Upregulated expression of monocyte chemoattractant protein-1 in human periodontal ligament cells induced by interleukin-1β

Background: Root resorption during orthodontic treatment is a complex and sterile inflammatory process, characterized by the recruitment of mononuclear cells in the local periodontal ligament. This study aimed to investigate whether interleukin (IL)-1 could induce the migration of monocytes through upregulating monocyte chemoattractant protein (MCP)-1 expression in human periodontal ligament cells. Methods: Human periodontal ligament cells were cultured in medium containing various IL-1 concentrations. After 24hours of incubation, the messenger RNA (mRNA) and MCP-1 protein in periodontal ligament cells were detected by reverse transcriptase-polymerase chain reaction and Western blot analysis, respectively. The effect of supernatants of periodontal ligament cells on THP-1 cells was analysed via migration assay. Results: IL-1 (10ng/mL and 25ng/mL) increased the expression of MCP-1 mRNA and protein in periodontal ligament cells (p<0.05). In addition, the supernatants from the IL-1-treated periodontal ligament cells increased the migratory response of THP-1 cells (p<0.05), which could be blocked by the anti-MCP-1 antibody. Conclusions: IL-1 had the potential to induce the migratory response of monocytes via upregulation of the expression of MCP-1 in human periodontal ligament cells and could contribute to orthodontic root resorption.