Altered Methylation Levels in LINE-1 in Dental Pulp Stem Cell-Derived Osteoblasts.

OBJECTIVES

Long interspersed nuclear element-1 (LINE-1) and Alu elements are major targets of methylation, an epigenetic mechanism that is associated with several biological processes. Alterations of methylation of LINE-1 and Alu have been reported in cancers, diseases, and ageing. However, these alterations have not been studied in osteogenic differentiation of dental pulp stem cells (DPSCs), which are a promising source of tissue regeneration.

METHOD

This study was performed to investigate the methylation level of LINE-1 and Alu in dental pulp stem cell-derived osteoblasts (DPSC-DOs). By using the combined bisulfite restriction analysis, the levels of total methylation and 4 patterns of methylated cytosine-phosphate-guanine (CpG) dinucleotides of LINE-1 and Alu were compared between DPSC-DOs and DPSCs.

RESULT

The levels of total methylation and hypermethylated CpG dinucleotides of LINE-1 were significantly lower (P = .015 and .021, respectively), whilst levels of one pattern of partial methylated CpG dinucleotides were significantly higher in DPSC-DOs than DPSCs (P = .021). The methylation of Alu was not significantly different between DPSCs and DPSC-DOs.

CONCLUSIONS

Methylation alterations of LINE-1 but not Alu were found in osteogenic differentiation of DPSCs. The results of this study offer foundational insights into osteoblast differentiation from an epigenetic perspective and may contribute to advancements in bone regeneration therapy in the future.