DataSheet_1_Colivelin, a synthetic derivative of humanin, ameliorates endothelial injury and glycocalyx shedding after sepsis in mice.pdf

Endothelial dysfunction plays a central role in the pathogenesis of sepsis-mediated multiple organ failure. Several clinical and experimental studies have suggested that the glycocalyx is an early target of endothelial injury during an infection. Colivelin, a synthetic derivative of the mitochondrial peptide humanin, has displayed cytoprotective effects in oxidative conditions. In the current study, we aimed to determine the potential therapeutic effects of colivelin in endothelial dysfunction and outcomes of sepsis in vivo. Male C57BL/6 mice were subjected to a clinically relevant model of polymicrobial sepsis by cecal ligation and puncture (CLP) and were treated with vehicle or colivelin (100-200 µg/kg) intraperitoneally at 1 h after CLP. We observed that vehicle-treated mice had early elevation of plasma levels of the adhesion molecules ICAM-1 and P-selectin, the angiogenetic factor endoglin and the glycocalyx syndecan-1 at 6 h after CLP when compared to control mice, while levels of angiopoietin-2, a mediator of microvascular disintegration, and the proprotein convertase subtilisin/kexin type 9, an enzyme implicated in clearance of endotoxins, raised at 18 h after CLP. The early elevation of these endothelial and glycocalyx damage biomarkers coincided with lung histological injury and neutrophil inflammation in lung, liver, and kidneys. At transmission electron microscopy analysis, thoracic aortas of septic mice showed increased glycocalyx breakdown and shedding, and damaged mitochondria in endothelial and smooth muscle cells. Treatment with colivelin ameliorated lung architecture, reduced organ neutrophil infiltration, and attenuated plasma levels of syndecan-1, tumor necrosis factor-α, macrophage inflammatory protein-1α and interleukin-10. These therapeutic effects of colivelin were associated with amelioration of glycocalyx density and mitochondrial structure in the aorta. At molecular analysis, colivelin treatment was associated with inhibition of the signal transducer and activator of transcription 3 and activation of the AMP-activated protein kinase in the aorta and lung. In long-term outcomes studies up to 7 days, co-treatment of colivelin with antimicrobial agents significantly reduced the disease severity score when compared to treatment with antibiotics alone. In conclusion, our data support that damage of the glycocalyx is an early pathogenetic event during sepsis and that colivelin may have therapeutic potential for the treatment of sepsis-associated endothelial dysfunction.

内皮功能障碍在脓毒症介导的多器官衰竭的发病机制中居于核心地位。多项临床与实验研究表明，糖萼（glycocalyx）是感染过程中内皮损伤的早期靶标。科里韦林（colivelin）是线粒体肽人类素（humanin）的合成衍生物，在氧化应激条件下已展现出细胞保护作用。本研究旨在探究科里韦林在体内对内皮功能障碍的潜在治疗效果，以及脓毒症的预后改善作用。将雄性C57BL/6小鼠采用盲肠结扎穿刺（cecal ligation and puncture, CLP）法构建临床相关的多重微生物脓毒症模型，并于造模后1小时经腹腔给予溶剂对照或科里韦林（100~200 μg/kg）处理。我们观察到，与对照组小鼠相比，溶剂处理组小鼠在盲肠结扎穿刺后6小时，血浆黏附分子细胞间黏附分子-1（ICAM-1）、P-选择素（P-selectin）、血管生成因子内皮糖蛋白（endoglin）以及糖萼成分多配体蛋白聚糖-1（syndecan-1）的水平即出现早期升高；而微血管崩解介质血管生成素-2（angiopoietin-2）以及参与内毒素清除的枯草溶菌素转换酶9（proprotein convertase subtilisin/kexin type 9, PCSK9）的水平则在造模后18小时升高。上述内皮与糖萼损伤生物标志物的早期升高，与肺组织病理学损伤以及肺、肝、肾组织的中性粒细胞炎症反应同时出现。透射电子显微镜分析显示，脓毒症小鼠的胸主动脉可见糖萼降解与脱落增加，内皮细胞和平滑肌细胞的线粒体结构受损。科里韦林治疗可改善肺组织结构，减少器官中性粒细胞浸润，并降低血浆中多配体蛋白聚糖-1、肿瘤坏死因子-α（tumor necrosis factor-α, TNF-α）、巨噬细胞炎症蛋白-1α（macrophage inflammatory protein-1α, MIP-1α）以及白细胞介素-10（interleukin-10, IL-10）的水平。科里韦林的上述治疗效果，与主动脉中糖萼密度以及线粒体结构的改善相关。分子生物学分析显示，科里韦林治疗可抑制主动脉与肺组织中信号转导与转录激活因子3（signal transducer and activator of transcription 3, STAT3）的活性，并激活腺苷酸活化蛋白激酶（AMP-activated protein kinase, AMPK）。在长达7天的长期预后研究中，与单独使用抗菌药物治疗相比，科里韦林联合抗菌药物治疗可显著降低疾病严重程度评分。综上，本研究数据表明，糖萼损伤是脓毒症发生过程中的早期致病事件，科里韦林或可用于治疗脓毒症相关内皮功能障碍，具有潜在临床应用价值。