陈慧伟++彭再梅

[摘要] 目的 探讨高迁移率蛋白1（HMGB1）在脂多糖诱导的急性肺损伤中的作用，以及甲基强的松龙注射剂干预后其在急性肺损伤中的表达变化。 方法 将54只清洁级成年雄性SD大鼠随机分成3组：①正常对照组（N组）：每只大鼠经尾静脉途径给予生理盐水2 mL/kg，1 h后再经尾静脉途径给予生理盐水1 mL/kg；②急性肺损伤组（ALI组）：尾静脉注射脂多糖6 mg/kg，1 h后再经尾静脉途径给予生理盐水1 mL/kg；③甲基强的松龙干预组（MPN组）：每只大鼠经尾静脉途径给予脂多糖6 mg/kg，1 h后再经尾静脉途径给予甲基强的松龙20 mg/kg。三组分别于注射后12、24、36 h麻醉处死后采集标本，每个时相点取6只大鼠。采用免疫组织化学法和实时定量PCR（Real-Time PCR）法检测各组各时相点大鼠肺组织HMGB1表达水平，同时观察肺组织病理学改变，并测定干湿重比（W/D）。采用SPSS 20.0统计学软件分析，数据处理采用方差分析。 结果 N组中大鼠肺组织有少量HMGB1 mRNA及其蛋白表达，ALI组和MPN组大鼠肺组织中HMGB1 mRNA及其蛋白表达水平明显高于N组，差异均有统计学意义（均P < 0.05），24 h表达达峰值；同一时相点ALI组大鼠肺组织HMGB1 mRNA及其蛋白表达水平高于MPN组，差异有统计学意义（P < 0.05）。ALI组大鼠与MPN组不同时相点W/D增高，与N组比较差异有高度统计学意义（P < 0.01），MPN组与ALI组比较W/D下降（P < 0.05或P < 0.01）。与N组比较，ALI组和MPN组组织病理学有不同程度的病理损害，MPN组比ALI组坏死程度轻，炎症细胞浸润少。 结论 HMGB1在炎症后期持续性高水平表达，在ALI发生、发展过程中，尤其是ALI后期失控性炎性反应过程中可能发挥重要作用。甲基强的松龙注射剂通过影响HMGB1 mRNA及其蛋白表达，对脂多糖所致的急性肺损伤有一定的保护作用。

[关键词] 脂多糖；急性肺损伤；高迁移率蛋白1；甲基强的松

[中图分类号] R96 [文献标识码] A [文章编号] 1673-7210（2014）11（c）-0029-04

Effect of Methyl Prednisolone on high mobility protein 1 expression in LPS-induced acute lung injury

CHEN Huiwei1 PENG Zaimei2

1.Department of Emergency， the Central Hospital of Zhuzhou City， Hu′nan Province， Zhuzhou 412000， China； 2.Department of Emergency， the Second Xiangya Hospital Alliliated of Central South University， Hu′nan Province， Changsha 410000， China

[Abstract] Objective To explore the function of high mobility group box1 （HMGB1） in rats′lung tissue with acute lung injury induced by lipopolysaccharide and the intervention effect of Methyly Prednisolone Injection. Methods Fifty-four male SD rats were randomly divided into three groups： control group （n=18， injected 1 mL/kg saline through tail vein after the 2 mL/kg saline was injected）， ALI group （n=18， injected 1 mL/kg saline through tail vein after the 6 mg/kg lipopolysaccharide was injected）， MPN group （n=18， injected 20 mg/kg Methyl Prednisolone through tail vein after the 6 mg/kg lipopolsaccharide was injected）. Six rats of each group were killed at the twelve hour， twenty-four hour and thirty-six hour after the lipopolsaccharide was injected. Rats′blood from carotid artery was collected for vigor analysis. The HMGB1 mRNA and its protein expression of the rats′lung was measured by immunohistochemistry and RT-PCR in different periods of each group. At the same time the pathological changes of the lung tissues， and the proportion of wet and dry （W/D） were observed. Results Little HMGB1 mRNA and its protein was expressed in the lung tissue of control group， but was increased quickly in ALI group and MPN group with peak levels being present at 24 h， which significantly higher than that in control group （P < 0.05）. HMGB1 mRNA and its protein in MPN group was less expressed than that in ALI group （P < 0.05）. The proportion of wet and dry in ALI group and MPN group increased significantly， which was higher than that in control group （P < 0.01）， but the proportion of wet and dry in MPN group was lower than that in ALI group in different times （P < 0.05 or P < 0.01）. Compared with control group， it was observed different degrees of damage of lung′s pathological structure in ALI group and MPN group. There was more inflammatory cell and cell necrosis in ALI group. Conclusion It shows HMGB1 mRNA and its protein has a persistent high levels of expression on the stage of inflammation. This uncontrolled inflammation reaction contributes to the development of acute lung injury. Methyl Prednisolone， which through the effect of the expression of HMGB1 mRNA and its protein， has a protective effect to acute lung injury induced by lipopolysaccharide.

[Key words] Lipopolsaccharide； Acute lung injury； High mobility group box1； Methyl Prednisolo

急性肺损伤（ALI）是由抗炎因子与促炎因子失衡引发多脏器功能紊乱在肺部的表现。高迁移率族蛋白（high mobility group box，HMGB）作为参与级联反应的晚期炎症介质成为了研究的热点和潜在的有效干预靶点。大中剂量糖皮质激素既不能预防ALI/急性呼吸窘迫综合征（ARDS）的发生，对早期ALI/ARDS也没有治疗作用，且副作用大，相关并发症多[1-3]；但小剂量激素治疗是否能改善其预后还不确定。……