Unfractionated heparin attenuates histone-mediated cytotoxicity in vitro and prevents intestinal microcirculatory dysfunction in histone-infused rats
Unfractionated heparin attenuates histone-mediated cytotoxicity in vitro and prevents intestinal microcirculatory dysfunction in histone-infused rats
复制标题
普通肝素在体外减弱组蛋白介导的细胞毒性并预防组蛋白输注大鼠的肠道微循环功能障碍
DOI：
10.1097/ta.0000000000002387
复制
发表时间：
2019-09-01
影响因子：
3.4
通讯作者：
Ma, Xiaochun
中科院分区：
文献类型：
--
作者：
Zhu, Chengrui;Liang, Yingjian;Ma, Xiaochun
背景细胞外组蛋白是脓毒症时器官功能障碍和死亡的主要介质，可导致微循环功能障碍。肝素在脓毒症中有有益的作用，据报道，肝素可与组蛋白结合并中和其细胞毒性。本研究旨在观察组蛋白对肠道微循环和肠内皮细胞的影响，并探讨普通肝素(UFH)对组蛋白诱导的内皮细胞毒性和微循环功能障碍的保护作用。方法麻醉大鼠静脉注射30 mg/kg小牛胸腺组蛋白，静脉注射UFH(100IU/kg/h)。用入射暗视野显微镜观察和测量肠道微循环。检测血浆血管性假血友病因子(VWF)和可溶性血栓调节蛋白，观察大鼠肠微血管内皮细胞的结构变化。研究了组蛋白和超滤过高对人肠微血管内皮细胞(HIMECs)细胞存活率、vWF释放和钙内流的影响。结果组蛋白灌注组大鼠在血流动力学未见明显改变的情况下，出现严重的肠道微循环障碍，UFH对组蛋白灌注组大鼠肠微循环有保护作用。组蛋白灌注组大鼠血浆内皮细胞损伤标志物vWF和可溶性血栓调节蛋白浓度升高，肠微血管内皮细胞结构异常。这些事件被超高频所减弱。在体外，UFH显著降低组蛋白诱导的HIMECs的细胞毒性，减少vWF从胞浆释放到培养液中，并抑制钙内流到HIMECs。结论组蛋白可导致肠微循环功能障碍，进而直接损伤内皮细胞，UFH对肠微循环的保护作用部分是通过拮抗组蛋白的内皮毒性而实现的。
BACKGROUND Extracellular histones are major mediators of organ dysfunction and death in sepsis, and they may cause microcirculatory dysfunction. Heparins have beneficial effects in sepsis and have been reported to bind to histones and neutralize their cytotoxicity. The aim of this study was to investigate the impact of histones on intestinal microcirculation and the intestinal endothelium and to discuss the protective effect of unfractionated heparin (UFH) on the endothelial cytotoxicity and microcirculatory dysfunction induced by histones. METHODS Anesthetized rats were infused with 30 mg/kg calf thymus histones, and UFH was administered intravenously at a concentration of 100 IU/kg per hour. The intestinal microcirculation was visualized and measured with incident dark field microscope. Plasma von Willebrand factor (vWF) and soluble thrombomodulin were detected, and structural changes in the rat intestinal microvascular endothelium were examined. The effects of histones and UFH on cell survival rates, vWF release and calcium influx were investigated in human intestinal microvascular endothelial cells (HIMECs). RESULTS Histone infusion caused severe intestinal microcirculatory dysfunction in the absence of obvious hemodynamic changes, and UFH protected intestinal microcirculation in histone-infused rats. Concentrations of the plasma endothelial injury markers vWF and soluble thrombomodulin were elevated, and structural abnormalities were found in the intestinal microvascular endothelium in the histone-infused rats. These events were attenuated by UFH. In vitro, UFH significantly reduced the histone-induced cytotoxicity of HIMECs, reduced the release of vWF from the cytoplasm into the culture medium, and inhibited calcium influx into HIMECs. CONCLUSION Histones induce intestinal microcirculatory dysfunction followed by direct injury to the endothelial cells; UFH protects the intestinal microcirculation partly by antagonizing the endothelial toxicity of histones.