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最先进的小分子铅和迄今为止可用的最先进的动物模型来临时验证转谷氨酰胺酶2（TG2）作为腹腔疾病的药物靶标（CED）。 CED是一种终身，麸质引起的小肠炎症性疾病，迄今为止尚无非乳腺治疗。尽管TG2被广泛认为是CED疗法最有吸引力的小分子药物靶标，但对该药物假说的确定支持仍然难以捉摸。在初步研究中，我们研究了一类不可逆的TG2抑制剂，该抑制剂基于轻度亲电的3-Bromo-4,5-二羟唑基唑基序，并鉴定出具有良好体外和体内活性的铅化合物（ERW1041E）。重要的是，据我们所知，ERW1041E是唯一在每天每天给出的给药时间表中阻止体内TG2的TG2抑制剂。另外，通过工程双重和三重转基因小鼠菌株，我们建立了一个动物模型，该模型显示了CED的所有四个标志：（i）依赖面筋的T细胞激活； （ii）依赖面筋的自身抗体产生； （iii）淋巴细胞浸润到肠上皮； （iv）依赖面筋的绒毛萎缩。最后但并非最不重要的一点是，我们已经证明了口服面筋暴露在该小鼠模型的小肠中激活TG2，并且可以通过我们的铅化合物ERW1041E阻止。我们将TG2验证为CED的治疗靶标的验证的计划在两个具体目的下进行了描述：1）我们将通过合成和对两个集中复合级数的体外评估来确定ERW1041E的改进类似物。最有希望的类似物将经过药代动力学和初步毒理学分析。特别是，我们寻求提高同工型特异性O ERW1041E而不牺牲其效力，耐受性，口服生物利用度或溶解度。 2）要验证TG2为CED药物靶标，将定义抑制剂剂量和肠TG2活性之间的药效学关系，并最多改进了四个改进的类似物。从这些数据中，将选择每种化合物的亚最大抑制剂量和最大抑制剂量，并用来询问TG2在不同临床相关的情况下的作用，在我们的鼠标模型中可以准确模拟TG2。总之，这些研究将为最有前途的候选药物提供明确的方向评估。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CED患者测试的合适候选者。值得注意的是，最近的努力导致了用于此类概念验证研究的短期（2周），小（40名患者）临床方案。因此，在适当的非临床安全研究之前，可以在下一个中临床验证CED治疗的新靶标 5年。