mmu-miR-146a-5p对小鼠巨噬细胞的免疫调节作用

Immunoregulation of mmu-miR-146a-5p on mouse macrophages

为了探究mmu-miR-146a-5p(小鼠源miR-146a-5p)对小鼠巨噬细胞分泌细胞因子的影响,本研究利用mmu-miR-146a-5p模拟物和抑制物分别转染小鼠巨噬细胞系RAW264.7,通过qPCR定量分析巨噬细胞中细胞因子和LPS/TLR4信号传导途径中关键基因的表达情况,通过Griess试剂测定巨噬细胞培养上清中的亚硝酸盐浓度来评价NO的分泌情况。检测结果显示,与阴性对照组相比,在模拟物转染组,LPS/TLR4信号传导途径的几个关键基因相对表达量显著上调,如TLR4和CD14(P<0.05),而促炎因子(IL-1α、IL-1β、IL-12β)的相对表达量显著下调(P<0.05),而在转染后第24和36小时NO的含量出现上调。在抑制剂转染组中,TLR4、CD14的表达水平下降,促炎因子IL-1α、IL-12β和TNF-α的表达水平上调,i NOS基因表达和NO产生在第24和36小时显著下降(P<0.05)。结果表明,mmu-miR-146a-5p对小鼠巨噬细胞分泌细胞因子具有免疫调节作用。

To investigate the effect of mmu-miR-146a-5p(murine miR-146-5p)on the secretion of cytokines by murine macrophages line RAW264.7,the cells were transfected with mmu-miR-146a-5p mimics and inhibitors,respec ti vely.The expressi on of cytok ines and key genes in LPS/TLR4 sig naming pathways in macrophages were quantitatively analyzed by qPCR,and the secretion level of NO were determined by measuring the nitrite concentration in macrophage culture supernatants by Griess reagent.The results showed that the relative expression levels of several key genes in the LPS/TLR4 signaling pathway were significantly up-regulated in the mimics-transfected group compared with the negative control group,such as TLR4 and CD14(P<0.05),and pro-inflammotory factors IL-1α,IL-1β and IL-12β were significantly down-regulated(P<O.05).The content of NO was up-regulated at 24 and 36 hours after transfection.In the inhibitors-transfected group,the expression of TLR4 and CD14 were decreased,while the expression of pro-inflammatory factors IL-lα,IL-12β and TNF-α were up-regulated,and iNOS gene expression and NO production were significantly decreased at 24 and 36 hours(P<0.05).The above resuIts indicated that mmu-miR-146a-5p had an immuno modulatory effect on the secretion of cytokines by murine macrophages.