title: Differentiation of dental pulp stem cells into regular-shaped dentin-pulp complex induced by tooth germ cell conditioned medium.
abstract: Investigations of the odontoblast phenotype are hindered by obstacles such as the limited number of odontoblasts within the dental pulp and the difficulty in purification of these cells. Therefore, it is necessary to develop a cell culture system in which the local environment is inductive and can promote dental pulp stem cells (DPSCs) to differentiate into odontoblast lineage. In this study, we investigated the effect of conditioned medium from developing tooth germ cells (TGCs) on the differentiation and dentinogenesis of DPSCs both in vitro and in vivo. DPSCs were enzymatically isolated from the lower incisors of 4-week-old Sprague-Dawley rats and co-cultured with TGC conditioned medium (TGC-CM). The cell phenotype of induced DPSCs presents many features of odontoblasts, as assessed by the morphologic appearance, cell cycle modification, increased alkaline phosphatase level, synthesis of dentin sialoprotein, type I collagen and several other noncollagenous proteins, expression of the dentin sialophosphoprotein and dentin matrix protein 1 genes, and the formation of mineralized nodules in vitro. The induced DPSC pellets in vivo generated a regular-shaped dentin-pulp complex containing distinct dentinal tubules and predentin, while untreated pellets spontaneously differentiated into bone-like tissues. To our knowledge, this is the first study to mimic the dentinogenic microenvironment from TGCs in vitro, and our data suggest that TGC-CM creates the most odontogenic microenvironment, a feature essential and effective for the regular dentinogenesis mediated by DPSCs.
authors.affiliation: Research and Development Center for Tissue Engineering, Fourth Military Medical University, Xi'an, Shaanxi, China.
authors.forename: Jinhua
authors.initials: J
authors.lastname: Yu
authors.forename: Zhihong
authors.initials: Z
authors.lastname: Deng
authors.forename: Junnan
authors.initials: J
authors.lastname: Shi
authors.forename: Huihong
authors.initials: H
authors.lastname: Zhai
authors.forename: Xin
authors.initials: X
authors.lastname: Nie
authors.forename: Heng
authors.initials: H
authors.lastname: Zhuang
authors.forename: Yucheng
authors.initials: Y
authors.lastname: Li
authors.forename: Yan
authors.initials: Y
authors.lastname: Jin
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002453:Cell Cycle; D002454:Cell Differentiation; D019070:Cell Lineage; D002478:Cells, Cultured; D018920:Coculture Techniques; D024042:Collagen Type I / Q000096:biosynthesis; D017077:Culture Media, Conditioned / Q000494:pharmacology; D003782:Dental Pulp / Q000166:cytology* / Q000378:metabolism; D003804:Dentin / Q000166:cytology; D005434:Flow Cytometry; D007150:Immunohistochemistry; D007180:Incisor / Q000166:cytology; D009804:Odontoblasts / Q000737:chemistry / Q000166:cytology / Q000378:metabolism; D010750:Phosphoproteins / Q000235:genetics* / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012795:Sialoglycoproteins / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology* / Q000378:metabolism; D014083:Tooth Germ / Q000196:embryology*
chemical_list: D024042:Collagen Type I; D017077:Culture Media, Conditioned; D010750:Phosphoproteins; D012795:Sialoglycoproteins; D000469:Alkaline Phosphatase; D002118:Calcium