Shear stress-induced changes of membrane transporter localization and expression in mouse proximal tubule cells Academic Article uri icon

Overview

MeSH Major

  • Cell Membrane
  • Kidney Tubules, Proximal
  • Sodium-Hydrogen Antiporter
  • Stress, Mechanical
  • Vacuolar Proton-Translocating ATPases

abstract

  • Our previous studies of microperfused single proximal tubule showed that flow-dependent Na(+) and HCO(3)(-) reabsorption is due to a modulation of both NHE3 and vacuolar H(+)-ATPase (V-ATPase) activity. An intact actin cytoskeleton was indicated to provide a structural framework for proximal tubule cells to transmit mechanical forces and subsequently modulate cellular functions. In this study, we have used mouse proximal tubule (MPT) cells as a model to study the role of fluid shear stress (FSS) on apical NHE3 and V-ATPase and basolateral Na/K-ATPase trafficking and expression. Our hypothesis is that FSS stimulates both apical and basolateral transporter expression and trafficking, which subsequently mediates salt and volume reabsorption. We exposed MPT cells to 0.2 dynes/cm(2) FSS for 3 h and performed confocal microscopy and Western blot analysis to compare the localization and expression of both apical and basolateral transporters in control cells and cells subjected to FSS. Our findings show that FSS leads to an increment in the amount of protein expression, and a translocation of apical NHE3 and V-ATPase from the intracellular compartment to the apical plasma membrane and Na/K-ATPase to the basolateral membrane. Disrupting actin by cytochalasin D blocks the FSS-induced changes in NHE3 and Na/K-ATPase, but not V-ATPase. In contrast, FSS-induced V-ATPase redistribution and expression are largely inhibited by colchicine, an agent that blocks microtubule polymerization. Our findings suggest that the actin cytoskeleton plays an important role in FSS-induced NHE3 and Na/K-ATPase trafficking, and an intact microtubule network is critical in FSS-induced modulation of V-ATPase in proximal tubule cells.

publication date

  • December 14, 2010

Research

keywords

  • Academic Article

Identity

Language

  • eng

PubMed Central ID

  • PMC3003103

Digital Object Identifier (DOI)

  • 10.1073/pnas.1015751107

PubMed ID

  • 21106755

Additional Document Info

start page

  • 21860

end page

  • 5

volume

  • 107

number

  • 50