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Jia H, Tang H, Wu W, Yan Z, Gao C, Gao L, Liu J, Tang L, Cui Y. Putrescine alleviates the oxidative damage of cumulus-oocyte complex via improving fatty acid oxidation. Biochem Biophys Res Commun 2023; 684:149127. [PMID: 37871520 DOI: 10.1016/j.bbrc.2023.149127] [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: 10/08/2023] [Accepted: 10/16/2023] [Indexed: 10/25/2023]
Abstract
BACKGROUND Fatty acid oxidation of cumulus-oocyte complex (COC) provides sufficient energy for oocyte maturation. But, the relationship between fatty acid oxidation and oxidative stress in aging follicles, as well as the effect of putrescine, is still unclear. METHODS The porcine COCs were randomly divided into four groups and cultured in in vitro maturation (IVM) medium with or without 1 mmol/L putrescine, with 50 μmol/L hydrogen peroxide (H2O2) or with 50 μmol/L H2O2 plus 1 mmol/L putrescine. Oocyte maturation was assessed by the first polar body extrusion. The expressions of genes involved in fatty acid oxidation were detected, and the mitochondrial function was analyzed by themembrane potential. RESULTS The maturation rate of oocyte was significantly lower in the H2O2 group when compared with the control group (P<0.001), and putrescine significantly increased this rate in the H2O2 plus putrescine group when compared with the H2O2 group (P<0.001). The expressions of LKB1, STRAD, ACC2, AMPKα1 and AMPKα2 mRNAs in cumulus cells (CCs) were significantly downregulated by H2O2 treatment, and partly rescued by putrescine addition (P<0.05-0.001). However, the changes of LKB1, STRAD, ACC2, AMPKα1 and AMPKα2 mRNAs in oocytes were inapparent. The mitochondrial membrane potential of CCs in the H2O2 group was significantly lower than that in the control group, while putrescine addition significantly increased the mitochondrial membrane potential (P<0.001). CONCLUSION The decrease of oocyte maturation due to oxidative stress is related with the decreased fatty acid oxidation, and putrescine may alleviate the COCs damage via improving fatty acid oxidation.
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Affiliation(s)
- Hongyan Jia
- State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, China; Lianyungang Maternal and Child Health Hospital, Kangda College of Nanjing Medical University, Lianyungang City, 222000, China
| | - Huaiyun Tang
- Lianyungang Maternal and Child Health Hospital, Kangda College of Nanjing Medical University, Lianyungang City, 222000, China
| | - Wei Wu
- State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, China
| | - Zhengjie Yan
- State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, China
| | - Chao Gao
- State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, China
| | - Li Gao
- State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, China
| | - Jiayin Liu
- State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, China
| | - Lisha Tang
- Lianyungang Maternal and Child Health Hospital, Kangda College of Nanjing Medical University, Lianyungang City, 222000, China
| | - Yugui Cui
- State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, China.
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Bicici E, Satilmis F, Bodu M, Demirel MA, Karakas Alkan K, Alkan H. Effect of putrescine supplementation to in vitro maturation medium on embryo development and quality in cattle. Anim Biotechnol 2023; 34:3887-3896. [PMID: 37466367 DOI: 10.1080/10495398.2023.2236660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2023]
Abstract
This study aimed to investigate the effect of putrescine supplementation to maturation medium during in vitro embryo production in cattle on maturation and embryo development/quality. Oocytes obtained from the ovaries of Holstein cattle were used in the study. Obtained cumulus-oocyte complexes were evaluated according to morphological structure, cytoplasmic features, and cumulus cell number, and only Category-I ones were used in the study. Before the in vitro maturation step, oocytes were randomly divided into two groups. In the first group (Putrescine group, n = 159), 0.5 mM putrescine was added to the maturation medium before in vitro maturation. No addition was applied to the maturation medium of the second group (Control group, n = 149). Cumulus expansion degrees of oocytes following maturation (Grade I: poor, Grade II: partial, and Grade III: complete) were determined. In addition, the meiosis of oocytes after maturation was evaluated by differential staining. Then the oocytes were left for fertilization with sperm and finally, possible zygotes were transferred to the culture medium. After determining the developmental stages and quality of the embryos after in vitro culture, only the embryos at the blastocyst stage were stained with the differential staining method to determine the cell numbers. When the cumulus expansion degrees of the groups were evaluated, the Grade III cumulus expansion rate in the putrescine group was higher than the control group (74.21% and 60.4%; respectively) and the Grade I expansion rate (11.95% and 26.17%; respectively) was found lower (p < .05). When the resumption of meiosis was evaluated according to the cumulus expansion degrees, it was determined that the rate of resumption of meiosis increased as the cumulus expansion increased. In addition, the cleavage rates of oocytes and reaching the blastocyst in the putrescine group were found to be higher than in the control group (p < .05). Moreover, inner cell mass, trophectoderm cells, and total cell counts were found to be higher in blastocysts obtained after the putrescine supplementation to the maturation medium compared to the control group (p < .05). As a result, it was determined that the putrescine supplementation to the maturation medium during in vitro embryo production in cattle increased the degree of cumulus expansion and the rate of resumption of meiosis. In addition, putrescine supplementation was thought to increase the rate of reaching the blastocyst of oocytes due to better cell development in embryos.
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Affiliation(s)
- Esra Bicici
- Department of Obstetrics and Gynecology, Selcuk University, Konya, Turkey
| | - Fatma Satilmis
- Department of Obstetrics and Gynecology, Selcuk University, Konya, Turkey
| | - Mustafa Bodu
- Department of Reproduction and Artificial Insemination, Selcuk University, Konya, Turkey
| | | | | | - Hasan Alkan
- Department of Obstetrics and Gynecology, Selcuk University, Konya, Turkey
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Sun Y, Hao L, Han W, Luo J, Zheng J, Yuan D, Ye H, Li Q, Huang G, Han T, Yang Z. Intrafollicular fluid metabolic abnormalities in relation to ovarian hyperstimulation syndrome: Follicular fluid metabolomics via gas chromatography-mass spectrometry. Clin Chim Acta 2023; 538:189-202. [PMID: 36566958 DOI: 10.1016/j.cca.2022.11.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Revised: 11/23/2022] [Accepted: 11/30/2022] [Indexed: 12/24/2022]
Abstract
INTRODUCTION Ovarian hyperstimulation syndrome (OHSS) is the most serious iatrogenic complication of ovulation stimulation during assisted reproductive technology. The main objective of this study was to investigate intrafollicular fluid metabolic change profiles of OHSS in non-ovarian etiologic infertility women (CON) and polycystic ovarian syndrome patients (PCOS). METHODS 87 infertile women were divided into four subgroups: CON-Norm (CON with normal ovarian response), CON-OHSS (CON with OHSS), PCOS-Norm (PCOS with normal ovarian response), and PCOS-OHSS (PCOS with OHSS). The intrafollicular fluid metabolic profiles were analyzed with gas chromatography-mass spectrometry. The multivariable-adjusted conditional logistic regression was applied to assess the association of metabolites with OHSS risk. RESULTS We identified 17 and 3 metabolites that related to OHSS risk in CON and PCOS, respectively. 13 OHSS risk-related metabolites in CON were unsaturated fatty acids, 8 of which were also the significantly altered metabolites between all PCOS and CON-Norm. CONCLUSION Our study may shed light on the role of intrafollicular fluid metabolic abnormalities in the pathophysiology of OHSS. The findings suggested that there might be some metabolic heterogeneities underlying the development of OHSS in CON and PCOS women and indicated possible shared etiological factors in the development of PCOS and OHSS.
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Affiliation(s)
- Yixuan Sun
- Department of Gynecology and Obstetrics, the Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P.R.China; Department of Obstetrics and Gynecology, Women and Children's Hospital of Chongqing Medical University, Chongqing 401147, P.R.China
| | - Lijuan Hao
- Department of Obstetrics and Gynecology, Women and Children's Hospital of Chongqing Medical University, Chongqing 401147, P.R.China
| | - Wei Han
- Center for Reproductive Medicine, Reproductive and Genetic Institute, Women and Children's Hospital of Chongqing Medical University, Chongqing 401147, P.R.China
| | - Jing Luo
- Department of Pathology, Basic Medical College of Chongqing Medical University, 400016, P.R.China
| | - Jing Zheng
- Department of Gynecology and Obstetrics, the Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P.R.China
| | - Dong Yuan
- Department of Gynecology and Obstetrics, the Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P.R.China
| | - Hong Ye
- Center for Reproductive Medicine, Reproductive and Genetic Institute, Women and Children's Hospital of Chongqing Medical University, Chongqing 401147, P.R.China
| | - Qinke Li
- Department of Gynecology and Obstetrics, the Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P.R.China
| | - Guoning Huang
- Center for Reproductive Medicine, Reproductive and Genetic Institute, Women and Children's Hospital of Chongqing Medical University, Chongqing 401147, P.R.China.
| | - Tingli Han
- Department of Gynecology and Obstetrics, the Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P.R.China.
| | - Zhu Yang
- Department of Gynecology and Obstetrics, the Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P.R.China.
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Shi C, Yan Z, Zhang Y, Qin L, Wu W, Gao C, Gao L, Liu J, Cui Y. Effects of putrescine on the quality and epigenetic modification of mouse oocytes during in vitro maturation. Reprod Fertil Dev 2022; 34:957-970. [PMID: 36031717 DOI: 10.1071/rd22064] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 07/29/2022] [Indexed: 11/23/2022] Open
Abstract
CONTEXT Low ovarian putrescine levels and decreased peak values following luteinising hormone peaks are related to poor oocyte quantity and quality in ageing women. AIMS To investigate the effects of putrescine supplementation in in vitro maturation (IVM) medium on oocyte quality and epigenetic modification. METHODS Germinal vesicle oocytes retrieved from the ovaries of 8-week-old and 9-month-old mice were divided into four groups (the young, young+difluoromethylornithine (DFMO), ageing and ageing+putrescine groups) and cultured in IVM medium with or without 1mM putrescine or DFMO for 16h. The first polar body extrusion (PBE), cleavage and embryonic development were evaluated. Spindles, chromosomes, mitochondria and reactive oxygen species (ROS) were measured. The expression levels of SIRT1, H3K9ac, H3K9me2, H3K9me3, and 5mC levels were evaluated. Sirt1 and imprinted genes were detected. RESULTS The PBE was higher in the ageing+putrescine group than in the ageing group. Putrescine increased the total and inner cell mass cell numbers of blastocysts in ageing oocytes. Putrescine decreased aberrant spindles and chromosome aneuploidy, increased the mitochondrial membrane potential and decreased ROS levels. Putrescine increased SIRT1 expression and attenuated the upregulation of H3K9ac levels in ageing oocytes. Putrescine did not affect 5mC, H3K9me2 or H3K9me3 levels or imprinted gene expression. CONCLUSIONS Putrescine supplementation during IVM improved the maturation and quality of ageing oocytes and promoted embryonic development by decreasing ROS generation, maintaining mitochondrial and spindle function and correcting aberrant epigenetic modification. IMPLICATIONS Putrescine shows application potential for human-assisted reproduction, especially for IVM of oocytes from ageing women.
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Affiliation(s)
- Chennan Shi
- State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu Province 210029, China
| | - Zhengjie Yan
- State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu Province 210029, China
| | - Yuexin Zhang
- State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu Province 210029, China
| | - Lianju Qin
- State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu Province 210029, China
| | - Wei Wu
- State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu Province 210029, China
| | - Chao Gao
- State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu Province 210029, China
| | - Li Gao
- State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu Province 210029, China
| | - Jiayin Liu
- State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu Province 210029, China
| | - Yugui Cui
- State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu Province 210029, China
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Hatırnaz Ş, Hatırnaz ES, Ellibeş Kaya A, Hatırnaz K, Soyer Çalışkan C, Sezer Ö, Dokuzeylül Güngor N, Demirel C, Baltacı V, Tan S, Dahan M. Oocyte maturation abnormalities - A systematic review of the evidence and mechanisms in a rare but difficult to manage fertility pheneomina. Turk J Obstet Gynecol 2022; 19:60-80. [PMID: 35343221 PMCID: PMC8966321 DOI: 10.4274/tjod.galenos.2022.76329] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
A small proportion of infertile women experience repeated oocyte maturation abnormalities (OMAS). OMAS include degenerated and dysmorphic oocytes, empty follicle syndrome, oocyte maturation arrest (OMA), resistant ovary syndrome and maturation defects due to primary ovarian insufficiency. Genetic factors play an important role in OMAS but still need specifications. This review documents the spectrum of OMAS and to evaluate the multiple subtypes classified as OMAS. In this review, readers will be able to understand the oocyte maturation mechanism, gene expression and their regulation that lead to different subtypes of OMAs, and it will discuss the animal and human studies related to OMAS and lastly the treatment options for OMAs. Literature searches using PubMed, MEDLINE, Embase, National Institute for Health and Care Excellence were performed to identify articles written in English focusing on Oocyte Maturation Abnormalities by looking for the following relevant keywords. A search was made with the specified keywords and included books and documents, clinical trials, animal studies, human studies, meta-analysis, randomized controlled trials, reviews, systematic reviews and options written in english. The search detected 3,953 sources published from 1961 to 2021. After title and abstract screening for study type, duplicates and relevancy, 2,914 studies were excluded. The remaining 1,039 records were assessed for eligibility by full-text reading and 886 records were then excluded. Two hundred and twenty seven full-text articles and 0 book chapters from the database were selected for inclusion. Overall, 227 articles, one unpublished and one abstract paper were included in this final review. In this review study, OMAS were classified and extensively evaluatedand possible treatment options under the light of current information, present literature and ongoing studies. Either genetic studies or in vitro maturation studies that will be handled in the future will lead more informations to be reached and may make it possible to obtain pregnancies.
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Affiliation(s)
- Şafak Hatırnaz
- Medicana Samsun International Hospital, In Vitro Fertilization-In Vitro Maturation Unit, Samsun, Turkey
| | - Ebru Saynur Hatırnaz
- Medicana Samsun International Hospital, In Vitro Fertilization-In Vitro Maturation Unit, Samsun, Turkey
| | - Aşkı Ellibeş Kaya
- Private Office, Clinic of Obstetrics and Gynecology Specialist, Samsun, Turkey
| | - Kaan Hatırnaz
- Ondokuz Mayıs University Faculty of Medicine, Department of Molecular Biology and Genetics, Samsun, Turkey
| | - Canan Soyer Çalışkan
- University of Health Sciences Turkey, Samsun Training and Research Hospital, Clinic of Obstetrics and Gynecology, Samsun, Turkey
| | - Özlem Sezer
- University of Health Sciences Turkey, Samsun Training and Research Hospital, Clinic of Genetics, Samsun, Turkey
| | | | - Cem Demirel
- Memorial Ataşehir Hospital, In Vitro Fertilization Unit, İstanbul, Turkey
| | | | - Seang Tan
- James Edmund Dodds Chair in ObGyn, Department of ObGyn, McGill University, OriginElle Fertility Clinic and Women, QC, Canada
| | - Michael Dahan
- McGill Reproductive Centre, Department of ObGyn, McGill University Montreal, Quebec, Canada
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Shi C, Zhang J, Yan Z, Gao L, Gao C, Wu W, Liu J, Cui Y. Epigenetic effect of putrescine supplementation during in vitro maturation of oocytes on offspring in mice. J Assist Reprod Genet 2022; 39:681-694. [PMID: 35254568 PMCID: PMC8995222 DOI: 10.1007/s10815-022-02448-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 02/25/2022] [Indexed: 01/12/2023] Open
Abstract
PURPOSE To investigate the epigenetic safety of putrescine supplementation during in vitro maturation (IVM) to offspring. METHODS Germinal vesicle oocytes retrieved from 12-week-old mice were randomly divided into two groups and cultured in IVM medium with or without 1 mmol/L putrescine for 16 h. Then, in vitro fertilization and embryo transplantation were conducted to produce the F1 offspring. The F1 mated with ordinary mice and bred the F2 offspring. The DNA methylation patterns in the brain and heart of F1 were investigated by reduced representation bisulfite sequencing. Imprinted gene expression levels of F1 oocytes were tested. The global methylation of F2 was examined by dot blot. RESULTS The weight, organ coefficient, and histology were normal in the F1 and F2 offspring from the putrescine-treated oocytes. An overall methylation level of 31.23 to 32.53% was observed for all CpG sites in the brain and heart of the two groups. The DNA methylation patterns of the brain and heart in F1 were not altered in general, with subtle differences. The expression levels of imprinted genes including H19, Snrpn, Peg3, Igf2, and Igf2r did not statistically change. The global 5mC level of F2 was consistent with the control group. CONCLUSION Putrescine supplementation during IVM did not directly affect the development, health, and reproduction, and did not affect the genome and global epigenetics of mouse offspring derived from those oocytes. The transient putrescine treatment for improving oocyte maturation shows its long-term safety of genome and epigenetics in the offspring of mice.
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Affiliation(s)
- Chennan Shi
- State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, 210029, Jiangsu Province, China
| | - Jingyi Zhang
- State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, 210029, Jiangsu Province, China
| | - Zhengjie Yan
- State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, 210029, Jiangsu Province, China
| | - Li Gao
- State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, 210029, Jiangsu Province, China
| | - Chao Gao
- State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, 210029, Jiangsu Province, China
| | - Wei Wu
- State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, 210029, Jiangsu Province, China
| | - Jiayin Liu
- State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, 210029, Jiangsu Province, China
| | - Yugui Cui
- State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, 210029, Jiangsu Province, China.
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Lavergne CLJ, Tao Y, Ren Y, Lafleur N, Liu XJ. Systemic L-ornithine supplementation specifically increases ovarian putrescine levels during ovulation in mice. Biol Reprod 2021; 106:792-801. [PMID: 34935905 DOI: 10.1093/biolre/ioab233] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 10/01/2021] [Accepted: 12/14/2021] [Indexed: 11/15/2022] Open
Abstract
In all mammalian species examined thus far, the ovaries produce a burst of ornithine decarboxylase (ODC) and putrescine during ovulation or after application of human chorionic gonadotropin (hCG). Aged mice have significantly reduced levels of this periovulatory ODC and putrescine rise. Putrescine supplementation, in vitro during oocyte maturation or in mouse drinking water during the periovulatory period, reduces egg aneuploidies and embryo resorption, improving fertility of aged mice. These studies suggest that periovulatory putrescine supplementation may be a simple and effective therapy for reproductive aging for women. However, putrescine supplementation is expected to increase widespread tissue putrescine levels, raising concerns of nonspecific and unwanted side effects. Given that ODC is highly expressed in the ovaries during ovulation but otherwise exhibits low activity in most tissues, we hypothesized that periovulatory supplementation of L-ornithine, the substrate of ODC, might be suitable for delivering putrescine specifically to the ovaries. In this study, we have demonstrated that systemic application of L-ornithine via oral gavage or subcutaneous injection increased ovarian putrescine levels; the increase was restricted to animals that had been injected with hCG. Furthermore, L-ornithine specifically increased ovarian putrescine levels without affecting putrescine levels in any other tissues. However, our attempts to improve fertility of aged mice through L-ornithine supplementation in mouse drinking water produced either no effects (1% L-ornithine) or negative impact on fertility (4% ornithine). Our results suggest that it might not be feasible to achieve fertility-enhancing ovarian putrescine levels via L-ornithine supplementation in drinking water without encountering undesired consequences of high dose of exogenous L-ornithine.
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Affiliation(s)
- Christopher L J Lavergne
- Ottawa Hospital Research Institute, The Ottawa Hospital, Ottawa, Ontario, Canada
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada
| | - Yong Tao
- Ottawa Hospital Research Institute, The Ottawa Hospital, Ottawa, Ontario, Canada
| | - Yanping Ren
- Ottawa Hospital Research Institute, The Ottawa Hospital, Ottawa, Ontario, Canada
- Department of Histology and Embryology, Zunyi Medical University, Zunyi, Guizhou, China
| | - Nahantara Lafleur
- Ottawa Hospital Research Institute, The Ottawa Hospital, Ottawa, Ontario, Canada
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada
| | - X Johné Liu
- Ottawa Hospital Research Institute, The Ottawa Hospital, Ottawa, Ontario, Canada
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada
- Department of Obstetrics and Gynaecology, University of Ottawa, Ottawa, Ontario, Canada
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Environmental Pollutant Benzo[a]pyrene Upregulated Long Non-coding RNA HZ07 Inhibits Trophoblast Cell Migration by Inactivating PI3K/AKT/MMP2 Signaling Pathway in Recurrent Pregnancy Loss. Reprod Sci 2021; 28:3085-3093. [PMID: 34050522 DOI: 10.1007/s43032-021-00630-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 05/19/2021] [Indexed: 02/05/2023]
Abstract
Benzo(a)pyrene (BaP) is a ubiquitous environmental endocrine-disrupting chemical that is known to have toxic effects on reproduction. However, the underlying mechanisms describing how BaP and its metabolite benzo[a]pyrene-7, 8-diol-9, 10-epoxide (BPDE) induce recurrent pregnancy loss (RPL) are still largely unclear. In this study, we identified a novel long non-coding RNA (lnc-HZ07, NCBI MT936329) that was upregulated in trophoblast cells after exposure to BPDE, and lnc-HZ07 expression was significantly higher in RPL villous tissues than that in control villous tissues. Knockdown of lnc-HZ07 promoted trophoblast cell migration, whereas overexpression of lnc-HZ07 inhibited trophoblast cell migration. Further study showed that lnc-HZ07 inhibited trophoblast migration by downregulating matrix metalloproteinase 2 (MMP2) expression via dephosphorylation of AKT. These results demonstrated a novel regulatory pathway in which BaP downregulated AKT phosphorylation and inhibited MMP2 expression by upregulating lnc-HZ07, suggesting that lnc-HZ07 could be considered as a potential pathological marker of BaP-induced RPL and therapeutic target for this disease.
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Niu C, Zhang S, Mo G, Jiang Y, Li L, Xu H, Han C, Zhao H, Yan Y, Hu S, Hu J, Kang B, Jiang D. Effects of ODC on polyamine metabolism, hormone levels, cell proliferation and apoptosis in goose ovarian granulosa cells. Poult Sci 2021; 100:101226. [PMID: 34175802 PMCID: PMC8254008 DOI: 10.1016/j.psj.2021.101226] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 04/13/2021] [Accepted: 04/14/2021] [Indexed: 11/16/2022] Open
Abstract
Ornithine decarboxylase (ODC) plays an indispensable role in the process of polyamine biosynthesis. Polyamines are a pivotal part of living cells and have diverse roles in the regulation of cell proliferation and apoptosis, aging and reproduction. However, to date, there have been no reports about ODC regulating follicular development in goose ovaries. Here, we constructed ODC siRNA and overexpression plasmids and transfected them into goose primary granulosa cells (GCs) to elucidate the effects of ODC interference and overexpression on the polyamine metabolism, hormone levels, cell apoptosis and proliferation of granulosa cells. After interfering with ODC in GCs, the mRNA and protein levels of ODC and the content of putrescine were greatly decreased (P < 0.05). When ODC was overexpressed, ODC mRNA and protein levels and putrescine content were greatly increased (P < 0.05). The polyamine-metabolizing enzyme genes ornithine decarboxylase antizyme 1 (OAZ1) and spermidine / spermine-N1-acetyltransferase (SSAT) were significantly increased, and spermidine synthase (SPDS) was significantly decreased when ODC was downregulated (P < 0.05). OAZ1, SPDS and SSAT were significantly increased when ODC was upregulated (P < 0.05). In addition, after interference with ODC, progesterone (P4) levels in the culture medium of GCs increased greatly (P < 0.05), while the overexpression of ODC caused the P4 level to decrease significantly (P < 0.05). After ODC downregulation, granulosa cell activity was significantly reduced, the apoptosis rate was significantly increased, and the BCL-2 / BAX ratio was downregulated (P < 0.05). Under ODC overexpression, the activity of GCs was notably increased, the apoptosis rate was significantly reduced, and the BCL-2 / BAX protein ratio was upregulated (P < 0.05). Our study successfully induced ODC interference and overexpression in goose ovarian GCs, and ODC regulated mainly putrescine content in GCs with a slight influence on spermidine and spermine. Moreover, ODC participated in the adjustment of P4 levels in the culture medium of GCs, promoted granulosa cell proliferation and inhibited granulosa cell apoptosis.
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Affiliation(s)
- Chunyang Niu
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, P. R. China
| | - Sujuan Zhang
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, P. R. China
| | - Guilin Mo
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, P. R. China
| | - Yilong Jiang
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, P. R. China
| | - Liang Li
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, P. R. China
| | - Hengyong Xu
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, P. R. China
| | - Chunchun Han
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, P. R. China
| | - Hua Zhao
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, P. R. China
| | - Yanhong Yan
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, P. R. China
| | - Shenqiang Hu
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, P. R. China
| | - Jiwei Hu
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, P. R. China
| | - Bo Kang
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, P. R. China
| | - Dongmei Jiang
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, P. R. China.
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Environmental Pollutant Benzo[a]pyrene Induces Recurrent Pregnancy Loss through Promoting Apoptosis and Suppressing Migration of Extravillous Trophoblast. BIOMED RESEARCH INTERNATIONAL 2020; 2020:8983494. [PMID: 33123590 PMCID: PMC7586159 DOI: 10.1155/2020/8983494] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Revised: 09/24/2020] [Accepted: 10/01/2020] [Indexed: 12/30/2022]
Abstract
Methods The implantation sites, fetus resorption, and abnormal fetuses were studied in pregnant mice treated with different doses of BaP by oral gavage from day 1 to day 10 of gestation. Additionally, apoptosis and related signaling pathway, and the migration and invasion of trophoblasts, were assessed before and after exposure of BPDE in Swan 71 trophoblast cell. Besides, the migration and invasion, and its related signaling pathway, were assessed in villi obtained from women. Results We observed a concentration-dependent incidence of abnormal murine fetuses, beginning with 0.1 mg/kg BaP; with a BaP concentration of 2 mg/kg, no fetuses developed. Correspondingly, a BPDE concentration-dependent apoptosis of human trophoblasts. Beginning with 0.5 μM BPDE exposure, Bax/Caspase-3 were increased and Bcl-2 decreased. Furthermore, BPDE also inhibited, in a dose-dependent manner, the migration of villous explants from elective abortion women, consistent with the reduced migration of villous explants from women with recurrent pregnancy loss (RPL), and reduced the cell immigration in Swan 71 trophoblasts, in a dose-dependent manner measured by transwell assays. Conclusions Our study results provide mechanistic insight to the effect of BPDE on trophoblast dysfunction through enhanced cell apoptosis and inhibited migration, providing further experimental evidence to the causative links between BaP exposure and PRL.
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11
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Mikwar M, MacFarlane AJ, Marchetti F. Mechanisms of oocyte aneuploidy associated with advanced maternal age. MUTATION RESEARCH. REVIEWS IN MUTATION RESEARCH 2020; 785:108320. [PMID: 32800274 DOI: 10.1016/j.mrrev.2020.108320] [Citation(s) in RCA: 119] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 06/24/2020] [Accepted: 06/29/2020] [Indexed: 12/30/2022]
Abstract
It is well established that maternal age is associated with a rapid decline in the production of healthy and high-quality oocytes resulting in reduced fertility in women older than 35 years of age. In particular, chromosome segregation errors during meiotic divisions are increasingly common and lead to the production of oocytes with an incorrect number of chromosomes, a condition known as aneuploidy. When an aneuploid oocyte is fertilized by a sperm it gives rise to an aneuploid embryo that, except in rare situations, will result in a spontaneous abortion. As females advance in age, they are at higher risk of infertility, miscarriage, or having a pregnancy affected by congenital birth defects such as Down syndrome (trisomy 21), Edwards syndrome (trisomy 18), and Turner syndrome (monosomy X). Here, we review the potential molecular mechanisms associated with increased chromosome segregation errors during meiosis as a function of maternal age. Our review shows that multiple exogenous and endogenous factors contribute to the age-related increase in oocyte aneuploidy. Specifically, the weight of evidence indicates that recombination failure, cohesin deterioration, spindle assembly checkpoint (SAC) disregulation, abnormalities in post-translational modification of histones and tubulin, and mitochondrial dysfunction are the leading causes of oocyte aneuploidy associated with maternal aging. There is also growing evidence that dietary and other bioactive interventions may mitigate the effect of maternal aging on oocyte quality and oocyte aneuploidy, thereby improving fertility outcomes. Maternal age is a major concern for aneuploidy and genetic disorders in the offspring in the context of an increasing proportion of mothers having children at increasingly older ages. A better understanding of the mechanisms associated with maternal aging leading to aneuploidy and of intervention strategies that may mitigate these detrimental effects and reduce its occurrence are essential for preventing abnormal reproductive outcomes in the human population.
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Affiliation(s)
- Myy Mikwar
- Department of Biology, Carleton University, Ottawa, Ontario, Canada; Nutrition Research Division, Health Canada, Ottawa, Ontario, Canada
| | - Amanda J MacFarlane
- Department of Biology, Carleton University, Ottawa, Ontario, Canada; Nutrition Research Division, Health Canada, Ottawa, Ontario, Canada
| | - Francesco Marchetti
- Department of Biology, Carleton University, Ottawa, Ontario, Canada; Mechanistic Studies Division, Health Canada, Ottawa, Ontario, Canada.
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12
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Can peri-ovulatory putrescine supplementation improve egg quality in older infertile women? J Assist Reprod Genet 2018; 36:395-402. [PMID: 30467617 DOI: 10.1007/s10815-018-1327-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Accepted: 09/28/2018] [Indexed: 10/27/2022] Open
Abstract
The aging-related decline in fertility is an increasingly pressing medical and economic issue in modern society where women are delaying family building. Increasingly sophisticated, costly, and often increasingly invasive, assisted reproductive clinical protocols and laboratory technologies (ART) have helped many older women achieve their reproductive goals. Current ART procedures have not been able to address the fundamental problem of oocyte aging, the increased rate of egg aneuploidy, and the decline of developmental potential of the eggs. Oocyte maturation, which is triggered by luteinizing hormone (LH) in vivo or by injection of human chorionic gonadotropin (hCG) in an in vitro fertilization (IVF) clinic, is the critical stage at which the majority of egg aneuploidies arise and when much of an egg's developmental potential is established. Our proposed strategy focuses on improving egg quality in older women by restoring a robust oocyte maturation process. We have identified putrescine deficiency as one of the causes of poor egg quality in an aged mouse model. Putrescine is a biogenic polyamine naturally produced in peri-ovulatory ovaries. Peri-ovulatory putrescine supplementation has reduced egg aneuploidy, improved embryo quality, and reduced miscarriage rates in aged mice. In this paper, we review the literature on putrescine, its occurrence and physiology in living organisms, and its unique role in oocyte maturation. Preliminary human data demonstrates that there is a maternal aging-related deficiency in ovarian ornithine decarboxylase (ODC), the enzyme responsible for putrescine production. We argue that peri-ovulatory putrescine supplementation holds great promise as a natural and effective therapy for infertility in women of advanced maternal age, applicable in natural conception and in combination with current ART therapies.
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13
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Lenis YY, Johnson GA, Wang X, Tang WW, Dunlap KA, Satterfield MC, Wu G, Hansen TR, Bazer FW. Functional roles of ornithine decarboxylase and arginine decarboxylase during the peri-implantation period of pregnancy in sheep. J Anim Sci Biotechnol 2018; 9:10. [PMID: 29410783 PMCID: PMC5781304 DOI: 10.1186/s40104-017-0225-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 12/19/2017] [Indexed: 01/03/2023] Open
Abstract
Background Polyamines stimulate DNA transcription and mRNA translation for protein synthesis in trophectoderm cells, as well as proliferation and migration of cells; therefore, they are essential for development and survival of conceptuses (embryo/fetus and placenta). The ovine conceptus produces polyamines via classical and non-classical pathways. In the classical pathway, arginine (Arg) is transformed into ornithine, which is then decarboxylated by ornithine decarboxylase (ODC1) to produce putrescine which is the substrate for the production of spermidine and spermine. In the non-classical pathway, Arg is converted to agmatine (Agm) by arginine decarboxylase (ADC), and Agm is converted to putrescine by agmatinase (AGMAT). Methods Morpholino antisense oligonucleotides (MAOs) were designed and synthesized to inhibit translational initiation of the mRNAs for ODC1 and ADC, in ovine conceptuses. Results The morphologies of MAO control, MAO-ODC1, and MAO-ADC conceptuses were normal. Double knockdown of ODC1 and ADC (MAO-ODC1:ADC) resulted in two phenotypes of conceptuses; 33% of conceptuses appeared to be morphologically and functionally normal (phenotype a) and 67% of the conceptuses presented an abnormal morphology and functionality (phenotype b). Furthermore, MAO-ODC1:ADC (a) conceptuses had greater tissue concentrations of Agm, putrescine, and spermidine than MAO control conceptuses, while MAO-ODC1:ADC (b) conceptuses only had greater tissue concentrations of Agm . Uterine flushes from ewes with MAO-ODC1:ADC (a) had greater amounts of arginine, aspartate, tyrosine, citrulline, lysine, phenylalanine, isoleucine, leucine, and glutamine, while uterine flushes of ewes with MAO-ODC1:ADC (b) conceptuses had lower amount of putrescine, spermidine, spermine, alanine, aspartate, glutamine, tyrosine, phenylalanine, isoleucine, leucine, and lysine. Conclusions The double-knockdown of translation of ODC1 and ADC mRNAs was most detrimental to conceptus development and their production of interferon tau (IFNT). Agm, polyamines, amino acids, and adequate secretion of IFNT are critical for establishment and maintenance of pregnancy during the peri-implantation period of gestation in sheep. Electronic supplementary material The online version of this article (10.1186/s40104-017-0225-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yasser Y Lenis
- 1Department of Animal Science, Texas A&M University, College Station, TX 77843-2471 USA.,2Center for Animal Biotechnology and Genomics, Texas A&M University, College Station, TX 77843 USA.,3Centauro Research Group, School of Veterinary Medicine, Faculty of Agrarian Science, Universidad de Antioquia, Calle 70 No, 52-21 Medellín, Colombia.,Faculty of Agricultural Sciences, Calle 222 No. 55-37, UDCA, Bogota, Colombia
| | - Gregory A Johnson
- 1Department of Animal Science, Texas A&M University, College Station, TX 77843-2471 USA.,2Center for Animal Biotechnology and Genomics, Texas A&M University, College Station, TX 77843 USA
| | - Xiaoqiu Wang
- 1Department of Animal Science, Texas A&M University, College Station, TX 77843-2471 USA.,2Center for Animal Biotechnology and Genomics, Texas A&M University, College Station, TX 77843 USA.,5Present address: National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709 USA
| | - Wendy W Tang
- 1Department of Animal Science, Texas A&M University, College Station, TX 77843-2471 USA.,2Center for Animal Biotechnology and Genomics, Texas A&M University, College Station, TX 77843 USA
| | - Kathrin A Dunlap
- 1Department of Animal Science, Texas A&M University, College Station, TX 77843-2471 USA.,2Center for Animal Biotechnology and Genomics, Texas A&M University, College Station, TX 77843 USA
| | - M Carey Satterfield
- 1Department of Animal Science, Texas A&M University, College Station, TX 77843-2471 USA
| | - Guoyao Wu
- 1Department of Animal Science, Texas A&M University, College Station, TX 77843-2471 USA.,2Center for Animal Biotechnology and Genomics, Texas A&M University, College Station, TX 77843 USA
| | - Thomas R Hansen
- 6Animal Reproduction and Biotechnology Laboratory, Department of Biomedical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523 USA
| | - Fuller W Bazer
- 1Department of Animal Science, Texas A&M University, College Station, TX 77843-2471 USA.,2Center for Animal Biotechnology and Genomics, Texas A&M University, College Station, TX 77843 USA
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Liu D, Mo G, Tao Y, Wang H, Liu XJ. Putrescine supplementation during in vitro maturation of aged mouse oocytes improves the quality of blastocysts. Reprod Fertil Dev 2017; 29:1392-1400. [DOI: 10.1071/rd16061] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 05/12/2016] [Indexed: 12/14/2022] Open
Abstract
Mouse ovaries exhibit a peri-ovulatory rise of ornithine decarboxylase and its product putrescine concurrent with oocyte maturation. Older mice exhibit a deficiency of both the enzyme and putrescine. Peri-ovulatory putrescine supplementation in drinking water increases ovarian putrescine levels, reduces embryo resorption and increases live pups in older mice. However, it is unknown if putrescine acts in the ovaries to improve oocyte maturation. This study examined the impact of putrescine supplementation during oocyte in vitro maturation (IVM) on the developmental potential of aged oocytes. Cumulus–oocyte complexes from 9–12-month-old C57BL/6 mice were subjected to IVM with or without 0.5 mM putrescine, followed by in vitro fertilisation and culture to the blastocyst stage. Putrescine supplementation during IVM did not influence the proportion of oocyte maturation, fertilisation or blastocyst formation, but significantly increased blastocyst cell numbers (44.5 ± 1.9, compared with 36.5 ± 1.9 for control; P = 0.003). The putrescine group also had a significantly higher proportion of blastocysts with top-grade morphology (42.9%, compared with 26.1% for control; P = 0.041) and a greater proportion with octamer-binding transcription factor 4 (OCT4)-positive inner cell mass (38.3%, compared with 19.8% for control; P = 0.005). Therefore, putrescine supplementation during IVM improves egg quality of aged mice, providing proof of principle for possible application in human IVM procedures for older infertile women.
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Tao Y, Liu XJ. The Majority of Resorptions in Old Mice Are Euploid. PLoS One 2015; 10:e0143360. [PMID: 26636341 PMCID: PMC4670076 DOI: 10.1371/journal.pone.0143360] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 11/03/2015] [Indexed: 11/29/2022] Open
Abstract
Chromosomal abnormality is a leading cause of aging-related infertility, spontaneous abortion and congenital birth defects in humans. Karyotype analyses of spontaneously aborted human fetuses reveal high proportions (~50%) being chromosomal abnormal with the majority being trisomies of various chromosomes. As a model organism, mice are widely used for studies of reproduction and reproductive aging. Like older women, older mice exhibit high incidences of early embryo death. However, it is not known if aneuploidy is prevalent amongst resorptions in older mice. We have karyotyped 65 retarded/resorbed fetuses in 10-month-old C57BL/6 mice, and found that 55 (84.6%±8.8%, with 95% confidence) were euploid. Similarly, of 40 such fetuses from 17 month-old C57BL/6 mice, we found 38 (95±7%, with 95% confidence 95%) being euploid. Therefore, aneuploidy is not a leading cause of embryo death in older mice.
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Affiliation(s)
- Yong Tao
- Ottawa Hospital Research Institute, The Ottawa Hospital—General Campus, 501 Smyth Road, Box 511, Ottawa, Ontario, K1H 8L6, Canada
| | - X. Johné Liu
- Ottawa Hospital Research Institute, The Ottawa Hospital—General Campus, 501 Smyth Road, Box 511, Ottawa, Ontario, K1H 8L6, Canada
- Department of Obstetrics and Gynaecology, and Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada
- * E-mail:
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Liu XJ. Targeting oocyte maturation to improve fertility in older women. Cell Tissue Res 2015; 363:57-68. [PMID: 26329301 DOI: 10.1007/s00441-015-2264-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 07/08/2015] [Indexed: 11/28/2022]
Abstract
Reproductive aging is an increasingly pressing problem facing women in modern society, due to delay in child bearing. According to Statistics Canada, 52% of all Canadian births in 2011 were by women aged 30 years and older, up from 24% in 1981 ( http://www.statcan.gc.ca/pub/91-209-x/2013001/article/11784-eng.htm ). Women older than 35 years of age experience significantly increased risks of infertility, miscarriage and congenital birth defects, mostly due to poor quality of the eggs. Increasingly sophisticated, and often invasive, assisted reproductive technologies (ARTs) have helped millions of women to achieve reproductive success. However, by and large, ARTs do not address the fundamental issue of reproductive aging in women: age-related decline in egg quality. More importantly, ARTs are not, and will never be, the main solution for the general population. Here, I attempt to review the scientific literature on age-related egg quality decline, based mostly on studies in mice and in humans. Emphasis is given to the brief period of time called oocyte maturation, which occurs just prior to ovulation. The rationale for this emphasis is that oocyte maturation represents a critical window where unfavorable ovarian conditions in older females contribute significantly to the decline of egg quality, and that science-based intervention during oocyte maturation represents the best chance of improving egg quality in older women. Finally, I summarize our own work in recent years on peri-ovulatory putrescine supplementation as a possible remedy for reproductive aging.
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Affiliation(s)
- X Johné Liu
- Ottawa Hospital Research Institute, The Ottawa Hospital - General Campus, 501 Smyth Road, Box 511, Ottawa, Ontario, K1H 8L6, Canada. .,Department of Obstetrics and Gynecology and Department of Biochemistry, Microbiology and Immunology (BMI), University of Ottawa, Ottawa, ON, Canada.
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