Shear-induced reorganization of renal proximal tubule cell actin cytoskeleton and apical junctional complexes
Shear-induced reorganization of renal proximal tubule cell actin cytoskeleton and apical junctional complexes
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DOI：
10.1073/pnas.0804954105
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发表时间：
2008-08-12
影响因子：
11.1
通讯作者：
Weinbaum, Sheldon
中科院分区：
文献类型：
--
作者：
Duan, Yi;Gotoh, Nanami;Weinbaum, Sheldon
在这项研究中，我们证明了流体剪切力(FSS)诱导的肾上皮细胞肌动蛋白细胞骨架重组和连接形成几乎完全与血管内皮细胞(ECs)的相应变化相反[Thi MM等人。(2004年)美国学报第101期：16483-16488页]。将小鼠近端小管细胞(PTCs)置于5h的FSS(1dyn/cm(2))中，观察FSS对丝状肌动蛋白(F-actin)、ZO-1、E-cadherin、vinculin和paxlin细胞骨架分布的动态响应。免疫荧光分析显示，FSS导致基础应力纤维断裂，周围肌动蛋白条带(DPAB)更密集，并形成紧密连接(TJ)和黏附连接(AJ)。在细胞边界和细胞内部发现明显的纽蛋白染色增强。这些反应被肌动蛋白干扰药物细胞松弛素D取消。为了解释这些结果，我们提出了PTC的“连接支撑”模型，在该模型中，FSS使DPAB、TJ和AJ变得更加紧密。相比之下，在ECs的“碰碰车”模型中，所有的连接都被FSS严重干扰。这种“连接支撑”模型解释了为什么只有EC研究中使用的1/10的FSS可以在这些高大的立方上皮细胞中引起类似戏剧性的细胞骨架反应；以及为什么相邻细胞之间的连接支撑在最大化流动激活、刷子边界依赖、跨细胞的盐和水重吸收方面可能有利于肾上皮细胞。
In this study, we demonstrate that fluid shear stress (FSS)-induced actin cytoskeletal reorganization and junctional formation in renal epithelial cells are nearly completely opposite the corresponding changes in vascular endothelial cells (ECs) [Thi MM et al. (2004) Proc Natl Acad Sci USA 101:16483-16488]. Mouse proximal tubule cells (PTCs) were subjected to 5 h of FSS (1 dyn/cm(2)) to investigate the dynamic responses of the cytoskeletal distribution of filamentous actin (F-actin), ZO-1, E-cadherin, vinculin, and paxillin to FSS. Immunofluorescence analysis revealed that FSS caused basal stress fiber disruption, more densely distributed peripheral actin bands (DPABs), and the formation of both tight junctions (TJs) and adherens junctions (AJs). A dramatic reinforcement of vinculin staining was found at the cell borders as well as the cell interior. These responses were abrogated by the actin-disrupting drug, cytochalasin D. To interpret these results, we propose a "junctional buttressing" model for PTCs in which FSS enables the DPABs, TJs, and AJs to become more tightly connected. In contrast, in the "bumper-car" model for ECs, all junctional connections were severely disrupted by FSS. This "junctional buttressing" model explains why a FSS of only 1/10 of that used in the EC study can cause a similarly dramatic, cytoskeletal response in these tall, cuboidal epithelial cells; and why junctional buttressing between adjacent cells may benefit renal epithelium in maximizing flow-activated, brush border-dependent, transcellular salt and water reabsorption.