microRNA-124-3p调控H1N1亚型猪流感病毒致小鼠肺损伤的研究

为研究microRNA-124-3p（miR-124-3p）对H1N1亚型猪流感病毒（swine influenza virus，SIV）感染小鼠所致肺损伤的调控作用，本试验构建miR-124-3p腺病毒表达载体，通过小鼠尾部静脉注射法构建miR-124-3p差异表达小鼠模型，试验分3组：过表达组、抑制组和对照组。48 h后，各组小鼠鼻腔接种H1N1亚型SIV，每只10⁵ EID₅₀（50 μL）。连续观察14 d，计算小鼠平均体重变化率、观察病理切片并测定相关炎症因子IL-1β、TNF-α和IL-6 mRNA相对表达量。结果显示，已成功将pre-miR序列及其sponge序列插入腺病毒的穿梭质粒，并将其共转染293A细胞。实时荧光定量PCR检测证实，与对照组相比，过表达组和抑制组小鼠黑色素瘤细胞miR-124-3p表达水平分别极显著升高（P<0.01）和显著降低（P<0.05），表明成功构建腺病毒表达载体。过表达组、抑制组和对照组小鼠体重变化率分别为－5.5%、－12.4%和－8.6%。抑制组和对照组均可见肺泡壁增厚，其间有多量淋巴细胞浸润，部分肺泡内出现纤维蛋白渗出，且抑制组病理变化更为严重，肺泡中还有大量的红细胞浸润；而过表达组仅有少量的淋巴细胞浸润，肺脏组织较正常。与对照组相比，过表达组检测的炎症因子IL-1β、TNF-α和IL-6 mRNA表达水平均显著降低（P<0.05）；抑制组炎症相关炎症因子mRNA表达水平均显著升高（P<0.05）。本试验结果表明，miR-124-3p对H1N1亚型SIV感染小鼠所致的肺脏炎症因子的表达具有抑制作用，同时能减轻肺脏病理损伤。

Study on the Regulation of microRNA-124-3p on Lung Injury in Mice Infected with H1N1 Subtype Swine Influenza Virus

In order to study the regulatory effect of microRNA-124-3p(miR-124-3p) on lung injury caused by H1N1 subtype swine influenza virus (SIV) in mice,the expression vector of miR-124-3p adenovirus was constructed,and the miR-124-3p differentially expressed mouse models were induced by intravenous injection in the tail of mice which were divided it into three groups (overexpression,inhibition and control groups).48 h later,mice in each group were inoculated with H1N1 subtype SIV in the nasal cavity,with 10⁵ EID₅₀ (50 μL) per mouse.The average body weight change rate,pathological section observation and relative mRNA expression level of related inflammatory factors IL-1β,TNF-α and IL-6 in mice were observed for 14 consecutive days.The results showed that the pre-miR sequence and its sponge sequence had been successfully inserted into the shuttle plasmid of adenovirus,and co-transfected into 293A cells.Real-time PCR detection confirmed that compared with control group,the expression level of miR-124-3p in overexpression and inhibition groups were extremely significantly increased (P<0.01) and significantly decreased (P<0.05),respectively,indicating that the adenovirus expression vectors were successfully constructed.The rates of weight change of overexpression,inhibition and control groups were －5.5%,－12.4% and －8.6%,respectively.The alveolar wall of inhibition and control groups were thickened,in which there were a lot of lymphocyte infiltration,some of the alveoli showed fibrin exudation,and the pathological changes were more serious in the inhibition group,there were a lot of RBC infiltration in alveoli.There were only a little lymphocyte infiltration in overexpression group,and the lung tissue was normal.Compared with control group,the mRNA expression levels of IL-1β,TNF-α and IL-6 in overexpression group were significantly decreased (P<0.05);The mRNA expression levels of inflammatory factors in inhibition group were significantly increased (P<0.05).The results showed that miR-124-3p inhibited the expression of pulmonary inflammatory factors induced by H1N1 subtype SIV in mice,and also alleviated pathological injury of lung.