A Circular RNA Controls Ribosomal RNA Maturation and Atherosclerosis in Humans

Circular RNAs (circRNAs) are broadly expressed in eukaryotic cells, but their role in human health and disease remains obscure. Here, we show that circular antisense non-coding RNA in the INK4 locus (circANRIL), which is transcribed at a locus of atherosclerotic cardiovascular disease on chromosome 9p21, confers athero-protection by controlling ribosomal RNA (rRNA) maturation and modulating pathways of atherogenesis. At the molecular level, circANRIL competes with precursor rRNA (pre-rRNA) for binding to pescadillo homolog 1 (PES1), an essential 60S-preribosomal assembly factor, thereby impairing exonuclease-mediated pre-rRNA processing and ribosome biogenesis. As a consequence, circANRIL induces nucleolar stress and p53 activation, resulting in the induction of apoptosis and inhibition of proliferation, which are key athero-protective cell functions within the arterial wall. Collectively, these findings identify circANRIL as a prototype of a circRNA regulating ribosome biogenesis and conferring athero-protection, thereby unveiling a therapeutic potential of certain circRNAs in human disease.