アブストラクト（34巻1号：The Bulletin of Kanagawa Dental College）

The Bulletin of Kanagawa Dental College

English

Title　： Fracture Healing and Cyclooxygenase-2 Induction by Mechanical Stress
Subtitle　： SYMPOSIUM ON 40TH CONFERENCE OF KANAGAWA DENTAL COLLEGE Present and Near-future of Regenerative Medicine in Dentistry
Authors　： Yuko Mikuni-Takagaki
Authors（kana）　：
Organization　： Department of Functional Biology, Kanagawa Dental College
Journal　： The Bulletin of Kanagawa Dental College
Volume　： 34
Number　： 1
Page　： 79-83
Year/Month　： 2006 / 3
Article　： Report
Publisher　： Kanagawa Odontological Society
Abstract　： [Abstract] In order to characterize the role of COX-2 in the fracture repair process in COX-2-/-mice, we applied low-intensity pulsed ultrasound (LIPUS), which induces COX-2 and is clinically used to accelerate repair processes. In one-yr-old COX-2-/-mice, cartilage formed similarly to the +/+ littermates up to postfracture day 10. Thereafter, the repair process halted at the endochondral remodeling stage and was not accelerated by LIPUS. The treatment, however, effectively increased the rate of endochondral remodeling in aged +/+ littermates, a process that is generally prolonged in senescence. In the COX-2-/-callus, transcripts of such critical components as MMP-9 and VEGFa were missing at day 7, regardless of exposure to LIPUS. COX-2 is indispensable for fracture healing in aged mice ; if absent, the gap filled with fibrotic tissue persists. Mechanical stimulation, we suggest, crucially affects latephase fracture repair because it induces COX-2 and provides PGE2 that, in turn, controls downstream molecules such as VEGFa and matrix metalloproteinases, which advance the endochondral remodeling.
Practice　： Dentistry
Keywords　： Fracture healing, COX-2, PGE2, LIPUS, Bone formation, Bone remodeling