Epidemiological studies have shown that maternal smoking during pregnancy is a risk factor for the development of asthma. However, the mechanisms underlying the increased risk of developing asthma are largely unknown. We have shown that maternal smoking during pregnancy increases smooth muscle layer and collagen III deposition around the airways in mouse offspring in association with increased airway hyper-responsiveness.1 Other factors also appear to contribute to the development of increased airway hyper-responsiveness. We hypothesise that lung development is such a factor. Since genes in the Wnt-β-catenin pathway are essential for lung development and epithelial stem cell differentiation/expansion, we investigated the effects of maternal smoking during pregnancy on Wnt gene expression in lung tissue from neonatal offspring.

Balb/c mice were exposed …