Mast cell-derived exosomes and claudin regulation in ulcerative colitis: emerging insights and therapeutic potential.

Ulcerative colitis (UC) is a chronic inflammatory condition marked by immune dysfunction and disruption of the intestinal epithelial barrier, in which mast cells play a significant role through the release of inflammatory mediators. Recent advances suggest that mast cell-derived exosomes and intraluminal vesicles (MC-EXOs and MC-ILVs) may contribute to disease pathogenesis by modulating epithelial tight junction proteins, particularly members of the Claudin family. Notably, transcriptomic analyses indicate that CLDN23, a gene encoding Claudin-23, is downregulated in active UC. Exosomes are emerging as key players in intercellular communication, capable of delivering functional microRNAs and proteins that influence intestinal permeability and immune cell behaviour. This mini-review summarizes current evidence on the interaction between mast cell-derived vesicles and intestinal epithelial cells, focusing on their regulatory role in Claudin expression and immune signalling pathways. Understanding these mechanisms may inform the development of exosome-based biomarkers and therapeutic strategies for UC.