In Vivo Testing of Microtubule-Stabilizing Drugs

微管稳定药物的体内测试

• 批准号: 7024801
• 负责人: MARY L. MICHAELIS
• 金额: $ 15.9万
• 依托单位: UNIVERSITY OF KANSAS LAWRENCE
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-02-15 至 2007-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7024801
• 关键词: Alzheimer' s disease; amyloid proteins; behavior test; blood brain barrier; centrally acting drug; disease /disorder model; dosage; drug screening /evaluation; genetically modified animals; immunocytochemistry; laboratory mouse; microtubules; neurofibrillary tangles; neuropathology; neuroprotectants; paclitaxel; tau proteins

DESCRIPTION (provided by applicant): Our long-term goal is to develop novel therapeutic agents targeted to slowing the development of t neurofibrillary pathology in Alzheimer's disease (AD) by preserving the integrity of the cytoskeleton. Based on the pronounced neuronal dystrophy and disruption of microtubule (MT) integrity observed in AD brain and neurons exposed to Ab fibrils, we have tested the effects of MT-stabilizing drugs such as Taxol for protection against Ab toxicity. Taxol and several other MT-stabilizing drugs markedly enhanced survival of Ab-treated neurons in culture. However, these drugs do not enter the brain and thus cannot be tested in an in vivo mouse model for AD. We have synthesized two novel compounds that protect neurons in culture and actually cross the blood brain barrier (BBB). Pharmacokinetic studies on the half-lives and the brain distribution of the drugs have already been completed, as have limited toxicity experiments. The goal of this project is to use a recently developed triple transgenic mouse model (3xTg-AD) with both Ab and t pathology to conduct an in vivo proof-of concept study. The Specific Aims are: (1) to determine the maximal tolerated doses of the two drugs in control mice receiving chronic administration for several weeks; (2) to test the in vivo effects of the brain permeant taxane Tx-67 and the non-taxane MT-interacting drug GS-164 in the 3xTg-AD mouse model by assessing the behavioral performance of the mice throughout the period of chronic drug administration; and (3) to evaluate the in vivo effects of chronic treatment with Tx-67 or GS-164 on the progression of the AD-like neuropathological lesions that develop in the 3xTg-AD mic. Drug-treated mice will be compared with control animals receiving only saline injections. Behavioral testing will be done bi-weekly throughout the treatment period. Brains will be analyzed for indicators of both amyloid and t lesions using standard neuropathological, immuno-histochemical, and biochemical strategies. Based on our in vitro studies with primary neurons in culture and a recent report that Taxol reversed peripheral axonal transport deficits in spinal cord neurons of a tauopathy mouse, we anticipate the drugs will moderate the brain pathology in the 3xTg-AD mice. The drugs we have identified make it possible for us to provide the very first in vivo evaluation of brain permeant MT-stabilizing drugs for their potential to slow the progression of AD-like neuropathology in the brain. If the drugs do indeed alter the progression of any cognitive changes and/or the accumulation of the brain lesions, the findings would support further investigation into this very novel therapeutic strategy for slowing age-dependent neurodegeneration such as occurs in AD.

描述（由申请人提供）：我们的长期目标是开发新型治疗剂，通过保持细胞骨架的完整性来减缓阿尔茨海默病（AD）中神经原纤维病理学的发展。基于在 AD 大脑和暴露于 Ab 原纤维的神经元中观察到的明显神经元营养不良和微管 (MT) 完整性破坏，我们测试了 MT 稳定药物（如紫杉醇）对于防止 Ab 毒性的效果。紫杉醇和其他几种 MT 稳定药物显着提高了培养中经 Ab 处理的神经元的存活率。然而，这些药物不会进入大脑，因此无法在 AD 小鼠体内模型中进行测试。我们合成了两种新型化合物，可以保护培养物中的神经元，并真正穿过血脑屏障（BBB）。关于药物半衰期和脑分布的药代动力学研究已经完成，有限的毒性实验也已完成。该项目的目标是使用最近开发的具有 Ab 和 t 病理学的三重转基因小鼠模型 (3xTg-AD) 进行体内概念验证研究。具体目的是：（1）确定慢性给药数周的对照小鼠对两种药物的最大耐受剂量； (2) 通过评估小鼠在整个慢性用药期间的行为表现，测试脑透性紫杉烷Tx-67和非紫杉烷MT相互作用药物GS-164在3xTg-AD小鼠模型中的体内作用行政; (3) 评估 Tx-67 或 GS​​-164 长期治疗对 3xTg-AD 麦克风中发生的 AD 样神经病理病变进展的体内影响。将接受药物治疗的小鼠与仅接受盐水注射的对照动物进行比较。在整个治疗期间，行为测试将每两周进行一次。将使用标准神经病理学、免疫组织化学和生化策略分析大脑中淀粉样蛋白和 t 损伤的指标。根据我们对培养的原代神经元的体外研究以及紫杉醇逆转 tau 蛋白病小鼠脊髓神经元外周轴突运输缺陷的最新报告，我们预计这些药物将缓解 3xTg-AD 小鼠的大脑病理学。我们已经确定的药物使我们能够首次对可渗透大脑的 MT 稳定药物进行体内评估，了解它们减缓大脑中 AD 样神经病理学进展的潜力。如果这些药物确实改变了任何认知变化的进展和/或脑部病变的积累，那么这些发现将支持进一步研究这种非常新颖的治疗策略，以减缓年龄依赖性神经变性，例如 AD 中发生的神经变性。