5 REVIEW Bridging endometrial receptivity and implantation: network of hormones, cytokines, and growth factors Mohan Singh, Parvesh Chaudhry and Eric Asselin Research Group in Molecular Oncology and Endocrinology, Department of Chemistry-Biology, University of Quebec, Trois-Rivieres, 3351, Boulevard Des Forges, CP 500, Trois-Rivieres, Quebec G8Y 5H7, Canada (Correspondence should be addressed to E Asselin; Email:
[email protected]) Abstract The prerequisite of successful implantation depends on due to ethical issues. In this study, we comprehend the data achieving the appropriate embryo development to the from both animal models and humans for better under- blastocyst stage and at the same time the development of an standing of implantation and positive outcomes of pregnancy. endometrium that is receptive to the embryo. Implantation is The purpose of this review is to describe the potential roles of a very intricate process, which is controlled by a number of embryonic and uterine factors in implantation process such as complex molecules like hormones, cytokines, and growth prostaglandins, cyclooxygenases, leukemia inhibitory factor, factors and their cross talk. A network of these molecules plays interleukin (IL) 6, IL11, transforming growth factor-b, IGF, a crucial role in preparing receptive endometrium and activins, NODAL, epidermal growth factor (EGF), and blastocyst. Furthermore, timely regulation of the expression heparin binding-EGF. Understanding the function of these of embryonic and maternal endometrial growth factors and players will help us to address the reasons of implantation cytokines plays a major role in determining the fate of failure and infertility. embryo. Most of the existing data comes from animal studies Journal of Endocrinology (2011) 210, 5–14 Introduction implantation requires a plethora of locally acting molecules that are involved in this early embryo–uterine interaction.