Entamoeba histolytica cysteine proteinases degrade human colonic mucin and alter its function.
Explore the source record for details and available documents.
Animals↗
Biomedical subjects
K Chadee
Publications and source records attributed to K Chadee.
Entamoeba histolytica: diffuse liver inflammation in gerbils (Meriones unguiculatus) with experimentally induced amebic liver abscess.
The histopathological changes that occur in the uninfected liver lobes of gerbils with a localized amebic liver abscess (left lobe) were studied from 5 to 60 days after inoculation. Early parenchymal changes (10 days) in the right and median liver lobes showed a lymphocytic infiltrate and bile duct proliferation in the portal areas. Maximum alterations occurred at 20 to 30 days after inoculation and were characterized by a dense portal infiltrate, hepatocyte degeneration, granulocytic infiltrate and marked glycogen depletion. In drug-treated infections with metronidazole, the diffuse liver inflammation was terminated. The results of this study suggest that the diffuse liver injury was directly or indirectly induced by the presence of a proliferating amebic liver abscess and that the pathology caused by amebic liver abscess is more extensive than previously thought.
Animals↗
Functional heterogeneity of colonic adenocarcinoma mucins for inhibition of Entamoeba histolytica adherence to target cells.
Mucins secreted from the gastrointestinal epithelium from the basis of the adherent mucus layer which is the host's first line of defense against invasion by Entamoeba histolytica. Galactose and N-acetyl-D-galactosamine residues of mucins specifically inhibit binding of the amebic 170 kDa heavy subunit Gal-lectin to target cells, an absolute prerequisite for pathogenesis. Herein we characterized the secretory mucins isolated from the human colon and from three human colonic adenocarcinoma cell lines: two with goblet cell-like (LS174T and T84) and one with absorptive cell-like morphology (Caco-2). By Northern blot analysis the intestinal mucin genes MUC2 and MUC3 were constitutively expressed by confluent LS174T and Caco-2 cells, whereas T84 cells only transcribed MUC2 and not MUC3 mRNA. 3H-glucosamine and 3H-threonine metabolically labeled proteins separated as high M, mucins in the void (Vo > 10(6) Da) of Sepharose-4B column chromatography and remained in the stacking gel of SDS-PAGE as depicted by fluorography. All mucin preparations contained high amounts of N-acetyl-glucosamine, galactose, N-acetyl-galactosamine, fucose and sialic acid, saccharides typical of the O-linked carbohydrate side chains. Mucin samples from the human colon and from LS174T and Caco-2 cells inhibited E. histolytica adherence to chinese hamster ovary cells, whereas mucins from T84 cells did not. These results suggest that genetic heterogeneity and/or posttranslational modification in glycosylation of colonic mucins can affect specific epithelial barrier function against intestinal pathogens.
Adenocarcinoma, Mucinous↗