Neurological dysfunction commonly occurs after cardiac surgery with
deep hypothermic circulatory arrest (DHCA). The mechanisms underlying DHCA-associated
brain injury remain poorly understood. This study determined the changes in expression profiles of
circular RNAs (
circRNAs) in the hippocampus in rats that underwent DHCA, with an attempt to explore the potential role of
circRNAs in the
brain injury associated with DHCA. Adult male Sprague Dawley rats were subjected to
cardiopulmonary bypass with DHCA.
Brain injury was evaluated by neurological severity scores and histological as well as transmission electron microscope examinations. The expression profiles of
circRNAs in the hippocampal tissues were screened by microarray. Quantitative real-time PCR (RT-qPCR) was used to validate the reliability of the microarray results. Bioinformatic algorithms were applied to construct a competing endogenous RNA (
ceRNA) network, and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed to explore the potential biological roles of the
circRNAs. Out of 14 145
circRNAs screened, 56 were differentially expressed in the hippocampus between the DHCA and
sham-operated rats, including 30 upregulated and 26 downregulated
circRNAs. The expression changes of six selected
circRNAs (upregulated: rno_
circRNA_011190, rno_
circRNA_012988, rno_
circRNA_000544; downregulated: rno_
circRNA_010393, rno_
circRNA_012043, rno_
circRNA_015149) were further confirmed by RT-qPCR. Bioinformatics analysis showed the enrichment of these confirmed
circRNAs and their potential target mRNAs in several KEGG pathways including
histidine metabolism,
adipocytokine signaling, and cAMP signaling. By revealing the change expression profiles of
circRNAs in the brain after DHCA, this study indicates possible involvements of these dysregulated
circRNAs in
brain injury and suggests a potential of targeting
circRNAs for prevention and treatment of neurological dysfunction associated with DHCA.