Interleukin-6 Inhibits Interleukin-1ß Release in Human Primary Dental Pulp Cells

Introduction: Interleukin-6 (IL-6) is a multifunctional cytokines that regulates immune response, inflammation, hematopoiesis and oncogenesis. Previously, we found that mechanical stress induced IL-6 release in human dental pulp cells. However, little is known about the roles of IL-6 in human dental pulp cells. Objectives: The aim of this study was to investigate the effects of IL-6 on inflammatory cytokines release in human primary and permanent dental pulp cells. Materials and methods: Cultures of human primary and permanent dental pulp cells were established from the explants of pulp tissues. Both groups of dental pulp cells were stimulated with 0-5 ng/ml of IL-6 in serum-free condition for 16 hours. The expressions of inflammatory cytokines were determined by using reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assay. Results: Results indicated that IL-6 suppressed IL-1ß release at both mRNA and protein levels in primary human dental pulp cells while there is no dramatical changes in permanent human dental pulp cells when compared to untreated primary and permanent dental pulp cells. Conclusions: The results demonstrated that IL-6 could regulate the expression of IL-1ß in primary dental pulp cells. This may lead to the implication that IL-6 might play a role in the regulation of inflammation in human primary dental pulp cells.