title: [Effects of chronic Aspergillus fumigatus exposure on the expression of mucin 5AC in the airways of asthmatic rats].
abstract: OBJECTIVE
  To explore the effects of chronic Aspergillus fumigatus (Af) exposure on the expression of mucin 5AC (MUC5AC) in the airways of asthmatic rats.
  
  
  METHODS
  Fifty-six male Wistar rats were randomly divided into 8 groups: chronic asthma (group A), chronic asthma plus Af spores inhalation for 1 week (group B), 3 weeks (group C) and 5 weeks (group D), chronic asthma plus saline inhalation for 5 weeks (group E), OVA-sensitized and-saline-challenged group (group F) and OVA-sensitized and-saline-challenged plus Af spores inhalation for 5 weeks (group G) (each n = 8). The airway resistance (Raw) and the change rate of Raw after acetylcholine provocation were detected using a computerized system. The level of MUC5AC mRNA in the lung tissue was measured by RT-PCR, and the expression of MUC5AC in airway epithelial cells were demonstrated by immunohistochemistry. The concentration of IL-13 in BALF was measured by ELISA. The extent of goblet cell hyperplasia was evaluated on periodic acid-Schiff stain (PAS) lung sections.
  
  
  RESULTS
  In group B, C, and D, the level of MUC5AC mRNA (MUC5AC mRNA/β-actin mRNA) (1.9 ± 0.4, 2.3 ± 0.6, 2.9 ± 0.8, respectively), the integrated optical density (value A) of MUC5AC positive stain in airway epithelial cells (278 ± 58, 566 ± 64, 891 ± 80, respectively), the concentration of IL-13 in BALF (µg/L) (96 ± 16, 136 ± 22, 197 ± 34, respectively), and the ratio of goblet cell area to epithelial cell area(%) (16 ± 5, 23 ± 7, 36 ± 9, respectively), were higher than those in group A, E, F and G (all P < 0.05). The change rate of Raw(%) in group C and D (61.91 ± 5.26 and 84.69 ± 6.38) were higher than that in group A, E, F and G (all P < 0.05). The level of MUC5AC mRNA and the value A of MUC5AC were positively correlated with the ratio of goblet cell area to epithelial cell area (r = 0.578, P < 0.05;r = 0.614, P < 0.05, respectively) and the change rate of Raw (r = 0.638, P < 0.05;r = 0.564, P < 0.05, respectively) in group B, C and D.
  
  
  CONCLUSIONS
  Chronic Aspergillus fumigatus exposure upregulated the expression of MUC5AC in the airway epithelial cells and induced goblet cell hyperplasia, resulting in increased airway hypersensitivity in rats with chronic asthma.
authors.affiliation: Department of Respiratory Medicine, the Affiliated Hospital of Weifang Medical College, Weifang 261031, China.
authors.forename: Fu-sheng
authors.initials: FS
authors.lastname: Gao
authors.forename: Yan-yan
authors.initials: YY
authors.lastname: Gao
authors.forename: Mei-juan
authors.initials: MJ
authors.lastname: Liu
authors.forename: Yong-quan
authors.initials: YQ
authors.lastname: Liu
mesh_terms: D000403:Airway Resistance; D000818:Animals; D001232:Aspergillus fumigatus; D001249:Asthma / Q000378:metabolism*; D001992:Bronchoalveolar Lavage Fluid; D004781:Environmental Exposure; D004847:Epithelial Cells / Q000378:metabolism; D020397:Goblet Cells / Q000378:metabolism; D018793:Interleukin-13 / Q000032:analysis; D008168:Lung / Q000378:metabolism / Q000382:microbiology; D008297:Male; D055271:Mucin 5AC / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D018793:Interleukin-13; C524680:Muc5ac protein, rat; D055271:Mucin 5AC