Heparan sulfate proteoglycans and their binding proteins in embryo implantation and placentation

Abstract

Complex interactions occur among embryonic, placental and maternal tissues during embryo implantation. Many of these interactions are controlled by growth factors, extracellular matrix and cell surface components that share the ability to bind heparan sulfate (HS) polysaccharides. HS is carried by several classes of cell surface and secreted proteins called HS proteoglycan that are expressed in restricted patterns during implantation and placentation. This review will discuss the expression of HS proteoglycans and various HS binding growth factors as well as extracellular matrix components and HS-modifying enzymes that can release HS-bound proteins in the context of implantation and placentation.

Assessment of the transcription levels for the complement activation control system in eutopic endometrium in women with two or more consecutive miscarriages of unknown etiology.

“…It is however impossible at this point, to exclude the role of HB-EGF on the expression of factors controlling the complement activation. The path from HB-EGF transcript to an active protein is in this situation dependant on other factors like: protein synthesis, binding to coreceptor-heparin sulfate, the activity of heparanse and steroid hormones [4,16]. Earlier works by Krussel et al [17] proved that in endometrium there is a synthesis of both the soluble and bound to the cell membrane VEGFR1, with its maximal expression observed in midproliferative phase, and minimal at the beginning of the luteal phase.…”

Comparative aspects of implantation

“…Thus, endothelial cells, vascular smooth muscle cells, and stromal cells of the uterus may be targets of action of IFNG. Furthermore, IFNG is targeted to heparan sulfate that is essential for implantation in mice (Kirn-Safran et al 2008), and this may protect IFNG from inactivation and increase its stability (Lortart-Jacob & Grimaud 1991) to allow protracted effects of IFNG on vascular development in decidual tissue. Type I and type II IFNs modify gene expression at implantation sites in rodents to affect the conceptus directly or to exert indirect effects through actions on blood vessels and decidual cells required for successful implantation and pregnancy (Lash et al 2006).…”

Regulated adhesion as a driving force of gastrulation movements

“…Integrins link to the actin cytoskeleton and to actin regulators, like Rac1 and Ccd42, via Talin and other cytoplasmic proteins of the focal adhesion complex, including focal adhesion kinase (FAK) or integrin-associated kinase (ILK), the scaffold protein Paxillin, Vinculin, α-actinin and others (Zaidel-Bar et al, 2007). HSPGs are categorized into the subfamilies of transmembrane syndecans, GPI-anchored glypicans and extracellular proteoglycans (Kirn-Safran et al, 2008). Syndecans can bind to fibronectin (FN), possibly modulating cellular focal adhesiveness (Morgan et al, 2007), while interfering with growth factor distribution by modifying the ECM.…”