The intestinal mucosa is in a constant state of controlled inflammation, but the processes whereby this occurs are poorly understood. The aims of this study were to look at the role of IL-10 and nerve growth factor (NGF) in intestinal epithelial cell regulation. The human colon epithelial cell lines T84, HT-29, and CACO-2 were used. RT-PCR, flow cytometry analysis, and immunohistochemistry were...

Caveolae-mediated endocytosis in endothelial cells is stimulated by the binding of albumin to gp60, a specific albumin-binding protein localized in caveolae. The activation of gp60 induces its cell surface clustering and association with caveolin-1, the caveolar-scaffolding protein. This interaction leads to Gi-induced Src kinase activation, which in turn signals dynamin2-mediated fission and d...

We expressed the heat-labile enterotoxin B (LTB) subunit from enterotoxigenic Escherichia coli and the cholera toxin B (CTB) subunit from Vibrio cholerae under the control of the rice (Oryza sativa) globulin (Glb) promoter. Binding of recombinant LTB and CTB proteins was confirmed based on GM1-ganglioside binding enzyme-linked immunosorbent assays (GM1-ELISA). Real-time PCR of three generations...

The intestinal mucosa is in a constant state of controlled inflammation, but the processes whereby this occurs are poorly understood. The aims of this study were to look at the role of IL10 and NGF in intestinal epithelial cell regulation. The human colon epithelial cell line T84, HT29 and CACO-2 were used. RT-PCR, flow cytometry analysis and immunohistochemistry were applied to measure the cyt...

Beta-adrenergic-mediated vasorelaxation declines with maturation and aging. Available data suggest that impaired stimulatory G-protein function could explain this deficit. We have previously found a loss of cholera toxin (CT)-stimulated adenosine diphosphate (ADP) ribosylation with age in rat aortic membrane preparations, without evidence for loss of the stimulatory alpha subunit of G protein (...

Chloride concentration ([Cl-]) was measured in defined organellar compartments using fluorescently labeled transferrin, alpha2-macroglobulin, and cholera toxin B-subunit conjugated with Cl--sensitive and -insensitive dyes. In pulse-chase experiments, [Cl-] in Tf-labeled early/recycling endosomes in J774 cells was 20 mM just after internalization, increasing to 41 mM over approximately 10 min in...

A study is presented on the in vivo effect of elevated cAMP levels induced by cholera toxin on the phosphorylation of subunits of the mitochondrial respiratory complexes and their activities in Balb/c 3T3 mouse fibroblast cultures. Treatment of serum-starved fibroblasts with cholera toxin promoted serine phosphorylation in the 18-kDa subunit of complex I. Phosphorylation of the 18-kDa subunit, ...

Enhanced sodium reabsorption by the kidney has a significant role in the development of genetic hypertension. In the spontaneously hypertensive rat (SHR) model of genetic hypertension, the enhanced sodium reabsorption likely arises from abnormal hormonal regulation of tubular transport. Since hormonal signaling pathways are coupled frequently via GTP binding proteins, one explanation for hormon...

The tryptophan residues on cholera toxin and its A and B protomers have been modified by reaction with 2-nitrophenylsulfenyl chloride and 2,4-dinitrophenylsulfenyl chloride. Modification of the tryptophan residues of cholera toxin results in complete loss of toxicity measured in a skin permeability assay. Modification of cholera toxin and its B protomer results in the complete loss of binding a...

Plasmid profiles, the location of cholera toxin subunit A genes, and the presence of the defective VcA1 prophage genome in classical Vibrio cholerae isolated from patients in Bangladesh in 1982 were compared with those in older classical strains isolated during the sixth pandemic and with those in selected eltor and nontoxigenic O1 isolates. Classical strains typically had two plasmids (21 and ...