MPTP对小鼠帕金森病造模条件探讨

目的观察不同剂量1-甲基-4-苯基-1,2,3,6-四氢吡啶(MPTP)对小鼠行为学及脑黑质酪氨酸羟化酶、纹状体多巴胺含量的影响,探讨MPTP致帕金森病(Parkinson′s disease,PD)样小鼠模型的最佳条件。方法C57BL小鼠分别给与MPTP不同剂量处理,测定各组小鼠爬竿时间检测动物运动协调性,应用免疫组化方法和高效液相法观察不同模型组多巴胺能神经元的变化。结果模型组各组均出现不同程度爬竿时间延长,酪氨酸羟化酶阳性细胞数减少和多巴胺含量减少。结论MPTP处理可造成小鼠的帕金森病样症状,在此种动物模型中,应根据科研目的选择MPTP的应用剂量和给药途径。     

尼古丁对帕金森病小鼠多巴胺能神经元的保护作用

目的：观察尼古丁对多巴胺能神经元的作用并探讨其作用机制。方法：采用1-甲基-4-苯基-1,2,3,6-四氢吡啶（1-methyl-4-phenyl—1,2,3,6-tetrahydmpyridine,MPTP）小鼠模型,通过行为学方法、免疫组织化学、电镜观察尼古丁预处理对帕金森病（parkinson’s disease,PD）小鼠的影响。结果：尼古丁预处理可以明显缩短PD小鼠的爬杆时间,提高悬挂的得分。免疫组化结果显示尼古丁显著减少多巴胺（doparnine,DA）能神经元变性（P〈0．01）和γ-氨基丁酸（γ-aminobutyric acid,GABA）能神经元的脱失（P〈0．05）,并可减轻尾核超微结构的损伤。结论：尼古丁可减轻MPTP小鼠多巴胺能神经元的损伤,对多巴胺能神经元有保护作用。     

毕赤酵母表达的neurturin对恒河猴帕金森氏病模型中黑质多巴胺能神经元的保护作用

帕金森氏病(PD)是由于多巴胺能神经元变性、坏死,导致黑质-纹状体系统的多巴胺含量下降而引起的一种神经系统退行性疾病,目前还没有一种很好的方法能使之治愈.Neurturin（NTN）能特异地作用于中脑多巴胺能神经元,对该类神经元具营养和保护作用.经静脉注射1-甲基-4-苯基-1,2,3,6-四氢吡啶(MPTP)诱导恒河猴产生帕金森氏病模型,并在NTN治疗组,注射MPTP之前48 h脑室内注射重组毕赤酵母表达的人NTN 1 mg. 结果表明：模型组猴均逐渐出现了PD症状,而NTN治疗组猴,PD症状比较轻或不明显;荧光分光光度法测定MPTP模型组猴黑质、壳核和尾状核多巴胺（DA）、5-羟色胺（5-HT）和5-羟吲哚乙酸（5-HIAA）的含量结果与正常对照组相比均显著降低,NTN治疗组猴的黑质、壳核和尾状核中的DA、5-HT和5-HIAA与对照组相比无显著性差异,而与模型组相比,DA、5-HT和5-HIAA含量均明显增加;光镜检查MPTP模型组猴黑质神经元细胞明显脱失,而NTN治疗组猴黑质神经元细胞丢失不明显,与正常对照组猴无差别.上述结果表明,制备的重组人NTN在恒河猴体内能保护中脑黑质多巴胺能神经元不受MPTP的损伤,使其DA含量及多巴胺能神经元维持正常,在MPTP存在下没有发生PD症状.     

人参总皂苷在神经干细胞移植治疗帕金森模型小鼠中的体内作用

目的：观察预先给小鼠体内注射人参总皂苷（TSPG）后,对帕金森病（PD）模型的建立以及神经干细胞（NSCs）移植的影响。方法：实验分5组。1～4组常规采用1-甲基4苯基-1,2,3,6-四羟吡啶（MPTP）建立PD小鼠模型;第5组建模前体内注射TSPG,干预PD模型的建立。建模前后用行为学指标以及震颤麻痹评分标准对模型进行评判。然后取第9周人胚胎大脑皮层NSCs,经TSPG预处理后植入上述5组PD小鼠纹状体内。移植60d后脑切片,做酪氨酸羟化酶（TH）免疫组化染色检测NSCs的分化状况。结果：体内预先注射TSPG能有效降低由MVFP引起的神经细胞损伤;在神经干细胞移植后,与其余4组相比,其震颤麻痹、自发活动、记忆功能的改善更为明显,脑切片中的多巴胺（DA）能神经元数量以及与相邻神经元建立的联系更为丰富。结论：TSPG的体内用药,可以更好的降低神经系统损害。并在NSCs移植治疗PD中发挥更好的作用。     

环加氧酶-2对帕金森病小鼠黑质多巴胺能神经元的影响

目的和方法 :选用C5 7BL种系环加氧酶 2 (cyclooxygenase 2 ,COX 2 )缺陷小鼠 ,腹腔注射 1 甲基 4 苯基 1,2 ,3,6 四氢吡啶 (MPTP)制备帕金森病小鼠模型 ,用免疫组织化学方法观察COX 2对帕金森病小鼠黑质多巴胺能神经元的影响。结果 :行为学及免疫组织化学观察显示 ,野生型帕金森病小鼠的死亡率明显高于COX 2缺陷杂合子帕金森病小鼠 (P <0 .0 1) ,野生型帕金森病小鼠黑质致密部酪氨酸羟化酶 (tyrosinehydroxylase,TH)免疫反应阳性神经元数目较杂合子帕金森病小鼠明显减少 (P <0 .0 1)。结论 :COX 2可能与帕金森病时黑质多巴胺能神经元的损伤有关     

脂多糖联合MPTP诱导的小鼠慢性帕金森病模型的评价

目的建立脂多糖(lipopolysaccharide,LPS)联合1-甲基-4-苯基-1,2,3,6-四氢吡啶(1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine,MPTP)诱导的慢性小鼠帕金森病模型,探讨其行为学和黒质多巴胺能神经元细胞的变化情况。方法将20只C57BL/6小鼠随机分为模型组和对照组,模型组每日腹腔注射LPS(0.25 mg/kg)一次,连续3 d,最后一次注射LPS 4 h后,每日腹腔注射MPTP(25 mg/kg)一次,连续2 d,对照组腹腔注射相同量的生理盐水。8周后用步态分析和转棒实验评价小鼠的行为学能力,免疫组化法观察黑质酪氨酸羟化酶(TH)阳性细胞变化情况。结果模型组小鼠行为学变化较对照组差异有显著性(P0.05),模型组小鼠中脑黒质区显示出严重的神经元细胞损伤。结论 LPS联合MPTP腹腔注射可成功诱导出慢性小鼠帕金森病模型,提示该模型可用于帕金森病的发病机制及药物治疗效果等相关研究。     

星形胶质细胞在MPTP帕金森小鼠脑内的变化研究

目的：研究神经毒素1-甲基-4-苯基-1,2,3,6-四氢吡啶（1-methy-4-phenyl-1,2,3,6-tetrahy-dropyridine,MPTP）对小鼠脑内星形胶质细胞及肿瘤坏死因子-α（Tunlomecrosis factor alpha,TNF-α）的影响,了解MPTP致帕金森病发病机制。方法：将神经毒素MPTP注入C57BL／6小鼠腹腔内,制备帕金森病动物模型。观察注药后小鼠行为学变化,免疫组化检测各时间点多巴胺能神经元缺失和星形胶质细胞增生与激活情况,以及TNF-α表达水平的变化。结果：MPTP组黑质多巴胺（dopamine,DA）能神经元的数量随注射天数增加而持续减少,星形胶质细胞数量明显增高,GFAP及TNF-α在模型组黑质内有中强阳性表达,与对照组相比差异有统计学意义（P〈0．05）。结论：MPTP可诱导星形胶质细胞的激活和增生,启动脑内炎症反应而介导DA神经元死亡。     

低分子肝素对MPTP帕金森小鼠的治疗作用及可能机制

目的：研究1．甲基4-苯基-1,2,3,6-四氢吡啶（1-methy-4-phenyl-1,2,3,6-tetrahy-dropyridine,MPTP）帕金森病（PD）模型中小胶质细胞的激活情况,探讨低分子肝素对MPTP导致的小胶质细胞活化的抑制作用。方法：C57BL随机分成正常对照组、MPTP组、低分子肝素＋MPTP组。MPTP组腹腔注射MPTP（30mg／kgx7d）同时腹部皮下注射生理盐水,低分子肝素＋MPTP组在注射MPTP同时腹部皮下注射低分子肝素（1501U／kg·12hx7d）。各组于末次给药后予行为学测试,7d后免疫组化检测酪氨酸羟化酶（TyrosineHydroxylase,TH）阳性细胞。镀银染色观察小胶质细胞激活情况。结果：MPTP组较低分子肝素＋MPTP组爬竿时间明显延长,并出现更多非随意动作。低分子肝素＋MPTP组黑质部位TH阳性细胞数量高于MPTP组。MPTP组活化的小胶质细胞数量高于低分子肝素＋MPTP组。结论：低分子肝素通过抑制小胶质细胞的激活减少MPTP帕金森小鼠多巴胺能神经元的损伤,提示低分子肝素可能有延缓PD进程的作用。     

多巴胺能神经细胞损伤过程中NCAM-140的表达变化

目的:检测NCAM.140在多巴胺能神经细胞损伤过程中中脑黑质部位的表达变化,探索其在多巴胺能神经细胞损伤中的可能作用.方法:采用MPTP腹腔注射建立小鼠中脑黑质多巴胺能神经细胞慢性损伤模型,采用免疫荧光染色和westernblotting检测中脑黑质部酪氨酸羟化酶(TH)和NCAM-140的表达情况.结果:在小鼠中脑黑质一直有NCAM-140阳性细胞存在,且与TH阳性细胞共表达;TH在给予MPTP后第三周表达开始降低,NCAM-140在给予MPTP后第一周至第三周持续高表达,并且从第四周开始,其表达量明显降低.结论:NCAM-140的表达与多巴胺能神经细胞损伤有关.     

AAV介导的α-synuclein基因过表达致多巴胺能神经元损伤-一种制作轻度帕金森病大鼠模型的新方法

目的：研究过表达α-synuclein基因是否导致大鼠黑质纹状体选择性损伤,为帕金森病（parkinson’s disease, PD）大鼠模型的制备提供一种新的方法。方法:用腺相关病毒(adeno-associated virus, AAV)做载体,将人野生型α突触核蛋白(α-synuclein, NACP)引入大鼠脑内,观察大鼠行为学的改变,通过免疫组织化学染色观察其对黑质多巴胺能神经元细胞的影响,高效液相色谱（HPLC）检测纹状体多巴胺（DA）的含量。结果:α-synuclein基因过表达后大鼠出现自发性活动减少、爬行活动减慢、暂时性躯干震颤、竖毛等类似PD初期的症状和体征;大鼠脑黑质TH阳性神经元细胞随时间的延长出现数目减少,并且纹状体DA含量也出现减少,并且出现α-synuclein的积聚。结论:上述结果表明α-synuclein基因的过表达引起黑质多巴胺能神经元细胞的死亡,对大鼠的运动行为有一定的影响,产生类似于PD早期的症状与体征,与化学毒素（如6-OHDA, MPTP）诱导的动物模型相比,此法制作的动物模型可模拟PD缓慢发展的进程,为研究PD的病程进展及发病机制提供一个理想的动物模型。     

Celastrol protects against MPTP- and 3-nitropropionic acid-induced neurotoxicity

Oxidative stress and inflammation are implicated in neurodegenerative diseases including Parkinson's disease (PD) and Huntington's disease (HD). Celastrol is a potent anti-inflammatory and antioxidant compound extracted from a perennial creeping plant belonging to the Celastraceae family. Celastrol is known to prevent the production of proinflammatory cytokines, inducible nitric oxide synthase and lipid peroxidation. Mice were treated with celastrol before and after injections of MPTP, a dopaminergic neurotoxin, which produces a model of PD. A 48% loss of dopaminergic neurons induced by MPTP in the substantia nigra pars compacta was significantly attenuated by celastrol treatment. Moreover, celastrol treatment significantly reduced the depletion in dopamine concentration induced by MPTP. Similarly, celastrol significantly decreased the striatal lesion volume induced by 3-nitropropionic acid, a neurotoxin used to model HD in rats. Celastrol induced heat shock protein 70 within dopaminergic neurons and decreased tumor necrosis factor-alpha and nuclear factor kappa B immunostainings as well as astrogliosis. Celastrol is therefore a promising neuroprotective agent for the treatment of PD and HD.     

Increased vulnerability of dopaminergic neurons in MPTP-lesioned interleukin-6 deficient mice

To test the hypothesis that neuroinflammation contributes to dopaminergic neuron death in the MPTP-lesioned mouse, we compared nigrostriatal degeneration in interleukin (IL)-6 (+/+) with IL-6 (-/-) mice. In the absence of IL-6, a single injection of MPTP (30 mg/kg) resulted in significantly greater striatal dopamine depletion than that measured in IL-6 (+/+) mice. The observed dopamine depletion was MPTP dose dependent. This loss of striatal dopamine and a significantly greater loss of TH+ cells in the substantia nigra pars compacta in IL-6 (-/-) mice as compared with control IL-6 (+/+) mice, suggest that IL-6 is neuroprotective in the MPTP-lesioned nigrostriatal system. Co-localization experiments identified striatal astrocytes as the source of IL-6 in IL-6 (+/+) mice at 1 and 7 days postinjection of MPTP. The increased sensitivity of dopaminergic neurons to neurotoxicant in the absence of IL-6, is compatible with a neuroprotective activity of IL-6 in the injured nigrostriatal system.     

The effects of docosahexaenoic acid on glial derived neurotrophic factor and neurturin in bilateral rat model of Parkinson's disease

Parkinson's disease (PD) is the second most common neurodegenerative disorder marked by cell death in the Substantia nigra (SN). Docosahexaenoic acid (DHA) is the major polyunsaturated fatty acid (PUFA) in the phospholipid fraction of the brain and is required for normal cellular function. Glial cell line derived neurotrophic factor (GDNF) and neurturin (NTN) are very potent trophic factors for PD. The aim of the study was to evaluate the neuroprotective effects of GDNF and NTN by investigating their immunostaining levels after administration of DHA in a model of PD. For this reason we hypothesized that DHA administration of PD might alter GDNF, NTN expression in SN. MPTP neurotoxin that induces dopaminergic neurodegeneration was used to create the experimental Parkinsonism model. Rats were divided into; control, DHA-treated (DHA), MPTP-induced (MPTP), MPTP-induced+DHA-treated (MPTP+DHA) groups. Dopaminergic neuron numbers were clearly decreased in MPTP, but showed an increase in MPTP+DHA group. As a result of this, DHA administration protected dopaminergic neurons as shown by tyrosine hydroxylase immunohistochemistry. In the MPTP+DHA group, GDNF, NTN immunoreactions in dopaminergic neurons were higher than that of the MPTP group. In conclusion, the characterization of GDNF and NTN will certainly help elucidate the mechanism of DHA action, and lead to better strategies for the use of DHA to treat neurodegenerative diseases.     

Preventive role of PD‐1 on MPTP‐induced dopamine depletion in mice

Many current studies of Parkinson's disease (PD) suggest that inflammation is involved in the neurodegenerative process. PD‐1, a traditional Korean medicine, used to treat various brain diseases in Korea. This study was designed to investigate the effect of PD‐1 extract in the Parkinson's model of 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP) lesioned mice. The MPTP administration caused the dopamine neuron loss in the striatum and substantia nigra pars compacta (SNpc), which was demonstrated by a depletion of tyrosine hydroxylase (TH). In addition, a reduction of bcl‐2 expression with elevation of bax expression, caspase‐3 activation, and release of cytochrome c into cytosol in dopaminergic neurons of SNpc were noted. Oral administration of PD‐1 extract (50 and 100 mg kg^?1) attenuated the MPTP‐induced depletion of TH proteins in the striatum and SNpc and prevented the apoptotic effects. These results indicate that PD‐1 extract is able to protect dopaminergic neurons from MPTP‐induced neuronal death, with important implications for the treatment of PD. Copyright © 2010 John Wiley & Sons, Ltd.     

MPTP as a Mitochondrial Neurotoxic Model of Parkinson's Disease

1-Methy-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is a potent neurotoxin extensively used to model Parkinson's disease (PD). A cascade of deleterous events, in which mitochondria play a pivotal role, drives MPTP neurotoxicity. How mitochondria are affected by MPTP and how their defect contributes to the demise of dopaminergic neurons in this model of PD are discussed in this review.     

PET imaging a MPTP-induced mouse model of Parkinson's disease using the fluoropropyl-dihydrotetrabenazine analog [18F]-DTBZ (AV-133)

Parkinson's disease (PD) is characterized by the loss of dopamine-producing neurons in the nigrostriatal system. Numerous researchers in the past have attempted to track the progression of dopaminergic depletion in PD. We applied a quantitative non-invasive PET imaging technique to follow this degeneration process in an MPTP-induced mouse model of PD. The VMAT2 ligand (18)F-DTBZ (AV-133) was used as a radioactive tracer in our imaging experiments to monitor the changes of the dopaminergic system. Intraperitoneal administrations of MPTP (a neurotoxin) were delivered to mice at regular intervals to induce lesions consistent with PD. Our results indicate a significant decline in the levels of striatal dopamine and its metabolites (DOPAC and HVA) following MPTP treatment as determined by HPLC method. Images obtained by positron emission tomography revealed uptake of (18)F-DTBZ analog in the mouse striatum. However, reduction in radioligand binding was evident in the striatum of MPTP lesioned animals as compared with the control group. Immunohistochemical analysis further confirmed PET imaging results and indicated the progressive loss of dopaminergic neurons in treated animals compared with the control counterparts. In conclusion, our findings suggest that MPTP induced PD in mouse model is appropriate to follow the degeneration of dopaminergic system and that (18)F-DTBZ analog is a potentially sensitive radiotracer that can used to diagnose changes associated with PD by PET imaging modality.     

Reduced MPTP toxicity in noradrenaline transporter knockout mice

The noradrenergic neurons of the locus coeruleus (LC) are damaged in Parkinson's disease (PD). Neurotoxin ablation of the LC noradrenergic neurons has been shown to exacerbate the dopaminergic toxicity of MPTP, suggesting that the noradrenergic system protects dopamine neurons. We utilized mice that exhibit elevated synaptic noradrenaline (NA) by genetically deleting the noradrenaline transporter (NET), a key regulator of the noradrenergic system (NET KO mice). NET KO and wild-type littermates were administered MPTP and striatal dopamine terminal integrity was assessed by HPLC of monoamines, immmunoblotting for dopaminergic markers and tyrosine hydroxylase (TH) immunohistochemistry. MPTP significantly reduced striatal dopamine in wild-type mice, but not in the NET KO mice. To confirm that the protection observed in the NET KO mice was due to the lack of NET, we treated wild-type mice with the specific NET inhibitor, nisoxetine, and then challenged them with MPTP. Nisoxetine conferred protection to the dopaminergic system. These data indicate that NA can modulate MPTP toxicity and suggest that manipulation of the noradrenergic system may have therapeutic value in PD.     

Glycine nano-selenium prevents brain oxidative stress and neurobehavioral abnormalities caused by MPTP in rats

BackgroundParkinson's disease (PD) is a common degenerative disease of the central nervous system in the elderly. In recent years, the results of clinical and experimental studies have shown that oxidative stress is one of the important pathogenesis of PD. Selenium is one of the minor elements reported to possess antioxidant properties. Thus, the purpose of this study was to investigate the recovery effect of glycine nano-selenium on neurobehavioral abnormalities and oxidative stress caused by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) in rat.Materials and methodsSD male rats weighing 280−310 g were purchased from the Chengdu Dossy Experimental Animals Company, China. All rats were housed in a temperature-controlled room, with a 12 h light–dark cycles and had free access to food and water ad libitum. Rats were randomly divided into 4 groups with 8 animals in each group: the control group (normal saline), 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine group (MPTP), MPTP + 0.05 mg/kg glycine nano-selenium (MPTP + 0.05 Se), MPTP + 0.1 mg/kg glycine nano-selenium (MPTP + 0.1 Se). Behavioral assessment, clinical symptoms, Immunohistochemistry analysis of tyrosine hydroxylase (TH) and antioxidant activity were accessed to determine the protective effects glycine nano-selenium have on PD rats.ResultsFrom the results, Rats showed a decrease in spontaneous motor behavior and an increase in pole test score. Also, the number of TH⁺ neurons were also significantly decreased (P < 0.05) after treated with MPTP for 7 days indicating that MPTP could successfully induce neurobehavioral abnormalities in rats. Furthermore, the lipid peroxide (MDA) levels of the PD model group were significantly increased and the antioxidant activities (SOD and GSH-PX) were significantly inhibited (P < 0.05) compared to the control group indicating the important role oxidative stress played in dopaminergic neuron death and neurobehavioral abnormalities in PD rats. Compared with the PD model group, glycine nano-selenium administration could significantly improve behavior and increase the number of TH⁺ neurons (P < 0.05) to protect against the loss of dopaminergic neurons. At the same time, glycine nano-selenium could decrease the MDA levels and increase the activities of SOD and GSH-PX significantly (P < 0.05).ConclusionIn conclusion, PD rat model was successfully developed by intraperitoneal injection of MPTP and the intragastric administration of glycine nano-selenium reduced neurobehavioral abnormalities by decreasing oxidative stress in rat brain.     

The antioxidative effect of electro-acupuncture in a mouse model of Parkinson's disease

Accumulating evidence indicates that oxidative stress plays a critical role in Parkinson's disease (PD). Our previous work has shown that 100 Hz electro-acupuncture (EA) stimulation at ZUSANLI (ST36) and SANYINJIAO (SP6) protects neurons in the substantia nigra pars compacta from 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) toxicity in male C57BL/6 mice, a model of PD. In the present study we administered 100 Hz EA stimulation at the two acupoints to MPTP-lesioned mice for 12 sessions starting from the day prior to the first MPTP injection. We found that in the striatum of MPTP treated mice 100 Hz EA stimulation effectively inhibited the production of hydrogen peroxide and malonaldehyde, and increased glutathione concentration and total superoxide dismutase activity through biochemical methods. However, it decreased glutathione peroxidase activity via biochemical analysis and did not affect the level of 1-methyl-4-phenylpyridinium in the striatum revealed by high performance liquid chromatography with ultraviolet detection. These data suggest that 100 Hz EA stimulation at ST36 and SP6 has antioxidative effects in the MPTP model of PD. This data, along with our previous work, indicates that 100 Hz EA stimulation at ST36 and SP6 protects the nigrostriatal system by multiple mechanisms including antioxidation and antiapoptosis, and suggests that EA stimulation is a promising therapy for treating PD.