FETAL DOPAMINE CELLS--IMPROVING GRAFT VIABILITY

胎儿多巴胺细胞——提高移植物活力

• 批准号: 6112264
• 负责人: JOHN RICHARD SLADEK
• 金额: $ 20.03万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-05-01 至 2002-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6112264
• 关键词: Cercopithecidae; Parkinson's disease; brain mapping; cell age; corpus striatum; cryopreservation; cyclosporines; deprenyl; dihydroxyphenylalanine; dopamine; dopamine receptor; electron microscopy; embryo /fetus cell /tissue; gestational age; histochemistry /cytochemistry; methylphenyltetrahydropyridine; nervous system regeneration; nervous system transplantation; neurons; neuropharmacology; neurotoxins; substantia nigra; tissue /cell culture; tyrosine 3 monooxygenase

One of the foremost difficulties with the application of neural transplantation to the treatment of neurodegenerative disorders is enhancing the survival of grafted donor tissue to ensure that adequate amounts of dopamine are produced and that transplant effect are long- lasting. One prominent laboratory reported that the survival rate of grafted, human dopamine neurons is as low as 2-5% using current techniques, tested in rodents. This laboratory and others have used this conclusion as the basis for substantially increasing the amount of tissue implanted in clinical experiments. We have been able to achieve a considerably higher survival rate in primates by studying factors which might enhance it. Improved survival of grafts may be achieved from tissue obtained from a critical stage of dopamine neurogenesis. It may be noteworthy that clinical experiments have utilized a much wider range of gestational ages than would be suggested from our new data. Moreover, we have found that chronically administered levodopa in rodents results in grafts with stunted dopamine neurons and diminished behavioral improvement. Other factors related to the preparation and storage of the donor tissue or pharmacological treatments after grafting may be equally important. Although some studies performed in rat may provide useful clues, it is understood that the greater size and complexity of the monkey brain and its similarity to the human brain makes it essential to optimize the viability of grafts in monkey models. Variables to be studied include the age of the donor tissue, graft survival over time, the method of preparation of the donor tissue such as cell suspension, solid grafts, and cryopreservation, and the effects of conventional pharmacotherapies such as levodopa, deprenyl and others on graft survival. These studies will be carried out using grafts of mesencephalic tissue into monkeys over several time periods, controlling for fetal age, matched comparisons of suspended vs. small solid grafts implanted on opposite sides of the caudate nucleus of the same monkey, fresh vs. cryopreserved tissue also implanted on opposite sides of the brain. Pharmacological studies will be done first in primate cell cultures and, if positive, subsequent experiments will test these effects on grafted monkeys. This project also will examine the effectiveness of grafts of embryonic striatum to promote growth of neurites from co-grafted mesencephalic tissue as a means of achieving greater outgrowth from grafted neurons. During the current award period we also discovered that striatal grafts have a growth enhancing effect on the host brain that can result int he growth of tyrosine hydroxylase positive fibers into grafts placed into the dorsolateral striatum. We will examine this phenomenon from the perspective of early intervention designed at protecting the residual host dopaminergic neurons.

应用神经网络的最大困难之一 移植治疗神经退行性疾病的方法是 提高移植供体组织的存活率，以确保足够的 产生大量的多巴胺，移植效果持久 持久。 一个著名的实验室报告称， 使用现有技术，移植的人类多巴胺神经元含量低至 2-5%， 在啮齿动物身上进行了测试。 本实验室和其他实验室已将此结论用作 大幅增加植入组织数量的基础 临床实验。 我们已经能够实现相当高的存活率 通过研究可能增强它的因素来研究灵长类动物。 提高生存率 移植物可以从关键阶段获得的组织来实现 多巴胺神经发生。 值得注意的是，临床实验 使用的胎龄范围比建议的范围大得多 从我们的新数据来看。 此外，我们还发现，长期服用 啮齿类动物的左旋多巴会导致移植物多巴胺神经元发育不良 行为改善减弱。 与此相关的其他因素 供体组织的准备和储存或药物治疗 嫁接后可能同样重要。 尽管一些研究进行了 在大鼠中可能提供有用的线索，据了解，较大的体型和 猴脑的复杂性及其与人脑的相似性使得 优化猴子模型中移植物的活力至关重要。 要研究的变量包括供体组织的年龄、移植物存活率 随着时间的推移，制备供体组织（例如细胞）的方法 悬浮液、固体移植物和冷冻保存，以及它们的影响 常规药物治疗，如左旋多巴、丙炔苯丙胺等 移植物存活。 这些研究将使用移植物进行 中脑组织经过几个时间段进入猴子体内，控制 对于胎儿年龄，悬浮移植物与小型实体移植物的匹配比较 植入同一只猴子尾状核的两侧， 新鲜组织与冷冻组织也分别植入到组织的两侧 脑。 药理学研究将首先在灵长类细胞培养物中进行 如果阳性，后续实验将测试这些对嫁接的影响 猴子。 该项目还将检查胚胎移植的有效性 纹状体促进共移植中脑组织神经突的生长 作为实现移植神经元更大生长的一种手段。 期间 当前奖励期间我们还发现纹状体移植物具有生长 增强对宿主大脑的影响，从而导致生长 将酪氨酸羟化酶阳性纤维放入移植物中 背外侧纹状体。 我们将从以下方面来考察这一现象： 旨在保护残留宿主的早期干预的观点 多巴胺能神经元。