血小板线粒体调节肺毛细血管屏障功能的实验研究

Platelet mitochondria modulate lung microvascular barrier function in acid-induced lung injury

目的探讨血小板线粒体对肺损伤(ALI)时肺毛细血管通透性的调节作用。方法建立盐酸(p H 1.2,1.5 ml/kg)诱发的急性肺损伤动物模型,通过肺毛细血管滤过系数、流式细胞仪检测、共聚焦显微镜方法,观察血小板线粒体对盐酸致急性肺损伤形成中肺毛细血管屏障功能的影响。结果与正常组比较,盐酸致肺损伤模型中肺毛细血管滤过系数增高2.5倍(n=4,P<0.05),灭活血小板线粒体后,肺毛细血管滤过系数增高5倍(n=4,P<0.05)。流式细胞仪分析血小板线粒体转移到白细胞中;共聚焦显微镜发现,血小板与中性粒细胞相互作用促进肺损伤。结论抑制血小板线粒体功能增加盐酸诱导的肺损伤,肺血管内皮屏障依赖于血小板线粒体的功能,线粒体从血小板传递给白细胞可导致增加白细胞粘附到损伤的微血管内皮。

Objective To determine the role of platelet mitochondria in lung microvascular barrier regulation in the mouse model of acid-induced acute lung injury（ ALI）. Methods To induce ALI,HCl（ p H1.2,1.5 ml / kg） was used in the isolated mouse lungs by airway instillation. After 1 h,it was determined the microvascular filtration coefficient（ Kf） to quantify lung microvascular barrier properties. pulmonary vascular cells were isolated for flow cytometry and confocal microscopy to detect the role of platelet mitochondria in lung microvascular barrier regulation in the mouse model of acid-induced ALI. Results Acid instillation increased Kf 2. 5- fold above baseline（ n = 4,P〈0. 05）,indicating that acid instillation caused major microvascular injury. In isolated mouse lung perfused with rotenone-treated platelets,acid instillation increased Kf 5-fold above baseline（ n = 4,P0.05）. The presence of platelet mitochondria in the leukocyte was evident optically,as well as by the flow cytometry and confocal microscopy. Conclusions Inhibiting platelet mitochondrial function increases lung injury in the acid-aspiration model of ALI. Lung endothelial barrier protection depends on functioning platelet mitochondria. The mitochondrial transfer from platelet to leukocyte resulted in increased leukocyte adhesion to injuried microvessel.