effects of conditionde media from periodontal ligament cells and gingival fibroblasts on the proliferation and differentiation in osteoblastic clond mc3t3-e1cells

Abstract

To determine whether the human periodintal ligament cell-conditioned medium (PDL-CM) and the human alngival fibroblast-conditioneed medium (GF-CM) affect the proligeration and differentiation of osteoblastic cline MC3T3-E1 cells, the effects of both conditioned media on [^(3)H]thymidine incorporation into DNA and alkalin phosphatase (ALP) activity in cline MC3T3-E1 cells were examined. Both PDL-Cm and GF-Cm increased [^(3)H]thymidine incroporation into DNA whereas decreased ALP activity in dose-dependent manner. Especially, their inhibitory effect on ALO activity was proportional to the seeding density of MC3T3-E1 cells and concentration of CM. These findings indicated that PDL and GF produce and release certain soluble factor(s) that stimulate cell proliferation and inhibit differentialtion in MV3T3-E1 cells and suggest that PDL and GF may play a role in the regulation of bone cell function in vivo as well.