Uncoordinated, transient mosaic patterns of intestinal hydrolase expression in differentiating human enterocytes

• Published in: Journal of cellular physiology Vol. 166; no. 1; pp. 198 - 207
• Main Authors: Vachon, Pierre H., Perreault, Nathalie, Magny, Pierre, Beaulieu, Jean-François
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.01.1996
• Subjects: Alkaline Phosphatase - metabolism; beta-Galactosidase - metabolism; Blotting, Western; Caco-2 Cells - cytology; Caco-2 Cells - enzymology; CD13 Antigens - metabolism; Cell Differentiation - physiology; Cell Division - physiology; Dipeptidyl Peptidase 4 - metabolism; Fluorescent Antibody Technique, Indirect; Humans; Hydrolases - metabolism; Intestines - cytology; Intestines - enzymology; Lactase; Microscopy, Electron, Scanning; Microvilli - enzymology
• ISSN: 0021-9541; 1097-4652
• DOI: 10.1002/(SICI)1097-4652(199601)166:1<198::AID-JCP21>3.0.CO;2-A

The heterogenous expression of brush border membrane hydrolases by the human enterocyte‐like Caco‐2 cell line during morphological and functional differentiation in vitro was investigated at the cellular level. Indirect immunofluorescence revealed that the heretogenous (“mosaic”) expression of sucrase‐isomaltase, lactase, aminopeptidase N, and alkaline phosphatase was, in fact, transient in nature. The labeling indexes for each hydrolase gradually increased during culture at postconfluence in order to reach a maximum (≥90%) after 30 days, concomitant with an upregulation of their respective protein expression levels. In contrast, dipeptidylpeptidase IV labeling remained relatively constant. Backscattered electron imaging analysis in midstage (12 days postconfluence) monolayers demonstrated a lack of correlation between brush border membrane development and expression of each enzyme studied. Moreover, double immunostaining revealed that none of the other four hydrolases correlated directly with sucrase‐isomaltase expression. Finally, immunodetection for the proliferation‐associated antigen Kl‐67 revealed a transient mosaic pattern of proliferation which was inversely related to Caco‐2 cell differentiation. These data indicate that enterocytic differentiation‐related (as well as proliferation‐related) gene expression in Caco‐2 cells is regulated but uncoordinated at the cellular level, suggesting that an overall control mechanism is lacking. © 1996 Wiley‐Liss, Inc.