Stromal-derived factor-1alpha (CXCL12) levels increase in periodontal disease.

BACKGROUND The CXC chemokine receptor 4 (CXCR4) and its ligand, stromal cell-derived factor-1 (SDF-1alpha or CXC chemokine ligand 12) are involved in the trafficking of leukocytes into and out of extravascular tissues. The purpose of this study was to determine whether SDF-1alpha secreted by host cells plays a role in recruiting inflammatory cells into the periodontia during local inflammation. METHODS SDF-1alpha levels were determined by enzyme-linked immunosorbent assay in gingival crevicular fluid (GCF) of 24 individuals with periodontitis versus healthy individuals in tissue biopsies and in a preclinical rat model of Porphyromonas gingivalis lipopolysaccharide-induced experimental bone loss. Neutrophil chemotaxis assays were also used to evaluate whether SDF-1alpha plays a role in the recruitment of host cells at periodontal lesions. RESULTS Subjects with periodontal disease had higher levels of SDF-1alpha in their GCF compared to healthy subjects. Subjects with periodontal disease who underwent mechanical therapy demonstrated decreased levels of SDF-1alpha. Immunohistologic staining showed that SDF-1alpha and CXCR4 levels were elevated in samples obtained from periodontally compromised individuals. Similar results were observed in the rodent model. Neutrophil migration was enhanced in the presence of SDF-1alpha, mimicking immune cell migration in periodontal lesions. CONCLUSIONS SDF-1alpha may be involved in the immune defense pathway activated during periodontal disease. Upon the development of diseased tissues, SDF-1alpha levels increase and may recruit host defensive cells into sites of inflammation. These studies suggest that SDF-1alpha may be a useful biomarker for the identification of periodontal disease progression.