1
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Homer HA. Understanding oocyte ageing. Minerva Obstet Gynecol 2024; 76:284-292. [PMID: 38536027 DOI: 10.23736/s2724-606x.24.05343-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/29/2024]
Abstract
Females are born with a finite and non-renewable reservoir of oocytes, which therefore decline both in number and quality with advancing age. A striking characteristic of oocyte quality is that "ageing" effects manifest whilst women are in their thirties and are therefore still chronologically and physically young. Furthermore, this decline is unrelenting and not modifiable to any great extent by lifestyle or diet. Since oocyte quality is rate-limiting for pregnancy success, as the proportion of good-quality oocytes progressively deteriorate, the chance of successful pregnancy during each 6-12-month period also decreases, becoming exponential after 37 years. Unlike oocyte quality, age-related attrition in the size of the ovarian reservoir is less impactful for natural fertility since only one mature oocyte is typically ovulated per menstrual cycle. In contrast, oocyte numbers are pivotal for in-vitro fertilization success, since larger numbers enable better-quality oocytes to be found and is important for buffering the inefficiencies of the IVF process. The ageing trajectory is accelerated in ~10% of women, so-called premature ovarian ageing, with ~1% of women at the extreme end of this spectrum with loss of ovarian function occurring before 40 years of age, termed premature ovarian insufficiency. The aim of this review was to analyze how ageing impacts the size and quality of the oocyte pool along with emerging interventions for combating low oocyte numbers and improving quality.
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Affiliation(s)
- Hayden A Homer
- Queensland Fertility Group, Christopher Chen Oocyte Biology Research Laboratory, UQ Center for Clinical Research, The University of Queensland, Brisbane, Australia -
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2
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Pan MH, Zhang KH, Wu SL, Pan ZN, Sun MH, Li XH, Ju JQ, Luo SM, Ou XH, Sun SC. FMNL2 regulates actin for endoplasmic reticulum and mitochondria distribution in oocyte meiosis. eLife 2024; 12:RP92732. [PMID: 38747713 PMCID: PMC11095938 DOI: 10.7554/elife.92732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/18/2024] Open
Abstract
During mammalian oocyte meiosis, spindle migration and asymmetric cytokinesis are unique steps for the successful polar body extrusion. The asymmetry defects of oocytes will lead to the failure of fertilization and embryo implantation. In present study, we reported that an actin nucleating factor Formin-like 2 (FMNL2) played critical roles in the regulation of spindle migration and organelle distribution in mouse and porcine oocytes. Our results showed that FMNL2 mainly localized at the oocyte cortex and periphery of spindle. Depletion of FMNL2 led to the failure of polar body extrusion and large polar bodies in oocytes. Live-cell imaging revealed that the spindle failed to migrate to the oocyte cortex, which caused polar body formation defects, and this might be due to the decreased polymerization of cytoplasmic actin by FMNL2 depletion in the oocytes of both mice and pigs. Furthermore, mass spectrometry analysis indicated that FMNL2 was associated with mitochondria and endoplasmic reticulum (ER)-related proteins, and FMNL2 depletion disrupted the function and distribution of mitochondria and ER, showing with decreased mitochondrial membrane potential and the occurrence of ER stress. Microinjecting Fmnl2-EGFP mRNA into FMNL2-depleted oocytes significantly rescued these defects. Thus, our results indicate that FMNL2 is essential for the actin assembly, which further involves into meiotic spindle migration and ER/mitochondria functions in mammalian oocytes.
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Affiliation(s)
- Meng-Hao Pan
- College of Animal Science and Technology, Nanjing Agricultural UniversityNanjingChina
- College of Veterinary Medicine, Northwest A&F UniversityShaanxiChina
| | - Kun-Huan Zhang
- College of Animal Science and Technology, Nanjing Agricultural UniversityNanjingChina
| | - Si-Le Wu
- College of Animal Science and Technology, Nanjing Agricultural UniversityNanjingChina
| | - Zhen-Nan Pan
- College of Animal Science and Technology, Nanjing Agricultural UniversityNanjingChina
| | - Ming-Hong Sun
- College of Animal Science and Technology, Nanjing Agricultural UniversityNanjingChina
| | - Xiao-Han Li
- College of Animal Science and Technology, Nanjing Agricultural UniversityNanjingChina
| | - Jia-Qian Ju
- College of Animal Science and Technology, Nanjing Agricultural UniversityNanjingChina
| | - Shi-Ming Luo
- Fertility Preservation Lab, Reproductive Medicine Center, Guangdong Second Provincial General HospitalGuangzhouChina
| | - Xiang-Hong Ou
- Fertility Preservation Lab, Reproductive Medicine Center, Guangdong Second Provincial General HospitalGuangzhouChina
| | - Shao-Chen Sun
- College of Animal Science and Technology, Nanjing Agricultural UniversityNanjingChina
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3
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Ye Y, Homer HA. A surge in cytoplasmic viscosity triggers nuclear remodeling required for Dux silencing and pre-implantation embryo development. Cell Rep 2024; 43:113917. [PMID: 38446665 DOI: 10.1016/j.celrep.2024.113917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 12/17/2023] [Accepted: 02/16/2024] [Indexed: 03/08/2024] Open
Abstract
Embryonic genome activation (EGA) marks the transition from dependence on maternal transcripts to an embryonic transcriptional program. The precise temporal regulation of gene expression, specifically the silencing of the Dux/murine endogenous retrovirus type L (MERVL) program during late 2-cell interphase, is crucial for developmental progression in mouse embryos. How this finely tuned regulation is achieved within this specific window is poorly understood. Here, using particle-tracking microrheology throughout the mouse oocyte-to-embryo transition, we identify a surge in cytoplasmic viscosity specific to late 2-cell interphase brought about by high microtubule and endomembrane density. Importantly, preventing the rise in 2-cell viscosity severely impairs nuclear reorganization, resulting in a persistently open chromatin configuration and failure to silence Dux/MERVL. This, in turn, derails embryo development beyond the 2- and 4-cell stages. Our findings reveal a mechanical role of the cytoplasm in regulating Dux/MERVL repression via nuclear remodeling during a temporally confined period in late 2-cell interphase.
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Affiliation(s)
- Yunan Ye
- The Christopher Chen Oocyte Biology Research Laboratory, Centre for Clinical Research, The University of Queensland, Herston, QLD 4029, Australia
| | - Hayden Anthony Homer
- The Christopher Chen Oocyte Biology Research Laboratory, Centre for Clinical Research, The University of Queensland, Herston, QLD 4029, Australia.
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4
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Yuen WS, Zhang QH, Bourdais A, Adhikari D, Halet G, Carroll J. Polo-like kinase 1 promotes Cdc42-induced actin polymerization for asymmetric division in oocytes. Open Biol 2023; 13:220326. [PMID: 36883283 PMCID: PMC9993042 DOI: 10.1098/rsob.220326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023] Open
Abstract
Polo-like kinase I (Plk1) is a highly conserved seronine/threonine kinase essential in meiosis and mitosis for spindle formation and cytokinesis. Here, through temporal application of Plk1 inhibitors, we identify a new role for Plk1 in the establishment of cortical polarity essential for highly asymmetric cell divisions of oocyte meiosis. Application of Plk1 inhibitors in late metaphase I abolishes pPlk1 from spindle poles and prevents the induction of actin polymerization at the cortex through inhibition of local recruitment of Cdc42 and Neuronal Wiskott-Aldrich Syndrome protein (N-WASP). By contrast, an already established polar actin cortex is insensitive to Plk1 inhibitors, but if the polar cortex is first depolymerized, Plk1 inhibitors completely prevent its restoration. Thus, Plk1 is essential for establishment but not maintenance of cortical actin polarity. These findings indicate that Plk1 regulates recruitment of Cdc42 and N-Wasp to coordinate cortical polarity and asymmetric cell division.
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Affiliation(s)
- Wai Shan Yuen
- Department of Anatomy and Developmental Biology and Development and Stem Cells Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia
| | - Qing Hua Zhang
- Department of Anatomy and Developmental Biology and Development and Stem Cells Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia
| | - Anne Bourdais
- University of Rennes, CNRS, IGDR - UMR 6290, F-35000 Rennes, France
| | - Deepak Adhikari
- Department of Anatomy and Developmental Biology and Development and Stem Cells Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia
| | - Guillaume Halet
- University of Rennes, CNRS, IGDR - UMR 6290, F-35000 Rennes, France
| | - John Carroll
- Department of Anatomy and Developmental Biology and Development and Stem Cells Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia
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5
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Ye Y, Homer HA. Two‐step nuclear centring by competing microtubule‐ and actin‐based mechanisms in 2‐cell mouse embryos. EMBO Rep 2022; 23:e55251. [DOI: 10.15252/embr.202255251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 09/01/2022] [Accepted: 09/12/2022] [Indexed: 11/07/2022] Open
Affiliation(s)
- Yunan Ye
- The Christopher Chen Oocyte Biology Research Laboratory, Centre for Clinical Research The University of Queensland Herston QLD Australia
| | - Hayden A Homer
- The Christopher Chen Oocyte Biology Research Laboratory, Centre for Clinical Research The University of Queensland Herston QLD Australia
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6
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The oocyte spindle midzone pauses Cdk1 inactivation during fertilization to enable male pronuclear formation and embryo development. Cell Rep 2022; 39:110789. [PMID: 35508138 DOI: 10.1016/j.celrep.2022.110789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 02/21/2022] [Accepted: 04/13/2022] [Indexed: 11/20/2022] Open
Abstract
Inactivation of cyclin-dependent kinase 1 (Cdk1), controlled by cyclin B1 proteolysis, orders events during mitotic exit. Here, we used a FRET biosensor to study Cdk1 activity while simultaneously monitoring anaphase II and pronuclear (PN) formation in live mouse eggs throughout fertilization. We find that Cdk1 inactivation occurs over two phases separated by a 3-h pause, the first induces anaphase II and the second induces PN formation. Although both phases require the inhibitory Cdk1 kinase Wee1B, only the first involves cyclin B1 proteolysis. Enforcing the 3-h pause is critical for providing the delay required for male PN formation and is mediated by spindle midzone-dependent sequestration of Wee1B between the first and second phases. Thus, unlike continuous Cdk1 inactivation driven by cyclin B1 proteolysis during mitotic exit, MII oocytes engineer a physiologically important pause during fertilization involving two different pathways to inactivate Cdk1, only the first of which requires proteolysis.
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7
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Bourdais A, Dehapiot B, Halet G. Cofilin regulates actin network homeostasis and microvilli length in mouse oocytes. J Cell Sci 2021; 134:273797. [PMID: 34841429 DOI: 10.1242/jcs.259237] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 11/18/2021] [Indexed: 11/20/2022] Open
Abstract
How multiple actin networks coexist in a common cytoplasm while competing for a shared pool of monomers is still an ongoing question. This is exemplified by meiotic maturation in the mouse oocyte, which relies on the dynamic remodeling of distinct cortical and cytoplasmic F-actin networks. Here, we show that the conserved actin-depolymerizing factor cofilin is activated in a switch-like manner upon meiosis resumption from prophase arrest. Interfering with cofilin activation during maturation resulted in widespread elongation of microvilli, while cytoplasmic F-actin was depleted, leading to defects in spindle migration and polar body extrusion. In contrast, cofilin inactivation in metaphase II-arrested oocytes resulted in a shutdown of F-actin dynamics, along with a dramatic overgrowth of the polarized actin cap. However, inhibition of the Arp2/3 complex to promote actin cap disassembly elicited ectopic microvilli outgrowth in the polarized cortex. These data establish cofilin as a key player in actin network homeostasis in oocytes and reveal that microvilli can act as a sink for monomers upon disassembly of a competing network.
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Affiliation(s)
- Anne Bourdais
- Institut Génétique et Développement de Rennes , CNRS IGDR UMR 6290, Université de Rennes 1, F-35000 Rennes, France
| | - Benoit Dehapiot
- Institut Génétique et Développement de Rennes , CNRS IGDR UMR 6290, Université de Rennes 1, F-35000 Rennes, France
| | - Guillaume Halet
- Institut Génétique et Développement de Rennes , CNRS IGDR UMR 6290, Université de Rennes 1, F-35000 Rennes, France
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8
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Wang H, Zhu S, Wu X, Liu Y, Ge J, Wang Q, Gu L. NAMPT reduction-induced NAD + insufficiency contributes to the compromised oocyte quality from obese mice. Aging Cell 2021; 20:e13496. [PMID: 34662475 PMCID: PMC8590097 DOI: 10.1111/acel.13496] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 08/14/2021] [Accepted: 09/12/2021] [Indexed: 12/27/2022] Open
Abstract
Maternal obesity is associated with multiple adverse reproductive outcomes, whereas the underlying molecular mechanisms are still not fully understood. Here, we found the reduced nicotinamide phosphoribosyl transferase (NAMPT) expression and lowered nicotinamide adenine dinucleotide (NAD+) content in oocytes from obese mice. Next, by performing morpholino knockdown assay and pharmacological inhibition, we revealed that NAMPT deficiency not only severely disrupts maturational progression and meiotic apparatus, but also induces the metabolic dysfunction in oocytes. Furthermore, overexpression analysis demonstrated that NAMPT insufficiency induced NAD+ loss contributes to the compromised developmental potential of oocytes and early embryos from obese mice. Importantly, in vitro supplement and in vivo administration of nicotinic acid (NA) was able to ameliorate the obesity‐associated meiotic defects and oxidative stress in oocytes. Our results indicate a role of NAMPT in modulating oocyte meiosis and metabolism, and uncover the beneficial effects of NA treatment on oocyte quality from obese mice.
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Affiliation(s)
- Hengjie Wang
- College of Animal Science & Technology Nanjing Agricultural University Nanjing China
| | - Shuai Zhu
- State Key Laboratory of Reproductive Medicine Suzhou Municipal Hospital Nanjing Medical University Nanjing China
| | - Xinghan Wu
- Department of Medical Genetics Maternal and Child Health Hospital of Hunan Province Changsha China
| | - Yuan Liu
- College of Animal Science & Technology Nanjing Agricultural University Nanjing China
| | - Juan Ge
- State Key Laboratory of Reproductive Medicine Suzhou Municipal Hospital Nanjing Medical University Nanjing China
| | - Qiang Wang
- State Key Laboratory of Reproductive Medicine Suzhou Municipal Hospital Nanjing Medical University Nanjing China
| | - Ling Gu
- College of Animal Science & Technology Nanjing Agricultural University Nanjing China
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9
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Greaney J, Subramanian GN, Ye Y, Homer H. Isolation and in vitro Culture of Mouse Oocytes. Bio Protoc 2021; 11:e4104. [PMID: 34458398 DOI: 10.21769/bioprotoc.4104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 04/11/2021] [Accepted: 04/12/2021] [Indexed: 11/02/2022] Open
Abstract
Females are endowed at birth with a fixed reserve of oocytes, which declines both in quantity and quality with advancing age. Understanding the molecular mechanisms regulating oocyte quality is crucial for improving the chances of pregnancy success in fertility clinics. In vitro culture systems enable researchers to analyse important molecular and genetic regulators of oocyte maturation and fertilisation. Here, we describe in detail a highly reproducible technique for the isolation and culture of fully grown mouse oocytes. We include the considerations and precautionary measures required for minimising the detrimental effects of in vitro culture conditions. This technique forms the starting point for a wide range of experimental approaches such as post-transcriptional gene silencing, immunocytochemistry, Western blotting, high-resolution 4D time-lapse imaging, and in vitro fertilization, which are instrumental in dissecting the molecular determinants of oocyte quality. Hence, this protocol serves as a useful, practical guide for any oocyte researcher beginning experiments aimed at investigating important oocyte molecular factors. Graphic abstract: A step-by-step protocol for the isolation and in vitro culture of oocytes from mice.
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Affiliation(s)
- Jessica Greaney
- The Christopher Chen Oocyte Biology Research Laboratory, University of Queensland Centre for Clinical Research, The University of Queensland, Brisbane, Australia
| | - Goutham Narayanan Subramanian
- The Christopher Chen Oocyte Biology Research Laboratory, University of Queensland Centre for Clinical Research, The University of Queensland, Brisbane, Australia
| | - Yunan Ye
- The Christopher Chen Oocyte Biology Research Laboratory, University of Queensland Centre for Clinical Research, The University of Queensland, Brisbane, Australia
| | - Hayden Homer
- The Christopher Chen Oocyte Biology Research Laboratory, University of Queensland Centre for Clinical Research, The University of Queensland, Brisbane, Australia
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10
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Shi F, Feng X. Decabromodiphenyl ethane exposure damaged the asymmetric division of mouse oocytes by inhibiting the inactivation of cyclin-dependent kinase 1. FASEB J 2021; 35:e21449. [PMID: 33724544 DOI: 10.1096/fj.202002585r] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 01/27/2021] [Accepted: 02/01/2021] [Indexed: 11/11/2022]
Abstract
Decabromodiphenyl ethane (DBDPE) is a new brominated flame retardant and is widely added to flammable materials to prevent fire. Because it has been continuously detected in a variety of organisms and humans, it is important to reveal the biological toxicity of DBDPE. However, the influence of DBDPE for female reproduction is unclear. In this study, we investigated whether and how DBDPE exposure affects oocyte development. Female mice as a model were orally exposed to DBDPE by 0, 0.05, 0.5, 5, 50 μg/kg bw/day for 30 days (0.05 μg/kg bw/day is close to the environmental exposure concentration). We found that exposure of mice to DBDPE did not affect the first polar body extrusion (PBE) of oocytes. Strikingly, however, asymmetric division of oocytes was markedly impaired in 5 and 50 μg/kg bw/day DBDPE exposed group, which resulted in oocytes with larger polar bodies (PBs). Then, we further explored and found that DBDPE exposure inhibited the spindle migration and membrane protrusion in oocytes during anaphase of meiosis I (anaphase I), thereby impairing asymmetric division. Additionally, we found that DBDPE exposure suppressed the inactivation of cyclin-dependent kinase 1 (Cdk1), resulting in the decrease of cytoplasmic formin2 (FMN2)-mediated F-actin polymerization in oocytes at the onset of anaphase I. Simultaneously, DBDPE exposure damaged the structural integrity of the spindle and the perpendicular relationship between spindle and cortex. These together led to the failure of spindle migration and membrane protrusion required for oocytes asymmetric division. Finally, DBDPE exposure injured the development of blastocysts, leading to blastocyst apoptosis.
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Affiliation(s)
- Feifei Shi
- College of Life Science, The Key Laboratory of Bioactive Materials, Ministry of Education, State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, China
| | - Xizeng Feng
- College of Life Science, The Key Laboratory of Bioactive Materials, Ministry of Education, State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, China
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11
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Thomas C, Wetherall B, Levasseur MD, Harris RJ, Kerridge ST, Higgins JMG, Davies OR, Madgwick S. A prometaphase mechanism of securin destruction is essential for meiotic progression in mouse oocytes. Nat Commun 2021; 12:4322. [PMID: 34262048 PMCID: PMC8280194 DOI: 10.1038/s41467-021-24554-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 06/24/2021] [Indexed: 11/10/2022] Open
Abstract
Successful cell division relies on the timely removal of key cell cycle proteins such as securin. Securin inhibits separase, which cleaves the cohesin rings holding chromosomes together. Securin must be depleted before anaphase to ensure chromosome segregation occurs with anaphase. Here we find that in meiosis I, mouse oocytes contain an excess of securin over separase. We reveal a mechanism that promotes excess securin destruction in prometaphase I. Importantly, this mechanism relies on two phenylalanine residues within the separase-interacting segment (SIS) of securin that are only exposed when securin is not bound to separase. We suggest that these residues facilitate the removal of non-separase-bound securin ahead of metaphase, as inhibiting this period of destruction by mutating both residues causes the majority of oocytes to arrest in meiosis I. We further propose that cellular securin levels exceed the amount an oocyte is capable of removing in metaphase alone, such that the prometaphase destruction mechanism identified here is essential for correct meiotic progression in mouse oocytes.
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Affiliation(s)
- Christopher Thomas
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK. .,Max Planck Institute for Biophysical Chemistry, Gottingen, Germany.
| | - Benjamin Wetherall
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Mark D Levasseur
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Rebecca J Harris
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Scott T Kerridge
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Jonathan M G Higgins
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Owen R Davies
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK.,Institute of Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, Edinburgh, UK
| | - Suzanne Madgwick
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK.
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12
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Homer HA. Senataxin: A New Guardian of the Female Germline Important for Delaying Ovarian Aging. Front Genet 2021; 12:647996. [PMID: 33995483 PMCID: PMC8118517 DOI: 10.3389/fgene.2021.647996] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 04/08/2021] [Indexed: 12/01/2022] Open
Abstract
Early decline in ovarian function known as premature ovarian aging (POA) occurs in around 10% of women and is characterized by a markedly reduced ovarian reserve. Premature ovarian insufficiency (POI) affects ~1% of women and refers to the severe end of the POA spectrum in which, accelerated ovarian aging leads to menopause before 40 years of age. Ovarian reserve refers to the total number of follicle-enclosed oocytes within both ovaries. Oocyte DNA integrity is a critical determinant of ovarian reserve since damage to DNA of oocytes within primordial-stage follicles triggers follicular apoptosis leading to accelerated follicle depletion. Despite the high prevalence of POA, very little is known regarding its genetic causation. Another little-investigated aspect of oocyte DNA damage involves low-grade damage that escapes apoptosis at the primordial follicle stage and persists throughout oocyte growth and later follicle development. Senataxin (SETX) is an RNA/DNA helicase involved in repair of oxidative stress-induced DNA damage and is well-known for its roles in preventing neurodegenerative disease. Recent findings uncover an important role for SETX in protecting oocyte DNA integrity against aging-induced increases in oxidative stress. Significantly, this newly identified SETX-mediated regulation of oocyte DNA integrity is critical for preventing POA and early-onset female infertility by preventing premature depletion of the ovarian follicular pool and reducing the burden of low-grade DNA damage both in primordial and fully-grown oocytes.
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Affiliation(s)
- Hayden A Homer
- The Christopher Chen Oocyte Biology Research Laboratory, UQ Centre for Clinical Research, The University of Queensland, Herston, QLD, Australia
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13
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Subramanian GN, Lavin M, Homer HA. Premature ovarian ageing following heterozygous loss of Senataxin. Mol Hum Reprod 2021; 27:gaaa080. [PMID: 33337500 DOI: 10.1093/molehr/gaaa080] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Revised: 11/09/2020] [Indexed: 12/21/2022] Open
Abstract
Premature loss of ovarian activity before 40 years of age is known as primary ovarian insufficiency (POI) and occurs in ∼1% of women. A more subtle decline in ovarian activity, known as premature ovarian ageing (POA), occurs in ∼10% of women. Despite the high prevalence of POA, very little is known regarding its genetic causation. Senataxin (SETX) is an RNA/DNA helicase involved in repair of oxidative stress-induced DNA damage. Homozygous mutation of SETX leads to the neurodegenerative disorder, ataxia oculomotor apraxia type 2 (AOA2). There have been reports of POI in AOA2 females suggesting a link between SETX and ovarian ageing. Here, we studied female mice lacking either one (Setx+/-) or both (Setx-/-) copies of SETX over a 12- to 14-month period. We find that DNA damage is increased in oocytes from 8-month-old Setx+/- and Setx-/- females compared with Setx+/+ oocytes leading to a marked reduction in all classes of ovarian follicles at least 4 months earlier than typically occurs in female mice. Furthermore, during a 12-month long mating trial, Setx+/- and Setx-/- females produced significantly fewer pups than Setx+/+ females from 7 months of age onwards. These data show that SETX is critical for preventing POA in mice, likely by preserving DNA integrity in oocytes. Intriguingly, heterozygous Setx loss causes an equally severe impact on ovarian ageing as homozygous Setx loss. Because heterozygous SETX disruption is less likely to produce systemic effects, SETX compromise could underpin some cases of insidious POA.
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Affiliation(s)
- G N Subramanian
- The Christopher Chen Oocyte Biology Research Laboratory, UQ Centre for Clinical Research, The University of Queensland, Herston, QLD, Australia
| | - M Lavin
- Cancer and Neuroscience Laboratory, UQ Centre for Clinical Research, The University of Queensland, Herston, QLD, Australia
| | - H A Homer
- The Christopher Chen Oocyte Biology Research Laboratory, UQ Centre for Clinical Research, The University of Queensland, Herston, QLD, Australia
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14
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Subramanian GN, Greaney J, Wei Z, Becherel O, Lavin M, Homer HA. Oocytes mount a noncanonical DNA damage response involving APC-Cdh1-mediated proteolysis. J Cell Biol 2020; 219:151594. [PMID: 32328643 PMCID: PMC7147104 DOI: 10.1083/jcb.201907213] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 12/15/2019] [Accepted: 01/31/2020] [Indexed: 12/26/2022] Open
Abstract
In mitotic cells, DNA damage induces temporary G2 arrest via inhibitory Cdk1 phosphorylation. In contrast, fully grown G2-stage oocytes readily enter M phase immediately following chemical induction of DNA damage in vitro, indicating that the canonical immediate-response G2/M DNA damage response (DDR) may be deficient. Senataxin (Setx) is involved in RNA/DNA processing and maintaining genome integrity. Here we find that mouse oocytes deleted of Setx accumulate DNA damage when exposed to oxidative stress in vitro and during aging in vivo, after which, surprisingly, they undergo G2 arrest. Moreover, fully grown wild-type oocytes undergo G2 arrest after chemotherapy-induced in vitro damage if an overnight delay is imposed following damage induction. Unexpectedly, this slow-evolving DDR is not mediated by inhibitory Cdk1 phosphorylation but by APC-Cdh1–mediated proteolysis of the Cdk1 activator, cyclin B1, secondary to increased Cdc14B-dependent APC-Cdh1 activation and reduced Emi1-dependent inhibition. Thus, oocytes are unable to respond immediately to DNA damage, but instead mount a G2/M DDR that evolves slowly and involves a phosphorylation-independent proteolytic pathway.
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Affiliation(s)
- Goutham Narayanan Subramanian
- The Christopher Chen Oocyte Biology Research Laboratory, University of Queensland Centre for Clinical Research, The University of Queensland, Queensland, Australia
| | - Jessica Greaney
- The Christopher Chen Oocyte Biology Research Laboratory, University of Queensland Centre for Clinical Research, The University of Queensland, Queensland, Australia
| | - Zhe Wei
- The Christopher Chen Oocyte Biology Research Laboratory, University of Queensland Centre for Clinical Research, The University of Queensland, Queensland, Australia
| | - Olivier Becherel
- Cancer and Neurosciences Lab, University of Queensland Centre for Clinical Research, The University of Queensland, Queensland, Australia
| | - Martin Lavin
- Cancer and Neurosciences Lab, University of Queensland Centre for Clinical Research, The University of Queensland, Queensland, Australia
| | - Hayden Anthony Homer
- The Christopher Chen Oocyte Biology Research Laboratory, University of Queensland Centre for Clinical Research, The University of Queensland, Queensland, Australia
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15
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Iljas JD, Wei Z, Homer HA. Sirt1 sustains female fertility by slowing age-related decline in oocyte quality required for post-fertilization embryo development. Aging Cell 2020; 19:e13204. [PMID: 32729989 PMCID: PMC7511857 DOI: 10.1111/acel.13204] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 06/21/2020] [Accepted: 07/07/2020] [Indexed: 02/06/2023] Open
Abstract
The NAD+‐dependent sirtuin deacetylase, Sirt1, regulates key transcription factors strongly implicated in ageing and lifespan. Due to potential confounding effects secondary to loss of Sirt1 function from the soma in existing whole‐animal mutants, the in vivo role of Sirt1 in oocytes (oocyte‐Sirt1) for female fertility remains unknown. We deleted Sirt1 specifically in growing oocytes and study how loss of oocyte‐Sirt1 affects a comprehensive range of female reproductive parameters including ovarian follicular reservoir, oocyte maturation, oocyte mitochondrial abundance, oxidative stress, fertilization, embryo development and fertility during ageing. Surprisingly, eliminating this key sirtuin from growing oocytes has no effect in young females. During a 10‐month‐long breeding trial, however, we find that 50% of females lacking oocyte‐Sirt1 become prematurely sterile between 9 and 11 months of age when 100% of wild‐type females remain fertile. This is not due to an accelerated age‐related decline in oocyte numbers in the absence of oocyte‐Sirt1 but to reduced oocyte developmental competence or quality. Compromised oocyte quality does not impact in vivo oocyte maturation or fertilization but leads to increased oxidative stress in preimplantation embryos that inhibits cleavage divisions. Our data suggest that defects emerge in aged females lacking oocyte‐Sirt1 due to concurrent age‐related changes such as reduced NAD+ and sirtuin expression levels, which compromise compensatory mechanisms that can cover for Sirt1 loss in younger oocytes. In contrast to evidence that increasing Sirt1 activity delays ageing, our data provide some of the only in vivo evidence that loss of Sirt1 induces premature ageing.
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Affiliation(s)
- Juvita D. Iljas
- The Christopher Chen Oocyte Biology Research Laboratory Centre for Clinical Research The University of Queensland Herston Qld Australia
| | - Zhe Wei
- The Christopher Chen Oocyte Biology Research Laboratory Centre for Clinical Research The University of Queensland Herston Qld Australia
| | - Hayden A. Homer
- The Christopher Chen Oocyte Biology Research Laboratory Centre for Clinical Research The University of Queensland Herston Qld Australia
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16
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Mechanical regulation of cell size, fate, and behavior during asymmetric cell division. Curr Opin Cell Biol 2020; 67:9-16. [PMID: 32768924 DOI: 10.1016/j.ceb.2020.07.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 06/15/2020] [Accepted: 07/06/2020] [Indexed: 01/03/2023]
Abstract
Asymmetric cell division (ACD) is an evolutionary conserved mechanism used by prokaryotes and eukaryotes alike to generate cell diversity. ACD can be manifested in biased segregation of macromolecules or differential partitioning of cell organelles. Cells are also constantly subject to extrinsic or intrinsic mechanical forces, influencing cell behavior and fate. During ACD, cell intrinsic forces generated through the spatiotemporal regulation of the actomyosin cytoskeleton can influence sibling cell size. External mechanical stresses are further translated by transcriptional coactivators or mechanically gated ion channels. Here, we will discuss recent literature, exploring how mechanical cues influence various aspects of ACD and stem cell behavior, and how these mechanical cues contribute to cell fate decisions.
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17
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Nampt-mediated spindle sizing secures a post-anaphase increase in spindle speed required for extreme asymmetry. Nat Commun 2020; 11:3393. [PMID: 32636388 PMCID: PMC7341875 DOI: 10.1038/s41467-020-17088-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 06/09/2020] [Indexed: 12/21/2022] Open
Abstract
Meiotic divisions in oocytes are extremely asymmetric and require pre- and post-anaphase-onset phases of spindle migration. The latter induces membrane protrusion that is moulded around the spindle thereby reducing cytoplasmic loss. Here, we find that depleting the NAD biosynthetic enzyme, nicotinamide phosphoribosyl-transferase (Nampt), in mouse oocytes results in markedly longer spindles and compromises asymmetry. By analysing spindle speed in live oocytes, we identify a striking and transient acceleration after anaphase-onset that is severely blunted following Nampt-depletion. Slow-moving midzones of elongated spindles induce cortical furrowing deep within the oocyte before protrusions can form, altogether resulting in larger oocyte fragments being cleaved off. Additionally, we find that Nampt-depletion lowers NAD and ATP levels and that reducing NAD using small molecule Nampt inhibitors also compromises asymmetry. These data show that rapid midzone displacement is critical for extreme asymmetry by delaying furrowing to enable protrusions to form and link metabolic status to asymmetric division. Meiotic cell division in oocytes is asymmetric and requires microtubule spindle migration after anaphase-onset. Here, the authors show that Nampt, an enzyme of the Nicotinamide adenine dinucleotide (NAD) biosynthetic pathway, contributes to post-anaphase spindle migration and oocyte division asymmetry by controlling spindle length.
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18
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Kimata Y, Leturcq M, Aradhya R. Emerging roles of metazoan cell cycle regulators as coordinators of the cell cycle and differentiation. FEBS Lett 2020; 594:2061-2083. [PMID: 32383482 DOI: 10.1002/1873-3468.13805] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 04/17/2020] [Accepted: 04/20/2020] [Indexed: 01/10/2023]
Abstract
In multicellular organisms, cell proliferation must be tightly coordinated with other developmental processes to form functional tissues and organs. Despite significant advances in our understanding of how the cell cycle is controlled by conserved cell-cycle regulators (CCRs), how the cell cycle is coordinated with cell differentiation in metazoan organisms and how CCRs contribute to this process remain poorly understood. Here, we review the emerging roles of metazoan CCRs as intracellular proliferation-differentiation coordinators in multicellular organisms. We illustrate how major CCRs regulate cellular events that are required for cell fate acquisition and subsequent differentiation. To this end, CCRs employ diverse mechanisms, some of which are separable from those underpinning the conventional cell-cycle-regulatory functions of CCRs. By controlling cell-type-specific specification/differentiation processes alongside the progression of the cell cycle, CCRs enable spatiotemporal coupling between differentiation and cell proliferation in various developmental contexts in vivo. We discuss the significance and implications of this underappreciated role of metazoan CCRs for development, disease and evolution.
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Affiliation(s)
- Yuu Kimata
- School of Life Science and Technology, ShanghaiTech University, China
| | - Maïté Leturcq
- School of Life Science and Technology, ShanghaiTech University, China
| | - Rajaguru Aradhya
- School of Biotechnology, Amrita Vishwa Vidyapeetham, Kollam, Kerala, India
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19
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Yang CX, Wang PC, Liu S, Miao JK, Liu XM, Miao YL, Du ZQ. Long noncoding RNA 2193 regulates meiosis through global epigenetic modification and cytoskeleton organization in pig oocytes. J Cell Physiol 2020; 235:8304-8318. [PMID: 32239703 DOI: 10.1002/jcp.29675] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Accepted: 03/10/2020] [Indexed: 12/13/2022]
Abstract
Long noncoding RNAs (lncRNAs) regulate a variety of physiological and pathological processes. However, the biological function of lncRNAs in mammalian germ cells remains largely unexplored. Here we identified one novel lncRNA (lncRNA2193) from single-cell RNA sequencing performed on porcine oocytes and investigated its function in oocyte meiosis. During in vitro maturation (IVM), from germinal vesicle (GV, 0 hr), GV breakdown (GVBD, 24 hr), to metaphase II stage (MII, 44 hr), the transcriptional abundance of lncRNA2193 remained stable and high. LncRNA2193 interference by small interfering RNA microinjection into porcine GV oocytes could significantly inhibit rates of GVBD and the first polar body extrusion, but enhance the rates of oocytes with a nuclear abnormality. Moreover, lncRNA2193 knockdown disturbed cytoskeletal organization (F-actin and spindle), and decreased DNA 5-methylcytosine (5mC) and histone trimethylation (H3K4me3, H3K9me3, H3K27me3, and H3K36me3) levels. The lncRNA2193 downregulation induced a decrease of 5mC level could be partially due to the reduction of DNA methyltransferase 3A and 3B, and the elevation of 5mC-hydroxylase ten-11 translocation 2 (TET2). After parthenogenetic activation of MII oocytes, parthenotes exhibited higher fragmentation but lower cleavage rates in the lncRNA2193 downregulated group. However, lncRNA2193 interference performed on mature MII oocytes and parthenotes at 1-cell stage did not affect the cleavage and blasctocyst rates of pathenotes. Taken together, lncRNA2193 plays an important role in porcine oocyte maturation, providing more insights for relevant investigations on mammalian germ cells.
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Affiliation(s)
- Cai-Xia Yang
- College of Animal Science, Yangtze University, Jingzhou, Hubei, China.,College of Animal Science and Technology, Northeast Agricultural University, Harbin, Heilongjiang, China
| | - Pei-Chao Wang
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, Heilongjiang, China
| | - Shuai Liu
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, Heilongjiang, China
| | - Jia-Kun Miao
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, Heilongjiang, China
| | - Xiao-Man Liu
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, Heilongjiang, China
| | - Yi-Liang Miao
- Institute of Stem Cell and Regenerative Biology, College of Animal Science and Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Zhi-Qiang Du
- College of Animal Science, Yangtze University, Jingzhou, Hubei, China.,College of Animal Science and Technology, Northeast Agricultural University, Harbin, Heilongjiang, China
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20
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Iljas JD, Homer HA. Sirt3 is dispensable for oocyte quality and female fertility in lean and obese mice. FASEB J 2020; 34:6641-6653. [PMID: 32212196 DOI: 10.1096/fj.202000153r] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 03/03/2020] [Accepted: 03/11/2020] [Indexed: 12/20/2022]
Abstract
Mammalian oocytes rely heavily on mitochondrial oxidative phosphorylation (OXPHOS) for generating ATP. However, mitochondria are also the primary source of damaging reactive oxygen species (ROS). Mitochondrial de-regulation, therefore, underpins poor oocyte quality associated with conditions such as obesity and aging. The mitochondrial sirtuin, Sirt3, is critical for mitochondrial respiration and redox regulation. Interestingly, however, Sirt3 knockout (Sirt3-/- ) mice do not exhibit systemic compromise under basal conditions, only doing so under stressed conditions such as high-fat diet (HFD)-induced obesity. Mouse oocytes depleted of Sirt3 exhibit increased ROS in vitro, but it is unknown whether Sirt3 is necessary for female fertility in vivo. Here, we test this for the first time by investigating ovarian follicular reserve, oocyte maturation (including detailed spindle assembly and chromosome segregation), and female fertility in Sirt3-/- females. We find that under basal conditions, young Sirt3-/- females exhibit no defects in any parameters. Surprisingly, all parameters also remain intact following HFD-induced obesity. Despite markedly increased ROS levels in HFD Sirt3-/- oocytes, ATP levels nevertheless remain normal. Our data support that ATP is sustained in vivo through increased mitochondrial mass possibly secondary to compensatory upregulation of another sirtuin, Sirt1, which has overlapping functions with Sirt3.
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Affiliation(s)
- Juvita D Iljas
- The Christopher Chen Oocyte Biology Research Laboratory, Centre for Clinical Research, The University of Queensland, Herston, QLD, Australia
| | - Hayden A Homer
- The Christopher Chen Oocyte Biology Research Laboratory, Centre for Clinical Research, The University of Queensland, Herston, QLD, Australia
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21
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Astbury P, Subramanian GN, Greaney J, Roling C, Irving J, Homer HA. The Presence of Immature GV- Stage Oocytes during IVF/ICSI Is a Marker of Poor Oocyte Quality: A Pilot Study. Med Sci (Basel) 2020; 8:medsci8010004. [PMID: 31963146 PMCID: PMC7151566 DOI: 10.3390/medsci8010004] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 01/06/2020] [Accepted: 01/13/2020] [Indexed: 12/13/2022] Open
Abstract
Here we investigate whether the presence of germinal vesicle-stage oocytes (GV- oocytes) reflects poor oocyte developmental competence (or quality). This was a prospective, non-randomised, cohort pilot-study involving 60 patients undergoing in vitro fertilization/ intracytoplasmic sperm injection for whom complete pregnancy outcome data were available. Patients in whom GV- oocytes were retrieved (GV+) at transvaginal oocyte retrieval (TVOR) were compared with those from whom no GVs were retrieved (GV-). We found that GV+ (n = 29) and GV- (n = 31) patients were similarly aged (35.4 vs. 36.4 years; p = 0.446). GV+ patients had a mean of 2.41 ± 2.03 GVs and comparable yields of MII oocytes to GV- patients (11 ± 6.88 vs. 8.26 ± 4.84; p = 0.077). Compared with GV- patients, GV+ patients had markedly lower implantation rates (11.8% vs. 30.2%; p = 0.022) as well as oocyte utilisation rates for clinical pregnancy (2.3% vs. 6.8%; p = 0.018) and live-birth (1.9% vs. 5.7%; p = 0.029). DNA damage levels measured using γH2AX immunostaining were not different in oocytes from women <36 years versus those ≥36 years (p = 0.606). Thus, patients who have GV- stage oocytes at TVOR exhibit poor oocyte quality reflected in reduced per-oocyte pregnancy success rates and uniformly high levels of oocyte DNA damage.
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Affiliation(s)
- Pia Astbury
- Christopher Chen Oocyte Biology Research Laboratory, UQ Centre for Clinical Research, The University of Queensland, Herston 4029, Queensland, Australia
- Queensland Fertility Group, Brisbane 4000, Queensland, Australia
| | - Goutham N. Subramanian
- Christopher Chen Oocyte Biology Research Laboratory, UQ Centre for Clinical Research, The University of Queensland, Herston 4029, Queensland, Australia
| | - Jessica Greaney
- Christopher Chen Oocyte Biology Research Laboratory, UQ Centre for Clinical Research, The University of Queensland, Herston 4029, Queensland, Australia
| | - Chris Roling
- Queensland Fertility Group, Brisbane 4000, Queensland, Australia
| | - Jacqui Irving
- Queensland Fertility Group, Brisbane 4000, Queensland, Australia
| | - Hayden A. Homer
- Christopher Chen Oocyte Biology Research Laboratory, UQ Centre for Clinical Research, The University of Queensland, Herston 4029, Queensland, Australia
- Queensland Fertility Group, Brisbane 4000, Queensland, Australia
- Reproductive Endocrinology & Infertility Clinic, Royal Brisbane & Women’s Hospital, Brisbane 4029, Queensland, Australia
- Correspondence:
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22
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Zhou C, Hancock JL, Khanna KK, Homer HA. First meiotic anaphase requires Cep55-dependent inhibitory cyclin-dependent kinase 1 phosphorylation. J Cell Sci 2019; 132:jcs.233379. [PMID: 31427428 DOI: 10.1242/jcs.233379] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 08/09/2019] [Indexed: 12/28/2022] Open
Abstract
During mitosis, anaphase is triggered by anaphase-promoting complex (APC)-mediated destruction of securin and cyclin B1, which leads to inactivation of cyclin-dependent kinase 1 (Cdk1). By regulating APC activity, the mitotic spindle assembly checkpoint (SAC) therefore has robust control over anaphase timing to prevent chromosome mis-segregation. Mammalian oocytes are prone to aneuploidy, the reasons for which remain obscure. In mitosis, Cep55 is required post-anaphase for the final steps of cytokinesis. We found that Cep55-depleted mouse oocytes progress normally through early meiosis I, but that anaphase I fails as a result of persistent Cdk1 activity. Unexpectedly, Cdk1 inactivation was compromised following Cep55 depletion, despite on-time SAC silencing and intact APC-mediated proteolysis. We found that impaired Cdk1 inactivation was caused by inadequate inhibitory Cdk1 phosphorylation consequent upon failure to suppress Cdc25 phosphatase, identifying a proteolysis-independent step necessary for anaphase I. Thus, the SAC in oocytes does not exert exclusive control over anaphase I initiation, providing new insight into vulnerability to error.
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Affiliation(s)
- Chenxi Zhou
- The Christopher Chen Oocyte Biology Research Laboratory, UQ Centre for Clinical Research, The University of Queensland, Herston 4029, QLD, Australia
| | - Janelle L Hancock
- Signal Transduction Laboratory, QIMR Berghofer Medical Research Institute, Herston, QLD, Australia
| | - Kum Kum Khanna
- Signal Transduction Laboratory, QIMR Berghofer Medical Research Institute, Herston, QLD, Australia
| | - Hayden A Homer
- The Christopher Chen Oocyte Biology Research Laboratory, UQ Centre for Clinical Research, The University of Queensland, Herston 4029, QLD, Australia
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23
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Gao L, Du M, Zhuan Q, Luo Y, Li J, Hou Y, Zeng S, Zhu S, Fu X. Melatonin rescues the aneuploidy in mice vitrified oocytes by regulating mitochondrial heat product. Cryobiology 2019; 89:68-75. [PMID: 31082378 DOI: 10.1016/j.cryobiol.2019.05.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Revised: 05/06/2019] [Accepted: 05/07/2019] [Indexed: 01/13/2023]
Abstract
Vitrification of germinal vesicle (GV) stage oocytes has been shown to be closely associated with decreased rates of meiosis maturation and increased rates of aneuploidy. However, little is known about the effects of melatonin on these events in mice vitrified GV oocytes. In this study, the effects of melatonin on meiosis maturation potential and the incidence rate of aneuploidy in mouse vitrified oocytes were analyzed by supplementing in vitro maturation (IVM) solution with melatonin at different concentrations. This study, for the first time, showed that the mitochondrial heat production was markedly increased in vitrified oocytes (P < 0.05), which compromised the first polar body extrusion (PBE) of vitrified oocytes (73.3% vs. 85.1%, P < 0.05). However, 10-11 mol/L melatonin could significantly decrease mitochondrial heat production and ROS level (9.1 vs. 12.0 pixels, P < 0.05), meanwhile increase ATP level (1.1 vs. 0.88 pmol, P < 0.05) and mtDNA copies (107438 vs. 67869, P < 0.05), which rescued the abnormal chromosome alignment (32% vs. 69%, P < 0.05) and reduced the incidence of aneuploidy (15.6% vs. 38.5%, P < 0.05) in vitrified oocytes. The meiosis maturation ability of vitrified oocytes with melatonin supplementation was similar to that of fresh ones (83.4% vs. 85.1%, P > 0.05). Collectively, our data revealed that melatonin has a protective action against vitrification-induced injuries of oocytes meiosis maturation.
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Affiliation(s)
- Lei Gao
- National Engineering Laboratory for Animal Breeding and Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture, College of Animal Science and Technology, China Agricultural University, Beijing, 100193, PR China
| | - Ming Du
- National Engineering Laboratory for Animal Breeding and Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture, College of Animal Science and Technology, China Agricultural University, Beijing, 100193, PR China
| | - Qingrui Zhuan
- National Engineering Laboratory for Animal Breeding and Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture, College of Animal Science and Technology, China Agricultural University, Beijing, 100193, PR China
| | - Yuxi Luo
- National Engineering Laboratory for Animal Breeding and Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture, College of Animal Science and Technology, China Agricultural University, Beijing, 100193, PR China
| | - Junyou Li
- Animal Resource Science Center, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Ibaraki, 319-0206, Japan
| | - Yunpeng Hou
- State Key Laboratory for Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, PR China
| | - Shenming Zeng
- National Engineering Laboratory for Animal Breeding and Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture, College of Animal Science and Technology, China Agricultural University, Beijing, 100193, PR China
| | - Shien Zhu
- National Engineering Laboratory for Animal Breeding and Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture, College of Animal Science and Technology, China Agricultural University, Beijing, 100193, PR China
| | - Xiangwei Fu
- National Engineering Laboratory for Animal Breeding and Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture, College of Animal Science and Technology, China Agricultural University, Beijing, 100193, PR China.
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