IL-17 stimulates the production of the inflammatory chemokines IL-6 and IL-8 in human dental pulp fibroblasts.

To investigate IL-17 expression in human pulpitis and to study the effects of IL-17 on the secretion of the chemokines IL-6 and IL-8 and the related signalling pathways. Samples of human dental pulp tissue were obtained from healthy controls and patients with pulpitis. Cytokine IL-17 messenger RNA (mRNA) expression in the pulp tissue was detected by real-time polymerase chain reaction. In addition, human dental pulp fibroblasts (HDPFs) were stimulated with IL-17. Production of IL-6 and IL-8 was determined by reverse transcriptase-polymerase chain reaction and enzyme-linked immunosorbent assay. Aspects of the nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinases (MAPKs) signalling pathways were examined by Western blot analysis. Increased levels of IL-17 mRNA were found in inflamed dental pulp tissue (pulpitis). Stimulation of dental pulp tissue with IL-17 induced the production of IL-6 and IL-8 in a dose-dependent manner. In addition, IL-17 stimulation resulted in rapid activation of nuclear factor-kappaB (NF-κB), phosphorylation of p38 MAPK, extracellular signal-regulated kinase (ERK) and Jun N-terminal kinase (JNK) in HDPFs. IL-17 may participate in pulp tissue inflammation through chemokine production and NF-κB and MAPKs signalling pathways.