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Ryu SA, Baek S, Kim KC, Lee ES, Lee ST. Effects of cumulus cells on the in vitro cytoplasmic maturation of immature oocytes in pigs. Theriogenology 2023; 206:133-139. [PMID: 37209433 DOI: 10.1016/j.theriogenology.2023.04.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 04/25/2023] [Accepted: 04/25/2023] [Indexed: 05/22/2023]
Abstract
The exposure of cumulus cells to nuclear matured oocytes can be regulated through the forced delay of nuclear maturation or the alteration of in vitro maturation (IVM) time in cumulus-oocyte complexes (COCs). However, to date, no evidence has been presented for the enhancement of cytoplasmic maturation by them, indicating irrelevance of cumulus cells in cytoplasmic maturation. Therefore, in order to identify the requirement of cumulus cells in achieving the cytoplasmic maturation of immature oocytes, this study investigated the effects of cumulus cells on the in vitro cytoplasmic maturation of oocytes within COCs derived from porcine medium antral follicles (MAFs) post-the completion of nuclear maturation. For these, with IVM of COCs for 44 h (control), cumulus cell-free oocytes with completed nuclear maturation were in-vitro-matured additionally for 0, 6, or 12 h, and then a variety of factors representing the cytoplasmic maturation of oocytes were analyzed and compared. As the results, the IVM of COCs for 32 h showed complete nuclear maturation and incomplete cytoplasmic maturation. Moreover, after the removal of cumulus cells from COCs with the completion of nuclear maturation, IVM for an additional 6 or 12 h resulted in significant increases in the size of the perivitelline space, the proportion of oocytes with a normal intracellular mitochondrial distribution and a normal round first polar body, and the preimplantation development into the 2-cell and blastocyst stages after parthenogenetic activation. Simultaneously, they showed significant reduction in the level of intracellular reactive oxygen species and no significant differences in the total number of blastocysts. Furthermore, oocytes obtained by this approach did not significantly differ from control oocytes produced by IVM of COCs for 44 h. Our results demonstrate that the cumulus cells enclosing COCs derived from porcine MAFs are not essential for the completion of cytoplasmic maturation after complete nuclear maturation by COCs.
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Affiliation(s)
- Seon Ah Ryu
- Department of Applied Animal Science, Kangwon National University, Chuncheon, 24341, Republic of Korea
| | - Song Baek
- Department of Applied Animal Science, Kangwon National University, Chuncheon, 24341, Republic of Korea
| | - Keun Cheon Kim
- Department of Obstetrics, Gynecology and Women's Health, University of Missouri, Columbia, 65201, USA
| | - Eun Song Lee
- College of Veterinary Medicine, Kangwon National University, Chuncheon, 24341, Republic of Korea.
| | - Seung Tae Lee
- Department of Applied Animal Science, Kangwon National University, Chuncheon, 24341, Republic of Korea; Kustogen, Chuncheon, 24341, Republic of Korea.
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2
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Lee IW, Adhikari D, Carroll J. Miro1 depletion disrupts spatial distribution of mitochondria and leads to oocyte maturation defects. Front Cell Dev Biol 2022; 10:986454. [PMID: 36325364 PMCID: PMC9619047 DOI: 10.3389/fcell.2022.986454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 09/29/2022] [Indexed: 11/22/2022] Open
Abstract
Mitochondria are dynamic organelles that undergo regulated microtubule- and actin-mediated trafficking to meet local energy and metabolic needs. Mitochondrial trafficking may be particularly critical in large cells such as eggs and early embryos where spindle formation and polar body extrusion occur in specific regions of the cytoplasm. To investigate the role of mitochondrial distribution in oocytes we have targeted the mitochondrial membrane protein, MIRO1, which couples mitochondria to the motor protein-TRAK complex. Oocyte-specific deletion of MIRO1 leads to the formation of large aggregates of mitochondria in perinuclear and cortical compartments. Mitochondria remain capable of long-range trafficking during maturation, indicating redundancy in the mechanisms coupling mitochondria to motor proteins. Polar body extrusion in the absence of MIRO1 was reduced by approximately 20%. In MIRO1-deleted zygotes, mitochondria showed increased accumulation around the pronuclei but this did not affect mitochondrial distribution to daughter blastomeres. In vitro development of parthenogenetic embryos was also reduced, although no differences were found in the fertility of oocyte-specific Miro1 KO mice. These findings demonstrate MIRO1 acts as a mitochondrial adaptor, setting mitochondrial distribution in oocytes and early embryos, and disrupting this process compromises in vitro oocyte maturation and embryo development.
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Affiliation(s)
| | | | - John Carroll
- *Correspondence: Deepak Adhikari, ; John Carroll,
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3
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Clérico G, Taminelli G, Veronesi JC, Polola J, Pagura N, Pinto C, Sansinena M. Mitochondrial function, blastocyst development and live foals born after ICSI of immature vitrified/warmed equine oocytes matured with or without melatonin. Theriogenology 2020; 160:40-49. [PMID: 33171351 DOI: 10.1016/j.theriogenology.2020.10.036] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 10/30/2020] [Accepted: 10/31/2020] [Indexed: 11/18/2022]
Abstract
Oocyte vitrification is considered experimental in the horse with only three live foals reported. The oxidative conditions induced by vitrification could in part explain the poor results and melatonin, a powerful antioxidant, could stimulate ROS metabolization and restore mitochondrial function in these oocytes. Our objective was to determine the oxidative status of vitrified equine oocytes and to analyze the effect of melatonin on mitochondrial-specific ROS (mROS), oocyte maturation, ICSI embryo development and viability. Immature, abattoir-derived oocytes were held for 15 h and vitrified in a final concentration of 20% EG, 20% DMSO and 0.65 M trehalose. In Experiment 1, overall ROS was determined by DCHF-DA; vitrification increased ROS production compared to non-vitrified controls (1.29 ± 0.22 vs 0.74 ± 0.25 a. u.; P = 0.0156). In Experiment 2, mROS was analyzed by MitoSOX™ in vitrified/warmed oocytes matured with (+) or without (-) supplementation of 10-9 M melatonin; mROS decreased in vitrified and non-vitrified oocytes matured in presence of melatonin (P < 0.05). In Experiment 3, we assessed the effect of melatonin supplementation on oocyte maturation, embryo development after ICSI, and viability by pregnancy establishment. Melatonin did not improve oocyte maturation, cleavage or blastocyst rate of non-vitrified oocytes. However, vitrified melatonin (+) oocytes reached similar cleavage (61, 75 and 77%, respectively) and blastocyst rate (15, 29 and 26%, respectively) than non-vitrified, melatonin (+) and (-) oocytes. Vitrified, melatonin (-) oocytes had lower cleavage (46%) and blastocyst rate (9%) compared to non-vitrified groups (P < 0.05), but no significant differences were observed when compared to vitrified melatonin (+). Although the lack of available recipients precluded the transfer of every blastocyst produced in our study, transferred embryos from non-vitrified oocytes resulted in 50 and 83% pregnancy rates while embryos from vitrified oocytes resulted in 17 and 33% pregnancy rates, from melatonin (+) and (-) treatments respectively. Two healthy foals, one colt from melatonin (+) and one filly from melatonin (-) treatment, were born from vitrified/warmed oocytes. Gestation lengths (considering day 0 = day of ICSI) were 338 days for the colt and 329 days for the filly, respectively. Our work showed for the first time that in the horse, as in other species, intracellular reactive oxygen species are increased by the process of vitrification. Melatonin was useful in reducing mitochondrial-related ROS and improving ICSI embryo development, although the lower pregnancy rate in presence of melatonin should be further analyzed in future studies. To our knowledge this is the first report of melatonin supplementation to an in vitro embryo culture system and its use to improve embryo developmental competence of vitrified oocytes following ICSI.
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Affiliation(s)
- G Clérico
- Facultad de Ingeniería y Ciencias Agrarians, Universidad Católica Argentina, 1107, Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
| | - G Taminelli
- Facultad de Ingeniería y Ciencias Agrarians, Universidad Católica Argentina, 1107, Buenos Aires, Argentina
| | - J C Veronesi
- Frigorífico Lamar, 6600, Buenos Aires, Argentina
| | - J Polola
- Haras La Aguada El Dok, 6708, Buenos Aires, Argentina; Facultad de Ciencias Veterinarias, Universidad Nacional de Rosario, 2170, Santa Fe, Argentina
| | - N Pagura
- Facultad de Ciencias Veterinarias, Universidad Nacional de Rosario, 2170, Santa Fe, Argentina
| | - C Pinto
- Louisiana State School of Veterinary Medicine, 70808, Baton Rouge, LA, USA
| | - M Sansinena
- Facultad de Ingeniería y Ciencias Agrarians, Universidad Católica Argentina, 1107, Buenos Aires, Argentina; Louisiana State School of Veterinary Medicine, 70808, Baton Rouge, LA, USA; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina.
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4
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Xu Y, Zhang KH, Sun MH, Lan M, Wan X, Zhang Y, Sun SC. Protective Effects of Melatonin Against Zearalenone Toxicity on Porcine Embryos in vitro. Front Pharmacol 2019; 10:327. [PMID: 31024301 PMCID: PMC6460015 DOI: 10.3389/fphar.2019.00327] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 03/19/2019] [Indexed: 12/11/2022] Open
Abstract
Zearalenone (ZEA) is an estrogenic mycotoxin produced by Fusarium fungi commonly found in corn, wheat, and other cereals which can infect food and feed commodities, and ZEA mainly has reproductive toxicity which causes widely reproductive disorders in pigs and other animals. However, the toxicity and the functional ways of ZEA on early embryo development is still unclear. In present study we showed that exposure to ZEA (10 μM) significantly decreased the 2-cell and blastocyst developmental rate in porcine early embryos in vitro. ZEA treatment resulted in the occurrence of oxidative stress, showing with increased reactive oxygen species (ROS) level, following with aberrant mitochondrial distribution. Moreover, we found positive signals of γH2A.X in the ZEA-treated embryos, indicating that ZEA induced DNA damage, and the increased autophagy confirmed this. These results suggested that ZEA induced oxidative stress, which further caused mitochondria dysfunction and DNA damage on early embryonic development. We next investigated the effects of melatonin on the ZEA-treated embryo development, and we found that melatonin supplementation could significantly ameliorate ZEA-induced oxidative stress, aberrant mitochondria distribution and DNA damage. In all, our results showed that ZEA was toxic for porcine embryos cultured in vitro and melatonin supplementation could protect their development from the effects of ZEA.
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Affiliation(s)
- Yao Xu
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Kun-Huan Zhang
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Ming-Hong Sun
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Mei Lan
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Xiang Wan
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Yu Zhang
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
| | - Shao-Chen Sun
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, China
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Yang L, Gao Z, Lei L, Lv Q, Zhao Q, Li L, Cao X, Fu W. Lycium barbarum polysaccharide enhances development of previously-cryopreserved murine two-cell embryos via restoration of mitochondrial function and down-regulated generation of reactive oxygen species. J Reprod Dev 2019; 65:163-170. [PMID: 30700637 PMCID: PMC6473105 DOI: 10.1262/jrd.2018-104] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Lycium barbarum polysaccharide (LBP) exhibits multiple pharmacological and biological effects, including displaying antioxidant and cytoprotective properties. The current
study investigated the effects of LBP-supplemented culture medium on mitochondrial distribution, mitochondrial membrane potential (MMP), adenosine triphosphate (ATP) production,
mitochondrial deoxyribonucleic acid (mtDNA) copy number, reactive oxygen species (ROS) accumulation, and development of previously-cryopreserved murine two-cell embryos. Results indicate
that LBP enhances development of such embryos, and that potential mechanisms include: (1) mitochondrial function enhancement via altering mitochondrial distribution and increasing MMP, ATP
production, mtDNA copy number, and expression of genes involved in mitochondrial biogenesis and energy metabolism (NAD-dependent deacetyltransferase sirtuin-1 (SIRT1) and phosphorylated
adenosine monophosphate-activated protein kinase (pAMPK)); (2) down-regulation of ROS generation and enhanced expression of the antioxidant genes glutathione peroxidase 4 (GPX4) and
superoxide dismutase 1 (SOD1), thereby increasing embryo oxidative stress tolerance; and (3) increased expression of B-cell lymphoma-2 (BCL2), a critical gene for cell survival and embryo
development. These results demonstrate that LBP improves development of previously-cryopreserved murine two-cell embryos via restoration of mitochondrial function and down-regulated
generation of ROS.
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Affiliation(s)
- Lei Yang
- College of Basic Medical Science, Jiujiang University, Jiangxi 332000, China.,Key Laboratory of System Bio-medicine of Jiangxi Province, Jiujiang University, Jiangxi 332000, China
| | - Zhen Gao
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Shaanxi 712100, China
| | - Lanjie Lei
- Affiliated Hospital of Jiujiang University, Jiujiang University, Jiangxi 332000, China
| | - Qizhuang Lv
- College of Biology & Pharmacy, Yulin Normal University, Guangxi 53700, China
| | - Qihan Zhao
- Key Laboratory of System Bio-medicine of Jiangxi Province, Jiujiang University, Jiangxi 332000, China
| | - Lixin Li
- College of Basic Medical Science, Jiujiang University, Jiangxi 332000, China
| | - Xiaoming Cao
- College of Basic Medical Science, Jiujiang University, Jiangxi 332000, China
| | - Wenxue Fu
- College of Basic Medical Science, Jiujiang University, Jiangxi 332000, China.,Key Laboratory of System Bio-medicine of Jiangxi Province, Jiujiang University, Jiangxi 332000, China
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6
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Molecular Mechanisms Responsible for Increased Vulnerability of the Ageing Oocyte to Oxidative Damage. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:4015874. [PMID: 29312475 PMCID: PMC5664291 DOI: 10.1155/2017/4015874] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 08/03/2017] [Indexed: 12/23/2022]
Abstract
In their midthirties, women experience a decline in fertility, coupled to a pronounced increase in the risk of aneuploidy, miscarriage, and birth defects. Although the aetiology of such pathologies are complex, a causative relationship between the age-related decline in oocyte quality and oxidative stress (OS) is now well established. What remains less certain are the molecular mechanisms governing the increased vulnerability of the aged oocyte to oxidative damage. In this review, we explore the reduced capacity of the ageing oocyte to mitigate macromolecular damage arising from oxidative insults and highlight the dramatic consequences for oocyte quality and female fertility. Indeed, while oocytes are typically endowed with a comprehensive suite of molecular mechanisms to moderate oxidative damage and thus ensure the fidelity of the germline, there is increasing recognition that the efficacy of such protective mechanisms undergoes an age-related decline. For instance, impaired reactive oxygen species metabolism, decreased DNA repair, reduced sensitivity of the spindle assembly checkpoint, and decreased capacity for protein repair and degradation collectively render the aged oocyte acutely vulnerable to OS and limits their capacity to recover from exposure to such insults. We also highlight the inadequacies of our current armoury of assisted reproductive technologies to combat age-related female infertility, emphasising the need for further research into mechanisms underpinning the functional deterioration of the ageing oocyte.
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7
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May-Panloup P, Boucret L, Chao de la Barca JM, Desquiret-Dumas V, Ferré-L'Hotellier V, Morinière C, Descamps P, Procaccio V, Reynier P. Ovarian ageing: the role of mitochondria in oocytes and follicles. Hum Reprod Update 2016; 22:725-743. [PMID: 27562289 DOI: 10.1093/humupd/dmw028] [Citation(s) in RCA: 320] [Impact Index Per Article: 40.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 07/15/2016] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND There is a great inter-individual variability of ovarian ageing, and almost 20% of patients consulting for infertility show signs of premature ovarian ageing. This feature, taken together with delayed childbearing in modern society, leads to the emergence of age-related ovarian dysfunction concomitantly with the desire for pregnancy. Assisted reproductive technology is frequently inefficacious in cases of ovarian ageing, thus raising the economic, medical and societal costs of the procedures. OBJECTIVE AND RATIONAL Ovarian ageing is characterized by quantitative and qualitative alteration of the ovarian oocyte reserve. Mitochondria play a central role in follicular atresia and could be the main target of the ooplasmic factors determining oocyte quality adversely affected by ageing. Indeed, the oocyte is the richest cell of the body in mitochondria and depends largely on these organelles to acquire competence for fertilization and early embryonic development. Moreover, the oocyte ensures the uniparental transmission and stability of the mitochondrial genome across the generations. This review focuses on the role played by mitochondria in ovarian ageing and on the possible consequences over the generations. SEARCH METHODS PubMed was used to search the MEDLINE database for peer-reviewed original articles and reviews concerning mitochondria and ovarian ageing, in animal and human species. Searches were performed using keywords belonging to three groups: 'mitochondria' or 'mitochondrial DNA'; 'ovarian reserve', 'oocyte', 'ovary' or 'cumulus cells'; and 'ageing' or 'ovarian ageing'. These keywords were combined with other search phrases relevant to the topic. References from these articles were used to obtain additional articles. OUTCOMES There is a close relationship, in mammalian models and humans, between mitochondria and the decline of oocyte quality with ageing. Qualitatively, ageing-related mitochondrial (mt) DNA instability, which leads to the accumulation of mtDNA mutations in the oocyte, plays a key role in the deterioration of oocyte quality in terms of competence and of the risk of transmitting mitochondrial abnormalities to the offspring. In contrast, some mtDNA haplogroups are protective against the decline of ovarian reserve. Quantitatively, mitochondrial biogenesis is crucial during oogenesis for constituting a mitochondrial pool sufficiently large to allow normal early embryonic development and to avoid the untimely activation of mitochondrial biogenesis. Ovarian ageing also seriously affects the dynamic nature of mitochondrial biogenesis in the surrounding granulosa cells that may provide interesting alternative biomarkers of oocyte quality. WIDER IMPLICATIONS A fuller understanding of the involvement of mitochondria in cases of infertility linked to ovarian ageing would contribute to a better management of the disorder in the future.
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Affiliation(s)
- Pascale May-Panloup
- Laboratoire de Biologie de la Reproduction, Centre Hospitalier Universitaire d'Angers, 49933 Angers Cedex 9, France .,PREMMi/Pôle de Recherche et d'Enseignement en Médecine Mitochondriale, Institut MITOVASC, CNRS 6214, INSERM U1083, Université d'Angers, Angers, France
| | - Lisa Boucret
- Laboratoire de Biologie de la Reproduction, Centre Hospitalier Universitaire d'Angers, 49933 Angers Cedex 9, France.,PREMMi/Pôle de Recherche et d'Enseignement en Médecine Mitochondriale, Institut MITOVASC, CNRS 6214, INSERM U1083, Université d'Angers, Angers, France
| | - Juan-Manuel Chao de la Barca
- PREMMi/Pôle de Recherche et d'Enseignement en Médecine Mitochondriale, Institut MITOVASC, CNRS 6214, INSERM U1083, Université d'Angers, Angers, France.,Département de Biochimie et Génétique, Centre Hospitalier Universitaire d'Angers, 49933 Angers Cedex 9, France
| | - Valérie Desquiret-Dumas
- PREMMi/Pôle de Recherche et d'Enseignement en Médecine Mitochondriale, Institut MITOVASC, CNRS 6214, INSERM U1083, Université d'Angers, Angers, France.,Département de Biochimie et Génétique, Centre Hospitalier Universitaire d'Angers, 49933 Angers Cedex 9, France
| | - Véronique Ferré-L'Hotellier
- Laboratoire de Biologie de la Reproduction, Centre Hospitalier Universitaire d'Angers, 49933 Angers Cedex 9, France
| | - Catherine Morinière
- Service de Gynécologie-Obstétrique, Centre Hospitalier Universitaire d'Angers, 49933 Angers Cedex 9, France
| | - Philippe Descamps
- Service de Gynécologie-Obstétrique, Centre Hospitalier Universitaire d'Angers, 49933 Angers Cedex 9, France
| | - Vincent Procaccio
- PREMMi/Pôle de Recherche et d'Enseignement en Médecine Mitochondriale, Institut MITOVASC, CNRS 6214, INSERM U1083, Université d'Angers, Angers, France.,Département de Biochimie et Génétique, Centre Hospitalier Universitaire d'Angers, 49933 Angers Cedex 9, France
| | - Pascal Reynier
- PREMMi/Pôle de Recherche et d'Enseignement en Médecine Mitochondriale, Institut MITOVASC, CNRS 6214, INSERM U1083, Université d'Angers, Angers, France.,Département de Biochimie et Génétique, Centre Hospitalier Universitaire d'Angers, 49933 Angers Cedex 9, France
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8
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Effect of mouse oocyte vitrification on mitochondrial membrane potential and distribution. ACTA ACUST UNITED AC 2014; 34:99-102. [DOI: 10.1007/s11596-014-1238-8] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Revised: 12/05/2013] [Indexed: 10/25/2022]
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Simsek-Duran F, Li F, Ford W, Swanson RJ, Jones HW, Castora FJ. Age-associated metabolic and morphologic changes in mitochondria of individual mouse and hamster oocytes. PLoS One 2013; 8:e64955. [PMID: 23741435 PMCID: PMC3669215 DOI: 10.1371/journal.pone.0064955] [Citation(s) in RCA: 94] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Accepted: 04/23/2013] [Indexed: 11/26/2022] Open
Abstract
Background In human oocytes, as in other mammalian ova, there is a significant variation in the pregnancy potential, with approximately 20% of oocyte-sperm meetings resulting in pregnancies. This frequency of successful fertilization decreases as the oocytes age. This low proportion of fruitful couplings appears to be influenced by changes in mitochondrial structure and function. In this study, we have examined mitochondrial biogenesis in both hamster (Mesocricetus auratus) and mouse (Mus musculus) ova as models for understanding the effects of aging on mitochondrial structure and energy production within the mammalian oocyte. Methodology/Principal Findings Individual metaphase II oocytes from a total of 25 young and old mice and hamsters were collected from ovarian follicles after hormone stimulation and prepared for biochemical or structural analysis. Adenosine triphosphate levels and mitochondrial DNA number were determined within individual oocytes from young and old animals. In aged hamsters, oocyte adenosine triphosphate levels and mitochondrial DNA molecules were reduced 35.4% and 51.8%, respectively. Reductions of 38.4% and 44% in adenosine triphosphate and mitochondrial genomes, respectively, were also seen in aged mouse oocytes. Transmission electron microscopic (TEM) analysis showed that aged rodent oocytes had significant alterations in mitochondrial and cytoplasmic lamellae structure. Conclusions/Significance In both mice and hamsters, decreased adenosine triphosphate in aged oocytes is correlated with a similar decrease in mtDNA molecules and number of mitochondria. Mitochondria in mice and hamsters undergo significant morphological change with aging including mitochondrial vacuolization, cristae alterations, and changes in cytoplasmic lamellae.
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Affiliation(s)
- Fatma Simsek-Duran
- Department of Physiological Sciences, Eastern Virginia Medical School, Norfolk, Virginia, United States of America
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10
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The role of mitochondria from mature oocyte to viable blastocyst. Obstet Gynecol Int 2013; 2013:183024. [PMID: 23766762 PMCID: PMC3671549 DOI: 10.1155/2013/183024] [Citation(s) in RCA: 164] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Revised: 04/23/2013] [Accepted: 04/29/2013] [Indexed: 12/19/2022] Open
Abstract
The oocyte requires a vast supply of energy after fertilization to support critical events such as spindle formation, chromatid separation, and cell division. Until blastocyst implantation, the developing zygote is dependent on the existing pool of mitochondria. That pool size within each cell decreases with each cell division. Mitochondria obtained from oocytes of women of advanced reproductive age harbor DNA deletions and nucleotide variations that impair function. The combination of lower number and increased frequency of mutations and deletions may result in inadequate mitochondrial activity necessary for continued embryo development and cause pregnancy failure. Previous reports suggested that mitochondrial activity within oocytes may be supplemented by donor cytoplasmic transfer at the time of intracytoplasmic sperm injection (ICSI). Those reports showed success; however, safety concerns arose due to the potential of two distinct populations of mitochondrial genomes in the offspring. Mitochondrial augmentation of oocytes is now reconsidered in light of our current understanding of mitochondrial function and the publication of a number of animal studies. With a better understanding of the role of this organelle in oocytes immediately after fertilization, blastocyst and offspring, mitochondrial augmentation may be reconsidered as a method to improve oocyte quality.
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11
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Seet VYK, Al-Samerria S, Wong J, Stanger J, Yovich JL, Almahbobi G. Optimising vitrification of human oocytes using multiple cryoprotectants and morphological and functional assessment. Reprod Fertil Dev 2013; 25:918-26. [DOI: 10.1071/rd12136] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2012] [Accepted: 08/01/2012] [Indexed: 11/23/2022] Open
Abstract
Oocyte vitrification is a clinical practice that allows preservation of fertility potential in women. Vitrification involves quick cooling using high concentrations of cryoprotectants to minimise freezing injuries. However, high concentrations of cryoprotectants have detrimental effects on oocyte quality and eventually the offspring. In addition, current assessment of oocyte quality after vitrification is commonly based only on the morphological appearance of the oocyte, raising concerns regarding its efficiency. Using both morphological and functional assessments, the present study investigated whether combinations of cryoprotectants at lower individual concentrations result in better cryosurvival rates than single cryoprotectants at higher concentrations. Surplus oocytes from IVF patients were vitrified within 24 h after retrieval using the Cryotop method with several cryoprotectants, either individually or in combination. The morphological and functional quality of the vitrified oocytes was investigated using light microscopy and computer-based quantification of mitochondrial integrity, respectively. Oocyte quality was significantly higher using a combination of cryoprotectants than vitrification with individual cryoprotectants. In addition, the quality of vitrified oocyte varied depending on the cryoprotectants and type of combination used. The results of the present study indicate that observations based purely on the morphological appearance of the oocyte to assess the cryosurvival rate are insufficient and sometimes misleading. The outcome will have a significant implication in the area of human oocyte cryopreservation as an important approach for fertility preservation.
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12
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Ceramide and its transport protein (CERT) contribute to deterioration of mitochondrial structure and function in aging oocytes. Mech Ageing Dev 2012; 134:43-52. [PMID: 23246342 DOI: 10.1016/j.mad.2012.12.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Revised: 11/03/2012] [Accepted: 12/01/2012] [Indexed: 11/22/2022]
Abstract
In women as well as in mice, oocytes exhibit decreased developmental potential (oocyte quality) with advanced age. Our current data implicate alterations in the levels of oocyte ceramide and associated changes in mitochondrial function and structure as being prominent elements contributing to reduced oocyte quality. Both ROS levels and ATP content were significantly reduced in aged oocytes. The decreased in ROS levels are of intrigue because it is contrary to what has been previously reported. Lowered levels of both ROS and ATP indicate diminished mitochondrial function that was accompanied by alterations in mitochondrial structure. Interestingly, developmental potential of old oocytes was improved by microinjection of mitochondria isolated from young oocytes. Co-treatment of aged oocytes with ceramide and a cytoplasmic lipid carrier (l-carnitine) improved both mitochondrial morphology and function, and totally rescued spontaneous in vitro fragmentation. In addition, ceramide localization was altered in old oocytes possibly due to downregulation of the ceramide transport protein (CERT). However, knockdown of CERT alone was not sufficient to increase young oocyte's susceptibility to death, because the sequential manipulation of ceramide levels (its chronic decrease, followed by downregulation of CERT, and finally a ceramide spike) were all necessary to replicate the aging phenotype. These results indicate that oocyte aging is due to a multiplicity of events; and that with increasing biological age, changes in levels of both ceramide and its transport protein contribute to deterioration of oocyte mitochondrial structure and function. Hence, those changes may represent potential targets to manipulate when attempting to ameliorate aging phenotypes in germ cells.
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13
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Ou XH, Li S, Wang ZB, Li M, Quan S, Xing F, Guo L, Chao SB, Chen Z, Liang XW, Hou Y, Schatten H, Sun QY. Maternal insulin resistance causes oxidative stress and mitochondrial dysfunction in mouse oocytes. Hum Reprod 2012; 27:2130-45. [DOI: 10.1093/humrep/des137] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Tejera A, Herrero J, de los Santos M, Garrido N, Ramsing N, Meseguer M. Oxygen consumption is a quality marker for human oocyte competence conditioned by ovarian stimulation regimens. Fertil Steril 2011; 96:618-623.e2. [DOI: 10.1016/j.fertnstert.2011.06.059] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2011] [Revised: 06/22/2011] [Accepted: 06/22/2011] [Indexed: 11/26/2022]
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Harvey A, Gibson T, Lonergan T, Brenner C. Dynamic regulation of mitochondrial function in preimplantation embryos and embryonic stem cells. Mitochondrion 2010; 11:829-38. [PMID: 21168533 DOI: 10.1016/j.mito.2010.12.013] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2010] [Revised: 12/06/2010] [Accepted: 12/09/2010] [Indexed: 01/14/2023]
Abstract
Mitochondrial function is dependent upon regulation of biogenesis and dynamics. A number of studies have documented the importance of these organelles in both preimplantation embryos and embryonic stem cells (ESCs), however it remains unclear how mitochondria respond to their immediate microenvironment through modulation of morphology and movement, or whether perturbations in these processes will have a significant impact following differentiation/implantation. Here we review existing literature on two key aspects of nuclear-mitochondrial cross-talk and the dynamic processes involved in mediating mitochondrial function through regulation of mitochondrial biogenesis, morphology and movement, with particular emphasis on embryos and ESCs.
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Affiliation(s)
- Alexandra Harvey
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201, USA
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Kameyama Y, Ohnishi H, Shimoi G, Hashizume R, Ito M, Smith LC. Asymmetrical allocation of mitochondrial DNA to blastomeres during the first two cleavages in mouse embryos. Reprod Fertil Dev 2010; 22:1247-53. [PMID: 20883650 DOI: 10.1071/rd10076] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2010] [Accepted: 06/21/2010] [Indexed: 12/14/2022] Open
Abstract
A recent report showed higher oxygen consumption, adenosine triphosphate (ATP) production and mitochondrial localisation in trophectoderm cells than in the inner cell mass of mouse blastocysts. We hypothesised that this phenomenon was due to the asymmetrical distribution of mitochondria in the blastomeres during the earlier stages. Oocytes, 2-cell embryos and 4-cell embryos were analysed to determine the volume, ATP content and mitochondrial DNA (mtDNA) copy number in the whole egg and individual blastomeres. Significant differences were detected in the volumes of cytoplasm and ATP contents between blastomeres from the 2-cell and 4-cell embryos. Moreover, whilst remaining stable in whole embryos, mtDNA copy number differed between blastomeres, indicating that mitochondria in oocytes are unevenly delivered into the daughter blastomeres during the first two cleavages. Although their volume and ATP content were not correlated, there was a significant correlation between volume and mtDNA copy number in 2- and 4-cell blastomeres. These results indicate that the number of mitochondria delivered to blastomeres during early cleavage is not precisely equal, suggesting that the allocation of mitochondria into daughter blastomeres is affected by uneven cytoplasmic distribution during cytokinesis in the oocyte and mother blastomeres.
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Affiliation(s)
- Yuichi Kameyama
- Tokyo University of Agriculture, Abashiri, Hokkaido 099-2493, Japan.
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Ramalho-Santos J, Varum S, Amaral S, Mota PC, Sousa AP, Amaral A. Mitochondrial functionality in reproduction: from gonads and gametes to embryos and embryonic stem cells. Hum Reprod Update 2009; 15:553-72. [DOI: 10.1093/humupd/dmp016] [Citation(s) in RCA: 308] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
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Antelman J, Manandhar G, Yi YJ, Li R, Whitworth K, Sutovsky M, Agca C, Prather R, Sutovsky P. Expression of mitochondrial transcription factor A (TFAM) during porcine gametogenesis and preimplantation embryo development. J Cell Physiol 2008; 217:529-43. [DOI: 10.1002/jcp.21528] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Abstract
Mitochondria have long been known to be the powerhouses of the cell but they also contribute to redox and Ca2+ homeostasis, provide intermediary metabolites and store proapoptotic factors. Mitochondria have a unique behavior during development. They are maternally transmitted with little (if any) paternal contribution, and they originate from a restricted founder population, which is amplified during oogenesis. Then, having established the full complement of mitochondria in the fully grown oocyte, there is no further increase of the mitochondrial population during early development. The localization of mitochondria in the egg during maturation and their segregation to blastomeres in the cleaving embryo are strictly regulated. Gradients in the distribution of mitochondria present in the egg have the potential to give rise to blastomeres receiving different numbers of mitochondria. Such maternally inherited differences in mitochondrial distribution are thought to play roles in defining the long-term viability of the blastomere in some cases and embryonic axes and patterning in others. Mitochondria may also regulate development by a number of other means, including modulating Ca2+ signaling, and the production of ATP, reactive oxygen species, and intermediary metabolites. If the participation of mitochondria in the regulation of sperm-triggered Ca2+ oscillations is now well established, the role of other properties of mitochondrial function during development remain largely unexplored probably due to the difficulty of accessing the mitochondrial compartment in an embryo. Maintaining a functional complement of maternally derived mitochondria is vital for the early embryo. Mitochondrial dysfunction may not only compromise developmental processes but also trigger apoptosis in the embryo. This dual role for mitochondria (to maintain life or to commit to cell death) may well represent a quality control system in the early embryo that will determine whether the embryo proceeds further into development or is quickly eliminated.
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Affiliation(s)
- Rémi Dumollard
- Department of Physiology, University College London, London WC1E 6BT, United Kingdom
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