Effects of interleukin-1β on mineralization potential of dental pulp stem cells

Abstract

To investigate the effects of pro-inflammatory cytokine interleukin-1β (IL-1β) on mineralization potential of dental pulp stem cells (DPSC). Rat DPSC were cultured in vitro and randomly divided into three groups, IL-1β (10 µg/L), osteogenic inductive medium and non-osteogenic inductive medium. After 3, 7, and 12 days of treatment, the cultures were evaluated for cell proliferation and calcium deposit. Real-time polymerase chain reaction was used to detect the gene expression levels of osteocalcin (OC), bone sialoprotein (BSP), dentin sialophosphoprotein (DSPP) and dentin matrix protein 1 (DMP-1). In vivo test, after 3 day's treatment with IL-1β, the cell-scaffold complexes were implanted subcutaneously in mice for 8 weeks. Histological analysis was performed to evaluate hard tissue formation. In vitro test, after 3-day's treatment, IL-1β improved cell proliferation to 137.22 DNA µg/L and cell viability becomes (97.12 ± 7.18)% of control. The gene expression levels of OC, BSP, DSPP and DMP-1 are (378.19 ± 16.22)%, (427.12 ± 18.22)%, (247.19 ± 10.11)% and (198.29 ± 10.23)% respectively. The results of IL-1β's group was notable increased compared with non-osteogenic induction medium and the statistical differences are significant. IL-1β induced the odontogenic differentiation of DPSC. However, these effects tended to continuously decrease with treatment time. Histological analysis demonstrated that in the group treated with IL-1β hard tissue was markedly formed in vivo. IL-1β may induce the mineralization of DPSC and play an important role in host defenses and tissue repair.