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Vol. 172, No. 3, 2002
Issue release date: 2002
Section title: Paper
Cells Tissues Organs 2002;172:237–252
(DOI:10.1159/000066963)

In vitro Studies on Endometrial Adhesiveness for Trophoblast: Cellular Dynamics in Uterine Epithelial Cells

Thie M. · Denker H.-W.
Institut für Anatomie, Lehrstuhl für Anatomie und Entwicklungsbiologie, Universitätsklinikum Essen, Germany

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Article / Publication Details

First-Page Preview
Abstract of Paper

Received: 9/3/2002
Published online: 12/18/2002

Number of Print Pages: 16
Number of Figures: 7
Number of Tables: 0

ISSN: 1422-6405 (Print)
eISSN: 1422-6421 (Online)

For additional information: http://www.karger.com/CTO

Abstract

Initiation of embryo implantation involves adhesion of trophoblast cells to the epithelial lining of the endometrium. The mechanisms regulating the adhesive properties of the uterine epithelium for trophoblast during initiation of human embryo implantation, however, are still incompletely understood. We report here on model studies that we have performed in our laboratory, and in particular on certain methodological approaches that seem to yield new insight into basic mechanisms involved. Of central interest is the ability of the uterine epithelium to develop an adhesion competence at its apical cell pole. This confronts us with a cell biological paradox in that adhesion must be established at the pole which in simple epithelia is typically specialized to resist adhesion. Gain of apical adhesion competence by uterine epithelial cells should be related to cellular rearrangements, i.e. a modulation of their apicobasal cell polarity. Here, we used monolayer-cultured uterine epithelial RL95-2 cells as an in vitro model for the human receptive uterine epithelium. We demonstrated that formation of stable cell-to-cell bonds between the free (apical) pole of these cells and attaching trophoblast (modelled by JAr cells) depends on a number of structural and functional peculiarities that RL95-2 cells have in contrast to other uterine epithelial cells (HEC-1-A cells) which resist attachment via this cell pole. RL95-2 cells were shown to lack tight junctions and to exhibit only rudimentary adherens junctions and a non-polar organization of the actin cytoskeleton. Using the atomic force microscope in a force spectroscopy mode, we exactly defined the time dependence of adhesive interactions between RL95-2 cells and trophoblast, measured the pressure force needed to initiate this process, and screened the buildup of the adhesive forces between the binding partners. A dynamic interaction between the actin cytoskeleton and integrins (a prerequisite for functional activity of integrins) was shown to be an important aspect of the adhesive properties of RL95-2 cells. In addition, at least two types of calcium channels in the plasma membrane of RL95-2 cells seem to play a role in activation of a variety of calcium-sensitive response mechanisms including adhesiveness for trophoblast, i.e. diltiazem-sensitive channels seem to contribute to the initiation of JAr cell binding and SKF-96365-sensitive channels to participate in a feedback loop that controls the balance of bonds. By extrapolation, these data suggest an active role of the uterine epithelium in the process of embryo implantation which we are just beginning to understand in terms of its cell biology.


Article / Publication Details

First-Page Preview
Abstract of Paper

Received: 9/3/2002
Published online: 12/18/2002

Number of Print Pages: 16
Number of Figures: 7
Number of Tables: 0

ISSN: 1422-6405 (Print)
eISSN: 1422-6421 (Online)

For additional information: http://www.karger.com/CTO


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Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in goverment regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
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