Epidemiological studies demonstrate an apparent sex-based difference in the prevalence of asthma, with a higher risk in boys than girls, which is reversed postpuberty, where women become more prone to asthma than men, suggesting a plausible beneficial role for male hormones, especially androgens as a regulator of pathophysiology in asthmatic lungs. Using a murine model of asthma developed with mixed allergen (MA) challenge, we report a significant change in airway hyperresponsiveness (AHR), as demonstrated by increased thickness of epithelial and airway smooth muscle layers and collagen deposition, as well as Th2/Th17-biased inflammation in the airways of non-gonadectomized (non-GDX) and gonadectomized (GDX) male mice. Here, compared with non-GDX mice, MA-induced AHR and inflammatory changes were more prominent in GDX mice. Activation of androgen receptor (AR) using 5α-dihydrotestosterone (5α-DHT, AR agonist) resulted in decreased Th2/Th17 inflammation and remodeling-associated changes, resulting in improved lung function compared with MA alone challenged mice, especially in GDX mice. These changes were not observed with Flutamide (Flut, AR antagonist). Overall, we show that AR exerts a significant and beneficial role in asthma by regulating AHR and inflammation.
Keywords: 5α-dihydrotestosterone; flutamide; lung function; sex-steroids; testosterone.