Biomedical Engineering Reference
In-Depth Information
2.1
TENSEGRITY, DYNAMIC NETWORKS, AND
COMPLEX SYSTEMS BIOLOGY:
EMERGENCE IN STRUCTURAL AND
INFORMATION NETWORKS
WITHIN LIVING CELLS
Sui Huang, Cornel Sultan, and Donald E. Ingber
Vascular Biology Program, Departments of Surgery and Pathology,
Children's Hospital and Harvard Medical School,
Boston, Massachusetts
The genomic revolution has led to the systematic characterization of all the genes of the
genome and the proteins they encode. But we still do not fully understand how many cell
behaviors are controlled, because many important biological properties of cells emerge at
the
whole-system
level from the collective action of thousands of molecular components,
which is orchestrated through specific regulatory interactions. In this chapter we present
two distinct approaches based on the concept of molecular networks to understand two
fundamental
system properties
of living cells: their ability to maintain their shape and
mechanical stability, and their ability to express stable, discrete cell phenotypes and
switch between them. We first describe how structural networks built using the principles
of tensegrity architecture and computational models that incorporate these features can
predict many of the complex mechanical behaviors that are exhibited by living mammal-
ian cells. We then discuss how genome-wide biochemical signaling networks produce
"attractor" states that may represent the stable cell phenotypes, such as growth, differen-
tiation, and apoptosis, and which explain how cells can make discrete cell fate decisions
in the presence of multiple conflicting signals. These network-based concepts help to
bridge the apparent gap between emergent system features characteristic of living cells
and the underlying molecular processes.
Address correspondence to: Donald E. Ingber, Department of Pathology, Children's Hospital, Karp
Family Research Laboratories, Room 11.127, 300 Longwood Avenue, Boston, MA 02115 (don-
ald.ingber@childrens.harvard.edu).
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