Koji Yoshinaga

Immune mechanisms at the maternal-fetal interface: perspectives and challenges

Leaders gathered at the US National Institutes of Health in November 2014 to discuss recent advances and emerging research areas in aspects of maternal-fetal immunity that may affect fetal development and pregnancy success.

REVIEW ARTICLE: Research on Blastocyst Implantation Essential Factors (BIEFs)

Citation Yoshinaga K. Research on Blastocyst Implantation Essential Factors (BIEFs). Am J Reprod Immunol 2010

A sequence of events in the uterus prior to implantation in the mouse.

I reviewed a series of events in the mouse uterus before implantation on Day 4 of pregnancy (the sperm positive day is counted as Day 1). Major events are spacing of embryos along the uterine horns, shedding of the zona pellucida, and closure of the uterine lumen. How subtle they may be, there appear to exist interactions between intrauterine blastocysts and the uterus which is regulated by ovarian steroids. Spacing of embryos along the uterine horn is not random, but they are rather evenly distributed along the entire horn. The mechanism of even distribution of embryos needs clarification, although studies indicate that adrenergic nerve activity, prostaglandins, and other molecules appear to be involved. Shedding of the zona pellucida involves trypsin-like proteinase lysis of the zona. Through the opening created by zona lysis, blastocyst gets out of the zona by repeating expansion-collapse movements. Closure of rat uterine lumen is reported to be the result of absorption of uterine fluid through uterine glands. This needs to be confirmed in other species of rodents. Since these events influence blastocyst implantation, we need more detailed information on their regulatory mechanisms in order to improve the rate of healthy implantation of transferred embryo.

Progesterone and Its Downstream Molecules as Blastocyst Implantation Essential Factors

This review is to update the previous review (Am J Reprod Immunol, 63, 2010 and 413) on the research on blastocyst implantation essential factors (BIEFs). Focus of the current review is on progesterone and its downstream molecules in the process of blastocyst implantation. To understand the process of implantation, we need to know where and when the BIEFs are expressed and what they do. Progress in this research area is rapid, and its update is indeed necessary. The basic concept of BIEFs is that they have dual functions, one physiological and the other immunological (J Reprod Dev, 58, 2012 and 196). As we are still exploring the mechanism of implantation, available data are incomplete and human data are few. Thus, I will use information obtained through research on animal models, in vitro studies, cell lines, and some human studies where available. The ultimate goal of the review is to understand human blastocyst implantation.

Future Prospect of Research on Endocrinology of Embryo-Endometrial Interactions

Although there are many interesting maternal-embryo interactions that deserve careful attention, this presentation will focus on the following four topics that represent, in my personal opinion, areas of investigation that attract research interest in the near future: (1) endocrine regulation in early pregnancy, (2) uterine receptivity for blastocyst implantation, (3) in vitro culture systems, and (4) step-by-step consideration of blastocyst-endometrial interactions.

Interdisciplinary Collaborative Team for Blastocyst Implantation Research: inception and perspectives

This study describes the currently active research team created by participation of investigators who are eager to work together with other investigators of different disciplines on implantation research. The name of this group is ‘Interdisciplinary Collaborative Team for Blastocyst Implantation Research’. From now on we will call the group the Team. It started with the publication of an NIH Program Announcement.

Research on Blastocyst Implantation Essential Factors (BIEFs): BLASTOCYST IMPLANTATION ESSENTIAL FACTORS

Citation Yoshinaga K. Research on Blastocyst Implantation Essential Factors (BIEFs). Am J Reprod Immunol 2010

A historical review of blastocyst implantation research

Abstract Research development on blastocyst implantation was reviewed in three sections: primate implantation, ungulate farm animal implantation, and the general process of blastocyst implantation in small rodents. Future research directions of this area are suggested. Summary Sentence Research on blastocyst implantation was historically reviewed.

Cellular and molecular events surrounding blastocyst implantation: report on a NICHD meeting, Bethesda, MD, USA, 15-16 November 1999.

This meeting, supported by the Reproductive Sciences Branch, Center for Population Research, National Institute of Child Health and Human Development (NICHD), NIH, was held to achieve dual purposes: (1) the evaluation of the ongoing National Cooperative Program on Markers of Uterine Receptivity for Blastocyst Implantation and (2) to update our knowledge of blastocyst implantation research. The Cooperative Program was evaluated as being highly successful, with good productivity, rapid exchange of information, and remarkable progress. Our knowledge of many molecules that concern interactions between blastocyst and maternal tissues was also updated as a result of the meeting.

Perspectives for Future Research on the Uterus

The papers presented in this symposium represent a good part of the research on the uterus. These areas of research are important and will continue to bring us new and exciting information. In this paper, I will describe several areas of the uterine research which need further studies.