Simvastatin modulates osteogenic differentiation in stem cells isolated from apical papilla

Background Simvastatin modulates numerous stem cell functions, including stemness maintenance and differentiation. The present study aimed to explore the effect of simvastatin on the osteogenic differentiation of SCAPs in vitro. Methods Cells were isolated from apical papilla, and mesenchymal stem cell features were characterised. Cells were treated with various concentrations of simvastatin (100-1,000 nM). The mRNA expression profile of simvastatin-treated SCAPs was examined using RNA sequencing technique. The osteogenic differentiation abilities were assessed. Alkaline phosphatase activity was determined. The mineralisation was visualised using Alizarin Red S and Von Kossa staining. The osteogenic marker gene expression was determined using a quantitative polymerase chain reaction. Results RNA sequencing data demonstrated that simvastatin upregulated genes enriched in those pathways involving osteogenic differentiation, including the TGF-beta signalling pathway, FoxO signalling pathway, and MAPK signalling pathway, while the downregulated genes were involved in pathways related to cell proliferation and apoptosis, for example, DNA replication, cell cycle, and p53 signalling pathway. Simvastatin promoted mineral deposition in a dose-dependent manner, corresponding with the upregulation of osteogenic marker genes namely OSX, DMP1, DSPP, and OCN. Pretreatment with TGF-beta receptor inhibitor, SB431542, resulted in a moderately attenuated effect on simvastatin-induced mineralisation and osteogenic marker gene expression. Conclusions Simvastatin enhances osteogenic differentiation in SCAPs, potentially via TGF-beta signalling, implicating its potential role as an adjunctive molecule in dental pulp healing and regeneration in vital pulp treatment approaches.