Identifying Novel Senolytic Agents and Molecular Targets

项目摘要/摘要 细胞衰老是衰老和老年性疾病的重要基础机制。一直以来 研究表明，衰老细胞(SCs)的遗传消除可以显著缓解与衰老相关的疾病 并延长小鼠的健康和寿命。感觉剂，指的是可以 选择性地诱导干细胞的凋亡，因此有可能被开发为延缓衰老的药物 人类通过预防或治疗与年龄有关的疾病来维持健康。我们和其他人最近发现了一个 针对不同的SC抗凋亡途径(SCAP)的感觉剂的数量。对这些问题的后续研究 动物模型中的感觉神经降解剂表明，清除干细胞可以治疗几种与年龄相关的疾病和 化疗/放射治疗在小鼠身上引起不良反应，从而证明了卡介苗的治疗潜力 感光剂。然而，大多数已报道的感光物质都具有潜在的靶上和靶外毒性。在……里面 此外，干细胞并不都是一样的；不同的干细胞可能使用不同的SCAP来抵抗细胞凋亡。因此，它是 继续寻找新的SCAP/蛋白质靶标和新的感觉剂非常重要。胡椒碱(Piperlong umine，PL)，a 饮食天然产物，通过我们的靶向筛选活动被确定为一种新型的感光剂。普莱 似乎是安全的，在体内没有可观察到的毒性，在小鼠身上有很高的最大口服耐受量。 然而，其抗SC的作用机制(MOA)尚未明确，增加了发现新奇事物的潜力 抗衰老药物开发的分子靶点。因此，我们假设PL可以用来识别 干细胞中的新分子靶点，然后可用于开发新型和特定的感觉剂。 我们的初步构效关系(SAR)研究已经确定了磷脂类似物(风笛子)与 与ABT263相当的感官分解谱，ABT263是被鉴定为最有效和选择性最高的感觉剂之一 Date，并设计和合成了基于PL的探针分子，用于SCs中靶蛋白的下拉。 通过蛋白质组学分析和RNAi技术，我们鉴定、验证和鉴定了氧化蛋白1 (OXR1)作为干细胞中PL的蛋白靶点之一。本应用程序的目标是继续 高效选择性感光物质的发现和评价及其分子鉴定 目标，并阐明了这些新型试剂的MOA。具体地说，我们将进行以下具体工作 目标：1)设计、合成和评价具有更强的感受性和药物性的新型风琴 2)鉴定和验证SC中PL和Piperlogues的蛋白质靶点，并阐明其MOA； 3)评价铅制风笛器的体内疗效和安全性。成功实现这些拟议的目标将不会 不仅生产抗衰老药物开发候选药物，而且还识别和验证其他新分子 目标(S)使未来能够设计和基于目标发现新的感觉剂，并获得更多关于 细胞衰老生物学与白喉和风笛草的MOA。

PROJECT SUMMARY/ABSTRACT Cellular senescence is an important fundamental mechanism of aging and age-related diseases. It has been demonstrated that genetic elimination of senescent cells (SCs) can dramatically alleviate aging-related phenotypes and extend both healthspan and lifespan in mice. Senolytics, referring to small-molecules that can selectively induce apoptosis in SCs, thus have the potential to be developed as “anti-aging” drugs that extend human healthspan by preventing or treating age-related diseases. We and others have recently discovered a number of senolytics that target various SC anti-apoptotic pathways (SCAPs). Subsequent studies on these senolytics in animal models have shown that clearance of SCs can treat several age-related diseases and chemo-/radio-therapy caused adverse effects in mice, thus demonstrating the therapeutic potential of senolytics. However, most of the reported senolytics have potential on-target and off-target toxicities. In addition, SCs are not all the same; different SCs may use different SCAPs to resist apoptosis. Thus, it is important to continue the search of new SCAPs/protein targets and new senolytics. Piperlongumine (PL), a dietary natural product, was identified as a novel senolytic agent through our targeted screening campaign. PL appears to be safe, without observable toxicity in vivo and having a high maximum tolerated oral dose in mice. However, its mechanism of action (MOA) against SC is undefined, raising the potential of discovering novel molecular targets for senolytic drug development. Therefore, we hypothesize that PL can be used to identify new molecular targets in SCs, which can then be exploited for the development of novel and specific senolytics. Our preliminary structure–activity relationship (SAR) studies have identified PL analogues (piperlogues) with senolytic profile comparable to that of ABT263, one of the most potent and selective senolytics identified to date, and also designed and synthesized PL-based probe molecules for the pulldown of target proteins in SCs. With proteomics analyses and RNAi technology, we identified, validated, and characterized oxidation protein 1 (OXR1) as one of the protein targets of PL in SCs. The objectives of this application are to continue the discovery and evaluation of piperlogues as potent and selective senolytics, identification of their molecular targets, and elucidation of the MOA of these novel agents. Specifically, we will pursue the following specific aims: 1) design, synthesize, and evaluate novel piperlogues with improved senolytic activity and druglike properties; 2) identify and validate the protein targets of PL and piperlogues in SCs, and elucidate their MOA; and 3) evaluate the in vivo efficacy and safety of lead piperlogues. Success in these proposed aims will not only produce anti-aging drug development candidates but also identify and validate additional novel molecular target(s) to enable future design and target-based discovery of novel senolytics and to gain more insights into the biology of cellular senescence and the MOA of PL and piperlogues.