Research progress of GBA1 variation and Parkinson′s disease / 中华神经科杂志

GBA1 is one of the common risk genes of Parkinson′s disease (PD), which encodes glucocerebrosidase. It is difficult to distinguish PD patients with heterozygous variants of GBA1 ( GBA1-PD) from idiopathic Parkinson′s disease patients, but GBA1-PD tends to progress faster, be more severe, and be more likely to be associated with cognitive impairment and other non-motor symptoms. The pathological mechanism of the increased risk of PD in GBA1 heterozygous variant carriers may be related to autophagy-lysosome dysfunction and mitochondrial dysfunction. Targeted therapy for GBA1 is expected to become a new direction of precision therapy for PD. In this article, the epidemiology and clinical features of GBA1-PD, the possible pathogenesis of GBA1 variation, and the therapeutic strategies for GBA1-PD were elaborated.

Recent progress of epigallocatechin 3-gallate for treatment of Parkinson's disease / 中国药理学通报

Epigallocatechin 3-gallate (EGCG) is an abundant polyphenolie component originating from green tea extract that has exhibited versatile bioactivities in combating several diseases. During the last decade, EGCG are effective in experimental models of Parkinson's disease (PD). Several experimental studies suggest the pleiotropic neuroprotective effects, aiding to EGCG as an appealing therapeutic strategy in PD. Therefore, in this review we focus on the effects of EGCG on anti-apoptosis, anti-oxidant, anti-inflammation, modulation of dopamine production, and the aggregation of a-synuclein. We aim to compile the recent updates and cellular and molecular mechanisms of neuroprotection of EGCG in PD. This review highlights the pharmacological features of EGCG and its therapeutic implications in PD.

Association of Glial Activation and α-Synuclein Pathology in Parkinson's Disease / 神经科学通报·英文版

The accumulation of pathological α-synuclein (α-syn) in the central nervous system and the progressive loss of dopaminergic neurons in the substantia nigra pars compacta are the neuropathological features of Parkinson's disease (PD). Recently, the findings of prion-like transmission of α-syn pathology have expanded our understanding of the region-specific distribution of α-syn in PD patients. Accumulating evidence suggests that α-syn aggregates are released from neurons and endocytosed by glial cells, which contributes to the clearance of α-syn. However, the activation of glial cells by α-syn species produces pro-inflammatory factors that decrease the uptake of α-syn aggregates by glial cells and promote the transmission of α-syn between neurons, which promotes the spread of α-syn pathology. In this article, we provide an overview of current knowledge on the role of glia and α-syn pathology in PD pathogenesis, highlighting the relationships between glial responses and the spread of α-syn pathology.

Parkinson's Disease: A Multisystem Disorder / 神经科学通报·英文版

The way sporadic Parkinson's disease (PD) is perceived has undergone drastic changes in recent decades. For a long time, PD was considered a brain disease characterized by motor disturbances; however, the identification of several risk factors and the hypothesis that PD has a gastrointestinal onset have shed additional light. Today, after recognition of prodromal non-motor symptoms and the pathological processes driving their evolution, there is a greater understanding of the involvement of other organ systems. For this reason, PD is increasingly seen as a multiorgan and multisystemic pathology that arises from the interaction of susceptible genetic factors with a challenging environment during aging-related decline.

Corynoxine B targets at HMGB1/2 to enhance autophagy for α-synuclein clearance in fly and rodent models of Parkinson's disease

Parkinson's disease (PD) is the most common neurodegenerative movement disease. It is featured by abnormal alpha-synuclein (α-syn) aggregation in dopaminergic neurons in the substantia nigra. Macroautophagy (autophagy) is an evolutionarily conserved cellular process for degradation of cellular contents, including protein aggregates, to maintain cellular homeostasis. Corynoxine B (Cory B), a natural alkaloid isolated from Uncaria rhynchophylla (Miq.) Jacks., has been reported to promote the clearance of α-syn in cell models by inducing autophagy. However, the molecular mechanism by which Cory B induces autophagy is not known, and the α-syn-lowering activity of Cory B has not been verified in animal models. Here, we report that Cory B enhanced the activity of Beclin 1/VPS34 complex and increased autophagy by promoting the interaction between Beclin 1 and HMGB1/2. Depletion of HMGB1/2 impaired Cory B-induced autophagy. We showed for the first time that, similar to HMGB1, HMGB2 is also required for autophagy and depletion of HMGB2 decreased autophagy levels and phosphatidylinositol 3-kinase III activity both under basal and stimulated conditions. By applying cellular thermal shift assay, surface plasmon resonance, and molecular docking, we confirmed that Cory B directly binds to HMGB1/2 near the C106 site. Furthermore, in vivo studies with a wild-type α-syn transgenic drosophila model of PD and an A53T α-syn transgenic mouse model of PD, Cory B enhanced autophagy, promoted α-syn clearance and improved behavioral abnormalities. Taken together, the results of this study reveal that Cory B enhances phosphatidylinositol 3-kinase III activity/autophagy by binding to HMGB1/2 and that this enhancement is neuroprotective against PD.

Effects of SKP1 gene interference on apoptosis and regulation mechanism of ubiquitin-proteasome system in Parkinson's disease cell model / 中华行为医学与脑科学杂志

Objective:To investigate the effect of interfering S-phase kinase associated protein 1 (SKP1) gene on apoptosis in Parkinson's disease(PD) cell model induced by 1-methyl-4-phenyl-pyridine ion (MPP+ ) and the mechanism of ubiquitin proteasome system degradation of α-synuclein (α-syn) influence.Methods:SH-SY5Y cells were divided into control group, MPP+ group, SKP1 interference group, and SKP1 interference+ MG132(UPS inhibitor) group.The cells in the control group were cultured normally. The cells in the latter three groups were incubated with MPP+ (0.5 mmol/L) for 24 h as PD model cells.The cells in SKP1 interference group were transfected with lentivirus SKP1-siRNA, and the cells in SKP1 interference+ MG132 group were transfected with lentivirus SKP1 siRNA and added with MG132 (0.5 μmol/L) for 24 h. The protein levels and mRNA levels of SKP1, microtubule-associated protein light chain 3 (LC3), lysosome-associated membrane protein (LAMP), α-syn, ubiquitin activating enzyme E1 (UBE1), parkin, and p27 in cells were detected by Western blot and RT-PCR.Flow cytometry was used to detect cell apoptosis and cycle level, and CCK-8 method was used to detect cell proliferation level.Co-immunoprecipitation method was used to explore the interaction between SKP1 and p27. SPSS 23.0 software was used for statistical analysis. One-way ANOVA was used for comparison among groups, and LSD test was used for further pairwise comparison.Results:RT-PCR and Western blot results showed that the mRNA levels and protein levels of autophagy related proteins and ubiquitin related proteins LC3, LAMP2, α-syn, UBE1, parkin and p27 in the four groups were statistically significant(mRNA: F=99.155, 43.028, 138.464, 28.200, 22.009, 28.147, all P<0.05; F=245.517, 157.634, 315.920, 2 336.472, 477.429, 2 350.201, all P<0.05). The mRNA and protein levels of LC3, Lamp2, α-syn and p27 in SKP1 interference group were lower than those in MPP+ group (all P<0.05), while the mRNA and protein levels of UBE1 and parkin were higher than those in MPP+ group (all P<0.05). The mRNA and protein levels of LC3, α-syn and p27 in SKP1 interference+ MG132 group were higher than those in SKP1 interference group (all P<0.05), and the mRNA and protein levels of UBE1 and parkin were lower than those in SKP1 interference group (all P<0.05). The results of flow cytometry and CCK-8 method showed that the apoptosis rate and cell inhibition rate among the four groups were significantly different( F=2 749.420, 171.508, both P<0.05). The apoptosis rate of SKP1 interference group was lower than that of MPP+ group ((8.22±0.25)%, (15.30±0.21)%, P<0.05), while the cell inhibition rate of SKP1 interference group was lower than that of MPP+ group((26.31±3.73)%, (55.05±3.84)%, P<0.05). The apoptosis rate of SKP1 interference+ MG132 group ((9.49±0.07)%) was higher than that of SKP1 interference group, and the cell inhibition rate ((36.06±2.85)%) was higher than that of SKP1 interference group (both P<0.05). The results of immunoprecipitation method showed that P27 decreased after SKP1 immunoprecipitation. Conclusion:After SKP1 gene was interfered, the autophagy function of PD cells decreased, which may be related to parkin promoting α-syn ubiquitination, activating UBE1/ Parkin-mediated UPS pathway to degrade α-syn, and mediating P27 to inhibit apoptosis.

The relationship between plasma phosphorylated α-synuclein and cognitive impairment in patients with Parkinson disease / 中华行为医学与脑科学杂志

Objective:To investigate the relationship between plasma phosphorylated α-synuclein (ps129-α-syn) and cognitive function in Parkinson disease (PD).Methods:This study recruited 90 PD patients who were hospitalized in the Department of Neurology, Henan province people's hospital from March 2019 to June 2020.Forty healthy middle-aged and elderly people with normal cognitive function who came to the hospital for physical examination were selected during the same period.Clinical characteristics and blood samples were collected.Patients with PD were classified into those with normally cognitive (PD-NC), mild cognitive impairment (PD-MCI), and dementia (PDD). The enzyme-linked immunosorbent assay was used to measure the plasma ps129-α-syn.Correlations between plasma ps129-α-syn and clinical characteristics such as disease duration, Hoehn-Yahr stage (H-Y), unified Parkinson's disease rating scale (UPDRS), Montreal cognitive assessment (MoCA), 14-item Hamilton anxiety rating scale (HAMA-14), the 24-item Hamilton depression rating scale (HAMD-24), levodopa equivalent daily dosage (LEDD), the scale of outcomes in Parkinson's disease for autonomic symptoms, SCOPA-AUT) were analyzed using Pearson or Spearman correlation analysis.Multiple linear regression analysis was used to evaluate the factors affecting the cognitive function of PD.Results:Plasma ps129-α-syn in PD patients was higher than that in healthy controls((19.44±8.93)μg/L, (10.78±5.87)μg/L, ( t=5.615, P<0.01). Plasma ps129-α-syn was higher in PD-MCI group((19.64±7.77)μg/L)and PDD group((23.79±9.47)μg/L) compared with that in PD-NC group((13.37±5.40)μg/L)( P<0.05). Plasma ps129-α-syn was positively correlated with H-Y ( r=0.404, P<0.01), UPDRS-Ⅲ( r=0.275, P=0.009), UPDRS-total ( r=0.211, P=0.046) and SCOPA-AUT( r=0.335, P=0.001). Plasma ps129-α-syn was negatively associated with MoCA ( r=-0.459, P<0.01). Multiple linear regression analysis suggested disease duration ( t=-4.618, P<0.01), ps129-α-syn( t=-3.792, P<0.01) and UPDRS-total ( t=-2.826, P=0.006) were independently associated with cognitive function.Plasma ps129-α-syn could discriminate between PD-NC and PD cognitive function impairment with an AUC of 0.7797 (95% CI: 0.686 3-0.873 2, P<0.01). Conclusions:Plasma ps129-α-syn is correlated with cognitive function and the severity of motor symptoms in PD patients, and have high sensitivity and specificity in diagnosing PD cognitive dysfunction.Therefore, plasma ps129-α-syn can serve as a biomarker to assess cognitive function in PD.

Clinical efficacy and mechanism of acupuncture for Parkinson's disease / 国际中医中药杂志

Acupuncture can improve the motor and non-motor symptoms of Parkinson's disease, and the effect of acupuncture combined with drug therapy is better than that of drug therapy alone. The possible mechanism includes inhibiting α-synuclein aggregation, oxidative stress, and neuroinflammation, inhibiting the apoptosis of dopaminergic neurons, and achieving a neuroprotective effect. The points mainly selected for Acupuncture treatment for this disease are Zusanli (ST 36), Yanglingquan (GB 34), Taichong (LR 3), Xuehai (SP 10), and other points. Early use of acupuncture and acupuncture combined with medical treatment strategy is worthy of clinical application.

Correlation between dementia with Lewy bodies and blood-brain barrier / 中华老年医学杂志

Dementia with Lewy bodies(DLB)is the second most common neurodegenerative dementia after Alzheimer's Disease(AD). This article will mainly elaborate the relationship between DLB and blood-brain barrier(BBB)from the following five aspects: (1)The structure and function of BBB; (2)In vivo assessment methods for the blood-brain barrier damage; (3)Evidence for the damage of blood-brain barrier in DLB; (4)The relationship between α-synuclein and the blood-brain barrier; (5)The relationship between APOE and the blood-brain barrier.Future research should focus on the pathogenesis of BBB damage in DLB patients, by which new drug targets for disease diagnosis and treatment may be found.

Disease-modifying therapy for multiply system atrophy / 中华老年医学杂志

Multiple system atrophy(MSA)is a rare and fatal neurodegenerative disease occurring in middle-aged and older people, mainly characterized by autonomic nervous system and motor dysfunction.At present, there is no effective method to prevent or reverse its progression, and its treatment is mostly symptom-based, with limited success.A large number of interventional trials have been conducted to explore new treatments for MSA, but there is no clearly effective disease-modifying therapy, probably as a result of poor understanding of the pathophysiological and physiological mechanisms underlying MSA, which may be influenced by multiple factors.The purpose of this paper is to review the existing intervention trials for disease modification therapy of MSA and to discuss the outlook for new therapeutic targets.

Lysosome TMEM175 Potassium Channel Protein and Parkinson’s Disease / 中国生物化学与分子生物学报

Parkinson’s disease (PD)is a complex neurodegenerative disorder by motor impairments and non-motor symptoms. While dopamine-based therapies are effective in fighting the symptoms in the early stages of the disease‚ a lack of neuroprotective drugs means that the disease continues to progress. New disease modifying therapies and novel therapeutic strategies are in high demand for PD patients. Genetic studies indicated that both rare and common genetic variants could induce the development PD. As a risk candidate gene for Parkinson’s disease‚ TMEM175 encodes a lysosomal potassium channel protein with new structures‚ and the protein plays an important role in maintaining lysosomal membrane potential and pH stability. With the in-depth understanding for its structure and function‚ TMEM175 deficiency results in decreased lysosomal catalytic activity and the pathological aggregation of α-synuclein. In view of the importance of lysosome potassium channel TMEM175‚ it could be an interesting target for the development of drugs to treat Parkinson’s disease and other neurodegenerative diseases. Herein we review the structure and function TMEM175‚ and focuses on its involvement in the occurrence and development of PD by affecting the function of lysosome as a homeostatic regulator. Future drug screenings based on lysosome TMEM175 may be carried out to maintain the active state or enhance the expression of TMEM175 to improve the condition of PD patients. Further investigations are needed to study how to maintain the balance between the open and closed state of TMEM175 channels to regulate the ion homeostasis of lysosomes. Studies of this ion channel protein will bring new strategies and ideas for the treatment of PD‚ and provide support for establishing the molecular status of TMEM175 in the diagnosis and treatment of PD.

Phospholipid remodeling and Parkinson's disease / 药学学报

The remodeling of phospholipid includes two processes: deacylation and reacylation. It realizes the conversion of nascent phospholipids to mature phospholipids by changing the length and types of fatty acids at specific sites of phospholipids, which is a key step in phospholipid metabolism. Phospholipids are not only the basic components of biological membranes, but also participate in the transduction of many molecular signals in cells. Therefore, phospholipid remodeling disorders can affect the structure and function of cell membranes, as well as the activity of membrane proteins, causing a series of intricate signaling cascades, and finally lead to many pathological changes including neurodegeneration. This paper reviews the basic process of phospholipid remodeling and the involvement of its key enzymes, calcium independent group VIA phospholipase A2 (iPLA2β), peroxiredoxin 6 (PRDX6), calcium independent group VIB phospholipase A2 (iPLA2γ) as well as acyl-CoA lysocardiolipin acyltransferase 1 (ALCAT1) in the pathology of Parkinson's disease. The mutations in the gene encoding iPLA2β, PLA2G6, have been widely reported to be directly related to hereditary Parkinson disease-14 (PARK14). Here we focus on the molecular mechanism of iPLA2β in the development of Parkinson's disease, mainly involving phospholipid fatty acid metabolism disorders, mitochondrial physiology abnormalities and α-synuclein aggregate formation and other aspects, which will help to understand the role of phospholipid remodeling in Parkinson's disease, and provide new clues for the development of new Parkinson's disease diagnosis and treatment strategies.

The glymphatic system: a new exploration of the clearance of alpha-synuclein in Parkinson′s disease / 中华神经科杂志

Parkinson′s disease (PD) is a common neurodegenerative disease. Impaired balance between deposition and clearance of α-synuclein lies at the core of PD pathogenesis. The glymphatic system is a highly organized fluid transport system that is capable of removing brain waste. Emerging evidence revealed that glymphatic dysfunction plays a critical role in the pathogenesis of neurodegenerative diseases, yet study on its implication in PD is at its early stage. An in-depth study of the relationship between the function of the glymphatic system and α-synuclein clearance in PD may shed light on the pathogenesis and therapeutics of the disease.

Progress in the diagnosis and treatment of rapid eye movement sleep behavior disorder / 中国临床药理学与治疗学

Rapid eye movement sleep behavior disorder (RBD) is characterized by dream enactment and rapid eye movement (REM) sleep without atonia. RBD is closely related to α-synucleinopathy disease, including Parkinson's disease (PD), Lewy body dementia (DLB) and multiple system atrophy (MSA). Many studies have discussed the markers, heredity, cognition, autonomic nervous function of RBD, and the predictive value for neurodegenerative diseases. This article reviews the research progress of early markers and treatments in recent years, and discusses future research directions.

Neurodegenerative lesions caused by ozone exposure in male mice / 西安交通大学学报(医学版)

【Objective】 To investigate the effects and potential mechanisms of neurodegenerative lesions in male mice caused by ozone exposure. 【Methods】 We divided 23 C57BL/6N male mice aged 8 to 9 months into control group （clean air group， 11） and ozone group （1 mg/m 3， 4h/d， 12）. After 8 weeks of continuous ozone exposure， the Morris water maze experiment was used to detect the mice’s learning and memory ability， HE dyeing to observe pathological changes in hippocampal tissue cells， and immunoprinting tests to detect the expression levels of Tau， p-Tau and α-synuclein proteins in the cerebral cortex tissue. 【Results】 After 8 weeks of ozone exposure， the mice’s spatial learning and memory ability were impaired to a certain extent， the incubation period decreased with time， and the two lines were separated， but the difference was not statistically significant. Ozone exposure caused changes in the morphology of the mice’s hippocampal tissue cells， disorders in the arrangement of hippocampal neuron， and nuclear wrinkles， and significantly increased levels of p-Tau and α-synuclein protein expressions in cerebral cortex tissues （P<0.01）， but there was no statistical significance in the total Tau expression level. 【Conclusion】 Ozone exposure leads to the loss of learning and memory in mice， changes in hippocampal neurocellular pathology， and increased expression levels of neurodegenerative variable-related proteins.

Immunohistochemical Overexpression of nNOS, S100 Protein, and α-Synuclein in Myenteric Plexus of AS/AGU Rats

Objective: There are four currently motor features characterizing Parkinson's disease (PD). These includerigidity of muscles, bradykinesia, tremors at rest, and instability of posture. Along the course of PD, theimpairment of motor functions is commonly preceded by nonmotor symptoms (NMS) such as olfactory deficit,difficult swallowing (dysphagia), drooling (sialorrhea), constipation, urinary bladder dysfunction, depression,and sleep disorder. It was suggested that the enteric nervous system could be the initial site for the pathologicalprocess leading to PD. Materials and Methods: Six male adult control AS rats (normal control) and six maleadults AS/AGU rats (model of PD) were sacrificed. A rectangular strip from the body of the stomach and across-section from the duodenum were dissected and processed for histological staining with hematoxylin andeosin, and immunohistochemical staining for detection of nNOS (neuronal NOS), S100 protein (astrocytemarker), and alpha-synuclein (α-synuclein). Results: The histological analysis of the stomach and duodenum ofAS/AGU rats demonstrated necrotic smooth muscle cells of muscularis externa. The immunohistochemicalanalysis of AS/AGU rats showed a statistically significant increase in the expression of nNOS, S100 protein, andα-synuclein expression of myenteric plexuses compared to the control strain AS rats. Conclusion:Gastroduodenal tract of AS/AGU rats showed marked histopathological changes and immunohistochemicaloverexpression of nNOS, S100, and α-synuclein.

Autophagic activity of piperine on small intestine in dementia model mice with Parkinson's disease / 中国中药杂志

This article is to investigate the effect of piperine on the small intestine of mice with Parkinson's disease with dementia(PDD). Ninety-six C57 BL/6 mice of SPF grade were randomly divided into 8 groups(male, 12 in each group): normal group, model group, autophagy inhibitor group(6-amino-3-methylpurine, 3 MA, 30 mg·kg~(-1)), autophagy activator group(rapamycin, 1 mg·kg~(-1)), low, medium, and high dose piperine groups(10, 20, 40 mg·kg~(-1)), and medopar group(112.5 mg·kg~(-1)). Except for the normal group, mice in each group were injected subcutaneously with reserpine(0.1 mg·kg~(-1)) once every 48 hours for 40 days. In addition, on the 20 th day of administration, except for the normal group, the mice in the other groups were subjected to bilateral common carotid artery occlusion to finally prepare PDD models. At the same time, each group was given the corresponding drug treatment once a day for 40 days. After the last administration, the behavioral changes of mice were observed by autonomic activity experiment and hot plate experiment. The expression levels of α-synuclein(α-syn) and tyrosine hydroxylase(TH) in the small intestine were detected by immunohistochemistry. The expression levels of beclin-1, microtubule-associated protein 1 light chain 3 B(LC3 B) and p62 in the small intestine were detected by immunofluorescence assay. Hematoxylin-eosin staining was used to observe the pathological morphology of small intestine tissues in each group. Enzyme-linked immunosorbent assay was adopted for detection of β-amyloid precursor protein(APP), p-tau, acetylcholine transferase(ChAT), interleukin-6(IL-6) and tumor necrosis factor-α(TNF-α) in small intestine. Real-time fluorescent quantitative polymerase chain reaction was used to detect the expression of α-syn, TH, beclin-1, microtubule-associated protein 1 light chain 3(LC3), and p62 mRNA and mmu-miR-99 a-5 p in the small intestine. The results of this study showed that, as compared with the model group, the number of activities, the expression levels of ChAT, TH, and p62 were significantly increased in the 3 MA group, the various piperine dose groups, and the medopar group(P<0.05), and their first foot licking time was shortened; APP, p-tau, IL-6, TNF-α, α-syn, beclin-1, LC3 B and mmu-miR-99 a-5 p expression levels were significantly reduced(P<0.05). However, as compared with the model group, the number of activities, ChAT, TH, and p62 expression levels in the rapamycin group were significantly reduced(P<0.05), and the APP, p-tau, IL-6, TNF-α, α-syn, beclin-1, LC3 B and mmu-miR-99 a-5 p expression levels were significantly increased(P<0.05). As compared with the 3 MA group, the number of activities, ChAT, TH, and p62 expression levels were significantly reduced in the low and medium dose piperine groups and rapamycin group(P<0.05); howe-ver, their first foot licking time was significantly prolonged, APP, p-tau, IL-6, TNF-α, α-syn, beclin-1, LC3 B and mmu-miR-99 a-5 p expression levels were increased significantly(P<0.05). As compared with the medopar group, the number of activities, ChAT, TH, and p62 expression levels were significantly reduced in low dose piperine group and rapamycin group(P<0.05), but their first foot licking time was significantly extended, and APP, p-tau, IL-6, TNF-α, α-syn, beclin-1, LC3 B and mmu-miR-99 a-5 p expression levels were significantly increased(P<0.05). In addition, as compared with the normal group, the small intestinal epithelial cells of the model group and the rapamycin group were shed off a lot, with severe damages of intestinal mucosa as well as edema and shedding of the small intestine villi. After administration of the therapeutic interventions, the small intestinal epithelial cells of the 3 MA group, each dose group of piperine, and the medopa group were slightly damaged and the villi were slightly shed off. In summary, piperine has a protective effect on the small intestine of PDD model mice, showing reduced expression of mmu-miR-99 a-5 p, pro-inflammatory factors and autophagy factors, and the mechanism of slowing PDD pathological symptoms may be related to the inhibition of autophagy.

Evaluating the Effect of Iron (II) Chloride Induced Oxidative Stress in SH-SY5Y Cells and Its Role in Upregulation of α-Synuclein Expression

The α-synuclein (SNCA) gene is a pathogenic gene identified in rare familial Parkinson Disease (PD). Recent studies highlight the role of DNA methylation in the pathogenesis of familial and sporadic PD. Hypomethylation in SNCAgene has been associated with increased SNCA gene expression and was observed in post mortem brains of patients with sporadic PD. This study was aimed at evaluating the effect of iron (II) chloride on SH-SY5Y cell models as pertain to cell death caused by oxidative stress, upregulation of SNCA gene expression and reduced SNCA gene methylation. Result obtained from LDH assay showed significant (p<0.05) evidence of cell death in treated cells as compared to the control sample. Analysis for SNCAgene quantification using RT-PCR showed significant increases in fold change. Cells treated with 1000μM of FeCl₂showed the highest fold change of 6.0 while cells treated with 250μM had the lowest fold change of 1.8. In DNA methylation assay using pyrosequencing, cells treated with varying concentrations of FeCl₂showed significant (p<0.05) decrease in DNA methylation. At 250μM, 500μM and 750μM concentrations of FeCl₂, an average mean methylation levels of 1.84%, 1.40% and 1.23% was obtained respectively while cells treated with 1000μM had the lowest average mean methylation level of 1.0%. Thus, the decrease in methylation is linked to the upregulation of the SNCAgene which has been reported to be among the causative factors in the pathogenesis of Parkinson’s disease.

Effects of chaperone-mediated autophagy on the level of α-synuclein oligomers in Parkinson's disease cell model / 上海交通大学学报（医学版）

Objective • To investigate the effects of chaperone-mediated autophagy (CMA) on α-synuclein oligomers level in the Parkinson's disease (PD) cell model with impaired ubiquitin proteasome system (UPS). Methods • The PD cell model was established by adding the proteasome inhibitor lactacystin in the SK-N-SH cell line stably transfected with wild type α-synuclein. The levels of α-synuclein oligomers, lysosome-associated membrane protein type 2A (LAMP2A) and 70 kDa heat shock homologous protein (HSC70) were detected using Western blotting. CMA function was inhibited with LAMP2A siRNA, and its effects on α-synuclein oligomers and cell viability were detected. Furthermore, the interaction of LAMP2A with α-synuclein oligomers was detected by immunoprecipitation. Results • In the PD cell model, the levels of α-synuclein oligomers, and CMA related proteins, i.e. LAMP2A and HSC70, were increased. Inhibiting the expression of LAMP2A further increased α-synuclein oligomers level, while it decreased cell viability. Furthermore, LAMP2A could interact with α-synuclein oligomers. Conclusion • In the PD cell model, CMA is one of the pathways regulating α-synuclein oligomers level. Inhibiting CMA function can further increase the α-synuclein oligomers level and deteriorate cell survival.

Construction of A30P Mutant α-Synuclein and Its Influence on Protein Degradation Systems in PC12 Cells / 中国药学杂志

OBJECTIVE: To explore the effects of human A30P mutant α-synuclein (α-syn) on autophagy lysosome pathway and ubiquitin proteasome system. METHODS: Constructing stable cell lines expressing human A30P mutant α-syn in PC12 cells, and detecting the levels of autophagy related proteins LC3-II and p62 as well as ubiquitinated proteins. Furthermore, the influence of A30P mutant α-syn on cell viability upon normal and stress conditions was conducted by MTT assay. RESULTS: Expressing A30P mutant α-syn could significantly reduce autophagy related protein LC3-II level and increase level of autophagy substrate p62, as well as promote aggregation of ubiquitinated proteins. Otherwise, expressing A30P mutant α-syn did not reduce cell viability under normal conditions. However, cell viability was significantly reduced under treatment with neurotoxin rotenone or serum free condition in A30P mutant α-syn groups compared with empty vector group. CONCLUSION: Over expression of human A30P mutant α-syn could impair the protein degradation system and increase the sensitivity of cells to toxic insults.