Preclinical Validation of Transglutaminase 2 as a Novel Target for Celiac Disease

转谷氨酰胺酶 2 作为乳糜泻新靶点的临床前验证

• 批准号: 8767913
• 负责人: CHAITAN KHOSLA
• 金额: $ 48.22万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-10 至 2019-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8767913
• 关键词: Animal Model; Animals; Autoantibodies; Biological Availability; Celiac Disease; Chemicals; Clinical Protocols; Data; Development; Diet; Disease; Disease Management; Dose; Drug Kinetics; Drug Targeting; Engineering; Evaluation; Gluten; Goals; HLA-DQ8 antigen; In Vitro; Inflammatory; Interleukin-15; Intestines; Knockout Mice; Lead; Life; Lymphocyte; Mouse Strains; Mus; Oral; Patients; Pharmacodynamics; Phenotype; Population Control; Production; Protein Isoforms; Rest; Role; Schedule; Series; Small Intestines; Solubility; Specificity; T-Cell Activation; Testing; Transgenic Mice; Validation; Villous Atrophy; analog; base; clinically relevant; drug candidate; improved; in vivo; inhibitor/antagonist; intestinal epithelium; mouse model; novel; pre-clinical; public health relevance; research clinical testing; response; safety study; small molecule; therapeutic target; transglutaminase 2

DESCRIPTION (provided by applicant): The overarching goal of the proposed studies is to preclinically validate transglutaminase 2 (TG2) as a drug target for celiac disease (CeD), using the most advanced small molecule leads and the most advanced animal models available to date. CeD is a life-long, gluten-induced inflammatory disorder of the small intestine for which no non-dietary therapy exists to date. Although TG2 is widely regarded as the most attractive small molecule drug target for CeD therapy, definitive support for this pharmacologic hypothesis remains elusive. In preliminary studies, we have studied a class of irreversible TG2 inhibitors based on the mildly electrophilic 3- bromo-4,5-dihydroisoxazole motif, and have identified a lead compound (ERW1041E) with good in vitro and in vivo activity. Importantly, ERW1041E is the only TG2 inhibitor to our knowledge that has been shown to block TG2 in vivo on a once-daily dosing schedule. Separately, by engineering double and triple transgenic mouse strains, we have established an animal model that shows all four hallmarks of CeD: (i) gluten-dependent T cell activation; (ii) gluten-dependent autoantibody production; (iii) gluten-dependent infiltrationof lymphocytes into the intestinal epithelium; and (iv) gluten-dependent villous atrophy. Last but not least, we have demonstrated that oral gluten exposure activates TG2 in the small intestine of this mouse model and can be blocked by our lead compound ERW1041E. Our plans for validation of TG2 as a therapeutic target for CeD are described under two Specific Aims: 1) We will identify improved analogs of ERW1041E through synthesis and in vitro evaluation of two focused compound series. The most promising analogs will be subjected to pharmacokinetic and preliminary toxicological analysis. In particular, we seek to improve the isoform specificity o ERW1041E without sacrificing its potency, tolerability, oral bioavailability, or solubility. 2) To validate TG2 as a CeD drug target, the pharmacodynamic relationship between inhibitor dose and intestinal TG2 activity will be defined for ERW1041E and up to four improved analogs. From this data, sub-maximal and maximal inhibitory doses of each compound will be selected, and used to interrogate the role of TG2 in different clinically relevant scenarios that can be accurately mimicked in our mouse models. Together, these studies will provide clear direction for clinical evaluation of the most promising drug candidate. If the above studies are successful, then the most promising TG2 inhibitor from this project may be a suitable candidate for testing in CeD patients. Notably, recent efforts have led to the development of a short (2-week), small (40-patient) clinical protocol for such proof-of-concept studies. Thus, pending appropriate non-clinical safety studies, a new target for CeD therapy could be clinically validated within the next 5 years.

描述（由申请人提供）：拟议研究的总体目标是临床前验证转谷氨酰胺酶2 （TG2）作为乳糜泻（CeD）的药物靶点，使用迄今为止最先进的小分子先导物和最先进的动物模型。CeD是一种终身的，由麸质引起的小肠炎症性疾病，迄今为止尚无非饮食治疗方法。尽管TG2被广泛认为是CeD治疗中最具吸引力的小分子药物靶点，但对这一药理学假设的明确支持仍然难以捉摸。在前期研究中，我们研究了一类基于温和亲电性的3-溴-4,5-二氢异恶唑基序的不可逆TG2抑制剂，并鉴定了一个具有良好体内外活性的先导化合物（ERW1041E）。重要的是，据我们所知，ERW1041E是唯一一种每日一次给药可阻断TG2的TG2抑制剂。另外，通过双转基因和三转基因小鼠菌株，我们建立了一个动物模型，显示了CeD的所有四个特征：(i)谷蛋白依赖性T细胞激活；（ii）谷蛋白依赖自身抗体的产生；（iii）谷蛋白依赖性淋巴细胞浸润肠上皮；(4)麸质依赖性绒毛萎缩。最后但并非最不重要的是，我们已经证明口服谷蛋白暴露激活了该小鼠模型小肠中的TG2，并且可以被我们的先导化合物ERW1041E阻断。我们验证TG2作为CeD治疗靶点的计划有两个具体目标：1)我们将通过两个重点化合物系列的合成和体外评价来鉴定ERW1041E的改进类似物。最有希望的类似物将进行药代动力学和初步毒理学分析。特别是，我们寻求在不牺牲其效力、耐受性、口服生物利用度或溶解度的情况下提高ERW1041E的异构体特异性。2)为了验证TG2作为CeD药物靶点，将确定ERW1041E和最多四种改进类似物的抑制剂剂量与肠道TG2活性之间的药效学关系。根据这些数据，每种化合物的亚最大和最大抑制剂量将被选择，并用于询问TG2在不同临床相关场景中的作用，这些场景可以在我们的小鼠模型中准确地模拟。总之，这些研究将为最有希望的候选药物的临床评价提供明确的方向。如果上述研究成功，那么该项目中最有希望的TG2抑制剂可能是适合在CeD患者中进行测试的候选者。值得注意的是，最近的努力已经导致了这种概念验证研究的短期（2周），小型（40名患者）临床方案的发展。因此，在适当的非临床安全性研究之前，一个新的CeD治疗靶点可能会在接下来的时间里得到临床验证