Effects of tobacco and P. gingivalis on gingival fibroblasts.

Cigarette smoke condensate (CSC) is the particulate matter of cigarette smoke. Porphyromonas gingivalis (P. gingivalis) is an opportunistic pathogen involved in periodontitis. It was hypothesized that the combination of CSC and P. gingivalis would increase the collagen-degrading ability of human gingival fibroblasts (HGFs). In this study, HGFs were exposed to CSC, P. gingivalis supernatant, and CSC plus P. gingivalis supernatant. The collagen-degrading ability and protein/mRNA levels of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) of HGFs were examined. The combined treatment increased collagen degradation, protein levels of active forms of MMP-1, MMP-2, MMP-3, and MMP-14 in conditioned media, and the low-molecular-weight fragment of MMP-14 in membrane extracts, as well as mRNA levels of MMP-1, MMP-2, and MMP-14. In conclusion, the combined effects of CSC and P. gingivalis increased HGF-mediated collagen degradation by destroying the balance between MMPs and TIMPs at multiple levels.