Early loss of E-cadherin from cell-cell contacts is involved in the onset of Anoikis in enterocytes.
Anoikis, i.e. apoptosis induced by detachment from the extracellular matrix, is thought to be involved in the shedding of enterocytes at the tip of intestinal villi. Mechanisms controlling enterocyte survival are poorly understood. We investigated the role of E-cadherin, a key protein of cell-cell adhesion, in the control of anoikis of normal intestinal epithelial cells, by detaching murine villus epithelial cells from the underlying basement membrane while preserving cell-cell interactions. We show that upon the loss of anchorage, normal enterocytes execute a program of apoptosis within minutes, via a Bcl-2-regulated and caspase-9-dependent pathway. E-cadherin is lost early from cell-cell contacts. This process precedes the execution phase of detachment-induced apoptosis as it is only weakly modulated by Bcl-2 overexpression or caspase inhibition. E-cadherin loss, however, is efficiently prevented by lysosome and proteasome inhibitors. We also found that a blocking anti-E-cadherin antibody increases the rate of anoikis, whereas the activation of E-cadherin using E-cadherin-Fc chimera proteins reduces anoikis. In conclusion, our results stress the striking sensitivity of normal enterocytes to the loss of anchorage and the contribution of E-cadherin to the control of their survival/apoptosis balance. They open new perspectives on the key role of this protein, which is dysregulated in the intestinal epithelium in both inflammatory bowel disease and cancer.
UMR 505 INSERM-UPMC, Laboratoire de Pharmacologie Cellulaire et Moléculaire de l'EPHE, 75006 Paris, France.
Stéphane
S
Fouquet
Verónica-Haydée
VH
Lugo-Martínez
Anne-Marie
AM
Faussat
Flore
F
Renaud
Philippe
P
Cardot
Jean
J
Chambaz
Martine
M
Pinçon-Raymond
Sophie
S
Thenet
D000818:Animals; D023102:Anoikis; D017209:Apoptosis; D001485:Basement Membrane / Q000378:metabolism; D015153:Blotting, Western; D015820:Cadherins / Q000737:chemistry* / Q000378:metabolism; D053453:Caspase 9; D020169:Caspases / Q000378:metabolism; D002450:Cell Communication; D003598:Cytoskeletal Proteins / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation; D020895:Enterocytes / Q000378:metabolism* / Q000473:pathology; D004848:Epithelium / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic; D007700:Kinetics; D008247:Lysosomes / Q000378:metabolism; D051379:Mice; D008854:Microscopy, Electron; D008856:Microscopy, Fluorescence; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D011485:Protein Binding; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D013997:Time Factors; D015534:Trans-Activators / Q000378:metabolism; D051176:beta Catenin
C495267:CTNNB1 protein, mouse; D015820:Cadherins; D003598:Cytoskeletal Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D015534:Trans-Activators; D051176:beta Catenin; C506434:Casp9 protein, mouse; D053453:Caspase 9; D020169:Caspases; D046988:Proteasome Endopeptidase Complex