Departmental Papers (CBE)

Document Type

Journal Article

Date of this Version

September 2004

Abstract

Contractile myocytes provide a test of the hypothesis that cells sense their mechanical as well as molecular microenvironment, altering expression, organization, and/or morphology accordingly. Here, myoblasts were cultured on collagen strips attached to glass or polymer gels of varied elasticity. Subsequent fusion into myotubes occurs independent of substrate flexibility. However, myosin/actin striations emerge later only on gels with stiffness typical of normal muscle (passive Young's modulus, E ~12 kPa). On glass and much softer or stiffer gels, including gels emulating stiff dystrophic muscle, cells do not striate. In addition, myotubes grown on top of a compliant bottom layer of glass-attached myotubes (but not softer fibroblasts) will striate, whereas the bottom cells will only assemble stress fibers and vinculin-rich adhesions. Unlike sarcomere formation, adhesion strength increases monotonically versus substrate stiffness with strongest adhesion on glass. These findings have major implications for in vivo introduction of stem cells into diseased or damaged striated muscle of altered mechanical composition.

Comments

Copyright The Rockefeller University Press. This research was originally published in The Journal of Cell Biology, Volume 166, Issue 6, September 13, 2004, pages 877-887.
Publisher URL: http://dx.doi.org/10.1083/jcb.200405004

Keywords

myofibrillogenesis, patterning, adhesion, differentiation, muscular dystrophy

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Date Posted: 21 February 2005

This document has been peer reviewed.