427. MDM2 maintains the latency of expression of TRP53 in the mouse preimplantation embryo

2008 ◽  
Vol 20 (9) ◽  
pp. 107
Author(s):  
X. Jin ◽  
V. Chandrakanthan ◽  
C. O.'Neill
Keyword(s):  
Preimplantation Embryo ◽  
Preimplantation Development ◽  
Signalling Pathway ◽  
Preimplantation Embryos ◽  
Normal Embryo ◽  
Embryo Viability ◽  
Preimplantation Embryo Development ◽  
Zygote Development ◽  
Dependent Inhibition

TRP53 is a tumour suppressor that causes cell-cycle arrest or cell death in response to a range of stressors. Normal preimplantation embryo development requires that TRP53 is maintained in a labile state1. Culture of mouse C57BL6 preimplantation embryos causes this latency to be breached and this is a cause of the low embryo viability following culture. MDM2 is an ubiquitin ligase that targets TRP53 for degradation by the proteosome. MDM2 is activated by Serine 166 phosphorylation (pMDM2). This is commonly catalysed by the phosphatidylinositol-3 kinase (PI3K) and AKT signalling pathway. A range of embryotrophins activate the PI3K and AKT pathway. This study tested the hypothesis that TRP53 is maintained in a latent state in the normal embryo by the activation of MDM2 by the actions of embryotrophins via a PI3K and AKT signalling pathway. Genetic deletion of Mdm2 prevents normal preimplantation development in a Trp53 dependent manner2. Addition of an MDM2 inhibitor (Nutlin-3) to culture medium caused a dose-dependent inhibition of zygote development (P < 0.001) that did not occur in Trp53−/−embryos. Immunofluorescence and western blot analysis detected pMDM2 throughout mouse preimplantation development. Zygote culture reduced the levels of pMDM2 formation. Furthermore, blocking the actions of Paf, PI3K or AKT in vitro reduced in the expression of pMDM2, and also resulted in higher levels of TRP53 expression in embryos. The embryopathy resulting from increased TRP53 could be partially ameliorated by the addition of the TRP53 antagonist α-pifithrin to media (P < 0.05). The results show MDM2 was activated by an embryotrophin (Paf), PI3K and AKT signalling pathway and was required for the latency of TRP53 expression in the preimplantation embryos. (1) Li A, Chandrakanthan V, Chami O, O’Neill C. (2007) Biology of Reproduction 76: 362–367. (2) Montes de Oca Luna R, Wagner DS, Lozano G. (1995) Nature 378: 203–205.

scholarly journals Intracellular oxygen metabolism during bovine oocyte and preimplantation embryo development

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Paul J. McKeegan ◽  
Selina F. Boardman ◽  
Amy A. Wanless ◽  
Grace Boyd ◽  
Laura J. Warwick ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Oxygen Consumption ◽  
Oxygen Concentration ◽  
Embryo Development ◽  
Preimplantation Embryo ◽  
Complex Iii ◽  
Preimplantation Embryos ◽  
Mitochondrial Oxygen Consumption ◽  
Preimplantation Embryo Development

AbstractWe report a novel method to profile intrcellular oxygen concentration (icO2) during in vitro mammalian oocyte and preimplantation embryo development using a commercially available multimodal phosphorescent nanosensor (MM2). Abattoir-derived bovine oocytes and embryos were incubated with MM2 in vitro. A series of inhibitors were applied during live-cell multiphoton imaging to record changes in icO2 associated with mitochondrial processes. The uncoupler carbonyl cyanide-p-trifluoromethoxyphenylhydrazone (FCCP) uncouples mitochondrial oxygen consumption to its maximum, while antimycin inhibits complex III to ablate mitochondrial oxygen consumption. Increasing oxygen consumption was expected to reduce icO2 and decreasing oxygen consumption to increase icO2. Use of these inhibitors quantifies how much oxygen is consumed at basal in comparison to the upper and lower limits of mitochondrial function. icO2 measurements were compared to mitochondrial DNA copy number analysed by qPCR. Antimycin treatment increased icO2 for all stages tested, suggesting significant mitochondrial oxygen consumption at basal. icO2 of oocytes and preimplantation embryos were unaffected by FCCP treatment. Inner cell mass icO2 was lower than trophectoderm, perhaps reflecting limitations of diffusion. Mitochondrial DNA copy numbers were similar between stages in the range 0.9–4 × 106 copies and did not correlate with icO2. These results validate the MM2 probe as a sensitive, non-toxic probe of intracellular oxygen concentration in mammalian oocytes and preimplantation embryos.

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 Interleukin Gene Expression in Mouse Preimplantation Development

1995 ◽  
Vol 4 (3) ◽  
pp. 169-179 ◽  
Author(s):  
Nicole Gerwin ◽  
Gui-Quan Jia ◽  
Robert Kulbacki ◽  
José C. Gutierrez-Ramos
Keyword(s):  
Growth Factors ◽  
Preimplantation Embryo ◽  
Preimplantation Development ◽  
Preimplantation Embryos ◽  
Positive Staining ◽  
Polypeptide Growth Factors ◽  
Mammalian Embryogenesis ◽  
Genes Encoding ◽  
Early Phases

Control of growth and differentiation during mammalian embryogenesis is regulated by growth factors from embryonic and/or maternal sources. Cytokines are polypeptide growth factors that are released by a variety of activated immune and nonimmune cells. To identify novel members of the cytokine family that could be involved in the growth and differentiation of the preimplantation embryo, we studied the expression pattern of several genes encoding cytokines and their receptors during mouse preimplantation developmentin vitroWe found that poly(A)+mRNAs for IL-1, IL-3, IL-6, IL-7, and TNFαare differentially expressed at several stages of mouse preimplantation development, including unfertilized oocytes. Immunostaining of preimplantation embryos using monoclonal antibodies specific for several cytokines and their receptors revealed that at least some of these mRNAs are translated into mature proteins during preimplantation development (IL-1, IL-6, and TNFα). Positive staining for IL-1 and IL-6 receptors was also detected at these stages of development. The controlled expression of these “inflammatory-type” cytokines and their receptors suggests a role for these growth factors during the early phases of mouse ontogeny.

Preimplantation development in the streptozotocin-induced diabetic mouse

1990 ◽  
Vol 2 (4) ◽  
pp. 407 ◽  
Author(s):  
LF Beebe ◽  
PL Kaye
Keyword(s):  
Mouse Model ◽  
Plasma Glucose ◽  
Preimplantation Embryo ◽  
Diabetic Mouse ◽  
Preimplantation Development ◽  
Preimplantation Embryos ◽  
Diabetic Mice

Streptozotocin (STZ) was used to develop a diabetic mouse model in which to study the development of the preimplantation embryo. STZ doses of 0, 160, 190, 210 and 240 mg kg-1 were given; 190 mg kg-1 was found to be the most suitable as the standard diabetogenic dose, providing about 60% mice with plasma glucose greater than 20 mM. The STZ-diabetic mice responded to superovulation with 10 i.u. of gonadotrophin in the same manner as control mice, producing similar embryo numbers at 48 h, 72 h and 96 h post-hCG. Furthermore, the proportion of 2-cell embryos collected from STZ-diabetic mice which developed to blastocysts in vitro was similar to that of 2-cell embryos from control mice. The STZ-diabetic mouse model after superovulation thus produced normal early preimplantation embryos whose development can be examined in detail in a diabetic environment.

Hemoglobin: potential roles in the oocyte and early embryo†

2019 ◽  
Vol 101 (2) ◽  
pp. 262-270 ◽  
Author(s):  
Megan Lim ◽  
Hannah M Brown ◽  
Karen L Kind ◽  
Jeremy G Thompson ◽  
Kylie R Dunning
Keyword(s):  
Embryo Development ◽  
Oocyte Maturation ◽  
Preimplantation Embryo ◽  
Cell Types ◽  
Cellular Function ◽  
Preimplantation Embryos ◽  
Low Oxygen ◽  
Preimplantation Embryo Development ◽  
Regulated Gene Expression

Abstract Hemoglobin (Hb) is commonly known for its capacity to bind and transport oxygen and carbon dioxide in erythroid cells. However, it plays additional roles in cellular function and health due to its capacity to bind other gases including nitric oxide. Further, Hb acts as a potent antioxidant, quenching reactive oxygen species. Despite its potential roles in cellular function, the preponderance of Hb research remains focused on its role in oxygen regulation. There is increasing evidence that Hb expression is more ubiquitous than previously thought, with Hb and its variants found in a myriad of cell types ranging from macrophages to spermatozoa. The majority of nonerythroid cell types that express Hb are situated within hypoxic environments, suggesting Hb may play a role in hypoxia-inducible factor-regulated gene expression by controlling the level of oxygen available or as an adaptation to low oxygen providing a mechanism to store oxygen. Oocyte maturation and preimplantation embryo development occur within the low oxygen environments of the antral follicle and oviduct/uterus, respectively. Interestingly, Hb was recently found in human cumulus and granulosa cells and murine cumulus–oocyte complexes and preimplantation embryos. Here, we consolidate and analyze the research generated todate on Hb expression in nonerythroid cells with a particular focus on reproductive cell types. We outline future directions of this research to elucidate the role of Hb during oocyte maturation and preimplantation embryo development and finally, we explore the potential clinical applications and benefits of Hb supplementation during the in vitro culture of gametes and embryos.

scholarly journals Preimplantation embryo programming: transcription, epigenetics, and culture environment

Reproduction ◽  
2008 ◽  
Vol 135 (2) ◽  
pp. 141-150 ◽  
Author(s):  
Veronique Duranthon ◽  
Andrew J Watson ◽  
Patrick Lonergan
Keyword(s):  
Gene Expression ◽  
Embryo Culture ◽  
Nuclear Transfer ◽  
Preimplantation Embryo ◽  
Later Life ◽  
Short Review ◽  
Basic Program ◽  
Preimplantation Development ◽  
Preimplantation Embryos ◽  
Negative Consequences

Preimplantation development directs the formation of an implantation- or attachment-competent embryo so that metabolic interactions with the uterus can occur, pregnancy can be initiated, and fetal development can be sustained. The preimplantation embryo exhibits a form of autonomous development fueled by products provided by the oocyte and also from activation of the embryo's genome. Despite this autonomy, the preimplantation embryo is highly influenced by factors in the external environment and in extreme situations, such as those presented by embryo culture or nuclear transfer, the ability of the embryo to adapt to the changing environmental conditions or chromatin to become reprogrammed can exceed its own adaptive capacity, resulting in aberrant embryonic development. Nuclear transfer or embryo culture-induced influences not only affect implantation and establishment of pregnancy but also can extend to fetal and postnatal development and affect susceptibility to disease in later life. It is therefore critical to define the basic program controlling preimplantation development, and also to utilize nuclear transfer and embryo culture models so that we may design healthier environments for preimplantation embryos to thrive in and also minimize the potential for negative consequences during pregnancy and post-gestational life. In addition, it is necessary to couple gene expression analysis with the investigation of gene function so that effects on gene expression can be fully understood. The purpose of this short review is to highlight our knowledge of the mechanisms controlling preimplantation development and report how those mechanisms may be influenced by nuclear transfer and embryo culture.

scholarly journals Inhibition of DRP1 Impedes Zygotic Genome Activation and Preimplantation Development in Mice

2021 ◽  
Vol 9 ◽  
Author(s):  
Yuanyuan Li ◽  
Ning-Hua Mei ◽  
Gui-Ping Cheng ◽  
Jing Yang ◽  
Li-Quan Zhou
Keyword(s):  
Embryo Development ◽  
Preimplantation Embryo ◽  
Preimplantation Embryos ◽  
Dependent Manner ◽  
Zygotic Genome Activation ◽  
Preimplantation Embryo Development ◽  
Cell Embryo ◽  
Embryo Stage ◽  
Genome Activation ◽  
Zygotic Genome

Mitochondrion plays an indispensable role during preimplantation embryo development. Dynamic-related protein 1 (DRP1) is critical for mitochondrial fission and controls oocyte maturation. However, its role in preimplantation embryo development is still lacking. In this study, we demonstrate that inhibition of DRP1 activity by mitochondrial division inhibitor-1, a small molecule reported to specifically inhibit DRP1 activity, can cause severe developmental arrest of preimplantation embryos in a dose-dependent manner in mice. Meanwhile, DRP1 inhibition resulted in mitochondrial dysfunction including decreased mitochondrial activity, loss of mitochondrial membrane potential, reduced mitochondrial copy number and inadequate ATP by disrupting both expression and activity of DRP1 and mitochondrial complex assembly, leading to excessive ROS production, severe DNA damage and cell cycle arrest at 2-cell embryo stage. Furthermore, reduced transcriptional and translational activity and altered histone modifications in DRP1-inhibited embryos contributed to impeded zygotic genome activation, which prevented early embryos from efficient development beyond 2-cell embryo stage. These results show that DRP1 inhibition has potential cytotoxic effects on mammalian reproduction, and DRP1 inhibitor should be used with caution when it is applied to treat diseases. Additionally, this study improves our understanding of the crosstalk between mitochondrial metabolism and zygotic genome activation.

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

Effect of early ovariectomy and steroid hormone replacement of embryo transport, development and implantation in mice

1991 ◽  
Vol 3 (1) ◽  
pp. 35 ◽  
Author(s):  
A Vinijsanun ◽  
L Martin
Keyword(s):  
Embryo Development ◽  
Preimplantation Embryo ◽  
Surgical Stress ◽  
Hormone Replacement ◽  
Surgical Trauma ◽  
Embryo Viability ◽  
Preimplantation Embryo Development ◽  
Bilateral Ovariectomy ◽  
Embryo Transport ◽  
Implantation Rates

Bilateral ovariectomy on Day 1 of pregnancy increased abnormal embryo numbers on Day 4 and delayed passage of embryos to the uterus. Progestins given on Day 1 reversed these effects; given on Day 3 they reduced numbers of abnormal embryos, but did not restore normal transport. Oestrogen given alone after ovariectomy increased embryo loss, but restored preimplantation embryo development to normal when given on Day 3 after progestins on Day 1. The results suggested that both oestrogen and progesterone were necessary for normal preimplantation embryo development in vivo. However, although Day-1 progestins produced the greatest improvement in embryo transport and preimplantation development, they supported only low implantation rates compared with progestins starting on Day 3, and no progestin treatment returned implantation rates to normal. Sham ovariectomy on Day 1 also reduced implantation rate, suggesting that surgical stress of Day-1 ovariectomy had major adverse effects on embryo viability. This view was supported by experiments involving unilateral ovariectomy, which produced abnormalities in embryo transport, development and implantation, but only on the operated side. Furthermore, the major abnormality induced in embryo development by unilateral and bilateral ovariectomy, viz embryonic autolysis, was not increased in experiments in which pregnancy was blocked by non-surgical antagonism of progesterone. It is concluded that abnormalities in embryo development induced by early ovariectomy are not caused by a deficit of endogenous hormones, but result largely from effects of surgical trauma on oviduct function which can be reversed by treatment with exogenous hormones.

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