To Explore The Effects Of STAT6 Decoy Oligonucleotides On Spleen Lymphocytes Of Bronchial Asthma Mice

Abstract:objective:Bronchial asthma is a chronic pulmonary disease associated with bronchoconstriction, chronic inflammation and remodeling of the airways. Overproduction of T helper cell type 2 (Th2) cells and their products interleukin (IL)-4, Both innate and adaptive Th2 cells prominently secrete IL-4 cytokines and respond to these cytokines through their signal transducer and activator of transcription 6 (STAT6). This study was to explore the effects of STAT6 decoy Oligonucleotides on spleen lymphocytes of bronchial asthma mice through STAT6 decoy ODN and spleen lymphocytes of bronchial asthma mice together culturing. Methods:25 BLB-C female mice were randomly divided into tow groups and spleen lymphocytes of mice were divided into 5 groups: normal control group(groupⅠ);asthmatic group(groupⅡ).an control group (group A),an asthma group(group B), an asthma STAT6 decoy ODN group(group C), an asthma STAT6 scrambled ODN group(group D), an asthma liposome group(group E).Asthma model was duplicated with ovalbumin(OVA) and aluminum hydroxide.Spleen lymphocytes of mice were separated by EZ-SepTM mouse and cultured in vitro,then synthetized STAT6 decoy Oligonucleotides(ST-ODN) modifyed by sulfide and scrambled STAT6 Oligonucleotides(SC-ODN) were introduced into lymphocytes of mice with cationic liposome transfection, then OVA stimulate lymphocytes to activate. The number of white blood cells, eosinophils and lymphocytes in branehoalveolar lavage fluid was measured by microscope; Pathological changes of lung were observed by HE staining; Then collection for RNA extraction and reverse transcription, real-time PCR was carried out after optimization of PCR parameter. The relative quantification analysis was performed with comparative threshold cycle method.IL-4 levels in the supernatants of culturing spleen lymphocytes were determined by ELISA. Results:1.The tissue section used to observed and found that the inflammation of the asthmatic group was significantly increased compared with the normal control group;2. white blood cells, lymphocytes, eosinophils in the branehoalveolar lavage fluid of the normal control group were significantly lower than those in the asthmatic group(P<0.01);3.The expression of IL-4mRNA in the spleen lymphocytes was increased significantly in group B and D and E than in group A and C (P<0.01,respectively). while there were no significant differences between the group A and group C,between group B and group D and group E(P>0.05); 4.IL-4 increased markedly in the supernatants of lymphocytes culturing in group B and D and E than in group A and C (P<0.01,respectively). while there were no significant differences between the group A and group C,between group B and group D and group E(P>0.05).4. Conclusion:The expression of IL-4mRNA and IL-4 protein could be inhibited by the by the STAT6 decoy ODN.It is supported that the production of IL-4 be inhibited through preventing the transcription of IL-4mRNA to disfunction STAT6.The study provides foundation for decoy ODN therapeutic asthma.