Study on the calcification by periodental ligament fibroblasts in the periodonta regeneration

点击翻译按钮获取中文摘要

In the aspect of periodontal regeneration, we focused on the regulation of the proliferation and the chemotaxis by fibroblast growth factor (FGF) and that of osteogenic functions by 1alpha, 25-dihydroxyvitamin D3 (vit.D3) in human periodontal ligament fibroblast (HPLF).Numbers of growth factors have been shown to induce cell migraiton as well as cell proliferation. To understand the mechanisms how the cells were driven to migration or proliferation upon same growth factor stimuli, we are interested in detecting the different phases of the cell of human fibroblasts undergoing migration. Cells migrated against FGF did not incorporate bromodeoxyuridine, suggesting that the cells in S phase were not induced to migrate. No dividing cells were found in the migrated cell population. However, migrated cells were found to express c-myc and c-fos mRNA,suggesting that these cells were exit from G0 phase of the cell cycle. Based upon the results, we conclude that the cells undergoing migration wer … More e most likely in G1 phase of the cell cycle.It has been shown that vit. D3 enhances alkaline phosphatase (ALP) activity and osteocalcin (OC) productivity in HPLF which have osteoblast-like cell functions. To evaluate the role of vit. D3 in ALP activity and OC productivity in HPLF,we examined the kinetics of gene expression of 1alpha, 25-dihydroxyvitamin D3 receptor (VDR), ALP activity and OC productivity at different phases of culture. The level of VDR gene expression, ALP activity and OC productivity were enhanced as culture cell density increased. Vit. D3 significantly enhanced ALP activity and OC productivity in each culture cell density. However, vit. D3 did not increase the level of VDR gene expression. The supernatant obtained from the culture of multilayred cells enhance the expression of the VDR genes in cells when the culture cell density was sparse. These sparse culture phase cells did not express the VDR gene and vit. D3 hardly affect ALP activity and OC productivity in these cells. Thus, if the sparse cells were previously stimulated with the culture supernatant, vit. D3 strongly enhanced OC productivity. These results suggest that vit. D3 enhances OC productivity and depends upon the level of VDR gene expression in HPLF culture cells and that the culture supernatant from multilayred cells contains the factors which increase VDR gene expression. Less