Maturational regulation of globotriaosylceramide, the Shiga-like toxin 1 receptor, in cultured human gut epithelial cells.
Differentiated villus intestinal epithelial cells express globotriaosylceramide, the Shiga-like toxin 1 (SLT-1) receptor, and are sensitive to toxin-mediated cytotoxicity, whereas undifferentiated crypt cells neither express Gb3 nor respond to toxin. To investigate if SLT-1 receptors are maturationally regulated in human intestinal cells, we examined the effect of butyrate, a known transcriptional regulator of differentiation genes in many cell types, using cultured colonic cancer-derived epithelial cell lines. Exposure to butyrate increased villus cell marker enzymes such as alkaline phosphatase, sucrase, and lactase, expression of toxin receptors, and sensitivity to SLT-1 in villus-like CaCo-2A and HT-29 cells. These effects were reversibly inhibited by preincubation of CaCo-2A cells with actinomycin D or cycloheximide. Butyrate-treated CaCo-2A cells unable to bind fluoresceinated SLT-1 B subunit were undifferentiated as assessed by alkaline phosphatase activity. HT-29 cells induced to differentiate by another signal, glucose deprivation, upregulated receptor content and response to toxin. Crypt-like T-84 cells responded to butyrate with a modest increase in alkaline phosphatase and toxin binding, but no induction of sucrase or lactase, and no change in sensitivity to toxin. The results demonstrate that expression of SLT-1 toxin receptors and toxin sensitivity are coregulated with cellular differentiation in cultured intestinal cells.
Jacewicz
M S
MS
Division of Geographic Medicine and Infectious Diseases, Tupper Research Institute, New England Medical Center, Boston, Massachusetts 02111, USA.
Acheson
D W
DW
Mobassaleh
M
M
Donohue-Rolfe
A
A
Balasubramanian
K A
KA
Keusch
G T
GT
D000230:Adenocarcinoma; D001427:Bacterial Toxins / Q000302:isolation & purification / Q000378:metabolism / Q000633:toxicity*; D002087:Butyrates / Q000494:pharmacology; D020148:Butyric Acid; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D003110:Colonic Neoplasms; D003513:Cycloheximide / Q000494:pharmacology; D003609:Dactinomycin / Q000494:pharmacology; D004768:Enterotoxins / Q000378:metabolism; D004848:Epithelium / Q000378:metabolism; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006017:Glycolipids / Q000096:biosynthesis*; D006801:Humans; D007700:Kinetics; D011956:Receptors, Cell Surface / Q000096:biosynthesis*; D022622:Shiga Toxin 1; D013997:Time Factors; D014158:Transcription, Genetic / Q000187:drug effects; D014281:Trihexosylceramides / Q000096:biosynthesis*; D014407:Tumor Cells, Cultured
D001427:Bacterial Toxins; D002087:Butyrates; D004768:Enterotoxins; D006017:Glycolipids; D011956:Receptors, Cell Surface; D022622:Shiga Toxin 1; C068556:Shiga-like toxin receptor; D014281:Trihexosylceramides; D020148:Butyric Acid; D003609:Dactinomycin; C018549:globotriaosylceramide; D003513:Cycloheximide