摘要
目的探讨miR-132在慢性阻塞性肺疾病(COPD)大鼠肺组织中的表达及其对大鼠肺功能及肺损伤的影响。方法根据随机数表法将30只SD大鼠分为3组,即对照组(Sham组)、COPD组和COPD+miR-132组,每组10只。COPD组和COPD+miR-132组大鼠气道内滴注脂多糖联合烟熏28d构建COPD模型,Sham组大鼠滴加等剂量的生理盐水,COPD+miR-132组大鼠额外滴加miR-132转染复合物,每周一次,持续4周。COPD疾病造模成功后,检测大鼠肺组织中miR-132的表达、大鼠肺功能、肺组织形态结构、肺组织中促炎症细胞因子、氧化应激及凋亡水平。检测各组大鼠肺组织中沉默调节蛋白1(SIRT1)及乙酰化的叉头转录因子-1(Ac-FOXO-1)的蛋白表达水平。结果与Sham组相比,COPD组大鼠肺组织中miR-132表达水平明显降低(P<0.05)、0.3s用力呼气量占用力肺活量比值(FEV0.3/FVC)和呼气峰流速(PEF)升高(P<0.05)、肺泡平均截距增宽(P<0.05)、促炎症细胞因子IL-1β,TNF-α及MCP-1的mRNA表达水平增高(P<0.05)、细胞凋亡和氧化应激水平升高(P<0.05)、SIRT1及Ac-FOXO-1的蛋白表达水平明显降低(P<0.05);与COPD组相比较,COPD+miR-132组大鼠肺组织的miR-132的表达水平明显升高(P<0.05)、FEV0.3/FVC和PEF升高(P<0.05);苏木精-伊红(HE)染色结果显示,miR-132明显降低了COPD大鼠肺泡平均截距(P<0.05);RT-PCR结果显示,miR-132表达增加可明显抑制大鼠肺组织中促炎症细胞因子IL-1β,TNF-α及MCP-1的mRNA表达水平(P<0.05);TUNEL染色结果表明,COPD+miR-132组大鼠肺组织中细胞凋亡水平明显低于COPD组(P<0.05);同时,miR-132预处理可明显抑制COPD大鼠肺组织的氧化应激水平(P<0.05);机制上,miR-132过表达可上调COPD大鼠肺组织中SIRT1及Ac-FOXO-1的蛋白表达水平(P<0.05)。结论在COPD大鼠模型中,miR-132的表达水平明显降低,过表达miR-132可以降低肺泡腔扩大,抑制大鼠肺组织炎症、凋亡及氧化应激水平,其保护作用可能与SIRT1信号通路的激活有关。
Objective To investigate the expression of miR-132 in the lung tissue of chronic obstructive pulmonary injury(COPD)rats and its effect on lung function and lung injury in rats.Methods Intra-airway infusion of lipopolysaccharide combined with smoking for 28 days was used to construct a COPD rat model.The rats were divided into 3 groups,namely the control group(Sham),COPD group and COPD+miR-132 group.After successful modeling,the lung function,morphological structure of lung tissue,proinflammatory cytokines,oxidative stress and apoptosis levels in lung tissue were detected.Finally,the Silent Information Regulator 1(SIRT1)and Acetylated-fork head transcription factor-1(Ac-FOXO-1)in the lung tissue of each group were detected separately Protein expression level.Results Compared with the Sham group,the expression level of miR-132 in the lung tissue of the COPD group was significantly reduced(P<0.05);compared with the COPD group,the 0.3-second forced expiratory volume occupancy of the COPD+miR-132 group rats Vital capacity ratio(FEV0.3/FVC)and peak expiratory flow rate(PEF)increased(P<0.05);H&E staining results showed that miR-132 significantly reduced the average alveolar intercept of COPD rats(P<0.05);RT-PCR results show that increased expression of miR-132 can significantly inhibit the mRNA expression levels of pro-inflammatory cytokines IL-1β,TNF-αand MCP-1 in rat lung tissue(P<0.05);TUNEL staining results show that COPD+The level of apoptosis in lung tissue of miR-132 group was significantly lower than that in COPD group(P<0.05);meanwhile,we found that miR-132 pretreatment could significantly inhibit the level of oxidative stress in lung tissue of COPD rats(P<0.05);mechanistically,miR-132 overexpression can reduce the protein expression levels of SIRT1 and Ac-FOXO-1 in the lung tissue of COPD rats(P<0.05).Conclusion In the COPD rat model,the expression level of miR-132 Significantly reduced,overexpression of miR-132 can reduce alveolar cavity expansion,inhibit inflammation,apoptosis and oxidation of rat lung tissue The protection level of stress may be related to the activation of SIRT1 signaling pathway.
作者
聂美玲
吴开松
NIE Mei-ling;WU Kai-song(Department of Respiratory and Critical Care Medicine,Zhongnan Hospital of Wuhan University,Wuhan Hubei 430071,China)
出处
《临床和实验医学杂志》
2020年第19期2029-2033,共5页
Journal of Clinical and Experimental Medicine