Plasma circulating cell–free DNA integrity and relative telomere length as diagnostic biomarkers for Parkinson's disease and multiple system atrophy:a cross-sectional study

In clinical specialties focusing on neurological disorders,there is a need for comprehensive and integrated non-invasive,sensitive,and specific testing methods.Both Parkinson's disease and multiple system atrophy are classified asα-synucleinopathies,characterized by abnormal accumulation ofα-synuclein protein,which provides a shared pathological background for their comparative study.In addition,both Parkinson's disease and multiple system atrophy involve neuronal death,a process that may release circulating cell–free DNA(cfDNA)into the bloodstream,leading to specific alterations.This premise formed the basis for investigating cell–free DNA as a potential biomarker.Cellfree DNA has garnered attention for its potential pathological significance,yet its characteristics in the context of Parkinson's disease and multiple system atrophy are not fully understood.This study investigated the total concentration,nonapoptotic level,integrity,and cellfree DNA relative telomere length of cell-free DNA in the peripheral blood of 171 participants,comprising 76 normal controls,62 patients with Parkinson's disease,and 33 patients with multiple system atrophy.In our cohort,75.8%of patients with Parkinson's disease(stage 1–2 of Hoehn&Yahr)and 60.6%of patients with multiple system atrophy(disease duration less than 3 years)were in the early stages.The diagnostic potential of the cell-free DNA parameters was evaluated using receiver operating characteristic(ROC)analysis,and their association with disease prevalence was examined through logistic regression models,adjusting for confounders such as age,sex,body mass index,and education level.The results showed that cell-free DNA integrity was significantly elevated in both Parkinson's disease and multiple system atrophy patients compared with normal controls(P<0.001 for both groups),whereas cell-free DNA relative telomere length was markedly shorter(P=0.003 for Parkinson's disease and P=0.010 for multiple system atrophy).Receiver operating characteristic analysis indicated that both cell-free DNA integrity and cell-free DNA relative telomere length possessed good diagnostic accuracy for differentiating Parkinson's disease and multiple system atrophy from normal controls.Specifically,higher cell-free DNA integrity was associated with increased risk of Parkinson's disease(odds ratio[OR]:5.72;95%confidence interval[CI]:1.54–24.19)and multiple system atrophy(OR:10.10;95%CI:1.55–122.98).Conversely,longer cell-free DNA relative telomere length was linked to reduced risk of Parkinson's disease(OR:0.16;95%CI:0.04–0.54)and multiple system atrophy(OR:0.10;95%CI:0.01–0.57).These findings suggest that cell-free DNA integrity and cellfree DNA relative telomere length may serve as promising biomarkers for the early diagnosis of Parkinson's disease and multiple system atrophy,potentially reflecting specific underlying pathophysiological processes of these neurodegenerative disorders.

Comparative proteomic analysis of plasma exosomes reveals the functional contribution of N-acetyl-alpha-glucosaminidase to Parkinson’s disease

Parkinson’s disease is the second most common progressive neurodegenerative disorder,and few reliable biomarkers are available to track disease progression.The proteins,DNA,mRNA,and lipids carried by exosomes reflect intracellular changes,and thus can serve as biomarkers for a variety of conditions.In this study,we investigated alterations in the protein content of plasma exosomes derived from patients with Parkinson’s disease and the potential therapeutic roles of these proteins in Parkinson’s disease.Using a tandem mass tag-based quantitative proteomics approach,we characterized the proteomes of plasma exosomes derived from individual patients,identified exosomal protein signatures specific to patients with Parkinson’s disease,and identified N-acetyl-alpha-glucosaminidase as a differentially expressed protein.N-acetyl-alpha-glucosaminidase expression levels in exosomes from the plasma of patients and healthy controls were validated by enzyme-linked immunosorbent assay and western blot.The results demonstrated that the exosomal N-acetyl-alpha-glucosaminidase concentration was not only lower in Parkinson’s disease,but also decreased with increasing Hoehn-Yahr stage,suggesting that N-acetyl-alpha-glucosaminidase could be used to rapidly evaluate Parkinson’s disease severity.Furthermore,western blot and immunohistochemistry analysis showed that N-acetyl-alpha-glucosaminidase levels were markedly reduced both in cells treated with 1-methyl-4-phenylpyridinium and cells overexpressingα-synuclein compared with control cells.Additionally,N-acetyl-alpha-glucosaminidase overexpression significantly increased cell viability and inhibitedα-synuclein expression in 1-methyl-4-phenylpyridinium-treated cells.Taken together,our findings demonstrate for the first time that exosomal N-acetyl-alpha-glucosaminidase may serve as a biomarker for Parkinson’s disease diagnosis,and that N-acetyl-alpha-glucosaminidase may reduceα-synuclein expression and 1-methyl-4-phenylpyridinium-induced neurotoxicity,thus providing a new therapeutic target for Parkinson’s disease.

The autophagy-lysosome pathway:a potential target in the chemical and gene therapeutic strategies for Parkinson’s disease

Parkinson’s disease is a common neurodegenerative disease with movement disorders associated with the intracytoplasmic deposition of aggregate proteins such asα-synuclein in neurons.As one of the major intracellular degradation pathways,the autophagy-lysosome pathway plays an important role in eliminating these proteins.Accumulating evidence has shown that upregulation of the autophagy-lysosome pathway may contribute to the clearance ofα-synuclein aggregates and protect against degeneration of dopaminergic neurons in Parkinson’s disease.Moreover,multiple genes associated with the pathogenesis of Parkinson’s disease are intimately linked to alterations in the autophagy-lysosome pathway.Thus,this pathway appears to be a promising therapeutic target for treatment of Parkinson’s disease.In this review,we briefly introduce the machinery of autophagy.Then,we provide a description of the effects of Parkinson’s disease–related genes on the autophagy-lysosome pathway.Finally,we highlight the potential chemical and genetic therapeutic strategies targeting the autophagy–lysosome pathway and their applications in Parkinson’s disease.

Additive neurorestorative effects of exercise and docosahexaenoic acid intake in a mouse model of Parkinson’s disease

There is a need to develop interventions to slow or reverse the degeneration of dopamine neurons in Parkinson’s disease after diagnosis.Given that preclinical and clinical studies suggest benefits of dietary n-3 polyunsaturated fatty acids,such as docosahexaenoic acid,and exercise in Parkinson’s disease,we investigated whether both could synergistically interact to induce recovery of the dopaminergic pathway.First,mice received a unilateral stereotactic injection of 6-hydroxydopamine into the striatum to establish an animal model of nigrostriatal denervation.Four weeks after lesion,animals were fed a docosahexaenoic acid-enriched or a control diet for the next 8 weeks.During this period,the animals had access to a running wheel,which they could use or not.Docosahexaenoic acid treatment,voluntary exercise,or the combination of both had no effect on(i)distance traveled in the open field test,(ii)the percentage of contraversive rotations in the apomorphine-induction test or(iii)the number of tyrosine-hydroxylase-positive cells in the substantia nigra pars compacta.However,the docosahexaenoic acid diet increased the number of tyrosine-hydroxylase-positive terminals and induced a rise in dopamine concentrations in the lesioned striatum.Compared to docosahexaenoic acid treatment or exercise alone,the combination of docosahexaenoic acid and exercise(i)improved forelimb balance in the stepping test,(ii)decreased the striatal DOPAC/dopamine ratio and(iii)led to increased dopamine transporter levels in the lesioned striatum.The present results suggest that the combination of exercise and docosahexaenoic acid may act synergistically in the striatum of mice with a unilateral lesion of the dopaminergic system and provide support for clinical trials combining nutrition and physical exercise in the treatment of Parkinson’s disease.

The cGAS-STING-interferon regulatory factor 7 pathway regulates neuroinflammation in Parkinson's disease

Interferon regulatory factor 7 plays a crucial role in the innate immune response.However,whether interferon regulatory factor 7-mediated signaling contributes to Parkinson's disease remains unknown.Here we report that interferon regulatory factor 7 is markedly up-regulated in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced mouse model of Parkinson's disease and co-localizes with microglial cells.Both the selective cyclic guanosine monophosphate adenosine monophosphate synthase inhibitor RU.521 and the stimulator of interferon genes inhibitor H151 effectively suppressed interferon regulatory factor 7 activation in BV2 microglia exposed to 1-methyl-4-phenylpyridinium and inhibited transformation of mouse BV2 microglia into the neurotoxic M1 phenotype.In addition,si RNA-mediated knockdown of interferon regulatory factor 7 expression in BV2 microglia reduced the expression of inducible nitric oxide synthase,tumor necrosis factorα,CD16,CD32,and CD86 and increased the expression of the anti-inflammatory markers ARG1 and YM1.Taken together,our findings indicate that the cyclic guanosine monophosphate adenosine monophosphate synthase-stimulator of interferon genes-interferon regulatory factor 7 pathway plays a crucial role in the pathogenesis of Parkinson's disease.

Multisensory mechanisms of gait and balance in Parkinson’s disease:an integrative review

Understanding the neural underpinning of human gait and balance is one of the most pertinent challenges for 21st-century translational neuroscience due to the profound impact that falls and mobility disturbances have on our aging population.Posture and gait control does not happen automatically,as previously believed,but rather requires continuous involvement of central nervous mechanisms.To effectively exert control over the body,the brain must integrate multiple streams of sensory information,including visual,vestibular,and somatosensory signals.The mechanisms which underpin the integration of these multisensory signals are the principal topic of the present work.Existing multisensory integration theories focus on how failure of cognitive processes thought to be involved in multisensory integration leads to falls in older adults.Insufficient emphasis,however,has been placed on specific contributions of individual sensory modalities to multisensory integration processes and cross-modal interactions that occur between the sensory modalities in relation to gait and balance.In the present work,we review the contributions of somatosensory,visual,and vestibular modalities,along with their multisensory intersections to gait and balance in older adults and patients with Parkinson’s disease.We also review evidence of vestibular contributions to multisensory temporal binding windows,previously shown to be highly pertinent to fall risk in older adults.Lastly,we relate multisensory vestibular mechanisms to potential neural substrates,both at the level of neurobiology(concerning positron emission tomography imaging)and at the level of electrophysiology(concerning electroencephalography).We hope that this integrative review,drawing influence across multiple subdisciplines of neuroscience,paves the way for novel research directions and therapeutic neuromodulatory approaches,to improve the lives of older adults and patients with neurodegenerative diseases.

Rosa moschata ameliorates haloperidol-induced Parkinson's disease via reduction of neurodegeneration and oxidative stress

Objective:To investigate the effect of Rosa moschata(R.moschata)extract on haloperidol-induced Parkinson’s disease(PD)in rats.Methods:Haloperidol(1 mg/kg)was given to rats intraperitoneally for 3 weeks for induction of PD.R.moschata extract(150,300 and 600 mg/kg)was administered orally for 21 days.The neuroprotective role of R.moschata leaf extract in PD was explored by performing neurobehavioral tests and RT-PCR analysis and measuring neurotransmitters and oxidative stress biomarkers.Results:An improvement in motor functions and muscle strength was observed in PD rats treated with R.moschata extract.The levels of dopamine,serotonin,noradrenaline,superoxide dismutase,catalase,glutathione,and superoxide dismutase were significantly increased(P<0.001),whereas acetylcholinesterase and malondialdehyde levels were markedly decreased by treatment with R.moschata extract(P<0.001).The extract also markedly downregulated the mRNA expressions of IL-1β,α-synuclein,IL-1α,and TNF-αin brain tissue.Moreover,histopathological analysis indicated that neurofibrillary tangles and plaques were noticeably decreased in a dose-dependent manner in PD rats treated with R.moschata extract.Conclusions:R.moschata extract alleviates haloperidol-induced PD in rats by reducing oxidative stress and neurodegeneration.It may be used for management and treatment of PD.However additional studies are required to confirm its efficacy and molecular mechanisms.

Gut–brain axis and environmental factors in Parkinson's disease:bidirectional link between disease onset and progression

Parkinson's disease has long been considered a disorder that primarily affects the brain,as it is defined by the dopaminergic neurodegeneration in the substantia nigra and the brain accumulation of Lewy bodies containingα-synuclein protein.In recent decades,however,accumulating research has revealed that Parkinson's disease also involves the gut and uncovered an intimate and important bidirectional link between the brain and the gut,called the“gut–brain axis.”Numerous clinical studies demonstrate that gut dysfunction frequently precedes motor symptoms in Parkinson's disease patients,with findings including impaired intestinal permeability,heightened inflammation,and distinct gut microbiome profiles and metabolites.Furthermore,α-synuclein deposition has been consistently observed in the gut of Parkinson's disease patients,suggesting a potential role in disease initiation.Importantly,individuals with vagotomy have a reduced Parkinson's disease risk.From these observations,researchers have hypothesized thatα-synuclein accumulation may initiate in the gut and subsequently propagate to the central dopaminergic neurons through the gut–brain axis,leading to Parkinson's disease.This review comprehensively examines the gut's involvement in Parkinson's disease,focusing on the concept of a gut-origin for the disease.We also examine the interplay between altered gut-related factors and the accumulation of pathologicalα-synuclein in the gut of Parkinson's disease patients.Given the accessibility of the gut to both dietary and pharmacological interventions,targeting gut-localizedα-synuclein represents a promising avenue for developing effective Parkinson's disease therapies.

Design of a Biomedical Device to Reduce Anxiety Experienced by Patients Diagnosed with Parkinson’s Disease

Parkinson’s disease (PD) is a neurodegenerative disease that occurs due to loss of nerve cells that produce dopamine in the brain, affecting approximately 4 million people worldwide. PD patients often feel an increase in anxiety levels daily. While there are medications/exercises to help relieve anxiety, there are limited methods to reduce anxiety without the help of a caretaker. As a result, MEDIC Foundation, a non-profit organization in British Columbia, Canada, is designing an automated system that consists of a wristband and an application which uses vi-bration therapy to help reduce anxiety of PD patients. Literature reviews were conducted to document the project’s needs. Phase I of the project focused on de-veloping a prototype for the application and phase II on developing the wrist-band. The team developed prototypes of a wristband that automatically applies vibration near the median nerve as the heart rate variability (HRV) deviates away from the normal threshold of the user, and an application that displays real-time heart rate variability signals as well as provides for relaxation. The development of the prototype is still in early progress. By creating this automated system, we aim to provide a solution to senior PD patients to relieve anxiety independently. .

Olfactory dysfunction and its related molecular mechanisms in Parkinson’s disease

Changes in olfactory function are considered to be early biomarkers of Parkinson’s disease.Olfactory dysfunction is one of the earliest non-motor features of Parkinson’s disease,appearing in about 90%of patients with early-stage Parkinson’s disease,and can often predate the diagnosis by years.Therefore,olfactory dysfunction should be considered a reliable marker of the disease.However,the mechanisms responsible for olfactory dysfunction are currently unknown.In this article,we clearly explain the pathology and medical definition of olfactory function as a biomarker for early-stage Parkinson’s disease.On the basis of the findings of clinical olfactory function tests and animal model experiments as well as neurotransmitter expression levels,we further characterize the relationship between olfactory dysfunction and neurodegenerative diseases as well as the molecular mechanisms underlying olfactory dysfunction in the pathology of early-stage Parkinson’s disease.The findings highlighted in this review suggest that olfactory dysfunction is an important biomarker for preclinical-stage Parkinson’s disease.Therefore,therapeutic drugs targeting non-motor symptoms such as olfactory dysfunction in the early stage of Parkinson’s disease may prevent or delay dopaminergic neurodegeneration and reduce motor symptoms,highlighting the potential of identifying effective targets for treating Parkinson’s disease by inhibiting the deterioration of olfactory dysfunction.

Effects of mesenchymal stem cell on dopaminergic neurons,motor and memory functions in animal models of Parkinson's disease:a systematic review and meta-analysis

Parkinson’s disease is chara cterized by the loss of dopaminergic neurons in the substantia nigra pars com pacta,and although restoring striatal dopamine levels may improve symptoms,no treatment can cure or reve rse the disease itself.Stem cell therapy has a regenerative effect and is being actively studied as a candidate for the treatment of Parkinson’s disease.Mesenchymal stem cells are considered a promising option due to fewer ethical concerns,a lower risk of immune rejection,and a lower risk of teratogenicity.We performed a meta-analysis to evaluate the therapeutic effects of mesenchymal stem cells and their derivatives on motor function,memory,and preservation of dopamine rgic neurons in a Parkinson’s disease animal model.We searched bibliographic databases(PubMed/MEDLINE,Embase,CENTRAL,Scopus,and Web of Science)to identify articles and included only pee r-reviewed in vivo interve ntional animal studies published in any language through J une 28,2023.The study utilized the random-effect model to estimate the 95%confidence intervals(CI)of the standard mean differences(SMD)between the treatment and control groups.We use the systematic review center for laboratory animal expe rimentation’s risk of bias tool and the collaborative approach to meta-analysis and review of animal studies checklist for study quality assessment.A total of 33studies with data from 840 Parkinson’s disease model animals were included in the meta-analysis.Treatment with mesenchymal stem cells significantly improved motor function as assessed by the amphetamine-induced rotational test.Among the stem cell types,the bone marrow MSCs with neurotrophic factor group showed la rgest effect size(SMD[95%CI]=-6.21[-9.50 to-2.93],P=0.0001,I^(2)=0.0%).The stem cell treatment group had significantly more tyrosine hydroxylase positive dopamine rgic neurons in the striatum([95%CI]=1.04[0.59 to 1.49],P=0.0001,I^(2)=65.1%)and substantia nigra(SMD[95%CI]=1.38[0.89 to 1.87],P=0.0001,I^(2)=75.3%),indicating a protective effect on dopaminergic neurons.Subgroup analysis of the amphetamine-induced rotation test showed a significant reduction only in the intracranial-striatum route(SMD[95%CI]=-2.59[-3.25 to-1.94],P=0.0001,I^(2)=74.4%).The memory test showed significant improvement only in the intravenous route(SMD[95%CI]=4.80[1.84 to 7.76],P=0.027,I^(2)=79.6%).Mesenchymal stem cells have been shown to positively impact motor function and memory function and protect dopaminergic neurons in preclinical models of Parkinson’s disease.Further research is required to determine the optimal stem cell types,modifications,transplanted cell numbe rs,and delivery methods for these protocols.

Interplay between the glymphatic system and neurotoxic proteins in Parkinson’s disease and related disorders:current knowledge and future directions

Parkinson’s disease is a common neurodegenerative disorder that is associated with abnormal aggregation and accumulation of neurotoxic proteins,includingα-synuclein,amyloid-β,and tau,in addition to the impaired elimination of these neurotoxic protein.Atypical parkinsonism,which has the same clinical presentation and neuropathology as Parkinson’s disease,expands the disease landscape within the continuum of Parkinson’s disease and related disorders.The glymphatic system is a waste clearance system in the brain,which is responsible for eliminating the neurotoxic proteins from the interstitial fluid.Impairment of the glymphatic system has been proposed as a significant contributor to the development and progression of neurodegenerative disease,as it exacerbates the aggregation of neurotoxic proteins and deteriorates neuronal damage.Therefore,impairment of the glymphatic system could be considered as the final common pathway to neurodegeneration.Previous evidence has provided initial insights into the potential effect of the impaired glymphatic system on Parkinson’s disease and related disorders;however,many unanswered questions remain.This review aims to provide a comprehensive summary of the growing literature on the glymphatic system in Parkinson’s disease and related disorders.The focus of this review is on identifying the manifestations and mechanisms of interplay between the glymphatic system and neurotoxic proteins,including loss of polarization of aquaporin-4 in astrocytic endfeet,sleep and circadian rhythms,neuroinflammation,astrogliosis,and gliosis.This review further delves into the underlying pathophysiology of the glymphatic system in Parkinson’s disease and related disorders,and the potential implications of targeting the glymphatic system as a novel and promising therapeutic strategy.

Cell reprogramming therapy for Parkinson’s disease

Parkinson’s disease is typically characterized by the progressive loss of dopaminergic neurons in the substantia nigra pars compacta.Many studies have been performed based on the supplementation of lost dopaminergic neurons to treat Parkinson’s disease.The initial strategy for cell replacement therapy used human fetal ventral midbrain and human embryonic stem cells to treat Parkinson’s disease,which could substantially alleviate the symptoms of Parkinson’s disease in clinical practice.However,ethical issues and tumor formation were limitations of its clinical application.Induced pluripotent stem cells can be acquired without sacrificing human embryos,which eliminates the huge ethical barriers of human stem cell therapy.Another widely considered neuronal regeneration strategy is to directly reprogram fibroblasts and astrocytes into neurons,without the need for intermediate proliferation states,thus avoiding issues of immune rejection and tumor formation.Both induced pluripotent stem cells and direct reprogramming of lineage cells have shown promising results in the treatment of Parkinson’s disease.However,there are also ethical concerns and the risk of tumor formation that need to be addressed.This review highlights the current application status of cell reprogramming in the treatment of Parkinson’s disease,focusing on the use of induced pluripotent stem cells in cell replacement therapy,including preclinical animal models and progress in clinical research.The review also discusses the advancements in direct reprogramming of lineage cells in the treatment of Parkinson’s disease,as well as the controversy surrounding in vivo reprogramming.These findings suggest that cell reprogramming may hold great promise as a potential strategy for treating Parkinson’s disease.

Netrin-1 signaling pathway mechanisms in neurodegenerative diseases

Netrin-1 and its receptors play crucial roles in inducing axonal growth and neuronal migration during neuronal development.Their profound impacts then extend into adulthood to encompass the maintenance of neuronal survival and synaptic function.Increasing amounts of evidence highlight several key points:(1)Diminished Netrin-1 levels exacerbate pathological progression in animal models of Alzheimer’s disease and Parkinson’s disease,and potentially,similar alterations occur in humans.(2)Genetic mutations of Netrin-1 receptors increase an individuals’susceptibility to neurodegenerative disorders.(3)Therapeutic approaches targeting Netrin-1 and its receptors offer the benefits of enhancing memory and motor function.(4)Netrin-1 and its receptors show genetic and epigenetic alterations in a variety of cancers.These findings provide compelling evidence that Netrin-1 and its receptors are crucial targets in neurodegenerative diseases.Through a comprehensive review of Netrin-1 signaling pathways,our objective is to uncover potential therapeutic avenues for neurodegenerative disorders.

Gut microbiota dysbiosis contributes toα-synuclein-related pathology associated with C/EBPβ/AEP signaling activation in a mouse model of Parkinson’s disease

Parkinson’s disease is a neurodegenerative disease characterized by motor and gastrointestinal dysfunction.Gastrointestinal dysfunction can precede the onset of motor symptoms by several years.Gut microbiota dysbiosis is involved in the pathogenesis of Parkinson’s disease,whether it plays a causal role in motor dysfunction,and the mechanism underlying this potential effect,remain unknown.CCAAT/enhancer binding proteinβ/asparagine endopeptidase(C/EBPβ/AEP)signaling,activated by bacterial endotoxin,can promoteα-synuclein transcription,thereby contributing to Parkinson’s disease pathology.In this study,we aimed to investigate the role of the gut microbiota in C/EBPβ/AEP signaling,α-synuclein-related pathology,and motor symptoms using a rotenone-induced mouse model of Parkinson’s disease combined with antibiotic-induced microbiome depletion and fecal microbiota transplantation.We found that rotenone administration resulted in gut microbiota dysbiosis and perturbation of the intestinal barrier,as well as activation of the C/EBP/AEP pathway,α-synuclein aggregation,and tyrosine hydroxylase-positive neuron loss in the substantia nigra in mice with motor deficits.However,treatment with rotenone did not have any of these adverse effects in mice whose gut microbiota was depleted by pretreatment with antibiotics.Importantly,we found that transplanting gut microbiota derived from mice treated with rotenone induced motor deficits,intestinal inflammation,and endotoxemia.Transplantation of fecal microbiota from healthy control mice alleviated rotenone-induced motor deficits,intestinal inflammation,endotoxemia,and intestinal barrier impairment.These results highlight the vital role that gut microbiota dysbiosis plays in inducing motor deficits,C/EBPβ/AEP signaling activation,andα-synuclein-related pathology in a rotenone-induced mouse model of Parkinson’s disease.Additionally,our findings suggest that supplementing with healthy microbiota may be a safe and effective treatment that could help ameliorate the progression of motor deficits in patients with Parkinson’s disease.

A review of the neurotransmitter system associated with cognitive function of the cerebellum in Parkinson's disease

The dichotomized brain system is a concept that was generalized from the‘dual syndrome hypothesis’to explain the heterogeneity of cognitive impairment,in which anterior and posterior brain systems are independent but partially overlap.The dopaminergic system acts on the anterior brain and is responsible for executive function,working memory,and planning.In contrast,the cholinergic system acts on the posterior brain and is responsible for semantic fluency and visuospatial function.Evidence from dopaminergic/cholinergic imaging or functional neuroimaging has shed significant insight relating to the involvement of the cerebellum in the cognitive process of patients with Parkinson’s disease.Previous research has reported evidence that the cerebellum receives both dopaminergic and cholinergic projections.However,whether these two neurotransmitter systems are associated with cognitive function has yet to be fully elucidated.Furthermore,the precise role of the cerebellum in patients with Parkinson’s disease and cognitive impairment remains unclear.Therefore,in this review,we summarize the cerebellar dopaminergic and cholinergic projections and their relationships with cognition,as reported by previous studies,and investigated the role of the cerebellum in patients with Parkinson’s disease and cognitive impairment,as determined by functional neuroimaging.Our findings will help us to understand the role of the cerebellum in the mechanisms underlying cognitive impairment in Parkinson’s disease.

A novel mechanism of PHB2-mediated mitophagy participating in the development of Parkinson's disease

Endoplasmic reticulum stress and mitochondrial dysfunction play important roles in Parkinson s disease,but the regulato ry mechanism remains elusive.Prohibitin-2(PHB2)is a newly discove red autophagy receptor in the mitochondrial inner membrane,and its role in Parkinson’s disease remains unclear.Protein kinase R(PKR)-like endoplasmic reticulum kinase(PERK)is a factor that regulates cell fate during endoplasmic reticulum stress.Parkin is regulated by PERK and is a target of the unfolded protein response.It is unclear whether PERK regulates PHB2-mediated mitophagy thro ugh Parkin.In this study,we established a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)-induced mouse model of Parkinson’s disease.We used adeno-associated virus to knockdown PHB2 expression.Our res ults showed that loss of dopaminergic neurons and motor deficits were aggravated in the MPTP-induced mouse model of Parkinson’s disease.Ove rexpression of PHB2 inhibited these abnormalities.We also established a 1-methyl-4-phenylpyridine(MPP+)-induced SH-SY5Y cell model of Parkinson’s disease.We found that ove rexpression of Parkin increased co-localization of PHB2 and microtubule-associated protein 1 light chain 3,and promoted mitophagy.In addition,MPP+regulated Parkin involvement in PHB2-mediated mitophagy through phosphorylation of PERK.These findings suggest that PHB2 participates in the development of Parkinson’s disease by intera cting with endoplasmic reticulum stress and Parkin.

Roles of neuronal lysosomes in the etiology of Parkinson’s disease

Therapeutic progress in neurodegenerative conditions such as Parkinson’s disease has been hampered by a lack of detailed knowledge of its molecular etiology.The advancements in genetics and genomics have provided fundamental insights into specific protein players and the cellular processes involved in the onset of disease.In this respect,the autophagy-lysosome system has emerged in recent years as a strong point of convergence for genetics,genomics,and pathologic indications,spanning both familial and idiopathic Parkinson’s disease.Most,if not all,genes linked to familial disease are involved,in a regulatory capacity,in lysosome function(e.g.,LRRK2,alpha-synuclein,VPS35,Parkin,and PINK1).Moreover,the majority of genomic loci associated with increased risk of idiopathic Parkinson’s cluster in lysosome biology and regulation(GBA as the prime example).Lastly,neuropathologic evidence showed alterations in lysosome markers in autoptic material that,coupled to the alpha-synuclein proteinopathy that defines the disease,strongly indicate an alteration in functionality.In this Brief Review article,I present a personal perspective on the molecular and cellular involvement of lysosome biology in Parkinson’s pathogenesis,aiming at a larger vision on the events underlying the onset of the disease.The attempts at targeting autophagy for therapeutic purposes in Parkinson’s have been mostly aimed at“indiscriminately”enhancing its activity to promote the degradation and elimination of aggregate protein accumulations,such as alpha-synuclein Lewy bodies.However,this approach is based on the assumption that protein pathology is the root cause of disease,while pre-pathology and pre-degeneration dysfunctions have been largely observed in clinical and pre-clinical settings.In addition,it has been reported that unspecific boosting of autophagy can be detrimental.Thus,it is important to understand the mechanisms of specific autophagy forms and,even more,the adjustment of specific lysosome functionalities.Indeed,lysosomes exert fine signaling capacities in addition to their catabolic roles and might participate in the regulation of neuronal and glial cell functions.Here,I discuss hypotheses on these possible mechanisms,their links with etiologic and risk factors for Parkinson’s disease,and how they could be targeted for disease-modifying purposes.

Deep brain implantable microelectrode arrays for detection and functional localization of the subthalamic nucleus in rats with Parkinson’s disease

The subthalamic nucleus(STN)is considered the best target for deep brain stimulation treatments of Parkinson’s disease(PD).It is difficult to localize the STN due to its small size and deep location.Multichannel microelectrode arrays(MEAs)can rapidly and precisely locate the STN,which is important for precise stimulation.In this paper,16-channel MEAs modified with multiwalled carbon nanotube/poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(MWCNT/PEDOT:PSS)nanocomposites were designed and fabricated,and the accurate and rapid identification of the STN in PD rats was performed using detection sites distributed at different brain depths.These results showed that nuclei in 6-hydroxydopamine hydrobromide(6-OHDA)-lesioned brains discharged more intensely than those in unlesioned brains.In addition,the MEA simultaneously acquired neural signals from both the STN and the upper or lower boundary nuclei of the STN.Moreover,higher values of spike firing rate,spike amplitude,local field potential(LFP)power,and beta oscillations were detected in the STN of the 6-OHDA-lesioned brain,and may therefore be biomarkers of STN localization.Compared with the STNs of unlesioned brains,the power spectral density of spikes and LFPs synchronously decreased in the delta band and increased in the beta band of 6-OHDA-lesioned brains.This may be a cause of sleep and motor disorders associated with PD.Overall,this work describes a new cellular-level localization and detection method and provides a tool for future studies of deep brain nuclei.

The pathogenesis of Parkinson’s disease and crosstalk with other diseases

In China,Parkinson’s disease(PD)is the second most prevalent central nervous system(CNS)degenerative illness affecting middle-aged and older persons.Movement disorders including resting tremor,bradykinesia,myotonia,postural instability,and gait instability are the predominant clinical symptoms.The two main types of PD are sporadic and familial,with sporadic PD being the more prevalent of the two.The environment,genetics,mitochondrial dysfunction,oxidative stress,inflammation,protein aggregation and misfolding,loss of trophic factors,cell death,and gut microbiota may all have a role in the etiology of PD.PD is inversely connected with other cancers and positively correlated with COVID-19,diabetes mellitus(DM),melanoma,and ischemic heart disease(IHD)risk.Delaying disease progression,managing motor and non-motor symptoms,and avoiding and controlling dysfunction in the middle and later phases of the disease are the key areas of research and development for its therapy.Presently,the development and progression of PD can be slowed down by using conventional pharmacology,natural items,and innovative technology.This article reviews the pathogenesis of PD,its correlations with other non-genetic diseases,and the research progress of drugs and technologies for alleviating PD.