Expression of Stromal cell-derived factor-1 in human inflamed dental pulp tissue

AIM: To investigate the expression of Stromal cell-derived factor-1(SDF-1) and CXCR4 in human inflammed dental pulps and to explore the role of SDF-1/CXCR4 axis in pulpal inflammation.METHODS: Inflamed dental pulp tissues were obtained from extracted teeth that showed spontaneous pain and/or lingering pain in response to cold and/or heat stimulus,and normal dental pulp tissues were obtained from healthy noncarious teeth.Distribution of SDF-1-positive and CXCR4-positive cells in the dental pulp tissues was investigated by immunohistochemistry.Real time RT-PCR was performed to detect SDF-1 mRNA expression in healthy and inflamed pulp tissues.RESULTS: In inflamed pulps,SDF-1 and CXCR4 were mostly distributed in inflammatory cells,odontoblasts and microvascular endothelial cells.In contrast,SDF-1 and CXCR4 were scarcely detected in normal pulp tissues.SDF-1 mRNA expression levels in clinically inflamed dental pulp were higher than those in healthy dental pulp.CONCLUSION: SDF-1-positive and CXCR4-positive cells were significantly increased in inflamed dental pulp tissues as compared with non-inflamed dental pulp tissues.Our findings suggest that SDF-1 plays an important role in the advancement of pulpal inflammation via the recruitment of CXCR4-expressing inflammatory cell and SDF-1/CXCR4 axis maybe involved in the recruitment of dental pulp inflammatory cells at the injury site.