Search results for "Embryo implantation"
showing 10 items of 92 documents
The role of the leptin in reproduction.
2006
Since its discovery in 1994, leptin has appeared to be a pleiotrophic hormone, governing energy homeostasis and affecting many tissues in the body. Numerous pieces of evidence have accumulated showing that leptin potentially plays an important role in the control of the reproductive function.This review presents the major concepts for the role of leptin in the modulation of reproductive function. As a marker of the nutritional status, leptin affects the hypothalamo-pituitary-gonadal axis, regulating gonadotrophin-releasing hormone and luteinising hormone secretion, and appears to be a permissive factor in the onset of the puberty. This protein and its receptor have been found in the reprodu…
Paracrine dialogue in implantation
2002
We know that the implantation process requires a functionally normal embryo at the blastocyst stage and a receptive endometrium, but also a communication link between them is needed. This paracrine dialogue between the embryo, endometrium and the corpus luteum are known to occur in ruminants and primates, more specifically endometrial-embryonic interactions have been reported in rodents and primates but not in humans. This process is a highly regulated mechanism and many molecules take part in this cross-talk. Here, we present updated information in humans on the embryonic regulation of endometrial epithelial molecules such as chemokines, adhesion and anti-adhesion molecules, and leptin dur…
Mating Increases Neuronal Tyrosine Hydroxylase Expression and Selectively Gates Transmission of Male Chemosensory Information in Female Mice
2013
Exposure to chemosensory signals from unfamiliar males can terminate pregnancy in recently mated female mice. The number of tyrosine hydroxylase-positive neurons in the main olfactory bulb has been found to increase following mating and has been implicated in preventing male-induced pregnancy block during the post-implantation period. In contrast, pre-implantation pregnancy block is mediated by the vomeronasal system, and is thought to be prevented by selective inhibition of the mate's pregnancy blocking chemosignals, at the level of the accessory olfactory bulb. The objectives of this study were firstly to identify the level of the vomeronasal pathway at which selective inhibition of the m…
Determinants of endometrial receptivity.
2005
Understanding the molecular changes that occur during the window of implantation is fundamental to our knowledge of human reproduction. Lately, the development of microarray technology has allowed this process to be studied from a global molecular perspective. In the last 2 years, researchers have focused their efforts on throwing light on the gene expression profile of the receptive endometrium. The genes hold the key to the development of the endometrium at any stage, and we have focused our work on the window of implantation. The four most recently published works in this field have revealed a long list of genes that are up- or downregulated at the time of implantation. Although these st…
Mir-661: A key Factor in Embryo-Maternal dialog With Potential Clinical Application to Predict Implantation Outcome?
2015
Implantation resulting in a full-term pregnancy is, by large, more than a passive process in which the developed conceptus is passively glued to the uterus through adhesive molecules. It is the result of a perfectly orchestrated dialog between a viable embryo and a receptive endometrium, through a mixture of paracrine and juxtacrine processes in which many key proteins and growth factors play fundamental roles (Pellicer et al., 2002.) Since their discovery, microRNAs have become prominent regulatory candidates, providing missing links for a few biological pathways in this process, although their exact role in human normal embryo formation and endometrial preparation for pregnancy remains un…
Unpredicted ovulations and conceptions during early pregnancy: an explanatory mechanism of human superfetation
2012
In this bioessay, a literature review on human superfetation was performed in order to find epidemiological variables associated with this phenomenon. Thereafter, an explanatory mechanism of superfetation compatible with the endocrinological, histological and physiological changes undergone by women during early pregnancy is proposed. Superfetation can be defined as the ovulation, fertilisation and implantation of a second or additional embryo(s) during pregnancy. The literature review evidences a small discordance in gestational age between dizygotic twins in humans (range: 2–4 weeks; mean ± s.e.m.: 3.3 ± 0.3 weeks). This difference is compatible with a luteal out-of-phase (LOOP; i.e. atyp…
MicroRNA-30d deficiency during preconception affects endometrial receptivity by decreasing implantation rates and impairing fetal growth.
2019
Background Maternal–embryonic crosstalk between the endometrium and the preimplantation embryo is required for normal pregnancy. Our previous results demonstrated that maternal microRNAs secreted into the endometrial fluid, specifically miR-30d, act as a transcriptomic regulator of the preimplantation embryo by the maternal intrauterine environment. Objective To investigate the reproductive and fetal effects of murine miR-30d deficiency at the maternal–embryonic interface according to the origin of its maternal or embryonic default. Study Design A miR-30d knockout murine model was used as the animal model to investigate the impact of maternal and/or embryonic origin of miR-30d deficiency on…
The human first cell cycle: impact on implantation.
2013
The morphology of fertilization events has been related to successful implantation by subjective criteria (pronuclei score, pronuclei symmetry and position). This work first described these events by time-lapse technology and then compared the timings of fertilization events (second polar body extrusion, first and second pronuclei appearance, abuttal and fading) in implanted versus nonimplanted embryos in a 2-year cohort retrospective study. A total of 1448 transferred embryos from 842 patients undergoing intracytoplasmic sperm injection with oocyte donation were monitored, 212 embryos from treatments where the number of gestational sacs matched the number of transferred embryos and 687 emb…
Proteomic analysis of extracellular vesicles secreted by primary human epithelial endometrial cells reveals key proteins related to embryo implantati…
2022
Abstract Background Successful implantation is dependent on coordination between maternal endometrium and embryo, and the role of EVs in the required cross-talk cell-to-cell has been recently established. In this regard, it has been reported that EVs secreted by the maternal endometrium can be internalized by human trophoblastic cells transferring their contents and enhancing their adhesive and invasive capacity. This is the first study to comprehensively evaluate three EV isolation methods on human endometrial epithelial cells in culture and to describe the proteomic content of EVs secreted by pHEECs from fertile women. Methods Ishikawa cells and pHEECs were in vitro cultured and hormonall…
Proprotein convertase 5/6 is critical for embryo implantation in women: regulating receptivity by cleaving ebp50, modulating ezrin binding, and membr…
2011
Establishment of endometrial receptivity is vital for successful embryo implantation; its failure causes infertility. Epithelial receptivity acquisition involves dramatic structural changes in the plasma membrane and cytoskeleton. Proprotein convertase 5/6 (PC6), a serine protease of the proprotein convertase (PC) family, is up-regulated in the human endometrium specifically at the time of epithelial receptivity and stromal cell decidualization. PC6 is the only PC member tightly regulated in this manner. The current study addressed the importance and mechanisms of PC6 action in regulating receptivity in women. PC6 was dysregulated in the endometrial epithelium during the window of implantat…