Expression and localization of lung surfactant protein B in Eustachian tube epithelium
Expression and localization of lung surfactant protein B in Eustachian tube epithelium
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DOI：
10.1152/ajplung.2001.280.2.l214
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发表时间：
2001-02-01
影响因子：
4.9
通讯作者：
Hallman, M
中科院分区：
文献类型：
--
作者：
Paananen, R;Glumoff, V;Hallman, M
表面活性蛋白（SP）B是肺表面活性物质复合物的重要组成部分，参与降低肺泡气液界面的表面张力。咽鼓管（ET）连接上呼吸道和中耳，作为咽和中耳之间的间歇性气道。最近，我们描述了SP-A和SP-D在ET中的表达，提示它们在中耳宿主防御中的作用。我们目前的目的是检测是否SP-B的表达是明显的猪ET。通过北方印迹分析、RT-PCR和原位杂交等方法，检测到SP-B mRNA在ET上皮中的表达。免疫组化、电镜和免疫电镜显示SP-B的细胞定位。该蛋白存在于上皮细胞的分泌颗粒中，也附着在这些细胞腔侧的微绒毛上。从ET灌洗液中分离的聚集物的SP-B免疫反应性与从支气管肺泡灌洗液中分离的聚集物相似。我们的结论是，有专门的细胞在ET上皮表达和分泌SP-B，并提出SP-B可能有助于正常开放的管和粘液纤毛运输。
Surfactant protein (SP) B is an essential component of the pulmonary surfactant complex, which participates in reducing the surface tension across the alveolar air-liquid interface. The Eustachian tube (ET) connects the upper respiratory tract to the middle ear, serving as an intermittent airway between the pharynx and the middle ear. Recently, we described the expression of SP-A and SP-D in the ET, suggesting their role in middle ear host defense. Our present aim was to detect whether the expression of SP-B is evident in the porcine ET. With Northern blot analysis, RT-PCR, and in situ hybridizations, SP-B mRNA was identified and localized in the ET epithelium. The cellular localization of SP-B was revealed with immunohistochemistry, electron microscopy, and immunoelectron microscopy. The protein was found in the secretory granules of epithelial cells and also attached to the microvilli at the luminal side of these cells. The SP-B immunoreactivity of aggregates isolated from ET lavage fluid was similar to that isolated from bronchoalveolar lavage fluid. We conclude that there are specialized cells in the ET epithelium expressing and secreting SP-B and propose that SP-B may facilitate normal opening of the tube and mucociliary transport.