Emerging functions of circular RNA in aging

Circular RNAs (circRNAs) are closed and cyclic RNAs that are widely expressed in eukaryotes and have multiple functions, including interacting with proteins, sponging miRNAs, encoding proteins, and regulating gene expression via binding promoters. The expression patterns and stability of circRNAs have emerged as promising candidate biomarkers of aging and age-associated diseases. The levels of circRNAs generally increase with age in various species and may play roles in aging and cellular senescence. Specifically, ciRS-7/circCDR1as and circSfl are associated with Alzheimer’s disease and fruit fly longevity, respectively. It will be important to identify functional circRNAs to elucidate the underlying mechanisms regarding their roles in aging and/or age-related diseases. Circular RNA (circRNA) is a closed, single-stranded transcript widely detected in eukaryotes. Recent studies indicate that the levels of circRNAs change with age in various tissues in multiple species, ranging from nematodes to mammals. Here we discuss the functional roles of circRNAs in animal aging and longevity. We review studies regarding the differential expression of circRNAs that contributes to cellular senescence and the pathogenesis of aging-associated diseases. We explore the features of aging-associated circRNAs by discussing their potential as biomarkers of aging, tissue specificity, physiological roles, action mechanisms, and evolutionarily conserved characteristics. Our review provides insights into current progress in circRNA research and their significant functions in the aging process. Circular RNA (circRNA) is a closed, single-stranded transcript widely detected in eukaryotes. Recent studies indicate that the levels of circRNAs change with age in various tissues in multiple species, ranging from nematodes to mammals. Here we discuss the functional roles of circRNAs in animal aging and longevity. We review studies regarding the differential expression of circRNAs that contributes to cellular senescence and the pathogenesis of aging-associated diseases. We explore the features of aging-associated circRNAs by discussing their potential as biomarkers of aging, tissue specificity, physiological roles, action mechanisms, and evolutionarily conserved characteristics. Our review provides insights into current progress in circRNA research and their significant functions in the aging process. a kind of alternative splicing of pre-mRNA. A downstream splice donor site is joined with an upstream splice acceptor site to generate a circularized structure of RNA. a measurable molecular indicator of a specific biological or pathological process. (circular RNA) covalently closed, single-stranded RNA produced through backsplicing of pre-mRNA. transcription factor; a member of the forkhead family containing a forkhead DNA-binding domain, which is associated with many cellular processes, including stress responses and aging. a group of proteins that are upregulated by conditions of cellular stress, such as heat shock; comprise an evolutionarily conserved system for organisms to adapt to harmful environments. endocrine signaling pathway that regulates multiple physiological functions, including aging and longevity, in multiple species ranging from nematodes to mammals. short, single-stranded (~22 nucleotides) noncoding RNA that regulates target gene expression through degradation or repressive translation of target mRNA. the ability to bind and sequester a specific miRNA to inhibit its activity. proteins that can bind to single-stranded or double-stranded RNAs through RNA-binding motifs, such as the RNA recognition motif and double-stranded RNA-binding motif. RBPs have important roles in post-transcriptional regulation of RNAs in various biological processes. permanent cell cycle arrest after the reduction of proliferation potential.