title: Effect of sulfur dioxide on inflammatory and immune regulation in asthmatic rats.
abstract: BACKGROUND
  Exposure to sulfur dioxide (SO2) increases asthma risk. Inflammatory and immune responses are typical in asthma disease. The exact effect of SO2 on modulation of the inflammatory and immune responses in asthmatic rats remains unclear.
  
  
  OBJECTIVE
  Here we sought to investigate the molecular mechanisms underlying the NF-κB inflammatory pathway and the Th1/Th2 imbalance in asthmatic rats exposed to SO2.
  
  
  METHODS
  Male Wistar rats were challenged by ovalbumin (OVA) or SO2 alone or together, and then mRNA and protein levels of some inflammatory and immune genes were measured. NF-κB nuclear translocation was analyzed. Bronchoalveolar lavage (BAL), inflammatory cell counts and histopathologic examination were performed.
  
  
  RESULTS
  (1) OVA plus SO2 induced abnormal pathological changes and inflammatory responses in lung relative to exposure to OVA alone; (2) showing NF-κB nuclear translocation and activation through up-regulating IKKβ mRNA and protein expression and down-regulating IκBα expression in the presence of OVA or OVA plus SO2; (3) OVA plus SO2 significantly raised TNF-α and IL-6 levels in BALF compared with the OVA group; (4) SO2 markedly elevated IL-4 levels and decreased IFN-γ levels in BALF in the asthmatic rats, stimulating IgE generation which was closely related to inhibiting the expression of Foxp3, a specific marker of regulatory T cells.
  
  
  CONCLUSIONS
  SO2 affects the airway inflammatory and immune responses of the asthmatic rats and enhances the susceptibility to OVA by aggravating inflammatory responses in lungs, up-regulating pro-inflammatory cytokine expression, and causing the Th1/Th2 imbalance, which might contribute to the increased risk of asthma disease.
authors.affiliation: Institute of Environmental Science, Shanxi University, Taiyuan, PR China; State Environmental Protection Key Laboratory of Efficient Utilization of Coal Waste Resources, Shanxi University, Taiyuan, PR China.
authors.forename: Ruijin
authors.initials: R
authors.lastname: Li
authors.affiliation: Institute of Environmental Science, Shanxi University, Taiyuan, PR China.
authors.forename: Xiaojing
authors.initials: X
authors.lastname: Kou
authors.affiliation: Institute of Environmental Science, Shanxi University, Taiyuan, PR China.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Tian
authors.affiliation: Institute of Environmental Science, Shanxi University, Taiyuan, PR China.
authors.forename: Ziqiang
authors.initials: Z
authors.lastname: Meng
authors.affiliation: Department of Chemistry, Hong Kong Baptist University, Hong Kong Special Administrative Region.
authors.forename: Zongwei
authors.initials: Z
authors.lastname: Cai
authors.affiliation: State Environmental Protection Key Laboratory of Efficient Utilization of Coal Waste Resources, Shanxi University, Taiyuan, PR China. Electronic address: cfangqin@sxu.edu.cn.
authors.forename: Fangqin
authors.initials: F
authors.lastname: Cheng
authors.affiliation: Institute of Environmental Science, Shanxi University, Taiyuan, PR China. Electronic address: dc@sxu.edu.cn.
authors.forename: Chuan
authors.initials: C
authors.lastname: Dong
mesh_terms: D000818:Animals; D001249:Asthma / Q000097:blood / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D004347:Drug Interactions; D004785:Environmental Pollutants / Q000494:pharmacology*; D005786:Gene Expression Regulation / Q000187:drug effects / Q000276:immunology; D007073:Immunoglobulin E / Q000097:blood; D007249:Inflammation / Q000097:blood / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D008168:Lung / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D008297:Male; D010047:Ovalbumin / Q000276:immunology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013458:Sulfur Dioxide / Q000494:pharmacology*
chemical_list: D016207:Cytokines; D004785:Environmental Pollutants; D012333:RNA, Messenger; D013458:Sulfur Dioxide; D007073:Immunoglobulin E; D010047:Ovalbumin
keywords: Asthma; Immune regulation; Inflammatory regulation; Rats; Sulfur dioxide