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Kashir J, Mistry BV, Rajab MA, BuSaleh L, Abu-Dawud R, Ahmed HA, Alharbi S, Nomikos M, AlHassan S, Coskun S, Assiri AM. The mammalian sperm factor phospholipase C zeta is critical for early embryo division and pregnancy in humans and mice. Hum Reprod 2024; 39:1256-1274. [PMID: 38670547 PMCID: PMC11145019 DOI: 10.1093/humrep/deae078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 03/13/2024] [Indexed: 04/28/2024] Open
Abstract
STUDY QUESTION Are sperm phospholipase C zeta (PLCζ) profiles linked to the quality of embryogenesis and pregnancy? SUMMARY ANSWER Sperm PLCζ levels in both mouse and humans correlate with measures of ideal embryogenesis whereby minimal levels seem to be required to result in successful pregnancy. WHAT IS KNOWN ALREADY While causative factors underlying male infertility are multivariable, cases are increasingly associated with the efficacy of oocyte activation, which in mammals occurs in response to specific profiles of calcium (Ca2+) oscillations driven by sperm-specific PLCζ. Although sperm PLCζ abrogation is extensively linked with human male infertility where oocyte activation is deficient, less is clear as to whether sperm PLCζ levels or localization underlies cases of defective embryogenesis and failed pregnancy following fertility treatment. STUDY DESIGN, SIZE, DURATION A cohort of 54 couples undergoing fertility treatment were recruited at the assisted reproductive technology laboratory at the King Faisal Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia. The recruitment criteria for males was a minimum sperm concentration of 5×106 sperm/ml, while all female patients had to have at least five oocytes. Sperm PLCζ analysis was performed in research laboratories, while semen assessments were performed, and time-lapse morphokinetic data were obtained, in the fertility clinic as part of routine treatment. The CRISPR/Cas9 system was concurrently used to induce indels and single-nucleotide mutations within the Plcζ gene to generate strains of Plcζ mutant mice. Sperm PLCζ was evaluated using immunofluorescence and immunoblotting with an antibody of confirmed consistent specificity against PLCζ. PARTICIPANTS/MATERIALS, SETTING, METHODS We evaluated PLCζ profiles in sperm samples from 54 human couples undergoing fertility treatment in the context of time-lapse morphokinetic analysis of resultant embryos, correlating such profiles to pregnancy status. Concurrently, we generated two strains of mutant Plcζ mice using CRISPR/Cas9, and performed IVF with wild type (WT) oocytes and using WT or mutant Plcζ sperm to generate embryos. We also assessed PLCζ status in WT and mutant mice sperm in the context of time-lapse morphokinetic analysis and breeding outcomes. MAIN RESULTS AND THE ROLE OF CHANCE A significant (P ≤ 0.05) positive relationship was observed between both PLCζ relative fluorescence and relative density with the times taken for both the second cell division (CC2) (r = 0.26 and r = 0.43, respectively) and the third cell division (S2) (r = 0.26). Examination of localization patterns also indicated significant correlations between the presence or absence of sperm PLCζ and CC2 (r = 0.27 and r = -0.27, respectively; P ≤ 0.025). Human sperm PLCζ levels were at their highest in the ideal times of CC2 (8-12 h) compared to time ranges outside the ideal timeframe (<8 and >12 h) where levels of human sperm PLCζ were lower. Following assignment of PLCζ level thresholds, quantification revealed a significantly higher (P ≤ 0.05) rate of successful pregnancy in values larger than the assigned cut-off for both relative fluorescence (19% vs 40%, respectively) and relative density (8% vs 54%, respectively). Immunoblotting indicated a single band for PLCζ at 74 kDa in sperm from WT mice, while a single band was also observed in sperm from heterozygous of Plcζ mutant mouse sperm, but at a diminished intensity. Immunofluorescent analysis indicated the previously reported (Kashir et al., 2021) fluorescence patterns in WT sperm, while sperm from Plcζ mutant mice exhibited a significantly diminished and dispersed pattern at the acrosomal region of the sperm head. Breeding experiments indicated a significantly reduced litter size of mutant Plcζ male mice compared to WT mice, while IVF-generated embryos using sperm from mutant Plcζ mice exhibited high rates of polyspermy, and resulted in significantly reduced numbers of these embryos reaching developmental milestones. LIMITATIONS, REASONS FOR CAUTION The human population examined was relatively small, and should be expanded to examine a larger multi-centre cohort. Infertility conditions are often multivariable, and it was not possible to evaluate all these in human patients. However, our mutant Plcζ mouse experiments do suggest that PLCζ plays a significant role in early embryo development. WIDER IMPLICATIONS OF THE FINDINGS We found that minimal levels of PLCζ within a specific range were required for optimal early embryogenesis, correlating with increased pregnancy. Levels of sperm PLCζ below specific thresholds were associated with ineffective embryogenesis and lower pregnancy rates, despite eliciting successful fertilization in both mice and humans. To our knowledge, this represents the first time that PLCζ levels in sperm have been correlated to prognostic measures of embryogenic efficacy and pregnancy rates in humans. Our data suggest for the first time that the clinical utilization of PLCζ may stand to benefit not just a specific population of male infertility where oocyte activation is completely deficient (wherein PLCζ is completely defective/abrogated), but also perhaps the larger population of couples seeking fertility treatment. STUDY FUNDING/COMPETING INTEREST(S) J.K. is supported by a faculty start up grant awarded by Khalifa University (FSU-2023-015). This study was also supported by a Healthcare Research Fellowship Award (HF-14-16) from Health and Care Research Wales (HCRW) to J.K., 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) for J.K. and A.M.A. The authors declare no conflicts of interest. TRIAL REGISTRATION NUMBER N/A.
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Affiliation(s)
- Junaid Kashir
- Department of Biological Sciences, College of Medicine and Health Sciences, Khalifa University, Abu Dhabi, United Arab Emirates
- Center for Biotechnology, Khalifa University, Abu Dhabi, United Arab Emirates
- Department of Comparative Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Bhavesh V Mistry
- Department of Comparative Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Mohamed A Rajab
- Department of Comparative Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Lujain BuSaleh
- Department of Comparative Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
- College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Raed Abu-Dawud
- Department of Comparative Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
- Institute for Molecular Medicine, MSH Medical School, Hamburg, Germany
| | - Hala A Ahmed
- Department of Comparative Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Sarah Alharbi
- Department of Pathology and Laboratory Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Michail Nomikos
- College of Medicine, QU Health, Qatar University, Doha, Qatar
| | - Saad AlHassan
- Department of Obstetrics and Gynaecology, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Serdar Coskun
- College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
- Department of Pathology and Laboratory Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Abdullah M Assiri
- Department of Comparative Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
- College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
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Dale B. Has the concept of polyspermy prevention been invented in the laboratory? ZYGOTE 2024; 32:103-108. [PMID: 38284288 DOI: 10.1017/s0967199424000030] [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] [Indexed: 01/30/2024]
Abstract
There is no evidence, nor need, for a fast block to polyspermy in animal oocytes. The idea that oocytes have evolved a mechanism to allow the entry of one spermatozoon and repel all others has, however, gained consensus over the last century. The main culprit is the sea urchin, which has been used for over a century in in vitro studies of the fertilization process. Images of sea urchin oocytes with thousands of sperm attached to the surface are commonplace in textbooks and appeal to the nature of the reader implying an intriguing surface mechanism of sperm selection despite these oocytes being fixed for photography (Figure ). The abundance of gametes in this marine invertebrate and the ease of experimentation have given us the possibility to elucidate many aspects of the mechanism of fertilization, but has also led to ongoing controversies in reproductive biology, one being polyspermy prevention. Kinetic experiments by Rothschild and colleagues in the 1950s led to the hypothesis of a fast partial block to polyspermy in sea urchin oocytes that reduced the probability of a second spermatozoon from entering the oocyte by 1/20th. In the 1970s, Jaffe and colleagues suggested, with circumstantial evidence, that this partial block was due to the sperm-induced depolarization of the oocyte plasma membrane. However, the fate of supernumerary spermatozoa is determined well before the plasma membrane of the oocyte depolarizes. Transmembrane voltage does not serve to regulate sperm entry. Scholastic texts have inadvertently promulgated this concept across the animal kingdom with no logical correlation or experimentation and, as of today, a molecular mechanism to regulate sperm entry in oocytes has not been identified.
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Affiliation(s)
- Brian Dale
- Centre for Assisted Fertilization, Naples, 80123, Italy
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Ustuner B, Yagcıoglu S, Nur Z, Alcay S, Demir K, Gokce E, Bakırer Ozturk G, Toker B, Sagirkaya H, Soylu MK, Birler S, Pabuccuoglu S. Effects of triton X-100 pretreatment of lyophilized and frozen-thawed ram sperm on preimplantation embryo developmental competence. Anim Biotechnol 2023; 34:1573-1582. [PMID: 35200102 DOI: 10.1080/10495398.2022.2041433] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
In this study, it was aimed to determine the effect of destruction of lyophilized and frozen-thawed ram sperm plasma and acrosomal membrane on development of embryos produced by intracytoplasmic sperm injection (ICSI). Semen samples were divided into two groups for lyophilization (L) and freezing (F). For the removal of the plasma membrane, L and F groups were incubated with Triton X-100 (LTX-100 and FTX-100, respectively). Integrities of the plasma membrane, acrosome and chromatin structure were evaluated. Oocytes were injected with these sperm groups. Although no plasma membrane and acrosome integrities of the L (0.0%) group were detected, the plasma membrane integrity of the F group (69.4%) was significantly higher than the FTX-100 group (23.6%) (p < 0.05). The acrosome integrity of the FTX-100 group (3.80%) was significantly lower than the F group (55.6%) (p < 0.05). The chromatin integrities of L and F groups were higher than the Triton X-100 treated groups (p < 0.05). ICSIs with L, LTX-100, F and FTX-100 sperm were produced similar cleavage and blastocyst rates. In conclusion, data presented here confirm that ram spermatozoa can effectively be lyophilized and injected into oocytes for initiation of embryonic development and Triton X-100 pretreatment is not necessary while using lyophilized and frozen semen.
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Affiliation(s)
- Burcu Ustuner
- Department of Reproduction and Artificial Insemination, Faculty of Veterinary Medicine, Bursa Uludag University, Bursa, Turkey
| | - Selin Yagcıoglu
- Department of Reproduction and Artificial Insemination, Faculty of Veterinary Medicine, Istanbul University-Cerrahpasa, Istanbul, Turkey
| | - Zekariya Nur
- Department of Reproduction and Artificial Insemination, Faculty of Veterinary Medicine, Bursa Uludag University, Bursa, Turkey
| | - Selim Alcay
- Department of Reproduction and Artificial Insemination, Faculty of Veterinary Medicine, Bursa Uludag University, Bursa, Turkey
| | - Kamber Demir
- Department of Reproduction and Artificial Insemination, Faculty of Veterinary Medicine, Istanbul University-Cerrahpasa, Istanbul, Turkey
| | - Elif Gokce
- Department of Reproduction and Artificial Insemination, Faculty of Veterinary Medicine, Namık Kemal University, Tekirdag, Turkey
| | - Gul Bakırer Ozturk
- Department of Laboratory Animal Sciences, Istanbul University Aziz Sancar Institute of Experimental Medicine, Istanbul, Turkey
| | - Berk Toker
- Department of Reproduction and Artificial Insemination, Faculty of Veterinary Medicine, Bursa Uludag University, Bursa, Turkey
| | - Hakan Sagirkaya
- Department of Reproduction and Artificial Insemination, Faculty of Veterinary Medicine, Bursa Uludag University, Bursa, Turkey
| | - Mustafa Kemal Soylu
- Department of Reproduction and Artificial Insemination, Faculty of Veterinary Medicine, Bursa Uludag University, Bursa, Turkey
| | - Sema Birler
- Department of Reproduction and Artificial Insemination, Faculty of Veterinary Medicine, Istanbul University-Cerrahpasa, Istanbul, Turkey
| | - Serhat Pabuccuoglu
- Department of Reproduction and Artificial Insemination, Faculty of Veterinary Medicine, Istanbul University-Cerrahpasa, Istanbul, Turkey
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Abdulsamad HMR, Murtaza ZF, AlMuhairi HM, Bafleh WS, AlMansoori SA, AlQubaisi SA, Hamdan H, Kashir J. The Therapeutic and Diagnostic Potential of Phospholipase C Zeta, Oocyte Activation, and Calcium in Treating Human Infertility. Pharmaceuticals (Basel) 2023; 16:441. [PMID: 36986540 PMCID: PMC10056371 DOI: 10.3390/ph16030441] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 02/19/2023] [Accepted: 03/06/2023] [Indexed: 03/17/2023] Open
Abstract
Oocyte activation, a fundamental event during mammalian fertilisation, is initiated by concerted intracellular patterns of calcium (Ca2+) release, termed Ca2+ oscillations, predominantly driven by testis-specific phospholipase C zeta (PLCζ). Ca2+ exerts a pivotal role in not just regulating oocyte activation and driving fertilisation, but also in influencing the quality of embryogenesis. In humans, a failure of Ca2+ release, or defects in related mechanisms, have been reported to result in infertility. Furthermore, mutations in the PLCζ gene and abnormalities in sperm PLCζ protein and RNA, have been strongly associated with forms of male infertility where oocyte activation is deficient. Concurrently, specific patterns and profiles of PLCζ in human sperm have been linked to parameters of semen quality, suggesting the potential for PLCζ as a powerful target for both therapeutics and diagnostics of human fertility. However, further to PLCζ and given the strong role played by Ca2+ in fertilisation, targets down- and up-stream of this process may also present a significantly similar level of promise. Herein, we systematically summarise recent advancements and controversies in the field to update expanding clinical associations between Ca2+-release, PLCζ, oocyte activation and human fertility. We discuss how such associations may potentially underlie defective embryogenesis and recurrent implantation failure following fertility treatments, alongside potential diagnostic and therapeutic avenues presented by oocyte activation for the diagnosis and treatment of human infertility.
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Affiliation(s)
- Haia M. R. Abdulsamad
- Department of Physiology and Immunology, College of Medicine and Health Sciences, Khalifa University, Abu Dhabi 127788, United Arab Emirates
| | - Zoha F. Murtaza
- Department of Physiology and Immunology, College of Medicine and Health Sciences, Khalifa University, Abu Dhabi 127788, United Arab Emirates
| | - Hessa M. AlMuhairi
- Department of Physiology and Immunology, College of Medicine and Health Sciences, Khalifa University, Abu Dhabi 127788, United Arab Emirates
| | - Wjdan S. Bafleh
- Department of Physiology and Immunology, College of Medicine and Health Sciences, Khalifa University, Abu Dhabi 127788, United Arab Emirates
| | - Salma A. AlMansoori
- Department of Physiology and Immunology, College of Medicine and Health Sciences, Khalifa University, Abu Dhabi 127788, United Arab Emirates
| | - Shaikha A. AlQubaisi
- Department of Physiology and Immunology, College of Medicine and Health Sciences, Khalifa University, Abu Dhabi 127788, United Arab Emirates
| | - Hamdan Hamdan
- Department of Physiology and Immunology, College of Medicine and Health Sciences, Khalifa University, Abu Dhabi 127788, United Arab Emirates
| | - Junaid Kashir
- Department of Biology, College of Arts and Science, Khalifa University, Abu Dhabi 127788, United Arab Emirates
- Department of Comparative Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh 12713, Saudi Arabia
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Bainbridge RE, Rosenbaum JC, Sau P, Carlson AE. Xenopus laevis lack the critical sperm factor PLCζ. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.02.526858. [PMID: 36778253 PMCID: PMC9915601 DOI: 10.1101/2023.02.02.526858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Fertilization of eggs from the African clawed frog Xenopus laevis is characterized by an increase in cytosolic calcium, a phenomenon that is also observed in other vertebrates such as mammals and birds. During fertilization in mammals and birds, the transfer of the soluble PLCζ from sperm into the egg is thought to trigger the release of calcium from the endoplasmic reticulum (ER). Injecting sperm extracts into eggs reproduces this effect, reinforcing the hypothesis that a sperm factor is responsible for calcium release and egg activation. Remarkably, this occurs even when sperm extracts from X. laevis are injected into mouse eggs, suggesting that mammals and X. laevis share a sperm factor. However, X. laevis lacks an annotated PLCZ1 gene, which encodes the PLCζ enzyme. In this study, we attempted to determine whether sperm from X. laevis express an unannotated PLCZ1 ortholog. We identified PLCZ1 orthologs in 11 amphibian species, including 5 that had not been previously characterized, but did not find any in either X. laevis or the closely related Xenopus tropicalis. Additionally, we performed RNA sequencing on testes obtained from adult X. laevis males and did not identify potential PLCZ1 orthologs in our dataset or in previously collected ones. These findings suggest that PLCZ1 may have been lost in the Xenopus lineage and raise the question of how fertilization triggers calcium release and egg activation in these species.
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Affiliation(s)
| | | | - Paushaly Sau
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh PA 15260
| | - Anne E. Carlson
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh PA 15260
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6
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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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7
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Uh K, Hay A, Chen P, Reese E, Lee K. Design of novel oocyte activation methods: The role of zinc. Biol Reprod 2021; 106:264-273. [PMID: 34935887 DOI: 10.1093/biolre/ioab235] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 12/13/2021] [Accepted: 12/15/2021] [Indexed: 11/15/2022] Open
Abstract
Oocyte activation occurs at the time of fertilization and is a series of cellular events initiated by intracellular Ca2+ increases. Consequently, oocytes are alleviated from their arrested state in meiotic metaphase II (MII), allowing for the completion of meiosis. Oocyte activation is also an essential step for somatic cell nuclear transfer (SCNT) and an important tool to overcome clinical infertility. Traditional artificial activation methods aim to mimic the intracellular Ca2+ changes which occur during fertilization. Recent studies emphasize the importance of cytoplasmic Zn2+ on oocyte maturation and the completion of meiosis, thus suggesting artificial oocyte activation approaches that are centered around the concentration of available Zn2+in oocytes. Depletion of intracellular Zn2+ in oocytes with heavy metal chelators leads to successful oocyte activation in the absence of cellular Ca2+ changes, indicating that successful oocyte activation does not always depends on intracellular Ca2+ increases. Current findings lead to new approaches to artificially activate mammalian oocytes by reducing available Zn2+ contents, and the approaches improve the outcome of oocyte activation when combined with existing Ca2+ based oocyte activation methods. Here, we review the important role of Ca2+ and Zn2+ in mammalian oocyte activation and development of novel oocyte activation approaches based on Zn2+ availability.
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Affiliation(s)
- Kyungjun Uh
- Division of Animal Sciences, University of Missouri, Columbia, MO, 65201, USA
| | - Alayna Hay
- Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Paula Chen
- Division of Animal Sciences, University of Missouri, Columbia, MO, 65201, USA
| | - Emily Reese
- Division of Animal Sciences, University of Missouri, Columbia, MO, 65201, USA
| | - Kiho Lee
- Division of Animal Sciences, University of Missouri, Columbia, MO, 65201, USA
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8
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Generation of developmentally competent oocytes and fertile mice from parthenogenetic embryonic stem cells. Protein Cell 2021; 12:947-964. [PMID: 34845589 PMCID: PMC8674391 DOI: 10.1007/s13238-021-00865-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Accepted: 06/20/2021] [Indexed: 12/11/2022] Open
Abstract
Parthenogenetic embryos, created by activation and diploidization of oocytes, arrest at mid-gestation for defective paternal imprints, which impair placental development. Also, viable offspring has not been obtained without genetic manipulation from parthenogenetic embryonic stem cells (pESCs) derived from parthenogenetic embryos, presumably attributable to their aberrant imprinting. We show that an unlimited number of oocytes can be derived from pESCs and produce healthy offspring. Moreover, normal expression of imprinted genes is found in the germ cells and the mice. pESCs exhibited imprinting consistent with exclusively maternal lineage, and higher X-chromosome activation compared to female ESCs derived from the same mouse genetic background. pESCs differentiated into primordial germ cell-like cells (PGCLCs) and formed oocytes following in vivo transplantation into kidney capsule that produced fertile pups and reconstituted ovarian endocrine function. The transcriptome and methylation of imprinted and X-linked genes in pESC-PGCLCs closely resembled those of in vivo produced PGCs, consistent with efficient reprogramming of methylation and genomic imprinting. These results demonstrate that amplification of germ cells through parthenogenesis faithfully maintains maternal imprinting, offering a promising route for deriving functional oocytes and having potential in rebuilding ovarian endocrine function.
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9
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Parthenogenetic activation of buffalo ( Bubalus bubalis) oocytes: comparison of different activation reagents and different media on their developmental competence and quantitative expression of developmentally regulated genes. ZYGOTE 2020; 29:49-58. [PMID: 33004105 DOI: 10.1017/s0967199420000519] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
This study was carried out to compare the efficacy of different methods to activate buffalo A + B and C + D quality oocytes parthenogenetically and to study the in vitro developmental competence of oocytes and expression of some important genes at the different developmental stages of parthenotes. The percentage of A + B oocytes (62.16 ± 5.06%, range 53.8-71.3%) was significantly higher (P < 0.001) compared with that of C + D oocytes (37.8 ± 5.00%, range 28.6-46.1%) retrieved from slaughterhouse buffalo ovaries. Among all combinations, ethanol activation followed by culture in research vitro cleave medium gave the highest cleavage and blastocyst yields for both A + B and C + D grade oocytes. Total cell numbers, inner cell mass/trophectoderm ratio and apoptotic index of A + B group blastocysts were significantly different (P < 0.05) from their C + D counterpart. To determine the status of expression patterns of developmentally regulated genes, the expression of cumulus-oocyte complexes, fertilization, developmental competence and apoptotic-related genes were also studied in parthenogenetically produced buffalo embryos at different stages, and indicated that the differential expression patterns of the above genes had a role in early embryonic development.
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10
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Handayani N, Wiweko B, Zakirah SC, Boediono A. In vitro Activation of Mouse Oocytes through Intracellular Ca2+ Regulation. J Hum Reprod Sci 2020; 13:138-144. [PMID: 32792763 PMCID: PMC7394099 DOI: 10.4103/jhrs.jhrs_122_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 12/26/2019] [Accepted: 02/28/2020] [Indexed: 11/30/2022] Open
Abstract
Background: Ca2+ signaling pathway is suggested to play an essential role in mediating oocyte maturation. Aims: The aim of this study was to evaluate intracellular Ca2+ of resistant immature oocytes that failed to resume meiosis following subsequent in vitro culture reach metaphase II after calcium ionophore A23187 activation. Settings and Design: This in vitro analytical experimental study was conducted at Animal Science Laboratory of Indonesian Medical Education and Research Institute (IMERI), Human Reproductive Infertility and Family Planning of IMERI, and Electrophysiology Imaging of Terpadu Laboratory, Faculty of Medicine, University of Indonesia. Methods: A total of 308 oocytes classed as resistant immature following in vitro culture were randomly allocated to control (n = 113) and treatment groups (n = 195). The oocyte activation group was exposed to A23187 solution for 15 min and then washed extensively. Maturation was evaluated by observing the first polar body extrusion 20‒24 h after A23187 exposure. Ca2+ imaging was conducted using a confocal laser scanning microscope to identify the dynamic of Ca2+ response. Statistical Analysis: SPSS 20, Chi-square, and Mann–Whitney U-test were used in this study. Results: Activation of resistant immature oocytes with A23187 significantly increased the number of oocyte maturation compared with the control group (P < 0.001). Furthermore, fluorescent intensity measurements exhibited a significant increase in the germinal vesicle stage when activated (P = 0.005), as well as the metaphase I stage, even though differences were not significant (P = 0.146). Conclusion: Artificial activation of resistant immature oocyte using chemical A23187/calcimycin was adequate to initiate meiosis progress.
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Affiliation(s)
- Nining Handayani
- Reproductive Science Master Program of Biomedical Science, Faculty of Medicine, University of Indonesia, Jakarta, Indonesia
| | - Budi Wiweko
- Department of Obstetrics and Gynecology, Division of Reproductive Endocrinology and Infertility, Faculty of Medicine, University of Indonesia, Jakarta, Indonesia.,Yasmin IVF Clinic, Dr. Cipto Mangunkusumo General Hospital, Jakarta, Indonesia.,Human Reproductive, Infertility, and Family Planning Research Center, Indonesian Medical Education and Research Institutes, Faculty of Medicine, University of Indonesia, Jakarta, Indonesia
| | - Sarah Chairani Zakirah
- Department of Obstetrics and Gynecology, Division of Reproductive Endocrinology and Infertility, Faculty of Medicine, University of Indonesia, Jakarta, Indonesia.,Human Reproductive, Infertility, and Family Planning Research Center, Indonesian Medical Education and Research Institutes, Faculty of Medicine, University of Indonesia, Jakarta, Indonesia
| | - Arief Boediono
- Department of Anatomy, Physiology and Pharmacology, IPB University, Bogor, Indonesia
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Stein P, Savy V, Williams AM, Williams CJ. Modulators of calcium signalling at fertilization. Open Biol 2020; 10:200118. [PMID: 32673518 PMCID: PMC7574550 DOI: 10.1098/rsob.200118] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 06/18/2020] [Indexed: 12/16/2022] Open
Abstract
Calcium (Ca2+) signals initiate egg activation across the animal kingdom and in at least some plants. These signals are crucial for the success of development and, in the case of mammals, health of the offspring. The mechanisms associated with fertilization that trigger these signals and the molecules that regulate their characteristic patterns vary widely. With few exceptions, a major contributor to fertilization-induced elevation in cytoplasmic Ca2+ is release from endoplasmic reticulum stores through the IP3 receptor. In some cases, Ca2+ influx from the extracellular space and/or release from alternative intracellular stores contribute to the rise in cytoplasmic Ca2+. Following the Ca2+ rise, the reuptake of Ca2+ into intracellular stores or efflux of Ca2+ out of the egg drive the return of cytoplasmic Ca2+ back to baseline levels. The molecular mediators of these Ca2+ fluxes in different organisms include Ca2+ release channels, uptake channels, exchangers and pumps. The functions of these mediators are regulated by their particular activating mechanisms but also by alterations in their expression and spatial organization. We discuss here the molecular basis for modulation of Ca2+ signalling at fertilization, highlighting differences across several animal phyla, and we mention key areas where questions remain.
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Affiliation(s)
- Paula Stein
- Reproductive and Developmental Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Virginia Savy
- Reproductive and Developmental Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Audrey M. Williams
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, IL 60637, USA
| | - Carmen J. Williams
- Reproductive and Developmental Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
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12
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Kashir J. Increasing associations between defects in phospholipase C zeta and conditions of male infertility: not just ICSI failure? J Assist Reprod Genet 2020; 37:1273-1293. [PMID: 32285298 PMCID: PMC7311621 DOI: 10.1007/s10815-020-01748-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 03/12/2020] [Indexed: 12/12/2022] Open
Abstract
PURPOSE Oocyte activation is a fundamental event at mammalian fertilization. In mammals, this process is initiated by a series of characteristic calcium (Ca2+) oscillations, induced by a sperm-specific phospholipase C (PLC) termed PLCzeta (PLCζ). Dysfunction/reduction/deletion of PLCζ is associated with forms of male infertility where the sperm is unable to initiate Ca2+ oscillations and oocyte activation, specifically in cases of fertilization failure. This review article aims to systematically summarize recent advancements and controversies in the field to update expanding clinical associations between PLCζ and various male factor conditions. This article also discusses how such associations may potentially underlie defective embryogenesis and recurrent implantation failure following fertility treatments, alongside potential diagnostic and therapeutic PLCζ approaches, aiming to direct future research efforts to utilize such knowledge clinically. METHODS An extensive literature search was performed using literature databases (PubMed/MEDLINE/Web of Knowledge) focusing on phospholipase C zeta (PLCzeta; PLCζ), oocyte activation, and calcium oscillations, as well as specific male factor conditions. RESULTS AND DISCUSSION Defective PLCζ or PLCζ-induced Ca2+ release can be linked to multiple forms of male infertility including abnormal sperm parameters and morphology, sperm DNA fragmentation and oxidation, and abnormal embryogenesis/pregnancies. Such sperm exhibit absent/reduced levels, and abnormal localization patterns of PLCζ within the sperm head. CONCLUSIONS Defective PLCζ and abnormal patterns of Ca2+ release are increasingly suspected a significant causative factor underlying abnormalities or insufficiencies in Ca2+ oscillation-driven early embryogenic events. Such cases could potentially strongly benefit from relevant therapeutic and diagnostic applications of PLCζ, or even alternative mechanisms, following further focused research efforts.
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Affiliation(s)
- Junaid Kashir
- College of Medicine, Alfaisal University, Riyadh, Kingdom of Saudi Arabia. .,School of Biosciences, Cardiff University, Cardiff, UK. .,Department of Comparative Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Kingdom of Saudi Arabia.
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13
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Saleh A, Kashir J, Thanassoulas A, Safieh-Garabedian B, Lai FA, Nomikos M. Essential Role of Sperm-Specific PLC-Zeta in Egg Activation and Male Factor Infertility: An Update. Front Cell Dev Biol 2020; 8:28. [PMID: 32064262 PMCID: PMC7000359 DOI: 10.3389/fcell.2020.00028] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 01/14/2020] [Indexed: 12/16/2022] Open
Abstract
Sperm-specific phospholipase C zeta (PLCζ) is widely considered to be the physiological stimulus responsible for generating calcium (Ca2+) oscillations that induce egg activation and early embryonic development during mammalian fertilization. In the mammalian testis, PLCζ expression is detected at spermiogenesis following elongated spermatid differentiation. Sperm-delivered PLCζ induces Ca2+ release via the inositol 1,4,5-trisphosphate (InsP3) signaling pathway. PLCζ is the smallest known mammalian PLC isoform identified to date, with the simplest domain organization. However, the distinctive biochemical properties of PLCζ compared with other PLC isoforms contribute to its unique potency in stimulating cytosolic Ca2+ oscillations within mammalian eggs. Moreover, studies describing PLCζ “knockout” mouse phenotypes confirm the supreme importance of PLCζ at egg activation and monospermic fertilization in mice. Importantly, a number of clinical reports have highlighted the crucial importance of PLCζ in human fertilization by associating PLCζ deficiencies with certain forms of male factor infertility. Herein, we give an update on recent advances that have refined our understanding of how sperm PLCζ triggers Ca2 + oscillations and egg activation in mammals, while also discussing the nature of a potential “alternative” sperm factor. We summarise PLCζ localization in mammalian sperm, and the direct links observed between defective PLCζ protein in sperm and documented cases of male infertility. Finally, we postulate how this sperm protein can be used as a potential diagnostic marker, and also as a powerful therapeutic agent for treatment of certain types of male infertility due to egg activation failure or even in more general cases of male subfertility.
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Affiliation(s)
- Alaaeldin Saleh
- Member of QU Health, College of Medicine, Qatar University, Doha, Qatar
| | - Junaid Kashir
- College of Medicine, Alfaisal University, Riyadh, Saudi Arabia.,Department of Comparative Medicine, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | | | | | - F Anthony Lai
- Member of QU Health, College of Medicine, Qatar University, Doha, Qatar.,Biomedical Research Center, Qatar University, Doha, Qatar
| | - Michail Nomikos
- Member of QU Health, College of Medicine, Qatar University, Doha, Qatar
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14
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Yamamoto Y, Hirose N, Kamimura S, Wakayama S, Ito J, Ooga M, Wakayama T. Production of mouse offspring from inactivated spermatozoa using horse PLCζ mRNA. J Reprod Dev 2019; 66:67-73. [PMID: 31852860 PMCID: PMC7040210 DOI: 10.1262/jrd.2019-043] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Improving artificial oocyte activation is essential for assisted reproduction or animal biotechnology that can obtain healthy offspring with a high success rate. Here, we examined whether
intracytoplasmic injection of equine sperm-specific phospholipase C zeta (ePLCζ) mRNA, the PLCζ with the strongest oocyte activation potential in mammals, could improve the mouse oocyte
activation rate and subsequent embryonic development using inactivated spermatozoa. mRNA of mouse PLCζ (mPLCζ) or ePLCζ were injected into mouse oocytes to determine the optimal mRNA
concentration to maximize the oocyte activation rate and developmental rate of parthenogenetic embryos in vitro. Full-term development was examined using NaOH-treated
inactive spermatozoa using the optimal activation method. We found that the most optimal ePLCζ mRNA concentration was 0.1 ng/µl for mouse oocyte activation, which was ten times stronger than
mPLCζ mRNA. The concentration did not affect parthenogenetic embryo development in vitro. Relatively normal blastocysts were obtained with the same developmental rate
(52–53% or 48–51%, respectively) when inactive spermatozoa were injected into activated oocytes using ePLCζ or mPLCζ mRNA injection. However, the birth rate after embryo transfer was
slightly but significantly decreased in oocytes activated by ePLCζ mRNA (24%) compared to mPLCζ mRNA (37%) or strontium treatment (40%) activation. These results suggest that the higher
activation rate does not always correlate the higher birth rate, and some mechanisms might exist in the oocyte activation process that could affect the later developmental stages like
full-term development.
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Affiliation(s)
- Yunosuke Yamamoto
- Faculty of Life and Environmental Science, University of Yamanashi, Yamanashi 400-8510, Japan
| | - Naoki Hirose
- Faculty of Life and Environmental Science, University of Yamanashi, Yamanashi 400-8510, Japan
| | - Satoshi Kamimura
- Faculty of Life and Environmental Science, University of Yamanashi, Yamanashi 400-8510, Japan.,Present: Department of Basic Medical Sciences for Radiation Damages, National Institute of Radiological Sciences, Chiba 263-8555, Japan
| | - Sayaka Wakayama
- Advanced Biotechnology Center, University of Yamanashi, Yamanashi 400-8510, Japan
| | - Junya Ito
- Laboratory of Animal Reproduction, Graduate School of Veterinary Science, Azabu University, Kanagawa 252-5201, Japan
| | - Masatoshi Ooga
- Faculty of Life and Environmental Science, University of Yamanashi, Yamanashi 400-8510, 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
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15
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Uh K, Ryu J, Zhang L, Errington J, Machaty Z, Lee K. Development of novel oocyte activation approaches using Zn2+ chelators in pigs. Theriogenology 2019; 125:259-267. [DOI: 10.1016/j.theriogenology.2018.11.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 10/31/2018] [Accepted: 11/14/2018] [Indexed: 10/27/2022]
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16
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Zhang S, Xiang S, Yang J, Shi J, Guan X, Jiang J, Wei Y, Luo C, Shi D, Lu F. Optimization of parthenogenetic activation of rabbit oocytes and development of rabbit embryo by somatic cell nuclear transfer. Reprod Domest Anim 2018; 54:258-269. [PMID: 30220080 DOI: 10.1111/rda.13344] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 09/10/2018] [Indexed: 11/28/2022]
Abstract
The present study explored a suitable parthenogenetic activation (PA) procedure for rabbit oocytes and investigated the developmental potential of somatic cell nuclear transfer (SCNT) embryos using rabbit foetal fibroblasts (RFFs). The electrical activation had the optimal rate of blastocyst (14.06%) when oocytes were activated by three direct current (DC) pulses (40 V/mm, 20 μs each) followed by 6-dimethylaminopurine (6-DMAP) and cycloheximide (CHX) treatment; the blastocyst rate of ionomycin (ION) + 6-DMAP + CHX (12.07%) activation was higher than that of ION + 6-DMAP (8.6%) activation or ION + CHX (1.24%) activation; there was no significant difference in blastocyst rate between ION + 6-DMAP + CHX and DC + 6-DMAP + CHX groups. The blastocyst rate of ION + 6-DMAP + CHX-activated oocytes in the basic rabbit culture medium (M-199) + 10% foetal bovine serum (FBS; 14.28%) was higher than that in buffalo conditioned medium (5.75%) or G1/G2 medium (0), and the blastocyst rate was increased when M-199 + 10% FBS was supplemented with amino acids. Refreshing culture medium every day or every other day significantly increased the blastocyst rate. Treatment of donor cells with 0.5% FBS for 3-5 days increased blastocyst rate of SCNT embryos (33.33%) than no serum starvation (22.47%) or 0.5% FBS treatment for 6-9 days (23.61%); the blastocyst rate of SCNT embryos derived from nontransgenic RFFs was higher than that derived from transgenic RFFs by electroporation. The blastocyst development ability of SCNT embryos derived from RFFs by electroporation (32.22%) was higher than that of liposome (19.11%) or calcium phosphate (20.00%) transfection, and only the embryos from electroporation group have the EGFP expression (24.44%). In conclusion, this study for the first time systematically optimized the conditions for yield of rabbit embryo by SCNT.
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Affiliation(s)
- Shun Zhang
- Animal Reproduction Institute, State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, China.,Department of Reproductive Medical Center, Affiliated Hospital of Guilin Medical University, Guilin, China
| | - Shu Xiang
- Animal Reproduction Institute, State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, China.,Department of Reproductive Medical Center, Kunming Calmette International Hospital, Kunming, China
| | - Jinji Yang
- Animal Reproduction Institute, State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, China
| | - Jinyue Shi
- Animal Reproduction Institute, State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, China
| | - Xiaomei Guan
- Animal Reproduction Institute, State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, China
| | - Jianrong Jiang
- Animal Reproduction Institute, State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, China
| | - Yingming Wei
- Animal Reproduction Institute, State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, China
| | - Chan Luo
- Animal Reproduction Institute, State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, China
| | - Deshun Shi
- Animal Reproduction Institute, State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, China
| | - Fenghua Lu
- Animal Reproduction Institute, State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, China
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17
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Swann K. The role of Ca 2+ in oocyte activation during In Vitro fertilization: Insights into potential therapies for rescuing failed fertilization. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018; 1865:1830-1837. [PMID: 29746897 DOI: 10.1016/j.bbamcr.2018.05.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 04/30/2018] [Accepted: 05/02/2018] [Indexed: 12/21/2022]
Abstract
At fertilization the mature mammalian oocyte is activated to begin development by a sperm-induced series of increases in the cytosolic free Ca2+ concentration. These so called Ca2+ oscillations, or repetitive Ca2+ spikes, are also seen after intracytoplasmic sperm injection (ICSI) and are primarily triggered by a sperm protein called phospholipase Czeta (PLCζ). Whilst ICSI is generally an effective way to fertilizing human oocytes, there are cases where oocyte activation fails to occur after sperm injection. Many such cases appear to be associated with a PLCζ deficiency. Some IVF clinics are now attempting to rescue such cases of failed fertilization by using artificial means of oocyte activation such as the application of Ca2+ ionophores. This review presents the scientific background for these therapies and also considers ways to improve artificial oocyte activation after failed fertilization.
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Affiliation(s)
- Karl Swann
- School of Biosciences, Cardiff University, Sir Martin Evans Building, Museum Avenue, Cardiff CF10 3AX, UK.
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18
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Zhou G, Wei H, Wang X, Yang M, Bunch TD, Polejaeva IA, White KL, Wang Z, Meng Q. Serial Culture Is Critical for In Vitro Development of Parthenogenetic Embryos in the Golden Syrian Hamster. Cell Reprogram 2018; 20:187-195. [PMID: 29688743 DOI: 10.1089/cell.2017.0070] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022] Open
Abstract
Unlike oocytes of many other mammalian species, parthenogenetically activated hamster oocytes have not been reported to develop beyond the two-cell stage. This study investigated the in vitro development into blastocysts of parthenogenetic embryos of Golden Syrian hamsters. We observed that hamster oocytes could easily be artificially activated (AA) by treatment with ionomycin plus 6-dimethylaminopurine + cycloheximide + cytochalasin B as assessed by embryo cleavage in HECM-9 (63.15%) or HECM-10 (63.82%). None of the cleaved embryos developed beyond the two-cell stage when cultured in either of the two media. However, some of the embryos overcame the two-cell block and developed to the blastocyst stage (26.45%) when they were first cultured in HECM-10 for 24 hours and then in HECM-9 (serial culture media HECM-10-9) for 72 hours. Blastocyst development was further significantly (66.2%) improved when embryos were cultured in HECM-10 supplemented with ethylenediaminetetraacetic acid for 24 hours, then in HECM-9 supplemented with glucose for 72 hours (serial culture media HECM-11a-b). Hamster oocytes activated with ionomycin, ethanol, or a combination of the two treatments would develop to the blastocyst stage in serial culture media HECM-11a-b, whereas none of the spontaneously activated oocytes cleaved (0% vs. 86.93%, p < 0.05). DNA and microtubule configurations of spontaneously activated and AA oocytes were assessed by immunocytochemical staining and fluorescence microscopy. The results indicate that serial culture and the method of activation are critical for overcoming the in vitro developmental block of hamster parthenogenetic embryos. This study is the first to report blastocyst development from parthenogenetically activated hamster oocytes.
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Affiliation(s)
- Guangbin Zhou
- 1 Department of Animal, Dairy, and Veterinary Sciences, Utah State University , Logan, Utah.,2 Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University , Chengdu, P.R. China
| | - Hengxi Wei
- 1 Department of Animal, Dairy, and Veterinary Sciences, Utah State University , Logan, Utah.,3 College of Animal Science, South China Agricultural University , Guangzhou, P.R. China
| | - Xinrong Wang
- 1 Department of Animal, Dairy, and Veterinary Sciences, Utah State University , Logan, Utah.,4 College of Animal Science and Technology, Gansu Agricultural University , Lanzhou, P.R. China
| | - Min Yang
- 1 Department of Animal, Dairy, and Veterinary Sciences, Utah State University , Logan, Utah
| | - Thomas D Bunch
- 1 Department of Animal, Dairy, and Veterinary Sciences, Utah State University , Logan, Utah
| | - Irina A Polejaeva
- 1 Department of Animal, Dairy, and Veterinary Sciences, Utah State University , Logan, Utah
| | - Kenneth L White
- 1 Department of Animal, Dairy, and Veterinary Sciences, Utah State University , Logan, Utah
| | - Zhongde Wang
- 1 Department of Animal, Dairy, and Veterinary Sciences, Utah State University , Logan, Utah
| | - Qinggang Meng
- 1 Department of Animal, Dairy, and Veterinary Sciences, Utah State University , Logan, Utah
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19
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Zhang L, Chao CH, Jaeger LA, Papp AB, Machaty Z. Calcium oscillations in fertilized pig oocytes are associated with repetitive interactions between STIM1 and ORAI1. Biol Reprod 2018; 98:510-519. [PMID: 29365044 PMCID: PMC5905661 DOI: 10.1093/biolre/ioy016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 12/01/2017] [Accepted: 01/19/2018] [Indexed: 11/15/2022] Open
Abstract
The Ca2+ entry mechanism that sustains the Ca2+ oscillations in fertilized pig oocytes was investigated. Stromal interaction molecule 1 (STIM1) and ORAI1 proteins tagged with various fluorophores were expressed in the oocytes. In some cells, the Ca2+ stores were depleted using cyclopiazonic acid (CPA); others were inseminated. Changes in the oocytes' cytosolic free Ca2+ concentration were monitored, while interaction between the expressed fusion proteins was investigated using fluorescence resonance energy transfer (FRET). Store depletion led to an increase of the FRET signal in oocytes co-expressing mVenus-STIM1 and mTurquoise2-ORAI1, indicating that Ca2+ release was followed by an interaction between these proteins. A similar FRET increase in response to CPA was also detected in oocytes co-expressing mVenus-STIM1 and mTurquoise2-STIM1, which is consistent with STIM1 forming punctae after store depletion. ML-9, an inhibitor that can interfere with STIM1 puncta formation, blocked store-operated Ca2+ entry (SOCE) induced by Ca2+ add-back after a CPA treatment; it also disrupted the Ca2+ oscillations in fertilized oocytes. In addition, oocytes overexpressing mVenus-STIM1 showed high-frequency Ca2+ oscillations when fertilized, arguing for an active role of the protein. High-frequency Ca2+ oscillations were also detected in fertilized oocytes co-expressing mVenus-STIM1 and mTurquoise2-ORAI1, and both of these high-frequency Ca2+ oscillations could be stopped by inhibitors of SOCE. Importantly, in oocytes co-expressing mVenus-STIM1 and mTurquoise2-ORAI1, we were also able to detect cyclic increases of the FRET signal indicating repetitive interactions between STIM1 and ORAI1. The results confirm the notion that in pig oocytes, SOCE is involved in the maintenance of the repetitive Ca2+ transients at fertilization.
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Affiliation(s)
- Lu Zhang
- Department of Animal Sciences, Purdue University, West Lafayette, Indiana, USA
| | | | - Laurie A Jaeger
- Department of Basic Medical Sciences, Purdue University, West Lafayette, Indiana, USA
| | - Agnes Bali Papp
- Department of Animal Sciences, Széchenyi István University, Győr, Hungary
| | - Zoltan Machaty
- Department of Animal Sciences, Purdue University, West Lafayette, Indiana, USA
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20
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Lu Y, Bonte D, Ferrer-Buitrago M, Popovic M, Neupane J, Van der Jeught M, Leybaert L, De Sutter P, Heindryckx B. Culture conditions affect Ca2+ release in artificially activated mouse and human oocytes. Reprod Fertil Dev 2018; 30:991-1001. [DOI: 10.1071/rd17145] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 11/17/2017] [Indexed: 11/23/2022] Open
Abstract
Inconsistent fertilisation and pregnancy rates have been reported by different laboratories after application of ionomycin as a clinical method of assisted oocyte activation (AOA) to overcome fertilisation failure. Using both mouse and human oocytes, in the present study we investigated the effects of ionomycin and Ca2+ concentrations on the pattern of Ca2+ release and embryonic developmental potential. In the mouse, application of 5 μM ionomycin in potassium simplex optimisation medium (KSOM) or 10 µM ionomycin in Ca2+-free KSOM significantly reduced the Ca2+ flux and resulted in failure of blastocyst formation compared with 10 μM ionomycin in KSOM. Increasing the Ca2+ concentration up to three- or sixfold did not benefit mouse embryonic developmental potential. Similarly, 10 μM ionomycin-induced rise in Ca2+ in human oocytes increased with increasing total calcium concentrations in the commercial medium. Remarkably, we observed significantly reduced mouse embryo development when performing AOA over a period of 10 min in Quinn’s AdvantageTM Fertilisation medium (Cooper Surgical) and IVFTM medium (Vitrolife) compared with Sydney IVF COOK cleavage medium (Cook Ireland), using the same sequential culture system from the post-activation stage to blastocyst formation stage in different AOA groups. In conclusion, concentrations of both ionomycin and Ca2+ in culture media used during AOA can have significant effects on Ca2+ release and further embryonic developmental potential.
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21
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Kashir J, Nomikos M, Lai FA. Phospholipase C zeta and calcium oscillations at fertilisation: The evidence, applications, and further questions. Adv Biol Regul 2017; 67:148-162. [PMID: 29108881 DOI: 10.1016/j.jbior.2017.10.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 10/25/2017] [Accepted: 10/25/2017] [Indexed: 12/26/2022]
Abstract
Oocyte activation is a fundamental event at mammalian fertilisation, initiated by a series of characteristic calcium (Ca2+) oscillations in mammals. This characteristic pattern of Ca2+ release is induced in a species-specific manner by a sperm-specific enzyme termed phospholipase C zeta (PLCζ). Reduction or absence of functional PLCζ within sperm underlies male factor infertility in humans, due to mutational inactivation or abrogation of PLCζ protein expression. Underlying such clinical implications, a significant body of evidence has now been accumulated that has characterised the unique biochemical and biophysical properties of this enzyme, further aiding the unique clinical opportunities presented. Herein, we present and discuss evidence accrued over the past decade and a half that serves to support the identity of PLCζ as the mammalian sperm factor. Furthermore, we also discuss the potential novel avenues that have yet to be examined regarding PLCζ mechanism of action in both the oocyte, and the sperm. Finally, we discuss the advances that have been made regarding the clinical therapeutic and diagnostic applications of PLCζ in potentially treating male infertility as a result of oocyte activation deficiency (OAD), and also possibly more general cases of male subfertility.
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Affiliation(s)
- Junaid Kashir
- College of Biomedical & Life Sciences, School of Biosciences, Cardiff University, Cardiff, UK; Alfaisal University, College of Medicine, Riyadh, Saudi Arabia; King Faisal Specialist Hospital & Research Center, Department of Comparative Medicine, Riyadh, Saudi Arabia.
| | - Michail Nomikos
- College of Medicine, Member of QU Health, Qatar University, PO Box 2713, Doha, Qatar
| | - F Anthony Lai
- College of Biomedical & Life Sciences, School of Biosciences, Cardiff University, Cardiff, UK; College of Medicine, Member of QU Health, Qatar University, PO Box 2713, Doha, Qatar.
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22
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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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23
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Fertilization 2: Polyspermic Fertilization. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1001:105-123. [DOI: 10.1007/978-981-10-3975-1_7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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24
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Jeve YB, Potdar N, Blower JA, Gelbaya T. Strategies to improve fertilisation rates with assisted conception: a systematic review. HUM FERTIL 2017; 21:229-247. [PMID: 28545312 DOI: 10.1080/14647273.2017.1324182] [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: 10/19/2022]
Abstract
Successful fertilisation is one of the key steps determining success of assisted conception. Various factors including sperm or oocyte pathology and environmental factors have a significant impact on fertilisation rates. This systematic review is aimed to evaluate the existing evidence about factors affecting fertilisation and strategies to improve fertilisation rates. A literature search was performed using Ovid MEDLINE ® (Jan 1950-April 2016), EMBASE (Jan 1950-April 2016), Ovid OLDMEDLINE ®, Pre-MEDLINE (Jan 1950-April 2016) and the Cochrane Library. Relevant key words were used to combine sets of results and a total 243 papers were screened. Only qualitative analysis was performed, as there was major heterogeneity in study design and methodology for quantitative synthesis. Factors affecting fertilisation were divided into sperm- and oocyte-related factors. The methods to improve fertilisation rates were grouped together based on the approach used to improve fertilisation rates. Optimising laboratory condition and procedural effects in techniques is associated with improved fertilisation rates. Various techniques are described to improve fertilisation rates including assisted oocyte activation, physiological intracytoplasmic sperm injection (PICSI) and intracytoplasmic morphologically selected sperm injection (IMSI). This review highlights the promising strategies under research to enhance fertilisation rates. Adequately powered multicentre randomised trials are required to evaluate these techniques before considering clinical application.
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Affiliation(s)
- Yadava Bapurao Jeve
- a Leicester Fertility Centre , University Hospitals of Leicester , Leicester , UK
| | - Neelam Potdar
- a Leicester Fertility Centre , University Hospitals of Leicester , Leicester , UK.,b Reproductive Sciences Section , University of Leicester , Leicester , UK
| | - Jane A Blower
- a Leicester Fertility Centre , University Hospitals of Leicester , Leicester , UK
| | - Tarek Gelbaya
- a Leicester Fertility Centre , University Hospitals of Leicester , Leicester , UK
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Golpour A, Pšenička M, Niksirat H. Subcellular distribution of calcium during spermatogenesis of zebrafish,Danio rerio. J Morphol 2017; 278:1149-1159. [DOI: 10.1002/jmor.20701] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Revised: 03/06/2017] [Accepted: 04/23/2017] [Indexed: 12/20/2022]
Affiliation(s)
- Amin Golpour
- University of South Bohemia in České Budějovice, Faculty of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Research Institute of Fish Culture and Hydrobiology; Zátiší 728/II Vodňany 389 25 Czech Republic
| | - Martin Pšenička
- University of South Bohemia in České Budějovice, Faculty of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Research Institute of Fish Culture and Hydrobiology; Zátiší 728/II Vodňany 389 25 Czech Republic
| | - Hamid Niksirat
- University of South Bohemia in České Budějovice, Faculty of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Research Institute of Fish Culture and Hydrobiology; Zátiší 728/II Vodňany 389 25 Czech Republic
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QIU X, LI N, XIAO X, LI Y. Aggregation of a parthenogenetic diploid embryo and a male embryo improves the blastocyst development and parthenogenetic embryonic stem cell derivation. Turk J Biol 2017. [DOI: 10.3906/biy-1612-30] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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Abstract
A series of intracellular oscillations in the free cytosolic Ca(2+) concentration is responsible for activating mammalian eggs at fertilization, thus initiating embryo development. It has been proposed that the sperm causes these Ca(2+) oscillations after membrane fusion by delivering a soluble protein into the egg cytoplasm. We previously identified sperm-specific phospholipase C (PLC)-ζ as a protein that can trigger the same pattern of Ca(2+) oscillations in eggs seen at fertilization. PLCζ appears to be the elusive sperm factor mediating egg activation in mammals. It has potential therapeutic use in infertility treatments to improve the rate of egg activation and early embryo development after intra-cytoplasmic sperm injection. A stable form of recombinant human PLCζ could be a prototype for use in such in vitro fertilization (IVF) treatments. We do not yet understand exactly how PLCζ causes inositol 1,4,5-trisphosphate (InsP3) production in eggs. Sperm PLCζ is distinct among mammalian PI-specific PLCs in that it is far more potent in triggering Ca(2+) oscillations in eggs than other PLCs, but it lacks a PH domain that would otherwise be considered essential for binding to the phosphatidylinositol 4,5-bisphosphate (PIP2) substrate. PLCζ is also unusual in that it does not appear to interact with or hydrolyse plasma membrane PIP2. We consider how other regions of PLCζ may mediate its binding to PIP2 in eggs and how interaction of PLCζ with egg-specific factors could enable the hydrolysis of internal sources of PIP2.
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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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Bianchi S, Macchiarelli G, Micara G, Linari A, Boninsegna C, Aragona C, Rossi G, Cecconi S, Nottola SA. Ultrastructural markers of quality are impaired in human metaphase II aged oocytes: a comparison between reproductive and in vitro aging. J Assist Reprod Genet 2015; 32:1343-58. [PMID: 26276431 DOI: 10.1007/s10815-015-0552-9] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 07/27/2015] [Indexed: 11/25/2022] Open
Abstract
PURPOSE Childbearing delay contributes to the increase of subfertile couples that require assisted reproductive technology (ART). Subfertility relates with reproductive aging (RA). In vitro aging (IvA) (due to extended culture) may also impair oocyte competence. Aims of this study were to evaluate and compare the oocyte ultrastructure after RA and IvA. METHODS Cumulus-oocyte complexes (COCs) (n = 68), with metaphase II oocyte and expanded cumulus, from consenting patients (<35 years old and ≥35 years old, n = 36), were selected by phase contrast microscopy and fixed at pick up, or after 24 h culture. COCs (n = 44) were studied by light and qualitative/morphometric transmission electron microscopy. Two-way ANOVA, with age and culture as grouping factors, was applied for statistical analysis (p < 0.05). Metaphase II cumulus-free oocytes (n = 24) were selected for confocal microscopy observations. RESULTS Significant decrease of mitochondria-smooth endoplasmic reticulum aggregates, increase of mitochondria-vesicle complexes size and amount, decrease of cortical granules and microvilli, and alterations of the spindle structure characterized both RA and IvA oocytes. These changes were significantly more evident in the RA oocytes submitted to IvA. RA oocytes also showed changes of the zona pellucida and occurrence of vacuoles after culture. Cumuli appeared re-compacted after culture, irrespective of the age of the patients. CONCLUSIONS These data demonstrated that aging is related to decay of oocyte ultrastructural quality, and that oocytes from elder women are more sensitive to prolonged culture (IvA) than the oocytes from younger women. These morphological results should be considered when applying ART in aged patients, rescue ICSI, or artificial oocyte activation.
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Affiliation(s)
- S Bianchi
- Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy
| | - G Macchiarelli
- Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy
| | - G Micara
- Department of Gynaecology-Obstetrics & Urology, "Sapienza" University, Rome, Italy
| | - A Linari
- Department of Gynaecology-Obstetrics & Urology, "Sapienza" University, Rome, Italy
| | - C Boninsegna
- Department of Gynaecology-Obstetrics & Urology, "Sapienza" University, Rome, Italy
| | - C Aragona
- Department of Gynaecology-Obstetrics & Urology, "Sapienza" University, Rome, Italy
| | - G Rossi
- Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy
| | - S Cecconi
- Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy
| | - S A Nottola
- Department of Anatomy, Histology, Forensic Medicine and Orthopaedics, "Sapienza" University, Rome, Italy.
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Sfontouris IA, Nastri CO, Lima ML, Tahmasbpourmarzouni E, Raine-Fenning N, Martins WP. Artificial oocyte activation to improve reproductive outcomes in women with previous fertilization failure: a systematic review and meta-analysis of RCTs. Hum Reprod 2015; 30:1831-1841. [DOI: 10.1093/humrep/dev136] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023] Open
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Santella L, Limatola N, Chun JT. Calcium and actin in the saga of awakening oocytes. Biochem Biophys Res Commun 2015; 460:104-13. [PMID: 25998739 DOI: 10.1016/j.bbrc.2015.03.028] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 03/06/2015] [Indexed: 12/12/2022]
Abstract
The interaction of the spermatozoon with the egg at fertilization remains one of the most fascinating mysteries of life. Much of our scientific knowledge on fertilization comes from studies on sea urchin and starfish, which provide plenty of gametes. Large and transparent, these eggs have served as excellent model systems for studying egg activation and embryo development in seawater, a plain natural medium. Starfish oocytes allow the study of the cortical, cytoplasmic and nuclear changes during the meiotic maturation process, which can also be triggered in vitro by hormonal stimulation. These morphological and biochemical changes ensure successful fertilization of the eggs at the first metaphase. On the other hand, sea urchin eggs are fertilized after the completion of meiosis, and are particularly suitable for the study of sperm-egg interaction, early events of egg activation, and embryonic development, as a large number of mature eggs can be fertilized synchronously. Starfish and sea urchin eggs undergo abrupt changes in the cytoskeleton and ion fluxes in response to the fertilizing spermatozoon. The plasma membrane and cortex of an egg thus represent "excitable media" that quickly respond to the stimulus with the Ca(2+) swings and structural changes. In this article, we review some of the key findings on the rapid dynamic rearrangements of the actin cytoskeleton in the oocyte/egg cortex upon hormonal or sperm stimulation and their roles in the modulation of the Ca(2+) signals and in the control of monospermic fertilization.
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Affiliation(s)
- Luigia Santella
- Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Villa Comunale 1, Napoli, I-80121, Italy.
| | - Nunzia Limatola
- Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Villa Comunale 1, Napoli, I-80121, Italy
| | - Jong T Chun
- Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Villa Comunale 1, Napoli, I-80121, Italy
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Leemans B, Gadella BM, Stout TA, Heras S, Smits K, Ferrer-Buitrago M, Claes E, Heindryckx B, De Vos WH, Nelis H, Hoogewijs M, Van Soom A. Procaine Induces Cytokinesis in Horse Oocytes via a pH-Dependent Mechanism1. Biol Reprod 2015; 93:23. [DOI: 10.1095/biolreprod.114.127423] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 06/05/2015] [Indexed: 01/16/2023] Open
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Lee K, Davis A, Zhang L, Ryu J, Spate LD, Park KW, Samuel MS, Walters EM, Murphy CN, Machaty Z, Prather RS. Pig oocyte activation using a Zn²⁺ chelator, TPEN. Theriogenology 2015; 84:1024-32. [PMID: 26143360 DOI: 10.1016/j.theriogenology.2015.05.036] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 05/21/2015] [Accepted: 05/27/2015] [Indexed: 02/03/2023]
Abstract
Artificial oocyte activation is a critical step during SCNT. Most current activation protocols focus on inducing an increase in the intracellular free Ca(2+) concentration of the oocyte. Here, we have used a zinc chelator, TPEN, to enhance the efficiency of oocyte activation during SCNT. TPEN treatment of matured pig oocytes resulted in the reduction of available Zn(2+) in pig oocytes; however, the cytosolic Ca(2+) concentration in the oocytes was not affected by the TPEN treatment. When various concentrations (100-250 μM) and incubation durations (45 minutes-2.5 hours) of TPEN were used to activate oocytes, the efficiency of oocyte activation was not different from conventional activation methods. When oocytes that were activated by conventional activation methods were incubated with a lower concentration of TPEN (5-10 μM), a significant increase in embryos developing to the blastocyst stage was observed. In addition, when oocytes receiving a small Ca(2+) stimulus were further activated by higher concentration of TPEN (100-200 μM), a significant increase in the frequency of blastocyst formation was observed, compared to a conventional activation method. This result indicated that TPEN can be a main reagent in oocyte activation. No increase in the cytosolic Ca(2+) level was detected when oocytes were exposed to various concentrations of TPEN, indicating the ability of TPEN to induce oocyte activation is independent of an intracellular Ca(2+) increase. We were able to produce clones through SCNT by using the TPEN-assisted activation procedure, and the piglets produced through the process did not show any signs of abnormality. In this study, we have developed an efficient way to use TPEN to increase the developmental potential of cloned embryos.
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Affiliation(s)
- Kiho Lee
- Division of Animal Science, University of Missouri, Columbia, Missouri, USA; Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg, USA.
| | - Alyssa Davis
- Division of Animal Science, University of Missouri, Columbia, Missouri, USA
| | - Lu Zhang
- Department of Animal Sciences, Purdue University, West Lafayette, Indiana, USA
| | - Junghyun Ryu
- Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg, USA
| | - Lee D Spate
- Division of Animal Science, University of Missouri, Columbia, Missouri, USA
| | - Kwang-Wook Park
- Division of Animal Science, University of Missouri, Columbia, Missouri, USA; Department of Animal Science and Technology, Sunchon National University, Suncheon, Jeonnam, Republic of Korea
| | - Melissa S Samuel
- Division of Animal Science, University of Missouri, Columbia, Missouri, USA; National Swine Resource and Research Center, University of Missouri, Columbia, Missouri, USA
| | - Eric M Walters
- National Swine Resource and Research Center, University of Missouri, Columbia, Missouri, USA
| | - Clifton N Murphy
- National Swine Resource and Research Center, University of Missouri, Columbia, Missouri, USA
| | - Zoltan Machaty
- Department of Animal Sciences, Purdue University, West Lafayette, Indiana, USA
| | - Randall S Prather
- Division of Animal Science, University of Missouri, Columbia, Missouri, USA; National Swine Resource and Research Center, University of Missouri, Columbia, Missouri, USA
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Kim JW, Yang SH, Yoon SH, Kim SD, Jung JH, Lim JH. Successful pregnancy and delivery after ICSI with artificial oocyte activation by calcium ionophore in in-vitro matured oocytes: a case report. Reprod Biomed Online 2015; 30:373-7. [DOI: 10.1016/j.rbmo.2014.11.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Revised: 10/29/2014] [Accepted: 11/04/2014] [Indexed: 11/29/2022]
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Pónya Z, Corsi I, Hoffmann R, Kovács M, Dobosy A, Kovács AZ, Cresti M, Barnabás B. When isolated at full receptivity, in vitro fertilized wheat (Triticum aestivum, L.) egg cells reveal [Ca2+]cyt oscillation of intracellular origin. Int J Mol Sci 2014; 15:23766-91. [PMID: 25535074 PMCID: PMC4284791 DOI: 10.3390/ijms151223766] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Revised: 08/19/2014] [Accepted: 09/25/2014] [Indexed: 11/28/2022] Open
Abstract
During in vitro fertilization of wheat (Triticum aestivum, L.) in egg cells isolated at various developmental stages, changes in cytosolic free calcium ([Ca2+]cyt) were observed. The dynamics of [Ca2+]cyt elevation varied, reflecting the difference in the developmental stage of the eggs used. [Ca2+]cyt oscillation was exclusively observed in fertile, mature egg cells fused with the sperm cell. To determine how [Ca2+]cyt oscillation in mature egg cells is generated, egg cells were incubated in thapsigargin, which proved to be a specific inhibitor of the endoplasmic reticulum (ER) Ca2+-ATPase in wheat egg cells. In unfertilized egg cells, the addition of thapsigargin caused an abrupt transient increase in [Ca2+]cyt in the absence of extracellular Ca2+, suggesting that an influx pathway for Ca2+ is activated by thapsigargin. The [Ca2+]cyt oscillation seemed to require the filling of an intracellular calcium store for the onset of which, calcium influx through the plasma membrane appeared essential. This was demonstrated by omitting extracellular calcium from (or adding GdCl3 to) the fusion medium, which prevented [Ca2+]cyt oscillation in mature egg cells fused with the sperm. Combined, these data permit the hypothesis that the first sperm-induced transient increase in [Ca2+]cyt depletes an intracellular Ca2+ store, triggering an increase in plasma membrane Ca2+ permeability, and this enhanced Ca2+ influx results in [Ca2+]cyt oscillation.
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Affiliation(s)
- Zsolt Pónya
- Department of Plant Production and Plant Protection, Institute of Plant Science, Faculty of Agricultural and Environmental Sciences, Kaposvár University, Kaposvár H-7400, Hungary.
| | - Ilaria Corsi
- Dipartimento di Scienze Ambientali "G. Sarfatti", University of Siena, Siena 53100, Italy.
| | - Richárd Hoffmann
- Department of Plant Production and Plant Protection, Institute of Plant Science, Faculty of Agricultural and Environmental Sciences, Kaposvár University, Kaposvár H-7400, Hungary.
| | - Melinda Kovács
- Institute of Physiology, Biochemistry and Animal Health, Faculty of Agricultural and Environmental Sciences, Kaposvár University, Kaposvár H-7400, Hungary.
| | - Anikó Dobosy
- Department of Plant Production and Plant Protection, Institute of Plant Science, Faculty of Agricultural and Environmental Sciences, Kaposvár University, Kaposvár H-7400, Hungary.
| | - Attila Zoltán Kovács
- Department of Technology of Animal Breeding and Management, Faculty of Agricultural and Environmental Sciences Kaposvár University, Kaposvár H-7400, Hungary.
| | - Mauro Cresti
- Dipartimento di Scienze Ambientali "G. Sarfatti", University of Siena, Siena 53100, Italy.
| | - Beáta Barnabás
- Department of Plant Cell Biology, Agricultural Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Martonvàsàr H-2462, Hungary.
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Liu S, Cui K, Li HL, Sun JM, Lu XR, Shen KY, Liu QY, Shi DS. Comparison of chemical, electrical, and combined activation methods for in vitro matured porcine oocytes. In Vitro Cell Dev Biol Anim 2014; 51:103-12. [PMID: 25424832 DOI: 10.1007/s11626-014-9819-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Accepted: 09/04/2014] [Indexed: 10/24/2022]
Abstract
Factors influencing porcine oocyte activation were systematically studied. This study included (1) the effect of ionomycin plus various chemical agents on activation, (2) comparison of different electrical activation parameters, (3) optimization of combined activation, and (4) evaluation of the optimized protocols. The results showed that (1) blastocyst rates of ionomycin (Ion) + 6-dimethylaminopurine (6-DMAP) (29.7 ± 1.1%), Ion + cytochalasin B (CB) + cycloheximide (CHX) (29.8 ± 1.2%), Ion + CB + 6-DMAP (30.4 ± 1.6%), and Ion + CB + CHX + 6-DMAP (30.2 ± 2.7%) were significantly higher than Ion + CHX (15.8 ± 1.5%, p < 0.05); (2) the parthenogenetic blastocyst formation of electrical activation was optimal when oocytes were activated by three direct current (DC) pulses of 1.00 kV cm(-1) for 80 μs (39.5 ± 1.1%); (3) blastocyst rates of DC + CB + CHX (55.4 ± 1.2%) and DC + CB + 6-DMAP (50.4 ± 2.9%) were significantly higher than DC + 6-DMAP, DC + CB + CHX + 6-DMAP, electrical activation, and chemical activation alone (p < 0.05); and (4) approximately 84% of parthenogenetic blastocysts yielded by the optimized protocol were diploid, which was significantly higher than that of electrical activation blastocysts (40%). Using the optimized electrical and combined activation protocol, high blastocyst rates were generated by intracytoplasmic sperm injection (ICSI) (34.6 ± 1.1%), cytoplasmic microinjection (CI) (52.3 ± 2.2%), and handmade cloning (HMC) (31.2 ± 1.0%), respectively. This study concludes that the optimal activation protocol of in vitro matured porcine oocytes was combined activation with parameter as three DC pulses of 1.00 kV cm(-1) for 80 μs plus CB and CHX treatment.
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Affiliation(s)
- Shuai Liu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Nanning, 530005, China
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Dale B. Is the idea of a fast block to polyspermy based on artifact? Biochem Biophys Res Commun 2014; 450:1159-65. [DOI: 10.1016/j.bbrc.2014.03.157] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Accepted: 03/31/2014] [Indexed: 01/25/2023]
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Liu Y, Han XJ, Liu MH, Wang SY, Jia CW, Yu L, Ren G, Wang L, Li W. Three-day-old human unfertilized oocytes after in vitro fertilization/intracytoplasmic sperm injection can be activated by calcium ionophore a23187 or strontium chloride and develop to blastocysts. Cell Reprogram 2014; 16:276-80. [PMID: 24960285 DOI: 10.1089/cell.2013.0081] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Our objective was to observe the effectiveness of the calcium ionophore A23187 or strontium chloride on the activation and subsequent embryonic development of 3-day-old human unfertilized oocytes after in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI). A total of 279 3-day-old unfertilized oocytes after IVF or ICSI were randomized to be activated by the calcium ionophore A23187 (n=138) or strontium chloride (n=141). The activated oocytes were cultured in vitro for 3-5 days. Activation rate, pronucleus formation, cleavage rate, and developmental potential of parthenotes during culture were evaluated. A total of 170 unfertilized oocytes were activated; 65 developed to cleavage stage, 19 developed to greater than the eight-cell stage, and five blastocysts were obtained. The activation rate of the calcium ionophore A23187 group was higher than that of the strontium chloride group (75.4% and 46.8%, respectively; p<0.05); there was significant difference between two groups (p<0.05). Among the 44 cleaved oocytes in the calcium ionophore A23187 group, eight developed to the two- to four-cell stage, 17 developed to the five- to eight-cell stage, 15 developed to greater than the eight-cell stage, and four blastocysts were obtained. Among the 21 cleaved oocytes in the strontium chloride group, six developed to the two- to four- cell stage, 10 developed to the five- to eight-cell stage, four developed to greater than the eight-cell stage, and one blastocyst was obtained. Three-day-old unfertilized human oocytes after IVF or ICSI could be activated by the calcium ionophore A23187 or strontium chloride, and a small part of parthenogenetic embryos developed into blastocysts. The treatment with the calcium ionophore A23187 was better than that of strontium chloride in respect to the activation rate of 3-day-old unfertilized human oocytes after IVF or ICSI.
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Affiliation(s)
- Ying Liu
- Department of Reproductive Medicine, Beijing Obstetrics and Gynecology Hospital, Capital Medical University , Beijing, China
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Calcium influx and male fertility in the context of the sperm proteome: an update. BIOMED RESEARCH INTERNATIONAL 2014; 2014:841615. [PMID: 24877140 PMCID: PMC4022195 DOI: 10.1155/2014/841615] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Accepted: 01/14/2014] [Indexed: 01/06/2023]
Abstract
Freshly ejaculated spermatozoa are incapable or poorly capable of fertilizing an oocyte. The fertilization aptness of spermatozoa depends on the appropriate and time-dependent acquisition of hyperactivation, chemotaxis, capacitation, and the acrosome reaction, where calcium (Ca2+) is extensively involved in almost every step. A literature review showed that several ion channel proteins are likely responsible for regulation of the Ca2+ uptake in spermatozoa. Therefore, manipulation of the functions of channel proteins is closely related to Ca2+ influx, ultimately affecting male fertility. Recently, it has been shown that, together with different physiological stimuli, protein-protein interaction also modifies the Ca2+ influx mechanism in spermatozoa. Modern proteomic analyses have identified several sperm proteins, and, therefore, these findings might provide further insight into understanding the Ca2+ influx, protein functions, and regulation of fertility. The objective of this review was to synthesize the published findings on the Ca2+ influx mechanism in mammalian spermatozoa and its implications for the regulation of male fertility in the context of sperm proteins. Finally, Pathway Studio (9.0) was used to catalog the sperm proteins that regulate the Ca2+ influx signaling by using the information available from the PubMed database following a MedScan Reader (5.0) search.
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Kim JW, Kim SD, Yang SH, Yoon SH, Jung JH, Lim JH. Successful pregnancy after SrCl2oocyte activation in couples with repeated low fertilization rates following calcium ionophore treatment. Syst Biol Reprod Med 2014; 60:177-82. [DOI: 10.3109/19396368.2014.900832] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Vanden Meerschaut F, Nikiforaki D, Heindryckx B, De Sutter P. Assisted oocyte activation following ICSI fertilization failure. Reprod Biomed Online 2014; 28:560-71. [PMID: 24656559 DOI: 10.1016/j.rbmo.2014.01.008] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2013] [Revised: 01/12/2014] [Accepted: 01/22/2014] [Indexed: 10/25/2022]
Abstract
The capacity of intracytoplasmic sperm injection (ICSI) to permit almost any type of spermatozoa to fertilize oocytes has made it the most successful treatment for male factor infertility. Despite its high success rates, fertilization failure following ICSI still occurs in 1-3% of couples. Assisted oocyte activation (AOA) is being increasingly applied in human assisted reproduction to restore fertilization and pregnancy rates in couples with a history of ICSI fertilization failure. However, controversy still exists mainly because the artificial activating agents do not mimic precisely the initial physiological processes of mammalian oocyte activation, which has led to safety concerns. This review addresses the mechanism of human oocyte activation and the relatively rare phenomenon of fertilization failure after ICSI. Next, it describes the current diagnostic approaches and focuses on the application, efficiency and safety of AOA in human assisted reproduction.
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Affiliation(s)
- Frauke Vanden Meerschaut
- Department for Reproductive Medicine, University Hospital Ghent, De Pintelaan 185 - 1P4, 9000 Ghent, Belgium
| | - Dimitra Nikiforaki
- Department for Reproductive Medicine, University Hospital Ghent, De Pintelaan 185 - 1P4, 9000 Ghent, Belgium
| | - Björn Heindryckx
- Department for Reproductive Medicine, University Hospital Ghent, De Pintelaan 185 - 1P4, 9000 Ghent, Belgium.
| | - Petra De Sutter
- Department for Reproductive Medicine, University Hospital Ghent, De Pintelaan 185 - 1P4, 9000 Ghent, Belgium
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Generation of parthenogenetic goat blastocysts: effects of different activation methods and culture media. ZYGOTE 2014; 23:327-35. [PMID: 24405529 DOI: 10.1017/s0967199413000580] [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: 01/12/2023]
Abstract
The present study was carried out to investigate the effects of different activation methods and culture media on the in vitro development of parthenogenetic goat blastocysts. Calcium (Ca2+) ionophore, ethanol or a combination of the two, used as activating reagents, and embryo development medium (EDM), modified Charles Rosenkrans (mCR2a) medium and research vitro cleave (RVCL) medium were used to evaluate the developmental competence of goat blastocysts. Quantitative expression of apoptosis, stress and developmental competence-related genes were analysed in different stages of embryos. In RVCL medium, the cleavage rate of Ca2+ ionophore-treated oocytes (79.61 ± 0.86) was significantly (P < 0.05) higher than in ethanol (74.90 ± 1.51) or in the combination of both Ca2+ ionophore and ethanol. In mCR2a or EDM, hatched blastocyst production rate of Ca2+ ionophore-treated oocytes (8.33 ± 1.44) was significantly higher than in ethanol (6.46 ± 0.11) or in the combined treatment (6.70 ± 0.24). In ethanol, the cleavage, blastocyst and hatched blastocyst production rates in RVCL medium (74.90 ± 1.51, 18.30 ± 1.52 and 8.24 ± 0.15, respectively) were significantly higher than in EDM (67.81 ± 3.21, 14.59 ± 0.27 and 5.59 ± 0.42) or mCR2a medium (65.09 ± 1.57, 15.36 ± 0.52 and 6.46 ± 0.11). The expression of BAX, Oct-4 and GlUT1 transcripts increased gradually from 2-cell stage to blastocyst-stage embryos, whereas the transcript levels of Bcl-2 and MnSOD were significantly lower in blastocysts. In addition, different activation methods and culture media had little effect on the pattern of variation and relative abundance of the above genes in different stages of parthenogenetic activated goat embryos. In conclusion, Ca2+ ionophore as the activating agent, and RVCL as the culture medium are better than other tested options for development of parthenogenetic activated goat blastocysts.
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Abstract
The former perception of the spermatozoon as a delivery device of the male genome has been expanded to include a new understanding of the cell's complex role in fertilization. Once the spermatozoon reaches the oocyte, it triggers egg activation and orchestrates the stages of pre- and post-fertilization in a preprogrammed pattern while tapping the oocyte's resources in an effort to generate a new life.
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Affiliation(s)
- Queenie V Neri
- The Ronald O. Perelman and Claudia Cohen Center for Reproductive Medicine, Weill Cornell Medical College, 1305 York Avenue, Suite 720, New York, NY, 10021, USA
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Nomikos M, Kashir J, Swann K, Lai FA. Sperm PLCζ: from structure to Ca2+ oscillations, egg activation and therapeutic potential. FEBS Lett 2013; 587:3609-16. [PMID: 24157362 DOI: 10.1016/j.febslet.2013.10.008] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Revised: 10/12/2013] [Accepted: 10/14/2013] [Indexed: 10/26/2022]
Abstract
Significant evidence now supports the assertion that cytosolic calcium oscillations during fertilization in mammalian eggs are mediated by a testis-specific phospholipase C (PLC), termed PLC-zeta (PLCζ) that is released into the egg following gamete fusion. Herein, we describe the current paradigm of PLCζ in this fundamental biological process, summarizing recent important advances in our knowledge of the biochemical and physiological properties of this enzyme. We describe the data suggesting that PLCζ has distinct features amongst PLCs enabling the hydrolysis of its substrate, phosphatidylinositol 4,5-bisphosphate (PIP2) at low Ca(2+) levels. PLCζ appears to be unique in its ability to target PIP2 that is present on intracellular vesicles. We also discuss evidence that PLCζ may be a significant factor in human fertility with potential therapeutic capacity.
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Affiliation(s)
- Michail Nomikos
- Institute of Molecular and Experimental Medicine, WHRI, Cardiff University School of Medicine, Heath Park, CF144XN Cardiff, UK.
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46
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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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Swann K, Lai FA. PLC? and the initiation of Ca2+ oscillations in fertilizing mammalian eggs. Cell Calcium 2013; 53:55-62. [DOI: 10.1016/j.ceca.2012.11.001] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Revised: 10/31/2012] [Accepted: 11/01/2012] [Indexed: 10/27/2022]
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Abstract
At fertilization mammalian eggs are activated by a prolonged series of oscillations in the intracellular free Ca(2+) concentration. These oscillations can be monitored with any number of Ca(2+)-sensitive fluorescent dyes. The oscillations last for several hours at fertilization and so there are some considerations with mammalian eggs that make them distinct from somatic cells that are commonly used in Ca(2+) imaging experiments. I describe the use of two particular dyes that can be loaded into mouse eggs and that give the most valuable results. The first one is PE3 which can be loaded by incubation with the AM form of the dye which is membrane permeable. The other is rhod dextran which requires microinjection. Either one of these dyes offers advantages over the more commonly used fura2. I describe the way that the fluorescence from dye-loaded eggs is measured with a conventional epifluorescence microscope and a CCD camera.
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Affiliation(s)
- Karl Swann
- School of Medicine, Cardiff University, Heath Park, Cardiff, UK,
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Kim JW, Choi JL, Yang SH, Yoon SH, Jung JH, Lim JH. Live birth after SrCl(2) oocyte activation in previous repeated failed or low fertilization rates after ICSI of frozen-thawed testicular spermatozoa: case report. J Assist Reprod Genet 2012. [PMID: 23179384 DOI: 10.1007/s10815-012-9887-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
PURPOSE To report a live birth resulting after strontium chloride (SrCl(2)) oocyte activation in a couple with complete fertilization failure or low fertilization rates following intracytoplasmic sperm injection (ICSI) of frozen-thawed testicular spermatozoa. METHODS The couple underwent ICSI of frozen-thawed testicular spermatozoa. After ICSI, the oocytes were artificially activated by SrCl(2) because the results of fertilization were not satisfactory in the previous cycles. The main outcome measures were fertilization, pregnancy, and birth. RESULTS In the first and second cycles performed previously at another clinic, fertilization rates were 9.1 % and 0.0 %, respectively. In the third cycle, 31 metaphase II oocytes were retrieved. After sperm injection, all of the oocytes were stimulated using SrCl(2) for activation. Sixteen oocytes were fertilized (51.6 %), and a single embryo was transferred into the uterus on Day 3. A healthy girl weighing 2750 g was born at 40 weeks of gestation by caesarean section. CONCLUSIONS This result suggests that SrCl(2) could be useful for oocyte fertilization in case of repeated complete fertilization failure or low fertilization rates following ICSI of frozen-thawed testicular spermatozoa.
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Affiliation(s)
- Jun-Woo Kim
- In Vitro Fertilization Center, Maria Fertility Hospital, 121-1 Garak-dong, Songpa-gu, Seoul, 138-160, Korea.
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Ramadan WM, Kashir J, Jones C, Coward K. Oocyte activation and phospholipase C zeta (PLCζ): diagnostic and therapeutic implications for assisted reproductive technology. Cell Commun Signal 2012; 10:12. [PMID: 22591604 PMCID: PMC3393615 DOI: 10.1186/1478-811x-10-12] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2012] [Accepted: 05/16/2012] [Indexed: 12/18/2022] Open
Abstract
Infertility affects one in seven couples globally and has recently been classified as a disease by the World Health Organisation (WHO). While in-vitro fertilisation (IVF) offers effective treatment for many infertile couples, cases exhibiting severe male infertility (19-57%) often remain difficult, if not impossible to treat. In such cases, intracytoplasmic sperm injection (ICSI), a technique in which a single sperm is microinjected into the oocyte, is implemented. However, 1-5% of ICSI cycles still fail to fertilise, affecting over 1000 couples per year in the UK alone. Pregnancy and delivery rates for IVF and ICSI rarely exceed 30% and 23% respectively. It is therefore imperative that Assisted Reproductive Technology (ART) protocols are constantly modified by associated research programmes, in order to provide patients with the best chances of conception. Prior to fertilisation, mature oocytes are arrested in the metaphase stage of the second meiotic division (MII), which must be alleviated to allow the cell cycle, and subsequent embryogenesis, to proceed. Alleviation occurs through a series of concurrent events, collectively termed 'oocyte activation'. In mammals, oocytes are activated by a series of intracellular calcium (Ca2+) oscillations following gamete fusion. Recent evidence implicates a sperm-specific phospholipase C, PLCzeta (PLCζ), introduced into the oocyte following membrane fusion as the factor responsible. This review summarises our current understanding of oocyte activation failure in human males, and describes recent advances in our knowledge linking certain cases of male infertility with defects in PLCζ expression and activity. Systematic literature searches were performed using PubMed and the ISI-Web of Knowledge. Databases compiled by the United Nations and World Health Organisation databases (UNWHO), and the Human Fertilization and Embryology Authority (HFEA) were also scrutinised. It is clear that PLCζ plays a fundamental role in the activation of mammalian oocytes, and that genetic, molecular, or biochemical perturbation of this key enzyme is strongly linked to human infertility where oocyte activation is deficient. Consequently, there is significant scope for our understanding of PLCζ to be translated to the ART clinic, both as a novel therapeutic agent with which to rescue oocyte activation deficiency (OAD), or as a prognostic/diagnostic biomarker of oocyte activation ability in target sperm samples.
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Affiliation(s)
- Walaa M Ramadan
- Nuffield Department of Obstetrics and Gynaecology, University of Oxford, Level 3, Women’s Centre, John Radcliffe Hospital, Headington, Oxford, OX3, 9DU, UK
| | - Junaid Kashir
- Nuffield Department of Obstetrics and Gynaecology, University of Oxford, Level 3, Women’s Centre, John Radcliffe Hospital, Headington, Oxford, OX3, 9DU, UK
| | - Celine Jones
- Nuffield Department of Obstetrics and Gynaecology, University of Oxford, Level 3, Women’s Centre, John Radcliffe Hospital, Headington, Oxford, OX3, 9DU, UK
| | - Kevin Coward
- Nuffield Department of Obstetrics and Gynaecology, University of Oxford, Level 3, Women’s Centre, John Radcliffe Hospital, Headington, Oxford, OX3, 9DU, UK
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