Maternal smoking during pregnancy induces airway remodeling in mice offspring

¹ Dept of Pathology and
² Pulmonology, University Medical Center Groningen, University of Groningen, The Netherlands

^* To whom correspondence should be addressed. E-mail: m.n.hylkema{at}path.umcg.nl.

	Abstract

Children from smoking mothers have an increased risk to develop asthma for reasons largely unknown. We investigated effects of maternal smoking during pregnancy on remodeling, allergic airway inflammation and hyperresponsiveness in offspring in an experimental asthma model.

Mice were exposed to fresh air or cigarette smoke from 3 weeks prior to conception until birth. Offspring were exposed to house dust mite (HDM) or PBS intranasally 4 times·week^-1 from week 5–10 after birth onwards.

Maternal smoking increased airway smooth muscle layer, collagen III deposition and HDM-induced goblet cell numbers in offspring. It additionally increased methacholine responsiveness which correlated significantly with increased airway smooth muscle layer and collagen deposition. Maternal smoking increased HDM-induced numbers of neutrophils and mast cells in lung tissue. No further effects were observed.

Smoking during pregnancy induces airway remodeling in mice offspring, which may contribute to increased methacholine responsiveness. This takes place irrespective of allergen exposure but may worsen the outcome of the allergic stimulus, resulting in higher methacholine responsiveness in HDM exposed offspring from smoking mothers when compared to non-smoking mothers. Our results provide a possible mechanism behind the association between maternal smoking and asthma.