Effect Of BCG-PSN On The IL-12/ST-AT4Signal Transduction Pathway In Asthmatic Rats

ObjectiveTo observe the effect of BCG-PSN on the IL-12/STAT4signal transductionpathway and the airway inflammation in asthmatic rats.MethodsForty male healthy SD rats of ordinary level were randomly divided into fourgroups (10rats in each group): normal control group (group A), asthma modelgroup (group B),BCG-PSN group (group C) and Dexmaethasone group (groupD). The asthmatic models of rats were established by using OVA and Al(OH)3sensitization and challenge. To observe the changes of general condition ofasthma rats after challenge. Detecte the white blood cell count and thepercentage of eosinophils. The pathology morphological changes wereobserved by HE staining. IL-12and pSTAT4protein expressions were detectedby immunohistochemical. The expression of pSTAT4in lung tissue wasmeasured with western-blot.ResultsThe rats in group B showed shortness of breath, frequently catch nose,sneeze, cough up, slow and sluggish, group C and group D general conditionwere improved markly compared with group B. The blood WBC count andEOS%of group B increased significantly comparec with group A(P<0.01).Group C and group D significantly reduced compared with group B(P<0.01),and the difference between group C and group D had no statistical significance(P>0.05). Compared with group A, airway smooth muscle cells were proliferatedand the inflammatory cells in airway were increased in group B. IL-12and pSTAT4protein expressions in lung tissue were lower, the average gray valuewas significantly higher than those in the group A(P<0.01). On the contrary,compared with group B, airway smooth muscle cells and the inflammatory cellswere significantly reduced in group C and group D. IL-12and pSTAT4proteinexpressions of lung tissue were higher, the average gray value was significantlylower than those in group B(P<0.01). For index mentioned above, there were nosignificantly differences between group C and group D (P>0.05). The correlationanalysis indicated that the pSTAT4protein expression level of group B andgroup C was positively correlated with the expression level of IL-12(r were0.894and0.908all P<0.01).ConclusionsBCG-PSN could reduce proliferation of the airway inflammation cells andsmooth muscle cells, also could stimulate expression of IL-12and STAT4protein in lung tissue in asthma rats. Indicating that BCG-PSN can adjust airwayinflammation in asthmatic rats,and the possible mechanism may be due toregulate the gene expression of IL-12/STAT4signal transduction pathway.