Expression of Cytokines and Adhesion Molecules in Cultured Dental Pulp Fibroblasts Affected by Bacteria-derived Factors

Abstract

Pulpitis mainly results from the invasion of dental caries-related bacteria into dental pulp. It is known that various proinflammatory cytokines and adhesion molecules play important roles in the exacerbation of pulpitis but detailed expression mechanisms have not been fully elucidated. The purpose of this study was to determine the effect of bacteria-derived factors on proinflammatory cytokines and adhesion molecules expression in cultured dental pulp fibroblasts. The expressions of interleukin-8 (IL-8) and vascular endothelial growth factor (VEGF) in pulp fibroblasts exposed to lipopolysaccharide (LPS) or peptidoglycan (PGN) were examined by reverse transcriptase-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). In addition, adhesion molecules (ICAM-1 and VCAM-1) expression on pulp fibroblasts was analyzed by flow cytometry. Both LPS and PGN increased not only the expression of IL-8 and VEGF but also the expression of ICAM-1 and VCAM-1 in pulp fibroblasts. These results suggest that pulp fibroblasts play an important role in pathogenesis of pulpitis via expression of proinflammatory cytokines and adhesion molecules in response to bacteria-derived factors.