Developmental Profile of Claudin‐3, ‐5, and ‐16 Proteins in the Epithelium of Chick Intestine

Abstract

Proteins in the claudin family are a main component of tight junctions and form a seal that modulates paracellular transport in intestinal epithelium. This research tests the hypothesis that claudins 3, 5, and 16 will appear in the epithelium of embryonic intestine during functional differentiation. Immunohistochemistry is utilized to explore the developmental patterns of claudin-3, -5, and -16 proteins in the epithelium of embryonic chick intestine from 9 days prior to hatching through the early post-hatch period. These claudin proteins either changed their cellular localization or first appeared around the time of hatching. After hatching, claudin-3 expression was prominent in basal-lateral regions of the epithelium along the entire villus, but was absent from crypts. Claudin-5 was expressed most strongly in the crypt and lower villus epithelium within junctional complexes, whereas immunostaining of claudin-16 was localized within goblet cells of the upper villus region. The relative mRNA levels of claudin-3, -5, and -16 showed similar patterns; transcript levels rose between 18 and 20 days of development, then dropped by 2 days post-hatch. Results of this work indicate that the claudin proteins assume their final locations within the epithelium around the time of hatching, suggesting that in addition to their known barrier and fence functions within tight junctions, these claudins may have additional roles in the differentiation and/or physiological function of chick intestine. The localization of claudin-16 to goblet cells and its distribution in the more mature cells of the upper villus region suggest an unexpected role in goblet cell maturation and mucus secretion. Anat Rec, 293:1175Rec, 293: -1183

The tight junction protein claudin-1 influences cranial neural crest cell emigration

“…Claudin-5 is also transiently expressed during the formation of the chick retinal pigment epithelium, with highest levels observed between embryonic days 10–14 (Kojima et al, 2002). The chick intestinal epithelium also expresses claudin-3, -5, and -16, with localization observed along the entire villus, in the crypt and lower villus, and in upper villus goblet cells, respectively (Ozden et al, 2010). In Xenopus , Xclaudin controls left-right patterning (Brizuela et al 2001), and gain or loss of the Xenopus claudin-1 homolog, XClaudin-1 , disrupts normal convergent-extension during gastrulation (Chang et al 2010).…”

Biology of the Gastrointestinal Tract in Poultry

“…These are key constituents of tight junctions. There are high levels of claudin-3 in the epithelial cells along the villus, of claudin-5 in the epithelium of the crypt and lower villus and of claudin-16 in goblet cells of the upper villus (Ozden et al, 2010). Similarly, development dependent shifts in expression of members of intestinal solute carrier (SLC) gene family in the small intestine are evident during late embryonic and early post-hatching growth .…”

Deoxynivalenol Impairs Hepatic and Intestinal Gene Expression of Selected Oxidative Stress, Tight Junction and Inflammation Proteins in Broiler Chickens, but Addition of an Adsorbing Agent Shifts the Effects to the Distal Parts of the Small Intestine

“…Claudin 1 and 5 are known to interact and are important to guarantee the intestinal barrier function. Both claudins have already been characterized in chickens [14]–[16]. The family of zona occludens, including zona occludens 1 (ZO 1) and zona occludens 2 (ZO 2), is a group of scaffolding proteins which is part of the cytoplasmic plaque of the tight junctions.…”