Abstract:

Objective  To investigate changes of the expression of extracellular matrix metalloproteinase inducer (EMMPRIN) in periodontal ligament fibroblasts (PDLFs) under cyclic tensile force and relevant effect on the expression of vascular endothelial growth factor (VEGF) and evaluate possible effect of EMMPRIN during the course of periodontium remodeling under mechanical stress. Methods  Immunofluorescent histochemical staining was performed to locate the expressions of EMMPRIN and VEGF in PDLFs. PDLFs were exposed to 6%, 12%, and 20% cyclic tensile force by the Flexcell System for 0.5, 2, 6, 12, 24, 36, 48, and 72 h. Changes of gene and protein expressions of EMMPRIN and VEGF in PDLFs were observed by real-time PCR and Western blotting. Changes of mRNA and protein expressions of VEGF in PDLFs were observed 6, 12, and 24 h after exogenous EMMPRIN protein was added into the PDLFs culture medium. Results  The protein expression of EMMPRIN was mainly detected in the cell membrane and cytoplasm of PDLFs, while the expression of VEGF was observed in nuclei as well as cell cytoplasm. The mRNA and protein expressions of both EMMPRIN and VEGF specifically up-regulated after PDLFs were exposed to 6%, 12%, and 20% mechanical tensile force. The exogenous EMMPRIN protein enhanced the mRNA expression of VEGF in PDLFs. Conclusion  The mechanical tensile force can specifically up-regulate the expressions of EMMPRIN and VEGF in PDLFs. EMMPRIN may regulate the expression of VEGF and involve in the course of periodontal remodeling under stress with VEGF.

Key words: mechanical loading, extracellular matrix metalloproteinase inducer, vascular endothelial growth factor, periodontal ligament fibroblasts