Abstract:

BACKGROUND: Runx-2 is the target for the bone morphogenetic protein signaling; signal transduction pathway of bone morphogenetic protein involves in the physiological response process of osteoblasts to the stimulation of mechanical centrifugal force. And it plays an important role in the osteoblast information transfer cascade reactions caused by mechanical signals.
OBJECTIVE: To investigate the effect of mechanical centrifugal force on the signaling pathway of osteoblast bone morphogenetic protein.
METHODS: MC3T3-E1 cells were pretreated with Dulbecco's modified Eagle’s medium containing 10% fetal bovine serum for 24 hours, and then divided into control group, 90 r/min group, 180 r/min group and 250 r/min group according to the rotational speed. Each group was divided into three subgroups: 6 hours subgroup, 12 hours subgroup and 24 hours subgroup according to the stimulation times of entrifugal force. The control group was treated in the same environment without centrifugation. The total RNA of each group was extracted, and reversed transcripted to cDNA. The expression of Runx2 was analyzed by quantitative real-time PCR.
RESULTS AND CONCLUSION: With the extension of applying time, the expression of the Runx-2 mRNA increased; it has a positive correlation with the applying time. The expression of the Runx-2 mRNA in the 180 r/min group was significantly higher than that in the 90 r/min group and 250 r/min group ( P < 0. 05); the expression of the Runx-2 mRNA in the 90 r/min group and   250 r/min group were slightly higher than that in the control group (P=0.119). The results show that different size of centrifugal force and different duration of centrifugation has different effects on the physiological responses of osteoblast bone morphogenetic protein signaling pathway. It plays an important role in the osteoblast information transfer cascade reactions caused by mechanical signals.