219 research outputs found
Endometrial stromal cells of women with recurrent miscarriage fail to discriminate between high- and low-quality human embryos
Background
The aetiology of recurrent miscarriage (RM) remains largely unexplained. Women with RM have a shorter time to pregnancy interval than normally fertile women, which may be due to more frequent implantation of non-viable embryos. We hypothesized that human endometrial stromal cells (H-EnSCs) of women with RM discriminate less effectively between high-and low-quality human embryos and migrate more readily towards trophoblast spheroids than H-EnSCs of normally fertile women.
Methodology/Principal Findings
Monolayers of decidualized H-EnSCs were generated from endometrial biopsies of 6 women with RM and 6 fertile controls. Cell-free migration zones were created and the effect of the presence of a high-quality (day 5 blastocyst, n = 13), a low-quality (day 5 blastocyst with three pronuclei or underdeveloped embryo, n = 12) or AC-1M88 trophoblast cell line spheroid on H-ESC migratory activity was analyzed after 18 hours. In the absence of a spheroid or embryo, migration of H-EnSCs from fertile or RM women was similar. In the presence of a low-quality embryo in the zone, the migration of H-EnSCs of control women was inhibited compared to the basal migration in the absence of an embryo (P<0.05) and compared to the migration in the presence of high-quality embryo (p<0.01). Interestingly, the migratory response H-EnSCs of women with RM did not differ between high- and low-quality embryos. Furthermore, in the presence of a spheroid their migration was enhanced compared to the H-EnSCs of controls (p<0.001).
Conclusions
H-EnSCs of fertile women discriminate between high- and low-quality embryos whereas H-EnSCs of women with RM fail to do so. H-EnSCs of RM women have a higher migratory response to trophoblast spheroids. Future studies will focus on the mechanisms by which low-quality embryos inhibit the migration of H-EnSCs and how this is deregulated in women with RM
Uterine selection of human embryos at implantation
Human embryos frequently harbor large-scale complex chromosomal errors that impede normal development. Affected embryos may fail to implant although many first breach the endometrial epithelium and embed in the decidualizing stroma before being rejected via mechanisms that are poorly understood. Here we show that developmentally impaired human embryos elicit an endoplasmic stress response in human decidual cells. A stress response was also evident upon in vivo exposure of mouse uteri to culture medium conditioned by low-quality human embryos. By contrast, signals emanating from developmentally competent embryos activated a focused gene network enriched in metabolic enzymes and implantation factors. We further show that trypsin, a serine protease released by pre-implantation embryos, elicits Ca2+ signaling in endometrial epithelial cells. Competent human embryos triggered short-lived oscillatory Ca2+ fluxes whereas low-quality embryos caused a heightened and prolonged Ca2+ response. Thus, distinct positive and negative mechanisms contribute to active selection of human embryos at implantation
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"Her bun in my oven": Motivations and experiences of two-mother families who have used reciprocal IVF
Objectives
What motivates same-gender female couples to choose reciprocal in vitro fertilization (IVF)? Do their experiences of becoming and being a mother via reciprocal IVF match their pre-parenthood expectations?
Background
Reciprocal IVF is a treatment route available to cis, same-gender female couples, and other couples in which both partners have a uterus and egg stores. One partner's egg is retrieved, fertilized in vitro with donor sperm, then carried by the other partner. Existing debate has considered the ethical implications of this treatment route. To date, no empirical research has explored the experiences of families who have used reciprocal IVF.
Method
Semistructured interviews were conducted with genetic and gestational mothers in 14 families headed by cis, same gender female couples who had conceived by reciprocal IVF in the United Kingdom (N = 28 mothers). Data were analyzed according to the principles of reflexive thematic analysis.
Results
Four themes were constructed: (a) becoming mums together; (b) legitimacy: “who's the real mum”; (c) choices and constraints; and (d) biological connections strengthen family connections.
Conclusion
Families had multiple and nuanced motivations for choosing reciprocal IVF, such as the desire to share the journey of motherhood with their partner, to be perceived as legitimate parents, to overcome practical barriers, and to build strong family relationships. Mothers' pre-parenthood expectations often mismatched the reality of becoming and being a mother via reciprocal IVF. Most parents found that the significance of reciprocal IVF diminished as their children grew up.
Implications
Findings demonstrate that reciprocal IVF offers a fulfilling route to parenthood. Parents should have access to routes to parenthood that meet their reproductive needs and feel right for them as a couple
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Double vitrification and warming of blastocysts does not affect IVF implantation rates, or birth outcomes
Research question: Does double blastocyst vitrification and warming affect pregnancy rates from embryos subjected to PGT-A testing?
Design: This is a retrospective observational analysis of embryo transfers performed at a single Centre between January 2017 and August 2022. The double vitrification (DV) group included frozen blastocysts that were vitrified after 5-7 days of culture, warmed, biopsied (either once or twice) and re-vitrified. The single vitrification (SV) group included fresh blastocysts that were biopsied at 5-7 days, and then vitrified.
Results: Comparison of the 84 DV blastocysts and 729 control SV blastocysts indicated that the DV embryos were frozen later in development and had expanded more than the SV embryos. Of the 813 embryo transfer procedures reported in this study, 452 resulted in the successful delivery of healthy infants (56%). There were however no significant differences between DV and SV embryos in the pregnancy rates achieved after single embryo transfer (55% vs 56%). Logistic regression indicated that while reduced pregnancy rates were associated with increasing maternal age at oocyte collection and at embryo transfer, and with longer culture prior to freezing, DV was not a significant predictor of outcome.
Conclusions: Blastocyst DV was not shown to impact pregnancy rates. While caution is necessary due to the study size, no effects of DV on miscarriage rates, birth weight or gestation period were noted. These data offer reassurance given the absence of influence of DV on pregnancy rates after PGT-A
Transfer of thawed frozen embryo versus fresh embryo to improve the healthy baby rate in women undergoing IVF : the E-Freeze RCT
Peer reviewedPublisher PD
Cell Lineage Specific Distribution of H3K27 Trimethylation Accumulation in an In Vitro Model for Human Implantation
Female mammals inactivate one of their two X-chromosomes to compensate for the difference in gene-dosage with males that have just one X-chromosome. X-chromosome inactivation is initiated by the expression of the non-coding RNA Xist, which coats the X-chromosome in cis and triggers gene silencing. In early mouse development the paternal X-chromosome is initially inactivated in all cells of cleavage stage embryos (imprinted X-inactivation) followed by reactivation of the inactivated paternal X-chromosome exclusively in the epiblast precursors of blastocysts, resulting temporarily in the presence of two active X-chromosomes in this specific lineage. Shortly thereafter, epiblast cells randomly inactivate either the maternal or the paternal X-chromosome. XCI is accompanied by the accumulation of histone 3 lysine 27 trimethylation (H3K27me3) marks on the condensed X-chromosome. It is still poorly understood how XCI is regulated during early human development. Here we have investigated lineage development and the distribution of H3K27me3 foci in human embryos derived from an in-vitro model for human implantation. In this system, embryos are co-cultured on decidualized endometrial stromal cells up to day 8, which allows the culture period to be extended for an additional two days. We demonstrate that after the co-culture period, the inner cell masses have relatively high cell numbers and that the GATA4-positive hypoblast lineage and OCT4-positive epiblast cell lineage in these embryos have segregated. H3K27me3 foci were observed in ∼25% of the trophectoderm cells and in ∼7.5% of the hypoblast cells, but not in epiblast cells. In contrast with day 8 embryos derived from the co-cultures, foci of H3K27me3 were not observed in embryos at day 5 of development derived from regular IVF-cultures. These findings indicate that the dynamics of H3K27me3 accumulation on the X-chromosome in human development is regulated in a lineage specific fashion
Male Microchimerism at High Levels in Peripheral Blood Mononuclear Cells from Women with End Stage Renal Disease before Kidney Transplantation
Patients with end stage renal diseases (ESRD) are generally tested for donor chimerism after kidney transplantation for tolerance mechanism purposes. But, to our knowledge, no data are available on natural and/or iatrogenic microchimerism (Mc), deriving from pregnancy and/or blood transfusion, acquired prior to transplantation. In this context, we tested the prevalence of male Mc using a real time PCR assay for DYS14, a Y-chromosome specific sequence, in peripheral blood mononuclear cells (PBMC) from 55 women with ESRD, prior to their first kidney transplantation, and compared them with results from 82 healthy women. Male Mc was also quantified in 5 native kidney biopsies obtained two to four years prior to blood testing and in PBMC from 8 women collected after female kidney transplantation, several years after the initial blood testing. Women with ESRD showed statistically higher frequencies (62%) and quantities (98 genome equivalent cells per million of host cells, gEq/M) of male Mc in their PBMC than healthy women (16% and 0.3 gEq/M, p<0.00001 and p = 0.0005 respectively). Male Mc was increased in women with ESRD whether they had or not a history of male pregnancy and/or of blood transfusion. Three out of five renal biopsies obtained a few years prior to the blood test also contained Mc, but no correlation could be established between earlier Mc in a kidney and later presence in PBMC. Finally, several years after female kidney transplantation, male Mc was totally cleared from PBMC in all women tested but one. This intriguing and striking initial result of natural and iatrogenic male Mc persistence in peripheral blood from women with ESRD raises several hypotheses for the possible role of these cells in renal diseases. Further studies are needed to elucidate mechanisms of recruitment and persistence of Mc in women with ESRD
Human predecidual stromal cells are mesenchymal stromal/stem cells and have a therapeutic effect in an immune-based mouse model of recurrent spontaneous abortion
Human decidual stromal cells (DSCs) are involved in the maintenance and development of
pregnancy, in which they play a key role in the induction of immunological maternal–fetal tolerance. Precursors of
DSCs (preDSCs) are located around the vessels, and based on their antigen phenotype, previous studies suggested
a relationship between preDSCs and mesenchymal stromal/stem cells (MSCs). This work aimed to further elucidate
the MSC characteristics of preDSCs. Under the effect of P4 and cAMP, the preDSC lines and clones decidualized in vitro: the cells became rounder
and secreted PRL, a marker of physiological decidualization. PreDSC lines and clones also exhibited MSC characteristics.
They differentiated into adipocytes, osteoblasts, and chondrocytes, and preDSC lines expressed stem cell markers OCT-
4, NANOG, and ABCG2; exhibited a cloning efficiency of 4 to 15%; significantly reduced the embryo resorption rate
(P < 0.001) in the mouse model of abortion; and survived for prolonged periods in immunocompetent mice. The fact
that 3 preDSC clones underwent both decidualization and mesenchymal differentiation shows that the same type of
cell exhibited both DSC and MSC characteristics. Together, our results confirm that preDSCs are decidual MSCs and suggest that these cells are involved
in the mechanisms of maternal–fetal immune toleranceThis work was supported by the Plan Estatal de Investigación Científica y
Técnica y de Innovación 2013–2016, ISCIII-Subdirección General de Evaluación y
Fomento de la Investigación, the Ministerio de Economía y Competitividad,
Spain (Grant PI16/01642) and European Regional Development Fund (ERDF/
FEDER funding), the European Community, and the Cátedra de Investigación
Anto nio Chamorro–Alejandro Otero, Universidad de Granada (CACH2017-1)
Efeito do alumínio sobre a absorção, o acúmulo e o fracionamento do fósforo em sorgo
O trabalho teve como objetivo estudar o efeito do Al sobre a absorção, o acúmulo e o fracionamento do P em duas cultivares de sorgo. As plantas foram expostas a níveis tóxicos de Al durante dez dias e, então, colhidas e determinados o crescimento em tamanho e produção de massa seca, os teores de Al e de P total e as diversas formas de P nas duas partes das plantas. Avaliou-se, também, o efeito do Al sobre a absorção de P pelas raízes de plantas intactas. O Al reduziu o crescimento da raiz seminal e a produção de matéria seca de raízes e parte aérea nas duas cultivares, especialmente na sensível. Os teores de Al e de P total aumentaram nas raízes, mas não foram modificados na parte aérea nas duas cultivares. A absorção de P, entretanto, decresceu na presença de Al nas duas cultivares, principalmente na sensível. O Al, de modo geral, modificou as concentrações das várias formas de P solúvel (Pi e Porg) e insolúvel (P RNA e Presidual), exceto a da forma P LIP. Algumas dessas modificações parecem ser importantes e podem estar relacionadas com o mecanismo de tolerância ao Al em sorgo.The objective of this work was to evaluate Al effect on uptake, accumulation and fractionation of P in two sorghum cultivars. Plants were treated with toxic levels of Al during ten days and then they were harvested and growth, dry matter yield, Al and total P contents and concentrations of the various P forms in the two parts of the plants were determined. Aluminum effect on P uptake was also evaluated in intact plants. Aluminum reduced the growth of the seminal root and dry matter yield in roots and tops of both cultivars, especially in the sensitive one. Aluminum and P contents increased in roots but did not change in the top of both cultivars. Phosphate uptake by roots, however, decreased in the presence of Al in both cultivars, especially in the sensitive one. Aluminum, in general, changed concentrations of all soluble (Pi e Porg) and insoluble P forms (P RNA e Presidual), except of the P LIP form. Some of these modifications seem to be important and may be related to Al tolerance mechanism in sorghum
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