Generation of hypochlorite-modified proteins by neutrophils during ischemia-reperfusion injury in rat liver: attenuation by ischemic preconditioning
Generation of hypochlorite-modified proteins by neutrophils during ischemia-reperfusion injury in rat liver: attenuation by ischemic preconditioning
复制标题
DOI：
10.1152/ajpgi.00141.2005
复制
发表时间：
2005-10-01
影响因子：
4.5
通讯作者：
Jaeschke, H
中科院分区：
文献类型：
--
作者：
Hasegawa, T;Malle, E;Jaeschke, H
尽管中性粒细胞是肝脏缺血再灌注损伤延迟期的关键因素，但尚无直接证据表明体内存在特定的中性粒细胞来源的氧化应激。因此，我们使用大鼠肝脏部分缺血60分钟和再灌注0-24小时的模型来研究中性粒细胞的聚集，并分析一般氧化应激[谷胱甘肽二硫化物(GSSG)和丙二醛(MDA)]和中性粒细胞特异性氧化应激[次氯酸盐(HOCl)修饰表位]的生物标志物。血浆丙氨酸氨基转移酶活性和组织学显示再灌流期间肝脏损伤逐渐增加，同时肝脏GSSG和可溶性丙二醛水平升高。当时，几乎没有中性粒细胞存在于肝窦中。再灌流后6~24 h，肝细胞HOCl修饰表位染色阳性的肝细胞数增加，这与大量中性粒细胞聚集和渗入实质有关。与后来更高的氧化应激一致，肝脏GSSG和蛋白结合的丙二醛水平进一步增加。在再灌注24小时，NADPH氧化酶抑制剂二苯基碘氯可减轻缺血后氧化应激(GSSG，蛋白结合的丙二醛，肝细胞HOCl修饰表位染色阳性)和肝损伤。缺血预适应抑制所有氧化应激生物标记物、肝损伤和中性粒细胞外溢。总之，在中性粒细胞介导的再灌注损伤阶段，外溢的中性粒细胞会产生HOCl，并扩散到肝细胞中，导致细胞内蛋白质的氧化修饰。缺血预适应是一种有效的干预措施，可降低全身炎症反应，特别是在再灌流后期限制中性粒细胞的细胞毒活性。
Although it is well documented that neutrophils are critical for the delayed phase of hepatic ischemia-reperfusion injury, there is no direct evidence for a specific neutrophil-derived oxidant stress in vivo. Therefore, we used a model of 60 min of partial hepatic ischemia and 0 - 24 h of reperfusion to investigate neutrophil accumulation and to analyze biomarkers for a general oxidant stress [ glutathione disulfide ( GSSG) and malondialdehyde (MDA)] and for a neutrophil-specific oxidant stress [ hypochlorite (HOCl)-modified epitopes] in rats. Plasma alanine transaminase activities and histology showed progressively increasing liver injury during reperfusion, when hepatic GSSG and soluble MDA levels were elevated. At that time, few neutrophils were present in sinusoids. However, the number of hepatocytes positively stained for HOCl-modified epitopes increased from 6 to 24 h of reperfusion, which correlated with the bulk of hepatic neutrophil accumulation and extravasation into the parenchyma. Consistent with a higher oxidant stress at later times, hepatic GSSG and protein-bound MDA levels further increased. Treatment with the NADPH oxidase inhibitor diphenyleneiodonium chloride attenuated postischemic oxidant stress ( GSSG, protein-bound MDA, and hepatocytes positively stained for HOCl-modified epitopes) and liver injury at 24 h of reperfusion. Ischemic preconditioning suppressed all oxidant stress biomarkers, liver injury, and extravasation of neutrophils. In conclusion, extravasated neutrophils generate HOCl, which diffuses into hepatocytes and causes oxidative modifications of intracellular proteins during the neutrophil-mediated reperfusion injury phase. Ischemic preconditioning is an effective intervention for reduction of the overall inflammatory response and, in particular, for limitation of the cytotoxic activity of neutrophils during the later reperfusion period.