Abstract:

BACKGROUND: When the teeth affected abnormal biting force, tooth absorption and periodontium would be greatly damaged.
OBJECTIVE: To study whether periodontal membrane fibroblast affected apoptosis following cyclic tensile stress stimulation and whether p38MAPK signaling pathway participated in apoptosis.
METHODS: Fibroblasts at passages from 4 to 7 were randomly assigned to control, loading and SB203580 groups after synchronization. In the loading and SB203580 groups, 12% strain was applied at a loading frequency of 6 cycles per minute, i.e. 5 seconds for tension and 5 seconds for relaxation. In the SB203580 group, cells were treated with 20 mmol/L p38MAPK inhibitor SB203580 at 1 hour before loading. At 6, 12 and 24 hours after loading, cells from each group were harvested, and cell apoptosis was detected using a flow cytometry. Expression of bax mRNA was determined using reverse transcription-polymerase chain reaction.
RESULTS AND CONCLUSION: Compared with the control group, apoptotic rate of fibroblasts and bax mRNA expression were increased after loading (P < 0.05), and enhanced over time, and peaked at 12 hour following loading, and then decreased gradually. Compared with the loading group, cell apoptosis was reduced at corresponding time points in the SB203580 group (P < 0.05), and bax mRNA expression was diminished. These results indicated that cells affected apoptosis after mechanics stimulation, and mitogen activated protein kinase p38MAPK signaling pathway participates in the process of apoptosis.