| Budget Amount *help |
¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2004: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2003: ¥2,600,000 (Direct Cost: ¥2,600,000)
|
|---|
| Research Abstract |
Three-dimensional orientation of stress fibers in vascular endothelial cells was observed by confocal scanning laser microscopy after staining actin filaments with rhodamine phalloidin. The results showed regular arrays of stress fibers at the bottom surface and at the apical surface. The orientation is in the direction which is perpendicular to the stretching direction and, at the same time, parallel to the substrate surface. Stress fibers between the apical surface and the bottom surface were not found. This may be because the formation of stress fibers is not only by dissociation with an excessive strain, polymerization of actin monomers, and crosslinking between adjacent actin filaments, but also by adhesion molecules at the cellular membranes.
Actin filaments are bundled to form a stress fiber. So mathematical modeling was carried out for the formation of stress fibers starting from actin monomers. In the modeling, actin filaments along the bottom surface of the cell were focused. The four factors i.e., polymerization/depolymerization, capping on actin filaments by, e.g., gelsolin, crosslinking between adjacent actin filaments, and dissociation by an excessive strain, were taken into account Integrins were placed on the cellular membrane with an equal interval Numerical simulations showed arrays of stress fibers by bundling actin filaments. Final patterns of arrays depend on the requirement of actin binding, Le., the angle and distance between actin filaments. One needs an improvement of the model to obtain parallel arrays of stress fibers without interacting each other.
|
