Rationale: Systemic inflammation compromises the reparative properties of endothelial progenitor cell (EPC) and their exosomes on myocardial repair, although the underlying mechanism of loss of function of exosomes from inflamed EPCs is still obscure. Objective: To determine the mechanisms of IL-10 (interleukin-10) deficient-EPC-derived exosome dysfunction in myocardial repair and to investigate if modification of specific exosome cargo can rescue reparative activity. Methods and Results: Using IL-10 knockout mice mimicking systemic inflammation condition, we compared therapeutic effect and protein cargo of exosomes isolated from wild-type EPC and IL-10 knockout EPC. In a mouse model of myocardial infarction (MI), wild-type EPC-derived exosome treatment significantly improved left ventricle cardiac function, inhibited cell apoptosis, reduced MI scar size, and promoted post-MI neovascularization, whereas IL-10 knockout EPC-derived exosome treatment showed diminished and opposite effects. Mass spectrometry analysis revealed wild-type EPC-derived exosome and IL-10 knockout EPC-derived exosome contain different protein expression pattern. Among differentially expressed proteins, ILK (integrin-linked kinase) was highly enriched in both IL-10 knockout EPC-derived exosome as well as TNFα (tumor necrosis factor-α)-treated mouse cardiac endothelial cell-derived exosomes (TNFα inflamed mouse cardiac endothelial cell-derived exosome). ILK-enriched exosomes activated NF-κB (nuclear factor κB) pathway and NF-κB-dependent gene transcription in recipient endothelial cells and this effect was partly attenuated through ILK knockdown in exosomes. Intriguingly, ILK knockdown in IL-10 knockout EPC-derived exosome significantly rescued their reparative dysfunction in myocardial repair, improved left ventricle cardiac function, reduced MI scar size, and enhanced post-MI neovascularization in MI mouse model. Conclusions: IL-10 deficiency/inflammation alters EPC-derived exosome function, content and therapeutic effect on myocardial repair by upregulating ILK enrichment in exosomes, and ILK-mediated activation of NF-κB pathway in recipient cells, whereas ILK knockdown in exosomes attenuates NF-κB activation and reduces inflammatory response. Our study provides new understanding of how inflammation may alter stem cell-exosome-mediated cardiac repair and identifies ILK as a target kinase for improving progenitor cell exosome-based cardiac therapies.

中文翻译：

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白介素10缺乏症通过整合素相关激酶富集改变了内皮祖细胞对心肌修复的外来体修复作用。

原理：全身性炎症损害了内皮祖细胞（EPC）及其外泌体在心肌修复中的修复特性，尽管发炎的EPC导致外泌体功能丧失的基本机制仍然不清楚。目的：确定IL-10（白细胞介素10）缺陷型EPC引起的外泌体功能障碍在心肌修复中的作用，并研究修饰特定的外泌体货物能否挽救修复活性。方法和结果：我们使用模仿系统性炎症条件的IL-10敲除小鼠，比较了从野生型EPC和IL-10敲除EPC分离的外泌体的治疗效果和蛋白质负荷。在小鼠心肌梗死（MI）模型中，野生型EPC衍生的外来体治疗显着改善了左心室的心脏功能，抑制了细胞凋亡，减少MI疤痕的大小，并促进MI后新血管形成，而IL-10基因敲除的EPC衍生的外泌体治疗显示出减弱的相反作用。质谱分析显示野生型EPC衍生的外泌体和IL-10敲除EPC衍生的外泌体包含不同的蛋白质表达模式。在差异表达的蛋白质中，ILK（整合素连接的激酶）在IL-10基因敲除的EPC衍生的外泌体以及TNFα（肿瘤坏死因子-α）治疗的小鼠心脏内皮细胞衍生的外泌体（TNFα炎症的小鼠心脏）中都高度富集内皮细胞来源的外来体）。富含ILK的外泌体激活受体内皮细胞中的NF-κB（核因子κB）途径和NF-κB依赖的基因转录，这种作用在外泌体中通过ILK敲低而部分减弱。有趣的是 IL-10基因敲除的EPC来源的外泌体中的ILK敲除可显着挽救其在心肌修复中的修复功能障碍，改善左心室心脏功能，减少MI疤痕大小，并增强MI小鼠模型的MI后新生血管形成。结论：IL-10缺乏/发炎通过上调外泌体中ILK的富集以及受体细胞中ILK介导的NF-κB途径的活化，改变了EPC衍生的外泌体功能，含量和对心肌修复的治疗作用，而外泌体中的ILK敲低则减弱了NF。 -κB激活并减少炎症反应。我们的研究为炎症如何改变干细胞外泌体介导的心脏修复提供了新的认识，并将ILK鉴定为可改善基于祖细胞外泌体的心脏疗法的靶激酶。