哮喘小鼠CD4^+T细胞中microRNA-31和FOXP3 mRNA的表达及相互关系的研究

Expression and relationship of microRNA-31 and FOXP3 mRNAs in CD4^+ T cells from a mouse asthma model

目的初步探讨哮喘CD4+T细胞中microRNA-31和FOXP3的表达水平、两者的相关性及激素对它们的影响。方法以卵蛋白(OVA)致敏激发建立哮喘小鼠模型。将15只BALB/c小鼠分为正常对照组、OVA组和地塞米松组,ELISA检测小鼠支气管肺泡灌洗液(BALF)中IL-4和IFN-γ水平;实时荧光定量PCR检测小鼠脾脏CD4+T细胞的microRNA-31和FOXP3 mRNA的水平,并分析二者之间的相关性。结果 OVA组BALF中IL-4水平高于正常对照组[(228.29±66.18)pg/ml vs(66.63±17.33)pg/ml,P<0.05],地塞米松组BALF中IL-4水平与正常对照组或OVA组相比,无统计学差异。各组间IFN-γ无统计学差异。OVA组CD4+T细胞中FOXP3 mRNA为正常对照组的0.10倍(P<0.05);地塞米松组CD4+T细胞中FOXP3 mRNA为OVA组的3.75倍(P<0.05);正常对照组与地塞米松组之间FOXP3mRNA无统计学差异。OVA组的microRNA-31为正常对照组4.79倍(P<0.05);地塞米松组的microRNA-31为正常对照组4.85倍(P<0.05);OVA组microRNA-31水平和地塞米松组相比无统计学差异。microRNA-31和FOXP3 mRNA的Pearson相关系数为-0.609(P<0.05)。结论哮喘中microRNA-31和FOXP3 mRNA具有相关性。microRNA-31与地塞米松可能通过不同的途径调节CD4+T细胞中FOXP3 mRNA的表达。

Objective To determine the expression levels of microRNA-31 and FOXP3 mRNAs in the spleen CD4＋ T cells from asthma mice,and identify their relationship.Methods A total of 15 Balb/c mice were randomly divided into 3 groups,normal control group,model group,and dexamethasone treatment group.The murine asthma model was sensitized and challenged by ovalbumin（OVA）.The inflammatory cytokines IL-4 and IFN-γ in the bronchoalveolar lavage fluid（BALF） in the 3 groups were measured by ELISA.Expression of microRNA-31 and FOXP3 mRNAs in spleen CD4＋ T cells from the 3 groups were detected by quantitative real time-PCR assay.The relationship of the expression were also analyzed.Results The BALF level of IL-4 was increased in the model group（228.29±66.18 pg/ml） compared with the normal control group（66.63±17.33 pg/ml,P0.05）,but no significant difference was found in its level between the dexamethasone treatment group（120.84±32.29） and normal control（P0.05）.There was no significant difference in levels of IFN-γ among the three groups（P0.05）.The expression of FOXP3 mRNA in the spleen CD4＋ T cells in the model group was 0.10 times as great as in the normal control group（P0.05）,and that in the dexamethasone treatment group was 3.75 times as great as in the model group（P0.05）.However,there was no significant difference in FOXP3 mRNA between the normal control and the dexamethasone treatment group（P0.05）.The expressions of microRNA-31 mRNA in the splenn CD4＋ T lymphocytes in the model group were 4.79 times as great as in the normal control（P0.05）,and that in the dexamethasone treatment group were 4.85 times as great as in the normal control（P0.05）.There was no significant difference in microRNA-31 expression between the model group and the dexamethasone treatment group（P0.05）.Pearson correlation coefficient between microRNA-31 and FOXP3 mRNA was-0.609（P0.05）.Conclusion There is a negative linear correlation between microRNA-31 and FOXP3 mRNA in asthma,and microRNA-31 and dexamethasone may affect the expression of FOXP3 mRNA via different pathways.