Cigarette smoke condensate affects the collagen-degrading ability of human gingival fibroblasts

Abstract

Background and objective: Cigarette smoke condensate, the particulate matter of cigarette smoke, is composed of thousands of chemicals, including nicotine. Cigarette smoking is a risk factor for periodontal disease. This study investigated the influence of cigarette smoke condensate on the collagen-degrading ability of human gingival fibroblasts and its mechanism.

Material and methods: Human gingival fibroblasts were exposed for 72 h to various concentrations of total particulate matter cigarette smoke condensate. Cell proliferation and cytotoxicity were evaluated using water-soluble tetrazolium-1 and lactate dehydrogenase, respectively. The collagen-degrading ability of human gingival fibroblasts was evaluated in collagen-coated six-well plates. Conditioned media and membrane extracts were collected for zymography and western blot analyses of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs).

Results: Cell proliferation decreased and cytotoxicity increased in human gingival fibroblasts with increasing concentrations of cigarette smoke condensate. Cell proliferation decreased by more than 50% (p < 0.05) when the concentrations of total particulate matter cigarette smoke condensate were above 200 microg/mL, and cytotoxicity increased to more than 30% (p < 0.05) when the concentrations of total particulate matter cigarette smoke condensate were above 400 microg/mL. Cigarette smoke condensate increased the collagen-degrading ability of human gingival fibroblasts, especially at a concentration of 100 microg/mL (1.5-fold increase, p < 0.05) compared with the control. Cigarette smoke condensate increased the production of proMMP-1, proMMP-2, MMP-14 and TIMP-1, and decreased the production of TIMP-2, in conditioned media. Furthermore, compared with the control group, cigarette smoke condensate increased the production of MMP-2, MMP-14 and TIMP-2 in membrane extracts, especially at concentrations of 50-100 microg/mL.

Conclusion: Cigarette smoke condensate affects human gingival fibroblast proliferation and is toxic at total particulate matter cigarette smoke condensate concentrations of >or= 400 microg/mL. Cigarette smoke condensate can increase the collagen-degrading ability of human gingival fibroblasts by altering the production and localization of MMPs and TIMPs.