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

基本信息

批准号：
10360504
负责人：
Tracy M Handel
金额：
$ 46.5万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN DIEGO
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-05-01 至 2024-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10360504
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 Nerve Degeneration Network-based Neurodegenerative Disorders Outcome Pathway interactions Pharmaceutical Preparations Pharmacology 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 base cell motility cell type chemokine chemokine receptor clinical efficacy cohesion 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 podocyte preclinical study receptor recruit response spatiotemporal therapeutic development therapeutic target trafficking

项目摘要

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.

在炎症趋化因子 CCL2 及其 G 蛋白偶联受体的引导下，单核细胞迁移到组织中 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、糖尿病肾病和非酒精性脂肪肝。此外，CCR2 是目前正在进行糖尿病肾病和胰腺癌临床试验的目标。鉴于尽管 CCR2 具有治疗意义，但令人惊讶的是，人们对它在单核细胞功能中的作用却知之甚少。在特别是，虽然 CCR2 被广泛认为可以促进细胞运动，但人们基本上不认识的是，它具有第二个同样重要的功能，即它通过以下方式从细胞外介质中清除趋化因子：将趋化因子内化并运输至溶酶体进行降解。清除可能使受体表达细胞沿着趋化因子浓度增加的梯度移动而不脱敏；它可能还通过改变特定细胞的可用性来调节不同细胞上受体的反应性趋化因子，从而调节细胞是否迁移以及迁移的类型。我们假设它实际上是这两种功能（细胞运动和清除）的紧密结合使 CCR2 能够有效地控制不同生物环境中的定向细胞迁移。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而保持响应并继续迁移的情况，并有效清除趋化因子。该提案的目标是实现全面且可预测的对调节 CCR2 迁移的信号传导和运输机制的系统性理解清除功能。在这里，我们提出三个目标：（i）我们将描述 CCR2- 的关键传感器的作用通过将药理学抑制和基因沉默与细胞相结合来介导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变的机制反应能力并成为高效的清道夫； (ii) 我们将发现并表征新的蛋白质使用基于无偏质谱的方法以及结合的方法调节 CCR2 迁移和清除正交分析方法和布尔网络建模可优先考虑关键监管机构进行验证，如下所示目标1； (iii) 我们将开发基于计算机网络的 CCR2 信号传导和贩运预测模型使用最初由文献提供的布尔反应应急网络，并根据系统数据进行细化在目标 1 和 2 中收集。该提案的预期结果是预测性的和时空解析的 CCR2 的相互作用组和信号网络揭示了目前未知的功能和调控单核细胞迁移和清除的机制。