The Effects of Cigarette Smoke Condensate on Human Pulp Cells

Cigarette smoke condensate (CSC) is produced when tobacco is burned and it is composed of more than 4,000 chemicals. It is well known that smoking tobacco can cause lung cancer and other health problems such as periodontal disease and oral cancer. However, very little is known about the effects of CSC on cell repairing and regeneration ability. Objectives: This research project examined the effects of CSC on human pulp cells (HPC) and is our first step to investigate smoking's effect on HPC repairing and regeneration ability. Materials and Methods: HPCs were collected from dental patients whose teeth were extracted for orthodontic treatment with Institutional Review Board approval. HPCs (50,000 cells/well) were exposed to various concentrations of CSC (0, 3.125, 6.25, 12.5, 50, 100, 200 and 400µg/ml) for three days. The cytotoxicity and cell viability effects of the CSC on HPCs were evaluated by performing lactate dehydrogenase (LDH, Roche Applied Science, Mannheim, Germany) and water soluble tetrazolium-1 (WST-1, Roche Applied Science) assays, respectively. To test their collagen degrading ability under the influence of CSC, HPCs (100,000 cells/well) were seeded as a single colony in each well of Type I collagen-coated 6-well plates and supplemented with CSC (0, 12.5, 25, and 400µg/ml) for 1, 3 and 5 days before staining with Coomassie blue. The conditioned media were also collected to test for proteinase activity utilizing zymography. Results: The CSC was toxic and inhibited HPC proliferation at 400µg/ml. Concentrations of CSC at 12.5 and 25µg/ml stimulated the HPC ability to degrade collagen. The production of pro- and active MMP-2 was increased in the cultured media. Conclusion: CSC is toxic to HPCs and affects pulp cell growth. CSC at non-toxic concentrations changes the HPC ability to remodel extracellular matrix, in part, by producing more MMP-2.