- 學位論文
週期性張力與低能量雷射對骨母細胞基因的表現
Study on Gene Expression of Cyclic Mechanical Tension and Low Level Laser Therapy of Osteoblast Cell
摘要
實驗目的 研究週期性張力與低能量雷射對老鼠骨細胞的相互影響。 材料與方法 本實驗以MC3T3-E1的骨細胞照射低能量雷射，能量為0 J/cm2 、5 J/cm2 、 10 J/cm2後放入Flexercell Strain Unit 以 12%張力，去觀察24hrs , 48hrs的Collagen-1(Col-1)、 Osteopontin(OPN)、osteoprotegerin (OPG)、receptor activator of nuclear factor-jB ligand (RANKL)、 bone morphogenetic proteins ( BMP-2、BMP-4) 、等等mRNA的表現。 實驗結果 結果顯示Col-1 mRNA經過24小時12%週期性張力表現上升，24小時後有下降的情況，張力去除表現也下降。BMP-2 mRNA經過24小時12%週期性張力表現上升。OPN mRNA經過照射低能量雷射 5 J/cm2 10 J/cm2 都能夠刺激表現。另外照射低能量雷射 5 J/cm2 加上週期性張力12% 經過24小時則可以明顯OPG mRNA表現上升，並降低RANKL mRNA 產生。BMP-4 mRNA經過照射 5 J/cm2 低能量雷射加上週期性張力12% 經過24小時表現會上升，24小時後有下降的情況 結語 週期性張力刺激可以對骨細胞產生生物性變化，而讓Col-1 mRNA, OPN mRNA , OPG mRNA , BMP-2 mRNA 和 BMP-4 mRNA表現上升，而讓RANKL mRNA表現下降。這樣有助於影響bone remodeling ，當配合5 J/cm2 低能量雷射可以增加整體效果。
並列摘要
Purpose The purpose of our study was to investigate interaction of cyclic mechanical tension and low level laser therapy of osteoblast cell. Materials and Methods MC3T3-E1 osteoblastic cells were stretched by 12% at a frequency of 6 cycles/min using a Flexercell Strain Unit after exposed to low-level laser treatment at 0, 5 and 10 J/cm2 using a 920nm diode laser for 24 hrs to 48 hrs, After stretching, expression of mRNAs encoding collagen type I (Col-I), osteopontin (OPN) , bone morphogenetic protein-2 (BMP-2), bone morphogenetic protein-4 (BMP-4),osteoprotegerin (OPG) and receptor activator of nuclear factor-jB ligand (RANKL) were investigated. Result The highest levels of Col-I and BMP-2 mRNA expression occurred at 24 hrs without LLLT , while those of BMP-4 occurred at 24 hrs with 5 J/cm2 LLLT. Col-I and BMP-4 mRNA expression decreased after 24hrs . LLLT at 5 and 10 J/cm2 significantly increased the expression of OPN mRNA. 12 % Cyclic tensile strain with 5 J/cm2 LLLT induced in OPG synthesis and a concomitant decrease in RANKL mRNA expression. Conclusion These results indicate that cyclic tensile strain influence the biological behavior of osteoblasts, Increased the expression of mRNAs encoding Col-1 mRNA, OPN mRNA , OPG mRNA , BMP-2 mRNA and BMP-4 mRNA , while those decrease in RANKL mRNA expression. Mechanical strain plays an important role in bone remodeling during growth and development In Addition to the stretching groups profoundly affects bone remodeling,the stretching groups with 5 J/cm2 had a better results.