Our bodies are protected from the external environment by mucosal barriers that are lined by epithelial cells. The epithelium plays a critical role as a highly dynamic, selective semipermeable barrier that separates luminal contents and pathogens from the rest of the body and controlling the absorption of nutrients, fluid and solutes. A series of protein complexes including the adherens junction, desmosomes, and tight junctions function as the principal barrier in paracellular diffusion and regulators of intracellular solute, protein, and lipid transport. Tight junctions are composed of a series of proteins called occludins, junctional adhesion molecules, and claudins that reside primarily as the most apical intercellular junction. Here we will review one of these protein families, claudins, and their relevance to gastrointestinal and liver diseases.
*Department of Pediatrics, Gastrointestinal Eosinophilic Diseases Program, Section of Pediatric Gastroenterology, Hepatology and Nutrition, University of Colorado School of Medicine
†Digestive Health Institute, Children's Hospital Colorado
‡Department of Medicine, Mucosal Inflammation Program, University of Colorado School of Medicine, Aurora, CO
§Department of Pediatrics and Adolescent Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan
||Department of Biology, Maynooth University, Co., Kildare, Ireland.
Address correspondence and reprint requests to Joanne C. Masterson, MD, Department of Biology, Maynooth University, Co. Kildare, Ireland W23 F2H6 (e-mail: Joanne.Masterson@mu.ie); Glenn T. Furuta, MD, Children's Hospital Colorado, Aurora, CO 80016 (e-mail: email@example.com).
Received 12 November, 2018
Accepted 26 January, 2019
The study was supported by NIH 1K24DK100303 (G.T.F.) and K01-DK106315 (J.C.M.).
The authors report no conflicts of interest.