| Objective: To study the differential expression of microRNAs（miRNAs) in peripheral blood of children with refractory epilepsy and to explore the role of miRNAs in the pathogenesis and the value of diagnosis and treatment of refractory epilepsy in children.Methods: Forty-six children with epilepsy treated in the Department of Neurology of XuZhou Children's Hospital affliated to XuZhou Medical University from May 2021 to May 2022 were collected and divided into refractory epilepsy group (group R, n = 20) and wellcontrolled epilepsy group (group C, n = 26). In addition, 26 healthy children in the child health department in the same period were selected as healthy control group (group N).The expression of miRNAs in peripheral blood was determined by high- throughput sequencing.The differentially expressed miRNAs were screened by DEseq2.Peripheral blood samples from 30 children in Group R, Group C, and Group N under the same conditions were collected again, and the expression level of candidate miRNAs in peripheral blood were verified using qRT-PCR amplification technology. The differentially expressed miRNAs target genes were predicted by miRanda and RNAhybrid online database, and the candidate target genes were analyzed by gene function (Gene Ontology,GO) and genomic encyclopedia (Kyoto Encyclopedia of Genes and Genomes,KEGG) pathway. Results: Compared with group N, there were 124 differentially expressed miRNAs in group R, including 74 up-regulated miRNAs and 50 down-regulated miRNAs,and there were 66 differentially expressed miRNAs in group C, including 21 up-regulated miRNAs and 45 down-regulated miRNAs.Compared with group C, there were 337 differentially expressed miRNAs in group R,including 197 up-regulated miRNAs and 140 down-regulated miRNAs.Among them, the most significant difference is miR-15a-5p（P=9.00*10-8, |log2(foldchange)|2=2.93）.The target genes of all differential miRNAs were predicted, and the candidate target genes were analyzed by GO and KEGG.Bioinformatics analysis found that the possible signal pathway miR-15a-5p participating in the refractory epilepsy of children included MAPK signal pathway,cAMP signal pathway,platinum drug resistance signal pathway,p53 signal pathway,Ras signal pathway,Fc-γ-R mediated phagocytosis signal pathway and neurodegeneration signal pathway.Conclusions: The expression profile of miRNAs in peripheral blood of refractory epilepsy children is significantly different from that of children with well controlled epilepsy and healthy children, Among them, the most significant difference is miR-15a-5p,and it participates in the pathophysiological process of epilepsy by regulating multiplepathways, which is expected to to become a new diagnostic biomarker and a potential therapeutic target for children with RE. |