Profiling and Validation of the Circular RNA Repertoire in Adult Murine Hearts

Tobias Jakobi, Lisa F. Czaja-Hasse, Richard Reinhardt, Christoph Dieterich

For several decades, cardiovascular diseases have been one of the leading causes of death throughout all countries. There is a strong genetic component to many disease subtypes (e.g., cardiomyopathy) and we are just beginning to understand what the relevant genetic factors are. Several studies have related RNA splicing to cardiovascular diseases and circular RNAs (circRNAs) are an emerging player in this game. circRNAs, which originate through back-splicing events from primary transcripts, are resistant to exonucleases and typically not polyadenylated. First perturbation studies show clear phenotypic outcomes for selected circRNAs. We provide, for the first time, a comprehensive catalogue of RNase R-resistant circRNA species for the adult murine heart. This work combines state-of-the-art circle sequencing with our novel DCC software to explore the circRNA landscape of heart tissue. Overall, we identified 575 circRNA species that pass a beta-binomial test for enrichment (false discovery rate of 1%) in the exonuclease-treated sequencing sample. Several circRNAs can be directly attributed to host genes that have been previously described as associated with cardiovascular diseases. Further studies of these candidate circRNAs may reveal disease-relevant properties or functions of specific circRNAs.