Circles in the heart and cardiovascular system.

The combination of next-generation sequencing, advanced bioinformatics analysis, and molecular research has now established circular RNAs (circRNAs) as a heterogeneous group of non-coding RNA that is widely and abundantly expressed. CircRNAs are single-stranded RNA, covalently backspliced to form closed circular loops. Different models of back-splicing have been proposed, and mechanisms for circRNA function include sequestering microRNAs, direct interaction with proteins, regulation of transcription, and translation. Exploring the role of circRNAs in different disease settings, and understanding how they contribute to disease progression promises to provide valuable insight into potential novel therapeutic approaches. Here, we review the growing number of published research on circRNAs in the heart and cardiovascular system and summarize the circRNAs that have been implicated in disease.