Environmental health perspectives 2016 Nov 4()
Foetal determinants of airway function, such as in utero exposure to maternal cigarette smoke (CS), may create a predisposition to adult airflow obstruction and COPD in adulthood. It has been suggested that active smoking in adolescence and pre-existing airflow obstruction have synergistic deleterious effects.
We used a mouse model to investigate whether there is a synergistic effect of exposure to CS in utero and during adolescence on lung function.
Female C57Bl/6J mice were exposed to CS or to filtered room air during pregnancy. Exposure to CS began two weeks before mating, and continued until delivery. After birth, the pups were not exposed to CS until day (D)21. Between D21 and D49, corresponding to "adolescence", litters were randomized for an additional 4 weeks of exposure to CS. Lung morphometry, lung mechanics, and the expression of genes involved in senescence were evaluated in different subsets of mice on D21 and D49.
In utero exposure to CS induced significant lung function impairment by D21. CS exposure between D21 and D49 induced significant functional impairment only in mice exposed to CS prenatally. On D49, no difference was observed between subgroups in terms of lung p53, p16, p21, and Bax mRNA levels.
Our findings suggest that prenatal and adolescent CS exposure have a synergistic effect on lung function in mice. The combined effect did not appear to be a consequence of early pulmonary senescence.