Transmission of ALS pathogenesis by the cerebrospinal fluid (original) (raw)
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Cureus, 2022
Introduction: Cerebrospinal fluid (CSF) has been implicated in amyotrophic lateral sclerosis (ALS) due to its ability to spread inflammatory proteins throughout the nervous system. We hypothesized that filtration of the CSF could remove pathogenic proteins and prevent them from altering motor phenotypes in a mouse model. Methods: We filtered the CSF from 11 ALS patients via 100 kilodaltons (kD) molecular weight cutoff filters. We used mass spectrometry-based discovery proteomics workflows to compare protein abundances before and after filtration. To test the effects of CSF filtration on motor function, we injected groups of mice with saline, filtered ALS-CSF, or unfiltered ALS-CSF (n=12 per group) and assessed motor function via pole descent and open field tests. Results: We identified proteins implicated in ALS pathogenesis and showed that these were removed in significant amounts in our workflow. Key filtered proteins included complement proteins, chitinases, serine protease inhibitors, and neuro-inflammatory proteins such as amyloid precursor protein, chromogranin A, and glial fibrillary acidic protein. Compared to the filtered ALS-CSF mice, unfiltered ALS-CSF mice took longer to descend a pole (10 days post-injection, 11.14 seconds vs 14.25 seconds, p = 0.02) and explored less on an open field (one day post-injection, 21.81 m vs 16.83 m, p = 0.0004). Conclusions: We demonstrated the ability to filter proteins from the CSF of ALS patients and identified potentially pathologic proteins that were reduced in quantity. Additionally, we demonstrated the ability of unfiltered ALS-CSF to induce motor deficits in mice on the pole descent and open field tests and showed that filtration could prevent this deficit. Given the lack of effective treatments for ALS, this could be a novel solution for patients suffering from this deadly and irreversible condition.
Proteome Analysis of Cerebrospinal Fluid in Amyotrophic Lateral Sclerosis (ALS)
Neurochemical Research, 2008
Cerebrospinal fluid (CSF) is a promising source of biomarkers in amyotrophic lateral sclerosis (ALS). Using the two-dimensional difference in gel electrophoresis (2-D-DIGE), we compared CSF samples from patients with ALS (n = 14) with those from normal controls (n = 14). Protein spots that showed significant differences between patients and controls were selected for further analysis by MALDI-TOF mass spectrometry. For validation of identified spots western blot analysis and ELISA was performed. We identified 2 proteins that were upregulated and 3 proteins that were down-regulated in CSF in ALS. Of these, two proteins (Zn-alpha-2-glycoprotein and ceruloplasmin precursor protein) have not been reported in CSF of patients with ALS so far. In contrast, several other proteins (transferrin, alpha-1-antitrypsin precursor and beta-2microglobulin) seem to be unspecifically affected in different neurological diseases and may therefore be of limited value as disease-related biochemical markers in ALS. Further evaluation of the candidate proteins identified here is necessary.
Brain research, 2009
We investigated the effect of Cerebrospinal Fluid (CSF) from sporadic Amyotrophic Lateral Sclerosis patients (SALS-CSF) on motor neuron-like cells to delineate the pathomechanism of SALS. Exposure of NSC-34 cells to SALS-CSF caused lower viability, reduction in differentiation and enhanced lactate dehydrogenase activity. Additionally, reduced choline acetyl transferase expression alongside intracellular aggregation of phosphorylated neurofilaments was prominently seen. The aggregates were immunopositive for ubiquitin. These findings are comparable to the pathological changes seen in the postmortem tissue of ALS patients.
Exploration of Neuroprotective Therapy, 2023
Aim: Amyotrophic lateral sclerosis (ALS) is a progressive disease of unknown etiology, characterized by degeneration of motoneurons and skeletal muscle strength decline that progressively evolves to respiratory failure and death. A key point in the therapeutic approach is to understand the pathological processes associated with disease evolution. In spite of intensive research on the molecular/cellular mechanisms involved in ALS initiation and progression disease etiology, unfortunately, poorly understood and there is no efficient specific/decisive treatment for ALS patients. The aims of the present study are to identify specific factors in the cerebrospinal fluid (CSF) of ALS patients and to test their potential relevance to the etiology of this disease. Methods: Peptides were identified by liquid chromatography tandem mass spectrometry (LC-MS/MS). Motor activity of mice was tested by the Rota-rod test and peptide-induced inflammation was assessed by induction nitric oxide synthase activity in BV2 microglia cells. Results: Analysis of CSF samples of ALS patients (n = 15) detected two peptides, C-terminal fragments of transthyretin and osteopontin, which were absent in a control group (n = 15). In addition to being potential biomarker candidates, the relevancy of these peptides to the disease etiology was tested by assessing their effects on motor activity in mice and inflammation model in cell culture. Intranasal administration of the peptides reduced motor activity in the Rota-rod test and activated lipopolysaccharide-induced inflammation in BV2 microglia cells. Conclusions: These findings suggest that during ALS onset and progression two potentially neurotoxic peptides are formed, released, or penetrated the central nervous system thus inducing neuroinflammation and neurodegeneration.
Molecular Therapy, 2010
Improved spread of transduction in the central nervous system (CNS) was achieved from intravenous administration of adeno-associated virus serotype-9 (AAV9) to neonatal rats. Spinal lower motor neuron transduction efficiency was estimated to be 78% using the highest vector dose tested at a 12-week interval. The widespread expression could aid studying diseases that affect both the spinal cord and brain, such as amyotrophic lateral sclerosis (ALS). The protein most relevant to neuropathology in ALS is transactive response DNA-binding protein 43 (TDP-43). When expressed in rats, human wild-type TDP-43 rapidly produced symptoms germane to ALS including paralysis of the hindlimbs and muscle wasting, and mortality over 4 weeks that did not occur in controls. The hindlimb atrophy and weakness was evidenced by assessments of rotarod, rearing, overall locomotion, muscle mass, and histology. The muscle wasting suggested denervation, but there was only 14% loss of motor neurons in the TDP-43 rats. Tissues were negative for ubiquitinated, cytoplasmic TDP-43 pathology, suggesting that altering TDP-43's nuclear function was sufficient to cause the disease state. Other relevant pathology in the rats included microgliosis and degenerating neuronal perikarya positive for phosphoneurofilament. The expression pattern encompassed the distribution of neuro pathology of ALS, and could provide a rapid, relevant screening assay for TDP-43 variants and other disease-related proteins.
Frontiers in Neuroscience, 2018
Amyotrophic lateral sclerosis (ALS) is a progressive adult-onset neurodegenerative disease, that affects cortical, bulbar and spinal motor neurons, and it is considered a proteinopathy, in which pathological proteins (SOD1, TDP-43, and FUS) may accumulate and interfere with neuronal functions eventually leading to cell death. These proteins can be released from cells and transported in the body fluids by extracellular vesicles (EVs). EVs are spherical vesicles, which are classified mainly in microvesicles (MVs) and exosomes (EXOs) based on their biogenesis, size and surface markers. In this study we characterized MVs and EXOs isolated from plasma of sporadic ALS patients and healthy controls and determined their number, size and SOD1, TDP-43, and FUS protein composition. No variation was found in the number of EVs between ALS patients and controls. However, the mean size both for MVs and for EXOs resulted increased in ALS patients compared to controls. MVs derived from ALS patients were enriched in SOD1, TDP-43, phospho-TDP-43, and FUS proteins compared to CTRLs. SOD1 was generally more concentrated in EXOs than in MVs, while TDP-43 and FUS protein levels were slightly higher in MVs than in EXOs. We demonstrated that MVs and EXOs size were increased in ALS patients compared to controls and that MVs of ALS patients were enriched with toxic proteins compared to CTRLs. EXOs did not show any protein changes. These data may suggest that MVs can transport toxic proteins and might play a role in prion-like propagation of ALS disease.
TDP-43 Redistribution is an Early Event in Sporadic Amyotrophic Lateral Sclerosis
Brain Pathology, 2010
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder consisting of progressive loss of motor neurons. TDP-43 has been identified as a component of ubiquitinimmunoreactive inclusions of motor neurons in ALS. We focused on the diffuse cytoplasmic TDP-43 immunoreactivity in ALS neurons, and quantitatively assessed it in comparison with skein/round TDP-43 and ubiquitin immunostaining in motor neurons of 30 sporadic ALS cases. The percentage of spinal motor neurons with cytoplasmic TDP-43 immunoreactivity was higher than that of ubiquitin-immunoreactive ones. The percentage of TDP-43positive motor neurons was independent of neuron counts in anterior horns, while the percentage of ubiquitinated neurons was inversely correlated. Aiming to define the cytosolic localization of TDP-43, the immunoblot analysis of spinal cord and frontal cortex showed that full-length TDP-43, the 45 kDa form and ubiquitinated TDP-43 are found in the soluble inclusion-free fraction. The present data suggest that delocalization, accumulation and ubiquitination of TDP-43 in the cytoplasm of motor neurons are early dysfunctions in the cascade of the events leading to motor neuron degeneration in ALS, preceding the formation of insoluble inclusion bodies. Being cytoplasmic accumulation an ongoing event during the course of the illness, a therapeutic approach to this incurable disease can be envisaged.
Background: TDP-43 proteinopathy is a pathological hallmark of many neurodegenerative diseases including amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). So far, there is no therapy available for these neurodegenerative diseases. In addition, the impact of TDP-43 proteinopathy on neuronal translational profile remains unknown. Methods: Biochemical, immunohistology and assay-based studies were done with cell cultures and transgenic mice models. We also used a Ribotag approach combined with microarray and proteomic analyses to investigate the neuronal translational profiles in mouse model of ALS/FTD. Results: Here, we report that oral administration of a novel analog (IMS-088) of withaferin-A, an antagonist of nuclear factor kappa-B (NF-ĸB) essential modulator (NEMO), induces autophagy and reduced TDP-43 proteinopathy in the brain and spinal cord of transgenic mice expressing human TDP-43 mutants, models of ALS/FTD. Treatment with IMS-088 ameliorated cognitive im...
TDP-43 and Cytoskeletal Proteins in ALS
Molecular Neurobiology, 2017
Amyotrophic lateral sclerosis (ALS) represents a rapidly progressing neurodegenerative disease and is characterized by a degeneration of motor neurons. Motor neurons are particularly susceptible to selective and early degeneration because of their extended axon length and their dependency on the cytoskeleton for its stability, signaling, and axonal transport. The motor neuron cytoskeleton comprises actin filaments, neurofilaments like peripherin, and microtubules. The Transactivating Response Region (TAR) DNA Binding Protein (TDP-43) forms characteristic cytoplasmic aggregates in motor neurons of ALS patients, and at least in part, the pathogenesis of ALS seems to be driven by toxic pTDP-43 aggregates in cytoplasm, which lead to a diminished axon formation and reduced axon length. Diminished axon formation and reduced axon length suggest an interaction of TDP-43 with the cytoskeleton of motor neurons. TDP-43 interacts with several cytoskeletal components, e.g., the microtubuleassociated protein 1B (MAP1B) or the neurofilament light chain (NFL) through direct binding to its RNA. From a clinical perspective, cytoskeletal biomarkers like phosphorylated neurofilament heavy chain (pNFH) and NFL are already clinically used in ALS patients to predict survival, disease progression, and duration. Thus, in this review, we focus on the interaction of TDP-43 with the different cytoskeleton components such as actin filaments, neurofilaments, and microtubules as well as their associated proteins as one aspect in the complex pathogenesis of ALS.