ABSTRACT
Severe acute respiratory coronavirus 2 (SARS-CoV-2) causes neurological disease in the peripheral and central nervous system (PNS and CNS, respectively) of some patients. It is not clear whether SARS-CoV-2 infection or the subsequent immune response are the key factors that cause neurological disease. Here, we addressed this question by infecting human induced pluripotent stem cell-derived CNS and PNS neurons with SARS-CoV-2. SARS-CoV-2 infected a low number of CNS neurons and did not elicit a robust innate immune response. On the contrary, SARS-CoV-2 infected a higher number of PNS neurons. This resulted in expression of interferon (IFN) λ1, several IFN-stimulated genes and proinflammatory cytokines. The PNS neurons also displayed alterations characteristic of neuronal damage, as increased levels of sterile alpha and Toll/interleukin receptor motif-containing protein 1, amyloid precursor protein and α-synuclein, and lower levels of cytoskeletal proteins. Interestingly, blockade of the Janus kinase and signal transducer and activator of transcription pathway by Ruxolitinib did not increase SARS-CoV-2 infection, but reduced neuronal damage, suggesting that an exacerbated neuronal innate immune response contributes to pathogenesis in the PNS. Our results provide a basis to study coronavirus disease 2019 (COVID-19) related neuronal pathology and to test future preventive or therapeutic strategies.
Subject(s)
COVID-19 , Induced Pluripotent Stem Cells , Humans , SARS-CoV-2 , Immunity, Innate , NeuronsABSTRACT
BACKGROUND: Diagnostic criteria for progressive supranuclear palsy (PSP) include midbrain atrophy in MRI and hypometabolism in [18F]fluorodeoxyglucose (FDG)-positron emission tomography (PET) as supportive features. Due to limited data regarding their relative and sequential value, there is no recommendation for an algorithm to combine both modalities to increase diagnostic accuracy. This study evaluated the added value of sequential imaging using state-of-the-art methods to analyse the images regarding PSP features. METHODS: The retrospective study included 41 PSP patients, 21 with Richardson's syndrome (PSP-RS), 20 with variant PSP phenotypes (vPSP) and 46 sex- and age-matched healthy controls. A pretrained support vector machine (SVM) for the classification of atrophy profiles from automatic MRI volumetry was used to analyse T1w-MRI (output: MRI-SVM-PSP score). Covariance pattern analysis was applied to compute the expression of a predefined PSP-related pattern in FDG-PET (output: PET-PSPRP expression score). RESULTS: The area under the receiver operating characteristic curve for the detection of PSP did not differ between MRI-SVM-PSP and PET-PSPRP expression score (p≥0.63): about 0.90, 0.95 and 0.85 for detection of all PSP, PSP-RS and vPSP. The MRI-SVM-PSP score achieved about 13% higher specificity and about 15% lower sensitivity than the PET-PSPRP expression score. Decision tree models selected the MRI-SVM-PSP score for the first branching and the PET-PSPRP expression score for a second split of the subgroup with normal MRI-SVM-PSP score, both in the whole sample and when restricted to PSP-RS or vPSP. CONCLUSIONS: FDG-PET provides added value for PSP-suspected patients with normal/inconclusive T1w-MRI, regardless of PSP phenotype and the methods to analyse the images for PSP-typical features.
ABSTRACT
OBJECTIVE: The Progressive Supranuclear Palsy quality of life scale (PSP-QoL) has been shown to be a useful tool for capturing health-related quality of life of patients in "everyday life" and in progressive supranuclear palsy (PSP) research. However, at 45 items in length, the questionnaire can take a long time, exhausting PSP patients, in particular if cognitive impaired, which can have a negative impact on the assessment. The aim of this study was to establish a condensed version of the PSP-QoL for research and routine clinical care. METHODS: In this retrospective study, data originating from a German cohort of PSP patients was analyzed. Data from 245 PSP patients were included in this study. The short PSP-QoL questionnaire was created using a two-factor solution and item-total and inter-item correlations for mental and physical aspects of daily living of the PSP-QoL followed by confirmatory factor analysis. RESULTS: The final scale included 12 items representing mental (five items) and physical symptoms (seven items). The specified two-factor model displayed an excellent fit in the confirmatory factor analysis. The short Progressive Supranuclear Palsy Quality of Life scale (PSP-ShoQoL) correlated moderately with the PSP Rating Scale (r [243] = 0.514, P < 0.001) and Geriatric depression scale (r [231] = 0.548, P < 0.001). Sensitivity to change confirmed a significant decrease in QoL after 12 months. DISCUSSION: In this study, we created a 12-item PSP-ShoQoL designed to "facilitate" daily clinical work that correlated strongly with the PSP-QoL and was sensitive to change. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
ABSTRACT
BACKGROUND: Progressive supranuclear palsy (PSP) is an atypical Parkinsonian syndrome characterized by supranuclear gaze palsy, early postural instability, and a frontal dysexecutive syndrome. Contrary to normal brain magnetic resonance imaging in Parkinson's disease (PD), PSP shows specific cerebral atrophy patterns and alterations, but these findings are not present in every patient, and it is still unclear if these signs are also detectable in early disease stages. OBJECTIVE: The aim of the present study was to analyze the metabolic profile of patients with clinically diagnosed PSP in comparison with matched healthy volunteers and PD patients using whole-brain magnetic resonance spectroscopic imaging (wbMRSI). METHODS: Thirty-nine healthy controls (HCs), 29 PD, and 22 PSP patients underwent wbMRSI. PSP and PD patients were matched for age and handedness with HCs. Clinical characterization was performed using the Movement Disorder Society Unified Parkinson's Disease Rating Scale, PSP rating scale, and DemTect (test for cognitive assessment). RESULTS: In PSP patients a significant reduction in N-acetyl-aspartate (NAA) was detected in all brain lobes. Fractional volume of the cerebrospinal fluid significantly increased in PSP patients compared to PD and healthy volunteers. CONCLUSIONS: In PSP much more neuronal degeneration and cerebral atrophy have been detected compared with PD. The most relevant alteration is the decrease in NAA in all lobes of the brain, which also showed a partial correlation with clinical symptoms. However, more studies are needed to confirm the additional value of wbMRSI in clinical practice. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
Subject(s)
Neurodegenerative Diseases , Parkinson Disease , Supranuclear Palsy, Progressive , Humans , Supranuclear Palsy, Progressive/pathology , Parkinson Disease/diagnosis , Brain/diagnostic imaging , Brain/pathology , Neurodegenerative Diseases/pathology , Magnetic Resonance Imaging , Atrophy/pathology , Magnetic Resonance SpectroscopyABSTRACT
BACKGROUND: Brain magnetic resonance imaging (MRI) is used to support the diagnosis of progressive supranuclear palsy (PSP). However, the value of visual descriptive, manual planimetric, automatic volumetric MRI markers and fully automatic categorization is unclear, particularly regarding PSP predominance types other than Richardson's syndrome (RS). OBJECTIVES: To compare different visual reading strategies and automatic classification of T1-weighted MRI for detection of PSP in a typical clinical cohort including PSP-RS and (non-RS) variant PSP (vPSP) patients. METHODS: Forty-one patients (21 RS, 20 vPSP) and 46 healthy controls were included. Three readers using three strategies performed MRI analysis: exclusively visual reading using descriptive signs (hummingbird, morning-glory, Mickey-Mouse), visual reading supported by manual planimetry measures, and visual reading supported by automatic volumetry. Fully automatic classification was performed using a pre-trained support vector machine (SVM) on the results of atlas-based volumetry. RESULTS: All tested methods achieved higher specificity than sensitivity. Limited sensitivity was driven to large extent by false negative vPSP cases. Support by automatic volumetry resulted in the highest accuracy (75.1% ± 3.5%) among the visual strategies, but performed not better than the midbrain area (75.9%), the best single planimetric measure. Automatic classification by SVM clearly outperformed all other methods (accuracy, 87.4%), representing the only method to provide clinically useful sensitivity also in vPSP (70.0%). CONCLUSIONS: Fully automatic classification of volumetric MRI measures using machine learning methods outperforms visual MRI analysis without and with planimetry or volumetry support, particularly regarding diagnosis of vPSP, suggesting the use in settings with a broad phenotypic PSP spectrum. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
Subject(s)
Brain , Supranuclear Palsy, Progressive , Humans , Brain/diagnostic imaging , Brain/pathology , Magnetic Resonance Imaging/methods , Mesencephalon/pathology , Supranuclear Palsy, Progressive/pathologyABSTRACT
BACKGROUND: To date, studies on positron emission tomography (PET) with 18 F-fluorodeoxyglucose (FDG) in progressive supranuclear palsy (PSP) usually included PSP cohorts overrepresenting patients with Richardson's syndrome (PSP-RS). OBJECTIVES: To evaluate FDG-PET in a patient sample representing the broad phenotypic PSP spectrum typically encountered in routine clinical practice. METHODS: This retrospective, multicenter study included 41 PSP patients, 21 (51%) with RS and 20 (49%) with non-RS variants of PSP (vPSP), and 46 age-matched healthy controls. Two state-of-the art methods for the interpretation of FDG-PET were compared: visual analysis supported by voxel-based statistical testing (five readers) and automatic covariance pattern analysis using a predefined PSP-related pattern. RESULTS: Sensitivity and specificity of the majority visual read for the detection of PSP in the whole cohort were 74% and 72%, respectively. The percentage of false-negative cases was 10% in the PSP-RS subsample and 43% in the vPSP subsample. Automatic covariance pattern analysis provided sensitivity and specificity of 93% and 83% in the whole cohort. The percentage of false-negative cases was 0% in the PSP-RS subsample and 15% in the vPSP subsample. CONCLUSIONS: Visual interpretation of FDG-PET supported by voxel-based testing provides good accuracy for the detection of PSP-RS, but only fair sensitivity for vPSP. Automatic covariance pattern analysis outperforms visual interpretation in the detection of PSP-RS, provides clinically useful sensitivity for vPSP, and reduces the rate of false-positive findings. Thus, pattern expression analysis is clinically useful to complement visual reading and voxel-based testing of FDG-PET in suspected PSP. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
Subject(s)
Movement Disorders , Supranuclear Palsy, Progressive , Humans , Fluorodeoxyglucose F18 , Positron-Emission Tomography/methods , Retrospective Studies , Supranuclear Palsy, Progressive/diagnosisABSTRACT
The fatal neurodegenerative disease amyotrophic lateral sclerosis (ALS) is characterized by a profound loss of motor neurons (MNs). Until now only riluzole minimally extends life expectancy in ALS, presumably by inhibiting glutamatergic neurotransmission and calcium overload of MNs. Therefore, the aim of this study was to investigate the glutamate receptor properties and key aspects of intracellular calcium dynamics in induced pluripotent stem cell (iPSC)-derived MNs from ALS patients with C9orf72 (n = 4 cell lines), fused in sarcoma (FUS) (n = 9), superoxide dismutase 1 (SOD1) (n = 3) or transactive response DNA-binding protein 43 (TDP43) (n = 3) mutations as well as healthy (n = 7 cell lines) and isogenic controls (n = 3). Using calcium imaging, we most frequently observed spontaneous transients in mutant C9orf72 MNs. Basal intracellular calcium levels and α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA)-induced signal amplitudes were elevated in mutant TDP43 MNs. Besides, a majority of mutant TDP43 MNs responded to 3.5-dihydroxyphenylglycine as metabotropic glutamate receptor agonist. Quantitative real-time PCR demonstrated significantly increased expression levels of AMPA and kainate receptors in mutant FUS cells compared to healthy and isogenic controls. Furthermore, the expression of kainate receptors and voltage gated calcium channels in mutant C9orf72 MNs as well as metabotropic glutamate receptors in mutant SOD1 cells was markedly elevated compared to controls. Our data of iPSC-derived MNs from familial ALS patients revealed several mutation-specific alterations in glutamate receptor properties and calcium dynamics that could play a role in ALS pathogenesis and may lead to future translational strategies with individual stratification of neuroprotective ALS treatments.
Subject(s)
Amyotrophic Lateral Sclerosis/genetics , Amyotrophic Lateral Sclerosis/metabolism , Calcium/metabolism , Induced Pluripotent Stem Cells/metabolism , Motor Neurons/cytology , Motor Neurons/metabolism , Mutation , Receptors, Glutamate/metabolism , Amyotrophic Lateral Sclerosis/diagnosis , Biomarkers , C9orf72 Protein/genetics , Calcium Signaling , DNA-Binding Proteins/genetics , Disease Susceptibility , Genetic Association Studies , Genetic Predisposition to Disease , Humans , Neural Stem Cells/cytology , Neural Stem Cells/metabolism , RNA-Binding Protein FUS/genetics , Superoxide Dismutase-1/geneticsABSTRACT
Myoclonus-dystonia (DYT-SGCE, formerly DYT11) is characterized by alcohol-sensitive, myoclonic-like appearance of fast dystonic movements. It is caused by mutations in the SGCE gene encoding ε-sarcoglycan leading to a dysfunction of this transmembrane protein, alterations in the cerebello-thalamic pathway and impaired striatal plasticity. To elucidate underlying pathogenic mechanisms, we investigated induced pluripotent stem cell (iPSC)-derived striatal medium spiny neurons (MSNs) from two myoclonus-dystonia patients carrying a heterozygous mutation in the SGCE gene (c.298T>G and c.304C>T with protein changes W100G and R102X) in comparison to two matched healthy control lines. Calcium imaging showed significantly elevated basal intracellular Ca2+ content and lower frequency of spontaneous Ca2+ signals in SGCE MSNs. Blocking of voltage-gated Ca2+ channels by verapamil was less efficient in suppressing KCl-induced Ca2+ peaks of SGCE MSNs. Ca2+ amplitudes upon glycine and acetylcholine applications were increased in SGCE MSNs, but not after GABA or glutamate applications. Expression of voltage-gated Ca2+ channels and most ionotropic receptor subunits was not altered. SGCE MSNs showed significantly reduced GABAergic synaptic density. Whole-cell patch-clamp recordings displayed elevated amplitudes of miniature postsynaptic currents and action potentials in SGCE MSNs. Our data contribute to a better understanding of the pathophysiology and the development of novel therapeutic strategies for myoclonus-dystonia.
Subject(s)
Corpus Striatum/pathology , Dendritic Spines/pathology , Dystonic Disorders/pathology , Acetylcholine/pharmacology , Action Potentials , Adult , Calcium Channel Blockers/pharmacology , Calcium Channels, L-Type/metabolism , Calcium Signaling , Cell Differentiation/physiology , Cells, Cultured , Dendritic Spines/drug effects , Dendritic Spines/metabolism , Female , Gene Expression , Glycine/pharmacology , Humans , Induced Pluripotent Stem Cells/cytology , Induced Pluripotent Stem Cells/physiology , Male , Mecamylamine/pharmacology , Middle Aged , Patch-Clamp TechniquesABSTRACT
Tau pathology is now considered to be the main cause of a wide spectrum of neurodegenerative diseases, which are collectively referred to as tauopathies. These include primary tauopathies, in which tau plays the main role in the pathogenesis as well as secondary tauopathies, such as Alzheimer's disease, in which amyloid beta also plays a substantial role in the disease process in addition to the tau pathology. Primary tauopathies include progressive supranuclear palsy, corticobasal degeneration, Pick's disease and rare hereditary tauopathies, which are referred to as frontotemporal lobar degeneration with microtubule-associated protein tau (MAPT) mutation. Tauopathies differ from each other pathologically by the affected brain regions and cell types as well as by the biochemical characteristics of the aggregated tau protein. Various tau-centered neuroprotective treatment approaches are currently in preclinical and clinical development. They target different mechanisms, including the reduction of tau expression, inhibition of tau aggregation, dissolution of tau aggregates, improvement of cellular mechanisms to eliminate toxic tau species, stabilization of microtubules and prevention of intercellular tau spreading. This review article gives an overview of tauopathies and the current concepts for the development of disease-modifying treatment.
Subject(s)
Alzheimer Disease , Corticobasal Degeneration , Tauopathies , Amyloid beta-Peptides , Humans , Tauopathies/drug therapy , tau ProteinsABSTRACT
To explore the correlations of botulinum toxin (BT) therapy with dysphagia, we wanted to study a group of cervical dystonia (CD) patients with optimised BT therapy during a prolonged period of time to record their dysphagia frequency, severity and duration, to study potential risk factors and try to avoid it by BT application with ultrasound guidance. BT therapy of 75 CD patients (23 males, 52 females, age 60 ± 12 years, BT total dose 303.5 ± 101.5 uMU) was retrospectively analysed for 1 year. BT therapy was optimised prior to the observation period. Dysphagia was noticed by one fifth of the patients. In those patients, it only occurred in about one third of the injection series. It was never associated with a functional deficit and lasted several days to 2 weeks. It was not related to patient age or gender, BT total dose, BT dose in the sternocleidomastoid muscle, BT dose in the sternocleidomastoid and scalenii muscles, by BT therapy with bilateral sternocleidomastoid muscle injections or BT therapy with abobotulinumtoxinA. Ultrasound guidance was not able to prevent it. Further prospective studies will be necessary to study underlying dystonia associated swallowing abnormalities as a potentially predisposing factor.
Subject(s)
Botulinum Toxins, Type A , Deglutition Disorders , Torticollis , Botulinum Toxins, Type A/therapeutic use , Deglutition Disorders/etiology , Female , Humans , Infant, Newborn , Male , Neck Muscles/diagnostic imaging , Prospective Studies , Retrospective Studies , Torticollis/complications , Torticollis/drug therapyABSTRACT
We have previously shown that knockout of fibroblast growth factor-2 (FGF-2) and potential compensatory effects of other growth factors result in amelioration of disease symptoms in a transgenic mouse model of amyotrophic lateral sclerosis (ALS). ALS is a rapidly progressive neurological disorder leading to degeneration of cortical, brain stem, and spinal motor neurons followed by subsequent denervation and muscle wasting. Mutations in the superoxide dismutase 1 (SOD1) gene are responsible for approximately 20% of familial ALS cases and SOD1 mutant mice still are among the models best mimicking clinical and neuropathological characteristics of ALS. The aim of the present study was a thorough characterization of FGF-2 and other growth factors and signaling effectors in vivo in the SOD1G93A mouse model. We observed tissue-specific opposing gene regulation of FGF-2 and overall dysregulation of other growth factors, which in the gastrocnemius muscle was associated with reduced downstream extracellular-signal-regulated kinases (ERK) and protein kinase B (AKT) activation. To further investigate whether the effects of FGF-2 on motor neuron death are mediated by glial cells, astrocytes lacking FGF-2 were cocultured together with mutant SOD1 G93A motor neurons. FGF-2 had an impact on motor neuron maturation indicating that astrocytic FGF-2 affects motor neurons at a developmental stage. Moreover, neuronal gene expression patterns showed FGF-2- and SOD1 G93A -dependent changes in ciliary neurotrophic factor, glial-cell-line-derived neurotrophic factor, and ERK2, implying a potential involvement in ALS pathogenesis before the onset of clinical symptoms.
Subject(s)
Amyotrophic Lateral Sclerosis/enzymology , Astrocytes/enzymology , Fibroblast Growth Factor 2/metabolism , Motor Neurons/enzymology , Muscle, Skeletal/enzymology , Superoxide Dismutase-1/metabolism , Amyotrophic Lateral Sclerosis/genetics , Amyotrophic Lateral Sclerosis/pathology , Animals , Astrocytes/pathology , Cell Death , Cells, Cultured , Disease Models, Animal , Enzyme Activation , Extracellular Signal-Regulated MAP Kinases/metabolism , Fibroblast Growth Factor 2/deficiency , Fibroblast Growth Factor 2/genetics , Gene Expression Regulation, Developmental , Mice, Inbred C57BL , Mice, Knockout , Motor Neurons/pathology , Mutation , Proto-Oncogene Proteins c-akt/metabolism , Signal Transduction , Superoxide Dismutase-1/geneticsABSTRACT
Mutations in the Parkin gene (PARK2) have been linked to a recessive form of Parkinson's disease (PD) characterized by the loss of dopaminergic neurons in the substantia nigra. Deficiencies of mitochondrial respiratory chain complex I activity have been observed in the substantia nigra of PD patients, and loss of Parkin results in the reduction of complex I activity shown in various cell and animal models. Using co-immunoprecipitation and proximity ligation assays on endogenous proteins, we demonstrate that Parkin interacts with mitochondrial Stomatin-like protein 2 (SLP-2), which also binds the mitochondrial lipid cardiolipin and functions in the assembly of respiratory chain proteins. SH-SY5Y cells with a stable knockdown of Parkin or SLP-2, as well as induced pluripotent stem cell-derived neurons from Parkin mutation carriers, showed decreased complex I activity and altered mitochondrial network morphology. Importantly, induced expression of SLP-2 corrected for these mitochondrial alterations caused by reduced Parkin function in these cells. In-vivo Drosophila studies showed a genetic interaction of Parkin and SLP-2, and further, tissue-specific or global overexpression of SLP-2 transgenes rescued parkin mutant phenotypes, in particular loss of dopaminergic neurons, mitochondrial network structure, reduced ATP production, and flight and motor dysfunction. The physical and genetic interaction between Parkin and SLP-2 and the compensatory potential of SLP-2 suggest a functional epistatic relationship to Parkin and a protective role of SLP-2 in neurons. This finding places further emphasis on the significance of Parkin for the maintenance of mitochondrial function in neurons and provides a novel target for therapeutic strategies.
Subject(s)
Blood Proteins/metabolism , Membrane Proteins/metabolism , Ubiquitin-Protein Ligases/metabolism , Aged , Animals , Cell Culture Techniques , Cell Line, Tumor , Dopaminergic Neurons/metabolism , Drosophila Proteins/metabolism , Drosophila melanogaster/genetics , Electron Transport Complex I/metabolism , Female , Humans , Induced Pluripotent Stem Cells/metabolism , Male , Middle Aged , Mitochondria/metabolism , Mutation , Neurons/metabolism , Parkinson Disease/genetics , Substantia Nigra/metabolismABSTRACT
Amyotrophic lateral sclerosis (ALS) is a lethal disease characterized by motor neuron degeneration and associated with aggregation of nuclear RNA-binding proteins (RBPs), including FUS. How FUS aggregation and neurodegeneration are prevented in healthy motor neurons remain critically unanswered questions. Here, we use a combination of ALS patient autopsy tissue and induced pluripotent stem cell-derived neurons to study the effects of FUS mutations on RBP homeostasis. We show that FUS' tendency to aggregate is normally buffered by interacting RBPs, but this buffering is lost when FUS mislocalizes to the cytoplasm due to ALS mutations. The presence of aggregation-prone FUS in the cytoplasm causes imbalances in RBP homeostasis that exacerbate neurodegeneration. However, enhancing autophagy using small molecules reduces cytoplasmic FUS, restores RBP homeostasis and rescues motor function in vivo. We conclude that disruption of RBP homeostasis plays a critical role in FUS-ALS and can be treated by stimulating autophagy.
Subject(s)
Amyotrophic Lateral Sclerosis/pathology , Autophagy/physiology , Motor Neurons/pathology , Cytoplasm/metabolism , Humans , Inclusion Bodies/pathology , Induced Pluripotent Stem Cells/pathology , Mutation/genetics , RNA-Binding Protein FUS/metabolismABSTRACT
Mutations in the VPS13A gene leading to depletion of chorein protein are causative for Chorea Acanthocytosis (ChAc), a rare devastating disease, which is characterized by neurodegeneration mainly affecting the basal ganglia as well as deformation of erythrocytes. Studies on patient blood samples highlighted a dysregulation of Actin cytoskeleton caused by downregulation of the PI3K pathway and hyper-activation of Lyn-kinase, but to what extent these mechanisms are present and relevant in the affected neurons remains elusive. We studied the effects of the absence of chorein protein on the morphology and trafficking of lysosomal and mitochondrial compartments in ChAc patient-specific induced pluripotent stem cell-derived medium spiny neurons (MSNs). Numbers of both organelle types were reduced in ChAc MSNs. Mitochondrial length was shortened and their membrane potential showed significant hyperpolarization. In contrast to previous studies, showing Lyn kinase dependency of ChAc-associated pathological events in erythrocytes, pharmacological studies demonstrate that the impairment of mitochondria and lysosomes are independent of Lyn kinase activity. These data suggest that impairment in mitochondrial and lysosomal morphologies in MSNs is not mediated by a dysregulation of Lyn kinase and thus the pathological pathways in ChAc might be - at least in part - cell-type specific.
Subject(s)
Lysosomes/metabolism , Mitochondria/metabolism , Neuroacanthocytosis/metabolism , src-Family Kinases/metabolism , Adult , Cells, Cultured , Female , Humans , Induced Pluripotent Stem Cells/metabolism , Induced Pluripotent Stem Cells/pathology , Lysosomes/pathology , Male , Membrane Potential, Mitochondrial , Middle Aged , Mitochondria/pathology , Neuroacanthocytosis/genetics , Neuroacanthocytosis/pathology , Signal Transduction , Vesicular Transport Proteins/geneticsABSTRACT
OBJECTIVE: Hippocampal inflammation in anti-LGI1 encephalitis causes memory deficits, seizures and behavioural abnormalities. Recent findings suggest that extralimbic brain areas are additionally affected and that patients also suffer from non-limbic cognitive symptoms. Moreover, up to 60% of patients show no structural MRI abnormalities in the acute disease stage. We therefore investigated whether functional connectivity analyses can identify brain network changes underlying disease-related symptoms. METHODS: We studied 27 patients and a matched healthy control group using structural and functional MRI. Intrinsic functional networks were analysed using Independent Component Analysis and Dual Regression. Cognitive testing covered working memory, episodic memory, attention and executive function. RESULTS: Our analysis revealed functional connectivity alterations in several large-scale networks, including the default mode network (DMN) which showed an aberrant structure-function relationship with the damaged hippocampus. In addition, connectivity in the sensorimotor, salience and higher visual networks was impaired independent of hippocampal damage. Increased connectivity in ventral and dorsal DMN regions significantly correlated with better memory performance. In contrast, stronger connectivity of the insula with the salience network and DMN was linked to impaired memory function. CONCLUSIONS: Anti-LGI1 encephalitis is associated with a characteristic pattern of widespread functional network alterations. Increased DMN connectivity seems to represent a compensatory mechanism for memory impairment induced by hippocampal damage. Network analyses may provide a key to the understanding of clinical symptoms in autoimmune encephalitis and reveal changes of brain function beyond apparent structural damage.
Subject(s)
Brain/diagnostic imaging , Encephalitis/immunology , Nerve Net/diagnostic imaging , Proteins/immunology , Aged , Attention/physiology , Autoantibodies , Brain/physiopathology , Brain Mapping , Encephalitis/diagnostic imaging , Encephalitis/physiopathology , Encephalitis/psychology , Executive Function/physiology , Female , Humans , Intracellular Signaling Peptides and Proteins , Magnetic Resonance Imaging , Male , Memory, Short-Term/physiology , Middle Aged , Nerve Net/physiopathology , Neuropsychological TestsABSTRACT
The paraneoplastic cerebellar syndrome presents as severe neuroimmunological disease associated with malignancies. Antibodies against antigens expressed by tumor cells cross-react with proteins of cerebellar Purkinje cells leading to neuroinflammation and neuronal loss. These antineuronal antibodies are preferentially investigated by serological analyses while examination of the cerebrospinal fluid is only performed infrequently. We retrospectively investigated 12 patients with antineuronal antibodies against Purkinje cells with a special focus on cerebrospinal fluid. Our results confirm a subacute disease with a severe cerebellar syndrome in 10 female patients due to anti-Yo antibodies associated mostly with gynecological malignancies. While standard cerebrospinal fluid parameters infrequently revealed pathological results, all patients presented oligoclonal bands indicating intrathecal IgG synthesis. Analyses of anti-Yo antibodies in cerebrospinal fluid by calculating the antibody specific index revealed intrathecal synthesis of anti-Yo antibodies in these patients. In analogy to anti-Yo syndrome, an intrathecal production of anti-Tr antibodies in one patient who presented with a paraneoplastic cerebellar syndrome was detected. In an additional patient, anti-Purkinje cell antibodies of unknown origin in the cerebrospinal fluid but not in serum were determined suggesting an isolated immune reaction within the central nervous system (CNS) and underlining the importance of investigating the cerebrospinal fluid. In conclusion, patients with a cerebellar syndrome display a distinct immune reaction within the cerebrospinal fluid including intrathecal synthesis of disease-specific antibodies. We emphasize the importance of a thorough immunological work up including investigations of both serum and cerebrospinal fluid.
Subject(s)
Autoantibodies/metabolism , Nerve Tissue Proteins/immunology , Paraneoplastic Cerebellar Degeneration/immunology , Paraneoplastic Cerebellar Degeneration/pathology , Purkinje Cells/metabolism , Receptors, Cell Surface/immunology , Adult , Aged , Female , Humans , Magnetic Resonance Imaging , Middle Aged , Paraneoplastic Cerebellar Degeneration/diagnostic imaging , Paraneoplastic Cerebellar Degeneration/metabolism , Purkinje Cells/immunology , Retrospective StudiesABSTRACT
Chorea-acanthocytosis (ChAc) is a fatal neurological disorder characterized by red blood cell acanthocytes and striatal neurodegeneration. Recently, severe cell membrane disturbances based on depolymerized cortical actin and an elevated Lyn kinase activity in erythrocytes from ChAc patients were identified. How this contributes to the mechanism of neurodegeneration is still unknown. To gain insight into the pathophysiology, we established a ChAc patient-derived induced pluripotent stem cell model and an efficient differentiation protocol providing a large population of human striatal medium spiny neurons (MSNs), the main target of neurodegeneration in ChAc. Patient-derived MSNs displayed enhanced neurite outgrowth and ramification, whereas synaptic density was similar to controls. Electrophysiological analysis revealed a pathologically elevated synaptic activity in ChAc MSNs. Treatment with the F-actin stabilizer phallacidin or the Src kinase inhibitor PP2 resulted in the significant reduction of disinhibited synaptic currents to healthy control levels, suggesting a Src kinase- and actin-dependent mechanism. This was underlined by increased G/F-actin ratios and elevated Lyn kinase activity in patient-derived MSNs. These data indicate that F-actin stabilization and Src kinase inhibition represent potential therapeutic targets in ChAc that may restore neuronal function. SIGNIFICANCE STATEMENT: Chorea-acanthocytosis (ChAc) is a fatal neurodegenerative disease without a known cure. To gain pathophysiological insight, we newly established a human in vitro model using skin biopsies from ChAc patients to generate disease-specific induced pluripotent stem cells (iPSCs) and developed an efficient iPSC differentiation protocol providing striatal medium spiny neurons. Using patch-clamp electrophysiology, we detected a pathologically enhanced synaptic activity in ChAc neurons. Healthy control levels of synaptic activity could be restored by treatment of ChAc neurons with the F-actin stabilizer phallacidin and the Src kinase inhibitor PP2. Because Src kinases are involved in bridging the membrane to the actin cytoskeleton by membrane protein phosphorylation, our data suggest an actin-dependent mechanism of this dysfunctional phenotype and potential treatment targets in ChAc.
Subject(s)
Actins/metabolism , Corpus Striatum/pathology , GABAergic Neurons/pathology , Induced Pluripotent Stem Cells/pathology , Neuroacanthocytosis/metabolism , Neuroacanthocytosis/pathology , src-Family Kinases/metabolism , Adult , Cell Differentiation , Cells, Cultured , Corpus Striatum/metabolism , Female , GABAergic Neurons/metabolism , Humans , Induced Pluripotent Stem Cells/metabolism , Neurons , Synaptic Transmission , src-Family Kinases/antagonists & inhibitorsABSTRACT
Despite decades of research on amyotrophic lateral sclerosis (ALS), there is only one approved drug, which minimally extends patient survival. Here, we investigated pathophysiological mechanisms underlying ALS using motor neurons (MNs) differentiated from induced pluripotent stem cells (iPSCs) derived from ALS patients carrying mutations in FUS or SOD1. Patient-derived MNs were less active and excitable compared to healthy controls, due to reduced Na(+) /K(+) ratios in both ALS groups accompanied by elevated potassium channel (FUS) and attenuated sodium channel expression levels (FUS, SOD1). ALS iPSC-derived MNs showed elevated endoplasmic reticulum stress (ER) levels and increased caspase activation. Treatment with the FDA approved drug 4-Aminopyridine (4AP) restored ion-channel imbalances, increased neuronal activity levels and decreased ER stress and caspase activation. This study provides novel pathophysiological data, including a mechanistic explanation for the observed hypoexcitability in patient-derived MNs and a new therapeutic strategy to provide neuroprotection in MNs affected by ALS. Stem Cells 2016;34:1563-1575.
Subject(s)
4-Aminopyridine/pharmacology , Amyotrophic Lateral Sclerosis/pathology , Induced Pluripotent Stem Cells/pathology , Motor Neurons/pathology , Amyotrophic Lateral Sclerosis/genetics , Caspases/metabolism , Cell Differentiation/drug effects , Endoplasmic Reticulum Stress/drug effects , Enzyme Activation/drug effects , Female , Humans , Ion Channels/metabolism , Male , Middle Aged , Mutation/genetics , Neuroprotection/drug effects , Phenotype , RNA-Binding Protein FUS/genetics , Superoxide Dismutase/genetics , Synapses/drug effects , Synapses/metabolismSubject(s)
Multiple System Atrophy , Antibodies , Carrier Proteins , Homer Scaffolding Proteins , HumansABSTRACT
Botulinum toxin is now used for numerous indications including dystonias, spasticity, cerebral palsy, hyperhidrosis, cosmetics and chronic migraine. It has to be injected into its target tissues thus causing injection site pain. We wanted to compare the efficacy of various analgesic interventions suggested for reduction of injection site pain. In 13 healthy controls, pain thresholds in the fingertips II and III bilaterally were determined by the Mechanical Pain Threshold Test and the Repetitive Pain Stimulation Test at baseline and under nitrous oxide/oxygen, ice spray, local anaesthetic cream and forearm ischaemia. All interventions studied produce statistically significant and robust elevations of the pain threshold in both tests. Nitrous oxide/oxygen had stronger effects than the other interventions, although this superiority was statistically significant only in the Repetitive Pain Stimulation Test and not against ice spray. Also considering duration, localisation and penetration depth of analgesic effects, hyperhidrosis treatment may benefit from nitrous oxide/oxygen, ice spray and local anaesthetic cream. In palmar hyperhidrosis, forearm ischaemia is possible and also reduces botulinum toxin washout. Cosmetic indications may also benefit from nitrous oxide/oxygen and local anaesthetic cream. For botulinum toxin therapy of spasticity, dystonia and tremor, only nitrous oxide/oxygen may offer intramuscular analgesic effect. Its systemic and prolonged effect is also an advantage in injections in several body parts. Future studies are necessary to test the influence of penetration depth and combinations of analgesic interventions.