[Cylic stretching force-induced late apoptosis in human periodontal ligament cells].

Purpose: To investigate the effect of stretching force on late apoptosis of human periodontal ligament cells.

Methods: HPDLCs were cultured in vitro, and cells were stretched by dynamic mechanical strain 1%, 10% and 20% for 6, 12, 24 and 48 h. Then late apoptosis were detected through TUNEL method binding by flow cytometry and confocal laser scanning microscopy. The data was analyzed with SPSS 11.0 software package.

Results: HPDCLs inclined parallel to each other and aligned their long axis perpendicular to the stretching force vector. The number of apoptotic cells increased significantly in a time-and force-dependent manner in response to stretching strain within 24 h.

Conclusions: It is found that stretching force can induce apoptosis in HPDLC and show time- and stress-dependent manner with a tendency of increase in 24 h.