Disruption of mitochondrial complex I induces progressive parkinsonism.

Loss of functional mitochondrial complex I (MCI) in the dopaminergic neurons of the substantia nigra is a hallmark of Parkinson's disease1. Yet, whether this change contributes to Parkinson's disease pathogenesis is unclear2. Here we used intersectional genetics to disrupt the function of MCI in mouse dopaminergic neurons. Disruption of MCI induced a Warburg-like shift in metabolism that enabled neuronal survival, but triggered a progressive loss of the dopaminergic phenotype that was first evident in nigrostriatal axons. This axonal deficit was accompanied by motor learning and fine motor deficits, but not by clear levodopa-responsive parkinsonism-which emerged only after the later loss of dopamine release in the substantia nigra. Thus, MCI dysfunction alone is sufficient to cause progressive, human-like parkinsonism in which the loss of nigral dopamine release makes a critical contribution to motor dysfunction, contrary to the current Parkinson's disease paradigm3,4.

5-HT4R agonism reduces L-DOPA-induced dyskinesia via striatopallidal neurons in unilaterally 6-OHDA lesioned mice.

Parkinson's disease is caused by a selective vulnerability and cell loss of dopaminergic neurons of the Substantia Nigra pars compacta and, consequently, striatal dopamine depletion. In Parkinson's disease therapy, dopamine loss is counteracted by the administration of L-DOPA, which is initially effective in ameliorating motor symptoms, but over time leads to a burdening side effect of uncontrollable jerky movements, termed L-DOPA-induced dyskinesia. To date, no efficient treatment for dyskinesia exists. The dopaminergic and serotonergic systems are intrinsically linked, and in recent years, a role has been established for pre-synaptic 5-HT1a/b receptors in L-DOPA-induced dyskinesia. We hypothesized that post-synaptic serotonin receptors may have a role and investigated the effect of modulation of 5-HT4 receptor on motor symptoms and L-DOPA-induced dyskinesia in the unilateral 6-OHDA mouse model of Parkinson's disease. Administration of RS 67333, a 5-HT4 receptor partial agonist, reduces L-DOPA-induced dyskinesia without altering L-DOPA's pro-kinetic effect. In the dorsolateral striatum, we find 5-HT4 receptor to be predominantly expressed in D2R-containing medium spiny neurons, and its expression is altered by dopamine depletion and L-DOPA treatment. We further show that 5-HT4 receptor agonism not only reduces L-DOPA-induced dyskinesia, but also enhances the activation of the cAMP-PKA pathway in striatopallidal medium spiny neurons. Taken together, our findings suggest that agonism of the post-synaptic serotonin receptor 5-HT4 may be a novel therapeutic approach to reduce L-DOPA-induced dyskinesia.

The 5-HT2A/2C inverse agonist nelotanserin alleviates L-DOPA-induced dyskinesia in the MPTP-lesioned marmoset.

Nelotanserin is a serotonin 2A and 2C (5-HT2A/2C) inverse agonist that was previously tested in the clinic for rapid-eye movement sleep behaviour disorder and psychosis in patients with Parkinson's disease (PD) dementia. Its effect on L-3,4-dihydroxyphenylalanine (L-DOPA)-induced dyskinesia has however not been investigated. As 5-HT2A antagonism/inverse agonism is a validated approach to alleviate dyskinesia, we undertook the current study to evaluate the anti-dyskinetic potential of nelotanserin in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-lesioned marmoset. Parkinsonism was induced in six common marmosets (Callithrix jacchus, three females and three males) that were then chronically treated with L-DOPA to induce dyskinesia. On experimental days, they were administered L-DOPA in combination with vehicle or nelotanserin (0.1, 0.3 and 1 mg/kg) subcutaneously, in a randomised fashion. Dyskinesia and parkinsonism were rated post hoc by a blinded observer. In comparison to vehicle, the addition of nelotanserin 0.3 and 1 mg/kg to L-DOPA diminished peak dose dyskinesia by 47% (P < 0.05) and 69% (P < 0.001). Nelotanserin 0.3 and 1 mg/kg also reduced the severity of global dyskinesia, by 40% (P < 0.01) and 55% (P < 0.001), when compared to vehicle. Nelotanserin 0.1 mg/kg did not alleviate peak dose or global dyskinesia severity. Nelotanserin had no impact on the anti-parkinsonian action of L-DOPA. Our results highlight that nelotanserin may represent an efficacious anti-dyskinetic drug and provide incremental evidence of the potential benefit of 5-HT2A/2C antagonism/inverse agonism for drug-induced dyskinesia in PD.

Dopamine synthesis and transport: current and novel therapeutics for parkinsonisms.

Parkinsonism is the primary type of movement disorder in adults, encompassing a set of clinical symptoms, including rigidity, tremors, dystonia, bradykinesia, and postural instability. These symptoms are primarily caused by a deficiency in dopamine (DA), an essential neurotransmitter in the brain. Currently, the DA precursor levodopa (synthetic L-DOPA) is the standard medication to treat DA deficiency, but it only addresses symptoms rather than provides a cure. In this review, we provide an overview of disorders associated with DA dysregulation and deficiency, particularly Parkinson's disease and rare inherited disorders leading predominantly to dystonia and/or parkinsonism, even in childhood. Although levodopa is relatively effective for the management of motor dysfunctions, it is less effective for severe forms of parkinsonism and is also associated with side effects and a loss of efficacy over time. We present ongoing efforts to reinforce the effect of levodopa and to develop innovative therapies that target the underlying pathogenic mechanisms affecting DA synthesis and transport, increasing neurotransmission through disease-modifying approaches, such as cell-based therapies, nucleic acid- and protein-based biologics, and small molecules.

Activation of mGlu 2/3 receptors with the orthosteric agonist LY-404,039 alleviates dyskinesia in experimental parkinsonism.

LY-404,039 is an orthosteric agonist at metabotropic glutamate 2 and 3 (mGlu 2/3 ) receptors, with a possible additional agonist effect at dopamine D 2 receptors. LY-404,039 and its pro-drug, LY-2140023, have previously been tested in clinical trials for psychiatric indications and could therefore be repurposed if they were shown to be efficacious in other conditions. We have recently demonstrated that the mGlu 2/3 orthosteric agonist LY-354,740 alleviated L-3,4-dihydroxyphenylalanine (L-DOPA)-induced abnormal involuntary movements (AIMs) in the 6-hydroxydopamine (6-OHDA)-lesioned rat without hampering the anti-parkinsonian action of L-DOPA. Here, we seek to take advantage of a possible additional D 2 -agonist effect of LY-404,039 and see if an anti-parkinsonian benefit might be achieved in addition to the antidyskinetic effect of mGlu 2/3 activation. To this end, we have administered LY-404,039 (vehicle, 0.1, 1 and 10 mg/kg) to 6-OHDA-lesioned rats, after which the severity of axial, limbs and oro-lingual (ALO) AIMs was assessed. The addition of LY-404,039 10 mg/kg to L-DOPA resulted in a significant reduction of ALO AIMs over 60-100 min (54%, P  < 0.05). In addition, LY-404,039 significantly enhanced the antiparkinsonian effect of L-DOPA, assessed through the cylinder test (76%, P  < 0.01). These results provide further evidence that mGlu 2/3 orthosteric stimulation may alleviate dyskinesia in PD and, in the specific case of LY-404,039, a possible D 2 -agonist effect might also make it attractive to address motor fluctuations. Because LY-404,039 and its pro-drug have been administered to humans, they could possibly be advanced to Phase IIa trials rapidly for the treatment of motor complications in PD.

Thymoquinone ameliorates symptoms of Parkinson's disease in a 6-OHDA rat model by downregulation of miR-204-3p.

microRNAs (miRNAs) play a significant role in the pathophysiology of Parkinson's disease. In this study, we evaluated the neuroprotective effect of thymoquinone on the expression profiles of miRNA and cognitive functions in the 6-hydroxydopamine (6-OHDA)-induced Parkinson's model. Male adult Wistar albino rats (200-230 g, n  = 36) were randomly assigned to six groups: Sham, thymoquinone (10 mg/kg, p.o.), 6-OHDA, 6-OHDA + thymoquinone (10 mg/kg), 6-OHDA + thymoquinone (20 mg/kg), and 6-OHDA + thymoquinone (50 mg/kg). Behavioral changes were detected using the open field and the elevated plus maze tests. The mature 728 miRNA expressions were evaluated by miRNA microarray (GeneChip miRNA 4.0). Ten miRNAs were selected (rno-miR-212-5p, rno-miR-146b-5p, rno-miR-150-5p, rno-miR-29b-2-5p, rno-miR-126a-3p, rno-miR-187-3p, rno-miR-34a-5p, rno-miR-181d-5p, rno-miR-204-3p, and rno-miR-30c-2-3p) and confirmed by real-time PCR. Striatum samples were stained with hematoxylin-eosin to determine the effect of dopaminergic lesions. One-way ANOVA test and independent sample t -test were used for statistical analyses. rno-miR-204-3p was upregulated at 6-OHDA and downregulated at the 50 mg/kg dose of thymoquinone. In conclusion, thymoquinone at a dose of 50 mg/kg ameliorates symptoms of Parkinson's disease in a 6-OHDA rat model by downregulation of miR-204-3p. Also, the results showed that thymoquinone can improve locomotor activity and willing exploration and decreased anxiety. Therefore, thymoquinone can be used as a therapeutic agent.

Progression of atypical parkinsonian syndromes: PROSPECT-M-UK study implications for clinical trials.

The advent of clinical trials of disease-modifying agents for neurodegenerative disease highlights the need for evidence-based end point selection. Here we report the longitudinal PROSPECT-M-UK study of progressive supranuclear palsy (PSP), corticobasal syndrome (CBS), multiple system atrophy (MSA) and related disorders, to compare candidate clinical trial end points. In this multicentre UK study, participants were assessed with serial questionnaires, motor examination, neuropsychiatric and MRI assessments at baseline, 6 and 12 months. Participants were classified by diagnosis at baseline and study end, into Richardson syndrome, PSP-subcortical (PSP-parkinsonism and progressive gait freezing subtypes), PSP-cortical (PSP-frontal, PSP-speech and language and PSP-CBS subtypes), MSA-parkinsonism, MSA-cerebellar, CBS with and without evidence of Alzheimer's disease pathology and indeterminate syndromes. We calculated annual rate of change, with linear mixed modelling and sample sizes for clinical trials of disease-modifying agents, according to group and assessment type. Two hundred forty-three people were recruited [117 PSP, 68 CBS, 42 MSA and 16 indeterminate; 138 (56.8%) male; age at recruitment 68.7 ± 8.61 years]. One hundred and fifty-nine completed the 6-month assessment (82 PSP, 27 CBS, 40 MSA and 10 indeterminate) and 153 completed the 12-month assessment (80 PSP, 29 CBS, 35 MSA and nine indeterminate). Questionnaire, motor examination, neuropsychiatric and neuroimaging measures declined in all groups, with differences in longitudinal change between groups. Neuroimaging metrics would enable lower sample sizes to achieve equivalent power for clinical trials than cognitive and functional measures, often achieving N < 100 required for 1-year two-arm trials (with 80% power to detect 50% slowing). However, optimal outcome measures were disease-specific. In conclusion, phenotypic variance within PSP, CBS and MSA is a major challenge to clinical trial design. Our findings provide an evidence base for selection of clinical trial end points, from potential functional, cognitive, clinical or neuroimaging measures of disease progression.

Kinect-based objective assessment of the acute levodopa challenge test in parkinsonism: a feasibility study.

INTRODUCTION: The acute levodopa challenge test (ALCT) is an important and valuable examination but there are still some shortcomings with it. We aimed to objectively assess ALCT based on a depth camera and filter out the best indicators. METHODS: Fifty-nine individuals with parkinsonism completed ALCT and the improvement rate (IR, which indicates the change in value before and after levodopa administration) of the Movement Disorder Society-Sponsored Revision of the Unified Parkinson's Disease Rating Scale part III (MDS-UPDRS III) was calculated. The kinematic features of the patients' movements in both the OFF and ON states were collected with an Azure Kinect depth camera. RESULTS: The IR of MDS-UPDRS III was significantly correlated with the IRs of many kinematic features for arising from a chair, pronation-supination movements of the hand, finger tapping, toe tapping, leg agility, and gait (rs = - 0.277 ~ - 0.672, P < 0.05). Moderate to high discriminative values were found in the selected features in identifying a clinically significant response to levodopa with sensitivity, specificity, and area under the curve (AUC) in the range of 50-100%, 47.22%-97.22%, and 0.673-0.915, respectively. The resulting classifier combining kinematic features of toe tapping showed an excellent performance with an AUC of 0.966 (95% CI = 0.922-1.000, P < 0.001). The optimal cut-off value was 21.24% with sensitivity and specificity of 94.44% and 87.18%, respectively. CONCLUSION: This study demonstrated the feasibility of measuring the effect of levodopa and objectively assessing ALCT based on kinematic data derived from an Azure Kinect-based system.

Role of the iNOS isoform in the cardiovascular dysfunctions of male rats with 6-OHDA-induced Parkinsonism.

INTRODUCTION: Available studies have shown the involvement of nitric oxide (NO) in the processes that lead to neurodegeneration in Parkinson's disease (PD). Also, the use of inhibitors of the inducible isoform of NO-synthase (iNOS) promotes neuroprotection and attenuates dopamine (DA) loss in experimental models of Parkinsonism. In addition, NO also appears to be involved in cardiovascular changes in 6-hydroxydopamine (6-OHDA)-induced Parkinsonism. The current study aimed to evaluate the effects of iNOS inhibition on cardiovascular and autonomic function in animals that were subjected to Parkinsonism by the administration of 6-OHDA. MATERIALS AND METHODS: The animals underwent stereotaxic surgery for bilateral microinfusion of the neurotoxin 6-OHDA (6 mg/mL in 0.2% ascorbic acid in sterile saline solution) or vehicle solution for the Sham group. From the day of stereotaxis until the day of femoral artery catheterization, the animals were treated with the iNOS inhibitor, S-methylisothiourea (SMT; 10 mg/kg; i. p.) or saline solution (0.9%; i. p.) for 7 days. The animals were divided into four groups: Sham-Saline, Sham-SMT, 6-OHDA-Saline, and 6-OHDA-SMT. Subsequent analyses were performed on these four groups. After 6 days, they underwent catheterization of the femoral artery, and 24 h later, mean arterial pressure (MAP) and heart rate (HR) were recorded. Another group of animals (the 6-OHDA and Sham groups) was assessed for aortic vascular reactivity after 7 days of bilateral infusion of 6-OHDA or vehicle, in which cumulative concentration-effect curves (CCEC) were made for phenylephrine (Phenyl), acetylcholine and sodium nitroprusside (NPS). Also, CCEC in the presence of Nw-nitro-arginine-methyl-ester (l-NAME) (10-5 M), SMT (10-6 M), and indomethacin (10-5 M) blockers were made. RESULTS: The effectiveness of the 6-OHDA lesion was confirmed with the reduction of DA in 6-OHDA animals. However, treatment with SMT could not reverse the loss of DA. Concerning the baseline parameters, SBP and MAP values were lower in 6-OHDA animals compared to their Sham control, with no effect of treatment with SMT. In the analysis of SBP variability, a decrease in variance, the VLFabs component, and the LFabs component were observed in the 6-OHDA groups when compared to their controls, regardless of treatment with SMT. It was also observed that intravenous injections of SMT resulted in an increase in BP and a decrease in HR. However, the response was not different between the Sham and 6-OHDA groups. In vascular function, there was a hyporeactivity to Phenyl in the 6-OHDA group, and when investigating the mechanisms of this hyporeactivity, it was seen that the Rmax to Phenyl increased with incubation with SMT, indicating that iNOS could be involved in the vascular hyporeactivity of animals with Parkinsonism. CONCLUSION: Thus, the set of results presented in this study suggests that part of the cardiovascular dysfunction in animals subjected to 6-OHDA Parkinsonism may be peripheral and involve the participation of endothelial iNOS.

Parkinsonism as the presenting manifestation of lupus: A case-based review.

INTRODUCTION: Neuropsychiatric manifestations in systemic lupus erythematosus (SLE) occur in about half of the patients; however, movement disorders like Parkinsonism are rare. We describe a case of SLE who presented solely with features of Parkinsonism. CASE REPORT: 50-year-old female presented with global slowing of movements and slowing of speech since 2 months. On examination, she had mask-like facies with a faint malar rash sparing the nasolabial folds, hard palate ulcer, cog-wheel rigidity, and proximal muscle weakness. Lab evaluation revealed lymphopenia, high ESR, elevated lactate dehydrogenase, creatinine phosphokinase, AST, and ALT levels. She had high anti-dsDNA levels with low complements. Urinalysis showed proteinuria and hematuria. ANA was positive at a titer of 1:320, and she had positive anti-ribosomal-P antibody. She had severe flare with a SLEDAI of 33. She was treated with pulse IV methylprednisolone followed by cyclophosphamide (NIH protocol). At 4 weeks follow-up, she had dramatic improvement in her Parkinsonian symptoms and her proximal muscle weakness. DISCUSSION: The prevalence of movement disorders in cases of neuropsychiatric SLE is very low at 0.7%, with chorea being most frequent and Parkinsonism rare. The pathogenesis is multifactorial including anti-dopaminergic antibodies or associated anti-phospholipids causing microvascular thrombosis or vasculitis of the thalamostriatal arteries or disease activity itself. As in our case, immunosuppression and optimal treatment of active lupus reverts symptoms in most cases. CONCLUSION: A high index of suspicion needs to be exercised in cases of SLE presenting with Parkinsonism as adequate immunosuppression translates to near-complete recovery.

The Extrapyramidal Symptom Rating Scale and Its Abbreviated Version: A Critical Review of Clinimetric Properties.

BACKGROUND: The Extrapyramidal Symptom Rating Scale - Abbreviated (ESRS-A) is an abbreviated version of the Extrapyramidal Symptom Rating Scale (ESRS) with instructions, definitions, and a semi-structured interview that follows clinimetric concepts of measuring clinical symptoms. Similar to the ESRS, the ESRS-A was developed to assess four types of drug-induced movement disorders (DIMD): parkinsonism, akathisia, dystonia, and tardive dyskinesia (TD). SUMMARY: The present review of the literature provides the most relevant clinimetric properties displayed by the ESRS and ESRS-A in clinical studies. Comprehensive ESRS-A definitions, official scale, and basic instructions are provided. ESRS inter-rater reliability was evaluated in two pivotal studies and in multicenter international studies. Inter-rater reliability was high for assessing both antipsychotic-induced movement disorders and idiopathic Parkinson's disease. Guidelines were also established for inter-rater reliability and the rater certification processes. The ESRS showed good concurrent validity with 96% agreement between Abnormal Involuntary Movement Scale (AIMS) for TD-defined cases and ESRS-defined cases. Similarly, concurrent validity for ESRS-A total and subscores for parkinsonism, akathisia, dystonia, and dyskinesia ranged from good to very good. The ESRS was particularly sensitive for detecting DIMD-related movement differences following treatment with placebo, antipsychotics, and antiparkinsonian and antidyskinetic medications. ESRS measurement of drug-induced extrapyramidal symptoms was shown to discriminate extrapyramidal symptoms from psychiatric symptoms. KEY MESSAGES: The ESRS and ESRS-A are valid clinimetric indices for measuring DIMD. They can be valuably implemented in clinical research, particularly in trials testing antipsychotic medications, and in clinics to detect the presence, severity, and response to treatment of movement disorders.

Novel FABP3 ligand, HY-11-9, ameliorates neuropathological deficits in MPTP-induced Parkinsonism in mice.

Parkinson's disease (PD) is characterized by dopaminergic (DAergic) neuronal loss in the substantia nigra pars compacta (SNpc), resulting from α-synuclein (αSyn) toxicity. We previously reported that αSyn oligomerization and toxicity are regulated by the fatty-acid binding protein 3 (FABP3), and the therapeutic effects of the FABP3 ligand, MF1, was successfully demonstrated in PD models. Here, we developed a novel and potent ligand, HY-11-9, which has a higher affinity for FABP3 (Kd = 11.7 ± 8.8) than MF1 (Kd = 302.8 ± 130.3). We also investigated whether the FABP3 ligand can ameliorate neuropathological deterioration after the onset of disease in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced Parkinsonism. Motor deficits were observed two weeks after MPTP treatment. Notably, oral administration of HY-11-9 (0.03 mg/kg) improved motor deficits in both beam-walking and rotarod tasks, whereas MF1 failed to improve the motor deficits in both tasks. Consistent with the behavioral tasks, HY-11-9 recovered dopamine neurons from MPTP toxicity in the substantia nigra and ventral tegmental areas. Furthermore, HY-11-9 reduced the accumulation of phosphorylated-serine129-α-synuclein (pS129-αSyn) and colocalization with FABP3 in tyrosine hydroxylase (TH)-positive DA neurons in the PD mouse model. Overall, HY-11-9 significantly improved MPTP-induced behavioral and neuropathological deterioration, suggesting that it may be a potential candidate for PD therapy.

The factor structure of extrapyramidal symptoms evaluated using the Drug-Induced Extrapyramidal Symptoms Scale in patients with schizophrenia: Results from the 2016 REAP AP-4 study.

INTRODUCTION: Drug-induced extrapyramidal syndrome (EPS) remains a major problem in clinical psychiatry. This study aimed to examine the factor structure of drug-induced extrapyramidal symptoms observed in patients with schizophrenia and assessed using the Drug-Induced Extrapyramidal Symptoms Scale (DIEPSS). METHODS: The participants were 1478 patients with a diagnosis of schizophrenia whose EPS was assessed using the DIEPSS in India, Indonesia, Japan, Malaysia, and Taiwan in the 2016 REAP AP-4 study. The records of the participants were randomly divided into two subgroups: the first for exploratory factor analysis of the eight DIEPSS items, and the second for confirmatory factor analysis. RESULTS: The factor analysis identified three factors: F1 (gait and bradykinesia), F2 (muscle rigidity and tremor), and F3 (sialorrhea, akathisia, dystonia, and dyskinesia). CONCLUSION: The results suggest that the eight individual items of the DIEPSS could be composed of three different mechanisms: acute parkinsonism observed during action (F1), acute parkinsonism observed at rest (F2), and central dopaminergic mechanisms with pathophysiology other than acute parkinsonism (F3).

Naringenin, a Functional Food Component, Improves Motor and Non-Motor Symptoms in Animal Model of Parkinsonism Induced by Rotenone.

Parkinson's disease (PD) and other age-related neurodegenerative ailments have a strong link to oxidative stress. Bioflavonoid naringenin has antioxidant properties. The effects of pre- and post-naringenin supplementation on a rotenone-induced PD model were examined in this work. Naringenin (50 mg/kg, p.o.) was administered to rats for two weeks before the administration of rotenone in the pre-treatment phase. In contrast, rotenone (1.5 mg/kg, s.c.) was administered for eight days before naringenin (50 mg/kg, p.o.) was supplemented for two weeks in the post-treatment phase. During behavioral investigation, the motor and non-motor signs of PD were observed. Additionally, estimation of neurochemical and biochemical parameters was also carried out. Compared to controls, rotenone treatment substantially increased oxidative stress, altered neurotransmitters, and caused motor and non-motor impairments. Rotenone-induced motor and non-motor impairments were considerably reduced by naringenin supplementation. The supplementation also increased antioxidant enzyme activities and restored the changes in neurotransmitter levels. The findings of this work strongly imply that daily consumption of flavonoids such as naringenin may have a therapeutic potential to combat PD.

Questionnaire survey of satisfaction with medication for five symptom domains of dementia with Lewy bodies among patients, their caregivers, and their attending physicians.

BACKGROUND: The real-world status of satisfaction with medication for dementia with Lewy bodies (DLB) has not been elucidated. We assessed the satisfaction of patients with DLB, their caregivers, and their attending physicians (trios) with medication according to the clinical symptom domains of DLB. METHODS: This was a subanalysis of a cross-sectional, questionnaire-based, survey study of trios. The subanalysis set comprised analysis populations for cognitive impairment, parkinsonism, psychiatric symptoms, sleep-related disorders, and autonomic dysfunction (orthostatic hypotension, constipation, and dysuria). These analysis populations included trios of patients who had any symptom domain and took medication for each symptom domain, and for which all trio data on satisfaction with medication for the symptom domain were available. The degrees of satisfaction with medication were classified as 'satisfied', 'neutral', or 'dissatisfied'. RESULTS: The analysis set for this study included 110 trios for cognitive impairment, 62 for parkinsonism, 47 for psychiatric symptoms, 29 for sleep-related disorders, none for orthostatic hypotension, 11 for constipation, and seven for dysuria. There were no statistically significant differences in the degree of satisfaction with medication for symptom domains other than parkinsonism and dysuria between patients-caregivers, patients-physicians, and caregivers-physicians. Regarding satisfaction with medication for parkinsonism, significantly more physicians than patients answered 'satisfied' (75.8% vs. 51.6%), and significantly more patients than physicians answered 'neutral' (35.5% vs. 14.5%) (P = 0.013). Regarding satisfaction with medication for dysuria, significantly more caregivers than physicians answered 'satisfied' (100% vs. 28.6%, P = 0.038). CONCLUSIONS: Satisfaction with medication for symptom domains other than parkinsonism and dysuria was similar among trios. Our results suggest that physicians should pay more attention to patients' satisfaction with medication for parkinsonism, and to caregivers' satisfaction with medication for dysuria to help prevent undermedication.

Monoamine Oxidase-B Inhibition Facilitates α-Synuclein Secretion In Vitro and Delays Its Aggregation in rAAV-Based Rat Models of Parkinson's Disease.

Cell-to-cell transmission of α-synuclein (α-syn) pathology is considered to underlie the spread of neurodegeneration in Parkinson's disease (PD). Previous studies have demonstrated that α-syn is secreted under physiological conditions in neuronal cell lines and primary neurons. However, the molecular mechanisms that regulate extracellular α-syn secretion remain unclear. In this study, we found that inhibition of monoamine oxidase-B (MAO-B) enzymatic activity facilitated α-syn secretion in human neuroblastoma SH-SY5Y cells. Both inhibition of MAO-B by selegiline or rasagiline and siRNA-mediated knock-down of MAO-B facilitated α-syn secretion. However, TVP-1022, the S-isomer of rasagiline that is 1000 times less active, failed to facilitate α-syn secretion. Additionally, the MAO-B inhibition-induced increase in α-syn secretion was unaffected by brefeldin A, which inhibits endoplasmic reticulum (ER)/Golgi transport, but was blocked by probenecid and glyburide, which inhibit ATP-binding cassette (ABC) transporter function. MAO-B inhibition preferentially facilitated the secretion of detergent-insoluble α-syn protein and decreased its intracellular accumulation under chloroquine-induced lysosomal dysfunction. Moreover, in a rat model (male Sprague Dawley rats) generated by injecting recombinant adeno-associated virus (rAAV)-A53T α-syn, subcutaneous administration of selegiline delayed the striatal formation of Ser129-phosphorylated α-syn aggregates, and mitigated loss of nigrostriatal dopaminergic neurons. Selegiline also delayed α-syn aggregation and dopaminergic neuronal loss in a cell-to-cell transmission rat model (male Sprague Dawley rats) generated by injecting rAAV-wild-type α-syn and externally inoculating α-syn fibrils into the striatum. These findings suggest that MAO-B inhibition modulates the intracellular clearance of detergent-insoluble α-syn via the ABC transporter-mediated non-classical secretion pathway, and temporarily suppresses the formation and transmission of α-syn aggregates.SIGNIFICANCE STATEMENT The identification of a neuroprotective agent that slows or stops the progression of motor impairments is required to treat Parkinson's disease (PD). The process of α-synuclein (α-syn) aggregation is thought to underlie neurodegeneration in PD. Here, we demonstrated that pharmacological inhibition or knock-down of monoamine oxidase-B (MAO-B) in SH-SY5Y cells facilitated α-syn secretion via a non-classical pathway involving an ATP-binding cassette (ABC) transporter. MAO-B inhibition preferentially facilitated secretion of detergent-insoluble α-syn protein and reduced its intracellular accumulation under chloroquine-induced lysosomal dysfunction. Additionally, MAO-B inhibition by selegiline protected A53T α-syn-induced nigrostriatal dopaminergic neuronal loss and suppressed the formation and cell-to-cell transmission of α-syn aggregates in rat models. We therefore propose a new function of MAO-B inhibition that modulates α-syn secretion and aggregation.

Role of excretion in manganese homeostasis and neurotoxicity: a historical perspective.

The essential metal manganese (Mn) induces incurable neurotoxicity at elevated levels that manifests as parkinsonism in adults and fine motor and executive function deficits in children. Studies on Mn neurotoxicity have largely focused on the role and mechanisms of disease induced by elevated Mn exposure from occupational or environmental sources. In contrast, the critical role of excretion in regulating Mn homeostasis and neurotoxicity has received less attention although 1) studies on Mn excretion date back to the 1920s; 2) elegant radiotracer Mn excretion assays in the 1940s to 1960s established the routes of Mn excretion; and 3) studies on patients with liver cirrhosis in the 1990s to 2000s identified an association between decreased Mn excretion and the risk of developing Mn-induced parkinsonism in the absence of elevated Mn exposure. Notably, the last few years have seen renewed interest in Mn excretion largely driven by the discovery that hereditary Mn neurotoxicity due to mutations in SLC30A10 or SLC39A14 is caused, at least in part, by deficits in Mn excretion. Quite remarkably, some of the recent results on SLC30A10 and SLC39A14 provide explanations for observations made ∼40-50 years ago. The goal of the current review is to integrate the historic studies on Mn excretion with more contemporary recent work and provide a comprehensive state-of-the-art overview of Mn excretion and its role in regulating Mn homeostasis and neurotoxicity. A related goal is to discuss the significance of some of the foundational studies on Mn excretion so that these highly consequential earlier studies remain influential in the field.

Sesquiterpenoids isolated from davana (Artemisia pallens Wall. ex DC) mitigates parkinsonism in Caenorhabditis elegans disease model.

Parkinson's disease (PD) is a multifactorial ailment that severely affects the viability of dopaminergic neurons leading to progressive loss of motor control. The current regimen for PD treatment includes synthetic drugs that lack efficacy and cause serious side effects. Consequently, recent drug development studies are focusing on alternative medicines from plant sources. Artemisia pallens Wall. ex DC, commonly known as davana, is an annual aromatic herb cultivated in southern India. Given the diverse traditional and scientifically documented therapeutic effects of A. pallens, the pharmacological potential of the isolates of the plant, namely bicyclogermacrene (D1), cis-davanone (D3), and cis-hydroxy davanone (D5), was tested for anti-Parkinson's activity in Caenorhabditis elegans model. The tested compounds alleviated α-synuclein (α-syn) aggregation and maximum decline was observed in 25 µM D1 supplemented worms. Additionally, D1 modulated dopamine regulated nonanol-1 repulsion and locomotory behaviour of C. elegans validating its future use as a dopamine-enhancing agent. The genetic regulation mediating the above effects validated through the qPCR study showed that D1 supplementation displayed its anti-Parkinson's effect through upregulation of the antioxidant defence system genes (superoxide dismutase (sod)-1, sod-2, and sod-4) and PD associated pdr-1 gene that maintains the mitochondrial proteostasis. The molecular docking studies of C. elegans PDR-1 with D1 further confirmed its contribution in D1 induced abridgment of Parkinson disease linked pathologies in C. elegans disease model. Hence, this article proposes D1 as an effective regimen for curtailing the Parkinson disease linked pathologies through mechanism of maintaining cellular redox state and proteostasis.

Targeting NAAA counters dopamine neuron loss and symptom progression in mouse models of parkinsonism.

The lysosomal cysteine hydrolase N-acylethanolamine acid amidase (NAAA) deactivates palmitoylethanolamide (PEA), a lipid-derived PPAR-α agonist that is critically involved in the control of pain and inflammation. In this study, we asked whether NAAA-regulated PEA signaling might contribute to dopamine neuron degeneration and parkinsonism induced by the mitochondrial neurotoxins, 6-hydroxydopamine (6-OHDA) and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). In vitro experiments showed that 6-OHDA and MPTP enhanced NAAA expression and lowered PEA content in human SH-SY5Y cells. A similar effect was observed in mouse midbrain dopamine neurons following intra-striatal 6-OHDA injection. Importantly, deletion of the Naaa gene or pharmacological inhibition of NAAA activity substantially attenuated both dopamine neuron death and parkinsonian symptoms in mice treated with 6-OHDA or MPTP. Moreover, NAAA expression was elevated in postmortem brain cortex and premortem blood-derived exosomes from persons with Parkinson's disease compared to age-matched controls. The results identify NAAA-regulated PEA signaling as a molecular control point for dopaminergic neuron survival and a potential target for neuroprotective intervention.

Long-Term Efficacy and Safety of Zonisamide for Treatment of Parkinsonism in Patients With Dementia With Lewy Bodies: An Open-Label Extension of a Phase three Randomized Controlled Trial.

OBJECTIVES: To evaluate the long-term efficacy and safety of zonisamide, an antiepileptic agent, in dementia with Lewy bodies (DLB). DESIGN: Phase three clinical trial with 12 week, randomized, placebo-controlled, double-blind, and subsequent 40 week, open-label, extension periods. SETTING: A total of 109 centers in Japan between April 2015 and November 2017. PARTICIPANTS: Outpatients diagnosed with probable DLB. INTERVENTION: Outpatients were randomly assigned to receive placebo (P) or zonisamide 25 or 50 mg/day for 12 weeks. In the subsequent open-label 40 week period, all patients initially received zonisamide 25 mg/day for at least 2 weeks followed by optional flexible dosing with zonisamide 25 or 50 mg/day for the remaining period. MEASUREMENTS: The primary outcome was efficacy on motor symptoms, assessed using the Unified Parkinson's Disease Rating Scale part III (UPDRS-III) score, over the total 52 week trial period. Effects on behavioral and psychological symptoms of dementia and cognitive function, and safety were also evaluated. RESULTS: In total, 335 patients were included in the long-term analysis: 106, 117, and 112 in the P-, 25mg-, and 50mg-Flex groups, respectively. UPDRS-III score continued to improve for an additional 12 to 16 weeks in the open-label period (mean [standard deviation] change from baseline at Week 28: -5.1 [7.3] and -6.3 [8.2] in the 25mg- and 50mg-Flex groups) and remained almost constant thereafter. No unexpected neurological or psychiatric adverse events occurred, and no adverse events increased in incidence in the open-label period. CONCLUSIONS: Long-term treatment with zonisamide was well tolerated and yielded sustained improvement in motor symptoms. TRIAL REGISTRATION: JapicCTI-152839 (Registered on 9 March 2015) https://www.clinicaltrials.jp/cti-user/trial/ShowDirect.jsp?japicId=JapicCTI-152839.