Expression profile of circular RNA in mouse cortex after subarachnoid hemorrhage

Objective To explore the altered expression of circular RNA (circRNA) and mRNA in the mouse cortex in the early phase of subarachnoid hemorrhage (SAH) and possible biological functions of the circRNA in early brain injury (EBI). Methods A total of 18 C57BL/6J male mice were randomly divided into a sham and a SAH group (n=9). SAH models were prepared by endovascular perforation. Total RNAs of brain samples were extracted to construct the cDNA library 24 h after operation. RNA-sequencing (RNA-seq) was carried out by HiSeqTM 2500 User Guide and followed by RT-qPCR for confirmation. Reads were aligned to the mouse transcriptome to obtain expression profiles of circRNA and mRNA. Bioinformatic study included GO analysis, KEGG pathway analysis and forecast of targeted miRNA of circRNA. Results A total of 26 circRNA (6 up-regulated and 20 down-regulated) and 804 mRNA (396 up-regulated and 408 down-regulated) were significantly changed. These altered mRNA were mainly related to regulation of neuronal synaptic plasticity, inflammatory and immune response. Bioinformatics showed that some significantly altered circRNA contained binding sites for many miRNA. The RT-qPCR analysis of 4 randomly selected circRNA (circFoxj3, circSetbp1, circArpp21 and circ2010111I01Rik) confirmed the accuracy of RNA-seq. Conclusions SAH alters the expression of circRNA in mouse cortex and the differentially expressed circRNA may be involved in regulation of EBI following SAH, promising a potential therapeutic target for the diagnosis, treatment and prognosis of SAH.