Development of E64d for Alzheimer's disease

描述（由申请人提供）：目前没有可用的药物可以阻止阿尔茨海默病（AD）的进展。神经毒性脑淀粉样肽（A?）的异常积累被认为是该疾病的可能原因。一个吗?是由一个较大的淀粉样前体蛋白被蛋白酶水解裂解而产生的，称为？-和？-分泌酶。抑制2-分泌酶裂解是降低A？积累和？-分泌酶抑制剂被认为可能有效减缓疾病的进展。我们发现了一种化合物，E64d，可以改善空间记忆缺陷，减少脑斑块，a ？清洁技术基金?在转基因AD小鼠脑室内（icv）给药。此外，E64d还能降低脑A？在人A？生产。CTF的减少？和一个吗?在受调节的分泌途径中表明E64d可能通过抑制？-分泌酶活性此前，其他研究发现口服E64d用于临床试验是安全的。因此，E64d在AD动物模型中有效，在人类中安全使用，因此具有作为AD治疗药物的潜力。E64d是其生物活性酸形式E64c的酯前药，E64c是半胱氨酸蛋白酶的特异性抑制剂。E64d在体内被快速水解为E64c。然而，icv给药E64d不是治疗上可接受的途径，口服E64d导致脑剂量低，这是由于肝脏在到达脑之前摄取了E64c。为了推进E64d作为AD治疗药物，需要开发治疗上可接受和有效的E64d给药途径。该基金将探索E64d给药的各种途径，并确定其在AD动物模型中的疗效和脑剂量反应。如果找到合适的途径，这项工作将使一种非常有前途的阿尔茨海默病治疗方法的临床开发得以进行。公共卫生相关性：该项目与公共卫生的相关性是开发新的有效的阿尔茨海默病药物。目前，还没有有效的手段来阻止这种毁灭性疾病的发展，因此迫切需要能够阻止这种疾病的新药。这个项目可能会产生一种新的阿尔茨海默病治疗方法，可能会阻止或可能逆转疾病的进展。

DESCRIPTION (provided by applicant): There currently is no drug available that stops the progression of Alzheimer's disease (AD). The abnormal accumulation of neurotoxic brain ss-amyloid peptides (A?) is thought to be a possible cause the disease. A? are produced by proteolytic cleavage of a larger amyloid precursor protein by proteases, called ?- and ?-secretases. Inhibiting 2-secretase cleavage is an attractive approach to reducing A? accumulation and ?-secretase inhibitors are thought to potentially effective for slowing the progression of the disease. We have found a compound, E64d, which improves spatial memory deficit and reduces brain plaque, A? and CTF? in a transgenic AD mouse when intracerebroventricularly (icv) administered. Moreover, E64d also reduces brain A? in the regulated secretory pathway in the guinea pig model of human A? production. The reduction in CTF? and A? in the regulated secretory pathway suggests that E64d may act by inhibiting ?-secretase activity in that pathway. Previously, others found that oral E64d administration safe to use in clinical trials. Thus, E64d is both efficacious in AD animal models and safe to use in humans and therefore has potential as an AD therapeutic. E64d is an ester prodrug of its biologically active acid form, E64c, which is a specific inhibitor of cysteine proteases. E64d is rapidly hydrolyzed to E64c in vivo. However, icv E64d administration is not a therapeutically acceptable route and oral E64d administration results in low brain doses, which is due to hepatic E64c uptake prior to reaching the brain. Therapeutically acceptable and efficacious routes of E64d administration need to be developed in order to advance E64d as an AD therapeutic. This grant will explore various routes of E64d administration and determine their efficacy and brain dose responses in AD animal models. If a suitable route is found, this work will allow the clinical development of a very promising AD therapeutic to proceed. PUBLIC HEALTH RELEVANCE: The relevance of this project to the public health is the development of new and effective Alzheimer's disease drug. Currently, there is no effective means of stopping the progress of this devastating disease and there is an urgent need for new drugs that do so. This project may result in a new Alzheimer's disease treatment that may halt or, possibly, reverse the progression of the disease.