PARACRINE SIGNALING IN THE ENDOMETRIUM - INTEGRINS AND THE ESTABLISHMENT OF UTERINE RECEPTIVITY

The importance of cell shape and polarity have long been recognized. I n the endometrium, a complex association of different cell types under go cyclic renewal, differentiation and eventually apoptosis and sheddi ng, with the sole purpose of allowing implantation of the nascent embr yo. Many of these physiologic processes depend on the timely expressio n of cell adhesion molecules which maintain tissue architecture by med iating cell-cell and cell-substratum attachments. One family of cell a dhesion molecules are the integrins, cell surface glycoproteins compos ed of heterodimeric alpha and beta subunits that serve as receptors fo r the extracellular matrix. We have studied the endometrium as a uniqu e site of integrin expression that appear to be under both endocrine a nd paracrine control. In addition, it is suspected that the engagement of integrins by extracellular matrix on the embryo results in signal transduction leading to the transcription and translation of genes cri tical for implantation. While the role of integrins in endometrial fun ction is not yet clearly defined, these interesting molecules represen t excellent markers of normal and abnormal states of receptivity and m ay provide clues to the regulation and mechanics of implantation in ge neral. (C) 1998 Published by Elsevier Science Ireland Ltd. All rights reserved.