Role of TBK1/IKK epsilon inhibition in pancreatic beta cell regeneration

TBK1/IKK epsilon 抑制在胰腺 β 细胞再生中的作用

• 批准号: 9539010
• 负责人: CHONG H SHIN
• 金额: --
• 依托单位: GEORGIA INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2017-09-02
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9539010
• 关键词: Address; Adult; Architecture; B Cell Proliferation; Beta Cell; Biochemical; Biological Availability; Cell Count; Cell physiology; Cyclic AMP; Data; Development; Diabetes Mellitus; Enhancers; Exhibits; FRAP1 gene; Failure; Functional disorder; Genetic; Genetic Screening; Goals; Human; IKKepsilon; Immune; Immune response; Impairment; In Vitro; Infection; Inflammatory Response; Insulin; Insulin Resistance; Insulin-Dependent Diabetes Mellitus; Interferons; Islets of Langerhans; Lead; Mediating; Metabolic; Mitogens; Modeling; Molecular; Mus; Natural regeneration; Obese Mice; Oral; Outcome; Pathway interactions; Peptides; Phosphotransferases; Play; Residual state; Role; Signal Transduction; Sirolimus; Specificity; Streptozocin; Structure of beta Cell of islet; Structure-Activity Relationship; System; TANK-binding kinase 1; Testing; Therapeutic; Toxic effect; Transgenic Organisms; Validation; Zebrafish; acrylic acid; amlexanox; analog; azastene; blood glucose regulation; chemical genetics; design; drug candidate; glucose metabolism; glycemic control; improved; in vivo; inhibitor/antagonist; insulin sensitivity; islet; kinase inhibitor; mouse model; novel; overexpression; scaffold; screening; small molecule; small molecule inhibitor

Diabetes mellitus is characterized by impaired glucose homeostasis resulting from insufficiency or functional failure of insulin-producing β−cells, alone or in association with insulin resistance. Therefore, restoring β-cell mass and function is essential to reverse the development of diabetes. Utilizing small molecule inducers of β-cell proliferation is a particularly promising strategy with numerous valuable features such as their oral bioavailability and target specificity. However, the slow rate of β-cell proliferation in adult humans is a major hurdle to overcome to use this approach. Through a chemical genetic screen for small molecule enhancers of β-cell regeneration in zebrafish, we identified several TBK1/IKKε inhibitors (TBK1/IKKε-Is). TBK1/IKKε-Is promoted β-cell regeneration by markedly increasing proliferation of β-cells. Mammalian target of rapamycin (mTOR) inhibitor rapamycin eliminated the effect of TBK1/IKKε-Is on regenerating β-cells, whereas TBK1/IKKε-Is augmented mTOR activity. Interestingly, treatment with TBK1/IKKε-Is led to pronounced increase in cAMP levels. The proliferation effect of TBK1/IKKε-Is was verified in primary mammalian islets including human islets. The goal of this application is to delineate the mechanisms and the strategies of how to increase functional β-cell mass with suppression of TBK1/IKKε. First, we will design and investigate the potency of novel TBK1/IKKε-Is on β-cell regeneration. Using (E)-3-(3-phenylbenzo[c]isoxazol-5-yl)acrylic acid (abbreviated as PIAA), which markedly increases β-cell regeneration, as a lead compound, we will perform structure-activity relationship (SAR) analyses of TBK1/IKKε-PIAA interaction. Furthermore, we will use the PIAA as a scaffold to design new molecular architectures that exhibit potent and selective TBK1/IKKε inhibition activities with minimum toxicity on β-cell regeneration. Second, we will elucidate underlying mechanisms of TBK1/IKKε-mediated β-cell regeneration. Given that rapamycin treatment abolished the effect of TBK1/IKKε suppression on β-cell regeneration and TBK1/IKKε-Is enhanced mTOR activity and cAMP levels, we will test whether TBK1/IKKε suppression promotes β-cell regeneration via modulating the cAMP-mTOR signaling cascade. We will perform biochemical and functional analyses to characterize the TBK1/IKKε-cAMP-mTOR interplay on β-cell regeneration in vitro and in vivo. Third, we will investigate the efficacy of TBK1/IKKε-Is on expanding functional β-cell mass in mammalian systems. We will use primary pancreatic islets to examine the potency of PIAA and its newly synthesized analogs on β-cell replication. Furthermore, we will evaluate the ability of PIAA and its analogs to promote β-cell expansion and enhance glycemic control in mice including a mouse model of streptozotocin (STZ)-induced diabetes.

糖尿病的特征是单独或与胰岛素抵抗相关的产生胰岛素的β细胞的不足或功能失败导致葡萄糖稳态受损。因此，恢复β细胞质量和功能对于扭转糖尿病的发展至关重要。利用β细胞增殖的小分子诱导剂是一种特别有前途的策略，具有许多有价值的特征，例如其口服生物利用度和靶标特异性。但是，成人人类的β细胞增殖速度缓慢是克服这种方法的主要障碍。通过斑马鱼中β细胞再生的小分子增强子的化学遗传筛选，我们鉴定了几个TBK1/IKKε抑制剂（TBK1/IKKε-IS）。 TBK1/IKKε-IS通过明显增加β细胞的增殖来促进β细胞再生。雷帕霉素（MTOR）抑制剂雷帕霉素的哺乳动物靶标消除了TBK1/IKKε-IS对再生β细胞的影响，而TBK1/IKKε-IS增强了MTOR活性。有趣的是，用TBK1/IKKε-IS治疗导致营地水平明显增加。 TBK1/IKKε-IS的增殖作用在包括人类胰岛在内的原发性哺乳动物胰岛中得到了验证。该应用的目的是描述如何通过抑制TBK1/IKKε来增加功能性β细胞质量的机制和策略。首先，我们将设计和研究新型TBK1/IKKε-IS对β细胞再生的效力。使用（e）-3-（3-苯基苯并[C] isoxazol-5-基）丙烯酸（缩写为PIAA），这显着增加了β细胞再生，作为铅化合物，我们将执行TBK1/IKK1/IKKKε-PIAA互动的结构 - 效率关系（SAR）分析。此外，我们将使用PIAA作为支架来设计新的分子体系结构，以杀死潜力和选择性的TBK1/IKKε抑制活性，对β细胞再生的毒性最小。其次，我们将阐明TBK1/IKKε介导的β细胞再生的潜在机制。鉴于雷帕霉素的治疗消除了TBK1/IKKε抑制对β细胞再生的影响，而TBK1/IKKε-IS增强了MTOR活性和cAMP水平，我们将测试TBK1/IKKε抑制是否会通过调节营地信号范围来促进β细胞再生。我们将执行生化和功能分析，以表征体外和体内β细胞再生上的TBK1/IKKε-训练 - camp-mtor相互作用。第三，我们将研究TBK1/IKKε-IS对扩展哺乳动物系统中功能性β细胞质量的有效性。我们将使用原发性胰岛胰岛来检查PIAA的效力及其在β细胞复制上的新合成类似物。此外，我们将评估PIAA及其类似物促进β细胞扩张的能力，并增强小鼠的血糖控制，包括链霉菌素（STZ）诱导的糖尿病的小鼠模型。