Inflammatory extracellular vesicles prompt heart dysfunction via TRL4-dependent NF-κB activation
Inflammatory extracellular vesicles prompt heart dysfunction via TRL4-dependent NF-κB activation
复制标题
DOI：
10.7150/thno.39072
复制
发表时间：
2020-01-01
期刊：
影响因子：
12.4
通讯作者：
Barile, Lucio
中科院分区：
文献类型：
--
作者：
Biemmi, Vanessa;Milano, Giuseppina;Barile, Lucio
背景：心肌梗死后，坏死性心肌细胞释放损伤相关蛋白，刺激天然免疫途径和巨噬细胞组织的浸润，从而推动炎症反应和心肌重塑。就炎症进展而言，循环炎性细胞外小泡在急性期和慢性期的缺血中起着至关重要的作用。在这项研究中，我们假设这些囊泡介导的旁分泌效应对心肌细胞产生直接的细胞毒性。因此，我们研究了在缺血事件发生后的最初几个小时内减少炎性小泡的产生是否能改善短时间和长时间的心脏结局。方法：用一种细胞外-囊泡生物生成的化学抑制剂预先在大鼠的腹膜腔内注射诱导心肌梗死。分别于心肌梗死后第7、14、28天进行超声心动图检查，评价心功能。处死时进行血流动力学分析，以评估心脏结局。通过测定灌流液中心肌肌钙蛋白I(CTnI)的水平来评价循环EV的体外细胞毒性效应。结果：心肌梗死后的炎症反应使携带IL-1α、IL-1β和RANTES等致炎因子的细胞外小泡数量显著增加。在缺血急性期减少炎性囊泡的增加可在活体内保留左心室射血分数。血流动力学分析证实功能恢复，表现为左室舒张速度加快，收缩能力改善。根据cTnI释放的评估，与健康(非梗死)大鼠分离的循环小泡相比，当添加到离体心的灌流液中时，梗死后的循环小泡在成年心肌细胞中诱导的细胞死亡明显更多。结论：心肌梗死急性期靶向循环细胞外小泡可能为保护缺血心脏功能提供一种有效的治疗途径。
Background: After myocardial infarction, necrotic cardiomyocytes release damage-associated proteins that stimulate innate immune pathways and macrophage tissue infiltration, which drives inflammation and myocardial remodeling. Circulating inflammatory extracellular vesicles play a crucial role in the acute and chronic phases of ischemia, in terms of inflammatory progression. In this study, we hypothesize that the paracrine effect mediated by these vesicles induces direct cytotoxicity in cardiomyocytes. Thus, we examined whether reducing the generation of inflammatory vesicles within the first few hours after the ischemic event ameliorates cardiac outcome at short and long time points.Methods: Myocardial infarction was induced in rats that were previously injected intraperitoneally with a chemical inhibitor of extracellular-vesicle biogenesis. Heart global function was assessed by echocardiography performed at 7, 14 and 28 days after MI. Cardiac outcome was also evaluated by hemodynamic analysis at sacrifice. Cytotoxic effects of circulating EV were evaluated ex-vivo in a Langendorff, system by measuring the level of cardiac troponin I (cTnI) in the perfusate. Mechanisms undergoing cytotoxic effects of EV derived from pro-inflammatory macrophages (MI) were studied in-vitro in primary rat neonatal cardiomyocytes.Results: Inflammatory response following myocardial infarction dramatically increased the number of circulating extracellular vesicles carrying alarmins such as IL-1 alpha, IL-1 beta and Rantes. Reducing the boost in inflammatory vesicles during the acute phase of ischemia resulted in preserved left ventricular ejection fraction in vivo. Hemodynamic analysis confirmed functional recovery by displaying higher velocity of left ventricular relaxation and improved contractility. When added to the perfusate of isolated hearts, post-infarction circulating vesicles induced significantly more cell death in adult cardiomyocytes, as assessed by cTnI release, comparing to circulating vesicles isolated from healthy (non-infarcted) rats. In vitro inflammatory extracellular vesicles induce cell death by driving nuclear translocation of NF-kappa B into nuclei of cardiomyocytes.Conclusion: Our data suggest that targeting circulating extracellular vesicles during the acute phase of myocardial infarction may offer an effective therapeutic approach to preserve function of ischemic heart.