Abstract
Cell mechanical properties are important in the adhesion of endothelial cells to synthetic vascular grafts exposed to shear flow. We hypothesized that the local apparent elastic modulus of the nucleus and the cell body would increase to a greater extent for cells adherent via the dual ligand (integrin-fibronectin/avidin-biotin) and exposed to flow, than for cells treated with either ligand alone. High affinity avidin-biotin bonds and in vitro flow exposure were used to improve adhesion to grafts thereby altering the mechanical properties of endothelial cells. Introduction of the dual ligand chemistry at the cell-substrate interface increased the apparent elastic modulus of the cells as compared to cells adherent with the fibronectin-integrin bonds only. Cells cultured on the dual ligand surface exhibited higher elastic moduli of the nucleus and cell body relative to cells cultured on fibronectin alone. Exposure of cells to flow increased the apparent elastic modulus of the cell body, nucleus, and stress fibers of cells adherent to the fibronectin surface. A similar effect was seen for cells adherent to the dual ligand surface, although there was little effect on the elastic modulus of the nucleus. While the dual ligand surface produces an increase in adhesion strength, focal contact area and elastic modulus, the change in elastic modulus after exposure to flow is due only to an increase in stress fibers and not an increase in contact area.
Similar content being viewed by others
References
Alberts B., Bray D., Lewis J., Raff M., Roberts K. J. D. W. 1994 Molecular Biology of the Cell. 3rd edn., New York: Garland Publishing Inc
Ballermann B. J., Dardik A., Eng E., Liu A. 1998 Shear stress and the endothelium. Kidney Int. 54: S100–S108
Barbee K. A., Davies P. F., Lal R. 1994 Shear stress-induced reorganization of the surface topography of living endothelial cells imaged by atomic force microscopy. Circulat. Res. 74:163–171
Bhat V. D., Truskey G. A., Reichert W. M. 1998a Fibronectin and avidin-biotin as a heterogeneous ligand system for enhanced endothelial cell adhesion. J. Biomed. Mater. Res. 41: 377–385
Burmeister J. S., Olivier L. A., Reichert W. M., Truskey G. A. 1998 Application of total internal reflection fluorescence microscopy to study cell adhesion to biomaterials. Biomaterials 19: 307–325
Chan B. P., Bhat V. D., Yegnasubramanian S., Reichert W. M., Truskey G. A. 1999 An equilibrium model of endothelial cell adhesion via integrin-dependent and integrin-independent ligands. Biomaterials. 20: 2395–2403
Cortese, J.D. and C. Frieden. Microhetreogeneity of actingels farmed under controlled linear shear. J. Cell. Biol. 107:1477–1487, 1988.
Costa K. D., Yin F. C. P. 1999 Analysis of indentation: implications for measuring mechanical properties with atomic force microscopy. J. Biomech. Eng. 121: 462–471
Dardik A., Liu A., Ballermann B. J. 1999 Chronic in vitro shear stress stimulates endothelial cell retention on prosthetic vascular grafts adn reduces subsequent in vivo neointimal thickness. J. Vascular Surg. 29: 157–167
Davies P. F., Robotewskyj A., Griem M. L. 1994 Quantitative studies of endothelial cell adhesion: directional remodeling of focal adhesion sites in response to flow forces. J. Clin. Invest. 93:2031–2038
Ezzell R. M., Goldmann W. H., Wang N., Parasharama N., Ingber D. E. 1997 Vinculin promotes cell spreading by mechanically coupling integrins to the cytoskeleton. Exp. Cell Res. 231: 14–26
Goldmann W. H., Galneder R., Ludwig M., Weiming X., Adamson E. D., Wang N., Ezzell R. M. 1998 Differences in elasticity of vinculin-deficient F9 cells measured by magnetometry and atomic force microscopy. Exp. Cell Res. 239: 235–242
Hofmann U. G., Rotsch C., Parak W. J., Radmacher M. 1997 Investigating the cytoskeleton of chicken cardiocytes with the atomic force microscope. J. Struct. Biol. 119: 84–91
Johnson, K. L. Contact Mechanics. Cambridge: Cambridge University Press, 1994
Mathur A. B., Collinsworth A. M., Kraus W. E., Reichert W. M., Truskey G. 2001 Viscous and elastic properties of endothelial, cardiac muscle and skeletal muscle cells measured by atomic force microscopy. J. Biomech. 34: 1545–1553
Mathur A. B., Truskey G. A., Reichert W. M. 2000 Atomic force and total internal reflection fluorescence microscopy to study force transmission in endothelial cells. Biophys. J. 78: 1725–1735
Mathur A. B., Truskey G. A., Reichert W. M. 2003a Synergistic effect of high affinity binding and flow preconditioning on endothelial cell adhesion. J. Biomed. Mater. Res. 64: 155–163
Mathur A. B., Truskey G. A., Reichert W. M. 2003b High-affinity augmentation of endothelial cell attachment: long term effects on focal contacts and actin filaments formation. J. Biomed. Mater. Res. 66A: 729–737
Nicolas A., Safran S. A. 2006 Limitation of cell adhesion by the elasticity of the extracellular matrix. Biophys. J. 91: 61–73
Ott M. J., Ballermann B. J. 1995 Shear stress-conditioned, endothelial cell-seeded vascular grafts: improved cell adherence in response to in vitro shear stress. Surgery 117: 334–339
Pompe T., Renner L., Werner C. 2005 Nanoscale features of fibronectin fibrillogenesis depend on protein-substrate interactions and cytoskeleton structure. Biophys. J. 88: 527–534
Pourati J., Maniotis A., Spiegel D., Schaffer J. L., Butler J. P., Fredberg J. J., Ingber D. E., Stamenovicn D. N. W. 1998 Is cytoskeletal tension a major determinant of cell deformability in adherent endothelial cells? Am. J. Physiol. 274: C1283–C1289
Radmacher, M. Measuring the elastic properties of biological samples with the AFM. IEEE Eng. Med. Biol. March/April:47–57, 1997
Radmacher M., Fritz M., Kacher C. M., Cleveland J. P., Hansma P. K. 1996 Measuring the viscoelastic properties of human platelets with the atomic force microscope. Biophys. J. 70: 556–567
Satcher R. L., Dewey Jr. C. 1996 Theoretical estimates of mechanical properties of the endothelial cell cytoskeleton. Biophys. J. 71: 109–118
Sato M., Levesque M. J., Nerem R. M. 1987 Micropipette aspiration of cultured bovine aortic endothelial cells exposed to shear stress. Arteriosclerosis 7: 276–286
Sato M., Nagayama K., Kataoka N., Sasaki M., Hane K. 2000 Local mechanical properties measured by atomic force microscopy for cultured bovine endothelial cells exposed to shear stress. J. Biomech. 33: 127–135
Savage, M. D. Avidin-Biotin Chemistry: A Handbook. Pierce Chemical Company, 1994
Sneddon I. N. 1965 The relation between load and penetration in the axisymmetric boussinesq problem for a punch of arbitrary profile. Int. J. Eng. Sci. 3: 47–57
Theret D. P., Levesque M. J., Sato M., Nerem R. M., Wheeler L. T. 1988 The application of a homogeneous half-space model in the analysis of endothelial cell micropipette measurements. J. Biomech. Eng. 110: 190–199
Wang N., Ingber D. E. 1994 Control of cytoskeletal mechanics by extracellular matrix, cell shape, and mechanical tension. Biophys. J. 66: 2181–2189
Weisenhorn A. L., Khorsandi M., Kasas S., Gotzos V., Butt H. J. 1993 Deformation and height anomaly of soft surfaces studied with an AFM. Nanotechnology 4: 106–113
Acknowledgments
This work was supported by NIH grant HL-44972, Musculoskeletal Transplant Foundation, and the Ovarian Cancer Research Fund. The support of the Clinical Research Unit of Duke University Medical Center and NIH grant MO1-RR-30 in obtaining blood samples is gratefully acknowledged.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Mathur, A.B., Reichert, W.M. & Truskey, G.A. Flow and High Affinity Binding Affect the Elastic Modulus of the Nucleus, Cell Body and the Stress Fibers of Endothelial Cells. Ann Biomed Eng 35, 1120–1130 (2007). https://doi.org/10.1007/s10439-007-9288-8
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10439-007-9288-8