Chemotactic response of periodontal ligament cells decreases with donor age: association with reduced expression of c-fos

OBJECTIVE: To understand the effects of aging on cellular motility of human periodontal ligament (PDL) cells, and to determine the possible link betwe en cell proliferation and migration in relation to cellular aging. MATERIALS AND METHODS: The chemotactic response of PDL cells from three juv enile and four older donors were compared. Then, migrated or unmigrated cel ls were examined for their cell cycle by morphological and immunocytochemic al procedures, Finally, migrated or unmigrated cells were examined for the expression of c-fos and c-myc by in situ hybridization. RESULTS: PDL cells from older donors showed lower chemotaxis compared with the cells from juvenile donors (P < 0.05), Cells undergoing migration were found not to be in the S- or M-phase of the cell cycle. However, all migrat ed cells were found to express c-fos, while many of the cells which did not migrate were found not to express c-fos, CONCLUSIONS: Cellular motility of PDL cells decreases with donor age as wel l as cell proliferation. Since the cells reaching senescence fail to expres s c-fos, the mechanisms linked to cellular senescence may be a possible und erlying mechanism for low migration seen in the older cells.