Claudin-3 and occludin tissue content in the glands of colonic mucosa with and without a fecal stream

Abstract

The synthesis of the proteins of the apical tight junctions (TJs) depends on a continuous supply of short-chain fatty acids (SCFAs) in colonic epithelium. No studies have evaluated the tissue contents of the TJs proteins in colon segments devoid of a fecal stream. To evaluate the contents of claudin-3 and occludin in the glands of colonic mucosa devoid of a fecal stream. Forty-five rats underwent a diversion of the fecal stream via a left side colostomy and distal mucous fistula. Three groups of 15 animals each were sacrificed at 6, 12 or 18 weeks after surgery. The presence and severity of colitis were defined by histology and inflammation grading scales, respectively. The expression of claudin-3 and occludin were evaluated by immunohistochemistry, and their contents were evaluated by computer-assisted image analysis. Mann-Whitney and Kruskal-Wallis tests were used to evaluate the results at a significance level of 5% (p < 0.05). The colonic epithelium without a fecal stream had a higher degree of inflammation. Colonic glands without a fecal stream showed a reduction in claudin-3 content independent of the time and reduction in occludin content after 12 weeks of intestinal exclusion. The content of claudin-3 and occludin were mainly reduced at the apical surfaces of the colon glands, whereas segments retaining the fecal stream were maintained. The content of claudin-3 was not reduced with time, although the levels of occludin were reduced after 6 weeks and did not vary thereafter. Deficiencies in SCFAs decreased the content of claudin-3 and occludin in colonic glands with the areas of worst inflammation, confirming the importance of an adequate supply of SCFAs in maintaining the integrity of TJ proteins.

Claudin-3 and occludin content in the glands of colonic mucosa devoid from fecal stream submitted to topical intervention with oil extract of Curcuma longa

“…For the immunoexpression study of claudin-3 and occludin proteins, we used standardized methodology adopted in other studies of our group and obeying the datasheet of the manufacturers of each of the primary antibodies [9][10][11] . As primary antibody, we used anti-claudin-3 monoclonal antibody (Ref.…”

“…In oxidative stress, the increase in the production of OFR, mainly hydroxyl radical (OH) can react with constitute substances of the colonic epithelial mucosa causing breakdown of the different structural defense mechanisms of the colonic barrier allowing the bacterial infiltration of the internal environment 4,7 . Studies showed that over production of OFR reduce and modify the mucus layer that covers the colonic mucosa, causes lipid peroxidation of the cell membranes, break the proteins constituents of adherents junctions (AJs) and tight junctions (TJs) [8][9][10][11] . Experimentally it has been demonstrated that the rupture of the epithelial barrier are related to higher levels of OFR and the development of CDC 9,10 .…”

“…Defective intestinal epithelial TJs barrier has been postulated to be an important pathogenic mechanism leading to the increase in intestinal antigenic penetration and subsequent development of intestinal inflammation 22 . Studies have showing that altered expression and structural changes of the intestinal TJs proteins are closely associated with the development of IBD and CDC 11,25,26 . Modification on TJs leads to the loss of epithelial barrier function induces epithelial damage and alter the intestinal epithelial permeability 11 .…”

“…Studies have showing that altered expression and structural changes of the intestinal TJs proteins are closely associated with the development of IBD and CDC 11,25,26 . Modification on TJs leads to the loss of epithelial barrier function induces epithelial damage and alter the intestinal epithelial permeability 11 . This epithelial barrier dysfunction increased uptake of antigens and toxins from the intestinal lumen and can exacerbate the inflammatory process, ending up in a vicious circle.…”

Characterization of a Novel Diarrheagenic Strain of Proteus mirabilis Associated With Food Poisoning in China

“…For detecting the expression of occludin protein in colon tissues, standardized method was adopted in the study (Martinez et al, 2015;Huang et al, 2018). Anti-occludin polyclonal antibody (Proteintech, United States) was mixed 1:1,000 in 5% skim milk.…”