【摘要】 目的探讨干预mi R-31对哮喘小鼠肺组织肺组织转化生长因子-β1(TGF-β1)/果蝇MAD基因3哺乳动物类似基因(Smad3)、Toll样受体2(TLR2)/髓样分化因子(My D88)/NF-κB信号通路的影响。方法选取40只SD健康雄性小鼠,10只为正常组,其余30只建立哮喘模型,建模成功后分为哮喘组、上调组、下调组,每组各10只。上调组小鼠尾部静脉注射mi R-31激动剂干预,下调组小鼠尾部静脉注射mi R-31拮抗剂干预,正常组、哮喘组小鼠尾部静脉注射等量0.9%氯化钠注射液干预。采用HE染色观察各组小鼠肺组织病理学改变情况,RT-PCR法检测各组小鼠肺组织mi R-31、CD44 m RNA表达水平,酶标分析仪检测各组小鼠血清IFN-γ、IL-2、IL-4、IL-22、IL-3水平,免疫透射比浊法各组小鼠血清总抗氧化能力(TAOC)、一氧化氮(NO)水平,Western blot法检测TGF-β1/Smad3、TLR2/My D88/NF-κB信号通路蛋白水平。结果与正常组比较,其他3组小鼠mi R-31、CD44 m RNA表达水平,IL-2、IL-4水平,TAOC、NO、IL-22、IL-3水平,TGF-β1、Smad3、TLR2、My D88、NF-κB p65蛋白表达水平均升高,IFN-γ水平均降低,差异均有统计学意义(均P<0.05)。与哮喘组、上调组比较,下调组小鼠mi R-31、CD44 m RNA表达水平,IL-2、IL-4水平,TAOC、NO、IL-22、IL-3水平,TGF-β1、Smad3、TLR2、My D88、NF-κB p65水平均降低,IFN-γ水平升高,差异均有统计学意义(均P<0.05)。结论下调哮喘小鼠mi R-31水平,能够调控CD44 m RNA水平,调节Th1/Th2平衡,减轻哮喘小鼠氧化应激反应、炎症反应的严重程度,其作用机制可能与调控TGF-β1/Smad3、TLR2/My D88/NF-κB信号通路蛋白水平有关。更多还原

【Abstract】 Objective To investigate the effect of mi R-31 on transforming growth factor-β1(TGF-β1)/drosophila mad gene 3 mammalian like gene(Smad3) and toll-like receptor 2(TLR2)/myeloid differentiation factor(My D88)/NF-κB signaling pathways in lung tissues of asthmatic mice. Methods Forty SD healthy male mice were divided into normal group, model group, up-regulated group and down-regulated group with 10 mice in each group. The asthma model was induced in last three groups. Mice in the up-regulation group were injected with Mir-31 agonist, mice in the down-regulation group were injected with mi R-31 antagonist, and mice in the normal group and model group were injected with 0.9 % sodium chloride solution. HE staining was used to observe the pathological changes in lung tissues of each group, the m RNA expression levels of mi R-31 and CD44 in lung tissues were detected by RT-PCR, and the serum levels of IFN-γ, IL-2, IL-4, IL-22 and IL-3 were detected by ELISA. The serum levels of total antioxidant capacity(TAOC) and nitric oxide(NO) were detected by immunotransmission turbometry, and the related protein levels of TGF-β1/Smad3, TLR2/My D88/NF-κB pathway were detected by Western blot. Results Compared with the normal group, the m RNA levels of mi R-31 and CD44 in the other three groups were higher, while compared with the model group and the up-regulated group, the m RNA levels of mi R-31 and CD44 in the down-regulated group were lower(all P<0.05).Compared with the normal group, the levels of IFN-γ, IL-2 and IL-4 were lower in the other three groups, while compared with the model group and the up-regulated group, the levels of IFN-γ, IL-2 and IL-4 in the down-regulated group were higher(all P<0.05). Compared with the normal group, the levels of TAOC, NO, IL-22 and IL-3 in the other three groups were higher,while compared with the model group and the up-regulated group, the levels of TAOC, NO, IL-22 and IL-3 in the down-regulated group were lower(all P<0.05). Compared with the normal group, the levels of TGF-β1, Smad3, TLR2, My D88 and NF-κB p65 in the other three groups were higher, while compared with the model group and the up-regulated group, the levels of TGF-β1, Smad3, TLR2, My D88 and NF-κB p65 in the down-regulated group were lower(all P<0.05). Conclusion Down-regulation of mi R-31 levels in asthmatic mice can regulate CD44 m RNA levels, regulate Th1/Th2 balance, and reduce the severity of oxidative stress and inflammatory response in asthmatic mice. The mechanism of action may be related to the regulation of related protein levels of TGF-β1/Smad3 and TLR2/My D88/NF-κB signaling pathways.更多还原