto(s)
Esclerosis Amiotrófica Lateral , Núcleo Celular , Daño del ADN , Células Madre Pluripotentes Inducidas , Neuronas Motoras , Estrés Oxidativo , Superóxido Dismutasa-1 , Animales , Humanos , Ratones , Esclerosis Amiotrófica Lateral/metabolismo , Esclerosis Amiotrófica Lateral/genética , Esclerosis Amiotrófica Lateral/patología , Núcleo Celular/metabolismo , Modelos Animales de Enfermedad , Células Madre Pluripotentes Inducidas/metabolismo , Ratones Transgénicos , Neuronas Motoras/metabolismo , Neuronas Motoras/patología , NADPH Oxidasas/metabolismo , NADPH Oxidasas/genética , Fenotipo , Médula Espinal/metabolismo , Médula Espinal/patología , Superóxido Dismutasa-1/genética , Superóxido Dismutasa-1/metabolismoRESUMEN
Spinal motor neurons (MNs) represent a highly vulnerable cellular population, which is affected in fatal neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA). In this study, we show that the heterozygous loss of SYT13 is sufficient to trigger a neurodegenerative phenotype resembling those observed in ALS and SMA. SYT13+/- hiPSC-derived MNs displayed a progressive manifestation of typical neurodegenerative hallmarks such as loss of synaptic contacts and accumulation of aberrant aggregates. Moreover, analysis of the SYT13+/- transcriptome revealed a significant impairment in biological mechanisms involved in motoneuron specification and spinal cord differentiation. This transcriptional portrait also strikingly correlated with ALS signatures, displaying a significant convergence toward the expression of pro-apoptotic and pro-inflammatory genes, which are controlled by the transcription factor TP53. Our data show for the first time that the heterozygous loss of a single member of the synaptotagmin family, SYT13, is sufficient to trigger a series of abnormal alterations leading to MN sufferance, thus revealing novel insights into the selective vulnerability of this cell population.
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Esclerosis Amiotrófica Lateral , Neuronas Motoras , Sinaptotagminas , Proteína p53 Supresora de Tumor , Humanos , Proteína p53 Supresora de Tumor/metabolismo , Proteína p53 Supresora de Tumor/genética , Neuronas Motoras/metabolismo , Neuronas Motoras/patología , Sinaptotagminas/metabolismo , Sinaptotagminas/genética , Esclerosis Amiotrófica Lateral/genética , Esclerosis Amiotrófica Lateral/metabolismo , Esclerosis Amiotrófica Lateral/patología , Heterocigoto , Fenotipo , Células Madre Pluripotentes Inducidas/metabolismo , Células Madre Pluripotentes Inducidas/patología , Diferenciación Celular/genética , Técnicas de Inactivación de GenesRESUMEN
Hyperexcitability of motor neurons and spinal cord motor circuitry has been widely reported in the early stages of Amyotrophic Lateral Sclerosis (ALS). Changes in the relative amount of excitatory to inhibitory inputs onto a neuron (E:I synaptic ratio), possibly through a developmental shift in synapse formation in favour of excitatory transmission, could underlie pathological hyperexcitability. Given that astrocytes play a major role in early synaptogenesis and are implicated in ALS pathogenesis, their potential contribution to disease mechanisms involving synaptic imbalances and subsequent hyperexcitability is also of great interest. In order to assess E:I ratios in ALS, we utilised a novel primary spinal neuron / astrocyte co-culture system, derived from neonatal mice, in which synapses are formed in vitro. Using multiple ALS mouse models we found that no combination of astrocyte or neuron genotype produced alterations in E:I synaptic ratios assessed using pre- and post-synaptic anatomical markers. Similarly, we observed that ephrin-B1, a major contact-dependent astrocytic synaptogenic protein, was not differentially expressed by ALS primary astrocytes. Further to this, analysis of E:I ratios across the entire grey matter of the lumbar spinal cord in young (post-natal day 16-19) ALS mice revealed no differences versus controls. Finally, analysis in co-cultures of human iPSC-derived motor neurons and astrocytes harbouring the pathogenic C9orf72 hexanucleotide repeat expansion showed no evidence of a bias toward excitatory versus inhibitory synapse formation. We therefore conclude, utilising multiple ALS models, that we do not observe significant changes in the relative abundance of excitatory versus inhibitory synapses as would be expected if imbalances in synaptic inputs contribute to early hyperexcitability.
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Esclerosis Amiotrófica Lateral , Astrocitos , Técnicas de Cocultivo , Modelos Animales de Enfermedad , Neuronas Motoras , Médula Espinal , Sinapsis , Esclerosis Amiotrófica Lateral/patología , Esclerosis Amiotrófica Lateral/fisiopatología , Esclerosis Amiotrófica Lateral/metabolismo , Esclerosis Amiotrófica Lateral/genética , Animales , Astrocitos/metabolismo , Astrocitos/patología , Ratones , Sinapsis/metabolismo , Sinapsis/fisiología , Neuronas Motoras/metabolismo , Neuronas Motoras/patología , Neuronas Motoras/fisiología , Médula Espinal/metabolismo , Médula Espinal/patología , Humanos , Potenciales Postsinápticos Excitadores , Ratones Transgénicos , Células Cultivadas , Transmisión SinápticaRESUMEN
BACKGROUND: Multiple sclerosis (MS) is an inflammatory disease of the central nervous system that causes damage to the myelin and axons and is caused by genetic or environmental factors. Amyotrophic lateral sclerosis (ALS) is characterized by rapidly progressive degeneration of the motor neurons resulting in the presence of upper and lower motor-neuron signs and symptoms. CASE PRESENTATION: A 46-year-old female patient presented with symmetrical weakness of the lower limbs and numbness that developed over weeks. Magnetic resonance imaging (MRI) of the brain exhibited typical demyelination features, high signal abnormality involving the periventricular and subcortical white matter, and an oval-shaped lesion. The patient was diagnosed with MS based on the clinical presentation and radiological examination. However, there was rapid progression of the symptoms, involvement of bulbar dysfunction, and muscle atrophy. Furthermore, the patient did not respond to acute therapy and immunotherapy, which made the diagnosis of MS less likely or suggested that it could be associated with another diagnosis. Her neurophysiological test met the criteria of ALS, and she was started on riluzole. LITERATURE REVIEW: We reviewed all articles from 1986 to 2023, and there were 32 reported cases describing the co-occurrence of ALS and MS in different populations. Our case is the 33rd, and to our knowledge, it is the only case reported in the Middle East and specifically in Saudi Arabia. The main proposed mechanism according to postmortem examinations is a combination of degenerative and inflammatory processes with a cascade of production of reactive oxygen species and nitric oxide, which lead to cell death and apoptosis during concomitant ALS with MS. CONCLUSION: The co-occurrence of ALS and MS is extremely rare, but it can be explained by pathogenesis related to neurodegeneration, inflammation, or genetic susceptibility. Rapid progressive motor and bulbar symptoms could be red-flag symptoms, extensive evaluation might be needed for these patients.
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Esclerosis Amiotrófica Lateral , Esclerosis Múltiple , Humanos , Femenino , Esclerosis Amiotrófica Lateral/diagnóstico , Esclerosis Amiotrófica Lateral/complicaciones , Esclerosis Amiotrófica Lateral/patología , Persona de Mediana Edad , Esclerosis Múltiple/complicaciones , Esclerosis Múltiple/diagnóstico , Esclerosis Múltiple/patología , Imagen por Resonancia MagnéticaRESUMEN
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder distinguished by gradual depletion of motor neurons. RNA binding motif protein 5 (RBM5), an abundantly expressed RNA-binding protein, plays a critical role in the process of cellular death. However, little is known about the role of RBM5 in the pathogenesis of ALS. Here, we found that RBM5 was upregulated in ALS hSOD1G93A-NSC34 cell models and hSOD1G93A mice due to a reduction of miR-141-5p. The upregulation of RBM5 increased the apoptosis of motor neurons by inhibiting Rac1-mediated neuroprotection. In contrast, genetic knockdown of RBM5 rescued motor neurons from hSOD1G93A-induced degeneration by activating Rac1 signaling. The neuroprotective effect of RBM5-knockdown was significantly inhibited by the Rac1 inhibitor, NSC23766. These findings suggest that RBM5 could potentially serve as a therapeutic target in ALS by activating the Rac1 signalling.
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Esclerosis Amiotrófica Lateral , Apoptosis , Neuronas Motoras , Proteínas Proto-Oncogénicas c-akt , Proteínas de Unión al ARN , Transducción de Señal , Proteína de Unión al GTP rac1 , Esclerosis Amiotrófica Lateral/metabolismo , Esclerosis Amiotrófica Lateral/genética , Esclerosis Amiotrófica Lateral/patología , Animales , Proteína de Unión al GTP rac1/metabolismo , Proteína de Unión al GTP rac1/genética , Neuronas Motoras/metabolismo , Neuronas Motoras/patología , Apoptosis/fisiología , Proteínas de Unión al ARN/metabolismo , Proteínas de Unión al ARN/genética , Ratones , Humanos , Transducción de Señal/fisiología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Ratones Transgénicos , Superóxido Dismutasa/metabolismo , Superóxido Dismutasa/genética , Masculino , Proteínas de Unión al ADN , Proteínas de Ciclo Celular , Proteínas Supresoras de TumorRESUMEN
Reactive astrocytes are known to exert detrimental effects upon neurons in several neurodegenerative diseases, yet our understanding of how astrocytes promote neurotoxicity remains incomplete, especially in human systems. In this study, we leveraged human pluripotent stem cell (hPSC) models to examine how reactivity alters astrocyte function and mediates neurodegeneration. hPSC-derived astrocytes were induced to a reactive phenotype, at which point they exhibited a hypertrophic profile and increased complement C3 expression. Functionally, reactive astrocytes displayed decreased intracellular calcium, elevated phagocytic capacity, and decreased contribution to the blood-brain barrier. Subsequently, co-culture of reactive astrocytes with a variety of neuronal cell types promoted morphological and functional alterations. Furthermore, when reactivity was induced in astrocytes from patient-specific hPSCs (glaucoma, Alzheimer's disease, and amyotrophic lateral sclerosis), the reactive state exacerbated astrocytic disease-associated phenotypes. These results demonstrate how reactive astrocytes modulate neurodegeneration, significantly contributing to our understanding of a role for reactive astrocytes in neurodegenerative diseases.
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Astrocitos , Técnicas de Cocultivo , Células Madre Pluripotentes , Astrocitos/metabolismo , Humanos , Células Madre Pluripotentes/metabolismo , Células Madre Pluripotentes/citología , Enfermedades Neurodegenerativas/metabolismo , Enfermedades Neurodegenerativas/patología , Complemento C3/metabolismo , Diferenciación Celular , Neuronas/metabolismo , Enfermedad de Alzheimer/patología , Enfermedad de Alzheimer/metabolismo , Fagocitosis , Barrera Hematoencefálica/metabolismo , Glaucoma/patología , Glaucoma/metabolismo , Esclerosis Amiotrófica Lateral/metabolismo , Esclerosis Amiotrófica Lateral/patología , Calcio/metabolismo , FenotipoRESUMEN
Identifying groups of patients with similar disease progression patterns is key to understand disease heterogeneity, guide clinical decisions and improve patient care. In this paper, we propose a data-driven temporal stratification approach, ClusTric, combining triclustering and hierarchical clustering. The proposed approach enables the discovery of complex disease progression patterns not found by univariate temporal analyses. As a case study, we use Amyotrophic Lateral Sclerosis (ALS), a neurodegenerative disease with a non-linear and heterogeneous disease progression. In this context, we applied ClusTric to stratify a hospital-based population (Lisbon ALS Clinic dataset) and validate it in a clinical trial population. The results unravelled four clinically relevant disease progression groups: slow progressors, moderate bulbar and spinal progressors, and fast progressors. We compared ClusTric with a state-of-the-art method, showing its effectiveness in capturing the heterogeneity of ALS disease progression in a lower number of clinically relevant progression groups.
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Esclerosis Amiotrófica Lateral , Progresión de la Enfermedad , Esclerosis Amiotrófica Lateral/patología , Esclerosis Amiotrófica Lateral/fisiopatología , Humanos , Masculino , Análisis por Conglomerados , Femenino , Persona de Mediana Edad , AncianoRESUMEN
Amyotrophic lateral sclerosis (ALS) is an extremely complex neurodegenerative disease involving different cell types, but motoneuronal loss represents its main pathological feature. Moreover, compensatory plastic changes taking place in parallel to neurodegeneration are likely to affect the timing of ALS onset and progression and, interestingly, they might represent a promising target for disease-modifying treatments. Therefore, a simplified animal model mimicking motoneuronal loss without the other pathological aspects of ALS has been established by means of intramuscular injection of cholera toxin-B saporin (CTB-Sap), which is a targeted neurotoxin able to kill motoneurons by retrograde suicide transport. Previous studies employing the mouse CTB-Sap model have proven that spontaneous motor recovery is possible after a subtotal removal of a spinal motoneuronal pool. Although these kinds of plastic changes are not enough to counteract the functional effects of the progressive motoneuron degeneration, it would nevertheless represent a promising target for treatments aiming to postpone ALS onset and/or delay disease progression. Herein, the mouse CTB-Sap model has been used to test the efficacy of mitochondrial division inhibitor 1 (Mdivi-1) as a tool to counteract the CTB-Sap toxicity and/or to promote neuroplasticity. The homeostasis of mitochondrial fission/fusion dynamics is indeed important for cell integrity, and it could be affected during neurodegeneration. Lesioned mice were treated with Mdivi-1 and then examined by a series of behavioral test and histological analyses. The results have shown that the drug may be capable of reducing functional deficits after the lesion and promoting synaptic plasticity and neuroprotection, thus representing a putative translational approach for motoneuron disorders.