title: Effect of aging on airway remodeling and muscarinic receptors in a murine acute asthma model.
abstract: OBJECTIVE
  The influence of aging on the development of asthma has not been studied thoroughly. The aim of this study was to investigate age-related airway responses involving lung histology and expression of muscarinic receptors in a murine model of acute asthma.
  
  
  METHODS
  Female BALB/c mice at the ages of 6 weeks and 6, 9, and 12 months were sensitized and challenged with ovalbumin (OVA) for 1 month (n = 8-12 per group). We analyzed inflammatory cells and T-helper (Th)2 cytokines in bronchoalveolar lavage (BAL) fluid and parameters of airway remodeling and expression of muscarinic receptors in lung tissue.
  
  
  RESULTS
  Among the OVA groups, total cell and eosinophil numbers in BAL fluid were significantly higher in the older (6-, 9-, and 12-month-old) mice than in the young (6-week-old) mice. Interleukin (IL) 4 (IL-4) concentration increased, but IL-5 and IL-13 concentrations showed a decreased tendency, with age. IL-17 concentration tended to increase with age, which did not reach statistical significance. Periodic acid-Schiff (PAS) staining area, peribronchial collagen deposition, and area of α-smooth muscle staining were significantly higher in the 6-month older OVA group than in the young OVA group. The expression of the M3 and M2 muscarinic receptors tended to increase and decrease, respectively, with age.
  
  
  CONCLUSIONS
  The aged mice showed an active and unique pattern not only on airway inflammation, but also on airway remodeling and expression of the muscarinic receptors during the development of acute asthma compared with the young mice. These findings suggest that the aging process affects the pathogenesis of acute asthma and age-specific approach might be more appropriate for better asthma control in a clinical practice.
authors.affiliation: Department of Internal Medicine, College of Medicine, Catholic University of Korea, Seoul, Korea.
authors.forename: Ji Young
authors.initials: JY
authors.lastname: Kang
authors.forename: Sook Young
authors.initials: SY
authors.lastname: Lee
authors.forename: Chin Kook
authors.initials: CK
authors.lastname: Rhee
authors.forename: Seung Joon
authors.initials: SJ
authors.lastname: Kim
authors.forename: Soon Seog
authors.initials: SS
authors.lastname: Kwon
authors.forename: Young Kyoon
authors.initials: YK
authors.lastname: Kim
mesh_terms: D000375:Aging / Q000502:physiology*; D056151:Airway Remodeling / Q000502:physiology*; D000818:Animals; D001249:Asthma / Q000209:etiology*; D015153:Blotting, Western; D001992:Bronchoalveolar Lavage Fluid / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D007120:Immunochemistry; D007378:Interleukins / Q000032:analysis; D008168:Lung / Q000276:immunology / Q000502:physiology; D051379:Mice; D008807:Mice, Inbred BALB C; D023421:Models, Animal; D043585:Receptor, Muscarinic M2 / Q000032:analysis; D043587:Receptor, Muscarinic M3 / Q000032:analysis; D011976:Receptors, Muscarinic / Q000378:metabolism*
chemical_list: D007378:Interleukins; D043585:Receptor, Muscarinic M2; D043587:Receptor, Muscarinic M3; D011976:Receptors, Muscarinic
keywords: aging; airway remodeling; asthma; muscarinic receptor