摘要目的 观察创伤弧菌脓毒症大鼠肺组织HMGB1表达和肺损伤的动态变化,并探讨HMGB1在创伤弧菌脓毒症肺损伤中作用.方法 温州医学院生命科学院实验室,清洁级SD大鼠60只,随机分为正常组(A组,n=10)和创伤弧菌脓毒症组(B组,n=50),采用大鼠左下肢皮下注射创伤弧菌悬液(浓度为6×108cfu/mL,剂量为0.1 mL/100 g)制作大鼠创伤弧菌脓毒症模型),B组于染菌后1、6、12、24、48 h后活杀(各时间点n=10),采用逆转录聚合酶链式反应(RT-PCR)和蛋白免疫印迹(Western blot)分别检测大鼠肺组织HMGB1基因与蛋白的表达,检测肺含水分数和光镜观察肺组织病理变化,数据采用单因素方差分析,并用LSD法进行组间两两比较,P＜0.05为差异有统计学意义.结果 B组染菌后12 h(1.161±0.358,P=0.013)、24 h(1.679±0.235,P=0.000)及48 h(1.258±0.274,P=0.004)大鼠肺组织HMGB1 mRNA表达量较A组(0.652±0.177)明显增高(P＜0.05),并于24 h达到高峰;与A组(0.594±0.190)比较,B组HMGB1蛋白表达量于感染后6 h(1.408±0.567,P=0.026)(P＜0.05)逐渐增加,24 h达到高峰(2.415±1.064,P=0.000);与A组(0.699±0.054)比较,B组大鼠肺含水分数于感染后6 h(0.759±0.030,P=0.001)、12 h(0.767±0.023,P=0.000)、24 h(0.771±0.043,P=0.000)和48 h(0.789±0.137,P=0.000)明显增大(P＜0.05),呈逐渐递增趋势;感染后12 h,大鼠肺内血管明显充血,间质水肿并伴炎性浸润,且逐渐加重,到48 h肺泡腔塌陷明显,肺泡间隔分界不清.结论 大鼠创伤弧菌脓毒症可导致肺脏损伤,HMGB1的表达增加可能是创伤弧菌脓毒症大鼠肺组织损伤的机制之一.

abstractsObjective To observe the dynamic changes of high mobility group protein B1 ( HMGB1 )expression in the lung of rats with Vibrio vulnificus sepsis so as to unravel the role of HMGB1 in lung injury.Methods Sixty rats of clean grade were randomly divided into normal control group ( A group, n = 10) and Vibrio vulnificus sepsis group (B group, n =50). Sepsis model was made in rats with subcutaneous injection of Vibrio vulnificus with concentration of 6 × 108 cfu/ml in dose of 0. 1 ml/100 g into left lower limb.The rats of group B were sacrificed 1 h, 6 h, 12 h, 24 h and 48 h after infection for taking lung tissues to detect the water content of lung and to observe the histopathological changes in lung under light microscope.The expression of HMGB1 mRNA and the level of HMGB1 protein in the lungs were detected by RT-PCR and Western blot, respectively. Data were analysed with ANOVA and LSD method for comparison between groups, and P ＜0.05 was considered statistically significant. Results Compared with the group A (0.652±0. 177), the expressions of HMGB1 mRNA in lung of rats of group B were significantly higher in 12 hours (1. 161 ±0.358, P=0.013), 24 hours (1.679 ±0.235, P =0.000) and 48 hours (1.258 ±0.274, P=0.004) and reached the peak in 24 h. Compared with group A (0.594 ±0. 190), the level of HMGB1 protein in rats of group B 6 h after infection ( 1. 408 ± 0. 567, P = 0. 026) was significantly increased (P＜0.05), and it reached peak in 24 h (2.415 ± 1.064, P =0.000) after infection. Compared with group A (0.699 ± 0.054), the lung water contents in rats of group B were significantly increased in 6 h (0.759±0.030, P=0.001), in 12 h (0.767 ±0.023, P =0.000), in 24 h (0.771 ±0.043, P=0.000) and in 48 h (0.789 ±0.137, P=0.000) after infection. Compared with group A, the pathological changes in the lung of rats in group B showed clearly marked pulmonary vascular congestion, interstitial edema and inflammatory cell infiltration, and those changes became more and more serious until alveolar sacs entirely collapsed and the boundaries of the alveolar septa could not be clearly identified in 48 h. Conclusions Vibrio vulnificus sepsis leads to the lung injury of infected rats, and the increase in the expression of HMGB1 mRNA in lung might be one of the mechanisms of lung injury in rats with Vibrio vulnificus sepsis.