Leveraging the Uniquely High Beta-Cell Zinc Content for Targeted Drug Delivery

项目总结 糖尿病是一种葡萄糖稳态紊乱，会导致过度住院、发病率和早期死亡。 在超过3420万受疾病影响的美国人中。因此，发展药理学 保存β细胞功能和/或刺激β细胞大量扩增的方法是人们非常感兴趣的。目前， 由于缺乏安全的治疗靶点，改进的糖尿病药物的创造受到阻碍。事实上，在目标上 但组织外药物效应正在减缓包括β细胞在内的多个糖尿病治疗领域的进展 再生、β细胞保存和免疫保护。原则上，刺激胰岛素的再生- 生产β细胞可用于恢复或提高内源性胰岛素的生产能力。最近，我们 开发了几种新的高效化学诱导剂--人类β细胞增殖。然而，非选择性的 这些分子的促生长活性阻止了临床的进一步发展。因此，一种“模块化” 实现下一代糖尿病需要β细胞靶向给药系统(易于转移) 治疗学。为了应对这一挑战，我们正在开发一种β细胞靶向药物输送模块，该模块基于 β电池独一无二的高锌含量。在这个体系中，锌螯合部分被共价结合到一个 复制促进(CARAD)化合物，以产生选择性地 增强β细胞的药物积累和复制促进活性。这里，我们结合了一种药物化学 通过系统的体外和体内试验促进我们的β细胞靶向药物平台技术的发展 送货。在目标1中，我们将定义管理锌依赖的β细胞靶向的化学“规则”。我们会 合成和测定多种βRepZCs，其中货物/螯合剂组成，锌结合亲和力和 物理化学性质是系统变化的。在目标2中，我们将检查体内β细胞的选择性 (蓄积和复制促进活性)系统递送的βRepZCs。我们将使用解吸 电喷雾电离质谱仪(DESI-MSI)测量组织特异性药物蓄积和预测 组织特异性生物活性。本工作将展示新型β修复锌C疗法的体内疗效。 多种糖尿病小鼠模型，并提供经过验证的方法学；克服开发的主要障碍 细胞靶向治疗：缺乏一种简便的体内测量组织特异性药物释放的方法。 在目标3中，我们将使用CRISPR技术从基因上剖析控制β的途径-细胞锌和锌- 约束性药物积聚。作为这项努力的一部分，我们将从基因上增强β-细胞βRepZCs的积累和 β-细胞选择性复制诱导。总体而言，我们的研究将推进β的模块化技术-以细胞为目标 药物传递，优化βRepZCs，验证了评估体内细胞靶向药物传递的迫切需要的工具 并提供了对β细胞生物学的基本(有针对性的)见解。

PROJECT SUMMARY Diabetes is a disorder of glucose homeostasis that causes excess hospitalization, morbidity and early mortality among the more than 34.2 million disease-affected Americans. Consequently, developing pharmacologic methods to preserve β-cell function and/or stimulate β-cell mass expansion is of intense interest. Presently, the creation of improved diabetes medications is stymied by a dearth of safe therapeutic targets. In fact, on-target but off-tissue drug effects are slowing progress across multiple diabetes therapeutic domains including β-cell regeneration, β-cell preservation, and immune-protection. In principle, stimulating the regeneration of insulin- producing β-cells could be used to restore or enhance endogenous insulin production capacity. Recently, we developed several new highly potent chemical inducers of human β-cell proliferation. However, the non-selective growth-promoting activity of these molecules prevents further clinical development. Consequently, a “modular” (readily transferable) system for β-cell-targeted drug delivery is needed to realize the next generation of diabetes therapeutics. To address this challenge, we are developing a β-cell-targeted drug delivery module based upon the uniquely high zinc content of β-cells. In this system, a zinc-chelating moiety is covalently integrated into a replication-promoting (cargo) compound to generate a bi-functional compound (βRepZnC) that selectively enhances β-cell drug accumulation and replication-promoting activity. Here, we combine a medicinal chemistry effort with systematic in vitro and in vivo interrogation to advance our platform technology for β-cell-targeted drug delivery. In Aim 1, we will define the chemical “rules” that govern zinc-dependent β-cell targeting. We will synthesize and assay diverse βRepZnCs where cargo/chelator composition, zinc-binding affinity and physicochemical properties are systematically varied. In Aim 2, we will examine the in vivo β-cell selectivity (accumulation and replication-promoting activity) of systemically-delivered βRepZnCs. We will use desorption electrospray ionization mass spectrometry (DESI-MSI) to measure tissue-specific drug accumulation and predict tissue-specific bioactivity. This work will demonstrate the in vivo efficacy of novel βRepZnC therapeutics in multiple diabetes mouse models and deliver a validated methodology; overcoming a major barrier to developing cell-targeted therapeutics: the lack of a facile method for in vivo measurement of tissue-specific drug delivery. In Aim 3, we will use CRISPR technology to genetically dissect the pathways that control β-cell zinc and zinc- binding drug accumulation. As part of this effort, we will genetically enhance β-cell βRepZnCs accumulation and β-cell selective replication induction. Overall, our studies will advance a modular technology for β-cell-targeted drug delivery, optimize βRepZnCs, validate a greatly needed tool for assessing cell-targeted drug delivery in vivo and provide fundamental (targetable) insights into β-cell biology.