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Bellido-Quispe DK, Arcce IML, Pinzón-Osorio CA, Campos VF, Remião MH. Chemical activation of mammalian oocytes and its application in camelid reproductive biotechnologies: A review. Anim Reprod Sci 2024; 266:107499. [PMID: 38805838 DOI: 10.1016/j.anireprosci.2024.107499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 04/10/2024] [Accepted: 05/10/2024] [Indexed: 05/30/2024]
Abstract
Mammalian oocyte activation is a critical process occurring post-gamete fusion, marked by a sequence of cellular events initiated by an upsurge in intracellular Ca2+. This surge in calcium orchestrates the activation/deactivation of specific kinases, leading to the subsequent inactivation of MPF and MAPK activities, alongside PKC activation. Despite various attempts to induce artificial activation using distinct chemical compounds as Ca2+ inducers and/or Ca2+-independent agents, the outcomes have proven suboptimal. Notably, incomplete suppression of MPF and MAPK activities persists, necessitating a combination of different agents for enhanced efficiency. Moreover, the inherent specificity of activation methods for each species precludes straightforward extrapolation between them. Consequently, optimization of protocols for each species and for each technique, such as PA, ICSI, and SCNT, is required. Despite recent strides in camelid biotechnologies, the field has seen little advancement in chemical activation methods. Only a limited number of chemical agents have been explored, and the effects of many remain unknown. In ICSI, despite obtaining blastocysts with different chemical compounds that induce Ca2+ and calcium-independent increases, viable offspring have not been obtained. However, SCNT has exhibited varying outcomes, successfully yielding viable offspring with a reduced number of chemical activators. This article comprehensively reviews the current understanding of the physiological activation of oocytes and the molecular mechanisms underlying chemical activation in mammals. The aim is to transfer and apply this knowledge to camelid reproductive biotechnologies, with emphasis on chemical activation in PA, ICSI, and SCNT.
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Affiliation(s)
| | | | - César Augusto Pinzón-Osorio
- Laboratório de Fisiopatologia e Biotécnicas da Reprodução Animal (FiBRA), Universidade Federal de Pelotas (UFPel), Pelotas, RS, Brazil
| | - Vinicius Farias Campos
- Laboratório de Genômica Estrutural, Universidade Federal de Pelotas (UFPel), Pelotas, RS, Brazil
| | - Mariana Härter Remião
- Laboratório de Genômica Estrutural, Universidade Federal de Pelotas (UFPel), Pelotas, RS, Brazil
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Akizawa H, Lopes EM, Fissore RA. Zn 2+ is essential for Ca 2+ oscillations in mouse eggs. eLife 2023; 12:RP88082. [PMID: 38099643 PMCID: PMC10723796 DOI: 10.7554/elife.88082] [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] [Indexed: 12/17/2023] Open
Abstract
Changes in the intracellular concentration of free calcium (Ca2+) underpin egg activation and initiation of development in animals and plants. In mammals, the Ca2+ release is periodical, known as Ca2+ oscillations, and mediated by the type 1 inositol 1,4,5-trisphosphate receptor (IP3R1). Another divalent cation, zinc (Zn2+), increases exponentially during oocyte maturation and is vital for meiotic transitions, arrests, and polyspermy prevention. It is unknown if these pivotal cations interplay during fertilization. Here, using mouse eggs, we showed that basal concentrations of labile Zn2+ are indispensable for sperm-initiated Ca2+ oscillations because Zn2+-deficient conditions induced by cell-permeable chelators abrogated Ca2+ responses evoked by fertilization and other physiological and pharmacological agonists. We also found that chemically or genetically generated eggs with lower levels of labile Zn2+ displayed reduced IP3R1 sensitivity and diminished ER Ca2+ leak despite the stable content of the stores and IP3R1 mass. Resupplying Zn2+ restarted Ca2+ oscillations, but excessive Zn2+ prevented and terminated them, hindering IP3R1 responsiveness. The findings suggest that a window of Zn2+ concentrations is required for Ca2+ responses and IP3R1 function in eggs, ensuring optimal response to fertilization and egg activation.
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Affiliation(s)
- Hiroki Akizawa
- Department of Veterinary and Animal Sciences, University of Massachusetts AmherstAmherstUnited States
| | - Emily M Lopes
- Department of Veterinary and Animal Sciences, University of Massachusetts AmherstAmherstUnited States
- Molecular and Cellular Biology Graduate Program, University of MassachusettsAmherstUnited States
| | - Rafael A Fissore
- Department of Veterinary and Animal Sciences, University of Massachusetts AmherstAmherstUnited States
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3
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Akizawa H, Lopes E, Fissore RA. Zn 2+ is Essential for Ca 2+ Oscillations in Mouse Eggs. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.13.536745. [PMID: 37131581 PMCID: PMC10153198 DOI: 10.1101/2023.04.13.536745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Changes in the intracellular concentration of free calcium (Ca2+) underpin egg activation and initiation of development in animals and plants. In mammals, the Ca2+ release is periodical, known as Ca2+ oscillations, and mediated by the type 1 inositol 1,4,5-trisphosphate receptor (IP3R1). Another divalent cation, zinc (Zn2+), increases exponentially during oocyte maturation and is vital for meiotic transitions, arrests, and polyspermy prevention. It is unknown if these pivotal cations interplay during fertilization. Here, using mouse eggs, we showed that basal concentrations of labile Zn2+ are indispensable for sperm-initiated Ca2+ oscillations because Zn2+-deficient conditions induced by cell-permeable chelators abrogated Ca2+ responses evoked by fertilization and other physiological and pharmacological agonists. We also found that chemically- or genetically generated eggs with lower levels of labile Zn2+ displayed reduced IP3R1 sensitivity and diminished ER Ca2+ leak despite the stable content of the stores and IP3R1 mass. Resupplying Zn2+ restarted Ca2+ oscillations, but excessive Zn2+ prevented and terminated them, hindering IP3R1 responsiveness. The findings suggest that a window of Zn2+ concentrations is required for Ca2+ responses and IP3R1 function in eggs, ensuring optimal response to fertilization and egg activation.
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Affiliation(s)
- Hiroki Akizawa
- Department of Veterinary and Animal Sciences, University of Massachusetts Amherst, 661 North Pleasant Street, Amherst, Massachusetts, 01003, United States
| | - Emily Lopes
- Department of Veterinary and Animal Sciences, University of Massachusetts Amherst, 661 North Pleasant Street, Amherst, Massachusetts, 01003, United States
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, Massachusetts, 01003, United States
| | - Rafael A. Fissore
- Department of Veterinary and Animal Sciences, University of Massachusetts Amherst, 661 North Pleasant Street, Amherst, Massachusetts, 01003, United States
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Hirose N, Kikuchi Y, Kageyama A, Sugita H, Sakurai M, Kawata Y, Terakawa J, Wakayama T, Ito J, Kashiwazaki N. Successful Production of Offspring Derived from Phospholipase C Zeta-Deficient Sperm by Additional Artificial Activation. Life (Basel) 2023; 13:life13040980. [PMID: 37109509 PMCID: PMC10143324 DOI: 10.3390/life13040980] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 04/04/2023] [Accepted: 04/06/2023] [Indexed: 04/29/2023] Open
Abstract
During mammalian fertilization, repetitive rises of intracellular calcium called calcium oscillations are required for full activation of oocytes. Therefore, oocytes such as round spermatid injected or somatic cell nuclear transferred require additional artificial activation which mimics the calcium oscillations. It is well recognized that sperm specific phospholipase C (PLCζ) is a strong candidate as the sperm factor which can induce calcium oscillations and, at least in mammals, the genetic mutation of PLCζ in human causes male infertility due to the lack of calcium oscillations in the oocytes. Recent studies showed that the sperm lacking PLCζ (Plcz1-/-) still could induce rise(s) of intracellular calcium in the oocytes after IVF but not intracytoplasmic sperm injection (ICSI). In the ICSI oocytes, no pronuclear formation or development to the two-cell stage was observed. However, it is still unclear whether additional activation treatment can rescue the low developmental ability of Plcz1-/--sperm-derived oocytes after ICSI. In this study, we examined whether oocytes injected with a Plcz1-/- sperm can develop to term by additional artificial activation. In oocytes injected a Plcz1-/- sperm and Plcz1-/- and eCS (another candidate of the sperm factor) double knockout sperm (Plcz1-/-eCS-/-), the rates of pronuclear formation were very low (2.0 ± 2.3% and 6.1 ± 3.7%, respectively) compared to control (92.1 ± 2.6%). However, these rates were dramatically improved by additional procedures of PLCζ-mRNA injection or SrCl2 treatment (Plcz1-/- sperm + PLCζ mRNA, Plcz1-/- sperm + SrCl2 and Plcz1-/-eCS-/- sperm + PLCζ mRNA; 64.2 ± 10.8%, 89.2 ± 2.4% and 72.6 ± 5.4%, respectively). Most of the oocytes were developed to the two-cell stage. After embryo transfer, healthy pups were obtained in all these groups (Plcz1-/- sperm + PLCζ mRNA:10.0 ± 2.8%, Plcz1-/- sperm + SrCl2:4.0 ± 4.3% and Plcz1-/-eCS-/- sperm + PLCζ mRNA: 10.0 ± 5.7%). The rate in Plcz1-/- sperm + SrCl2 group was significantly lower than that in control (26.0 ± 2.4%). Taken together, our present results show that additional activation treatment such as SrCl2 and PLCζ mRNA can fully support to develop to term even in oocyte injected Plcz1-/- sperm. In addition, PLCζ-induced oocyte activation is more suitable for successful development to term compared to that such as phenomenon induced by SrCl2. These findings will contribute to improvement for male-dependent human infertility and reproductive technologies in other mammalian species.
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Affiliation(s)
- Naoki Hirose
- Faculty of Life and Environmental Science, University of Yamanashi, Yamanashi 400-8510, Japan
| | - Yasuyuki Kikuchi
- Faculty of Life and Environmental Science, University of Yamanashi, Yamanashi 400-8510, Japan
| | - Atsuko Kageyama
- Laboratory of Animal Reproduction, Graduate School of Veterinary Medicine, Azabu University, Kanagawa 252-0206, Japan
| | - Hibiki Sugita
- School of Veterinary Medicine, Azabu University, Kanagawa 252-0206, Japan
| | - Miu Sakurai
- School of Veterinary Medicine, Azabu University, Kanagawa 252-0206, Japan
| | - Yui Kawata
- Laboratory of Animal Reproduction, Graduate School of Veterinary Medicine, Azabu University, Kanagawa 252-0206, Japan
| | - Jumpei Terakawa
- School of Veterinary Medicine, Azabu University, Kanagawa 252-0206, Japan
| | - Teruhiko Wakayama
- Faculty of Life and Environmental Science, University of Yamanashi, Yamanashi 400-8510, Japan
- Advanced Biotechnology Center, University of Yamanashi, Yamanashi 400-8510, Japan
| | - Junya Ito
- Laboratory of Animal Reproduction, Graduate School of Veterinary Medicine, Azabu University, Kanagawa 252-0206, Japan
- School of Veterinary Medicine, Azabu University, Kanagawa 252-0206, Japan
- Center for Human and Animal Symbiosis Science, Azabu University, Kanagawa 252-0206, Japan
| | - Naomi Kashiwazaki
- Laboratory of Animal Reproduction, Graduate School of Veterinary Medicine, Azabu University, Kanagawa 252-0206, Japan
- School of Veterinary Medicine, Azabu University, Kanagawa 252-0206, Japan
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Di Berardino C, Peserico A, Capacchietti G, Zappacosta A, Bernabò N, Russo V, Mauro A, El Khatib M, Gonnella F, Konstantinidou F, Stuppia L, Gatta V, Barboni B. High-Fat Diet and Female Fertility across Lifespan: A Comparative Lesson from Mammal Models. Nutrients 2022; 14:nu14204341. [PMID: 36297035 PMCID: PMC9610022 DOI: 10.3390/nu14204341] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 10/10/2022] [Accepted: 10/14/2022] [Indexed: 11/18/2022] Open
Abstract
Female reproduction focuses mainly on achieving fully grown follicles and competent oocytes to be successfully fertilized, as well as on nourishing the developing offspring once pregnancy occurs. Current evidence demonstrates that obesity and/or high-fat diet regimes can perturbate these processes, leading to female infertility and transgenerational disorders. Since the mechanisms and reproductive processes involved are not yet fully clarified, the present review is designed as a systematic and comparative survey of the available literature. The available data demonstrate the adverse influences of obesity on diverse reproductive processes, such as folliculogenesis, oogenesis, and embryo development/implant. The negative reproductive impact may be attributed to a direct action on reproductive somatic and germinal compartments and/or to an indirect influence mediated by the endocrine, metabolic, and immune axis control systems. Overall, the present review highlights the fragmentation of the current information limiting the comprehension of the reproductive impact of a high-fat diet. Based on the incidence and prevalence of obesity in the Western countries, this topic becomes a research challenge to increase self-awareness of dietary reproductive risk to propose solid and rigorous preventive dietary regimes, as well as to develop targeted pharmacological interventions.
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Affiliation(s)
- Chiara Di Berardino
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, 64100 Teramo, Italy
| | - Alessia Peserico
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, 64100 Teramo, Italy
- Correspondence:
| | - Giulia Capacchietti
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, 64100 Teramo, Italy
| | - Alex Zappacosta
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, 64100 Teramo, Italy
| | - Nicola Bernabò
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, 64100 Teramo, Italy
- Institute of Biochemistry and Cell Biology (IBBC), National Research Council, A. Buzzati-Traverso Campus, via E. Ramarini 32, Monterotondo Scalo, 00015 Rome, Italy
| | - Valentina Russo
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, 64100 Teramo, Italy
| | - Annunziata Mauro
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, 64100 Teramo, Italy
| | - Mohammad El Khatib
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, 64100 Teramo, Italy
| | - Francesca Gonnella
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, 64100 Teramo, Italy
- Department of Psychological Health and Territorial Sciences, School of Medicine and Health Sciences, “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy
- Unit of Molecular Genetics, Center for Advanced Studies and Technology (CAST), “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy
| | - Fani Konstantinidou
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, 64100 Teramo, Italy
- Department of Psychological Health and Territorial Sciences, School of Medicine and Health Sciences, “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy
- Unit of Molecular Genetics, Center for Advanced Studies and Technology (CAST), “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy
| | - Liborio Stuppia
- Department of Psychological Health and Territorial Sciences, School of Medicine and Health Sciences, “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy
- Unit of Molecular Genetics, Center for Advanced Studies and Technology (CAST), “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy
| | - Valentina Gatta
- Department of Psychological Health and Territorial Sciences, School of Medicine and Health Sciences, “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy
- Unit of Molecular Genetics, Center for Advanced Studies and Technology (CAST), “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy
| | - Barbara Barboni
- Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, 64100 Teramo, Italy
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Yuan LM, Chen YL, Shi XH, Wu XX, Liu XJ, Liu SP, Chen N, Sai WJF. PLCζ can stably regulate Ca2+ fluctuations in early embryo. Theriogenology 2022; 191:16-21. [DOI: 10.1016/j.theriogenology.2022.06.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 06/05/2022] [Accepted: 06/17/2022] [Indexed: 12/01/2022]
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Effect of A23187 ionophore treatment on human blastocyst development-a sibling oocyte study. J Assist Reprod Genet 2022; 39:1225-1232. [PMID: 35357606 DOI: 10.1007/s10815-022-02467-3] [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: 10/04/2021] [Accepted: 03/15/2022] [Indexed: 10/18/2022] Open
Abstract
PURPOSE To investigate whether treatment with commercially available ready-to-use A23187 ionophore (GM508-CultActive) improves embryo development outcome in patients with a history of embryo developmental problems. METHODS This is a uni-center prospective study in which sibling oocytes of patients with embryos of poor quality on day 5 in the previous cycle were treated or not with CultActive. RESULTS Two hundred forty-seven metaphase II (MII) oocytes from 19 cycles performed between 2016 and 2019 were included in the study. After ICSI, the sibling oocytes were assigned to the treatment group or to the control group, following an electronically generated randomization list. A number of 122 MII were treated with CultActive and 125 MII had no treatment and were assigned to the control group. No difference in fertilization rate (p = 0.255) or in the capacity of embryos to reach good quality on day 5 (p = 0.197) was observed between the two groups. The utilization rates defined as the number of embryos transferred or cryopreserved per mature oocyte (p = 0.438) or per fertilized oocytes (p = 0.299) were not significantly different between the treated group and the control group. CONCLUSION The results of the current study do not support the use of CultActive in cases with embryo developmental problems.
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Kashir J, Ganesh D, Jones C, Coward K. OUP accepted manuscript. Hum Reprod Open 2022; 2022:hoac003. [PMID: 35261925 PMCID: PMC8894871 DOI: 10.1093/hropen/hoac003] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 01/16/2022] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Oocyte activation deficiency (OAD) is attributed to the majority of cases underlying failure of ICSI cycles, the standard treatment for male factor infertility. Oocyte activation encompasses a series of concerted events, triggered by sperm-specific phospholipase C zeta (PLCζ), which elicits increases in free cytoplasmic calcium (Ca2+) in spatially and temporally specific oscillations. Defects in this specific pattern of Ca2+ release are directly attributable to most cases of OAD. Ca2+ release can be clinically mediated via assisted oocyte activation (AOA), a combination of mechanical, electrical and/or chemical stimuli which artificially promote an increase in the levels of intra-cytoplasmic Ca2+. However, concerns regarding safety and efficacy underlie potential risks that must be addressed before such methods can be safely widely used. OBJECTIVE AND RATIONALE Recent advances in current AOA techniques warrant a review of the safety and efficacy of these practices, to determine the extent to which AOA may be implemented in the clinic. Importantly, the primary challenges to obtaining data on the safety and efficacy of AOA must be determined. Such questions require urgent attention before widespread clinical utilization of such protocols can be advocated. SEARCH METHODS A literature review was performed using databases including PubMed, Web of Science, Medline, etc. using AOA, OAD, calcium ionophores, ICSI, PLCζ, oocyte activation, failed fertilization and fertilization failure as keywords. Relevant articles published until June 2019 were analysed and included in the review, with an emphasis on studies assessing large-scale efficacy and safety. OUTCOMES Contradictory studies on the safety and efficacy of AOA do not yet allow for the establishment of AOA as standard practice in the clinic. Heterogeneity in study methodology, inconsistent sample inclusion criteria, non-standardized outcome assessments, restricted sample size and animal model limitations render AOA strictly experimental. The main scientific concern impeding AOA utilization in the clinic is the non-physiological method of Ca2+ release mediated by most AOA agents, coupled with a lack of holistic understanding regarding the physiological mechanism(s) underlying Ca2+ release at oocyte activation. LIMITATIONS, REASONS FOR CAUTION The number of studies with clinical relevance using AOA remains significantly low. A much wider range of studies examining outcomes using multiple AOA agents are required. WIDER IMPLICATIONS In addition to addressing the five main challenges of studies assessing AOA safety and efficacy, more standardized, large-scale, multi-centre studies of AOA, as well as long-term follow-up studies of children born from AOA, would provide evidence for establishing AOA as a treatment for infertility. The delivery of an activating agent that can more accurately recapitulate physiological fertilization, such as recombinant PLCζ, is a promising prospect for the future of AOA. Further to PLCζ, many other avenues of physiological oocyte activation also require urgent investigation to assess other potential physiological avenues of AOA. STUDY FUNDING/COMPETING INTERESTS D.G. was supported by Stanford University’s Bing Overseas Study Program. J.K. was supported by a Healthcare Research Fellowship Award (HF-14-16) made by Health and Care Research Wales (HCRW), alongside a National Science, Technology, and Innovation plan (NSTIP) project grant (15-MED4186-20) awarded by the King Abdulaziz City for Science and Technology (KACST). The authors have no competing interests to declare.
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Affiliation(s)
| | | | - Celine Jones
- Nuffield Department of Women’s & Reproductive Health, University of Oxford, Level 3, Women’s Centre, John Radcliffe Hospital, Oxford, UK
| | - Kevin Coward
- Correspondence address. Nuffield Department of Women’s & Reproductive Health, University of Oxford, Level 3, Women’s Centre, John Radcliffe Hospital, Oxford, OS3 9DU, UK. E-mail: https://orcid.org/0000-0003-3577-4041
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9
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Kageyama A, Suyama A, Kinoshita R, Ito J, Kashiwazaki N. Dynamic changes of intracellular zinc ion level during maturation, fertilization, activation, and development in mouse oocytes. Anim Sci J 2022; 93:e13759. [PMID: 35880318 DOI: 10.1111/asj.13759] [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: 05/24/2022] [Revised: 06/12/2022] [Accepted: 06/30/2022] [Indexed: 11/29/2022]
Abstract
Although it is well known that calcium oscillations are required for fertilization in all mammalian species studied to date, recent studies also showed the ejection of zinc into the extracellular milieu in a series of coordinated events, called "zinc spark," during mammalian fertilization. These results led us to the hypothesis that a zinc ion-dependent signal is important for oocyte maturation, fertilization (activation), and further embryonic development. In this study, we evaluated the amounts and localization of intracellular zinc ions during maturation, fertilization, activation, and embryonic development in mouse oocytes. Our results show that abundant zinc ions are present in both immature and mature oocytes. After in vitro fertilization, the amounts of zinc ions were dramatically decreased at the pronuclear (PN) stage. Artificial activation by cycloheximide, SrCl2 , and TPEN also reduced the amounts of zinc ions in the PN stage. On the other hand, PN embryos derived from sperm injection still showed high level of zinc ions. However, the amounts of zinc ions rapidly increased at the blastocysts regardless of activation method. We showed here that the amounts of zinc ions dramatically changed during maturation, fertilization, activation, and development in mouse oocytes.
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Affiliation(s)
- Atsuko Kageyama
- Laboratory of Animal Reproduction, Graduate School of Veterinary Sciences, Azabu University, Sagamihara, Japan
| | - Ayumi Suyama
- Laboratory of Animal Reproduction, Graduate School of Veterinary Sciences, Azabu University, Sagamihara, Japan
| | - Ruka Kinoshita
- School of Veterinary Medicine, Azabu University, Sagamihara, Japan
| | - Junya Ito
- Laboratory of Animal Reproduction, Graduate School of Veterinary Sciences, Azabu University, Sagamihara, Japan.,School of Veterinary Medicine, Azabu University, Sagamihara, Japan.,Center for Human and Animal Symbiosis Science, Azabu University, Sagamihara, Japan
| | - Naomi Kashiwazaki
- Laboratory of Animal Reproduction, Graduate School of Veterinary Sciences, Azabu University, Sagamihara, Japan.,School of Veterinary Medicine, Azabu University, Sagamihara, Japan
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10
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Pu L, Shahzad Q, Chen F, Yao S, Tang Y, Chen D, Yu K, Xie L, Xu H, Zhang M, Lu Y. Proteomic analysis demonstrates that parthenogenetically activated swamp buffalo embryos have dysregulated energy metabolism. Reprod Domest Anim 2020; 55:1764-1773. [PMID: 33031588 DOI: 10.1111/rda.13838] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Accepted: 10/02/2020] [Indexed: 01/06/2023]
Abstract
The comprehensive understanding of early embryo development is essential to optimize in vitro culture conditions. Protein expression landscape of parthenogenetically produced embryo remains unexplored. This study aimed to investigate the protein expression dynamics with a particular focus on energy metabolism throughout the early developmental stages of parthenogenetic buffalo embryos. For this purpose, we performed iTRAQ-based quantitative mass spectrometry and identified 280 proteins common in all stages. A total of 933 proteins were identified during the proteomics analysis. The data depicted that morula and blastocyst had distinct protein expression dynamics as compared to 2- to 16-cell-stage embryo. KEGG pathway analysis showed 23 proteins belonging to energy metabolism appeared in the data. Study of energy metabolism-related protein's expression pattern demonstrated that there was asynchrony in proteins related to glycolysis throughout the examined developmental stages. The expression pattern of pyruvate kinase mutase (PKM), an essential protein of glycolysis, indicated a slightly decreasing trend from 2-cell-stage embryo to blastocyst, and it was supported by expression of proteins involved in lactate production (LDHA and LDHB) suggesting the decreasing rate of aerobic glycolysis (Warburg Effect) at morula and blastocyst stage. The increased Warburg Effect is considered as the hallmark of proliferating cells or embryo at the blastocyst stage. Furthermore, the proteins involved in the citric acid cycle also showed down-regulation at the blastocyst stage, indicating a lesser role of oxidative phosphorylation at this stage. Therefore, it could be divulged from the study that there may be an irregular pattern of energy metabolism in early parthenogenetic embryos. Further studies are recommended to understand this phenomenon.
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Affiliation(s)
- Liping Pu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, China
| | - Qaisar Shahzad
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, China
| | - Fumen Chen
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, China
| | - Shun Yao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, China
| | - Yuyan Tang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, China
| | - Dongrong Chen
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, China
| | - Kai Yu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, China
| | - Long Xie
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, China
| | - Huiyan Xu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, China
| | - Ming Zhang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, China
| | - Yangqing Lu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, China
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11
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McLennan HJ, Sutton-McDowall ML, Heng S, Abell AD, Thompson JG. Time-lapse confocal imaging-induced calcium ion discharge from the cumulus-oocyte complex at the time of cattle oocyte activation. Reprod Fertil Dev 2020; 32:1223-1238. [PMID: 33027608 DOI: 10.1071/rd20143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 09/15/2020] [Indexed: 11/23/2022] Open
Abstract
Oocyte activation, the dynamic transformation of an oocyte into an embryo, is largely driven by Ca2+ oscillations that vary in duration and amplitude across species. Previous studies have analysed intraoocyte Ca2+ oscillations in the absence of the oocyte's supporting cumulus cells. Therefore, it is unknown whether cumulus cells also produce an ionic signal that reflects fertilisation success. Time-lapse confocal microscopy and image analysis on abattoir-derived cattle cumulus-oocyte complexes coincubated with spermatozoa revealed a distinct discharge of fluorescence from the cumulus vestment. This study demonstrated that this Ca2+ fluorescence discharge was an artefact induced by the imaging procedure independently of oocyte activation success. The fluorescence discharge was a direct result of cumulus cell membrane integrity loss, and future studies should consider the long-term effect of fluorescent labels on cells in time-lapse imaging. However, this study also demonstrated that the distinctive pattern of a coordinated fluorescence discharge was associated with both the presence of spermatozoa and subsequent embryo development to the morula stage, which was affected by Ca2+ chelation and a reduction in the active efflux of the fluorophore. This indicates that the cumulus vestment may have a relationship with oocyte activation at and beyond fertilisation that requires further investigation.
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Affiliation(s)
- Hanna J McLennan
- Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, Australia; and Robinson Research Institute, Adelaide Medical School, University of Adelaide, SA 5005, Australia; and Institute for Photonics and Advanced Sensing, School of Physical Sciences, University of Adelaide, SA 5005, Australia; and Corresponding author.
| | - Melanie L Sutton-McDowall
- Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, Australia; and Robinson Research Institute, Adelaide Medical School, University of Adelaide, SA 5005, Australia; and Institute for Photonics and Advanced Sensing, School of Physical Sciences, University of Adelaide, SA 5005, Australia
| | - Sabrina Heng
- Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, Australia; and Institute for Photonics and Advanced Sensing, School of Physical Sciences, University of Adelaide, SA 5005, Australia; and Department of Chemistry, School of Physical Sciences, University of Adelaide, SA 5005, Australia
| | - Andrew D Abell
- Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, Australia; and Institute for Photonics and Advanced Sensing, School of Physical Sciences, University of Adelaide, SA 5005, Australia; and Department of Chemistry, School of Physical Sciences, University of Adelaide, SA 5005, Australia
| | - Jeremy G Thompson
- Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, Australia; and Robinson Research Institute, Adelaide Medical School, University of Adelaide, SA 5005, Australia; and Institute for Photonics and Advanced Sensing, School of Physical Sciences, University of Adelaide, SA 5005, Australia
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12
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Abstract
The process of embryonic development is crucial and radically influences preimplantation embryo competence. It involves oocyte maturation, fertilization, cell division and blastulation and is characterized by different key phases that have major influences on embryo quality. Each stage of the process of preimplantation embryonic development is led by important signalling pathways that include very many regulatory molecules, such as primary and secondary messengers. Many studies, both in vivo and in vitro, have shown the importance of the contribution of reactive oxygen species (ROS) as important second messengers in embryo development. ROS may originate from embryo metabolism and/or oocyte/embryo surroundings, and their effect on embryonic development is highly variable, depending on the needs of the embryo at each stage of development and on their environment (in vivo or under in vitro culture conditions). Other studies have also shown the deleterious effects of ROS in embryo development, when cellular tissue production overwhelms antioxidant production, leading to oxidative stress. This stress is known to be the cause of many cellular alterations, such as protein, lipid, and DNA damage. Considering that the same ROS level can have a deleterious effect on the fertilizing oocyte or embryo at certain stages, and a positive effect at another stage of the development process, further studies need to be carried out to determine the rate of ROS that benefits the embryo and from what rate it starts to be harmful, this measured at each key phase of embryonic development.
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13
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Matsu-Ura T, Shirakawa H, Suzuki KGN, Miyamoto A, Sugiura K, Michikawa T, Kusumi A, Mikoshiba K. Dual-FRET imaging of IP 3 and Ca 2+ revealed Ca 2+-induced IP 3 production maintains long lasting Ca 2+ oscillations in fertilized mouse eggs. Sci Rep 2019; 9:4829. [PMID: 30886280 PMCID: PMC6423007 DOI: 10.1038/s41598-019-40931-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 02/19/2019] [Indexed: 01/31/2023] Open
Abstract
In most species, fertilization induces Ca2+ transients in the egg. In mammals, the Ca2+ rises are triggered by phospholipase Cζ (PLCζ) released from the sperm; IP3 generated by PLCζ induces Ca2+ release from the intracellular Ca2+ store through IP3 receptor, termed IP3-induced Ca2+ release. Here, we developed new fluorescent IP3 sensors (IRIS-2s) with the wider dynamic range and higher sensitivity (Kd = 0.047-1.7 μM) than that we developed previously. IRIS-2s employed green fluorescent protein and Halo-protein conjugated with the tetramethylrhodamine ligand as fluorescence resonance energy transfer (FRET) donor and acceptor, respectively. For simultaneous imaging of Ca2+ and IP3, using IRIS-2s as the IP3 sensor, we developed a new single fluorophore Ca2+ sensor protein, DYC3.60. With IRIS-2s and DYC3.60, we found that, right after fertilization, IP3 concentration ([IP3]) starts to increase before the onset of the first Ca2+ wave. [IP3] stayed at the elevated level with small peaks followed after Ca2+ spikes through Ca2+ oscillations. We detected delays in the peak of [IP3] compared to the peak of each Ca2+ spike, suggesting that Ca2+-induced regenerative IP3 production through PLC produces small [IP3] rises to maintain [IP3] over the basal level, which results in long lasting Ca2+ oscillations in fertilized eggs.
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Affiliation(s)
- Toru Matsu-Ura
- Laboratory for Developmental Neurobiology, Center for Brain Sciences, RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Hideki Shirakawa
- Department of Applied Physics and Chemistry, The University of Electro-Communications, Tokyo, 182-8585, Japan
| | - Kenichi G N Suzuki
- Center for Highly Advanced Integration of Nano and Life Sciences (G-CHAIN), Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan
| | - Akitoshi Miyamoto
- Laboratory for Developmental Neurobiology, Center for Brain Sciences, RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.,Laboratory of Single-Molecule Cell Biology, Kyoto University Graduate School of Biostudies, Konoe-cho, Sakyo-ku, Kyoto, 606-8501, Japan
| | - Kotomi Sugiura
- Division of Mucosal Vaccines, International Research and Development Center for Mucosal Vaccine, The Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo, 108-8639, Japan
| | - Takayuki Michikawa
- Laboratory for Biotechnological Optics Research, Center for Advanced Photonics, RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Akihiro Kusumi
- Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna, Okinawa, 904-0495, Japan
| | - Katsuhiko Mikoshiba
- Laboratory for Developmental Neurobiology, Center for Brain Sciences, RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan. .,Department of Pharmacology, Keio University School of Medicine, 35 Shinanomachi, Shnjukuku, Tokyo, 160-8582, Japan. .,Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, 201210, China.
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14
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Parrington J, Arnoult C, Fissore RA. The eggstraordinary story of how life begins. Mol Reprod Dev 2018; 86:4-19. [PMID: 30411426 DOI: 10.1002/mrd.23083] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2018] [Accepted: 11/06/2018] [Indexed: 12/24/2022]
Abstract
More than 15 years have elapsed since the identification of phospholipase C ζ1 (PLCζ) from a genomic search for mouse testis/sperm-specific PLCs. This molecule was proposed to represent the sperm factor responsible for the initiation of calcium (Ca2+ ) oscillations required for egg activation and embryo development in mammals. Supporting evidence for this role emerged from studies documenting its expression in all mammals and other vertebrate species, the physiological Ca2+ rises induced by injection of its messenger RNA into mammalian and nonmammalian eggs, and the lack of expression in infertile males that fail intracytoplasmic sperm injection. In the last year, genetic animal models have added support to its role as the long sought-after sperm factor. In this review, we highlight the findings that demonstrated the role of Ca2+ as the universal signal of egg activation and the experimental buildup that culminated with the identification of PLCζ as the soluble sperm factor. We also discuss the structural-functional properties that make PLCζ especially suited to evoke oscillations in eggs. Lastly, we examine unresolved aspects of the function and regulation of PLCζ and whether or not it is the only sperm factor in mammalian sperm.
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Affiliation(s)
- John Parrington
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Christophe Arnoult
- Université Grenoble Alpes, Grenoble, France.,Institut pour l'Avancée des Biosciences (IAB), INSERM 1209, CNRS UMR 5309, La Tronche, France
| | - Rafael A Fissore
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, Massachusetts
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15
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Águila L, Felmer R, Arias ME, Navarrete F, Martin-Hidalgo D, Lee HC, Visconti P, Fissore R. Defective sperm head decondensation undermines the success of ICSI in the bovine. Reproduction 2018; 154:307-318. [PMID: 28751536 DOI: 10.1530/rep-17-0270] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 06/20/2017] [Accepted: 06/30/2017] [Indexed: 12/25/2022]
Abstract
The efficiency of intracytoplasmic sperm injection (ICSI) in the bovine is low compared to other species. It is unknown whether defective oocyte activation and/or sperm head decondensation limit the success of this technique in this species. To elucidate where the main obstacle lies, we used homologous and heterologous ICSI and parthenogenetic activation procedures. We also evaluated whether in vitro maturation negatively impacted the early stages of activation after ICSI. Here we showed that injected bovine sperm are resistant to nuclear decondensation by bovine oocytes and this is only partly overcome by exogenous activation. Remarkably, when we used heterologous ICSI, in vivo-matured mouse eggs were capable of mounting calcium oscillations and displaying normal PN formation following injection of bovine sperm, although in vitro-matured mouse oocytes were unable to do so. Together, our data demonstrate that bovine sperm are especially resistant to nuclear decondensation by in vitro-matured oocytes and this deficiency cannot be simply overcome by exogenous activation protocols, even by inducing physiological calcium oscillations. Therefore, the inability of a suboptimal ooplasmic environment to induce sperm head decondensation limits the success of ICSI in the bovine. Studies aimed to improve the cytoplasmic milieu of in vitro-matured oocytes and to replicate the molecular changes associated with in vivo capacitation and acrosome reaction will deepen our understanding of the mechanism of fertilization and improve the success of ICSI in this species.
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Affiliation(s)
- Luis Águila
- Laboratory of Reproduction, Centre of Reproductive Biotechnology (CEBIOR-BIOREN), Universidad de La Frontera, Temuco, Chile.,Department of Agricultural Sciences and Natural Resources, Faculty of Agriculture and Forestry, Universidad de La Frontera, Temuco, Chile.,School of Veterinary Medicine, Faculty of Sciences, Universidad Mayor Sede Temuco, Temuco, Chile
| | - Ricardo Felmer
- Laboratory of Reproduction, Centre of Reproductive Biotechnology (CEBIOR-BIOREN), Universidad de La Frontera, Temuco, Chile.,Department of Agricultural Sciences and Natural Resources, Faculty of Agriculture and Forestry, Universidad de La Frontera, Temuco, Chile
| | - María Elena Arias
- Laboratory of Reproduction, Centre of Reproductive Biotechnology (CEBIOR-BIOREN), Universidad de La Frontera, Temuco, Chile.,Department of Agricultural Sciences and Natural Resources, Faculty of Agriculture and Forestry, Universidad de La Frontera, Temuco, Chile
| | - Felipe Navarrete
- Department of Veterinary and Animal Science, Integrated Sciences Building, University of Massachusetts, Amherst, Massachusetts, USA
| | - David Martin-Hidalgo
- Research Group of Intracellular Signaling and Technology of Reproduction, Research Institute INBIO G+C, University of Extremadura, Caceres, Spain.,Department of Veterinary and Animal Science, Integrated Sciences Building, University of Massachusetts, Amherst, Massachusetts, USA
| | - Hoi Chang Lee
- Department of Veterinary and Animal Science, Integrated Sciences Building, University of Massachusetts, Amherst, Massachusetts, USA
| | - Pablo Visconti
- Department of Veterinary and Animal Science, Integrated Sciences Building, University of Massachusetts, Amherst, Massachusetts, USA
| | - Rafael Fissore
- Department of Veterinary and Animal Science, Integrated Sciences Building, University of Massachusetts, Amherst, Massachusetts, USA
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16
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Dehydroepiandrosterone (DHEA) and Its Sulfate (DHEA-S) in Mammalian Reproduction: Known Roles and Novel Paradigms. VITAMINS AND HORMONES 2018; 108:223-250. [PMID: 30029728 DOI: 10.1016/bs.vh.2018.02.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Steroid hormones form an integral part of normal development in mammalian organisms. Cholesterol is the parent compound from which all steroid hormones are synthesized. The product pregnenolone formed from cholesterol serves as precursor for mineralocorticoids, glucocorticoids, as well as dehydroepiandrosterone (DHEA) and its derived sexual hormones. DHEA assumes the prohormone status of a predominant endogenous precursor and a metabolic intermediate in ovarian follicular steroidogenesis. DHEA supplementation has been used to enhance ovarian reserve. Steroids like estradiol and testosterone have long been contemplated to play important roles in regulating meiotic maturation of oocytes in conjunction with gonadotropins. It is known that oocyte priming with estrogen is necessary to develop calcium (Ca2+) oscillations during maturation. Accruing evidence from diverse studies suggests that DHEA and its sulfate (dehydroepiandrosterone sulfate, DHEA-S) play significantly vital role not only as intermediates in androgen and estrogen formation, but may also be the probable 'oocyte factor' and behave as endogenous agonists triggering calcium oscillations for oocyte activation. DHEA/DHEA-S have been reported to regulate calcium channels for the passage of Ca2+ through the oocyte cytoplasm and for maintaining required threshold of Ca2+ oscillations. This role of DHEA/DHEA-S assumes critical significance in assisted reproductive technology and in-vitro fertilization treatment cycles where physical, chemical, and mechanical methods are employed for artificial oocyte activation to enhance fertilization rates. However, since these methods are invasive and may also cause adverse epigenetic modifications; oral or culture-media supplementation with DHEA/DHEA-S provides a noninvasive innate mechanism of in-vitro oocyte activation based on physiological metabolic pathway.
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17
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The role and mechanism of action of sperm PLC-zeta in mammalian fertilisation. Biochem J 2017; 474:3659-3673. [PMID: 29061915 DOI: 10.1042/bcj20160521] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 09/14/2017] [Accepted: 09/18/2017] [Indexed: 12/26/2022]
Abstract
At mammalian fertilisation, the fundamental stimulus that triggers oocyte (egg) activation and initiation of early embryonic development is an acute rise of the intracellular-free calcium (Ca2+) concentration inside the egg cytoplasm. This essential Ca2+ increase comprises a characteristic series of repetitive Ca2+ oscillations, starting soon after sperm-egg fusion. Over the last 15 years, accumulating scientific and clinical evidence supports the notion that the physiological stimulus that precedes the cytosolic Ca2+ oscillations is a novel, testis-specific phospholipase C (PLC) isoform, known as PLC-zeta (PLCζ). Sperm PLCζ catalyses the hydrolysis of phosphatidylinositol 4,5-bisphosphate triggering cytosolic Ca2+ oscillations through the inositol 1,4,5-trisphosphate signalling pathway. PLCζ is the smallest known mammalian PLC isoform with the most elementary domain organisation. However, relative to somatic PLCs, the PLCζ isoform possesses a unique potency in stimulating Ca2+ oscillations in eggs that is attributed to its novel biochemical characteristics. In this review, we discuss the latest developments that have begun to unravel the vital role of PLCζ at mammalian fertilisation and decipher its unique mechanism of action within the fertilising egg. We also postulate the significant potential diagnostic and therapeutic capacity of PLCζ in alleviating certain types of male infertility.
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18
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Nair R, Manikkath J, Hegde AR, Mutalik S, Kalthur G, Adiga SK. Liposome-encapsulated diacyl glycerol and inositol triphosphate-induced delayed oocyte activation and poor development of parthenotes. J Turk Ger Gynecol Assoc 2017; 18:102-109. [PMID: 28890423 PMCID: PMC5590204 DOI: 10.4274/jtgga.2017.0014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Objective: To explore the ability of diacyl glycerol (DAG) and inositol triphosphate (IP3), two major secondary messengers in the calcium signaling pathway, in activating oocytes. Material and Methods: Oocyte cumulus complex obtained from superovulated Swiss albino mice were incubated in M16 medium with liposome-encapsulated 1,2-Dipalmitoyl-sn-glycerol (LEDAG) and/or IP3 for 3 h. Strontium chloride was used as positive control. The activation potential, ploidy status, and blastocyst rate was calculated. Results: Both DAG and IP3, individually, induced activation in ~98% of oocytes, which was significantly higher (p<0.01) than activation induced by strontium chloride (60%). Delayed pronucleus formation and a higher percentage of diploid parthenotes was observed in oocytes activated with LEDAG and/or IP3. However, these embryos failed to progress beyond the 6-8–cell stage. Only when the medium was supplemented with LEDAG (5 μg/mL) and IP3 (10 μg/mL) could activated oocytes progress till the blastocyst stage (5.26%), which was lower than the blastocyst rate in the positive controls (13.91%). Conclusion: The results of the present study indicate that DAG and IP3 can induce delayed oocyte activation and poor development of parthenotes in vitro.
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Affiliation(s)
- Ramya Nair
- Department of Clinical Embryology, Central Research Lab, Kasturba Medical College, Manipal University, Manipal, India
| | - Jyothsna Manikkath
- Department of Pharmaceutics, Manipal College of Pharmaceutical Sciences, Manipal University, Manipal, India
| | - Aswathi R Hegde
- Department of Pharmaceutics, Manipal College of Pharmaceutical Sciences, Manipal University, Manipal, India
| | - Srinivas Mutalik
- Department of Pharmaceutics, Manipal College of Pharmaceutical Sciences, Manipal University, Manipal, India
| | - Guruprasad Kalthur
- Department of Clinical Embryology, Central Research Lab, Kasturba Medical College, Manipal University, Manipal, India
| | - Satish Kumar Adiga
- Department of Clinical Embryology, Central Research Lab, Kasturba Medical College, Manipal University, Manipal, India
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19
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Fertility: Store-Operated Ca 2+ Entry in Germ Cells: Role in Egg Activation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 993:577-593. [PMID: 28900934 DOI: 10.1007/978-3-319-57732-6_29] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
At the time of fertilization, the sperm activates the egg and induces embryonic development by triggering an elevation in the egg's intracellular free Ca2+ concentration. In mammals the initial Ca2+ rise is followed by a series of repetitive Ca2+ transients (known as oscillations) that last for several hours. Although the source of Ca2+ during the signaling process is primarily the egg's smooth endoplasmic reticulum, the oscillations stop in the absence of extracellular Ca2+ indicating that a Ca2+ influx across the plasma membrane is essential to sustain them. Depletion of the intracellular stores using specific inhibitors generates a Ca2+ entry across the plasma membrane of eggs of various species, and a continuous influx of Ca2+ has been linked to the sperm-induced Ca2+ oscillations in the mouse; these data indicate that store-operated Ca2+ entry (SOCE) operates in eggs and may be the mechanism that maintains the long-lasting Ca2+ signal at fertilization. Recent findings suggest that the signaling proteins STIM1 and Orai1 are present in eggs; they are responsible for mediating SOCE, and their functions are essential for proper Ca2+ signaling at fertilization to support normal embryo development.
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20
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Nakai M, Suzuki SI, Ito J, Fuchimoto DI, Sembon S, Noguchi J, Onishi A, Kashiwazaki N, Kikuchi K. Efficient pig ICSI using Percoll-selected spermatozoa; evidence for the essential role of phospholipase C-ζ in ICSI success. J Reprod Dev 2016; 62:639-643. [PMID: 27725346 PMCID: PMC5177984 DOI: 10.1262/jrd.2016-103] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
In pigs, the damaged sperm membrane leads to leakage of phospholipase C-ζ (PLCζ), which has been identified as a sperm factor, and a reduction of
oocyte-activating ability. In this study, we investigated whether sperm selected by Percoll gradient centrifugation (Percoll) have sufficient PLCζ, and whether
the efficiency of fertilization and blastocyst formation after intracytoplasmic sperm injection (ICSI) using Percoll-selected sperm can be improved.
Percoll-selected sperm (Percoll group) or sperm without Percoll selection (Control group) were used. A proportion of the oocytes injected with control sperm
were subjected to electrical stimulation at 1 h after ICSI (Cont + ES group). It was found that the Percoll group showed a large amount of PLCζ in comparison
with the Control group. Furthermore, application of Percoll-selected sperm for ICSI increased the efficiency of fertilization and embryo development. Thus,
these results indicate the Percoll-selected sperm have sufficient PLCζ and high oocyte-activating ability after ICSI in pigs.
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Affiliation(s)
- Michiko Nakai
- Division of Animal Sciences, Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, Ibaraki 305-8602, Japan
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21
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Nakai M, Ito J, Suzuki SI, Fuchimoto DI, Sembon S, Suzuki M, Noguchi J, Kaneko H, Onishi A, Kashiwazaki N, Kikuchi K. Lack of calcium oscillation causes failure of oocyte activation after intracytoplasmic sperm injection in pigs. J Reprod Dev 2016; 62:615-621. [PMID: 27725347 PMCID: PMC5177980 DOI: 10.1262/jrd.2016-113] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In pigs, the efficiency of embryo production after intracytoplasmic sperm injection (ICSI) is still low because of frequent failure of normal fertilization,
which involves formation of two polar bodies and two pronuclei. To clarify the reasons for this, we hypothesized that ICSI does not properly trigger
sperm-induced fertilization events, especially intracellular Ca2+ signaling, also known as Ca2+ oscillation. We also suspected that the
use of in vitro-matured oocytes might negatively affect fertilization events and embryonic development of sperm-injected oocytes. Therefore, we
compared the patterns of Ca2+ oscillation, the efficiency of oocyte activation and normal fertilization, and embryo development to the blastocyst
stage among in vivo- or in vitro-matured oocytes after ICSI or in vitro fertilization (IVF). Unexpectedly, we
found that the pattern of Ca2+ oscillation, such as the frequency and amplitude of Ca2+ rises, in oocytes after ICSI was similar to that
in oocytes after IVF, irrespective of the oocyte source. However, half of the oocytes failed to become activated after ICSI and showed no Ca2+
oscillation. Moreover, the embryonic development of normal fertilized oocytes was reduced when in vitro-matured oocytes were used, irrespective
of the fertilization method employed. These findings suggest that low embryo production efficiency after ICSI is attributable mainly to poor developmental
ability of in vitro-matured oocytes and a lack of Ca2+ oscillation, rather than the pattern of oscillation.
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Affiliation(s)
- Michiko Nakai
- Division of Animal Sciences, Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, Ibaraki 305-8602, Japan
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22
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Ellinger I. The Calcium-Sensing Receptor and the Reproductive System. Front Physiol 2016; 7:371. [PMID: 27625611 PMCID: PMC5003915 DOI: 10.3389/fphys.2016.00371] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Accepted: 08/11/2016] [Indexed: 12/14/2022] Open
Abstract
Active placental transport of maternal serum calcium (Ca2+) to the offspring is pivotal for proper development of the fetal skeleton as well as various organ systems. Moreover, extracellular Ca2+ levels impact on distinct processes in mammalian reproduction. The calcium-sensing receptor (CaSR) translates changes in extracellular Ca2+-concentrations into cellular reactions. This review summarizes current knowledge on the expression of CaSR and its putative functions in reproductive organs. CaSR was detected in placental cells mediating materno-fetal Ca2+-transport such as the murine intraplacental yolk sac (IPYS) and the human syncytiotrophoblast. As shown in casr knock-out mice, ablation of CaSR downregulates transplacental Ca2+-transport. Receptor expression was reported in human and rat ovarian surface epithelial (ROSE) cells, where CaSR activation stimulates cell proliferation. In follicles of various species a role of CaSR activation in oocyte maturation was suggested. Based on studies in avian follicles, the activation of CaSR expressed in granulosa cells may support the survival of follicles after their selection. CaSR in rat and equine sperms was functionally linked to sperm motility and sperm capacitation. Implantation involves complex interactions between the blastocyst and the uterine epithelium. During early pregnancy, CaSR expression at the implantation site as well as in decidual cells indicates that CaSR is important for blastocyst implantation and decidualization in the rat uterus. Localization of CaSR in human extravillous cytotrophoblasts suggests a role of CaSR in placentation. Overall, evidence for functional involvement of CaSR in physiologic mammalian reproductive processes exists. Moreover, several studies reported altered expression of CaSR in cells of reproductive tissues under pathologic conditions. However, in many tissues we still lack knowledge on physiological ligands activating CaSR, CaSR-linked G-proteins, activated intracellular signaling pathway, and functional relevance of CaSR activation. Clearly, more work is required in the future to decode the complex physiologic and pathophysiologic relationship of CaSR and the mammalian reproductive system.
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Affiliation(s)
- Isabella Ellinger
- Pathophysiology of the Placenta, Department of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University Vienna Vienna, Austria
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23
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Bury L, Coelho PA, Glover DM. From Meiosis to Mitosis: The Astonishing Flexibility of Cell Division Mechanisms in Early Mammalian Development. Curr Top Dev Biol 2016; 120:125-71. [PMID: 27475851 DOI: 10.1016/bs.ctdb.2016.04.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The execution of female meiosis and the establishment of the zygote is arguably the most critical stage of mammalian development. The egg can be arrested in the prophase of meiosis I for decades, and when it is activated, the spindle is assembled de novo. This spindle must function with the highest of fidelity and yet its assembly is unusually achieved in the absence of conventional centrosomes and with minimal influence of chromatin. Moreover, its dramatic asymmetric positioning is achieved through remarkable properties of the actin cytoskeleton to ensure elimination of the polar bodies. The second meiotic arrest marks a uniquely prolonged metaphase eventually interrupted by egg activation at fertilization to complete meiosis and mark a period of preparation of the male and female pronuclear genomes not only for their entry into the mitotic cleavage divisions but also for the imminent prospect of their zygotic expression.
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Affiliation(s)
- L Bury
- University of Cambridge, Cambridge, United Kingdom.
| | - P A Coelho
- University of Cambridge, Cambridge, United Kingdom
| | - D M Glover
- University of Cambridge, Cambridge, United Kingdom
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24
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Machaty Z. Signal transduction in mammalian oocytes during fertilization. Cell Tissue Res 2016; 363:169-183. [PMID: 26453398 PMCID: PMC4700098 DOI: 10.1007/s00441-015-2291-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 08/28/2015] [Indexed: 01/22/2023]
Abstract
Mammalian embryo development begins when the fertilizing sperm triggers a series of elevations in the oocyte's intracellular free Ca(2+) concentration. The elevations are the result of repeated release and re-uptake of Ca(2+) stored in the smooth endoplasmic reticulum. Ca(2+) release is primarily mediated by the phosphoinositide signaling system of the oocyte. The system is stimulated when the sperm causes the hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2) into inositol 1,4,5-trisphosphate (IP3) and diacylglycerol (DAG); IP3 then binds its receptor on the surface of the endoplasmic reticulum that induces Ca(2+) release. The manner in which the sperm generates IP3, the Ca(2+) mobilizing second messenger, has been the subject of extensive research for a long time. The sperm factor hypothesis has eventually gained general acceptance, according to which it is a molecule from the sperm that diffuses into the ooplasm and stimulates the phosphoinositide cascade. Much evidence now indicates that the sperm-derived factor is phospholipase C-zeta (PLCζ) that cleaves PIP2 and generates IP3, eventually leading to oocyte activation. A recent addition to the candidate sperm factor list is the post-acrosomal sheath WW domain-binding protein (PAWP), whose role at fertilization is currently under debate. Ca(2+) influx across the plasma membrane is also important as, in the absence of extracellular Ca(2+), the oscillations run down prematurely. In pig oocytes, the influx that sustains the oscillations seems to be regulated by the filling status of the stores, whereas in the mouse other mechanisms might be involved. This work summarizes the current understanding of Ca(2+) signaling in mammalian oocytes.
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Affiliation(s)
- Zoltan Machaty
- Department of Animal Sciences, Purdue University, 915 W. State Street, West Lafayette, IN, 47907, USA.
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Bernhardt ML, Zhang Y, Erxleben CF, Padilla-Banks E, McDonough CE, Miao YL, Armstrong DL, Williams CJ. CaV3.2 T-type channels mediate Ca²⁺ entry during oocyte maturation and following fertilization. J Cell Sci 2015; 128:4442-52. [PMID: 26483387 DOI: 10.1242/jcs.180026] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 10/12/2015] [Indexed: 01/05/2023] Open
Abstract
Initiation of mouse embryonic development depends upon a series of fertilization-induced rises in intracellular Ca(2+). Complete egg activation requires influx of extracellular Ca(2+); however, the channels that mediate this influx remain unknown. Here, we tested whether the α1 subunit of the T-type channel CaV3.2, encoded by Cacna1h, mediates Ca(2+) entry into oocytes. We show that mouse eggs express a robust voltage-activated Ca(2+) current that is completely absent in Cacna1h(-/-) eggs. Cacna1h(-/-) females have reduced litter sizes, and careful analysis of Ca(2+) oscillation patterns in Cacna1h(-/-) eggs following in vitro fertilization (IVF) revealed reductions in first transient length and oscillation persistence. Total and endoplasmic reticulum (ER) Ca(2+) stores were also reduced in Cacna1h(-/-) eggs. Pharmacological inhibition of CaV3.2 in wild-type CF-1 strain eggs using mibefradil or pimozide reduced Ca(2+) store accumulation during oocyte maturation and reduced Ca(2+) oscillation persistence, frequency and number following IVF. Overall, these data show that CaV3.2 T-type channels have prev8iously unrecognized roles in supporting the meiotic-maturation-associated increase in ER Ca(2+) stores and mediating Ca(2+) influx required for the activation of development.
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Affiliation(s)
- Miranda L Bernhardt
- Reproductive and Developmental Biology Laboratory, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Yingpei Zhang
- Reproductive and Developmental Biology Laboratory, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Christian F Erxleben
- Neurobiology Laboratory, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Elizabeth Padilla-Banks
- Reproductive and Developmental Biology Laboratory, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Caitlin E McDonough
- Reproductive and Developmental Biology Laboratory, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Yi-Liang Miao
- Key Laboratory of Animal Genetics, Breeding, and Reproduction of Ministry of Education, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - David L Armstrong
- Neurobiology Laboratory, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Carmen J Williams
- Reproductive and Developmental Biology Laboratory, National Institutes of Health, Research Triangle Park, NC 27709, USA
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Abstract
Vertebrate reproduction requires a myriad of precisely orchestrated events-in particular, the maternal production of oocytes, the paternal production of sperm, successful fertilization, and initiation of early embryonic cell divisions. These processes are governed by a host of signaling pathways. Protein kinase and phosphatase signaling pathways involving Mos, CDK1, RSK, and PP2A regulate meiosis during maturation of the oocyte. Steroid signals-specifically testosterone-regulate spermatogenesis, as does signaling by G-protein-coupled hormone receptors. Finally, calcium signaling is essential for both sperm motility and fertilization. Altogether, this signaling symphony ensures the production of viable offspring, offering a chance of genetic immortality.
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Affiliation(s)
- Sally Kornbluth
- Duke University School of Medicine, Durham, North Carolina 27710
| | - Rafael Fissore
- University of Massachusetts, Amherst, Veterinary and Animal Sciences, Amherst, Massachusetts 01003
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Suttirojpattana T, Somfai T, Matoba S, Nagai T, Parnpai R, Geshi M. The effect of temperature during liquid storage of in vitro-matured bovine oocytes on subsequent embryo development. Theriogenology 2015; 85:509-518.e1. [PMID: 26483307 DOI: 10.1016/j.theriogenology.2015.09.033] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Revised: 09/16/2015] [Accepted: 09/18/2015] [Indexed: 11/24/2022]
Abstract
The aim of the present study was to optimize the temperature for the temporal storage of matured bovine oocytes. In vitro-matured bovine oocytes were preserved in HEPES-buffered TCM199 medium supplemented with 10% newborn calf serum at different temperatures (4 °C, 15 °C, 25 °C, and 38.5 °C) for 20 hours. Embryo development and blastocyst quality after in vitro fertilization, cytoplasmic ATP and glutathione levels in oocytes, and the frequency of apoptotic oocytes were compared among storage groups and a control group without storage. Among the storage groups, those at 25 °C and 38.5 °C showed the highest rates of blastocyst development (19.3% and 24.5%, respectively) compared with those stored at 4 °C and 15 °C (8.5% and 14.9%, respectively); however, blastocyst formation rates in all storage groups were lower than that in the control group (39.8%; P < 0.05). Storage at 38.5 °C and 15 °C was associated with reduced cell numbers in resultant blastocysts compared with the control and the 25 °C storage groups. Storage at 4 °C reduced metabolic activity of oocytes characterized by their lower ATP levels compared with the other groups. Storage for 20 hours significantly reduced the glutathione content in oocytes in all groups in a similar manner, irrespective of the temperature. Storage at 4 °C or 15 °C but not at 25 °C and 38.5 °C significantly increased the percentage of apoptotic oocytes compared with the control group. In conclusion, 25 °C was found to be the most suitable temperature for the temporal storage of matured bovine oocytes regarding both the developmental competence of oocytes and the quality of resultant blastocysts.
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Affiliation(s)
- Tayita Suttirojpattana
- Animal Breeding and Reproduction Research Division, NARO Institute of Livestock and Grassland Science, Tsukuba, Japan; Embryo Technology and Stem Cell Research Center, Suranaree University of Technology, Nakhon Ratchasima, Thailand
| | - Tamas Somfai
- Animal Breeding and Reproduction Research Division, NARO Institute of Livestock and Grassland Science, Tsukuba, Japan.
| | - Satoko Matoba
- Animal Breeding and Reproduction Research Division, NARO Institute of Livestock and Grassland Science, Tsukuba, Japan
| | - Takashi Nagai
- Food and Fertilizer Technology Center, Taipei, Taiwan; Department of Agricultural Biotechnology, College of Agriculture and Life Sciences, Seoul National University, Seoul, Korea
| | - Rangsun Parnpai
- Embryo Technology and Stem Cell Research Center, Suranaree University of Technology, Nakhon Ratchasima, Thailand.
| | - Masaya Geshi
- Animal Breeding and Reproduction Research Division, NARO Institute of Livestock and Grassland Science, Tsukuba, Japan
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Zhang N, Yoon SY, Parys JB, Fissore RA. Effect of M-phase kinase phosphorylations on type 1 inositol 1,4,5-trisphosphate receptor-mediated Ca2+ responses in mouse eggs. Cell Calcium 2015; 58:476-88. [PMID: 26259730 DOI: 10.1016/j.ceca.2015.07.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Revised: 07/28/2015] [Accepted: 07/30/2015] [Indexed: 12/26/2022]
Abstract
The type 1 inositol 1,4,5-trisphosphate receptor (IP3R1) mediates increases in the intracellular concentration of Ca(2+) ([Ca(2+)]i) during fertilization in mammalian eggs. The activity of IP3R1 is enhanced during oocyte maturation, and phosphorylations by M-phase kinases are thought to positively regulate the activity of IP3R1. Accordingly, we and others have found that IP3R1 is phosphorylated at S(421), T(799) (by Cdk1) and at S(436) (by ERK). Nevertheless, the effects of these phosphorylations on the function of the receptor and their impact on [Ca(2+)]i oscillations in eggs have not been clearly examined. To address this, we expressed in mouse oocytes an IP3R1 variant with the three indicated phosphorylation sites replaced by acidic residues, IIIE-IP3R1, such that it would act like a constitutively phosphorylated IP3R1, and examined [Ca(2+)]i parameters in response to stimuli. We found that overexpression of wild type (wt-IP3R1) or IIIE-IP3R1 in oocytes containing endogenous receptors caused dominant negative-like effects on Ca(2+) release and oscillations. Therefore, we first selectively removed the endogenous IP3R1, and subsequently expressed the exogenous receptors. We found that in response to injection of PLCζ cRNA, eggs without endogenous IP3R1 failed to mount persistent Ca(2+) oscillations, although expression of wt-IP3R1 restored their [Ca(2+)]i oscillatory activity. We also observed that the Ca(2+) oscillatory ability and the sensitivity to IP3 in eggs expressing IIIE-IP3R1 were greater than in those expressing wt-IP3R1. Lastly, we found that exogenous IP3R1s are resistant to downregulation and support longer oscillations and of higher amplitude. Altogether, our results show that phosphorylations by Cdk1 and MAPK enhance the activity of IP3R1, which is consistent with its maximal activity observed at the time of fertilization and the role of Ca(2+) release in egg activation.
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Affiliation(s)
- Nan Zhang
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, MA 01003, USA; Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Sook Young Yoon
- Fertility Center of CHA Gangnam Medical Center, College of Medicine, CHA University, Seoul 135-081, Republic of Korea
| | - Jan B Parys
- KU Leuven, Laboratory of Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine, Campus Gasthuisberg O/N-I box 802, Herestraat 49, BE-3000 Leuven, Belgium
| | - Rafael A Fissore
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, MA 01003, USA.
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Prasad S, Tiwari M, Koch B, Chaube SK. Morphological, cellular and molecular changes during postovulatory egg aging in mammals. J Biomed Sci 2015; 22:36. [PMID: 25994054 PMCID: PMC4440248 DOI: 10.1186/s12929-015-0143-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 05/01/2015] [Indexed: 11/29/2022] Open
Abstract
Postovulatory aging is associated with several morphological, cellular and molecular changes that deteriorate egg quality either by inducing abortive spontaneous egg activation (SEA) or by egg apoptosis. The reduced egg quality results in poor fertilization rate, embryo quality and reproductive outcome. Although postovulatory aging-induced abortive SEA has been reported in several mammalian species, the molecular mechanism(s) underlying this process remains to be elucidated. The postovulatory aging-induced morphological and cellular changes are characterized by partial cortical granules exocytosis, zona pellucida hardening, exit from metaphase-II (M-II)arrest and initiation of extrusion of second polar body in aged eggs. The molecular changes include reduction of adenosine 3',5'- cyclic monophosphate (cAMP) level, increase of reactive oxygen species (ROS) and thereby cytosolic free calcium (Ca2+) level. Increased levels of cAMP and/or ROS trigger accumulation of Thr-14/Tyr-15 phosphorylated cyclin-dependent kinase 1 (Cdk1) on one hand and degradation of cyclin B1 through ubiquitin-mediated proteolysis on the other hand to destabilize maturation promoting factor (MPF). The destabilized MPF triggers postovulatory aging-induced abortive SEA and limits various assisted reproductive technologies (ARTs) outcome in several mammalian species. Use of certain drugs that can either increase cAMP or reduce ROS level would prevent postovulatory aging-induced deterioration in egg quality so that more number of good quality eggs can be made available to improve ART outcome in mammals including human.
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Affiliation(s)
- Shilpa Prasad
- Cell Physiology Laboratory, Biochemistry Unit, Department of Zoology, Banaras Hindu University, Varanasi, 221005, UP, India.
| | - Meenakshi Tiwari
- Cell Physiology Laboratory, Biochemistry Unit, Department of Zoology, Banaras Hindu University, Varanasi, 221005, UP, India.
| | - Biplob Koch
- Genotoxicology and Cancer Biology Laboratory, Department of Zoology, Banaras Hindu University, Varanasi, 221005, UP, India.
| | - Shail K Chaube
- Cell Physiology Laboratory, Biochemistry Unit, Department of Zoology, Banaras Hindu University, Varanasi, 221005, UP, India.
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Armant DR. Intracellular Ca2+ signaling and preimplantation development. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 843:151-71. [PMID: 25956298 PMCID: PMC10412982 DOI: 10.1007/978-1-4939-2480-6_6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The key, versatile role of intracellular Ca2+ signaling during egg activation after fertilization has been appreciated for several decades. More recently, evidence has accumulated supporting the concept that cytoplasmic Ca2+ is also a major signaling nexus during subsequent development of the fertilized ovum. This chapter will review the molecular reactions that regulate intracellular Ca2+ levels and cell function, the role of Ca2+ signaling during egg activation and specific examples of repetitive Ca2+ signaling found throughout pre- and peri-implantation development. Many of the upstream and downstream pathways utilized during egg activation are also critical for specific processes that take place during embryonic development. Much remains to be done to elucidate the full complexity of Ca2+ signaling mechanisms in preimplantation embryos to the level of detail accomplished for egg activation. However, an emerging concept is that because this second messenger can be modulated downstream of numerous receptors and is able to bind and activate multiple cytoplasmic signaling proteins, it can help the coordination of development through up- and downstream pathways that change with each embryonic stage.
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Affiliation(s)
- D Randall Armant
- Department of Obstetrics and Gynecology, Wayne State University C.S. Mott Center for Human Growth and Development, 275 E. Hancock Street, 48201-1405, Detroit, MI, USA,
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31
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Sato KI. Transmembrane signal transduction in oocyte maturation and fertilization: focusing on Xenopus laevis as a model animal. Int J Mol Sci 2014; 16:114-34. [PMID: 25546390 PMCID: PMC4307238 DOI: 10.3390/ijms16010114] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 12/15/2014] [Indexed: 11/16/2022] Open
Abstract
Fertilization is a cell biological phenomenon of crucial importance for the birth of new life in a variety of multicellular and sexual reproduction species such as algae, animal and plants. Fertilization involves a sequence of events, in which the female gamete "egg" and the male gamete "spermatozoon (sperm)" develop, acquire their functions, meet and fuse with each other, to initiate embryonic and zygotic development. Here, it will be briefly reviewed how oocyte cytoplasmic components are orchestrated to undergo hormone-induced oocyte maturation and sperm-induced activation of development. I then review how sperm-egg membrane interaction/fusion and activation of development in the fertilized egg are accomplished and regulated through egg coat- or egg plasma membrane-associated components, highlighting recent findings and future directions in the studies using Xenopus laevis as a model experimental animal.
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Affiliation(s)
- Ken-ichi Sato
- Laboratory of Cell Signaling and Development, Department of Molecular Biosciences, Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo-motoyama, Kita-ku, Kyoto 603-8555, Japan.
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Chemical activation in Rhinella arenarum oocytes: effect of dehydroleucodine (DhL) and its hydrogenated derivative (2H-DhL). ZYGOTE 2014; 23:924-32. [PMID: 25424172 DOI: 10.1017/s0967199414000641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Mature oocytes are arrested in metaphase II due to the presence of high levels of active maturation promoting factor (MPF). After fertilization, active MPF levels decline abruptly, enabling oocytes to complete meiosis II. One of the first and universal events of oocyte activation is an increase in cytosolic Ca2+ that would be responsible for MPF inactivation. Mature oocytes can also be activated by parthenogenetic activation. The aims of this work are to test the ability of dehydroleucodine (DhL) and its hydrogenated derivative 11,13-dihydro-dehydroleucodine (2H-DhL) to induce chemical activation in amphibian oocytes and to study the participation of calcium in the process. Results indicated that DhL and 2H-DhL induced oocyte activation in a dose-dependent manner. After 90 min of treatment, DhL 36 μM was able to induce 95% activation, while 2H-DhL 36 μM was less active, with only 40% activation. Our results suggest that DhL induced the inhibition of MPF activity, probably by an increase in intracellular Ca2+ concentration. Extracellular Ca2+ would not be significant, although Ca2+ release from intracellular stores is critical. In this sense, IP3Rs and RyRs were involved in the Ca2+ transient induced by lactones. In this species, RyRs appears to be the largest contributor to Ca2+ release in DhL-induced activation. Although more studies are needed on the mechanism of action through which these lactones induce oocyte activation in Rhinella arenarum, the results of this research provide interesting perspectives for the use of these lactones as chemical activators in in vitro fertilization and cloning.
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Excess cholesterol induces mouse egg activation and may cause female infertility. Proc Natl Acad Sci U S A 2014; 111:E4972-80. [PMID: 25368174 DOI: 10.1073/pnas.1418954111] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The HDL receptor scavenger receptor, class B type I (SR-BI) controls the structure and fate of plasma HDL. Female SR-BI KO mice are infertile, apparently because of their abnormal cholesterol-enriched HDL particles. We examined the growth and meiotic progression of SR-BI KO oocytes and found that they underwent normal germinal vesicle breakdown; however, SR-BI KO eggs, which had accumulated excess cholesterol in vivo, spontaneously activated, and they escaped metaphase II (MII) arrest and progressed to pronuclear, MIII, and anaphase/telophase III stages. Eggs from fertile WT mice were activated when loaded in vitro with excess cholesterol by a cholesterol/methyl-β-cyclodextrin complex, phenocopying SR-BI KO oocytes. In vitro cholesterol loading of eggs induced reduction in maturation promoting factor and MAPK activities, elevation of intracellular calcium, extrusion of a second polar body, and progression to meiotic stages beyond MII. These results suggest that the infertility of SR-BI KO females is caused, at least in part, by excess cholesterol in eggs inducing premature activation and that cholesterol can activate WT mouse eggs to escape from MII arrest. Analysis of SR-BI KO female infertility raises the possibility that abnormalities in cholesterol metabolism might underlie some cases of human female infertility of unknown etiology.
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RyR channel-mediated increase of cytosolic free calcium level signals cyclin B1 degradation during abortive spontaneous egg activation in rat. In Vitro Cell Dev Biol Anim 2014; 50:640-7. [PMID: 24696373 DOI: 10.1007/s11626-014-9749-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Accepted: 03/13/2014] [Indexed: 10/25/2022]
Abstract
In few mammalian species including rat, post-ovulatory aging induces abortive spontaneous egg activation (SEA), which is morphologically characterized by exit from metaphase-II (M-II) arrest. A possibility exists that the RyR channel-mediated insufficient increase of cytosolic free Ca(2+) level could be one of the causes for post-ovulatory aging-induced abortive SEA. To test this possibility, eggs collected after 17 h post-hCG surge were cultured with or without various concentrations of nifedipine (NF), ruthenium red (RR), and KN-93 for 3 h in vitro. Morphological changes characteristic of abortive SEA, cytosolic free Ca(2+) level, cyclin B1 level, and meiotic status were analyzed. Data of the present study indicate that NF and RR inhibited post-ovulatory aging-induced abortive SEA in a concentration-dependent manner. Further, RR protected against RyR channel as well as caffeine-mediated increase of cytosolic free Ca(2+) level. In addition, KN-93 inhibited post-ovulatory aging-induced abortive SEA in a concentration-dependent manner. An increase of cytosolic free Ca(2+) level was associated with a reduction of cyclin B1 level during post-ovulatory aging-induced abortive SEA. These data indirectly suggest the involvement of RyR channels in the increase of cytosolic free Ca(2+) level. The increased cytosolic free Ca(2+) level triggers cyclin B1 degradation possibly through CaMK-II activity during post-ovulatory aging-induced abortive SEA in rat eggs cultured in vitro.
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35
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Medvedev S, Stein P, Schultz RM. Specificity of calcium/calmodulin-dependent protein kinases in mouse egg activation. Cell Cycle 2014; 13:1482-8. [PMID: 24626179 DOI: 10.4161/cc.28432] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
CaMKIIγ, the predominant CaMKII isoform in mouse eggs, controls egg activation by regulating cell cycle resumption. In this study we further characterize the involvement and specificity of CaMKIIγ in mouse egg activation. Using exogenous expression of different cRNAs in Camk2g(-/-) eggs, we show that the other multifunctional CaM kinases, CaMKI, and CaMKIV, are not capable of substituting CaMKIIγ to initiate cell cycle resumption in response to a rise in intracellular Ca (2+). Exogenous expression of Camk2g or Camk2d results in activation of nearly 80% of Camk2g(-/-) MII eggs after stimulation with SrCl 2, which does not differ from the incidence of activation of wild-type eggs expressing exogenous Egfp. In contrast, none of the Camk2g(-/-) MII eggs expressing Camk1 or Camk4 activate in response to SrCl 2 treatment. Expression of a constitutively active form of Camk4 (ca-Camk4), but not Camk1, triggers egg activation. EMI2, an APC/C repressor, is a key component in regulating egg activation downstream of CaMKII in both Xenopus laevis and mouse. We show that exogenous expression of either Camk2g, Camk2d, or ca-Camk4, but not Camk1, Camk4, or a catalytically inactive mutant form of CaMKIIγ (kinase-dead) in Camk2g(-/-) mouse eggs leads to almost complete degradation (~90%) of exogenously expressed EMI2 followed by cell cycle resumption. Thus, degradation of EMI2 following its phosphorylation specifically by CaMKII is mechanistically linked to and promotes cell cycle resumption in MII eggs.
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Affiliation(s)
- Sergey Medvedev
- Department of Biology; University of Pennsylvania; Philadelphia, PA USA
| | - Paula Stein
- Department of Biology; University of Pennsylvania; Philadelphia, PA USA
| | - Richard M Schultz
- Department of Biology; University of Pennsylvania; Philadelphia, PA USA
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36
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Basile N, Meseguer M. Time-lapse technology: evaluation of embryo quality and new markers for embryo selection. ACTA ACUST UNITED AC 2014. [DOI: 10.1586/eog.12.8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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37
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Carvacho I, Lee HC, Fissore RA, Clapham DE. TRPV3 channels mediate strontium-induced mouse-egg activation. Cell Rep 2013; 5:1375-86. [PMID: 24316078 DOI: 10.1016/j.celrep.2013.11.007] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Revised: 10/02/2013] [Accepted: 11/04/2013] [Indexed: 11/29/2022] Open
Abstract
In mammals, calcium influx is required for oocyte maturation and egg activation. The molecular identities of the calcium-permeant channels that underlie the initiation of embryonic development are not established. Here, we describe a transient receptor potential (TRP) ion channel current activated by TRP agonists that is absent in TrpV3(-/-) eggs. TRPV3 current is differentially expressed during oocyte maturation, reaching a peak of maximum density and activity at metaphase of meiosis II (MII), the stage of fertilization. Selective activation of TRPV3 channels provokes egg activation by mediating massive calcium entry. Widely used to activate eggs, strontium application is known to yield normal offspring in combination with somatic cell nuclear transfer. We show that TRPV3 is required for strontium influx, because TrpV3(-/-) eggs failed to conduct Sr(2+) or undergo strontium-induced activation. We propose that TRPV3 is a major mediator of calcium influx in mouse eggs and is a putative target for artificial egg activation.
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Affiliation(s)
- Ingrid Carvacho
- Howard Hughes Medical Institute, Department of Cardiology, Boston Children's Hospital, Boston, MA 02115, USA; Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Hoi Chang Lee
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, MA 01003, USA
| | - Rafael A Fissore
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, MA 01003, USA
| | - David E Clapham
- Howard Hughes Medical Institute, Department of Cardiology, Boston Children's Hospital, Boston, MA 02115, USA; Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA.
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38
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Wakai T, Zhang N, Vangheluwe P, Fissore RA. Regulation of endoplasmic reticulum Ca(2+) oscillations in mammalian eggs. J Cell Sci 2013; 126:5714-24. [PMID: 24101727 DOI: 10.1242/jcs.136549] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Changes in the intracellular concentration of free calcium ([Ca(2+)]i) regulate diverse cellular processes including fertilization. In mammalian eggs, the [Ca(2+)]i changes induced by the sperm unfold in a pattern of periodical rises, also known as [Ca(2+)]i oscillations. The source of Ca(2+) during oscillations is the endoplasmic reticulum ([Ca(2+)]ER), but it is presently unknown how [Ca(2+)]ER is regulated. Here, we show using mouse eggs that [Ca(2+)]i oscillations induced by a variety of agonists, including PLCζ, SrCl2 and thimerosal, provoke simultaneous but opposite changes in [Ca(2+)]ER and cause differential effects on the refilling and overall load of [Ca(2+)]ER. We also found that Ca(2+) influx is required to refill [Ca(2+)]ER, because the loss of [Ca(2+)]ER was accelerated in medium devoid of Ca(2+). Pharmacological inactivation of the function of the mitochondria and of the Ca(2+)-ATPase pumps PMCA and SERCA altered the pattern of oscillations and abruptly reduced [Ca(2+)]ER, especially after inactivation of mitochondria and SERCA functions. We also examined the expression of SERCA2b protein and found that it was expressed throughout oocyte maturation and attained a conspicuous cortical cluster organization in mature eggs. We show that its overexpression reduces the duration of inositol-1,4,5-trisphosphate-induced [Ca(2+)]i rises, promotes initiation of oscillations and enhances refilling of [Ca(2+)]ER. Collectively, our results provide novel insights on the regulation of [Ca(2+)]ER oscillations, which underlie the unique Ca(2+)-signalling system that activates the developmental program in mammalian eggs.
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Affiliation(s)
- Takuya Wakai
- Department of Veterinary and Animal Sciences, University of Massachusetts Amherst, 661 North Pleasant Street, Amherst, MA 01003, USA
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Kashir J, Deguchi R, Jones C, Coward K, Stricker SA. Comparative biology of sperm factors and fertilization-induced calcium signals across the animal kingdom. Mol Reprod Dev 2013; 80:787-815. [PMID: 23900730 DOI: 10.1002/mrd.22222] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Accepted: 07/23/2013] [Indexed: 11/08/2022]
Abstract
Fertilization causes mature oocytes or eggs to increase their concentrations of intracellular calcium ions (Ca²⁺) in all animals that have been examined, and such Ca²⁺ elevations, in turn, provide key activating signals that are required for non-parthenogenetic development. Several lines of evidence indicate that the Ca²⁺ transients produced during fertilization in mammals and other taxa are triggered by soluble factors that sperm deliver into oocytes after gamete fusion. Thus, for a broad-based analysis of Ca²⁺ dynamics during fertilization in animals, this article begins by summarizing data on soluble sperm factors in non-mammalian species, and subsequently reviews various topics related to a sperm-specific phospholipase C, called PLCζ, which is believed to be the predominant activator of mammalian oocytes. After characterizing initiation processes that involve sperm factors or alternative triggering mechanisms, the spatiotemporal patterns of Ca²⁺ signals in fertilized oocytes or eggs are compared in a taxon-by-taxon manner, and broadly classified as either a single major transient or a series of repetitive oscillations. Both solitary and oscillatory types of fertilization-induced Ca²⁺ signals are typically propagated as global waves that depend on Ca²⁺ release from the endoplasmic reticulum in response to increased concentrations of inositol 1,4,5-trisphosphate (IP₃). Thus, for taxa where relevant data are available, upstream pathways that elevate intraoocytic IP3 levels during fertilization are described, while other less-common modes of producing Ca²⁺ transients are also examined. In addition, the importance of fertilization-induced Ca²⁺ signals for activating development is underscored by noting some major downstream effects of these signals in various animals.
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Affiliation(s)
- Junaid Kashir
- Nuffield Department of Obstetrics and Gynaecology, University of Oxford, Level 3, Women's Centre, John Radcliffe Hospital, Headington, Oxford, UK
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Ca(2+) homeostasis and regulation of ER Ca(2+) in mammalian oocytes/eggs. Cell Calcium 2012; 53:63-7. [PMID: 23260016 DOI: 10.1016/j.ceca.2012.11.010] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Revised: 11/02/2012] [Accepted: 11/03/2012] [Indexed: 11/23/2022]
Abstract
The activation of the developmental program in mammalian eggs relies on the initiation at the time of fertilization of repeated rises in the intracellular concentration of free calcium ([Ca(2+)](i)), also known as [Ca(2+)](i) oscillations. The ability to mount the full complement of oscillations is only achieved at the end of oocyte maturation, at the metaphase stage of meiosis II (MII). Over the last decades research has focused on addressing the mechanisms by which the sperm initiates the oscillations and identification of the channels that mediate intracellular Ca(2+) release. This review will describe the up-to-date knowledge of other aspects of Ca(2+) homeostasis in mouse oocytes, such as the mechanisms that transport Ca(2+) out of the cytosol into the endoplasmic reticulum (ER), the Ca(2+) store of the oocyte/egg, into other organelles and also those that extrude Ca(2+). Evidence pointing to channels in the plasma membrane that mediate Ca(2+) entry from the extracellular milieu, which is required for the persistence of the oscillations, is also discussed, along with the modifications that these mechanisms undergo during maturation. Lastly, we highlight areas where additional research is needed to obtain a better understating of the molecules and mechanisms that regulate Ca(2+) homeostasis in this unique Ca(2+) signaling system.
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Premkumar KV, Chaube SK. An insufficient increase of cytosolic free calcium level results postovulatory aging-induced abortive spontaneous egg activation in rat. J Assist Reprod Genet 2012; 30:117-23. [PMID: 23239129 DOI: 10.1007/s10815-012-9908-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Accepted: 11/29/2012] [Indexed: 11/27/2022] Open
Abstract
PURPOSE The present study was aimed to find out whether postovulatory aging-induced abortive spontaneous egg activation (SEA) is due to insufficient increase of cytosolic free Ca(2+) level. METHODS Immature female rats (22-24 days old) were subjected to superovulation induction protocol. Eggs were collected 14, 17 and 19 h post-hCG surge to induce in vivo egg aging. The eggs were collected 14 h post-hCG surge and cultured in vitro for 3, 5 and 7 h to induce in vitro egg aging. The morphological changes, rate of abortive SEA, chromosomal status and cytosolic free Ca(2+) levels were analyzed. RESULTS Postovulatory aging induced morphological features characteristics of abortive SEA in a time-dependent manner in vivo as well as in vitro. The extracellular Ca(2+) increased rate of abortive SEA during initial period of culture, while co-addition of a nifedipine (L-type Ca(2+) channel blocker) protected against postovulatory aging-induced abortive SEA. However, CI induced morphological features characteristics of egg activation (EA) in a dose-dependent manner. As compare to control, an increase of cytosolic free Ca(2+) level (1.42 times) induced abortive SEA, while further increase of cytosolic free Ca(2+) level (2.55 times) induced EA. CONCLUSION Our results show that an insufficient cytosolic free Ca(2+) level is associated with postovulatory aging -induced abortive SEA, while furthermore increase is required to induce EA in rat.
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Affiliation(s)
- Karuppanan V Premkumar
- Cell Physiology Laboratory, Department of Zoology, Banaras Hindu University, Varanasi, 221005, India
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Miao YL, Williams CJ. Calcium signaling in mammalian egg activation and embryo development: the influence of subcellular localization. Mol Reprod Dev 2012; 79:742-56. [PMID: 22888043 DOI: 10.1002/mrd.22078] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2012] [Accepted: 07/27/2012] [Indexed: 11/07/2022]
Abstract
Calcium (Ca(2+) ) signals drive the fundamental events surrounding fertilization and the activation of development in all species examined to date. Initial studies of Ca(2+) signaling at fertilization in marine animals were tightly linked to new discoveries of bioluminescent proteins and their use as fluorescent Ca(2+) sensors. Since that time, there has been rapid progress in our understanding of the key functions for Ca(2+) in many cell types and of the impact of cellular localization on Ca(2+) signaling pathways. In this review, which focuses on mammalian egg activation, we consider how Ca(2+) is regulated and stored at different stages of oocyte development and examine the functions of molecules that serve as both regulators of Ca(2+) release and effectors of Ca(2+) signals. We then summarize studies exploring how Ca(2+) directs downstream effectors mediating both egg activation and later signaling events required for successful preimplantation embryo development. Throughout this review, we focus attention on how localization of Ca(2+) signals influences downstream signaling events, and attempt to highlight gaps in our knowledge that are ripe for future research.
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Affiliation(s)
- Yi-Liang Miao
- Reproductive Medicine Group, Laboratory of Reproductive and Developmental Toxicology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina 27709, USA
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Machaty Z, Peippo J, Peter A. Production and manipulation of bovine embryos: Techniques and terminology. Theriogenology 2012; 78:937-50. [DOI: 10.1016/j.theriogenology.2012.04.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2011] [Revised: 04/06/2012] [Accepted: 04/06/2012] [Indexed: 10/28/2022]
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Abstract
SummaryTransient increases in the concentration of cytosolic Ca2+ are essential for triggering egg activation events. Increased Ca2+ results from its rapid release from intracellular stores, mainly mediated by one or both intracellular calcium channels: the inositol trisphosphate receptor (IP3R) and the ryanodine receptor (RyR). Several regulatory pathways that tailor the response of these channels to the specific cell type have been proposed. Among its many modulatory actions, calcium can serve as an activator of a cytosolic phospholipase A2 (cPLA2), which releases arachidonic acid from phospholipids of the endoplasmic reticulum as well as from the nuclear envelope. Previous studies have suggested that arachidonic acid and/or its metabolites were able to modulate the activity of several ion channels. Based on these findings, we have studied the participation of the phospholipase A2 (PLA2) pathway in the process of Bufo arenarum oocyte activation and the interrelation between any of its metabolites and the ion channels involved in the calcium release from the intracellular reservoirs at fertilization. We found that addition of both melittin, a potent PLA2 activator, and arachidonic acid, the main PLA2 reaction metabolite, was able to induce activation events in a bell-shaped manner. Differential regulation of IP3Rs and RyRs by arachidonic acid and its products could explain melittin and arachidonic acid behaviour in Bufo arenarum egg activation. The concerted action of arachidonic acid and/or its metabolites could provide controlled mobilization of calcium from intracellular reservoirs and useful tools for understanding calcium homeostasis in eggs that express both types of receptors.
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Wakai T, Vanderheyden V, Yoon SY, Cheon B, Zhang N, Parys JB, Fissore RA. Regulation of inositol 1,4,5-trisphosphate receptor function during mouse oocyte maturation. J Cell Physiol 2012; 227:705-17. [PMID: 21465476 DOI: 10.1002/jcp.22778] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
At the time of fertilization, an increase in the intracellular Ca(2+) concentration ([Ca(2+)](i)) underlies egg activation and initiation of development in all species studied to date. The inositol 1,4,5-trisphosphate receptor (IP(3)R1), which is mostly located in the endoplasmic reticulum (ER) mediates the majority of this Ca(2+) release. The sensitivity of IP(3)R1, that is, its Ca(2+) releasing capability, is increased during oocyte maturation so that the optimum [Ca(2+)](i) response concurs with fertilization, which in mammals occurs at metaphase of second meiosis. Multiple IP(3)R1 modifications affect its sensitivity, including phosphorylation, sub-cellular localization, and ER Ca(2+) concentration ([Ca(2+)](ER)). Here, we evaluated using mouse oocytes how each of these factors affected IP(3)R1 sensitivity. The capacity for IP(3)-induced Ca(2+) release markedly increased at the germinal vesicle breakdown stage, although oocytes only acquire the ability to initiate fertilization-like oscillations at later stages of maturation. The increase in IP(3)R1 sensitivity was underpinned by an increase in [Ca(2+)](ER) and receptor phosphorylation(s) but not by changes in IP(3)R1 cellular distribution, as inhibition of the former factors reduced Ca(2+) release, whereas inhibition of the latter had no impact. Therefore, the results suggest that the regulation of [Ca(2+)](ER) and IP(3)R1 phosphorylation during maturation enhance IP(3)R1 sensitivity rendering oocytes competent to initiate oscillations at the expected time of fertilization. The temporal discrepancy between the initiation of changes in IP(3)R1 sensitivity and acquisition of mature oscillatory capacity suggest that other mechanisms that regulate Ca(2+) homeostasis also shape the pattern of oscillations in mammalian eggs.
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Affiliation(s)
- Takuya Wakai
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, Massachusetts 01003, USA
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Calcium Oscillations, Oocyte Activation, and Phospholipase C zeta. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 740:1095-121. [DOI: 10.1007/978-94-007-2888-2_50] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Nomikos M, Swann K, Lai FA. Starting a new life: sperm PLC-zeta mobilizes the Ca2+ signal that induces egg activation and embryo development: an essential phospholipase C with implications for male infertility. Bioessays 2011; 34:126-34. [PMID: 22086556 DOI: 10.1002/bies.201100127] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We have discovered that a single sperm protein, phospholipase C-zeta (PLCζ), can stimulate intracellular Ca(2+) signalling in the unfertilized oocyte ('egg') culminating in the initiation of embryonic development. Upon fertilization by a spermatozoon, the earliest observed signalling event in the dormant egg is a large, transient increase in free Ca(2+) concentration. The fertilized egg responds to the intracellular Ca(2+) rise by completing meiosis. In mammalian eggs, the Ca(2+) signal is delivered as a train of long-lasting cytoplasmic Ca(2+) oscillations that begin soon after gamete fusion and persist beyond the completion of meiosis. Sperm PLCζ effects Ca(2+) release from egg intracellular stores by hydrolyzing the membrane lipid PIP(2) and consequent stimulation of the inositol 1,4,5-trisphosphate (InsP(3) ) receptor Ca(2+) -signalling pathway, leading to egg activation and early embryogenesis. Recent advances have refined our understanding of how PLCζ induces Ca(2+) oscillations in the egg and also suggest its potential dysfunction as a cause of male infertility.
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Affiliation(s)
- Michail Nomikos
- Cell Signalling Laboratory, WHRI, Institute of Molecular and Experimental Medicine, Cardiff University School of Medicine, Cardiff, UK
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Chebotareva T, Taylor J, Mullins JJ, Wilmut I. Rat eggs cannot wait: Spontaneous exit from meiotic metaphase-II arrest. Mol Reprod Dev 2011; 78:795-807. [PMID: 21910153 DOI: 10.1002/mrd.21385] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Accepted: 08/15/2011] [Indexed: 11/06/2022]
Abstract
Mammalian eggs await fertilisation while arrested at the second metaphase stage of meiotic division. A network of signalling pathways enables the establishment and maintenance of this metaphase-II arrest. In the absence of fertilisation, mammalian eggs can spontaneously exit metaphase II when parthenogenetically stimulated, or sometimes without any obvious stimulation. Ovulated rat eggs abortively release from metaphase-II arrest once removed from egg donors. Spontaneously activated rat eggs extrude the second polar body and proceed to the so-called metaphase III-'like' stage, with clumps of condensed chromatin scattered in the egg cytoplasm. It is still unclear what makes rat eggs susceptible to spontaneous activation; however, a vague picture of the signalling pathways involved in the process of spontaneous activation is beginning to emerge. Such cell cycle instability is one of the major reasons why it is more difficult to establish nuclear transfer in the rat. This review examines the known predisposing factors and biochemical mechanisms involved in spontaneous activation. The strategies used to prevent spontaneous metaphase-II release in rat eggs will also be discussed.
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Affiliation(s)
- Tatiana Chebotareva
- MRC Centre for Regenerative Medicine, Edinburgh University, Edinburgh, Scotland, UK.
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Liang SL, Zhao QJ, Li XC, Jin YP, Wang YP, Su XH, Guan WJ, Ma YH. Dynamic analysis of Ca²+ level during bovine oocytes maturation and early embryonic development. J Vet Sci 2011; 12:133-42. [PMID: 21586872 PMCID: PMC3104167 DOI: 10.4142/jvs.2011.12.2.133] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Mammalian oocyte maturation and early embryo development processes are Ca2+-dependent. In this study, we used confocal microscopy to investigate the distribution pattern of Ca2+ and its dynamic changes in the processes of bovine oocytes maturation, in vitro fertilization (IVF), parthenogenetic activation (PA) and somatic cell nuclear transfer (SCNT) embryo development. During the germinal vesicle (GV) and GV breakdown stage, Ca2+ was distributed in the cortical ooplasm and throughout the oocytes from the MI to MII stage. In IVF embryos, Ca2+ was distributed in the cortical ooplasm before the formation of the pronucleus. In 4-8 cell embryos and morulas, Ca2+ was present throughout the blastomere. In PA embryos, Ca2+ was distributed throughout the blastomere at 48 h, similar to in the 4-cell and 8-cell phase and the morula. At 6 h after activation, there was almost no distribution of Ca2+ in the SCNT embryos. However, Ca2+ was distributed in the donor nucleus at 10 h and it was distributed throughout the blastomere in the 2-8 cell embryos. In this study, Ca2+ showed significant fluctuations with regularity of IVF and SCNT groups, but PA did not. Systematic investigation of the Ca2+ location and distribution changes during oocyte maturation and early embryo development processes should facilitate a better understanding of the mechanisms involved in oocyte maturation, reconstructed embryo activation and development, ultimately improving the reconstructed embryo development rate.
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Affiliation(s)
- Su Li Liang
- College of Veterinary Medicine, Northwest Agriculture and Forestry University, Yangling 712100, China
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