TGF‐β3 induces ectopic mineralization in fetal mouse dental pulp during tooth germ development

Abstract

Several members of the transforming growth factor (TGF)-β superfamily are expressed in developing teeth from the initiation stage through adulthood. Of those, TGF-β1 regulates odontoblast differentiation and dentin extracellular matrix synthesis. However, the molecular mechanism of TGF-β3 in dental pulp cells is not clearly understood. In the present study, beads soaked with human recombinant TGF-β3 induced ectopic mineralization in dental pulp from fetal mouse tooth germ samples, which increased in a dose-dependent manner. Further, TGF-β3 promoted mRNA expression, and increased protein levels of osteocalcin (OCN) and type I collagen (COL I) in dental pulp cells. We also observed that the expression of dentin sialophosphoprotein and dentin matrix protein 1 was induced by TGF-β3 in primary cultured dental pulp cells, however, not in calvaria osteoblasts, whereas OCN, osteopontin and osteonectin expression was increased after treatment with TGF-β3 in both dental pulp cells and calvaria osteoblasts. Dentin sialoprotein was also partially detected in the vicinity of TGF-β3 soaked beads in vivo. These results indicate for the first time that TGF-β3 induces ectopic mineralization through upregulation of OCN and COL I expression in dental pulp cells, and may regulate the differentiation of dental pulp stem cells to odontoblasts.

Differentiation of Human Skeletal Muscle Stem Cells into Odontoblasts Is Dependent on Induction of α1 Integrin Expression

“…Cells and Culture-The ␣7 integrin-positive human skeletal muscle stem cells (␣7 ϩ hSMSCs) 2 were isolated from fetal tongue (14 -24 weeks prenatal) and maintained as described previously (14) with minor modifications. In brief, cells (passage 6 -8) were cultured in Ham's F-10 medium (Invitrogen) containing 20% fetal bovine serum (Invitrogen), 50 units/ml penicillin, 50 g/ml streptomycin (Invitrogen), 1 g/ml insulin (Invitrogen), 2.5 g/ml Fungizone (Invitrogen), 0.5 g/ml gentamicin (Invitrogen), and 2 mM L-glutamine (Invitrogen).…”

“…The PCR within the exponential phase of the amplification curve was performed for 25 cycles for MYOD (muscle-specific marker); FOXD3 and SOX10 (neural crest markers); MEOX1 (presomitic mesoderm marker); RUNX2 (osteogenic transcription factor); DSPP, dentin matrix protein 1 (DMP-1), and MMP-20 (odontoblast markers); osteopontin and osteocalcin (osteoblast markers); and glyceraldehyde-3-phosphate dehy- 2 The abbreviations used are: ␣7 ϩ hSMSC, ␣7 integrin-positive human skeletal muscle stem cell; BMP, bone morphogenetic protein; RA, retinoic acid; GS, gelatin scaffold; DSPP, dentin sialophosphoprotein; MMP, matrix metalloproteinase; DSP, dentin sialoprotein; EB, embryoid body; ECM, extracellular matrix; ALPase, alkaline phosphatase; ARS, Alizarin Red S; Col, collagen; DMP-1, dentin matrix protein 1.…”

“…Stem cell-based tooth regeneration is a promising approach to solving the problems of tooth loss. Previous studies have demonstrated that tooth germ cells and dental pulp stem cells from adult or deciduous tooth have the potential to differentiate into odontoblast lineages and undergo dentinogenesis (1)(2)(3)(4). However, these cells cannot meet all of the clinical requirements.…”

Elevated TGF-β2 signaling in dentin results in sex related enamel defects

“…However, the mechanisms by which TGF-β acts to control dentin and enamel formation remain unclear. For example, TGF-β1 has been shown to stimulate pulp cell proliferation but inhibit odontoblast differentiation, whereas, Huojia and co-workers showed that TGF-β3 enhanced terminal odontoblast differentiation and promoted the formation of ectopic dentin (15). The relevance of these in vitro studies to tooth formation is difficult to assess in view of the complicated epithelial mesenchymal interactions of tooth development in vitro.…”

The role of transforming growth factor beta in tertiary dentinogenesis

“…13,41,48 In addition, TGF-β1 induces type I collagen production by the odontoblastic/subodontoblastic pulp cells. 49 Huojia et al 50 reported that TGF-β3 induces ectopic mineralization through upregulation of osteocalcin and type I collagen expression in the dental pulp cells and may regulate the differentiation of the dental pulp stem cells to odontoblasts. Such activities might be important during reparative processes in the dentin-pulp complex after tissue injury.…”