Glucagonlike peptide 2 analogue teduglutide: stimulation of proliferation but reduction of differentiation in human Caco-2 intestinal epithelial cells.
OBJECTIVE
Short bowel syndrome occurs when a shortened intestine cannot absorb sufficient nutrients or fluids. Teduglutide is a recombinant analogue of human glucagonlike peptide 2 that reduces dependence on parenteral nutrition in patients with short bowel syndrome by promoting enterocytic proliferation, increasing the absorptive surface area. However, enterocyte function depends not only on the number of cells that are present but also on differentiated features that facilitate nutrient absorption and digestion.


OBJECTIVE
To test the hypothesis that teduglutide impairs human intestinal epithelial differentiation.


METHODS
We investigated the effects of teduglutide in the modulation of proliferation and differentiation in human Caco-2 intestinal epithelial cells at a basic science laboratory. This was an in vitro study using Caco-2 cells, a human-derived intestinal epithelial cell line commonly used to model enterocytic biology.


METHODS
Cells were exposed to teduglutide or vehicle control.


METHODS
We analyzed the cell cycle by bromodeoxyuridine incorporation or propidium iodide staining and flow cytometry and measured cell proliferation by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay. We used quantitative reverse transcription-polymerase chain reaction to assay the expression of the enterocytic differentiation markers villin, sucrase-isomaltase, glucose transporter 2 (GLUT2), and dipeptidyl peptidase 4 (DPP-4), as well as that of the putative differentiation signals schlafen 12 (SLFN12) and caudal-related homeobox intestine-specific transcription factor (Cdx2). Villin promoter activity was measured by a luciferase-based assay.


RESULTS
The MTS assay demonstrated that teduglutide increased cell numbers by a mean (SD) of 10% (2%) over untreated controls at a maximal 500 nM (n = 6, P < .05). Teduglutide increased bromodeoxyuridine-positive cells vs untreated controls by a mean (SD) of 19.4% (2.3%) vs 12.0% (0.8%) (n = 6, P < .05) and increased the S-phase fraction by flow cytometric analysis. Teduglutide reduced the mean (SD) expression of villin by 29% (6%), Cdx2 by 31% (10%), DPP-4 by 15% (6%), GLUT2 by 40% (11%), SLFN12 by 61% (14%), and sucrase-isomaltase by 28% (8%) (n = 6, P < .05 for all).


CONCLUSIONS
Teduglutide increased Caco-2 proliferation but tended to inhibit intestinal epithelial differentiation. The effects of mitogenic stimulation with teduglutide in patients with short bowel syndrome might be greater if the more numerous teduglutide-treated cells could be stimulated toward a more fully differentiated phenotype.
Department of Surgery, College of Human Medicine, Michigan State University, East Lansing2Research Service, John D. Dingell Veterans Affairs Medical Center, Detroit, Michigan3Department of Anesthesiology, Wayne State University, Detroit, Michigan.
Lakshmi S
LS
Chaturvedi
Marc D
MD
Basson
D015415:Biomarkers / Q000378:metabolism; D018938:Caco-2 Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D018929:Cell Culture Techniques; D002454:Cell Differentiation / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects*; D018819:Dipeptidyl Peptidase 4 / Q000378:metabolism; D020895:Enterocytes / Q000166:cytology* / Q000187:drug effects* / Q000502:physiology; D051273:Glucose Transporter Type 2 / Q000378:metabolism; D006801:Humans; D008840:Microfilament Proteins / Q000378:metabolism; D010455:Peptides / Q000494:pharmacology*; D013394:Sucrase-Isomaltase Complex / Q000378:metabolism
D015415:Biomarkers; D051273:Glucose Transporter Type 2; D008840:Microfilament Proteins; D010455:Peptides; C026615:villin; C494910:teduglutide; D013394:Sucrase-Isomaltase Complex; D018819:Dipeptidyl Peptidase 4