小鼠机械性肺损伤肺组织中microRNA表达差异的研究

摘要

Objective Differential expression and significance of microRNA were studied in the lung tissue of mice with acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) induced by mechanical ventilation. Method 20 C57BL mice were divided into control group (10 mice) and ventilator-induced lung injury (VILI) group (10 mice) according to random number table. The mice in VILI group after endotracheal intubation were treated with 10 ml/kg tidal volume mechanical ventilation and muscle relaxant under anaesthetic, building (ALI/ARDS) model. The mice in control group were treated without muscle relaxant and mechanical ventilation but to spontaneous breathing. All mice were sacrificed 24 hours after operation, the left lung was excised to measure the wet-to-dry weight (W/D) ratio, and the right middle lobe was stained with hematoxylin and eosin (HE), the levels of TNF-α, IL-β were detected by ELISA. A microRNA mieroarray chip was used to profile microRNA expressions in the lung of mice in both groups. Predicted target genes among the different microRNA and analysed the pathway of the targets of microRNA in this study. Result Compared with the control group, the VILI group mice had obvious respiratory symptoms, the pathology was characterized with ALI/ARDS, W/D and the levels of TNF-α, IL-β had significantly increased (P < 0.01). The microarray chip results demonstrated that the expressions of 34 microRNA were significantly changed in the ALI/ARDS mice. Among these microRNA 19 cases were up-regulated, 15 cases were down-regulated. Conclusion Pathophysiology of VILI may be involved in the microRNA-regulated inflammation pathway et al.%目的 研究小鼠机械通气所致急性肺损伤(acute lung injury,ALI)/急性呼吸窘迫综合征(acute respiratory distress syndrome,ARDS)肺组织中microRNAs的差异表达及其意义.方法 将20只小鼠按照随机数表法分为模型组(10只)与对照组(10只).模型组小鼠麻醉下气管插管后予肌松药,并予10 ml/kg潮气量行机械通气,构建(ALI/ARDS)模型.对照组小鼠麻醉下气管插管后不予肌松药,且不行机械通气,使其自主呼吸.24小时后将所有小鼠处死,测量左肺组织湿重/干重比值,HE染色观察右中肺病理变化,取肺泡灌洗液行肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)、白介素-β(interleukin-β,IL-β)水平检测.应用microRNA芯片技术检测两组小鼠肺组织中microRNA表达,对存在差异的microRNA进行靶基因预测,并对靶基因行信号通路分析.结果 模型组小鼠呼吸系统症状明显,肺组织湿重/干重比值明显高于对照组(P<0.01),与ALI/ARDS病理结果相符.模型组小鼠TNF-α、IL-1β 表达水平显著高于对照组(P<0.05).芯片结果显示模型组与对照组小鼠间存在34个明显差异表达的microRNA,上调19个,下调15个.结论 机械性ALI/ARDS病理生理可能与microRNA调控的炎症相关信号通路等有关.