Modeling and Pathological Study of Sporadic Parkinson's Disease

散发性帕金森病的建模与病理学研究

• 批准号: 8552511
• 负责人: Huaibin Cai
• 金额: $ 37.48万
• 依托单位: NATIONAL INSTITUTE ON AGING
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/8552511
• 关键词: Address; Affect; Age-Months; Alpha-Synuclein transgenic mouse; Alzheimer' s Disease; Animal Model; Antibodies; Autopsy; Axonal Transport; Behavioral; Brain; Breeding; Cerebral cortex; Corpus striatum structure; Crossbreeding; Data; Development; Dopamine; Etiology; Gene Expression; Genes; Genetic; Hippocampus (Brain); Human; In Vitro; Knock-out; LRRK2 gene; Lewy Bodies; Mediating; Microtubules; Midbrain structure; Modeling; Molecular Target; Mus; Mutant Strains Mice; Mutation; Names; Nerve Degeneration; Neurites; Neurodegenerative Disorders; Neurofibrillary Tangles; Neurons; Parkinson Disease; Pathology; Pathway interactions; Peripheral Nervous System; Phenotype; Prosencephalon; Reporting; Research; Substantia nigra structure; Transgenic Mice; Tubulin; Up-Regulation; Vesicle; alpha synuclein; calmodulin-dependent protein kinase II; cohort; dopaminergic neuron; genetic risk factor; genome wide association study; interest; mutant; nervous system disorder; neurochemistry; neuron loss; pars compacta; risk sharing; selective expression; stem; synuclein; tau Proteins; tau aggregation; tau expression; tau interaction

1. Pathogenic Interplay between LRRK2 and Tau in PD. To examine a potential pathogenic interplay between LRRK2 and tau in neurodegeneration, we crossbred CaMKII-tTA/tetO-G2019S LRRK2 double transgenic mice with a line of tau transgenic mice Prnp-tau B6D2-Tg(Prnp-MAPT)43Vle/J to generate CaMKII-tTA/tetO-G2019S/Prnp-tau triple transgenic mice that co-expressed human LRRK2 and tau in neurons of forebrain regions such as cerebral cortex, striatum and hippocampus. We found that co-expression of human G2019S LRRK2 and wild-type tau further decreased the level of free tubulin in the brain homogenate. Meanwhile, the formation of tau-positive aggregates was increased in the cortex of CaMKII-tTA/tetO-G2019S/Prnp-tau triple transgenic mice as revealed by immunostaining with antibodies against tau. These preliminary data indicate that LRRK2 may regulate the function and aggregation of tau and a synergistic interaction between LRRK2 and tau may further impair the microtubule dynamics in neurons. To further investigate whether LRRK2 and tau act synergistically in the midbrain dopaminergic (DA) neurons, we have generated a cohort of PITX3-tTA/tetO-LRRK2 WT/tetO-Tau WT transgenic mice in which wild-type human LRRK2 and tau are selectively expressed by the midbrain DA neurons. In the coming fiscal year, we will carry out behavioral, pathological, neurochemical studies of these mice. Meanwhile, we will also examine the subcellular phenotype in the affected DA neurons, particularly on the axonal transport and dopamine release. 2. Pathogenic Interplay between alpha-synuclein and LRRK2 in PD. We have previously shown that over-expression of LRRK2 exacerbates PD-related A53T alpha-synuclein-mediated neurodegeneration in the forebrain regions; while inhibition of LRRK2 expression ameliorates the alpha-synuclein-induced neuronal loss. However, it remains unclear whether LRRK2 and alpha-synuclein act the same way in the midbrain DA neurons. To address this question, we generate PITX3-tTA/tetO-LRRK2/tetO-alpha-synuclein triple transgenic mice to allow a selective expression of human wild-type as well as PD-related mutant LRRK2 (G2019) and alpha-synuclein (A53T) in the midbrain DA neurons. In addition, we also bred PITX3/A53T mice in the LRRK2 knockout background. We have systematically examined the numbers of midbrain DA neurons in the alpha-synuclein and LRRK2 mutant mice at one and eighteen months of age. Our preliminary data indicate that over-expression of both wild-type and G2019S LRRK2 accelerated A53T alpha-synuclein-mediated DA neuron loss in 1-month old mice. By contrast, loss of LRRK2 ameliorated A53T alpha-synuclein-induced DA neurodegeneration. In the coming fiscal year, we will generate a new cohort of wild-type LRRK2 and alpha-synuclein transgenic mice in order to investigate if the up-regulation of both wild-type alpha-synuclein and LRRK2 is sufficient to cause DA neuronal loss, and the underlying pathogenic mechanisms. This study may provide a useful animal model for studying the cause and treatment of sporadic PD. 3. Pathogenic Interplay between alpha-synuclein and tau in PD. It has been shown previously that over-expression of alpha-synuclein and tau greatly accelerate their aggregation in vitro. We decided to evaluate the pathogenic consequence of alpha-synuclein and tau interaction in the midbrain DA neurons. Together with Dr. Xian Lin's lab, we will generate PITX3/alpha-synuclein/tau triple transgenic mice to study the potential pathogenic interplay between alpha-synuclein and LRRK2 using the same strategy as we outlined the above. 4. Pathogenic Interplay between Wild-type alpha-synuclein, LRRK2, and tau in PD. Finally, we plan to develop PITX3/alpha-synuclein/LRRK2/tau compound transgenic mice to investigate the contribution of these three genetic risk factors in the degeneration of midbrain DA neurons. This study may provide a useful animal model for studying the cause and treatment of sporadic PD.

1。pd中的lrrk2和tau之间的病原性相互作用。 为了检查LRRK2和Tau在神经变性中的潜在病原性相互作用，我们用一系列Tau转基因小鼠PRNP-TAU B6D2-TG（PRNP-MAPT）43VLE/JO generate Camkii杂交了Camkii-TTA/TETO-G2019S LRRK2双重转基因小鼠LRRK2双转基因小鼠-TTA/TTA/TETO-G2019S/PRNP-TAU三重转基因小鼠，它们在前脑区域的神经元中共表达人LRRK2和TAU，例如脑皮质，纹状体和海马。我们发现，人类G2019S LRRK2和野生型Tau的共表达进一步降低了脑匀浆中游离微管蛋白的水平。同时，在CAMKII-TTA/TETO-G2019S/PRNP-TAU三重转基因小鼠的皮层中，Tau阳性聚集体的形成增加了，抗抗Tau的抗体免疫染色显示。这些初步数据表明，LRRK2可能调节Tau的功能和聚集，LRRK2和TAU之间的协同相互作用可能会进一步损害神经元中的微管动力学。为了进一步研究LRRK2和TAU是否在中脑多巴胺能（DA）神经元中协同作用，我们已经产生了一组Pitx3-TTA/TETO-LRRK2 WT/TETO-TETO-TAU WT转基因小鼠，其中野生型人类LRRK2和野生型人类Lrrk2和由中脑DA神经元表达。在未来的财政年度，我们将对这些小鼠进行行为，病理，神经化学研究。同时，我们还将检查受影响的DA神经元中的亚细胞表型，尤其是在轴突运输和多巴胺释放上。 2。PD中的α-核蛋白和LRRK2之间的致病性相互作用。 我们先前已经表明，LRRK2的过表达加剧了PD与PD相关的A53Tα-突触核蛋白介导的前脑区域中的神经变性。而抑制LRRK2表达可以缓解α-核蛋白诱导的神经元丧失。但是，尚不清楚LRRK2和α-核蛋白在中脑DA神经元中的作用相同。为了解决这个问题，我们生成PITX3-TTA/TETO-LRK2/TETO-ALPHA-甲核蛋白三重转基因小鼠允许人类野生型和PD相关的突变体LRRK2（G2019）和Alpha-synuclein（A53TTT）的选择性表达）在中脑DA神经元中。此外，我们还在LRRK2敲除背景中繁殖了Pitx3/A53T小鼠。我们已经系统地检查了一个和18个月大的α-核蛋白和LRRK2突变体小鼠中的中脑DA神经元的数量。我们的初步数据表明，在1个月大的小鼠中，野生型和G2019S LRRK2的过度表达加速了A53Tα-突触核蛋白介导的DA神经元损失。相比之下，LRRK2的损失改善了A53Tα-突触核蛋白诱导的DA神经变性。在即将到来的会计年度，我们将产生新的野生型LRRK2和α-突触核蛋白转基因小鼠，以研究野生型α-核蛋白和LRRK2的上调是否足以引起DA神经元丧失，以及潜在的致病机制。这项研究可能会提供有用的动物模型，用于研究零星PD的原因和治疗。 3。α-核蛋白和tau之间的致病性相互作用。 先前已经表明，α-核蛋白和tau的过表达大大加速了它们在体外的聚集。我们决定评估中脑DA神经元中α-核蛋白和Tau相互作用的致病结果。与西林博士的实验室一起，我们将使用与上述策略相同的策略来研究pitx3/alpha-synclein/tau三重转基因小鼠，以研究alpha-synclein和lrrk2之间的潜在致病相互作用。 4。野生型α-核蛋白，lrrk2和tau之间的致病性相互作用。 最后，我们计划开发PITX3/Alpha-核蛋白/LRRK2/TAU化合物转基因小鼠，以研究这三个遗传危险因素在中脑DA神经元退化中的贡献。这项研究可能会提供有用的动物模型，用于研究零星PD的原因和治疗。