Effects Of ICS On The Expression Of TLR-7in Lung Tissue Of Asthmatic Rats

ObjectiveTo explore the effect of the glucocorticoids on the airway inflammation and the airwayhyper responsiveness (AHR), the genic expression of TLR7、interferon-γ、interleukin-12inthe lung tissues of the asthma rat after Aerosol inhalation of Budesonide(BUD) understandingthe effect of inhaled the glucocortiocods for TLR7receptors and the change of relatedcytokines in the lun tissuesMethods1.40male SD rats were randomly assigned to four groups which were clean and healthy,about a month old, weighing150-170g.the four groups were normal control group (Controlgroup), asthma model group (Model group), Dexamethasone intervention group (DXMgroup), budesonide intervention group (BUD group), each10.2.the experimental rats in Model group, DXM group, BUD group were intraperitonealinjected by10%egg albumin (Ovalbumin, OVA) solution of1ml contains100mg ofaluminum hydroxide on the first day,the8th days. Then were atomized inhalated with2%ovalbumin solution4ml on the15th day,10minutes each time, once a day, lasting for14days.The Control group used0.9%sodium chloride solution instead of ovalbumin inintraperitoneal injection and inhalation.And in half an hour before inhalation, DXM groupwere given intraperitoneal injection of dexamethasone injection, at a dose of0.5mg/kg, BUDgroup received2ml budesonide inhalation.3. On the28th day of experiment, four groups of rats were anesthetized byintraperitoneal injection of chloral hydrate,then detected the airway hyperresponsiveness.After test the rats were sacrificed with abdominal aorta bleedingmethods,every lung tissue was detected by quantitative real-time PCR,to observerthe expression of TLR7、IL-12and IFN-γ mRNA in lung tissue, the expression ofTLR7protein was detected by Western Blot. At the same time the morphology of lungtissue of rats in each group were observed.Results1. Construction of subacute asthma rat model: From the fourteenth day of the experiment these following symptoms begin to appear.facial scratching, respiratory frequency speed,nodding breathing, facial cyanosis, incontinence.on the twenty-eighth day the airway hyperresponsiveness were detected, The results suggest that airway resistance in asthma modelgroup rats increased significantly, compared with the normal control group were statisticallysignificant (P <0.05);HE staining of lung tissue sections suggest that bronchial and alveolarlung tissue of rats with inflammatory cells increased significantly, more viscous secretions,bronchial wall thickening2. Changes of airway inflammation and the airway hyper responsiveness in lung tissue ofBUD group: inflammatory cells surrounding the alveoli significantly increased in lungtissue of asthma model group, eosinophils increased, there are more viscous secretions,bronchial wall thickening. In BUD group, the viscous secretion of inflammatory cells wassignificantly reduced, the bronchial wall slightly thickened. DXM group and BUD groups thesame. Significant inflammatory reaction was not found in the control group.After givinghistamine dihydrochloride atomized inhalation, the airway resistances in Model groupcompared with Control group increased significantly (P <0.05). Airway resistance in BUDgroupcompared with Control group increased (P <0.05), decreased compared with Modelgroup (P <0.05), compared with the DXM group, no significant difference.3. Expression of TLR7mRNA and TLR7protein in lung tissue of BUD group: Theexpression of TLR7mRNA and TLR7protein in lung tissue of Model group compared withControl group decreased significantly (P <0.05). Expression of TLR7mRNA and TLR7protein in lung tissue of BUD group compared with Model group increased (P<0.05),decreased compared with Control group (P <0.05), compared with the DXM group, nosignificant difference.4. Expression of IFN-γ mRNA and IL-12mRNA in lung tissue of BUD group: Theexpression of IFN-γ mRNA and IL-12mRNA in lung tissue of Model group compared withControl group decreased significantly (P <0.05). Expression of IFN-γ mRNA and IL-12mRNA in lung tissue of BUD group compared with Model group increased (P<0.05),decreased compared with Control group (P <0.05), compared with the DXM group, nosignificant difference.Conclusion1.After intraperitoneal injection of ovalbumin solution and atomization inhalation canconstruct the model of subacute asthmatic rats. Aerosol inhalation of Budesonide can relievethe airway hyper responsiveness 2. Aerosol inhalation of Budesonide can increase the local expression of TLR7mRNA andTLR7protein in lung tissue.3. Aerosol inhalation of Budesonide can increase the local expression of IL-12and IFN-γmRNA protein in lung tissue.