热休克蛋白A12A改善内毒素血症肺损伤的实验研究

Heat shock protein A12A is necessary for pulmonary protection during endotoxemia

目的研究热休克蛋白(HSP)A12A在细菌脂多糖(LPS)诱导的内毒素血症肺损伤中的作用。方法采用8~10周龄的HSPA12A基因敲除鼠(Hspa12a^(-/-))和野生型对照鼠(WT)进行实验,分别对小鼠腹腔注射LPS诱导内毒素血症,或腹腔注射生理盐水(NS)作为对照组,根据小鼠类型及处理方式将小鼠分为4组NS-WT组、NS-Hspa12a^(-/-)组、LPS-WT组、LPS-Hspa12a^(-/-)组。腹腔注射6 h后取肺组织,检测肺组织中蛋白表达水平并制作肺组织石蜡切片;收集动脉血液用于动脉血气分析。通过免疫印迹检测蛋白表达水平;对肺组织石蜡切片行HE染色,评价肺组织的病理学变化得到肺损伤评分;通过血气分析评估肺功能。结果LPS处理后,HSPA12A在LPS-WT组小鼠肺组织中的表达水平是NS-WT组的1.5倍(P<0.05);LPS处理后,小鼠的肺组织出现了明显的病理变化,并且与WT鼠相比,HSPA12A基因敲除小鼠肺组织病理改变加重,肺损伤评分显著升高(P<0.01);与WT鼠相比,HSPA12A基因敲除小鼠动脉血中CO2蓄积明显增加(P<0.05)。结论HSPA12A在保护脓毒症/感染性休克肺损伤中具有重要作用。

Objective To investigate the effects of heat shock protein A12A(HSPA12A)on lung injury during endotoxemia.Methods HSPA12A knockout mice(Hspa12a^(-/-))and wild type littermates(WT)mice aged 8-10 weeks were enrolled in this study.The mice were injected with lipopolysaccharide(LPS)intraperitoneally to induce endotoxemia,while normal saline(NS)-treated mice served as the controls.According to the type of mice and treatment mode,the mice were divided into NS-WT group,NS-Hspa12a^(-/-)group,LPS-WT group and LPS-Hspa12a^(-/-)group.Six hours after LPS or NS treatment,the lung tissues were harvested for the detection of protein levels and paraffin sections.The arterial blood was collected for arterial blood gas analysis.Protein expression levels were detected by immunoblotting.Pulmonary injury scores were obtained according to the histopathological changes of the lung tissues by H&E staining,and the pulmonary function was evaluated by blood gas analysis.Results The expression level of HSPA12A in the lungs of LPS-treated mice was 150%of that in NS-treated mice(P<0.05).After LPS treatment,the lung tissues showed obvious pathological changes,and Hspa12a^(-/-)mice showed severer pulmonary histological abnormalities and higher injury scores than those in WT mice(P<0.01).Hspa12a^(-/-)mice showed increased CO2 accumulation in arterial blood than WT mice during endotoxemia(P<0.05).Conclusions HSPA12A plays an important role in the protection against sepsis/septic shock-induced lung injury.