Gao Xin, Hao Shuangying, Yan Huiying, Ding Weiwei, Li Kuanyu, Li Jieshou
Research Institute of General Surgery, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, Jiangsu Province, China.
Jiangsu Key Laboratory for Molecular Medicine, Medical School of Nanjing University, Nanjing, Jiangsu Province, China.
J Surg Res. 2015 May 1;195(1):211-8. doi: 10.1016/j.jss.2014.12.019. Epub 2014 Dec 19.
Sepsis is one of the most troublesome problems in critically ill patients and often accompanied with multiple organ dysfunction and high mortality. Gut injury or dysfunction may contribute to the pathogenesis of sepsis. Neutrophil extracellular traps (NETs) do not only kill microorganisms but also damage host cells during inflammatory response to infection. The aim of this study was to investigate whether NETs are capable of promoting the impairment of the gut in a rat model of lipopolysaccharide (LPS)-induced sepsis.
The sepsis model was induced in rats by intraperitoneal injection of LPS (10 mg/kg). All rats were divided into three groups as follows: 1) control group; 2) LPS group; and 3) LPS + DNase I group. The DNase I solution (10 mg/kg) was injected intravenously to disrupt NETs 30 min after the LPS treatment. The animals were sacrificed at 3 h and 24 h after LPS or saline challenge. The intestinal cell apoptosis was examined by detecting the level of cleaved caspase-3 and terminal deoxynucleotidyl transferase dUTP nick-end labeling assays. The length and morphology of Villi were assessed histologically through hematoxylin and eosin stain. The levels of tumor necrosis factor-alpha and interleukin-10 in serum and intestine were detected by enzyme-linked immunosorbent assay. Intestinal injury was evaluated with Chiu scoring system.
A large number of neutrophils infiltrated were activated to release NETs in the intestine of LPS-induced septic rats. The disruption of NETs reduced the acute systemic inflammatory response and apoptosis of intestinal epithelial cells and alleviated histologic pathogenesis. Removal of NETs provided a beneficial effect on intestinal injury.
This study demonstrates that the release of NETs may contribute to the intestinal damage during sepsis.
脓毒症是重症患者最棘手的问题之一，常伴有多器官功能障碍和高死亡率。肠道损伤或功能障碍可能参与脓毒症的发病机制。中性粒细胞胞外陷阱（NETs）不仅能杀死微生物，还会在感染的炎症反应中损伤宿主细胞。本研究旨在探讨在脂多糖（LPS）诱导的脓毒症大鼠模型中，NETs是否会促进肠道损伤。
通过腹腔注射LPS（10mg/kg）诱导大鼠产生脓毒症模型。所有大鼠分为以下三组：1）对照组；2）LPS组；3）LPS + DNase I组。LPS处理30分钟后静脉注射DNase I溶液（10mg/kg）以破坏NETs。在LPS或生理盐水攻击后3小时和24小时处死动物。通过检测裂解的半胱天冬酶-3水平和末端脱氧核苷酸转移酶dUTP缺口末端标记试验来检测肠细胞凋亡。通过苏木精和伊红染色组织学评估绒毛的长度和形态。采用酶联免疫吸附测定法检测血清和肠道中肿瘤坏死因子-α和白细胞介素-10的水平。用Chiu评分系统评估肠道损伤。
在LPS诱导的脓毒症大鼠肠道中，大量浸润的中性粒细胞被激活以释放NETs。破坏NETs可降低急性全身炎症反应和肠上皮细胞凋亡，并减轻组织病理学病变。去除NETs对肠道损伤有有益作用。
本研究表明，NETs的释放可能在脓毒症期间导致肠道损伤。
