The study of the factors of root development and reparative dentine formation

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We prepared the cDNA library as odontoblast-like cell enriched cDNA in vivo with mRNA from the laser irradiated pulp of a rat incisor. The glypican-1 (GPC-1) was detected among the identical genes in the cDNA library as odontoblast-like cell enriched cDNA in vivo. GPC-1 is a member of a family of glycosylphosphatidylinositol anchored cell surface heparin sulfate proteoglycans (HSPG) .Objectives : The purpose of this study was to identify the expression of HSPG in odontoblast-like cells and evaluate their relation to the formation of reparative dentine.Methods: 6 and 10 days after Nd: YAG laser irradiation in the pulp, mandibles of rats were dissected and histological procedure was proceeded. We detected the expression of the GPC-1 and Syndecan-1 inununohistologically. To investigate the expression of the GPC-1 gene, Syndecan-1, -2, -3, -4 gene comparing with Tgf-beta 1, osteocalcin, Dspp, we used the cell culture system that reflects the dentine formation in dental pulp tissue. The mandibles were removed from seven male wistar rats (5 weeks old) from the same litter. The pulp tissues were cut into several pieces and incubated in a sterile enzyme solution containing 0.1 % collagenase, 0.05% trypsin. The total RNA were extracted from the cultured cells on days 3, 6, 10 and 15. The RT-PCR amplification was performed.Results : The immunohistological examination showed stainings of GPC-1 and Syndecan-1 were observed in odontoblast-like cells. In the cell culture system, the expression of mRNA of GPC-1, Syndecan-land Syndecan-4 gradually increased by 15 days, but the expression of Syndecan-2 and Syndecan-3 were almost same during 15 days. The levels of relative quantity mRNA of GPC-1, Syndecan-land syndecan-4 were increased with the process of the odontoblast-like cell differentiation.Conclusion : These findings suggest that GPC-1, Syndecan-land synclecan-4 might be associated with differentiation of odontoblast-like cell.