Objective: To predict the target genes of rno-miR-181b-5p selected from Small RNA sequence and to perform bioinformatics analysis and identification for laying a foundation for the biological function of miR-181b-5p in the treatment of cerebral ischemia-reperfusion injury with biliverdin. Methods: The target genes of rno-miR-181b-5p were screened through TargetScan

miRDB and miRwalk databases respectively. Then

bioinformatic analysis of these intersection target genes of the three databases were performed by gene ontology analysis and KEGG pathway analysis. Subsequently

dual luciferase reporter gene assays were performed to identify the targets

and the expression changes of endothelial cell specific molecule-1 (Ems1) after overexpression of miR-181b-5p in rat vascular endothelial cells were detected by RT-QPCR and Western blot. Results: There were 28 target genes intersected by the three databases

which were mainly located in such GO items of biological process as regulating stimulus response (P=0.013)

regulating cell growth (P=0.014) and positive regulation (P=0.048). The cellular component of these genes principally were involved in such GO items as intracellular membrane-bounded organelles (P=0.045) and adherens junction (P=0.049). At the molecular function level

these target genes were significantly involved in such GO items as mRNA 5’-UTR binding (P=0.017)

receptor binding (P=0.032)

and protein binding (P=0.046). The KEGG pathway analysis demonstrated that these genes were mainly enriched in synaptic vesicle circulation (P=0.024)

basal transcription factors pathway (P=0.040) and RIG-I-like receptor signaling pathway (P=0.047)

etc. The results of dual luciferase reporter gene assays suggested rno-miR-181b-5p could target and regulate Esm1 genes. Moreover

RT-QPCR and Western blot results also showed that overexpression of miR-181b-5p can negatively regulate Esm1 in rat vascular endothelial cells.Conclusion: rno-miR-181b-5p may play an important biologically role in the treatment of cerebral ischemia-reperfusion injury in rats with biliverdin by targeting regulation of Esm1 gene.