p38αMAP kinase promotes asthmatic inflammation through modulation of alternatively activated macrophages

Asthma is characterized by reversible airflow obstruction, bronchial hyper-reactivity, and chronic airway remodeling (Al-Muhsen et al., 2011). Pulmonary macrophages have been implicated in asthmatic inflammation (Lee et al., 2015;Qian et al., 2015). The p38 mitogen-activated protein kinase (MAPK) plays an essential role in inflammation, but its role in asthma has not been determined (Kim et al., 2008). Here, our data show that macrophage-specific p38α MAPK-deficient mice displayed attenuated asthmatic inflammation in response to three allergens (dust mite, ragweed, and Aspergillus;DRA). Furthermore, we found that the protective effect was strongly associated with a reduction in the alternatively activated macrophage (AAM) polarization in vivo and in vitro. Taken together, our data indicate that p38α MAPK in macrophages contributes to AAM polarization and could be a therapeutic target for asthma.