HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Supplemental Movies All Versions of this Article: 290/2/C444    most recent 00218.2005v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (7) Citing Articles via Google Scholar Google Scholar Articles by Osborn, E. A. Articles by Hartwig, J. H. Search for Related Content PubMed PubMed Citation Articles by Osborn, E. A. Articles by Hartwig, J. H.

VASCULAR BIOLOGY

Endothelial actin cytoskeleton remodeling during mechanostimulation with fluid shear stress

¹Brigham and Women's Hospital and Harvard Medical School, Boston; and ²Biological Engineering Division and Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts

Submitted 6 May 2005 ; accepted in final form 16 September 2005

Fluid shear stress stimulation induces endothelial cells to elongate and align in the direction of applied flow. Using the complementary techniques of photoactivation of fluorescence and fluorescence recovery after photobleaching, we have characterized endothelial actin cytoskeleton dynamics during the alignment process in response to steady laminar fluid flow and have correlated these results to motility. Alignment requires 24 h of exposure to fluid flow, but the cells respond within minutes to flow and diminish their movement by 50%. Although movement slows, the actin filament turnover rate increases threefold and the percentage of total actin in the polymerized state decreases by 34%, accelerating actin filament remodeling in individual cells within a confluent endothelial monolayer subjected to flow to levels used by dispersed nonconfluent cells under static conditions for rapid movement. Temporally, the rapid decrease in filamentous actin shortly after flow stimulation is preceded by an increase in actin filament turnover, revealing that the earliest phase of the actin cytoskeletal response to shear stress is net cytoskeletal depolymerization. However, unlike static cells, in which cell motility correlates positively with the rate of filament turnover and negatively with the amount polymerized actin, the decoupling of enhanced motility from enhanced actin dynamics after shear stress stimulation supports the notion that actin remodeling under these conditions favors cytoskeletal remodeling for shape change over locomotion. Hours later, motility returned to pre-shear stress levels but actin remodeling remained highly dynamic in many cells after alignment, suggesting continual cell shape optimization. We conclude that shear stress initiates a cytoplasmic actin-remodeling response that is used for endothelial cell shape change instead of bulk cell translocation.

atherosclerosis; cytoskeletal dynamics; endothelial cells; mechanotransduction

This article has been cited by other articles:

				J. C. del Alamo, G. N. Norwich, Y.-s. J. Li, J. C. Lasheras, and S. Chien Anisotropic rheology and directional mechanotransduction in vascular endothelial cells PNAS, October 7, 2008; 105(40): 15411 - 15416. [Abstract] [Full Text] [PDF]

				J. H. Dangaria and P. J. Butler Macrorheology and adaptive microrheology of endothelial cells subjected to fluid shear stress Am J Physiol Cell Physiol, November 1, 2007; 293(5): C1568 - C1575. [Abstract] [Full Text] [PDF]

				Y. Yao, A. Rabodzey, and C. F. Dewey Jr. Glycocalyx modulates the motility and proliferative response of vascular endothelium to fluid shear stress Am J Physiol Heart Circ Physiol, August 1, 2007; 293(2): H1023 - H1030. [Abstract] [Full Text] [PDF]