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

项目摘要 糖尿病是一种葡萄糖稳态紊乱，导致过度住院，发病率和早期死亡率 在超过3420万受疾病影响的美国人中。因此，开发药理学 保持β-细胞功能和/或刺激β-细胞团扩增的方法受到强烈关注。如今 由于缺乏安全的治疗靶点，改进的糖尿病药物的产生受到阻碍。事实上， 但组织外药物效应正在减缓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- 产生β-细胞可用于恢复或增强内源性胰岛素产生能力。最近我们 开发了几种新的人类β细胞增殖的高效化学诱导剂。然而，非选择性 这些分子的促生长活性阻止了进一步的临床发展。因此，“模块化” 为实现下一代糖尿病，需要用于β细胞靶向药物递送的（易转移的）系统 治疗学为了应对这一挑战，我们正在开发一种β细胞靶向药物递送模块， β细胞中独特的高锌含量。在该系统中，锌螯合部分共价整合到 复制促进（货物）化合物，以产生选择性地 增强β细胞药物积累和复制促进活性。在这里，我们将联合收割机 通过系统的体外和体内研究，努力推进我们的β细胞靶向药物平台技术 交付.在目标1中，我们将定义控制锌依赖性β细胞靶向的化学“规则”。我们将 合成和测定不同β RepZnC，其中货物/螯合剂组成、锌结合亲和力和 物理化学性质系统地变化。在目标2中，我们将检查体内β细胞选择性 （积累和复制促进活性）。我们将使用解吸 电喷雾离子化质谱法（ESI-MSI）测量组织特异性药物蓄积并预测 组织特异性生物活性。这项工作将证明新的βRepZnC治疗剂在体内的功效， 多种糖尿病小鼠模型，并提供经过验证的方法;克服开发的主要障碍 细胞靶向治疗：缺乏体内测量组织特异性药物递送的简便方法。 在目标3中，我们将使用CRISPR技术从遗传学上剖析控制β细胞锌和锌的途径。 结合药物蓄积。作为这项工作的一部分，我们将在遗传上增强β细胞βRepZnCs的积累， β细胞选择性复制诱导。总的来说，我们的研究将推进β细胞靶向的模块化技术， 药物递送，优化βRepZnCs，验证用于评估体内细胞靶向药物递送的急需工具 并提供对β细胞生物学的基本（可靶向）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.