Airway remodeling is reversed by aerobic training in a murine model of chronic asthma

The aim of this study was to investigate if the aerobic training (AT) reverses airway remodeling (AR) in an asthma model. BALB/c were divided into four groups: control (unsensitized and untrained); ovalbumin (OVA: sensitized and untrained); AT (unsensitized and trained) and OVA + AT. Allergic inflammation was induced with intraperitoneal and OVA inhalation. AT (low intensity; 5×/week; 60 min/session) was performed at 7, 15, and 30 days. Leukocyte counting in the bronchoalveolar lavage fluid; the expression of IL-5, eotaxin, RANTES, intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1); AR features (airway smooth muscle, epithelium thickness, collagen and elastic fibers, mucus production); and AR inducers (transforming growing factor-beta, osteopontin, vascular endothelial growth factor). OVA induced an increase in leukocyte airway migration and increased AR features (P < 0.05). After 7 days, AT reversed the OVA-induced eosinophil and macrophage airway migration, the expression of IL-5, eotaxin, RANTES, ICAM-1, VCAM-1, and all AR inducers. However, total reversion of the AR features and inducers and airway inflammation occurred only after 15 days of AT compared with the OVA groups (P < 0.05) and the effects were maintained until the 30th day. AT reverses AR after 15 days and this effect is preceded by the inhibition of leukocyte migration and occurs simultaneously with the reduction in the expression of inflammatory mediators and AR inducers.