Discovery of 12/15-lipoxygenase therapeutics for Alzheimer's disease

项目概要： 阿尔茨海默病（AD）的特点是复杂的发病机制， 一直在积极寻求。其中，自噬受到了很多关注，今天有一个 普遍认为其功能障碍在AD发病机制中起着核心作用，建立了这种细胞 系统作为理想的治疗靶点。因此，发现了可以恢复自噬的药理学工具 是一个非常理想的目标。我们最近发现，神经元12/15- 脂氧合酶（12/15-LOX）是自噬的内源性调节剂，因为其药理学抑制或抑制自噬。 遗传缺失导致自噬激活和不溶性淀粉样蛋白β（Aβ）和tau的清除。 本研究的目的是开发选择性和有效的12/15-LOX和 以评估它们作为AD和相关tau蛋白病模型中的新型疾病修饰剂。蛋白质广泛 在易于神经变性的区域，如皮质和海马中表达，并且其水平是 在AD和轻度认知障碍患者中， AD发病机制中的通路。我们的实验室已经表明，12/15-LOX的遗传操作调节了 认知障碍和AD样神经病理学的发展。在 此外，我们证明了PD 146176的12/15-LOX药理学阻断激活了自噬， 从而挽救学习/记忆缺陷，促进Aβ和不溶性tau的清除，并改善突触 在老年3xTg小鼠中的完整性。然而，PD 146176是专利过期的，并且具有差的LOX同工酶选择性。 因此，探索保留促自噬活性的更有选择性和更有效的12/15-LOX抑制剂可以 最终为AD提供了一种具有真实的疾病改善能力的新的治疗方法。 作为这项工作的一部分，我们最近发现了一种新型的高选择性12/15-LOX抑制剂ML 351， 其是脑渗透剂并具有良好的药代动力学特征。在本提案中，我们将评估ML 351， AD和相关tau蛋白病的小鼠模型：一种发展Aβ斑块和tau蛋白缠结的小鼠模型， 记忆损伤（即，3xTg小鼠）;仅表现出tau病理和行为缺陷（htau 小鼠）。同时，我们将寻找更多的候选分子用于治疗开发 针对AD，利用我们的测定来鉴定人12/15-LOX的新型选择性抑制剂。我们已经 具有ML 351的衍生物，并对新的500，000个样品进行了成功的12/15-LOX高通量筛选。 化合物库，并将测试其体外和体内有效性的最有效/选择性命中。 考虑到ML 351已经被证明可以穿过血脑屏障并防止中风， 我们相信这些研究将证明ML 351通过激活自噬， 抗AD样表型的发展，因此有很好的机会成为一种有效的 本发明提供了一种治疗工具，用于预防AD和相关tau蛋白病的发作或停止其进展。

PROJECT SUMMARY: Alzheimer’s disease (AD) is characterized by a complex pathogenesis for which unifying mechanisms have been actively sought. Among them, autophagy has received a lot of attention, and today there is a general consensus that its dysfunction plays a central role in AD pathogenesis, establishing this cellular system as an ideal therapeutic target. Hence the discovery of pharmacologic tools that can restore autophagy in the brains of AD patients is a highly desirable goal. We have recently discovered that the neuronal 12/15- Lipoxygenase (12/15-LOX) is an endogenous regulator of autophagy since its pharmacologic inhibition or genetic absence result in autophagy activation and clearance of insoluble amyloid beta (Aβ) and tau. The goal of this research is to develop selective and potent pharmacologic inhibitors of 12/15-LOX and to assess them as novel disease-modifying agents in AD and related tauopathy models. The protein is widely expressed in areas prone to neurodegeneration, such as cortex and hippocampus, and its levels are significantly elevated in patients with AD and mild cognitive impairment, suggesting an early involvement of the pathway in AD pathogenesis. Our laboratories have shown that genetic manipulation of 12/15-LOX modulates cognitive impairment and the development of AD-like neuropathology in mouse models of the disease. In addition, we demonstrated the 12/15-LOX pharmacological blockade by PD146176 activates autophagy and thus rescues learning/memory deficits, facilitates Aβ and insoluble tau clearance and improves synaptic integrity in aged 3xTg mice. However, PD146176 is off-patent and has poor LOX isozyme selectivity. Therefore, probing more selective and potent 12/15-LOX inhibitors that retain the pro-autophagy activity may ultimately provide a novel therapeutic approach with real disease-modifying capacity for AD. As part of this effort, we recently discovered a novel and highly selective 12/15-LOX inhibitor, ML351, which is brain penetrant and has a good pharmacokinetic profile. In this proposal we will assess ML351 in mouse models of AD and related tauopathies: one that develops Aβ plaques and tau tangles together with memory impairments (i.e., 3xTg mice); a one that manifests only tau pathology and behavioral deficits (htau mice). At the same time, we will search for additional candidate molecules toward therapeutic development against AD, utilizing our assays to identify novel, selective inhibitors for the human 12/15-LOX. We already have derivatives of ML351, and performed a successful 12/15-LOX high-throughput screen of a new 500,000 compound library and will test the top potent/selective hits for their in vitro and in vivo effectiveness. Considering that ML351 has already been shown to cross the blood-brain barrier and protect against stroke damage, we are confident these studies will demonstrate that ML351, by activating autophagy, protects against the development of the AD-like phenotype and thus has an excellent chance of becoming an effective therapeutic tool to prevent the onset or halt the progression of AD and related tauopathies.