title: Intestinal epithelial cells in inflammatory bowel diseases.
abstract: The pathogenesis of inflammatory bowel diseases (IBDs) seems to involve a primary defect in one or more of the elements responsible for the maintenance of intestinal homeostasis and oral tolerance. The most important element is represented by the intestinal barrier, a complex system formed mostly by intestinal epithelial cells (IECs). IECs have an active role in producing mucus and regulating its composition; they provide a physical barrier capable of controlling antigen traffic through the intestinal mucosa. At the same time, they are able to play the role of non-professional antigen presenting cells, by processing and presenting antigens directly to the cells of the intestinal immune system. On the other hand, immune cells regulate epithelial growth and differentiation, producing a continuous bi-directional cross-talk within the barrier. Several alterations of the barrier function have been identified in IBD, starting from mucus features up to its components, from epithelial junctions up to the Toll-like receptors, and altered immune responses. It remains to be understood whether these defects are primary causes of epithelial damage or secondary effects. We review the possible role of the epithelial barrier and particularly describe the role of IECs in the pathogenesis of IBD.
authors.affiliation: Department of Clinical Medicine, University of Bologna, Gastroenterology Unit, S. Orsola - Malpighi Hospital, 40138 Bologna, Italy. giuliaroda@gmail.com
authors.forename: Giulia
authors.initials: G
authors.lastname: Roda
authors.forename: Alessandro
authors.initials: A
authors.lastname: Sartini
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Zambon
authors.forename: Andrea
authors.initials: A
authors.lastname: Calafiore
authors.forename: Margherita
authors.initials: M
authors.lastname: Marocchi
authors.forename: Alessandra
authors.initials: A
authors.lastname: Caponi
authors.forename: Andrea
authors.initials: A
authors.lastname: Belluzzi
authors.forename: Enrico
authors.initials: E
authors.lastname: Roda
mesh_terms: D000818:Animals; D001419:Bacteria / Q000472:pathogenicity; D023082:Defensins / Q000502:physiology; D006801:Humans; D007113:Immunity, Innate; D015212:Inflammatory Bowel Diseases / Q000209:etiology*; D007413:Intestinal Mucosa / Q000276:immunology / Q000502:physiology*; D008214:Lymphocytes / Q000502:physiology; D053473:Nod2 Signaling Adaptor Protein / Q000235:genetics; D015398:Signal Transduction; D051193:Toll-Like Receptors / Q000502:physiology
chemical_list: D023082:Defensins; C429018:NOD2 protein, human; D053473:Nod2 Signaling Adaptor Protein; D051193:Toll-Like Receptors
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