The pathogenesis of Parkinson's disease is closely related to genetic factors. This article has systematically reviewed the research progress of molecular genetic mechanism on Parkinson's disease by focusing on the role of six high-penetrance pathogenic genes (SNCA, LRRK2, PRKN, PINK1, PARK7, and VPS35) and some risk genes (such as GBA1). These genetic variants eventually converge in three core pathogenic biological pathways, including lysosomal-autophagy pathway disorder, mitochondrial quality control disorder and α-synuclein metabolic abnormality. In-depth understanding of these molecular mechanisms is of great significance for the development of targeted therapy and realization of precision medicine for this disease.
Humans ; Parkinson Disease/metabolism* ; alpha-Synuclein/genetics* ; Leucine-Rich Repeat Serine-Threonine Protein Kinase-2/genetics* ; Genetic Predisposition to Disease ; Protein Kinases/genetics* ; Animals ; Glucosylceramidase/genetics* ; Ubiquitin-Protein Ligases/genetics*

Objective To investigate the association between excessive daytime sleepiness （EDS） and other non-motor symptoms （NMS） in patients with Parkinson disease （PD） using a graphical LASSO （GLASSO） network analysis， as well as the potential role of the sleepiness-olfaction-emotion axis in the onset of EDS. Methods A total of 500 PD patients who attended Xuanwu Hospital， Capital Medical University， from February 2023 to February 2024 were enrolled， and according to the Epworth Sleepiness Scale （ESS） score， they were divided into EDS group （ESS score ≥10） and non-EDS group （ESS score<10）. General clinical data were collected from all patients， and NMSS， HAMA， HAMD， PDSS， RBDQ-HK， MoCA， MMSE， and QOD-F scales were used to assess NMS. A graphical LASSO analysis was used to construct the NMS network in PD， and centrality indices were calculated to investigate the core role of EDS in the NMS network. Results The incidence rate of EDS was 7.12% in this study population. Compared with the non-EDS group， the EDS group had significantly higher HAMA， HAMD， NMSS， PDSS， and RBDQ-HK scores （P<0.05）. The network analysis showed that NMSS had the highest centrality （strength=0.906） in the non-EDS group， serving as the core node of the NMS network. However， in the EDS group， there was a significant increase in the centrality of olfactory function （strength=0.930）， replacing NMSS as the core of the network， and there was also an increase in the influence of RBDQ-HK （strength=0.318）. Conclusion EDS is closely associated with multiple NMS in PD patients， and the state of somnolence may alter the structure of the NMS network. Further studies can be conducted to investigate the role of the sleepiness-olfaction-emotion axis in the development of EDS.
Parkinson Disease

Emerging evidence suggests that dysbiosis of the gut microbiota is associated with the pathogenesis of Parkinson's disease (PD), a prevalent neurodegenerative disorder. The microbiota-gut-brain axis plays a crucial role in the development and progression of PD, and numerous studies have demonstrated the potential therapeutic benefits of modulations in the intestinal microbiota. This review provides insights into the characterization of the gut microbiota in patients with PD and highlights associations with clinical symptoms and underlying mechanisms. The discussion underscores the increased influence of the gut microbiota in the pathogenesis of PD. While the relationship is not fully elucidated, existing research demonstrates a strong correlation between changes in the composition of gut microbiota and disease development, and further investigation is warranted to explain the specific underlying mechanisms.
Humans ; Parkinson Disease/microbiology* ; Gastrointestinal Microbiome/physiology* ; Dysbiosis/microbiology*

BACKGROUND: Physical activity, sedentary behavior (SB), and sleep duration are associated with brain health. Effects of those on developing Parkinson's disease (PD) are poorly investigated. This study aimed to examine the independent and joint associations of physical activity, SB, sleep with PD risk. METHODS: We analyzed data on 401,697 participants from the UK Biobank cohort, which was enrolled in 2006-2010. Physical activities were measured based on a questionnaire. Sleep and SB time were defined through self-reported total number of hours. Models fitted with restricted cubic spline were conducted to test for linear and non-linear shapes of each association. Cox proportional hazards regression models were used to estimate the association of three modifiable behaviors. RESULTS: Our analytic sample included 401,697 participants with 3030 identified cases of PD (mean age, 63 years; 62.9% male). PD risk was 18% lower in the high total physical activity group (95% CI, 0.75-0.90), 22% lower in the high leisure-time physical activity (LTPA) group (95% CI, 0.71-0.86) compared with the low level and 14% higher in the high sleep duration group (95% CI, 1.05-1.24) compared to moderate group. Total SB time was irrelevant with PD risk, while high TV viewing showed a 12% increase of PD risk compared to the low group (95% CI, 1.02-1.22). Low computer use (0 h/day) was associated with a 14% higher risk compared to 1 h/day use (95% CI, 1.04-1.26). Those associations were independent. A combination of 7 h/day sleep, moderate-to-high computer use, and moderate-to-vigorous intensity of LTPA showed lowest PD risk (HR, 0.70; 95% CI, 0.57-0.85). CONCLUSIONS Physical activity, SB, and sleep were associated with PD risks separately. Our findings emphasize the possibility for changing these three daily activities concurrently to lower the risk of PD. These findings may promote an active lifestyle for PD prevention.
Humans ; Parkinson Disease/physiopathology* ; Male ; Sedentary Behavior ; Female ; Middle Aged ; Exercise/physiology* ; Prospective Studies ; Sleep/physiology* ; Aged ; Surveys and Questionnaires ; Proportional Hazards Models ; Risk Factors

BACKGROUND: Gait impairment is closely related to quality of life in patients with Parkinson's disease (PD). This study aimed to explore alterations in brain microstructure in PD patients and healthy controls (HCs) and to identify the correlation of gait impairment in the ON and OFF states of patients with PD, respectively. METHODS: We enrolled 24 PD patients and 29 HCs from the Movement Disorders Program at Beijing Friendship Hospital Capital Medical University between 2019 and 2020. We acquired magnetic resonance imaging (MRI) scans and processed the diffusion kurtosis imaging (DKI) images. Preprocessing of diffusion-weighted data was performed with Mrtrix3 software, using a directional distribution function to track participants' main white matter fiber bundles. Demographic and clinical characteristics were recorded. Quantitative gait and clinical scales were used to assess the status of medication ON and OFF in PD patients. RESULTS: The axial kurtosis (AK), mean kurtosis (MK), and radial kurtosis (RK) of five specific white matter fiber tracts, the bilateral corticospinal tract, left superior longitudinal fasciculus, left anterior thalamic radiation, forceps minor, and forceps major were significantly higher in PD patients compared to HCs. Additionally, the MK values were negatively correlated with Timed Up and Go Test (TUG) scores in both the ON and OFF in PD patients. Within the PD group, higher AK, MK, and RK values, whether the patients were ON or OFF, were associated with better gait performance (i.e., higher velocity and stride length). CONCLUSIONS PD exhibits characteristic regional patterns of white matter microstructural degradation. Correlations between objective gait parameters and DKI values suggest that dopamine-responsive gait function depends on preserved white matter microstructure. DKI-based Tract-Based Spatial Statistics (TBSS) analysis may serve as a tool for evaluating PD-related motor impairments (e.g., gait impairment) and could yield potential neuroimaging biomarkers.
Humans ; Parkinson Disease/diagnostic imaging* ; White Matter/physiopathology* ; Male ; Female ; Middle Aged ; Aged ; Gait/physiology* ; Diffusion Magnetic Resonance Imaging/methods* ; Diffusion Tensor Imaging/methods*

Parkinson's disease (PD) is a neurodegenerative disorder characterized by the progressive loss of dopaminergic neurons and the accumulation of Lewy bodies, leading to motor and nonmotor symptoms. While both genetic and environmental factors contribute to PD, recent studies highlight the crucial role of lipid metabolism disturbances in disease progression. Altered lipid homeostasis promotes protein aggregation and oxidative stress, with significant changes in lipid classes such as sphingolipids and glycerolipids observed in patients with PD. These disturbances are involved in key pathological processes, such as α-synuclein aggregation, organelle dysfunction, lipid-mediated neuroinflammation, and impaired lipid homeostasis. This review examines the relationship between lipid species and PD progression, focusing on the physiological roles of lipids in the central nervous system. It explores the mechanistic links between lipid metabolism and PD pathology, along with lipid-related genetic risk factors. Furthermore, this review discusses lipid-targeting therapeutic strategies to mitigate PD progression, emphasizing the potential of lipid modulation for effective treatment development.
Humans ; Parkinson Disease/metabolism* ; Lipid Metabolism/physiology* ; Animals ; Oxidative Stress/physiology* ; alpha-Synuclein/metabolism*

BACKGROUND: Parkinson's disease (PD) is a leading cause of death and disability worldwide, and is associated with a significant Global Burden of Disease (GBD). We analyzed the trends in PD incidence, mortality, and disability-adjusted life year (DALY) burden in China, and compared them with global data. METHODS: Estimates and 95% uncertainty intervals (UIs) for incidence, mortality, DALYs, years lived with disability (YLDs), and years of life lost (YLLs) for PD were extracted from the GBD, Injuries, and Risk Factors Study 2021. We describe the epidemiology of PD at global and Chinese levels, analyze trends in incidence and mortality from 1990 to 2021 by joinpoint regression models, and decompose PD burden according to population size, age structure, and epidemiological changes. RESULTS: GBD 2021 estimated 508,378 (95% UI: 430,499-592,748) incident cases of PD, 92,035 (95% UI: 75,908-108,133) deaths, and 2,159,514 (95% UI: 1,826,196-2,521,344) DALYs in China, with the higher age-standardized rate (ASR) in incidence, mortality and DALYs than the global levels. The DALY burden of PD in China increased slightly from 1990 to 2021, consistent with the global upward trend. Joinpoint regression analysis indicated that the ASR of incidence in China increased faster than the global average, while the ASR of mortality decreased, with the fastest decline in 2004-2014. Decomposition analysis revealed that men and the middle sociodemographic index (SDI) quintile (32.82%) were responsible for the most significant DALYs, whose changes were primarily driven by population growth and aging. CONCLUSIONS The burden of PD showed an overall increasing trend from 1990 to 2021, which was primarily driven by population growth and aging. This study highlights the significant challenges in controlling and managing PD, including the increase in cases and gender differences, which may provide guidance for comprehensive strategies to address the changing profiles of PD in China.
Humans ; Parkinson Disease/mortality* ; China/epidemiology* ; Global Burden of Disease ; Male ; Incidence ; Female ; Disability-Adjusted Life Years ; Middle Aged ; Aged ; Adult ; Quality-Adjusted Life Years ; Aged, 80 and over ; Cost of Illness ; Adolescent ; Pattern Analysis, Machine

The study aimed to investigate the effect of the CD200R1 gene deletion on microglia activation and nigrostriatal dopamine neuron loss in the Parkinson's disease (PD) process. The CRISPR-Cas9 technology was applied to construct the CD200R1^-/- mice. The primary microglia cells of wild-type and CD200R1^-/- mice were cultured and treated with bacterial lipopolysaccharide (LPS). Microglia phagocytosis level was assessed by a fluorescent microsphere phagocytosis assay. PD mouse model was prepared by nigral stereotaxic injection of recombinant adeno-associated virus vector carrying human α-synuclein (α-syn). The changes in the motor behavior of the mice with both genotypes were evaluated by cylinder test, open field test, and rotarod test. Immunohistochemical staining was used to assess the loss of dopamine neurons in substantia nigra. Immunofluorescence staining was used to detect the expression level of CD68 (a key molecule involved in phagocytosis) in microglia. The results showed that CD200R1 deletion markedly enhanced LPS-induced phagocytosis in vitro by the microglial cells. In the mouse model of PD, CD200R1 deletion exacerbated motor behavior impairment and dopamine neuron loss in substantia nigra. Fluorescence intensity analysis results revealed a significant increase in CD68 expression in microglia located in the substantia nigra of CD200R1^-/- mice. The above results suggest that CD200R1 deletion may further activates microglia by promoting microglial phagocytosis, leading to increased loss of the nigrostriatal dopamine neurons in the PD model mice. Therefore, targeting CD200R1 could potentially serve as a novel therapeutic target for the treatment of early-stage PD.
Animals ; Microglia/physiology* ; Mice ; Phagocytosis ; Parkinson Disease/genetics* ; Disease Models, Animal ; Receptors, Cell Surface/physiology* ; Dopaminergic Neurons/pathology* ; Antigens, CD/metabolism* ; Gene Deletion ; Substantia Nigra ; Mice, Inbred C57BL ; Mice, Knockout ; Cells, Cultured ; Male ; alpha-Synuclein ; CD68 Molecule ; Orexin Receptors

Currently, the incidence of Parkinson's disease (PD) is on the rise. More and more evidences suggest that mitochondrial dysfunction plays a crucial role in the etiology of PD, and dysfunction of mitochondrial complex I (MCI) is one of the most critical factors leading to mitochondrial dysfunction. On one hand, MCI dysfunction stimulates dopaminergic neurons to produce reactive oxygen species (ROS). On the other hand, MCI dysfunction decreases dopaminergic neuron viability and reduces ATP production. All these outcomes promote the pathological progression of PD. This review summarizes research progress on the role of MCI in the pathogenesis of PD, as well as PD treatment strategies based on MCI.
Parkinson Disease/metabolism* ; Humans ; Electron Transport Complex I/metabolism* ; Mitochondria/physiology* ; Reactive Oxygen Species/metabolism* ; Dopaminergic Neurons/metabolism* ; Animals ; Adenosine Triphosphate/metabolism*

The etiology of nervous system diseases is complicated, posing significant harm to patients and often resulting in poor prognoses. In recent years, the role of dopaminergic system in nervous system diseases has attracted much attention, and its complex regulatory mechanism and therapeutic potential have been gradually revealed. This paper reviews the role of dopaminergic neurons, the neurotransmitter dopamine, dopamine receptors and dopamine transporters in neurological diseases (including Alzheimer's disease, Parkinson's disease and schizophrenia), with a view to further elucidating the disease mechanism and providing new insights and strategies for the treatment of neurological diseases.
Humans ; Dopamine/metabolism* ; Nervous System Diseases/physiopathology* ; Parkinson Disease/physiopathology* ; Receptors, Dopamine/metabolism* ; Dopaminergic Neurons/physiology* ; Dopamine Plasma Membrane Transport Proteins/metabolism* ; Alzheimer Disease/physiopathology* ; Schizophrenia/physiopathology* ; Animals