SHIMIZU Yoshinobu Tohoku University, School of Dentistry, Tohoku University Associate Profesor, 歯学部, 助教授 (20005078)
MITANI Hideo Tohoku University, School of Dentistry, Tohoku University Profesor, 歯学部, 教授 (50014220)
|Budget Amount *help
¥2,200,000 (Direct Cost : ¥2,200,000)
Fiscal Year 1996 : ¥500,000 (Direct Cost : ¥500,000)
Fiscal Year 1995 : ¥1,700,000 (Direct Cost : ¥1,700,000)
The purpose of this study was to examine the induction of various heat shock proteins by mechanical stress in human periodontal ligament fibroblasts (PDL). PDL were obtained from freshly extracted human premolars. Small peaces of periodontium were taken from middle one-third of the root and incubated in alpha-MEM medium containing 10% fatal bovine serum. Outgrowing fibroblast-like cells were subcultured and seeded into 6-well culture plates or 6-well flexible silicon plate coated with type I collagen. At the confluent phase, 1,2,4,6g/cm^2 of continuous compressive stress or 1 sec stretching/1 sec relaxation, maximum 15%elongation of cyclic stretching stress was applied for 72 hours. At the end of stimulation period, the cells were washed with PBS and fixed with TCA.The cells were sclaped and homogenized in Urea-Triton-X solution. The cell homogenate was subjected into 10 or 15% SDS polyaclylamide gel electrophoresis and immunoblotted against anti-HSP 27,47,60,70,90 antibody. Expressions of HSP 47,60,70 were slightly stimulated by continuous compressive stress after 20-30 minutes of stimulation and were decreased to equal or lower intense of 0 time control. In contrast, expression of HSP 27 was slightly inhibited but almost constant during 120 minutes stimulation. Expressions of HSP60 and 70 were almost constant after recovery for 72 hours. On the other hand, expression of HSP 47,60 and 70 were stimulated by cyclic stretching stress after 12 hours of stimulation. Expressions of these HSP were increased to the end of incubation for 96 hours. These results indicated expressions of HSP were controlled by mechanical stress in PDL and HSP may play an important role in the reconstruction process of a periodontium of orthodontically moving tooth.