Progress in Understanding the Relationship Between Circular RNAs and Neurological Disorders.

Circular RNAs (circRNAs), a type of endogenous noncoding RNAs distinct from linear forms, are produced by backsplicing events within genes. circRNAs are structurally stable, highly conserved molecules found widely in organisms, and display tissue-type and developmental-stage specific expression patterns, which reveal their significant regulatory functions in gene expression. Based on accumulating evidence, some circRNAs are now believed to be a class of competitive endogenous RNAs that regulate gene expression. For example, circRNAs may prevent microRNAs from inhibiting target RNAs acting as microRNA sponges, or interact with RNA binding proteins and thereby efficiently and post-transcriptionally regulate expression of the parental and other genes. In addition, an increasing number of studies have shown that circRNAs play important roles in the development and progression of neurological disorders. In this review, we provide a comprehensive overview on the biogenesis, characteristics, and functions of circRNAs. We also discuss the critical role of circRNAs in neurological disorders.