Development of siRNA conjugates for combination treatment of acute kidney injury

项目摘要 由于缺乏有效的药物治疗，急性肾损伤（阿基）是一个主要的未满足的医疗需求 选择和疾病的重大医疗负担。阿基死亡率保持在50-80%， 几十年来没有改善，凸显了对更好治疗的迫切需要。缺血再灌注损伤（IRI） 和肾毒性药物（例如，顺铂）是阿基病理生理学中的关键致病因素。IRI是一个专业 在器官移植和心胸、血管和普通外科手术期间的挑战。广泛的 病理过程，包括氧化应激、炎症和细胞死亡程序的激活，例如 细胞凋亡和坏死有助于阿基中的组织损伤和肾功能障碍。我们选择了p53， CXCR 4作为联合治疗的潜在靶点，可影响重要的代谢和促炎作用 阿基中的路径该建议通过开发一种新的肾脏保护治疗方法来解决迫切需要的问题。 能够选择性联合抑制阿基中p53和CXCR 4的新型整合siRNA递送平台。的 目的是开发创新的聚合物-siRNA缀合物，用于有效和安全地递送CXCR 4拮抗剂 和抗p53 siRNA（sip 53）对损伤肾的近端小管细胞的作用。为了达到这个目标，我们会使用 聚合物CXCR 4拮抗剂（PCX）作为sip 53载体，并测试PCX-sip 53缀合物是否递送至CXCR 4 过度表达近端小管逆转ATP耗竭并改善炎症、肾损伤和 功能障碍我们将通过实现以下具体目标来实现总体目标。在目标1中， 使用不同接头化学和不同分子量合成共价PCX-siRNA缀合物， PCX的化学成分我们将确定偶联物的安全性、CXCR 4拮抗作用以及 由于PCX对促进siRNA的细胞质递送的有益作用， siRNA。在目标2中，我们将通过进行以下操作来验证缀合物的近端小管选择性递送： 综合药代动力学和生物分布研究，并评估IRI和顺铂的疗效 小鼠阿基模型。在目标3中，我们将详细评估性能最佳的PCX的治疗效果- SIP 53结合物。使用野生型小鼠和近端小管选择性小鼠中的一组机制研究， p53基因敲除后，我们将阐明p53和CXCR 4的联合抑制如何改善病理生理学。 关于阿基总之，PCX-siRNA缀合物的创新设计将建立一种广泛适用的方法 用于将治疗性siRNA特异性递送至受损的肾脏。PCX-siRNA缀合物设计还将具有 更广泛的影响，并作为各种其他缺血性疾病的有效治疗方法的前奏 包括心肌缺血和中风。

PROJECT SUMMARY Acute kidney injury (AKI) is a major unmet medical need due to the lack of effective pharmacological treatment options and significant healthcare burden of the disease. The fact that AKI mortality remains at 50-80% and has not improved in decades underscores the critical need for better treatments. Ischemia-reperfusion injury (IRI) and nephrotoxic agents (e.g., cisplatin) are critical causative factors in AKI pathophysiology. IRI is a major challenge during organ transplantation and cardiothoracic, vascular and general surgery. A wide range of pathological processes including oxidative stress, inflammation and activation of cell death programs, such as apoptosis and necrosis contribute to tissue injury and renal dysfunction in AKI. We have selected p53 and CXCR4 as potential targets for combination therapies that affect important metabolic and proinflammatory pathways in AKI. This proposal addresses the urgent need for new renoprotective treatments by developing a novel integrated siRNA delivery platform capable of selective combined inhibition of p53 and CXCR4 in AKI. The objective is to develop innovative polymer-siRNA conjugates for efficient and safe delivery of CXCR4 antagonist and anti-p53 siRNA (sip53) to proximal tubule cells of the injured kidneys. To achieve the objective, we will use polymeric CXCR4 antagonist (PCX) as the sip53 carrier and test if delivery of PCX-sip53 conjugates to CXCR4 overexpressing proximal tubule reverses ATP depletion and ameliorates inflammation, renal injury and dysfunction. We will accomplish the overall objective by pursuing the following specific aims. In aim 1, we will synthesize covalent PCX-siRNA conjugates using different linker chemistries and different molecular weight and chemical composition of PCX. We will establish the conjugate safety, CXCR4 antagonism, and the ability to deliver siRNA to proximal tubule cells due to the beneficial effect of PCX on facilitating cytoplasmic delivery of the siRNA. In aim 2, we will validate the proximal tubule-selective delivery of the conjugates by conducting comprehensive pharmacokinetic and biodistribution study and evaluating therapeutic efficacy in IRI and cisplatin models of AKI in mice. In aim 3, we will assess in detail the therapeutic efficacy of the best-performing PCX- sip53 conjugate. Using a set of mechanistic studies in wild type mice and in mice with proximal tubule-selective p53 knockout, we will illuminate how the combined inhibition of p53 and CXCR4 ameliorates the pathophysiology of AKI. Overall, the innovative design of the PCX-siRNA conjugates will establish a widely applicable approach for specific delivery of therapeutic siRNA to the injured kidney. The PCX-siRNA conjugate design will also have broader impact and serve as a prelude to efficacious treatment approaches in various other ischemic diseases including myocardial ischemia and stroke.