Targeting GLP-1 receptor trafficking to improve therapies for type 2 diabetes

靶向 GLP-1 受体转运以改善 2 型糖尿病的治疗

• 批准号: MR/R010676/1
• 负责人: Alejandra Tomas
• 金额: $ 71.58万
• 依托单位: Imperial College London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2018
• 资助国家: 英国
• 起止时间: 2018 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=MR%2FR010676%2F1
• 关键词: Targeting; GLP; receptor; trafficking; improve

Type 2 diabetes (T2D) kills around 4 million people worldwide every year and causes ill health in many more. A major underlying problem in T2D is that specialised cells in the pancreas known as beta cells start to fail and do not produce or secrete enough insulin, which is needed to control blood sugar. Beta cells can be stimulated to release more insulin by activating a surface protein known as glucagon-like peptide-1 receptor (GLP-1R). GLP-1R treatments, known as GLP-1R agonists, are already used in T2D. We have found that a process known as "receptor trafficking" limits the effectiveness of GLP-1R agonists. When the agonist activates the receptor, it also "internalises" it into the cell where it is hidden and can no longer be activated by agonists outside the cell. We showed this using a modified version of a GLP-1R agonist currently used in T2D (exendin-4, also known as "Exenatide"), which we engineered to reduce the internalisation process. This new agonist called "Ex-phe1" was much more effective than unmodified exendin-4 in mice with T2D, as it allowed the receptor to remain longer at the cell surface and be continually reactivated, leading to more insulin release. Also, despite being more effective in beta cells, Ex-phe1 did not cause more nausea, a well-known side effect of GLP-1R agonists.This project has two goals. The first is to understand how changes in GLP-1R trafficking modify insulin release from beta cells. The second, to be performed in parallel, is to optimise the compounds we generated in our preliminary work to produce new, better, treatments for T2D. Our approach includes experiments in beta cells and pancreatic tissue ("islets"), which allow us to understand events in molecular detail, and in mice with T2D, which tell us what happens at the whole body level. We place a lot of emphasis on using human islets (provided for research when surplus to requirements for organ donation), as we believe this is essential to understand and treat human disease.We highlight below some key experiments:1) We will use a combination of computer modelling and genetic modification of the GLP-1R to identify specific interactions between the receptor and Ex-phe1 or other biased GLP-1R agonists which underpin their different trafficking and therapeutic effects. This knowledge will be critical for the design of even more effective drugs in the future.2) We will genetically modify human islets to reduce levels of "beta-arrestin-2", a protein in beta cells that we believe is a key link between GLP-1R activation, trafficking, and beneficial insulin release. We will also breed genetically modified mice lacking beta-arrestin-2 in beta cells. We will use these systems to look at complex patterns of protein and gene activation within beta cells in response to GLP-1R agonist treatment. From this we hope to identify molecules that could in the future be targeted as new T2D treatments.3) We will study the long-term effects of our new, improved GLP-1R agonist Ex-phe1 on human islets transplanted into diabetic mice. Importantly, we will use a new approach in which the islets are actually transplanted in the eye, where changes to islet shape, behaviour and overall health can be directly and repeatedly viewed in a microscope. The mice will be treated with a long-lasting formulation of Ex-phe1 or exendin-4 for several months, and we will monitor changes to blood sugar, allowing us to compare the treatments for their effects on overall islet function. Due to well-known differences between mouse and human islets, we believe that using this "humanised" mice is critical to understanding long-term treatment effects.In summary, we have identified an exciting new approach based on GLP-1R trafficking for improving the treatment of T2D. In this project we will establish the molecular details of why this approach works, identify new potential drug targets and demonstrate the long-term effects of this new treatment in unique humanised mice.

2 型糖尿病 (T2D) 每年导致全球约 400 万人死亡，并导致更多人健康状况不佳。 T2D 的一个主要潜在问题是，胰腺中被称为 β 细胞的特殊细胞开始衰竭，无法产生或分泌足够的胰岛素，而胰岛素是控制血糖所需的。通过激活一种称为胰高血糖素样肽-1 受体 (GLP-1R) 的表面蛋白，可以刺激 Beta 细胞释放更多胰岛素。 GLP-1R 治疗（称为 GLP-1R 激动剂）已用于治疗 T2D。我们发现一种称为“受体运输”的过程限制了 GLP-1R 激动剂的有效性。当激动剂激活受体时，它也会将其“内化”到隐藏的细胞中，并且不能再被细胞外的激动剂激活。我们使用目前用于 T2D 的 GLP-1R 激动剂的改良版本（exendin-4，也称为“艾塞那肽”）展示了这一点，我们对其进行了设计以减少内化过程。这种名为“Ex-phe1”的新激动剂在患有 T2D 的小鼠中比未修饰的 exendin-4 更有效，因为它允许受体在细胞表面停留更长时间并不断重新激活，从而导致更多的胰岛素释放。此外，尽管 Ex-phe1 对 β 细胞更有效，但它并没有引起更多恶心，这是 GLP-1R 激动剂众所周知的副作用。该项目有两个目标。首先是了解 GLP-1R 运输的变化如何改变 β 细胞的胰岛素释放。第二个任务是同时进行，是优化我们在前期工作中生成的化合物，以产生新的、更好的 T2D 治疗方法。我们的方法包括在 β 细胞和胰腺组织（“胰岛”）中进行实验，这使我们能够了解分子细节的事件，以及在患有 T2D 的小鼠中进行实验，这告诉我们全身水平上发生了什么。我们非常重视使用人类胰岛（当超出器官捐赠要求时用于研究），因为我们相信这对于理解和治疗人类疾病至关重要。我们在下面重点介绍一些关键实验：1）我们将使用组合对 GLP-1R 进行计算机建模和基因修饰，以确定受体与 Ex-phe1 或其他偏向 GLP-1R 激动剂之间的特定相互作用，这些相互作用支撑着它们不同的运输和治疗效果。这些知识对于未来设计更有效的药物至关重要。2）我们将对人类胰岛进行基因改造，以降低“β-arrestin-2”的水平，“β-arrestin-2”是β细胞中的一种蛋白质，我们认为它是胰岛细胞之间的关键联系。 GLP-1R 激活、运输和有益的胰岛素释放。我们还将培育β细胞中缺乏β-arrestin-2的转基因小鼠。我们将使用这些系统来研究 β 细胞内响应 GLP-1R 激动剂治疗的蛋白质和基因激活的复杂模式。由此，我们希望能够识别出未来可以作为新的 T2D 治疗药物的分子。3) 我们将研究我们的新型改进型 GLP-1R 激动剂 Ex-phe1 对移植到糖尿病小鼠体内的人类胰岛的长期影响。重要的是，我们将使用一种新方法，将胰岛实际移植到眼睛中，可以在显微镜下直接、重复地观察胰岛形状、行为和整体健康状况的变化。这些小鼠将接受 Ex-phe1 或 exendin-4 长效制剂治疗几个月，我们将监测血糖变化，从而比较治疗对整体胰岛功能的影响。由于小鼠和人类胰岛之间众所周知的差异，我们相信使用这种“人源化”小鼠对于了解长期治疗效果至关重要。总之，我们已经确定了一种基于 GLP-1R 运输的令人兴奋的新方法，用于改善T2D 的治疗。在这个项目中，我们将建立这种方法起作用的分子细节，确定新的潜在药物靶点，并证明这种新疗法在独特的人源化小鼠中的长期效果。

项目成果

LUXendins reveal endogenous glucagon-like peptide-1 receptor distribution and dynamics

LUXendins 揭示内源性胰高血糖素样肽-1 受体分布和动态

• DOI: 10.1101/557132
• 发表时间: 2019
• 作者: Ast J

An expanded LUXendin color palette for GLP1R detection and visualization in vitro and in vivo

用于体外和体内 GLP1R 检测和可视化的扩展 LUXendin 调色板

• DOI: 10.26434/chemrxiv-2021-7rngq
• 发表时间: 2021
• 作者: Ast J

GRK2 regulates GLP-1R-mediated early phase insulin secretion in vivo.

• DOI: 10.1186/s12915-021-00966-w
• 发表时间: 2021-03-03
• 期刊: BMC biology
• 影响因子: 5.4
• 作者: Arcones AC;Vila-Bedmar R;Mirasierra M;Cruces-Sande M;Vallejo M;Jones B;Tomas A;Mayor F Jr;Murga C
• 通讯作者: Murga C

Glucagon-like peptide 1 receptor (GLP-1R) expression by nerve fibres in inflammatory bowel disease and functional effects in cultured neurons.

• DOI: 10.1371/journal.pone.0198024
• 发表时间: 2018
• 期刊: PloS one
• 影响因子: 3.7
• 作者: Anand U;Yiangou Y;Akbar A;Quick T;MacQuillan A;Fox M;Sinisi M;Korchev YE;Jones B;Bloom SR;Anand P
• 通讯作者: Anand P

Expanded LUXendin Color Palette for GLP1R Detection and Visualization In Vitro and In Vivo.

• DOI: 10.1021/jacsau.2c00130
• 发表时间: 2022-04-25
• 期刊: JACS AU
• 影响因子: 8
• 作者: Ast, Julia;Novak, Alissa N;Podewin, Tom;Fine, Nicholas H F;Jones, Ben;Tomas, Alejandra;Birke, Ramona;RoSSmann, Kilian;Mathes, Bettina;Eichhorst, Jenny;Lehmann, Martin;Linnemann, Amelia K;Hodson, David J;Broichhagen, Johannes
• 通讯作者: Broichhagen, Johannes