| Project/Area Number |
16591515
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Orthopaedic surgery
|
|---|
| Research Institution | Kinki University |
|---|
Principal Investigator |
HAMANISI C. Kinki University, School Med., Professor, 医学部, 教授 (00164921)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
FUKUDA K. Kinki University, School Med., Professor, 医学部, 教授 (50201744)
NONAKA T. Kinki University, School Med., Lecturer, 医学部, 講師 (70268407)
MORI S. Kinki University, School Med., Hospital Assistant, 医学部, 助手 (80351584)
山崎 顕二 近畿大学, 医学部附属病院, 助手 (70368322)
|
|---|
| Project Period (FY) |
2004 – 2006
|
| Project Status |
Completed (Fiscal Year 2006)
|
| Budget Amount *help |
¥2,700,000 (Direct Cost: ¥2,700,000)
Fiscal Year 2006: ¥100,000 (Direct Cost: ¥100,000)
Fiscal Year 2005: ¥100,000 (Direct Cost: ¥100,000)
Fiscal Year 2004: ¥2,500,000 (Direct Cost: ¥2,500,000)
|
|---|
| Keywords | osteo genesis / leg-lengthening / osteo blast / active oxygen / tissue environment |
|---|
| Research Abstract |
Biophysical stimulation loaded on the bone must rely on both the biological and biomechanical principle according to the local tissue environment and the type of mechanical stress. Physiological loading is widely believed to benefit the maintenance of skeletal integrity. However, excessive nonphysiological loading is associated with bone injuries, including stress fractures and osteoporotic fractures, indicating that such loading decreases the functional capacity of bone. Consequently, this mechanical stress must be transduced to a biochemical signal in bone and osteoblasts.
We previously loaded cyclic tensile stretch on osteoblast-like cells and found an enhanced synthesis of reactive oxygen species (ROS) and superoxide dismutase (SOD). However, the precise pathway of SOD induction has not been elucidated. Cyclic tensile stretch was loaded on the osteoblast-like cells using Flexercell Strain Instrument. To generate intracellular ROS, paraquat was used.
Paraquat significantly enhanced SOD activity, suggesting that the intracellular generation of ROS, is essential for the induction of SOD. Cyclic tensile stretch enhanced ROS and SOD synthesis. SOD inhibited stretch-enhanced ROS and SOD synthesis. SOD induction by mechanical stimuli is regulated by intracellular ROS.
We also examined the effect of axial loading using axial shortening during distraction osteogenesis in vivo. We found mechanical stress leads to enhanced bone formation in a rabbit model through the hypoxia-inducing-factor-1 alpha/vascular endothelial growth factor system.
Taken together, redox status plays an important role in the signal transduction of mechanical stress loaded on the bone.
|
