腺病毒介导的p53消减基因对慢性低氧性肺动脉高压大鼠的影响

Effect of p53 knockdown gene on rats with pulmonary artery hypertension induced by hypoxia

目的探讨p53消减基因对低氧性肺动脉高压(pulmonary artery hypertension,PAH)大鼠肺动脉压力及平滑肌细胞凋亡的影响。方法SD大鼠60只随机分为常氧对照组、常氧实验Adeno-null组、常氧实验Adeno-p53组、低氧对照组、低氧实验Adeno-null组和低氧实验Adeno-p53组各10只。低氧组大鼠置于含有10%O2浓度的低氧舱中。培养2周后气管滴入3×108 MOI腺病毒,继续培养2周。利用右心导管测压法测定各组大鼠平均颈总动脉压、平均肺动脉压;称重右心室、室间隔+左心室的重量,计算右心室肥厚指数,TUNEL染色法检测左肺肺动脉平滑肌细胞的凋亡指数,评价p53消减基因转染对大鼠肺动脉压力及平滑肌细胞凋亡的影响。结果常压下持续通入10.0%O2培养4周的大鼠与正常情况下培养的大鼠相比,平均肺动脉压力显著升高,右心室明显肥厚(P<0.01或P<0.05)。低氧培养条件下,与低氧实验Adeno-null组相比,低氧实验Adeno-P53组肺动脉压和右心室肥厚指数降低(P<0.05)。低氧实验Adeno-P53组的肺动脉平滑肌细胞的凋亡指数显著高于低氧实验Adeno-null组常氧实验Adeno-p53组大鼠肺动脉平滑肌细胞的凋亡指数高于常氧实验Adeno-null组(P<0.05)。结论p53消减基因能在一定程度上缓解低氧性PAH的发展,其机制可能与p53消减基因诱导肺动脉平滑肌细胞的增加有关。

Objective To investigate the influences of transfection of adenovirus-mediated p53 knockdown gene(Adeno-p53)on the pressure of the pulmonary artery and apoptosis of smooth muscle cells in pulmonary arteries of rats under hypoxia.Methods Sixty SD rats were randomly divided into 6 groups(n=10):normoxic control group,normoxic experiment Adeno-null group,normoxic experiment Adeno-p53 group,hypoxic control group,hypoxia experiment Adeno-null group,hypoxic experiment Adeno-p53 group.Pulmonic hypertension in the hypoxia groups was induced in a hypoxic chamber by exposing the rats to an isobaric atmosphere containing 10%O2.During the third week,3×108 MOI titers Adeno-p53 and Adeno-null were dropped into the trachea below epiglottis for the experimental groups respectively,and the culture was continued for 2 weeks.The mean carotid artery pressure and the mean pulmonary arterial pressure were measured by right heart catheterization.The right ventricle,ventricular septum,and left ventricle were weighed and the right ventricular hypertrophy index was calculated.The apoptotic index of pulmonary artery smooth muscle cells was detected by TUNEL staining in the left lung tissues.Influences of p53-knockdown gene on the pressure of the pulmonary and smooth muscle cell apoptosis were evaluated.Results Compared with the rats cultured under normal pressure,the rats that continuously cultured in 10.0%O2 for 4 weeks had a significantly higher mean pulmonary artery pressure and right ventricular hypertrophy(P<0.01 or P<0.05).Under hypoxia culture conditions,compared with the hypoxia experiment Adeno-null group,the hypoxia experiment Adeno-p53 group had lower pulmonary artery pressure and right ventricular hypertrophy index(P<0.05).The apoptosis index of pulmonary artery smooth muscle cells in the hypoxia experiment Adeno-p53 group was significantly higher than that of the hypoxia experiment Adeno-null group,The apoptosis index of pulmonary artery smooth muscle cells in the Adeno-p53 group was higher than that of the Adeno-null group(P<0.05).Conclusion The p53 knockdown gene can alleviate the development of hypoxic pulmonary hypertension,which may be related to the apoptosis of vascular smooth muscle in the pulmonary artery induced by the p53 gene.