Effect of Dicer-mediated let-7 expression in inflammatory macrophages on atherosclerosis

Dicer介导的炎症巨噬细胞let-7表达对动脉粥样硬化的影响

• 批准号: 326327422
• 负责人: Professor Dr. Andreas Schober
• 金额: --
• 依托单位: Institut für Prophylaxe und Epidemiologie der Kreislaufkrankheiten
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/326327422?language=en
• 关键词: Effect; Dicer; mediated; let; expression

Atherosclerosis is a main cause of myocardial infarction and stroke and thus contributes crucially to worldwide mortality. At a cellular level, different types of immune cells, mainly macrophages, accumulate in the arterial wall, where they take up lipoproteins and develop into foam cells. However, macrophages can also polarize into a pro- and anti-inflammatory phenotype, which play key roles in innate immunity. The RNase Dicer produces microRNAs that regulate macrophage polarization. We found that Dicer regulates mitochondrial function in anti-inflammatory macrophages and foam cells by producing miR-10a and let-7, thus reducing atherosclerosis. Moreover, our preliminary results show that Dicer regulates gene expression in inflammatory macrophages, which promotes the removal of dead cells (efferocytosis) and reduces cell death (apoptosis). This proposal aims to study the role of Dicer in inflammatory macrophages in atherosclerosis. We hypothesize that Dicer's production of let-7 miRNAs in inflammatory macrophages reduces atherosclerosis by regulating efferocytosis and apoptosis through mitochondrial proteins and receptors for efferocytosis. This hypothesis will be addressed by three working packages using genetically modified mouse models of atherosclerosis. In the first and second parts, we will investigate the effect of Dicer and let-7 in inflammatory macrophages on efferocytosis using a novel efferocytosis assay. Moreover, we will perform 4D live plaque imaging using confocal microscopy to evaluate the effect of Dicer and let-7 in macrophages on efferocytosis. In addition, we will study how Dicer and let-7 affect mitochondrial dynamics in inflammatory macrophages. In the second part of the proposal, we will also study how let-7 mediates the function of Dicer in inflammatory macrophages by determining functionally relevant binding sites in the Dicer-regulated genes. We will use target site blockers to specifically inhibit the interaction between let-7 and individual potential targets. Thus, we will analyze in the third part the effect of these interactions on efferocytosis, apoptosis, mitochondrial dynamics, and atherosclerosis. The results of this project aim to gain novel insights into the role of inflammatory macrophages in atherosclerosis. Losing miRNAs like let-7 may impair their function and thus promote plaque formation.

动脉粥样硬化是心肌梗塞和中风的主要原因，因此对全世界的死亡率起着至关重要的作用。在细胞水平上，不同类型的免疫细胞（主要是巨噬细胞）积聚在动脉壁中，在那里它们吸收脂蛋白并发育成泡沫细胞。然而，巨噬细胞也可以极化为促炎和抗炎表型，这在先天免疫中发挥着关键作用。 RNase Dicer 产生调节巨噬细胞极化的 microRNA。我们发现 Dicer 通过产生 miR-10a 和 let-7 来调节抗炎巨噬细胞和泡沫细胞中的线粒体功能，从而减少动脉粥样硬化。此外，我们的初步结果表明，Dicer 调节炎症巨噬细胞中的基因表达，从而促进死亡细胞的清除（胞吞作用）并减少细胞死亡（细胞凋亡）。该提案旨在研究 Dicer 在动脉粥样硬化炎症巨噬细胞中的作用。我们假设 Dicer 在炎症巨噬细胞中产生 let-7 miRNA，通过线粒体蛋白和胞吞作用受体调节胞吞作用和细胞凋亡，从而减少动脉粥样硬化。这一假设将通过使用转基因小鼠动脉粥样硬化模型的三个工作包来解决。在第一部分和第二部分中，我们将使用新型胞吞作用测定法研究炎症巨噬细胞中的 Dicer 和 let-7 对胞吞作用的影响。此外，我们将使用共焦显微镜进行 4D 活斑成像，以评估巨噬细胞中的 Dicer 和 let-7 对胞吞作用的影响。此外，我们将研究 Dicer 和 let-7 如何影响炎症巨噬细胞中的线粒体动力学。在该提案的第二部分中，我们还将通过确定 Dicer 调节基因中功能相关的结合位点来研究 let-7 如何介导炎症巨噬细胞中 Dicer 的功能。我们将使用目标位点阻断剂来特异性抑制 let-7 与单个潜在目标之间的相互作用。因此，我们将在第三部分分析这些相互作用对胞吞作用、细胞凋亡、线粒体动力学和动脉粥样硬化的影响。该项目的结果旨在获得关于炎症巨噬细胞在动脉粥样硬化中的作用的新见解。丢失像 let-7 这样的 miRNA 可能会损害它们的功能，从而促进斑块形成。