Proteomic analysis of the neuroprotective mechanisms of acupuncture treatment in a Parkinson's disease mouse model

Acupuncture is frequently used as an alternative therapy for Parkinson's disease (PD), and it attenuates dopaminergic (DA) neurodegeneration in the substantia nigra (SN) in PD animal models. Using proteomic analysis, we investigated whether acupuncture alters protein expression in the SN to favor attenuation of neuronal degeneration. In C57BL/6 mice treated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP, 30 mg/kg/day), intraperitoneal (i.p.) for 5 days, 2 or 100 Hz electroacupuncture (EA) was applied at the effective and specific acupoint, GB34, once a day for 12 consecutive days from the first MPTP treatment. Both treatments in MPTP mice led to restoration of behavioral impairment and rescued tyrosine hydroxylase (TH)-positive DA neurodegeneration. Using peptide fingerprinting MS, we identified changes in 22 proteins in the SN following MPTP treatment, and nine of these proteins were normalized by EA. They were involved in cell death regulation, inflammation, or restoration from damage. The levels of cyclophilin A (CypA), which is a neuroprotective agent, were unchanged by MPTP treatment but were increased in MPTP-EA mice. These results suggest that acupoint GB34-specific EA changes protein expression profiles in the SN in favor of DA neuronal survival in MPTP-treated mice, and that EA treatment may be an effective therapy for PD patients.     

Arcuate nucleus of hypothalamus is involved in mediating the satiety effect of electroacupuncture in obese rats

Obesity is a major health problem in the world. Since effective remedies are rare, researchers are trying to discover new therapies for obesity, and acupuncture is among the most popular alternative approaches. This study investigated the anti-obesity mechanisms of EA, using a rat model of diet-induced obesity. After feeding with a high-fat diet for 9 weeks, a number of rats who gained weight that surpassed the maximal body weight of rats in the chow-fed group were considered obese and employed in the study. A 2 Hz EA treatment at the acupoints ST36/SP6 with the intensity increasing stepwise from 0.5-1-1.5 mA was given once a day for 30 min. Rats treated with EA showed significantly decreased food intake and reduced body weight compared with the rats in DIO and restraint group. EA treatment increased peptide levels of α-MSH and mRNA levels of its precursor POMC in the arcuate nuclear of hypothalamus (ARH) neurons. In addition, the cerebral spinal fluid (CSF) content of α-MSH was elevated by EA application. ARH lesions by monosodium glutamate abolished the inhibition effect of EA on food intake and body weight. A non-acupoint stimulation did not show the benefit effect on food intake inhibition and body weight reduction compared with restraint and ST36/SP6 EA treatment. We concluded that EA treatment at ST36/SP6 acted through ARH to significantly inhibit food intake and body weight gain when fed a high-fat diet and that the stimulation of α-MSH expression and release might be involved in the mechanism.     

High-frequency electro-acupuncture stimulation modulates intracerebral γ-aminobutyric acid content in rat model of Parkinson's disease

The purpose of the present study is to observe the effect of electro-acupuncture (EA) stimulation on intracerebral neurotransmitters in a rat model of Parkinson's disease (PD), and explore the possible mechanism. We used 6-hydroxydopamine (6-OHDA) injection in medial forebrain bundle (MFB) in the right brain of Sprague Dawley (SD) rat to establish the parkinsonian rat model, and randomly divided the PD rats into model and 100 Hz EA stimulation groups (n =10 in each group). EA stimulation group received 4 courses of EA stimulation on Baihui (GV-20) and Dazhui (GV-14) acupuncture points. Moreover, ten rats were randomly selected as sham operation group, only receiving normal saline (NS) injection in MFB. Then apomorphine (APO)-induced rotational behavior in different groups was recorded, and the contents of γ-aminobutyric acid (GABA) in the brain were analyzed with high pressure/performance liquid chromatography-electrochemical detection (HPLC-ECD). The results showed that model group exhibited abnormal rotational behavior with APO treatment, suggesting the successful establishment of PD model. Compared with sham operation group, model group showed increased GABA contents in cortex and striatum, as well as decreased GABA content in ventral midbrain, on the lesioned side. EA stimulation could effectively ameliorate the abnormal rotational behavior of PD rat. Compared with the model group, EA stimulation decreased the ratio of GABA content on the lesioned side to that on unlesioned side in the cortex, while increased the ratios in the striatum and cerebellum. However, there was no difference of the ratio in the ventral midbrain among three groups. These results suggest high-frequency EA stimulation significantly improves the abnormal behavior of PD rats, which may exert through enhancing the inhibitory effect of cerebellum-basal ganglia-cortical loop on motor center.     

Antioxidant responses and lipid peroxidation following intranasal 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) administration in rats: increased susceptibility of olfactory bulb

We evaluated an alternative method to investigate a possible involvement of environmental toxins in the pathology of Parkinson's disease (PD). There is considerable evidence supporting the role of oxidative stress in the toxicity of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), a neurotoxin largely used to modeling PD in primates and rodents. We have recently demonstrated that rats treated with intranasal (i.n.) infusion of MPTP suffer from progressive signs of PD that are correlated with time-dependent degeneration in dopaminergic neurons. In the present study, we investigated the time-dependent (2 h to 7 days) effect of a single i.n. administration of MPTP (0.1 mg/nostril) on the glutathione-related antioxidant status and lipid peroxidation (TBARS) in the adult Wistar rat brain. The effects were more pronounced in the olfactory bulb at 6 h after i.n. MPTP administration, as indicated by an increase in TBARS and total glutathione (GSH-t) levels, and also in the gamma-glutamyl transpeptidase (GGT) activity. Increased levels of TBARS, GSH-t and GGT activity were also observed at 6 h post-MPTP infusion in some structures (e.g. striatum, hippocampus and prefrontal cortex). No difference regarding glutathione reductase activity was observed in any of the brain structures analyzed, while a marked decrease in glutathione peroxidase activity was specifically observed in the substantia nigra 7 days after MPTP treatment. These results demonstrate that a single i.n. infusion of MPTP in rats induces significant alterations in the brain antioxidant status and lipid peroxidation, reinforcing the notion that the olfactory system represents a particularly sensitive route for the transport of neurotoxins into the central nervous system that may be related to the etiology of PD.     

Electroacupuncture inhibits CB1 upregulation induced by ethanol withdrawal in mice

CB1R play a role in alcohol withdrawal and in some effects of acupuncture. Interestingly, acupuncture has been used to alleviate alcohol withdrawal. Here, we investigated electroacupuncture (EA) effects during ethanol withdrawal on CB1R immunoreactivity. Male Swiss mice were daily injected with ethanol (2g/kg, i.p) (EtOH group), for 21 days. EA was performed daily during 4 days of ethanol withdrawal. The stimuli of 2 or 100 Hz were provided in two acupoints combination: Ea1 [(ST-36/Zusanli) and (PC-6/Neiguan)] or Ea2 [(DU-14/Dazhui) and (DU-20/Baihui)]. The specificity of the acupoints were assessed by the inclusion of three additional groups, Ea3 [(ST 25/Tianshu - acupoints used to other non-related disorders)], Sham1 and Sham2 (transdermic stimulation nearly to the respective acupoints). EtOH group were only handled during withdrawal and Saline group was chronically treated with Saline and handled similarly to EtOH group. One day after withdrawal the animals were perfused and their brains processed for immunohistochemistry. There was an increase of CB1R in the prefrontal cortex, striatum, hippocampus, amygdala and ventral tegmental area. The procedures used in the 2HzEa1 and 100HzEa2 groups were the most effective and specific to inhibit this CB1R upregulation. Therefore, EA inhibits CB1R upregulation seen in ethanol withdrawn mice. The specificity of acupoints stimulation depends of the encephalic nuclei, acupoints association and frequency of stimulation.     

人脑对不同频率穴位电刺激反应的功能性磁共振成像

利用功能性磁共振方法研究人脑对不同频率穴位体表电刺激（transcutaneous electric nerve stimulation,TENS)的反应。实验对11名志愿得进行了22次脑部功能性磁共振成像。成像过程中,每名志愿者分别接受了2和100HzTENS刺激,刺激部位为左腿足三里和三阴交穴,结果为不同频率TENS都激活了初级和次级躯体感觉区,频率特异性的激活信号出现在与运动相关的区域、丘脑、边缘系统和联络皮层。结果显示,在相同穴位给予不同频率的TENS要以在大脑引起不同的反应,提示2和100HzTENS可能激活了不同的神经通路,这些神经通路分别在中枢神经系统起着不同的作用。     

电针对氯胺酮成瘾大鼠内侧前额叶皮质酪氨酸羟化酶表达的影响

目的观察不同时辰电针“足三里”和“三阴交”穴对氯胺酮成瘾大鼠内侧前额叶皮质（mPFC）酪氨酸羟化酶（TH）表达的影响,探讨电针治疗氯胺酮滥用成瘾的作用机制。方法将56只SD大鼠随机分为正常对照组、生理盐水对照组、模型组、电针治疗组,电针治疗组再分为子时（23：00）、卯时（05：00）、午时（11：00）、酉时（17：00）4个电针组,每组8只。每天1次经腹腔注射氯胺酮复制氯胺酮成瘾模型,不同时辰电针组在给药7d后分别选取一侧“足三里”和“三阴交”穴给予低频（2Hz）电针治疗,每次30min,连续治疗7d。采用免疫组织化学染色方法检测mPFC内TH的表达。结果与正常对照组和生理盐水对照组相比较,模型组mPFC内TH免疫反应阳性神经元的数量明显增多（P〈0．01）,细胞平均灰度值降低（P〈0．01）,与模型组相比较,午时、酉时电针组TH免疫反应阳性神经元的数量明显减少（P〈0．01）,细胞平均灰度值升高（P〈0．01）;子时、卯时电针组则无明显变化（P〉0．05）。结论氯胺酮成瘾使mPFC内TH的表达明显增加;午时、酉时电针“足三里”和“三阴交”穴可明显下调mPFC内TH的表达,改善氯胺酮成瘾症状。     

Post-MPTP Treatment with Granulocyte Colony-Stimulating Factor Improves Nigrostriatal Function in the Mouse Model of Parkinson’s Disease

The neuroprotective effects of granulocyte colony-stimulating factor (G-CSF) were reported in several neurological disease models, including Parkinson’s disease (PD). In the present study, we investigated the therapeutic effect of G-CSF after the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of PD was established. G-CSF was subcutaneously administered into C57BL/6 mice that had undergone systemic MPTP injections. We found that G-CSF treatment markedly increased the number of dopaminergic neurons in the substantia nigra pars compacta (SNpc) of the G-CSF-treated group. Consistent with this finding, we found a significant increase in dopamine release under high K⁺ stimulation in the striatum of the G-CSF-treated animals compared to the MPTP-exposed mice. Finally, we observed a persistent recovery of locomotor function in the G-CSF-treated animals. These results suggest the potential therapeutic value of G-CSF in treating PD. However, our bromodeoxyuridine labeling experiment failed to identify any newly generated dopaminergic neurons in SNpc. This might indicate an indirect effect of G-CSF on cell proliferation. The underlying mechanism of G-CSF is under further investigation.     

Glutathione S-Transferase pi Mediates MPTP-Induced c-Jun N-Terminal Kinase Activation in the Nigrostriatal Pathway

Parkinson's disease (PD) is a progressive movement disorder resulting from the death of dopaminergic neurons in the substantia nigra. Neurotoxin-based models of PD using 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) recapitulate the neurological features of the disease, triggering a cascade of deleterious events through the activation of the c-Jun N-terminal kinase (JNK). The molecular mechanisms underlying the regulation of JNK activity under cellular stress conditions involve the activation of several upstream kinases along with the fine-tuning of different endogenous JNK repressors. Glutathione S-transferase pi (GSTP), a phase II detoxifying enzyme, has been shown to inhibit JNK-activated signaling by protein-protein interactions, preventing c-Jun phosphorylation and the subsequent trigger of the cell death cascade. Here, we use C57BL/6 wild-type and GSTP knockout mice treated with MPTP to evaluate the regulation of JNK signaling by GSTP in both the substantia nigra and the striatum. The results presented herein show that GSTP knockout mice are more susceptible to the neurotoxic effects of MPTP than their wild-type counterparts. Indeed, the administration of MPTP induces a progressive demise of nigral dopaminergic neurons together with the degeneration of striatal fibers at an earlier time-point in the GSTP knockout mice when compared to the wild-type mice. Also, MPTP treatment leads to increased p-JNK levels and JNK catalytic activity in both wild-type and GSTP knockout mice midbrain and striatum. Moreover, our results demonstrate that in vivo GSTP acts as an endogenous regulator of the MPTP-induced cellular stress response by controlling JNK activity through protein-protein interactions.     

Tauroursodeoxycholic Acid Prevents MPTP-Induced Dopaminergic Cell Death in a Mouse Model of Parkinson’s Disease

Mitochondrial dysfunction and oxidative stress are implicated in the neurodegenerative process in Parkinson??s disease (PD). Moreover, c-Jun N-terminal kinase (JNK) plays an important role in dopaminergic neuronal death in substantia nigra pars compacta. Tauroursodeoxycholic acid (TUDCA) acts as a mitochondrial stabilizer and anti-apoptotic agent in several models of neurodegenerative diseases. Here, we investigated the role of TUDCA in preventing 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced neurodegeneration in a mouse model of PD. We evaluated whether TUDCA modulates MPTP-induced degeneration of dopaminergic neurons in the nigrostriatal axis, and if that can be explained by regulation of JNK phosphorylation, reactive oxygen species (ROS) production, glutathione S-transferase (GST) catalytic activation, and Akt signaling, using C57BL/6 glutathione S-transferase pi (GSTP) null mice. TUDCA efficiently protected against MPTP-induced dopaminergic degeneration. We have previously demonstrated that exacerbated JNK activation in GSTP null mice resulted in increased susceptibility to MPTP neurotoxicity. Interestingly, pre-treatment with TUDCA prevented MPTP-induced JNK phosphorylation in mouse midbrain and striatum. Moreover, the anti-oxidative role of TUDCA was demonstrated in vivo by impairment of ROS production in the presence of MPTP. Finally, results herein suggest that the survival pathway activated by TUDCA involves Akt signaling, including downstream Bad phosphorylation and NF-??B activation. We conclude that TUDCA is neuroprotective in an in vivo model of PD, acting mainly by modulation of JNK activity and cellular redox thresholds, together with activation of the Akt pro-survival pathway. These results open new perspectives for the pharmacological use of TUDCA, as a modulator of neurodegeneration in PD.     

帕金森病小鼠模型行为学检测方法的比较研究

目的比较目前常用的5种帕金森病(PD)小鼠模型行为学检测方法在PD研究中的作用。方法用MPTP建立C57BL小鼠PD模型,通过行为学检测(自主活动计数、滚轴实验、游泳实验、爬杆实验、悬挂实验)、免疫组织化学和荧光分光光度法,对比5种行为学检测方法的平均数与变异系数,观察MPTP对PD小鼠模型的行为学、黑质多巴胺(DA)神经元和纹状体酪氨酸羟化酶免疫反应阳性(TH-ir)神经纤维以及纹状体DA水平的影响。结果给与MPTP后,小鼠行为学计数降低,爬杆实验未能得到检测结果,悬挂实验变异系数很高,结果有明显的偶然性,滚轴实验结果变异系数中等,平均数呈现一定的上升趋势,自主活动计数中移动与站立和游泳实验的平均数则呈现明显的下降趋势,变异系数很低,而黑质DA神经元数目减少约58%,纹状体TH-ir神经纤维密度减低,纹状体DA水平明显降低约88%,两组相比差异有显著性(P<0.01)。结论MPTP所致的C57BL小鼠的神经病理、生化改变与PD患者近似,自主活动计数和游泳实验优于其他行为学检测方法。     

Influences of Chronic Mild Stress Exposure on Motor,Non-Motor Impairments and Neurochemical Variables in Specific Brain Areas of MPTP/Probenecid Induced Neurotoxicity in Mice

Parkinson''s disease (PD) is regarded as a movement disorder mainly affecting the elderly population and occurs due to progressive loss of dopaminergic (DAergic) neurons in nigrostriatal pathway. Patients suffer from non-motor symptoms (NMS) such as depression, anxiety, fatigue and sleep disorders, which are not well focussed in PD research. Depression in PD is a predominant /complex symptom and its pathology lies exterior to the nigrostriatal system. The main aim of this study is to explore the causative or progressive effect of chronic mild stress (CMS), a paradigm developed as an animal model of depression in1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (25 mg/kg. body wt.) with probenecid (250 mg/kg, s.c.) (MPTP/p) induced mice model of PD. After ten i.p. injections (once in 3.5 days for 5 weeks) of MPTP/p or exposure to CMS for 4 weeks, the behavioural (motor and non-motor) impairments, levels and expressions of dopamine (DA), serotonin (5-HT), DAergic markers such as tyrosine hydroxylase (TH), dopamine transporter (DAT), vesicular monoamine transporters—2 (VMAT 2) and α-synuclein in nigrostriatal (striatum (ST) and substantia nigra (SN)) and extra-nigrostriatal (hippocampus, cortex and cerebellum) tissues were analysed. Significantly decreased DA and 5-HT levels, TH, DAT and VMAT 2 expressions and increased motor deficits, anhedonia-like behaviour and α-synuclein expression were found in MPTP/p treated mice. Pre and/or post exposure of CMS to MPTP/p mice further enhanced the MPTP/p induced DA and 5-HT depletion, behaviour abnormalities and protein expressions. Our results could strongly confirm that the exposure of stress after MPTP/p injections worsens the symptoms and neurochemicals status of PD.     

The endogenous CCK mediation of electroacupuncture stimulation-induced satiety in rats

A major satiety hormone, cholecystokinin (CCK) is well known to be released by electroacupuncture (EA) stimulation at certain body sites which elicits profound psychophysiological responses. Previous clinical and animal studies have shown that EA stimulation reduces food intake and body weight in both normal and obese subjects. The aim of the present study was to elucidate the satiety effect of EA stimulation and its mechanism related to CCK in rats. Here we show that EA stimulation at "Zusanli" (ST36) acupoint significantly reduced 30-min and 60-min food intake in 48-h fasted Sprague-Dawley rats, and such effect was reversed by a lorglumide (CCK-1 receptor antagonist, 10mg/kg, i.p.) pretreatment. The ST36 EA stimulation-induced satiety was not observed in CCK-1 receptor knockout, Otsuka Long-Evans Tokushima Fatty rats, but in their controls, Long-Evans Tokushima Otsuka rats. Subdiaphragmatic vagotomy also blocked the satiety effect of ST36 EA stimulation in Sprague-Dawley rats. These results suggest that ST36 EA stimulation elicits satiety in rats and this is mediated by the endogenous CCK signaling pathway.     

Melatonin attenuates MPTP-induced neurotoxicity via preventing CDK5-mediated autophagy and SNCA/α-synuclein aggregation

Autophagy is involved in the pathogenesis of neurodegenerative diseases including Parkinson disease (PD). However, little is known about the regulation of autophagy in neurodegenerative process. In this study, we characterized aberrant activation of autophagy induced by neurotoxin 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP) and demonstrated that melatonin has a protective effect on neurotoxicity. We found an excessive activation of autophagy in monkey brain tissues and C6 cells, induced by MPTP, which is mediated by CDK5 (cyclin-dependent kinase 5). MPTP treatment significantly reduced total dendritic length and dendritic complexity of cultured primary cortical neurons and melatonin could reverse this effect. Decreased TH (tyrosine hydroxylase)-positive cells and dendrites of dopaminergic neurons in the substantia nigra pars compacta (SNc) were observed in MPTP-treated monkeys and mice. Along with decreased TH protein level, we observed an upregulation of CDK5 and enhanced autophagic activity in the striatum of mice with MPTP injection. These changes could be salvaged by melatonin treatment or knockdown of CDK5. Importantly, melatonin or knockdown of CDK5 reduced MPTP-induced SNCA/α-synuclein aggregation in mice, which is widely thought to trigger the pathogenesis of PD. Finally, melatonin or knockdown of CDK5 counteracted the PD phenotype in mice induced by MPTP. Our findings uncover a potent role of CDK5-mediated autophagy in the pathogenesis of PD, and suggest that control of autophagic pathways may provide an important clue for exploring potential target for novel therapeutics of PD.     

Gastrodin prevents motor deficits and oxidative stress in the MPTP mouse model of Parkinson's disease: Involvement of ERK1/2–Nrf2 signaling pathway

Aims

Current no effective therapy is available to halt the progression of Parkinson's disease (PD). Oxidative stress has been implicated in the etiology of PD. The present study evaluates the hypothesis that prevention of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced motor deficits by gastrodin might mainly result from its antioxidant property via interrupting extracellular signal regulated protein kinases (ERK) 1/2-nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway.

Main methods

Pretreatment of mouse model of PD is established by treating C57BL/6 mice with 4 doses of MPTP (30 mg/kg per day, i.p.), with gastrodin (60 mg/kg per day) administered by daily intraperitoneal injection for 2 weeks. Motor behavior of mice was monitored by open-field test and rotarod test. Real-time polymerase chain reaction and Western blotting were used to analyze the expression of genes.

Key findings

MPTP-induced motor deficits were partially and significantly forestalled by gastrodin. Gastrodin treatment prevented MPTP-induced oxidative stress, as measured by malondialdehyde in midbrain. Interestingly, MPTP-intoxicated mice treated with gastrodin robustly increased heme oxygenase 1, superoxide dismutase, glutathione levels, and Nrf2 nuclear translocation in striatum of MPTP-intoxicated mice. Furthermore, results herein suggest that the antioxidant pathway activated by gastrodin involves ERK1/2 phosphorylation.

Significance

Gastrodin protects midbrain of MPTP-intoxicated mice against oxidative stress, in part, through interrupting ERK1/2–Nrf2 pathway mechanism, which will give us an insight into the potential of gastrodin in terms of opening up new therapeutic avenues for PD.     

Neuroprotective activities of palmitoylethanolamide in an animal model of Parkinson's disease

The biochemical and cellular changes that occur following treatment with 1-methyl-4-phenyl-1,2,3,6-tetrahyropyridine (MPTP) are remarkably similar to that seen in idiopathic Parkinson's disease (PD). PD is characterized by the degeneration of dopaminergic nigrostriatal neurons, which results in disabling motor disturbances. Activation of glial cells and the consequent neuroinflammatory response is increasingly recognized as a prominent neuropathological feature of PD. There is currently no effective disease-modifying therapy. Targeting the signaling pathways in glial cells responsible for neuroinflammation represents a promising new therapeutic approach designed to preserve remaining neurons in PD. Chronic treatment with palmitoylethanolamide (PEA, 10 mg/kg, i.p.), initiated 24 hr after MPTP injection (20 mg/kg), protected against MPTP-induced loss of tyrosine hydroxylase positive neurons in the substantia nigra pars compacta. Treatment with PEA reduced MPTP-induced microglial activation, the number of GFAP-positive astrocytes and S100β overexpression, and protected against the alterations of microtubule-associated protein 2a,b-, dopamine transporter-, nNOS- positive cells in the substantia nigra. Furthermore, chronic PEA reversed MPTP-associated motor deficits, as revealed by the analysis of forepaw step width and percentage of faults. Genetic ablation of peroxisome proliferator activated receptor (PPAR)-α in PPAR-αKO mice exacerbated MPTP systemic toxicity, while PEA-induced neuroprotection seemed be partially PPARα-dependent. The effects of PEA on molecules typically involved in apoptotic pathways were also analyzed. Our results indicate that PEA protects against MPTP-induced neurotoxicity and the ensuing functional deficits even when administered once the insult has been initiated.     

Nei-like 1 inhibition results in motor dysfunction and promotes inflammation in Parkinson’s disease mice model

Parkinson’s disease (PD) is well known as a neurodegenerative disorder with progressive loss of dopaminergic (DA) neurons. Nei-like 1 (NEIL1) is one of four mammalian DNA glycosylases involved in the progression of various diseases, including neuroinflammation. However, it is still unknown if the expression changes of NEIL1 could contribute to PD progression. In the present study, we established mouse model with PD using 6-hydroxydopamine (6-OHDA) and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to explore the effects of NEIL1 on PD development. Here, we found that NEIL1 deletion significantly promoted the motor dysfunction in the wild type mice treated with 6-OHDA. Furthermore, DA neuronal loss was further accelerated by NEIL1 deletion in 6-OHDA-injected mice, as evidenced by the significantly reduced expression of tyrosine hydroxylase (TH) and dopamine transporter (DAT). Furthermore, in PD mice induced by MPTP, remarkably reduced expression of NEIL1 was observed in nigra and striatum of mice. A strong positive correlation was detected in the expression of NEIL1 and the survival rate of DA neurons. Also, NEIL1 ablation further elevated the DA neuronal loss in MPTP-treated mice, accompanied with higher glial activation, as evidenced by the obvious up-regulation of glial fibrillary acidic protein (GFAP) and Ionized calcium-Binding Adapter molecule 1 (Iba1). Moreover, MPTP-triggered inflammation was highly aggravated by the loss of NEIL1 through inducing the expression of pro-inflammatory cytokines and chemokines. In contrast, promoting NEIL1 expression effectively reversedPD progression induced by MPTP in mice. Together, these results demonstrated that NEIL1 insufficiency might be a contributing factor for the progression of PD, which therefore could be considered as a novel candidate to develop effective treatments against PD progression.     

Mulberry fruit ameliorates Parkinson's-disease-related pathology by reducing α-synuclein and ubiquitin levels in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine/probenecid model

Mulberry fruit, which has been long used in traditional oriental medicine, was reported to ameliorate motor dysfunction and dopaminergic neuronal degeneration via antioxidant and antiapoptotic effects in an animal model of Parkinson's disease (PD). More than 95% of PD patients exhibit nonmotor problems such as olfactory dysfunction and gastrointestinal constipation, which are generally considered to be early symptoms of PD. However, few studies have actually examined potential drugs to treat early PD symptoms. The present study examined the protective effects of mulberry fruit extract (ME) against neurotoxicity in a 1-methyl-4-phenyl 1,2,3,6-tetrahydropyridine/probenecid (MPTP/p) model of early PD. MPTP/p model was developed by systemic administration with MPTP (25 mg/kg) and probenecid (250 mg/kg) over 5 weeks. The behavioral studies showed that treatment of mice with ME significantly improved PD-related nonmotor symptoms as well as motor impairment, demonstrated by utilizing the olfactory, pole, rotarod and open field tests. In addition, immunohistochemical analysis indicated that ME exhibits the protective effects against dopaminergic neuronal damage induced by MPTP/p in the substantia nigra and striatum. Moreover, by using Western blot analysis, we found that treatment with ME inhibited the up-regulation of α-synuclein and ubiquitin, well known as composition of Lewy bodies in the substantia nigra and striatum of the MPTP/p mice. Taken together, these data suggest that ME may have therapeutic potential for preventing PD.     

100Hz电针刺受时大鼠脑和脊髓k受体结构特性的改变

西方采用放射配体结合实验研究了１００ＨＺ电针耐受发生发展过程中大鼠脑和脊髓Ｋ受体结构特性的变化。大鼠每天给予１００ＨＺ电针１次,连续７ｄ。分别在电针的第１、３、５、７天取不同脑区进行观察。