This Article Full Text Full Text (PDF) Data Supplement All Versions of this Article: 98/1/81    most recent 01.RES.0000197785.51819.e8v1 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 PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Nishimura, S. Articles by Sugiura, S. Search for Related Content PubMed PubMed Citation Articles by Nishimura, S. Articles by Sugiura, S. Related Collections Structure Related Article

(Circulation Research. 2006;98:81.)
© 2006 American Heart Association, Inc.

Cellular Biology

Microtubules Modulate the Stiffness of Cardiomyocytes Against Shear Stress

Satoshi Nishimura, Shinya Nagai, Masayoshi Katoh, Hiroshi Yamashita, Yasutake Saeki, Jun-ichi Okada, Toshiaki Hisada, Ryozo Nagai, Seiryo Sugiura

From the Department of Cardiovascular Medicine (S. Nishimura, M.K., H.Y., R.N.), Graduate School of Medicine, and The Institute of Environmental Studies (S. Nagai, J.-i.O., T.H., S.S.), Graduate School of Frontier Sciences, The University of Tokyo; and the Department of Physiology (Y.S.), Dental School, Tsurumi University, Japan.

Correspondence to Seiryo Sugiura, Institute of Environmental Studies, Graduate School of Frontier Sciences, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan. E-mail sugiura{at}k.u-tokyo.ac.jp

Although microtubules are involved in various pathological conditions of the heart including hypertrophy and congestive heart failure, the mechanical role of microtubules in cardiomyocytes under such conditions is not well understood. In the present study, we measured multiple aspects of the mechanical properties of single cardiomyocytes, including tensile stiffness, transverse (indentation) stiffness, and shear stiffness in both transverse and longitudinal planes using carbon fiber–based systems and compared these parameters under control, microtubule depolymerized (colchicine treated), and microtubule hyperpolymerized (paclitaxel treated) conditions. From all of these measurements, we found that only the stiffness against shear in the longitudinal plane was modulated by the microtubule cytoskeleton. A simulation model of the myocyte in which microtubules serve as compression-resistant elements successfully reproduced the experimental results. In the complex strain field that living myocytes experience in the body, observed changes in shear stiffness may have a significant influence on the diastolic property of the diseased heart.

Key Words: cytoskeleton • microtubules • cardiomyocyte

Related Article:

Myocyte Shearing, Myocardial Sheets, and Microtubules

Andrew D. McCulloch and Jeffrey H. Omens
Circ. Res. 2006 98: 1-3. [Extract] [Full Text] [PDF]

This article has been cited by other articles:

				G. Iribe, C. W. Ward, P. Camelliti, C. Bollensdorff, F. Mason, R. A.B. Burton, A. Garny, M. K. Morphew, A. Hoenger, W. J. Lederer, et al. Axial Stretch of Rat Single Ventricular Cardiomyocytes Causes an Acute and Transient Increase in Ca2+ Spark Rate Circ. Res., March 27, 2009; 104(6): 787 - 795. [Abstract] [Full Text] [PDF]

				L. Shmuylovich and S. J. Kovacs Stiffness and relaxation components of the exponential and logistic time constants may be used to derive a load-independent index of isovolumic pressure decay Am J Physiol Heart Circ Physiol, December 1, 2008; 295(6): H2551 - H2559. [Abstract] [Full Text] [PDF]

				K. G. Young, S. F. Thurston, S. Copeland, C. Smallwood, and J. W. Copeland INF1 Is a Novel Microtubule-associated Formin Mol. Biol. Cell, December 1, 2008; 19(12): 5168 - 5180. [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]

				C. S. Chung and S. J. Kovacs Physical determinants of left ventricular isovolumic pressure decline: model prediction with in vivo validation Am J Physiol Heart Circ Physiol, April 1, 2008; 294(4): H1589 - H1596. [Abstract] [Full Text] [PDF]

				G. Cooper IV Cytoskeletal networks and the regulation of cardiac contractility: microtubules, hypertrophy, and cardiac dysfunction Am J Physiol Heart Circ Physiol, September 1, 2006; 291(3): H1003 - H1014. [Abstract] [Full Text] [PDF]

				A. D. McCulloch and J. H. Omens Myocyte Shearing, Myocardial Sheets, and Microtubules Circ. Res., January 6, 2006; 98(1): 1 - 3. [Full Text] [PDF]