The Effect Of RhBMP-4 And RhIGF-Ⅰ On The Proliferation And Differentiation Of Human Periodontal Ligament Fibroblasts

The key of periodontal regeneration is the proliferation, differentiation and migration of the periodontal ligament cells. Bone morphogenetic protein-4 (BMP-4) is regarded as a member of TGF-? superfamily by characteristic features in their amino acid sequences which induces the caryocinesis of undifferentiated mesenchymal and increases the alkaline phosphatase(ALP) activity, moreover, it regulates the migration, adhesion, proliferation and differentiation of periodontal ligament cells. The effect of insulin-like growth factors (IGF-â… ) on periodontal regeneration is to promote chemotexis, caryocinesis and protein synthesis of periodontal ligament cells. The purpose of this study is to estimate the potential effect of exogenous growth factors on periodontal regeneration. Human periodontal ligament fibroblasts (PDLFs) were cultured in vitro and the osteoblasts-like phenotypes of the cells were investigated in our experiments; the effect of rhBMP-4 and rhIGF-â… on the proliferation and differentiation of human periodontal ligament fibroblasts were investigated. This study has included two parts:Part one: The best concentration of rhBMP-4 and rhIGF-â… on the proliferation and differentiation of human periodontal ligament fibroblastsMethods: Periodontal ligament fibroblasts were treated with differernt dosages of rhBMP-4 or rhIGF-â… for 5 days, the proliferation were mesured by MTT colorimetric essay and the ALP activity were mesured by ALP kit. Results: There were significant differences between experimental groups of rhBMP-4 or rhIGF-â… at different concentration and the control ones in the proliferation and differentiation in 3 days, the best concentration of them is 10ng/ml. Conclusion: both rhBMP-4 and rhIGF-â… have promoting effect on proliferation and differentiation of periodontal ligament fibroblasts.Part two: The effect of rhBMP-4 and rhIGF-â… on the proliferation and differentiation of human periodontal ligament fibroblastsMethods: Periodontal ligament fibroblasts were treated with 10 ng/ml rhBMP-4, 10 ng/ml rhIGF-â… or 10 ng/ml rhBMP-4 plus 10 ng/ml rhIGF-â… for 3 days, the proliferation were mesured by MTT colorimetric essay, the ALP activity were mesured by ALP kit and typeâ… collagen in periodontal ligament fibroblasts were mesured by hydroxyprolline kit. Results: There were significant difference between experimental groups of rhBMP-4, rhIGF-â… , rhBMP-4 plus rhIGF-â… and the control ones in the proliferation of cells in 3 days, but compared with the groups of rhIGF-â… or rhBMP-4, the ALP activity and the level of hydroxyprolline in groups of rhBMP-4 plus rhIGF-â… did not increase. Conclusion: There were synergistical effect on proliferation, but no synergistical effect on differentiation in periodontal ligament fibroblasts on groups of rhBMP-4 plus rhIGF-â… .