Cigarette Smoke Extract Induces Select Matrix Metalloproteinases and Integrin Expression in Periodontal Ligament Fibroblasts

Background: The periodontal ligament (PDL) is the connective tissue that anchors the cementum of the teeth to the alveolar bone. PDL fibroblasts are responsible for the production of collagen and remodeling of the PDL. Periodontal disease is increased among smokers in both incidence and severity. This study examines the direct effect of smoking on PDL fibroblasts and their production of various matrix components and remodeling enzymes. Methods: PDL cells were plated for 1 day and then treated with various concentrations of cigarette smoke extract (CSE). Survival of PDL cells was quantified after exposure to CSE, and their ability to contract three-dimensional collagen gels was examined. Changes in transcript expression after CSE treatment was compared using reverse transcription-polymerase chain reaction analysis for matrix metalloproteinases (MMPs), collagens, and integrins. Results: Treatment with CSE-induced cell death at concentrations of >= 5% PDL-cell-induced collagen gel contraction was reduced at concentrations of 1.5% CSE. Treatment with CSE selectively increased the expression of collagen v alpha 3 and decreased collagen XI alpha 1 CSE increased the expression of MMP1 and MMP3 and, to a lesser extent, MMP2 and MMP8. SE also increased the expression of integrins alpha 1, alpha 2, and alpha 10 (collagen receptors) and alpha 9 (a tenascin receptor). Conclusions: This study shows that cigarette smoking has local effects on the cells of the PDL. CSE reduced survival of PDL cells and their ability to contract collagen matrices. CSE also altered the expression of molecules known to provide the structural integrity of the ligament by altering collagen synthesis and remodeling as well as cell adhesion. J Periodontol 2012;83:787-796.