Effects Of P38MAPK Signaling Pathway On Cyclic Stretch-induced Fibroblast Apoptosis

Objective:Periodontal disease is the oldest and most widespread human diseases, it is not only one of the reasons of teeth column defect, also the risk factors of some systemic diseases such as diabetes mellitus, cardiovascular disease and pregnancy complications. In the last one hundred years, periodontal disease pathogenesis is still not completely solved, but existing studies have demonstrated that occlusal traumatism can aggravate the occurrence and development of periodontal disease, and even affect periodontal tissue repair. Periodontal membrane fibroblasts are main feeling sex cells and effect sex cells in periodontal tissue. In appropriate cyclical stress, it can happen under the proliferation, migration and differentiation produce adaptability rebuilt and then affect the periodontal ligament reconstruction of the reconstruction. It plays a very important role to maintain the health of periodontal tissue and function This study first successfully constructs fibroblast cells in vitro model of mechanical stimulation, and then in the field of cell mechanics to clarify the relationship between a certain size and frequency cyclical tensile stress and fibroblasts apoptosis. Then we imposed P38MAPK specific inhibitors SB203580 to clarify the role of the P38MAPK playing in fibroblasts apoptosis, which explains the role of cyclic tensile stretch of fibroblasts apoptosis, specific mechanisms for adaptive remodeling. It is hoped that clinicians can use different means and methods of regulation of vascular alterations, and provide a theoretical basis for clinical intervention understanding this process will help to further explore the failure mechanism of occlusal trauma, in order to provide a theoretical basis for clinical intervention.Methods:In vitro cultured fibroblast for experimental object. Experiment was divided into loading group (Oh,6h,12h and 24h) and loading+ SB203580 group (Oh,6h,12h and 24h). The Flexcell Strain Unit FX-4000T was used to expose to fibroblasts equiaxial cyclic stretch of 12% magnitude and a frequency of 6 cycles/min, each cycle including the 5-s stretch/5-s relaxation. Cells by flow cytometry analysis of apoptosis, RT-PCR detection of cell apoptosis. This time makes the fibroblast prior to impose cell-specific inhibitor SB203580, and then imposed on the same tensile stress, and then we detected the changes of cell apoptosis. The experimental data were analyzed used SPSS 10.0 Statistical PackageResults:Flow cytometry, RT-PCR results show that the test imposed by 12%, cyclical tensile stress can induce apoptosis of fibroblasts, and with the extension of time, the apoptosis of fibroblast cells also increased, to 12 hours to reach the peak, and then begin to decline but still higher than the group without tensile stress.(P<0.05) Cells imposed on SB203580 before imposing cyclical tensile stress, the results showed that the expression of apoptosis gene bax load than the same time in the loading group with low expression of bax (p<0.05))Conclusions:fibroblasts by certain force value of mechanical stimulation (the value of the deformation force and frequency) could occur apoptosis, and the extent of apoptosis and stimulation of the role of time in a certain range of positive correlation. Mitogen-activated protein kinase p38MAPK signaling pathway may be involved in the apoptotic process.