Glia maturation factor-gamma modulation of signaling pathways in macrophages

巨噬细胞信号通路的神经胶质成熟因子-γ调节

基本信息

批准号：
9357228
负责人：
GRIFFIN RODGERS
金额：
$ 58.81万
依托单位：
NATIONAL HEART, LUNG, AND BLOOD INSTITUTE
依托单位国家：
美国
项目类别：
财政年份：
资助国家：
美国
起止时间：
至
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/9357228
关键词：
Address Adhesions Back Binding Proteins Biological Process Blood Categories Cell Lineage Cell membrane Cell surface Cells Chemotactic Factors Chemotaxis Clinic Complex Data Development Disease Dysmyelopoietic Syndromes Endocytosis Erythroid Exocytosis Exposure to Gene Expression Profile Gene Expression Profiling Genes Genetic Transcription Glia Maturation Factor Global Change Granulopoiesis Hematopoiesis Hematopoietic Hematopoietic stem cells Human Integrins Length Leukemic Cell Liquid substance Maps Mediating Methods Molecular Molecular Profiling Mutation Myelogenous Myeloproliferation Oncogenes Ontology Population Process Proteins Recycling Role Signal Pathway Stem cells Stromal Cell-Derived Factor 1 Structure Suggestion System T-Lymphocyte Techniques Time Trees Two-Dimensional Gel Electrophoresis Ubiquitin Ubiquitination cell type gene product knock-down leucyl-phenylalanine leukemia macrophage meetings migration monocyte neutrophil novel overexpression prevent progenitor stem syntaxin syntaxin 4 tool ubiquitin mediated proteasome degradation

项目摘要

Monocyte migration requires the dynamic redistribution of integrins through a regulated endo-exocytosis cycle, but the complex molecular mechanisms underlying this process have not been fully elucidated. Glia maturation factor- (GMFG), a novel regulator of the Arp2/3 complex, has been shown to regulate directional migration of neutrophils and T-lymphocytes. In this study, we explored the important role of GMFG in monocyte chemotaxis, adhesion, and 1-integrin turnover. We found that knockdown of GMFG in monocytes resulted in impaired chemotactic migration toward formyl-Met-Leu-Phe (fMLP) and stromal cell-derived factor 1 (SDF-1) as well as decreased 51-integrin-mediated chemoattractant-stimulated adhesion. These GMFG knockdown impaired effects could be reversed by cotransfection of GFP-tagged full-length GMFG. GMFG knockdown cells reduced the cell surface and total protein levels of 51-integrin and increased its degradation. Importantly, we demonstrate that GMFG mediates the ubiquitination of 1-integrin through knockdown or overexpression of GMFG. Moreover, GMFG knockdown retarded the efficient recycling of 1-integrin back to the plasma membrane following normal endocytosis of 51-integrin, suggesting that the involvement of GMFG in maintaining 51-integrin stability may occur in part by preventing ubiquitin-mediated degradation and promoting 1-integrin recycling. Furthermore, we observed that GMFG interacted with syntaxin 4 (STX4) and syntaxin-binding protein 4 (STXBP4); however, only knockdown of STXBP4, but not STX4, reduced monocyte migration and decreased 1-integrin cell surface expression. Knockdown of STXBP4 also substantially inhibited 1-integrin recycling in human monocytes. These results indicate that the effects of GMFG on monocyte migration and adhesion probably occur through preventing ubiquitin-mediated proteasome degradation of 51-integrin and facilitating effective 1-integrin recycling back to the plasma membrane.

单核细胞迁移需要通过受调节的胞吐循环动态重新分配整合素，但这一过程背后的复杂分子机制尚未完全阐明。神经胶质成熟因子 (GMFG) 是 Arp2/3 复合物的一种新型调节剂，已被证明可以调节中性粒细胞和 T 淋巴细胞的定向迁移。在这项研究中，我们探讨了 GMFG 在单核细胞趋化性、粘附性和 1-整合素周转中的重要作用。我们发现，单核细胞中GMFG的敲低导致向甲酰基-Met-Leu-Phe (fMLP)和基质细胞衍生因子1 (SDF-1)的趋化迁移受损，以及51-整合素介导的趋化剂刺激的粘附减少。这些 GMFG 敲低受损效应可以通过 GFP 标记的全长 GMFG 共转染来逆转。 GMFG 敲低细胞降低了细胞表面和 51-整合素总蛋白水平，并增加了其降解。重要的是，我们证明GMFG通过GMFG的敲低或过表达来介导1-整合素的泛素化。此外，GMFG 敲低阻碍了 51-整合素正常内吞后 1-整合素有效再循环回质膜，这表明 GMFG 参与维持 51-整合素稳定性可能部分是通过阻止泛素介导的降解和促进 1 -整合素回收。此外，我们观察到 GMFG 与突触融合蛋白 4 (STX4) 和突触融合蛋白结合蛋白 4 (STXBP4) 相互作用；然而，只有 STXBP4 的敲低（而不是 STX4）会减少单核细胞迁移并减少 1-整合素细胞表面表达。 STXBP4 的敲除也显着抑制了人单核细胞中 1-整合素的再循环。这些结果表明，GMFG 对单核细胞迁移和粘附的影响可能是通过阻止泛素介导的 51-整合素蛋白酶体降解并促进 1-整合素有效回收回质膜而发生的。