Salivary levels of disease-related biomarkers in the early stages of Parkinson's and Alzheimer's disease: A cross-sectional study

Introduction

Finding a non-invasive and repeatable tool has been recommended to make an accurate diagnosis of Alzheimer's disease (AD) and Parkinson's disease (PD).

Methods

70 volunteers participated in three groups: 24 with mild dementia of AD, 24 in the first and second stages of PD, and 22 healthy controls. After valuing the scores of cognitive tests, the salivary levels of phosphorylated tau (p-tau), total alpha-synuclein (α-syn), and beta-amyloid 1-42 (Aβ)‏‎ proteins have been evaluated. Finally, the cutoff points, receiver operating characteristic (ROC), sensitivity, and specificity have been calculated to find accurate and detectable biomarkers.

Results

Findings showed that the salivary level of Aβ was higher in both PD (p < 0.01) and AD (p < 0.001) patients than in controls. Moreover, the level of α-syn in both PD and AD patients was similarly lower than in controls (p < 0.05). However, the level of p-tau was only ‎higher in the AD group than in the control (p < 0.01). Salivary Aβ 1-42 level at a 60.3 pg/ml cutoff point revealed an excellent performance for diagnosing AD (AUC: 0.81).

Conclusion

Evaluation of p-tau, α-syn, and Aβ 1-42 levels in the saliva of AD and PD patients could help the early diagnosis. The p-tau level might be valuable for differentiation between AD and PD. Therefore, these hopeful investigations could be done to reduce the usage of invasive diagnostic methods, which alone is a success in alleviating the suffering of AD and PD patients. Moreover, introducing accurate salivary biomarkers according to the pathophysiology of AD and PD should be encouraged.

Intrasession Repeatability of OCT Angiography Parameters in Neurodegenerative Disease

Purpose

To assess the intrasession repeatability of macular OCT angiography (OCTA) parameters in Alzheimer's disease (AD), mild cognitive impairment (MCI), Parkinson's disease (PD), and normal cognition (NC).

Design

Cross sectional study.

Subjects

Patients with a clinical diagnosis of AD, PD, MCI, or NC were imaged. Images with poor quality and of those with diabetes mellitus, glaucoma, or vitreoretinal disease were excluded from analysis.

Methods Intervention or Testing

All participants were imaged using the Zeiss Cirrus HD-5000 with AngioPlex (Carl Zeiss Meditec, Software Version 11.0.0.29946) and repeat OCTA images were obtained for both eyes. Perfusion density (PFD), vessel density (VD), and Foveal avascular zone (FAZ) area were measured from 3 × 3 mm and 6 × 6 mm OCTA images centered on the fovea using an ETDRS grid overlay.

Main Outcome Measures

Intraclass correlation coefficients were used to quantify repeatability of PFD, VD, and FAZ area measurements obtained from imaging.

Results

3 × 3 mm scans of 22 AD, 40 MCI, 21 PD, and 26 NC participants and 6 × 6 mm scans of 29 AD, 44 MCI, 29 PD, and 30 NC participants were analyzed. Repeatability values ranged from 0.64 (0.49-0.82) for 6 × 6 mm PFD in AD participants to 0.87 (0.67-0.92) for 3 × 3 mm PFD in AD participants. No significant differences were observed in repeatability between NC participants and those with neurodegenerative disease.

Conclusions

Overall, similar OCTA repeatability was observed between NC participants and those with neurodegeneration. Regardless of diagnostic group, macular OCTA metrics demonstrated moderate to good repeatability.

Financial Disclosures

The authors have no proprietary or commercial interest in any materials discussed in this article.

Electroacupuncture for motor dysfunction and constipation in patients with Parkinson's disease: a randomised controlled multi-centre trial

BACKGROUND

Motor disturbances and non-motor disturbances such as constipation are the main factors affecting the quality of life in patients with Parkinson's disease (PD). We investigated the efficacy and safety of electroacupuncture combined with conventional pharmacological treatment on motor dysfunction and constipation in PD.

METHODS

In this multi-centre randomised controlled trial, we enrolled 166 eligible participants between September 19, 2018 and September 25, 2019 in four hospitals in China. Participants were randomly assigned (1:1) to the electroacupuncture (EA) group and the waitlist control group. Each participant in both groups received the conventional pharmacological treatment, EA group received 3 sessions of electroacupuncture per week for 12 weeks. The primary outcome was the change in the Unified Parkinson's Disease Rating Scale (UPDRS) score from baseline to week 12. The secondary outcomes included the evaluation of functional disability in motor symptoms and constipation, the adherence and adverse events were also recorded. Registered with Chictr.org.cn, ChiCTR1800019517.

FINDINGS

At week 12, the change in the UPDRS score of the EA group was significantly higher than that of the control group, with a difference of -9.1 points (95% CI, -11.8 to -6.4), and this difference continued into weeks 16 and 24. From baseline to week 12, the 39-item Parkinson Disease Question (PDQ-39) decreased by 10 points (interquartile range, IQR -26.0 to 0.0) in the EA group and 2.5 points (IQR: -11.0 to 4.0) in the control group, the difference was statistically significant. The time and steps for the 20-m walk at week 12, as well as the changes from baseline in the EA group, were comparable with that in the control group. But the EA group had a greater decrease than the control group from baseline in the times for 20-m walks at weeks 16 and 24. From week 4 to week 24, the median values of spontaneous bowel movements (SBMs) per week in the EA group were higher than that in the control group, the differences were all statistically significant. The incidence of EA-related adverse events during treatment was low, and they are mild and transient.

INTERPRETATION

The findings of our study suggested that compared with conventional pharmacological treatment, conventional pharmacological treatment combined with electroacupuncture significantly enhances motor function and increased bowel movements in patients with PD, electroacupuncture is a safe and effective treatment for PD.

FUNDING

Shanghai "Science and Technology Innovation Action Plan" Clinical Medicine Field Project (18401970700), Shanghai Special Project on Aging and Women's and Children's Health Research (020YJZX0134), Shanghai Clinical Research Centre for Acupuncture and Moxibustion (20MC1920500).

Association between C-reactive protein-albumin ratio and overall survival in Parkinson's disease using publicly available data: A retrospective cohort study

Background

At present, many studies have confirmed that inflammation plays a central role in Parkinson's disease (PD). The inflammatory index is related to the prognosis of the disease, but a single inflammatory index has some limitations. The C-reactive protein-albumin ratio (CAR) is a better marker of inflammation or nutritional status than C-reactive protein (CRP) or albumin (Alb), but there is limited study on the association between CAR and the overall survival (OS) of PD.

Object

To study the association between CAR and OS in PD patients.

Methods

All of these data were obtained from the Dryad Digital Repository, based on which we conducted a secondary analysis. The study was conducted by the Department of Neurology, the National Regional Center for Neurological Disorders, and the National Hospital of Utano study between March 2004 to November 2007. The final analytic sample included 235 PD patients with the outcome of survival or all-cause death from the study registration to the endpoint. In this study, univariate and multivariate COX regression analyses were used to calculate the adjusted hazard ratio (HR), with a 95% confidence interval (CI). In addition, the association between CAR and OS in PD patients was explored by Kaplan-Meier curve and subgroup analysis.

Results

This study included 235 PD patients with an average age of 62.25 years, including 135 females and 100 males, and 45 died during the follow-up period. CAR was associated with gender, modified Hoehn-Yahr stages (mH-Y), and Mini-Mental State Examination (MMSE) of PD patients. In the COX multivariate regression model, after adjusting the age, gender, PD duration, mH-Y, MMSE, and the non-steroidal anti-inflammatory drugs, CAR was found to be associated with the OS in PD (HR = 1.54, 95% CI = 1.01-2.34, p = 0.044). Subgroup analysis showed that the subgroup did not play an interactive role in the association between the prognosis of patients with CAR and PD (p for interaction >0.05), and the results remained stable.

Conclusions

The all-cause mortality of PD patients with a high level of CAR is higher, which indicates that the poor overall survival of PD patients is associated with the increase of CAR. The CAR may be a reliable prognostic biomarker for PD patients.

Bridging potential of Taurine-loading PCL conduits transplanted with hEnSCs on resected sciatic nerves

Reconstruction of nerve conduits is a promising method for functional improvement in peripheral nerve repair. Besides choosing of a suitable polymer for conduit construction, adding factors such as Taurine improve a more advantageous microenvironment for defect nerve regeneration. Showing several major biological properties of Taurine, for example, regulation of the osmotic pressure, modulation of neurogenesis, and calcium hemostasis, makes it an appropriate option for repairing of defected nerves. To this, we examined repairing effects of Taurine-loading PCL conduits cultured with human endothelial stem cells (hEnSCs) on resected sciatic nerves. PCL/Taurine/Cell conduits transplanted to a 10-mm sciatic nerve gap. Forty-two wistar rats were randomly divided to seven groups: (1) Normal group, (2) Negative control (NC), (3) Positive control (nerve Autograft group), (4) PCL conduits group (PCL), (5) Taurine loaded PCL conduits group (PCL/Taurine), (6) hEnSCs cultured on the PCL conduits (PCL/Cell), (7) hEnSCs cultured on the PCL/Taurine conduits (PCL/Taurine/Cell). Functional recovery of motor and sensory nerves, the action potential of exciting muscle and motor distal latency has seen in PCL/Taurine/Cell conduits. Histological studies showed also remarkable nerve regeneration and obvious bridging has seen in this group. In conclusion, PCL/Taurine/Cell conduits showing suitable mechanical properties and biocompatibility may improve sciatic nerve regeneration.

An opinion on the debatable function of brain resident immune protein, T-cell receptor beta subunit in the central nervous system

In recent years scientific research has established that the nervous and immune systems have shared molecular signaling components. Proteins native to immune cells, which are also found in the brain, have neuronal functions in the nervous system where they affect synaptic plasticity, axonal regeneration, neurogenesis, and neurotransmission. Certain native immune molecules like major histocompatibility complex I (MHC-I), paired immunoglobulin receptor B (PirB), toll-like receptor (TLR), cluster of differentiation-3 zeta (CD3ζ), CD4 co-receptor, and T-cell receptor beta (TCR-β) expression in neurons have been extensively documented. In this review, we provide our opinion and discussed the possible roles of T-cell receptor beta subunits in modulating the function of neurons in the central nervous system. Based on the previous findings of Syken and Shatz., 2003; Nishiyori et al., 2004; Rodriguez et., 1993 and Komal et., 2014; we discuss whether restrictive expression of TCR-β subunits in selected brain regions could be involved in the pathology of neurological disorders and whether their aberrant enhancement in expression may be considered as a suitable biomarker for aging or neurodegenerative diseases like Huntington's disease (HD).

Unravelling the neuroprotective mechanisms of carotenes in differentiated human neural cells: Biochemical and proteomic approaches

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Total mixed carotenes (TMC) protect differentiated human neural cells against 6-hydroxydopamine-induced toxicity.

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TMC elevated the antioxidant enzymes activities and suppressed generation of reactive oxygen species.

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TMC augmented the dopamine and tyrosine hydroxylase levels.

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TMC exerted differential protein expression in human neural cells.

Carotenoids, fat-soluble pigments found ubiquitously in plants and fruits, have been reported to exert significant neuroprotective effects against free radicals. However, the neuroprotective effects of total mixed carotenes complex (TMC) derived from virgin crude palm oil have not been studied extensively. Therefore, the present study was designed to establish the neuroprotective role of TMC on differentiated human neural cells against 6-hydroxydopamine (6-OHDA)-induced cytotoxicity. The human neural cells were differentiated using retinoic acid for six days. Then, the differentiated neural cells were pre-treated for 24 hr with TMC before exposure to 6-OHDA. TMC pre-treated neurons showed significant alleviation of 6-OHDA-induced cytotoxicity as evidenced by enhanced activity of the superoxide dismutase (SOD) and catalase (CAT) enzymes. Furthermore, TMC elevated the levels of intra-neuronal dopamine and tyrosine hydroxylase (TH) in differentiated neural cells. The 6-OHDA induced overexpression of α-synuclein was significantly hindered in neural cells pre-treated with TMC. In proteomic analysis, TMC altered the expression of ribosomal proteins, α/β isotypes of tubulins, protein disulphide isomerases (PDI) and heat shock proteins (HSP) in differentiated human neural cells. The natural palm phytonutrient TMC is a potent antioxidant with significant neuroprotective effects against free radical-induced oxidative stress.

Spatio-temporal dynamics of large-scale electrophysiological networks during cognitive action control in healthy controls and Parkinson's disease patients

Among the cognitive symptoms that are associated with Parkinson's disease (PD), alterations in cognitive action control (CAC) are commonly reported in patients. CAC enables the suppression of an automatic action, in favor of a goal-directed one. The implementation of CAC is time-resolved and arguably associated with dynamic changes in functional brain networks. However, the electrophysiological functional networks involved, their dynamic changes, and how these changes are affected by PD, still remain unknown. In this study, to address this gap of knowledge, 10 PD patients and 10 healthy controls (HC) underwent a Simon task while high-density electroencephalography (HD-EEG) was recorded. Source-level dynamic connectivity matrices were estimated using the phase-locking value in the beta (12-25 Hz) and gamma (30-45 Hz) frequency bands. Temporal independent component analyses were used as a dimension reduction tool to isolate the task-related brain network states. Typical microstate metrics were quantified to investigate the presence of these states at the subject-level. Our results first confirmed that PD patients experienced difficulties in inhibiting automatic responses during the task. At the group-level, we found three functional network states in the beta band that involved fronto-temporal, temporo-cingulate and fronto-frontal connections with typical CAC-related prefrontal and cingulate nodes (e.g., inferior frontal cortex). The presence of these networks did not differ between PD patients and HC when analyzing microstates metrics, and no robust correlations with behavior were found. In the gamma band, five networks were found, including one fronto-temporal network that was identical to the one found in the beta band. These networks also included CAC-related nodes previously identified in different neuroimaging modalities. Similarly to the beta networks, no subject-level differences were found between PD patients and HC. Interestingly, in both frequency bands, the dominant network at the subject-level was never the one that was the most durably modulated by the task. Altogether, this study identified the dynamic functional brain networks observed during CAC, but did not highlight PD-related changes in these networks that might explain behavioral changes. Although other new methods might be needed to investigate the presence of task-related networks at the subject-level, this study still highlights that task-based dynamic functional connectivity is a promising approach in understanding the cognitive dysfunctions observed in PD and beyond.

Peripheral inflammatory cytokines and motor symptoms in persons with Parkinson's disease

Background

Many of the motor symptoms of Parkinson's disease (PD) impact quality of life and are not fully ameliorated by current pharmacological and surgical treatments. A better understanding of the pathophysiology underlying these symptoms is needed. Previous research has suggested that inflammation may play a significant role in PD pathophysiology and progression, but there is limited research exploring how inflammation directly relates to motor symptoms in PD. Thus, the purpose of this study was to evaluate associations between peripheral immune inflammatory markers and motor symptoms of PD, specifically, tremor, bradykinesia, and postural and gait instability. We hypothesized that peripheral inflammatory cytokines would predict the severity of motor symptoms in persons with PD, and that there will be higher levels of peripheral inflammatory cytokine markers in persons with PD when compared to age-matched healthy older adults.

Methods

Twenty-six participants with PD and fourteen healthy older adults completed the study. For participants with PD, the motor section of the Unified Parkinson's Disease Rating Scale (UPDRS) was recorded and scored by two Movement Disorders Neurologists masked to the study. A blood sample was collected from both participants with PD and the healthy older adults. Through the MILLIPLEX® map High Sensitivity Human Cytokine Kit, key inflammation-related markers were analyzed (TNF-α, IFN-γ, IL-1β, IL-8, IL-2, IL-7, IL-5, IL-13, IL, 4, IL-10 IL-12p70, GM-CSF, and IL-6).

Results

Results revealed significantly higher levels of IL-6 in persons with PD when compared to healthy older adults (p ​= ​0.005). Moreover, results revealed that higher levels of IL-4 (p ​= ​0.011) and lower levels of IFNγ (p ​= ​0.003) significantly predicted more severe tremor in persons with PD. No other associations between the peripheral inflammation markers and other motor symptoms were observed.

Conclusions

Overall, these results are consistent with a growing body of literature that implicates inflammatory cytokines in the PD, and further suggests that inflammatory cytokines, or lack thereof, may be associated with tremor in persons with PD.

Mitochondrial complex I as a therapeutic target for Alzheimer's disease

Alzheimer's disease (AD), the most prominent form of dementia in the elderly, has no cure. Strategies focused on the reduction of amyloid beta or hyperphosphorylated Tau protein have largely failed in clinical trials. Novel therapeutic targets and strategies are urgently needed. Emerging data suggest that in response to environmental stress, mitochondria initiate an integrated stress response (ISR) shown to be beneficial for healthy aging and neuroprotection. Here, we review data that implicate mitochondrial electron transport complexes involved in oxidative phosphorylation as a hub for small molecule-targeted therapeutics that could induce beneficial mitochondrial ISR. Specifically, partial inhibition of mitochondrial complex I has been exploited as a novel strategy for multiple human conditions, including AD, with several small molecules being tested in clinical trials. We discuss current understanding of the molecular mechanisms involved in this counterintuitive approach. Since this strategy has also been shown to enhance health and life span, the development of safe and efficacious complex I inhibitors could promote healthy aging, delaying the onset of age-related neurodegenerative diseases.

Zonisamide improves axial symptoms in dementia with Lewy bodies with parkinsonism: Post hoc analysis of clinical trials

Patients with dementia with Lewy bodies (DLB) experience worsening axial symptoms with disease progression, which can negatively affect quality of life. Previous phase 2 and 3 clinical trials conducted in Japan showed that zonisamide improved parkinsonism in patients with DLB. In the present study, we performed a post hoc analysis of pooled data from the previous phase 2 and 3 trials to examine the effect of zonisamide on axial symptoms in this patient group. In our pooled analysis, the primary outcome was the change from baseline to 12 weeks in axial symptom score, measured as the sum of Unified Parkinson's Disease Rating Scale Part III items relevant to gait/balance/midline function. A total of 498 patients were included in this analysis. Zonisamide 25 mg and 50 mg significantly reduced the axial symptom score at week 12 compared with placebo (p < 0.01 and p < 0.001, respectively, by mixed model of repeated measures). Our findings indicate that zonisamide may improve axial symptoms in DLB with parkinsonism and, thus, may potentially reduce the risk of falls and improve quality of life in this vulnerable patient population.

An introduction to therapeutic approaches to vascular cognitive impairment

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Vascular disease is a significant part of the clinical picture in common dementias.

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Multiple connections link vascular risk, vascular disease and cognitive impairment.

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This has inspired multiple therapeutic approaches, see this special issue.

Vascular cognitive impairment (VCI), encompassing vascular dementia, has been claimed as the “second-most common dementia” after Alzheimer Disease. Whether or not this is true, the clinical picture of most dementia in older people includes vascular disease. There are no validated pharmacological targets for prevention or treatment of VCI. This has inspired a multitude of potential treatment approaches, reflected by the articles in this Special Issue. These include in vitro testing of the novel oral anticoagulant dabigatran for protection against β-amyloid neurotoxicity, and an overview of neuroinflammation in VCI and the role of circulating markers (PIGF, VEGF-D) identified by the MarkVCID study. There are reviews of potential therapeutics, including adrenomedullin and nootropic preparations (exemplified by cerebrolysin). The role of sleep is reviewed, with possible therapeutic targets (5HT2A receptors). There is a clinical study protocol (INVESTIGATE-SVD) and a feasibility analysis for a secondary prevention trial in small vessel disease. Clinical data include secondary analyses of blood pressure and cerebral blood flow from a longitudinal clinical trial (NILVAD), differences between methylphenidate and galantamine responders and non-responders (STREAM-VCI), appraisal of treatment approaches in India, and primary outcomes from a randomised trial of Argentine tango dancing to preserve cognition in African American women (ACT). Treating vascular disease has great potential to improve global cognitive health, with public health impacts alongside individual benefit. Vascular disease burden varies across populations, offering the possibility of proactively addressing health inequity in dementia using vascular interventions. The next 5–10 years will witness cost-effective lifestyle interventions, repurposed drugs and novel therapeutics.

Association of visual impairment with risk for future Parkinson's disease

BACKGROUND

Although visual dysfunction is one of the most common non-motor symptoms among patients with Parkinson's disease (PD), it is not known whether visual impairment (VI) predates the onset of clinical PD. Therefore, we aim to examine the association of VI with the future development of PD in the UK Biobank Study.

METHODS

The UK Biobank Study is one of the largest cohort studies of health, enrolling over 500,000 participants aged 40-69 years between 2006 and 2010 across the UK. VI was defined as a habitual distance visual acuity (VA) worse than 0·3 logarithm of the minimum angle of resolution (LogMAR) in the better-seeing eye. Incident cases of PD were determined by self report data, hospital admission records or death records, whichever came first. Multivariable Cox proportional hazard regression models were used to investigate the association between VI and the risk of incident PD.

FINDINGS

A total of 117,050 participants were free of PD at the baseline assessment. During the median observation period of 5·96 (IQR: 5·77-6·23) years, PD occurred in 222 (0·19%) participants. Visually impaired participants were at a higher risk of developing PD than non-VI participants (p < 0·001). Compared with the non-VI group, the adjusted hazard ratio was 2·28 (95% CI 1·29-4·05, p = 0·005) in the VI group. These results were consistent in the sensitivity analysis, where incident PD cases diagnosed within one year after the baseline assessment were excluded.

INTERPRETATION

This cohort study found that VI was associated with an increased risk of incident PD, suggesting that VI may serve as a modifiable risk factor for prevention of future PD.

Circulatory 25(OH)D and 1,25(OH)2D as differential biomarkers between multiple system atrophy and Parkinson's disease patients

Background and purpose

There is sufficient evidence to support vitamin D's noncalcemic effects and the role of vitamin D deficiency in the development of a wide range of neurological disorders. This study aimed to evaluate whether serum 25(OH)D and 1,25(OH) 2 D could be used as biomarkers to differentiate between healthy subjects (HS), multiple system atrophy (MSA) and Parkinson's disease (PD) patients of both genders.

Methods

A total of 107 subjects were included in this study, divided into three groups: 1- HS (n = 61), 2- MSA patients (n = 19), and 3- PD patients (n = 27). The patients were assessed using UMSARS II, UPDRS III, H&Y, MMSE and MoCA rating scales. The levels of 25(OH)D and 1,25(OH) 2 D in serum were determined using the radioimmunoassay technique.

Results

The levels of 25(OH)D and 1,25(OH) 2 D in HS were 26.85 +/- 7.62 ng/mL and 53.63 +/- 13.66 pg/mL respectively. 25(OH)D levels were lower in both MSA and PD by 61% and 50%, respectively (P = 0.0001 vs. HS). 1,25(OH) 2 D levels were lower in MSA by 29%(P = 0.001 vs HS). There was a correlation between 25(OH)D and 1,25(OH) 2 D in MSA and PD, but not in HS. 1,25(OH) 2 D regressed with MMSE (β = 0.476, P = 0.04, R 2 = 0.226) in MSA, and with UPDRS III (β = -0.432, P = 0.024, R 2 = 0.187) and MoCA (β = 0.582, P = 0.005,R 2 = 0.279) in PD. 25(OH)D displayed considerable differentiative strength between HS and MSA (Wald = 17.123, OR = 0.586, P = 0.0001; AUC = 0.982, sensitivity and Youden index = 0.882, P = 0.0001) and PD (Wald = 18.552, OR = 0.700, P = 0.0001; AUC = 0.943, sensitivity = 0.889, YI = 0.791, P = 0.0001). 1,25(OH) 2 D distinguished MSA from PD (Wald 16.178, OR = 1.117, P = 0.0001; AUC = 0.868, sensitivity = 0.926, Youden index =0.632, P = 0.0001). H&Y exhibited the highest sensitivity, AUC, and significant distinguishing power between MSA and PD.

Conclusions

Serum 25(OH)D and 1,25(OH) 2 D could be useful biomarkers for MSA and PD. 25(OH)D and H&Y provided the highest sensitivity and group classification characteristics.

Targeting autophagy using small-molecule compounds to improve potential therapy of Parkinson's disease

Parkinson's disease (PD), known as one of the most universal neurodegenerative diseases, is a serious threat to the health of the elderly. The current treatment has been demonstrated to relieve symptoms, and the discovery of new small-molecule compounds has been regarded as a promising strategy. Of note, the homeostasis of the autolysosome pathway (ALP) is closely associated with PD, and impaired autophagy may cause the death of neurons and thereby accelerating the progress of PD. Thus, pharmacological targeting autophagy with small-molecule compounds has been drawn a rising attention so far. In this review, we focus on summarizing several autophagy-associated targets, such as AMPK, mTORC1, ULK1, IMPase, LRRK2, beclin-1, TFEB, GCase, ERRα, C-Abelson, and as well as their relevant small-molecule compounds in PD models, which will shed light on a clue on exploiting more potential targeted small-molecule drugs tracking PD treatment in the near future.

Novel compound FLZ alleviates rotenone-induced PD mouse model by suppressing TLR4/MyD88/NF-κB pathway through microbiota-gut-brain axis

Parkinson's disease (PD) is the second most common neurodegenerative disease, but none of the current treatments for PD can halt the progress of the disease due to the limited understanding of the pathogenesis. In PD development, the communication between the brain and the gastrointestinal system influenced by gut microbiota is known as microbiota-gut-brain axis. However, the explicit mechanisms of microbiota dysbiosis in PD development have not been well elucidated yet. FLZ, a novel squamosamide derivative, has been proved to be effective in many PD models and is undergoing the phase I clinical trial to treat PD in China. Moreover, our previous pharmacokinetic study revealed that gut microbiota could regulate the absorption of FLZ in vivo. The aims of our study were to assess the protective effects of FLZ treatment on PD and to further explore the underlying microbiota-related mechanisms of PD by using FLZ as a tool. In the current study, chronic oral administration of rotenone was utilized to induce a mouse model to mimic the pathological process of PD. Here we revealed that FLZ treatment alleviated gastrointestinal dysfunctions, motor symptoms, and dopaminergic neuron death in rotenone-challenged mice. 16S rRNA sequencing found that PD-related microbiota alterations induced by rotenone were reversed by FLZ treatment. Remarkably, FLZ administration attenuated intestinal inflammation and gut barrier destruction, which subsequently inhibited systemic inflammation. Eventually, FLZ treatment restored blood-brain barrier structure and suppressed neuroinflammation by inhibiting the activation of astrocytes and microglia in the substantia nigra (SN). Further mechanistic research demonstrated that FLZ treatment suppressed the TLR4/MyD88/NF-κB pathway both in the SN and colon. Collectively, FLZ treatment ameliorates microbiota dysbiosis to protect the PD model via inhibiting TLR4 pathway, which contributes to one of the underlying mechanisms beneath its neuroprotective effects. Our research also supports the importance of microbiota-gut-brain axis in PD pathogenesis, suggesting its potential role as a novel therapeutic target for PD treatment.

Evolution of blood-brain barrier in brain diseases and related systemic nanoscale brain-targeting drug delivery strategies

Blood–brain barrier (BBB) strictly controls matter exchange between blood and brain, and severely limits brain penetration of systemically administered drugs, resulting in ineffective drug therapy of brain diseases. However, during the onset and progression of brain diseases, BBB alterations evolve inevitably. In this review, we focus on nanoscale brain-targeting drug delivery strategies designed based on BBB evolutions and related applications in various brain diseases including Alzheimer's disease, Parkinson's disease, epilepsy, stroke, traumatic brain injury and brain tumor. The advances on optimization of small molecules for BBB crossing and non-systemic administration routes (e.g., intranasal treatment) for BBB bypassing are not included in this review.

Natural compounds modulate the autophagy with potential implication of stroke

Stroke is considered a leading cause of mortality and neurological disability, which puts a huge burden on individuals and the community. To date, effective therapy for stroke has been limited by its complex pathological mechanisms. Autophagy refers to an intracellular degrading process with the involvement of lysosomes. Autophagy plays a critical role in maintaining the homeostasis and survival of cells by eliminating damaged or non-essential cellular constituents. Increasing evidence support that autophagy protects neuronal cells from ischemic injury. However, under certain circumstances, autophagy activation induces cell death and aggravates ischemic brain injury. Diverse naturally derived compounds have been found to modulate autophagy and exert neuroprotection against stroke. In the present work, we have reviewed recent advances in naturally derived compounds that regulate autophagy and discussed their potential application in stroke treatment.

The influence of the gut microbiota on the bioavailability of oral drugs

Due to its safety, convenience, low cost and good compliance, oral administration attracts lots of attention. However, the efficacy of many oral drugs is limited to their unsatisfactory bioavailability in the gastrointestinal tract. One of the critical and most overlooked factors is the symbiotic gut microbiota that can modulate the bioavailability of oral drugs by participating in the biotransformation of oral drugs, influencing the drug transport process and altering some gastrointestinal properties. In this review, we summarized the existing research investigating the possible relationship between the gut microbiota and the bioavailability of oral drugs, which may provide great ideas and useful instructions for the design of novel drug delivery systems or the achievement of personalized medicine.

Freezing of saccades in dopa-responsive parkinsonian syndrome

Purpose

Ocular motor abnormalities such as abnormal saccades are common in idiopathic Parkinson's disease (PD) and atypical parkinsonian syndrome, such as progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD). In this study, we describe a case of patient with PD and show a video illustrating severe delay of reflexive saccades.

Observations

A 68-year-old Caucasian woman with diagnosis of PD presented for evaluation of diplopia. Neuro-ophthalmic examination revealed good visual acuity in both eyes and normal optic nerves but prominent ocular motor abnormalities, including hypometric saccades, impaired smooth pursuit, and convergence insufficiency causing diplopia at near. Despite treatment with carbidopa-levodopa three times per day, she exhibited episodic, severe delay of reflexive saccades. During these episodes, the patient appeared frozen and unable to initiate reflexive saccades for 20 s or longer. This freezing of reflexive saccades was variable and occurred suddenly during exam but could be interrupted by smooth pursuit. There was no gait freezing, eyelid apraxia, or prominent exacerbation of other motor symptoms. Freezing of saccades dramatically resolved after increasing dosage of carbidopa-levodopa.

Conclusions and Importance

We describe a patient with dopa-responsive parkinsonian syndrome with intermittent difficulty initiating reflexive saccades mimicking ocular motor apraxia. Resolution of saccadic freezing with higher carbidopa-levodopa is consistent with ocular motor impairment as a result of degeneration and dysfunction of the dopaminergic pathways in supranuclear ocular motor control.

Curcumin pre-treatment may protect against mitochondrial damage in LRRK2-mutant Parkinson's disease and healthy control fibroblasts

Mitochondrial dysfunction has been proposed as one of the pathobiological underpinnings in Parkinson's disease. Environmental stressors, such as paraquat, induce mitochondrial dysfunction and promote reactive oxygen species production. Targeting oxidative stress pathways could prevent mitochondrial dysfunction and thereby halt the neurodegeneration in Parkinson's disease. Since curcumin is touted as an antioxidant and neuroprotective agent, the aim of this study was to investigate if curcumin is a suitable therapy to target mitochondrial dysfunction in Parkinson's disease using a paraquat-toxicity induced model in fibroblasts from LRRK2-mutation positive Parkinson's disease individuals and healthy controls. The fibroblasts were exposed to five treatment groups, (i) untreated, (ii) curcumin only, (iii) paraquat only, (iv) pre-curcumin group: with curcumin for 2hr followed by paraquat for 24hr and (v) post-curcumin group: with paraquat for 24hr followed by curcumin for 2hr. Mitochondrial function was determined by measuring three parameters of mitochondrial respiration (maximal respiration, ATP-associated respiration, and spare respiratory capacity) using the Seahorse XF^e96 Extracellular Flux Analyzer. As expected, paraquat effectively disrupted mitochondrial function for all parameters. Pre-curcumin treatment improved maximal and ATP-associated respiration whereas, post-curcumin treatment had no effect. These findings indicate that curcumin may be most beneficial as a pre-treatment before toxin exposure, which has implications for its therapeutic use. These promising findings warrant future studies testing different curcumin dosages, exposure times and curcumin formulations in larger sample sizes of Parkinson's disease and control participants.

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Paraquat reduced respiration in Parkinson's disease and control fibroblasts.

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Curcumin, an antioxidant, improved mitochondrial respiration, as a pre-treatment.

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Post-treatment with curcumin did not improve mitochondrial respiration.

Long non-coding RNAs: From disease code to drug role

Enormous studies have corroborated that long non-coding RNAs (lncRNAs) extensively participate in crucial physiological processes such as metabolism and immunity, and are closely related to the occurrence and development of tumors, cardiovascular diseases, nervous system disorders, nephropathy, and other diseases. The application of lncRNAs as biomarkers or intervention targets can provide new insights into the diagnosis and treatment of diseases. This paper has focused on the emerging research into lncRNAs as pharmacological targets and has reviewed the transition of lncRNAs from the role of disease coding to acting as drug candidates, including the current status and progress in preclinical research. Cutting-edge strategies for lncRNA modulation have been summarized, including the sources of lncRNA-related drugs, such as genetic technology and small-molecule compounds, and related delivery methods. The current progress of clinical trials of lncRNA-targeting drugs is also discussed. This information will form a latest updated reference for research and development of lncRNA-based drugs.

Recent developments on PET radiotracers for TSPO and their applications in neuroimaging

The 18 kDa translocator protein (TSPO), previously known as the peripheral benzodiazepine receptor, is predominately localized to the outer mitochondrial membrane in steroidogenic cells. Brain TSPO expression is relatively low under physiological conditions, but is upregulated in response to glial cell activation. As the primary index of neuroinflammation, TSPO is implicated in the pathogenesis and progression of numerous neuropsychiatric disorders and neurodegenerative diseases, including Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), Parkinson's disease (PD), multiple sclerosis (MS), major depressive disorder (MDD) and obsessive compulsive disorder (OCD). In this context, numerous TSPO-targeted positron emission tomography (PET) tracers have been developed. Among them, several radioligands have advanced to clinical research studies. In this review, we will overview the recent development of TSPO PET tracers, focusing on the radioligand design, radioisotope labeling, pharmacokinetics, and PET imaging evaluation. Additionally, we will consider current limitations, as well as translational potential for future application of TSPO radiopharmaceuticals. This review aims to not only present the challenges in current TSPO PET imaging, but to also provide a new perspective on TSPO targeted PET tracer discovery efforts. Addressing these challenges will facilitate the translation of TSPO in clinical studies of neuroinflammation associated with central nervous system diseases.

Kynurenine pathway in Parkinson's disease-An update

Parkinson's disease (PD) is a complex multi-factorial neurodegenerative disorder where various altered metabolic pathways contribute to the progression of the disease. Tryptophan (TRP) is a major precursor in kynurenine pathway (KP) and it has been discussed in various in vitro studies that the metabolites quinolinic acid (QUIN) causes neurotoxicity and kynurenic acid (KYNA) acts as neuroprotectant respectively. More studies are also focused on the effects of other KP metabolites and its enzymes as it has an association with ageing and PD pathogenesis. Until now, very few studies have targeted the role of genetic mutations in abnormal KP metabolism in adverse conditions of PD. Therefore, the present review gives an updated research studies on KP in connection with PD. Moreover, the review emphasizes on the urge for the development of biomarkers and also this would be an initiative in generating an alternative therapeutic approach for PD.

Recent advances in screening active components from natural products based on bioaffinity techniques

Natural products have provided numerous lead compounds for drug discovery. However, the traditional analytical methods cannot detect most of these active components, especially at their usual low concentrations, from complex natural products. Herein, we reviewed the recent technological advances (2015–2019) related to the separation and screening bioactive components from natural resources, especially the emerging screening methods based on the bioaffinity techniques, including biological chromatography, affinity electrophoresis, affinity mass spectroscopy, and the latest magnetic and optical methods. These screening methods are uniquely advanced compared to other traditional methods, and they can fish out the active components from complex natural products because of the affinity between target and components, without tedious separation works. Therefore, these new tools can reduce the time and cost of the drug discovery process and accelerate the development of more effective and better-targeted therapeutic agents.

Tumor necrosis factor receptor-associated factor 6 interaction with alpha-synuclein enhances cell death through the Nuclear Factor-kB pathway

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TRAF6 binds to both WT and the mutant form A30 P asyn in SH-SY5Y cell model.

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The activation of NF-κB leads to changes in cytokines levels induced by TRAF6 - WT asyn interaction decreasing cell viability.

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The interaction between TRAF6 and A30P asyn does not induce NF-κB activation and cytokine regulation in SH-SY5Y cells.

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The present work demonstrates a novel role of TRAF6 in the pathophysiology of Parkinson's disease.

Background

Parkinson's disease (PD) is a neurodegenerative disease characterized by intracellular inclusions named Lewy bodies (LB), and alpha-synuclein (asyn) is the major component of these protein aggregates. The precise physiological and pathological roles of asyn are not fully understood. Nevertheless, asyn present in LB is ubiquitinated but fails to reach the 26S proteasome. The mutation A30 P is related to an aggressive and early-onset form of PD. Tumor necrosis factor receptor-associated factor 6 (TRAF6) is an E3 ubiquitin ligase, and it interacts and ubiquitinates the asyn in atypical chains (lysine K6, K27, K29, and K33). Methods: Here, we investigated the role of TRAF6 interaction with asyn and the involvement of nuclear factor κB (NF-κB), a key transcription factor in pro-inflammatory signaling pathway activation.

Results and Conclusion

We demonstrated that TRAF6 binds to both WT and the mutant form A30 P asyn in an SH-SY5Y cell model. Additionally, the interaction between TRAF6 and WT asyn induced an increase in the activation of NF-κB, leading to changes in TNF, IL-1β and IL-10 levels and culminating in reduced cell viability. Interestingly, the activation of NF-κB and gene regulation were not found in A30 P asyn. These data point to a novel role of TRAF6 in the pathophysiology of PD.

Altered visual functions, macular ganglion cell and papillary retinal nerve fiber layer thickness in early-treated adult PKU patients

Purpose

Retinal changes are poorly described in early treated phenylketonuria (ETPKU). We aimed to investigate possible visual functional and ocular microstructural changes in adult patients with ETPKU. Optical coherence tomography (OCT) and its angiography (OCTA) data from patients with PKU were compared to healthy controls.

Methods

In this prospective, monocentric, cross-sectional, case-control study 50 patients with ETPKU and 50 healthy subjects were evaluated with OCT and OCTA. Measurements were performed on right eyes. The following visual function parameters were studied: best corrected visual acuity (BCVA), spherical equivalent (SE), contrast sensitivity and near stereoacuity; microstructural parameters: retinal nerve fiber layer thickness (RNFLT), ganglion cell layer (GCC) thickness, focal loss of volume (FLV), global loss of volume (GLV), peripapillary, papillary vessel density (VD), ocular axial length (AL) and intraocular pressure (IOP).

Results

Among functional tests there were significant differences in contrast sensitivity at 1.5 (p < 0.001), 6 (p < 0.013), 12 (p < 0.001), 18 (p < 0.003) cycles per degree, in near stereoacuity (Titmus Wirt circles, p < 0.001) and in best corrected visual acuity (BCVA, p < 0.001). A statistically significant, moderate positive linear correlation was observed between BCVA and average Phe levels over the last ten years (β = 0.49, p < 0.001). The average (p < 0.001), superior (p < 0.001) inferior GCC (p < 0.001), the FLV (p < 0.003), GLV (p < 0.001) and the average RNFLT (p < 0.004) values of the PKU group were significantly lower than the controls. The serum phenylalanine level (Phe) in the PKU group negatively correlated with inferior (−0.32, p < 0.007), superior (r = −0.26, p < 0.028) and average (−0.29 p < 0.014) RNFL and with AL (−0.32, p < 0.026). In AL we detected a significant difference (p < 0.04) between the good and suboptimal dietary controlled group. There was no significant difference between the ETPKU and control group in the measured vessel density parameters and in IOP.

Conclusions

Our results suggest that functional and ocular microstructural defects are present in patients with PKU, and some of them may depend on dietary control. The mechanism is unclear, but the correlation indicates the importance of strict dietary control in terms of preservation of retinal functions.

Prescription pattern of anti-Parkinson's disease drugs in Japan based on a nationwide medical claims database

Introduction

Parkinson's disease (PD) treatment should follow guidelines and be tailored to each patient. Large database analyses can provide insights into prescribing patterns.

Methods

Retrospective, cross-sectional study of patients (≥30 years) with PD diagnosis (ICD-10; schizophrenia/cerebrovascular disease excluded) using health insurance claims data (April 2008-December 2016) from the Japan Medical Data Vision database. Prescription patterns of anti-PD drugs were analysed by patient age and sex, calendar year, and overall.

Results

The analysis comprised 155,493 PD patient-years (56.1% women, mean 73.4 years). Patient number increased each year, mainly because of database expansion. L-dopa as monotherapy was the most common prescription (22.7% of patient-years); non-ergot dopamine agonists (DAs) were also common (7.6% as monotherapy, 6.8% with L-dopa). Monotherapy was prescribed for ~50% of patient-years, two drugs for 14.1%, and at least three drugs for 18.4%. Consistent with Japanese guidelines, L-dopa was mostly prescribed to older patients (≥60 years), whereas non-ergot DAs were mostly prescribed to middle-aged patients (peak at 50-69 years). Between 2008 and 2011, L-dopa prescription decreased while that of non-ergot DAs increased; this pattern reversed between 2012 and 2016.

Conclusion

These results indicate that Japanese clinicians are adhering to Japanese guidelines and tailoring anti-PD treatment to individual patients.

Gene therapy for neurodegenerative disorders: advances, insights and prospects

Gene therapy is rapidly emerging as a powerful therapeutic strategy for a wide range of neurodegenerative disorders, including Alzheimer's disease (AD), Parkinson's disease (PD) and Huntington's disease (HD). Some early clinical trials have failed to achieve satisfactory therapeutic effects. Efforts to enhance effectiveness are now concentrating on three major fields: identification of new vectors, novel therapeutic targets, and reliable of delivery routes for transgenes. These approaches are being assessed closely in preclinical and clinical trials, which may ultimately provide powerful treatments for patients. Here, we discuss advances and challenges of gene therapy for neurodegenerative disorders, highlighting promising technologies, targets, and future prospects.

Visual processing speed in freezing and non-freezing Parkinson's disease patients

Introduction

Parkinson's disease patients are usually characterized by body motor dysfunction due to dopaminergic reduction in the central nervous system. Freezing of gait is a motor disorder that affects certain Parkinson's disease patients. However, it is hypothesized that non-motor functions mediated by the cholinergic system are also involved in developing freezing of gait. Visual information processing speed, or inspection time is independent of the motor response, and can be used a reliable measure of the cholinergic system integrity.

Objective

Inspection time can be used to investigate whether Parkinson's disease patients with freezing of gait symptoms have a larger impairment in cholinergic mediated functions than those patients who have no freezing of gait symptoms and healthy controls.

Methods

The inspection time was determined by a simple length discrimination task. Twenty-two Parkinson's disease patients with freezing of gait, 25 Parkinson's disease patients without freezing of gait, and 25 aged matched healthy controls participated in the study.

Results

Based on the log values of IT score, Parkinson's disease patients with freezing of gait symptoms had statistically significant slower inspection times (mean of 1.793 ms) than Parkinson's disease patients without freezing of gait (mean of 1.655 ms) and healthy controls (mean of 1.523 ms). Inspection times for the Parkinson's disease patients without FOG symptoms were also significantly slower than healthy controls.

Conclusion

The results of this study support the hypothesis that the cholinergic system integrity is affected more in Parkinson's disease patients with freezing of gait symptoms.

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Non-motor symptoms are associated with Parkinson’s disease patients.

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Inspection time can be used as a reliable tool to evaluate the integrity of the cholinergic system.

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Patients with Parkinson’s disease especially those who showed freezing of gait symptoms had longer inspection time score which suggest they have deficit in the cholinergic system.

Monoacylglycerol lipase inhibitors: modulators for lipid metabolism in cancer malignancy, neurological and metabolic disorders

Monoacylglycerol lipase (MAGL) is a serine hydrolase that plays a crucial role catalysing the hydrolysis of monoglycerides into glycerol and fatty acids. It links the endocannabinoid and eicosanoid systems together by degradation of the abundant endocannabinoid 2-arachidaoylglycerol into arachidonic acid, the precursor of prostaglandins and other inflammatory mediators. MAGL inhibitors have been considered as important agents in many therapeutic fields, including anti-nociceptive, anxiolytic, anti-inflammatory, and even anti-cancer. Currently, ABX-1431, a first-in-class inhibitor of MAGL, is entering clinical phase 2 studies for neurological disorders and other diseases. This review summarizes the diverse (patho)physiological roles of MAGL and will provide an overview on the development of MAGL inhibitors. Although a large number of MAGL inhibitors have been reported, novel inhibitors are still required, particularly reversible ones.

Targeting autophagy-related protein kinases for potential therapeutic purpose

Autophagy, defined as a scavenging process of protein aggregates and damaged organelles mediated by lysosomes, plays a significant role in the quality control of macromolecules and organelles. Since protein kinases are integral to the autophagy process, it is critically important to understand the role of kinases in autophagic regulation. At present, intervention of autophagic processes by small-molecule modulators targeting specific kinases has becoming a reasonable and prevalent strategy for treating several varieties of human disease, especially cancer. In this review, we describe the role of some autophagy-related kinase targets and kinase-mediated phosphorylation mechanisms in autophagy regulation. We also summarize the small-molecule kinase inhibitors/activators of these targets, highlighting the opportunities of these new therapeutic agents.

Biomimetic carbon nanotubes for neurological disease therapeutics as inherent medication

Nowadays, nanotechnology is revolutionizing the approaches to different fields from manufacture to health. Carbon nanotubes (CNTs) as promising candidates in nanomedicine have great potentials in developing novel entities for central nervous system pathologies, due to their excellent physicochemical properties and ability to interface with neurons and neuronal circuits. However, most of the studies mainly focused on the drug delivery and bioimaging applications of CNTs, while neglect their application prospects as therapeutic drugs themselves. At present, the relevant reviews are not available yet. Herein we summarized the latest advances on the biomedical and therapeutic applications of CNTs in vitro and in vivo for neurological diseases treatments as inherent therapeutic drugs. The biological mechanisms of CNTs-mediated bio-medical effects and potential toxicity of CNTs were also intensely discussed. It is expected that CNTs will exploit further neurological applications on disease therapy in the near future.

The gut microbiome: an orchestrator of xenobiotic metabolism

Microbes inhabiting the intestinal tract of humans represent a site for xenobiotic metabolism. The gut microbiome, the collection of microorganisms in the gastrointestinal tract, can alter the metabolic outcome of pharmaceuticals, environmental toxicants, and heavy metals, thereby changing their pharmacokinetics. Direct chemical modification of xenobiotics by the gut microbiome, either through the intestinal tract or re-entering the gut via enterohepatic circulation, can lead to increased metabolism or bioactivation, depending on the enzymatic activity within the microbial niche. Unique enzymes encoded within the microbiome include those that reverse the modifications imparted by host detoxification pathways. Additionally, the microbiome can limit xenobiotic absorption in the small intestine by increasing the expression of cell-cell adhesion proteins, supporting the protective mucosal layer, and/or directly sequestering chemicals. Lastly, host gene expression is regulated by the microbiome, including CYP450s, multi-drug resistance proteins, and the transcription factors that regulate them. While the microbiome affects the host and pharmacokinetics of the xenobiotic, xenobiotics can also influence the viability and metabolism of the microbiome. Our understanding of the complex interconnectedness between host, microbiome, and metabolism will advance with new modeling systems, technology development and refinement, and mechanistic studies focused on the contribution of human and microbial metabolism.

Parkinsonism and neurosarcoidosis: Cause and effect or coincidence?

Movement disorders in demyelinating diseases can be coincidental or secondary to a demyelinating lesion. We here report the first case of coincidental association of neurosarcoidosis and idiopathic Parkinson's disease.

Chronic unpredictable stress influenced the behavioral but not the neurodegenerative impact of paraquat

The impact of psychological stressors on the progression of motor and non-motor disturbances observed in Parkinson's disease (PD) has received little attention. Given that PD likely results from many different environmental “hits”, we were interested in whether a chronic unpredictable stressor regimen would act additively or possibly even synergistically to augment the impact of the toxicant, paraquat, which has previously been linked to PD. Our findings support the contention that paraquat itself acted as a systemic stressor, with the pesticide increasing plasma corticosterone, as well as altering glucocorticoid receptor (GR) expression in the hippocampus. Furthermore, stressed mice that also received paraquat displayed synergistic motor coordination impairment on a rotarod test and augmented signs of anhedonia (sucrose preference test). The individual stressor and paraquat treatments also caused a range of non-motor (e.g. open field, Y and plus mazes) deficits, but there were no signs of an interaction (neither additive nor synergistic) between the insults. Similarly, paraquat caused the expected loss of substantia nigra dopamine neurons and microglial activation, but this effect was not further influenced by the chronic stressor. Taken together, these results indicate that paraquat has many effects comparable to that of a more traditional stressor and that at least some behavioral measures (i.e. sucrose preference and rotarod) are augmented by the combined pesticide and stress treatments. Thus, although psychological stressors might not necessarily increase the neurodegenerative effects of the toxicant exposure, they may promote co-morbid behaviors pathology.

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Paraquat induced behavioral and neurochemical alterations similar to those induced by a chronic unpredictable stressor.

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Chronic unpredictable stress did not influence the degeneration of midbrain dopamine neurons or microglia activation.

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The paraquat and chronic stressor exposure resulted in augmented motor impairment and anhedonic-like behavior.

Evaluation of iron deposition in brain basal ganglia of patients with Parkinson's disease using quantitative susceptibility mapping

Aim of the study

Parkinson's disease is associated with iron deposition in the brain. The QSM (quantitative susceptibility mapping) is more sensitive than T2-weighted imaging, T2* and R2. Few studies have been used QSM to evaluate the iron in the basal ganglia of patients with Parkinson's disease. Our aim was to evaluate the iron deposition in the basal ganglia using QSM and determination of diagnostic value of this method and evaluation of the association between disease stage with QSM and age with QSM in all nuclei, separately.

Materials and methods

Thirty patients were tested using Hoehn and Yahr test in three different stages. Fifteen healthy subjects were considered as control group. MRI sequences were performed using SIEMENS 3 T scanner.The Signal Processing in NMR software was used to process and analyze the images. The QSM in every of the basal ganglia was measured separately.

Results

There was a significant difference for QSM in the Subtania Nigera, Red Nucleus, Thalamic Nucleus and Globus Pallidus nucleus between two groups. The relationship between disease stage with QSM was significant in Subtania Nigera, Red Nucleus, and Globus Pallidus nucleus. The QSM values had a significant association with disease stage in all nuclei. The results showed that QSM has a higher accuracy in Subtania Nigera, Globus Pallidus, Red Nucleus and Thalamic Nucleus, respectively.

Conclusions

Using QSM in Red Nucleus, Subtania Nigera, and Globus Pallidus nuclei can help diagnosis and staging the patients with Parkinson's disease. In future, studies with emphasis on the disease stage can be helpful in evaluation the different parts of these three nuclei.

Computational Simulations Identified Two Candidate Inhibitors of Cdk5/p25 to Abrogate Tau-associated Neurological Disorders

Deregulation of Cdk5 is a hallmark in neurodegenerative diseases and its complex with p25 forms Cdk5/p25, thereby causes severe neuropathological insults. Cdk5/p25 abnormally phosphorylates tau protein, and induces tau-associated neurofibrillary tangles in neurological disorders. Therefore, the pharmacological inhibition of Cdk5/p25 alleviates tau-associated neurological disorders. Herein, computational simulations probed two candidate inhibitors of Cdk5/p25. Structure-based pharmacophore investigated the essential complementary chemical features of ATP-binding site of Cdk5 in complex with roscovitine. Resultant pharmacophore harbored polar interactions with Cys83 and Asp86 residues and non-polar interactions with Ile10, Phe80, and Lys133 residues of Cdk5. The chemical space of selected pharmacophore was comprised of two hydrogen bond donors, one hydrogen bond acceptor, and three hydrophobic features. Decoy test validation of pharmacophore obtained highest Guner-Henry score (0.88) and enrichment factor score (7.23). The screening of natural product drug-like databases by validated pharmacophore retrieved 1126 compounds as candidate inhibitors of Cdk5/p25. The docking of candidate inhibitors filtered 10 molecules with docking score >80.00 and established polar and non-polar interactions with the ATP-binding site residues of Cdk5/p25. Finally, molecular dynamics simulation and binding free energy analyses identified two candidate inhibitors of Cdk5/p25. During 30 ns simulation, the candidate inhibitors established <3.0 Å root mean square deviation and stable hydrogen bond interactions with the ATP-binding site residues of Cdk5/p25. The final candidate inhibitors obtained lowest binding free energies of -122.18 kJ/mol and - 117.26 kJ/mol with Cdk5/p25. Overall, we recommend two natural product candidate inhibitors to target the pharmacological inhibition of Cdk5/p25 in tau-associated neurological disorders.

Corticobasal syndrome in a man with Gaucher disease type 1: Expansion of the understanding of the neurological spectrum

Gaucher disease (GD) is an autosomal recessive condition that results from a deficiency of the enzyme β-glucocerebrosidase. The increased risk of primary parkinsonism symptoms among individuals affected with GD and carriers for the disorder is well-documented in the literature. However, these risks and case reports often reflect patients with classical Parkinson's disease (PD) symptoms. We report a patient with GD type 1 who was diagnosed with corticobasal syndrome (CBS), a clinical atypical parkinsonism diagnosis, in his sixth decade of life. Our case highlights the need to consider forms of atypical parkinsonism such as CBS in addition to PD in the differential diagnosis of cognitive and motor changes in patients with GD type 1. We also recommend careful assessment and routine monitoring of cognition, mood, behavior, sleep patterns, olfaction, and memory in patients with GD type 1 to identify early symptoms indicative of neurological involvement.

Pharmacokinetics and safety/efficacy of levodopa pro-drug ONO-2160/carbidopa for Parkinson's disease

We conducted a phase I study investigating the efficacy, safety, and tolerability of ONO-2160, a newly developed levodopa pro-drug, and carbidopa compared with levodopa and carbidopa to stabilize levodopa plasma concentration fluctuations in Japanese patients with Parkinson's disease. In an open-label two-period design, patients (n = 12) with Parkinson's disease received levodopa and carbidopa for 3 days before 7 days of treatment with ONO-2160 and carbidopa. Patients were primarily evaluated using the Unified Parkinson's Disease Rating Scale Part III, a Parkinson's disease symptom diary, and analysis of adverse events. Pharmacokinetic analysis of plasma levodopa concentration was also performed.

ONO-2160 and carbidopa therapy stabilized effective plasma levodopa concentration. No adverse events with safety concerns were observed. The combination of ONO-2160 and carbidopa produced a prolonged and stable plasma levodopa concentration with a reduction in Unified Parkinson's Disease Rating Scale Part III total scores. The combination was well tolerated, with no safety concerns, when administered to Japanese patients with Parkinson's disease.

Beta-band oscillations in the supplementary motor cortex are modulated by levodopa and associated with functional activity in the basal ganglia

We investigated the effect of acute levodopa administration on movement-related cortical oscillations and movement velocity in Parkinson's disease (PD). Patients with PD on and off medication and age- and sex-matched healthy controls performed a ballistic upper limb flexion movement as fast and accurately as possible while cortical oscillations were recorded with high-density electroencephalography. Patients off medication were also studied using task-based functional magnetic resonance imaging (fMRI) using a force control paradigm. Percent signal change of functional activity during the force control task was calculated for the putamen and subthalamic nucleus (STN) contralateral to the hand tested. We found that patients with PD off medication had an exaggerated movement-related beta-band (13–30 Hz) desynchronization in the supplementary motor area (SMA) compared to controls. In PD, spectral power in the beta-band was correlated with movement velocity. Following an acute dose of levodopa, we observed that the beta-band desynchronization in the SMA was reduced in PD, and was associated with increased movement velocity and increased voltage of agonist muscle activity. Further, using fMRI we found that the functional activity in the putamen and STN in the off medication state, was related to how responsive that cortical oscillations in the SMA of PD were to levodopa. Collectively, these findings provide the first direct evaluation of how movement-related cortical oscillations relate to movement velocity during the ballistic phase of movement in PD and demonstrate that functional brain activity in the basal ganglia pathways relate to the effects of dopaminergic medication on cortical neuronal oscillations during movement.

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Acute levodopa decreased beta-band desynchronization in the SMA, while improving movement velocity and muscle activity.

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Beta-band cortical activity during movement is positively correlated with upper limb movement velocity.

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fMRI in basal ganglia predicted the response of beta-band cortical activity to levodopa.

Bioactive constituents from cinnamon, hemp seed and polygonum cuspidatum protect against H2O2 but not rotenone toxicity in a cellular model of Parkinson's disease

Mitochondrial dysfunction and oxidative stress are two factors that are thought to contribute to the pathogenesis of Parkinson's disease (PD), a debilitating progressive neurodegenerative disorder that results in the loss of catecholamine producing cells throughout specific regions of the brain. In this study we aimed to compare the effects of hydrogen peroxide (H₂O₂) and rotenone (a pesticide and mitochondrial complex 1 inhibitor) on cell viability and the expression of tyrosine hydroxylase (TH) in a cellular model of PD. We also sought to investigate the potential neuroprotective benefits of bioactive constituents from cinnamon, hemp seed and polygonum cuspidatum. To create a model, SH-SY5Y cells transfected with human TH isoform 1 were treated with varying concentrations of H₂O₂ and rotenone, in the presence or absence of bioactive constituents. The effect of these toxins and constituents on cell viability, apoptosis and protein expression was assessed using MTT viability assays and western blotting. Rotenone treatment caused a significant decrease in cell viability but a significant increase in TH in the remaining cells. H₂O₂ treatment caused a significant decrease in cell viability but had no significant effect on TH expression. Curcumin, cinnamaldehyde, caffeoyltyramide (hemp seed extract) and piceatannol glucoside (polygonum cuspidatum extract) were unable to attenuate rotenone induced cell death, however they were able to provide protection against H₂O₂ induced cell death. This is the first study to demonstrate the neuroprotective properties of cinnamaldehyde, caffeoyltyramide and piceatannol glucoside in a dopaminergic cell line in response to H₂O₂.

[18F]fallypride characterization of striatal and extrastriatal D2/3 receptors in Parkinson's disease

Parkinson's disease (PD) is characterized by widespread degeneration of monoaminergic (especially dopaminergic) networks, manifesting with a number of both motor and non-motor symptoms. Regional alterations to dopamine D2/3 receptors in PD patients are documented in striatal and some extrastriatal areas, and medications that target D2/3 receptors can improve motor and non-motor symptoms. However, data regarding the combined pattern of D2/3 receptor binding in both striatal and extrastriatal regions in PD are limited. We studied 35 PD patients off-medication and 31 age- and sex-matched healthy controls (HCs) using PET imaging with [18F]fallypride, a high affinity D2/3 receptor ligand, to measure striatal and extrastriatal D2/3 nondisplaceable binding potential (BPND). PD patients completed PET imaging in the off medication state, and motor severity was concurrently assessed. Voxel-wise evaluation between groups revealed significant BPND reductions in PD patients in striatal and several extrastriatal regions, including the locus coeruleus and mesotemporal cortex. A region-of-interest (ROI) based approach quantified differences in dopamine D2/3 receptors, where reduced BPND was noted in the globus pallidus, caudate, amygdala, hippocampus, ventral midbrain, and thalamus of PD patients relative to HC subjects. Motor severity positively correlated with D2/3 receptor density in the putamen and globus pallidus. These findings support the hypothesis that abnormal D2/3 expression occurs in regions related to both the motor and non-motor symptoms of PD, including areas richly invested with noradrenergic neurons.

Impact of gender and genetics on emotion processing in Parkinson's disease - A multimodal study

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Understanding of the phenotypic heterogeneity of Parkinson's disease is needed.

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Gender and genetics determine manifestation and progression of Parkinson's disease.

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Altered emotion processing in Parkinson's disease is specific to male patients.

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This is influenced by endocrinal and genetic factors in both genders.

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This finding may impact the diagnosis and treatment of emerging clinical features.

Can suitable candidates for levodopa/carbidopa intestinal gel therapy be identified using current evidence?

Advanced Parkinson's disease (APD) is characterized by increased functional disability, caused by motor complications, the presence of axial symptoms, and emergent disease- and drug-related non-motor symptoms. One of the advanced therapies available is intrajejunal infusion of levodopa/carbidopa intestinal gel (LCIG); however, patient selection for this treatment is sometimes difficult, particularly because of overlapping indications with other alternatives. In recent years, strong evidence has supported the use of LCIG in treating motor fluctuations associated with APD, and several clinical studies provide emerging evidence for additional benefits of LCIG treatment in certain patients. This article provides an overview of the published literature on the benefits, limitations, and drawbacks of LCIG in relation to PD symptoms, the psychosocial impact of the disease, and the quality of life of patients, with the aim of determining candidates for whom treatment with LCIG would be beneficial. According to current evidence, patients with APD (defined as inability to achieve optimal control of the disease with conventional oral treatment), a relatively well-preserved cognitive-behavioral status, and good family/caregiver would count as suitable candidates for LCIG treatment. Contraindications in the opinion of the authors are severe dementia and active psychosis.

Challenges and trends in apomorphine drug delivery systems for the treatment of Parkinson's disease

Parkinson's disease (PD) is a chronic debilitating disease affecting approximately 1% of the population over the age of 60. The severity of PD is correlated to the degree of dopaminergic neuronal loss. Apomorphine has a similar chemical structure as the neurotransmitter dopamine and has been used for the treatment of advanced PD patients. In PD patients, apomorphine is normally administered subcutaneously with frequent injections because of the compound's extensive hepatic first-pass metabolism. There is, hence, a large unmet need for alternative administrative routes for apomorphine to improve patient compliance. The present review focuses on the research and development of alternative delivery of apomorphine, aiming to highlight the potential of non-invasive apomorphine therapy in PD, such as sublingual delivery and transdermal delivery.

Attenuated levels of phospholipids in the striatum of rats infused with rotenone causing hemiparkinsonism as detected by simple dye-lipid complex

Parkinson's disease (PD), a progressive neurodegeneration, is characterized by loss of dopaminergic neurons in the substantia nigra (SN) and loss of motor co-ordination. Impaired metabolism of major lipids such as phospholipids which play regulatory roles in cellular functions and signaling has been implicated in the pathology of PD. We aim to investigate the striatal phospholipids (PLs) in hemiparkinsonism infused by rotenone in rats. As there are no cost-effective modes of PL, we have utilized dye-lipid complex technique for the first time in PD models for screening and also for semi-quantifying (individually) the levels of the deregulated PL in brain samples. Rats were divided into 2 groups: i. control and ii. ROT-infused which received intracranial injection of Rotenone (6 μg/μl; flow rate 0.2 μl/min). At the end of experimental period of 14 days, the striatum was dissected out for the analyses of PLs. Dye-based detection of PL and two-dimensional thin-layer chromatographic analyses of PL were performed. Detection of dye-PL complex was possible for phosphatidyl choline (PC), phosphatidyl inositol (PI), and spingomyelin (SM) (but not for phosphatidyl ethanolamine-PE) using dyes viz victoria blue B, toluidine blue and ammonium ferrothiocyanate, respectively. Two-dimensional analyses of phospholipids confirmed the dye-PL complex and depicted significant reduction (p < 0.05) on semi-quantitative assessment, in the striatum of control and hemiparkinsonic rats. We suggest a low level of PLs esp of PI in striatum of rats using a simple dye-detection that was validated by HR-LCMS. The finding implies that a critical role is being played by these PLs (PC, PI and SM) mainly PI (p < 0.001), in rotenone infused hemiparkinsonism, thus deserving wider but simpler investigations to detect and identify their role in parkinsonism.

Connectome analysis with diffusion MRI in idiopathic Parkinson's disease: Evaluation using multi-shell, multi-tissue, constrained spherical deconvolution

Parkinson's disease (PD) is a progressive neurodegenerative disorder that affects extensive regions of the central nervous system. In this work, we evaluated the structural connectome of patients with PD, as mapped by diffusion-weighted MRI tractography and a multi-shell, multi-tissue (MSMT) constrained spherical deconvolution (CSD) method to increase the precision of tractography at tissue interfaces. The connectome was mapped with probabilistic MSMT-CSD in 21 patients with PD and in 21 age- and gender-matched controls. Mapping was also performed by deterministic single-shell, single tissue (SSST)-CSD tracking and probabilistic SSST-CSD tracking for comparison. A support vector machine was trained to predict diagnosis based on a linear combination of graph metrics. We showed that probabilistic MSMT-CSD could detect significantly reduced global strength, efficiency, clustering, and small-worldness, and increased global path length in patients with PD relative to healthy controls; by contrast, probabilistic SSST-CSD only detected the difference in global strength and small-worldness. In patients with PD, probabilistic MSMT-CSD also detected a significant reduction in local efficiency and detected clustering in the motor, frontal temporoparietal associative, limbic, basal ganglia, and thalamic areas. The network-based statistic identified a subnetwork of reduced connectivity by MSMT-CSD and probabilistic SSST-CSD in patients with PD, involving key components of the cortico–basal ganglia–thalamocortical network. Finally, probabilistic MSMT-CSD had superior diagnostic accuracy compared with conventional probabilistic SSST-CSD and deterministic SSST-CSD tracking. In conclusion, probabilistic MSMT-CSD detected a greater extent of connectome pathology in patients with PD, including those with cortico–basal ganglia–thalamocortical network disruptions. Connectome analysis based on probabilistic MSMT-CSD may be useful when evaluating the extent of white matter connectivity disruptions in PD.

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Connectomes mapped in Parkinson's disease (PD) using multi-shell tractography.

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Multi-shell tractography provided improved sensitivity to connectome pathology.

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Machine learning accurately predicted PD diagnosis based on connectome.

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Connectome pathology in PD was localized to basal ganglia-thalamocortical circuits.

The current agonists and positive allosteric modulators of α7 nAChR for CNS indications in clinical trials

The alpha-7 nicotinic acetylcholine receptor (α7 nAChR), consisting of homomeric α7 subunits, is a ligand-gated Ca²⁺-permeable ion channel implicated in cognition and neuropsychiatric disorders. Enhancement of α7 nAChR function is considered to be a potential therapeutic strategy aiming at ameliorating cognitive deficits of neuropsychiatric disorders such as Alzheimer's disease (AD) and schizophrenia. Currently, a number of α7 nAChR modulators have been reported and several of them have advanced into clinical trials. In this brief review, we outline recent progress made in understanding the role of the α7 nAChR in multiple neuropsychiatric disorders and the pharmacological effects of α7 nAChR modulators used in clinical trials.