EGR1 supports the osteogenic differentiation of dental stem cells

Abstract

Aim: To evaluate whether and how the transcription factor early growth response gene 1 (EGR1) affects the osteogenic differentiation of dental stem cells.

Methodology: Dental stem cells from apical papilla (SCAPs) and from the dental follicle (DFCs) were transfected with EGR1-specific siRNA or EGR-1 expression plasmid. Gene regulation was verified at protein level by Western blotting. The expression of the transcription factors distal-less homeobox 3 (DLX3), alkaline phosphatase (ALP) and bone morphogenetic protein 2 (BMP2), which are all regulators and markers of the osteogenic differentiation in dental stem cells, was determined by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). To investigate mineralization, SCAP long-term cultures were stained with alizarin red after EGR1 over-expression.

Results: EGR1 was induced in SCAPs during osteogenic differentiation. DLX3 and bone morphogenetic protein 2 (BMP2) were up-regulated after EGR1 over-expression and down-regulated after EGR1 depletion. The expression of ALP was also down-regulated after EGR1 depletion. The over-expression of EGR1 in SCAPs promoted mineralization after osteogenic differentiation.

Conclusions: EGR1 supported the osteogenic differentiation of dental stem cells by potentially regulating the expression of DLX3 and BMP2.

Keywords: bone morphogenetic protein 2; dental follicle precursor cells; distal-less homeobox 3; early growth response gene 1; stem cells from apical papilla.