高迁移率族-1蛋白在烫伤后金葡菌脓毒症中的改变与意义

Significance of changes in high mobility group-1 protein in rats with postburn staphylococcus aureus sepsis

目的 探讨高迁移率族 1(HMG 1)蛋白在烫伤后金黄色葡萄球菌 (简称金葡菌 )脓毒症中的变化规律及其调控机制。方法 采用大鼠 2 0 %体表面积Ⅲ度烫伤复合金葡菌攻击所致脓毒症模型。 70只动物随机分为正常对照组 ( n =10 )、烫伤对照组 ( n =10 )和烫伤后金葡菌感染组(n =5 0 ) ,留取肝、肺组织检测HMG 1及脂多糖结合蛋白 (LBP)mRNA表达 ,同时测定组织中金葡菌肠毒素B(SEB)和内毒素含量。结果 烫伤后金葡菌感染可导致动物肝、肺组织HMG 1基因表达明显升高 ,于伤后 6～ 12h达峰值 (P <0 .0 5～ 0 .0 1) ,至 2 4h仍持续于较高水平。相关分析显示 ,肝、肺组织LBP基因表达与相应脏器HMG 1mRNA表达呈显著正相关 (分别为r =0 .80 0 ,P =0 .0 31和r =0 .942 ,P =0 .0 0 2 ) ,但内毒素与之无明显相关性。结论 烫伤后金葡菌感染可导致动物体内HMG 1基因表达上调 ,后者作为“晚期炎症介质”可能参与了脓毒症的发病过程。

Objective To investigate the changes in high mobility group-1 (HMG-1) protein in postburn staphylococcus aureus inf ection and its potential role inthe pathogenesis of sepsis.Methods Seventy male wistar rats were randomly divi ded into three groups as follows: normal control group (n=10), scald control group (n=10) and postburn sepsis group (n=50). The tissue samples from liver and lungs were collected to detect HMG-1 and lipopolysaccharide-binding proptein (LBP) mRNA expression, staphylococcal enterotoxin B(SEB) and endotoxin levels in these tissues were also measured. Results After staphylococcus aureus challenge, HM G-1 mRNA expression were up-regulated markedly in both liver and lungs, peakin g at 6～12h (P<0.05～0.01), and keeping at high levels up to 24 h. It wa s also shown that LBP gene expression was significantly positively correlated wi th hepatic and pulmonary HMG-1 gene expression (r=0.800,P=0.031 and r =0.942, P=0.002, respectively). Conclusion Thermal injury combined with staphylococcus aureus challenge could up-regulate HMG-1 expression, which may serve as a 'la te' mediator involved in the pathogenesis of postburn sepsis.