Signaling circuits that drive cell movement and ligand scavenging by chemokine receptor CCR2

趋化因子受体 CCR2 驱动细胞运动和配体清除的信号通路

• 批准号: 10727691
• 负责人: Tracy M Handel
• 金额: $ 2.73万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-05-01 至 2025-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10727691
• 关键词: Arthritis; Biological; Biological Process; CCL2 gene; Cells; Clinical Trials; Complex; Coupled; Cues; Data; Diabetic Nephropathy; Disease; Endothelial Cells; Etiology; Extracellular Matrix; Feedback; G-Protein-Coupled Receptors; GTP-Binding Proteins; Gene Silencing; Inflammatory; Inflammatory Response; Intervention; Ligands; Literature; Location; Lysosomes; Malignant neoplasm of pancreas; Mass Spectrum Analysis; Mediating; Methods; Migration Assay; Modeling; Mutation; Network-based; Neurodegenerative Disorders; Outcome; Pathway interactions; Pharmaceutical Preparations; Phosphorylation; Physiological; Plasma; Preparation; Property; Proteins; Reaction; Role; Signal Pathway; Signal Transduction; Stimulus; System; Testing; Therapeutic; Time; Tissues; Transducers; Traumatic Brain Injury; Validation; Work; antagonist; cell motility; cell type; chemokine; chemokine receptor; clinical efficacy; computer framework; desensitization; directional cell; experimental study; extracellular; fatty liver disease; fluorescence imaging; follow-up; in silico; migration; monocyte; monocyte chemoattractant protein 1 receptor; network models; non-alcoholic fatty liver disease; novel; pharmacologic; podocyte; preclinical study; receptor; recruit; response; spatiotemporal; therapeutic development; therapeutic target; trafficking

Monocyte migration into tissues, guided by inflammatory chemokine CCL2 and its G protein-coupled receptor CCR2, is key to both normal physiological responses and many diseases including neurodegenerative disease, traumatic brain injury, arthritis, diabetic nephropathy and non-alcoholic fatty liver disease. Moreover, CCR2 is currently the target of ongoing clinical trials for diabetic nephropathy and pancreatic cancer. Given the therapeutic significance of CCR2, it is surprising that its role in monocyte function is so poorly understood. In particular, while CCR2 is well-recognized to promote cell movement, what is largely unappreciated, is that it has a second, equally important function, whereby it scavenges chemokines from the extracellular medium by internalizing and trafficking chemokine to lysosomes for degradation. Scavenging may enable receptor- expressing cells to move along gradients of increasing chemokine concentration without desensitizing; it may also modulate the responsiveness of receptors on different cells by altering the availability of specific chemokines, thereby regulating whether and what type of cells migrate. We hypothesize that it is, in fact, the cohesive integration of these two functions (cell movement and scavenging) that enables CCR2 to effectively control directional cell migration in different biological contexts. Moreover, we hypothesize that external cues involving ligand concentration and interactions with extracellular matrix components define a switch between a scenario where the receptor rapidly desensitizes and one where it remains responsive, continues to migrate, and efficiently scavenges chemokine. The objective of this proposal is to achieve a comprehensive and predictive systems-based understanding of the signaling and trafficking mechanisms that regulate CCR2 migration and scavenging functions. Here we propose three Aims: (i) We will delineate the roles of key transducers of CCR2- mediated migration and scavenging by combining pharmacological inhibition and gene silencing with cell based assays of migration and scavenging and fluorescence imaging of receptor trafficking. We will also further define the mechanisms that regulate the switch from receptors being desensitized upon activation to maintaining responsiveness and becoming efficient scavengers; (ii) We will discover and characterize novel proteins that regulate CCR2 migration and scavenging using unbiased Mass Spectrometry based approaches coupled with orthogonal methods of analysis and Boolean network modeling to prioritize key regulators for validation as in Aim 1; (iii) We will develop predictive in silico network-based models of CCR2 signaling and trafficking using Boolean reaction-contingency networks initially informed by literature with refinement from systematic data collected in Aims 1 and 2. The expected outcome of this proposal is predictive and spatiotemporally-resolved interactome and signaling network of CCR2 that reveals currently unknown functional and regulatory mechanisms of monocyte migration and scavenging.

炎性趋化因子CCL2及其G蛋白偶联受体引导单核细胞向组织内迁移 CCR2是正常生理反应和包括神经退行性疾病在内的许多疾病的关键， 创伤性脑损伤、关节炎、糖尿病肾病和非酒精性脂肪肝。此外，CCR2是 目前正在进行的糖尿病肾病和胰腺癌临床试验的靶点。给定 CCR2的治疗意义，令人惊讶的是，人们对其在单核细胞功能中的作用知之甚少。在……里面 特别是，虽然CCR2被公认为促进细胞运动，但人们很大程度上没有意识到它具有 第二个同样重要的功能是，它通过以下方式从细胞外介质中清除趋化因子 内化和运输趋化因子到溶酶体进行降解。清除可能使受体- 表达细胞沿趋化因子浓度增加的梯度移动而不减敏；它可能 还通过改变特定受体的可用性来调节不同细胞上受体的反应性 趋化因子，从而调节是否和什么类型的细胞迁移。我们假设，事实上，它是 这两个功能(细胞移动和清除)的紧密集成使CCR2能够有效地 控制细胞在不同生物环境中的定向迁移。此外，我们假设外部线索 涉及配体浓度和与细胞外基质成分的相互作用定义了 受体迅速脱敏，保持反应，继续迁移的情景， 并有效地清除趋化因子。这项建议的目标是实现全面和可预测的 以系统为基础了解规范CCR2迁移和交易的信令和交易机制 清道夫功能。在这里，我们提出了三个目标：(I)我们将描绘CCR2关键转导分子的角色- 药物抑制和基因沉默与细胞结合介导的迁移和清除 基于迁移和清除的分析以及受体运输的荧光成像。我们还将进一步 定义调节受体从激活时脱敏到维持的转换的机制 响应性和成为有效的清道夫；(Ii)我们将发现和表征新的蛋白质， 利用基于无偏向质谱学的方法结合 采用正交分析方法和布尔网络建模来确定验证关键调节器的优先级，如下所示 目标1；(3)我们将开发基于计算机网络的CCR2信令和交易的预测性模型 使用最初由文献提供的布尔反应-偶发网络，并从系统数据中进行改进 在目标1和目标2中收集。这一提议的预期结果是预测性的和时空分辨率的 CCR2的互动组和信号网络揭示了目前未知的功能和调节 单核细胞迁移和清除机制。