Expression Profiles, Biological Functions and Clinical Significance of Circular RNAs in Inflammatory Bowel Disease.

Inflammatory bowel disease (IBD) is a chronic, relapsing inflammatory condition affecting the gastrointestinal tract, primarily encompassing Crohn's disease (CD) and ulcerative colitis (UC). IBD is characterized by insidious onset, diagnostic challenges, and lack of curative therapies. Despite substantial research efforts, the precise etiology and pathogenesis of IBD remain incompletely elucidated. Furthermore, reliable biomarkers and satisfactory therapeutic strategies for clinical management of IBD patients are still lacking. Circular RNAs (circRNAs) constitute a class of non-coding RNAs characterized by covalently closed circular structures, which are abundantly expressed in eukaryotic cells. Circular RNAs are characterized by their biochemical stability, tissue specificity, and developmental stage specificity. Accumulating evidence suggests that circRNAs are implicated in the development and progression of IBD. Aberrant circRNA expression in IBD is considered a critical factor modulating intestinal immune homeostasis and barrier function through the regulation of immuno-inflammatory responses, tight junction protein expression, autophagy, apoptosis, and other pathophysiological processes. This review comprehensively examines relevant articles published in recent years, elucidating the biogenesis and functional roles of circRNAs, summarizing their biological implications and potential mechanisms in IBD, and exploring their clinical significance. We anticipate that this review will provide valuable insights into the potential of circRNAs as specific targets for the diagnosis and treatment of IBD in future research.