Flow-induced hardening of endothelial nucleus as an intracellular stress-bearing organelle

The mechanical contribution of nucleus in adherent cells to bearing intracellular stresses remains unclear. In this paper, the effects of fluid shear stress on morphology and elastic properties of endothelial nuclei were investigated. The morphological observation suggested that the nuclei in the cytoplasm were being vertically compressed under static conditions, whereas they were elongated and more compressed with a fluid shear stress of 2 Pa (20 dyn/cm(2)) onto the cell. The elongated nuclei remained the shape even after they were isolated from the cells. The micropipette aspiration technique on the isolated nuclei revealed that the elastic modulus of elongated nuclei, 0.62 +/- 0.15 kPa (n = 13, mean +/- SD), was significantly higher than that of control nuclei, 0.42 +/- 0.12 kPa (n = 11), suggesting that the nuclei remodeled their structure due to the shear stress. Based of these results and a transmission electron microscopy, a possibility of the nucleus as an intracellular compression-bearing organelle was proposed, which will impact interpretation of stress distribution in adherent cells. (C) 2005 Elsevier Ltd. All rights reserved.

Digital Object Identifer:10.1016/j.jbiomech.2005.06.003
Published with permission from the copyright holder. This is the author's copy, as published in Journal of Biomechanics, September 2005, Volume 38, Issue 9, Pages 1751-1759.
Publisher URL:http://dx.doi.org/10.1016/j.jbiomech.2005.06.003
Direct access to Thomson Web of Science record
Copyright © 2005 Elsevier Ltd. All rights reserved.