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Wang J, Li YH, Liu RP, Wang XQ, Zhu MB, Cui XS, Dai Z, Kim NH, Xu YN. Supplementation with Eupatilin during In Vitro Maturation Improves Porcine Oocyte Developmental Competence by Regulating Oxidative Stress and Endoplasmic Reticulum Stress. Animals (Basel) 2024; 14:449. [PMID: 38338092 PMCID: PMC10854851 DOI: 10.3390/ani14030449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2023] [Revised: 01/22/2024] [Accepted: 01/25/2024] [Indexed: 02/12/2024] Open
Abstract
Eupatilin (5,7-dihydroxy-3',4',6-trimethoxyflavone) is a flavonoid derived from Artemisia plants that has beneficial biological activities, such as anti-apoptotic, anti-oxidant, and anti-inflammatory activities. However, the protective effects of eupatilin against oxidative stress and endoplasmic reticulum stress in porcine oocyte maturation are still unclear. To investigate the effect of eupatilin on the development of porcine oocytes after in vitro maturation and parthenogenetic activation, we added different concentrations of eupatilin in the process of porcine oocyte maturation in vitro, and finally selected the optimal concentration following multiple comparisons and analysis of test results using SPSS (version 17.0; IBM, Chicago, IL, USA) software. The results showed that 0.1 μM eupatilin supplementation did not affect the expansion of porcine cumulus cells, but significantly increased the extrusion rate of porcine oocyte polar bodies, the subsequent blastocyst formation rate, and the quality of parthenogenetically activated porcine embryos. Additionally, it reduced the level of reactive oxygen species in cells and increased glutathione production. Further analysis revealed that eupatilin supplementation could reduce apoptosis, DNA double-strand breaks, and endoplasmic reticulum stress. In conclusion, supplementation with 0.1 μM eupatilin during in vitro maturation improved oocyte maturation and subsequent embryo development by reducing oxidative stress and endoplasmic reticulum stress.
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Affiliation(s)
- Jing Wang
- Guangdong Provincial Key Laboratory of Large Animal Models for Biomedicine, School of Biotechnology and Health Sciences, Wuyi University, Jiangmen 529000, China
| | - Ying-Hua Li
- Guangdong Provincial Key Laboratory of Large Animal Models for Biomedicine, School of Biotechnology and Health Sciences, Wuyi University, Jiangmen 529000, China
| | - Rong-Ping Liu
- Guangdong Provincial Key Laboratory of Large Animal Models for Biomedicine, School of Biotechnology and Health Sciences, Wuyi University, Jiangmen 529000, China
| | - Xin-Qin Wang
- Guangdong Provincial Key Laboratory of Large Animal Models for Biomedicine, School of Biotechnology and Health Sciences, Wuyi University, Jiangmen 529000, China
| | - Mao-Bi Zhu
- Guangdong Provincial Key Laboratory of Large Animal Models for Biomedicine, School of Biotechnology and Health Sciences, Wuyi University, Jiangmen 529000, China
| | - Xiang-Shun Cui
- Department of Animal Science, Chungbuk National University, Cheongju 28644, Republic of Korea
| | - Zhen Dai
- Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China
| | - Nam-Hyung Kim
- Guangdong Provincial Key Laboratory of Large Animal Models for Biomedicine, School of Biotechnology and Health Sciences, Wuyi University, Jiangmen 529000, China
| | - Yong-Nan Xu
- Guangdong Provincial Key Laboratory of Large Animal Models for Biomedicine, School of Biotechnology and Health Sciences, Wuyi University, Jiangmen 529000, China
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Liu Z, Jin X, Miao Y, Wang P, Gu Y, Shangguan X, Chen L, Wang G. Identification and Characterization of C-Mos in Pearl Mussel Hyriopsis cumingii and Its Role in Gonadal Development. Biomolecules 2023; 13:931. [PMID: 37371511 DOI: 10.3390/biom13060931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 05/29/2023] [Accepted: 05/31/2023] [Indexed: 06/29/2023] Open
Abstract
C-Mos, a proto-oncogene, regulates oocyte maturation by activating the classical MAPK pathway in cells. To examine the function of C-Mos in Hyriopsis cumingii, C-Mos was identified in this study. The full-length cDNA of C-Mos was 2213 bp, including 144 bp in the 5' UTR, 923 bp in 3' the UTR, and 1146 bp in the open reading frame (ORF) region. During early gonad development, the expression of C-Mos from 4 to 6 months of age in H. cumingii was significantly higher than that in other months, with the highest expression in 6-month-old H. cumingii, suggesting that C-Mos may be involved in early gonadal development in H. cumingii. Clear hybridization signals were found by in situ hybridization in the oocytes, oocyte nucleus and oogonium, and a small number of hybridization signals were found in the follicular wall of the male gonads. In addition, the C-Mos RNA interference (RNAi) assay results showed that the knockdown of C-Mos caused a down-regulation of ERK and P90rsk. In summary, these results indicate that C-Mos has a crucial part to play in gonadal development in H. cumingii.
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Affiliation(s)
- Zongyu Liu
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai 201306, China
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai 201306, China
- Shanghai Engineering Research Center of Aquaculture, Shanghai 201306, China
| | - Xin Jin
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai 201306, China
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai 201306, China
- Shanghai Engineering Research Center of Aquaculture, Shanghai 201306, China
| | - Yulin Miao
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai 201306, China
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai 201306, China
- Shanghai Engineering Research Center of Aquaculture, Shanghai 201306, China
| | - Ping Wang
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai 201306, China
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai 201306, China
- Shanghai Engineering Research Center of Aquaculture, Shanghai 201306, China
| | - Yang Gu
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai 201306, China
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai 201306, China
- Shanghai Engineering Research Center of Aquaculture, Shanghai 201306, China
| | - Xiaozhao Shangguan
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai 201306, China
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai 201306, China
- Shanghai Engineering Research Center of Aquaculture, Shanghai 201306, China
| | - Lijing Chen
- Shanghai Vocational College of Agriculture and Forestry, Shanghai 201699, China
| | - Guiling Wang
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai 201306, China
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai 201306, China
- Shanghai Engineering Research Center of Aquaculture, Shanghai 201306, China
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Jiao Y, Wang Y, Jiang T, Wen K, Cong P, Chen Y, He Z. Quercetin protects porcine oocytes from in vitro aging by reducing oxidative stress and maintaining the mitochondrial functions. Front Cell Dev Biol 2022; 10:915898. [PMID: 36274842 PMCID: PMC9581393 DOI: 10.3389/fcell.2022.915898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 09/15/2022] [Indexed: 11/13/2022] Open
Abstract
Quercetin (QUE) is a component of the flavonoid family that shows various therapeutic properties, such as antioxidant effects. However, whether QUE affects porcine oocyte in vitro aging has not yet been investigated. Therefore, in this study, we applied various doses of QUE to freshly isolated porcine oocytes and found that 10 µM QUE improved the oocyte maturation rate in vitro, as reflected by the increased degree of cumulus cell expansion and first polar body extrusion. More importantly, we found that QUE reduced in vitro aging and improved the maturity level of porcine oocytes after another 24 h of culturing, accompanied by the upregulated expression levels of bone morphogenetic protein 15, growth differentiation factor 9, Moloney sarcoma oncogene, and cyclin-dependent kinase 2. In addition, we found that QUE treatment significantly reduced the intracellular reactive oxygen species levels, apoptosis, and autophagy and upregulated the expression levels of superoxide dismutase 2 and catalase in aged porcine oocytes. In addition, QUE restored impaired mitochondrial membrane potential and spindle assembly in aged porcine oocytes. Our findings demonstrate that QUE can protect porcine oocytes from in vitro aging by reducing oxidative stress and maintaining mitochondrial function.
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PI3K inhibitor reduces in vitro maturation and developmental competence of porcine oocytes. Theriogenology 2020; 157:432-439. [PMID: 32877843 DOI: 10.1016/j.theriogenology.2020.08.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 07/28/2020] [Accepted: 08/13/2020] [Indexed: 01/10/2023]
Abstract
The phosphatidylinositol -3- kinase (PI3K) signaling pathway is critical for the cell proliferation, apoptosis, metabolism, DNA repair and protein synthesis. Significant effort has focused on elucidating the relationship between PI3K signaling pathway and other nuclear signal transducers; However, little is known about the connection between PI3K signaling pathway and porcine oocyte meiotic maturation. In this study, we investigated the function of PI3K signaling pathway in porcine oocytes. PI3K signaling pathway was important during oocyte maturation. Furthermore, the PI3K signaling pathway inhibitor LY-294002 blocked porcine oocyte maturation, reducing the percentage of oocytes that first polar body (PBI) extrusion. LY-294002 also decreased the expression of oocyte proliferation-related gene PCNA and reduced the mRNA and protein levels of PI3K. What's more, LY-294002 also decreased other maturation-related genes that are predominantly expressed duringporcine oocyte maturation, including bone morphogenetic protein 15 (BPM15), growth differentiation factor 9 (GDF9), cell division cycle protein 2 (CDC2), phosphatase and tensin homolog (PTEN), CyclinB1, MOS and Akt. LY-294002 treatment decreased the developmental potential of blastocysts following parthenogenetic activation, increased the level of cell apoptosis and reduced the level of cell-cycle. This study revealed that inhibiting the PI3K signaling pathway could reduce in vitro maturation and developmental competence of porcine oocytes, probably by reducing cell cycle arrest and proliferation, promoting the oocyte apoptosis, and altering the expression of other maternal genes.
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Kalous J, Tetkova A, Kubelka M, Susor A. Importance of ERK1/2 in Regulation of Protein Translation during Oocyte Meiosis. Int J Mol Sci 2018; 19:ijms19030698. [PMID: 29494492 PMCID: PMC5877559 DOI: 10.3390/ijms19030698] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 02/23/2018] [Accepted: 02/26/2018] [Indexed: 02/07/2023] Open
Abstract
Although the involvement of the extracellular signal-regulated kinases 1 and 2 (ERK1/2) pathway in the regulation of cytostatic factor (CSF) activity; as well as in microtubules organization during meiotic maturation of oocytes; has already been described in detail; rather less attention has been paid to the role of ERK1/2 in the regulation of mRNA translation. However; important data on the role of ERK1/2 in translation during oocyte meiosis have been documented. This review focuses on recent findings regarding the regulation of translation and the role of ERK1/2 in this process in the meiotic cycle of mammalian oocytes. The specific role of ERK1/2 in the regulation of mammalian target of rapamycin (mTOR); eukaryotic translation initiation factor 4E (eIF4E) and cytoplasmic polyadenylation element binding protein 1 (CPEB1) activity is addressed along with additional focus on the other key players involved in protein translation.
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Affiliation(s)
- Jaroslav Kalous
- Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, Rumburska 89, 27721 Libechov, Czech Republic.
| | - Anna Tetkova
- Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, Rumburska 89, 27721 Libechov, Czech Republic.
- Department of Cell Biology, Faculty of Science, Charles University in Prague, Albertov 6, 12843 Prague 2, Czech Republic.
| | - Michal Kubelka
- Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, Rumburska 89, 27721 Libechov, Czech Republic.
| | - Andrej Susor
- Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, Rumburska 89, 27721 Libechov, Czech Republic.
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Zhou L, Yang Y, Zhang J, Guo X, Bi Y, Li X, Zhang P, Zhang J, Lin M, Zhou Z, Shen R, Guo X, Huo R, Ling X, Sha J. The role of RING box protein 1 in mouse oocyte meiotic maturation. PLoS One 2013; 8:e68964. [PMID: 23874827 PMCID: PMC3708900 DOI: 10.1371/journal.pone.0068964] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Accepted: 06/04/2013] [Indexed: 11/18/2022] Open
Abstract
RING box protein-1 (RBX1) is an essential component of Skp1-cullin-F-box protein (SCF) E3 ubiquitin ligase and participates in diverse cellular processes by targeting various substrates for degradation. However, the physiological function of RBX1 in mouse oocyte maturation remains unknown. Here, we examined the expression, localization and function of RBX1 during mouse oocyte meiotic maturation. Immunofluorescence analysis showed that RBX1 displayed dynamic distribution during the maturation process: it localized around and migrated along with the spindle and condensed chromosomes. Rbx1 knockdown with the appropriate siRNAs led to a decreased rate of first polar body extrusion and most oocytes were arrested at metaphase I. Moreover, downregulation of Rbx1 caused accumulation of Emi1, an inhibitor of the anaphase-promoting complex/cyclosome (APC/C), which is required for mouse meiotic maturation. In addition, we found apparently increased expression of the homologue disjunction-associated protein securin and cyclin B1, which are substrates of APC/C E3 ligase and need to be degraded for meiotic progression. These results indicate the essential role of the SCFβTrCP-EMI1-APC/C axis in mouse oocyte meiotic maturation. In conclusion, we provide evidence for the indispensable role of RBX1 in mouse oocyte meiotic maturation.
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Affiliation(s)
- Lin Zhou
- State Key Laboratory of Reproductive Medicine, Department of Histology and Embryology, Nanjing Medical University, Nanjing, China
- State Key Laboratory of Reproductive Medicine, Nanjing Maternity and Child Health Hospital, Nanjing Medical University, Nanjing, China
| | - Ye Yang
- State Key Laboratory of Reproductive Medicine, Department of Histology and Embryology, Nanjing Medical University, Nanjing, China
| | - Juanjuan Zhang
- State Key Laboratory of Reproductive Medicine, Nanjing Maternity and Child Health Hospital, Nanjing Medical University, Nanjing, China
| | - Xuejiang Guo
- State Key Laboratory of Reproductive Medicine, Department of Histology and Embryology, Nanjing Medical University, Nanjing, China
| | - Ye Bi
- State Key Laboratory of Reproductive Medicine, Department of Histology and Embryology, Nanjing Medical University, Nanjing, China
| | - Xin Li
- State Key Laboratory of Reproductive Medicine, Nanjing Maternity and Child Health Hospital, Nanjing Medical University, Nanjing, China
| | - Ping Zhang
- State Key Laboratory of Reproductive Medicine, Department of Histology and Embryology, Nanjing Medical University, Nanjing, China
| | - Junqiang Zhang
- State Key Laboratory of Reproductive Medicine, Nanjing Maternity and Child Health Hospital, Nanjing Medical University, Nanjing, China
| | - Min Lin
- State Key Laboratory of Reproductive Medicine, Department of Histology and Embryology, Nanjing Medical University, Nanjing, China
| | - Zuomin Zhou
- State Key Laboratory of Reproductive Medicine, Department of Histology and Embryology, Nanjing Medical University, Nanjing, China
| | - Rong Shen
- State Key Laboratory of Reproductive Medicine, Nanjing Maternity and Child Health Hospital, Nanjing Medical University, Nanjing, China
| | - Xirong Guo
- State Key Laboratory of Reproductive Medicine, Nanjing Maternity and Child Health Hospital, Nanjing Medical University, Nanjing, China
| | - Ran Huo
- State Key Laboratory of Reproductive Medicine, Department of Histology and Embryology, Nanjing Medical University, Nanjing, China
- * E-mail: (RH); (XL)
| | - Xiufeng Ling
- State Key Laboratory of Reproductive Medicine, Nanjing Maternity and Child Health Hospital, Nanjing Medical University, Nanjing, China
- * E-mail: (RH); (XL)
| | - Jiahao Sha
- State Key Laboratory of Reproductive Medicine, Department of Histology and Embryology, Nanjing Medical University, Nanjing, China
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Messina V, Meikar O, Paronetto MP, Calabretta S, Geremia R, Kotaja N, Sette C. The RNA binding protein SAM68 transiently localizes in the chromatoid body of male germ cells and influences expression of select microRNAs. PLoS One 2012; 7:e39729. [PMID: 22745822 PMCID: PMC3382170 DOI: 10.1371/journal.pone.0039729] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Accepted: 05/25/2012] [Indexed: 12/13/2022] Open
Abstract
The chromatoid body (CB) is a unique structure of male germ cells composed of thin filaments that condense into a perinuclear organelle after meiosis. Due to the presence of proteins involved in different steps of RNA metabolism and of different classes of RNAs, including microRNAs (miRNAs), the CB has been recently suggested to function as an RNA processing centre. Herein, we show that the RNA binding protein SAM68 transiently localizes in the CB, in concomitance with the meiotic divisions of mouse spermatocytes. Precise staging of the seminiferous tubules and co-localization studies with MVH and MILI, two well recognized CB markers, documented that SAM68 transiently associates with the CB in secondary spermatocytes and early round spermatids. Furthermore, although SAM68 co-immunoprecipitated with MVH in secondary spermatocytes, its ablation did not affect the proper localization of MVH in the CB. On the other hand, ablation of the CB constitutive component MIWI did not impair association of SAM68 with the CB. Isolation of CBs from Sam68 wild type and knockout mouse testes and comparison of their protein content by mass spectrometry indicated that Sam68 ablation did not cause overall alterations in the CB proteome. Lastly, we found that SAM68 interacts with DROSHA and DICER in secondary spermatocytes and early round spermatids and that a subset of miRNAs were altered in Sam68−/−germ cells. These results suggest a novel role for SAM68 in the miRNA pathway during spermatogenesis.
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Affiliation(s)
- Valeria Messina
- Section of Anatomy, Department of Public Health and Cell Biology, University of Rome “Tor Vergata”, Rome, Italy
- Laboratory of Neuroembryology, Fondazione Santa Lucia IRCCS, Rome, Italy
| | - Oliver Meikar
- Department of Physiology, Institute of Biomedicine, University of Turku, Turku, Finland
| | - Maria Paola Paronetto
- Laboratory of Neuroembryology, Fondazione Santa Lucia IRCCS, Rome, Italy
- Department of Health Sciences, University of Rome “Foro Italico”, Rome, Italy
| | - Sara Calabretta
- Section of Anatomy, Department of Public Health and Cell Biology, University of Rome “Tor Vergata”, Rome, Italy
- Digestive and Liver Disease Unit, II Medical School, University of Rome “La Sapienza”, S. Andrea Hospital, Rome, Italy
| | - Raffaele Geremia
- Section of Anatomy, Department of Public Health and Cell Biology, University of Rome “Tor Vergata”, Rome, Italy
| | - Noora Kotaja
- Department of Physiology, Institute of Biomedicine, University of Turku, Turku, Finland
| | - Claudio Sette
- Section of Anatomy, Department of Public Health and Cell Biology, University of Rome “Tor Vergata”, Rome, Italy
- Laboratory of Neuroembryology, Fondazione Santa Lucia IRCCS, Rome, Italy
- * E-mail:
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Cui W, Zhang J, Lian HY, Wang HL, Miao DQ, Zhang CX, Luo MJ, Tan JH. Roles of MAPK and spindle assembly checkpoint in spontaneous activation and MIII arrest of rat oocytes. PLoS One 2012; 7:e32044. [PMID: 22384134 PMCID: PMC3288063 DOI: 10.1371/journal.pone.0032044] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Accepted: 01/18/2012] [Indexed: 11/18/2022] Open
Abstract
Rat oocytes are well known to undergo spontaneous activation (SA) after leaving the oviduct, but the SA is abortive with oocytes being arrested in metaphase III (MIII) instead of forming pronuclei. This study was designed to investigate the mechanism causing SA and MIII arrest. Whereas few oocytes collected from SD rats at 13 h after hCG injection that showed 100% of mitogen-activated protein kinase (MAPK) activities activated spontaneously, all oocytes recovered 19 h post hCG with MAPK decreased to below 75% underwent SA during in vitro culture. During SA, MAPK first declined to below 45% and then increased again to 80%; the maturation-promoting factor (MPF) activity fluctuated similarly but always began to change ahead of the MAPK activity. In SA oocytes with 75% of MAPK activities, microtubules were disturbed with irregularly pulled chromosomes dispersed over the spindle and the spindle assembly checkpoint (SAC) was activated. When MAPK decreased to 45%, the spindle disintegrated and chromosomes surrounded by microtubules were scattered in the ooplasm. SA oocytes entered MIII and formed several spindle-like structures by 6 h of culture when the MAPK activity re-increased to above 80%. While SA oocytes showed one Ca2+ rise, Sr2+-activated oocytes showed several. Together, the results suggested that SA stimuli triggered SA in rat oocytes by inducing a premature MAPK inactivation, which led to disturbance of spindle microtubules. The microtubule disturbance impaired pulling of chromosomes to the spindle poles, caused spindle disintegration and activated SAC. The increased SAC activity reactivated MPF and thus MAPK, leading to MIII arrest.
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Affiliation(s)
| | | | | | | | | | | | | | - Jing-He Tan
- College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai-an City, People's Republic of China
- * E-mail:
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Abstract
RNA silencing is a common term for homology-dependent silencing phenomena found in the majority of eukaryotic species. RNA silencing pathways share several conserved components. The common denominator of these pathways is the presence of specific, short (21-25 nt) RNA molecules generated from different double-stranded RNA substrates by a specific RNase III activity. Short RNA molecules serve as a template for sequence-specific effects including transcriptional silencing, mRNA degradation, and inhibition of translation. This review will discuss possible roles of RNA silencing pathways in mouse oocytes and early embryos as well as the use of RNA silencing for experimental inhibition of gene expression in this model system.
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Vogt E, Kirsch-Volders M, Parry J, Eichenlaub-Ritter U. Spindle formation, chromosome segregation and the spindle checkpoint in mammalian oocytes and susceptibility to meiotic error. Mutat Res 2007; 651:14-29. [PMID: 18096427 DOI: 10.1016/j.mrgentox.2007.10.015] [Citation(s) in RCA: 143] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2007] [Accepted: 10/28/2007] [Indexed: 01/21/2023]
Abstract
The spindle assembly checkpoint (SAC) monitors attachment to microtubules and tension on chromosomes in mitosis and meiosis. It represents a surveillance mechanism that halts cells in M-phase in the presence of unattached chromosomes, associated with accumulation of checkpoint components, in particular, Mad2, at the kinetochores. A complex between the anaphase promoting factor/cylosome (APC/C), its accessory protein Cdc20 and proteins of the SAC renders APC/C inactive, usually until all chromosomes are properly assembled at the spindle equator (chromosome congression) and under tension from spindle fibres. Upon release from the SAC the APC/C can target proteins like cyclin B and securin for degradation by the proteasome. Securin degradation causes activation of separase proteolytic enzyme, and in mitosis cleavage of cohesin proteins at the centromeres and arms of sister chromatids. In meiosis I only the cohesin proteins at the sister chromatid arms are cleaved. This requires meiosis specific components and tight regulation by kinase and phosphatase activities. There is no S-phase between meiotic divisions. Second meiosis resembles mitosis. Mammalian oocytes arrest constitutively at metaphase II in presence of aligned chromosomes, which is due to the activity of the cytostatic factor (CSF). The SAC has been identified in spermatogenesis and oogenesis, but gender-differences may contribute to sex-specific differential responses to aneugens. The age-related reduction in expression of components of the SAC in mammalian oocytes may act synergistically with spindle and other cell organelles' dysfunction, and a partial loss of cohesion between sister chromatids to predispose oocytes to errors in chromosome segregation. This might affect dose-response to aneugens. In view of the tendency to have children at advanced maternal ages it appears relevant to pursue studies on consequences of ageing on the susceptibility of human oocytes to the induction of meiotic error by aneugens and establish models to assess risks to human health by environmental exposures.
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Affiliation(s)
- E Vogt
- University of Bielefeld, Faculty of Biology, Gene Technology/Microbiology, Bielefeld, Germany
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Kashima K, Kano K, Naito K. Mos and the mitogen-activated protein kinase do not show cytostatic factor activity in early mouse embryos. J Reprod Dev 2007; 53:1175-82. [PMID: 17827876 DOI: 10.1262/jrd.19075] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mos and the mitogen-activated protein kinase (MAPK) cascade have been established as crucial regulators of second meiotic metaphase arrest, the so-called CSF arrest, in mammalian oocytes. They are also thought to play a role in regulating mitotic metaphase arrest of early mammalian embryos. In the present study, we examined whether mitotic arrest is induced in early mouse embryos by activation of extracellular signal-regulated kinases (ERKs), which are major MAPKs in mouse eggs, and their substrate, p90Ribosomal S6 kinase (RSK), as reported in Xenopus embryos. Wild-type Mos (wt-Mos), degradation-resistant Mos mutant (P2G-Mos) or constitutive active mutant of MAPK/ERK kinase, MEK (SDSE-MEK), was expressed in early mouse embryos by injecting the respective expression vectors into the pronucleus of fertilized eggs, and the developmental rates were then examined up to 72 h after insemination. Expression of P2G-Mos and SDSE-MEK succeeded in activating ERKs and RSK in developing mouse embryos, while wt-Mos failed to activate them in spite of expression of mos mRNA, indicating that the wt-Mos protein is unstable in early mouse embryos. Although the activated levels of ERKs and RSK in the vector-injected embryos were comparable to those of meiotically arrested mouse oocytes, their developmental rates were identical to those of the control embryos. These results suggest that activation of MAPK and RSK does not induce mitotic arrest in early mouse embryos. The present study indicates that there are large physiological differences between early mouse embryos and mouse oocytes and that CSF arrest of mouse eggs in mitosis should be discussed separately from that in meiosis.
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Affiliation(s)
- Koji Kashima
- Laboratory of Applied Genetics, Graduate School of Agriculture and Life Science, University of Tokyo, Japan
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Ito J, Kato M, Hochi S, Hirabayashi M. Effect of Enucleation on Inactivation of Cytostatic Factor Activity in Matured Rat Oocytes. CLONING AND STEM CELLS 2007; 9:257-66. [PMID: 17579558 DOI: 10.1089/clo.2006.0042] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
In mammals, matured oocytes are arrested at the MII stage until fertilization, which is regulated by cytostaticfactor (CSF) activity. Maturation-promoting factor (MPF) and the mitogen-activated protein kinase (MAPK) pathway are known as candidates for CSF. Despite of the results that nuclear and perinuclear materials were dispensable for activation of MPF and MAPK in other species, our previous study in rats demonstrated that MPF activity was rapidly decreased after enucleation. We showed here for the first time that nuclear and perinuclear materials were indispensable for CSF activity in matured rat oocytes. In both cytoplasm-removed and enucleated oocytes, high activity of p34(cdc2) kinase was observed immediately after manipulation, but the activity of enucleated oocytes was dramatically reduced within 1 h. Cyclin B level was also decreased, corresponding with inactivation of p34(cdc2) kinase. In enucleated oocytes, the Mos level was dramatically decreased, and both MEK and MAPK dephosphorylation were also induced. A combined treatment with a proteasome inhibitor, MG132, and a protein phosphatase inhibitor, okadaic acid, dramatically improved both levels of p-MAPK and cyclin B in these enucleated oocytes. These data suggest that nuclear and perinuclear materials of matured rat oocytes suppress proteasome and protein phosphatase activation, which is indispensable for stability of CSF.
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Affiliation(s)
- Junya Ito
- Section of Molecular Genetics, Center for Brain Experiment, National Institute for Physiological Sciences, Okazaki, Aichi, Japan.
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13
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Lee KY, Bignone PA, Ganesan TS. p90 Ribosomal S6 kinases- eclectic members of the human kinome. ACTA ACUST UNITED AC 2007. [DOI: 10.1002/sita.200600091] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Marangos P, Verschuren EW, Chen R, Jackson PK, Carroll J. Prophase I arrest and progression to metaphase I in mouse oocytes are controlled by Emi1-dependent regulation of APC(Cdh1). ACTA ACUST UNITED AC 2006; 176:65-75. [PMID: 17190794 PMCID: PMC2063628 DOI: 10.1083/jcb.200607070] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Mammalian oocytes are arrested in prophase of the first meiotic division. Progression into the first meiotic division is driven by an increase in the activity of maturation-promoting factor (MPF). In mouse oocytes, we find that early mitotic inhibitor 1 (Emi1), an inhibitor of the anaphase-promoting complex (APC) that is responsible for cyclin B destruction and inactivation of MPF, is present at prophase I and undergoes Skp1–Cul1–F-box/βTrCP-mediated destruction immediately after germinal vesicle breakdown (GVBD). Exogenous Emi1 or the inhibition of Emi1 destruction in prophase-arrested oocytes leads to a stabilization of cyclin B1–GFP that is sufficient to trigger GVBD. In contrast, the depletion of Emi1 using morpholino oligonucleotides increases cyclin B1–GFP destruction, resulting in an attenuation of MPF activation and a delay of entry into the first meiotic division. Finally, we show that Emi1-dependent effects on meiosis I require the presence of Cdh1. These observations reveal a novel mechanism for the control of entry into the first meiotic division: an Emi1-dependent inhibition of APCCdh1.
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Affiliation(s)
- Petros Marangos
- Department of Physiology, University College London, London WC1E 6BT, England, UK.
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15
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Cukurcam S, Betzendahl I, Michel G, Vogt E, Hegele-Hartung C, Lindenthal B, Eichenlaub-Ritter U. Influence of follicular fluid meiosis-activating sterol on aneuploidy rate and precocious chromatid segregation in aged mouse oocytes. Hum Reprod 2006; 22:815-28. [PMID: 17114196 DOI: 10.1093/humrep/del442] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Follicular fluid meiosis-activating sterol (FF-MAS) protects young oocytes from precocious chromatid separation (predivision). Reduced expression of cohesion and checkpoint proteins and predivision has been hypothesized to occur in age-related aneuploidy in oocytes. METHODS To know whether FF-MAS also protects aged oocytes from predivision and from age-related non-disjunction, we analysed chromosome constitution in mouse oocytes matured spontaneously with or without 10 microM FF-MAS and in hypoxanthine (HX)-arrested young and aged oocytes induced to resume maturation by FF-MAS. Messenger RNA for checkpoint protein MAD2 and cohesion protein SMC1beta was compared between oocytes matured with or without FF-MAS. RESULTS Aged oocytes possessed many bivalents with single distal chiasma at meiosis I. Predivision was especially high in aged oocytes cultured sub-optimally to metaphase II in alpha-minimum essential medium (alpha-MEM). FF-MAS reduced predivision significantly (P < 0.001) but neither reduced non-disjunction nor induced aneuploidy in aged oocytes. Polyploidy was high in FF-MAS-stimulated maturation, in particular in the aged oocytes (P > 0.001). Relative levels of Smc1beta mRNA appeared increased by maturation in FF-MAS, and mitochondrial clustering was restored. CONCLUSIONS Sister chromatids of aged oocytes appear to be highly susceptible to precocious chromatid separation, especially when maturation is under sub-optimal conditions, e.g. in the absence of cumulus and FF-MAS. This may relate to some loss of chromatid cohesion during ageing. FF-MAS protects aged oocytes from predivision during maturation, possibly by supporting Smc1beta expression, thus reducing risks of meiotic errors, but it cannot prevent age-related non-disjunction. Aged oocytes appear prone to loss of co-ordination between nuclear maturation and cytokinesis suggesting age-related relaxed cell cycle control.
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Affiliation(s)
- S Cukurcam
- Research Laboratories of Schering AG, Berlin, Germany
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16
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Schmidt A, Rauh NR, Nigg EA, Mayer TU. Cytostatic factor: an activity that puts the cell cycle on hold. J Cell Sci 2006; 119:1213-8. [PMID: 16554437 DOI: 10.1242/jcs.02919] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Fertilization is the fundamental process in which two gametes - sperm and oocyte - fuse to generate a zygote that will form a new multicellular organism. In most vertebrates, oocytes await fertilization while arrested at metaphase of meiosis II. This resting state can be stable for many hours and depends on a cytoplasmic activity termed cytostatic factor (CSF). Recently, members of the novel Emi/Erp family of proteins have been put forward as important components of CSF. These proteins inhibit the anaphase-promoting complex/cyclosome (APC/C), which acts at the very core of the cell cycle regulatory machinery. Initially, Xenopus early mitotic inhibitor 1 (Emi1) was proposed to be a component of CSF, but newer work suggests that a structural relative, Emi-related protein 1 (Erp1/Emi2), is essential for maintenance of CSF arrest in Xenopus. Most importantly, studies on Erp1/Emi2 regulation have led to a detailed molecular understanding of the Ca2+-mediated release from CSF arrest that occurs upon fertilization.
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Affiliation(s)
- Andreas Schmidt
- Chemical Genetics, Independent Research Group, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
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17
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Chesnel F, Vignaux F, Richard-Parpaillon L, Huguet A, Kubiak JZ. Differences in regulation of the first two M-phases in Xenopus laevis embryo cell-free extracts. Dev Biol 2006; 285:358-75. [PMID: 16087172 DOI: 10.1016/j.ydbio.2005.06.028] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2004] [Revised: 06/21/2005] [Accepted: 06/23/2005] [Indexed: 11/28/2022]
Abstract
The first embryonic M-phase is special, being the time when paternal and maternal chromosomes mix together for the first time. Reports from a variety of species suggest that the regulation of first M-phase has many particularities; however, no systematic comparative study of the biochemical aspects of first and the following M-phases has been previously undertaken. Here, we ask whether the regulation of the first embryonic M-phase is modified, using Xenopus cell-free extracts. We developed new types of extract specific for the first and the second M-phase obtained either from parthenogenetic or from in vitro fertilized embryos. Analyses of these extracts confirmed that the amplitude of histone H1 kinase activity reflecting CDK1/cyclin B (or MPF for M-phase Promoting Factor) activity is higher and persists longer than during the second M-phase, and that levels of cyclins B1 and B2 are correspondingly higher during the first than the second embryonic M-phase. Inhibition of protein synthesis shortly before M-phase entry reduced mitotic histone H1 kinase amplitude, shortened the period of mitotic phosphorylation of chosen marker proteins, and reduced cyclin B1 and B2 levels, suggesting a role of B-type cyclins in regulating the duration of mitotic events. Moreover, addition of exogenous cyclin B to the extract prior the second mitosis brought forward the activation of mitotic histone H1 kinase but prolonged the duration of this activity. We also confirmed that the inhibitory phosphorylation of CDK1 on tyrosine 15 oscillates between the first two embryonic M-phases, but is clearly more pronounced before the first than the second mitosis, while the MAP kinase ERK2 tended to show greater activation during the first embryonic M-phase but with a similar duration of activation. We conclude that discrete differences exist between the first two M-phases in Xenopus embryo and that higher CDK1/cyclin B activity and B-type cyclin levels could account for the different characteristics of these M-phases.
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Affiliation(s)
- Franck Chesnel
- UMR 6061 CNRS, Biology and Genetics of Development, Mitosis and Meiosis Group, IFR140 GFAS, University of Rennes 1, Faculty of Medicine, 2 Ave. Prof. Léon Bernard, CS 34317, 35043 Rennes cedex, France
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18
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Sikora-Polaczek M, Hupalowska A, Polanski Z, Kubiak JZ, Ciemerych MA. The First Mitosis of the Mouse Embryo Is Prolonged by Transitional Metaphase Arrest1. Biol Reprod 2006; 74:734-43. [PMID: 16382027 DOI: 10.1095/biolreprod.105.047092] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
The first mitosis of the mouse embryo is almost twice as long as the second. The mechanism of the prolongation of the first mitosis remains unknown, and it is not clear whether prometaphase or metaphase or both are prolonged. Prometaphase is characterized by dynamic chromosome movements and spindle assembly checkpoint activity, which prevents anaphase until establishment of stable kinetochore-microtubule connections. The end of prometaphase is correlated with checkpoint inactivation and disappearance of MAD2L1 (MAD2) and RSN (CLIP-170) proteins from kinetochores. Spindle assembly checkpoint operates during the early mouse mitoses, but it is not clear whether it influences their duration. Here, we determine the length of prometaphases and metaphases during the first two embryonic mitoses by time-lapse video recording of chromosomes and by immunolocalization of MAD2L1 and RSN proteins. We show that the duration of the two prometaphases does not differ and that MAD2L1 and RSN disappear from kinetochores very early during each mitosis. The first metaphase is significantly longer than the second one. Therefore, the prolongation of the first embryonic mitosis is due to a prolonged metaphase, and the spindle assembly checkpoint cannot be involved in this process. We show also that MAD2L1 staining disappears gradually from kinetochores of oocytes arrested at metaphase of the second meiotic division. This shows a striking similarity between the first embryonic mitosis and metaphase arrest in oocytes. We postulate that the first embryonic mitosis is prolonged by a transient metaphase arrest that is independent of the spindle assembly checkpoint and is similar to metaphase II arrest. The molecular mechanism of this transient arrest remains to be elucidated.
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Affiliation(s)
- Marta Sikora-Polaczek
- Department of Embryology, Institute of Zoology, Warsaw University, 02-096 Warsaw, Poland
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19
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Assou S, Anahory T, Pantesco V, Le Carrour T, Pellestor F, Klein B, Reyftmann L, Dechaud H, De Vos J, Hamamah S. The human cumulus--oocyte complex gene-expression profile. Hum Reprod 2006; 21:1705-19. [PMID: 16571642 PMCID: PMC2377388 DOI: 10.1093/humrep/del065] [Citation(s) in RCA: 218] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND The understanding of the mechanisms regulating human oocyte maturation is still rudimentary. We have identified transcripts differentially expressed between immature and mature oocytes and cumulus cells. METHODS Using oligonucleotide microarrays, genome-wide gene expression was studied in pooled immature and mature oocytes or cumulus cells from patients who underwent IVF. RESULTS In addition to known genes, such as DAZL, BMP15 or GDF9, oocytes up-regulated 1514 genes. We show that PTTG3 and AURKC are respectively the securin and the Aurora kinase preferentially expressed during oocyte meiosis. Strikingly, oocytes overexpressed previously unreported growth factors such as TNFSF13/APRIL, FGF9, FGF14 and IL4 and transcription factors including OTX2, SOX15 and SOX30. Conversely, cumulus cells, in addition to known genes such as LHCGR or BMPR2, overexpressed cell-to-cell signalling genes including TNFSF11/RANKL, numerous complement components, semaphorins (SEMA3A, SEMA6A and SEMA6D) and CD genes such as CD200. We also identified 52 genes progressively increasing during oocyte maturation, including CDC25A and SOCS7. CONCLUSION The identification of genes that were up- and down-regulated during oocyte maturation greatly improves our understanding of oocyte biology and will provide new markers that signal viable and competent oocytes. Furthermore, genes found expressed in cumulus cells are potential markers of granulosa cell tumours.
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Affiliation(s)
- Said Assou
- IRB, Institut de recherche en biothérapie
CHRU MontpellierUniversité Montpellier IHôpital Saint-Eloi
34000 Montpellier,FR
- Immunopathologie des maladies tumorales et autoimmunes
INSERM : U475IFR76Institut de recherche en biothérapieUniversité Montpellier ICentre de Recherche Inserm
99, Rue Puech Villa
34197 MONTPELLIER CEDEX 5,FR
| | - Tal Anahory
- UFR Médecine
Université Montpellier IMontpellier,FR
| | - Véronique Pantesco
- Immunopathologie des maladies tumorales et autoimmunes
INSERM : U475IFR76Institut de recherche en biothérapieUniversité Montpellier ICentre de Recherche Inserm
99, Rue Puech Villa
34197 MONTPELLIER CEDEX 5,FR
| | - Tanguy Le Carrour
- IRB, Institut de recherche en biothérapie
CHRU MontpellierUniversité Montpellier IHôpital Saint-Eloi
34000 Montpellier,FR
| | - Franck Pellestor
- UFR Médecine
Université Montpellier IMontpellier,FR
- IGH, Institut de génétique humaine
CNRS : UPR1142institut de Génétique humaine
141 Rue de la Cardonille
34396 MONTPELLIER CEDEX 5,FR
| | - Bernard Klein
- IRB, Institut de recherche en biothérapie
CHRU MontpellierUniversité Montpellier IHôpital Saint-Eloi
34000 Montpellier,FR
- Immunopathologie des maladies tumorales et autoimmunes
INSERM : U475IFR76Institut de recherche en biothérapieUniversité Montpellier ICentre de Recherche Inserm
99, Rue Puech Villa
34197 MONTPELLIER CEDEX 5,FR
| | - Lionel Reyftmann
- Service de gynécologie-obstétrique et médecine de la reproduction
CHRU MontpellierHôpital Arnaud de VilleneuveUniversité Montpellier IFR
| | - Hervé Dechaud
- Service de gynécologie-obstétrique et médecine de la reproduction
CHRU MontpellierHôpital Arnaud de VilleneuveUniversité Montpellier IFR
| | - John De Vos
- IRB, Institut de recherche en biothérapie
CHRU MontpellierUniversité Montpellier IHôpital Saint-Eloi
34000 Montpellier,FR
- Immunopathologie des maladies tumorales et autoimmunes
INSERM : U475IFR76Institut de recherche en biothérapieUniversité Montpellier ICentre de Recherche Inserm
99, Rue Puech Villa
34197 MONTPELLIER CEDEX 5,FR
- * Correspondence should be adressed to: John De Vos
| | - Samir Hamamah
- IRB, Institut de recherche en biothérapie
CHRU MontpellierUniversité Montpellier IHôpital Saint-Eloi
34000 Montpellier,FR
- Immunopathologie des maladies tumorales et autoimmunes
INSERM : U475IFR76Institut de recherche en biothérapieUniversité Montpellier ICentre de Recherche Inserm
99, Rue Puech Villa
34197 MONTPELLIER CEDEX 5,FR
- UFR Médecine
Université Montpellier IMontpellier,FR
- * Correspondence should be adressed to: Samir Hamamah
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20
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Shoji S, Yoshida N, Amanai M, Ohgishi M, Fukui T, Fujimoto S, Nakano Y, Kajikawa E, Perry ACF. Mammalian Emi2 mediates cytostatic arrest and transduces the signal for meiotic exit via Cdc20. EMBO J 2006; 25:834-45. [PMID: 16456547 PMCID: PMC1383546 DOI: 10.1038/sj.emboj.7600953] [Citation(s) in RCA: 139] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2005] [Accepted: 12/08/2005] [Indexed: 11/08/2022] Open
Abstract
Fertilizable mammalian oocytes are arrested at the second meiotic metaphase (mII) by the cyclinB-Cdc2 heterodimer, maturation promoting factor (MPF). MPF is stabilized via the activity of an unidentified cytostatic factor (CSF), thereby suspending meiotic progression until fertilization. We here present evidence that a conserved 71 kDa mammalian orthologue of Xenopus XErp1/Emi2, which we term endogenous meiotic inhibitor 2 (Emi2) is an essential CSF component. Depletion in situ of Emi2 by RNA interference elicited precocious meiotic exit in maturing mouse oocytes. Reduction of Emi2 released mature mII oocytes from cytostatic arrest, frequently inducing cytodegeneration. Mos levels autonomously declined to undetectable levels in mII oocytes. Recombinant Emi2 reduced the propensity of mII oocytes to exit meiosis in response to activating stimuli. Emi2 and Cdc20 proteins mutually interact and Cdc20 ablation negated the ability of Emi2 removal to induce metaphase release. Consistent with this, Cdc20 removal prevented parthenogenetic or sperm-induced meiotic exit. These studies show in intact oocytes that the interaction of Emi2 with Cdc20 links activating stimuli to meiotic resumption at fertilization and during parthenogenesis in mammals.
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Affiliation(s)
- Shisako Shoji
- Laboratory of Mammalian Molecular Embryology, RIKEN Center for Developmental Biology, Chuo-ku, Kobe, Japan
| | - Naoko Yoshida
- Laboratory of Mammalian Molecular Embryology, RIKEN Center for Developmental Biology, Chuo-ku, Kobe, Japan
| | - Manami Amanai
- Laboratory of Mammalian Molecular Embryology, RIKEN Center for Developmental Biology, Chuo-ku, Kobe, Japan
| | - Maki Ohgishi
- Laboratory of Mammalian Molecular Embryology, RIKEN Center for Developmental Biology, Chuo-ku, Kobe, Japan
| | - Tomoyuki Fukui
- Laboratory of Mammalian Molecular Embryology, RIKEN Center for Developmental Biology, Chuo-ku, Kobe, Japan
| | - Satoko Fujimoto
- Laboratory of Mammalian Molecular Embryology, RIKEN Center for Developmental Biology, Chuo-ku, Kobe, Japan
| | - Yoshikazu Nakano
- Laboratory of Mammalian Molecular Embryology, RIKEN Center for Developmental Biology, Chuo-ku, Kobe, Japan
| | - Eriko Kajikawa
- Laboratory of Mammalian Molecular Embryology, RIKEN Center for Developmental Biology, Chuo-ku, Kobe, Japan
| | - Anthony C F Perry
- Laboratory of Mammalian Molecular Embryology, RIKEN Center for Developmental Biology, Chuo-ku, Kobe, Japan
- Laboratory of Mammalian Molecular Embryology, RIKEN Center for Developmental Biology, 2-2-3 Minatojima Minamimachi, Chuo-ku, Kobe 650-0047, Japan. Tel.: +81 78 306 3054; Fax: +81 78 306 3144; E-mail:
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21
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Mizutani T, Fukushi S, Saijo M, Kurane I, Morikawa S. Regulation of p90RSK phosphorylation by SARS-CoV infection in Vero E6 cells. FEBS Lett 2006; 580:1417-24. [PMID: 16458888 PMCID: PMC7094696 DOI: 10.1016/j.febslet.2006.01.066] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2005] [Revised: 01/10/2006] [Accepted: 01/17/2006] [Indexed: 01/21/2023]
Abstract
The 90 kDa ribosomal S6 kinases (p90RSKs) are a family of broadly expressed serine/threonine kinases with two kinase domains activated by extracellular signal‐regulated protein kinase in response to many growth factors. Our recent study demonstrated that severe acute respiratory syndrome (SARS)‐coronavirus (CoV) infection of monkey kidney Vero E6 cells induces phosphorylation and dephosphorylation of signaling pathways, resulting in apoptosis. In the present study, we investigated the phosphorylation status of p90RSK, which is a well‐known substrate of these signaling pathways, in SARS‐CoV‐infected cells. Vero E6 mainly expressed p90RSK1 and showed weak expression of p90RSK2. In the absence of viral infection, Ser221 in the N‐terminal kinase domain was phosphorylated constitutively, whereas both Thr573 in the C‐terminal kinase domain and Ser380 between the two kinase domains were not phosphorylated in confluent cells. Ser380, which has been reported to be involved in autophosphorylation by activation of the C‐terminal kinase domain, was phosphorylated in confluent SARS‐CoV‐infected cells, and this phosphorylation was inhibited by http://SB203580, which is an inhibitor of p38 mitogen‐activated protein kinases (MAPK). Phosphorylation of Thr573 was not upregulated in SARS‐CoV‐infected cells. Thus, in virus‐infected cells, phosphorylation of Thr573 was not necessary to induce phosphorylation of Ser380. On the other hand, Both Thr573 and Ser380 were phosphorylated by treatment with epidermal growth factor (EGF) in the absence of p38 MAPK activation. Ser220 was constitutively phosphorylated despite infection. These results indicated that phosphorylation status of p90RSK by SARS‐CoV infection is different from that by stimulation of EGF. This is the first detailed report regarding regulation of p90RSK phosphorylation by virus infection.
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Affiliation(s)
- Tetsuya Mizutani
- Special Pathogens Laboratory, Department of Virology 1, National Institute of Infectious Diseases, Gakuen 4-7-1, Musashimurayama, Tokyo 208-0011, Japan.
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22
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Hansen DV, Tung JJ, Jackson PK. CaMKII and polo-like kinase 1 sequentially phosphorylate the cytostatic factor Emi2/XErp1 to trigger its destruction and meiotic exit. Proc Natl Acad Sci U S A 2006; 103:608-13. [PMID: 16407128 PMCID: PMC1325965 DOI: 10.1073/pnas.0509549102] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
In vertebrate meiosis, unfertilized eggs are arrested in metaphase II by cytostatic factor (CSF), which is required to maintain mitotic cyclin-dependent kinase activity. Fertilization triggers a transient increase in cytosolic free Ca(2+), which leads to CSF inactivation and ubiquitin-dependent cyclin destruction through the anaphase promoting complex or cyclosome (APC/C). The Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) and the Polo-like kinase Plx1 are essential factors for Ca(2+)-induced meiotic exit, but the critical targets of these kinases were unknown. The APC/C inhibitor Emi2 or XErp1 has recently been characterized as a pivotal CSF component, required to maintain metaphase II arrest and rapidly destroyed in response to Ca(2+) signaling through phosphorylation by Plx1 and ubiquitination by the SCF(betaTrCP) complex. An important question is how the increase in free Ca(2+) targets Plx1 activity toward Emi2. Here, we demonstrate that CaMKII is required for Ca(2+)-induced Emi2 destruction, and that CaMKII functions as a "priming kinase," directly phosphorylating Emi2 at a specific motif to induce a strong interaction with the Polo Box domain of Plx1. We show that the strict requirement for CaMKII to phosphorylate Emi2 is a specific feature of CSF arrest, and we also use phosphatase inhibitors to demonstrate an additional mode of Emi2 inactivation independent of its destruction. We firmly establish the CSF component Emi2 as the first-known critical and direct target of CaMKII in CSF release, providing a detailed molecular mechanism explaining how CaMKII and Plx1 coordinately direct APC/C activation and meiotic exit upon fertilization.
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Affiliation(s)
- David V Hansen
- Program in Cancer Biology, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA
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23
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Abstract
Mammalian eggs arrest at metaphase of the second meiotic division (MetII). Sperm break this arrest by inducing a series of Ca2+spikes that last for several hours. During this time cell cycle resumption is induced, sister chromatids undergo anaphase and the second polar body is extruded. This is followed by decondensation of the chromatin and the formation of pronuclei. Ca2+spiking is both the necessary and solely sufficient sperm signal to induce full egg activation. How MetII arrest is established, how the Ca2+spiking is induced and how the signal is transduced into cell cycle resumption are the topics of this review. Although the roles of most components of the signal transduction pathway remain to be fully investigated, here I present a model in which a sperm-specific phospholipase C (PLCζ) generates Ca2+spikes to activate calmodulin-dependent protein kinase II and so switch on the Anaphase-Promoting Complex/Cyclosome (APC/C). APC/C activation leads to securin and cyclin B1 degradation and in so doing allows sister chromatids to be segregated and to decondense.
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Affiliation(s)
- Keith T Jones
- Institute for Cell and Molecular Biosciences, The Medical School, Framlington Place, University of Newcastle, Newcastle, NE2 4HH, UK.
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24
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Madgwick S, Levasseur M, Jones KT. Calmodulin-dependent protein kinase II, and not protein kinase C, is sufficient for triggering cell-cycle resumption in mammalian eggs. J Cell Sci 2005; 118:3849-59. [PMID: 16091425 DOI: 10.1242/jcs.02506] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Mouse eggs arrest at metaphase II following ovulation and are only triggered to complete meiosis when fertilized. Sperm break the cell-cycle arrest by a long-lasting series of Ca2+ spikes that lead to an activation of the anaphase-promoting complex/cyclosome. The signal transduction pathway is not fully resolved but both protein kinase C (PKC) and calmodulin-dependent protein kinase II (CamKII) activities increase at fertilization and previous pharmacological studies have implicated both in cell-cycle resumption. We have used a combination of pharmacological inhibitors and constitutively active cRNA constructs of PKCα and CamKIIα microinjected into mouse eggs to show that it is CamKII and not PKC that is the sufficient trigger for cell-cycle resumption from metaphase II arrest.
Constitutively active PKC constructs had no effect on the resumption of meiosis but caused an immediate and persistent elevation in intracellular Ca2+ when store-operated Ca2+ entry was stimulated. With respect to resumption of meiosis, the effects of constitutively active CamKII on eggs were the same as sperm. Eggs underwent second polar body extrusion and pronucleus formation with normal timings; while both securin and cyclin B1 destruction, visualised by coupling to fluorescent protein tags, were complete by the time of polar body extrusion. Induction of a spindle checkpoint by overexpression of Mad2 or by spindle poisons blocked CamKII-induced resumption of meiosis, but the Ca2+ chelator BAPTA did not. Furthermore direct measurement of Ca2+ levels showed that CamKII did not induce exit from metaphase II arrest by raising Ca2+. Therefore, we conclude that PKCs may play an important role in maintaining Ca2+ spiking at fertilization by promoting store-operated Ca2+ entry, while CamKII transduces cell-cycle resumption, and lies downstream of sperm-induced Ca2+ release but upstream of a spindle checkpoint. These data, combined with the knowledge that CamKII activity increase at fertilization, suggest that mouse eggs undergo cell-cycle resumption through stimulation of CamKII.
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Affiliation(s)
- Suzanne Madgwick
- Institute for Cell and Molecular Biosciences, The Medical School, Framlington Place, University of Newcastle, Newcastle, NE2 4HH, UK
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25
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Dumont J, Umbhauer M, Rassinier P, Hanauer A, Verlhac MH. p90Rsk is not involved in cytostatic factor arrest in mouse oocytes. ACTA ACUST UNITED AC 2005; 169:227-31. [PMID: 15837801 PMCID: PMC2171868 DOI: 10.1083/jcb.200501027] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Vertebrate oocytes arrest in metaphase of the second meiotic division (MII), where they maintain a high cdc2/cyclin B activity and a stable, bipolar spindle because of cytostatic factor (CSF) activity. The Mos-MAPK pathway is essential for establishing CSF. Indeed, oocytes from the mos-/- strain do not arrest in MII and activate without fertilization, as do Xenopus laevis oocytes injected with morpholino oligonucleotides directed against Mos. In Xenopus oocytes, p90Rsk (ribosomal S6 kinase), a MAPK substrate, is the main mediator of CSF activity. We show here that this is not the case in mouse oocytes. The injection of constitutively active mutant forms of Rsk1 and Rsk2 does not induce a cell cycle arrest in two-cell mouse embryos. Moreover, these two mutant forms do not restore MII arrest after their injection into mos-/- oocytes. Eventually, oocytes from the triple Rsk (1, 2, 3) knockout present a normal CSF arrest. We demonstrate that p90Rsk is not involved in the MII arrest of mouse oocytes.
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Affiliation(s)
- Julien Dumont
- Equipe Divisions Méiotiques chez la souris, UMR7622, Centre National de la Recherche Scientifique/Université Pierre et Marie Curie, Paris, France
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Tung JJ, Hansen DV, Ban KH, Loktev AV, Summers MK, Adler JR, Jackson PK. A role for the anaphase-promoting complex inhibitor Emi2/XErp1, a homolog of early mitotic inhibitor 1, in cytostatic factor arrest of Xenopus eggs. Proc Natl Acad Sci U S A 2005; 102:4318-23. [PMID: 15753281 PMCID: PMC552977 DOI: 10.1073/pnas.0501108102] [Citation(s) in RCA: 126] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Unfertilized vertebrate eggs are arrested in metaphase of meiosis II with high cyclin B/Cdc2 activity to prevent parthenogenesis. Until fertilization, exit from metaphase is blocked by an activity called cytostatic factor (CSF), which stabilizes cyclin B by inhibiting the anaphase-promoting complex (APC) ubiquitin ligase. The APC inhibitor early mitotic inhibitor 1 (Emi1) was recently found to be required for maintenance of CSF arrest. We show here that exogenous Emi1 is unstable in CSF-arrested Xenopus eggs and is destroyed by the SCF(betaTrCP) ubiquitin ligase, suggesting that endogenous Emi1, an apparent 44-kDa protein, requires a stabilizing factor. However, anti-Emi1 antibodies crossreact with native Emi2/Erp1/FBXO43, a homolog of Emi1 and conserved APC inhibitor. Emi2 is stable in CSF-arrested eggs, is sufficient to prevent CSF release, and is rapidly degraded in a Polo-like kinase 1-dependent manner in response to calcium-mediated egg activation. These results identify Emi2 as a candidate CSF maintenance protein.
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Affiliation(s)
- Jeffrey J Tung
- Department of Pathology, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA
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Abstract
Vertebrate eggs prevent parthenogenetic development by producing cytostatic factor (CSF), which blocks exit from metaphase of meiosis II until fertilization. CSF was never purified but recently suspected to inhibit the anaphase-promoting complex (APC), an ubiquitin ligase required for entry into anaphase. In a recent paper in Genes & Development, Schmidt et al. describe the Xenopus APC inhibitor Erp1, which seems to be the best candidate yet for the downstream effector of CSF activity.
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Affiliation(s)
- Wolfgang Zachariae
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
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