肠缺血再灌注损伤小鼠髓样细胞触发受体-1表达的改变及意义

目的 建立小鼠肠缺血再灌注（I/R）损伤模型,观察小鼠小肠I/R损伤后髓样细胞触发受体-1（TREM-1）的表达及其与炎症因子水平变化的关系。方法 将72只小鼠按数字表法随机分为3组,对照组（N组）8只、假手术组（S组）32只、I/R损伤组（I/R组）32只。制备肠I/R损伤模型,制模后S组与I/R组分别于6、12、24、48 h处死8只小鼠取标本：ELISA测定外周血清中可溶性（s）TREM-1、TNF-α的水平并进行相关性分析;免疫组织化学检测小肠组织中TREM-1的表达。结果 I/R组24 h时TREM-1浓度达峰值为（1 272.88±295.52）pg/ml,各时段浓度均高于N组（168.99±22.79） pg/ml]和S组24 h（178.58±10.98） pg/ml],差异均有统计学意义（P值均〈0.01）。I/R组TNF-α值 12 h（33.03±4.12） pg/ml]开始升高, 24 h（94.01±9.44） pg/ml]达峰值。sTREM-1表达和TNF-α浓度的变化呈正相关（r=0.840,P=0.000）。免疫组化显示在I/R损伤后小鼠肠sTREM-1表达增高,24 h组染色积分最高为（3.38±0.66）分,且阳性部位主要是小肠黏膜固有层和上皮细胞。结论 小肠组织sTREM-1的表达上调可能是导致肠黏膜屏障功能下降及系统性炎症反应的重要环节;sTREM-1可作为判断肠I/R肠黏膜损伤严重程度的的检测指标。

Change and significance of triggering recepter expressed on myeloid cell-1 expression in mice with intestinal ischemia reperfusion injury

Objective To establish intestinal ischemia reperfusion injury model in mice and investigate the changes of triggering recepter expressed on myeloid cell-1（TREM-1） expression in ileum after intestine ischemia reperfusion injury and the relationship between TREM-1 expression and TNF-α level in peripheral blood. Methods Seventy-two mice were randomly divided into 3 groups： normal control group（group N）, sham operation group（group S）, ischemia reperfusion injury group（group I/R）. Intestinal ischemia reperfusion injury model was established, mice in group S and group I/R were respectively sacrificed after 6 h,12 h,24 h and 48 h, enzyme linked immunosorbent assay was used to detect the TREM-1 expression and TNF-α levels in peripheral blood and the correlation between TREM-1 expression and TNF-α levels was analyzed. The expression of TREM-1 in the small intestine tissue was observed by immunohistochemistry. Results The concentration of sTREM-1 in peripheral blood by ELISA in the group R/I reached the peak after 24 h and in this time point the concentration of sTREM-1 in peripheral blood in the group R/I was higher than the groups （178.58±10.98）pg/ml], the concentration in the group R/I displayed at all time points was higher compared with the group N （168.99±22.79）pg/ml].The difference was significant （all P values〈0.01）. TNF-α level in the group R/I began to increase after 12 h（33.03±4.12）pg/ml] and reached the peak after 24 h（94.01±9.44）pg/ml], the changes of sTREM-1 expression were positively correlated with the TNF-α levels（r=0.840,P=0.000）. Immunohistochemistry showed that the TREM-1 expression in the intestine in mice increased after ischemia reperfusion injury and the staining points was the highest in group I/R 24 h（3.38±0.66） and the positive parts were mainly small intestinal lamina propria and epithelial cells. Conclusions Upregulation of TREM-1 expression in intestinal tissue might lead to dysfunction of intestinal mucosal barrier and it might be an important link to the systemic inflammation. sTREM-1 could be used to determine the severity of intestinal mucosa injury in intestinal ischemia reperfusion injury.