Issue 2, 2011

Fluid-shear-stress-induced translocation of aquaporin-2 and reorganization of actin cytoskeleton in renal tubular epithelial cells

Abstract

In vivo, renal tubular epithelial cells are exposed to luminal fluid shear stress (FSS) and a transepithelial osmotic gradient. In this study, we used a simple collecting-duct-on-a-chip to investigate the role of an altered luminal microenvironment in the translocation of aquaporin-2 (AQP2) and the reorganization of actin cytoskeleton (F-actin) in primary cultured inner medullary collecting duct (IMCD) cells of rat kidney. Immunocytochemistry demonstrated that 3 h of exposure to luminal FSS at 1 dyn cm−2 was sufficient to induce depolymerization of F-actin in those cells. We observed full actin depolymerization after 5 h exposure and substantial re-polymerization within 2 h of removing the luminal FSS, suggesting that the process is reversible and the fluidic environment regulates the reorganization of intracellular F-actin. We demonstrate that several factors (i.e., luminal FSS, hormonal stimulation, transepithelial osmotic gradient) collectively exert a profound effect on the AQP2 trafficking in the collecting ducts, which is associated with actin cytoskeletal reorganization.

Graphical abstract: Fluid-shear-stress-induced translocation of aquaporin-2 and reorganization of actin cytoskeleton in renal tubular epithelial cells

Article information

Article type
Paper
Submitted
24 Mar 2010
Accepted
20 Sep 2010
First published
16 Nov 2010

Integr. Biol., 2011,3, 134-141

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