SENP1在大鼠低氧性肺动脉高压形成中肺血管壁中表达及可能作用

The expression and possible role of SENP1 in the pulmonary vascular wall of rat during the development of hypoxic pulmonary hypertension

目的:探讨大鼠低氧性肺动脉高压(HPH)形成过程中SENP1在肺小动脉的动态表达变化及作用。方法:40只成年雄性Wistar大鼠随机分为5组(n=8):对照组和缺氧3 d、7 d、14 d2、1 d组,常压间断低氧复制HPH大鼠模型。测各组大鼠平均肺动脉压(mPAP)、右心室肥大指数(RVHI)、血管形态学指标;原位杂交、逆转录-聚合酶链反应(RT-PCR)检测肺内SUMO特异性蛋白酶-1(SUMO-specific proteases-1,SENP1)mRNA表达,免疫组化、Westernblot检测其蛋白质水平。结果:①缺氧7 d后,肺小动脉出现血管重塑,且mPAP明显上升;低氧14 d后,肺小动脉重塑更明显,mPAP达高峰。RVHI在低氧14 d后明显增加。②原位杂交显示,SENP1 mRNA在对照组肺小动脉壁呈阳性表达,低氧后其相对量无明显变化。RT-PCR显示肺组织SENP1 mRNA表达与原位杂交所观察到的肺小动脉壁SENP1 mRNA变化趋势一致;SENP1蛋白在对照组呈阳性表达,低氧7 d后其表达量开始呈进行性下降。Western blot显示肺组织内SENP1蛋白表达与免疫组化观察到的肺小动脉壁SENP1蛋白变化趋势一致。③SENP1蛋白与mPAP、重塑指数、RVHI均呈负相关。结论:慢性低氧诱导肺小动脉壁SENP1蛋白降解,进而可能在HPH发病过程中发挥一定的作用。

Objective： To investigate the dynamic expression and role of SENP1（SUMO-specific proteases-1） in the pulmonary vascular wall of rat during the development of hypoxic pulmonary hypertension（HPH）.Methods： Forty adult male Wistar rats were randomly divided into 5 groups（n=8）,and exposed to normoxia（Control group） or exposed to hypoxia for 3,7,14 or 21 d,respectively.The HPH models were established by normobaric intermittent hypoxia.Mean pulmonary arterial pressure（mPAP）,right ventricle hypertrophy index（RVHI）,and vessel morphometry were measured.Reverse transcriptase-polymerase chain reaction（RT-PCR） and in situ hybridization were used to determine the mRNA expression of SENP1.Immunohistochemistry and Western blot were used to determine the protein expression of SENP1.Results： The hypoxic rats developed pulmonary vascular remodeling in pulmonary arterioles after 7 d of hypoxia exposure.Pulmonary vascular remodeling in pulmonary arterioles significantly increased after 14 d of hypoxia.The level of mPAP in hypoxic rats increased significantly after 7 d of hypoxia,reached its peak after 14 d of hypoxic exposure.RVHI was markedly increased after 14 d of hypoxia.In situ hybridization and immunohistochemical analysis showed that SENP1 mRNA and protein were positively stained in control.SENP1 mRNA expression had little changes after exposure to hypoxia compared with the control,however,SENP1 protein expression was declined gradually after 7 d of hypoxia.The results of RT-PCR and Western blot showed that the same dynamic expression of SENP1 mRNA and protein in lung tissues of rats.Linear correlation analysis showed that SENP1 protein were negatively correlated with mPAP,pulmonary vascular remodeling index and RVHI.Conclusion： Under chronic hypoxia,SENP1 protein can be degradated.The dynamic expression of SENP1 protein may play a role in implicating in the development of HPH.