Protective Effects of Coptis chinensis Rhizome Extract and Its Constituents (Berberine, Coptisine, and Palmatine) against α-Synuclein Neurotoxicity in Dopaminergic SH-SY5Y Cells.

Parkinson's disease (PD) is a common neurodegenerative disease with progressive loss of dopaminergic neurons in substantia nigra and the presence of α-synuclein-immunoreactive inclusions. Gaucher's disease is caused by homozygous mutations in ß-glucocerebrosidase gene (GBA). GBA mutation carriers have an increased risk of PD. Coptis chinensis (C. chinensis) rhizome extract is a major herb widely used to treat human diseases. This study examined the association of GBA L444P mutation with Taiwanese PD in 1016 cases and 539 controls. In addition, the protective effects of C. chinensis rhizome extract and its active constituents (berberine, coptisine, and palmatine) against PD were assayed using GBA reporter cells, LC3 reporter cells, and cells expressing mutated (A53T) α-synuclein. Case-control study revealed that GBA L444P carriers had a 3.93-fold increased risk of PD (95% confidence interval (CI): 1.37-11.24, p = 0.006) compared to normal controls. Both C. chinensis rhizome extract and its constituents exhibited chemical chaperone activity to reduce α-synuclein aggregation. Promoter reporter and endogenous GBA protein analyses revealed that C. chinensis rhizome extract and its constituents upregulated GBA expression in 293 cells. In addition, C. chinensis rhizome extract and its constituents induced autophagy in DsRed-LC3-expressing 293 cells. In SH-SY5Y cells expressing A53T α-synuclein, C. chinensis rhizome extract and its constituents reduced α-synuclein aggregation and associated neurotoxicity by upregulating GBA expression and activating autophagy. The results of reducing α-synuclein aggregation, enhancing GBA expression and autophagy, and protecting against α-synuclein neurotoxicity open up the therapeutic potentials of C. chinensis rhizome extract and constituents for PD.

Modulating motor cortical oscillation with coordinated reset multifocal transcranial magnetic stimulation.

According to the theory of coordinated reset (CR) stimulation, multifocal bursts of stimuli delivered in a random order with a specific interval may reduce the resonance power of the oscillatory generator in the epicenter. We develop a noninvasive coordinated multifocal burst stimulation (COMBS) with three repetitive transcranial stimulation machines based on CR theory to modulate the target frequency in the primary motor cortex and to assess its effect on motor cortical excitability in separate experiments. Electroencephalography and electromyography were recorded in 16 healthy participants during a finger-tapping task, both before and after the intervention. The resting oscillatory power at the targeted frequency was not changed by COMBS. α-Band power was increased in both preparation and movement stages and the low ß-band power was increased in the movement stage of the finger tapping task. The extent of low ß-band event-related desynchronization was reduced by COMBS. There were no changes in reaction time, but there was a trend for a reduced error rate after COMBS. In another 14 healthy participants, there were no significant changes in cortical excitability before and after COMBS measured by rest motor threshold, short interval intracortical inhibition, short interval intracortical facilitation, and cortical silent period. The result indicates that COMBS may modify the cortical oscillatory power and its perturbation within specific movement stage.NEW & NOTEWORTHY This is the first study, to our knowledge, to apply coordinated reset (CR) neuromodulation to the motor cortex with three repetitive transcranial magnetic stimulation (rTMS) stimulators to assess its effect on cortical oscillation. The results revealed enhancement of α-band power specifically in preparation and movement stages and low ß-band power in the movement stage of a motor task. It postulated that CR stimulation may modify the motor cortical oscillation in the specific movement stages.

Myasthenia gravis and independent risk factors for recurrent infection: a retrospective cohort study.

BACKGROUND: Approximately 10% to 20% of myasthenia gravis (MG) patients have experienced a myasthenic crisis (MC), which contributes to morbidity and mortality. MC triggered by infection is associated with poor outcomes. However, there is a lack of prognostic factors that clinicians can utilize to target interventions for preventing recurrent infection-triggered MC. This study aimed to characterize clinical manifestations, comorbidities, and biochemical profiles associated with recurrent infection-triggered MC in MG patients. METHODS: This retrospective study included 272 MG patients hospitalized with an infection requiring at least 3 days of antibiotics from January 2001 to December 2019. Patients were further stratified into non-recurrent or recurrent infection groups. Clinical features such as gender, age, concomitant diseases, acetylcholine receptor antibodies and biochemical data (including electrolytes and coagulants), muscle strength of pelvic and shoulder girdle, bulbar and respiratory function, management with an endotracheal tube, Foley catheter, or plasmapheresis, duration of hospitalization, and culture pathogens were recorded. RESULTS: The recurrent infection group was significantly older than the non-recurrent group (median age, 58.5 versus 52.0 years). Pneumonia was the most common infection and Klebsiella pneumoniae was the most common pathogen. The presence of concomitant diabetes mellitus, activated partial thromboplastin time prolongation, the duration of hospitalization, and hypomagnesaemia were independently associated with recurrent infection. The presence of deep vein thrombosis, thymic cancer, and electrolyte imbalances i.e., hypokalemia, and hypoalbuminemia were significantly associated with a risk for infection. The influence of endotracheal intubation, anemia, and plasmapheresis during hospitalization were inconsistent. CONCLUSIONS: The independent risk factors for recurrent infections in MG patients identified in this study include the presence of concomitant diabetes mellitus, hypomagnesaemia, activated partial thromboplastin time prolongation, and longer duration of hospitalization, highlighting the need for targeted interventions to prevent recurrent infections in this population. Further research and prospective studies are warranted to validate these findings and refine interventions for optimizing patient care.

The effects of high versus low frequency of combined physical and cognitive training on cognitive function in older adults with cognitive decline: a quasi-experimental study.

BACKGROUND: The effects of combined training can be affected by training characteristics such as frequency, session length, and duration. No empirical studies to date have directly compared how combined physical and cognitive training offered at different training frequencies affects cognitive function for older adults with cognitive decline. This study investigated the impact of training frequency on cognitive outcomes after combined physical and cognitive training for older adults with cognitive decline. METHODS: A quasi-experimental study was conducted in community facilities and day care centers. The study assigned 89 older adults with cognitive decline into high-frequency (HF) or low-frequency (LF) training groups. The participants received 90- to 105-min training sessions, one (LF) or three (HF) times a week, for 12 weeks. Outcome measures were the Montreal Cognitive Assessment, Word List subtest of the Wechsler Memory Scale, Digit Symbol Substitution Test (DSST), and Stroop Color Word Test. RESULTS: The HF group demonstrated greater improvement in immediate memory measured by the WL-IM (F = 8.7, P = 0.004) and in executive function measured by the SCWT (F = 5.89, P = 0.017) than the LF group. Compared with the HF group, the LF group showed a great improvement in delayed memory measured by the WL-DM (F = 9.62, P = 0.003). The HF and LF groups both increased in processing speed and global cognitive function. CONCLUSIONS: Our study indicated that the different training frequency of combined physical and cognitive training may result in benefits on different cognitive functions in older adults with cognitive decline. These findings may assist clinical practitioners in choosing appropriate training frequencies based on various intervention purposes for the elderly with cognitive decline. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT03619577 (08/08/2018).

Investigating Therapeutic Effects of Indole Derivatives Targeting Inflammation and Oxidative Stress in Neurotoxin-Induced Cell and Mouse Models of Parkinson's Disease.

Neuroinflammation and oxidative stress have been emerging as important pathways contributing to Parkinson's disease (PD) pathogenesis. In PD brains, the activated microglia release inflammatory factors such as interleukin (IL)-ß, IL-6, tumor necrosis factor (TNF)-α, and nitric oxide (NO), which increase oxidative stress and mediate neurodegeneration. Using 1-methyl-4-phenylpyridinium (MPP+)-activated human microglial HMC3 cells and the sub-chronic 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse model of PD, we found the potential of indole derivative NC009-1 against neuroinflammation, oxidative stress, and neurodegeneration for PD. In vitro, NC009-1 alleviated MPP+-induced cytotoxicity, reduced NO, IL-1ß, IL-6, and TNF-α production, and suppressed NLR family pyrin domain containing 3 (NLRP3) inflammasome activation in MPP+-activated HMC3 cells. In vivo, NC009-1 ameliorated motor deficits and non-motor depression, increased dopamine and dopamine transporter levels in the striatum, and reduced oxidative stress as well as microglia and astrocyte reactivity in the ventral midbrain of MPTP-treated mice. These protective effects were achieved by down-regulating NLRP3, CASP1, iNOS, IL-1ß, IL-6, and TNF-α, and up-regulating SOD2, NRF2, and NQO1. These results strengthen the involvement of neuroinflammation and oxidative stress in PD pathogenic mechanism, and indicate NC009-1 as a potential drug candidate for PD treatment.

Establishment of a new classification system for chronic inflammatory demyelinating polyneuropathy based on unsupervised machine learning.

INTRODUCTION/AIMS: A model for predicting responsiveness to immunotherapy in patients with chronic inflammatory demyelinating polyneuropathy (CIDP) has not been well established. We aimed to establish a new classifier for CIDP patients based on clinical characteristics, laboratory findings, and electrophysiological features. METHODS: The clinical, laboratory, and electrophysiological features of 172 treatment-naïve patients with CIDP between 2003 and 2019 were analyzed using an unsupervised hierarchical clustering. The identified pivotal features were used to establish simple classifications using a tree-based model. RESULTS: Three clusters were identified: 1, n = 65; 2, n = 70; and 3, n = 37. Patients in Cluster 1 scored lower on the disability assessment score before treatment. More patients in Clusters 2 (90.0%) fulfilled demyelinating criteria than patients in Cluster 1 (30.8%, p < .001). Cluster 3 had more patients with chronic kidney disease (CKD) (27.0%) and hypoalbuminemia (3.40 g/dL) than did Cluster 2 (CKD: 0%, p < .001; hypoalbuminemia: 4.09 g/dL, p < .001). The responsiveness to pulse steroid therapy was higher in Cluster 2 (70.0%) than in Clusters 1 (31.8%; p = .043) and 3 (25.0%; p = .014). A tree-based model with four pivotal features classified patients in our cohort into new clusters with high accuracy (89.5%). DISCUSSION: The established hierarchical clustering with the tree-based model identified key features contributing to differences in disease severity and response to pulse steroid therapy. This classification system could assist clinicians in the selection of treatments and could also help researchers by clustering patients for clinical treatment trials.

Isaacs' syndrome as the initial presentation of malignant thymoma and associated with double-positive voltage-gated potassium channel complex antibodies, a case report.

BACKGROUND: Isaacs' syndrome is a peripheral nerve hyperexcitability (PNH) syndrome due to peripheral motor nerve instability. Acquired Isaacs' syndrome is recognized as a paraneoplastic autoimmune disease with possible pathogenic voltage-gated potassium channel (VGKC) complex antibodies. However, the longitudinal correlation between clinical symptoms, VGKC antibodies level, and drug response is still unclear. CASE PRESENTATION: A 45-year-old man had progressive four limbs soreness, muscle twitching, cramps, and pain 4 months before admission. Electromyography (EMG) studies showed myokymic discharges, neuromyotonia, and an incremental response in the high-rate (50 Hz) repetitive nerve stimulation (RNS) test. Isaacs' syndrome was diagnosed based on clinical presentations and EMG reports. Serum studies showed positive VGKC complex antibodies, including leucine-rich glioma-inactivated 1 (LGI1) and contactin-associated protein-like 2 (CASPR2) antibodies. The acetylcholine receptor antibody was negative. Whole-body computed tomography (CT) and positron emission tomography revealed a mediastinal tumor with the great vessels encasement, right pleura, and diaphragm seeding. Biopsy confirmed a World Health Organization type B2 thymoma, with Masaoka stage IVa. His symptoms gradually improved and both LGI1 and CASPR2 antibodies titer became undetectable after concurrent chemoradiotherapy (CCRT) and high dose steroid treatment. However, his Isaacs' syndrome recurred after the steroid was reduced 5 months later. Follow-up chest CT showed probable thymoma progression. LGI1 antibody turned positive again while CASPR2 antibody remained undetectable. CONCLUSIONS: Our patient demonstrates that Isaacs' syndrome could be the initial and only neuromuscular manifestation of malignant thymoma. His Isaacs' syndrome is correlated well with the LGI1 antibody level. With an unresectable thymoma, long-term immunosuppressant therapy may be necessary for the management of Isaacs' syndrome in addition to CCRT for thymoma.

Association of ITPKB, IL1R2 and COQ7 with Parkinson's disease in Taiwan.

BACKGROUND/PURPOSE: Genetic and environmental factors play significant roles in the pathogenesis of Parkinson's disease (PD). Recently, 17 novel risk loci of PD were identified in a meta-analysis of genome-wide association study (GWAS) in the European populations. In order to clarify if these risk loci are associated with PD in Taiwanese population, we conducted a case-control study including 14 of the novel risk loci and analyzed the genetic distribution and allele frequency. METHODS: A total of 2798 subjects were recruited in this study. Genotyping was performed in 672 PD patients and 609 healthy controls by using Mass ARRAY, and data of another 1517 healthy controls from Taiwan Biobank were also examined. RESULTS: Our results show that the dominant models of ITPKB rs4653767 (OR (95% CI) = 0.832 (0.699, 0.990), p = 0.038), IL1R2 rs34043159 (OR (95% CI) = 0.812 (0.665, 0.992), p = 0.041) and COQ7 rs11343 (OR (95% CI) = 0.304 (0.180, 0.512), p < 0.001) were associated with PD. In allelic analysis, the T allele of IL1R2 rs34043159 (OR (95% CI) = 0.873 (0.772, 0.987), p = 0.03) and T allele of COQ7 rs11343 (OR (95% CI) = 0.098 (0.040, 0.238), p < 0.001) showed lower risk of PD. After Bonferroni correction, only dominant model and T allele of COQ7 rs11343 showed significantly reduced the risk of PD. CONCLUSION: This study suggests that ITPKB, IL1R2 and COQ7 have influence on the risk of PD in Taiwan.

Variants in saposin D domain of prosaposin gene linked to Parkinson's disease.

Recently, the genetic variability in lysosomal storage disorders has been implicated in the pathogenesis of Parkinson's disease. Here, we found that variants in prosaposin (PSAP), a rare causative gene of various types of lysosomal storage disorders, are linked to Parkinson's disease. Genetic mutation screening revealed three pathogenic mutations in the saposin D domain of PSAP from three families with autosomal dominant Parkinson's disease. Whole-exome sequencing revealed no other variants in previously identified Parkinson's disease-causing or lysosomal storage disorder-causing genes. A case-control association study found two variants in the intronic regions of the PSAP saposin D domain (rs4747203 and rs885828) in sporadic Parkinson's disease had significantly higher allele frequencies in a combined cohort of Japan and Taiwan. We found the abnormal accumulation of autophagic vacuoles, impaired autophagic flux, altered intracellular localization of prosaposin, and an aggregation of α-synuclein in patient-derived skin fibroblasts or induced pluripotent stem cell-derived dopaminergic neurons. In mice, a Psap saposin D mutation caused progressive motor decline and dopaminergic neurodegeneration. Our data provide novel genetic evidence for the involvement of the PSAP saposin D domain in Parkinson's disease.

Objective assessment of impulse control disorder in patients with Parkinson's disease using a low-cost LEGO-like EEG headset: a feasibility study.

BACKGROUND: Patients with Parkinson's disease (PD) can develop impulse control disorders (ICDs) while undergoing a pharmacological treatment for motor control dysfunctions with a dopamine agonist (DA). Conventional clinical interviews or questionnaires can be biased and may not accurately diagnose at the early stage. A wearable electroencephalogram (EEG)-sensing headset paired with an examination procedure can be a potential user-friendly method to explore ICD-related signatures that can detect its early signs and progression by reflecting brain activity. METHODS: A stereotypical Go/NoGo test that targets impulse inhibition was performed on 59 individuals, including healthy controls, patients with PD, and patients with PD diagnosed by ICDs. We conducted two Go/NoGo sessions before and after the DA-pharmacological treatment for the PD and ICD groups. A low-cost LEGO-like EEG headset was used to record concurrent EEG signals. Then, we used the event-related potential (ERP) analytical framework to explore ICD-related EEG abnormalities after DA treatment. RESULTS: After the DA treatment, only the ICD-diagnosed PD patients made more behavioral errors and tended to exhibit the deterioration for the NoGo N2 and P3 peak amplitudes at fronto-central electrodes in contrast to the HC and PD groups. Particularly, the extent of the diminished NoGo-N2 amplitude was prone to be modulated by the ICD scores at Fz with marginal statistical significance (r = - 0.34, p = 0.07). CONCLUSIONS: The low-cost LEGO-like EEG headset successfully captured ERP waveforms and objectively assessed ICD in patients with PD undergoing DA treatment. This objective neuro-evidence could provide complementary information to conventional clinical scales used to diagnose ICD adverse effects.

Association of SOD2 p.V16A polymorphism with Parkinson's disease: A meta-analysis in Han Chinese.

BACKGROUND: Oxidative stress could participate in the pathogenesis of Parkinson's disease (PD). However, the role of genetic variation of superoxide dismutase 2 (SOD2), an important regulator against oxidative stress, in PD remains to be elucidated. METHODS: We screened SOD2 gene variation by sequencing cDNA from 72 patients with early onset PD. A cohort of PD (n = 609) and ethnically matched controls (n = 681) were further examined for the identified sequence variant by PCR and NaeI restriction analysis. RESULTS: Only a reported c.47T>C polymorphism (rs4880, SOD2 p.V16A) was found by cDNA sequencing. Case-control study of c.47T>C revealed that genotype and allele frequencies were in Hardy-Weinberg equilibrium in both patients and healthy controls. In a recessive model, those with CC genotype had a 2.61-fold increased risk of PD (95% CI: 1.08-6.30, P = 0.03) compared to subjects with TT and TC genotypes. Significant association between CC genotype and PD in non-smokers was also observed after stratification according to the history of smoking (3.54-fold increased risk of PD, 95% CI: 1.17-10.72, P = 0.02). Meta-analysis by combining studies of Chinese in China, Singapore, and Taiwan (total 2302 cases and 2029 controls) consistently showed CC genotype with increased risk of PD (OR = 1.77, 95% CI: 1.15-2.71, P = 0.01). CONCLUSION: Our findings demonstrate that SOD2 p.V16A may play a role in the susceptibility of PD in Han Chinese.

Pathomechanism Characterization and Potential Therapeutics Identification for Parkinson's Disease Targeting Neuroinflammation.

Parkinson's disease (PD) is a common neurodegenerative disorder characterized by the loss of dopaminergic (DAergic) neurons and the presence of α-synuclein-containing Lewy bodies. The unstructured α-synuclein forms insoluble fibrils and aggregates that result in increased reactive oxygen species (ROS) and cellular toxicity in PD. Neuroinflammation engaged by microglia actively contributes to the pathogenesis of PD. In this study, we showed that VB-037 (a quinoline compound), glycyrrhetic acid (a pentacyclic triterpenoid), Glycyrrhiza inflata (G. inflata, a Chinese herbal medicine), and Shaoyao Gancao Tang (SG-Tang, a formulated Chinese medicine) suppressed the nitric oxide (NO) production and interleukin (IL)-1ß maturation in α-synuclein-stimulated BV-2 cells. Mouse inflammation antibody array further revealed increased IL-1α, IL-1ß, tumor necrosis factor (TNF)-α, interferon (IFN)-γ, IL-6, granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte colony-stimulating factor (G-CSF) expression in α-synuclein-inflamed BV-2 cells and compound pretreatment effectively reduced the expression and release of these pro-inflammatory mediators. The test compounds and herbal medicines further reduced α-synuclein aggregation and associated oxidative stress, and protected cells against α-synuclein-induced neurotoxicity by downregulating NLR family pyrin domain containing 1 (NLRP1) and 3 (NLRP3), caspase 1, IL-1ß, IL-6, and associated nuclear factor (NF)-κB inhibitor alpha (IκBα)/NF-κB P65 subunit (P65), c-Jun N-terminal kinase (JNK)/proto-oncogene c-Jun (JUN), mitogen-activated protein kinase 14 (P38)/signal transducer and activator of transcription 1 (STAT1) and Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) pathways in dopaminergic neurons derived from α-synuclein-expressing SH-SY5Y cells. Our findings indicate the potential of VB-037, glycyrrhetic acid, G. inflata, and SG-Tang through mitigating α-synuclein-stimulated neuroinflammation in PD, as new drug candidates for PD treatment.

Does the M.D. Anderson Dysphagia Inventory correlate with dysphagia-limit and the Unified Parkinson Disease Rating Scale in early-stage Parkinson's disease?

BACKGROUND: Dysphagia is a common and critical condition that occurs in Parkinson's disease (PD), and it may appear in early stages. However, few reliable swallowing-related questionnaires are currently available. Therefore, finding efficient questionnaires for surveying dysphagia during the early stages of PD is necessary. PURPOSE: This prospective study aimed to identify the correlations between the M.D. Anderson Dysphagia Inventory (MDADI) with dysphagia limit (DL) and the Unified Parkinson Disease Rating Scale (UPDRS) in early-stage PD. METHODS: Forty-two patients with early-stage PD were recruited from a medical center. Data were collected for analysis of swallowing-related quality of life using the MDADI, symptom severity using the UPDRS, and DL using a noninvasive swallowing-respiration assessment system. RESULTS: Our results showed that the MDADI, including its composite and subscales, was not correlated with DL. The composite scores of the MDADI were moderately correlated with the total score of the UPDRS (r = -0.504; p < 0.05) as well as with the second and third sections of the UPDRS scores (r = -0.453 to -0.478; p < 0.05). These results indicated that the impaired MDADI score can predict symptom severity (UPDRS), especially in activities of daily life and motor function. CONCLUSION: The impaired MDADI for early-stage PD was determined, and decreased DL as a presentation of dysphagia could not be reflected by the MDADI. The MDADI may be used as a quick and convenient questionnaire for predicting the severity of early-stage PD, but not for the screening of early or subclinical dysphagia.

Psychometric Evaluation of an ICF-Based Instrumental Activities of Daily Living Assessment With Older Adults With Cognitive Decline.

IMPORTANCE: Identifying cognitive or physical limitations that contribute to difficulties in instrumental activities of daily living (IADLs) is critical for adequate intervention with community-dwelling older adults with cognitive decline. OBJECTIVE: To establish the validity and responsiveness of an IADL scale based on the International Classification of Functioning, Disability and Health (the ICF-IADL) with respect to both cognitive and physical limitations. DESIGN: Cross-sectional study. SETTING: Multiple community care and senior centers. PARTICIPANTS: Eighty-two older adults. INTERVENTION: Combination of physical exercise and cognitive training. MEASURES: Five criterion measures-Lawton IADL Scale, Montreal Cognitive Assessment (MoCA), Digit Symbol Substitution Test (DSS), Word Lists Test (WLT), and Timed Up and Go Test (TUG). RESULTS: The ICF-IADL's three summary scales-Disability Index (DI), Cognitive Disability Index (CDI), and Physical Disability Index (PDI)-had good concurrent validity with the Lawton IADL Scale. The DI and CDI had moderate to good associations with the MoCA. The DI's and CDI's predictive validity for scores on the Lawton IADL Scale, MoCA, and TUG was moderate to good and that of the PDI was fair. Responsiveness was large for the DI, moderate for the CDI, and small for the PDI. CONCLUSIONS AND RELEVANCE: The ICF-IADL can be used to measure disability in IADLs related to cognitive and physical limitations. The DI and CDI were better than the PDI in predicting outcomes in general cognitive function and dynamic balance and were more responsive to change after intervention than the PDI. WHAT THIS ARTICLE ADDS: The ICF-IADL addresses both cognitive and physical limitations and can be a valid assessment of IADLs. Occupational therapists can use it to determine difficulties in IADLs and causes of those difficulties, guide treatment planning, and monitor intervention effectiveness with community-dwelling older adults with cognitive decline.

Targeting ENT1 and adenosine tone for the treatment of Huntington's disease.

Huntington's disease (HD) is caused by an abnormal CAG expansion in the exon 1 of huntingtin gene. The treatment of HD is an unmet medical need. Given the important role of adenosine in modulating brain activity, in this study, levels of adenosine and adenine nucleotides in the cerebral spinal fluid of patients with HD and in the brain of two mouse models of HD (R6/2 and Hdh150Q) were analysed. The expression and activity of ENT1 in the striatum of mice with HD were measured. Targeting adenosine tone for treating HD was examined in R6/2 mice by genetic removal of ENT1 and by giving an ENT1 inhibitor, respectively. The results showed that the adenosine homeostasis is dysregulated in the brain of patients and mice with HD. In patients, the ratio of adenosine/ATP in the cerebral spinal fluid was negatively correlated with the disease duration, and tended to have a positive correlation with independence scale and functional capacity. In comparison to controls, mRNA level of ENT1 was higher in the striatum of R6/2 and Hdh150Q mice. Intrastriatal administration of ENT1 inhibitors increased extracellular level of adenosine in the striatum of R6/2 mice to a much higher level than controls. Chronic inhibition of ENT1 or by genetic removal of ENT1 enhanced the survival of R6/2 mice. Collectively, adenosine homeostasis and ENT1 expression are altered in HD. The inhibition of ENT1 can enhance extracellular adenosine level and be a potential therapeutic approach for treating HD.

Genome-wide association study of Parkinson's disease in East Asians.

Genome-wide association studies (GWAS) on Parkinson's disease (PD) have mostly been done in Europeans and Japanese. No study has been done in Han Chinese, which make up nearly a fifth of the world population. We conducted the first Han Chinese GWAS analysing a total of 22,729 subjects (5,125 PD cases and 17,604 controls) from Singapore, Hong Kong, Malaysia, Korea, mainland China and Taiwan. We performed imputation, merging and logistic regression analyses of 2,402,394 SNPs passing quality control filters in 779 PD cases, 13,227 controls, adjusted for the first three principal components. 90 SNPs with association P < 10-4 were validated in 9 additional sample collections and the results were combined using fixed-effects inverse-variance meta-analysis. We observed strong associations reaching genome-wide significance at SNCA, LRRK2 and MCCC1, confirming their important roles in both European and Asian PD. We also identified significant (P < 0.05) associations at 5 loci (DLG2, SIPA1L2, STK39, VPS13C and RIT2), and observed the same direction of associations at 9 other loci including BST1 and PARK16. Allelic heterogeneity was observed at LRRK2 while European risk SNPs at 6 other loci including MAPT and GBA-SYT11 were non-polymorphic or very rare in our cohort. Overall, we replicate associations at SNCA, LRRK2, MCCC1 and 14 other European PD loci but did not identify Asian-specific loci with large effects (OR > 1.45) on PD risk. Our results also demonstrate some differences in the genetic contribution to PD between Europeans and Asians. Further pan-ethnic meta-analysis with European GWAS cohorts may unravel new PD loci.

Functional properties of LRRK2 mutations in Taiwanese Parkinson disease.

BACKGROUND/PURPOSE: Leucine-rich repeat kinase 2 (LRRK2) is a large protein encoding multiple functional domains. Mutations within different LRRK2 domains have been considered to be involved in the development of Parkinson disease by different mechanisms. Our previous study found three LRRK2 mutations-p.R767H, p.S885N, and p.R1441H-in Taiwanese patients with Parkinson disease. METHODS: We evaluated the functional properties of LRRK2 p.R767H, p.S885N, and p.R1441H mutations by overexpressing them in human embryonic kidney 293 and neuroblastoma SK-N-SH cells. The common p.G2019S mutation in the kinase domain was included for comparison. RESULTS: In 293 cells, overexpressed p.R1441H-but not p.R767H, p.S885N, or p.G2019-increased GTP binding affinity to prolong the active state. Overexpressed p.R1441H and p.G2019S generated inclusions in 293 cells. In SK-N-SH cells, the α-synuclein was coexpressed with wild type as well as mutated p.R767H, p.S885N, p.R1441H, and p.G2019 LRRK2 proteins. Part of the perinuclear inclusions formed by p.R1441H and p.G2019S were colocalized with α-synuclein. Additionally, p.S885N and p.R1441H mutations caused reduced interaction between LRRK2 and ARHGEF7, a putative guanine nucleotide exchange factor for LRRK2, whereas this interaction was well preserved in p.R767H and p.G2019S mutations. CONCLUSION: Our study suggests that p.R1441H protein facilitates the formation of intracellular inclusions, compromises GTP hydrolysis by increasing its affinity for GTP, and reduces its interaction with ARHGEF7.

Altered Aconitase 2 Activity in Huntington's Disease Peripheral Blood Cells and Mouse Model Striatum.

Huntington's disease (HD) is caused by an unstable cytosine adenine guanine (CAG) trinucleotide repeat expansion encoding a polyglutamine tract in the huntingtin protein. Previously, we identified several up- and down-regulated protein molecules in the striatum of the Hdh(CAG)150 knock-in mice at 16 months of age, a mouse model which is modeling the early human HD stage. Among those molecules, aconitase 2 (Aco2) located in the mitochondrial matrix is involved in the energy generation and susceptible to increased oxidative stress that would lead to inactivation of Aco2 activity. In this study, we demonstrate decreased Aco2 protein level and activity in the brain of both Hdh(CAG)150 and R6/2 mice. Aco2 activity was decreased in striatum of Hdh(CAG)150 mice at 16 months of age as well as R6/2 mice at 7 to 13 weeks of age. Aco2 activity in the striatum of R6/2 mice could be restored by the anti-oxidant, N-acetyl-l-cysteine, supporting that decreased Aco2 activity in HD is probably caused by increased oxidative damage. Decreased Aco2 activity was further found in the peripheral blood mononuclear cells (PBMC) of both HD patients and pre-symptomatic HD mutation (PreHD) carriers, while the decreased Aco2 protein level of PBMC was only present in HD patients. Aco2 activity correlated significantly with motor score, independence scale, and functional capacity of the Unified Huntington's Disease Rating Scale as well as disease duration. Our study provides a potential biomarker to assess the disease status of HD patients and PreHD carriers.

Inhibition of soluble tumor necrosis factor is therapeutic in Huntington's disease.

Neuroinflammation is a common feature of many neurodegenerative diseases, including Huntington's disease (HD). HD is an autosomal dominant genetic disease caused by an expanded CAG repeat in exon 1 of the huntingtin (HTT) gene. Previous studies demonstrated that levels of several proinflammatory cytokines, including tumor necrosis factor (TNF)-α, were higher in the plasma and brain tissues of mice and patients with HD, suggesting that inflammation may contribute to HD progression. To evaluate the pathological role of TNF-α in HD pathogenesis, we blocked TNF-α signaling using a dominant negative inhibitor of soluble TNF-α (XPro1595). XPro1595 effectively suppressed the inflammatory responses of primary astrocytes-enriched culture isolated from a transgenic mouse model (R6/2) and human astrocytes-enriched culture derived from induced pluripotent stem cells (iPSCs) of HD patients evoked by lipopolysaccharide and cytokines, respectively. Moreover, XPro1595 protected the cytokine-induced toxicity of primary R6/2 neurons and human neurons derived from iPSCs of HD patients. To assess the beneficial effect of XPro1595 in vivo, an intracerebroventricular (i.c.v.) infusion was provided with an osmotic minipump. ELISA analyses showed that i.c.v. infusion of XPro1595 decreased elevated levels of TNFα in the cortex and striatum, improved motor function, reduced caspase activation, diminished the amount of mutant HTT aggregates, increased neuronal density and decreased gliosis in brains of R6/2 mice. Moreover, reducing the peripheral inflammatory response by a systemic injection of XPro1595 improved the impaired motor function of R6/2 mice but did not affect caspase activation. Collectively, our findings suggest that an effective and selective anti-inflammatory treatment targeting the abnormal brain inflammatory response is a potential therapeutic strategy for HD.

Eukaryotic translation initiation factor 4-γ, 1 gene mutations are rare in Parkinson's disease among Taiwanese.

BACKGROUND/PURPOSE: Parkinson's disease (PD) is the second most common neurodegenerative disorder worldwide. Although idiopathic PD accounts for most of the cases, several genetic mutations have been found to cause PD. Mutations in the eukaryotic translation initiation factor 4-γ, 1 (EIF4G1) gene have been identified since 2011, which were reported to be associated with PD among Caucasians in subsequent research. However, this observation was not consistent. The contribution to other ethnic groups remains limited, with < 1% of sporadic cases. We conducted a case-control study to analyze if EIF4G1 is a risk factor for PD patients in Taiwan. METHODS: There were 595 PD patients and 600 controls without neurological diseases enrolled in this study. Four reported mutations-A502V (c.1505C>T), G686C (c.2056 G>T), R1197W (c.3589C>T), and R1205H (c.3614G>A)-were analyzed. RESULTS: There were no mutations found in either PD patients or controls. CONCLUSION: This study indicates that the EIF4G1 mutation is rare in Taiwan, which is consistent with other reports from Asia. Ethnicity could have a great influence on EIF4G1 in PD. Further large scale studies are warranted to evaluate the association of PD and EIF4G1 gene.