Cyclic Tensile Stress On Fibroblast Apoptosis And Its Regulation Mechanism

Objective:To study the cyclic tensile stress on apoptosis in fibroblasts and its mechanism. Methods:Cyclic tensile stress was applied on the fibroblasts respectively for 0h,6h,12h,24h, morphological changes of cells were observed in using Hoechst 33258,so as to flow cytometry analysis of cell cycle,while detection of Caspase-3 activity. Results:The results of Hoechst 33258 showed that the nucleus for the group without afterburner dispersed uniformly round or oval-shaped fluorescent, while the afterburner groups can be seen within the nucleus or cytoplasm, dense stain particles, crescent or ring fluorescence, nuclear fast shrinkage, some slices of nuclear fragmentation can be seen.Flow cytometry analysis showed that fibroblast cell cycle with the afterburner with the extension of time has changed. Compared with non-afterburner, afterburner group significantly prolonged the cell cycle.6h,12h group with the afterburner time prolonged,the cell cycle also be extended to the 12h peak.24h group also appeared to shorten the cell cycle.Detection of Caspase-3 activity can be seen 6h group,12h group of Caspase-3 activity was significantly higher than that without afterburner group, while the 24h group of Caspase-3 activity was significantly lower than 12h but higher than the group without afterburner. That cyclical tensile stress can induce apoptosis in fibroblasts, within 12 hours afterburner longer the more obvious early apoptosis.Conclusion: Cyclical tensile stress can induce fibroblast apoptosis,can change the cell cycle, and Caspase3 involved in this process.