Abstract:

BACKGROUND: In vivo study of cellular mechanics obtains poor results due to complexity of physiological environment and uncontrollable experiment conditions.
OBJECTIVE: To study the cyclic stretch effects on human periodontal ligament fibroblasts proliferation and its mechanism as well as whether p38 mitogen-activated protein kinase signaling pathway participated in cell proliferation.
METHODS: In vitro culture-tensile stimulate models of human periodontal ligament fibroblasts were established by using a multi-passage load adding system. Control group was established without cyclic stretch. At the same time, cyclic stretch was applied on the fibroblasts for 1, 6, 12 and 24 hours. Cells in the control group and 12-hour load group were treated with p38 mitogen-activated protein kinase inhibitor SB203580 at 1 hour before loading. The cell proliferation was determined by cell counting kit-8 method, and the mRNA expression was detected on proliferating cell nuclear antigen by reverse transcription-PCR technology.
RESULTS AND CONCLUSION: Compared with the control group, the proliferation activity of human periodontal ligament fibroblasts was improved at 1 hour after loading, then increased at 6 hours and reached the peak at 12 hours; the proliferation of human periodontal ligament fibroblasts was inhibited obviously at 24 hours. SB203580 inhibited cell proliferation and inhibited mRNA expression of proliferating cell nuclear antigen. These results indicated, in a certain time, cyclic stretch can promote the proliferation of human periodontal ligament fibroblasts; as time went by, the proliferation of human periodontal ligament fibroblasts was obviously inhibited. p38 mitogen-activated protein kinase signaling pathway plays an important role during cyclic stretch-induced proliferation of human periodontal ligament fibroblasts.