Aerobic Exercise Protects from Pseudomonas aeruginosa-Induced Pneumonia in Elderly Mice

Abstract

Background: Pseudomonas aeruginosa (PS) infection results in severe morbidity and mortality, especially in immune-deficient populations. Aerobic exercise (AE) modulates the immune system, but its effects on the outcomes of pulmonary PS infection in elderly mice are unknown. Methods: BALB/c mice (24 weeks old) were randomized to sedentary, exercise (EX), PS, and PS + EX groups for the acute experimental setting, and PS and PS + EX groups for the chronic setting. Low-intensity AE was performed for 5 weeks, 60 min/day; 24 h after the final AE session, mice were inoculated with 5 × 10⁴ colony-forming units (CFU) of PS, and 24 h and 14 days after PS inoculation, mice were studied. Results: AE inhibited PS colonization (p < 0.001) and lung inflammation (total cells, neutrophils, lymphocytes [p < 0.01] in bronchoalveolar lavage [BAL]), with significant differences in BAL levels of IL-1β (p < 0.001), IL-6 (p < 0.01), CXCL1 (p < 0.001), and TNF-α (p < 0.001), as well as parenchymal neutrophils (p < 0.001). AE increased BAL levels of IL-10 and parenchymal (p < 0.001) and epithelial (p < 0.001) IL-10 expression, while epithelial (p < 0.001) and parenchymal (p < 0.001) NF-κB expression was decreased. AE diminished pulmonary lipid peroxidation (p < 0.001) and increased glutathione peroxidase (p < 0.01). Pre-incubation of BEAS-2B with IL-10 inhibited PS-induced epithelial cell expression of TNF-α (p < 0.05), CD40 (p < 0.01), and dichlorodihydrofluorescein diacetate (p < 0.05). Conclusions: AE inhibits PS-induced lung inflammation and bacterial colonization in elderly mice, involving IL-10/NF-κB, and redox signaling.

Exercise Improves Lung Inflammation, but Not Lung Remodeling and Mechanics in a Model of Bleomycin-Induced Lung Fibrosis

“…After lung excision, a part of tissue was mixed with 5 mL of phosphate-saline buffer (PBS 1×, pH 7.3) and macerated. The solution obtained was centrifuged (4 min at 1400g), and 1 mL of the supernatant was stored at −80°C for further analysis of leukotriene B 4 (LTB 4 ) and nitric oxide (NO) concentrations, and enzyme activities of superoxide dismutase (SOD), glutathione reductase (GR), and glutathione peroxidase (GPX) [ 19 ].…”

“…Samples (50 μ L) were placed in triplicates in a microplate (96-well plate), and a volume of 50 μ L of Griess reagent (0.1% naphthyl ethylenediamine dihydrochloride, 1% sulphanilamide, and 2.5% orthophosphoric acid) was added. After 10 minutes of reaction at room temperature in the dark, the NO concentration was determined at absorbance of 570 nm using a microplate reader [ 19 ].…”

“…Protein determination was performed by the Bradford protocol. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizes the principle of protein-dye binding [ 19 ].…”

“…The following cytokines (IL-10, IL-12, and TGF-beta (LAP); all in PE) in each cell type were also analyzed (Becton Dickinson–BD™, East Rutherford, NJ, USA), by using the surface marker with posterior intracellular marker using CitoFix/CitoPerm permeabilization kit (Becton Dickinson–BD™, East Rutherford, NJ, USA). The readings were done using the FACS Accury C6 (Becton Dickinson–BD™, East Rutherford, NJ, USA) [ 19 ].…”

With Complement

“…This can result in an increased morbidity and mortality, especially in immunodeficient or elderly individuals. In an elegant study Stravinskas Durigon et al [8] demonstrate that aerobic exercise can boost the immune system and prevent P. aeruginosa -induced lung inflammation as well as bacterial colonization in aged mice. These findings suggest that physical fitness in elderly people help in maintaining an adequate responsiveness of the immune system.…”