Airway exposure to perfluorooctanoate exacerbates airway hyperresponsiveness and downregulates glucocorticoid receptor expression in asthmatic mice

BACKGROUND: Multiple environmental risk factors play a vital role in the pathogenesis of asthma, which contribute to the phenotypic expression of asthma. Perfluorooctanoate (PFOA) is the most common and abundant perfluorocarbon (PFC) in humans, and it has been detected in water and the atmosphere worldwide. Glucocorticoid receptor (GR) is considered to exert a protective effect on asthma and is associated with the sensitivity to glucocorticoids. Dermal or oral exposure to PFOA has been shown to contribute various effects on airway inflammation in individuals with ovalbumin (OVA)-induced asthma. Notably, airway exposure has a critical contribution to the pathogenesis of asthma. However, the effect of airway exposure to PFOA on airway hyperresponsiveness (AHR) in patients with asthma is not currently understood. METHODS: BALB/c mice were administered OVA to induce asthma. PFOA was then administered intratracheally to OVA-induced mice for seven days. Then we assessed the effect of airway exposure to PFOA on AHR and the regulation of the GR expression in asthmatic mice. RESULTS: The results showed aggravated AHR and T helper type 2 (Th2) airway inflammation in asthmatic mice. Furthermore, these mice show a substantial decrease in the expression of the GR mRNA and protein. CONCLUSIONS: These data strongly suggest that acute airway exposure to PFOA leads to Th2-related AHR and decreases GR expression, which may increase the difficulty in the treatment of asthma.