Abstract
The regular practice of aerobic exercise (AE) has been shown to reduce chronic allergic airway inflammation and remodeling (CAAIR), but the mechanisms involved remains poorly understood. In the present study we investigated if 4 weeks of AE deactivates airway epithelium and peribronchial leukocytes in a model of CAAIR. Thirty-two animals were divided in control, aerobic exercise, ovalbumin and ovalbumin+aerobic exercise groups. Mice sensitized (10ug/mouse, days 0, 14, 28 and 42) and challenged with ovalbumin (3x/week; 21st until 50th day), were submitted to AE (21st until 50th day, 60min/session; 5x/week). The results demonstrated that AE in OVA-sensitized mice significantly reduced eosinophils in BAL and in airway wall and also the accumulation of collagen fibers on airway wall. This anti-inflammatory and anti-fibrotic response induced by AE in sensitized animals was followed by reduced expression of the followings markers by airway epithelial cells and also by peribronchial leukocytes: IL-4, IL-5, IL-13, CCL11, CCL5, ICAM-1, VCAM-1, iNOS, NF-kB, GP91phox, 3-nitrotyrosine, 8-Isoprostane, IGF-1, EGFr, VEGF, TGF-beta, MMP-12 and TIMP-2 (p<0.01). AE in sensitized animals also increased the expression of anti-inflammatory cytokine IL-10 by leukocytes and airway epithelial cells. Taken together, these results demonstrate that the beneficial effects of AE on allergic airway inflammation and remodeling is a multifactorial response involving deactivation of airway epithelial cells and also of leukocytes, by inhibition of Th2 response, chemokines, adhesion molecules, oxidative and nitrosative stress, and also on the growth factors and matrix metalloproteinases.
- © 2011 ERS