The clinical symptoms of Parkinson's disease

A functionalized hydroxydopamine quinone links thiol modification to neuronal cell death

Recent findings suggest that dopamine oxidation contributes to the development of Parkinson's disease (PD); however, the mechanistic details remain elusive. Here, we compare 6-hydroxydopamine (6-OHDA), a product of dopamine oxidation that commonly induces dopaminergic neurodegeneration in laboratory animals, with a synthetic alkyne-functionalized 6-OHDA variant. This synthetic molecule provides insights into the reactivity of quinone and neuromelanin formation. Employing Huisgen cycloaddition chemistry (or “click chemistry”) and fluorescence imaging, we found that reactive 6-OHDA p-quinones cause widespread protein modification in isolated proteins, lysates and cells. We identified cysteine thiols as the target site and investigated the impact of proteome modification by quinones on cell viability. Mass spectrometry following cycloaddition chemistry produced a large number of 6-OHDA modified targets including proteins involved in redox regulation. Functional in vitro assays demonstrated that 6-OHDA inactivates protein disulfide isomerase (PDI), which is a central player in protein folding and redox homeostasis. Our study links dopamine oxidation to protein modification and protein folding in dopaminergic neurons and the PD model.

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Chemical modification of 6-OHDA increases stability of 6-OHDA p-quinone by preventing neuromelanin formation.

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Modified 6-OHDA enables visualization of thiol-dependent protein modification by p-quinone.

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Wide-spread proteome modification by 6-OHDA p-quinone impairs neuroblastoma viability.

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6-OHDA p-quinone inactivates PDI linking dopamine oxidation to protein unfolding.

Hash Transformation and Machine Learning-Based Decision-Making Classifier Improved the Accuracy Rate of Automated Parkinson's Disease Screening

Digitalized hand-drawn pattern is a noninvasive and reproducible assistive manner to obtain hand actions and motions for evaluating functional tremors and upper-limb movement disorders. In this study, spirals and straight lines in polar coordinates are used to extract polar expression features such as the key parameters deviation (cm) and accumulation angle (rad). These parameters are quantitative manner to scale the variations of functional tremors in normal control subjects and patients with Parkinson's disease (PD) and essential tremor (ET). However, difficulty arises in using nonlinear polar expression features in the two-dimensional feature space to separate normal control subjects from those with PD and ET. To solve the nonlinear separable classification problem, hash transformation is used to map polar expression features to a high-dimensional space using hash weighing function and modulo operation. Then, a machine learning method, such as the generalized regression neural network (GRNN), is implemented to train a decision-making classifier using the particle swarm optimization (PSO) algorithm for possible class assessment. With the enrolled data from 50 subjects, the fivefold cross validation, mean true positive, mean true negative, and mean hit rates of 98.93%, 98.96%, and 98.93%, respectively, are obtained to quantify the performance of the proposed decision-making classifier to identify normal controls and subjects with PD or ET. The experimental results indicate that the proposed screening model can improve the accuracy rate compared with the conventional machine learning classifier.

From protocol to product: ventral midbrain dopaminergic neuron differentiation for the treatment of Parkinson's disease

Current cell therapy product limitations include the need for in-depth product understanding to ensure product potency, safety and purity. New technologies require development and validation to address issues of production scale-up to meet clinical need; assays are required for process control, validation and release. Prior to clinical realization, an understanding of production processes is required to implement process changes that are essential for process control. Identification of key parameters forms the basis of process tolerances, allowing for validated, adaptive manufacturing processes. This enables greater process control and yield while withstanding regulatory scrutiny. This report summaries key milestones in specifically for ventral midbrain dopaminergic neuroprogenitor differentiation and key translational considerations and recommendations to enable successful, robust and reproducible current cell therapy product-manufacturing.

Cicadidae Periostracum, the Cast-Off Skin of Cicada, Protects Dopaminergic Neurons in a Model of Parkinson's Disease

Parkinson's disease (PD) is characterized by dopaminergic neuronal loss in the substantia nigra pars compacta (SNPC) and the striatum. Nuclear receptor-related 1 protein (Nurr1) is a nuclear hormone receptor implicated in limiting mitochondrial dysfunction, apoptosis, and inflammation in the central nervous system and protecting dopaminergic neurons and a promising therapeutic target for PD. Cicadidae Periostracum (CP), the cast-off skin of Cryptotympana pustulata Fabricius, has been used in traditional medicine for its many clinical pharmacological effects, including the treatment of psychological symptoms in PD. However, scientific evidence for the use of CP in neurodegenerative diseases, including PD, is lacking. Here, we investigated the protective effects of CP on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine- (MPTP-) induced PD in mice and explored the underlying mechanisms of action, focusing on Nurr1. CP increased the expression levels of Nurr1, tyrosine hydroxylase, DOPA decarboxylase, dopamine transporter, and vesicular monoamine transporter 2 via extracellular signal-regulated kinase phosphorylation in differentiated PC12 cells and the mouse SNPC. In MPTP-induced PD, CP promoted recovery from movement impairments. CP prevented dopamine depletion and protected against dopaminergic neuronal degradation via mitochondria-mediated apoptotic proteins such as B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X, cytochrome c, and cleaved caspase-9 and caspase-3 by inhibiting MPTP-induced neuroinflammatory cytokines, inducible nitric oxide synthase, cyclooxygenase 2, and glial/microglial activation. Moreover, CP inhibited lipopolysaccharide-induced neuroinflammatory cytokines and response levels and glial/microglial activation in BV2 microglia and the mouse brain. Our findings suggest that CP might contribute to neuroprotective signaling by regulating neurotrophic factors primarily via Nurr1 signaling, neuroinflammation, and mitochondria-mediated apoptosis.

Cardinal Motor Features of Parkinson's Disease Coexist with Peak-Dose Choreic-Type Drug-Induced Dyskinesia

Background:

Clinical and anecdotal observations propose that patients with Parkinson’s disease (PD) may show drug-induced dyskinesia (DID) concomitantly with cardinal motor features. However, the extent of the concomitant presence of DID and cardinal features remains to be determined.

Objectives:

This cross-sectional study measured peak-dose choreic-type DID in a quantitative manner in patients diagnosed with PD, and determined whether symptoms such as tremor, bradykinesia, rigidity, postural instability or freezing of gait (FoG) were still detectable in these patients.

Methods:

89 patients diagnosed with PD were recruited and assessed using a combination of quantitative measures using inertial measurement units to capture DID, tremor, bradykinesia, and FoG. Clinical evaluations were also used to assess rigidity and postural instability. Motor symptoms of PD were assessed 3 times during the testing period, and a series of activities of daily living were repeated twice, in between clinical tests, during which the level of DID was quantified. Peak-dose was identified as the period during which patients had the highest levels of DID. Levels of tremor, rigidity, bradykinesia, postural instability, and FoG were used to determine the percentage of patients showing these motor symptoms simultaneously with DID.

Results:

72.4% of patients tested presented with measurable DID during the experiment. Rest, postural and kinetic tremor (12.7% , 38.1% , and 15.9% respectively), bradykinesia (28.6% ), rigidity (55.6% ), postural instability (71.4% ) and FoG (9.5% ) were detected simultaneously with DID.

Conclusions:

PD symptomatology remains present in patients showing peak-dose choreic-type DID, illustrating the challenge facing physicians when trying to avoid dyskinesia while attempting to alleviate motor symptoms.

Are There Benefits in Adding Catechol-O Methyltransferase Inhibitors in the Pharmacotherapy of Parkinson's Disease Patients? A Systematic Review

BACKGROUND

A qualified consensus suggests that a combination of levodopa with a peripherally acting dopa decarboxylase inhibitor continues to present the gold standard treatment of Parkinson's disease (PD). However, as the disease progresses the therapeutic window of levodopa becomes narrowed. Pharmacological strategies for motor fluctuations are focused on providing less pulsatile and more continuous dopaminergic stimulation. Peripheral catechol-O-methyltransferase (COMT) inhibition improves the bioavailability of levodopa and results in a prolonged response.

OBJECTIVE

The primary aim of this study was to investigate the efficacy and safety of the two available COMT inhibitors; entacapone and tolcapone and the recently introduced opicapone.

METHODS

Electronic databases were systematically searched for original studies published within the last 37 years. In addition, lists of identified studies, reviews and their references were examined.

RESULTS

Twelve studies fulfilled the inclusion criteria. 3701 patients with PD were included in this systematic review.

CONCLUSIONS

Adjuvant treatment of PD patients experiencing motor fluctuations with entacapone resulted in improvement of motor function and was well tolerated. Therefore, entacapone presented an acceptable benefit to risk ratio. Tolcapone appeared to result in a greater therapeutic effect. However, this was not consistent across all motor variables and studies, and thus would not support its use, given the current onerous monitoring that is required. Opicapone was not associated with adverse reactions in a phase III trial but did not present a greater efficacy than entacapone, and thus further studies are required in order to illustrate its cost effectiveness.

Elucidating Critical Proteinopathic Mechanisms and Potential Drug Targets in Neurodegeneration

Neurodegeneration entails progressive loss of neuronal structure as well as function leading to cognitive failure, apathy, anxiety, irregular body movements, mood swing and ageing. Proteomic dysregulation is considered the key factor for neurodegeneration. Mechanisms involving deregulated processing of proteins such as amyloid beta (Aβ) oligomerization; tau hyperphosphorylation, prion misfolding; α-synuclein accumulation/lewy body formation, chaperone deregulation, acetylcholine depletion, adenosine 2A (A2A) receptor hyperactivation, secretase deregulation, leucine-rich repeat kinase 2 (LRRK2) mutation and mitochondrial proteinopathies have deeper implications in neurodegenerative disorders. Better understanding of such pathological mechanisms is pivotal for exploring crucial drug targets. Herein, we provide a comprehensive outlook about the diverse proteomic irregularities in Alzheimer's, Parkinson's and Creutzfeldt Jakob disease (CJD). We explicate the role of key neuroproteomic drug targets notably Aβ, tau, alpha synuclein, prions, secretases, acetylcholinesterase (AchE), LRRK2, molecular chaperones, A2A receptors, muscarinic acetylcholine receptors (mAchR), N-methyl-D-aspartate receptor (NMDAR), glial cell line-derived neurotrophic factor (GDNF) family ligands (GFLs) and mitochondrial/oxidative stress-related proteins for combating neurodegeneration and associated cognitive and motor impairment. Cross talk between amyloidopathy, synucleinopathy, tauopathy and several other proteinopathies pinpoints the need to develop safe therapeutics with ability to strike multiple targets in the aetiology of the neurodegenerative disorders. Therapeutics like microtubule stabilisers, chaperones, kinase inhibitors, anti-aggregation agents and antibodies could serve promising regimens for treating neurodegeneration. However, drugs should be target specific, safe and able to penetrate blood-brain barrier.

Dynamic Alterations of Spontaneous Neural Activity in Parkinson's Disease: A Resting-State fMRI Study

Objective: To investigate the dynamic amplitude of low-frequency fluctuations (dALFFs) in patients with Parkinson's disease (PD) and healthy controls (HCs) and further explore whether dALFF can be used to test the feasibility of differentiating PD from HCs. Methods: Twenty-eight patients with PD and 28 demographically matched HCs underwent resting-state functional magnetic resonance imaging (rs-fMRI) scans and neuropsychological tests. A dynamic method was used to calculate the dALFFs of rs-fMRI data obtained from all subjects. The dALFF alterations were compared between the PD and HC groups, and the correlations between dALFF variability and disease duration/neuropsychological tests were further calculated. Then, the statistical differences in dALFF between both groups were selected as classification features to help distinguish patients with PD from HCs through a linear support vector machine (SVM) classifier. The classifier performance was assessed using a permutation test (repeated 5,000 times). Results: Significantly increased dALFF was detected in the left precuneus in patients with PD compared to HCs, and dALFF variability in this region was positively correlated with disease duration. Our results show that 80.36% (p < 0.001) subjects were correctly classified based on the SVM classifier by using the leave-one-out cross-validation method. Conclusion: Patients with PD exhibited abnormal dynamic brain activity in the left precuneus, and the dALFF variability could distinguish PD from HCs with high accuracy. Our results showed novel insights into the pathophysiological mechanisms of PD.

Neuroprotective carbazole alkaloids from the stems and leaves of Clausena lenis

The investigation on the stems and leaves of Clausena lenis led to the isolation of a previously undescribed carbazole alkaloid, clausenalenine A (1), along with seven known analogues (2-8). The structure of 1 was elucidated based on comprehensive spectroscopic analyses and the known compounds were identified by comparisons with data reported in the literatures. All known compounds (2-8) were isolated from C. lenis for the first time. All isolated compounds were evaluated for their neuroprotective activities against 6-hydroxydopamine induced cell death in human neuroblastoma SH-SY5Y cells in vitro. Compounds 1-8 showed significant neuroprotective effects with EC₅₀ values ranging from 0.68 to 18.76 μM.

The energetic brain - A review from students to students

The past 20 years have resulted in unprecedented progress in understanding brain energy metabolism and its role in health and disease. In this review, which was initiated at the 14th International Society for Neurochemistry Advanced School, we address the basic concepts of brain energy metabolism and approach the question of why the brain has high energy expenditure. Our review illustrates that the vertebrate brain has a high need for energy because of the high number of neurons and the need to maintain a delicate interplay between energy metabolism, neurotransmission, and plasticity. Disturbances to the energetic balance, to mitochondria quality control or to glia-neuron metabolic interaction may lead to brain circuit malfunction or even severe disorders of the CNS. We cover neuronal energy consumption in neural transmission and basic ('housekeeping') cellular processes. Additionally, we describe the most common (glucose) and alternative sources of energy namely glutamate, lactate, ketone bodies, and medium chain fatty acids. We discuss the multifaceted role of non-neuronal cells in the transport of energy substrates from circulation (pericytes and astrocytes) and in the supply (astrocytes and microglia) and usage of different energy fuels. Finally, we address pathological consequences of disrupted energy homeostasis in the CNS.

Parkinson's disease and changes in the appreciation of art: A comparison of aesthetic and formal evaluations of paintings between PD patients and healthy controls

Parkinson's disease (PD) is a progressing neurodegenerative disease predominantly involving the loss of dopamine producing neurons with hallmark symptoms of motor disorders and cognitive, motivational, emotional, and perceptual impairments. Intriguingly, PD can also be connected-often anecdotally-with a sudden burst of artistic creativity, motivation, or changed quality/style of produced art. This has led to growing empirical interest, promising a window into brain function and the unique neurological signature of artists. This topic also fits a growing interest from researchers in other areas, including Alzheimer's or other dementia, which have suggested that specific changes in art production/appraisal may provide a unique basis for therapy, diagnosis, or understanding of these diseases. However, whether PD also shows similar impacts on how we perceive and evaluate art has never been systematically addressed. We compared a cohort of PD patients against age-matched healthy controls, asking participants to rate paintings using scales of liking and beauty and terms pertaining to artworks' formal and conceptual qualities previously designed to provide a rubric for symptom identification. We found no evidence for PD-related differences in liking or beauty. However, PD patients showed higher ratings on assessed "emotionality," potentially relating to the tie between PD, dopamine pathways, and emotion/reward.

Downregulated lncRNA-SNHG1 enhances autophagy and prevents cell death through the miR-221/222 /p27/mTOR pathway in Parkinson's disease

Autophagy has been shown to be critically associated with the central mechanisms underlying Parkinson's disease (PD), while the mechanisms contributing to the imbalance of autophagy remain unclear. Small nucleolar RNA host gene 1 (SNHG1), a well-studied long noncoding RNA, has been reported to be significantly increased in PD. The potential biological functions of SNHG1 in the regulation of neuronal autophagy and cell death in PD, however, have not yet been completely elucidated. In this study, we examined the existence of regulatory networks involving SNHG1, the miR-221/222 cluster and the cyclin-dependent kinase inhibitor 1B (CDKN1B/p27)/mammalian target of rapamycin (mTOR) signaling pathway in PD. We observed that SNHG1 expression was gradually upregulated in PD cellular and animal models. Furthermore, silencing SNHG1 promoted autophagy and prevented MPP⁺-induced cell death, similar to the overexpression of the miR-221/222 cluster. Mechanistically, SNHG1 competitively binds to the miR-221/222 cluster and indirectly regulates the expression of p27/mTOR. In conclusion, these results demonstrated that downregulation of SNHG1 attenuated MPP⁺-induced decreases in LC3-II (an autophagic marker) levels and cytotoxicity through the miR-221/222/p27/mTOR pathway, suggesting that SNHG1 may be a therapeutic target for neuroprotection and disease treatment in PD.

Treatment Patterns in Patients with Incident Parkinson's Disease in the United States

BACKGROUND

Treatment patterns in Parkinson's disease (PD) have not been extensively studied for nearly two decades. Insurance claims are appropriate for such analysis.

OBJECTIVE

To understand the standard of care use of symptomatic treatments in new cases of PD and factors associated with treatment choice.

METHODS

Retrospective cohort study using claims data from the United States between 2008 and 2016. We used Kaplan-Meier methodology to estimate time to treatment start and switch or add-on therapy and Cox proportional hazards models to identify predictors.

RESULTS

We identified 68,532 patients eligible for treatment pattern analyses. Median time from diagnosis until first treatment was 37 days (95% confidence interval: 36-38). Two distinct patterns of treatment initiation were identified: fast initiators and patients with delayed treatment start (or no recorded treatment). Levodopa therapies were the most commonly prescribed treatment class (52.6%). Increased age was associated with shorter time to start of treatment with levodopa. Younger age was associated with shorter time to initiation of dopamine agonists and other symptomatic treatments. Patients that initiated treatment with levodopa/combinations had the fewest switches/add-ons [30.4%; median time 7.29 (6.71, 8.13) years]. Older patients had fewer switch/add-on therapies, but only in the group that started with levodopa/combination therapy.

CONCLUSIONS

Time from diagnosis to treatment start was relatively short, suggesting that PD diagnosis, as reflected in the database, is closely linked to start of symptomatic treatment. Levodopa treatment remains the most common treatment, especially for older patients. Delayed treatment start was associated with increased age and comorbidity.

A Stage-Based Approach to Therapy in Parkinson's Disease

Parkinson’s disease (PD) is a neurodegenerative disorder that features progressive, disabling motor symptoms, such as bradykinesia, rigidity, and resting tremor. Nevertheless, some non-motor symptoms, including depression, REM sleep behavior disorder, and olfactive impairment, are even earlier features of PD. At later stages, apathy, impulse control disorder, neuropsychiatric disturbances, and cognitive impairment can present, and they often become a heavy burden for both patients and caregivers. Indeed, PD increasingly compromises activities of daily life, even though a high variability in clinical presentation can be observed among people affected. Nowadays, symptomatic drugs and non-pharmaceutical treatments represent the best therapeutic options to improve quality of life in PD patients. The aim of the present review is to provide a practical, stage-based guide to pharmacological management of both motor and non-motor symptoms of PD. Furthermore, warning about drug side effects, contraindications, as well as dosage and methods of administration, are highlighted here, to help the physician in yielding the best therapeutic strategies for each symptom and condition in patients with PD.

Case of Early-Onset Parkinson's Disease in a Heterozygous Mutation Carrier of the ATP7B Gene

In this paper, we report a clinically proven case of Parkinson’s disease (PD) with early onset in a patient who is a heterozygous mutation carrier of ATP7B (the Wilson’s disease gene). The patient was observed from 2011 to 2018 in the Center for Neurodegenerative Diseases, Institute of Experimental Medicine (St. Petersburg, Russia). During this period, the patient displayed aggravation of PD clinical symptoms that were accompanied by a decrease in the ceruloplasmin concentration (from 0.33 to 0.27 g/L) and an increase in serum nonceruloplasmin copper, which are typical of the late stages of Wilson’s disease. It was found that one of the alleles of exon 14 in the ATP7B gene, which partially codes of the nucleotide-binding domain (N-domain), carries a mutation not previously reported corresponding to Cys1079Gly substitution. Alignment of the ATP7B N-domain amino acid sequences of representative vertebrate species has shown that the Cys at 1079 position is conserved throughout the evolution. Molecular dynamic analysis of a polypeptide with Cys1079Gly substitution showed that the mutation causes profound conformational changes in the N-domain, which could potentially lead to impairment of its functions. The role of ATP7B gene mutations in PD development is discussed.

A computational approach to identify blood cell-expressed Parkinson's disease biomarkers that are coordinately expressed in brain tissue

Identification of genes whose regulation of expression is functionally similar in both brain tissue and blood cells could in principle enable monitoring of significant neurological traits and disorders by analysis of blood samples. We thus employed transcriptional analysis of pathologically affected tissues, using agnostic approaches to identify overlapping gene functions and integrating this transcriptomic information with expression quantitative trait loci (eQTL) data. Here, we estimate the correlation of gene expression in the top-associated cis-eQTLs of brain tissue and blood cells in Parkinson's Disease (PD). We introduced quantitative frameworks to reveal the complex relationship of various biasing genetic factors in PD, a neurodegenerative disease. We examined gene expression microarray and RNA-Seq datasets from human brain and blood tissues from PD-affected and control individuals. Differentially expressed genes (DEG) were identified for both brain and blood cells to determine common DEG overlaps. Based on neighborhood-based benchmarking and multilayer network topology approaches we then developed genetic associations of factors with PD. Overlapping DEG sets underwent gene enrichment using pathway analysis and gene ontology methods, which identified candidate common genes and pathways. We identified 12 significantly dysregulated genes shared by brain and blood cells, which were validated using dbGaP (gene SNP-disease linkage) database for gold-standard benchmarking of their significance in disease processes. Ontological and pathway analyses identified significant gene ontology and molecular pathways that indicate PD progression. In sum, we found possible novel links between pathological processes in brain tissue and blood cells by examining cell pathway commonalities, corroborating these associations using well validated datasets. This demonstrates that for brain-related pathologies combining gene expression analysis and blood cell cis-eQTL is a potentially powerful analytical approach. Thus, our methodologies facilitate data-driven approaches that can advance knowledge of disease mechanisms and may, with clinical validation, enable prediction of neurological dysfunction using blood cell transcript profiling.

Targeting leucine-rich repeat kinase 2 (LRRK2) for the treatment of Parkinson's disease

Leucine-rich repeat kinase 2 (LRRK2) is a serine-threonine kinase involved in multiple cellular processes and signaling pathways. LRRK2 mutations are associated with autosomal-inherited Parkinson's disease (PD), and evidence suggests that LRRK2 pathogenic variants generally increase kinase activity. Therefore, inhibition of LRRK2 kinase function is a promising therapeutic strategy for PD treatment. The search for drug-like molecules capable of reducing LRRK2 kinase activity in PD led to the design of selective LRRK2 inhibitors predicted to be within the CNS drug-like space. This review highlights the journey that translates chemical tools for interrogating the role of LRRK2 in PD into promising drug candidates, addressing the challenges in discovering selective and brain-penetrant LRRK2 modulators and exploring the structure–activity relationship of distinct LRRK2 inhibitors.

Effects of in vivo conditions on amyloid aggregation

One of the grand challenges of biophysical chemistry is to understand the principles that govern protein misfolding and aggregation, which is a highly complex process that is sensitive to initial conditions, operates on a huge range of length- and timescales, and has products that range from protein dimers to macroscopic amyloid fibrils. Aberrant aggregation is associated with more than 25 diseases, which include Alzheimer's, Parkinson's, Huntington's, and type II diabetes. Amyloid aggregation has been extensively studied in the test tube, therefore under conditions that are far from physiological relevance. Hence, there is dire need to extend these investigations to in vivo conditions where amyloid formation is affected by a myriad of biochemical interactions. As a hallmark of neurodegenerative diseases, these interactions need to be understood in detail to develop novel therapeutic interventions, as millions of people globally suffer from neurodegenerative disorders and type II diabetes. The aim of this review is to document the progress in the research on amyloid formation from a physicochemical perspective with a special focus on the physiological factors influencing the aggregation of the amyloid-β peptide, the islet amyloid polypeptide, α-synuclein, and the hungingtin protein.

Phase lag index and spectral power as QEEG features for identification of patients with mild cognitive impairment in Parkinson's disease

OBJECTIVES

To identify quantitative EEG frequency and connectivity features (Phase Lag Index) characteristic of mild cognitive impairment (MCI) in Parkinson's disease (PD) patients and to investigate if these features correlate with cognitive measures of the patients.

METHODS

We recorded EEG data for a group of PD patients with MCI (n = 27) and PD patients without cognitive impairment (n = 43) using a high-resolution recording system. The EEG files were processed and 66 frequency along with 330 connectivity (phase lag index, PLI) measures were calculated. These measures were used to classify MCI vs. MCI-free patients. We also assessed correlations of these features with cognitive tests based on comprehensive scores (domains).

RESULTS

PLI measures classified PD-MCI from non-MCI patients better than frequency measures. PLI in delta, theta band had highest importance for identifying patients with MCI. Amongst cognitive domains, we identified the most significant correlations between Memory and Theta PLI, Attention and Beta PLI.

CONCLUSION

PLI is an effective quantitative EEG measure to identify PD patients with MCI.

SIGNIFICANCE

We identified quantitative EEG measures which are important for early identification of cognitive decline in PD.

Neuroprotective Effects of Methanolic Extract of Avocado Persea americana (var. Colinred) Peel on Paraquat-Induced Locomotor Impairment, Lipid Peroxidation and Shortage of Life Span in Transgenic knockdown Parkin Drosophila melanogaster

Parkinson's disease (PD) is a progressive neurodegenerative disorder associated with oxidative stress. Therefore, finding new antioxidant sources might be beneficial for its treatment. Avocado Persea americana is a fruit widely cultivated in tropical and subtropical climates worldwide. Although avocado by-products in the form of peel, seed coat and seeds are currently of no commercial use, they constitute a natural source of bioactive compounds. Methanolic (80%) extract obtained from lyophilized ground peels, seed coats, and seeds of the avocado Hass, Fuerte, Reed and Colinred varieties were analyzed for their total phenolic content (TPC) and their correlations with antioxidant capacity (AC) were assessed by ABTS, FRAP, and ORAC assays. For all varieties, the var. Colinred peel shows the highest TPC and AC. Further analysis showed that the var. Colinred peel presented major phenolic compounds B-type procyanidins and epicatechin according to HPLC-MS. The antioxidant effect of peel extract was evaluated upon in vivo oxidative stress (OS) model. We show for the first time that the peel extract can protect and/or prevent transgenic parkinDrosophila melanogaster fly against paraquat-induced OS, movement impairment and lipid peroxidation, as model of PD. Our findings offer an exceptional opportunity to test natural disease-modifying substances from avocado's by-products.

Development of hypotension in patients newly diagnosed with heart failure in UK general practice: retrospective cohort and nested case-control analyses

OBJECTIVES

Hypotension is of particular relevance for patients with heart failure (HF), since almost all HF drugs cause lowering of blood pressure (BP) and it is associated with a poor prognosis. We aimed to investigate hypotension incidence and risk factors in patients with incident HF in the UK.

DESIGN

Retrospective cohort study including nested case-control analyses.

SETTING

The Health Improvement Network UK primary care database.

PARTICIPANTS

18 677 adult patients with incident HF during 2000-2005 were followed and cases of hypotension (systolic BP ≤90 mm Hg) were identified. Controls were age-matched, sex-matched and date-matched to cases (1:2).

PRIMARY AND SECONDARY OUTCOME MEASURES

We estimated hypotension incidence in the full study population and relevant subgroups (eg, sex and age). Potential risk factors for hypotension overall and for multiple versus single hypotensive episodes were evaluated using conditional logistic regression and unconditional regression models, respectively.

RESULTS

During a mean follow-up of 3.31 years, 2565 patients (13.7%) developed hypotension. The incidence of hypotension was 3.17 cases per 100 patient years (95% confidence interval (CI): 3.05-3.30), and was markedly increased in women aged 18-39 years (n=32; 17.72 cases per 100 patient-years; 95% CI: 9.69-29.73). Hypotension risk factors included high healthcare utilisation (proxy measure for HF severity and general comorbidity; eg, ≥10 primary care physician visits versus none, odds ratio (OR): 2.29; 95% CI: 1.34-3.90), previous hypotensive episodes (OR: 2.32; 95% CI: 1.84-2.92), renal failure and use of aldosterone antagonists, angiotensin-converting enzyme inhibitors and angiotensin receptor blockers. Risk factors identified for hypotension generally overlapped with those for multiple versus single hypotensive episodes.

CONCLUSIONS

Hypotension occurs frequently in patients with incident HF. Our findings may help identify patients most likely to benefit from close BP monitoring. The increased incidence of hypotension in young women with HF requires investigation.

NEAT1 regulates MPP+-induced neuronal injury by targeting miR-124 in neuroblastoma cells

Long non-coding RNAs (lncRNAs) have been reported to play important roles in Parkinson's disease (PD) pathogenesis. It was indicated that lncRNA nuclear enriched abundant transcript 1 (NEAT1) is involved in PD. However, the underlying mechanism of NEAT1 is still not fully explored. Human neuroblastoma cell line SH-SY5Y was treated with 1-Methyl-4-phenylpyridinium (MPP⁺) to mimic PD model in vitro. qRT-PCR was employed to detect the expression of NEAT1, IL-1β, IL-6 and TNF-α. Starbase database, RNA pull-down assay and RNA immunoprecipitation (RIP) assay were performed to verify the relationship between NEAT1 and miR-124. MTT assay and flow cytometry assay were used to detect cell viability and apoptosis. Elisa was introduced to measure the levels of IL-1β, IL6 and TNF-α in culture media. We found that NEAT1 expression was significantly increased in SH-SY5Y cells after MPP⁺ treatment in dose- and time- dependent manners. MPP⁺ induced the expression and secretion of IL-1β, IL-6 and TNF-α, inhibited cell viability and induced apoptosis while these effects could be rescued by NEAT1 silencing. miR-124 was a target of NEAT1. Anti-miR-124 could reverse the effects caused by NEAT1 knockdown in MPP⁺ treated SH-SY5Y cells. Therefore, we speculated that NEAT1 may regulate MPP⁺ induced neuronal injury by targeting miR-124 in SH-SY5Y cells.

Evidence for using pimavanserin for the treatment of Parkinson's disease psychosis

The aim of this editorial is to evaluate the evidence for using pimavanserin for the treatment of Parkinson's disease psychosis (PDP) from randomized controlled trials (RCTs). We only identified two published trials that evaluated the use of pimavanserin among individuals with PDP. Both studies found that pimavanserin improved psychotic symptoms among individuals with PDP when compared to placebo. Pimavanserin was fairly well tolerated in both studies and did not appear to cause significant sedation or worsen motor symptoms among individuals with PDP. However, given the limited data, additional confirmatory studies are required before pimavanserin can be considered as a first line agent for the treatment of psychotic symptoms among individuals with PD.

Transcriptome and proteome profiling of neural stem cells from the human subventricular zone in Parkinson's disease

It is currently accepted that the human brain has a limited neurogenic capacity and an impaired regenerative potential. We have previously shown the existence of CD271-expressing neural stem cells (NSCs) in the subventricular zone (SVZ) of Parkinson's disease (PD) patients, which proliferate and differentiate towards neurons and glial cells in vitro. To study the molecular profile of these NSCs in detail, we performed RNA sequencing and mass spectrometry on CD271⁺ NSCs isolated from human post-mortem SVZ and on homogenates of the SVZ. CD271⁺ cells were isolated through magnetic cell separation (MACS). We first compared the molecular profile of CD271⁺ NSCs to the SVZ homogenate from control donors and then compared CD271⁺ cells to CD11b⁺ microglia. These results confirmed their neural stem cell identity. Finally we compared controls and PD patients to establish a specific molecular profile of NSCs and the SVZ in PD. While our transcriptome analysis did not identify any differentially expressed genes in the SVZ between control and PD patients, our proteome analysis revealed several proteins that were differentially expressed in PD. Some of these proteins are involved in cytoskeletal organization and mitochondrial function. Transcriptome and proteome analyses of NSCs from PD revealed changes in the expression of genes and proteins involved in metabolism, transcriptional activity and cytoskeletal organization. Our data suggest that NSCs may transit into a primed-quiescent state, that is in an "alert" non-proliferative phase in PD. Our results not only confirm pathological hallmarks of PD (e.g. impaired mitochondrial function), but also show that the NSCs from SVZ undergo significant changes at both transcriptome and proteome level following PD.

L-3-n-butylphthalide soft capsules in the treatment of Parkinson disease dementia: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

In recent years, L-3-n-butylphthalide (L-NBP) has been used for Parkinson disease dementia (PDD) to attenuate cognitive impairments in China. Therefore, we selected published and qualified clinical trials to conduct a systematic review and meta-analysis with the aim of assessing the effectiveness and safety of L-NBP in the treatment of PDD.

OBJECTIVE

This systematic review and meta-analysis aimed to assess the effectiveness and safety of L-NBP in the treatment of PDD.

METHODS

We searched PubMed, EMBASE, China National Knowledge Infrastructure, Chinese Scientific Journal Database (VIP database), and Wan-Fang Database to collect eligible articles. We calculated pooled estimates of odds ratios or the standard mean deviation with 95% confidence intervals.

RESULTS

Eight randomized controlled trials were included in our meta-analysis. Our meta-analysis showed that L-NBP combined with Western medicine (WM) had a better effect on improving cognitive dysfunction, the total effective rate, symptoms of Parkinson disease (PD), and activities of daily living function than WM alone. Regarding safety, no serious adverse events were observed in the experimental group.

CONCLUSION

We found that L-NBP as a complementary therapy may have a positive therapeutic effect for improving cognitive dysfunction, the total effective rate, symptoms of PD, quality of life, and the related serum factors in the treatment of PDD. Furthermore, L-NBP was a safe treatment for PDD. However, the findings of our meta-analysis may be influenced by the low quality of the included studies. We highlight the need to conduct trials with higher methodological quality.

Carbazole Alkaloids with Potential Neuroprotective Activities from the Fruits of Clausena lansium

Clausena lansium, also known as wampee, is a species of strongly scented evergreen trees belonging to the genus Clausena (Rutaceae), which is native to southern China. Its ripe fruits have been consumed as a very popular fruit and reported to possess a range of biological activities. To study the potential health-promoting constituents from the fruits of C. lansium, a chemical investigation on its fruits was thus carried out. In this study, 16 carbazole alkaloids (1-16), including six new carbazole alkaloids, clausenalansines A-F (1-6), were separated from the fruits of C. lansium. The molecular structures of these isolated new carbazole alkaloids (1-6) were ambiguously established on the basis of comprehensive spectroscopic methods. The known analogues (7-16) were determined via comparing their experimental data with those described in the literature, which were separated from C. lansium for the first time. All these isolated alkaloids were tested in vitro for their neuroprotective effects against 6-hydroxydopamine induced cell death in human neuroblastoma SH-SY5Y cells. Carbazole alkaloids 1-16 displayed remarkable neuroprotective effects possessing the EC₅₀ values ranging from 0.36 ± 0.02 to 10.69 ± 0.15 μM. These findings indicate that regular consumption of the fruits of C. lansium may help people prevent the occurrence of Parkinson's disease. In addition, the separation and identification of these carbazole alkaloids possessing remarkable neuroprotective effects from the fruits of C. lansium could be extremely important to the discovery of new agents for the prevention and treatment of Parkinson's disease.

Variants in the SNCA Locus Are Associated With the Progression of Parkinson's Disease

Background: Genetic factors have a well-known influence on Parkinson's disease (PD) susceptibility; however, no previous studies have investigated the influence of SNCA mutations on the natural history of PD using a prospective follow-up study. The aim of this study was to assess the risk factors of variation of SNCA on the prognosis symptoms of PD patients.

Methods: Fifty PD patients were recruited with 38 v-PSG confirmed PD+RBD patients, and the median follow-up period was 30 months. All patients underwent a comprehensive clinical evaluation at baseline and follow-up, and six SNPs of SNCA (rs356165, rs3857053, rs1045722, rs894278, rs356186, and rs356219) were analyzed. Cox proportional hazards regression models and Kaplan–Meier plot analysis were used to assess the associations between the SNCA variation and the primary and secondary progression outcomes.

Results: Based on the clinical assessment, we found that hyposmia was substantially easier to aggravate. Regression analysis showed that patients with the T allele of rs1045722 and the G allele of rs356219 presented a 34 and 20% decreased risk of progression to the H-Y stage, respectively (p = 0.022; p = 0.005). While for rs894278, G allele patients showed a 47% decreased risk of olfactory dysfunction (p = 0.029). Further subgroup analysis showed that PD+RBD patients with rs356219/G exhibited a 30% and 20% decreased risk of progression on the H-Y stage and MoCA score (p = 0.038; p = 0.045).

Conclusions: Our results indicated that genetic variation in SNCA may contribute to variability natural progression of PD and could possibly be used as a prognostic marker.

Dysfunction of Cellular Proteostasis in Parkinson's Disease

Despite decades of research, current therapeutic interventions for Parkinson’s disease (PD) are insufficient as they fail to modify disease progression by ameliorating the underlying pathology. Cellular proteostasis (protein homeostasis) is an essential factor in maintaining a persistent environment for neuronal activity. Proteostasis is ensured by mechanisms including regulation of protein translation, chaperone-assisted protein folding and protein degradation pathways. It is generally accepted that deficits in proteostasis are linked to various neurodegenerative diseases including PD. While the proteasome fails to degrade large protein aggregates, particularly alpha-synuclein (α-SYN) in PD, drug-induced activation of autophagy can efficiently remove aggregates and prevent degeneration of dopaminergic (DA) neurons. Therefore, maintenance of these mechanisms is essential to preserve all cellular functions relying on a correctly folded proteome. The correlations between endoplasmic reticulum (ER) stress and the unfolded protein response (UPR) that aims to restore proteostasis within the secretory pathway are well-established. However, while mild insults increase the activity of chaperones, prolonged cell stress, or insufficient adaptive response causes cell death. Modulating the activity of molecular chaperones, such as protein disulfide isomerase which assists refolding and contributes to the removal of unfolded proteins, and their associated pathways may offer a new approach for disease-modifying treatment. Here, we summarize some of the key concepts and emerging ideas on the relation of protein aggregation and imbalanced proteostasis with an emphasis on PD as our area of main expertise. Furthermore, we discuss recent insights into the strategies for reducing the toxic effects of protein unfolding in PD by targeting the ER UPR pathway.

Earliest Mechanisms of Dopaminergic Neurons Sufferance in a Novel Slow Progressing Ex Vivo Model of Parkinson Disease in Rat Organotypic Cultures of Substantia Nigra

The current treatments of Parkinson disease (PD) are ineffective mainly due to the poor understanding of the early events causing the decline of dopaminergic neurons (DOPAn). To overcome this problem, slow progressively degenerating models of PD allowing the study of the pre-clinical phase are crucial. We recreated in a short ex vivo time scale (96 h) all the features of human PD (needing dozens of years) by challenging organotypic culture of rat substantia nigra with low doses of rotenone. Thus, taking advantage of the existent knowledge, the model was used to perform a time-dependent comparative study of the principal possible causative molecular mechanisms undergoing DOPAn demise. Alteration in the redox state and inflammation started at 3 h, preceding the reduction in DOPAn number (pre-diagnosis phase). The number of DOPAn declined to levels compatible with diagnosis only at 12 h. The decline was accompanied by a persistent inflammation and redox imbalance. Significant microglia activation, apoptosis, a reduction in dopamine vesicle transporters, and the ubiquitination of misfolded protein clearance pathways were late (96 h, consequential) events. The work suggests inflammation and redox imbalance as simultaneous early mechanisms undergoing DOPAn sufferance, to be targeted for a causative treatment aimed to stop/delay PD.

Mediating role of caregiver burden among family caregivers of patients with Parkinson's disease in Mexico

OBJECTIVE

This study examined the mediating role of caregiver distress on family factors and caregiver life satisfaction among an understudied population of Parkinson's disease caregiver in Mexico.

METHODS

A cross-sectional design was used to examine psychosocial factors pertinent to caregiver of individuals with Parkinson's disease ( n = 95). Guided by a caregiver stress process model, relations among family factors (e.g., cohesion, flexibility, quality of functioning), gender, distress, and satisfaction with life among caregiver were examined. Mediation analyses were performed to test the role of caregiver distress on the associations between family factors, gender, and caregiver satisfaction with life.

RESULTS

Mediation models demonstrated that caregiver distress fully mediated the relation between quality of family functioning and caregiver satisfaction with life and partially mediated the association between family flexibility and caregiver satisfaction with life. Caregiver gender did not emerge as a significant covariate, and null results were found in the model examining family cohesion as a predictor.

CONCLUSION

These results underscore the critical role of caregiver distress and family factors on features of caregiver well-being, notably satisfaction with life. This evidence also offers cross cultural evidence for the caregiver stress process model, which has primarily been observed in Western samples. Accordingly, the need to build and disseminate empirically supported family-based treatments that emphasize caregiver distress is warranted.

Mulberrin attenuates 1-methyl-4-phenyl-1,2,3,6- tetrahydropyridine (MPTP)-induced Parkinson's disease by promoting Wnt/β-catenin signaling pathway

Abnormal neuroinflammation and oxidative stress has been shown to cause neuronal loss in the progressive neurodegenerative Parkinson's disease (PD). Mulberrin is the key component of Ramulus Mori that has various biological activities. This study was to investigate the functions and mechanisms of mulberrin in PD. PD models were established by administering 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to Sprague Dawley rats in vivo and Lipopolysaccharide (LPS) treatment on microglial BV2 cells in vitro. Rota-rod test was applied to investigate the roles of mulberrin on MPTP-induced behavioral impairment. The effects of mulberrin on neuronal number and microglia activation were assessed by tyrosine hydroxylase (TH) immunohistochemistry and ionized calcium binding adaptor molecule-1 (Iba-1) immunofluorescence. Inflammatory cytokines and oxidative markers were measured by qRT-PCR. Wnt/β-catenin components were compared by Western blot. Mulberrin alleviated MPTP-induced impairment of motor coordination in a dose-dependent manner, and partially restored neuronal and microglial population. Neuroinflammation and oxidative stress were suppressed after mulberrin treatment both in vivo and in vitro. Wnt/β-catenin pathway was partially restored in BV2 cells. Finally, mulberrin rescued MPTP-induced abnormality in tracer elimination by MRI. Our study indicates that mulberrin is a potent suppressor of PD abnormalities and warrants further investigations in the clinical application of mulberrin for treating PD.

Parkinson's disease patients experiencing peak-dose dyskinesia redistribute involuntary movements throughout their body to improve motor control

INTRODUCTION

In Parkinson's disease (PD), dyskinesia is considered a major side effect of dopamine replacement therapy. Nevertheless, many patients with dyskinesia function adequately.

OBJECTIVE

To study objectively dyskinesia phenomenology in order to understand why or how patients with dyskinesia are still able to perform motor tasks.

METHODS

Patients with and without dyskinesia, as well as healthy older adults, performed a geostationary task during which they attempted to stabilize a glass of water at eye level. Dyskinesia amplitude displayed by each body segment was extracted from accelerometers, and its distribution among the segments, analyzed.

RESULTS

Patients experiencing dyskinesia initially distributed most of their dyskinesia away from the segments directly involved in the task. With time, this distribution shifts back towards the hand.

CONCLUSION

Our results suggest that patients developed a strategy of involuntary movement's redistribution to attenuate their functional impact on voluntary movements. However, this strategy can only be maintained for a certain period before "re-emerging" dyskinesia occurs.

Rab GTPases as Physiological Substrates of LRRK2 Kinase

LRRK2 (Leucine-Rich Repeat Kinase 2) is a gene whose specific mutations cause Parkinson's disease (PD), the most common neurodegenerative movement disorder. LRRK2 harbors GTPase and kinase activities, two enzyme activities that play critical roles in the regulation of cellular signal transduction. Among the several LRRK2 pathogenic mutations, the most prevalent G2019S mutation increases its kinase activity when compared with the wild-type (WT), suggesting that LRRK2 kinase substrates are potential culprits of PD pathogenesis. Although there were several studies to identify LRRK2 kinase substrates, most of them mainly employed in vitro kinase assays. Therefore, it remains uncertain whether the identified substrates were real physiological substrates. However, efforts to determine physiological LRRK2 kinase substrates have recently identified several members of the Rab GTPase family as physiological LRRK2 kinase substrates. A conserved threonine or serine in the switch II domain of certain Rab GTPase family members (Rab3A/B/C/D, Rab5A/B, Rab8A/B, Rab10, Rab12, Rab29, Rab35 and Rab43) has been pinpointed to be phosphorylated by LRRK2 in cells using sophisticated phosphoproteomics technology in combination with LRRK2-specific kinase inhibitors. The Rab GTPases regulate vesicle trafficking, suggesting that LRRK2 may be a regulator of such vesicle trafficking, confirming previously suggested LRRK2 functions. However, how the consequence of the LRRK2-mediated Rab phosphorylation is related to PD pathogenesis is not clear. This review briefly summarizes the recent results about LRRK2-mediated Rab phosphorylation studies.

The role of neuronal nitric oxide and its pathways in the protection and recovery from neurotoxin-induced de novo hypokinetic motor behaviors in the embryonic zebrafish (Danio rerio)

Neuronal nitric oxide (nNO) has been shown to affect motor function in the brain. Specifically, nNO acts in part through regulation of dopamine (DA) release, transporter function, and the elicitation of neuroprotection/neurodegeneration of neurons in conditions such as Parkinson's disease (PD). Recently, the zebrafish has been proposed to be a new model for the study of PD since neurotoxin damage to their nigrostriatal-like neurons exhibit PD-like motor dysfunctions similar to those of mammalian models and human patients. Results from this study demonstrate that treatment of 5 days post fertilization (dpf) fish with a nNO synthase inhibitor as a co-treatment with 6-OHDA facilitates long-term survival and accelerates the recovery from 6-OHDA-induced hypokinesia-like symptoms. These findings are unique in that under conditions of neurotoxin-induced stress, the inhibition of the NO-related S-nitrosylation indirect pathway dramatically facilitates recovery from 6-OHDA treatment but inhibition of the NO-sGC-cGMP direct pathway is essential for survival in 5 dpf treated fish. In conclusion, these results indicate that nNOS and the inhibition of the NO-linked S-nitrosylation pathway plays an important role in antagonizing the protection and recovery of fish from neurotoxin treatment. These data begin to help in the understanding of the role of NO as a neuroprotectant in dopaminergic pathways, particularly those that influence motor dysfunctions.

Cerebellar functional abnormalities in early stage drug-naïve and medicated Parkinson's disease

Parkinson's disease (PD) is a progressive neurological degenerative disorder characterized by impaired motor function and non-motor dysfunctions. While recent studies have highlighted the role of the cerebellum in PD, our understanding of its role in PD remains limited. In the present study, we used resting-state fMRI to evaluate dysfunctions within the cerebellum in PD patients treated with medication and drug-naïve PD patients. We applied amplitude of low-frequency fluctuation (ALFF) and degree centrality (DC) analysis methods. Thirty-one patients with early stage PD (22 drug-naïve and 9 medicated patients) and 31 gender- and age-matched healthy controls were recruited in this study. ALFFs increased in the left cerebellar areas (lobules VI/VIIb/CruI/CruII and the dentate gyrus) and right cerebellar areas (lobules VI/VIIb/VIIIa/CruI/CruII and the dentate gyrus) of all PD patients and in the left and right cerebellar areas (lobules VI/VIIb/CruI and the dentate gyrus) of drug-naive PD patients but were not significantly changed in medicated PD patients. DC increased in the right cerebellar areas of all PD patients and medicated PD patients. All PD patients and all drug-naive PD patients showed significantly weaker functional connectivity (FC) between the left cerebellum and the left medial frontal gyrus. However, FC was significantly stronger between the right cerebellum and the left precentral and right middle occipital gyri in the medicated PD patients than in controls. Furthermore, a correlation analyses revealed that ALFF z scores in the left cerebellum (lobule VI) and right cerebellum (lobule VI/CruI and dentate gyrus) were negatively correlated with Mini-Mental State Examination (MMSE) scores in all PD patients and drug-naive patients. These results indicate that the cerebellum plays an important role in PD, mainly by exerting a compensatory effect in early stage PD. Additionally, antiparkinsonian medication would modified PD-induced changes in local neural activity and FC in PD patients. The results of this study offer novel insights into the roles of the cerebellum in early stage drug-naïve PD.

Detection of Parkinson's Disease through the Peptoid Recognizing α-Synuclein in Serum

Parkinson's disease (PD) is a severe neurodegenerative disease and there is great need for developing a biochemical detection method to precisely diagnose it. Alpha-synuclein (α-syn) participates in the main pathology of PD and serves as an important biomarker of PD. Here, we identified peptoid ASBP-7 that had high affinity and specificity to α-syn by screening a peptoid library using the high-throughput surface plasmon resonance imaging method. We confirmed that ASBP-7 could significantly distinguish PD sera from the normal ones through identifying α-syn in the serum. We also demonstrated the high sensitivity of this system in detecting PD serum. This work provides a method for the blood-based, label-free, high-throughput analysis of PD serum, and holds great potential for the early diagnosis and dynamic monitoring of PD.

Parkinson's Disease is Associated with Dysregulations of a Dopamine-Modulated Gene Network Relevant to Sleep and Affective Neurobehaviors in the Striatum

In addition to the characteristic motor symptoms, Parkinson’s disease (PD) often involves a constellation of sleep and mood symptoms. However, the mechanisms underlying these comorbidities are largely unknown. We have previously reconstructed gene networks in the striatum of a population of (C57BL/6J x A/J) F2 mice and associated the networks to sleep and affective phenotypes, providing a resource for integrated analyses to investigate perturbed sleep and affective functions at the gene network level. Combining this resource with PD-relevant transcriptomic datasets from humans and mice, we identified four networks that showed elevated gene expression in PD patients, including a circadian clock and mitotic network that was altered similarly in mouse models of PD. We then utilized multiple types of omics data from public databases and linked this gene network to postsynaptic dopamine signaling in the striatum, CDK1-modulated transcriptional regulation, and the genetic susceptibility of PD. These findings suggest that dopamine deficiency, a key aspect of PD pathology, perturbs a circadian/mitotic gene network in striatal neurons. Since the normal functions of this network were relevant to sleep and affective behaviors, these findings implicate that dysregulation of functional gene networks may be involved in the emergence of non-motor symptoms in PD. Our analyses present a framework for integrating multi-omics data from diverse sources in mice and humans to reveal insights into comorbid symptoms of complex diseases.

Elevated Plasma microRNA-105-5p Level in Patients With Idiopathic Parkinson's Disease: A Potential Disease Biomarker

Parkinson's disease (PD) is the second most common neurodegenerative disease, which still lacks a biomarker to aid in diagnosis and to differentiate diagnosis at the early stage of the disease. microRNAs (miRNAs) are small and evolutionary conserved non-coding RNAs that are involved in post-transcriptional gene regulation. Several miRNAs have been proposed as potential biomarkers in several diseases. In the present study, we screened miRNAs using a network vulnerability analysis, to evaluate their potential as PD biomarkers. We first extracted miRNAs that were differentially expressed between PD and healthy controls (HC) samples. Then we constructed the PD-specific miRNA-mRNA network and screened miRNA biomarkers using a new bioinformatics model. With this model, we identified miR-105-5p as a putative biomarker for PD. Moreover, we measured miR-105-5p levels in the plasma of patients with idiopathic PD (IPD) (n = 319), neurological disease controls (NDC, n = 305) and HC (n = 273) using reverse transcription real-time quantitative PCR (RT-qPCR). Our data clearly demonstrated that the plasma miR-105-5p level in IPD patients was significantly higher than those of HC (251%, p < 0.001) and NDC (347%, p < 0.001). There was no significant difference in miR-105-5p expression between IPD patients with or without anti-PD medications. Interestingly, we found that the plasma miR-105-5p expression level may be able to differentiate IPD from parkinsonian syndrome, essential tremor and other neurodegenerative diseases. We believe that a change in the plasma miR-105-5p level is a potential biomarker for IPD.

Plasma α-synuclein levels are increased in patients with obstructive sleep apnea syndrome

Objective

Obstructive sleep apnea syndrome (OSAS) is characterized by nocturnal intermittent hypoxemia and can increase the risk of Parkinson's disease. This study aimed to investigate the association between plasma α‐synuclein levels and hypoxia in the patients with OSAS.

Methods

We recruited 42 OSAS patients and 46 controls with simple snoring matched for age and gender. OSAS was diagnosed on the basis of the clinical symptoms as well as the nighttime polysomnography. Plasma total α‐synuclein and phosphorylated α‐synuclein levels were measured by ELISA kits.

Results

The OSAS patients had significant higher levels of plasma total α‐synuclein and phosphorylated α‐synuclein levels. Both of the above indexes were positively correlated with the apnea–hypopnea index and the oxygen desaturation index, while they were negatively correlated with the mean and lowest oxyhemoglobin saturations.

Interpretation

This study suggests that chronic intermittent hypoxia can increase the α‐synuclein levels, which may contribute to the pathogenesis of Parkinson's disease.

Time Perception of an Artwork's Manipulation Is Distorted by Patients With Parkinson's Disease

Objectives: In artwork appreciation situations, individuals often show altered time perception. We tested the hypothesis that Parkinson's disease (PD) patients present movement patterns that have an impact on the time perception of artwork manipulation time. We predicted that, compared to healthy controls (non-PD), differences in the exploratory behavior of patients would evoke alteration of artwork manipulation time perception. Methods: Ten PD patients and 10 non-PD participants manipulated two reproductions of artwork with different complexity levels from the series "Bichos" by Lygia Clark. Subsequently, participants performed a verbal estimation regarding the temporal duration of their manipulations. The exploratory behavior was analyzed. Results: All participants overestimated the artwork manipulation time. However, PD patients, regardless of the artwork's level of complexity, showed shorter manipulation time and minor time overestimation compared to the non-PD participants. PD patients touched the artworks more often, especially the more complex artworks, than the non-PD participants; in contrast, PD patients moved the artworks less often, particularly the less complex artwork. Conclusion: PD patients showed an altered perception of artwork manipulation time. This suggests that exploratory behavior influenced temporal estimation. Besides, it is likely that PD patients had presented a decreased ability to manage attention during the task, which interfered in the cognitive reconstruction of its duration. Considered altogether, these appointments indicate that, as a result of cognitive and motor deficits, PD patients showed impairment in temporal information processing. The exploratory behavior facilitated the understanding of these results and processes in terms of motor-timing operations of the basal ganglia-thalamocortical system.

Impact of microbiota on central nervous system and neurological diseases: the gut-brain axis

Development of central nervous system (CNS) is regulated by both intrinsic and peripheral signals. Previous studies have suggested that environmental factors affect neurological activities under both physiological and pathological conditions. Although there is anatomical separation, emerging evidence has indicated the existence of bidirectional interaction between gut microbiota, i.e., (diverse microorganisms colonizing human intestine), and brain. The cross-talk between gut microbiota and brain may have crucial impact during basic neurogenerative processes, in neurodegenerative disorders and tumors of CNS. In this review, we discuss the biological interplay between gut-brain axis, and further explore how this communication may be dysregulated in neurological diseases. Further, we highlight new insights in modification of gut microbiota composition, which may emerge as a promising therapeutic approach to treat CNS disorders.

Nicotine protects against manganese and iron-induced toxicity in SH-SY5Y cells: Implication for Parkinson's disease

Manganese (Mn) and iron (Fe) are trace elements that are essential for proper growth and physiological functions as both play critical role in a variety of enzymatic reactions. At high concentrations, however, they can be toxic and cause neurodegenerative disorders, particularly Parkinson-like syndromes. Nicotine, on the other hand, has been shown to have neuroprotective effects against various endogenous or exogenous toxins that selectively damage the dopaminergic cells. These cells include neuroblastoma-derived SH-SY5Y cells which express significant dopaminergic activity. However, practically no information on possible neuroprotective effects of nicotine against toxicity induced by trace elements is available. Therefore, in this study we investigated the effects of nicotine on toxicity induced by manganese or iron in these cells. Exposure of SH-SY5Y cells for 24 h to manganese (20 μM) or iron (20 μM) resulted in approximately 30% and 35% toxicity, respectively. Pretreatment with nicotine (1 μM) completely blocked the toxicities of Mn and Fe. The effects of nicotine, in turn, were blocked by selective nicotinic receptor antagonists. Thus, dihydro-beta erythroidine (DHBE), a selective alpha 4-beta 2 subtype antagonist and methyllycaconitine (MLA), a selective alpha7 antagonist, as well as mecamylamine, a non-selective nicotinic antagonist all dose-dependently blocked the protective effects of nicotine against both Mn and Fe. These findings provide further support for the potential utility of nicotine or nicotinic agonists in Parkinson's disease-like neurodegenerative disorders, including those that might be precipitated by trace elements, such as Fe and Mn. Moreover, both alpha4-beta2 and alpha7 nicotinic receptor subtypes appear to mediate the neuroprotective effects of nicotine against toxicity induced by these two trace metals.

Immune system and new avenues in Parkinson’s disease research and treatment

Parkinson’s disease (PD) is a progressive neurological disorder characterized by degeneration of dopaminergic neurons in the substantia nigra. However, although 200 years have now passed since the primary clinical description of PD by James Parkinson, the etiology and mechanisms of neuronal loss in this disease are still not fully understood. In addition to genetic and environmental factors, activation of immunologic responses seems to have a crucial role in PD pathology. Intraneuronal accumulation of α-synuclein (α-Syn), as the main pathological hallmark of PD, potentially mediates initiation of the autoimmune and inflammatory events through, possibly, auto-reactive T cells. While current therapeutic regimens are mainly used to symptomatically suppress PD signs, application of the disease-modifying therapies including immunomodulatory strategies may slow down the progressive neurodegeneration process of PD. The aim of this review is to summarize knowledge regarding previous studies on the relationships between autoimmune reactions and PD pathology as well as to discuss current opportunities for immunomodulatory therapy.

Switching on Endogenous Metal Binding Proteins in Parkinson's Disease

The formation of cytotoxic intracellular protein aggregates is a pathological signature of multiple neurodegenerative diseases. The principle aggregating protein in Parkinson’s disease (PD) and atypical Parkinson’s diseases is α-synuclein (α-syn), which occurs in neural cytoplasmic inclusions. Several factors have been found to trigger α-syn aggregation, including raised calcium, iron, and copper. Transcriptional inducers have been explored to upregulate expression of endogenous metal-binding proteins as a potential neuroprotective strategy. The vitamin-D analogue, calcipotriol, induced increased expression of the neuronal vitamin D-dependent calcium-binding protein, calbindin-D28k, and this significantly decreased the occurrence of α-syn aggregates in cells with transiently raised intracellular free Ca, thereby increasing viability. More recently, the induction of endogenous expression of the Zn and Cu binding protein, metallothionein, by the glucocorticoid analogue, dexamethasone, gave a specific reduction in Cu-dependent α-syn aggregates. Fe accumulation has long been associated with PD. Intracellularly, Fe is regulated by interactions between the Fe storage protein ferritin and Fe transporters, such as poly(C)-binding protein 1. Analysis of the transcriptional regulation of Fe binding proteins may reveal potential inducers that could modulate Fe homoeostasis in disease. The current review highlights recent studies that suggest that transcriptional inducers may have potential as novel mechanism-based drugs against metal overload in PD.

Motor Learning Deficits in Parkinson's Disease (PD) and Their Effect on Training Response in Gait and Balance: A Narrative Review

Parkinson's disease (PD) is a neurological disorder traditionally associated with degeneration of the dopaminergic neurons within the substantia nigra, which results in bradykinesia, rigidity, tremor, and postural instability and gait disability (PIGD). The disorder has also been implicated in degradation of motor learning. While individuals with PD are able to learn, certain aspects of learning, especially automatic responses to feedback, are faulty, resulting in a reliance on feedforward systems of movement learning and control. Because of this, patients with PD may require more training to achieve and retain motor learning and may require additional sensory information or motor guidance in order to facilitate this learning. Furthermore, they may be unable to maintain these gains in environments and situations in which conscious effort is divided (such as dual-tasking). These shortcomings in motor learning could play a large part in degenerative gait and balance symptoms often seen in the disease, as patients are unable to adapt to gradual sensory and motor degradation. Research has shown that physical and exercise therapy can help patients with PD to adapt new feedforward strategies to partially counteract these symptoms. In particular, balance, treadmill, resistance, and repeated perturbation training therapies have been shown to improve motor patterns in PD. However, much research is still needed to determine which of these therapies best alleviates which symptoms of PIGD, the needed dose and intensity of these therapies, and long-term retention effects. The benefits of such technologies as augmented feedback, motorized perturbations, virtual reality, and weight-bearing assistance are also of interest. This narrative review will evaluate the effect of PD on motor learning and the effect of motor learning deficits on response to physical therapy and training programs, focusing specifically on features related to PIGD. Potential methods to strengthen therapeutic effects will be discussed.

Improving posture to reduce the symptoms of Parkinson's: a CBP® case report with a 21 month follow-up

[Purpose] To demonstrate the reduction of symptoms related to Parkinson’s disease by improvement in posture. [Participant and Methods] A 59-year-old male patient presented with a prior diagnosis of Parkinson’s. Symptoms included a resting right hand tremor, intermittent ‘freezing episodes’ with gait, mild ataxia with shuffling on toes and bradykinesia assisted with a cane, as well as low back pain and right knee pain. Radiography revealed gross postural and spine deformity. The patient received Chiropractic BioPhysics care including mirror image exercises, spinal traction, spinal adjustments as well as gait rehabilitation. [Results] After 38 treatments over 5 months, the patient had significant improvements in posture alignment as well as gait, balance, hand tremors, low back and knee pains and SF-36 values. A 21 month follow-up revealed the patient had remained essentially well and the initial postural improvements were maintained. [Conclusion] This case demonstrates improvement of various symptoms in a patient with Parkinson’s disease. Since poor posture is a long known clinical manifestation of this disorder, it is proposed that the improvement of posture in these patients may lead to improved outcomes. X-ray use in the diagnosis and management in those with spine deformity is safe and not carcinogenic.