257. Activation of a calcium-activated chloride channel by paf is required for normal preimplantation mouse embryo development in vitro

2008 ◽  
Vol 20 (9) ◽  
pp. 57
Author(s):  
Y. Li ◽  
M. L. Day ◽  
C. O.'Neill
Keyword(s):  
Embryo Development ◽  
Mouse Embryo ◽  
Preimplantation Embryo ◽  
Platelet Activating Factor ◽  
Outward Current ◽  
Normal Embryo ◽  
Cell Stage ◽  
Preimplantation Embryo Development ◽  
Cl Channel

Platelet activating factor (paf) is an autocrine survival factor for preimplantation embryo. Binding of paf to its receptor activates PI3kinase, causing an IP3-dependent release of Ca2+ from intracellular stores as well as activation of Ca2+ influx via a dihydropyridine-sensitive Ca2+ channel. These actions result in the generation of a defined intracellular calcium ([Ca2+]i) transient in the 2-cell embryo[1]. By using combined whole-cell patch-clamp and real-time [Ca2+]i analyses, we have shown that paf also induces a concomitant hyperpolarisation of the membrane potential in 2-cell embryos, accompanied by an increased net outward ion current. Both the membrane hyperpolarisation and outward current were dependent upon the occurrence of the paf-induced [Ca2+]i transient[2]. The aim of this study was to investigate the characteristics of the paf-induced outward current in 2-cell embryos and to assess whether it has a role in normal mouse preimplantation development. We show that: (1) removal of extracellular anions or treatment with niflumic acid (NFA, 100 μM, a Ca2+-activated Cl- channel blocker) prevented activation of the outward current by paf but had no effect on the paf-induced [Ca2+]i transient; and (2) The culture of embryos with NFA (100 μM) from the 1-cell to late 2-cell stage significantly reduced their development to the blastocyst stage (P < 0.001), but treatment with NFA from the late 2-cell stage had no effect on development. The results show that paf induces an increase in [Ca2+]i which in turn activates a Ca2+-activated Cl- channel. The activity of this NFA-sensitive channel during the zygote to 2-cell stage is required for normal embryo development. (1) C. O’Neill (2008) The potential roles of embryotrophic ligands in preimplantation embryo development. Hum Reprod Update 14:275–288. (2) Y. Li, M.L. Day & C. O’Neill (2007) Autocrine activation of ions currents in the two-cell mouse embryo. Exp Cell Res. 313:2785–2794.

scholarly journals l-Carnitine affects preimplantation embryo development toward infertility in mice

Reproduction ◽  
2016 ◽  
Vol 152 (4) ◽  
pp. 283-291 ◽  
Author(s):  
Christiana Kyvelidou ◽  
Dimitris Sotiriou ◽  
Tania Antonopoulou ◽  
Margarita Tsagkaraki ◽  
George J Tserevelakis ◽  
...  
Keyword(s):  
Embryo Development ◽  
Preimplantation Embryo ◽  
Day Treatment ◽  
Intraperitoneal Administration ◽  
Blastocyst Development ◽  
Cell Stage ◽  
Preimplantation Embryo Development ◽  
Early Stages

l-Carnitine (l-Cn), despite the beneficial role as energy-generating substance delivering long-chain fatty acids to the β-oxidation pathway in mitochondria, has been accused to cause an endometriosis-like state to BALB/c mice manifested by increased inflammatory cytokines in serum and peritoneal fluid, accumulation of immune cells in the peritoneal cavity and uterine walls and most importantly, correlating to infertility. Exploring this type of infertility, the effect of l-Cn on preimplantation embryo development, ovarian integrity and systemic maternal immunity was studied. Using nonlinear microscopy analysis, which was shown to be a powerful tool for determining embryo quality by quantitatively estimating the lipid body (LB) content of the cells, it was shown that in vitro and in vivo administration of l-Cn significantly decreased LB mean area in zygotes. Daily intraperitoneal administration of 2.5mg l-Cn for 3, 4 and 7days to mice significantly decreased the percent of normal zygotes. However, only the 7-day treatment persisted by affecting 2- and 8-cell stage embryos, while almost abolishing blastocyst development. Such effects were accompanied by abnormal ovarian histology, showing increased numbers of corpora luteus and elevated progesterone concentration in the serum. In addition, it was shown that the 7-day l-Cn treatment pushed maternal systemic immunity toward inflammation and immunosuppression by increasing CD11b-, CD25- and CD11bGr1-positive cells in spleen, which opposed the necessity for immunostimulation at these early stages of pregnancy. In conclusion, the results presented here demonstrated that elevated doses of l-Cn affect early stages of embryo development, leading to infertility.

The effect of perfluorohexanesulfonate (PFHxS) on bovine preimplantation embryo development in vitro

2021 ◽  
Vol 350 ◽  
pp. S169-S170
Author(s):  
I. Hallberg ◽  
M. Moberg ◽  
M. Olovsson ◽  
P. Damdimopoulou ◽  
J. Rüegg ◽  
...  
Keyword(s):  
Embryo Development ◽  
Preimplantation Embryo ◽  
Preimplantation Embryo Development ◽  
Development In Vitro

Mycotoxin effects on in vitro preimplantation embryo development

1994 ◽  
Vol 11 (3) ◽  
pp. 172-175 ◽  
Author(s):  
Peter C. Svalander ◽  
Matts Olovsson ◽  
Paul V. Holmes
Keyword(s):  
Embryo Development ◽  
Preimplantation Embryo ◽  
Preimplantation Embryo Development

Leptin enhances porcine preimplantation embryo development in vitro

2005 ◽  
Vol 229 (1-2) ◽  
pp. 141-147 ◽  
Author(s):  
Jesse A. Craig ◽  
Hai Zhu ◽  
Paul W. Dyce ◽  
Lihua Wen ◽  
Julang Li
Keyword(s):  
Embryo Development ◽  
Preimplantation Embryo ◽  
Preimplantation Embryo Development ◽  
Development In Vitro

scholarly journals Mitochondria and human preimplantation embryo development

Reproduction ◽  
2009 ◽  
Vol 137 (4) ◽  
pp. 619-624 ◽  
Author(s):  
Martin Wilding ◽  
Gianfranco Coppola ◽  
Brian Dale ◽  
Loredana Di Matteo
Keyword(s):  
Embryo Development ◽  
Preimplantation Embryo ◽  
Anaerobic Respiration ◽  
Mitochondrial Metabolism ◽  
Human Reproduction ◽  
Aerobic Respiration ◽  
Human Embryos ◽  
Developmental Potential ◽  
Preimplantation Embryo Development

Human reproduction, like all biological systems, is characterised by a large level of variability. In this field, the variability is observed as a large difference in implantation potential of human embryos developing in vitro, despite similarities in observable parameters such as rate of development and morphology of these embryos. One of the underlying factors that determines developmental potential in these embryos is the availability of energy in the form of ATP for development. Here, we suggest that, despite the evidence suggesting that mitochondrial metabolism is relatively inactive during preimplantation embryo development, aerobic (mitochondrial) metabolism contributes a major role in the supply of ATP. A second pathway, anaerobic respiration, is also active and the two pathways work in synchrony to supply all the ATP necessary. We discuss the differences in the two forms of energy production and suggest that, although anaerobic respiration can supplement deficiencies in the energy supply in the short term, this is not sufficient to substitute for aerobic respiration over long periods. Therefore, we suggest that deficiencies in the levels of aerobic respiration can explain variability in the implantation potential of apparently equivalent embryos.

60 TELOMERE LENGTH DYNAMICS DURING BOVINE PREIMPLANTATION EMBRYO DEVELOPMENT

2012 ◽  
Vol 24 (1) ◽  
pp. 142
Author(s):  
C. de Frutos ◽  
P. Bermejo-Alvarez ◽  
D. Rizos ◽  
A. Gutierrez-Adan
Keyword(s):  
Developmental Stage ◽  
Telomere Length ◽  
Embryo Development ◽  
Relative Abundance ◽  
Preimplantation Embryo ◽  
Telomerase Activity ◽  
Alternative Mechanism ◽  
Cell Stage ◽  
Preimplantation Embryo Development ◽  
Early Embryos

The establishment of telomere length (TL) during embryogenesis determines telomere reserves in newborn mammals. However, limited information is available on TL dynamics during preimplantation in contrast to the extensive existing data on telomerase activity in germ cells and embryogenesis. Telomerase activity is high in the male germ line, low or absent in oocytes and early stage embryos and high in blastocysts (Bl). Mechanisms allowing early embryos to reset TL remain poorly understood. The documented telomere lengthening at the morula/Bl transition in mice and bovines is dependent on telomerase activity. A recombinant-based mechanism termed alternative lengthening of telomeres (ALT) has been postulated to be responsible for the lengthening of telomeres in early embryos. The aims of the present study were to analyse the telomere dynamics during preimplantation embryo development in 2 species of known different TL: mice and bovines and the relative expression of 2 components of telomerase [telomerase reverse transcriptase (Tert; the key factor that controls the activity of the telomerase) and telomerase RNA component (Terc)]. Twenty samples for each developmental stage with an equivalent number of cells (matured oocytes/zygotes: 8 and 32; 2-cell embryos: 4 and 16; 4-cell embryos: 2 and 8; 8-cell embryos: 1 and 4; 16-cell embryos: 2 only for bovine; morulae: 1 and 1; and Bl: 1 and 1 for mice and bovines, respectively) were analysed for relative TL measurement using the real-time quantitative PCR method described previously (Bermejo-Alvarez et al. 2008 Physiol. Genomics 32, 264272). For measuring the mRNA, 3 groups of 10 oocytes/embryos for each developmental stage were used. Data were analysed by 1-way ANOVA. In mice, matured oocytes had the shortest telomeres of all stages examined (P < 0.01); a slight increase up to the 4-cell stage and a decrease at the 8-cell and morula stages was noted (P < 0.05), while a marked increase was observed in Bl, as expected (P < 0.01). In contrast, bovine matured oocytes had longer telomeres than zygotes and this length gradually decreased up to the 4-cell stage and increased again at the 16-cell stage (P < 0.05). Then, telomeres shortened at the morula stage (P < 0.05) and a significant increase was observed at the Bl stage like in mice (P < 0.01). The relative abundance of mTerc increased throughout development with a marked up-regulation at the morula and Bl stages (P < 0.01). On the other hand, the relative abundance of mTert was significantly higher in the mature oocytes and zygotes compared to later stages (P < 0.01); however, it should be noted that there was a gradual increase from the 2-cell stage up to Bl. In conclusion, in contrast to mice, bovine oocytes have longer telomeres than zygotes. Knowing that the telomerase activity is low or absent until the Bl stage (indicated by the low expression of Tert), the TL increase detected in 16-cell bovine embryos indicates an alternative mechanism for telomere elongation during early development, like that observed in mice. Understanding how telomeres reset during early embryo development has implications for the study of stem cells and regenerative biology.

scholarly journals Deadly decisions: the role of genes regulating programmed cell death in human preimplantation embryo development

Reproduction ◽  
2004 ◽  
Vol 128 (3) ◽  
pp. 281-291 ◽  
Author(s):  
Andrea Jurisicova ◽  
Beth M Acton
Keyword(s):  
Gene Expression ◽  
Cell Death ◽  
Cell Fate ◽  
Embryo Development ◽  
Preimplantation Embryo ◽  
Culture Media ◽  
Culture Conditions ◽  
Early Embryo ◽  
Preimplantation Embryo Development

Human preimplantation embryo development is prone to high rates of early embryo wastage, particularly under currentin vitroculture conditions. There are many possible underlying causes for embryo demise, including DNA damage, poor embryo metabolism and the effect of suboptimal culture media, all of which could result in an imbalance in gene expression and the failed execution of basic embryonic decisions. In view of the complex interactions involved in embryo development, a thorough understanding of these parameters is essential to improving embryo quality. An increasing body of evidence indicates that cell fate (i.e. survival/differentiation or death) is determined by the outcome of specific intracellular interactions between pro- and anti-apoptotic proteins, many of which are expressed during oocyte and preimplantation embryo development. The recent availability of mutant mice lacking expression of various genes involved in the regulation of cell survival has enabled rapid progress towards identifying those molecules that are functionally important for normal oocyte and preimplantation embryo development. In this review we will discuss the current understanding of the regulation of cell death gene expression during preimplantation embryo development, with a focus on human embryology and a discussion of animal models where appropriate.

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