肾上腺髓质素对高氧肺损伤的保护作用研究

目的 通过观察不同实验条件下肾上腺髓质素（adrenomedullin，ADM）对人肺微血管内皮细胞中降钙素受体样受体（calcitonin receptor-like receptor，CRLR）、受体活性修饰蛋白2（receptor activity-modifying proteins，RAMP2）、细胞外信号调节激酶（extracellular regulated kinase，ERK）与蛋白激酶B（protein kinase B，PKB）表达的影响，从而探讨ADM在高氧肺损伤过程中的作用。 方法 将人肺微血管内皮细胞随机分为空气组及高氧组（各组n=3），高氧组细胞置于3 L/min 92%O₂+5%CO₂高纯混合气中培养；应用实时荧光定量逆转录聚合酶链反应和Western blot法分别检测ADM、CRLR、RAMP2、ERK1/2和PKB的mRNA及其蛋白表达水平。另取细胞分为未干扰组和干扰组（n=3），向干扰组细胞转染ADM siRNA后，检测ADM、ERK1/2、PKB的mRNA及其蛋白表达水平。 结果 与空气组相比，高氧组ADM、CRLR、RAMP2、ERK1/2、PKB的mRNA及其蛋白表达量均显著增高（P<0.05）。与未干扰组相比，干扰组ADM、ERK1/2、PKB的mRNA及其蛋白表达量均显著降低（P<0.05）。 结论 ERK1/2、PKB可能为ADM信号通路下游靶点，ADM通过调控CRLR/RAMP2介导ERK/PKB信号通路，共同参与高氧肺损伤的保护过程。

Protective effect of adrenomedullin on hyperoxia-induced lung injury

Objective To study the role of adrenomedullin (ADM) in hyperoxia-induced lung injury by examining the effect of ADM on the expression of calcitonin receptor-like receptor (CRLR), receptor activity-modifying protein 2 (RAMP2), extracellular signal-regulated kinase (ERK), and protein kinase B (PKB) in human pulmonary microvascular endothelial cells (HPMECs) under different experimental conditions. Methods HPMECs were randomly divided into an air group and a hyperoxia group (n=3 each).The HPMECs in the hyperoxia group were cultured in an atmosphere of 92% O2 (3 L/minute) +5% CO2. RT-qPCR and Western blot were used to measure the mRNA and protein expression levels of ADM, CRLR, RAMP2, ERK1/2, and PKB. Other HPMECs were divided into a non-interference group and an interference group (n=3 each), and the mRNA and protein expression levels of ADM, ERK1/2, and PKB were measured after the HPMECs in the interference group were transfected with ADM siRNA. Results Compared with the air group, the hyperoxia group had significant increases in the mRNA and protein expression levels of ADM, CRLR, RAMP2, ERK1/2, and PKB (P<0.05). Compared with the non-interference group, the interference group had significant reductions in the mRNA and protein expression levels of ADM, ERK1/2, and PKB (P<0.05). Conclusions ERK1/2 and PKB may be the downstream targets of the ADM signaling pathway. ADM mediates the ERK/PKB signaling pathway by regulating CRLR/RAMP2 and participates in the protection of hyperoxia-induced lung injury.