Jacobs:Research:Structural Analysis of Cytoskeletal Deformation in Bone Cells Exposed to Shear Stress

Objective
Understanding the micromechanics of cellular and cytoskeletal deformation may be key in understanding the process of mechanotransduction. Many questions regarding the mechanics of cytoskeletal deformation under load remain unanswered. What are the overall mechanics of deformation, and where are the stress concentrations located at? What are the stresses experienced by the cytoskeletal filaments when the cell is deformed? What are the stresses at the interface between focal adhesion proteins and the cytoskeleton? Similarly, what are the stresses felt at the interface between the plasma membrane and cytoskeleton? How do cellular level mechanical properties compare with the mechanical properties of the individual filaments? How will the cell deform when exposed to various loading conditions?

Research Plan
In order to help answer these questions, a finite element model of the actin cytoskeleton constructed from reconstructed three dimensional image data is proposed. F-actin is chosen since it is generally accepted that the actin cytoskeletal network is primarily responsible for cellular mechanical properties and overall morphology. Construction of the mesh via three dimensional image data eliminates the need to make assumptions and simplifications concerning cytoskeletal organization. A detailed finite element analysis will allow insight into the micromechanics of deformation of the cytoskeleton, possibly revealing or verifying key mechanisms and events in cellular mechanotranscution.

http://www.stanford.edu/group/cmbl/cyto4.gif 3D reconstruction of actin cytoskeleton obtained from confocal microscopy images (.avi movie)

http://www.stanford.edu/group/cmbl/cyto5.gif 3D reconstruction of actin cytoskeleton obtained from confocal microscopy images (.avi movie)