| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
* Johns Hopkins University, Baltimore, Maryland 21202; and University of Pennsylvania, Philadelphia, Pennsylvania 19104
Correspondence: Address reprint requests to Dennis E. Discher, E-mail: discher{at}seas.upenn.edu.
Force-induced changes in genome expression as well as remodeling of nuclear architecture in development and disease motivate a deeper understanding of nuclear mechanics. Chromatin and green fluorescent protein-lamin B dynamics were visualized in a micropipette aspiration of isolated nuclei, and both were shown to contribute to viscoelastic properties of the somatic cell nucleus. Reversible swelling by almost 200% in volume, with changes in salt, demonstrates the resilience and large dilational capacity of the nuclear envelope, nucleoli, and chromatin. Swelling also proves an effective way to separate the mechanical contributions of nuclear elements. In unswollen nuclei, chromatin is a primary force-bearing element, whereas swollen nuclei are an order of magnitude softer, with the lamina sustaining much of the load. In both cases, nuclear deformability increases with time, scaling as a power law—thus lacking any characteristic timescale—when nuclei are either aspirated or indented by atomic force microscopy. The nucleus is stiff and resists distortion at short times, but it softens and deforms more readily at longer times. Such results indicate an essentially infinite spectrum of timescales for structural reorganization, with implications for regulating genome expression kinetics.
This article has been cited by other articles:
 |
|
 |
|
  A. Mazumder, T. Roopa, A. Basu, L. Mahadevan, and G. V. Shivashankar Dynamics of Chromatin Decondensation Reveals the Structural Integrity of a Mechanically Prestressed Nucleus Biophys. J., September 15, 2008; 95(6): 3028 - 3035. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. U. Azeloglu, J. Bhattacharya, and K. D. Costa Atomic force microscope elastography reveals phenotypic differences in alveolar cell stiffness J Appl Physiol, August 1, 2008; 105(2): 652 - 661. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. Roca-Cusachs, J. Alcaraz, R. Sunyer, J. Samitier, R. Farre, and D. Navajas Micropatterning of Single Endothelial Cell Shape Reveals a Tight Coupling between Nuclear Volume in G1 and Proliferation Biophys. J., June 15, 2008; 94(12): 4984 - 4995. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. N. Dahl, A. J.S. Ribeiro, and J. Lammerding Nuclear Shape, Mechanics, and Mechanotransduction Circ. Res., June 6, 2008; 102(11): 1307 - 1318. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. T. B. Nguyen and J. J. Fredberg Strange Dynamics of a Dynamic Cytoskeleton Proceedings of the ATS, January 1, 2008; 5(1): 58 - 61. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. A. Smith, H. Roy, P. De Koninck, P. Grutter, and Y. De Koninck Dendritic Spine Viscoelasticity and Soft-Glassy Nature: Balancing Dynamic Remodeling with Structural Stability Biophys. J., February 15, 2007; 92(4): 1419 - 1430. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. C. Rowat, J. Lammerding, and J. H. Ipsen Mechanical Properties of the Cell Nucleus and the Effect of Emerin Deficiency Biophys. J., December 15, 2006; 91(12): 4649 - 4664. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. N. Dahl, P. Scaffidi, M. F. Islam, A. G. Yodh, K. L. Wilson, and T. Misteli Distinct structural and mechanical properties of the nuclear lamina in Hutchinson-Gilford progeria syndrome PNAS, July 5, 2006; 103(27): 10271 - 10276. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
