氯化锂对PD小鼠黑质多巴胺能神经元保护作用的实验研究

目的研究氯化锂(LiCL)对KM小鼠中脑黑质受损伤的多巴胺能神经元的保护作用。方法利用1-甲基4-苯基1,2,3,6四氢吡啶(MPTP)腹腔注射以损伤小鼠中脑黑质多巴胺(DA)能神经元,再将实验动物分实验组,腹腔注射氯化锂;实验对照组,腹腔注射PBS;和空白对照组(MPTP注射后不再注射其他物质)。动物存活一周后,一部分取其中脑黑质节段,固定、包埋做连续冠状石蜡切片,以免疫组织化学染色方法,显示各组酪氨酸羟化酶(TH)和钙结合蛋白(CB)表达阳性细胞,光镜观察并细胞计数,统计学分析;另一部分取其中脑黑质组织匀浆,行TH、CB的Westernblot测量,用Labworks软件分析处理。结果免疫组织化学染色结果显示:实验组小鼠黑质致密部TH与CB阳性神经元数量显著多于实验对照组;Westernblot免疫印迹结果显示:实验组TH、CB蛋白含量表达水平显著多于实验对照组。结论氯化锂对成年PD小鼠黑质多巴胺能神经元具有保护作用,且这种保护作用可能与细胞内CB表达增加有关。     

帕金森病小鼠黑质多巴胺能神经元凋亡规律的实验研究

目的:探讨MPTP诱导小鼠黑质多巴胺能神经元凋亡的规律。方法:采用慢性MPTP处理(30mg/kg/d×7)的模式,建立小鼠帕金森病模型;应用酪氨酸羟化酶(TH)免疫组织化学染色和TUNEL染色,观察黑质多巴胺能神经元数目改变和凋亡情况。结果:慢性MPTP处理过程中,小鼠黑质TH阳性细胞数逐渐减少;于MPTP注射第3天开始出现凋亡细胞,第8天达到高峰。结论:采用慢性MPTP处理的模式,可诱导小鼠黑质神经元凋亡;在这类模型中,细胞凋亡是MPTP发挥神经损害效应的主要形式。     

MPTP致帕金森病小鼠黑质钙结合蛋白表达变化及氯化锂对其影响

目的观察氯化锂(LiCl)对1-甲基4-苯基-1,2,3,6四氢吡啶(MPTP)致帕金森病(PD)小鼠模型钙结合蛋白D28K(CaBP)表达及保护作用的可能机制。方法实验小鼠随机分为正常对照(NS)组、MPTP组、LiCl组,采用腹腔注射MPTP制备模型,免疫组化与蛋白印迹技术观察中脑黑质CaBP表达的变化,以自主活动、滚轴、游泳实验对各组神经行为学评分。结果 MPTP组自主活动、滚轴、游泳评分均低于正常对照组,MPTP组CaBP阳性细胞数比正常对照组少,MPTP组CaBP蛋白表达较对照组表达少(P0.05)。与MPTP组比较,LiC l组各行为学指标明显改善,CaBP阳性细胞数与蛋白表达均升高(P0.05)。结论 LiCl可增加CaBP的表达,减轻细胞内钙超载,是其保护PD损伤的机制之一。     

咪多吡拮抗MPTP诱致小鼠黑质神经元凋亡的实验研究

目的探讨MPTP和MPP     

衰老对帕金森病模型小鼠线粒体复合物活性的影响

目的探讨衰老对帕金森病(PD)模型小鼠线粒体复合物的影响。方法选用8个月龄、16个月龄雌性C57BL/6小鼠,随机分为8个月龄对照组、8个月龄模型组、16个月龄对照组及16个月龄模型组。模型组小鼠皮下注射1-甲基-4-苯基-1,2,3,6-四氢吡啶(MPTP)制成PD模型,对照组注射等量生理盐水;进行行为学测试,并检测其黑质多巴胺含量,采用紫外分光光度法检测线粒体复合物Ⅰ~Ⅳ的活性。结果与对照组相比,模型组小鼠行为学异常,黑质多巴胺含量显著下降(P<0.05),线粒体复合物Ⅰ的活性明显低于对照组(P<0.05);与8个月龄PD小鼠相比,16个月龄小鼠行为学成绩、多巴胺含量及线粒体复合物Ⅰ的活性降低更明显(P<0.05)。各组线粒体复合物Ⅱ、Ⅲ、Ⅳ无显著差异。结论小鼠黑质纹状体系统线粒体复合物Ⅰ功能障碍可能是导致PD发生的重要原因之一,衰老可加速其功能障碍。     

PDTC对MPTP帕金森病鼠黑质NF-κB表达的影响

目的研究二硫代氨基甲酸吡咯烷(PDTC)对1-甲基-4-苯基-1,2,3,6-四氢吡啶(MPTP)帕金森病(PD)鼠黑质核因子-κB(NF-κB)表达的影响。方法实验组C57/BL小鼠按体重30 mg/(kg.d)经腹腔注射MPTP共7 d制成PD模型,预防组小鼠按体重40 mg/(kg.d)经腹腔注射PDTC半小时后再经腹腔注射MPTP。观察两组小鼠注射前后行为变化,并采用SABC法检测注射后黑质部NF-κB及酪氨酸羟化酶(TH)的表达情况。结果实验组小鼠表现出PD的典型症状,预防组则无异常行为表现。实验组小鼠黑质部NF-κB阳性表达较预防组显著,并有明显核易位现象,TH阳性神经元显著减少(均P<0.01)。结论NF-κB参与了MPTP PD鼠发病过程,黑质中NF-κB过度激活是MPTP对小鼠造成损害作用的机制之一。预先使用PDTC对MPTP PD鼠起到一定神经保护作用。     

皮下注射MPTP诱导猕猴双侧慢性帕金森病模型的制作

目的探讨猕猴双侧慢性不可逆性帕金森病（PD）模型的制作方法。方法 4只猕猴分别采用不同剂量（0.1 mg/kg/d和0.4 mg/kg/d）和不同频率（每天一次和隔天一次）及不同次数皮下注射1-甲基-4-苯基-1,2,3,6-四氢吡啶（MPTP）制作PD模型,注射MPTP前后观察行为学表现并进行非人类灵长类PD评分量表（PPRS）评分。结果猕猴注射MPTP一段时间后开始出现PD症状,主要表现为倦怠、迟缓;继续给药PD症状会出现进行性快速加重导致后续动物因进食困难而死亡;若过早停止给药,则导致PD模型不稳定,动物症状可自愈。采用剂量为0.1 mg/kg/d的MPTP连续皮下注射14 d后,猕猴出现中度PD症状（PPRS评分为6~8分）时,改隔日注射一次,共4次,猕猴出现不可逆性PD症状,且可自主摄食并长期存活,是一个成功的模型。结论适量皮下注射MPTP可制作猕猴慢性、不可逆性、双侧PD模型,其更接近人PD的临床特征,且无需鼻饲喂养可长期存活。     

白藜芦醇通过SIRT1/AMPK信号通路减轻MPTP诱导的小鼠多巴胺能神经元丢失

目的观察白藜芦醇(RV)对帕金森病(PD)小鼠的神经保护作用,并探索其发挥神经保护作用的可能机制。方法将48只小鼠随机分为CON组、MPTP组、RV+MPTP组和EX527+RV+MPTP组,每组12只。腹腔注射MPTP建立PD小鼠模型,并给予RV灌胃、SIRT1特异性抑制剂EX257腹腔注射处理,利用免疫荧光、western blot等检测相关蛋白表达。结果给予RV后,与MPTP组相比,RV+MPTP组SIRT1蛋白表达显著增加(P0.001),p-AMPK蛋白水平显著升高(P0.01),Cleaved caspase 3蛋白水平显著下降(P0.01),小鼠黑质区TH阳性神经元丢失率明显降低,纹状体组织中TH蛋白表达显著增加(P0.01)。给予EX527后,阻断了RV的上述作用,p-AMPK蛋白水平显著降低(P0.01),Cleaved caspase 3显著升高(P0.01),小鼠黑质区TH阳性神经元丢失率明显升高,纹状体组织中TH蛋白表达显著下降(P0.001)。结论 RV可能通过激活SIRT1/AMPK信号通路,SIRT1与AMPK相互调控,减少MPTP小鼠黑质区多巴胺能神经元丢失。     

茶多酚对MPTP-帕金森病模型小鼠多巴胺神经元保护作用的免疫组化分析

目的探讨茶多酚对1-甲基-4-苯基-1,2,3,6-四氢吡啶(MPTP)致帕金森病模型小鼠多巴胺能神经元的保护作用。方法40只小鼠分为4组,A组为生理盐水(NS) 生理盐水(NS),B组为NS 茶多酚(TPGs)组,C组(模型组)为NS MPTP组,D组(治疗组)为TPGs MPTP组,其中D组又分为D1组(10mg/kg)及D2(50mg/kg)组,在注射TPGs后1/2h注射MPTP×3次,通过给C57BL小鼠腹腔注射MPTP制作帕金森病(parkinsin disease,PD)模型,腹腔注射茶多酚后,应用免疫组织化学方法测定TH阳性细胞数。结果A组TH阳性细胞最高,B组与A组差异无统计学意义;C组最低,与A组比较有显著差异(P<0.05);D组与C组相比TH阳性细胞数增加,比较有显著差异(P<0.05)。结论TPGs对MPTP诱发的PD模型小鼠黑质多巴胺神经元有明显的保护作用。     

Neuroprotection of MPTP-induced toxicity in zebrafish dopaminergic neurons

Parkinson's disease is characterized by a severe loss of dopaminergic neurons resulting in a range of motor deficits. The neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is known to cause a similar loss of dopaminergic neurons in the human midbrain with corresponding Parkinsonian symptoms. Several animal species have also shown sensitivity to MPTP, including primates, mice, goldfish, and, most recently, zebrafish. This study demonstrates that the effect of MPTP on dopaminergic neurons in zebrafish larvae is mediated by the same pathways that have been demonstrated in mammalian species. MPTP-induced neurodegeneration was prevented by co-incubation with either the monoamine oxidase-B (MAO-B) inhibitor l-deprenyl or the dopamine transporter (DAT) inhibitor nomifensine. Furthermore, targeted inactivation of the DAT gene by antisense morpholinos also protected neurons from MPTP damage. Thus, the mechanism for MPTP-induced dopaminergic neuron toxicity in mammals is conserved in zebrafish larvae. Effects on swimming behavior and touch response that result from MPTP damage are partially ameliorated by both l-deprenyl and DAT knockdown.     

Nicotine, but not cotinine, partially protects dopaminergic neurons against MPTP-induced degeneration in mice

In order to analyze the putative neuroprotective role of nicotine and cotinine in parkinsonian syndromes, these two compounds were administered in male C57Bl6 mice for 4 weeks. On day 8, four injections of 1-methyl-4-phenyl-1,2,3,6,-tetrahydropyridine (MPTP) were administered. MPTP intoxication induced a 50% loss of dopaminergic neurons in the substantia nigra and a 45% reduction in dopaminergic fibers in the striatum. Administration of cotinine did not affect MPTP toxicity in the nigrostriatal system but chronic nicotine treatment showed a slight protection (15%) of nigrostriatal dopaminergic neurons against MPTP.     

共聚物-1对帕金森病模型小鼠多巴胺能神经元的保护作用

目的探讨共聚物-1(Cop-1)免疫或致敏淋巴细胞移植对帕金森病模型小鼠黑质多巴胺(DA)神经元的保护作用。方法选用雄性C57BL/6J小鼠随机分为Cop-1/BSA免疫组、Cop-1/BSA致敏淋巴细胞移植组、MPTP模型组和正常对照组。Cop-1/BSA免疫组在注射MPTP之前10天接受Cop-1/BSA抗原免疫;Cop-1/BSA致敏淋巴细胞移植组动物在MPTP末次注射后,立即接受Cop-1/BSA致敏淋巴细胞移植;MPTP模型组动物仅接受MPTP注射;正常对照组动物仅接受生理盐水注射。MPTP末次注射7天后处死动物,取脑。酪氨酸羟化酶免疫组化及体视学方法定量分析黑质DA神经元数。结果 MPTP注射显著地减少了模型动物黑质DA神经元数量。Cop-1免疫和Cop-1致敏淋巴细胞移植明显增加了MPTP模型动物黑质DA神经元数,对黑质DA神经元有保护作用。BSA免疫或BSA致敏淋巴细胞移植则没有表现出这种保护作用。结论在C57BL/6J小鼠,Cop-1免疫和Cop-1致敏淋巴细胞移植可有效对抗MPTP毒性,保护黑质DA神经元。     

Neuroimmunophilin ligands exert neuroregeneration and neuroprotection in midbrain dopaminergic neurons

Immunosuppressant drugs, like FK506, and nonimmunosuppressant compounds like, GPI1046 and L685818, are immunophilin ligands that specifically bind to immunophilins, like FK506 binding protein 12 (FKBP12). Several lines of evidence show that these ligands exert neurotrophic properties in neural injury models and in PC12 cells. However, the mechanism of the neurotrophic function of the immunophilin ligands is poorly known. In the present study, we use MPP+ and 6-OHDA toxicity models to examine both neuroprotective and neuroregenerative effects of immunophilin ligands on primary cultures of midbrain dopaminergic neurons. We find that FK506, GPI1046 and L685818 at concentrations from 0.01 to 1 microM partially, but significantly, protect dopaminergic neurons against both MPP+ and 6-OHDA toxicity. By Western blot analysis, we also find that all three compounds prevent tyrosine hydroxylase (TH) loss induced by MPP+ and 6-OHDA treatments. Morphologic analysis of dopaminergic neurons, by immunocytochemistry, shows that MPP+ and 6-OHDA cause the retraction and loss of neuronal processes, while FK506, GPI1046 and L685818 promote regeneration of these processes as indicated by increases in process number and length. To examine if FKBP12 is required for neurotrophic effects of immunophilin ligands, we cultured dopaminergic neurons from FKBP12 knockout mice and find that FK506 still protects dopaminergic neurons against MPP+ toxicity. These results suggest that FKBP12 is not essential for the neurotrophic properties of immunophilin ligands, and immunophilin ligands are a new class of neuroprotective and neuroregenerative agents that may have therapeutic potential in a variety of neurological disorders.     

川芎嗪对MPTP所致小鼠多巴胺能神经元损伤的保护作用及机制

目的 探讨川芎嗪对MPTP所致小鼠多巴胺能神经元损伤的保护作用及可能机制.方法 C57BL/6J雄性小鼠32只,随机分为4组:生理盐水对照组(NS+NS)、生理盐水组(NS+MPTP)、川芎嗪高剂量组(LT50+MPTP)、川芎嗪低剂量组(LT20+MPTP),每组8只动物.分别采用HPLC法检测纹状体中DA的含量,免疫组化检测黑质中TH阳性细胞数,荧光显色法检测黑质SOD活力、GSH含量.结果 LT50+MPTP组纹状体DA含量、黑质DA神经元数量、黑质SOD活力、黑质GSH含量较NS+MPTP组显著增高(P<0.01).结论 川芎嗪对对MPTP所致的小鼠多巴胺能神经元损伤具有保护作用,其保护机制可能与其调节调节小鼠黑质中的SOD、GSH含量有关.

Abstract：

Objective To investigate the neuroprotective effects and mechanisms of ligustrazine on the MPTP-in-duced dopaminergic neurodegeneration in a mouse model of PD. Methods Male C57BL/6J mice were randomly divided into following four treatment groups ( n = 8/group) : ( 1 ) the saline control group ( NS + NS), mice pretreated with saline followed by saline treatment;(2) the mice pre-treated with saline followed by saline treatment (NS + MPTP) ; (3) the mice pretreated with 50mg/kg of ligustrazine followed by MPTP treatment (LT50 + MPTP) ;(4) the mice pretreated with 20mg/kg of ligustrazine followed by MPTP ( LT20 + MPTP). HPLC,immunohistochemistry and fluorimetry were used. Results The residual DA contents, TH-IR positive cells, SOD activity and GSH content in the mice pretreated with 50mg/kg ligustrazine ( LT50 + MPTP) were significantly higher than those of the saline-pretreatd mice ( NS + MPTP) ( P < 0.01 ).Conclusions Ligustrazine ameliorated MPTP-induced dopaminergic neurodegeneration in mice. The neuroprotective effect of ligustrazine may be associated with their strong antioxidant capacity in vivo.     

美满霉素对脂多糖诱导帕金森病模型多巴胺能神经元保护作用的研究

目的 探讨美满霉素(Mino)对脂多糖(LPS)诱导小胶质细胞(Mic)激活的抑制作用和对黑质多巴胺能神经元的保护作用.方法 20只雄性SD大鼠随机分为单纯LPS干预组和LPS+Mino干预组,并设5只作为生理盐水注射对照组,于不同时间点观察大鼠行为学改变,并采用免疫组织化学、原位杂交、Western-blot等方法观察Mic的激活情况以及酪氨酸羟化酶(TH)神经元、mRNA、蛋白的表达水平.结果 LPS+Mino干预组在LPS诱导后7、14 d的旋转次数均较单纯LPS干预组明显减少;两组均以激活型Mic为主,LPS+Mino组"阿米巴样"Mic数目较单纯LPS组明显减少,尚存有少许"分支样"Mic;LPS术后2组术侧中脑OX-42蛋白水平较生理盐水注射对照组均明显增高,LPS+Mino组(0.91±0.04)增加水平明显低于单纯LPS组(1.03±0.03,P＜0.01);2组术侧中脑TH阳性神经元数量、mRNA、蛋白水平均较生理盐水注射对照组明显下降,单纯LPS组(21.5±4.9,39.9±7.0,0.42±0.03)下降水平显著高于LPS+Mino组(53.4±8.4,65.1±9.1,0.63±0.04;P＜0.01).结论 Mino的干预可显著抑制LPS诱导的Mic激活,减轻LPS对黑质多巴胺能神经元的毒性作用,并延缓PD模型的病情进展.     

Superoxide dismutase overexpression protects dopaminergic neurons in a Drosophila model of Parkinson's disease

Parkinson's disease (PD) is characterized by the progressive loss of dopaminergic neurons in the substantia nigra pars compacta. Some of the inherited forms of the disease are caused by mutations in the alpha-synuclein gene and the triplication of its locus. Oxidative stress has been proposed as a central mechanism for the progression of the disease although its relation with alpha-synuclein toxicity remains obscure. Targeted expression of human alpha-synuclein has been effectively used to recreate the pathology of PD in Drosophila melanogaster and it has been proved an excellent tool for the study of testable hypothesis in relation to the disease. We show that dopaminergic neurons are specifically sensitive to hyperoxia induced oxidative stress and that mutant forms of alpha-synuclein show an enhanced toxicity under these conditions suggesting synergic interactions. In addition, the co-expression of Cu/Zn superoxid dismutase protects against the dopaminergic neuronal loss induced by mutant alpha-synuclein overexpression thus identifying oxidative stress as an important causative factor in the pathology of autosomal-dominant Parkinsonism.     

Chinese herbs and herbal extracts for neuroprotection of dopaminergic neurons and potential therapeutic treatment of Parkinson's disease

Parkinson's disease (PD) is a common and debilitating degenerative disease resulting from massive degenerative loss of dopamine neurons, particularly in the substantia nigra. The most classic therapy for PD is levodopa administration, but the efficacy of levodopa treatment declines as the disease progresses. The neuroprotective strategies to rescue nigral dopamine neurons from progressive death are currently being explored, and among them, the Chinese herbs and herbal extracts have shown potential clinical benefit in attenuating the progression of PD in human beings. Growing studies have indicated that a range of Chinese herbs or herbal extracts such as green tea polyphenols or catechins, panax ginseng and ginsenoside, ginkgo biloba and EGb 761, polygonum, triptolide from tripterygium wilfordii hook, polysaccharides from the flowers of nerium indicum, oil from ganoderma lucidum spores, huperzine and stepholidine are able to attenuate degeneration of dopamine neurons and sympotoms caused by the neurotoxins 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and 6-hydroxydopamine (6-OHDA) in vitro and in vivo conditions. In addition, accumulating data have suggested that Chinese herbs or herbal extracts may promote neuronal survival and neurite growth, and facilitate functional recovery of brain injures by invoking distinct mechanisms that are related to their neuroprotective roles as the antioxidants, dopamine transporter inhibitor, monoamine oxidase inhibitor, free radical scavengers, chelators of harmful metal ions, modulating cell survival genes and signaling, anti-apoptosis activity, and even improving brain blood circulation. New pharmaceutical strategies against PD will hopefully be discovered by understanding the various active entities and valuable combinations that contribute to the biological effects of Chinese herbs and herbal extracts.