Restor Dent Endod.  2015 Aug;40(3):223-228. 10.5395/rde.2015.40.3.223.

Changes in SIRT gene expression during odontoblastic differentiation of human dental pulp cells

• Jang YE
• Go SH
• Lee BN
• Chang HS
• Hwang IN
• Oh WM
• Hwang YC

• KMID: 2396466
• DOI: http://doi.org/10.5395/rde.2015.40.3.223

Abstract

OBJECTIVES
The aim of this study was to investigate the expression of 7 different sirtuin genes (SIRT1-SIRT7) in human dental pulp cells (HDPCs), and to determine the role of SIRTs in the odontoblastic differentiation potential of HDPCs.
MATERIALS AND METHODS
HDPCs were isolated from freshly extracted third molar teeth of healthy patients and cultulred in odontoblastic differentiation inducing media. Osteocalcin (OCN) and dentin sialophosphoprotein (DSPP) expression was analyzed to evaluate the odontoblastic differentiation of HDPCs by reverse transcription-polymerase chain reaction (RT-PCR), while alizarin red staining was used for the mineralization assay. To investigate the expression of SIRTs during odontoblastic differentiation of HDPCs, real time PCR was also performed with RT-PCR.
RESULTS
During the culture of HDPCs in the differentiation inducing media, OCN, and DSPP mRNA expressions were increased. Mineralized nodule formation was also increased in the 14 days culture. All seven SIRT genes were expressed during the odontogenic induction period. SIRT4 expression was increased in a time-dependent manner.
CONCLUSIONS
Our study identified the expression of seven different SIRT genes in HDPCs, and revealed that SIRT4 could exert an influence on the odontoblast differentiation process. Further studies are needed to determine the effects of other SIRTs on the odontogenic potential of HDPCs.

Keyword

Dentin sialophosphoprotein; Human dental pulp cell; Pulp; Sirtuin; SIRT4

MeSH Terms

Dental Pulp*
Dentin
Gene Expression*
Humans*
Molar, Third
Odontoblasts*
Osteocalcin
Real-Time Polymerase Chain Reaction
RNA, Messenger
Tooth
Osteocalcin
RNA, Messenger

Figure

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  Figure 1 Expression of OCN and DSPP during the odontogenic differentiation of HDPCs analyzed by RT-PCR. OCN, osteocalcin; DSPP, dentin sialophosphoprotein; HDPC, human dental pulp cell; RT-PCR, reverse transcription-polymerase chain reaction.

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  Figure 2 Mineralization during the odontogenic differentiation of HDPCs analyzed by alizarin red staining. HDPC, human dental pulp cell; GM, growth media; OIM, odontogenic induction media.

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  Figure 3 Expression of SIRT genes during the odontogenic differentiation of HDPCs analyzed by RT-PCR. SIRT, sirtuin; HDPC, human dental pulp cell; RT-PCR, reverse transcription-polymerase chain reaction.

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  Figure 4 Expression level of SIRT4 mRNA during the odontogenic differentiation of HDPCs analyzed by realtime PCR. SIRT, sirtuin; mRNA, messenger ribonucleic acid; HDPC, human dental pulp cell.

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