Could conservative iron chelation lead to neuroprotection in amyotrophic lateral sclerosis?

Iron accumulation has been observed in mouse models and both sporadic and familial forms of Amyotrophic lateral sclerosis. Iron chelation could reduce iron accumulation and the related excess of oxidative stress in the motor pathways. However, classical iron chelation would induce systemic iron depletion. We assess the safety and efficacy of conservative iron chelation (i.e. chelation with low risk of iron depletion) in a murine preclinical model and pilot clinical trial. In Sod1G86R mice, deferiprone increased the mean life span as compared with placebo. The safety was good, without anemia after 12 months of deferiprone in the 23 ALS patients enrolled in the clinical trial. The decreases in the ALS Functional Rating Scale and the body mass index (BMI) were significantly smaller for the first 3 months of deferiprone treatment (30 mg/kg/day) than for the first treatment-free period. Iron levels in the cervical spinal cord, medulla oblongata and motor cortex (according to MRI), as well as cerebrospinal fluid levels of oxidative stress and neurofilament light chains were lower after deferiprone treatment. Our observation leads to the hypothesis that moderate iron chelation regimen that avoids changes in systemic iron levels may constitute a novel therapeutic modality of neuroprotection for ALS

Metabolomics study of an in vitro model of amyotrophic lateral sclerosis exposed to oxidative stress

La Sclérose Latérale Amyotrophique (SLA) est une affection neurodégénérative affectant sélectivement les motoneurones et conduisant au décès en 2 à 4 ans. Des facteurs génétiques, ainsi que diverses hypothèses physiopathologiques, telles que l’excitotoxicité et le stress oxydant, ont été évoqués pour expliquer la dégénérescence des motoneurones, mais aucune étiologie n’explique aujourd’hui la survenue de cette pathologie. Afin d’améliorer les connaissances des voies métaboliques impliquées dans la physiopathologie de la SLA, nous avons développé un modèle in vitro de co-Culture de motoneurones et d’astrocytes sur-Exprimant la Superoxyde Dismutase (SOD1) humaine sauvage ou mutée (SOD1G93C) et exposée au stress oxydant. Nous avons étudié les modifications de métabolisme après traitement oxydant par une approche métabolomique utilisant la chromatographie gazeuse couplée à la spectrométrie de masse et une analyse statistique multivariée des résultats. Ainsi nous avons observé une modification de métabolites impliqués notamment dans le cycle de Krebs, la neurotransmission excitatrice et la synthèse du glutathion, dans un modèle in vitro de SLA exposé au stress oxydant.Amyotrophic Lateral Sclerosis (ALS) is a neurodegenerative disorder affecting selectively motor neurons and leading to death in 2 to 4 years. Genetic factors and various pathophysiological hypotheses, such as excitotoxicity and oxidative stress, have been suggested to explain the degeneration of motor neurons, but today no etiology explains the occurrence of this disease. In order to improve the knowledge of the metabolic pathways involved in the pathogenesis of ALS, we developed an in vitro model of co-Culture of motor neurons and astrocytes over-Expressing human superoxide dismutase (SOD1), wild-Type or mutated (SOD1G93C), and exposed to oxidative stress. We studied the changes in metabolism after oxidative treatment with a metabolomics approach using gas chromatography-Mass spectrometry and multivariate statistical analysis. Thus we observed a change in metabolites involved in the citric acid cycle, the excitatory neurotransmission and the glutathione synthesis, in an in vitro model of ALS exposed to oxidative stress

Etude du bilan martial chez des patients atteints de sclérose latérale amyotrophique

La sclérose latérale amyotrophique (SLA) est une maladie neurodégénérative caractérisée par une atteinte quasi-sélective des neurones moteurs spinaux et corticaux conduisant au décès en 3 à 5 ans. Le diagnostic de SLA est posé sur des critères cliniques et il n'existe à ce jour pas de marqueur diagnostique spécifique de la maladie. Divers facteurs génétiques et environnementaux sont connus. Le stress oxydatif ainsi que l excitotoxicité au glutamate sont des hypothèses physiopathologiques aujourd hui unanimement reconnues. Plusieurs données incitent à suspecter l implication du fer dans la physiopathologie de la SLA. Une accumulation et des concentrations élevées de fer ont été observées dans le système nerveux central des patients atteints de SLA. Le fer pourrait contribuer à la formation de radicaux libres oxygénés par l intermédiaire de la réaction de Fenton et ainsi participer au stress oxydatif, un des mécanismes physiopathologiques de la SLA. Des modifications du métabolisme du fer sont aussi supposées depuis l observation de concentrations élevées de ferritine dans le sérum de patients SLA. Ainsi le but de cette étude est d évaluer la concentration de ferritine ainsi que du bilan martial au complet dans une cohorte de patients SLA de Tours comparée à des témoins. Nous avons pu mettre en évidence une augmentation des concentrations de fer, de ferritine et une diminution de la transferrine chez les patients SLA par rapport aux témoins. Cette étude est la première a montré une concentration de fer plus élevée chez les patients SLA et conforte l implication d une dérégulation du métabolisme du fer dans la physiopathologie de la SLA.TOURS-BU Sciences Pharmacie (372612104) / SudocSudocFranceF

Metabolomics: A Tool to Understand the Impact of Genetic Mutations in Amyotrophic Lateral Sclerosis

Metabolomics studies performed in patients with amyotrophic lateral sclerosis (ALS) reveal a set of distinct metabolites that can shed light on the pathological alterations taking place in each individual. Metabolites levels are influenced by disease status, and genetics play an important role both in familial and sporadic ALS cases. Metabolomics analysis helps to unravel the differential impact of the most common ALS-linked genetic mutations (as C9ORF72, SOD1, TARDBP, and FUS) in specific signaling pathways. Further, studies performed in genetic models of ALS reinforce the role of TDP-43 pathology in the vast majority of ALS cases. Studies performed in differentiated cells from ALS-iPSC (induced Pluripotent Stem Cells) reveal alterations in the cell metabolism that are also found in ALS models and ultimately in ALS patients. The development of metabolomics approaches in iPSC derived from ALS patients allow addressing and ultimately understanding the pathological mechanisms taking place in any patient. Lately, the creation of a “patient in a dish” will help to identify patients that may benefit from specific treatments and allow the implementation of personalized medicine

How Can a Ketogenic Diet Improve Motor Function?

A ketogenic diet (KD) is a normocaloric diet composed by high fat (80–90%), low carbohydrate, and low protein consumption that induces fasting-like effects. KD increases ketone body (KBs) production and its concentration in the blood, providing the brain an alternative energy supply that enhances oxidative mitochondrial metabolism. In addition to its profound impact on neuro-metabolism and bioenergetics, the neuroprotective effect of specific polyunsaturated fatty acids and KBs involves pleiotropic mechanisms, such as the modulation of neuronal membrane excitability, inflammation, or reactive oxygen species production. KD is a therapy that has been used for almost a century to treat medically intractable epilepsy and has been increasingly explored in a number of neurological diseases. Motor function has also been shown to be improved by KD and/or medium-chain triglyceride diets in rodent models of Alzheimer’s disease, Parkinson’s disease, amyotrophic lateral sclerosis, and spinal cord injury. These studies have proposed that KD may induce a modification in synaptic morphology and function, involving ionic channels, glutamatergic transmission, or synaptic vesicular cycling machinery. However, little is understood about the molecular mechanisms underlying the impact of KD on motor function and the perspectives of its use to acquire the neuromuscular effects. The aim of this review is to explore the conditions through which KD might improve motor function. First, we will describe the main consequences of KD exposure in tissues involved in motor function. Second, we will report and discuss the relevance of KD in pre-clinical and clinical trials in the major diseases presenting motor dysfunction

Panel of oxidative stress and inflammatory biomarkers in als: a pilot study

International audiencePathophysiological mechanisms that contribute to neurodegeneration in Amyotrophic Lateral Sclerosis (ALS) include oxidative stress and inflammation. We conducted a preliminary study to explore these mechanisms, to discuss their link in ALS, and to determine the feasibility of incorporating this combined analysis into current biomarkers research.METHODS: We enrolled 10 ALS patients and 10 controls. We measured the activities of glutathione peroxidase, glutathione reductase, superoxyde dismutase (SOD), and the levels of serum total antioxidant status (TAS), malondialdehyde (MDA), 8-hydroxy-2'-deoxyguanosine (8-OHdG), and glutathione status (e.g. glutathione disulfide, GSSG/reduced glutathione, GSH). We analysed the concentrations of homocysteine, several cytokines, vitamins and metals by standard methods used in routine practice.RESULTS: There was a significant decrease in TAS levels (p=0.027) and increase in 8-OHdG (p=0.014) and MDA (p=0.011) levels in ALS patients. We also observed a significantly higher GSSG/GSH ratio (p=0.022), and IL-6 (p=0.0079) and IL-8 (p=0.009) concentrations in ALS patients. Correlations were found between biological and clinical markers (homosysteine vs. clinical status at diagnosis, p=0.02) and between some biological markers such as IL-6 vs. GSSG/GSH (p=0.045) or SOD activity (p=0.017).CONCLUSIONS: We confirmed the systemic alteration of both the redox and the inflammation status in ALS patients, and we observed a link with some clinical parameters. These promising results encourage us to pursue this study with collection of combined oxidative stress and inflammatory markers.Détermination d’un panel de biomarqueurs du stress oxydant et de l’inflammation dans la SLA: une étude pilote.Contexte: Parmi les mécanismes impliqués dans la physiopathologie de la Sclérose Latérale Amyotrophique (SLA), on note un stress oxydant et des mécanismes inflammatoires. Nous avons ainsi mené une étude préliminaire afin de 1) d’explorer ces mécanismes, 2) de discuter leur lien dans la SLA, 3) de déterminer la faisabilité d’une telle analyse combinée pour une utilisation courante en recherche de biomarqueurs. Méthodes: Nous avons inclus prospectivement 10 patients SLA et 10 contrôles. Nous avons mesuré l’activité des enzymes suivantes : glutathion peroxydase, glutathion réductase, superoxyde dismutase (SOD), et les concentrations sériques des paramètres suivants : statut antioxydant total (SAT), malondialdéhyde (MDA), 8-hydroxy-2’-déoxyguanosine (8-OHdG), et le statut en glutathion (e.g. glutathione oxydé, GSSG/glutathione réduit, GSH). Nous avons analysé les concentrations d’homocystéine, de plusieurs cytokines, de vitamines et de différents métaux par des méthodes validées en routine. Résultats: Nous avons montré une diminution significative du SAT (p=0.027) et une augmentation de la 8-OHdG (p=0.014) ainsi que du MDA (p=0.011) chez les patients SLA. Nous avons observé une augmentation du rapport GSSG/GSH (p=0.022), ainsi que des concentrations d’IL-6 (p=0.0079) et d’IL-8 (p=0.009) chez les patients SLA. Des corrélations ont été observées entre certains marqueurs biologiques et cliniques (homosysteine vs sévérité de la pathologie au diagnostic, p=0.02) mais également entre les marqueurs biologiques entre eux tels que l’IL-6 vs GSSG/GSH (p=0.045) ou vs l’activité de la SOD (p=0.017). Conclusion: Nous avons confirmé l’altération du statut redox et la composante inflammatoire importante dans la SLA, en dehors du SNC. Nous avons également observé un lien entre certains paramètres cliniques et biologiques, ce qui nous incite à poursuivre cette étude en analysant la combinaison de ces marqueurs de stress oxydant et d’inflammation

Taking Advantages of Blood–Brain or Spinal Cord Barrier Alterations or Restoring Them to Optimize Therapy in ALS?

International audienceAmyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disorder that still lacks an efficient therapy. The barriers between the central nervous system (CNS) and the blood represent a major limiting factor to the development of drugs for CNS diseases, including ALS. Alterations of the blood–brain barrier (BBB) or blood–spinal cord barrier (BSCB) have been reported in this disease but still require further investigations. Interestingly, these alterations might be involved in the complex etiology and pathogenesis of ALS. Moreover, they can have potential consequences on the diffusion of candidate drugs across the brain. The development of techniques to bypass these barriers is continuously evolving and might open the door for personalized medical approaches. Therefore, identifying robust and non-invasive markers of BBB and BSCB alterations can help distinguish different subgroups of patients, such as those in whom barrier disruption can negatively affect the delivery of drugs to their CNS targets. The restoration of CNS barriers using innovative therapies could consequently present the advantage of both alleviating the disease progression and optimizing the safety and efficiency of ALS-specific therapies

The Roles of NEDD4 Subfamily of HECT E3 Ubiquitin Ligases in Neurodevelopment and Neurodegeneration

The ubiquitin pathway regulates the function of many proteins and controls cellular protein homeostasis. In recent years, it has attracted great interest in neurodevelopmental and neurodegenerative diseases. Here, we have presented the first review on the roles of the 9 proteins of the HECT E3 ligase NEDD4 subfamily in the development and function of neurons in the central nervous system (CNS). We discussed their regulation and their direct or indirect involvement in neurodevelopmental diseases, such as intellectual disability, and neurodegenerative diseases, such as Alzheimer’s disease, Parkinson’s disease or Amyotrophic Lateral Sclerosis. Further studies on the roles of these proteins, their regulation and their targets in neurons will certainly contribute to a better understanding of neuronal function and dysfunction, and will also provide interesting information for the development of therapeutics targeting them

Some CSF Kynurenine Pathway Intermediates Associated with Disease Evolution in Amyotrophic Lateral Sclerosis

The aim of this study was to evaluate the kynurenine pathway (KP) and amino acids profile, using mass spectrometry, in the cerebrospinal fluid (CSF) of 42 amyotrophic lateral sclerosis (ALS) patients at the diagnosis and 40 controls to detect early disorders of these pathways. Diagnostic and predictive ability (based on weight loss, forced vital capacity, ALS Functional Rating Scale—Revised evolution over 12 months, and survival time) of these metabolites were evaluated using univariate followed by supervised multivariate analysis. The multivariate model between ALS and controls was not significant but highlighted some KP metabolites (kynurenine (KYN), kynurenic acid (KYNA), 3-Hydroxynurenine (3-HK)/KYNA ratio), and amino acids (Lysine, asparagine) as involved in the discrimination between groups (accuracy 62%). It revealed a probable KP impairment toward neurotoxicity in ALS patients and in bulbar forms. Regarding the prognostic effect of metabolites, 12 were commonly discriminant for at least 3 of 4 disease evolution criteria. This investigation was crucial as it did not show significant changes in CSF concentrations of amino acids and KP intermediates in early ALS evolution. However, trends of KP modifications suggest further exploration. The unclear kinetics of neuroinflammation linked to KP support the interest in exploring these pathways during disease evolution through a longitudinal strategy

Metabolomics in Cerebrospinal Fluid of Patients with Amyotrophic Lateral Sclerosis: An Untargeted Approach via High-Resolution Mass Spectrometry

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