缺血后适应对大鼠脑缺血再灌注脑组织LC3-Ⅱ、Beclin1及lncRNA表达水平的影响

Effects of ischemic postconditioning on the expression of LC3-Ⅱ,Beclin1 and lncRNA levels in brain tissue of rats with cerebral ischemia-reperfusion

目的研究缺血后适应对大鼠脑缺血再灌注脑组织微管相关蛋白轻链(LC)3-Ⅱ、Beclin1及lncRNA表达水平的影响。方法选取健康雄性SD大鼠45只,随机分为假手术(sham)组、缺血再灌注(I/R)组、缺血后适应(IPostC)组各15只。于线栓拔除后进行改良神经功能缺损评分测定及2,3,5三苯基氯化四氮唑(TTC)染色测定梗死体积,定量聚合酶链反应(qPCR)检测LC3-Ⅱ、Beclin1 mRNA水平表达,Western印迹检测LC3-Ⅱ、Beclin1蛋白表达水平,lncRNA芯片筛查lncRNAs差异表达水平。结果IPostC组神经功能缺损评分、脑梗死体积均显著低于I/R组(P<0.05)。IPostC组LC3-Ⅱ、Beclin1 mRNA和蛋白表达均显著低于I/R组(P<0.05)。IPostC组较I/R组lncRNAs表达存在明显不同,其中IPostC组上调的lncRNAs为174条,下调的lncRNAs为725条。基因本体数据库(GO)分析和通路分析显示差异表达的转录本在凋亡和RNA调节等生物过程及相关通路显著富集。结论缺血后适应通过减少细胞内自噬而减轻脑缺血再灌注损伤,同时缺血后适应可能通过lncRNAs对脑缺血再灌注损伤起到保护作用。

Objective To study the effects of ischemic postconditioning on the expression of microtubule-associated protein light chain(LC)3-Ⅱ,Beclin1 and lncRNA levels in brain tissue of rats with cerebral ischemia-reperfusion.Methods 45 healthy male SD rats were randomly assigned into sham-operation(sham)group,ischemia-reperfusion(I/R)group and ischemic postconditioning(IPostC)group,with 15 rats in each group.The modified mNSS neurological function score was applied and 2,3,5-Triphenyltetrazolium chloride(TTC)staining was used to measure the infarct volume after the removal of the cable plug.The mRNA and protein expressions of LC3-Ⅱand Beclin1 levels were detected by quantitative polymerase chain reaction(q-PCR)and Western blot,respectively.The lncRNAs chip was used to screen out the differential expression levels of lncRNAs.Results Compared to I/R group,neurological deficit score and cerebral infarction area in the IPostC group were significantly decreased(P<0.05).The expressions of LC3-Ⅱand Beclin1 mRNA and protein in IPostC group were significantly lower than those in I/R group(P<0.05).The expression of lncRNAs in IPostC group was significantly different from that in I/R group,there were 174 up-regulated lncRNAs and 725 down-regulated lncRNAs in the IPostC group.The gene ontology database(GO)analysis and KEGG pathway analysis showed that differentially expressed transcripts were significantly enriched in biological processes such as apoptosis and RNA regulation and related pathways.Conclusions Ischemic postconditioning could reduce brain ischemia reperfusion damage by reducing intracellular autophagy,and ischemic postconditioning might protect cerebral ischemia-reperfusion injury through lncRNAs.