PARACRINE ACTIONS OF INSULIN-LIKE GROWTH-FACTORS AND IGF BINDING PROTEIN-1 IN NONPREGNANT HUMAN ENDOMETRIUM AND AT THE DECIDUAL-TROPHOBLASTINTERFACE

Insulin-like growth factors, IGF-I, IGF-II, and IGF binding protein (I GFBP-1) appear to play major roles in endometrial development during t he menstrual cycle and in the process of implantation. The mitogenic, differentiative, and anti-apoptotic properties of these growth factors , as well as their spatial and temporal expression in cycling endometr ium, suggest that they may participate in endometrial growth, differen tiation,inhibition of apoptosis, and perhaps angiogenesis. IGFBP-1 is a major protein product of non-pregnant endometrium during the mid-lat e secretory phase and occurs in abundance in decidua. Its roles as an IGF-binding protein and as a trophoblast integrin ligand suggest that it may have multiple roles in endometrial development and in interacti ons between the decidua and the invading trophoblast. Precise elucidat ion of the mechanisms underlying IGF and IGFBP-1 action at the decidua l-trophoblast interface in early pregnancy awaits further investigatio n. The future also awaits elucidation of the potential predictive util ity of IGFBP-1 in serum and in decidua in, for example, pre-eclampsia and perhaps implantation failure. (C) 1998 Elsevier Science Ireland Lt d. All rights reserved.