大鼠急性肺栓塞模型中CA3和NHE_1表达的变化

Expression changes of CA3 and NHE_1 in lung tissues of a rat acute pulmonary embolism model

目的研究大鼠急性肺栓塞模型肺组织中与酸碱平衡相关的碳酸酐酶3(CA3)和Na+/H+交换器(NHE1)的表达变化。方法建立大鼠急性肺栓塞模型,分别在急性肺栓塞后1、8、24和48 h开胸取出肺组织,然后提取肺组织的总RNA和总蛋白,以正常组为对照,采取半定量RT-PCR的方法研究CA3和NHE1在mRNA水平表达的变化;采用western-b lot方法进一步验证CA3和NHE1在蛋白水平表达的变化;同时采用免疫组织化学的方法检测大鼠肺组织中NHE1在肺栓塞前后表达的变化。结果在大鼠急性肺栓塞后的不同时间点,CA3的mRNA水平和蛋白水平均逐渐降低,而NHE1在mRNA水平和蛋白水平的表达都出现逐渐升高现象。免疫组化研究表明NHE1主要分布在支气管黏膜上皮和细支气管黏膜上皮的胞浆内,急性肺栓塞后NHE1在上皮细胞内的表达明显升高。结论大鼠急性肺栓塞后肺组织内CA3的表达降低,NHE1的表达升高,这一现象可能与机体的酸碱平衡调节相关。

AIM To study the expression changes of acid-base equilibrium related enzymes carbonic anhydrase3 （CA3） and sodium hydrogen exchanger （NHE1 ） in the lung tissues of a rat acute pulmonary embolism （PE） model. MEHTODS In this study, we constructed a rat acute PE model by injecting 3 -4 emboli into the left jugular vein. The lung tissue samples were collected at different time points of 1 h, 8 h, 24 h and 48h and the total RNA and total proteins of the lung tissues were then obtained. Normal rats were used as control. The mRNA level changes of CA3 and NHE1 were identified by semi-quantitative RT-PCR and the protein level changes of CA3 and NHE1 were validated by western blot methods. The immunohistochemical method was employed to study the distribution and expression changes of NHE1 in the lung tissues after PE. RESULTS Compared with those in controls, the mRNA levels of CA3 gradually decreased at different time points and the protein levels decreased in the lung tissues of rat acute PE models. On the contrary, the mRNA levels and protein levels of NHE1 increased gradually compared with those controls. The immunohistochemical study indicated that NHE1 was expressed mainly in the cytoplasm of epithelia of bronchi and bronchiole and up-regulated obviously after PE. CONCLUSION The expression of CA3 is down-regulated and that of NHEI is up-regulated after PE. These changes may be related to the acid-base equilibrium of the body, but their roles in the molecular mechanisms of PE still need further study