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.

单核细胞迁移到组织中，在炎性趋化因子CCL2及其G蛋白偶联受体的指导下 CCR2是正常生理反应和许多疾病（包括神经退行性疾病）的关键， 脑外伤，关节炎，糖尿病性肾病和非酒精性脂肪肝病。而且，CCR2是 目前，正在进行的糖尿病性肾病和胰腺癌临床试验的目标。鉴于 CCR2的治疗意义，令人惊讶的是，其在单核细胞功能中的作用是如此鲜为人知。在 尤其是，尽管CCR2已被众所周知促进细胞运动，但在很大程度上没有欣赏的是它具有 第二个同样重要的功能，通过它从细胞外培养基中清除趋化因子 内部化和运输趋化因子向溶酶体降解。清除可能使受体 - 表达细胞以沿趋化因子浓度升高而不会脱敏的梯度移动；可能 还通过改变特定的可用性来调节不同细胞上受体的反应性 趋化因子，从而调节哪种类型的细胞迁移。我们假设它实际上是 这两个函数（细胞运动和清除）的内聚整合，使CCR2有效 在不同的生物学环境中控制定向细胞迁移。此外，我们假设外部提示 涉及配体浓度以及与细胞外基质组件的相互作用定义了 受体迅速脱敏的场景，并且它保持响应能力，继续迁移， 并有效地清除趋化因子。该建议的目的是实现全面和预测的 基于系统的对调节CCR2迁移和运输机制的信号传导和运输机制的理解 清除功能。在这里，我们提出了三个目标：（i）我们将描述CCR2-关键传感器的作用 通过将药理抑制和基因沉默与细胞结合的介导的迁移和清除 基于受体运输的迁移，清除和荧光成像的基于基础测定。我们还将进一步 定义调节开关的机制，从激活后被脱敏的受体到维持 响应能力并成为有效的清道夫； （ii）我们将发现并表征新颖的蛋白质 使用基于公正的质谱方法与CCR2迁移和清除 分析和布尔网络建模的正交方法，以优先考虑关键调节器的验证，如 目标1; （iii）我们将在基于硅网络的CCR2信号传导和运输模型中发展预测性 使用最初由文献告知的布尔反应 - 蒙温态网络，并从系统数据中进行改进 在目标1和2中收集。该提案的预期结果是预测的，并且存在时空分辨 CCR2的Interactome和信号网络揭示了当前未知的功能和调节性 单核细胞迁移和清除的机制。