Development of orally delivered, non-absorbable AT1 receptor antagonists for infl

描述（由申请人提供）：目前大多数治疗炎症性肠病（IBD）的药物的主要限制是这些药物的不加区分的免疫抑制作用。我们最近在小鼠右旋糖酐硫酸钠（DSS）模型中证明了通过阻断肾素-血管紧张素系统1a型（AT1a）受体的信号传导来缓解结肠炎进展的能力。干预导致结肠炎临床严重程度显著降低，组织学评分改善，促炎细胞因子表达下调。AT1a受体是触发NF？B级联，最终导致细胞凋亡。它也是纤维化形成的起始特异性，并已被证明在IBD的DDS模型中选择性过表达。因此，寻求AT1a受体拮抗剂有可能导致IBD的有效和选择性治疗。尽管这种疗法在治疗IBD方面显示出巨大的潜力，但AT1a阻断的一个主要后果是全身性低血压。为了规避这一问题，我们选择了一系列具有高阻断AT1a受体信号能力，但肠通透性差的原型药物。这些原型药物的初步临床前研究表明，经肛门给药对治疗结肠炎非常有效，没有全身血流动力学副作用。由于这些AT1a受体拮抗剂的口服有效性较差，且与AT1a受体结合较强，因此我们推测这些AT1a受体拮抗剂将是口服给药的良好候选者。我们建议合成一系列的AT1a受体拮抗剂，并在细胞基础上测试它们的有效性。这些候选药物将通过标准的啮齿动物肠道通透性和生物利用度模型测试其在整个胃肠道的吸收潜力。最后，我们将在临床前小鼠IBD模型中确定潜在先导化合物的功效。该提案的目标是开发一种使用AT1a拮抗剂的全新类型的IBD药物治疗，其重点是局部控制炎症反应，无全身副作用。由于这类药物目前尚未用于IBD，因此这种方法可能用于单一治疗，或添加到当前的方案中，从而减少全身免疫抑制。这些研究的发现可能会导致一种治疗炎症性肠病的独特策略。TSRL与dr。密歇根大学的Dan Teitelbaum， Scott Larsen和Hollis Showalter来解决这个问题。该团队在药物化学、炎症性肠病药理学和口服吸收策略等领域拥有丰富的经验和专业知识。公共卫生相关性：这个一期SBIR项目正在寻求开发治疗炎症性肠病的新药，炎症性肠病是一种使人衰弱的疾病，目前只能用引起严重副作用的药物治疗。其目标是开发一种既可以在疾病发作期间轻松口服又可以维持治疗的药物。

DESCRIPTION (provided by applicant): A major limitation with most current medical therapies for inflammatory bowel disease (IBD) is the indiscriminant immunosuppressive effect of these drugs. We have recently demonstrated the ability to palliate the progression of colitis in a mouse dextran sodium sulfate (DSS) model through blockage of signaling via the type 1a (AT1a) receptor of the renin-angiotensin system. The intervention leads to significant reduction in the clinical severity of colitis, improvement in histologic scores and a down-regulation in the expression of proinflammatory cytokines. The AT1a receptor is a specific receptor which triggers the NF?B cascade, ultimately resulting in apoptosis. It is also specific for the initiation of fibrosis formation and has been shown to be selectively overexpressed in the DDS model of IBD. Hence, pursuing the AT1a receptor antagonists has the potential to result in a potent and selective therapy for IBD. Although this treatment shows tremendous potential in treating IBD, a major consequence of the AT1a blockade is systemic hypotension. To circumvent this problem, we have selected a series of prototype drugs that display a high capacity for blockage of AT1a receptor signaling, but show poor intestinal permeability. Preliminary pre-clinical studies of these prototype drugs demonstrate very high efficacy in the treatment of colitis when delivered via the transanal route, without systemic hemodynamic side-effects. Due to their poor oral availability and their strong AT1a receptor binding, we theorize that these AT1a receptor antagonists would be good candidates for oral delivery. We propose to synthesize a series of AT1a receptor antagonists and test their efficacy in cell based assays. These candidates will be tested for their absorption potential along the entire gastrointestinal tract using standard rodent models of intestinal permeability and bioavailability. Finally, we will determine the efficacy of the potential lead compounds in a preclinical murine model of IBD. The goal of this proposal is to develop an entirely new type of drug therapy for IBD using the AT1a antagonists, which focuses on local control of the inflammatory response, without systemic side effects. Since this class of drugs is not currently used for IBD, this approach potentially could be used as either single therapy, or added to current regimens, allowing for reduced systemic immune suppression. Findings from these studies could lead to a unique strategy to treat inflammatory bowel disease. TSRL has formed a collaboration with Drs. Dan Teitelbaum, Scott Larsen and Hollis Showalter of the University of Michigan to address this problem. The team brings a wealth of experience and expertise in the areas of medicinal chemistry, inflammatory bowel disease pharmacology and oral absorption strategies to the program. PUBLIC HEALTH RELEVANCE: This phase I SBIR project is seeking to develop novel medicines for the treatment of inflammatory bowel disease, a debilitating disease that is currently only treatable with drugs which cause significant side effects. The goal is the development of a medicine that can be easily taken by mouth both during a flare-up of the disease as well as a maintenance treatment.