Circular RNA Expression Profiles Alter Significantly after Traumatic Brain Injury in Rats.

Circular RNAs (circRNAs) are involved in a variety of diseases. However, the roles of circRNAs in traumatic brain injury (TBI) remain unknown. In this study, circRNA microarray was used to profile the altered circRNAs in the rat hippocampus following TBI. A total of 192 circRNAs were observed to be differentially expressed (fold change [FC] ≥1.5 and p < 0.05) after TBI, including 98 upregulated and 94 downregulated. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicated that many messenger RNAs (mRNAs) transcribed from the host genes of altered circRNAs were implicated in brain damage and neural regeneration. CircRNA/microRNA (miRNA) interaction was predicted using Arraystar's homemade miRNA target prediction software based on TargetScan and miRanda. Thus, our studies have demonstrated altered circRNA expression pattern in the rat hippocampus after TBI, which may play important roles in post-TBI physiological and pathological processes. These findings may provide not only a new direction for studying the molecular mechanisms underlying TBI but also a new possibility for the treatment of TBI by modulating circRNAs.