MPTP帕金森病动物模型研究进展

用神经毒素1-甲基-4-苯基-1,2,3,6-四氢吡啶(MPTP)制备的动物模型,无论在神经生化和病理组织学特征,还是在运动行为表现方面都酷似人帕金森病(PD),是目前研究PD的理想模型。对MPTP动物模型发病机制等方面的深入研究将有助于PD的防治。     

一种新的帕金森病动物模型

帕金森病(Pakinson’s disease,PD)是目前世界性多发病,常见病,以选择性脑区域进行性神经变性为特征[1],发病机制不清,其研究一直是神经疾病的热点。以往的PD动物模型仅局限于神经变性的急性诱导,与临床实际相差较远。广大研究者迫切希望有实用可行的新动物模型的出现。McNaught等最新研究建立了应用蛋白酶抑制因子(proteasomeinhibitors I,PSI)导致进行性神经变性的慢性动物模型[2],该模型的最大优点是:慢性模型,更接近临床;在建立PD模型的同时,可检测治疗及延缓该病发展的因素的作用。新模型的建立为帕金森病的研究开辟了新的广阔前…     

帕金森病模型研究进展

帕金森病（Parkinson’s disease,PD）是一种常见于中老年的神经退行性疾病,其特征性的病理改变为黑质纹状体多巴胺能神经元选择性缺失以及胞浆内涵物Lewy小体的形成。PD的发病机制目前尚不清楚,但已经明确环境因素和遗传因素在PD的发病中起重要作用。为阐明PD的病理生理机制,进一步探索新的治疗手段,迫切需要与PD密切相似的模型。本文将就目前发展的各种PD模型做一综述。     

胰岛素抵抗与帕金森病

帕金森病(PD)是第二大神经退行性疾病,而糖尿病是帕金森病的一个高危因素。胰岛素不仅是一种作用于外周的激素,负责葡萄糖平衡和能量代谢,它也可以通过血脑屏障,影响大脑的许多生命过程,包括调节神经元存活和生长、维持突触稳定性等。越来越多的研究显示,在帕金森病患者和动物模型的脑中出现胰岛素抵抗。胰岛素信号通路的异常引起α-突触核蛋白的聚集、线粒体功能障碍、神经炎症,以及认知功能减退等。这些都是与PD的发病机制紧密相关的。使用胰岛素增敏药物将是一种潜在的,缓解PD神经退行性病变的新策略。     

非人灵长类帕金森病模型研究进展

帕金森病是第二大神经退行性疾病,目前没有有效的治疗措施。非人灵长类动物在基因序列、大脑解剖、生殖生理和免疫系统等方面与人类有着极高的相似性,非人灵长类PD动物模型有助于阐明PD病因和发病机制,在新的治疗方法和药物研发中具有重大的应用价值。该文对当前非人灵长类PD模型研究进展作一综述。     

MPTP慢性帕金森病小鼠纹状体差异蛋白质的研究

目的分离、鉴定MPTP诱导慢性帕金森病模型小鼠纹状体差异表达的蛋白质,对MPTP慢性PD动物模型的特异性蛋白质组进行初步探讨,为PD的发病机制提供一定的蛋白质组学依据。方法成功建立MPTP诱导慢性帕金森病小鼠模型,提取模型组和对照组小鼠脑纹状体蛋白质,分别以固相pH梯度等电聚焦为第一向,SDS-PAGE垂直电泳为第二向进行2-DE。图像分析软件PDQUEST8.0分析电泳图谱找出差异表达蛋白,运用MALDI-TOF MS质谱鉴定;其肽质量指纹图（PMF）经MS Fit检索。结果比较MPTP诱导慢性PD模型小鼠和正常对照小鼠纹状体二向电泳图,发现12个蛋白表达异常,最终鉴定出其中4个蛋白质：线粒体裂殖调节因子1（mitochondrial fission regulator 1）、类泛素样蛋白3前体（ubiquitin-like protein 3 precursor）表达下调;S100蛋白A10（proteinS100-A10）、Lin-7 homolog B为新出现点。结论初步鉴定出MPTP慢性PD模型小鼠纹状体部分差异表达蛋白,所发现4个表达异常的蛋白质与帕金森病线粒体的损伤和兴奋性神经毒性密切相关,与PD的发病机制相符,为深入研究帕金森病病理机制奠定了基础。     

帕金森病大鼠模型运动行为测评方法的研究进展

帕金森病(Parkinson’s disease,PD)是以静止性震颤、肌强直、动作迟缓、姿势平衡障碍为主要临床特征的神经退行性疾病。动物模型实验是PD研究的重要组成方面,针对PD动物模型运动行为的评价不仅有利于阐述PD的发病原因及发病机制,而且有利于判定新型治疗方法的疗效。本文以偏侧6-OHDA大鼠模型为研究对象,着重介绍非药物诱导行为学测试方法对PD大鼠运动功能障碍进行测试与评价的研究进展。     

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。     

帕金森病实验动物模型的研究进展及评价

帕金森病(Parkinson disease,PD)是一种常见于中老年人的神经系统变性疾病,临床上以静止性震颤、运动迟缓、肌强直和姿势平衡障碍为主要特征.由于缺乏对人脑的研究,且帕金森病在动物中没有自发趋势,因此科学合理的动物模型是基础和临床研究中必不可少的研究工具,有助于揭示疾病的发生机制和新药研发.     

维生素D及其受体在帕金森病中的作用

帕金森病(Parkinson's disease,PD)是一种常见的中枢神经系统退行性疾病,引起帕金森病的发病机制至今尚未明确。帕金森病患者及老年人普遍存在维生素D缺乏,这可能是帕金森病的重要发病机制之一。由于维生素D具有免疫调节,抗氧化,调节神经营养因子,降低神经毒性的功能,能同时针对几种导致神经退行性病变因素发挥作用,特别是老年人纠正维生素D缺乏可能会阻止神经元的损失和PD相关的认知功能下降。因此补充维生素D可能成为治疗PD的方法。近年来研究发现,维生素D受体基因多态性与帕金森病的发病有相关性。该文就维生素D及其受体在帕金森病中可能发生的保护作用及其机制作一综述。     

Alpha-synuclein and Parkinson's disease: a proteomic view

In this review, we report how proteomic methodologies have been used to investigate cellular and animal models of Parkinson's disease (PD), with a special focus on alpha-synuclein. PD is a complex, multifactorial neurodegenerative disease affecting approximately 2% of the population over 65 years of age, pathologically characterized by alpha-synuclein intraneuronal inclusions. Etiopathogenetic mechanisms of PD are not fully understood, although a number of factors contributing to the selective degeneration of substantia nigra neurons have been identified. Therefore, cellular and animal models of the disease have been developed to investigate single factors contributing to disease pathogenesis; for example, alpha-synuclein aggregation and altered dopamine homeostasis. Proteomic studies on cellular and animal models have not only confirmed existing theories on PD pathogenesis (mitochondrial impairment, oxidative stress, failure of the ubiquitine-proteasome system), but also allowed the discovery of new important common features of presymptomatic (or premotor) stages of PD, such as dysregulation of cytoskeletal proteins that could be involved at the origin of the disorder.     

Animal models of Parkinson's disease

Animal models of Parkinson's disease (PD) have been widely used in the past four decades to investigate the pathogenesis and pathophysiology of this neurodegenerative disorder. These models have been classically based on the systemic or local (intracerebral) administration of neutoxins that are able to replicate most of the pathological and phenotypic features of PD in mammals (i.e. rodents or primates). In the last decade, the advent of the 'genetic era' of PD has provided a phenomenal enrichment of the research possibilities in this field, with the development of various mammalian (mice and, more recently, rats) and non-mammalian transgenic models that replicate most of the disease-causing mutations identified for monogenic forms of familial PD. Both toxic and transgenic classes of animal PD models have their own specificities and limitations, which must be carefully taken into consideration when choosing the model to be used. If a substantial and reproducible nigrostriatal lesion is required (e.g. for testing therapeutic interventions aimed at counteracting PD-related cell death), a classic toxic model such as one based on the administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine or 6-hydroxydopamine will adequately serve the purpose. On the other hand, if selected molecular mechanisms of PD pathogenesis must be investigated, transgenic models will offer invaluable insights. Therefore, until the 'perfect' model is developed, indications to use one model or another will depend on the specific objectives that are being pursued.     

Disease model: Parkinson's disease

Parkinson's disease (PD) is a progressive neurodegenerative disorder that is primarily characterized by the degeneration of dopaminergic neurons in the nigrostriatal pathway. The pathology of PD is typified by the presence of cytoplasmic inclusions (Lewy bodies) containing alpha-synuclein and ubiquitin. The pathogenesis of PD is not completely understood but environmental and genetic factors are thought to play important roles. To understand the pathophysiology of PD, and to develop novel therapies for improved symptomatic management, it is important to have relevant disease models. In this review, we summarize the available in vivo and in vitro models of PD and discuss their value.     

Parkinson's disease: genetic versus toxin-induced rodent models

Parkinson's disease (PD), a common progressive neurodegenerative disorder, is characterized by degeneration of dopamine neurons in the substantia nigra and neuronal proteinaceous aggregates called Lewy bodies (LBs). The etiology of PD is probably a combination of environmental and genetic factors. Recent progress in molecular genetics has identified several genes causing PD, including alpha-synuclein, leucine-rich repeat kinase 2 (LRRK2), Parkin, DJ-1 and PTEN-induced kinase 1 (PINK1), many of them coding for proteins found in LBs and/or implicated in mitochondrial function. However, the mechanism(s) leading to the development of the disease have not been identified, despite intensive research. Animal models help us to obtain insights into the mechanisms of several symptoms of PD, allowing us to investigate new therapeutic strategies and, in addition, provide an indispensable tool for basic research. As PD does not arise spontaneously in animals, characteristic and specific functional changes have to be induced by administration of toxins or by genetic manipulations. This review will focus on the comparison of three types of rodent animal models used to study different aspects of PD: (a) animal models using neurotoxins; (b) genetically modified mouse models reproducing findings from PD linkage studies or based on ablation of genes necessary for the development and survival of dopamine neurons; and (c) tissue-specific knockouts in mice targeting dopamine neurons. The advantages and disadvantages of these models are discussed.     

Mitochondrial alterations in Parkinson's disease: new clues

Mitochondrial dysfunction has long been associated with Parkinson's disease (PD). In particular, complex I impairment and subsequent oxidative stress have been widely demonstrated in experimental models of PD and in post-mortem PD samples. A recent wave of new studies is providing novel clues to the potential involvement of mitochondria in PD. In particular, (i) mitochondria-dependent programmed cell death pathways have been shown to be critical to PD-related dopaminergic neurodegeneration, (ii) many disease-causing proteins associated with familial forms of PD have been demonstrated to interact either directly or indirectly with mitochondria, (iii) aging-related mitochondrial changes, such as alterations in mitochondrial DNA, are increasingly being associated with PD, and (iv) anomalies in mitochondrial dynamics and intra-neuronal distribution are emerging as critical participants in the pathogenesis of PD. These new findings are revitalizing the field and reinforcing the potential role of mitochondria in the pathogenesis of PD. Whether a primary or secondary event, or part of a multi-factorial pathogenic process, mitochondrial dysfunction remains at the forefront of PD research and holds the promise as a potential molecular target for the development of new therapeutic strategies for this devastating, currently incurable, disease.     

Animal models of Parkinson's disease

Animal models are important tools in experimental medical science to better understand pathogenesis of human diseases. Once developed, these models can be exploited to test therapeutic approaches for treating functional disturbances observed in the disease of interest. On the basis of experimental and clinical findings, Parkinson's disease (PD) was the first neurological disease to be modeled and, subsequently, to be treated by neurotransmitter replacement therapy. Agents that selectively disrupt or destroy catecholaminergic systems, such as reserpine, methamphetamine, 6-hydroxydopamine and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine have been used to develop PD models. Recently, it has been found that agricultural chemicals, such as rotenone and paraquat, when administered systemically, can reproduce specific features of PD in rodents, apparently via oxidative damage. Transgenic animals that over-express alpha-synuclein are used to study the role of this protein in dopaminergic degeneration. This review critically discusses animal models of PD and compares them with characteristics of the human disease.     

Nonhuman primate models of Parkinson's disease

Nonhuman primate (NHP) models of Parkinson's disease (PD) play an essential role in the understanding of PD pathophysiology and the assessment of PD therapies. NHP research enabled the identification of environmental risk factors for the development of PD. Electrophysiological studies in NHP models of PD identified the neural circuit responsible for PD motor symptoms, and this knowledge led to the development of subthalamic surgical ablation and deep brain stimulation. Similar to human PD patients, parkinsonian monkeys are responsive to dopamine replacement therapies and present complications associated with their long-term use, a similarity that facilitated the assessment of new symptomatic treatments, such as dopaminergic agonists. New generations of compounds and novel therapies that use directed intracerebral delivery of drugs, cells, and viral vectors benefit from preclinical evaluation in NHP models of PD. There are several NHP models of PD, each with characteristics that make it suitable for the study of different aspects of the disease or potential new therapies. Investigators who use the models and peer scientists who evaluate their use need information about the strengths and limitations of the different PD models and their methods of evaluation. This article provides a critical review of available PD monkey models, their utilization, and how they compare to emerging views of PD as a multietiologic, multisystemic disease. The various models are particularly useful for representing different aspects of PD at selected time points. This conceptualization provides clues for the development of new NHP models and facilitates the clinical translation of findings. As ever, successful application of any model depends on matching the model to the scientific question to be answered. Adequate experimental designs, with multiple outcome measures of clinical relevance and an appropriate number of animals, are essential to minimize the limitations of models and increase their predictive clinical validity.     

Genetic models of Parkinson disease

To date, a truly representative animal model of Parkinson disease (PD) remains a critical unmet need. Although toxin-induced PD models have served many useful purposes, they have generally failed to recapitulate accurately the progressive process as well as the nature and distribution of the human pathology. During the last decade or so, the identification of several genes whose mutations are causative of rare familial forms of PD has heralded in a new dawn for PD modelling. Numerous mammalian as well as non mammalian models of genetically-linked PD have since been created. However, despite initial optimism, none of these models turned out to be a perfect replica of PD. Meanwhile, genetic and toxin-induced models alike continue to evolve towards mimicking the disease more faithfully. Notwithstanding this, current genetic models have collectively illuminated several important pathways relevant to PD pathogenesis. Here, we have attempted to provide a comprehensive discussion on existing genetic models of PD.     

Genetic susceptibility in Parkinson's disease

It is hoped that an understanding of the genetic basis of Parkinson's disease (PD) will lead to an appreciation of the molecular pathogenesis of disease, which in turn will highlight potential points of therapeutic intervention. It is also hoped that such an understanding will allow identification of individuals at risk for disease prior to the onset of motor symptoms. A large amount of work has already been performed in the identification of genetic risk factors for PD and some of this work, particularly those efforts that focus on genes implicated in monogenic forms of PD, have been successful, although hard won. A new era of gene discovery has begun, with the application of genome wide association studies; these promise to facilitate the identification of common genetic risk loci for complex genetic diseases. This is the first of several high throughput technologies that promise to shed light on the (likely) myriad genetic factors involved in this complex, late-onset neurodegenerative disorder.     

Controlling the mass action of alpha-synuclein in Parkinson's disease

Parkinson's disease (PD) is an age-related neurodegenerative disease with unknown etiology. Growing evidence from genetic, pathologic, animal modeling, and biochemical studies strongly support the theory that abnormal aggregation of alpha-synuclein plays a critical role in the pathogenesis of PD. Protein aggregation is an alternative folding process that competes with the native folding pathway. Whether or not a protein is subject to the aggregation process is determined by the concentration of the protein as well as thermodynamic properties inherent to each polypeptide. An increase in cellular concentration of alpha-synuclein has been associated with the disease in both familial and sporadic forms of PD. Thus, maintenance of the intraneuronal steady state levels of alpha-synuclein below the critical concentration is a key challenge neuronal cells are facing. Expression of the alpha-synuclein gene is under the control of environmental factors and aging, the two best-established risk factors for PD. Studies also suggest that the degradation of this protein is mediated by proteasomal and autophagic pathways, which are two mechanisms that are related to the pathogenesis of PD. Recently, vesicle-mediated exocytosis has been suggested as a novel mechanism for disposal of neuronal alpha-synuclein. Relocalization of the protein to specific compartments may be another method for increasing its local concentration. Regulation of the neuronal steady state levels of alpha-synuclein has significant implications in the development of PD, and understanding the mechanism may disclose potential therapeutic targets for PD and other related diseases.