Abstract:

Objective To study the cyclic stretch on human periodontal ligament fibroblasts（hPDLF） prliferation and its mechanism. Methods In vitro culture -tensile stimulate models of hPDLF were established by using a multi-passage load adding system. Cyclic stretch was applied on the fibroblasts for 1, 2, 4, 6, 12 and 24 hours, respectively, the load was set for 10% surface elongation, with frequency 0.1 Hz. At the same time, the normal control group was established by static group. The cell promote was determined by cell counting kit-8（CCK-8） method; and the expression of mRNA was detected on proliferating cell nuclear antigen（PCNA） and nuclear factor- κB（NF-κB） by RT-PCR technology. Results Compared with static group, the proliferation activity of hPDLF was decreased in 1, 2 h; hPDLF began to proliferate in 6 h, cell proliferation reached the peak in 12 h; the proliferation of hPDLF were inhibited obviously. Pyrrolidine dithiocarbamate（PDTC） inhibited cell proliferation and inhibited mRNA expression of PCNA and NF-κB；and the differences between the two groups were significant. Conclusion In a certain time, within the scope of cyclic stretch can promote the in vitro hPDLF proliferation; as time went by, the hPDLF was obvious inhibition. NF-κB signaling pathway play an important role during cyclic stretch-induced hPDLF proliferation.

Key words: cyclic stretch； human periodontal ligament fibroblast； proliferation； cell counting kit-8； nuclear factor-&kappa, B