Combined diagnosis for Parkinson's disease via gait and eye movement disorders

BACKGROUND AND OBJECTIVES

With the discovery of the potential role of gait and eye movement disorders in Parkinson's disease (PD) recognition, we intend to investigate the combined diagnostic value of gait and eye movement disorders for PD.

METHODS

We enrolled some Chinese PD patients and healthy controls and separated them into the training and validation sets based on enrollment time. Performance in five oculomotor paradigms and in one gait paradigm was examined using an infrared eye tracking device and a wearable gait analysis device. We developed and validated a combined model for PD diagnosis via multivariate stepwise logistic regression analysis. Furthermore, subgroup comparisons and multi-model comparison were performed to assess its applicability and advantages.

RESULTS

A total of 145 PD patients and 80 healthy controls in China were recruited. The pro-saccade velocity, the trunk-sway max, and the turn mean angular velocity were finally screened out for the model development. Incorporating age factor, the ternary model demonstrated more satisfactory performance on ROC (AUC of 0.953 in the training set and AUC of 0.972 in the validation set), calibration curve, and decision curve. A nomogram was drawn to visualize the model. The combined model outperforms individual models with a broad application and the unique diagnostic value for early detection of PD patients, especially TD-PD patients.

CONCLUSION

We demonstrated the presence of gait and eye movement disorders, as well as the feasibility, applicability, and superiority of employing them together to diagnose PD.

Adversarially Trained Persistent Homology Based Graph Convolutional Network for Disease Identification Using Brain Connectivity

Brain disease propagation is associated with characteristic alterations in the structural and functional connectivity networks of the brain. To identify disease-specific network representations, graph convolutional networks (GCNs) have been used because of their powerful graph embedding ability to characterize the non-Euclidean structure of brain networks. However, existing GCNs generally focus on learning the discriminative region of interest (ROI) features, often ignoring important topological information that enables the integration of connectome patterns of brain activity. In addition, most methods fail to consider the vulnerability of GCNs to perturbations in network properties of the brain, which considerably degrades the reliability of diagnosis results. In this study, we propose an adversarially trained persistent homology-based graph convolutional network (ATPGCN) to capture disease-specific brain connectome patterns and classify brain diseases. First, the brain functional/structural connectivity is constructed using different neuroimaging modalities. Then, we develop a novel strategy that concatenates the persistent homology features from a brain algebraic topology analysis with readout features of the global pooling layer of a GCN model to collaboratively learn the individual-level representation. Finally, we simulate the adversarial perturbations by targeting the risk ROIs from clinical prior, and incorporate them into a training loop to evaluate the robustness of the model. The experimental results on three independent datasets demonstrate that ATPGCN outperforms existing classification methods in disease identification and is robust to minor perturbations in network architecture. Our code is available at https://github.com/CYB08/ATPGCN.

Comprehensive analysis of clinical and biological features in Parkinson's disease associated with the LRRK2 G2019S mutation: Data from the PPMI study

The Parkinson's Progression Marker Initiative (PPMI) aims to identify biomarkers for Parkinson's disease (PD) risk, onset, and progression. This study focuses on the G2019S missense mutation in the LRRK2 gene, which is associated with hereditary and sporadic PD. Utilizing data from the PPMI database, we conducted an analysis of baseline clinical characteristics, as well as serum and cerebrospinal fluid levels in two groups: patients with PD with the G2019S mutation (PD + G2019S) and patients with PD without the mutation (PD-G2019S). Multiple linear regression and longitudinal analysis were performed, controlling for confounding factors. Compared to the PD-G2019S group, the PD + G2019S group showed more obvious initial motor dysfunction-higher baseline Movement Disorder Society-Sponsored Revision of the Unified Parkinson Disease Rating Scale (MDS-UPDRS) scores (false discovery rate [FDR]-adjusted p < 0.001), but progressed more slowly. Mechanism of Coordinated Access and activities of daily living (ADL) scores were lower at baseline (FDR-adjusted p < 0.001), whereas Scales for Outcomes of Parkinson's Disease (SCOPA)-Thermoregulatory (FDR-adjusted p = 0.015) scores were higher, emphasizing the increase of non-motor symptoms associated with LRRK2-G2019S mutation. During the follow-up period, the motor and non-motor symptoms changed dynamically with time, and there were longitudinal differences in the scores of MDS-UPDRS (FDR-adjusted PI  = 0.013, PII  = 0.008, PIV  < 0.001), Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease (FDR-adjusted p = 0.027), SCOPA-Thermoregulatory (FDR-adjusted p = 0.021), and ADL (FDR-adjusted p = 0.027) scale scores. PD associated with the LRRK2 G2019S mutation demonstrated more severe symptoms at baseline but slower progression. Motor complications and thermoregulatory disorders were more pronounced.

Abnormal eye movements in Parkinson's disease: From experimental study to clinical application

Parkinson's disease (PD) is a neurodegenerative disease that integrates a series of motor symptoms and non-motor symptoms, making early recognition challenging. The exploration of biomarkers is urgently required. Abnormal eye movements in PD have been reported to appear in a variety of ways since eye tracking technology was developed, such as decreased saccade amplitude, extended saccade latency, and unique saccade patterns. Non-invasive, objective and simple eye tracking has the potential to provide effective biomarkers for the PD diagnosis, progression and cognitive impairment, as well as ideas for research into the occurrence and treatment strategy of motor symptoms. In this review, we introduced the fundamental eye movement patterns and typical eye movement paradigms (such as fixation, pro-saccade, anti-saccade, smooth tracking, and visual search), summarized the symptoms of various ocular motor abnormalities in PD, and discussed the research implications of oculomotor investigation to the pathogenesis of PD and related motor symptoms, as well as the clinical implications as biomarkers and its inspiration on treatment.

Clinical characteristics in early Parkinson's disease with excessive daytime sleepiness: A cross-sectional and longitudinal study

We aimed to explore excessive daytime sleepiness (EDS) and correlates of clinical characteristics by using cross-sectional and longitudinal analyses from the Parkinson's Progression Markers Initiative database. Four hundred twenty-three patients with Parkinson's disease (PD; EDS: non-EDS = 357:66) and 195 healthy controls (HCs; EDS: nEDS = 171:24) were enrolled in our study at baseline. Multiple linear and linear mixed-effects models were used to research the relationships between EDS/daytime sleepiness severity and clinical characteristics. Relationships between the change rates of clinical characteristics and daytime sleepiness severity were further investigated through multiple linear regression models. Mediating effect analysis was used to determine whether autonomic dysfunction was the mediator between cognition assessments and daytime sleepiness severity. Patients with PD with EDS and greater daytime sleepiness severity presented faster cognitive decline, high possibility for rapid eye movement sleep behavior disorder, autonomic dysfunction, depression, and anxiety from cross-sectional and longitudinal analyses. Furthermore, HC individuals with EDS showed a higher striatal binding ratio of the right putamen, right striatum, and mean striatum. Autonomic dysfunction may act as a mediator between PD and cognitive decline. In early PD, EDS and daytime sleepiness severity were related to several clinical variables, suggesting that EDS might play an essential role in regulating PD progression.

CD33 polymorphisms and Parkinson's disease Parkinson's disease in northern Chinese Han population: A case-control study

OBJECTIVE

Parkinson's disease (PD) represents the multisystem illness involving immunological and neuroinflammatory dysfunction. The present work focused on evaluating link of CD33 single nucleotide polymorphisms (SNPs) with PD vulnerability of the northern Chinese Han people, considering CD33's role as a critical immunoregulatory receptor in neuroinflammatory responses.

METHODS

The present case-control study included 475 PD cases together with 475 normal controls. A further division of PD patients into two categories was made: 74 patients with early-onset PD (EOPD; onset age ≤ 50 years) and 401 patients with late-onset PD (LOPD; onset age > 50 years). DNA extraction was conducted, followed by genotyping for 2SNPs of CD33 polymorphisms with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

RESULTS

Alleles (G vs. A, P = 0.028) and AA genotypes (P = 0.042) of rs12985029 were significantly different between the groups. Distinctions were observed between the two groups in the recessive, co-dominant, and additive models (nominal P = 0.030, nominal P = 0.045, and P = 0.032). AA genotype frequency among male PD was higher compared to corresponding male controls (P = 0.034), and in the male group allele A was a factor causing the disease (P = 0.026). The rs12985029 genotypes and allele frequency were different in EOPD compared with LOPD (P = 0.002, P = 0.002, respectively), and in LOPD group relative to healthy control group (P = 0.020 and P = 0.004, separately). Regarding the rs3826656 polymorphism, the frequency of GA genotype was higher in the control group than in the case group (nominal P = 0.036). Overdominance and co-dominant models were different between these groups (P = 0.026, nominal P = 0.030). Subgroup analysis revealed genotype frequency differences between rs3826656 LOPD group and control group (P = 0.018). Furthermore, relationship between rs3826656 and rs12985029 (D' = 0.162, r2 = 0.021) did not reach a complete level of linkage disequilibrium (LD) of northern Chinese Han people.

CONCLUSION

This study establishes an association between CD33 rs12985029 and rs3826656 polymorphisms and PD risk among the selected northern Chinese Han people. The GA genotype, rs3826656, may act as a protective factor against PD, while the A allele, rs12985029,could be genetic risk factor related to PD. Future research should include larger sample sizes and other human populations to further investigate how CD33 polymorphisms contribute to PD.

Repetitive transcranial magnetic stimulation alleviates glial activation through suppressing HMGB1/TLR4 pathway in a rat model of Parkinson's disease

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) has been demonstrated to be effective in Parkinson's disease (PD), but whether rTMS treatment has a relieving effect on neuroinflammation remains to be investigated. In this article, we explored the effects of rTMS on forelimb use asymmetry and neuroinflammation-related mechanisms in a 6-hydroxydopamine (6-OHDA)-induced PD rat model.

METHODS AND RESULTS

Rats in the 6-OHDA+rTMS group received 10 Hz rTMS daily for 4 weeks. Behavioral tests (the cylinder test) were performed at the 3rd and 7th weeks after the operation. Astrocyte and microglia activation and protein levels of tyrosine hydroxylase(TH), high-mobility group box 1(HMGB1) and toll-like receptors 4(TLR4) were investigated by immunohistochemistry and Western blot analyses, respectively. After 4 weeks of treatment, forelimb use asymmetry was ameliorated in the 6-OHDA+rTMS group. Consistent with the behavioral tests, rTMS increased TH in the substantia nigra (SN) and the striatum of PD rats. High glial activation and HMGB1/TLR4 expression in the SN and the striatum were observed in the 6-OHDA group, while rTMS alleviated these changes.

CONCLUSIONS

This study showed that rTMS might be a promising method for alleviating neuroinflammation in PD rat models, and the effects might be mediated through the downregulation of the HMGB1/TLR4 pathway.

Effects of soluble TREM2 on motor progression in Parkinson's disease

OBJECTIVES

To determine whether sTREM2 is changed during the pathogenesis of PD and reflect motor decline in PD individuals METHODS: The cerebrospinal fluid (CSF) from PD and healthy individuals were obtained to measure the expression of sTREM2 and further to evaluate the motor function at baseline and after four years of follow-up using the Parkinson's Progression Markers Initiative (PPMI) database. The relationship between motor disease progression at baseline and longitudinal CSF sTREM2 was evaluated by linear mixed-effects (LME) and multiple linear regression (MLR) models. The change rates of the motor symptoms and sTREM2 level in CSF were further rigorously analyzed using the LME model. Cox proportional-hazards regression models were used to evaluate the predictive values of sTREM2 in CSF for motor progression. The regulatory role of CSF α-syn and Tau between sTREM2 and motor assessments was evaluated by Mediating effect analysis.

RESULTS

We found no significant difference in CSF sTREM2 levels between the PD and HC groups (p = 0.155). However, late-onset PD patients had higher CSF sTREM2 levels than early-onset PD patients (p = 0.044). The basal levels of sTREM2 could predict motor progression over the four years of follow-up. The change rate of CSF sTREM2 was correlated with the progressive deterioration of motor function in PD individuals. Our observations also showed that CSF Tau was a significant mediator of the association between CSF sTREM2 and total UPDRS scores and UPDRS III and tremor at baseline with 26.5% and 33.5%, and 28.7% mediation, respectively.

CONCLUSION

Our results indicated that CSF sTREM2 was associated with the prognosis of PD motor symptoms. Besides, CSF Tau could effectively mediate the association of sTREM2 with motor progression.

Associations of striatal dopamine transporter binding with motor and non-motor symptoms in early Parkinson's disease

Dopamine transporter (DAT) imaging is an in vivo tool to assess presynaptic dopaminergic function in the clinical practices of Parkinson's disease (PD). Current clinical practices focused on qualitatively visual interpretation of DAT imaging, whereas quantitative analyses are potentially more helpful when monitoring the progression of PD. Previous cross-sectional studies indicated certain motor and non-motor features were associated with striatal DAT binding, whereas limited data were reported in terms of the longitudinal correlation between clinical features of PD with striatal DAT binding. The purpose of our study is to clarify current and longitudinal correlations between striatal DAT binding and clinical measures. A total of 352 untreated PD individuals and 167 healthy controls with complete baseline clinical measures and neuroimaging data were identified from the Parkinson's Progression and Markers Initiative (PPMI) database. Patients with PD underwent DAT imaging at the screening visit and following months 12, 24, and 48. Multiple linear regression models and linear mixed-effect models were respectively conducted to investigate the cross-sectional and longitudinal correlation between clinical characteristics and DAT binding. Associations between changes in clinical characteristics and changes in DAT binding were further evaluated and the Spearman rank correlation coefficients were reported. In the cross-sectional analysis, baseline striatal DAT binding was significantly associated with the Hoehn and Yahr scale, the Movement Disorder Society-Sponsored Revision of the Unified Parkinson Disease Rating Scale (MDS-UPDRS) scores, the rigidity scores, and the axial scores in PD individuals (false discovery rate [FDR]-adjusted p = 0.0017 for all above). Patients who developed freezing of gait had lower striatal DAT binding (FDR-adjusted p = 0.0161). Healthy controls who had higher tremor scores and suffered more severe olfactory dysfunction had lower striatal DAT binding (FDR-adjusted p = 0.0257 for all above). Longitudinal analysis indicated that baseline severity of rapid-eye-movement sleep behavior disorder was significantly associated with longitudinal striatal DAT binding in patients with PD (FDR-adjusted p = 0.0120). Furthermore, changes in MDS-UPDRS scores and the State-Trait Anxiety Inventory (STAI) scores demonstrated significant correlations with changes in striatal DAT binding over 4 years (p = 0.005 and p = 0.032, respectively). Our findings clarified quantitative associations between certain motor and non-motor features with current and future striatal dopamine binding, suggesting the feasibility of using DAT images as a progression predictive marker for PD. Further studies are needed to investigate correlations between different regional dopamine binding with specific clinical features.

Evaluation of Nocturnal Symptoms in Chinese Parkinson's Disease Patients Based on the PDSS-2 Scale: A Multicenter Cross-Sectional Study

BACKGROUND

Nocturnal symptoms have a significant effect on the quality of life in Parkinson's disease (PD) patients.

OBJECTIVE

This study aimed to investigate the prevalence and associated factors of nocturnal symptoms in Chinese PD patients.

METHODS

This multicenter cross-sectional study included 1,500 patients with primary PD from 18 centers in China was carried out between February 2019 and February 2020. Questionnaires including Parkinson's disease sleep scale 2 (PDSS-2), Parkinson's disease questionnaire 8 (PDQ-8), Beck depression inventory (BDI), and generalized anxiety disorder scale 7 (GAD-7) were used to assess nocturnal symptoms, quality of life, depression, and anxiety.

RESULTS

Among 1,500 Chinese PD patients, 576 (38.4%) reported nocturnal symptoms. Of them, 59.2% were older than 65 years. The PDQ-8 total score was higher in patients with nocturnal symptoms (p < 0.01). Moderate and severe depression was reported more often in patients with nocturnal symptoms (p < 0.01), and the occurrence and severity of anxiety were higher as well (p < 0.01). Longer disease duration and higher Hoehn-Yahr (HY) stage were independently associated with nocturnal symptoms (p < 0.01). Education level, depression, disease course, HY stage, and nocturnal symptoms were related to the quality of life in Chinese PD patients (p < 0.01).

CONCLUSION

Our study found that 38.4% of Chinese PD patients have nocturnal symptoms, even in early and mid-stage PD. Nocturnal symptoms were associated with worse quality of life and higher incidences of depression and anxiety. Nocturnal symptoms should be included in the assessment and care plan, especially in patients with longer disease courses and higher HY stages.

The associations of cerebrospinal fluid biomarkers with cognition, and rapid eye movement sleep behavior disorder in early Parkinson's disease

Background

In Parkinson's disease (PD), levels of cerebrospinal fluid (CSF) biomarkers and progression of non-motor symptoms are associated, but the specifics are not yet clear.

Objective

The aim of this study was to investigate the associations of non-motor symptoms with CSF biomarkers in PD.

Materials and methods

We assessed 487 individuals from the Parkinson's Progression Markers Initiative (PPMI), consisting of 155 healthy controls (HCs) and 332 individuals with PD. Patients with PD were grouped according to non-motor symptoms and compared CSF α-synuclein (α-syn), amyloid-beta 1-42 (Aβ_1-42), and total tau (t-tau) levels. Multiple linear regressions were used in baseline analysis and linear mixed-effects models in longitudinal analysis. Analyses of mediating effects between cognition and CSF biomarkers were also performed.

Results

At baseline, PD patients with cognitive impairment (PDCI) exhibited significantly lower CSF α-syn (β = -0.1244; P = 0.0469), Aβ (β = -0.1302; P = 0.0447), and t-tau (β = -0.1260; P = 0.0131) levels than PD patients without cognitive impairment (PDCU). Moreover, a faster decline of α-syn (β = -0.2152; P = 0.0374) and Aβ (β = -0.3114; P = 0.0023) and a faster rise of t-tau (β = -0.1534; P = 0.0274) have been found in longitudinal analysis. The Aβ positive group showed an earlier decline in cognitive performance (β = -0.5341; P = 0.0180) compared with the negative Aβ group in both analyses. In addition, we found that PD patients with probable rapid eye movement sleep behavior disorder (pRBD) showed decreased CSF α-syn (β = -0.1343; P = 0.0033) levels. Finally, mediation analysis demonstrated that olfactory function partially mediated the relationship between cognition and CSF biomarkers levels.

Conclusion

Our study shows that CSF biomarkers are associated with cognition at baseline and longitudinally. Cognitive impairment is more severe in patients with a heavier Aβ burden. CSF α-syn decreased in PD patients with pRBD. This study suggests that early recognition of the increased risk of non-motor symptoms is important for disease surveillance and may be associated with the pathological progression of CSF markers.

Neurofilament light as a biomarker for motor decline in Parkinson’s disease

Objectives

The aim of this study was to determine whether neurofifilament light (NfL) could reflect motor decline and compare the predictive values of cerebrospinal fluid (CSF) and serum NfL in individuals with PD.

Methods

CSF/serum samples were collected from patients with PD and healthy controls (HCs) with motor assessments at baseline and after three years of follow-up from the Parkinson’s Progression Markers Initiative (PPMI). Multiple linear regression models and linear mixed-effects models were used to investigate the associations of motor assessments with baseline and longitudinal CSF/serum NfL. Associations between the change rates of motor assessments and CSF/serum NfL were further investigated via multiple linear regression models. Mediating effect analysis was used to research whether CSF alpha-synuclein (α-syn) acts as the mediator between NfL and motor assessments.

Results

We found patients with PD had higher baseline CSF/serum NfL levels than HCs. Both baseline CSF/serum NfLs and their change rates predicted measurable motor decline in PD assessed by different motor scores. Baseline serum NfL and its rate of change were strongly associated with CSF NfL levels in patients with PD (P < 0.001). Besides, there were also significant differences in CSF/serum NfL levels and predicted values of motor decline between men and women with PD. Mediating effect analysis showed CSF α-syn mediated the effect of CSF NfL on total Unified Parkinson’s Disease Rating Scale (UPDRS) scores and UPDRSIII with 30.6 and 20.2% mediation, respectively.

Conclusion

Our results indicated that NfL, especially serum NfL concentration, could serve as an easily accessible biomarker to monitor the severity and progression of motor decline in individuals with PD, especially in men with PD. Besides, CSF α-syn acts as a mediator between NfL and motor progression.

Multi-predictor modeling for predicting early Parkinson’s disease and non-motor symptoms progression

Background

Identifying individuals with high-risk Parkinson’s disease (PD) at earlier stages is an urgent priority to delay disease onset and progression. In the present study, we aimed to develop and validate clinical risk models using non-motor predictors to distinguish between early PD and healthy individuals. In addition, we constructed prognostic models for predicting the progression of non-motor symptoms [cognitive impairment, Rapid-eye-movement sleep Behavior Disorder (RBD), and depression] in de novo PD patients at 5 years of follow-up.

Methods

We retrieved the data from the Parkinson’s Progression Markers Initiative (PPMI) database. After a backward variable selection approach to identify predictors, logistic regression analyses were applied for diagnosis model construction, and cox proportional-hazards models were used to predict non-motor symptom progression. The predictive models were internally validated by correcting measures of predictive performance for “optimism” or overfitting with the bootstrap resampling approach.

Results

For constructing diagnostic models, the final model reached a high accuracy with an area under the curve (AUC) of 0.93 (95% CI: 0.91–0.96), which included eight variables (age, gender, family history, University of Pennsylvania Smell Inventory Test score, Montreal Cognitive Assessment score, RBD Screening Questionnaire score, levels of cerebrospinal fluid α-synuclein, and SNCA rs356181 polymorphism). For the construction of prognostic models, our results showed that the AUC of the three prognostic models improved slightly with increasing follow-up time. The overall AUCs fluctuated around 0.70. The model validation established good discrimination and calibration for predicting PD onset and progression of non-motor symptoms.

Conclusion

The findings of our study facilitate predicting the individual risk at an early stage based on the predictors derived from these models. These predictive models provide relatively reliable information to prevent PD onset and progression. However, future validation analysis is still needed to clarify these findings and provide more insight into the predictive models over more extended periods of disease progression in more diverse samples.

Update to the Treatment of Parkinson's Disease Based on the Gut-Brain Axis Mechanism

Gastrointestinal (GI) symptoms represented by constipation were significant non-motor symptoms of Parkinson’s disease (PD) and were considered early manifestations and aggravating factors of the disease. This paper reviewed the research progress of the mechanism of the gut-brain axis (GBA) in PD and discussed the roles of α-synuclein, gut microbiota, immune inflammation, neuroendocrine, mitochondrial autophagy, and environmental toxins in the mechanism of the GBA in PD. Treatment of PD based on the GBA theory has also been discussed, including (1) dietary therapy, such as probiotics, vitamin therapy, Mediterranean diet, and low-calorie diet, (2) exercise therapy, (3) drug therapy, including antibiotics; GI peptides; GI motility agents, and (4) fecal flora transplantation can improve the flora. (5) Vagotomy and appendectomy were associated but not recommended.

Associations of Sleep Disorders With Depressive Symptoms in Early and Prodromal Parkinson's Disease

Background

Non-motor symptoms, including sleep disorders and depression, are common in Parkinson’s disease (PD). The purpose of our study is to explore the effect of sleep disorders, including the probable rapid eye movement (REM) sleep behavior disorder (pRBD) and the daytime sleepiness, on depressive symptoms in patients with early and prodromal PD.

Methods

A total of 683 participants who obtained from the Parkinson Progression Markers Initiative (PPMI) were included, consisting of 423 individuals with early PD, 64 individuals with prodromal PD, and 196 healthy controls (HCs), who were followed up to 5 years from baseline. Multiple linear regression models and linear mixed-effects models were conducted to explore the relationship between sleep disorders and depression at baseline and longitudinally, respectively. Multiple linear regression models were used to further investigate the association between the change rates of daytime sleepiness score and depression-related score. Mediation analyses were also performed.

Results

At baseline analysis, individuals with early and prodromal PD, who had higher RBD screening questionnaire (RBDSQ) score, or who were considered as pRBD, or who manifested specific behaviors of RBD (things falling down when sleep or disturbance of sleep), showed significantly the higher score of depression-related questionnaires. Our 5-year follow-up study showed that sleep disorders, including pRBD and daytime sleepiness, were associated with the increased depressive-related score in individuals with early and prodromal PD. Interestingly, we also found that the increased possibilities of daytime sleepiness were associated with depressive-related score. Finally, mediation analysis demonstrated that the relationship between RBD and depressive symptoms was partially mediated by autonomic symptoms, such as postural hypertension, salivation, dysphagia, and constipation.

Conclusion

Our study shows that sleep disorders, including pRBD and daytime sleepiness, are associated with depression at baseline and longitudinally, which is partially mediated by the autonomic dysfunction in early and prodromal PD, with an implication that sleep management is of great value for disease surveillance.

Association between ABCA7 gene polymorphisms and Parkinson's disease susceptibility in a northern Chinese Han population

OBJECTIVE

As a typical member of the ABC transporter superfamily, ABCA7 has been shown to play an important role in stalling the pathogenesis of neurodegenerative disorders through maintaining the normal microglial function, regulating cellular responses to inflammation and ER stress, and modulating lipid metabolism. Variants in the ABCA7 locus have been hypothesized to be correlated with the genetic predisposition of several neurodegenerative disorders. The goal of this study was to examine whether there is a link between three specific single nucleotide polymorphisms in the ABCA7 gene, namely, rs3764650, rs4147929, and rs3752246, with the risk of developing Parkinson's disease (PD) in a northern Chinese Han community.

METHODS

In this case-control study, we recruited 821 participants, including 411 patients with sporadic PD and 410 independent, healthy controls. A Polymerase Chain Reaction-Restriction Fragment Length Polymorphism genotyping assay was used to identify polymorphisms of the three selected single nucleotide polymorphisms (rs3764650, rs4147929, and rs3752246) of the ABCA7 gene. Sanger sequencing was further applied to identify the accuracy of the genotyping results. The chi-square test was used to compare the frequencies of alleles and genotypes in patients and controls. Odds ratios and 95% confidence intervals were calculated using logistic regression.

RESULTS

We found significant between-group differences in the alleles (A vs. G, nominal P = 0.014) and dominant models (AA + GA vs. GG, nominal P = 0.015) of rs4147929. Subgroup analysis showed that the frequency of the rs4147929 A allele in male patients with PD was significantly higher than that in male controls (nominal P = 0.036). For the rs3752246 polymorphism, the frequency of the G allele was significantly higher in patients with PD than in controls, and the dominant model fit the data best when considering the nominal P-values (nominal P = 0.019, nominal P = 0.033, respectively). Differences in G allele and genotypes frequencies between patients and controls remained significant in women (nominal P = 0.032 for allele, nominal P = 0.015 for genotype), as well as in individuals aged more than 50 years (nominal P = 0.044, nominal P = 0.020, respectively). No significant differences were observed in allele or genotype frequencies between patients with PD and healthy controls for rs3764650. The frequency of the TCG (rs3764650-rs3752246-rs4147929) haplotype was significantly lower in the PD group than in the healthy control group (odds ratio = 0.772; 95% confidence interval = 0.634-0.940; P = 0.011).

CONCLUSION

The rs4147929 polymorphism was significantly associated with PD susceptibility in the northern Chinese Han population. The A allele of rs4147929 was a risk factor for developing PD. The TCG haplotype presented a protective role in the pathogenesis of PD. Further studies using larger sample sizes, considering different clinical and biochemical parameters such as the cognitive status of subjects at the same time, are warranted to better clarify the effects of these common variants on the pathogenesis and development of PD.

Role of CD36 rs1761667 AA genotype in the expression of inflammatory cytokines and Parkinson's disease progression: A case-control study in a northern Han Chinese population

OBJECTIVE

This study aimed to investigate the effect of CD36 rs1761667 gene polymorphisms on the expression of CD36 and inflammatory cytokines and the progression of Parkinson's disease (PD).

METHODS

A total of 138 patients with PD (60 men and 78 women) and 132 healthy controls (48 men and 84 women) from a northern Han Chinese population were enrolled in this case-control study. Polymerase chain reaction-restriction fragment length polymorphism was used to detect the CD36 rs1761667 genotype. An enzyme-linked immunosorbent assay was used to determine the expression of CD36, interleukin (IL)-6, IL-1β, and tumor necrosis factor (TNF)-α in the plasma.

RESULTS

The frequency of the rs1761667 AA genotype was significantly higher in patients with PD than that in healthy controls, suggesting AA genotype to be a risk factor for PD. When compared with those in healthy controls, CD36 levels were significantly lower in patients with PD, whereas IL-6, IL-1β, and TNF-α levels were significantly higher in patients with PD. Furthermore, GA and AA carriers with PD showed lower levels of CD36, and GG, GA, and AA carriers showed higher levels of IL-6, IL-1β, and TNF-α than those in healthy controls. In the PD patient group, AA and GA carriers had lower expression levels of CD36 than GG carriers did, and CD36 levels were lower in AA carriers than in GA carriers. Conversely, AA carriers had elevated expression levels of IL-6 compared with that of GG and GA carriers. Logistic regression analysis revealed that IL-6, IL-1β, and TNF-α levels were risk factors for PD in a northern Han Chinese population.

CONCLUSION

The CD36 rs1761667 AA genotype may increase susceptibility to PD and the expression of inflammatory cytokines.

Parkinson's disease peripheral immune biomarker profile: a multicentre, cross-sectional and longitudinal study

BACKGROUND

Inflammations play crucial role in the pathogenesis of Parkinson's disease (PD), however, their possible value in the diagnosis or tracking of the progress of PD is still limited, because of discordant results in the literature and a lack of information regarding its reproducibility. Thus, overall longitudinal and cross-sectional studies are needed. This multicentre study was designed to investigate the association between multiple peripheral immune biomarkers and the development and progression of PD.

METHODS

This was a longitudinal and multicentre study. First, we measured the levels of five typical cytokines and five focused chemokines in 76 PD patients and 76 healthy controls (HCs) in a discovery cohort. Then, a validation cohort of 80 PD and 80 HC participants was recruited from four multicentre locations. In addition, a prospective follow-up of early-stage PD patients was performed with significant biomarkers. Finally, we performed further verification in an exploratory set of patients with idiopathic REM sleep behaviour disorder (iRBD).

RESULTS

In the discovery set, CXCL12, CX3CL1 and IL-8 levels were significantly higher in PD patients than in HCs (p < 0.05). The receiver-operating characteristic (ROC) curve for a combination of these three biomarkers produced a high area under the curve (AUC) of 0.89 (p < 0.001). Moreover, four biomarkers (the previous three and CCL15) were significantly associated with PD in the discovery and validation cohorts. Furthermore, in the prospective follow-up cohort, CX3CL1 levels were associated with motor progression after a mean interval of 43 months. In addition, CX3CL1 and IL-8 levels were higher in iRBD patients than in HCs.

CONCLUSION

We showed a correlation between a profile of four peripheral immune biomarkers and PD development and progression. Our findings may provide a basis whereby PD patients with abnormal inflammatory profiles can be identified and receive timely therapeutic interventions.

Association of PGLYRP2 gene polymorphism and sporadic Parkinson's disease in northern Chinese Han population

Gut inflammation is increasingly corroborated to take part in the pathogenesis of Parkinson's disease (PD). The PGLYRP2 gene has been proven to increase susceptibility to inflammatory bowel disease (IBD). The present study aimed to explore the genetic relationship between single nucleotide polymorphism (SNP) of the PGLYRP2 gene and the risk of sporadic PD in the Han population of northern China. The genotypes of the rs3813135 T/C, rs733731 C/T and rs892145 A/T polymorphisms of the PGLYRP2 gene in 400 Chinese Han patients with PD and 400 healthy age-and sex-matched individuals were identified by the Polymerase Chain Reaction and Restriction Fragment Length Polymorphism (PCR-RFLP) method. The results showed that the frequency of the rs892145 AT heterozygote significantly differed between the PD and control groups (OR = 1.459, 95%CI = 1.459-1.039, P = 0.029), as well as the early-onset PD and control groups (P = 0.024). The rs3813135 polymorphism yielded only one significant result: C allele was more common in the male PD group than in the male control group (P = 0.045). Conversely, no significant difference in the genotype frequency of rs733731 was found between the PD and control groups. Five common haplotypes were assessed, of which the TTA and TCA haplotypes were related to PD susceptibility. In summary, our results indicated that the PGLYRP2 gene is associated with sporadic PD in the Chinese Han population, in which the rs892145 AT heterozygote might increase the risk of PD and possibly the risk of early-onset PD. Moreover, linkage disequilibrium (LD) analysis showed these three PGLYRP2 polymorphisms has a strong linkage in causing mutations.

Identification of Hub Genes of Mesio Temporal Lobe Epilepsy and Prognostic Biomarkers of Brain Low-grade Gliomas Based on Bioinformatics Analysis

Mesio temporal lobe epilepsy (MTLE) syndrome is the most common form of intractable epilepsies. Meanwhile, seizures are common in patients with cancer as a consequence of brain tumors, including brain low-grade gliomas (LGG). However, the underlying molecular mechanisms of MTLE remain poorly understood. Also, the relationship between MTLE and LGG needs our attention. In this study, we aimed to investigate the hub genes and potential mechanism in MTLE, and the relationship between MTLE and LGG, the gene expression profiles (GSE88992) were downloaded from the Gene Expression Omnibus (GEO) database. Difference analysis for MTLE versus control groups under the three time points was conducted to select the differentially expressed genes (DEGs). Time series clustering analysis was used to select the trend genes. Then a series of bioinformatics analyses including functional enrichment analysis, protein–protein interaction (PPI) network and module analyses, and transcription factor (TF) and miRNA prediction were performed. Also, the overall survival analysis and expression of hub genes in LGG were performed using UALCAN from TCGA database. At 6 h, there were 351 upregulated and 80 downregulated DEGs. At 12 h, there were 499 upregulated and 231 downregulated DEGs. Additionally, 532 upregulated and 402 downregulated DEGs were obtained at 24 h. After time series clustering analysis of the DEGs, we obtained 323 uptrend and 248 downtrend genes. We identified 10 key genes with higher degrees, including C3, TIMP1, PENK, CKAP4, etc. Five PPI modules were identified by MCODE. TF analysis predicted four TFs: JUN, STAT3, NR4A2, and Myc. A total of 26,834 miRNA–mRNA pairs were predicted. Moreover, survival analysis of UALCAN suggested that C3, TIMP1, PENK, GNG2, CKAP4, TNC, JUN, STAT3, NR4A2, and Myc can be potential biomarkers for the prognosis of LGG. In summary, DEGs and hub genes were identified in the present study, which provides novel insight into the development of MTLE.

Highly expressed lncRNA FOXD3-AS1 promotes non-small cell lung cancer progression via regulating miR-127-3p/mediator complex subunit 28 axis

OBJECTIVE

The present study aimed to determine the expression of long non-coding RNA (lncRNA) FOXD3 antisense RNA 1 (FOXD3-AS1) in lung cancer tissues and to explore its underlying mechanisms in mediating non-small cell lung cancer (NSCLC) progression.

MATERIALS AND METHODS

Gene expression levels were determined by quantitative real-time PCR; lung cancer cell proliferation and invasion were determined by in vitro functional assays; protein levels were determined by Western blot assay; xenograft nude mice model was used to evaluate the in vivo tumor growth of lung cancer cells; Luciferase reporter assay determined the interactions among FOXD3-AS1, miR-127-3p, and mediator complex subunit 28 (MED28).

RESULTS

Data mining and analysis of the clinical sample showed that FOXD3-AS1 expression was significantly up-regulated in lung cancer tissues. In vitro functional assays demonstrated that FOXD3-AS1 overexpression promoted NSCLC cell proliferation and invasion, while FOXD3-AS1 knockdown exerted tumor-suppressive effects on NSCLC cells. Moreover, FOXD3-AS1 interacted with miR-127-3p by acting as a competing endogenous RNA to suppress miR-127-3p expression, while miR-127-3p repressed MED28 expression by targeting MED28 3' untranslated region in NSCLC cells. Mechanistically, the oncogenic effects of FOXD3-AS1 overexpression were significantly attenuated by miR-127-3p overexpression and MED28 knockdown in NSCLC cells. In the xenograft mice model, FOXD3-AS1 knockdown suppressed in vivo tumor growth of A549 cells, and also up-regulated miR-127-3p expression and repressed MED28 expression in the xenograft tumors. In the clinical aspect, the downregulation of miR-127-3p and up-regulation of MED28 were respectively detected in lung cancer tissues.

CONCLUSIONS

Our findings provided new evidence that the FOXD3-AS1 regulated NSCLC progression via targeting the miR-127-3p/MED28 axis.

Prevalence and Clinical Features of FOG in Chinese PD Patients, a Multicenter and Cross-Sectional Clinical Study

Objectives: Freezing of gait (FOG) is generally considered as an independent symptom of Parkinson's disease (PD) with a complex pathophysiology. There is a wide range of associated clinical features of FOG reported from different studies without consistent conclusion. Thus, a multicenter, cross-sectional study was designed to investigate the prevalence and clinical features of FOG together with its unique contribution quality of life in Chinese PD patients.

Methods: Eight hundred and thirty eight PD patients were consecutively recruited into this study from 12 hospital centers in six provinces in China. Clinical information, including motor and neuropsychological features as well as pharmacological details, was collected.

Results: Of 827 PD patients, 245 (29.63%) reported FOG. The prevalence of FOG was strongly correlated with modified H-Y stages and symptomatic duration (p < 0.01). 84.90% freezers experienced FOG during turning and 88.98% experienced when initiating the first step. Compared with non-freezers, freezers reported longer disease duration (7.73 ± 5.44 vs. 4.69 ± 3.94, p < 0.000), higher frequent PIGD phenotype (61.22 vs. 35.91%, p < 0.000), higher scores of UPDRS III (32.85 ± 15.47 vs. 22.38 ± 12.89, p < 0.000), HAMA (10.99 ± 7.41 vs. 7.59 ± 6.47, p < 0.000), HAMD (15.29 ± 10.29 vs. 10.58 ± 8.97, p < 0.000) and lower MMSE score (25.12 ± 5.27 vs. 26.63 ± 3.97, p < 0.000), and higher daily levodopa dosage (432.65 ± 264.31 vs. 319.19 ± 229.15, p < 0.000) with less frequent initial use of dopaminergic agonist (8.57 vs. 14.78%, p < 0.05). Using binary logistic regression, the associated factors of FOG might be non-tremor dominant onset (OR = 3.817, p < 0.000), the presence of anxiety (OR = 2.048, p < 0.000) and imbalance (OR = 4.320, p = 0.012). Freezers had poorer quality of life than non-freezers and FOG impacted PDQ-8 independently.

Conclusion: Nearly one third of the PD patients experienced FOG. Its frequency increased with PD progression and FOG reduced independently the quality of life. Non-tremor dominant, disease progression, and anxiety were risk factors of FOG.

Molecular Mechanisms Underlying Reciprocal Interactions Between Sleep Disorders and Parkinson's Disease

Sleep-wake disruptions are among the most prevalent and burdensome non-motor symptoms of Parkinson's disease (PD). Clinical studies have demonstrated that these disturbances can precede the onset of typical motor symptoms by years, indicating that they may play a primary function in the pathogenesis of PD. Animal studies suggest that sleep facilitates the removal of metabolic wastes through the glymphatic system via convective flow from the periarterial space to the perivenous space, upregulates antioxidative defenses, and promotes the maintenance of neuronal protein homeostasis. Therefore, disruptions to the sleep-wake cycle have been associated with inefficient metabolic clearance and increased oxidative stress in the central nervous system (CNS). This leads to excessive accumulation of alpha-synuclein and the induction of neuronal loss, both of which have been proposed to be contributing factors to the pathogenesis and progression of PD. Additionally, recent studies have suggested that PD-related pathophysiological alterations during the prodromal phase disrupt sleep and circadian rhythms. Taken together, these findings indicate potential mechanistic interactions between sleep-wake disorders and PD progression as proposed in this review. Further research into the hypothetical mechanisms underlying these interactions would be valuable, as positive findings may provide promising insights into novel therapeutic interventions for PD.

MicroRNA expression profiling after recurrent febrile seizures in rat and emerging role of miR-148a-3p/SYNJ1 axis

Febrile seizures (FSs) are common neurological disorders in both infants and children, although the precise underlying mechanism remains to be explored, especially in the expression pattern and function of microRNAs (miRNAs). In this report, we aimed to screen new potential miRNAs and examine the role of miR-148a-3p in hippocampal neurons in FS rats via Synaptojanin-1 (SYNJ1). Thirty rats were randomly divided into the normal and FS model groups, which were investigated by miRNA array. This process identified 31 differentially expressed (20 upregulated and 11 downregulated) miRNAs and potential miRNA target genes. In addition, hippocampal neurons were assigned into five groups for different transfections. Apoptosis was detected by TUNEL and flow cytometry. SYNJ1 was identified as a target gene of miR-148-3p. In vitro experiments revealed that inhibition of miR-148a-3p decreased neuronal cell apoptosis. Moreover, overexpression of miR-148a-3p resulted in activation of PI3K/Akt signaling pathway and the apoptosis of hippocampal neurons. MiR-148a-3p inhibitor could reverse the above events. Taken together, our data demonstrated that the hippocampal miRNA expression profiles of a rat model of FS provide a large database of candidate miRNAs and neuron-related target genes. Furthermore, miR-148a-3p acted as a apoptosis enhcaner via the activation of the SYNJ1/PI3K/Akt signaling pathway, highlighting a potential therapeutic target in the treatment of infants with hyperthermia-induced brain injury.

Zonisamide for the Treatment of Parkinson Disease: A Current Update

Zonisamide has been used as an add-on treatment in order to overcome the deficiencies of the general therapies currently used to resolve the motor complications and non-motor symptoms of Parkinson disease. Various trials have been designed to investigate the mechanism of action and treatment effects of zonisamide in this condition. Most clinical trials of zonisamide in Parkinson disease were from Japan. The vast majority of studies used changes in the Unified Parkinson’s Disease Rating Scale (UPDRS) scores and daily “OFF” time as primary endpoints. Based on adequate randomized controlled trials, zonisamide is considered a safe and efficacious add-on treatment in Parkinson disease. The most convincing proof is available for a dosage of 25–50 mg, which was shown to lead to a significant reduction in the UPDRS III score and daily “OFF” time, without increasing disabling dyskinesia. Furthermore, zonisamide may play a beneficial role in improving non-motor symptoms in PD, including impulsive–compulsive disorder, rapid eye movement sleep behavior disorder, and dementia. Among the various mechanisms reported, inhibition of monoamine oxidase-B, blocking of T-type calcium channels, modulation of the levodopa–dopamine metabolism, modulation of receptor expression, and neuroprotection are the most often cited. The mechanisms underlying neuroprotection, including modulation of dopamine turnover, induction of neurotrophic factor expression, inhibition of oxidative stress and apoptosis, inhibition of neuroinflammation, modulation of synaptic transmission, and modulation of gene expression, have been most extensively studied. This review focuses on structure, pharmacokinetics, mechanisms, therapeutic effectiveness, and safety and tolerability of zonisamide in patients with Parkinson disease.

P2X4R Overexpression Upregulates Interleukin-6 and Exacerbates 6-OHDA-Induced Dopaminergic Degeneration in a Rat Model of PD

The pathogenesis of Parkinson’s disease (PD) remains elusive. Current thinking suggests that the activation of microglia and the subsequent release of inflammatory factors, including interleukin-6 (IL-6), are involved in the pathogenesis of PD. P2X4 receptor (P2X4R) is a member of the P2X superfamily of ion channels activated by ATP. To study the possible effect of the ATP-P2X4R signal axis on IL-6 in PD, lentivirus carrying the P2X4R-overexpression gene or empty vector was injected into the substantia nigra (SN) of rats, followed by treatment of 6-hydroxydopamine (6-OHDA) or saline 1 week later. The research found the relative expression of P2X4R in the 6-OHDA-induced PD rat models was notably higher than that in the normal. And P2X4R overexpression could upregulate the expression of IL-6, reduce the amount of dopaminergic (DA) neurons in the SN of PD rats, suggesting that P2X4R may mediate the production of IL-6 to damage DA neurons in the SN. Our data revealed the important role of P2X4R in modulating IL-6, which leads to neuroinflammation involved in PD pathogenesis.

Association between epidermal growth factor receptor gene polymorphisms and susceptibility to Parkinson's disease

OBJECTIVE

The progressive loss of dopaminergic neurons in the mesencephalic substantia nigra is recognized as an important pathological feature of Parkinson's disease (PD). Several research studies have suggested that the EGFR signaling pathway may play a significant role in the survival and functional development of dopaminergic neurons. Therefore, genetic variations in these pathways may be related with PD susceptibility. The aim of our study was to explore the association between selected single nucleotide polymorphisms (SNPs) of the epidermal growth factor receptor (EGFR) gene, including rs730437, rs3752651 and rs11506105, and susceptibility to Parkinson's disease in a Han Chinese population.

METHODS

A total of 870 Han Chinese subjects, including 435 PD patients and 435 healthy controls, were enrolled in this case-control study. Peripheral blood was obtained from all subjects for DNA extraction, and selected SNPs (rs730437, rs3752651, rs11506105) of the EGFR gene were genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Differences in the frequencies of genotype and allele gene polymorphisms between patients with PD and healthy controls were analyzed using the Chi-square test. Logistic regression analysis was applied for calculating the odds ratios (ORs) and 95 % confidence intervals (CIs) to evaluate potential associations.

RESULTS

We observed statistically significant differences in rs730437 in the additive models (AC vs. AA: P = 0.047), dominant models (CC + AC vs. AA: P = 0.024) and alleles (C vs. A: P = 0.018). Further subgroup analyses indicated that the C allele of rs730437 showed lower prevalence in the EOPD, compared with matched controls (P = 0.005). The frequency of the GG genotype and G allele for rs11506105 was lower in PD subjects than in healthy controls in the entire study population (P = 0.028, P = 0.034, respectively) and female group (P = 0.024, P = 0.007, respectively). No significant association was found between rs3752651 polymorphism and PD susceptibility in either the whole or subgroup analyses. The analysis of gene haplotypes revealed that the AAT haplotype was related with PD susceptibility.

CONCLUSION

The rs730437 and rs11506105 polymorphisms, but not the rs3752651 polymorphism, of the EGFR gene may be related with susceptibility to PD in a Han Chinese population. An investigation using a larger sample size is warranted to further analyze potential associations between the EGFR gene and PD.

SAT0096 DISCORDANCE BETWEEN SUBJECTIVE AND OBJECTIVE INDEX OF THE DISEASE ACTIVITY SCORE MAY REDUCE THE CORRELATION BETWEEN CLINICAL AND ULTRASOUND ASSESSMENT IN RHEUMATOID ARTHRITIS

Background:

There was discordance between subjective and objective index of the disease activity score, or between clinical parameters and ultrasound findings in some RA patients. Therefore, we set out to determine whether the discordance between subjective and objective index of the composite score could reduce the correlation between clinical and ultrasound parameters in RA.

Objectives:

To investigate whether the discordance between tender and swollen joint count (TJC and SJC) as well as patient’s and evaluator’s global assessment (PGA and EGA) influences the correlation between clinical and US parameters in RA.

Methods:

RA patients with available ultrasonography of 28 joints from Jan 2014 to Jan 2018 were enrolled in the study. Gray-scale (GS) synovial hypertrophy and Power Doppler (PD) synovitis were measured and semi-quantitatively graded. The total GS/PD score was the sum score of 28 joints. SJC and TJC based on 28 joints, PGA and EGA of all the patients were evaluated by one rheumatologist. The numeric difference between TJC and SJC (ΔTSJ) and that between PGA and EGA (ΔPEG) were calculated. The correlation between clinical and ultrasound parameters in different ΔTSJ and ΔPEG subgroups was explored.

Results:

Totally 163 patients were enrolled in the study. Clinical composite disease activity scores and all the components were significantly correlated with the total GS and PD scores (p<0.01 for all). But the relevance between the clinical disease parameters and total PD score became weak, with the increase of ΔTSJ. For the patients with ΔTSJ > 5, the total PD score was only correlated with CRP, EGA and PGA, while the total GS score was only correlated with CRP. Similarly, no correlation between total PD score and clinical parameters, except for SJC, was observed in patients with ΔPEG < 0 (p < 0.05).

Conclusion:

Total PD/GS score was correlated well with the clinical parameters of disease activity, including both the subjective and objective indexes. But for patients with ΔTSJ > 5,there was no correlation between total GS/PD scores and clinical composite disease activity scores, except that only the objective index (CRP, SJC and EGA) were more likely to correlate with total GS/PD scores.

Disclosure of Interests:

None declared

RAGE Silencing Ameliorates Neuroinflammation by Inhibition of p38-NF-κB Signaling Pathway in Mouse Model of Parkinson's Disease

Accumulating evidence suggested that neuroinflammation played a crucial role in dopaminergic neuronal death in Parkinson's disease (PD). The receptor for advanced glycation end products (RAGE), a multi-ligand receptor of the immunoglobulin superfamily, has been proposed as a key molecule in the onset and sustainment of the inflammatory response. Engagement of RAGE contributed to neuroinflammation by upregulating nuclear factor-κB (NF-κB) as well as cytokines. The aim of the present study was to investigate the expression of RAGE in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated mice and elucidate the RAGE signal pathway involved in the inflammation. Results showed that RAGE protein and pro-inflammatory cytokines cyclooxygenase type 2 (COX-2) were upregulated in MPTP-treated mice. Further experiments showed that RAGE ablation inhibited phosphorylation of IκB and p38 and protected nigral dopaminergic neurons against cell death in the substantia nigra (SN). These results suggested that RAGE participated in the pathogenesis of PD by neuroinflammation and p38MAPK-NFκB signal pathway may be involved in the process. Moreover, interfering with RAGE signaling pathway may be a reasonable therapeutic option in slowing PD development and progression.

microRNA-331-3p attenuates neuropathic pain following spinal cord injury via targeting RAP1A

Neuropathic pain (NP) after spinal cord injury (SCI) leads to compromised physical and cognitive functions in a majority of patients. Aberrant miRNA expression plays vital roles in the pathogenesis of SCI. This study aims to investigate the effect of miR-331-3p in rats following SCI. Microarray assay was performed in SCI- and sham-operated rats to evaluate the expression of miR-331-3p. Assigned SCI rats were treated with miR-331-3p agomiR alone or miR-331-3p agomiR plus RAP1A-expressing lentivirus or control agomiR. Rat locomotor performance was evaluated by BBB locomotor rating scale. Neuronal tissue damage and apoptosis were detected by histological analyses and Western blot. Inflammation in spinal cord was determined by detection of the expression of inflammatory genes with qRT-PCR, and ELISA. Downstream expression of RAP1A was measured by Western blot. The results showed that SCI induced the downregulation of miR-331-3p in the spinal cord of SCI rats. Overexpression of miR-331-3p improved the locomotor performance, reduced tissue damage, neuronal apoptosis and inflammation in rat SCI model. Rap1a (Ras-related protein Rap-1A) was predicted as a downstream target for miR-331-3p, and upregulation of RAP1A impaired the beneficial effect of miR-331-3p post- SCI, which was shown as worse locomotor activity, more severe tissue damage, as well as promoting apoptosis and inflammation in SCI rats. Furthermore, miR-331-3p reduced the activation of RAP1A downstream genes via inhibiting RAP1A expression. These findings indicate a protective role of miR- 331-3p in the development of SCI via the modulation of RAP1A, and may help to develop novel therapy against SCI-induced complications.

Laquinimod inhibits MMP+ induced NLRP3 inflammasome activation in human neuronal cells

Objective: Nod-like receptor protein 3 (NLRP3) inflammasome plays anessentialrole in neuroinflammation in the Parkinson's disease (PD) progression. Laquinimodis an immunomodulator that is clinically used for the treatment of multiple sclerosis. This study aims to investigate whether laquinimod possessesa protective effect against MPP+-induced NLRP3 activation.Materials and methods: In a variety of tests on human SH-SY5Y neuronal cells, 1-methyl-4-phenyl Pyridine (MPP+) was used to mimic the microenvironment of PD. Activation of NLRP3 inflammasome was measured by western blot analysis and enzyme linked immunosorbent assay (ELISA).Results: Laquinimod had a significant protective impact against MPP+-induced neurotoxicity. Our results demonstrate that laquinimod prevented MPP+-induced reduction of cell proliferation, the release of lactate dehydrogenase (LDH), and apoptosis. Importantly, treatment with laquinimod significantly inhibited the activation of the NLRP3 inflammasome by reducing the levels of its components, including NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC), and cleaved caspase 1 (P10). Consistently, laquinimod prevented MPP+-induced secretions of interleukin 1β (IL-1β) and interleukin-18 (IL-18). Additionally, laquinimod also reduced the expression of other related factors, such as intracellular reactive oxygen species (ROS), NADPH oxidase 4 (NOX-4), thioredoxin-interacting protein (TxNIP). Furthermore, laquinimod prevented the reduction of sirtuin 1 (SIRT1) from MPP+ stimulation. Inhibition of SIRT1 abolished the protective effects of laquinimod against the activation of the NLRP3 inflammasome, suggesting the involvement of SIRT1 in this process.Conclusion: These findings suggest that laquinimod treatment might be a possible therapeutic strategy for neuroinflammation in PD.

Association Between Stroke and Parkinson's Disease: a Meta-analysis

Parkinson's disease (PD) and stroke are both associated with aging, but the relationship between these two disorders remains unclear. Recent evidence has shown that they frequently co-occur and are influenced by each another, although some studies have found inconsistent results. We performed this meta-analysis of patients with PD on stroke risk to clarify the relationship between these two disorders on the basis of the studies published from 1975 to July 2019 in the PubMed, EMBASE, and Cochrane Library databases. In total, 13 case-control studies met the inclusion criteria for meta-analysis. The pooled odds ratio (OR) for PD in relation to the stroke risk was 1.72 (95% confidence interval (CI) 1.19-2.49). The OR for the presence of cerebral infarct among PD in the four studies was 1.35 (95% CI 1.04-1.74). Moreover, the OR for the presence of stroke pathology among PD in the four postmortem studies was 1.86 (95% CI 1.17-2.98). In conclusion, our meta-analysis suggests that there is an association between stroke and PD. Sensitivity analysis was used to test the robustness of our results through the sequential removal of each one study at time, in order to investigate if a single study was driving the study results. These results indicate that PD and stroke may have a common pathogenesis and may share preventive treatment measures.

Emerging Role of Sirtuin 2 in Parkinson's Disease

Parkinson’s disease (PD), the main risk factor of which is age, is one of the most common neurodegenerative diseases, thus presenting a substantial burden on the health of affected individuals as well as an economic burden. Sirtuin 2 (SIRT2), a subtype in the family of sirtuins, belongs to class III histone deacetylases (HDACs). It is known that SIRT2 levels increase with aging, and a growing body of evidence has been accumulating, showing that the activity of SIRT2 mediates various processes involved in PD pathogenesis, including aggregation of α-synuclein (α-syn), microtubule function, oxidative stress, inflammation, and autophagy. There have been conflicting reports about the role of SIRT2 in PD, in that some studies indicate its potential to induce the death of dopaminergic (DA) neurons, and that inhibition of SIRT2 may, therefore, have protective effects in PD. Other studies suggest a protective role of SIRT2 in the context of neuronal damage. As current treatments for PD are directed at alleviating symptoms and are very limited, a comprehensive understanding of the enzymology of SIRT2 in PD may be essential for developing novel therapeutic agents for the treatment of this disease. This review article will provide an update on our knowledge of the structure, distribution, and biological characteristics of SIRT2, and highlight its role in the pathogenesis of PD.

418 Ultrasound molecular imaging of the role of von willebrand factor-mediated platelet adhesion in atherogenesis

Funding Acknowledgements

JSPS Overseas Research Fellowship

Background

Platelets are known to be both pro-inflammatory and pro-mitogenic. However, the role of platelet-endothelial interactions in the initiation and growth of atherosclerotic lesions is not well understood.

Purpose

We used contrast-enhanced ultrasound (CEU) molecular imaging of the arterial endothelium to test the hypothesis that platelet attachment to endothelial Von Willebrand Factor (VWF) promotes atherogenesis.

Methods

We studied wild-type mice (WT), low-density lipoprotein deficient mice fed western diet to produce atherosclerosis (LDLR-/-), and LDLR-/- mice also deficient for ADAMTS-13 (LDLR-/-ADAMTS13-/-) which is the enzyme responsible for proteolytic cleavage of endothelial-associated VWF. Mice were studied at 20 weeks and 30 weeks of age. A subset of LDLR-/- mice were treated with recombinant ADAMTS13 1 hr prior to study. Proximal aortic CEU molecular imaging of P-selectin, vascular cell adhesion molecule (VCAM)-1, von Willebrand factor (VWF), and platelet GPIbα was performed. Aortic distensibility was assessed using high-frequency (30 MHz) transthoracic echocardiography and tail cuff blood pressure systems. NF-κB of aorta was assessed by ELISA kit. Plaque size and composition were assessed by histology. Platelets and macrophage immunohistochemistry were also performed on confocal microscopy.

Results

Aortic molecular imaging signal for P-selectin, VCAM-1, VWF, and platelet adhesion was significantly higher in LDLR-/- than WT mice, and increased by 2-fold between 20 and 30 wks of age. Signal for VWF and platelet adhesion was abolished 1 h after administration of ADAMTS13, confirming that platelet adhesion was VWF-mediated. At 20 and 30 wks of age, molecular imaging signal for all targets was 2-fold higher (p &lt; 0.01) in LDLR-/-ADAMTS13-/- versus LDLR-/- mice. The LDLR-/-ADAMTS13-/- mice also had lower aortic distensibility (p &lt; 0.05), had a 2-fold higher NF-κB signal (p &lt; 0.05), and had a 2-fold greater total plaque area (p &lt; 0.01). Fluorescent immunohistochemistry confirmed that the LDLR-/-ADAMTS13-/- mice also had greater platelets (p &lt; 0.05) and increased macrophage content (p &lt; 0.05) than LDLR-/- mice in aortic plaque.

Conclusion

In early to mid-stage atherosclerosis, abnormal regulation of endothelial-associated VWF results in platelet adhesion and secondary up-regulation of endothelial inflammatory adhesion molecules, thereby promoting atherosclerotic plaque progression. These results indicate an important role of platelet-endothelial interactions in early atherogenesis.

Abstract 418 Figure

Prion-Like Mechanisms in Parkinson's Disease

Formation and aggregation of misfolded proteins in the central nervous system (CNS) is a key hallmark of several age-related neurodegenerative diseases, including Parkinson’s disease (PD), Alzheimer’s disease (AD), and amyotrophic lateral sclerosis (ALS). These diseases share key biophysical and biochemical characteristics with prion diseases. It is believed that PD is characterized by abnormal protein aggregation, mainly that of α-synuclein (α-syn). Of particular importance, there is growing evidence indicating that abnormal α-syn can spread to neighboring brain regions and cause aggregation of endogenous α-syn in these regions as seeds, in a “prion-like” manner. Abundant studies in vitro and in vivo have shown that α-syn goes through a templated conformational change, propagates from the original region to neighboring regions, and eventually cause neuron degeneration in the substantia nigra and striatum. The objective of this review is to summarize the mechanisms involved in the aggregation of abnormal intracellular α-syn and its subsequent cell-to-cell transmission. According to these findings, we look forward to effective therapeutic perspectives that can block the progression of neurodegenerative diseases.

Determinants of diagnostic latency in Chinese people with Parkinson's disease

Background

Clinical diagnosis of Parkinson’s disease (PD) has always lagged behind clinical symptoms. The diagnostic latency might be influenced by many factors. The diagnostic latency of Chinese people with PD has been unknown. Here we designed this cross-sectional study with the purpose to identify the diagnostic latency and its determinants in Chinese people with PD.

Methods

One hundred and thirty-one newly diagnosed people with PD were recruited into this study. Demographic and clinical characteristics as well as a detailed clinical history were collected. Motor and non-motor symptoms (NMSs) severity were assessed with appropriate assessment scales. Medical professional types in the first medical consultations were also recorded. According to the initially presenting motor phenotypes, patients would be divided into the groups of rest tremor, limb rigidity, movement slowness and walking problems. The investigated variables would be compared among the four groups.

Results

The PD diagnostic latency in China was around 15 months. It closely correlated to the severity of motor symptoms, anxiety and depression as well as the number of NMSs. The diagnostic latency significantly varied among the groups of different motor phenotypes of onset. Finally, initially presenting with limb rigidity, having more NMSs, motor symptoms at a more serious degree and the initial medical consultations with physicians or specialists of non-neurology were considered as determinants of a longer diagnostic latency of PD.

Conclusions

Patients presenting with minor motor symptoms and disturbing NMSs as well as physicians’ unfamiliarity with PD symptomology were determinants of the diagnostic delay of PD. Health education in community and improvement of the referral system might be proper strategies to shorten the diagnostic latency of PD.

TGF-β in Mice Ameliorates Experimental Autoimmune Encephalomyelitis in Regulating NK Cell Activity

Multiple sclerosis is a disease characterized by inflammation and demyelination located in the central nervous system. Experimental autoimmune encephalomyelitis (EAE) is the most common animal model for multiple sclerosis (MS). Although the roles of T cells in MS/EAE have been well investigated, little is known about the functions of other immune cells in the neuroinflammation model. Here we found that an essential cytokine transforming growth factor β (TGF-β) which could mediate the differentiation of Th17/regulatory T cells was implicated in the natural killer (NK) cells’ activity in EAE. In EAE mice, TGF-β expression was first increased at the onset and then decreased at the peak, but the expressions of TGF-β receptors and downstream molecules were not affected in EAE. When we immunized the mice with MOG antigen, it was revealed that TGF-β treatment reduced susceptibility to EAE with a lower clinical score than the control mice without TGF-β. Consistently, inflammatory cytokine production was reduced in the TGF-β treated group, especially with downregulated pathogenic interleukin-17 in the central nervous system tissue. Furthermore, TGF-β could increase the transcription level of NK cell marker NCR1 both in the spleen and in the CNS without changing other T cell markers. Meanwhile TGF-β promoted the proliferation of NK cell proliferation. Taken together, our data demonstrated that TGF-β could confer protection against EAE model in mice through NK cells, which would be useful for the clinical therapy of MS.

Mortality and prognostic factors in Chinese patients with systemic lupus erythematosus

Objectives

To investigate the mortality and causes of death in Chinese patients with systemic lupus erythematosus.

Methods

We collected the clinical data of all consecutive adult systemic lupus erythematosus patients at the Rheumatology department of Peking University First Hospital between January 2007 and December 2015. The primary causes of death were identified, the standardized mortality ratio and years of life lost were calculated, and the survival and variables associated with mortality were determined by Kaplan–Meier and Cox regression analysis respectively.

Results

The mean age of all 911 patients (814 females and 97 males) was 37.8 ± 14.7 years, the median disease duration at recruitment was 2.6 (0.5–7.0) years, and the median follow-up duration was 3.0 (1.4–5.1) years. Among the 911 patients who were successfully followed up, 45 patients died. Infection (31.1%) was the leading cause of death followed by renal failure, pulmonary arterial hypertension and cerebrovascular diseases. The overall age and sex-adjusted standardized mortality ratio was 3.2 (95% confidence interval 2.4–4.0), and the years of life lost for women and men were 29.8 and 9.4 respectively. Overall survival at 1, 5 and 10 years was 98.2%, 95.3% and 93.7% respectively. Older age at disease onset, infection, autoimmune hemolytic anemia, thrombocytopenia and pulmonary arterial hypertension were independent risk factors for the mortality of systemic lupus erythematosus patients, and longer disease duration at recruitment was an independent protective factor.

Conclusions

Mortality of systemic lupus erythematosus patients in China was substantial, especially in females, with infection the leading cause of death. Older age at disease onset, infection, autoimmune hemolytic anemia, thrombocytopenia and pulmonary arterial hypertension were associated with poor outcomes.

The Role of Insulin/IGF-1/PI3K/Akt/GSK3β Signaling in Parkinson's Disease Dementia

Dementia, a condition that frequently afflicts patients in advanced stages of Parkinson's disease (PD), results in decreased quality of life and survival time. Nevertheless, the pathological mechanisms underlying Parkinson's disease dementia (PDD) are not completely understood. The symptoms characteristic of PDD may be the result of functional and structural deficiencies. The present study implicates the accumulation of Lewy bodies in the cortex and limbic system as a potent trigger in the development of PDD. In addition, significant Alzheimer-type pathologies, including amyloid-β (Aβ) plaques and NFTs, are observed in almost half of PDD patients. Interestingly, links between PDD pathogenesis and the mechanisms underlying the development of insulin resistance have begun to emerge. Furthermore, previous studies have demonstrated that insulin treatment reduces amyloid plaques in Alzheimer's disease (AD), and normalizes the production and functionality of dopamine and ameliorates motor impairments in 6-OHDA-induced rat PD models. GSK3β, a downstream substrate of PI3K/Akt signaling following induction by insulin and IGF-1, exerts an influence on AD and PD physiopathology. The genetic overexpression of GSK3β in cortex and hippocampus results in signs of neurodegeneration and spatial learning deficits in in vivo models (Lucas et al., 2001), whereas its inhibition results in improvements in cognitive impairment in these rodents, including AD and PD. Accordingly, insulin- or IGF-1-activated PI3K/Akt/GSK3β signaling may be involved in PDD pathogenesis, at least in the pathology of PD-type + AD-type.

Association between SNCA rs2736990 polymorphism and Parkinson's disease: a meta-analysis

Emerging evidence suggests that the SNP rs2736990 of SNCA is a susceptibility factor for idiopathic Parkinson's disease (PD) in different populations, but the studies which examined the association have provided inconsistent results. Therefore, we performed a meta-analysis of some case-control studies to obtain a more exact estimation of there associations. All the relevant studies were extracted from PubMed, Embase, EBSCO, Chineses national knowledge infrastructure, Google Scholar and Wanfang databases (up to February 2017). A total of six studies with 2525 PD cases and 2165 controls were eventually enrolled in the present meta-analysis based on the strict inclusion and exclusion criteria. The pooled analysis showed that there is a significant association between rs2736990 polymorphism and PD susceptibility in all genetic models (T vs. C: OR=0.772, 95%CI: 0.709-0.840, P=0.001; TT vs. CC: OR=0.586, 95%CI: 0.490-0.701, P=0.001; TC vs. CC: OR=0.814, 95%CI: 0.716-0.925, P=0.002; TT+TC vs. CC: OR=0.752, 95%CI: 0.666-0.848, P=0.001; TT vs. TC+CC: OR=0.658, 95%CI: 0.561-0.772, P=0.001). Our meta-analysis provides evidence that the T allele, TT and TC genotype of rs2736990(C/T) polymorphism may decrease the risk of PD.

Relationship between mitochondrial DNA A10398G polymorphism and Parkinson's disease: a meta-analysis

Many studies have researched the mitochondrial DNA (mtDNA) A10398G in Parkinson's disease (PD) to determine the association between mtDNA A10398G and PD, but the results of their research were not consistent. Therefore, we performed a meta-analysis to demonstrate the connection between mtDNA A10398G and the susceptibility of PD. We searched PubMed, Web of Science, Springer Link, EMBASE and EBSCO databases up to identify relevant studies. Through strict inclusion and exclusion criteria, at last, 9 studies (total 3381 cases and 2810 controls) were included in our meta-analysis. We used the STATA 12.0 statistics software to calculate the pooled odds ratios (ORs) and 95% confidence intervals (CIs) to evaluate the genetic association between mtDNA A10398G and the risk of PD. We performed subgroup analysis to clarify the possible roles of the mtDNA A10398G polymorphism in the aetiology of PD in different ethnicities. Our meta-analysis indicates that although there was no significant association between mtDNA A10398G and PD in the Asian population (G vs. A: OR = 1.090, 95% CI = 0.939–1.284, P = 0.242), in the Caucasian population the G allele of mtDNA A10398G mutations may be a potential protective factor of PD (G vs. A: OR = 0.699, 95% CI = 0.546–0.895, P = 0.005). Further well-designed studies with larger samples are needed to validate these results.

Single nucleotide polymorphisms in the toll-like receptor 2 (TLR2) gene are associated with sporadic Parkinson's disease in the North-eastern Han Chinese population

Growing evidences suggested that inflammatory process played a critical role in the pathogenesis of Parkinson's disease (PD). Given that TLR2 has been implicated in the perpetuation of inflammatory responses in the central nervous system (CNS), we investigated the association between two genetic variants (rs3804099 and rs3804100) of TLR2 and sporadic PD in Han Chinese population. 395 Han Chinese sporadic PD patients and 413 healthy age and gender-matched controls were genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The sporadic PD patients showed a higher T allele frequency than the healthy-matched control (p=0.019). Furthermore rs3804099 dominate model TT versus (vs.) TC+CC increase the risk of sporadic PD (OR=1.376, 95%CI=1.043-1.814, p=024). From the subgroup analysis, the variant allele T of rs3804099 was higher in sporadic PD cases (73.1%) than in controls (67.4%) in the late-onset cohort. Meanwhile rs3804099 revealed significant association in dominant model: Subjects with TT genotypes vs. those with TC+CC genotype showed evident significant in late-onset cohort (LOPD OR=1.417, 95%CI=1.051-1.911, p=022). In contrast, allele frequencies at rs3804100 were similar between patients and controls. Taken together, this study reveals that polymorphism of TLR2 locus is associated with risk of sporadic PD in the North-eastern part of Han Chinese population. Further studies are required to evaluate the association.

Gq-activated fibroblasts induce cardiomyocyte action potential prolongation and automaticity in a three-dimensional microtissue environment

Cardiac fibroblasts (CFs) are known to regulate cardiomyocyte (CM) function in vivo and in two-dimensional in vitro cultures. This study examined the effect of CF activation on the regulation of CM electrical activity in a three-dimensional (3-D) microtissue environment. Using a scaffold-free 3-D platform with interspersed neonatal rat ventricular CMs and CFs, G_q-mediated signaling was selectively enhanced in CFs by Gα_q adenoviral infection before coseeding with CMs in nonadhesive hydrogels. After 3 days, the microtissues were analyzed by signaling assay, histological staining, quantitative PCR, Western blots, optical mapping with voltage- or Ca²⁺-sensitive dyes, and microelectrode recordings of CF resting membrane potential (RMP_CF). Enhanced G_q signaling in CFs increased microtissue size and profibrotic and prohypertrophic markers. Expression of constitutively active Gα_q in CFs prolonged CM action potential duration (by 33%) and rise time (by 31%), prolonged Ca²⁺ transient duration (by 98%) and rise time (by 65%), and caused abnormal electrical activity based on depolarization-induced automaticity. Constitutive G_q activation in CFs also depolarized RMP_CF from -33 to -20 mV and increased connexin 43 and connexin 45 expression. Computational modeling confers that elevated RMP_CF and increased cell-cell coupling between CMs and CFs in a 3-D environment could lead to automaticity. In conclusion, our data demonstrate that CF activation alone is capable of altering action potential and Ca²⁺ transient characteristics of CMs, leading to proarrhythmic electrical activity. Our results also emphasize the importance of a 3-D environment where cell-cell interactions are prevalent, underscoring that CF activation in 3-D tissue plays a significant role in modulating CM electrophysiology and arrhythmias.NEW & NOTEWORTHY In a three-dimensional microtissue model, which lowers baseline activation of cardiac fibroblasts but enables cell-cell, paracrine, and cell-extracellular matrix interactions, we demonstrate that selective cardiac fibroblast activation by enhanced G_q signaling, a pathophysiological trigger in the diseased heart, modulates cardiomyocyte electrical activity, leading to proarrhythmogenic automaticity.

Assessments of plasma ghrelin levels in the early stages of parkinson's disease

BACKGROUND

Gastrointestinal symptoms are early events in Parkinson's disease (PD). The gastrointestinal hormone ghrelin was neuroprotective in the nigrostriatal dopamine system. The objective of this study was to assess ghrelin levels in the early stages of PD.

METHODS

Plasma was collected in the fasting state in 291 PD patients in stages 1-3 and 303 age- and sex-matched healthy controls. Additional samples were taken in the glucose response test to assess nutrition-related ghrelin levels in 20 PD patients and 20 healthy controls. The enzyme-linked immunosorbent assay was used to measure total and active plasma ghrelin levels.

RESULTS

We reported that total and active plasma ghrelin levels were decreased in PD, although there was no difference across progressive PD stages. Postprandial ghrelin suppression and preprandial peak responses were both attenuated in PD.

CONCLUSIONS

Plasma ghrelin levels were decreased in PD; however, this event might be irrelevant to PD progression. Ghrelin responses to meals were also impaired in PD. © 2017 International Parkinson and Movement Disorder Society.