Amelogenin Peptide Promotes Human Dental Pulp Cell Proliferation and Odontogenic Differentiation via ERK1/2 Pathway

Objectives Enamel matrix derivative (EMD) is widely recognized for its ability to induce osteogenic and odontogenic differentiation. However, the complex composition of EMD frequently results to inconsistent experimental and clinical outcomes. Amelogenin, a key component of EMD, plays crucial roles in tooth germ development as well as in the repair and regeneration of dental tissue. In this study, an amelogenin peptide was investigated on the proliferation and odontogenic differentiation of human dental pulp cells (HDPCs). Methods The amelogenin peptide with the amino acid sequence KWYQNMIR was synthesized using solid-phase techniques. HDPCs were stimulated with various concentrations of the peptide. CCK-8 assays, alkaline phosphatase (ALP) activity measurements, quantitative reverse transcription-polymerase chain reaction, Western blot analysis, Alizarin red staining, and scanning electron microscopy were used to assess the effects. Results The amelogenin peptide concentrations of 100 nM and 1 μM significantly enhanced HDPC proliferation at 5 and 7 days ( P < .01), with 1 μM exhibiting the most pronounced effect. Treatment with 1 μM amelogenin peptide enhanced ALP activity in HDPCs at 7 and 14 days ( P < .01) and markedly upregulated the mRNA expression of DSPP, DMP-1 , and RUNX-2 . Western blot analysis revealed that 1 μM amelogenin peptide enhanced the protein expression of DSPP, DMP-1, and ALP in HDPCs at 7 and 14 days. Additionally, it promoted calcium deposition and mineralized nodule formation at 28 days. Importantly, the amelogenin peptide upregulated the phosphorylation level of ERK1/2 (p-ERK1/2), and the application of an ERK1/2 inhibitor suppressed HDPC differentiation. Conclusions The amelogenin peptide stimulates both the proliferation and odontogenic differentiation of HDPCs via the ERK1/2 pathway. These findings suggest that the amelogenin peptide may have significant implications for regenerative dentistry, particularly in the context of dentine-pulp complex regeneration.