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El diagnóstico de enfermedad de Parkinson (ED) se basa en las principales manifestaciones motoras: bradicinesia en combinación con temblor en reposo, rigidez o ambos. Cuando se realiza el diagnóstico basado en la sintomatología motora clínica típica ya se han perdido hasta el 60 % de las neuronas dopaminérgicas de la sustancia negra pars compacta mesencefálica. La identificación de los síntomas premotores son un marcador temprano para sospechar la aparición futura de la enfermedad, así como su progresión y gravedad. La hipótesis sobre la patogénesis que mejor expone la progresión de la enfermedad es la teoría de Braak. Esta se basa en la aparición y presencia de cuerpos de Lewy en diferentes estructuras anatómicas, las cuales representadas en cada uno de sus seis estadios y podrían ser la explicación biológica de los síntomas premotores, motores y no motores. La detección temprana de los síntomas premotores puede tener repercusiones positivas en el enfoque, seguimiento, diagnóstico y tratamiento de la EP. El propósito de este artículo es identificar las aproximaciones neurológicas descritas por la teoría de Braak para los síntomas premotores de la enfermedad de Parkinson de acuerdo con la literatura publicada en los últimos 20 años.
The diagnosis of Parkinson's disease (PD) is based on the main motor manifestations: bradykinesia in combination with tremor at rest, rigidity, or both. When the diagnosis is made based on typical clinical motor symptoms, up to 60 % of the dopaminergic neurons of the mesencephalic substantia nigra pars compacta have already been lost. The identification of premotor symptoms is an early marker to suspect the future appearance of the disease, as well as its progression and severity. The hypothesis about the pathogenesis that best exposes the progression of the disease is Braak's theory. It is based on the appearance and presence of Lewy bodies in different anatomical structures, which are represented in each of its six stages and could be the biological explanation biological of premotor, motor, and non-motor symptoms. Early detection of premotor symptoms can have positive repercussions in the approach, follow-up, diagnosis and treatment of PD. The purpose of this article is to identify the neurological approaches described by Braak's theory for the premotor symptoms of Parkinson's disease according to the literature published in the last 20 years.
O diagnóstico da doença de Parkinson (DP) baseia-se nas principais manifestações motoras: bradicinesia combinada com tremor de repouso, rigidez ou ambos. Quando o diagnóstico é feito com base em sintomas clínicos motores típicos, até 60% dos neurônios dopaminérgicos da substância negra pars compacta mesencefálica já foram perdidos. A identificação de sintomas pré-motores é um marcador precoce para suspeitar do futuro aparecimento da doença, bem como da sua progressão e gravidade. A hipótese sobre a patogênese que melhor expõe a progressão da doença é a teoria de Braak. Isto se baseia no aparecimento e presença de corpos de Lewy em diferentes estruturas anatômicas, que estão representados em cada uma de suas seis etapas e podem ser a explicação biológica dos sintomas pré-motores, motores e não motores. A detecção precoce de sintomas pré-motores pode repercutir positivamente na abordagem, acompanhamento, diagnóstico e tratamento da DP. O objetivo deste artigo é identificar as abordagens neurológicas descritas pela teoria de Braak para os sintomas pré-motores da doença de Parkinson de acordo com a literatura publicada nos últimos 20 anos.
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Humans , Adult , Middle Aged , Aged , Aged, 80 and overРеферат
BACKGROUND:C2 ceramide reduces the formation of Alpha-Synuclein(α-Syn)oligomers as the protein phosphatase 2A agonist,which has an important regulatory effect on cell aging in the central nervous system. OBJECTIVE:To investigate the protective mechanism of C2 ceramide on dopaminergic neurons. METHODS:Twenty-five C57BL/6 mice were randomly divided into control group,model group,C2 ceramide low-,medium-and high-dose groups(n=5 per group).Except for the control group,a mouse model of Parkinson's disease was established by injecting mutant A53T α-Syn oligomers into the left striatum in the other groups.On the 30th day after the striatal injection,three C2 ceramide groups were intragastrically administered with C2 ceramide(1,5,10 μg/g)dissolved in saline at one time,while the control and model groups were administered with the same amount of saline within 30-90 days after modeling,for a total of 60 days.Behavioral changes in each group of mice were observed during this period.On the 90th day after striatal injection,mouse brain tissue was extracted by perfusion under anesthesia,and the changes of dopaminergic neurons in the midbrain substantia nigra were analyzed by immunohistochemical staining.The levels of α-Syn oligomerization and phosphorylation in the midbrain of mice were detected by ELISA,and the changes of enzyme activities related to α-Syn phosphorylation were analyzed. RESULTS AND CONCLUSION:C2 ceramide had an ameliorating effect on Parkinson's disease-like dyskinesia in mice caused by the striatal injection of mutant A53T α-Syn oligomers.High-dose C2 ceramide showed better effects on dyskinesia in mice with Parkinson's disease(P<0.01).The mutant A53T α-Syn oligomers significantly reduced the number of dopaminergic neurons in the substantia nigra of mice(P<0.01),while the number of dopaminergic neurons in the substantia nigra increased significantly in the C2 ceramide high-dose group(P<0.01).The levels of α-Syn oligomers and phosphorylated α-Syn in the brain were significantly reduced in the C2 ceramide high-dose group compared with the model group(P<0.01),while the level of ceramide was increased(P<0.05)and the activity of protein phosphatase 2A was significantly upregulated(P<0.01).To conclude,C2 ceramide can attenuate the neurotoxic effects induced by oligomerized α-Syn by the phosphorylation modification environment of α-Syn in mouse midbrain tissue and protect against the reduction in the number of nigrostriatal dopaminergic neurons in mice,thereby reducing the degree of dyskinesia in Parkinson's disease.
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BACKGROUND:Studies have found that nicotine can activate the dopamine system,slowing the progression of Parkinson's disease,but the specific mechanism is still unclear.Research on the neuroprotective mechanism of nicotine in animal models of Parkinson's disease is lacking. OBJECTIVE:To investigate the neuroprotective effect of nicotine on rotenone-induced Parkinson's disease in mice. METHODS:Twenty-eight C57BL/6 mice were randomly divided into vehicle group,rotenone group,autophagy agonist group and nicotine group,with seven mice in each group.Dopaminergic nerve damage was induced by rotenone in C57BL/6 mice,and the autophagy agonist(rapamycin)or nicotine was given before modeling.The spatial exploration function of the mice was observed by open field test.Western blot and Q-PCR were used to detect the expression of α-synuclein,autophagy related factors Beclin-1 and P62,and apoptosis-related factors Bax,Bcl-2 and Cleaved-caspase3 in the nigra of each group.The deposition of mitochondria,autophagosomes and lipofuscin in nigra cells were observed by transmission electron microscopy.The survival of neurons was observed by Nissl staining.The expression of tyrosine hydroxylase was observed by immunofluorescence and immunohistochemical staining. RESULTS AND CONCLUSION:The open field test showed that the distance,average speed and time of movement were reduced in the rotenone group compared with the solvent group.Compared with the rotenone group,the exercise distance,average speed and exercise time of mice were increased in the nicotine group and autophagy agonist group(P＜0.05).The results of immunofluorescence and immunohistochemistry showed that the mean fluorescence intensity and mean absorbance value of tyrosine hydroxylase in the rotenone group decreased compared with that in the solvent group.Compared with the rotenone group,the mean fluorescence intensity and mean absorbance value of tyrosine hydroxylase were increased in the nicotine group and autophagy agonist group.Western blot and Q-PCR results showed that compared with the solvent group,the expressions of α-synuclein and P62 in the rotenone group were increased,while Beclin-1 expression was decreased(P＜0.05);compared with the rotenone group,the expression of α-synuclein and P62 decreased in the nicotine group and autophagy agonist group,and the expression of Beclin-1 increased(P＜0.05).Compared with the solvent group,the expressions of Bax and Cleaved caspase3 were increased and Bcl-2 expression was decreased in the rotenone group(P＜0.05);compared with the rothenone group,the expressions of Bax and Cleaved-caspase3 were decreased and the expression of Bcl-2 was increased in the nicotine and autophagy agonist groups(P＜0.05).To conclude,nicotine may have a dopaminergic neuroprotective effect on rotenone-induced Parkinson's disease mouse models by improving autophagy dysfunction and reducing apoptosis.
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Isolated rapid-eye-movement sleep behavior disorder (iRBD) is considered to be a prodromal stage of α-synucleinopathies, providing an important period for investigating biomarkers of conversion risk and potentially disease-modifying intervention. Many previous studies investigating biomarkers in patients with iRBD have focused on different domains including clinical, body fluid and imaging. Due to their direct response to the pathological changes of brain and advantaged accessibility, body fluid markers have become promising potential biomarkers. These studies have involved different molecules related to different pathogenic mechanisms with poor consistency of results. In this paper, a review of previous work on body fluid markers in patients with iRBD is presented.
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BACKGROUND: Increasing evidence suggests a double-faceted role of alpha-synuclein (α-syn) following infection by a variety of viruses, including SARS-CoV-2. Although α-syn accumulation is known to contribute to cell toxicity and the development and/or exacerbation of neuropathological manifestations, it is also a key to sustaining anti-viral innate immunity. Consistently with α-syn aggregation as a hallmark of Parkinson's disease, most studies investigating the biological function of α-syn focused on neural cells, while reports on the role of α-syn in periphery are limited, especially in SARS-CoV-2 infection. RESULTS: Results herein obtained by real time qPCR, immunofluorescence and western blot indicate that α-syn upregulation in peripheral cells occurs as a Type-I Interferon (IFN)-related response against SARS-CoV-2 infection. Noteworthy, this effect mostly involves α-syn multimers, and the dynamic α-syn multimer:monomer ratio. Administration of excess α-syn monomers promoted SARS-CoV-2 replication along with downregulation of IFN-Stimulated Genes (ISGs) in epithelial lung cells, which was associated with reduced α-syn multimers and α-syn multimer:monomer ratio. These effects were prevented by combined administration of IFN-ß, which hindered virus replication and upregulated ISGs, meanwhile increasing both α-syn multimers and α-syn multimer:monomer ratio in the absence of cell toxicity. Finally, in endothelial cells displaying abortive SARS-CoV-2 replication, α-syn multimers, and multimer:monomer ratio were not reduced following exposure to the virus and exogenous α-syn, suggesting that only productive viral infection impairs α-syn multimerization and multimer:monomer equilibrium. CONCLUSIONS: Our study provides novel insights into the biology of α-syn, showing that its dynamic conformations are implicated in the innate immune response against SARS-CoV-2 infection in peripheral cells. In particular, our results suggest that promotion of non-toxic α-syn multimers likely occurs as a Type-I IFN-related biological response which partakes in the suppression of viral replication. Further studies are needed to replicate our findings in neuronal cells as well as animal models, and to ascertain the nature of such α-syn conformations.
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Humans , Interferon Type I , alpha-Synuclein , SARS-CoV-2 , COVID-19 , Virus Replication , Cell Line , Endothelial CellsРеферат
ABSTRACT Background: In Parkinson's disease (PD), exosomes carry α-synuclein (α-syn), a fibrillar protein aggregates with potential value as a biomarker. Objective: Evidence on blood levels of exosomal α-syn in PD patients and controls was reviewed for their consistency. Methods: Thirty-six studies on exosomal α-syn concentrations in PD were identified in a systematic literature search and meta-analysis. Results: Both raw and ratio-adjusted blood exosomal α-syn levels were consistently higher in PD patients than in controls. The standardized mean difference (SMD) was 1.54 (0.18-2.90, CI95%, p < 0.01) and 1.53 (0.23-2.83, CI95%, p < 0.01), respectively. Conclusion: Our results suggest that exosomal α-syn concentrations could be a useful biomarker for PD.
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Objective:To investigate the incidence of various non-motor symptoms (NMS) in early stage of Parkinson′s disease (PD) patients and the differences between the body-first and brain-first subtypes.Methods:A total of 121 patients with PD (Hoehn-Yahr stage 1-2) were recruited from PD Clinic, Department of Neurology, Beijing Hospital from January 2012 to January 2015. The general information and clinical features of the patients were collected. The minimal diagnostic criteria of parasomnias described in the International Classification of Sleep Disorders-Revised were used to diagnose rapid eye movement sleep behavior disorder (RBD).According to the sequence of RBD and motor symptoms, the patients were divided into 2 groups: body-first subtype and brain-first subtype. NMS was evaluated by the Non-Motor Symptom Questionnaire (NMSQuest). The clinical features and the incidence of various NMS were compared between the 2 groups. The Unified Parkinson′s Disease Rating Scale (UPDRS) was used to evaluate the severity of the disease, and its third part (UPDRS-Ⅲ) was used to evaluate the motor function of the patients. Hamilton Rating Scale for Depression (HAMD) and Hamilton Rating Scale for Anxiety (HAMA) were used to evaluate the depression and anxiety status of the patients. The sleep status of patients was assessed by Parkinson′s Disease Sleep Scale (PDSS). The quality of life of the patients was assessed by 39-item Parkinson′s Disease Questionnaire (PDQ-39).Results:Of all the patients, 49.59% (60/121) had the body-first subtype and 50.41% (61/121) had the brain-first subtype of PD. There was no significant difference in UPDRS-Ⅲ score between the 2 groups. The average number of NMS in all PD patients was 10.97±4.88. Body-first subtype patients had higher NMS incidence than brain-first subtype in difficulty in swallowing [46.7% (28/60) vs 23.0% (14/61), χ 2=7.507, P=0.006], nausea and vomiting [16.7% (10/60) vs 3.3% (2/61), χ 2=6.069, P=0.014], constipation [85.0% (51/60) vs 55.7% (34/61), χ 2=12.393, P<0.001], fecal incontinence [8.3% (5/60) vs 0 (0/61), χ 2=5.302, P=0.021], difficulty in remembering recent events [58.3% (35/60) vs 32.8% (20/61), χ 2=7.962, P=0.005], loss of interest [43.3% (26/60) vs 24.6% (15/61), χ 2=4.743, P=0.029], inattention [45.0% (27/60) vs 19.7% (12/61), χ 2=8.884, P=0.003], depression [55.0% (33/60) vs 34.4% (21/61), χ 2=5.181, P=0.023], intense vivid dreams [73.3% (44/60) vs 39.3% (24/61), χ 2=14.196, P<0.001] and restless legs [53.3% (32/60) vs 27.9% (17/61), χ 2=8.140, P=0.004]. The differences were significant. Body-first subtype and NMSQuest ( r=-0.489, P<0.001), UPDRS ( r=-0.189, P=0.038), HAMD ( r=-0.231, P=0.011), HAMA ( r=-0.298, P=0.001) and PDQ-39 scores ( r=-0.276, P=0.002) were negatively correlated. Body-first subtype and PDSS score was positively correlated. NMSQuest (Δ R2=0.265, P<0.001) was the main determinant of PDQ-39 score. Conclusions:PD patients are accompanied by various NMS, which is a major factor affecting the quality of life. Compared with brain-first subtype, body-first subtype might have more NMS burden and higher incidence rate in most NMS in early PD patients.
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The prion-like propagation of α-synuclein (α-syn) is considered to be the key to the pathogenesis of synucleinopathies. A variety of α-syn detection methods have high sensitivity and specificity in the diagnosis of synucleinopathies. The detection of α-syn using skin samples is minimally invasive and less invasive, with high sensitivity and specificity, which has potential clinical application value in the diagnosis of synucleinopathies. In this paper, the latest development of α-syn detection in the diagnosis of synucleinopathies using skin samples is reviewed, emphasizing the clinical application of α-syn seeding activity in the early stage and differential diagnosis.
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Objective:To observe the effects of acupuncture and moxibustion on phosphatase and PTEN-induced putative kinase 1(PINK1)/Parkin signaling pathway in the midbrain substantia nigra of Thy1-α synuclein(αSyn)transgenic model mice with Parkinson disease(PD). Methods:Twenty-four Thy1-αSyn transgenic mice were randomly divided into a model group,an acupuncture group,an acupuncture + moxibustion group,and a Western medicine group.Six wild-type mice in the same litter were used as the wild-type group.In the acupuncture group,Baihui(GV20)and Yanglingquan(GB34)were selected for acupuncture.In the acupuncture + moxibustion group,Guanyuan(CV4)was added on the basis of the acupuncture group.The Western medicine group was given rapamycin intraperitoneal injection at a dose of 10 mg/(kg·bw).The wild-type group and the model group were fixed without intervention.The overall rod performance(ORP)score of mice was observed in each group.The immunohistochemical method was used to detect the tyrosine hydroxylase(TH)positive neurons in the substantia nigra of mice in each group.The αSyn was detected by the immunofluorescence chemical method.The expression levels of αSyn,microtubule-associated protein 1 light chain 3(LC3)-Ⅱ/LC3-Ⅰ,autophagy protein sequestosome-1/protein 62(SQSTM-1/p62),PINK1,Parkin,and ubiquitin-specific protease 30(USP30)proteins were detected by Western blotting assay.The expression levels of LC3B,p62,PINK1,Parkin,and USP30 mRNAs were detected by fluorescence quantitative polymerase chain reaction. Results:Compared with the wild-type group,the ORP score,the p62,PINK1,and Parkin protein expression levels decreased significantly(P<0.01),the PINK1 mRNA expression level decreased(P<0.05),while the protein and mRNA expression levels of USP30 increased(P<0.05)in the model group.Compared with the model group,the ORP score in the acupuncture group and the acupuncture + moxibustion group increased(P<0.05);the expression level of LC3-Ⅱ/LC3-Ⅰ protein in the acupuncture + moxibustion group and the Western medicine group increased(P<0.05);the protein expression levels of p62,PINK1,and Parkin increased(P<0.05),while the USP30 protein expression level decreased significantly(P<0.01)in the acupuncture group,the acupuncture + moxibustion group,and the Western medicine group;the Parkin mRNA expression level in the acupuncture group and the acupuncture + moxibustion group increased(P<0.05);the USP30 mRNA expression level in the acupuncture + moxibustion group decreased(P<0.05). Conclusion:Acupuncture and moxibustion regulate the related molecule expression levels of PINK1/Parkin signaling pathway in the Thy1-αSyn transgenic PD model mice and promote the autophagy degradation of αSyn to exert the protective effect of dopaminergic neurons.
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Parkinson's disease(PD)is a progressive neurodegenerative disorder that tends to occur in the elderly.Its clinical manifestations mainly include motor symptoms and non-motor symptoms, with sleep disorders among common non-motor symptoms of PD.The latest lines of evidence show that sleep disorders are not only clinical manifestations of neurodegenerative diseases, but also an important risk factor for the development and progression of neurodegenerative diseases.There is a bidirectional relationship between sleep disorders and neurodegenerative diseases, including PD.The possible mechanisms include accelerated α-synuclein pathology, deposition of Tau protein, inhibition of the glymphatic system, neuroinflammation and changes in the circadian rhythm system.In this article, we review research progress on the bidirectional relationship between sleep disorders and PD, related mechanisms, and the outlook on the treatment of PD through the management of sleep disorders.
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Parkinson′s disease (PD) is the most common age-related neurodegenerative disease, which has the effects on the patients′ quality of life and brings a huge burden to the society and family. The pathological feature of PD is the abnormal accumulation of alpha-synuclein (α-syn) in the brain of substantia nigra-striatum, mediating the death of dopaminergic neurons. However, further studies have found that α-syn mediates the abnormal function of astrocytes leading to the destruction of the blood-brain barrier and the release of inflammatory factors caused by microglia, which are related to the pathogenesis of PD. Therefore, neurons, glial cells, and blood vessels as a whole named neurovascular unit can better reflect the pathophysiological environment of PD and reveal the PD pathogenesis. Studies have detected the ways of α-syn transmission, such as prion-like, tunneling nanotubes, exosomes, are connected with the pathogenesis and progression of PD. The Braak stage and the prospective cohort of early PD provide a view that the peripheral α-syn to the central nervous system may be an another important way to mediate the pathogenesis and progression of PD. The research about the abnormal aggregation and spread of α-syn can provide the new theory for the pathogenesis of PD and the new disease modifying therapy of PD. This article reviews the role of abnormal aggregation and transmission of α-syn in the pathogenesis of PD.
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Objective: To observe the dynamic changes of brainstem locus coeruleus (LC) damage in Parkinson' s disease (PD) -like mice by paraquat (PQ) . Methods: In October 2019, 36 male C57BL/6 mice were randomly divided into the exposure group and the control group, with 18 mice in each group. The mice in the exposure group were given intraperitoneal injection of 15 mg/kg PQ, and the mice in the control group were given intraperitoneal injection of 0.9% saline, twice a week for 8 weeks. Neurobehavioral changes (pole climbing test, swimming test, open field test, tail hanging test, high plus maze test and water maze test) were observed at 4 weeks, 6 weeks and 8 weeks, respectively, and the changes of motor ability, emotion and cognitive function were evaluated. The brain tissue of mice were taken and stained with Hematoxylin-Eosin (HE) to observe the pathological changes of LC. Nissl staining was used to detect the changes of neuronal Nissl bodies in LC. Immunohistochemistry (IHC) staining was used to detect the expression of neuron nuclear antigen (NeuN) , dopamine (DA) neurons and norepinephrine (NE) neuron markers tyrosine hydroxylase (TH) , α-synuclein (α-syn) in substantia nigra (SN) and LC. The expression levels of NeuN, TH and α-syn in the midbrain and brainstem were detected by Western blotting. TUNEL staining was used to detect neuronal apoptosis in LC. Results: Compared with the 4th week of PQ exposure group, the time of pole climbing and swimming immobility were gradually increased, the ratio of open arm residence time of high plus maze test and the number of times of the platform and the residence time of platform quadrant in water maze test were gradually decreased (P<0.05) in the exposure group with the progress of exposure time. The results of HE and Nissl staining showed that the neurons in LC gradually arranged loosely, the nucleus were deeply stained, the cytoplasm was pyknosis, and the number of Nissl bodies gradually decreased (P<0.05) in the exposure group with the progress of exposure time. IHC results showed that the number of NeuN and TH positive cells in SN and LC of mice were gradually decreased, and the positive expression of α-syn was gradually increased (P<0.05) in the exposure group with the progress of exposure time. Western blotting results showed that the expression levels of NeuN and TH in the midbrain and brainstem were gradually decreased, and the expression level of α-syn was gradually increased (P<0.05) in the exposure group with the progress of exposure time. TUNEL staining showed that the apoptosis rates of neurons in LC were gradually increased (P<0.05) in the exposure group with the progress of exposure time. Conclusion: PQ induces progressive damage in the LC area of PD-like mice, which may be caused by the abnormal accumulation of pathological α-syn in the LC area.
Тема - темы
Animals , Male , Mice , Dopaminergic Neurons , Locus Coeruleus/pathology , Mice, Inbred C57BL , Paraquat/toxicity , Parkinson Disease/metabolism , Substantia Nigra , Tyrosine 3-Monooxygenase/metabolismРеферат
Parkinson′s disease is a degenerative disease of the central nervous system with abnormal protein deposition in the brain as the main pathological changes. The onset of Parkinson′s disease is related to abnormal deposition protein removal disorders, and the relevant mechanisms are still unclear. The glymphatic system is a metabolic waste and abnormal protein deposition removal system in the brain. In recent years, studies have shown that the changes of aquaporin 4, perivascular space and dural lymphatic vessels in Parkinson′s disease are closely related to the level of relevant pathological proteins in cerebrospinal fluid, leading to the occurrence and development of Parkinson′s disease. The researches on structure and biomarkers of the glymphatic system in Parkinson′s disease in recent years are reviewed in this article.
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Background Paraquat (PQ), one of the environmental poisons associated with sporadic Parkinson's disease (PD), can cause abnormal aggregation of alpha-synuclein (α-syn), but the research on its conformational changes and subcellular localization is limited. Objective To investigate the effect of PQ on α-syn conformation and subcellular localization in dopaminergic neurons. Methods Forty-eight SPF C57BL/6 male mice were selected and randomly divided into a control group and a model group. The model group was intraperitoneally injected with PQ (15 mg·kg−1), and the control group was intraperitoneally injected with 0.9% normal saline, twice a week for eight weeks to construct a PD-like mouse model. The changes of neurobehavior (by open field test and pole climbing test) were observed to evaluate motor ability of mice. Immunohistochemical staining (IHC) was used to detect the expression levels of tyrosine hydroxylase (TH) and α-syn in the midbrain. Western blotting (WB) was used to measure the protein expression levels of TH and α-syn in midbrain. Human neuroblastoma SH-SY5Y cells were used as dopaminergic neuron in vitro models. After the cells were treated with PQ (100 μmol·L−1) for 0, 12, 24, 36 and 48 h, the expressions of α-syn in whole cell, cytoplasm, and nucleus were detected by WB; the expression level of extracellular α-syn was detected by enzyme-linked immunosorbent assay (ELISA); the change of α-syn location was observed by immunofluorescence assay (IFA). Results The neurobehavioral tests' results showed that compared with the control group, the residence time in peripheral area of mice in the PQ model group increased with the increase of exposure time (P<0.05), the residence time and moving distance in the central region decreased (P<0.05), and the pole climbing time increased (P<0.05). The mouse IHC results showed that compared with the control group, the number of TH positive cells in the midbrain decreased in the model group at week 6 and 8 (P<0.05), while the expression level of α-syn increased at week 4, 6, and 8 (P<0.05). The WB results of mouse showed that the relative expression of TH decreased significantly after 6 and 8 weeks of PQ exposure (P<0.05), and the relative expression of oligomer α-syn increased after 4, 6, and 8 weeks of PQ exposure (P<0.05). The WB of in vitro models results showed that the relative expression of α-syn in cells increased with time (R2=0.7440, P<0.05); the relative expression of α-syn in cytoplasm increased firstly and then decreased with time (P<0.05); the relative expression of α-syn in nucleus increased with time (R2=0.7913, P<0.05). The IFA results of in vitro models showed that the expression of oligomerized α-syn increased and translocated to the nucleus (P<0.05). The ELISA results of in vitro models showed that α-syn increased with the increase of PQ exposure time (P<0.05). Conclusion PQ can increase the expression of α-syn in dopaminergic neurons, induce oligomerization and translocation to the nucleus.
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Parkinson′s disease (PD) is a neurodegenerative disease commonly found in middle-aged and elderly people. It is characterized by resting tremor, bradykinesia, myotonia, and abnormal posture gait. The main pathological changes were the loss of dopaminergic neurons in the substantia nigra and the formation of Lewy bodies in the cytoplasm of the residual neurons. The main component of the Lewy bodies was α-synuclein. And why it causes the degeneration of dopaminergic neurons in the substantia nigra is not known. At present, most studies on Parkinson′s disease focus on the pathogenesis of the disease. More and more evidence shows that respiratory chain injury is a key feature of sporadic PD patients, and the proteins encoded by PD-related genes are related to the disorder of mitochondrial function. We believe that the important mechanism of the disease is impaired mitochondrial function due to environmental and (or) genetic inheritance. This article highlights new advances in mitochondrial dysfunction in Parkinson′s pathogenesis, including mitochondria and cell-mediated immunity, endoplasmic reticulum (ER)-mitochondrial axis, sirtuin-mediated mitochondrial stress response, and the role of microRNA in the etiology of PD. A deeper understanding of these mechanisms may provide inspiration for the development of new targeted therapies.
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Objective:To investigate the value of α-synuclein (α-syn) concentration in cerebrospinal fluid (CSF) in predicting postoperative delirium (POD).Methods:One thousand patients underwent elective surgery with combined epidural-spinal anesthesia in our hospital from January 2018 to September 2020 were selected.The epidural puncture was performed at L 3, 4 interspace, and 2 ml of CSF was collected after the needle reaching the subarachnoid space.The concentrations of α-syn, β-amyloid (Aβ)40, Aβ42, total tau protein (T-tau), and phosphorylated tau protein (P-tau) in CSF were determined by enzyme-linked immunosorbent assay.The concentrations of α-syn in CSF and occurrence of POD in patients of different ages were recorded.Patients were divided into POD group and non-POD group according to whether POD occurred, and frequency matching (1∶1) was performed based on five matching variables of age, ASA physical status, education level, duration of operation, and intraoperative blood loss. Results:Eight hundred and forty-one patients were finally included in the study, and the incidence of POD was 15.0%. There were 126 cases in POD group and 126 cases in non-POD group after matching. The concentrations of α-syn in CSF and incidence of POD were gradually increased with age ( P<0.05). Compared with non-POD group, the concentrations of α-syn, T-tau and P-tau in CSF were significantly increased, the concentrations of Aβ40 and Aβ42 were decreased, Aβ40/P-tau, Aβ42/P-tau, Aβ42/Aβ40 and P-tau/T-tau were decreased in POD group ( P<0.05). After confounding factors were corrected by logistic regression analysis, increased concentrations of α-syn, p-tau, and T-tau in CSF were risk factors for POD ( P<0.05). Increased concentrations of Aβ40 and Aβ42 in CSF and increased Aβ40/P-tau and Aβ42/P-tau were protective factors for POD ( P<0.05). Multiple linear regression analysis showed that the concentration of α-syn in CSF was negatively correlated with Aβ40 and Aβ42 concentrations and positively correlated with P-tau and T-tau concentrations ( P<0.05). The area under the receiver operating characteristic curve of concentrations of α-syn in CSF predicting POD was 0.895, Youden index was 0.664, sensitivity was 80.00%, and specificity was 86.36% ( P<0.001). Conclusion:The concentration of α-syn in CSF is related to the occurrence of POD, and it provides higher accuracy in predicting POD.
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Objective:To evaluate the effects of propofol on inflammatory responses in substantia nigra in mice with Parkinson′s disease (PD) and its relationship with α-synuclein (α-syn) expression.Methods:Thirty-three SPF healthy male C57BL/6 mice, aged 12 weeks, weighing 24-26 g, were divided into 3 groups ( n=11 each) using a random number table method: control group (group Con), group PD and propofol group (group Pro). In PD and Pro groups, 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP) 30 mg/kg was intraperitoneally injected once a day for 5 consecutive days to induce PD.Propofol 50 mg/kg was intraperitoneally injected at 2 h after the last injection of MPTP in group Pro, while the equal volume of normal saline was given instead in Con and PD groups.The rotarod test was performed at 24 h after administration.The animals were then sacrificed and substantia nigra was removed for determination of contents of interleukin-1β (IL-1β) and tumor necrosis factor (TNF)-α (by enzyme-linked immunosorbent assay), the expression of nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) and p-caspase-1 (by Western blot) and the expression of α-syn (by immunofluorescence staining). Results:Compared with Con group, the first fall-off time was significantly shortened, the number of falling off was increased, the contents of IL-1β and TNF-α were increased, and the expression NLRP3, p-caspase-1and α-syn was up-regulated in substantia nigra in group PD ( P<0.05). Compared with PD group, the first fall-off time was significantly prolonged, the number of falling off was decreased, the contents of IL-1β and TNF-α were decreased, and the expression NLRP3, p-caspase-1and α-syn was down-regulated in substantia nigra in group Pro ( P<0.05). Conclusion:Propofol can improve behaviors of the mice through inhibiting inflammatory responses in substantia nigra, and the mechanism is related to down-regulating the expression of α-syn.
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Introducción. El consumo excesivo de alcohol resulta en neuroadaptación, neurodegeneración y expresión diferencial de numerosos genes. Objetivo. Determinar la relación entre la expresión del gen de la alfa sinucleína (SNCA) en sangre, las variantes de nucleótido único (Single Nucleotide Variant, SNV) en su región promotora y el estreñimiento crónico en personas con problemas de consumo de alcohol. Materiales y métodos. La muestra estuvo conformada por 35 controles y 27 casos, seleccionados según el puntaje obtenido con la herramienta AUDIT. En el diagnóstico del estreñimiento se aplicaron los criterios de Roma IV. La extracción de ácidos nucleicos se hizo a partir de sangre periférica y se evaluó la expresión del gen mediante qPCR, la cuantificación proteica por ELISA y la presencia de SNV en la región promotora del gen por la secuenciación de Sanger. Resultados. Se observó sobreexpresión génica relativa de ARNm del gen SNCA en el grupo de casos sin relación con el estreñimiento crónico. Se evidenció un riesgo 4,8 veces mayor de presentar estreñimiento en el grupo de casos. Se encontraron nueve variantes de nucleótido simple en un segmento de la región promotora del gen rica en secuencias reguladoras CpG, con frecuencia similar entre los grupos, y se detectó una variante en la posición -2171 que no se encuentra reportada en GenBank para variantes clínicas y cuyo genotipo A/T se relacionó con el incremento de la expresión del ARNm del SNCA. Conclusión. En personas con problemas de consumo de alcohol se evidenció la sobreexpresión del ARNm de alfa sinucleína, lo cual no se relacionó con el diagnóstico de estreñimiento crónico.
Introduction: Excessive alcohol consumption results in neuroadaptation, neurodegeneration, and differential expression of numerous genes. Objective: To determine the relationship between the expression of the alpha synuclein gene (SNCA) in blood, single nucleotide variant (SNV) in its promoter region, and chronic constipation in people with problems of alcohol consumption. Materials and methods: The sample consisted of 35 controls and 27 cases selected according to the score obtained with the AUDIT tool. For the diagnosis of constipation, the Rome IV criteria were applied. Nucleic acid extraction was performed from peripheral blood and the expression of the gene was evaluated by qPCR, protein quantification by ELISA, and the presence of SNV in the promoter region of the gene by Sanger sequencing. Results: We observed a relative gene overexpression of SNCA mRNA in the case group, which was not related to the diagnosis of chronic constipation. There was 4.8 times greater risk of presenting constipation in the group of cases. Besides, nine single nucleotide variants were found in a segment of the promoter region of the gene rich in CpG regulatory sequences with similar frequency between the groups while a variant was identified in position -2171, which is not reported in GenBank for variants and whose genotype A/T was associated with increased expression of SNCA mRNA. Conclusion: We evidenced an overexpression of alpha synuclein mRNA in people with problems of alcohol consumption that was not related to the diagnosis of chronic constipation.
Тема - темы
Constipation , Alcoholism , alpha-Synuclein , Polymorphism, Genetic , Gene Expression , InflammationРеферат
OBJECTIVE@#To analyze the effect of benzopyrene on the decrease of dopaminergic neurons, and the increase and aggregation of α-synuclein, which are the pathological features of Parkinson's disease, and to explore its possible mechanisms.@*METHODS@#Eight-month-old transgenic mice with human SNCA gene were randomly divided into a BaP-exposed group and a control group. BaP and solvent corn oil were injected intraperitoneally to BaP-exposed group and control group respectively, once a day for 60 days. The motor dysfunction of mice was tested by rotarod test. The effects of BaP on the decrease of dopaminergic neurons and increase and aggregation of α-synuclein were observed by immunohistochemistry and Western blot experiments respectively, and the expression of related mRNA was detected by quantitative real-time PCR (qRT-PCR). Twenty genes were tested in the study, mainly related to neurotransmitter transporter (2 genes), neurotransmitter receptor function (10 genes), cellular autophagy (5 genes), and α-synuclein aggregation and degradation (3 genes).@*RESULTS@#After BaP exposure, the movement time of the mice in the rotarod test was significantly reduced (P<0.05). The substantia nigra dopami-nergic neurons in the mice were significantly reduced, which was 62% of the control group (P<0.05), and the expression of α-synuclein in the midbrain increased, which was 1.36 times that of the control group (P<0.05). After BaP exposure, mRNA expressions of 14 genes in the midbrain of the mice were significantly down-regulated (P<0.05). Alpha-synuclein degradation and cell autophagy (5 genes), neuron transporters (2 genes), and neurotransmitter receptor functions (5 genes) were involved. The expression of one gene, Synphilin-1, was significantly up-regulated (P<0.01), which was related to α-synuclein aggregation.@*CONCLUSION@#BaP exposure not only inhibited function of neurotransmitter receptor and dopamine transporter, but also interfered cell autophagy, thereby hindering the degradation of α-synuclein, which could lead to decrease of dopaminergic neurons in substantia nigra and increase and aggregation of α-synuclein in midbrain, as the significant pathology of Parkinson's disease. Therefore, BaP exposure may increase the risk of Parkinson's disease.
Тема - темы
Animals , Humans , Mice , Benzo(a)pyrene , Brain , Dopamine , Dopaminergic Neurons , alpha-SynucleinРеферат
BACKGROUND AND PURPOSE: It is essential to develop a reliable predictive serum biomarker for Parkinson's disease (PD). The accumulation of alpha-synuclein (αSyn) and up-regulated expression of Rab35 participate in the etiology of PD. The purpose of this investigation was to determine whether the combined assessment of serum αSyn and Rab35 is a useful predictive biomarker for PD. METHODS: Serum levels of αSyn or Rab35 were determined in serum samples from 59 sporadic PD patients, 19 progressive supranuclear palsy (PSP) patients, 20 multiple system atrophy (MSA) patients, and 60 normal controls (NC). Receiver operating characteristics (ROC) curves were calculated to determine the diagnostic accuracy of αSyn or/and Rab35 in discriminating PD patients from NC or atypical parkinsonian patients. RESULTS: The levels of αSyn and Rab35 were increased in PD patients. The serum level of Rab35 was positively correlated with that of αSyn in PD patients. Compared to analyzing αSyn or Rab35 alone, the combined analysis of αSyn and Rab35 produced a larger area under the ROC curve and performed better in discriminating PD patients from NC, MSA patients, or PSP patients. When age was dichotomized at 55, 60, 65, or 70 years, the combined assessment of αSyn and Rab35 for classifying PD was better in the group below the cutoff age than in the group above the cutoff age. CONCLUSIONS: Combined assessment of serum αSyn and Rab35 is a better biomarker for discriminating PD patients from NC or atypical parkinsonian patients, and is a useful predictive biomarker for younger sporadic PD patients.