CIGARETTE-SMOKE INHIBITS LUNG FIBROBLAST PROLIFERATION AND CHEMOTAXIS

Cigarette smoking is the most clearly recognized cause of pulmonary em physema. Since loss of lung tissue, which characterizes emphysema, rep resents a balance between injury and repair, we hypothesized that ciga rette smoke might contribute to the development of emphysema by inhibi ting fibroblast proliferation and migration. To evaluate this, we exam ined the effect of cigarette smoke extract (CSE) on the proliferation and migration of human lung fibroblasts in vitro. CSE inhibited fibrob last proliferation and migration at noncytotoxic concentrations. When CSE was treated to remove volatile components, it showed less inhibito ry activity on fibroblast proliferation. Therefore, we also examined a crolein and acetaldehyde, which are volatile components of cigarette s moke. Micromolar concentrations of acrolein and millimolar concentrati ons of acetaldehyde induced significant inhibition of fibroblast proli feration. In contrast, removal of volatile components did not eliminat e the inhibitory activity of CSE for fibroblast migration, although ac etaldehyde and acrolein alone were also capable of inhibiting chemotax is. Cigarette smoke-induced inhibition of fibroblast proliferation and migration may impair lung repair following lung injury, and may thus contribute to the development of pulmonary emphysema.