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

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 μg/mL, and cytotoxicity increased to more than 30% (p < 0.05) when the concentrations of total particulate matter cigarette smoke condensate were above 400 μg/mL. Cigarette smoke condensate increased the collagen‐degrading ability of human gingival fibroblasts, especially at a concentration of 100 μg/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 μg/mL. Conclusion: Cigarette smoke condensate affects human gingival fibroblast proliferation and is toxic at total particulate matter cigarette smoke condensate concentrations of ≥ 400 μg/mL. Cigarette smoke condensate can increase the collagen‐degrading ability of human gingival fibroblasts by altering the production and localization of MMPs and TIMPs.