Bronchiolar expression of aquaporin-3 (AQP3) in rat lung and its dynamics in pulmonary oedema
Bronchiolar expression of aquaporin-3 (AQP3) in rat lung and its dynamics in pulmonary oedema
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DOI：
10.1007/s00424-004-1310-5
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发表时间：
2004-10-01
影响因子：
4.5
通讯作者：
Tamai, S
中科院分区：
文献类型：
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作者：
Sato, K;Kobayashi, K;Tamai, S
水通道蛋白(AQP)是一种水通道蛋白，允许渗透驱动的水运动。为了确定AQP1、AQP3、AQP4和AQP5在肺水肿中的动态变化，我们检测了正常和硫脲处理的大鼠肺组织中AQP1、AQP3、AQP4和AQP5的mRNA和蛋白的表达。半定量逆转录聚合酶链式反应(RT-PCR)显示，硫尿组AQP3mRNA表达显著升高，在4~8h左右达到高峰，AQP1、AQP4、AQP5、ENaC和CFTRmRNA的表达在肺水含量达到峰值后的一段时间均显著下降。免疫印迹分析显示，用药后4~10h，糖基化的AQP3蛋白表达增加。除AQP4外，其余AQP蛋白的表达无明显变化。免疫组织化学染色显示，AQP1表达于内皮细胞，AQP3表达于大气道基底部细胞，AQP3表达于细支气管立方细胞，AQP4表达于气道基外侧膜，AQP5表达于I型肺泡细胞。我们的结果表明，AQP3不仅在大气道中表达，而且在细支气管处也有表达，并与肺水肿中的水运动有关。
Aquaporins (AQPs) are water channel proteins that permit osmotically driven water movement. To determine their dynamics in pulmonary oedema, we examined the expression of mRNA and protein for AQP1, AQP3, AQP4, and AQP5 in the lungs of normal and thiourea-treated rats. In the thiourea group, lung water content increased significantly (vs. controls) with the peak at around 4 h. Semi-quantitative RT-PCR showed that AQP3 mRNA in the thiourea group rose significantly, peaking at around 4-8 h. The expression of AQP1, AQP4, AQP5, ENaC and CFTR mRNA each decreased significantly some time after the peak in lung water content. Immunoblot analysis showed that glycosylated AQP3 protein was increased 4-10 h after treatment. Expression of the other AQP proteins was not significantly altered, except for that of AQP4. Immunohistochemical examination revealed that AQP1 was expressed in endothelia, AQP3 in the basal cells of the large airways and in cuboidal cells in the bronchioles, AQP4 in the basolateral membrane of airway cells and AQP5 in type-I pneumocytes. Our results suggest that AQP3 is expressed not only in large airways, but also in bronchioles, and is related to water movement in pulmonary oedema.