Method: Gingival tissues were collected from 10 healthy subjects and 15 chronic periodontitis (CP) subjects. EMMPRIN, Caveolin-1 and MMP-1 expressions were analyzed by immunohistochemistry. EMMPRIN and Caveolin-1 co-localization was detected by immunofluorescence. EMMPRIN glycosylation, Caveolin-1, active MMP-1 and proMMP-1 expression was assessed by western blot.
Results: EMMPRIN was expressed in gingival epithelial cells, inflammatory cells, endothelial and fibroblast-like cells. Strong Caveolin-1 immunoreactivity was detected in gingival epithelial and endothelial cells. Double immunofluorescence studies revealed EMMPRIN and Caveolin-1 co-localization in gingival epithelium, endothelial and fibroblast-like cells. Compared with healthy subjects, the CP group had increased high glycoforms EMMPRIN (HG-EMMPRIN) and active MMP-1 expression (p < 0.05). Active MMP-1 and proMMP-1 protein levels were positively correlated with HG-EMMPRIN levels (p < 0.05).
Conclusion: EMMPRIN and Caveolin-1 colocalize in periodontal tissues. The increased active MMP-1 and proMMP-1 production may be associated with elevated HG-EMMPRIN levels.