Rationale: Incomplete combustion produces a pollutant mixture that includes polycyclic aromatic hydrocarbons (PAH). Prior work by the Columbia Center for Children’s Environmental Health (CCCEH) and others has linked exposure to PAH with asthma symptoms and other adverse health effects in young children. Inhaled β2-adrenergic agonists are mainstays in the treatment of reactive airways diseases. These exogenous catecholamines engage membrane bound β2-adrenergic receptors (β2AR) on airway epithelial and smooth muscle cells to cause airway dilation.
Objective: We hypothesized that exposure to PAH might similarly interfere with β2AR function on airway epithelial and/or smooth muscle cells, thereby reducing the efficacy of a medication important for treatment of asthma symptoms.
Methods: A PAH mixture was devised based on ambient levels measured prenatally among a cohort of pregnant women participating in the Columbia Center for Children’s Environmental Health. Primary airway epithelial and smooth muscle cells were exposed to varying concentrations of the PAH mixture and β2AR expression, function and signaling assessed. Results: Mouse tracheal epithelial cells and humans airway smooth muscle cells exposed to a PAH mixture experienced reduced β2AR expression and function.