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

项目总结： 阿尔茨海默病(AD)的特点是发病机制复杂，发病机制不统一 已经被积极寻找了。其中，自噬受到了极大的关注，今天有一种 普遍的共识是，它的功能障碍在AD的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工具 在阿尔茨海默病患者的大脑中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因子，因为它的药物抑制或 基因缺失导致自噬激活和清除难溶的淀粉样β蛋白(Aβ)和tau。 这项研究的目标是开发选择性和有效的药物抑制剂12/15-LOX和 评估它们在AD和相关的肌萎缩侧索硬化症模型中作为新型疾病改良剂的作用。这种蛋白质广泛存在于 在容易发生神经变性的区域表达，如大脑皮层和海马区，其水平为 在AD和轻度认知障碍患者中显著升高，提示早期参与 阿尔茨海默病的发病途径。我们的实验室已经证明，12/15-LOX的基因操作可以调节 阿尔茨海默病小鼠模型中的认知障碍和AD样神经病理学的发展。在……里面 此外，我们还证明了PD146176的12/15-LOX药理阻断激活了自噬和 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 老年3xTg小鼠的完整性。然而，PD146176是非专利的，LOX同工酶选择性很差。 因此，探索更有选择性和更有效的12/15-LOX抑制剂来保持自噬活性可能会 最终为AD提供了一种新的治疗方法，具有真正的疾病修正能力。 作为这一努力的一部分，我们最近发现了一种新型的、高度选择性的12/15-LOX抑制剂ML351， 它是脑渗透性的，具有良好的药动学特征。在本提案中，我们将评估ML351在 AD及相关肌萎缩侧索硬化症的小鼠模型：一种发生Aβ斑块和tau缠结的小鼠模型 记忆损伤(即3xTg小鼠)；仅表现为tau病理和行为缺陷(htau 老鼠)。与此同时，我们将寻找更多用于治疗开发的候选分子 抗AD，利用我们的检测方法为人类12/15-LOX寻找新的选择性抑制剂。我们已经 拥有ML351的衍生品，并成功地进行了12/15-LOX高通量筛选的新50万 并将测试最具效力/选择性的药物在体外和体内的有效性。 考虑到ML351已经被证明可以穿越血脑屏障，预防中风 我们相信这些研究将证明ML351通过激活自噬来保护 抑制AD样表型的发展，因此有很好的机会成为有效的 预防阿尔茨海默病及相关疾病发生或发展的治疗工具。

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.