[Clinical characteristics of seizure-predominant autoimmune encephalitis and utility of anti-neuronal antibody scores for early treatment].

We analyzed 20 patients diagnosed with autoimmune neurological diseases with seizure predominance. In these patients, we examined the usefulness of Antibody Prevalence in Epilepsy and Encephalopathy (APE2) score and Antibodies Contributing to Focal Epilepsy Signs and Symptoms (ACES) score in autoimmune encephalitis (AE) for facilitating early treatment. APE2 score was positive in 19 of 20 patients. ACES score was positive in 15 of 20 patients, and 4 of 5 of the patients with negative ACES score did not have AE. Comprehensive assessment including the use of the above scores is desirable in the early stage of AE.

Cerebral Tuberculoma Diagnosed by Nested Polymerase Chain Reaction of a Formalin-fixed Paraffin-embedded Brain Biopsy Sample.

A 38-year-old man was taken to hospital with generalized clonic seizure. Brain magnetic resonance imaging (MRI) showed multiple ring-enhancing lesions centered in the left frontoparietal lobe. A histopathological examination of a brain biopsy sample revealed granulomatous lesions with caseous necrosis. We extracted DNA from a formalin-fixed paraffin-embedded (FFPE) brain specimen, and nested polymerase chain reaction (PCR) of the DNA sample detected the Mycobacterium tuberculosis-specific insertion sequence IS6110. The lesions worsened after anti-tuberculosis drugs were administered, which we considered to be a paradoxical response and continued treatment. A genetic diagnosis of M. tuberculosis using FFPE specimens is useful for diagnosing tuberculoma.

Anti-signal Recognition Particle Antibody-positive Immune-mediated Myopathy after mRNA-1273 SARS-CoV-2 Vaccination.

A 26-year-old Japanese woman developed a fever, myalgia and gait disturbance one day after receiving the second dose of the mRNA-1273 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine. A neurological examination revealed symmetrical weakness and myalgia in proximal lower limbs, and a blood examination showed prominent elevation of creatinine kinase. Magnetic resonance imaging (MRI) revealed a high signal intensity in the thigh muscles on short-tau inversion recovery images, and antibody testing revealed positive findings for anti-signal recognition particle (SRP) antibody. Thus, anti-SRP antibody-positive immune-mediated myopathy was diagnosed. We initiated immunotherapy, and she was ultimately able to walk stably.

Sporadic Amyotrophic Lateral Sclerosis Due to a FUS P525L Mutation with Asymmetric Muscle Weakness and Anti-ganglioside Antibodies.

Amyotrophic lateral sclerosis (ALS) due to a fused in sarcoma (FUS) P525L mutation is characterized by a rapidly progressive course. Multifocal motor neuropathy (MMN) may resemble ALS in early stage and is associated with anti-ganglioside antibodies. A 38-year-old woman was admitted to our hospital because of progressive muscle weakness in the right limbs. She had mild mental retardation and minor deformities. Initially, we suspected MMN given the asymmetric muscle weakness and detection of anti-ganglioside antibodies. However, physical and electrophysiological tests did not support MMN, instead suggesting ALS. We confirmed a heterozygous P525L mutation and finally diagnosed this case as ALS due to an FUS mutation.

SIRT1 decelerates morphological processing of oligodendrocyte cell lines and regulates the expression of cytoskeleton-related oligodendrocyte proteins.

SIRT1 is involved in the regulation of a variety of biological processes such as metabolism, stress response, autophagy and differentiation. Although progenitor cells of oligodendrocytes (OPCs) express high level of SIRT1, its function on differentiation is unknown. Because we have shown that SIRT1 plays a pivotal role in differentiation of neural precursor cells, we hypothesized that SIRT1 may also participate in the differentiation of oligodendrocytes (OLGs). We examined whether SIRT1 was expressed in two human oligodendrocyte cell lines: KG-1-C and MO 3.13 OLG. Transfection of cell lines with SIRT1-siRNA and SIRT2-siRNA promoted the extension of cellular processes. SIRT1-siRNA and SIRT2-siRNA increased acetyl-α-tubulin level, conversely, over expression of SIRTs resulted in decreased the ratio of acetyl-α-tubulin to α-tubulin. We also found knockdown of SIRT1 and SIRT2 induced overexpression of ßIV-tubulin and tubulin polymerization promoting protein (TPPP) (OLG-specific cytoskeleton-related molecules) that distributed widely in cell bodies. Taken together, SIRT1 may play a role in oligodenroglial differentiation and myelinogenesis.

[A case of facial-onset sensory and motor neuronopathy (FOSMN) with cerebellar ataxia and abnormal decrement in repetitive nerve stimulation test].

A 59-year-old woman presented with a 7-year history of facial numbness on the left side, and gradual worsening of symptoms. Over several years, facial muscle weakness, dysarthria, tongue atrophy and fasciculation had progressed. Then, she developed cerebellar ataxia affecting the left extremities, in addition to earlier symptoms. Brain MRI revealed cerebellar atrophy, and 99mTc-SPECT depicted cerebellar hypoperfusion. A repetitive nerve stimulation test (RNS) indicated abnormal decrement in the nasalis and trapezius muscles on the left side. Facial-onset sensory and motor neuronopathy (FOSMN) was diagnosed. Administration of intravenous immunoglobulin resulted in improvement of some symptoms. Although cerebellar ataxia is not a common symptom of FOSMN, a case showing TDP-43-positive glial cytoplasmic inclusions in cerebellar white matter has been reported. Therefore, it is possible that FOSMN may cause cerebellum impairment in some patients. Furthermore, RNS positive rate in the trapezius muscle is known to be high in amyotrophic lateral sclerosis (ALS) patients. It is speculated that RNS of the affected muscles in FOSMN may show abnormal decrement by the same mechanisms as ALS.

Hyperemesis-induced Wernicke-Korsakoff Syndrome due to Hypergastrinemia during Long-term Treatment with Proton Pump Inhibitors.

We herein report a patient with Wernicke-Korsakoff syndrome (WKS) who had neither a history of alcoholism or of history of gastric surgery. A 56-year-old woman was transferred to our hospital because of the loss of consciousness and she was diagnosed to have Wernicke encephalopathy. She showed proton pump inhibitor-induced refractory hypergastrinemia with the subsequent development of hyperemesis and a vitamin B1 deficiency.

Transplantation of Mesenchymal Stem Cells Improves Amyloid-ß Pathology by Modifying Microglial Function and Suppressing Oxidative Stress.

Mesenchymal stem cells (MSC) are increasingly being studied as a source of cell therapy for neurodegenerative diseases, and several groups have reported their beneficial effects on Alzheimer's disease (AD). In this study using AD model mice (APdE9), we found that transplantation of MSC via the tail vein improved spatial memory in the Morris water maze test. Using electron paramagnetic resonance imaging to evaluate the in vivo redox state of the brain, we found that MSC transplantation suppressed oxidative stress in AD model mice. To elucidate how MSC treatment ameliorates oxidative stress, we focused on amyloid-ß (Aß) pathology and microglial function. MSC transplantation reduced Aß deposition in the cortex and hippocampus. Transplantation of MSC also decreased Iba1-positive area in the cortex and reduced activated ameboid shaped microglia. On the other hand, MSC transplantation accelerated accumulation of microglia around Aß deposits and prompted microglial Aß uptake and clearance as shown by higher frequency of Aß-containing microglia. MSC transplantation also increased CD14-positive microglia in vivo, which play a critical role in Aß uptake. To confirm the effects of MSC on microglia, we co-cultured the mouse microglial cell line MG6 with MSC. Co-culture with MSC enhanced Aß uptake by MG6 cells accompanied by upregulation of CD14 expression. Additionally, co-culture of MG6 cells with MSC induced microglial phenotype switching from M1 to M2 and suppressed production of proinflammatory cytokines. These data indicate that MSC treatment has the potential to ameliorate oxidative stress through modification of microglial functions, thereby improving Aß pathology in AD model mice.

Early administration of galantamine from preplaque phase suppresses oxidative stress and improves cognitive behavior in APPswe/PS1dE9 mouse model of Alzheimer's disease.

Alzheimer's disease (AD) is a common neurodegenerative disease that progressively impairs memory and cognition. Deposition of amyloid-ß (Aß) peptides is the most important pathophysiological hallmark of AD. Oxidative stress induced by generation of reactive oxygen species (ROS) is a prominent phenomenon in AD and known to occur early in the course of AD. Several reports suggest a relationship between change in redox status and AD pathology including progressive Aß deposition, glial cell activation, and inflammation. Galantamine is an acetylcholinesterase inhibitor and has been reported to have an oxidative stress inhibitory function. In the present study, galantamine was administered orally to AD model mice from before the appearance of Aß plaques (preplaque phase), and in vivo change in redox status of the brain was measured using electron paramagnetic resonance (EPR) imaging. Administration of galantamine from the preplaque phase ameliorated memory decline in Morris water maze test and novel object recognition test. Monitoring of the redox status of the brain using EPR imaging showed that galantamine treatment improved the unbalanced redox state. Additionally, galantamine administration enhanced microglial function to promote Aß clearance, reducing the Aß-positive area in the cortex and amount of insoluble Aß in the brain. In contrast, galantamine treatment from the preplaque phase suppressed the production of proinflammatory cytokines through neurotoxic microglial activity. Therefore, galantamine administration from the preplaque phase may have the potential of clinical application for the prevention of AD. In addition, our results demonstrate the usefulness of EPR imaging for speedy and quantitative evaluation of the efficacy of disease-modifying drugs for AD.

CD14 and Toll-Like Receptor 4 Promote Fibrillar Aß42 Uptake by Microglia Through A Clathrin-Mediated Pathway.

We previously demonstrated that microglia play an essential role in clearance of amyloid-ß (Aß) in Alzheimer's disease (AD)-like pathology. Our prior work also showed that several receptors expressed on microglia participated in Aß phagocytosis. However, clathrin-mediated endocytosis (CME), which is associated with production and release of Aß in neurons, has received much less attention in the context of microglial Aß uptake. To elucidate the detailed mechanisms of microglial Aß uptake pathways, we focused on CD14 and Toll-like receptor 4 (TLR4), which have been shown to mediate fibrillar Aß1 - 42 (fAß42) phagocytosis in microglia. CD14 has also been known to control lipopolysaccharide-induced internalization of TLR4 in a clathrin-dependent manner. However, it remains unclear whether CD14 and TLR4 engage in CME in microglial fAß42 uptake, including whether CD14 interacts with TLR4 in the process. In the present study, we found that CD14-positive microglia increased in an age-dependent manner in the cortex of AD model mice. Immunostaining showed that CD14 interacted with TLR4 to internalize fAß42 in the mouse microglial cell line MG6. Knock-down of CD14 and TLR4 in MG6 cells significantly reduced intracellular fAß42, showing their involvement in fAß42 uptake. We also found that clathrin participated in fAß42 uptake by MG6 cells. Furthermore, CD14 and TLR4 mediated fAß42 uptake via clathrin-dependent mechanisms. These results indicate that CD14 and TLR4 participate not only in phagocytosis but also in clathrin-dependent fAß42 internalization in microglia. These findings provide novel molecular understanding of microglial fAß42 uptake, which could be of therapeutic relevance for AD.

Evaluation of Mitochondrial Oxidative Stress in the Brain of a Transgenic Mouse Model of Alzheimer's Disease by in vitro Electron Paramagnetic Resonance Spectroscopy.

Alzheimer's disease (AD) is one of the most common neurodegenerative diseases responsible for progressive dementia. Deposition of amyloid-ß (Aß) in the brain is the most important pathophysiological hallmark of AD. In addition, recent evidence indicates that reactive oxygen species (ROS) derived from mitochondria contribute to progression of AD pathology. We thus hypothesized that Aß accumulates and oxidative stress increases in the brain mitochondria of a transgenic mouse model of AD (APdE9). We measured the quantity of Aß and the activity of the antioxidant enzyme superoxide dismutase (SOD) in brain mitochondrial fractions prepared from APdE9 and wild-type (WT) mice aged 6, 9, 15, and 18 months. We also quantified the age-related changes in redox status in the mitochondrial fractions obtained from both APdE9 and WT mouse brains by electron paramagnetic resonance (EPR) spectrometry using a paramagnetic nitroxide "Mito-Tempo" [(2-(2,2,6,6-Tetramethylpiperidin-1-oxyl-4-ylamino)-2-oxoethyl) triphenylphosphonium chloride monohydrate] as a mitochondria-targeted redox-sensitive probe. In APdE9 mice, Aß accumulated in brain mitochondria earlier than in the non-mitochondrial fraction of the brain. Furthermore, increased oxidative stress was demonstrated in brain mitochondria of APdE9 mice by in vitro SOD assay as well as EPR spectroscopy. EPR combined with a mitochondria-targeted redox-sensitive nitroxide probe is a potentially powerful tool to elucidate the etiology of AD and facilitate the development of new therapeutic strategies for AD.

Role of Suppressor of Cytokine Signaling 3 (SOCS3) in Altering Activated Microglia Phenotype in APPswe/PS1dE9 Mice.

In response to changes of the central nervous system environment, microglia are capable of acquiring diverse phenotypes for cytotoxic or immune regulation and resolution of injury. Alzheimer's disease (AD) pathology also induces several microglial activations, resulting in production of pro-inflammatory cytokines and reactive oxygen species or clearance of amyloid-ß (Aß) through phagocytosis. We previously demonstrated that microglial activation and increase in oxidative stress started from the middle age in APPswe/PS1dE9 mice, and hypothesized that M1 activation occurs in middle-aged AD mice by Aß stimulation. In the present study, we analyzed in vivo expressions of pro-inflammatory cytokines (M1 microglial markers), M2 microglial markers, and suppressor of cytokine signaling (SOCS) family, and examined the microglial phenotypic profile in APPswe/PS1dE9 mice. Then we compared the in vitro gene expression patterns of Aß- and lipopolysaccharide (LPS)-stimulated primary-cultured microglia. Microglia in APPswe/PS1dE9 mice exhibited an M1-like phenotype, expressing tumor necrosis factor α (TNFα) but not interleukin 6 (IL6). Aß-stimulated primary-cultured microglia also expressed TNFα but not IL6, whereas LPS-stimulated primary-cultured microglia expressed both pro-inflammatory cytokines. Furthermore, both microglia in APPswe/PS1dE9 mice and Aß-stimulated primary-cultured microglia expressed SOCS3. Reduction of SOCS3 expression in Aß-challenged primary-cultured microglia resulted in upregulation of IL6 expression. Our findings indicate that SOCS3 suppresses complete polarization to M1 phenotype through blocking IL6 production, and Aß-challenged primary-cultured microglia replicate the in vivo gene expression pattern of microglia in APPswe/PS1dE9 mice. Aß may induce the M1-like phenotype through blocking of IL6 by SOCS3.

Fisher syndrome with delayed facial weakness and taste impairment: a case report.

A 55-year-old man was admitted to our hospital because of acute onset of diplopia and gait disturbance. On admission, ophthalmoplegia, ataxia and areflexia were observed. He was diagnosed with Fisher syndrome and given intravenous immunoglobulin therapy from day 6 to day 10 after disease onset. After treatment, ophthalmoplegia and ataxia began to improve. However, he developed taste impairment on day 13 and right hemifacial weakness on day 16 after onset. A blink reflex test revealed right facial nerve impairment. On day 42 after onset, facial weakness and taste impairment remitted, and the blink reflex test result was normalized without additional treatment. Although it has been known that 10% of patients with Fisher syndrome complicated by delayed facial nerve palsy, the mechanism of the facial nerve palsy has not been elucidated. Therefore, this is a significant report to describe delayed facial nerve palsy combined with taste impairment and successive recordings of blink reflex and facial nerve conduction in a patient with Fisher syndrome.

Evaluation of oxidative stress in the brain of a transgenic mouse model of Alzheimer disease by in vivo electron paramagnetic resonance imaging.

Alzheimer disease (AD) is a neurodegenerative disease clinically characterized by progressive cognitive dysfunction. Deposition of amyloid-ß (Aß) peptides is the most important pathophysiological hallmark of AD. Oxidative stress induced by reactive oxygen species is prominent in AD, and several reports suggest the relationship between a change in redox status and AD pathology containing progressive Aß deposition, the activation of glial cells, and mitochondrial dysfunction. Therefore, we performed immunohistochemical analysis using a transgenic mouse model of AD (APdE9) and evaluated the activity of superoxide dismutase in brain tissue homogenates of APdE9 mice in vitro. Together with those analyses, in vivo changes in redox status with age in both wild-type (WT) and APdE9 mouse brains were measured noninvasively by three-dimensional electron paramagnetic resonance (EPR) imaging using nitroxide (3-methoxycarbonyl-2,2,5,5-tetramethylpyrrolidine-1-yloxy) as a redox-sensitive probe. Both methods found similar changes in redox status with age, and in particular a significant change in redox status in the hippocampus was observed noninvasively by EPR imaging between APdE9 mice and age-matched WT mice from 9 to 18 months of age. EPR imaging clearly visualized the accelerated change in redox status of APdE9 mouse brain compared with WT. The evaluation of the redox status in the brain of AD model rodents by EPR imaging should be useful for diagnostic study of AD.

Temporal changes of CD68 and α7 nicotinic acetylcholine receptor expression in microglia in Alzheimer's disease-like mouse models.

We previously reported that activated microglia are involved in amyloid-ß (Aß) clearance and that stimulation of α7 nicotinic acetylcholine receptors (nAChR) in microglia enhances Aß clearance. Nevertheless, how microglia and α7 nAChR in microglia are affected in Alzheimer's disease (AD) remains unknown. The present study aimed to collect fundamental data for considering whether microglia are potential targets for AD treatment and the appropriate timing of therapeutic intervention, by evaluating the temporal changes of Aß, microglia, neurons, presynapses, and α7 nAChR by immunohistochemical studies in mouse models of AD. In an Aß-injected AD mouse model, we observed early accumulation of CD68-positive microglia at Aß deposition sites and gradual reduction of Aß. Microglia were closely associated with Aß deposits, and were confirmed to participate in clearing Aß. In a transgenic mouse model of AD, we observed an increase in Aß deposition from 6 months of age, followed by a gradual increase in microglial accumulation at Aß deposit sites. Activated microglia in APdE9 mice showed two-step transition: a CD68-negative activated form at 6-9 months and a CD68-positive form from 12 months of age. In addition, α7 nAChR in microglia increased markedly at 6 months of age when activated microglia appeared for the first time, and decreased gradually coinciding with the increase of Aß deposition. These findings suggest that early microglial activation is associated with α7 nAChR upregulation in microglia in APdE9 mice. These novel findings are important for the development of new therapeutic strategy for AD.

Intravenous mesenchymal stem cell administration exhibits therapeutic effects against 6-hydroxydopamine-induced dopaminergic neurodegeneration and glial activation in rats.

To explore a novel therapy against Parkinson's disease (PD), we evaluated the therapeutic effects of human bone marrow-derived mesenchymal stem cells (hBM-MSCs), pluripotent stromal cells with secretory potential of various neurotrophic and anti-inflammatory factors, in a hemi-parkinsonian rat model. The unilateral intrastriatal 6-hydroxydopamine (6-OHDA)-lesioned rats were injected hBM-MSCs (1.0 × 10(7)cells) or PBS intravenously 16 days after lesioning. Administration of hBM-MSCs inhibited methamphetamine-stimulated rotational behavior at 7, 14, 21 and 28 days after transplantation. Immunohistochemical analysis also showed that number of TH-positive neurons in the substantia nigra pars compacta was significantly preserved in hBM-MSCs-transplanted rats compared to sham-operated rats, whereas the immunoreactivity of ionized calcium binding adaptor molecule 1 was markedly inhibited. In this study, we demonstrated the therapeutic effects of intravenous hBM-MSCs administration in parkinsonian model rats presenting distinct parkinsonian phenotype at 16 days after 6-OHDA lesioning. The favorable findings raise the possibility that hBM-MSCs could be a novel therapeutic option to promote survival of dopaminergic neurons in PD.

3-[(2,4-Dimethoxy)benzylidene]-anabaseine dihydrochloride protects against 6-hydroxydopamine-induced parkinsonian neurodegeneration through α7 nicotinic acetylcholine receptor stimulation in rats.

To explore a novel therapy against Parkinson's disease through enhancement of α7 nicotinic acetylcholine receptor (nAChR), we evaluated the neuroprotective effects of 3-[(2,4-dimethoxy)benzylidene]-anabaseine dihydrochloride (DMXBA; GTS-21), a functionally selective α7 nAChR agonist, in a rat 6-hydroxydopamine (6-OHDA)-induced hemiparkinsonian model. Microinjection of 6-OHDA into the nigrostriatal pathway of rats destroys dopaminergic neurons selectively. DMXBA dose dependently inhibited methamphetamine-stimulated rotational behavior and dopaminergic neuronal loss induced by 6-OHDA. The protective effects were abolished by methyllycaconitine citrate salt hydrate, an α7 nAChR antagonist. Immunohistochemical study confirmed abundant α7 nAChR expression in the cytoplasm of dopaminergic neurons. These results indicate that DMXBA prevented 6-OHDA-induced dopaminergic neuronal loss through stimulating α7 nAChR in dopaminergic neurons. Injection of 6-OHDA elevated immunoreactivities to glial markers such as ionized calcium binding adaptor molecule 1, CD68, and glial fibrillary acidic protein in the substantia nigra pars compacta of rats. In contrast, these immunoreactivities were markedly inhibited by comicroinjection of DMXBA. Microglia also expressed α7 nAChR in both resting and activated states. Hence, we hypothesize that DMXBA simultaneously affects microglia and dopaminergic neurons and that both actions lead to dopaminergic neuroprotection. The findings that DMXBA attenuates 6-OHDA-induced dopaminergic neurodegeneration and glial activation in a rat model of Parkinson's disease raisethe possibility that DMXBA could be a novel therapeutic compound to prevent Parkinson's disease development.

α7 nicotinic acetylcholine receptor mediated neuroprotection in Parkinson's disease.

Parkinson's disease (PD) is characterized by relatively selective degeneration of dopaminergic neurons in the substantia nigra and loss of dopamine in the striatum. More than 50 epidemiological studies confirmed the low incidence of PD in smokers. Examining the distribution of subtypes of nicotinic acetylcholine receptors (nAChRs) in dopaminergic neurons of nigrostriatal system and its change in PD patients is quite important to elucidate possible neuroprotective cascade triggered by nicotine. Evidences of nAChR-mediated protection against neurotoxicity induced by rotenone, 6- hydroxydopamine (6-OHDA), and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) are briefly reviewed. In rotenone- and 6-OHDA-induced PD models, nAChR-mediated neuroprotection was blocked not only by α4ß2 but also by α7 nAChR antagonists. The survival signal transduction, α7 nAChR-Src family-PI3K-Akt/PKB cascade and subsequent upregulation of Bcl-2, would lead to neuroprotection. These findings suggest that nAChR-mediated neuroprotection is achieved through subtypes of nAChRs and common signal cascades. An early diagnosis and protective therapy with specific nAChR modulations could be effective in delaying the progression of PD.

Mesenchymal stem cells transmigrate across brain microvascular endothelial cell monolayers through transiently formed inter-endothelial gaps.

Mesenchymal stem cells (MSCs) hold much promise for cell therapy for neurological diseases such as cerebral ischemia and Parkinson's disease. Intravenously administered MSCs accumulate in lesions within the brain parenchyma, but little is known of the details of MSC transmigration across the blood-brain barrier (BBB). To study MSC transmigration across the BBB, we developed an in vitro culture system consisting of rat brain microvascular endothelial cells (BMECs) and bone marrow-derived MSCs using Transwell or Millicell culture inserts. Using this system, we first investigated the influence of the number of MSCs added to the upper chamber on BMEC barrier integrity. The addition of MSCs at a density of 1.5 × 105 cells/cm² led to disruption of the BMEC monolayer structure and decreased barrier function as measured by the transendothelial electrical resistance (TEER). When applied at a density of 1.5 × 104 cells/cm², neither remarkable disruption of the BMEC monolayers nor a significant decrease in TEER was observed until at least 12 h. After cultivation for 24 h under this condition, MSCs were found in the subendothelial space or beneath the insert membrane, suggesting that MSCs transmigrate across BMEC monolayers. Time-lapse imaging revealed that MSCs transmigrated across the BMEC monolayers through transiently formed intercellular gaps between the BMECs. These results show that our in vitro culture system consisting of BMECs and MSCs is useful for investigating the molecular and cellular mechanisms underlying MSC transmigration across the BBB.