Comprehensive Transcriptome Analysis Implicates Expression Profiles Of MicroRNA Markers At Different Stages After Cerebral Ischemic Stroke

At present,Cerebral Stroke is the first cause of death in China.The number of deaths caused by stroke each year accounts for 22.45%^[1].The treatment of stroke is still based on traditional thrombolysis and anticoagulant therapy.These treatments have really strict time windows and indications for adaptation,which has become the bottleneck of clinical treatment for stroke patients.Therefore,on the basis of the original treatment,it is necessary to find a more effective treatment method for stroke.With the popularity and advancement of Next Generation Sequencing?NGS?technology,the use of NGS technology for medical results is obvious to all,which has also led to the study of the genetic mechanism of stroke.Here,our team used the Middle Cerebral Artery Occlusion?MCAO?model,the most classic animal model of Cerebral Ischemic Stroke,to make Transient Middle Cerebral Artery Occlusion?tMCAO?surgery in 4 months old C57BL/6J mice,ischemia time is 1 hour.Then,at 1-day,3-days,7-days,14-days,28-days after tMCAO,the ischemic cortex?Cortex?was performed at double-ended 150 bp whole transcriptome sequencing?RNA-Seq?and single-ended 50 bp small RNA sequencing?smallRNA-seq?on the illumina sequencing platform.Combined with bioinformatics analysis methods,the pathological mechanism of stroke is explored in all aspects.Our research found that:1.At different stages after ischemic stroke,miRNAs expression profiles and mRNAs bexpression profiles of the ischemic cortex vary with time.2.The miRNA Markers on day 1 after ischemic stroke are:mmu-miR-2137,mmu-miR-3085-3p,mmu-miR-3470b,mmu-miR-5126,mmu-miR-6240,and mmu-miR-874-5p.Their target genes functional enrichment are mainly concentrated invesicle production and transport as well as signal release?Fig.6-b?.Of these miRNA Markers,only miR-2137 and miR-874-5p have been reported to be likely to function in other diseases^[2,3],all these miRNAs are first discovered to be associated with the progression of ischemic stroke.3.The miRNA Markers on the 3rd day after ischemic stroke are:mmu-miR-223-3p, mmu-miR-142a-3p and mmu-miR-5099.Their target genes functional enrichment are mainly concentrated in calcium ion export,endocytosis,cell communication through electrical coupling and migration of fibroblasts.miR-223-3p has been reported to be associated with tumor cell migration and invasiveness^[4,5],miR-142a-3p directly regulates the P53 pathway^[6],miR-5099 is a function unknownmiRNA.4.The miRNA Markers on the 7th day after ischemic stroke are:mmu-miR-21a-5p, mmu-miR-199b-3p,mmu-miR-199a-5p and mmu-miR-214-3p,whose target genes functional enrichment are mainly concentrated on developmental growth and differentiation.miR-21a-5p has been reported to promote fibroblastic fibrosis after mechanical injury^[7],miR-214-3p has neuroprotective effects^[8,9],miR-199b-3p and miR-199a-5p are function unknown.5.Through further functional analysis,the above findings can reveal:?1?miRNA-3085-3p/-3470b cluster regulates Elf1 to play an immunoregulatory and angiogenic role in the early stage of ischemic stroke;?2?miRNA-214-3p/-199b-3p cluster inhibits neuronal apoptosis by regulating Pon2 and Qk during the recovery of ischemic stroke,and exerts neuroprotective effects;?3?miRNA-199a-5p/-199b-3p regulates the Taok1 gene,inhibits inflammatory response during the recovery phase of ischemic stroke,and exerts neuroprotective effects.Conclusion:We performed a integrative bioinformatics analysis of RNA-Seq and smallRNA-seq data,found out miRNA Markers at different stages after ischemic stroke;three new possible mechanisms to promote ischemic stroke recovery have also been identified.