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，在临床前验证转谷氨酰胺酶 2 (TG2) 作为乳糜泻 (CeD) 的药物靶标。 CeD 是一种由麸质引起的终生小肠炎症性疾病，迄今为止尚无非饮食疗法。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，但对该药理学假设的明确支持仍然难以捉摸。在初步研究中，我们研究了一类基于轻度亲电子3-溴-4,5-二氢异恶唑基序的不可逆TG2抑制剂，并鉴定了具有良好体外和体内活性的先导化合物（ERW1041E）。重要的是，ERW1041E 是我们所知的唯一一种 TG2 抑制剂，已被证明每天一次的给药方案可以在体内阻断 TG2。另外，通过改造双重和三重转基因小鼠品系，我们建立了一个动物模型，该模型显示了 CeD 的所有四个特征：（i）麸质依赖性 T 细胞激活； (ii) 麸质依赖性自身抗体的产生； (iii) 淋巴细胞依赖于麸质的方式浸润肠上皮； (iv) 麸质依赖性绒毛萎缩。最后但并非最不重要的一点是，我们已经证明，口服麸质暴露会激活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 治疗靶点的计划在两个具体目标下进行了描述：1) 我们将通过合成和体外评估两个重点化合物系列来鉴定 ERW1041E 的改进类似物。最有希望的类似物将接受药代动力学和初步毒理学分析。特别是，我们寻求提高 ERW1041E 的异构体特异性，而不牺牲其效力、耐受性、口服生物利用度或溶解度。 2) 为了验证 TG2 作为 CeD 药物靶点，将为 ERW1041E 和最多四种改进的类似物定义抑制剂剂量和肠道 TG2 活性之间的药效关系。根据这些数据，将选择每种化合物的次最大和最大抑制剂量，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模拟。总之，这些研究将为最有希望的候选药物的临床评估提供明确的方向。如果上述研究成功，那么该项目中最有前途的 TG2 抑制剂可能是在 CeD 患者中进行测试的合适候选者。值得注意的是，最近的努力已经导致为此类概念验证研究制定了短期（2 周）、小型（40 名患者）临床方案。因此，在进行适当的非临床安全性研究之前，CeD 治疗的新目标可能会在接下来的时间内得到临床验证。 5年。