**New Insights on Pathophysiology of Celiac Disease**

**1** 

*Hungary* 

**Mucosal Expression of Claudins** 

Mária Papp4, András Arató1 and Gábor Veres1

*and Hungarian Academy of Sciences, Budapest, 4Department of Medicine, University of Debrecen,* 

*1First Department of Pediatrics, Semmelweis University, Budapest, 2Second Department of Pathology, Semmelweis University, Budapest, 3Research Group for Pediatrics and Nephrology, Semmelweis University* 

Dorottya Nagy-Szakál1, Hajnalka Győrffy2, Katalin Eszter Müller1, Kriszta Molnár1, Ádám Vannay1,3, Erna Sziksz1,3, Beáta Szebeni1,3,

Celiac disease is an autoimmune gluten-sensitive enteropathy or nontropical sprue occurring in genetically susceptible individuals, triggered by dietary gluten and related prolamins, which damage small intestine and interfere with absorption of nutrients. Tight junctions play an important role in the pathomechanism of different gastrointestinal diseases. Claudins, the main tight junction proteins are found in the monolayer of the gastrointestinal epithelium (Bornholdt et al., 2011). The presence and distribution of claudin depend on the organs and the function of the tissues (Gonzales-Mariscal et al., 2003). The expression levels of various claudins correlate to the distinct physiological and pathological conditions. Claudins modulate the permeability of the epithelial barrier (Bornholdt et al., 2011). Surprisingly, there is only one study analyzing different claudins at protein level of intestinal biopsies in patients with celiac disease. At first, general information of tight junctions and the characteristics of claudins in different gastrointestinal disorders will be

Intercellular junctions are presented in multicellular organism as linking cells and maintaining barrier function between the two sides of cell layer (Staehelin et al., 1974). It plays a structural role in maintaining biological compartments, cell polarity, and a barrier function separating the internal and external environments (Krause et al., 2008). It also controls the paracellular transport (Balda et al., 1996). The barrier and fence function are dynamically changing and guide cell behavior. Three major types of intercellular junctions are the zonula occludens (tight junction), the zonula adherens (adherens junction) and the macula adherens (desmosome). The tight junction is an intercellular junction by interlinked rows of integral membrane proteins limiting the intercellular transport. One of the most

highlighted for a better understanding of the role of claudins in celiac disease.

**2. Characteristics of tight junctions** 

important components of tight junction is claudin (Figure 1).

**1. Introduction** 

**in Celiac Disease** 
