重组人促红细胞生成素对高氧肺损伤新生大鼠细胞凋亡及蛋白激酶B表达的影响

Effects of recombinant human erythropoietin on apoptosis and Akt expression in the lungs of neonatal rats with hyperoxic lung injury

目的支气管肺发育不良(bronchopulmonary dysplasia,BPD)是新生儿呼吸系统常见疾病,文中探讨rhEPO对高氧肺损伤新生大鼠肺细胞凋亡和蛋白激酶B(又称Akt)表达的影响,为BPD的防治提供实验依据。方法将新生大鼠给予60%高氧暴露,rhEPO组皮下注射rhEPO,采用TUNEL法检测肺细胞凋亡和RT-PCR法检测Akt mRNA表达水平。结果①高氧组新生大鼠肺细胞凋亡指数为44.312±12.337,明显高于空气组的12.810±4.353(P<0.01);rhEPO组凋亡指数为23.371±9.508,明显低于高氧组(P<0.01)。②高氧组肺组织Akt mRNA表达水平为0.462±0.122,明显低于空气组的1.236±0.357(P<0.01);rhEPO组肺组织Akt mRNA表达水平为0.893±0.235,明显高于高氧组(P<0.01)。结论高氧可引起新生大鼠肺细胞凋亡增多,rhEPO可明显减少肺细胞凋亡,其机制可能与肺组织Akt mRNA表达有关。

Objective Bronchopulmonary dysplasia （BPD） is a common neonatal respiratory system disease. The aim of this study is to investigate the effects of recombinant human erythropoietin（rhEPO） on Akt expression and apoptosis in the lungs of neonatal rats with hyperoxic lung injury in order to provide experimental proofs for the prevention and treatmen of BPD. Methods The neonatal rats were exposed to 60% 02 , and were subcutaneously injected with rhEPO. Finally lung cell apoptosis was evaluated by TUNEL assay and levels of Akt mRNA expression was evaluated by RT-PCR. Results （1）The of lung cells in neonatal rats exposed to hyperoxic room was 44. 312 ± 12. 337, which was higher than those exposed to room air （ 12. 810 ±4. 353）. And the apoptotic index of lung cells in rhEPO-treatment group was 23. 371 ± 9. 508, which was obviously lower than those exposed to hyperoxic room（ P 〈 0.01 ）. （2） The expression levels of Akt mRNA were 0.462 ± 0. 122 and 1. 236 ± 0.357 respectively in hyperoxic and room air group, which were statistically significant. Meanwhile, the expression levels of Akt mRNA in rhEPO-treatment group was significantly higher than that exposed to hyperoxic room. Conclusion The increasing number of lung cells may be due to the hyperoxia-exposure, while rhEPO can obviously reduce apoptosis, which may be related with Akt mRNA expression.