Development and characterization of peptidomimetic small molecule activators of peptidase neurolysin for stroke therapy.

摘要 目前的中风研究更多地关注于了解大脑的自我保护和修复机制。详细 阐明这些机制是至关重要的，因为这种知识可能导致治疗干预措施的发展 模仿或参与大脑的自我保护/修复机制，可以成功地治疗中风。与建议的 研究我们寻求开发有效和选择性的肽酶神经溶素(NLN)小分子激活剂。 将被用作研究工具和主导化学实体，以推动药物发现过程，以开发 新奇的药物类别。最近发表的和我们实验室的初步研究发现，NLN是大脑的自我- 保护机制，对中风后大脑的保护和恢复起作用。的功能意义 中风后大脑中的NLN是基于其灭活几种神经毒素并产生三种大脑的能力- 保护性/再生性神经肽，从大量的实验和临床研究中得知，对 对中风的转归有贡献。基于这一证据，我们认为NLN是一种参与大脑恢复的中枢多肽酶 中风后的机制。在这个协作应用中，我们将利用我们在药物的多个方面的专业知识 发现过程，并将开发有效的“类药物”小分子，可以选择性地提高催化效率 可作为卒中后脑保护和康复的实验性治疗药物。这项建议具有 根据我们令人信服的实验数据得出的公式表明，NLN的催化活性可以提高两倍 结构上相关的二肽和一种独特的非肽化学型。建议的研究是可行的，我们的 已鉴定的NLN激活剂的初步构效关系研究和两种不同的体内实验 小鼠中风模型表明，中风后内源性NLN的抑制会加重中风损伤，而 NLN在大脑中的过度表达或其传递到中风后大脑中，极大地改善了中风的预后。目标 这项提案的三个综合目标将实现：(1)设计和表征多样化和专有的 基于三个活性命中的化合物文库和用于识别关键功能残基相互作用的指导性生物测定 在NLN结合位点内，开发高效、脑透性、选择性的NLN激活剂 性质；(2)进行生化和结构研究，以表征已鉴定的NLN的激活机制 激活剂的开发；(3)确定NLN激活剂在卒中后脑保护和康复中的治疗潜力 中风的小鼠模型。这项工作具有很高的创新性，因为科学上没有描述NLN的激活剂 文献和此类化合物从未被认为具有治疗潜力。合作调查小组， 由药物化学和药物发现、结晶学和结构生物学、酶生物化学等领域的专家组成 而药理学、血脑屏障生理学和中风药理学，是非常有资格进行建议的 学习。我们的长期目标是将主要的NLN激活剂从工作台转移到床边，并开发一种有效的治疗方法， 这将改变目前对大量中风患者的治疗模式。

SUMMARY Current stroke research focuses more on understanding the brain’s self-protective and repair mechanisms. Detailed elucidation of these mechanisms is crucial as such knowledge could lead to development of therapeutic interventions which mimic or engage the brain’s self-protective/repair mechanisms and can lead to successful stroke therapy. With the proposed research we seek to develop potent and selective ‘drug-like’ small molecule activators of peptidase neurolysin (Nln) which will be used as research tools and lead chemical entities to move the drug discovery process forward for development of a novel class of drugs. Recently published and pilot studies from our laboratory have identified Nln as one of the brain’s self- protective mechanisms, functioning towards preservation and recovery of the brain after stroke. Functional significance of Nln in the post-stroke brain is based on its ability to inactivate several neurotoxic and generate three cerebro- protective/regenerative neuropeptides, which are known from numerous experimental and clinical studies to critically contribute to the outcome of stroke. Based on this evidence we view Nln as a central peptidase involved in brain restorative mechanisms following stroke. In this collaborative application we will leverage our expertise in multiple aspects of the drug discovery process and will develop potent ‘drug-like’ small molecules which can selectively enhance the catalytic efficiency of Nln and can be used as experimental therapeutic agents for post-stroke brain protection and recovery. This proposal has been formulated based on our compelling experimental data indicating that catalytic activity of Nln can be enhanced by two structurally related dipeptides and a distinct non-peptide chemotype. Feasibility of the proposed studies is shown by our initial structure-activity relationship studies of the identified Nln activators and by in vivo experiments in two different mouse stroke models indicating that inhibition of endogenous Nln after stroke aggravates stroke injury, whereas overexpression of Nln in the brain or its delivery to the post-stroke brain substantially improves stroke outcome. The goals of this proposal will be accomplished in three well-integrated aims: (1) design and characterize a diverse and proprietary library of compounds based on three active hits and guided bioassays to identify critical functional residue interactions within the Nln binding site, and to develop high-potency, brain-permeable, selective activators of Nln with ‘drug-like’ properties; (2) conduct biochemical and structural studies to characterize the activation mechanism that the identified Nln activators exploit; (3) determine the therapeutic potential of Nln activators in post-stroke brain protection and recovery using a mouse model of stroke. This work is highly innovative because there are no activators of Nln described in the scientific literature and such compounds were never considered to have therapeutic potential. The collaborative investigative team, comprising experts in medicinal chemistry and drug discovery, crystallography and structural biology, enzyme biochemistry and pharmacology, blood-brain barrier physiology and stroke pharmacology, is highly qualified to conduct the proposed studies. Our long-term goal is to translate the lead Nln activators from bench to bedside and develop an effective therapy, which would transform the current treatment modalities for a vast number of stroke patients.