肺泡巨噬细胞线粒体活性氧触发IL-8释放在机械通气肺损伤中相关性研究

Study on the Correlation of IL-8 Release Triggered by Mitochondrial Reactive Oxygen Species of Alveolar Macrophages in Mechanically Ventilated Lung Injury

摘要: 目的：研究大鼠机械通气肺损伤中，肺泡巨噬细胞活性氧与炎性因子IL-8变化及相关性，揭示机械通气肺损伤中，肺泡巨噬细胞线粒体活性氧是否通过触发肺组织IL-8释放，引起肺病理损伤。方法：健康雄性SD大鼠30只，体重250~300 g，6~8周龄，采用随机数字表法分为5组(n = 6)：正常对照组(NC组)、高潮气量组 + 生理盐水组(HV + NS组)、高潮气量 + 去铁胺组(200 mg∙kg⁻¹) (HV + DFO组)、低潮气量组 + 生理盐水组(LV + NS组)、低潮气量 + 去铁胺组(200 mg∙kg⁻¹) (LV + DFO组)。NC组和HV + NS组、LV + NS组腹腔注射生理盐水2 ml；HV + DFO组、LV + DFO组腹腔注射去铁胺200 mg/kg (溶于2 ml生理盐水中)。15 min后HV + NS组、LV + NS组、HV + DFO组与LV + DFO组连接小动物呼吸机，行容量控制机械通气4 h。机械通气结束后处死大鼠，取左肺组织，光镜下观察病理学结果，并行病理损伤评分，计算肺湿/干(W/D)比值；行右肺灌洗，收集灌洗液，制备巨噬细胞悬液，采用流式细胞仪测定线粒体ROS水平，ELISA法检测肺组织IL-8。结果：与HV + NS组比较，LV + NS组肺组织病理损伤评分和W/D比值、肺泡巨噬细胞及线粒体ROS水平明显降低(P < 0.05)；LV + DFO组较HV + DFO组肺组织病理损伤评分和W/D比值、肺泡巨噬细胞及线粒体ROS水平显著降低(P < 0.05)。其中LV + DFO组与对照组比较，差异无统计学意义(P < 0.05)；线粒体ROS与肺组织IL-8具有正相关。结论：初步揭示机械通气肺损伤中，巨噬细胞活性氧释放可能触发了炎性反应，从而引起肺病理损伤。

Abstract: Objective: To study the changes and correlation between the reactive oxygen species of alveolar macrophages and the inflammatory factor IL-8 in mechanically ventilated lung injury in rats, and reveal whether the mitochondrial reactive oxygen species of alveolar macrophages trigger the release of IL-8 in the mechanically ventilated lung injury to cause lung pathological damage. Methods: Thirty healthy male SD rats, weighing 250~300 g and 6~8 weeks old, were divided into 5 groups (n = 6) by random number table: normal control group (NC group), high tidal volume group + physiological saline group (HV + NS group), high tidal volume + deferoxamine group (200 mg∙kg⁻¹) (HV + DFO group), low tidal volume group + normal saline group (LV + NS group), low tidal volume + deferoxamine group (200 mg∙kg⁻¹) (LV + DFO group). The NC group, HV + NS group and LV + NS group were intraperitoneally injected with 2 ml of normal saline; the HV + DFO group and LV + DFO group were intraperitoneally injected with 200 mg/kg deferoxamine (dissolved in 2 ml of normal saline). After 15 minutes, the HV + NS group, LV + NS group, HV + DFO group, and LV + DFO group were connected to a small animal ventilator, and volume-controlled mechanical ventilation was performed for 4 hours. After the mechanical ventilation, the rats were sacrificed, the left lung tissue was taken, the pathological results were observed under a light microscope, and the pathological damage score was concurrently calculated, and the wet weight/dry weight (W/D) ratio was calculated; the right lung was lavaged and the lavage fluid was collected. Right lung lavage was performed, lavage fluid was collected, macrophage suspension was prepared, mitochondrial ROS level was determined by flow cytometry, and IL-8 in lung tissue was detected by ELISA. Results: Compared with the HV + NS group, the lung tissue pathological damage score and W/D ratio, alveolar macrophages and mitochondrial ROS levels in the LV + NS group were significantly reduced (P < 0.05). The LV + NS group was still higher than the control group (P < 0.05); compared with HV + DFO group, lung tissue pathological damage score and W/D ratio, alveolar macrophages and mitochondrial ROS levels were significantly lower in the LV + DFO group than in the HV + DFO group (P < 0.05). Among them, there was no significant difference between the LV + DFO group and the control group (P < 0.05); there was a positive correlation between mitochondrial ROS and lung IL-8. Conclusion: In mechanically ventilated lung injury, the release of reactive oxygen species from macrophage mitochondria may trigger IL-8 inflammatory factors and cause lung pathological damage.