Self-organization of muscle cell structure and function
Journal
PLoS Computational Biology
Journal Volume
7
Journal Issue
2
Date Issued
2011-02
Author(s)
Abstract
The organization of muscle is the product of functional adaptation over several length scales spanning from the sarcomere to the muscle bundle. One possible strategy for solving this multiscale coupling problem is to physically constrain the muscle cells in microenvironments that potentiate the organization of their intracellular space. We hypothesized that boundary conditions in the extracellular space potentiate the organization of cytoskeletal scaffolds for directed sarcomeregenesis. We developed a quantitative model of how the cytoskeleton of neonatal rat ventricular myocytes organizes with respect to geometric cues in the extracellular matrix. Numerical results and in vitro assays to control myocyte shape indicated that distinct cytoskeletal architectures arise from two temporally-ordered, organizational processes: the interaction between actin fibers, premyofibrils and focal adhesions, as well as cooperative alignment and parallel bundling of nascent myofibrils. Our results suggest that a hierarchy of mechanisms regulate the self-organization of the contractile cytoskeleton and that a positive feedback loop is responsible for initiating the break in symmetry, potentiated by extracellular boundary conditions, is required to polarize the contractile cytoskeleton. © 2011 Grosberg et al.
Other Subjects
actin filament; animal cell; article; cell polarity; cell shape; cell structure; controlled study; cytoskeleton; extracellular matrix; focal adhesion; heart muscle cell; in vitro study; mathematical model; muscle cell; muscle development; muscle fibril; muscle function; newborn; nonhuman; positive feedback; quantitative analysis; rat; sarcomere length; animal; biological model; cell culture; chemistry; computer simulation; cytology; heart muscle cell; immunohistochemistry; metabolism; muscle contraction; muscle fibril; physiology; sarcomere; Sprague Dawley rat; Rattus; actin; Actins; Animals; Cells, Cultured; Computer Simulation; Cytoskeleton; Focal Adhesions; Immunohistochemistry; Models, Biological; Muscle Contraction; Myocytes, Cardiac; Myofibrils; Rats; Rats, Sprague-Dawley; Sarcomeres
Type
journal article