Parkinson's disease

Human amniotic epithelial stem cell-derived dopaminergic neuron-like cells ameliorate motor dysfunction in a rat model of Parkinson's disease

AIMS

Parkinson's disease (PD) remains a substantial clinical challenge due to the progressive loss of midbrain dopaminergic (DA) neurons in nigrostriatal pathway. In this study, human amniotic epithelial stem cells (hAESCs)-derived dopaminergic neuron-like cells (hAESCs-DNLCs) were generated, with the aim of providing new therapeutic approach to PD.

MATERIALS AND METHODS

hAESCs, which were isolated from discarded placentas, were induced to differentiate into hAESCs-DNLCs by following a "two stages" induction protocol. The differentiation efficiency was assessed by quantitative real-time PCR (qRT-PCR), immunocytochemistry (ICC), and ELISA. Immunogenicity, cell viability and tumorigenicity of hAESCs-DNLC were analyzed before in vivo experiments. Subsequently, hAESCs-DNLCs were transplanted into PD rats, behavioral tests were monitored after graft, and the regeneration of DA neurons was detected by immunohistochemistry (IHC). Furthermore, to trace hAESCs-DNLCs in vivo, cells were pre-labeled with PKH67 green fluorescence.

KEY FINDINGS

hAESCs were positive for pluripotent markers and highly expressed neural stem cells (NSCs) markers. Based on this, we established an induction method reliably generates hAESCs-DNLCs, which was evidenced by epithelium-to-neuron morphological changes, elevated expressions of neuronal and DA neuronal markers, and increased secretion of dopamine. Moreover, hAESCs-DNLCs maintained high cell viability, no tumorigenicity and low immunogenicity, suggesting hAESCs-DNLCs an attractive implant for PD therapy. Transplantation of hAESCs-DNLCs into PD rats significantly ameliorated motor disorders, as well as enhanced the reinnervation of TH+ DA neurons in nigrostriatal pathway.

SIGNIFICANCE

Our study has demonstrated evident therapeutic effects of hAESCs-DNLCs, and provides a safe and promising solution for PD.

The Role of Glia Telomere Dysfunction in the Pathogenesis of Central Nervous System Diseases

Maintaining the telomere length is decisive for the viability and homeostasis process of all the cells of an organism, including human glial cells. Telomere shortening of microglial cells has been widely associated with the onset and progression of neurodegenerative diseases such as Parkinson's and Alzheimer's disease. Additionally, traumatic brain injury appears to have a positive correlation with the telomere-shortening process of microglia, and telomere length can be used as a non-invasive biomarker for the clinical management of these patients. Moreover, telomere involvement through telomerase reactivation and homologous recombination also known as the alternative lengthening of telomeres (ALT) has been described in gliomagenesis pathways, and particular focus has been given in the translational significance of these mechanisms in gliomas diagnosis and prognostic classification. Finally, glia telomere shortening is implicated in some psychiatric diseases. Given that telomere dysfunction of glial cells is involved in the central nervous system (CNS) disease pathogenesis, it represents a promising drug target that could lead to the incorporation of new tools in the medicinal arsenal for the management of so far incurable conditions.

Exploring the complex interplay between Parkinson's disease and BAG proteins

Parkinsons disease (PD) is a chronic fast growing neurodegenerative disorder of Central Nervous System (CNS) characterized by progressive loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc) and formation of Lewy bodies (LBs) which causes dopamine deficiency within basal ganglia leading to motor and non-motor manifestation. According to reports, many factors are responsible for pathogenesis of PD which includes environmental factors, genetic factors, and aging factors. Whereas death of dopaminergic neurons is also caused by oxidative stress, neuroinflammation, and autophagy disorder. Molecular chaperones/co-chaperones are proteins that binds to an unstable conformer of another protein and stabilizes it. Chaperones prevent incorrect interaction between non-native polypeptides which increases the yield but not the rate of reaction. The Bcl-2-associated athanogene (BAG) is a multifunctional group of proteins belonging to BAG family of co-chaperones. Recent studies demonstrates that chaperones interact with PD-related proteins. Co-chaperones like BAG family proteins regulate the function of chaperones. Molecular chaperones regulate the mitochondrial functions by interacting with the PD-related proteins associated with it. This review studies the contribution of chaperones and PD-related proteins in pathogenesis of PD aiming to provide an alternate molecular target for preventing the disease progression.

Targeting calciumopathy for neuroprotection: focus on calcium channels Cav1, Orai1 and P2X7

As the uncontrolled entry of calcium ions (Ca2+) through plasmalemmal calcium channels is a cell death trigger, the conjecture is here raised that mitigating such an excess of Ca2+ entry should rescue from death the vulnerable neurons in neurodegenerative diseases (NDDs). However, this supposition has failed in some clinical trials (CTs). Thus, a recent CT tested whether isradipine, a blocker of the Cav1 subtype of voltage-operated calcium channels (VOCCs), exerted a benefit in patients with Parkinson's disease (PD); however, outcomes were negative. This is one more of the hundreds of CTs done under the principle of one-drug-one-target, that have failed in Alzheimer's disease (AD) and other NDDs during the last three decades. As there are myriad calcium channels to let Ca2+ ions gain the cell cytosol, it seems reasonable to predict that blockade of Ca2+ entry through a single channel may not be capable of preventing the Ca2+ flood of cells by the uncontrolled Ca2+ entry. Furthermore, as Ca2+ signaling is involved in the regulation of myriad functions in different cell types, it seems also reasonable to guess that a therapy should be more efficient by targeting different cells with various drugs. Here, we propose to mitigate Ca2+ entry by the simultaneous partial blockade of three quite different subtypes of plasmalemmal calcium channels that is, the Cav1 subtype of VOCCs, the Orai1 store-operated calcium channel (SOCC), and the purinergic P2X7 calcium channel. All three channels are expressed in both microglia and neurons. Thus, by targeting the three channels with a combination of three drug blockers we expect favorable changes in some of the pathogenic features of NDDs, namely (i) to mitigate Ca2+ entry into microglia; (ii) to decrease the Ca2+-dependent microglia activation; (iii) to decrease the sustained neuroinflammation; (iv) to decrease the uncontrolled Ca2+ entry into neurons; (v) to rescue vulnerable neurons from death; and (vi) to delay disease progression. In this review we discuss the arguments underlying our triad hypothesis in the sense that the combination of three repositioned medicines targeting Cav1, Orai1, and P2X7 calcium channels could boost neuroprotection and delay the progression of AD and other NDDs.

Combining blood pressure variability and heart rate variability to analyze the autonomic nervous function of rotenone induced Parkinson's rat model

BACKGROUND

Parkinson's patients have significant autonomic dysfunction, early detect the disorder is a major challenge. To assess the autonomic function in the rat model of rotenone induced Parkinson's disease (PD), Blood pressure and ECG signal acquisition are very important.

NEW METHOD

We used telemetry to record the electrocardiogram and blood pressure signals from awake rats, with linear and nonlinear analysis techniques calculate the heart rate variability (HRV) and blood pressure variability (BPV). we applied nonlinear analysis methods like sample entropy and detrended fluctuation analysis to analyze blood pressure signals. Particularly, this is the first attempt to apply nonlinear analysis to the blood pressure evaluate in rotenone induced PD model rat.

RESULTS

HRV in the time and frequency domains indicated sympathetic-parasympathetic imbalance in PD model rats. Linear BPV analysis didn't reflect changes in vascular function and blood pressure regulation in PD model rats. Nonlinear analysis revealed differences in BPV, with lower sample entropy results and increased detrended fluctuation analysis results in the PD group rats.

COMPARISON WITH EXISTING METHODS AND CONCLUSIONS

our experiments demonstrate the ability to evaluate autonomic dysfunction in models of Parkinson's disease by combining the analysis of BPV with HRV, consistent with autonomic impairment in PD patients. Nonlinear analysis by blood pressure signal may help in early detection of the PD. It indicates that the fluctuation of blood pressure in the rats in the rotenone model group tends to be regular and predictable, contributes to understand the PD pathophysiological mechanisms and to find strategies for early diagnosis.

The marine-derived compound TAG alleviates Parkinson's disease by restoring RUBCN-mediated lipid metabolism homeostasis

Parkinson's disease (PD) is the second most common neurodegenerative disease, and its prevalence is increasing. Currently, no effective therapies for PD exist. Marine-derived natural compounds are considered important resources for the discovery of new drugs due to their distinctive structures and diverse activities. In this study, tetrahydroauroglaucin (TAG), a polyketide isolated from a marine sponge, was found to have notable neuroprotective effects on MPTP/MPP+-induced neurotoxicity. RNA sequencing analysis and metabolomics revealed that TAG significantly improved lipid metabolism disorder in PD models. Further investigation indicated that TAG markedly decreased the accumulation of lipid droplets (LDs), downregulated the expression of RUBCN, and promoted autophagic flux. Moreover, conditional knockdown of Rubcn notably attenuated PD-like symptoms and the accumulation of LDs, accompanied by blockade of the neuroprotective effect of TAG. Collectively, our results first indicated that TAG, a promising PD therapeutic candidate, could suppress the accumulation of LDs through the RUBCN-autophagy pathway, which highlighted a novel and effective strategy for PD treatment.

Outcomes following spinal instrumented fusions in patients with parkinson's disease: a systematic review and meta-analysis

BACKGROUND

Parkinson's Disease (PD) patients represent challenging spinal surgery candidates due to associated frailty and deformity. This study consolidates the literature concerning spinal surgery outcomes in PD versus non-PD patients, to evaluate if PD predisposes patients to worse post-operative outcomes, so that treatment protocols can be optimised.

METHODS

A systematic review and meta-analysis was conducted of PubMed/Medline, Embase, and Google Scholar databases per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies of interest included comparative (PD versus non-PD) cohorts undergoing spinal instrumented fusions. Post-operative clinical outcomes were collated and compared for significance between cohorts. Further analysis was made on outcomes based on the different surgical procedures performed (Anterior Cervical Discectomy and Fusion (ACDF), Thoracolumbar or Lumbar fusions, Thoracolumbar or Lumbar fusions without Osteoporotic Vertebral Compression fracture (OVCF) patients). All statistical analysis was performed using The R Project for Statistical Computing (version 4.1.2), with a p-value of < 0.05 deemed statistically significant.

RESULTS

In total, 2,323,650 patients were included across 16 studies. Of those, 2,308,949 (99.37%) were patients without PD (non-PD), while 14,701 (0.63%) patients had PD at time of surgery. The collective mean age was 68.23 years (PD: 70.14 years vs non-PD: 64.86 years). Comparatively, there were 844,641 males (PD: 4,574; non-PD: 840,067) and 959,908 females (PD: 3,213; non-PD: 956,695). Overall, there were more post-operative complications in the PD cohort. Specifically, PD patients experienced significantly more surgical site infections (p = 0.01), increased rates of revision surgeries (p = 0.04) and increased venous thromboembolic events (p = 0.02) versus the non-PD cohort. In thoracolumbar/lumbar spinal fusions without OVCF patients, the PD cohort had increased rates of revision surgeries (p < 0.01) in comparison to the non-PD cohort. However, when including OVCF patients in thoracolumbar/lumbar spinal fusions, the PD cohort had significantly higher amounts of postoperative complications (p = 0.01), pneumonia (p = 0.02), and revision surgeries (p < 0.01) when compared to the non-PD cohort.

CONCLUSION

Although more robust prospective studies are needed, the results of this study highlight the need for advanced wound care management in the postoperative period, both in-hospital and in the community, in addition to comprehensive multidisciplinary care from allied health professionals, with potential for the use of Enhanced Recovery After Surgery (ERAS) protocols in PD patients undergoing spinal instrumented fusions.

Zeolite and Neurodegenerative Diseases

Neurodegenerative diseases (NDs), characterized by progressive degeneration and death of neurons, are strongly related to aging, and the number of people with NDs will continue to rise. Alzheimer's disease (AD) and Parkinson's disease (PD) are the most common NDs, and the current treatments offer no cure. A growing body of research shows that AD and especially PD are intricately related to intestinal health and the gut microbiome and that both diseases can spread retrogradely from the gut to the brain. Zeolites are a large family of minerals built by [SiO4]4- and [AlO4]5- tetrahedrons joined by shared oxygen atoms and forming a three-dimensional microporous structure holding water molecules and ions. The most widespread and used zeolite is clinoptilolite, and additionally, mechanically activated clinoptilolites offer further improved beneficial effects. The current review describes and discusses the numerous positive effects of clinoptilolite and its forms on gut health and the gut microbiome, as well as their detoxifying, antioxidative, immunostimulatory, and anti-inflammatory effects, relevant to the treatment of NDs and especially AD and PD. The direct effects of clinoptilolite and its activated forms on AD pathology in vitro and in vivo are also reviewed, as well as the use of zeolites as biosensors and delivery systems related to PD.

Left corticospinal tract could be a biomarker to identify the dual prodromal LRRK2/GBA mutated Parkinson's disease

INTRODUCTION

Prodromal Parkinson's disease (PD) carriers of dual leucine-rich repeat kinase 2 (LRRK2) and glucosylceramidase β (GBA) variants are rare, and their biomarkers are less well developed.

OBJECTIVE

This study aimed to investigate the biomarkers for diagnosing the prodromal phase of LRRK2-GBA-PD (LRRK2-GBA-prodromal).

METHODS

We assessed the clinical and whole-brain white matter microstructural characteristics of 54 prodromal PD carriers of dual LRRK2 (100% M239T) and GBA (95% N409S) variants, along with 76 healthy controls (HCs) from the Parkinson's Progression Markers Initiative (PPMI) cohort.

RESULTS

By analyzing the four values of 100 nodes on 20 fiber bundles, totaling 8000 data points, we identified the smallest p value in the fractional anisotropy (FA) value of the 38th segment of left corticospinal tract (L-CST) with differences between LRRK2-GBA-prodromal and HCs (p = 8.94 × 10-9). The FA value of the 38th node of the L-CST was significantly lower in LRRK2-GBA-prodromal (FA value, 0.65) compared with HCs (FA value, 0.71). The receiver-operating characteristic curve showed a cut-off value of 0.218 for the FA value of L-CST, providing sufficient sensitivity (79.2%) and specificity (72.2%) to distinguish double mutation prodromal PD from the healthy population.

CONCLUSION

L-CST, especially the 38th node, may potentially serve as a biomarker for distinguishing individuals with double mutation prodromal PD from the healthy population.

Association Analysis of Essential Tremor-Associated Genetic Variants in Sporadic Late-Onset Parkinson's Disease

Background

Parkinson's disease (PD) and Essential tremor (ET) are the two most common tremor diseases with recognized genetic pathogenesis. The overlapping clinical features suggest they may share genetic predispositions. Our previous study systematically investigated the association between rare coding variants in ET-associated genes and early-onset PD (EOPD), and found the suggestive association between teneurin transmembrane protein 4 (TENM4) and EOPD. In the current research, we explored the potential genetic interplay between ET-associated genetic loci/genes and sporadic late-onset PD (LOPD).

Methods

We performed whole-genome sequencing in the 1962 sporadic LOPD cases and 1279 controls from mainland China. We first used logistic regression analysis to test the top 16 SNPs identified by the ET genome-wide association study for the association between ET and LOPD. Then we applied the optimized sequence kernel association testing to explore the rare variant burden of 33 ET-associated genes in this cohort.

Results

We did not observe a significant association between the included SNPs with LOPD. We also did not discover a significant burden of rare deleterious variants of ET-associated genes in association with LOPD risk.

Conclusion

Our results do not support the role of ET-associated genetic loci and variants in LOPD.

Highlights

1962 cases and 1279 controls were recruited to study the potential genetic interplay between ET-associated genetic loci/variants and sporadic LOPD.No significant association between the ET-associated SNPs and LOPD were observed.No significant burden of rare deleterious variants of ET-associated gene in LOPD risk were found.

Proximity hybridization induced molecular machine for signal-on electrochemical detection of α-synuclein oligomers

α-synuclein oligomer is a marker of Parkinson's disease. The traditional enzyme-linked immunosorbent assay for α-synuclein oligomer detection is not conducive to large-scale application due to its time-consuming, high cost and poor stability. Recently, DNA-based biosensors have been increasingly used in the detection of disease markers due to their high sensitivity, simplicity and low cost. In this study, based on the DNAzyme-driven DNA bipedal walking method, we developed a signal-on electrochemical sensor for the detection of α-syn oligomers. Bipedal DNA walkers have a larger walking area and faster walking kinetics, providing higher amplification efficiency compared to conventional DNA walkers. The DNA walker is driven via an Mg2+-dependent DNAzyme, and the binding-induced DNA walker will continuously clamp the MB, resulting in the proliferation of Fc confined near the GE surface. The linear range and limit of detection were 1 fg/mL to 10 pg/mL and 0.57 fg/mL, respectively. The proposed signal-on electrochemical sensing strategy is more selective. It will play a significant role in the sensitive and precise electrochemical analysis of other proteins.

Attitudes Toward the Adoption of Remote Patient Monitoring and Artificial Intelligence in Parkinson's Disease Management: Perspectives of Patients and Neurologists

OBJECTIVE

Early detection of Parkinson's Disease (PD) progression remains a challenge. As remote patient monitoring solutions (RMS) and artificial intelligence (AI) technologies emerge as potential aids for PD management, there's a gap in understanding how end users view these technologies. This research explores patient and neurologist perspectives on AI-assisted RMS.

METHODS

Qualitative interviews and focus-groups were conducted with 27 persons with PD (PwPD) and six neurologists from Finland and Italy. The discussions covered traditional disease progression detection and the prospects of integrating AI and RMS. Sessions were recorded, transcribed, and underwent thematic analysis.

RESULTS

The study involved five individual interviews (four Italian participants and one Finnish) and six focus-groups (four Finnish and two Italian) with PwPD. Additionally, six neurologists (three from each country) were interviewed. Both cohorts voiced frustration with current monitoring methods due to their limited real-time detection capabilities. However, there was enthusiasm for AI-assisted RMS, contingent upon its value addition, user-friendliness, and preservation of the doctor-patient bond. While some PwPD had privacy and trust concerns, the anticipated advantages in symptom regulation seemed to outweigh these apprehensions.

DISCUSSION

The study reveals a willingness among PwPD and neurologists to integrate RMS and AI into PD management. Widespread adoption requires these technologies to provide tangible clinical benefits, remain user-friendly, and uphold trust within the physician-patient relationship.

CONCLUSION

This study offers insights into the potential drivers and barriers for adopting AI-assisted RMS in PD care. Recognizing these factors is pivotal for the successful integration of these digital health tools in PD management.

The Contribution of Type 2 Diabetes to Parkinson's Disease Aetiology

Type 2 diabetes (T2D) and Parkinson's disease (PD) are chronic disorders that have a significant health impact on a global scale. Epidemiological, preclinical, and clinical research underpins the assumption that insulin resistance and chronic inflammation contribute to the overlapping aetiologies of T2D and PD. This narrative review summarises the recent evidence on the contribution of T2D to the initiation and progression of PD brain pathology. It also briefly discusses the rationale and potential of alternative pharmacological interventions for PD treatment.

New frontiers in salivary extracellular vesicles: transforming diagnostics, monitoring, and therapeutics in oral and systemic diseases

Salivary extracellular vesicles (EVs) have emerged as key tools for non-invasive diagnostics, playing a crucial role in the early detection and monitoring of diseases. These EVs surpass whole saliva in biomarker detection due to their enhanced stability, which minimizes contamination and enzymatic degradation. The review comprehensively discusses methods for isolating, enriching, quantifying, and characterizing salivary EVs. It highlights their importance as biomarkers in oral diseases like periodontitis and oral cancer, and underscores their potential in monitoring systemic conditions. Furthermore, the review explores the therapeutic possibilities of salivary EVs, particularly in personalized medicine through engineered EVs for targeted drug delivery. The discussion also covers the current challenges and future prospects in the field, emphasizing the potential of salivary EVs in advancing clinical practice and disease management.

Associations of vitamin D receptor polymorphisms with risk of Alzheimer's disease, Parkinson's disease, and mild cognitive impairment: a systematic review and meta-analysis

Vitamin D is a lipid soluble steroid hormone, which plays a critical role in the calcium homeostasis, neuronal development, cellular differentiation, and growth by binding to vitamin D receptor (VDR). Associations between VDR gene polymorphism and Alzheimer's disease (AD), Parkinson's disease (PD), and mild cognitive impairment (MCI) risk has been investigated extensively, but the results remain ambiguous. The aim of this study was to comprehensively assess the correlations between four VDR polymorphisms (FokI, BsmI, TaqI, and ApaI) and susceptibility to AD, PD, and MCI. Crude odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to determine the relationship of interest. Pooled analyses suggested that the ApaI polymorphism decreased the overall AD risk, and the TaqI increased the overall PD susceptibility. In addition, the BsmI and ApaI polymorphisms were significantly correlated with the overall MCI risk. Stratified analysis by ethnicity further showed that the TaqI and ApaI genotypes reduced the AD predisposition among Caucasians, while the TaqI polymorphism enhanced the PD risk among Asians. Intriguingly, carriers with the BB genotype significantly decreased the MCI risk in Asian descents, and the ApaI variant elevated the predisposition to MCI in Caucasians and Asians. Further studies are need to identify the role of VDR polymorphisms in AD, PD, and MCI susceptibility.

Enhancing selegiline hydrochloride efficacy: Box Behnken-optimized liposomal delivery via intranasal route for Parkinson's disease intervention

The clinical use of selegiline hydrochloride in conventional dosage forms is to reduce the progression of Parkinson's disease (PD). However, its limited access to the brain, short half-life, and first-pass metabolism minimize brain uptake. Nano-based liposomes offer promising tools for brain-targeted delivery of therapeutics, especially intranasally administered cationic liposomes that target the brain region via the olfactory route and reduce biodistribution. In the present work, cationic liposomes encapsulated with selegiline hydrochloride were fabricated for intranasal administration against PD. The liposomes were initially optimized by Box Behnken design, and the selected run was coated with stearylamine to provide a cationic charge to the liposomes. The final coated liposomes, SH-LP3, demonstrated a minimum size of 173 ± 2.13 nm, an ideal zeta potential of +16 ± 1.98, and achieved a maximum entrapment efficiency of 40.14 ± 1.83%. Morphology analysis showed the spherical shape of liposomes in the size range of 100-200 nm. The in vitro cytotoxicity assay in SHSY5Y cell lines showed a significant decrease in toxicity, almost ten times less, compared to pure selegiline hydrochloride. Animal studies on rotenone-lesioned C57BL6 mice model for PD were performed to investigate the effect of intranasally administered liposomes. The SH-LP3 formulation exhibited remarkable effectiveness in relieving symptoms of PD. This extensive analysis emphasizes the possibility of intranasally administered SH-LP3 liposomes as a feasible treatment option for PD. The formulation not only delivers continuous drug release but also displays better safety and efficacy, providing a platform for additional studies and growth in the domain of PD treatment.

Neuroprotective effect of green tea extract (-)-epigallocatechin-3-gallate in a preformed fibril-induced mouse model of Parkinson's disease

Parkinson's disease (PD) is the second most common neurodegenerative disease characterized by the progressive degeneration of dopaminergic neurons in the substantia nigra (SN). The main bioactive component of green tea polyphenols (-)-epigallocatechin-3-gallate (EGCG) exerts protective effects against diseases such as neurodegenerative diseases and cancer. Therefore, this study investigated the effect of EGCG on the amelioration of neural damage in a chronic PD mouse model induced by α-synuclein preformed fibrils (α-syn-PFFs). A total of 20 C57BL/6J female mice were randomly divided into 3 groups: control group (saline, n = 6), model group (PFFs, n = 7), and prevention group (EGCG+PFFs, n = 7). A chronic PD mouse model was obtained by the administration of α-syn-PFFs by stereotaxic localization in the striatum. Behavioral tests were performed to evaluate PD-related anxiety-like behavior and motor impairments in the long-term PD progression. Tyrosine hydroxylase (TH) immuno-positive neurons and Ser129-phosphorylated α-syn (p-α-syn) were identified by immunohistochemistry. Pro-inflammatory and anti-inflammatory cytokines were measured by real-time quantitative PCR. EGCG pretreatment reduced anxiety-like behavior and motor impairments as revealed by the long-term behavioral test (2 weeks, 1 month, 3 months, and 6 months) on PD mice. EGCG also ameliorated PFF-induced degeneration of TH immuno-positive neurons and accumulation of p-α-syn in the SN and striatum at 6 months. Additionally, EGCG reduced the expression of pro-inflammatory cytokines while promoting the release of anti-inflammatory cytokines. EGCG exerts a neuroprotective effect on long-term progression of the PD model.

Effectiveness and safety of different catechol-o-methyl transferase inhibitors for patients with parkinson's disease: Systematic review and network meta-analysis

BACKGROUND

Levodopa treatment requires the addition of other drugs, such as catechol-O-methyl transferase (COMT) inhibitors, to alleviate motor fluctuations in advanced parkinson's disease (PD). However, the optimal strategy, including the type and dose of COMT inhibitors remains unknown. This systematic review and network meta-analysis aimed to assess the efficacy and safety of different COMT inhibitors and for treating PD patients.

METHODS

PubMed, Embase, Cochrane Library and Web of Science were screened up to November 20, 2022. Randomized controlled trials (RCTs) of COMT inhibitors (entacapone, opicapone, tolcapone) for PD patients were included. Eligible outcomes were total ON-time, rate of ON-time >1 h, total daily dose of levodopa therapy, mean change from baseline to final follow up in Unified Parkinson's Disease Rating Scale (UPDRS) part III scores, adverse events and dyskinesia. Network meta-analyses integrated direct and indirect evidence with placebo as a common comparator.

RESULTS

We identified 18 studies with 7564 patients. Opicapone, entacapone, and tolcapone could increase total ON-time when compared with placebo. However, opicapone (25 mg, MD 4.0, 95%CrI: 1.1-7.5) and opicapone (50 mg, MD 5.1, 95%CrI: 2.2-8.7) statistically significant increase the total ON-time. opicapone and entacapone could increase the rate of ON-time >1 h when compared with placebo. Only opicapone (5 mg) showed no statistically significant with placebo (OR 1.4, 95%CrI: 0.74-2.4). We found that opicapone (50 mg, SURCA, 0.796) is the best option compared with other treatments. TOL (200 mg) was ranked highest in the rank probability test for total daily dose of levodopa therapy, followed by OPI (50 mg), TOL (400 mg) and TOL (100 mg) in order. SUCRA rankings identified TOL (200 mg) as the most likely therapy for increasing adverse events (SUCRA 27.19%), followed by TOL (400 mg, SUCRA 27.20%) and OPI (5 mg, SUCRA 30.81%). The SUCRA probabilities were 91.6%, 75.2%, 67.9%, 59.3%, 45.6%, 41.1%, 35.1%, 24.6% and 9.4% for PLA, TOL (400 mg), ENT (100 mg), ENT (200 mg), OPI (5 mg), TOL (100 mg), OPI (25 mg), OPI (50 mg), and TOL (200 mg) respectively.

CONCLUSION

In conclusion, opicapone (50 mg) may be a better choice for treatment PD when compared with other COMT inhibitors.

Association between irritable bowel syndrome and Parkinson's disease by Cohort study and Mendelian randomization analysis

This study aimed to investigate the association between irritable bowel syndrome (IBS) and Parkinson's disease (PD) utilizing prospective cohort study and Mendelian randomization. The dataset contained a substantial cohort of 426,911 participants from the UK Biobank, discussing the association between IBS and PD with Cox proportional hazards models and case-control analysis while adjusting for covariates such as age, gender, ethnicity and education level. In univariate Cox regression model, the risk of PD was reduced in IBS patients (HR: 0.774, 95%CI: 0.625-0.956, P = 0.017), but the statistical significance diminished in the three models after adjusting for other variables. In a few subgroup analyses, IBS patients are less likely to develop into PD, and patients diagnosed with IBS after 2000 also had a lower risk (HR: 0.633, 95%CI: 0.403-0.994, P = 0.047) of subsequently developing PD. In addition, we matched five healthy control participants based on gender and age at the end of the study for each IBS patient diagnosed during the follow-up period, and logistic regression results (OR:1.239, 95%CI: 0.896-1.680, P = 0.181) showed that IBS was not associated with the risk of PD. Mendelian randomization did not find significant evidence of the causal relationship between IBS and Parkinson's disease (OR: 0.801, 95%CI: 0.570-1.278, P = 0.204). Overall, we suggest that IBS status is not associated with the risk of developing PD, and that these findings provide valuable insights into the clinical management and resource allocation of patients with IBS.

Mechanisms of Swallowing, Speech and Voice Disorders in Parkinson's Disease: Literature Review with Our First Evidence for the Periperal Nervous System Involvement

The majority of patients with Parkinson's disease (PD) develop swallowing, speech, and voice (SSV) disorders. Importantly, swallowing difficulty or dysphagia and related aspiration are life-threatening conditions for PD patients. Although PD treatments have significant therapeutic effects on limb motor function, their effects on SSV disorders are less impressive. A large gap in our knowledge is that the mechanisms of SSV disorders in PD are poorly understood. PD was long considered to be a central nervous system disorder caused by the death of dopaminergic neurons in the basal ganglia. Aggregates of phosphorylated α-synuclein (PAS) underlie PD pathology. SSV disorders were thought to be caused by the same dopaminergic problem as those causing impaired limb movement; however, there is little evidence to support this. The pharynx, larynx, and tongue play a critical role in performing upper airway (UA) motor tasks and their dysfunction results in disordered SSV. This review aims to provide an overview on the neuromuscular organization patterns, functions of the UA structures, clinical features of SSV disorders, and gaps in knowledge regarding the pathophysiology underlying SSV disorders in PD, and evidence supporting the hypothesis that SSV disorders in PD could be associated, at least in part, with PAS damage to the peripheral nervous system controlling the UA structures. Determining the presence and distribution of PAS lesions in the pharynx, larynx, and tongue will facilitate the identification of peripheral therapeutic targets and set a foundation for the development of new therapies to treat SSV disorders in PD.

Metabolomics comparison of metabolites and functional pathways in the SH-SY5Y cell model of Parkinson's disease under PEMF exposure

Objective

PEMF is an emerging technique in the treatment of Parkinson's disease (PD) due to its potential improvement of movement speed. The aim of this study was to investigate the metabolic profiles of pulsed electromagnetic fields (PEMFs) in an SH-SY5Y cell model of PD.

Methods

The SH-SY5Y cell model of PD was induced by 1-methyl-4-phenylpyridinium (MPP+). Liquid chromatography mass spectrometry (LC‒MS)-based untargeted metabolomics was performed to examine changes in the PD cell model with or without PEMF exposure. We conducted KEGG pathway enrichment analysis to explore the potentially related pathways of the differentially expressed metabolites.

Results

A total of 275 metabolites were annotated, and 27 significantly different metabolites were found between the PEMF treatment and control groups (VIP >1, P < 0.05), mainly including 4 amino acids and peptides, 4 fatty acid esters, 2 glycerophosphoethanolamines, 2 ceramides and 2 monoradylglycerols; among them, 12 metabolites were upregulated, and 15 were downregulated. The increased expression levels of glutamine, adenosine monophosphate and taurine were highly associated with PEMF stimulation in the PD model. The enrichment results of differentially abundant metabolite functional pathways showed that biological processes such as the mTOR signaling pathway, PI3K-Akt signaling pathway, and cAMP signaling pathway were significantly affected.

Conclusion

PEMFs affected glutamine, adenosine monophosphate and taurine as well as their functional pathways in an in vitro model of PD. Further functional studies regarding the biological effect of these changes are required to evaluate the clinical efficacy and safety of PEMF treatment in PD.

Neurocognitive changes at different follow-up times after bilateral subthalamic nucleus deep brain stimulation in patients with Parkinson's disease

Background

Bilateral deep thalamic nucleus brain stimulation (STN-DBS) surgery is often used to treat the motor symptoms of patients with Parkinson's disease. The change of neurocognitive symptoms in patients is, however, still unclear.

Objective

We aimed at analyzing the deterioration of neurocognitive symptoms in patients with Parkinson's disease after deep brain stimulation surgery under different follow-up times.

Methods

A comprehensive literature review was conducted using Pubmed, Cochrane Library, and Web of Science to screen eligible study records, the meta-analysis was performed using an inverse variance method and a random-effects model. Additionally, the areas of analysis include five: cognition, executive function, memory capacity, and verbal fluency (phonetic fluency and semantic fluency). They were analyzed for changes at six and twelve months postoperatively compared to baseline. The Meta-analysis has been registered with PROSPERO under the registration number: CRD42022308786.

Results

In terms of overall cognitive performance, executive function, and memory capacity, the original studies show a trend of improvement in these areas at 12 months postoperatively compared with 6 months, at variance, patients did not improve or deteriorated in phonetic fluency(d = -0.42 at both 6-month and 12-month follow-up) and semantic fluency from 6 to 12 months postoperatively.

Conclusion

In terms of most neurocognitive symptoms, including cognitive ability, executive function, and learning memory capacity, bilateral STN-DBS surgery appears to be safe at relatively long follow-up times. However, postoperative phonetic and semantic fluency changes should still not be underestimated, and clinicians should pay more attention to patients' changes in both.

Nanoparticles and neurodegeneration: Insights on multiple pathways of programmed cell death regulated by nanoparticles

Currently, nanoparticles (NPs) are extensively applied in the diagnosis and treatment of neurodegenerative diseases (NDs). With the rapid development and increasing exposure to the public, the potential neurotoxicity associated with NDs caused by NPs has attracted the researchers' attentions but their biosafety assessments are still far behind relevant application studies. Based on recent research, this review aims to conduct a comprehensive and systematic analysis of neurotoxicity induced by NPs. The 191 studies selected according to inclusion and exclusion criteria were imported into the software, and the co-citations and keywords of the included literatures were analyzed to find the breakthrough point of previous studies. According to the available studies, the routes of NPs entering into the normal and injured brain were various, and then to be distributed and accumulated in living bodies. When analyzing the adverse effects induced by NPs, we focused on multiple programmed cell deaths (PCDs), especially ferroptosis triggered by NPs and their tight connection and crosstalk that have been found playing critical roles in the pathogenesis of NDs and their underlying toxic mechanisms. The activation of multiple PCD pathways by NPs provides a scientific basis for the occurrence and development of NDs. Furthermore, the adoption of new methodologies for evaluating the biosafety of NPs would benefit the next generation risk assessment (NGRA) of NPs and their toxic interventions. This would help ensure their safe application and sustainable development in the field of medical neurobiology.

Levistilide A Exerts a Neuroprotective Effect by Suppressing Glucose Metabolism Reprogramming and Preventing Microglia Polarization Shift: Implications for Parkinson's Disease

The microglia, displaying diverse phenotypes, play a significant regulatory role in the development, progression, and prognosis of Parkinson's disease. Research has established that glycolytic reprogramming serves as a critical regulator of inflammation initiation in pro-inflammatory macrophages. Furthermore, the modulation of glycolytic reprogramming has the potential to reverse the polarized state of these macrophages. Previous studies have shown that Levistilide A (LA), a phthalide component derived from Angelica sinensis, possesses a range of pharmacological effects, including anti-inflammatory, antioxidant, and neuroprotective properties. In our study, we have examined the impact of LA on inflammatory cytokines and glucose metabolism in microglia induced by lipopolysaccharide (LPS). Furthermore, we explored the effects of LA on the AMPK/mTOR pathway and assessed its neuroprotective potential both in vitro and in vivo. The findings revealed that LA notably diminished the expression of M1 pro-inflammatory factors induced by LPS in microglia, while leaving M2 anti-inflammatory factor expression unaltered. Additionally, it reduced ROS production and suppressed IκB-α phosphorylation levels as well as NF-κB p65 nuclear translocation. Notably, LA exhibited the ability to reverse microglial glucose metabolism reprogramming and modulate the phosphorylation levels of AMPK/mTOR. In vivo experiments further corroborated these findings, demonstrating that LA mitigated the death of TH-positive dopaminergic neurons and reduced microglia activation in the ventral SNpc brain region of the midbrain and the striatum. In summary, LA exhibited neuroprotective benefits by modulating the polarization state of microglia and altering glucose metabolism, highlighting its therapeutic potential.

Apoptosis signal-regulating kinase 1 (Ask1) deficiency alleviates MPP+-induced impairment of evoked dopamine release in the mouse hippocampus

The dopaminergic system is susceptible to dysfunction in numerous neurological diseases, including Parkinson's disease (PD). In addition to motor symptoms, some PD patients may experience non-motor symptoms, including cognitive and memory deficits. A possible explanation for their manifestation is a disturbed pattern of dopamine release in brain regions involved in learning and memory, such as the hippocampus. Therefore, investigating neuropathological alterations in dopamine release prior to neurodegeneration is imperative. This study aimed to characterize evoked hippocampal dopamine release and assess the impact of the neurotoxin MPP+ using a genetically encoded dopamine sensor and gene expression analysis. Additionally, considering the potential neuroprotective attributes demonstrated by apoptosis signal-regulating kinase 1 (Ask1) in various animal-disease-like models, the study also aimed to determine whether Ask1 knockdown restores MPP+-altered dopamine release in acute hippocampal slices. We applied variations of low- and high-frequency stimulation to evoke dopamine release within different hippocampal regions and discovered that acute application of MPP+ reduced the amount of dopamine released and hindered the recovery of dopamine release after repeated stimulation. In addition, we observed that Ask1 deficiency attenuated the detrimental effects of MPP+ on the recovery of dopamine release after repeated stimulation. RNA sequencing analysis indicated that genes associated with the synaptic pathways are involved in response to MPP+ exposure. Notably, Ask1 deficiency was found to downregulate the expression of Slc5a7, a gene encoding a sodium-dependent high-affinity choline transporter that regulates acetylcholine levels. Respective follow-up experiments indicated that Slc5a7 plays a role in Ask1 deficiency-mediated protection against MPP+ neurotoxicity. In addition, increasing acetylcholine levels using an acetylcholinesterase inhibitor could exacerbate the toxicity of MPP+. In conclusion, our data imply that the modulation of the dopamine-acetylcholine balance may be a crucial mechanism of action underlying the neuroprotective effects of Ask1 deficiency in PD.

Orally administered neohesperidin attenuates MPTP-induced neurodegeneration by inhibiting inflammatory responses and regulating intestinal flora in mice

Parkinson's disease (PD), a neurodegenerative disease, is the leading cause of movement disorders. Neuroinflammation plays a critical role in PD pathogenesis. Neohesperidin (Neo), a natural flavonoid extracted from citric fruits exhibits anti-inflammatory effects. However, the effect of Neo on PD progression is unclear. This study aimed to investigate the effects of Neo on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD in mice and its underlying mechanism. Our results indicated that Neo administration ameliorated motor impairment and neural damage in MPTP-injected mice, by inhibiting neuroinflammation and regulating gut microbial imbalance. Additionally, Neo administration reduced colonic inflammation and tissue damage. Mechanistic studies revealed that Neo suppressed the MPTP-induced inflammatory response by inhibiting excessive activation of NF-κB and MAPK pathways. In summary, the present study demonstrated that Neo administration attenuates neurodegeneration in MPTP-injected mice by inhibiting inflammatory responses and regulating the gut microbial composition. This study may provide the scientific basis for the use of Neo in the treatment of PD and other related diseases.

Apolipoprotein E Gene in α-Synucleinopathies: A Narrative Review

In this narrative review, we delved into the intricate interplay between Apolipoprotein E (APOE) alleles (typically associated with Alzheimer's disease-AD) and alpha-synucleinopathies (aS-pathies), involving Parkinson's disease (PD), Parkinson's disease dementia (PDD), dementia with Lewy bodies (DLB), and multiple-system atrophy (MSA). First, in-vitro, animal, and human-based data on the exacerbating effect of APOE4 on LB pathology were summarized. We found robust evidence that APOE4 carriage constitutes a risk factor for PDD-APOE2, and APOE3 may not alter the risk of developing PDD. We confirmed that APOE4 copies confer an increased hazard towards DLB, as well. Again APOE2 and APOE3 appear unrelated to the risk of conversion. Of note, in individuals with DLB APOE4, carriage appears to be intermediately prevalent between AD and PDD-PD (AD > DLB > PDD > PD). Less consistency existed when it came to PD; APOE-PD associations tended to be markedly modified by ethnicity. Finally, we failed to establish an association between the APOE gene and MSA. Phenotypic associations (age of disease onset, survival, cognitive-neuropsychiatric- motor-, and sleep-related manifestations) between APOE alleles, and each of the aforementioned conditions were also outlined. Finally, a synopsis of literature gaps was provided followed by suggestions for future research.

The intestinal microbiota exerts a sex-specific influence on neuroinflammation in a Parkinson's disease mouse model

Parkinson's disease (PD) is a neurodegenerative disorder characterised by chronic and progressive symptoms; it is more prevalent in men than in women. The sex-specific influence of the intestinal microbiota has been associated with some neurodegenerative diseases, but the relationship with PD is currently unclear. In this study, we treated mice with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to establish a PD mouse model, and we utilised an antibiotic cocktail (Abx) to deplete the intestinal microbiota to evaluate the influence of the intestinal microbiota on male and female PD mice. MPTP treatment obviously caused bradykinesia and low mobility in female and male mice. Meanwhile, Abx treatment exerted a greater effect on male mice than female mice. Western blotting and immunofluorescence revealed that male mice treated with MPTP had higher expression of α-synuclein and proteins related to neuroinflammation and intestinal inflammation based on activation of glial cells and the TLR4-MyD88 signalling pathway. The sex-specific differences could be due to the different composition of the intestinal microbiota. Specifically, female mice had significantly higher abundance of Allobaculum, Turicibacter and Ruminococcus than male mice. Moreover, the abundance of the probiotic genus Bifidobacterium showed opposite trends in male and female mice. Our results indicate that the intestinal microbiota has an important effect on PD mice, especially male mice, by influencing neuroinflammation through the microbiota-gut-brain axis. In the future, there should be a focus on providing more reliable evidence for the pathogenesis and precise treatment of PD.

Activation of Ca2+ phosphatase Calcineurin regulates Parkin translocation to mitochondria and mitophagy in flies

Selective removal of dysfunctional mitochondria via autophagy is crucial for the maintenance of cellular homeostasis. This event is initiated by the translocation of the E3 ubiquitin ligase Parkin to damaged mitochondria, and it requires the Serine/Threonine-protein kinase PINK1. In a coordinated set of events, PINK1 operates upstream of Parkin in a linear pathway that leads to the phosphorylation of Parkin, Ubiquitin, and Parkin mitochondrial substrates, to promote ubiquitination of outer mitochondrial membrane proteins. Ubiquitin-decorated mitochondria are selectively recruiting autophagy receptors, which are required to terminate the organelle via autophagy. In this work, we show a previously uncharacterized molecular pathway that correlates the activation of the Ca2+-dependent phosphatase Calcineurin to Parkin translocation and Parkin-dependent mitophagy. Calcineurin downregulation or genetic inhibition prevents Parkin translocation to CCCP-treated mitochondria and impairs stress-induced mitophagy, whereas Calcineurin activation promotes Parkin mitochondrial recruitment and basal mitophagy. Calcineurin interacts with Parkin, and promotes Parkin translocation in the absence of PINK1, but requires PINK1 expression to execute mitophagy in MEF cells. Genetic activation of Calcineurin in vivo boosts basal mitophagy in neurons and corrects locomotor dysfunction and mitochondrial respiratory defects of a Drosophila model of impaired mitochondrial functions. Our study identifies Calcineurin as a novel key player in the regulation of Parkin translocation and mitophagy.

Extracellular Vesicles as Biomarkers for Parkinson's Disease: How Far from Clinical Translation?

Parkinson's disease (PD) is a neurodegenerative disorder affecting about 10 million people worldwide with a prevalence of about 2% in the over-80 population. The disease brings in also a huge annual economic burden, recently estimated by the Michael J Fox Foundation for Parkinson's Research to be USD 52 billion in the United States alone. Currently, no effective cure exists, but available PD medical treatments are based on symptomatic prescriptions that include drugs, surgical approaches and rehabilitation treatment. Due to the complex biology of a PD brain, the design of clinical trials and the personalization of treatment strategies require the identification of accessible and measurable biomarkers to monitor the events induced by treatment and disease progression and to predict patients' responsiveness. In the present review, we strive to briefly summarize current knowledge about PD biomarkers, focusing on the role of extracellular vesicles as active or involuntary carriers of disease-associated proteins, with particular attention to those research works that envision possible clinical applications.

Biomaterials-Based Antioxidant Strategies for the Treatment of Oxidative Stress Diseases

Oxidative stress is characterized by an increase in reactive oxygen species or a decrease in antioxidants in the body. This imbalance leads to detrimental effects, including inflammation and multiple chronic diseases, ranging from impaired wound healing to highly impacting pathologies in the neural and cardiovascular systems, or the bone, amongst others. However, supplying compounds with antioxidant activity is hampered by their low bioavailability. The development of biomaterials with antioxidant capacity is poised to overcome this roadblock. Moreover, in the treatment of chronic inflammation, material-based strategies would allow the controlled and targeted release of antioxidants into the affected tissue. In this review, we revise the main causes and effects of oxidative stress, and survey antioxidant biomaterials used for the treatment of chronic wounds, neurodegenerative diseases, cardiovascular diseases (focusing on cardiac infarction, myocardial ischemia-reperfusion injury and atherosclerosis) and osteoporosis. We anticipate that these developments will lead to the emergence of new technologies for tissue engineering, control of oxidative stress and prevention of diseases associated with oxidative stress.

Brain photobiomodulation therapy on neurological and psychological diseases

Photobiomodulation (PBM) therapy is an innovative treatment for neurological and psychological conditions. Complex IV of the mitochondrial respiratory chain can be stimulated by red light, which increases ATP synthesis. In addition, the ion channels' light absorption causes the release of Ca2+, which activates transcription factors and changes gene expression. Neuronal metabolism is improved by brain PBM therapy, which also promotes synaptogenesis and neurogenesis as well as anti-inflammatory. Its depression-treating potential is attracting attention for other conditions, including Parkinson's disease and dementia. Giving enough dosage for optimum stimulation using the transcranial PBM technique is challenging because of the rapidly increasing attenuation of light transmission in tissue. Different strategies like intranasal and intracranial light delivery systems have been proposed to overcome this restriction. The most recent preclinical and clinical data on the effectiveness of brain PBM therapy are studied in this review article.

The role of sphingosine-1-phosphate in the development and progression of Parkinson's disease

Parkinson's disease (PD) could be viewed as a proteinopathy caused by changes in lipids, whereby modifications in lipid metabolism may lead to protein alterations, such as the accumulation of alpha-synuclein (α-syn), ultimately resulting in neurodegeneration. Although the loss of dopaminergic neurons in the substantia nigra is the major clinical manifestation of PD, the etiology of it is largely unknown. Increasing evidence has highlighted the important role of lipids in the pathophysiology of PD. Sphingosine-1-phosphate (S1P), a signaling lipid, has been suggested to have a potential association with the advancement and worsening of PD. Therefore, better understanding the mechanisms and regulatory proteins is of high interest. Most interestingly, S1P appears to be an important target to offers a new strategy for the diagnosis and treatment of PD. In this review, we first introduce the basic situation of S1P structure, function and regulation, with a special focus on the several pathways. We then briefly describe the regulation of S1P signaling pathway on cells and make a special focused on the cell growth, proliferation and apoptosis, etc. Finally, we discuss the function of S1P as potential therapeutic target to improve the clinical symptoms of PD, and even prevent the progression of the PD. In the context of PD, the functions of S1P modulators have been extensively elucidated. In conclusion, S1P modulators represent a novel and promising therapeutic principle and therapeutic method for PD. However, more research is required before these drugs can be considered as a standard treatment option for PD.

Monipar: movement data collection tool to monitor motor symptoms in Parkinson's disease using smartwatches and smartphones

Introduction

Parkinson's disease (PD) is a neurodegenerative disorder commonly characterized by motor impairments. The development of mobile health (m-health) technologies, such as wearable and smart devices, presents an opportunity for the implementation of clinical tools that can support tasks such as early diagnosis and objective quantification of symptoms.

Objective

This study evaluates a framework to monitor motor symptoms of PD patients based on the performance of standardized exercises such as those performed during clinic evaluation. To implement this framework, an m-health tool named Monipar was developed that uses off-the-shelf smart devices.

Methods

An experimental protocol was conducted with the participation of 21 early-stage PD patients and 7 healthy controls who used Monipar installed in off-the-shelf smartwatches and smartphones. Movement data collected using the built-in acceleration sensors were used to extract relevant digital indicators (features). These indicators were then compared with clinical evaluations performed using the MDS-UPDRS scale.

Results

The results showed moderate to strong (significant) correlations between the clinical evaluations (MDS-UPDRS scale) and features extracted from the movement data used to assess resting tremor (i.e., the standard deviation of the time series: r = 0.772, p < 0.001) and data from the pronation and supination movements (i.e., power in the band of 1-4 Hz: r = -0.662, p < 0.001).

Conclusion

These results suggest that the proposed framework could be used as a complementary tool for the evaluation of motor symptoms in early-stage PD patients, providing a feasible and cost-effective solution for remote and ambulatory monitoring of specific motor symptoms such as resting tremor or bradykinesia.

The Application of Deep Brain Stimulation for Parkinson's Disease on the Motor Pathway: A Bibliometric Analysis across 10 Years

BACKGROUND AND OBJECTIVE

Since its initial report by James Parkinson in 1817, Parkinson's disease (PD) has remained a central subject of research and clinical advancement. The disease is estimated to affect approximately 1% of adults aged 60 and above. Deep brain stimulation, emerging as an alternative therapy for end-stage cases, has offered a lifeline to numerous patients. This review aimed to analyze publications pertaining to the impact of deep brain stimulation on the motor pathway in patients with PD over the last decade.

METHODS

Data were obtained from the Web of Science Core Collection through the library of Huazhong University of Science and Technology (China). The search strategy encompassed the following keywords: "deep brain stimulation", "Parkinson's disease", "motor pathway", and "human", from January 1, 2012, to December 1, 2022. Additionally, this review visualized the findings using the Citespace software.

RESULTS

The results indicated that the United States, the United Kingdom, Germany, and China were the primary contributors to this research field. University College London, Capital Medical University, and Maastricht University were the top 3 research institutions in the research area. Tom Foltynie ranked first with 6 publications, and the journals of Brain and Brain Stimulation published the greatest number of relevant articles. The prevailing research focal points in this domain, as determined by keywords "burst analysis", "encompassed neuronal activity", "nucleus", "hyper direct pathway", etc. CONCLUSION: This study has provided a new perspective through bibliometric analysis of the deep brain stimulation therapy for treating patients with PD, which can shed light on future research to advance our comprehension of this particular field of study.

The interplay between α-Synuclein and NLRP3 inflammasome in Parkinson's disease

α-Synuclein is a member of a protein of synucleins, which is a presynaptic neuron protein. It is usually highly expressed in the brain and participates in the formation and transmission of nerve synapses. It has been reported that abnormal aggregation of α-Syn can induce the activation of NLRP3 inflammasome in microglia, increase the production of IL-1β, and aggravate neuroinflammation. Therefore, it is recognized as one of the important factors leading to neuroinflammation in Parkinson's disease. In this paper, we aimed to explore the influence of post-translational modification of α-Syn on its pathological aggregation and summarize various pathways that activate NLRP3 triggered by α-Syn and targeted therapeutic strategies, which provided new insights for further exploring the origin and targeted therapy of Parkinson's disease.

Protein Biomarkers Shared by Multiple Neurodegenerative Diseases Are Calmodulin-Binding Proteins Offering Novel and Potentially Universal Therapeutic Targets

Seven major neurodegenerative diseases and their variants share many overlapping biomarkers that are calmodulin-binding proteins: Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), frontotemporal lobar dementia (FTD), Huntington's disease (HD), Lewy body disease (LBD), multiple sclerosis (MS), and Parkinson's disease (PD). Calcium dysregulation is an early and persistent event in each of these diseases, with calmodulin serving as an initial and primary target of increased cytosolic calcium. Considering the central role of calcium dysregulation and its downstream impact on calcium signaling, calmodulin has gained interest as a major regulator of neurodegenerative events. Here, we show that calmodulin serves a critical role in neurodegenerative diseases via binding to and regulating an abundance of biomarkers, many of which are involved in multiple neurodegenerative diseases. Of special interest are the shared functions of calmodulin in the generation of protein biomarker aggregates in AD, HD, LBD, and PD, where calmodulin not only binds to amyloid beta, pTau, alpha-synuclein, and mutant huntingtin but also, via its regulation of transglutaminase 2, converts them into toxic protein aggregates. It is suggested that several calmodulin binding proteins could immediately serve as primary drug targets, while combinations of calmodulin binding proteins could provide simultaneous insight into the onset and progression of multiple neurodegenerative diseases.

Sericin alleviates motor dysfunction by modulating inflammation and TrkB/BDNF signaling pathway in the rotenone-induced Parkinson's disease model

BACKGROUND

Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by the degeneration of nigrostriatal dopaminergic neurons and movement impairment. Based on theories, neuroinflammatory processes may be vital in the etiology of PD and other neurodegenerative diseases. Reports show that rotenone has neurotoxic, inflammatory, and motor impairment effects in PD. Sericin is a natural polymer with effective properties, such as neuroprotective and anti-inflammatory. Therefore, this study aimed to examine the effects of sericin administration on motor dysfunction by modulating inflammation and tyrosine kinase B/brain-derived neurotrophic factor (TrkB/BDNF) pathway in the rotenone-induced PD model.

METHODS

Wistar male rats (3-months-old) were treated with rotenone (2 mg/kg every 48 h for 30 days) to induce a rotenone-induced PD model. Also, sericin was administered orally at dose of 200 mg/kg every 48 h for 30 days. Rotarod and bar tests were performed for motor dysfunction. The protein levels of BDNF, c-fos, TrkB, tumor necrosis factor- α (TNF-α), interleukin-6 (IL-6) and catalase activity were evaluated in the striatum area.

RESULTS

Results showed that sericin increased latent time in the rotarod test and decreased the time staying on the pole in the bar test compared to the PD group (P < 0.001 for both tests). Moreover, sericin treatments decreased TNF-α (P < 0.001) and IL-6 (P < 0.001) concentration levels and enhanced the levels of BDNF (P < 0.001), c-fos (P < 0.001), TrkB (P < 0.001) proteins and catalase activity (P < 0.05) in the striatum area compared to the PD group.

CONCLUSION

These results support a protective benefit of sericin therapy in a rotenone-induced PD paradigm by reducing motor impairment, inflammatory response, and disruption of the TrkB/BDNF signaling pathway.

Shikimic acid (SA) inhibits neuro-inflammation and exerts neuroprotective effects in an LPS-induced in vitro and in vivo model

Numerous studies have shown that neuroinflammation is involved in the process of neuronal damage in neurodegenerative diseases such as Parkinson's disease (PD), for example, and that inhibiting neuroinflammation help improve PD. Shikimic acid (SA) has anti-inflammatory, analgesic and antioxidant activities in numerous diseases. However, its effect and mechanism in PD remain unclear. In this experiment, we found that SA inhibits production of pro-inflammatory mediators and ROS in LPS-induced BV2 cells. Mechanistic studies demonstrated that SA suppresses neuro-inflammation by activating the AKT/Nrf2 pathway and inhibiting the NF-κB pathway. Further in vivo study, we confirmed that SA ameliorated the neurological damage and behavioral deficits caused by LPS injection in mice. In summary, these study highlighted the beneficial role of SA as a novel therapy with potential PD drug by targeting neuro-inflammation.

The effects of exercise dose on patients with Parkinson's disease: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

The effects of different exercise doses on motor function, balance, mobility, and quality of life (QOL) in patients with Parkinson's disease (PD) were evaluated.

METHOD

The exercise intervention dose was evaluated based on the recommendations of the American College of Sports Medicine (ACSM) for developing and maintaining cardiorespiratory health, muscle strength, and physical function for PD patients and classified into high ACSM compliance and low or uncertain ACSM compliance. The impact of ACSM compliance on Unified Parkinson's Disease Rating Scale, Part III (UPDRS-III), Berg Balance Scale (BBS), Timed Up and Go (TUG), and 39-item Parkinson's Disease Questionnaire (PDQ-39) in patients with PD was compared using the standardized mean difference (SMD) along with the corresponding 95% confidence interval (95% CI).

RESULTS

A total of 26 articles were included, comprising 32 studies. Twenty-one studies were classified as high ACSM compliance, and 11 studies were classified as low or uncertain ACSM compliance. For the four outcome measures, the SMD ratio of exercise interventions with high ACSM compliance to those with low or uncertain ACSM compliance was as follows: UPDRS-III (- 0.74: - 0.17), TUG (- 0.62: - 0.17), PDQ-39 (- 0.58: - 0.31), and BBS (0.51: 0.52).

CONCLUSION

The results suggest that compared with exercise interventions with low or uncertain ACSM compliance, exercise interventions with high ACSM compliance had a more significant improvement effect on motor function, mobility, and QOL in PD patients. However, the effect on balance was not as pronounced, and further research is needed to validate these findings.

Key Subdomains of Cerebral Dopamine Neurotrophic Factor Regulate Its Protective Function in 6-Hydroxydopamine-Lesioned PC12 Cells

Cerebral dopamine neurotrophic factor (CDNF) is a unique neurotrophic factor (NTF) that has shown significant neuroprotective and neurorestorative functions on midbrain dopaminergic neurons. The secondary structure of human CDNF protein contains eight α-helices. We previously found that two key helices, α1 and α7, regulated the intracellular trafficking and secretion of CDNF protein in different manners. The α1 mutation (M1) induced most CDNF proteins to reside in the endoplasmic reticulum and little be secreted extracellularly, while the α7 mutation (M7) caused the majority of CDNF proteins to be secreted out of the cells and little reside in the cells. However, the regulation of the two mutants on the function of CDNF remains unclear. In this study, we investigated the effects of M1 and M7 on the protective activity of CDNF in PC12 cells, which were treated with 6-hydroxydopamine (6-OHDA) to mimic Parkinson's disease. We found that both M1 and M7 could promote survival and inhibit apoptosis more effectively than Wt in 6-OHDA-lesioned PC12 cells. Therefore, these findings will advance our understanding of the important regulation of subdomains on the function of NTFs.

The association between the neuroendocrine system and the tumor immune microenvironment: Emerging directions for cancer immunotherapy

This review summarizes emerging evidence that the neuroendocrine system is involved in the regulation of the tumor immune microenvironment (TIME) to influence cancer progression. The basis of the interaction between the neuroendocrine system and cancer is usually achieved by the infiltration of nerve fibers into the tumor tissue, which is called neurogenesis; the migration of cancer cells toward nerve fibers, which is called perineural invasion (PNI), and the neurotransmitters. In addition to the traditional role of neurotransmitters in neural communications, neurotransmitters are increasingly recognized as mediators of crosstalk between the nervous system, cancer cells, and the immune system. Recent studies have revealed that not only nerve fibers but also cancer cells and immune cells within the TIME can secrete neurotransmitters, exerting influence on both neurons and themselves. Furthermore, immune cells infiltrating the tumor environment have been found to express a wide array of neurotransmitter receptors. Hence, targeting these neurotransmitter receptors may promote the activity of immune cells in the tumor microenvironment and exert anti-tumor immunity. Herein, we discuss the crosstalk between the neuroendocrine system and tumor-infiltrating immune cells, which may provide feasible cancer immunotherapy options.

A review of studies on the implication of NLRP3 inflammasome for Parkinson's disease and related candidate treatment targets

Parkinson's disease (PD) is a neurodegenerative disease for which the prevalence is second only to Alzheimer's disease (AD). This disease primarily affects people of middle and old age, significantly impacting their health and quality of life. The main pathological features include the degenerative nigrostriatal dopaminergic (DA) neuron loss and Lewy body (LB) formation. Currently, available PD medications primarily aim to alleviate clinical symptoms, however, there is no universally recognized therapy worldwide that effectively prevents, clinically treats, stops, or reverses the disease. Consequently, the evaluation and exploration of potential therapeutic targets for PD are of utmost importance. Nevertheless, the pathophysiology of PD remains unknown, and neuroinflammation mediated by inflammatory cytokines that prompts neuron death is fundamental for the progression of PD. The nucleotide-binding oligomerization domain-like receptor pyrin domain-containing 3 (NLRP3) inflammasome is a key complex of proteins linking the neuroinflammatory cascade in PD. Moreover, mounting evidence suggests that traditional Chinese medicine (TCM) alleviates PD by suppressing the NLRP3 inflammasome. This article aims to comprehensively review the available studies on the composition and activating mechanism of the NLRP3 inflammasome, along with its significance in PD pathogenesis and potential treatment targets. We also review natural products or synthetic compounds which reduce neuroinflammation via modulating NLRP3 inflammasome activity, aiming to identify new targets for future PD diagnosis and treatment through the exploration of NLRP3 inhibitors. Additionally, this review offers valuable references for developing new PD treatment methods.

Ferroptosis in Parkinson's disease: Molecular mechanisms and therapeutic potential

Parkinson's Disease (PD) is characterized by the progressive loss of dopaminergic neurons in the substantia nigra (SN), leading to motor and non-motor symptoms. While the exact mechanisms remain complex and multifaceted, several molecular pathways have been implicated in PD pathology, including accumulation of misfolded proteins, impaired mitochondrial function, oxidative stress, inflammation, elevated iron levels, etc. Overall, PD's molecular mechanisms involve a complex interplay between genetic, environmental, and cellular factors that disrupt cellular homeostasis, and ultimately lead to the degeneration of dopaminergic neurons. Recently, emerging evidence highlights ferroptosis, an iron-dependent non-apoptotic cell death process, as a pivotal player in the advancement of PD. Notably, oligomeric α-synuclein (α-syn) generates reactive oxygen species (ROS) and lipid peroxides within cellular membranes, potentially triggering ferroptosis. The loss of dopamine, a hallmark of PD, could predispose neurons to ferroptotic vulnerability. This unique form of cell demise unveils fresh insights into PD pathogenesis, necessitating an exploration of the molecular intricacies connecting ferroptosis and PD progression. In this review, the molecular and regulatory mechanisms of ferroptosis and their connection with the pathological processes of PD have been systematically summarized. Furthermore, the features of ferroptosis in PD animal models and clinical trials targeting ferroptosis as a therapeutic approach in PD patients' management are scrutinized.

Oscillometry of the respiratory system in Parkinson's disease: physiological changes and diagnostic use

BACKGROUND

Lung function analysis in Parkinson's disease (PD) is often difficult due to the demand for adequate forced expiratory maneuvers. Respiratory oscillometry exams require onlyquiet tidal breathing and provide a detailed analysis of respiratory mechanics. We hypothesized that oscillometry would simplify the diagnosis of respiratory abnormalitiesin PD and improve our knowledge about the pathophysiological changes in these patients.

MATERIALS AND METHODS

This observational study includes 20 controls and 47 individuals with PD divided into three groups (Hoehn and Yahr Scale 1-1.5; H&Y scale 2-3 and PD smokers).The diagnostic accuracy was evaluated by investigating the area under the receiver operating characteristic curve (AUC).

RESULTS

Initial stages are related to increased peripheral resistance (Rp; p = 0.001). In more advanced stages, a restrictive pattern is added, reflected by reductions in dynamic compliance (p < 0.05) and increase in resonance frequency (Fr; p < 0.001). Smoking PD patients presented increased Rp (p < 0.001) and Fr (p < 0.01). PD does not introduce changes in the central airways. Oscillometric changes were correlated with respiratory muscle weakness (R = 0.37, p = 0.02). Rp showed adequate accuracy in the detection of early respiratory abnormalities (AUC = 0.858), while in more advanced stages, Fr showed high diagnostic accuracy (AUC = 0.948). The best parameter to identify changes in smoking patients was Rp (AUC = 0.896).

CONCLUSION

The initial stages of PD are related to a reduction in ventilation homogeneity associated with changes in peripheral airways. More advanced stages also include a restrictive ventilatory pattern. These changes were correlated with respiratory muscle weakness and were observed in mild and moderate stages of PD in smokers and non-smokers. Oscillometry may adequately identify respiratory changes in the early stages of PD and obtain high diagnostic accuracy in more advanced stages of the disease.

The effectiveness and safety of botulinum toxin injections for the treatment of sialorrhea with Parkinson's disease: a systematic review and meta-analysis

BACKGROUND

Botulinum toxin (BoNT) injection is an important adjunctive method to treat sialorrhea. The purpose of this systematic review was to analyze the effect and safety of BoNT injections in the intervention of sialorrhea with Parkinson's disease (PD).

METHODS

We searched PubMed, Web Of Science (WOS), Scopus, Cochrane CENTRAL, and Embase from inception until April 2022. Randomized controlled trials or randomized crossover trials comparing BoNT with placebo in sialorrhea with PD were eligible. PRISMA guidelines were used to carry out the meta-analysis. The Drooling Severity Frequency Scale (DSFS) score and the number of adverse events (AEs) were the primary and secondary outcomes, respectively. Standardized mean differences (SMDs) and risk differences (RDs) are used to express continuous and categorical outcomes, respectively. Heterogeneity among these studies was evaluated using I2 tests. We used the GRADE tool to assess the certainty of evidence (COE).

RESULTS

Eight articles involving 259 patients compared BoNT injections with a placebo for PD with sialorrhea. This meta-analysis showed a significant reduction in DSFS scores between BoNT injections and placebo (SMD=-0.98; 95% CI, -1.27 to 0.70, p<0.001; COE: high). This meta-analysis showed a significant difference in AEs between BoNT injections and placebo (RD=0.15; 95% CI, 0.05 to 0.24, p=0.002; COE: low).

CONCLUSIONS

The pooled results suggest that BoNT injections have some effect on DSFS scores with sialorrhea caused by PD. There are also mild adverse events, which generally recover within a week or so. The results indicate that BoNT injection is one of the treatments for sialorrhea caused by PD, but we need to pay attention to adverse events. In addition, the follow-up time was extended to observe oral hygiene, ulceration or dental caries, and digestive function.

TRIAL REGISTRATION

Our review protocol was registered on PROSPERO (42021288334).

Circular RNAs: Diagnostic and Therapeutic Perspectives in CNS Diseases

Circular RNAs (circRNAs) are a class of regulatory non-coding RNAs characterized by the presence of covalently closed ends. A growing body of evidence suggests that circRNAs play important roles in physiology and pathology. In particular, accumulating data on circRNA functions in various central nervous system (CNS) diseases and their correlations indicate that circRNAs are critical contributors to the onset and development of brain disorders. In this review, we focus on the regulatory and functional roles of circRNAs in CNS diseases, highlighting their diagnostic and therapeutic potential, with the aim of providing new insights into CNS diseases.

Expression of RAD9B in the mesostriatal system of rats and humans: Overexpression in a 6-OHDA rat model of Parkinson's disease

BACKGROUND

Parkinson's disease (PD) is a neurodegenerative disorder that affects primarily the dopaminergic (DAergic) neurons of the mesostriatal system, among other nuclei of the brain. Although it is considered an idiopathic disease, oxidative stress is believed to be involved in DAergic neuron death and therefore plays an important role in the onset and development of the disease. RAD9B is a paralog of the RAD9 checkpoint, sharing some similar functions related to DNA damage resistance and apoptosis, as well as the ability to form 9-1-1 heterotrimers with RAD1 and HUS1.

METHODS

In addition to immunohistochemistry, immunofluorescence and Western-blot analysis, we implemented Quantitative RT-PCR and in situ hybridization techniques.

RESULTS

We demonstrated RAD9B expression in rat and human mesencephalic DAergic cells using specific markers. Additionally, we observed significant overexpression of RAD9B mRNA (p<0.01) and protein (p<0.01) in the midbrain 48 h after inducing damage with 150 µg of 6-hydroxydopamine (6-OHDA) injected in a rat model of PD. Regarding protein expression, the increased levels were observed in neurons of the mesostriatal system and returned to normal 5 days post-injury.

CONCLUSIONS

This response to a neurotoxin, known to produce oxidative stress specifically on DAergic neurons indicates the potential importance of RAD9B in this highly vulnerable population to cell death. In this model, RAD9B function appears to provide neuroprotection, as the induced lesion resulted in only mild degeneration. This observation highlights the potential of RAD9B checkpoint protein as a valuable target for future therapeutic interventions aimed at promoting neuroprotection.

Impaired skeletal muscle health in Parkinsonian syndromes: clinical implications, mechanisms and potential treatments

There is increasing evidence that neurodegenerative disorders including the Parkinsonian syndromes are associated with impaired skeletal muscle health, manifesting as wasting and weakness. Many of the movement problems, lack of muscle strength and reduction in quality of life that are characteristic of these syndromes can be attributed to impairments in skeletal muscle health, but this concept has been grossly understudied and represents an important area of unmet clinical need. This review describes the changes in skeletal muscle health in idiopathic Parkinson's disease and in two atypical Parkinsonian syndromes, the most aggressive synucleinopathy multiple system atrophy, and the tauopathy progressive supranuclear palsy. The pathogenesis of the skeletal muscle changes is described, including the contribution of impairments to the central and peripheral nervous system and intrinsic alterations. Pharmacological interventions targeting the underlying molecular mechanisms with therapeutic potential to improve skeletal muscle health in affected patients are also discussed. Although little is known about the mechanisms underlying these conditions, current evidence implicates multiple pathways and processes, highlighting the likely need for combination therapies to protect muscle health and emphasizing the merit of personalized interventions for patients with different physical capacities at different stages of their disease. As muscle fatigue is often experienced by patients prior to diagnosis, the identification and measurement of this symptom and related biomarkers to identify early signs of disease require careful interrogation, especially for multiple system atrophy and progressive supranuclear palsy where diagnosis is often made several years after onset of symptoms and only confirmed post-mortem. We propose a multidisciplinary approach for early diagnosis and implementation of personalized interventions to preserve muscle health and improve quality of life for patients with typical and atypical Parkinsonian syndromes.

Exploring the Efficacy of the Effortful Swallow Maneuver for Improving Swallowing in People With Parkinson Disease-A Pilot Study

Objectives

To determine the immediate (compensatory) and longer term (rehabilitative) effect of the effortful swallow (ES) maneuver on physiological swallowing parameters in Parkinson disease.

Design

Virtual intervention protocol via Microsoft Teams with pre- and post-videofluoroscopic swallowing studies.

Setting

Outpatient hospital setting, with intervention performed virtually.

Participants

Eight participants (median age 74 years [63-82])with Parkinson disease (years post onset 3-20) with a Hoehn and Yahr scale score between 2 and 4 (N=8).

Interventions

ES maneuver, initiated using a maximum effort isometric tongue-to-palate press, with biofeedback provided using the Iowa Oral Performance Instrument. The protocol included 30 minute sessions twice daily, 5 days/week for 4 weeks.

Main Outcome Measures

Penetration-Aspiration Scale scores, time-to-laryngeal-vestibule-closure, total pharyngeal residue, and pharyngeal area at maximum constriction as seen on lateral view videofluoroscopy.

Results

No consistent, systematic trends were identified in the direction of improvement or deterioration across Penetration-Aspiration Scale scores, time-to-laryngeal-vestibule-closure, pharyngeal area at maximum constriction, or total pharyngeal residue.

Conclusions

Heterogeneous response to the ES as both a compensatory and rehabilitative technique. Positive response on the compensatory probe was predictive of positive response after rehabilitation.