Expression, Purification, and Characterization of a Dentin Phosphoprotein Produced by Escherichia coli, and Its Odontoblastic Differentiation Effects on Human Dental Pulp Cells

Abstract

To investigate the functions of recombinant human dentin phosphoprotein (rhDPP), we examined cell adhesion, viability and the odontoblastic differentiation activity of human dental pulp cells (hDPCs). Firstly, rhDPP was constructed using pBAD-HisA plasmid in Escherichia coli. Cell adhesion and viability of hDPCs by rhDPP was examined using a crystal violet assay and a MTT assay, ALP, mineralization activity and odontoblastic differentiation-related mRNA levels of hDPCs were measured to elucidate the odontoblastic differentiation effect of rhDPP on hDPCs. Initially, rhDPP significantly and dose-dependently increased hDPCs adhesion versus the untreated control (p < 0.05). Cell viability was also significantly increased by rhDPP at 5 days (p < 0.001). Furthermore, the odontoblastic differentiation effect of rhDPP was verified by measuring ALP activity, mineralization activity and the mRNA levels of odontoblastic differentiation markers. Taken together, rhDPP is expected to play an important role on hDPCs, thereby suggesting its potential use for tooth repair and regeneration.

Recombinant stromal cell‑derived factor‑1 protein promotes neurite outgrowth in PC‑12 cells

“…For instance, Jo et al (23) reported that, in the presence of oxidative-stress, Tat-DJ-1 promoted cell survival in HepG2 cells without cytotoxicity. Similarly, recombinant human dentin phosphoprotein also demonstrated low toxicity in our previous study (24). In the present study, purified recombinant SDF-1 protein was not toxic to PC-12 cells.…”

Medium modification with bone morphogenetic protein 2 addition for odontogenic differentiation

“…For instance, enamel and dentin specific transcript expression have been reported as necessary to confirm odontogenic differentiation. 24 Therefore, gene expression analysis was also performed for human enamel-dentin specific transcripts in this study. The increased expression responsible for the formation of predentin matrix (Dspp), 25 collagen (Dmp1), 26 enamel matrix, (MMP20) 27 and phosphate haemostasis (Phex) 28 consistent with the culture period in the (+) group compared to the (-) group (Figure 4) were the evidence of odontogenic differentiation.…”