Macrophages, Cell-Cell Communication, Ischemic Injury in Diabetes and the RAGE/DIAPH1 Signaling Axis

项目概要：总体 缺血是糖尿病心血管（CVD）和外周动脉疾病（PAD）的并发症， 通过单核细胞/巨噬细胞（MΦ）的募集、浸润和活化进入受影响的组织。在 糖尿病时，MΦ特性受到干扰，修复显著减轻，导致器官衰竭。的 心脏与骨骼肌的微环境对局部缺血显示出独特的反应，但 机制尚未完全理解。晚期糖基化终产物受体（receptor for advanced glycation endproducts，RECEPTOR）的配体， 如非酶促糖化和氧化的晚期糖化终产物; S100/钙颗粒蛋白和更高 - 迁移族蛋白1，其在非糖尿病和糖尿病CVD和PAD组织中积累，并自身降解， 有助于MΦ和对缺血的小生境特异性反应。小鼠总体上缺乏Ager（编码Ager的基因）。 无髓性Ager（致死性照射/骨髓移植）或无髓性Ager（致死性照射/骨髓移植）的受试者， 结扎冠状动脉左前降支和股动脉对心肌缺血模型的影响 梗死（MI）和后肢缺血（HLI）。在MI和HLI模型中，Ager缺失伴随着 通过组织MΦ含量的显著降低和炎性介质表达的减少。令人惊讶的是，在 HLI，Ager的缺失伴随着MΦ含量的增加和炎症介质的表达， 骨骼肌。然而，在这两种情况下，Ager缺失都促进了修复。我们发现， 细胞因子与细胞因子DIAPH 1的相互作用介导了信号转导、氧化应激的产生和 线粒体功能障碍（由于我们的新发现，DIAPH 1结合线粒体融合蛋白2（MFN 2）， 缺血组织MΦ，心肌细胞和内皮细胞），可能是这些RAGE依赖性的关键。 调查结果。该计划的三个项目将使用新的小鼠模型，最先进的分子生物学 技术，RAGE-DIAPH 1相互作用的新型小分子拮抗剂，NMR光谱和细胞内 荧光测定来检验以下假设，S/DIAPH 1有助于MΦ细胞内源性和MΦ- 心肌细胞串扰MI和到和MΦ-内皮细胞串扰HLI，从而放大组织 损害我们证实RAGE-DIAPH 1和DIAPH 1-MFN 2相互作用控制MΦ炎症， RAGE-DIAPH 1-MFN 2相互作用的药理学阻断和/或单核细胞/MΦ缺乏的给药 Ager或Diaph 1的表达将促进从促损伤到适应性MΦ炎症的转变，从而加速 糖尿病心脏和外周动脉系统的组织修复。体内生物学的精细整合 和分子机制研究（项目1和2）与结构生物学（项目3）确保创新， 这项工作的意义和最终的相关性，为糖尿病的新的治疗策略的发展 和局部缺血。

Project Summary: OVERALL Ischemia, a complication of diabetic cardiovascular (CVD) and peripheral arterial disease (PAD), is accompanied by the recruitment, infiltration and activation of monocytes/macrophages (MΦs), into affected tissues. In diabetes, MΦ properties are perturbed and repair is significantly mitigated, leading to organ failure. The microenvironments in the heart vs. the skeletal muscle display unique responses to ischemia, but the mechanisms are not fully understood. The ligands of the receptor for advanced glycation endproducts (RAGE), such as nonenzymatically glycated and oxidized advanced glycation endproducts; S100/calgranulins and high mobility group box 1, which accumulate in non-diabetic and diabetic CVD and PAD tissue, and RAGE itself, contribute to MΦ and niche-specific responses to ischemia. Mice globally devoid of Ager (the gene encoding RAGE) or devoid of myeloid Ager (lethal irradiation/bone marrow transplantation) are protected from the adverse effects of ligation of the left anterior descending coronary artery and the femoral artery, models for myocardial infarction (MI) and hind limb ischemia (HLI), respectively. In MI and HLI models, Ager deletion is accompanied by a marked reduction in tissue MΦ content and reduced expression of inflammatory mediators. Surprisingly, in HLI, deletion of Ager is accompanied by increased MΦ content and expression of inflammatory mediators in the skeletal muscle. Yet, in both cases, Ager deletion augured repair. Our discovery that the cytoplasmic domain of RAGE interaction with the formin, DIAPH1, mediates signal transduction, generation of oxidative stress and mitochondrial dysfunction (on account of our novel discovery that DIAPH1 binds to Mitofusin2 (MFN2) in ischemic tissue MΦs, cardiomyocytes and endothelial cells), may hold the key to these RAGE-dependent findings. The three Projects of this Program will use novel mouse models, state-of-the-art molecular biology techniques, novel small molecule antagonists of RAGE-DIAPH1 interaction, NMR spectroscopy and in-cell fluorescence assays to test the hypothesis that RAGE/DIAPH1 contributes to MΦ cell-intrinsic and MΦ- cardiomyocyte cross talk in MI and to and MΦ-endothelial cell cross talk in HLI, thereby amplifying tissue damage. We posit that RAGE-DIAPH1 and DIAPH1-MFN2 interactions control MΦ inflammation and that pharmacological blockade of RAGE-DIAPH1-MFN2 interaction and/or administration of monocytes/MΦs devoid of Ager or Diaph1 will facilitate the transition from pro-injury to adaptive MΦ inflammation and, thereby, hasten tissue repair in the diabetic heart and peripheral arterial systems. The meticulous integration of in vivo biology and molecular mechanisms studies (Projects 1 and 2) with structural biology (Project 3) assures the innovation, significance and ultimate relevance of this work for the development of novel therapeutic strategies for diabetes and ischemia.