Bladder filling and voiding affect umbrella cell tight junction organization and function
Bladder filling and voiding affect umbrella cell tight junction organization and function
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DOI：
10.1152/ajprenal.00282.2013
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发表时间：
2013-10-01
影响因子：
4.2
通讯作者：
Apodaca, Gerard
中科院分区：
文献类型：
--
作者：
Carattino, Marcelo D.;Prakasam, H. Sandeep;Apodaca, Gerard
Carattino MD，Prakasam HS，Ruiz WG，Clayton DR，McGuire M，Gallo Li，Apodaca G.膀胱填充和无效影响雨伞细胞紧密连接的组织和功能。 Am J Physiol肾脏生理学305：F1158-F1168，2013。首次发布于2013年7月24日； doi：10.1152/ajprenal.00282.2013.-上皮细胞不断暴露于包括剪切应力和拉伸在内的机械力，尽管这些力对紧密连接（TJ）组织和功能的影响知之甚少。伞状细胞形成分层的滴虫的最外层，并在膀胱循环中经历大细胞形状和表面积变化。在这里，我们研究了膀胱填充和排尿对伞状细胞TJ的影响。我们发现，膀胱填充促进了TJ环长度的显着增加，该长度在空隙后的5分钟内迅速逆转。有趣的是，当将隔离的卵子组织安装在Ussing Chamber中并暴露于生理延伸时，我们观察到旋转的电阻（TER）和伞状细胞连接性耐药性的下降10倍。拉伸对TER的影响是可逆的，并取决于施加的力。此外，如生物素，荧光素和红色氟烷的有限渗透性所暗示的那样，将伞状细胞TJ的完整性保持在拉伸的静脉内。最后，我们发现EGTA对细胞外Ca2+的耗竭完全破坏了未拉伸的uro上皮，但没有耗尽。综上所述，我们的研究表明，伞状细胞TJ在膀胱周期内经历了主要的结构和功能重组。讨论了这些变化对膀胱功能的影响。
Carattino MD, Prakasam HS, Ruiz WG, Clayton DR, McGuire M, Gallo LI, Apodaca G. Bladder filling and voiding affect umbrella cell tight junction organization and function. Am J Physiol Renal Physiol 305: F1158-F1168, 2013. First published July 24, 2013; doi:10.1152/ajprenal.00282.2013.-Epithelial cells are continuously exposed to mechanical forces including shear stress and stretch, although the effect these forces have on tight junction (TJ) organization and function are poorly understood. Umbrella cells form the outermost layer of the stratified uroepithelium and undergo large cell shape and surface area changes during the bladder cycle. Here we investigated the effects of bladder filling and voiding on the umbrella cell TJ. We found that bladder filling promoted a significant increase in the length of the TJ ring, which was quickly reversed within 5 min of voiding. Interestingly, when isolated uroepithelial tissue was mounted in Ussing chambers and exposed to physiological stretch, we observed a 10-fold drop in both transepithelial electrical resistance (TER) and the umbrella cell junctional resistance. The effects of stretch on TER were reversible and dependent on the applied force. Furthermore, the integrity of the umbrella cell TJ was maintained in the stretched uroepithelium, as suggested by the limited permeability of biotin, fluorescein, and ruthenium red. Finally, we found that depletion of extracellular Ca2+ by EGTA completely disrupted the TER of unstretched, but not of stretched uroepithelium. Taken together, our studies indicate that the umbrella cell TJ undergoes major structural and functional reorganization during the bladder cycle. The impact of these changes on bladder function is discussed.