Shear-induced reorganization of renal proximal tubule cell actin cytoskeleton and apical junctional complexes
- 12 August 2008
- journal article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences
- Vol. 105 (32), 11418-11423
- https://doi.org/10.1073/pnas.0804954105
Abstract
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.Keywords
This publication has 19 references indexed in Scilit:
- Flow-dependent transport in a mathematical model of rat proximal tubuleAmerican Journal of Physiology-Renal Physiology, 2007
- Mechanosensory function of microvilli of the kidney proximal tubuleProceedings of the National Academy of Sciences, 2004
- The left-right determinant Inversin is a component of node monocilia and other 9+0 ciliaDevelopment, 2003
- Chemical anoxia of tubular cells induces activation of c-Src and its translocation to the zonula adherensAmerican Journal of Physiology-Renal Physiology, 2003
- Mechanical strains induced by tubular flow affect the phenotype of proximal tubular cellsAmerican Journal of Physiology-Renal Physiology, 2001
- A hydrodynamic mechanosensory hypothesis for brush border microvilliAmerican Journal of Physiology-Renal Physiology, 2000
- Luminal flow rate regulates proximal tubule H-HCO3 transportersAmerican Journal of Physiology-Renal Physiology, 1992
- Flow dependence of K+ secretion in cortical distal tubules of the ratAmerican Journal of Physiology-Renal Physiology, 1989
- Regional distribution of N-acetyl-D-galactosamine residues in the glycocalyx of glomerular podocytes.The Journal of cell biology, 1983
- Balance between tubular flow rate and net fluid reabsorption in the proximal convolution of the rat kidneyPflügers Archiv - European Journal of Physiology, 1968