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Lowther KM, Bartolucci AF, Massey RE, Brown J, Peluso JJ. Supplementing culture medium with the weak acid, 5,5-dimethyl-2,4-oxazolidinedione (DMO) limits the development of aneuploid mouse embryos through a Trp53-dependent mechanism. J Assist Reprod Genet 2023; 40:1215-1223. [PMID: 37058262 PMCID: PMC10239418 DOI: 10.1007/s10815-023-02788-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 03/22/2023] [Indexed: 04/15/2023] Open
Abstract
PURPOSE This study was designed to determine if DMO limits in vitro development of aneuploid-enriched mouse embryos by activating a Trp53-dependent mechanism. METHODS Mouse cleavage-stage embryos were treated with reversine to induce aneuploidy or vehicle to generate controls, and then cultured in media supplemented with DMO to reduce the pH of the culture media. Embryo morphology was assessed by phase microscopy. Cell number, mitotic figures, and apoptotic bodies were revealed by staining fixed embryos with DAPI. mRNA levels of Trp53, Oct-4, and Cdx2 were monitored by quantitative polymerase chain reactions (qPCRs). The effect of Trp53 on the expression of Oct-4 and Cdx2 was assessed by depleting Trp53 using Trp53 siRNA. RESULTS Aneuploid-enriched late-stage blastocysts were morphologically indistinguishable from control blastocysts but had fewer cells and reduced mRNA levels of Oct-4 and Cdx2. Adding 1 mM DMO to the culture media during the 8-cell to blastocyst transition reduced the formation of aneuploid-enriched late-stage blastocysts but not control blastocysts and further suppressed the levels of Oct-4 and Cdx2 mRNA. Trp53 RNA levels in aneuploid-enriched embryos that were exposed to DMO were > twofold higher than controls, and Trp53 siRNA levels reduced the levels of Trp53 and increased levels of Oct-4 and Cdx2 mRNA by > twofold. CONCLUSION These studies suggest that the development of morphologically normal aneuploid-enriched mouse blastocysts can be inhibited by adding low amounts of DMO to the culture media, which results in elevated levels of Trp53 mRNA that suppresses Oct-4 and Cdx2 expression.
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Affiliation(s)
- Katie M Lowther
- Department of Cell Biology, University of Connecticut Health Center, 263 Farmington Ave., CT, 06030, Farmington, USA
| | - Alison F Bartolucci
- Department of Obstetrics and Gynecology, University of Connecticut Health Center, Farmington, CT, 06030, USA
- The Center for Advanced Reproductive Services, University of Connecticut Health Center, Farmington, CT, 06030, USA
| | | | - Judy Brown
- Institute for Systems Genomics, UCONN, Storrs, CT, 06268, USA
| | - John J Peluso
- Department of Cell Biology, University of Connecticut Health Center, 263 Farmington Ave., CT, 06030, Farmington, USA.
- Department of Obstetrics and Gynecology, University of Connecticut Health Center, Farmington, CT, 06030, USA.
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The Impact of Unbalanced Maternal Nutritional Intakes on Oocyte Mitochondrial Activity: Implications for Reproductive Function. Antioxidants (Basel) 2021; 10:antiox10010091. [PMID: 33440800 PMCID: PMC7826933 DOI: 10.3390/antiox10010091] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 12/30/2020] [Accepted: 01/07/2021] [Indexed: 12/11/2022] Open
Abstract
Accumulating evidence on the effect of nutrition on reproduction is emerging from both animal and human studies. A healthy dietary pattern and nutrient supplementation, especially during the peri-conceptional period, might be helpful to achieve a live birth, although the mechanisms implicated are not fully understood. The endocrine system and the ooplasmic organelles apparatus, in particular the mitochondria, are clearly key elements during oogenesis and subsequent embryo development, and their proper functioning is associated with nutrition, even beyond maternal aging. Several studies in animal models have reported various adverse effects on mitochondria caused by unbalanced dietary intakes such as high fat diet, high fat high sugar diet, and low protein diet. The alterations produced might include mitochondrial intracellular distribution, content, structure, biogenesis, and functioning. This review summarizes the key role of mitochondria in female reproduction and the effects of different dietary macronutrient compositions on oocyte mitochondrial activity with their possible short-, medium-, and long-term effects.
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Gardner DK, Balaban B. Assessment of human embryo development using morphological criteria in an era of time-lapse, algorithms and 'OMICS': is looking good still important? Mol Hum Reprod 2016; 22:704-718. [PMID: 27578774 DOI: 10.1093/molehr/gaw057] [Citation(s) in RCA: 108] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 08/24/2016] [Indexed: 02/07/2023] Open
Abstract
With the worldwide move towards single embryo transfer there has been a renewed focus on the requirement for reliable means of assessing embryo viability. In an era of 'OMICS' technologies, and algorithms created through the use of time-lapse microscopy, the actual appearance of the human embryo as it progresses through each successive developmental stage to the blastocyst appears to have been somewhat neglected in recent years. Here we review the key features of the human preimplantation embryo and consider the relationship between morphological characteristics and developmental potential. Further, the impact of the culture environment on morphological traits, how key morphological qualities reflect aspects of embryo physiology, and how computer-assisted analysis of embryo morphology may facilitate a more quantitative approach to selection are discussed. The clinical introduction of time-lapse systems has reopened our eyes and given us a new vantage point from which to view the beauty of the initial stages of human life. Rather than a future in which the morphology of the embryo is deemed irrelevant, we propose that key features, such as multinucleation, cell size and blastocyst differentiation should be included in future iterations of selection/deselection algorithms.
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Affiliation(s)
- David K Gardner
- School of BioSciences, University of Melbourne, Victoria 3010, Australia
| | - Basak Balaban
- VKF American Hospital Assisted Reproduction Unit, Guzelbahce St. No. 20, Istanbul, Turkey
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Master JS, Thouas GA, Harvey AJ, Sheedy JR, Hannan NJ, Gardner DK, Wlodek ME. Low female birth weight and advanced maternal age programme alterations in next-generation blastocyst development. Reproduction 2015; 149:497-510. [PMID: 25667431 DOI: 10.1530/rep-14-0619] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Low birth weight is associated with an increased risk for adult disease development with recent studies highlighting transmission to subsequent generations. However, the mechanisms and timing of programming of disease transmission to the next generation remain unknown. The aim of this study was to examine the effects of low birth weight and advanced maternal age on second-generation preimplantation blastocysts. Uteroplacental insufficiency or sham surgery was performed in late-gestation WKY pregnant rats, giving rise to first-generation (F1) restricted (born small) and control offspring respectively. F1 control and restricted females, at 4 or 12 months of age, were naturally mated with normal males. Second-generation (F2) blastocysts from restricted females displayed reduced expression of genes related to growth compared with F2 control (P<0.05). Following 24 h culture, F2 restricted blastocysts had accelerated development, with increased total cell number, a result of increased trophectoderm cells compared with control (P<0.05). There were alterations in carbohydrate and serine utilisation in F2 restricted blastocysts and F2 restricted outgrowths from 4-month-old females respectively (P<0.05). F2 blastocysts from aged restricted females were developmentally delayed at retrieval, with reduced total cell number attributable to reduced trophectoderm number with changes in carbohydrate utilisation (P<0.05). Advanced maternal age resulted in alterations in a number of amino acids in media obtained from F2 blastocyst outgrowths (P<0.05). These findings demonstrate that growth restriction and advanced maternal age can alter F2 preimplantation embryo physiology and the subsequent offspring growth.
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Affiliation(s)
- Jordanna S Master
- Department of PhysiologySchool of BioSciencesThe University of Melbourne, Parkville, Victoria 3010, AustraliaDepartment of Obstetrics and GynaecologyMercy Hospital, The University of Melbourne, Heidelberg, Victoria 3084, Australia
| | - George A Thouas
- Department of PhysiologySchool of BioSciencesThe University of Melbourne, Parkville, Victoria 3010, AustraliaDepartment of Obstetrics and GynaecologyMercy Hospital, The University of Melbourne, Heidelberg, Victoria 3084, Australia
| | - Alexandra J Harvey
- Department of PhysiologySchool of BioSciencesThe University of Melbourne, Parkville, Victoria 3010, AustraliaDepartment of Obstetrics and GynaecologyMercy Hospital, The University of Melbourne, Heidelberg, Victoria 3084, Australia
| | - John R Sheedy
- Department of PhysiologySchool of BioSciencesThe University of Melbourne, Parkville, Victoria 3010, AustraliaDepartment of Obstetrics and GynaecologyMercy Hospital, The University of Melbourne, Heidelberg, Victoria 3084, Australia
| | - Natalie J Hannan
- Department of PhysiologySchool of BioSciencesThe University of Melbourne, Parkville, Victoria 3010, AustraliaDepartment of Obstetrics and GynaecologyMercy Hospital, The University of Melbourne, Heidelberg, Victoria 3084, Australia Department of PhysiologySchool of BioSciencesThe University of Melbourne, Parkville, Victoria 3010, AustraliaDepartment of Obstetrics and GynaecologyMercy Hospital, The University of Melbourne, Heidelberg, Victoria 3084, Australia
| | - David K Gardner
- Department of PhysiologySchool of BioSciencesThe University of Melbourne, Parkville, Victoria 3010, AustraliaDepartment of Obstetrics and GynaecologyMercy Hospital, The University of Melbourne, Heidelberg, Victoria 3084, Australia
| | - Mary E Wlodek
- Department of PhysiologySchool of BioSciencesThe University of Melbourne, Parkville, Victoria 3010, AustraliaDepartment of Obstetrics and GynaecologyMercy Hospital, The University of Melbourne, Heidelberg, Victoria 3084, Australia
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Gardner DK, Harvey AJ. Blastocyst metabolism. Reprod Fertil Dev 2015; 27:638-54. [DOI: 10.1071/rd14421] [Citation(s) in RCA: 95] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Accepted: 01/10/2015] [Indexed: 12/15/2022] Open
Abstract
The mammalian blastocyst exhibits an idiosyncratic metabolism, reflecting its unique physiology and its ability to undergo implantation. Glucose is the primary nutrient of the blastocyst, and is metabolised both oxidatively and through aerobic glycolysis. The production of significant quantities of lactate by the blastocyst reflects specific metabolic requirements and mitochondrial regulation; it is further proposed that lactate production serves to facilitate several key functions during implantation, including biosynthesis, endometrial tissue breakdown, the promotion of new blood vessel formation and induction of local immune-modulation of the uterine environment. Nutrient availability, oxygen concentration and the redox state of the blastocyst tightly regulate the relative activities of specific metabolic pathways. Notably, a loss of metabolic normality is associated with a reduction in implantation potential and subsequent fetal development. Even a transient metabolic stress at the blastocyst stage culminates in low fetal weights after transfer. Further, it is evident that there are differences between male and female embryos, with female embryos being characterised by higher glucose consumption and differences in their amino acid turnover, reflecting the presence of two active X-chromosomes before implantation, which results in differences in the proteomes between the sexes. In addition to the role of Hypoxia-Inducible Factors, the signalling pathways involved in regulating blastocyst metabolism are currently under intense analysis, with the roles of sirtuins, mTOR, AMP-activated protein kinase and specific amino acids being scrutinised. It is evident that blastocyst metabolism regulates more than the production of ATP; rather, it is apparent that metabolites and cofactors are important regulators of the epigenome, putting metabolism at centre stage when considering the interactions of the blastocyst with its environment.
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D'Alessandro A, Federica G, Palini S, Bulletti C, Zolla L. A mass spectrometry-based targeted metabolomics strategy of human blastocoele fluid: a promising tool in fertility research. ACTA ACUST UNITED AC 2012; 8:953-8. [DOI: 10.1039/c1mb05358b] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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D'Alessandro A, Gevi F, Zolla L. A robust high resolution reversed-phase HPLC strategy to investigate various metabolic species in different biological models. MOLECULAR BIOSYSTEMS 2011; 7:1024-32. [DOI: 10.1039/c0mb00274g] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Gómez E, Muñoz M, Rodríguez A, Caamaño JN, Facal N, Díez C. Vitrification of Bovine Blastocysts ProducedIn VitroInflicts Selective Damage to the Inner Cell Mass. Reprod Domest Anim 2009; 44:194-9. [DOI: 10.1111/j.1439-0531.2007.01026.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Jansen S, Esmaeilpour T, Pantaleon M, Kaye PL. Glucose affects monocarboxylate cotransporter (MCT) 1 expression during mouse preimplantation development. Reproduction 2006; 131:469-79. [PMID: 16514190 DOI: 10.1530/rep.1.00953] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Cleavage-stage embryos have an absolute requirement for pyruvate and lactate, but as the morula compacts, it switches to glucose as the preferred energy source to fuel glycolysis. Substrates such as glucose, amino acids, and lactate are moved into and out of cells by facilitated diffusion. In the case of lactate and pyruvate, this occurs via H+-monocarboxylate cotransporter (MCT) proteins. To clarify the role of MCT in development, transport characteristics for DL-lactate were examined, as were mRNA expression and protein localisation for MCT1 and MCT3, using confocal laser scanning immunofluorescence in freshly collected and cultured embryos. Blastocysts demonstrated significantly higher affinity for DL-lactate than zygotes (Km 20 +/- 10 vs 87 +/- 35 mmol lactate/l; P = 0.03 by linear regression) but was similar for all stages. For embryos derived in vivo and those cultured with glucose, MCT1 mRNA was present throughout preimplantation development, protein immunoreactivity appearing diffuse throughout the cytoplasm with brightest intensity in the outer cortical region of blastomeres. In expanding blastocysts, MCT1 became more prominent in the cytoplasmic cortex of blastomeres, with brightest intensity in the polar trophectoderm. Without glucose, MCT1 mRNA was not expressed, and immunoreactivity dramatically reduced in intensity as morulae died. MCT3 mRNA and immunoreactivity were not detected in early embryos. The differential expression of MCT1 in the presence or absence of glucose demonstrates that it is important in the critical regulation of pH and monocarboxylate transport during preimplantation development, and implies a role for glucose in the control of MCT1, but not MCT3, expression.
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Affiliation(s)
- Sarah Jansen
- School of Biomedical Sciences, University of Queensland, Brisbane 4072, QLD, Australia
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Abstract
Gap junctional communication plays a central role in the maintenance of cellular homeostasis by allowing the passage of small molecules between adjacent cells. Gap junctions are composed of a family of proteins termed connexins. During preimplantation development several connexin proteins are expressed and assembled into gap junctions in the plasma membrane at compaction but the functional significance of connexin diversity remains controversial. Although, many of the connexin genes have been disrupted using homologous recombination in embryonic stem cells to obtain unique phenotypes, none of these studies has demonstrated a specific role for connexins during preimplantation development in the null mutants. This review surveys evidence for the involvement of gap junctional communication during embryo development highlighting discrepancies in the literature. Although some evidence suggests that gap junctions may be dispensable during preimplantation development this is difficult to envisage particularly for the process of cavitation and the maintenance of homeostasis between the differentiated trophectoderm cells and the pluripotent inner cell mass cells of the blastocyst.
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Augustin R, Pocar P, Navarrete-Santos A, Wrenzycki C, Gandolfi F, Niemann H, Fischer B. Glucose transporter expression is developmentally regulated in in vitro derived bovine preimplantation embryos. Mol Reprod Dev 2001; 60:370-6. [PMID: 11599048 DOI: 10.1002/mrd.1099] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Glucose is readily been taken up and utilized by preimplantation embryos from different species. However, a comprehensive analysis of the glucose transporter expression throughout preimplantation development is still missing. Here, we have investigated the expression of facilitative glucose transporters (Glut1-5 and 8) and sodium-dependent-glucose transporter (SGLT-I) in bovine oocytes and preimplantation embryos up to d16 of development, using RT-PCR and immunohistochemistry. The embryos were produced in vitro by IVM-IVF. Glut1, Glut3, Glut8, and SGLT-I were expressed in all stages studied. Glut4 transcripts were first detected at the blastocyst stage. Glut2 expression was restricted to the period of blastocyst elongation at d14 and d16. Transcription of the fructose transporter Glut5 started at the 8-/16-cell stage. Our results show a distinct expression pattern for glucose transporters during bovine embryo development in vitro indicating specialized functions for these isoforms at different developmental stages in bovine embryos. Mol. Reprod. Dev. 60:370-376,
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Affiliation(s)
- R Augustin
- Department of Anatomy and Cell Biology, Martin Luther University Faculty of Medicine, Grosse Steinstrasse 52, D-06097 Halle (Saale), Germany.
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Pampfer S. Apoptosis in rodent peri-implantation embryos: differential susceptibility of inner cell mass and trophectoderm cell lineages--a review. Placenta 2000; 21 Suppl A:S3-10. [PMID: 10831115 DOI: 10.1053/plac.1999.0519] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Inner cell mass (ICM) and trophectoderm cell lineages diverge early in cleavage in response to a complex combination of cellular and molecular determinative events. The resulting differences in metabolic requirements, cell positioning and micro-environments are considered as some of the major causes underlying the differential sensitivity of ICM and trophectoderm cell lines to embryotoxic agents. In most instances, ICM cells appear less resistant to disruption than trophectoderm cells, and past observations suggest that over-stimulation of apoptosis is probably one of the mechanisms leading to selective ICM depletion at the blastocyst stage. Disproportionate deficiency in this lineage below a certain threshold level may then prevent the ICM core from providing sufficient prefetal stem cells during gastrulation and from sending regulatory signals to the trophectoderm, leading to compromised post-implantation development. The aim of this review article is to discuss the above observations and to show the value of the impact of hyperglycaemia on blastocyst metabolism and development as an exciting model for further studies.
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Affiliation(s)
- S Pampfer
- Université Catholique de Louvain Medical School, Brussels, Belgium.
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Kim CH, Chae HD, Cheon YP, Kang BM, Chang YS, Mok JE. The effect of epidermal growth factor on the preimplantation development, implantation and its receptor expression in mouse embryos. J Obstet Gynaecol Res 1999; 25:87-93. [PMID: 10379122 DOI: 10.1111/j.1447-0756.1999.tb01128.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To investigate the influence of epidermal growth factor (EGF) on preimplantation development, implantation, and expression of epidermal growth factor receptor (EGFR) itself in mouse embryos. MATERIALS AND METHOD Eight-cell stage mouse embryos were cultured for 48 hours with EGF at concentrations of 0.1, 1.0, 10 and 100 ng/ml. Embryos not treated with EGF were served as control. The percentages of embryos which developed to the expanded, hatched blastocyst stage and in vitro implantation at 48 hours were determined. Reverse transcription-polymerase chain reaction (RT-PCR) has been used to examine the expression of EGFR in developed hatched blastocysts. Following reverse transcription, strategically designed nested primers, optimized for specificity, were used for amplification from the cDNA equivalent of a single embryo. The products were then verified by restriction enzyme digestion and sequence analysis. Results were analyzed with chi 2 test and Student's t-test as appropriate, and statistical significance was defined as p < 0.05. RESULTS The percentages of fully expanded blastocysts at 48 hours in all the EGF treated group were not significantly different from the control. The percentages of hatched blastocysts were significantly higher in the EGF treatment group at 0.1 ng/ml (90.5 +/- 9.8%) compared to the control (82.1 +/- 7.2%), 1.0 ng/ml (82.2 +/- 12.7%), and 100 mg/ml (81.9 +/- 11.8%) (p < 0.05, p < 0.05, p < 0.05, respectively). The percentages of hatched blastocysts were significantly higher in the EGF treatment group at 10 ng/ml (89.4 +/- 7.5%) compared to the control, and 100 ng/ml (p < 0.05, p < 0.05, respectively). The percentages of attached blastocysts in vitro were significantly higher following incubation with EGF at concentrations of 0.1 ng/ml (37.0 +/- 17.0%), 1.0 ng/ml (32.0 +/- 14.3%), 10 ng/ml (21.3 +/- 7.2%) compared to the control (9.5 +/- 7.7%) (p < 0.05, p < 0.05, p < 0.05, respectively). The attachment rates in 0.1 ng/ml and 1.0 ng/ml EGF treatment groups were also significantly higher than those in other EGF treatment groups. Embryo development and attachment were not significantly inhibited or enhanced in cultures supplemented with 100 ng/ml EGF compared to the control. The mRNA concentration of EGFR in embryos treated with 0.1 ng/ml of EGF was significantly higher than those of the control and other EGF treatment groups. CONCLUSION EGF may have a stimulatory role in later stage embryonic development, implantation and expression of EGFR in hatched blastocyst itself at the specific concentration.
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Affiliation(s)
- C H Kim
- Department of Obstetrics and Gynecology, College of Medicine, University of Ulsan, Asan Medical Center, Seoul, Korea
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Cell Polarity and Mouse Early Development. ACTA ACUST UNITED AC 1998. [DOI: 10.1016/s1569-2558(08)60019-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Gibb CA, Poronnik P, Day ML, Cook DI. Control of cytosolic pH in two-cell mouse embryos: roles of H(+)-lactate cotransport and Na+/H+ exchange. THE AMERICAN JOURNAL OF PHYSIOLOGY 1997; 273:C404-19. [PMID: 9277338 DOI: 10.1152/ajpcell.1997.273.2.c404] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
In this study we used imaging techniques with the fluorescent pH-sensitive dye 2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein to investigate the control of cytosolic pH (pHi) in two-cell mouse embryos in nominally HCO3(-)-free conditions. We found that the resting pHi of two-cell embryos (40-50 h after human chorionic gonadotropin) in HCO3(-)-free M2 was 7.31 +/- 0.01 (n = 172 embryos), which is significantly above the level predicted if H+ is at electrochemical equilibrium. We showed that two-cell embryos contain a H(+)-monocarboxylate cotransport system with apparent Michaelis constants for D-lactate, L-lactate, and pyruvate of 11.5, 3.7, and 3.5 mM, respectively. It is inhibited by p-chloromercuribenzoic acid (300 microM), p-chloromercuriphenylsulfonic acid (300 microM), and alpha-cyano-4-hydroxycinnamate (1 mM) and is insensitive to 4,4'-diisothiocyanodihydrostilbene-2,2'-disulfonic acid (500 microM). We also showed that the pHi response to the acid load produced by an NH4Cl pulse has two components, one due to H(+)-monocarboxylate cotransport and the other due to Na+/H+ exchange. We found no evidence that a H+ conductance was responsible in these cells for the recovery in pHi after an acid load.
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Affiliation(s)
- C A Gibb
- Department of Physiology, University of Sydney, New South Wales, Australia
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Barnett DK, Bavister BD. What is the relationship between the metabolism of preimplantation embryos and their developmental competence? Mol Reprod Dev 1996; 43:105-33. [PMID: 8720119 DOI: 10.1002/(sici)1098-2795(199601)43:1<105::aid-mrd13>3.0.co;2-4] [Citation(s) in RCA: 104] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- D K Barnett
- Department of Animal Health and Biomedical Sciences, University of Wisconsin-Madison 53706, USA
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Brison DR, Leese HJ. The role of exogenous energy substrates in blastocoele fluid accumulation in the rat. ZYGOTE 1994; 2:69-77. [PMID: 7881919 DOI: 10.1017/s0967199400001787] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Preimplantation mammalian development culminates in the formation of a fluid-filled cavity, the blastocoele, which is a prerequisite for successful implantation and further development. The blastocoele is enclosed by a single layer of polarised cells, the trophectoderm, which is the first epithelium formed in development. In embryos of the mouse and the rabbit, a basolaterally located Na+/K(+)-ATPase hydrolyses ATP to drive the vectorial transport of ions, which is responsible for the accumulation of blastocoele fluid. Using non-invasive assays of energy substrate consumption and blastocoele fluid accumulation, experiments were carried out on single preimplantation rat embryos, to establish: (1) the roles of the Na+/K(+)-ATPase and exogenous energy substrates, and (2) the relationship between the consumption and metabolism of energy substrates and fluid accumulation, during blastocoele cavity formation in this species. Ouabain 0.5 mM and energy-substrate-free medium both caused an inhibition in the number of embryos forming a blastocoele in culture, and also reduced the rate of fluid accumulation by day 5 blastocysts collapsed in cytochalasin-D and allowed to re-expand. Ouabain also reduced the consumption of glucose (but not pyruvate) and the production of lactate by re-expanding blastocysts. In the absence of the inhibitor, a direct relationship was seen between fluid accumulation and both glucose (but not pyruvate) consumption and lactate production. However, ouabain had no effect on intact, expanded blastocysts.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- D R Brison
- Department of Biology, University of York, York, UK
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Hewitson LC, Leese HJ. Energy metabolism of the trophectoderm and inner cell mass of the mouse blastocyst. THE JOURNAL OF EXPERIMENTAL ZOOLOGY 1993; 267:337-43. [PMID: 8228868 DOI: 10.1002/jez.1402670310] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The two cell populations of the day 5 mouse blastocyst--the inner cell mass (ICM) and trophectoderm (TE)--were isolated by immunosurgery and TE biopsy. The uptake of glucose and pyruvate and the production of lactate were measured in the isolated cell populations and in single day 5 blastocysts, using a non-invasive ultramicrofluorescence technique. The number of cells in isolated ICMs, TE vesicles, and intact blastocysts were counted after differential labeling with fluorochromes. The uptake of glucose and the formation of lactate were approximately three and five times greater, respectively, in the ICM cells compared with the TE cells. All the glucose consumed by the ICM could be accounted for by lactate formation, whereas the value for TE was 55%. The uptake of pyruvate was low in both cell types. The results are consistent with the proposition that the TE acts as a transporting epithelium, sparing nutrients for metabolism by the ICM.
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Affiliation(s)
- L C Hewitson
- Department of Biology, University of York, Heslington, England
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