SP1 promotes the odontoblastic differentiation of dental papilla cells

Odontoblasts are a type of terminally differentiated and matrix-secreting cells that are responsible for dentinogenesis. The process of odontoblast differentiation is regulated by a variety of transcription factors. The transcription factor SP1 is known to play an essential regulatory role in cell proliferation and differentiation. The purpose of this study was to investigate the role of SP1 in odontoblastic differentiation. Immunohistochemistry verified that SP1 was specifically expressed in polarizing and secretory odontoblasts in vivo. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and immunofluorescence revealed that the expression of SP1 was significantly upregulated during odontoblastic differentiation of mDPC6T cells, a dental papilla cell line. Overexpression of SP1 significantly increased the expression of odontoblast-related genes, including DSPP, DMP1 and ALP, and promoted the formation of mineralized nodules. Meanwhile, knockdown of SP1 decreased the expression of these odontoblast-related genes and suppressed the formation of mineralized nodules. Our results demonstrate that SP1 promotes the odontoblastic differentiation and mineralization of dental papilla cells.