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Bahety D, Böke E, Rodríguez-Nuevo A. Mitochondrial morphology, distribution and activity during oocyte development. Trends Endocrinol Metab 2024:S1043-2760(24)00064-X. [PMID: 38599901 DOI: 10.1016/j.tem.2024.03.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 03/06/2024] [Accepted: 03/08/2024] [Indexed: 04/12/2024]
Abstract
Mitochondria have a crucial role in cellular function and exhibit remarkable plasticity, adjusting both their structure and activity to meet the changing energy demands of a cell. Oocytes, female germ cells that become eggs, undergo unique transformations: the extended dormancy period, followed by substantial increase in cell size and subsequent maturation involving the segregation of genetic material for the next generation, present distinct metabolic challenges necessitating varied mitochondrial adaptations. Recent findings in dormant oocytes challenged the established respiratory complex hierarchies and underscored the extent of mitochondrial plasticity in long-lived oocytes. In this review, we discuss mitochondrial adaptations observed during oocyte development across three vertebrate species (Xenopus, mouse, and human), emphasising current knowledge, acknowledging limitations, and outlining future research directions.
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Affiliation(s)
- Devesh Bahety
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain; Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Elvan Böke
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain; Universitat Pompeu Fabra (UPF), Barcelona, Spain.
| | - Aida Rodríguez-Nuevo
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Barcelona, Spain.
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Figla promotes secondary follicle growth in mature mice. Sci Rep 2021; 11:9842. [PMID: 33972571 PMCID: PMC8110814 DOI: 10.1038/s41598-021-89052-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 04/20/2021] [Indexed: 11/09/2022] Open
Abstract
The in vitro growth (IVG) of human follicles is a potential fertility option for women for whom cryopreserved ovarian tissues cannot be transplanted due to the risk of cancer cell reintroduction; however, there is currently no established method. Furthermore, optimal IVG conditions may differ between the follicles of adult and pre-pubertal females due to molecular differences suggested by basic research. To systematically identify differences between the secondary follicles of adult and pre-pubertal females, a comparative transcriptomic study using mice was conducted herein. Among differentially expressed genes (DEGs), Figla was up-regulated in mature mice. We successfully down-regulated Figla expression in secondary follicle oocytes by a Figla siRNA microinjection, and the subsequent IVG of follicles showed that the diameter of these follicles was smaller than those of controls in mature mice, whereas no significant difference was observed in premature mice. The canonical pathways of DEGs between control and Figla-reduced secondary follicles suggest that Figla up-regulates VDR/RXR activation and down-regulates stem cell pluripotency as well as estrogen signaling. We demonstrated for the first time that folliculogenesis of the secondary follicles of premature and mature mice may be regulated by different factors, such as Figla with its possible target genes, providing insights into optimal IVG conditions for adult and pre-pubertal females, respectively.
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Meiotic Instability Generates a Pathological Condition in Mammalian Ovum. Stem Cell Rev Rep 2020; 17:777-784. [PMID: 33140233 DOI: 10.1007/s12015-020-10072-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/27/2020] [Indexed: 02/02/2023]
Abstract
Maintenance of metaphase-II (M-II) arrest in ovum is required to present itself as a right gamete for successful fertilization in mammals. Surprisingly, instability of meiotic cell cycle results in spontaneous exit from M-II arrest, chromosomal scattering and incomplete extrusion of second polar body (PB-II) without forming pronuclei so called abortive spontaneous ovum activation (SOA). It remains unclear what causes meiotic instability in freshly ovulated ovum that results in abortive SOA. We propose the involvement of various signal molecules such as reactive oxygen species (ROS), cyclic 3',5' adenosine monophosphate (cAMP) and calcium (Ca2+) in the induction of meiotic instability and thereby abortive SOA. These signal molecules through their downstream pathways modulate phosphorylation status and activity of cyclin dependent kinase (cdk1) as well as cyclin B1 level. Changes in phosphorylation status of cdk1 and its activity, dissociation and degradation of cyclin B1 destabilize maturation promoting factor (MPF). The premature MPF destabilization and defects in other cell cycle regulators possibly cause meiotic instability in ovum soon after ovulation. The meiotic instability results in a pathological condition of abortive SOA and deteriorates ovum quality. These ova are unfit for fertilization and limit reproductive outcome in several mammalian species including human. Therefore, global attention is required to identify the underlying causes in greater details in order to address the problem of meiotic instability in ova of several mammalian species icluding human. Moreover, these activated ova may be used to create parthenogenetic embryonic stem cell lines in vitro for the use in regenerative medicine.Graphical abstract.
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Zhou CX, Wang Y, Shi LY, Wang ZB, Ma Y, Li CR, Zhang NN, Zhang YX, Zhang F, Zhang D, Xia ZR. GTPases Arf5 and Arl2 function partially distinctly during oocyte meiosis. J Cell Biochem 2020; 122:198-208. [PMID: 32985032 DOI: 10.1002/jcb.29839] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2019] [Revised: 07/09/2020] [Accepted: 07/30/2020] [Indexed: 01/11/2023]
Abstract
Mammalian female meiosis must be tightly regulated to produce high-quality mature oocytes for subsequent regular fertilization and healthy live birth of the next generation. GTPases control many important signal pathways involved in diverse cellular activities. ADP-ribosylation factor family members (Arfs) in mice possess GTPase activities, and some members have been found to function in meiosis. However, whether other Arfs play a role in meiosis is unknown. In this study, we found that Arl2 and Arf5 are the richest among Arfs in mouse oocytes, and they are more abundant in oocytes than in granular cells. Furthermore, Arl2 and Arf5 depletion both impeded meiotic progression, but by affecting spindles and microfilaments, respectively. Moreover, Arl2 and Arf5 depletion both significantly increased regular reactive oxygen species levels and decreased mitochondrial membrane potential and autophagy, indicating that oocyte quality was damaged by Arl2 and Arf5 depletion. These results suggest that Arl2 and Arf5 are two novel essential GTPases required for oocyte meiosis and quality control.
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Affiliation(s)
- Chun-Xiang Zhou
- Drum Tower Hospital Affiliated to Medical College of Nanjing University, Nanjing, Jiangsu, China
| | - Yang Wang
- Nanjing Medical University, Nanjing, Jiangsu, China
| | - Li-Ya Shi
- Tongji University School of Medicine, Shanghai East Hospital, Shanghai, Pudong, China
| | - Zi-Bin Wang
- Nanjing Medical University, Nanjing, Jiangsu, China
| | - Yang Ma
- The Second Hospital of Changzhou, Nanjing Medical University, Changzhou, Jiangsu, China
| | - Cong-Rong Li
- Nanjing Medical University, Nanjing, Jiangsu, China
| | - Na-Na Zhang
- Nanjing Medical University, Nanjing, Jiangsu, China
| | | | - Fenli Zhang
- College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu, China
| | - Dong Zhang
- Nanjing Medical University, Nanjing, Jiangsu, China
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Tiwari M, Prasad S, Shrivastav TG, Chaube SK. Calcium Signaling During Meiotic Cell Cycle Regulation and Apoptosis in Mammalian Oocytes. J Cell Physiol 2016; 232:976-981. [PMID: 27791263 DOI: 10.1002/jcp.25670] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 10/27/2016] [Indexed: 01/07/2023]
Abstract
Calcium (Ca++ ) is one of the major signal molecules that regulate various aspects of cell functions including cell cycle progression, arrest, and apoptosis in wide variety of cells. This review summarizes current knowledge on the differential roles of Ca++ in meiotic cell cycle resumption, arrest, and apoptosis in mammalian oocytes. Release of Ca++ from internal stores and/or Ca++ influx from extracellular medium causes moderate increase of intracellular Ca++ ([Ca++ ]i) level and reactive oxygen species (ROS). Increase of Ca++ as well as ROS levels under physiological range trigger maturation promoting factor (MPF) destabilization, thereby meiotic resumption from diplotene as well as metaphase-II (M-II) arrest in oocytes. A sustained increase of [Ca++ ]i level beyond physiological range induces generation of ROS sufficient enough to cause oxidative stress (OS) in aging oocytes. The increased [Ca++ ]i triggers Fas ligand-mediated oocyte apoptosis. Further, OS triggers mitochondria-mediated oocyte apoptosis in several mammalian species. Thus, Ca++ exerts differential roles on oocyte physiology depending upon its intracellular concentration. A moderate increase of [Ca++ ]i as well as ROS mediate spontaneous resumption of meiosis from diplotene as well as M-II arrest, while their high levels cause meiotic cell cycle arrest and apoptosis by operating both mitochondria- as well as Fas ligand-mediated apoptotic pathways. Indeed, Ca++ regulates cellular physiology by modulating meiotic cell cycle and apoptosis in mammalian oocytes. J. Cell. Physiol. 232: 976-981, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Meenakshi Tiwari
- Cell Physiology Laboratory, Department of Zoology, Institute of Science, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Shilpa Prasad
- Cell Physiology Laboratory, Department of Zoology, Institute of Science, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Tulsidas G Shrivastav
- Department of Reproductive Biomedicine, National Institute of Health and Family Welfare, Munirka, New Delhi, India
| | - Shail K Chaube
- Cell Physiology Laboratory, Department of Zoology, Institute of Science, Banaras Hindu University, Varanasi, Uttar Pradesh, India
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Tiwari M, Chaube SK. Moderate increase of reactive oxygen species triggers meiotic resumption in rat follicular oocytes. J Obstet Gynaecol Res 2016; 42:536-46. [PMID: 26913578 DOI: 10.1111/jog.12938] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 10/16/2015] [Accepted: 11/29/2015] [Indexed: 01/03/2023]
Abstract
AIM The mammalian ovary generates reactive oxygen species (ROS) on an extraordinary scale; however, the role of ROS during meiotic cell cycle progression in follicular oocytes remains poorly understood. The present study was aimed to determine whether a moderate increase of ROS level in the ovary is beneficial for meiotic resumption from diplotene arrest in follicular oocytes. METHODS Cumulus oocyte complexes were collected from the ovaries of female rats that had been treated with either: (i) pregnant mare's serum gonadotrophin; or (ii) pregnant mare's serum gonadotrophin + human chorionic gonadotrophin. We analyzed morphological changes, ROS and hydrogen peroxide levels, catalase activity, 3',5'-cyclic adenosine monophosphate and 3',5'-cyclic guanosine monophosphate levels, Thr14/Tyr15, Th-161, total cyclin-dependent kinase 1 (Cdk1) and cyclin B1 levels. RESULTS Human chorionic gonadotrophin treatment induced meiotic resumption from diplotene arrest and extrusion of first polar body in cumulus oocyte complexes collected from ovaries and cultured for 3 h in vitro. Meiotic resumption from diplotene arrest was associated with increased ROS and hydrogen peroxide levels but decreased 3',5'-cyclic adenosine monophosphate as well as 3',5'-cyclic guanosine monophosphate levels. The reduced cyclic nucleotide levels were associated with decreased Thr161 phosphorylated Cdk1 and cyclin B1 level but increased Thr14/Tyr15 phosphorylated Cdk1 level leading to maturation promoting factor destabilization. Destabilized maturation-promoting factor triggered meiotic resumption from diplotene arrest and progression to metaphase-I as well as metaphase-II stage in follicular oocytes. CONCLUSION Our findings suggest that a moderate increase of ROS in the ovary is beneficial for meiotic resumption from diplotene arrest and extrusion of first polar body in follicular oocytes.
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Affiliation(s)
- Meenakshi Tiwari
- Cell Physiology Laboratory, Biochemistry Unit, Department of Zoology, Banaras Hindu University, Varanasi, UP, India
| | - Shail K Chaube
- Cell Physiology Laboratory, Biochemistry Unit, Department of Zoology, Banaras Hindu University, Varanasi, UP, India
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Premkumar KV, Chaube SK. Increased level of reactive oxygen species persuades postovulatory aging-mediated spontaneous egg activation in rat eggs cultured in vitro. In Vitro Cell Dev Biol Anim 2016; 52:576-88. [PMID: 26896066 DOI: 10.1007/s11626-016-0007-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 01/25/2016] [Indexed: 11/29/2022]
Abstract
The present study was aimed to find out whether increased level of reactive oxygen species (ROS) particularity hydrogen peroxide (H2O2) could persuade postovulatory aging-mediated abortive spontaneous egg activation (SEA) in rat eggs cultured in vitro. For this purpose, ROS and H2O2 levels, mitochondria distribution and its membrane potential, p286-CaMK-II, Emi2, Thr-161 phophorylated cyclin-dependent protein kinase1 (Cdk1) as well as cyclin B1 levels, in vitro effects of 3-tert-butyl-4 hydroxy anisole (BHA), pentoxifylline and dibutyryl-adenosine 3',5'-cyclic monophosphate (db-cAMP) were analyzed during postovulatory aging-induced abortive SEA in vitro. Data of the present study suggest that postovulatory aging increased H2O2 levels, disturbed mitochondrial distribution pattern and mitochondrial membrane potential (MMP) in eggs. There was an significant increase of p286-CaMK-II level, while Emi2 level reduced significantly during egg aging in vitro. The reduced Emi2 level was associated with decreased Thr-161 phosphorylated cyclin-dependent kinase-1 (Cdk1) as well as cyclin B1 level in aged eggs that underwent abortive SEA. Further, supplementation of pentoxifylline, db-cAMP, and BHA protected postovulatory aging-mediated abortive SEA in concentration-dependent manner. These data suggest that postovulatory aging increased H2O2 levels, reduced MMP, and increased p286-CaMK-II. The increased p286-CaMK-II was associated with reduced Emi2 level and maturation-promoting factor levels during postovulatory aging-mediated abortive SEA. Drugs that elevate cAMP directly or indirectly and BHA protected postovulatory aging-mediated abortive SEA possibly by reducing ROS level in rat eggs cultured in vitro.
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Affiliation(s)
- Karuppanan V Premkumar
- Cell Physiology Laboratory, Department of Zoology, Centre of Advanced Study, Banaras Hindu University, Varanasi, 221005, UP, India
| | - Shail K Chaube
- Cell Physiology Laboratory, Department of Zoology, Centre of Advanced Study, Banaras Hindu University, Varanasi, 221005, UP, India.
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Zhang Y, Duan X, Cao R, Liu HL, Cui XS, Kim NH, Rui R, Sun SC. Small GTPase RhoA regulates cytoskeleton dynamics during porcine oocyte maturation and early embryo development. Cell Cycle 2015; 13:3390-403. [PMID: 25485583 DOI: 10.4161/15384101.2014.952967] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Mammalian oocyte maturation is distinguished by asymmetric division that is regulated primarily by cytoskeleton, including microtubules and microfilaments. Small Rho GTPase RhoA is a key regulator of cytoskeletal organization which regulates cell polarity, migration, and division. In this study, we investigated the roles of RhoA in mammalian oocyte meiosis and early embryo cleavage. (1) Disrupting RhoA activity or knock down the expression of RhoA caused the failure of polar body emission. This may have been due to decreased actin assembly and subsequent spindle migration defects. The involvement of RhoA in this process may have been though its regulation of actin nucleators ROCK, p-Cofilin, and ARP2 expression. (2) In addition, spindle morphology was also disrupted and p-MAPK expression decreased in RhoA inhibited or RhoA KD oocytes, which indicated that RhoA also regulated MAPK phosphorylation for spindle formation. (3) Porcine embryo development was also suppressed by inhibiting RhoA activity. Two nuclei were observed in one blastomere, and actin expression was reduced, which indicated that RhoA regulated actin-based cytokinesis of porcine embryo. Thus, our results demonstrated indispensable roles for RhoA in regulating porcine oocyte meiosis and cleavage during early embryo development.
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Affiliation(s)
- Yu Zhang
- a College of Animal Science and Technology , Nanjing Agricultural University , Nanjing , China
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Prasad S, Tiwari M, Koch B, Chaube SK. Morphological, cellular and molecular changes during postovulatory egg aging in mammals. J Biomed Sci 2015; 22:36. [PMID: 25994054 PMCID: PMC4440248 DOI: 10.1186/s12929-015-0143-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 05/01/2015] [Indexed: 11/29/2022] Open
Abstract
Postovulatory aging is associated with several morphological, cellular and molecular changes that deteriorate egg quality either by inducing abortive spontaneous egg activation (SEA) or by egg apoptosis. The reduced egg quality results in poor fertilization rate, embryo quality and reproductive outcome. Although postovulatory aging-induced abortive SEA has been reported in several mammalian species, the molecular mechanism(s) underlying this process remains to be elucidated. The postovulatory aging-induced morphological and cellular changes are characterized by partial cortical granules exocytosis, zona pellucida hardening, exit from metaphase-II (M-II)arrest and initiation of extrusion of second polar body in aged eggs. The molecular changes include reduction of adenosine 3',5'- cyclic monophosphate (cAMP) level, increase of reactive oxygen species (ROS) and thereby cytosolic free calcium (Ca2+) level. Increased levels of cAMP and/or ROS trigger accumulation of Thr-14/Tyr-15 phosphorylated cyclin-dependent kinase 1 (Cdk1) on one hand and degradation of cyclin B1 through ubiquitin-mediated proteolysis on the other hand to destabilize maturation promoting factor (MPF). The destabilized MPF triggers postovulatory aging-induced abortive SEA and limits various assisted reproductive technologies (ARTs) outcome in several mammalian species. Use of certain drugs that can either increase cAMP or reduce ROS level would prevent postovulatory aging-induced deterioration in egg quality so that more number of good quality eggs can be made available to improve ART outcome in mammals including human.
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Affiliation(s)
- Shilpa Prasad
- Cell Physiology Laboratory, Biochemistry Unit, Department of Zoology, Banaras Hindu University, Varanasi, 221005, UP, India.
| | - Meenakshi Tiwari
- Cell Physiology Laboratory, Biochemistry Unit, Department of Zoology, Banaras Hindu University, Varanasi, 221005, UP, India.
| | - Biplob Koch
- Genotoxicology and Cancer Biology Laboratory, Department of Zoology, Banaras Hindu University, Varanasi, 221005, UP, India.
| | - Shail K Chaube
- Cell Physiology Laboratory, Biochemistry Unit, Department of Zoology, Banaras Hindu University, Varanasi, 221005, UP, India.
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Prasad S, Tiwari M, Tripathi A, Pandey AN, Chaube SK. Changes in signal molecules and maturation promoting factor levels associate with spontaneous resumption of meiosis in rat oocytes. Cell Biol Int 2015; 39:759-69. [PMID: 25604742 DOI: 10.1002/cbin.10444] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Accepted: 01/13/2015] [Indexed: 11/11/2022]
Abstract
The present study was aimed to find out changes in signal molecules and maturation promoting factor (MPF) levels during meiotic cell cycle progression from diplotene and metaphase-II (M-II) arrest, a period during which oocyte achieves meiotic competency. Data suggest that high levels of adenosine 3'-5'-cyclic monophosphate (cAMP), guanosine 3'-5'-cyclic monophosphate (cGMP), and nitric oxide (NO) are associated with diplotene arrest, while reduction in their levels correlates with reduced MPF level and meiotic resumption from diplotene arrest. On the other hand, increased intracellular NO, calcium (Ca(2+) ) as well as hydrogen peroxide (H2 O2 ) levels correlate with decreased cAMP, Thr-161 phosphorylated cyclin-dependent kinase-1 (Cdk1) as well as cyclin B1 levels. The decreased Thr-161 phosphorylated Cdk1 and cyclin B1 level reduce MPF level leading to exit from M-II arrest in oocytes cultured in vitro. These data suggest that the decrease of cAMP level and increase of cytosolic free Ca(2+) as well as H2 O2 levels associate with the reduced MPF level and meiotic resumption from diplotene arrest. On the other hand, increase of NO, cGMP, Ca(2+) as well as H2 O2 levels are associated with reduced MPF and spontaneous exit from M-II arrest in rat oocytes cultured in vitro.
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Affiliation(s)
- Shilpa Prasad
- Cell Physiology Laboratory, Biochemistry Unit, Department of Zoology, Banaras Hindu University, Varanasi, 221005, India
| | - Meenakshi Tiwari
- Cell Physiology Laboratory, Biochemistry Unit, Department of Zoology, Banaras Hindu University, Varanasi, 221005, India
| | - Anima Tripathi
- Cell Physiology Laboratory, Biochemistry Unit, Department of Zoology, Banaras Hindu University, Varanasi, 221005, India
| | - Ashutosh N Pandey
- Cell Physiology Laboratory, Biochemistry Unit, Department of Zoology, Banaras Hindu University, Varanasi, 221005, India
| | - Shail K Chaube
- Cell Physiology Laboratory, Biochemistry Unit, Department of Zoology, Banaras Hindu University, Varanasi, 221005, India
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Pandey AN, Chaube SK. A moderate increase of hydrogen peroxide level is beneficial for spontaneous resumption of meiosis from diplotene arrest in rat oocytes cultured in vitro. Biores Open Access 2014; 3:183-91. [PMID: 25126482 PMCID: PMC4120648 DOI: 10.1089/biores.2014.0013] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Hydrogen peroxide (H2O2) acts as a signaling molecule and modulates various aspects of cell functions in a wide variety of cells including mammalian germ cells. We examined whether a decreased level of intra-oocyte cyclic 3′,5′-adenosine monophosphate (cAMP) leads to accumulation of H2O2, and if so, whether a moderate increase of H2O2 inactivates maturation promoting factor (MPF) during spontaneous resumption of meiosis in rat oocytes cultured in vitro. Removal of cumulus cells and culture of denuded oocytes in vitro significantly decreased oocyte cAMP level and led to spontaneous meiotic resumption from diplotene arrest. The reduced oocyte cAMP level was associated with an increased oocyte H2O2 level and reduced catalase activity. Exogenous supplementation of H2O2 induced meiotic resumption from diplotene arrest in a concentration- and time-dependent manner in oocytes treated with 0.1 mM of 3-isobutyl-1-methylxanthine, while dibutyryl-cAMP and 3-t-butyl-4-hydroxyanisole inhibited the stimulatory effect of exogenous H2O2. The increased intra-oocyte H2O2 level induced Thr-14/Tyr-15 phosphorylation of CDK1, while Thr-161 phosphorylated CDK1 and cyclin B1 levels were reduced significantly. These results suggest that a decreased level of intra-oocyte cAMP is associated with an increased level of H2O2. The increased level of H2O2 was associated with high phosphorylation of Thr-14/Tyr-15 and dephosphorylation of the Thr-161 residue of CDK1 and reduced the cyclin B1 level, which eventually inactivated MPF. The MPF inactivation triggered spontaneous resumption of meiosis from diplotene arrest in rat oocytes cultured in vitro.
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Affiliation(s)
- Ashutosh N Pandey
- Cell Physiology Laboratory, Department of Zoology, Banaras Hindu University , Varanasi, India
| | - Shail K Chaube
- Cell Physiology Laboratory, Department of Zoology, Banaras Hindu University , Varanasi, India
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Zhang JY, Dong HS, Oqani RK, Lin T, Kang JW, Jin DI. Distinct roles of ROCK1 and ROCK2 during development of porcine preimplantation embryos. Reproduction 2014; 148:99-107. [DOI: 10.1530/rep-13-0556] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Cell-to-cell contact mediated by cell adhesion is fundamental to the compaction process that ensures blastocyst quality during embryonic development. In this study, we first showed that Rho-associated coiled-coil protein kinases (ROCK1 and ROCK2) were expressed both in porcine oocytes and IVF preimplantation embryos, playing different roles in oocytes maturation and embryo development. The amount of mRNA encoding ROCK1 and the protein concentration clearly increased between the eight-cell and morula stages, but decreased significantly when blastocysts were formed. Conversely, ROCK2 was more abundant in the blastocyst compared with other embryonic stages. Moreover, immunostaining showed that ROCK1 protein distribution changed as the embryo progressed through cleavage and compaction to the morula stage. Initially, the protein was predominantly associated with the plasma membrane but later became cytoplasmic. By contrast, ROCK2 protein was localized in both the cytoplasm and the spindle rotation region during oocyte meiosis, but in the cytoplasm and nucleus as the embryo developed. In addition, ROCK2 was present in the trophectoderm cells of the blastocyst. Treatment with 15 μM Y27632, a specific inhibitor of ROCKs, completely blocked further development of early four-cell stage embryos. Moreover, we did not detect the expression ofROCK1but did detectROCK2expression in blastocysts. Moreover, lysophosphatidic acid an activator of ROCKs significantly improved the rates of blastocyst formation. These data demonstrate that ROCKs are required for embryo development to the blastocyst stage. Together, our results indicate that ROCK1 and ROCK2 may exert different biological functions during the regulation of compaction and in ensuring development of porcine preimplantation embryos to the blastocyst stage.
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Pandey AN, Tripathi A, Premkumar KV, Shrivastav TG, Chaube SK. Reactive oxygen and nitrogen species during meiotic resumption from diplotene arrest in mammalian oocytes. J Cell Biochem 2011; 111:521-8. [PMID: 20568115 DOI: 10.1002/jcb.22736] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Mammalian ovary is metabolically active organ and generates by-products such as reactive oxygen species (ROS) and reactive nitrogen species (RNS) on an extraordinary scale. Both follicular somatic cells as well as oocyte generate ROS and RNS synchronously and their effects are neutralized by intricate array of antioxidants. ROS such as hydrogen peroxide (H(2)O(2)) and RNS such as nitric oxide (NO) act as signaling molecules and modulate various aspects of oocyte physiology including meiotic cell cycle arrest and resumption. Generation of intraoocyte H(2)O(2) can induce meiotic resumption from diplotene arrest probably by the activation of adenosine monophosphate (AMP)-activated protein kinase A (PRKA)-or Ca(2+)-mediated pathway. However, reduced intraoocyte NO level may inactivate guanylyl cyclase-mediated pathway that results in the reduced production of cyclic 3',5'-guanosine monophosphate (cGMP). The reduced level of cGMP results in the activation of cyclic 3',5'-adenosine monophosphate (cAMP)-phosphodiesterase 3A (PDE3A), which hydrolyses cAMP. The reduced intraoocyte cAMP results in the activation of maturation promoting factor (MPF) that finally induces meiotic resumption. Thus, a transient increase of intraoocyte H(2)O(2) level and decrease of NO level may signal meiotic resumption from diplotene arrest in mammalian oocytes.
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Affiliation(s)
- Ashutosh N Pandey
- Cell Physiology Laboratory, Department of Zoology, Banaras Hindu University, Varanasi, 221005 Uttar Pradesh, India
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Elbaz J, Reizel Y, Nevo N, Galiani D, Dekel N. Epithelial cell transforming protein 2 (ECT2) depletion blocks polar body extrusion and generates mouse oocytes containing two metaphase II spindles. Endocrinology 2010; 151:755-65. [PMID: 19996184 DOI: 10.1210/en.2009-0830] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Completion of the first meiosis in oocytes is achieved by the extrusion of the first polar body (PBI), a particular example of cell division. In mitosis, the small GTPase RhoA, which is activated by epithelial cell transforming protein 2 (ECT2), orchestrates contractile ring constriction, thus enabling cytokinesis. However, the involvement of this pathway in mammalian oocytes has not been established. To characterize the role of ECT2 in PBI emission in mouse oocytes, the small interfering RNA approach was employed. We found that ECT2 depletion significantly reduces PBI emission, induces first metaphase arrest, and generates oocytes containing two properly formed spindles of the second metaphase. Moreover, we describe, for the first time, that before PBI emission, RhoA forms a ring that is preceded by a dome-like accumulation at the oocyte cortex, next to the spindle. This unique mode of RhoA translocation failed to occur in the absence of ECT2. We further found that the Rho-dependent kinase, a main RhoA effector, is essential for PBI emission. In addition, we demonstrate herein that ECT2 is subjected to phosphorylation/dephosphorylation throughout meiosis in oocytes and further reveal that PBI emission is temporally associated with ECT2 dephosphorylation. Our data provide the first demonstration that an active cyclin-dependent kinase 1, the catalytic subunit of the maturation-promoting factor, phosphorylates ECT2 during the first meiotic metaphase and that cyclin-dependent kinase 1 inactivation at anaphase allows ECT2 dephosphorylation. In conclusion, our study demonstrates the indispensable role of the maturation-promoting factor/ECT2/RhoA pathway in PBI extrusion in mouse oocytes.
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Affiliation(s)
- Judith Elbaz
- Weizmann Institute of Science, Department of Biological Regulation, Herzel Street 1, Rehovot 76100, Israel
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16
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Zhong ZS, Huo LJ, Liang CG, Chen DY, Sun QY. Small GTPase RhoA is required for ooplasmic segregation and spindle rotation, but not for spindle organization and chromosome separation during mouse oocyte maturation, fertilization, and early cleavage. Mol Reprod Dev 2005; 71:256-61. [PMID: 15791586 DOI: 10.1002/mrd.20253] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
RhoA, a small GTPase, plays versatile roles in many aspects of cell function such as stress fiber formation, cytokinesis, and cell polarization. In this study, we investigated the subcellular localization of RhoA and its possible roles during oocyte maturation and fertilization. RhoA was localized in the cytoplasm of eggs from the germinal vesicle (GV) stage to 2-cell stage, especially concentrating in the midbody of telophase spindle when oocyte extruded PB1 and PB2. The RhoA kinases (ROCKs) specific inhibitor Y-27632 blocked GV breakdown (GVBD) and first polar body extrusion, but did not affect apparatus formation and anaphase/telophase I entry. Anti-RhoA antibody microinjection into the oocytes showed similar results. RhoA inhibitor caused abnormal organization of microfilaments, failure of spindle rotation, PB2 extrusion as well as cleavage furrow formation, while sister chromatid separation was not affected. Microinjection of RhoA antibody also blocked PB2 emission. Our findings indicate that RhoA, by regulating microfilament organization, regulates several important events including GVBD, polar body emission, spindle rotation, and cleavage.
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Affiliation(s)
- Zhi-Sheng Zhong
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
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17
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Covián-Nares F, Martínez-Cadena G, López-Godínez J, Voronina E, Wessel GM, García-Soto J. A Rho-signaling pathway mediates cortical granule translocation in the sea urchin oocyte. Mech Dev 2004; 121:225-35. [PMID: 15003626 DOI: 10.1016/j.mod.2004.01.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2003] [Revised: 01/13/2004] [Accepted: 01/23/2004] [Indexed: 11/27/2022]
Abstract
Cortical granules are secretory vesicles of the egg that play a fundamental role in preventing polyspermy at fertilization. In the sea urchin egg, they localize directly beneath the plasma membrane forming a compact monolayer and, upon fertilization, undergo a Ca(2+)-dependent exocytosis. Cortical granules form during early oogenesis and, during maturation, translocate from the cytosol to the oocyte cortex in a microfilament-mediated process. We tested the hypothesis that these cortical granule dynamics were regulated by Rho, a GTPase of the Ras superfamily. We observed that Rho is synthesized early in oogenesis, mainly in a soluble form. At the end of maturation, however, Rho associates with cortical granules. Inhibition of Rho with the C3 transferase from C. botulinum blocks cortical granule translocation and microfilaments undergo a significant disorganization. A similar effect is observed by GGTI-286, a geranylgeranyl transferase inhibitor, suggesting that the association of Rho with the cortical granules is indispensable for its function. In contrast, the anchorage of the cortical granules in the cortex, as well as their fusion at fertilization, are Rho-independent processes. We conclude that Rho association with the cortical granules is a critical regulatory step in their translocation to the egg cortex.
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Affiliation(s)
- Fernando Covián-Nares
- Instituto de Investigación en Biología Experimental, Facultad de Química, Universidad de Guanajuato, Col. Noria Alta, Guanajuato, Gto 3600, A.P. 187, Mexico
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18
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Kim SW, Lee ZW, Lee C, Im KS, Ha KS. The role of tissue transglutaminase in the germinal vesicle breakdown of mouse oocytes. Biochem Biophys Res Commun 2001; 286:229-34. [PMID: 11500025 DOI: 10.1006/bbrc.2001.5381] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We have investigated the novel function of tissue transglutaminase (tTG) in the germinal vesicle breakdown (GVBD) of mouse oocyte. tTG was identified in ooplasm and germinal vesicle by immunostaining with less amount in germinal vesicle. Spontaneous maturation of the oocytes elevated in situ activity of tTG by over 2.5-fold at 3 h, which was determined by a confocal microscopic assay. However, incubation with monodansylcadaverine (MDC), a tTG inhibitor, blocked the activation of tTG. The possible role of tTG in GVBD was investigated by the use of two tTG inhibitors, MDC and cystamine. MDC largely inhibited the GVBD by a concentration-dependent manner. GV-stage oocytes were matured to the GVBD stage by 78% at 3 h in the normal culture condition. However, in the oocytes incubated with MDC for 3 h, the GVBD rates were 43 and 11% by 50 and 100 microM, respectively. MDC also blocked the entry of 70 kDa RITC-dextran from the ooplasm to the compartment of germinal vesicle, indicating a possible inhibition of nuclear pore disassembly by MDC. The role of tTG in GVBD was further investigated by microinjection with cystamine. The control oocytes, injected with DPBS, showed about 80% of GVBD at 3 h. But the oocytes injected with cystamine showed 15% of GVBD at 3 h and a little higher rate at 6 h. In addition, the inhibition of GVBD maturation by MDC was reversible by washing. These results suggested that tTG was involved in the early event of mouse oocyte maturation.
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Affiliation(s)
- S W Kim
- Biomolecule Research Team, Korea Basic Science Institute, Taejon, 305-333, Korea
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