Complementary expression and repulsive signaling suggest that EphB receptors and ephrin-B ligands control cell positioning in the gastric epithelium |
| |
Authors: | Kazushige Ogawa Natsuki Takemoto Maki Ishii Elena B Pasquale Takayuki Nakajima |
| |
Institution: | (1) Department of Veterinary Anatomy, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58 Rinku-Ourai-Kita, Izumisano Osaka, 598-8531, Japan;(2) Sanford-Burnham Medical Research Institute, 10901 N. Torrey Pines Rd., La Jolla, CA 92037, USA;(3) Pathology Department, University of California San Diego, 9500 Gilman Dr., La Jolla, CA 92093, USA |
| |
Abstract: | Eph receptors and ephrin ligands are membrane-bound cell–cell communication molecules with well-defined roles in development.
However, their expression and functions in the gastric epithelium are virtually unknown. We detected several EphB receptors
and ephrin-Bs in the gastric corpus mucosa of the adult rodent stomach by RT-PCR amplification. Immunostaining showed complementary
expression patterns, with EphB receptors preferentially expressed in the deeper regions and ephrin-Bs in the superficial regions
of the gastric units. EphB1, EphB2 and EphB3 are expressed in mucous neck, chief and parietal cells, respectively. In contrast,
ephrin-B1 is in pit cells and proliferating cells of the isthmus. In a mouse ulcer model, EphB2 expression was upregulated
in the regenerating epithelium and expanded into the isthmus. Thus, EphB/ephrin-B signaling likely occurs preferentially in
the isthmus, where receptor-ligand overlap is highest. We show that EphB signaling in primary gastric epithelial cells promotes
cell retraction and repulsion at least in part through RhoA activation. Based on these findings, we propose that the EphB-positive
progeny of gastric stem cells migrates from the isthmus toward the bottom of the gastric glands due to repulsive signals arising
from contact with ephrin-Bs, which are preferentially expressed in the more superficial regions of the isthmus and gastric
pits. |
| |
Keywords: | |
本文献已被 PubMed SpringerLink 等数据库收录! |
|