Serum Butyrylcholinesterase Activity: A Biomarker for Parkinson's Disease and Related Dementia

Plasma proteomics identify biomarkers predicting Parkinson's disease up to 7 years before symptom onset

Parkinson's disease is increasingly prevalent. It progresses from the pre-motor stage (characterised by non-motor symptoms like REM sleep behaviour disorder), to the disabling motor stage. We need objective biomarkers for early/pre-motor disease stages to be able to intervene and slow the underlying neurodegenerative process. Here, we validate a targeted multiplexed mass spectrometry assay for blood samples from recently diagnosed motor Parkinson's patients (n = 99), pre-motor individuals with isolated REM sleep behaviour disorder (two cohorts: n = 18 and n = 54 longitudinally), and healthy controls (n = 36). Our machine-learning model accurately identifies all Parkinson patients and classifies 79% of the pre-motor individuals up to 7 years before motor onset by analysing the expression of eight proteins-Granulin precursor, Mannan-binding-lectin-serine-peptidase-2, Endoplasmatic-reticulum-chaperone-BiP, Prostaglaindin-H2-D-isomaerase, Interceullular-adhesion-molecule-1, Complement C3, Dickkopf-WNT-signalling pathway-inhibitor-3, and Plasma-protease-C1-inhibitor. Many of these biomarkers correlate with symptom severity. This specific blood panel indicates molecular events in early stages and could help identify at-risk participants for clinical trials aimed at slowing/preventing motor Parkinson's disease.

Near-infrared ratiometric fluorescent strategy for butyrylcholinesterase activity and its application in the detection of pesticide residue in food samples and biological imaging

Butyrylcholinesterase (BChE) is an essential esterase synthesized by the liver, and its level is considered as a vital index for health evaluation. Therefore, it is of great need to develop a highly sensitive and selective tool to monitor BChE activity, which remains a considerable challenge on account of its usage in complex biological systems. A near-infrared (NIR) fluorescent probe was elaborated in this work, employing cyanine backbone to provide the intrinsic NIR fluorescence and avoid interference from bioluminescence. There presented an intriguing structural transformation upon the sensing event to shrink the conjugation in this protocol, leading to an eye-catching fluorescence change from NIR (816 nm) to red (637 nm) region, which gave rise to the proposed ratiometric assay. After an overall investigation, this receptor was verified to be applicable in a wide bio-area with ratiometric pattern, including the cellular level and slice platform. It was worth mentioning that this receptor was also discovered to be capable of monitoring pesticide dichlorvos (DDVP) residue in food samples with high sensitivity and accuracy, with significant potential to be developed as an alternative candidate for monitoring environmental pollution.

Possible Signaling Pathways in the Gut Microbiota-Brain Axis for the Development of Parkinson's Disease Caused by Chronic Consumption of Food Additives

It is well-known that consumption of synthetic and natural food additives has both positive and negative effects in the human body. However, it is not clear yet how food additives are related to the development of Parkinson's disease. Therefore, in this review work, the food additive effects related to the gut microbiota-brain axis and the processes that are carried out to develop Parkinson's disease are studied. To this end, a systematic literature analysis is performed with the selected keywords and the food additive effects are studied to draw possible routes of action. This analysis leads to the proposition of a model that explains the pathways that relate the ingestion of food additives to the development of Parkinson's disease. This work motivates further research that ponders the safety of food additives by measuring their impacts over the gut microbiota-brain axis.

First report on the toxicity of SARS-CoV-2, alone and in combination with polyethylene microplastics in neotropical fish

The COVID-19 pandemic has caused unprecedented negative impacts in the modern era, including economic, social, and public health losses. On the other hand, the potential effects that the input of SARS-CoV-2 in the aquatic environment from sewage may represent on non-target organisms are not well known. In addition, it is not yet known whether the association of SARS-CoV-2 with other pollutants, such as microplastics (MPs), may further impact the aquatic biota. Thus, we aimed to evaluate the possible ecotoxicological effects of exposure of male adults Poecilia reticulata, for 15 days, to inactivated SARS-CoV-2 (0.742 pg/L; isolated SARS.CoV2/SP02.2020.HIAE.Br) and polyethylene MP (PE MPs) (7.1 × 10⁴ particles/L), alone and in combination, from multiple biomarkers. Our data suggest that exposure to SARS-CoV-2 induced behavioral changes (in the open field test), nephrotoxic effect (inferred by the increase in creatinine), hepatotoxic effect (inferred by the increase in bilirubin production), imbalance in the homeostasis of Fe, Ca, and Mg, as well as an anticholinesterase effect in the animals [marked by the reduction of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activity]. On the other hand, exposure to PE MPs induced a genotoxic effect (assessed by the comet assay), as well as an increase in enzyme activity alpha-amylase, alkaline phosphatase, and carboxylesterases. However, we did not show synergistic, antagonistic, or additive effects caused by the combined exposure of P. reticulata to SARS-CoV-2 and PE MPs. Principal component analysis (PCA) and values from the "Integrated Biomarker Response" index indicate that exposure to SARS-CoV-2 was determinant for a more prominent effect in the evaluated animals. Therefore, our study sheds light on the ecotoxicity of the new coronavirus in non-target organisms and ratifies the need for more attention to the impacts of COVID-19 on aquatic biota.

Liquid chromatography-mass spectrometry-based metabolomic profiling reveals sex differences of lipid metabolism among the elderly from Southwest China

BACKGROUND

The sexual dimorphism represents one of the triggers of the metabolic disparities while the identification of sex-specific metabolites in the elderly has not been achieved.

METHODS

A group of aged healthy population from Southwest China were recruited and clinical characteristics were collected. Fasting plasma samples were obtained and untargeted liquid chromatography-mass spectrometry-based metabolomic analyses were performed. Differentially expressed metabolites between males and females were identified from the metabolomic analysis and metabolite sets enrichment analysis was employed.

RESULTS

Sixteen males and fifteen females were finally enrolled. According to clinical characteristics, no significant differences can be found except for smoking history. There were thirty-six differentially expressed metabolites between different sexes, most of which were lipids and lipid-like molecules. Twenty-three metabolites of males were increased while thirteen were decreased compared with females. The top four classes of metabolites were fatty acids and conjugates (30.6%), glycerophosphocholines (22.2%), sphingomyelins (11.1%), and flavonoids (8.3%). Fatty acids and conjugates, glycerophosphocholines, and sphingomyelins were significantly enriched in metabolite sets enrichment analysis.

CONCLUSIONS

Significant lipid metabolic differences were found between males and females among the elderly. Fatty acids and conjugates, glycerophosphocholines, and sphingomyelins may partly account for sex differences and can be potential treatment targets for sex-specific diseases.

Dysregulation of butyrylcholinesterase, BCHE gene SNP rs1803274, and pro-inflammatory cytokines in occupational workers

BACKGROUND

People in different occupations are exposed to a variety of xenobiotics which affect the health and physiological processes of the body. Butyrylcholinesterase (BChE), has been reported to play neuronal and non-neuronal roles, though its exact function is yet to be established. This study aimed to find the status and role of BChE in seven different occupational groups; gasoline fillers, auto-mechanics, carpenters, textile shop workers, furniture shop workers, electricians, and office workers.

METHODS

A total of 400 samples were screened. BChE activity was determined by Worek et al. method based on Ellman's principle. Pro-inflammatory cytokines were determined by ELISA. Genotypic analysis of the K-variant of BCHE gene SNP was carried out by standard molecular methods. Among seven groups, office workers were taken as a control to compare the results with all other occupational groups.

RESULTS

The results revealed a significant decrease in BChE activity in gasoline fillers (79.52%) followed by carpenters (73.49%), auto mechanics (39.76%), textile shop workers (18.07%), electricians (10.84%), and furniture shop workers (7.23%). TNF-α, IL-6, and IL1-β were elevated in all groups. IL-6 and IL1-β in gasoline fillers, and electricians were not statistically significantly increased. Binomial regression to determine the odd ratio was found to be significant (p < 0.05) in all groups. However, correlation (Pearson) did not reveal significance between different biochemical parameters. Genotypic analysis of the K-variant SNP of the BCHE gene showed a significant association with occupational groups when compared with control which indicates a possible association with xenobiotics exposure and the physiological role of K-variant in understudied occupational groups.

CONCLUSION

The study concluded that BChE and its gene SNP rs 1803274 and proinflammatory cytokines significantly dysregulates under the exposure to cumulative multiple xenobiotics in different occupational groups which may lead to pathophysiological conditions.

Association between cholinesterase activity and critical illness brain dysfunction

BACKGROUND

Delirium is a frequent manifestation of acute brain dysfunction and is associated with cognitive impairment. The hypothesized mechanism of brain dysfunction during critical illness is centered on neuroinflammation, regulated in part by the cholinergic system. Point-of-care serum cholinesterase enzyme activity measurements serve as a real-time index of cholinergic activity. We hypothesized that cholinesterase activity during critical illness would be associated with delirium in the intensive care unit (ICU) and cognitive impairment after discharge.

METHODS

We enrolled adults with respiratory failure and/or shock and measured plasma acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activity on days 1, 3, 5, and 7 after enrollment. AChE values were also normalized per gram of hemoglobin (AChE/Hgb). We assessed for coma and delirium twice daily using the Richmond Agitation Sedation Scale and the Confusion Assessment Method for the ICU to evaluate daily mental status (delirium, coma, normal) and days alive without delirium or coma. Cognitive impairment, disability, and health-related quality of life were assessed at up to 6 months post-discharge. We used multivariable regression to determine whether AChE, AChE/Hgb, and BChE activity were associated with outcomes after adjusting for relevant covariates.

RESULTS

We included 272 critically ill patients who were a median (IQR) age 56 (39-67) years and had a median Sequential Organ Failure Assessment score at enrollment of 8 (5-11). Higher daily AChE levels were associated with increased odds of being delirious versus normal mental status on the same day (Odds Ratio [95% Confidence Interval] 1.64 [1.11, 2.43]; P = 0.045). AChE/Hgb and BChE activity levels were not associated with delirious mental status. Lower enrollment BChE was associated with fewer days alive without delirium or coma (P = 0.048). AChE, AChE/Hgb, and BChE levels were not significantly associated with cognitive impairment, disability, or quality of life after discharge.

CONCLUSION

Cholinesterase activity during critical illness is associated with delirium but not with outcomes after discharge, findings that may reflect mechanisms of acute brain organ dysfunction.

TRIAL REGISTRATION

NCT03098472. Registered 31 March 2017.

Mulberry leaves juice attenuates arsenic-induced neurobehavioral and hepatic disorders in mice

Arsenic (As) poisoning has caused an environmental catastrophe in Bangladesh as millions of people are exposed to As-contaminated drinking water. Chronic As-exposure causes depression, memory impairment, and liver injury in experimental animals. This study was carried out to assess the protective effect of mulberry leaves juice (Mul) against As-induced neurobehavioral and hepatic dysfunctions in Swiss albino mice. As-exposed mice spent significantly reduced time in open arms and increased time spent in closed arms in the elevated plus maze (EPM) test, whereas they took significantly longer time to find the hidden platform in the Morris water maze (MWM) test and spent significantly less time in the desired quadrant when compared to the control mice. A significant reduction in serum BChE activity, an indicator of As-induced neurotoxicity-associated behavioral changes, was noted in As-exposed mice compared to control mice. Supplementation of Mul to As-exposed mice significantly increased serum BChE activity, increased the time spent in open arms and reduced time latency to find the hidden platform, and stayed more time in the target quadrant in EPM and MWM tests, respectively, compared to As-exposed-only mice. Also, a significantly reduced activity of BChE, AChE, SOD, and GSH in brain, and elevated ALP, AST, and ALT activities in serum were noted in As-exposed mice when compared to control mice. Mul supplementation significantly restored the activity of these enzymes and also recovered As-induced alterations in hepatic tissue in As-exposed mice. In conclusion, this study suggested that mulberry leaves juice attenuates As-induced neurobehavioral and hepatic dysfunction in mice.

Global, in situ analysis of the structural proteome in individuals with Parkinson's disease to identify a new class of biomarker

Parkinson's disease (PD) is a prevalent neurodegenerative disease for which robust biomarkers are needed. Because protein structure reflects function, we tested whether global, in situ analysis of protein structural changes provides insight into PD pathophysiology and could inform a new concept of structural disease biomarkers. Using limited proteolysis-mass spectrometry (LiP-MS), we identified 76 structurally altered proteins in cerebrospinal fluid (CSF) of individuals with PD relative to healthy donors. These proteins were enriched in processes misregulated in PD, and some proteins also showed structural changes in PD brain samples. CSF protein structural information outperformed abundance information in discriminating between healthy participants and those with PD and improved the discriminatory performance of CSF measures of the hallmark PD protein α-synuclein. We also present the first analysis of inter-individual variability of a structural proteome in healthy individuals, identifying biophysical features of variable protein regions. Although independent validation is needed, our data suggest that global analyses of the human structural proteome will guide the development of novel structural biomarkers of disease and enable hypothesis generation about underlying disease processes.

Parental Lead Exposure Promotes Neurobehavioral Disorders and Hepatic Dysfunction in Mouse Offspring

Lead (Pb) induces neurotoxicity in both children and adults. Children are more vulnerable to Pb toxicity than adults. Little is known about the effects of Pb on the mental health of the children who are prenatally exposed. Therefore, we designed an animal experiment to compare the adverse effects of Pb on neurobehavioral and hepatic functions between Pb-exposed (Pb mice) and parental Pb-exposed (P-Pb mice) group mice. Mice were treated with Pb-acetate (10 mg/kg bodyweight/day) via drinking water. Male mice from unexposed parents treated with Pb for 90 days were defined as Pb mice, whereas male mice from Pb-exposed parents treated with Pb for further 90 days were defined as P-Pb mice. Anxiety-like behavior and spatial memory and learning were assessed by elevated plus maze and Morris water maze. Serum hepatic enzyme activities and butyrylcholinesterase activity were measured by an analyzer. P-Pb mice displayed increased anxiety-like behavior and memory and learning impairments compared to Pb mice. BChE activity was significantly decreased in P-Pb mice compared to Pb mice. Pb levels in the brains of P-Pb mice were significantly higher than those of Pb mice. The activities of serum hepatic enzymes of P-Pb mice were also higher than those of Pb mice. Additionally, histopathology data revealed that hepatic tissue injury was more pronounced in P-Pb mice than in Pb mice. Thus, the results suggest that persistent exposure to Pb from fetus to adult causes more severe neurobehavioral changes and hepatic toxicities than adult exposure only.

Lower Blood Lipid Level Is Associated with the Occurrence of Parkinson's Disease: A Meta-Analysis and Systematic Review

BACKGROUND

The changes of blood lipid levels in patients with Parkinson's disease (PD) and its clinical relevance remain unclear. We aimed to evaluate the potential association of blood lipid and the occurrence of PD, to provide evidence to the clinical treatment and nursing care of PD.

METHODS

We searched PubMed, Medline, Web of Science, Cochrane Library, Wanfang Database, Weipu Database, and China National Knowledge Infrastructure for studies related to the blood lipid levels and PD until November 30, 2021. Two researchers independently screened the literature and extricated the data including the levels of total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C). Newcastle-Ottawa Scale (NOS) was used to evaluate the quality of included studies. RevMan5.3 and Stata 12.0 software were used for statistical processing and analysis.

RESULTS

A total of 15 cohort studies with 9740 participants involving 2032 PD patients and 7708 controls were included. Meta-analysis indicated that TC (SMD = -0.29, 95% CI -0.55∼-0.03, P=0.04), TG (SMD = -16.83, 95% CI -20.71∼-12.95, P < 0.001), HDL-C (SMD = -0.14, 95% CI -0.26∼-0.02, P < 0.001) and LDL-C (SMD = -0.26, 95% CI -0.50∼-0.01, P=0.04) level in the PD patients was significantly lower than that of health controls. Sensitivity analysis indicated that the results were stable. No significant publication bias was found between the synthesized outcomes.

CONCLUSIONS

Lower blood TC, TG, HDL-C, and LDL-C level are associated with the occurrence of PD. Limited by sample size and study population, further high-quality, large-sample clinical trials in different areas are needed to further determine the relationship between blood lipids and PD in the future.

Salivary GFAP as a potential biomarker for diagnosis of mild cognitive impairment and Alzheimer's disease and its correlation with neuroinflammation and apoptosis

Glial fibrillary acidic protein (GFAP) is the main constituent of the astrocytic cytoskeleton, overexpressed during reactive astrogliosis-a hallmark of Alzheimer's Disease (AD). GFAP and established biomarkers of neurodegeneration, inflammation, and apoptosis have been determined in the saliva of amnestic-single-domain Mild Cognitive Impairment (MCI) (Ν = 20), AD (Ν = 20) patients, and cognitively healthy Controls (Ν = 20). Salivary GFAP levels were found significantly decreased in MCI and AD patients and were proven an excellent biomarker for discriminating Controls from MCI or AD patients. GFAP levels correlate with studied biomarkers and Aβ₄₂, IL-1β, and caspase-8 are its main predictors.

The disturbance of lipid metabolism is correlated with neuropsychiatric symptoms in patients with Parkinson's disease

OBJECTIVE

We aimed to identify the detailed relationships between serum lipid levels and neuropsychiatric symptoms in patients with Parkinson's disease (PD).

METHODS

Consecutive PD patients and healthy controls were recruited and demographic data were collected. The disease stages of PD patients were assessed using Hoehn-Yahr scale while neuropsychiatric symptoms were determined using Hamilton depression rating scale (HAMD), Hamilton anxiety rating scale (HAMA), and mini-mental state examination scale. Fast serum samples were obtained and the serum levels of lipids were identified. Linear regression analyses and correlation analyses were performed to explore the relationships between serum lipid levels and neuropsychiatric symptoms.

RESULTS

The serum levels of triglyceride had significantly decreased while the levels of HDL-c and lipoprotein a had increased in PD patients. Linear regression analyses confirmed that the levels of triglyceride were mainly correlated with age and HAMA score, the levels of HDL-c were correlated with disease duration and gender, and the levels of lipoprotein a were correlated with HAMD score. Correlation analyses further confirmed that the levels of triglyceride were negatively correlated with HAMA score when the levels of lipoprotein a were negatively correlated with HAMD score.

CONCLUSIONS

Lipid metabolism is significantly correlated with neuropsychiatric disorders in PD patients.

Cholinergic Modulation of the Immune System in Neuroinflammatory Diseases

Frequent diseases of the CNS, such as Alzheimer’s disease, Parkinson’s disease, multiple sclerosis, and psychiatric disorders (e.g., schizophrenia), elicit a neuroinflammatory response that contributes to the neurodegenerative disease process itself. The immune and nervous systems use the same mediators, receptors, and cells to regulate the immune and nervous systems as well as neuro-immune interactions. In various neurodegenerative diseases, peripheral inflammatory mediators and infiltrating immune cells from the periphery cause exacerbation to current injury in the brain. Acetylcholine (ACh) plays a crucial role in the peripheral and central nervous systems, in fact, other than cells of the CNS, the peripheral immune cells also possess a cholinergic system. The findings on peripheral cholinergic signaling, and the activation of the “cholinergic anti-inflammatory pathway” mediated by ACh binding to α7 nAChR as one of the possible mechanisms for controlling inflammation, have restarted interest in cholinergic-mediated pathological processes and in the new potential therapeutic target for neuro-inflammatory-degenerative diseases. Herein, we focus on recent progress in the modulatory mechanisms of the cholinergic anti-inflammatory pathway in neuroinflammatory diseases.

Serum lipids and the pathogenesis of Parkinson's disease: A systematic review and meta-analysis

BACKGROUND

The role of serum lipids in the pathogenesis of Parkinson's disease (PD) remains unclear, and the results of previous reports remain conflicting. We aimed to conduct this systematic review and meta-analysis to identify the potential relationships of blood lipids and the pathogenesis of PD.

METHODS

PubMed, Medline, Web of Science, Cochrane Library, and China National Knowledge Infrastructure (CNKI) databases were searched from inception to March 31, 2020, to identify potential studies with case-control or cohort study design on the relationship of serum lipids and PD. Stata 15.1 software was used for data syntheses after extraction of relevant data.

RESULTS

A total of 12 studies with 1506 PD patients and 7330 healthy controls were included. There were no significant differences in the TC (SMD = -0.08, 95% CI [-0.45, 0.33]), LDL-C (SMD = -0.12, 95% CI [-0.46, 0.18]), and TG (SMD = -0.05, 95% CI [-0.18, 0.06]) among PD patients and healthy controls. There was significant difference (SMD = -0.32, 95% CI [-0.42, -0.25]) in the TG level among PD patients and healthy controls. Subgroup analysis by Asian and non-Asian countries indicated that geographical location was not the source of heterogeneity. And no significant publication bias was found (all P > .05).

CONCLUSIONS

TG serum levels are significantly lower in PD patients, more studies are needed to further elucidate role of lipid in the PD development.

Lipid metabolic dysregulation is involved in Parkinson's disease dementia

Dementia is very common in the late stage of patient with Parkinson's disease (PD). We aim to explore its underlying pathogenesis and identify candidate biomarkers using untargeted metabolomics analysis. Consecutive PD patients and healthy controls were recruited. Clinical data were assessed and patients were categorized into Parkinson's disease without dementia (PDND) and Parkinson's disease dementia (PDD). Fast plasma samples were obtained and untargeted liquid chromatography-mass spectrometry-based metabolomics analysis was performed. Based on the identified differentially-expressed metabolites from the metabolomics analysis, multivariate linear regression analyses and receiver operating characteristic (ROC) curves were further employed. According to the clinical data, the mean ages of PDND and PDD patients were significantly higher than those of healthy controls. The incidence of hypercholesterolemia was decreased in PDD patients. PDD patients also had lower levels of triglyceride, low-density lipoprotein cholesterol, and apolipoprotein B. There were 24 and 57 differentially expressed metabolites in PDD patients when compared with the healthy controls and PDND patients from the metabolomics analysis. Eleven lipid metabolites were simultaneously decreased between these two groups, and can be further subcategorized into fatty acyls, glycerolipids, glycerophospholipids, sphingolipids, and prenol lipids. The plasma levels of the eleven metabolites were positively correlated with MMSE score and can be candidate biomarkers for PDD patients with areas under the curve ranging from 0.724 to 0.806 based on the ROC curves. Plasma lipoproteins are significantly lower in PDD patients. A panel of eleven lipid metabolites were also decreased and can be candidate biomarkers for the diagnosis of PDD patients. Lipid metabolic dysregulation is involved in the pathogenesis of Parkinson's disease dementia.

Metabolomics profiling reveals altered lipid metabolism and identifies a panel of lipid metabolites as biomarkers for Parkinson's disease related anxiety disorder

OBJECTIVES

Anxiety disorder is a common non-motor symptom in patient with Parkinson's disease (PD). We aimed to explore its pathogenesis and identify plasma biomarkers using untargeted metabolomics analysis.

METHODS

Consecutive PD patients and healthy controls were recruited. Clinical data were assessed and patients with Parkinson's disease related anxiety disorder (PDA) were recognized. Fast plasma samples were obtained and untargeted liquid chromatography-mass spectrometry-based metabolomics analysis was performed. Based on the differentially expressed metabolites from the above metabolomics analysis, correlation analyses and receiver operating characteristic curves (ROC) were further employed.

RESULTS

According to the clinical data, PDA patients had lower plasma levels of total cholesterol, triglyceride, low-density lipoprotein cholesterol, and apolipoprotein B. There were thirty-nine differentially expressed metabolites in PDA patients when compared with the other two groups from the metabolomics analysis, respectively. Fourteen lipid metabolites were simultaneously altered between these two groups, and all of them were significantly decreased. They can be further subcategorized into fatty acyls, glycerolipids, sterol lipids, sphingolipids, and prenol lipids. The plasma levels of thirteen metabolites were negatively correlated with HAMA scores except 10-oxo-nonadecanoic acid. Based on the ROC curves, the fourteen lipid metabolites can be diagnostic biomarkers for PDA patients separately and the areas under the curve of the fourteen lipid metabolites ranged from 0.681 to 0.798.

CONCLUSIONS

Significantly lower plasma lipoproteins can be found in PDA patients. A panel of fourteen lipid metabolites were also significantly decreased and can be clinical biomarkers for the diagnosis of PDA patients.

Dopaminergic System Alteration in Anxiety and Compulsive Disorders: A Systematic Review of Neuroimaging Studies

Objective: The dopaminergic system is involved in many psychiatric disorders as a GABAergic, serotonergic, and glutamatergic system. A systematic review and meta-analysis was performed to elucidate the alteration of the dopaminergic system in anxiety and compulsive disorders.

Methods: The databases of Pubmed, Embase, and ScienceDirect were searched and articles reporting the involvement of the dopaminergic system in patients with anxiety disorder and obsessive compulsive disorder (OCD) were recognized. The key research data were extracted from the included articles and standardized mean differences were calculated using meta-analyses if there were more than two studies with obtainable data. Sensitivity analyses were further performed to detect the stability of results, and the qualities of all the included studies were assessed using the Newcastle Ottawa scale.

Results: Finally, we identified 8 and 11 studies associated with anxiety disorder and OCD for further analysis, respectively. Most consistently, the striatal dopamine D₂ receptor (D₂R) of OCD patients had decreased while no significant correlation was found between striatal D2R and disease severity. The striatal dopamine transporter (DAT) had not been significantly altered in both the anxiety disorder and OCD patients. The heterogeneity values from the meta-analyses were extremely high while those results remained stable after sensitivity analyses. Inconsistent data were found in the striatal D₂R of patients with anxiety disorder. Limited data had suggested that dopamine synthesis increased in most regions of the cerebral cortex and cerebellum in OCD patients.

Conclusions: The most convincing finding was that the D₂ receptor decreased in patients with obsessive compulsive disorder. The dopamine transporter may have no relationship with anxiety and compulsive disorder.

Integrated Metabolomics and Proteomics Analysis Reveals Plasma Lipid Metabolic Disturbance in Patients With Parkinson's Disease

Parkinson’s disease (PD) is a common neurodegenerative disease in the elderly with a pathogenesis that remains unclear. We aimed to explore its pathogenesis through plasma integrated metabolomics and proteomics analysis. The clinical data of consecutively recruited PD patients and healthy controls were assessed. Fasting plasma samples were obtained and analyzed using metabolomics and proteomics methods. After that, differentially expressed metabolites and proteins were identified for further bioinformatics analysis. No significant difference was found in the clinical data between these two groups. Eighty-three metabolites were differentially expressed in PD patients identified by metabolomics analysis. These metabolites were predominately lipid and lipid-like molecules (63%), among which 25% were sphingolipids. The sphingolipid metabolism pathway was enriched and tended to be activated in the following KEGG pathway analysis. According to the proteomics analysis, forty proteins were identified to be differentially expressed, seven of which were apolipoproteins. Furthermore, five of the six top ranking Gene Ontology terms from cellular components and eleven of the other fourteen Gene Ontology terms from biological processes were directly associated with lipid metabolism. In KEGG pathway analysis, the five enriched pathways were also significantly related with lipid metabolism (p < 0.05). Overall, Parkinson’s disease is associated with plasma lipid metabolic disturbance, including an activated sphingolipid metabolism and decreased apolipoproteins.

Possible Correlation between Cholinergic System Alterations and Neuro/Inflammation in Multiple Sclerosis

Multiple sclerosis (MS) is an autoimmune and demyelinating disease of the central nervous system. Although the etiology of MS is still unknown, both genetic and environmental factors contribute to the pathogenesis of the disease. Acetylcholine participates in the modulation of central and peripheral inflammation. The cells of the immune system, as well as microglia, astrocytes and oligodendrocytes express cholinergic markers and receptors of muscarinic and nicotinic type. The role played by acetylcholine in MS has been recently investigated. In the present review, we summarize the evidence indicating the cholinergic dysfunction in serum and cerebrospinal fluid of relapsing-remitting (RR)-MS patients and in the brains of the MS animal model experimental autoimmune encephalomyelitis (EAE). The correlation between the increased activity of the cholinergic hydrolyzing enzymes acetylcholinesterase and butyrylcholinesterase, the reduced levels of acetylcholine and the increase of pro-inflammatory cytokines production were recently described in immune cells of MS patients. Moreover, the genetic polymorphisms for both hydrolyzing enzymes and the possible correlation with the altered levels of their enzymatic activity have been also reported. Finally, the changes in cholinergic markers expression in the central nervous system of EAE mice in peak and chronic phases suggest the involvement of the acetylcholine also in neuro-inflammatory processes.

In vivo evaluation of arsenic-associated behavioral and biochemical alterations in F0 and F1 mice

Groundwater contaminated with arsenic (As) is the biggest threat to public health in Bangladesh. The children of As-exposure parents are also exposing to As through drinking water. The effects of As on the children's health of As-exposure parents are poorly understood. An animal study was taken to evaluate the effects of As on behavioral and biochemical changes in F₁ mice. Swiss albino mice were separated into three groups: a) control, b) As-treated F₀ and c) As-treated F₁. Elevated plus maze and Morris water maze tests were used for evaluating anxiety, spatial memory and learning, respectively. We found that the effect of As on anxiety like behavior, spatial memory and learning impairment in As-treated F₁ mice was significantly higher than that of As-treated F₀ mice and control group. Additionally, we also evaluated the effects of As on biochemical parameters by measuring ALT, AST, ALP, BChE, SOD activities and the level of creatinine in As-induced mice, where we found that all of the blood parameters were significantly changed in F₁ generation. A significant portion of As accumulated in the brain, liver and kidney of F₁ mice than F₀ mice. Histological analysis revealed a significant change in tissue damage related to hepatic and renal dysfunctions that might be associated with As-induced biochemical alterations. In conclusion, arsenic plays an important role for the development of As-associated neurological disorders, hepatic toxicities, and renal dysfunctions in both F₀ and F₁ generations. Notably F₁ mice were much more vulnerable to As-exposure than F₀ mice.

Salivary biomarkers in Alzheimer's disease

OBJECTIVES

The objective of this study was to evaluate the changes that can occur in saliva components in patients with Alzheimer's disease (AD) of different severity and determine if any of these components could be a biomarker of this disease. Therefore, a panel of selected analytes related to the amyloid cascade, the immune and adrenergic systems, among others, were analyzed in the saliva of patients with Alzheimer's disease.

METHODS

A total of 152 patients with AD and controls were included. The severity of the disease was established according to the Global Deterioration Scale. Unstimulated whole saliva was collected.

RESULTS

Salivary amyloid-β42 was significantly lower, and complement C4 was significantly higher in the patients with AD than in the controls (p < 0.05 in both cases). Only complement C4 maintained its significant effect in the multivariate regression analysis. However, the area under the receiver operating characteristic curve of C4 was 0.613. No changes were found in any analyte regarding the severity of the disease.

CONCLUSIONS

A decrease in amyloid-β42 and an increase in complement C4 were detected in the saliva of patients with AD, but the changes did not show a high diagnostic performance for the detection of AD and were not associated with its severity.

CLINICAL RELEVANCE

Although some analytes showed significant differences in saliva in patients with AD, in our study conditions the salivary biomarkers analyzed were not of enough diagnostic utility for being used in routine.

Serum Level and Activity of Butylcholinesterase: A Biomarker for Post-Stroke Dementia

Cholinergic neurotransmission regulates the immune response and inhibits cytokine release after stroke. The changes in the level/activity of blood cholinesterase (ChE) in patients with post-stroke dementia (PSD) are less known. This study aimed to examine post-stroke plasma acetylcholinesterase (AChE) and butylcholinesterase (BChE) and determine whether they are biomarkers for PSD. Thirty patients with PSD, 87 post-stroke patients without dementia (PSNoD), and 117 age- and gender-matched healthy controls were recruited. Missense genetic variants AChE rs1799806 and BChE rs1803274 were genotyped. The plasma AChE level did not differ between the PSD and PSNoD groups. However, BChE levels were significantly lower in the PSD than in the PSNoD group (3300.66 ± 515.35 vs 3855.74 ± 677.60 ng/mL, respectively; p = 0.0033). The activities of total ChE, BChE, and AChE were all lower in the PSD group (19,563.33 ± 4366.03, 7650.17 ± 1912.29, 11,913.17 ± 2992.42 mU/mL, respectively) than in the PSNoD group (23,579.08 ± 5251.55, 9077.72 ± 1727.28, and 14,501.36 ± 4197.17 mU/mL, respectively). When further adjusting for age and sex, significance remained in BChE level and activity and in total ChE activity. BChE rs1803274 was associated with reduced BChE activity, while AChE rs1799806 did not influence AChE activity. The level and activity of BChE, but not of AChE, were decreased in PSD patients and may therefore aid in PSD diagnosis.

Manganese attenuates the effects of arsenic on neurobehavioral and biochemical changes in mice co-exposed to arsenic and manganese

An unsafe level of manganese (Mn) was detected in the drinking water in some arsenic (As)-contaminated areas in Bangladesh. Mn is an essential trace element; however, the intake of a higher level of Mn through the drinking water is associated with the development of toxicity in humans. This study was designed to evaluate the effects of As and Mn co-exposure on neurobehavioral and biochemical alterations in a mouse model. Sodium arsenite (10 mg/kg body weight) and manganese chloride tetrahydrate (10 mg/kg body weight) were given to mice individually and in combination with drinking water for 90 days. Results showed that individual As and Mn exposure as well as co-exposure of As and Mn significantly (p < 0.05) reduced the percent of time spent in the open arms when compared with that of control mice. In addition, percent of time spent in open arms significantly (p < 0.05) increased in co-exposed mice compared with As exposure in elevated plus maze (42.05 ± 1.10 versus 38.94 ± 0.66). In the Morris water maze test, the mean time latency to find the platform was longer in metal-treated mice in comparison to that of control mice (p < 0.05). Importantly, the co-exposed group had shorter time when compared with the As-exposed group during the training periods (p < 0.05). Moreover, co-exposed mice stayed significantly (p < 0.05) more time in the target quadrant in the probe trial in comparison with that of As-exposed mice (27.25 ± 1.21 versus 23.83 ± 0.87 s) but less time than control mice (27.25 ± 1.21 versus 43.17 ± 1.49 s). In addition, a significant (p < 0.05) alteration of biochemical parameters such as ALT, AST, ALP, BChE, and SOD as well as urea and creatinine levels were noted in the As-exposed group compared with the control group and Mn significantly (p < 0.05) attenuated the effects of As in co-exposed mice. Therefore, the results of this study suggest that As and Mn may have some antagonistic effect and Mn could attenuate the As-induced neurobehavioral and biochemical alterations in co-exposed mice.

Understanding the enzyme-ligand complex: insights from all-atom simulations of butyrylcholinesterase inhibition

All-atom molecular dynamics simulations of butyrylcholinesterase (BChE) sans inhibitor and in complex with each of 15 dialkyl phenyl phosphate derivatives were conducted to characterize inhibitor binding modes and strengths. Each system was sampled on the 250 ns timescale in explicit ionic solvent, for a total of over 4 μs of simulation time. A K-means algorithm was used to cluster the resulting structures into distinct binding modes, which were further characterized based on atomic-level contacts between inhibitor chemical groups and active site residues. Comparison of experimentally observed inhibition constants (K_I) with the resulting contact tables provides structural explanations for relative binding coefficients and highlights several notable interaction motifs. These include ubiquitous contact between glycines in the oxyanion hole and the inhibitor phosphate group; a sterically driven binding preference for positional isomers that extend aromaticity; a stereochemical binding preference for choline-containing inhibitors, which mimic natural BChE substrates; and the mechanically induced opening of the omega loop region to fully expose the active site gorge in the presence of choline-containing inhibitors. Taken together, these observations can greatly inform future design of BChE inhibitors, and the approach reported herein is generalizable to other enzyme-inhibitor systems and similar complexes that depend on non-covalent molecular recognition.Communicated by Ramaswamy H. Sarma.

Butyrylcholinesterase-a potential plasma biomarker in manganese-induced neurobehavioral changes

Groundwater particularly drinking water contamination with metals has created an environmental disaster in Bangladesh. Manganese (Mn), an essential trace element, plays a key role in the development and function of the brain. Excess Mn exposure is reported to be associated with complex neurological disorders. Here, we have found a notably large extent of Mn above the permissive limit in the tube-well water of Rajshahi and Naogaon districts in Bangladesh. Higher levels of Mn in hair and nail samples, and a decreasing level of butyrylcholinesterase (BChE) activity were detected in plasma samples of the human subjects recruited from Naogaon district. Mn concentrations in water, hair, and nails were negatively correlated with the plasma BChE levels in Mn-exposed populations. To compare and validate these human studies, an animal model was used to determine the in vivo effects of Mn on neurobehavioral changes and blood BChE levels. In elevated plus maze, the time spent was significantly reduced in open arms and increased in closed arms of Mn-exposed mice compared to control group. The mean latency time to find the platform was declined significantly in control mice compared to Mn-treated group during 7 days in Morris water maze test, and Mn-exposed group also spent significantly less time in the desired quadrant as compared to the control group in probe trial. BChE activity was significantly reduced in Mn-exposed mice compared to control mice. Taken together, these results suggest that plasma BChE levels may serve as reliable biomarker of Mn-induced neurotoxicity related to behavioral changes.

Integrated Analysis Reveals Altered Lipid and Glucose Metabolism and Identifies NOTCH2 as a Biomarker for Parkinson's Disease Related Depression

Depression is a common comorbidity in Parkinson's disease (PD) but is underdiagnosed. We aim to investigate the altered metabolic pathways of Parkinson's disease-related depression (PDD) in plasma and to identify potential biomarkers for clinical diagnosis. Consecutive patients with PD were recruited, clinically assessed, and patients with PDD identified. Fasting plasma samples were collected from 99 patients and differentially expressed metabolites and proteins between patients with PDD and PD were identified using non-targeted liquid chromatography-mass spectrometry (LC-MS)-based metabolomics and tandem mass tag (TMT)-based proteomics analysis, followed by an integrated analysis. Based on the above results, enzyme-linked immune sorbent assay (ELISA) tests were then performed to identify potential biomarkers for PDD. In clinics, patients with PDD suffered less hypertension and had lower serum low-density lipoprotein cholesterol and apolipoprotein B levels when compared to the other patients with PD. A total of 85 differentially expressed metabolites were identified in metabolomics analysis. These metabolites were mainly lipids and lipid-like molecules, involved in lipid and glucose metabolic pathways. According to proteomics analysis, 17 differentially expressed proteins were identified, and 12 metabolic pathways were enriched, which were predominantly related to glucose metabolism. Integrated analysis indicated that altered lipid and glucose metabolism in PDD may induce cellular injury through oxidative stress. Additionally, plasma levels of several proteins were confirmed to be significantly altered and correlated with depressive severity. NOTCH2 may be a potential blood biomarker for PDD, with an optimal cut-off point of 0.91 ng/ml, a sensitivity value of 95.65%, and a specificity value of 81.58%. Depressive symptoms are associated with lipid and glucose metabolism in patients with PD and NOTCH2 may be a potential blood biomarker for the clinical diagnosis of PDD.