1
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Lafontaine S, Sirard MA. IGF2R, KCNQ1, PLAGL1, and SNRPN DNA methylation is completed in bovine by the early antral follicle stage. Mol Reprod Dev 2022; 89:290-297. [PMID: 35698757 DOI: 10.1002/mrd.23621] [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: 01/07/2022] [Revised: 05/03/2022] [Accepted: 06/03/2022] [Indexed: 11/06/2022]
Abstract
Imprinted genes are inherited with different DNA methylation patterns depending on the maternal or paternal origin of the allele. In cattle (Bos taurus), abnormal methylation of these genes is linked to the large offspring syndrome, a neonatal overgrowth phenotype analogous to the human Beckwith-Wiedemann syndrome. We hypothesized that in bovine oocytes, some of the methylation patterns on maternally imprinted genes are acquired in the last phase of folliculogenesis. The pyrosequencing analysis of IGF2R, KCNQ1, PLAGL1, and SNRPN imprinted genes showed no clear progression of methylation in oocytes from follicles 1-2 mm (late pre antral/early antral) and up. Instead, these oocytes displayed complete methylation at the imprinted differentially methylated regions (>80%). Other mechanisms related to imprint maintenance should be investigated to explain the hypomethylation at IGF2R, KCNQ1, PLAGL1, and SNRPN maternally imprinted sites observed in some bovine embryos.
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Affiliation(s)
- Simon Lafontaine
- Centre de recherche en reproduction, développement et santé intergénérationnelle, Département des Sciences Animales, Faculté des sciences de l'agriculture et de l'alimentation, Université Laval, Québec, Québec, Canada
| | - Marc-André Sirard
- Centre de recherche en reproduction, développement et santé intergénérationnelle, Département des Sciences Animales, Faculté des sciences de l'agriculture et de l'alimentation, Université Laval, Québec, Québec, Canada
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2
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Mohan KN. DNMT1: catalytic and non-catalytic roles in different biological processes. Epigenomics 2022; 14:629-643. [PMID: 35410490 DOI: 10.2217/epi-2022-0035] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
DNMT1 is the main enzyme that uses the information on DNA methylation patterns in the parent strand and methylates the daughter strand in freshly replicated hemimethylated DNA. It is widely known that DNMT1 is a component of the epigenetic machinery mediating gene repression via increased promoter methylation. However, recent data suggest that DNMT1 can also modulate gene expression independent of its catalytic activity and participates in multiple processes including the cell cycle, DNA damage repair and stem cell function. This review summarizes the noncanonical functions of DNMT1, some of which are clearly independent of maintenance methylation. Finally, phenotypic data on altered DNMT1 levels suggesting that maintenance of optimal levels of DNMT1 is vital for normal development and health is presented.
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Affiliation(s)
- Kommu Naga Mohan
- Department of Biological Sciences, Birla Institute of Technology & Science, Pilani - Hyderabad Campus, 500078, India.,Centre for Human Disease Research, Birla Institute of Technology & Science, Pilani - Hyderabad Campus, 500078, India
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3
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Behera J, Kelly KE, Tyagi N. Hydrogen sulfide prevents ethanol-induced ZO-1 CpG promoter hypermethylation-dependent vascular permeability via miR-218/DNMT3a axis. J Cell Physiol 2021; 236:6852-6867. [PMID: 33855696 DOI: 10.1002/jcp.30382] [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: 11/27/2020] [Revised: 03/15/2021] [Accepted: 03/17/2021] [Indexed: 01/11/2023]
Abstract
Ethanol (ET) causes cerebrovascular dysfunction by altering homocysteine (Hcy) metabolism and by causing oxidative stress. However, there are no strategies to prevent ET-induced epigenetic deregulation of tight junction protein (hyper-methylation) and endothelial cell permeability to date. Hydrogen sulfide (H2 S) has an antioxidative, antiapoptotic, and anti-inflammatory effect. Here, we investigated the protective role of H2 S in ET-induced endothelial permeability through epigenetic changes in mouse brain endothelial cells (bEnd3). The bEnd3 cells were exposed to 50 mM ET treatment in the presence or absence of 50 μM NaHS (H2 S donor). The result demonstrates that ET-induced cellular toxicity increased intracellular Hcy levels, which further intensified mitochondrial dysfunction and energy defects. Using miScript microRNA (miRNA) polymerase chain reaction array-based screening, we identified a particular miRNA, miR-218, as a novel target of ET-induced DNA methyltransferase-3a (DNMT3a) activation. miR-218 influences CpG island methylation of the zonula occludens 1 (ZO-1) promoter in the endothelial cells. We discovered that ET suppressed miR-218 levels and induced endothelial permeability via DNMT3a-mediated ZO-1 hyper-methylation. Treatment with mito-TEMPO (mitochondria-targeted antioxidant), 5'-azacitidine (DNMT inhibitor), or miR-218 overexpression was shown to protect endothelial cells against ET-induced permeability. Also, bEnd3 cells pretreated with NaHS attenuated ET-induced vascular permeability and prevented CpG island methylation at the promoter. In conclusion, our data provide evidence that H2 S treatment protects vascular integrity from ET-induced stress by mitigating CpG (ZO-1 promoter) DNA hyper-methylation. This finding uncovers a new mechanistic understanding of NaHS/H2 S, that may have therapeutic potential in preventing or diminishing ET-induced brain vascular permeability and dysfunction induced by alcoholism.
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Affiliation(s)
- Jyotirmaya Behera
- Department of Physiology, School of Medicine, University of Louisville, Louisville, Kentucky, USA
| | - Kimberly E Kelly
- Department of Physiology, School of Medicine, University of Louisville, Louisville, Kentucky, USA
| | - Neetu Tyagi
- Department of Physiology, School of Medicine, University of Louisville, Louisville, Kentucky, USA
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4
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Legault LM, Doiron K, Breton-Larrivée M, Langford-Avelar A, Lemieux A, Caron M, Jerome-Majewska LA, Sinnett D, McGraw S. Pre-implantation alcohol exposure induces lasting sex-specific DNA methylation programming errors in the developing forebrain. Clin Epigenetics 2021; 13:164. [PMID: 34425890 PMCID: PMC8381495 DOI: 10.1186/s13148-021-01151-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 08/11/2021] [Indexed: 12/26/2022] Open
Abstract
Background Prenatal alcohol exposure is recognized for altering DNA methylation profiles of brain cells during development, and to be part of the molecular basis underpinning Fetal Alcohol Spectrum Disorder (FASD) etiology. However, we have negligible information on the effects of alcohol exposure during pre-implantation, the early embryonic window marked with dynamic DNA methylation reprogramming, and on how this may rewire the brain developmental program. Results Using a pre-clinical in vivo mouse model, we show that a binge-like alcohol exposure during pre-implantation at the 8-cell stage leads to surge in morphological brain defects and adverse developmental outcomes during fetal life. Genome-wide DNA methylation analyses of fetal forebrains uncovered sex-specific alterations, including partial loss of DNA methylation maintenance at imprinting control regions, and abnormal de novo DNA methylation profiles in various biological pathways (e.g., neural/brain development). Conclusion These findings support that alcohol-induced DNA methylation programming deviations during pre-implantation could contribute to the manifestation of neurodevelopmental phenotypes associated with FASD. Supplementary Information The online version contains supplementary material available at 10.1186/s13148-021-01151-0.
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Affiliation(s)
- L M Legault
- CHU Sainte-Justine Research Center, 3175 Chemin de La Côte-Sainte-Catherine, Montréal, QC, H3T 1C5, Canada.,Department of Biochemistry and Molecular Medicine, Université de Montréal, 2900 Boulevard Edouard-Montpetit, Montréal, QC, H3T 1J4, Canada
| | - K Doiron
- CHU Sainte-Justine Research Center, 3175 Chemin de La Côte-Sainte-Catherine, Montréal, QC, H3T 1C5, Canada
| | - M Breton-Larrivée
- CHU Sainte-Justine Research Center, 3175 Chemin de La Côte-Sainte-Catherine, Montréal, QC, H3T 1C5, Canada.,Department of Biochemistry and Molecular Medicine, Université de Montréal, 2900 Boulevard Edouard-Montpetit, Montréal, QC, H3T 1J4, Canada
| | - A Langford-Avelar
- CHU Sainte-Justine Research Center, 3175 Chemin de La Côte-Sainte-Catherine, Montréal, QC, H3T 1C5, Canada.,Department of Biochemistry and Molecular Medicine, Université de Montréal, 2900 Boulevard Edouard-Montpetit, Montréal, QC, H3T 1J4, Canada
| | - A Lemieux
- CHU Sainte-Justine Research Center, 3175 Chemin de La Côte-Sainte-Catherine, Montréal, QC, H3T 1C5, Canada.,Department of Biochemistry and Molecular Medicine, Université de Montréal, 2900 Boulevard Edouard-Montpetit, Montréal, QC, H3T 1J4, Canada
| | - M Caron
- CHU Sainte-Justine Research Center, 3175 Chemin de La Côte-Sainte-Catherine, Montréal, QC, H3T 1C5, Canada
| | - L A Jerome-Majewska
- McGill University Health Centre Glen Site, 1001 Boulevard Décarie, Montréal, QC, H4A 3J1, Canada.,Department of Pediatrics, McGill University, 1001 Boulevard Décarie, Montréal, QC, H4A 3J1, Canada
| | - D Sinnett
- CHU Sainte-Justine Research Center, 3175 Chemin de La Côte-Sainte-Catherine, Montréal, QC, H3T 1C5, Canada.,Department of Pediatrics, Université de Montréal, 2900 Boulevard Edouard-Montpetit, Montréal, QC, H3T 1J4, Canada
| | - S McGraw
- CHU Sainte-Justine Research Center, 3175 Chemin de La Côte-Sainte-Catherine, Montréal, QC, H3T 1C5, Canada. .,Department of Biochemistry and Molecular Medicine, Université de Montréal, 2900 Boulevard Edouard-Montpetit, Montréal, QC, H3T 1J4, Canada. .,Department of Obstetrics and Gynecology, Université de Montréal, 2900 Boulevard Edouard-Montpetit, Montréal, QC, H3T 1J4, Canada.
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5
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Barberet J, Barry F, Choux C, Guilleman M, Karoui S, Simonot R, Bruno C, Fauque P. What impact does oocyte vitrification have on epigenetics and gene expression? Clin Epigenetics 2020; 12:121. [PMID: 32778156 PMCID: PMC7418205 DOI: 10.1186/s13148-020-00911-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 07/21/2020] [Indexed: 02/07/2023] Open
Abstract
Children conceived by assisted reproductive technologies (ART) have a moderate risk for a number of adverse events and conditions. The question whether this additional risk is associated with specific procedures used in ART or whether it is related to the intrinsic biological factors associated with infertility remains unresolved. One of the main hypotheses is that laboratory procedures could have an effect on the epigenome of gametes and embryos. This suspicion is linked to the fact that ART procedures occur precisely during the period when there are major changes in the organization of the epigenome. Oocyte freezing protocols are generally considered safe; however, some evidence suggests that vitrification may be associated with modifications of the epigenetic marks. In this manuscript, after describing the main changes that occur during epigenetic reprogramming, we will provide current information regarding the impact of oocyte vitrification on epigenetic regulation and the consequences on gene expression, both in animals and humans. Overall, the literature suggests that epigenetic and transcriptomic profiles are sensitive to the stress induced by oocyte vitrification, and it also underlines the need to improve our knowledge in this field.
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Affiliation(s)
- Julie Barberet
- CHU Dijon Bourgogne, Laboratoire de Biologie de la Reproduction, CECOS, 14 rue Gaffarel, 21079 Dijon Cedex, France
| | - Fatima Barry
- CHU Dijon Bourgogne, Laboratoire de Biologie de la Reproduction, CECOS, 14 rue Gaffarel, 21079 Dijon Cedex, France
| | - Cécile Choux
- Gynécologie-Obstétrique, CHU Dijon Bourgogne, 14 rue Gaffarel, 21079 Dijon Cedex, France
| | - Magali Guilleman
- CHU Dijon Bourgogne, Laboratoire de Biologie de la Reproduction, CECOS, 14 rue Gaffarel, 21079 Dijon Cedex, France
| | - Sara Karoui
- CHU Dijon Bourgogne, Laboratoire de Biologie de la Reproduction, CECOS, 14 rue Gaffarel, 21079 Dijon Cedex, France
| | - Raymond Simonot
- CHU Dijon Bourgogne, Laboratoire de Biologie de la Reproduction, CECOS, 14 rue Gaffarel, 21079 Dijon Cedex, France
| | - Céline Bruno
- CHU Dijon Bourgogne, Laboratoire de Biologie de la Reproduction, CECOS, 14 rue Gaffarel, 21079 Dijon Cedex, France
| | - Patricia Fauque
- CHU Dijon Bourgogne, Laboratoire de Biologie de la Reproduction, CECOS, 14 rue Gaffarel, 21079 Dijon Cedex, France
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6
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Marcho C, Oluwayiose OA, Pilsner JR. The preconception environment and sperm epigenetics. Andrology 2020; 8:924-942. [PMID: 31901222 DOI: 10.1111/andr.12753] [Citation(s) in RCA: 76] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 11/12/2019] [Accepted: 12/31/2019] [Indexed: 12/13/2022]
Abstract
BACKGROUND Infertility is a common reproductive disorder, with male factor infertility accounting for approximately half of all cases. Taking a paternal perceptive, recent research has shown that sperm epigenetics, such as changes in DNA methylation, histone modification, chromatin structure, and noncoding RNA expression, can impact reproductive and offspring health. Importantly, environmental conditions during the preconception period has been demonstrated to shape sperm epigenetics. OBJECTIVES To provide an overview on epigenetic modifications that regulate normal gene expression and epigenetic remodeling that occurs during spermatogenesis, and to discuss the epigenetic alterations that may occur to the paternal germline as a consequence of preconception environmental conditions and exposures. MATERIALS AND METHODS We examined published literature available on databases (PubMed, Google Scholar, ScienceDirect) focusing on adult male preconception environmental exposures and sperm epigenetics in epidemiologic studies and animal models. RESULTS The preconception period is a sensitive developmental window in which a variety of exposures such as toxicants, nutrition, drugs, stress, and exercise, affects sperm epigenetics. DISCUSSION AND CONCLUSION Understanding the environmental legacy of the sperm epigenome during spermatogenesis will enhance our understanding of reproductive health and improve reproductive success and offspring well-being.
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Affiliation(s)
- Chelsea Marcho
- Department of Environmental Health Sciences, School of Public Health and Health Sciences, University of Massachusetts Amherst, Amherst, Massachusetts
| | - Oladele A Oluwayiose
- Department of Environmental Health Sciences, School of Public Health and Health Sciences, University of Massachusetts Amherst, Amherst, Massachusetts
| | - J Richard Pilsner
- Department of Environmental Health Sciences, School of Public Health and Health Sciences, University of Massachusetts Amherst, Amherst, Massachusetts
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7
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Gedda MR, Babele PK, Zahra K, Madhukar P. Epigenetic Aspects of Engineered Nanomaterials: Is the Collateral Damage Inevitable? Front Bioeng Biotechnol 2019; 7:228. [PMID: 31616663 PMCID: PMC6763616 DOI: 10.3389/fbioe.2019.00228] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 09/05/2019] [Indexed: 12/31/2022] Open
Abstract
The extensive application of engineered nanomaterial (ENM) in various fields increases the possibilities of human exposure, thus imposing a huge risk of nanotoxicity. Hence, there is an urgent need for a detailed risk assessment of these ENMs in response to their toxicological profiling, predominantly in biomedical and biosensor settings. Numerous "toxico-omics" studies have been conducted on ENMs, however, a specific "risk assessment paradigm" dealing with the epigenetic modulations in humans owing to the exposure of these modern-day toxicants has not been defined yet. This review aims to address the critical aspects that are currently preventing the formation of a suitable risk assessment approach for/against ENM exposure and pointing out those researches, which may help to develop and implement effective guidance for nano-risk assessment. Literature relating to physicochemical characterization and toxicological behavior of ENMs were analyzed, and exposure assessment strategies were explored in order to extrapolate opportunities, challenges, and criticisms in the establishment of a baseline for the risk assessment paradigm of ENMs exposure. Various challenges, such as uncertainty in the relation of the physicochemical properties and ENM toxicity, the complexity of the dose-response relationships resulting in difficulty in its extrapolation and measurement of ENM exposure levels emerged as issues in the establishment of a traditional risk assessment. Such an appropriate risk assessment approach will provide adequate estimates of ENM exposure risks and will serve as a guideline for appropriate risk communication and management strategies aiming for the protection and the safety of humans.
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Affiliation(s)
- Mallikarjuna Rao Gedda
- Department of Biochemistry, Institute of Science, Banaras Hindu University, Varanasi, India
| | - Piyoosh Kumar Babele
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN, United States
| | - Kulsoom Zahra
- Department of Biochemistry, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India
| | - Prasoon Madhukar
- Department of Zoology, Institute of Science, Banaras Hindu University, Varanasi, India
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8
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Legault LM, Bertrand-Lehouillier V, McGraw S. Pre-implantation alcohol exposure and developmental programming of FASD: an epigenetic perspective. Biochem Cell Biol 2018; 96:117-130. [DOI: 10.1139/bcb-2017-0141] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Exposure to alcohol during in-utero development can permanently change the developmental programming of physiological responses, thereby increasing the risk of neurological illnesses during childhood and later adverse health outcomes associated with fetal alcohol spectrum disorder (FASD). There is an increasing body of evidence indicating that exposure to alcohol during gestation triggers lasting epigenetic alterations in offspring, long after the initial insult; together, these studies support the role of epigenetics in FASD etiology. However, we still have little information about how ethanol interferes with the fundamental epigenetic reprogramming wave (e.g., erasure and re-establishment of DNA methylation marks) that characterizes pre-implantation embryo development. This review examines key epigenetic processes that occur during pre-implantation development and especially focus on the current knowledge regarding how prenatal exposure to alcohol during this period could affect the developmental programming of the early stage pre-implantation embryo. We will also outline the current limitations of studies examining the in-vivo and in-vitro effects of alcohol exposure on embryos and underline the next critical steps to be taken if we want to better understand the implicated mechanisms to strengthen the translational potential for epigenetic markers for non-invasive early detection, and the treatment of newborns that have higher risk of developing FASD.
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Affiliation(s)
- Lisa-Marie Legault
- Department of Biochemistry and Molecular Medicine, Université de Montreal, Research Center of the CHU Sainte-Justine, 3175 Côte Sainte-Catherine, Montreal, QC H3T 1C5, Canada
| | - Virginie Bertrand-Lehouillier
- Department of Biochemistry and Molecular Medicine, Université de Montreal, Research Center of the CHU Sainte-Justine, 3175 Côte Sainte-Catherine, Montreal, QC H3T 1C5, Canada
| | - Serge McGraw
- Department of Biochemistry and Molecular Medicine, Université de Montreal, Research Center of the CHU Sainte-Justine, 3175 Côte Sainte-Catherine, Montreal, QC H3T 1C5, Canada
- Obstetrics and Gynecology, Université de Montreal, Research Center of the CHU Sainte-Justine, Montreal, Canada
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9
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Takahashi N, Gray D, Strogantsev R, Noon A, Delahaye C, Skarnes WC, Tate PH, Ferguson-Smith AC. ZFP57 and the Targeted Maintenance of Postfertilization Genomic Imprints. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2018; 80:177-87. [PMID: 27325708 DOI: 10.1101/sqb.2015.80.027466] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Epigenetic modifications play an important role in modulating genome function. In mammals, inappropriate epigenetic states can cause embryonic lethality and various acquired and inherited diseases; hence, it is important to understand how such states are formed and maintained in particular genomic contexts. Genomic imprinting is a process in which epigenetic states provide a sustained memory of parental origin and cause gene expression/repression from only one of the two parental chromosomes. Genomic imprinting is therefore a valuable model to decipher the principles and processes associated with the targeting and maintenance of epigenetic states in general. Krüppel-associated box zinc finger proteins (KRAB-ZFPs) are proteins that have the potential to mediate this. ZFP57, one of the best characterized proteins in this family, has been shown to target and maintain epigenetic states at imprinting control regions after fertilization. Its role in imprinting through the use of ZFP57 mutants in mouse and the wider implications of KRAB-ZFPs for the targeted maintenance of epigenetic states are discussed here.
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Affiliation(s)
- Nozomi Takahashi
- Department of Genetics, University of Cambridge, Cambridge CB2 3EH, United Kingdom
| | - Dionne Gray
- Department of Genetics, University of Cambridge, Cambridge CB2 3EH, United Kingdom
| | | | - Angela Noon
- Department of Genetics, University of Cambridge, Cambridge CB2 3EH, United Kingdom
| | - Celia Delahaye
- Department of Genetics, University of Cambridge, Cambridge CB2 3EH, United Kingdom
| | - William C Skarnes
- Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, United Kingdom
| | - Peri H Tate
- Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, United Kingdom
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10
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Whidden L, Martel J, Rahimi S, Chaillet JR, Chan D, Trasler JM. Compromised oocyte quality and assisted reproduction contribute to sex-specific effects on offspring outcomes and epigenetic patterning. Hum Mol Genet 2018; 25:4649-4660. [PMID: 28173052 DOI: 10.1093/hmg/ddw293] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 08/04/2016] [Accepted: 08/25/2016] [Indexed: 11/13/2022] Open
Abstract
Clinical studies have revealed an increased incidence of growth and genomic imprinting disorders in children conceived using assisted reproductive technologies (ARTs), and aberrant DNA methylation has been implicated. We propose that compromised oocyte quality associated with female infertility may make embryos more susceptible to the induction of epigenetic defects by ART. DNA methylation patterns in the preimplantation embryo are dependent on the oocyte-specific DNA methyltransferase 1o (DNMT1o), levels of which are decreased in mature oocytes of aging females. Here, we assessed the effects of maternal deficiency in DNMT1o (Dnmt1Δ1o/+) in combination with superovulation and embryo transfer on offspring DNA methylation and development. We demonstrated a significant increase in the rates of morphological abnormalities in offspring collected from Dnmt1Δ1o/+ females only when combined with ART. Together, maternal oocyte DNMT1o deficiency and ART resulted in an accentuation of placental imprinting defects and the induction of genome-wide DNA methylation alterations, which were exacerbated in the placenta compared to the embryo. Significant sex-specific trends were also apparent, with a preponderance of DNA hypomethylation in females. Among genic regions affected, a significant enrichment for neurodevelopmental pathways was observed. Taken together, our results demonstrate that oocyte DNMT1o-deficiency exacerbates genome-wide DNA methylation abnormalities induced by ART in a sex-specific manner and plays a role in mediating poor embryonic outcome.
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Affiliation(s)
- Laura Whidden
- Montreal Children's Hospital and Research Institute of the McGill University Health Centre, Montreal, QC, Canada.,Department of Pharmacology and Therapeutics, McGill University, Montreal, QC, Canada
| | - Josée Martel
- Montreal Children's Hospital and Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Sophia Rahimi
- Department of Human Genetics, McGill University, Montreal, QC, Canada
| | - J Richard Chaillet
- Department of OB/GYN and Reproductive Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Donovan Chan
- Montreal Children's Hospital and Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Jacquetta M Trasler
- Montreal Children's Hospital and Research Institute of the McGill University Health Centre, Montreal, QC, Canada.,Department of Pharmacology and Therapeutics, McGill University, Montreal, QC, Canada,Department of Human Genetics, McGill University, Montreal, QC, Canada,Department of Pediatrics, McGill University, Montreal, QC, Canada
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11
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The Role of Maternal-Effect Genes in Mammalian Development: Are Mammalian Embryos Really an Exception? Stem Cell Rev Rep 2017; 12:276-84. [PMID: 26892267 DOI: 10.1007/s12015-016-9648-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The essential contribution of multiple maternal factors to early mammalian development is rapidly altering the view that mammals have a unique pattern of development compared to other species. Currently, over 60 maternal-effect mutations have been described in mammalian systems, including critical determinants of pluripotency. This data, combined with the evidence for lineage bias and differential gene expression in early blastomeres, strongly suggests that mammalian development is to some extent mosaic from the four-cell stage onward.
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12
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Anckaert E, Fair T. DNA methylation reprogramming during oogenesis and interference by reproductive technologies: Studies in mouse and bovine models. Reprod Fertil Dev 2017; 27:739-54. [PMID: 25976160 DOI: 10.1071/rd14333] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 04/01/2015] [Indexed: 12/24/2022] Open
Abstract
The use of assisted reproductive technology (ART) to overcome fertility problems has continued to increase since the birth of the first baby conceived by ART over 30 years ago. Similarly, embryo transfer is widely used as a mechanism to advance genetic gain in livestock. Despite repeated optimisation of ART treatments, pre- and postnatal outcomes remain compromised. Epigenetic mechanisms play a fundamental role in successful gametogenesis and development. The best studied of these is DNA methylation; the appropriate establishment of DNA methylation patterns in gametes and early embryos is essential for healthy development. Superovulation studies in the mouse indicate that specific ARTs are associated with normal imprinting establishment in oocytes, but abnormal imprinting maintenance in embryos. A similar limited impact of ART on oocytes has been reported in cattle, whereas the majority of embryo-focused studies have used cloned embryos, which do exhibit aberrant DNA methylation. The present review discusses the impact of ART on oocyte and embryo DNA methylation with regard to data available from mouse and bovine models.
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Affiliation(s)
- Ellen Anckaert
- Follicle Biology Laboratory and Center for Reproductive Medicine, UZ Brussel, Vrije Universiteit Brussel, Laarbeeklaan 101, Brussels 1090, Belgium
| | - Trudee Fair
- School of Agriculture and Food Sciences, University College Dublin, Belfield, Dublin 4, Ireland
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13
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Mahadevan S, Sathappan V, Utama B, Lorenzo I, Kaskar K, Van den Veyver IB. Maternally expressed NLRP2 links the subcortical maternal complex (SCMC) to fertility, embryogenesis and epigenetic reprogramming. Sci Rep 2017; 7:44667. [PMID: 28317850 PMCID: PMC5357799 DOI: 10.1038/srep44667] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 02/13/2017] [Indexed: 11/09/2022] Open
Abstract
Mammalian parental genomes contribute differently to early embryonic development. Before activation of the zygotic genome, the maternal genome provides all transcripts and proteins required for the transition from a highly specialized oocyte to a pluripotent embryo. Depletion of these maternally-encoded transcripts frequently results in failure of preimplantation embryonic development, but their functions in this process are incompletely understood. We found that female mice lacking NLRP2 are subfertile because of early embryonic loss and the production of fewer offspring that have a wide array of developmental phenotypes and abnormal DNA methylation at imprinted loci. By demonstrating that NLRP2 is a member of the subcortical maternal complex (SCMC), an essential cytoplasmic complex in oocytes and preimplantation embryos with poorly understood function, we identified imprinted postzygotic DNA methylation maintenance, likely by directing subcellular localization of proteins involved in this process, such as DNMT1, as a new crucial role of the SCMC for mammalian reproduction.
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Affiliation(s)
- Sangeetha Mahadevan
- Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, Texas, 77030, USA.,Century Scholars Program, Rice University, Houston, Texas, 77005, USA.,Shared Equipment Authority, Rice University, Houston, Texas, 77005, USA
| | - Varsha Sathappan
- Department of Molecular Human Genetics, Baylor College of Medicine, Houston, Texas, 77030, USA
| | - Budi Utama
- Interdepartmental Graduate Program in Translational Biology and Molecular Medicine, Baylor College of Medicine, Houston, Texas, 77030, USA
| | - Isabel Lorenzo
- Jan and Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas, 77030, USA
| | - Khalied Kaskar
- Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, Texas, 77030, USA
| | - Ignatia B Van den Veyver
- Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, Texas, 77030, USA.,Century Scholars Program, Rice University, Houston, Texas, 77005, USA.,Jan and Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas, 77030, USA
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Li Y, Seah MKY, O'Neill C. Mapping global changes in nuclear cytosine base modifications in the early mouse embryo. Reproduction 2016; 151:83-95. [PMID: 26660107 PMCID: PMC4676261 DOI: 10.1530/rep-15-0207] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Reprogramming epigenetic modifications to cytosine is required for normal embryo development. We used improved immunolocalization techniques to simultaneously map global changes in the levels of 5'-methylcytosine (5meC) and 5'-hydroxymethylcytosine (5hmC) in each cell of the embryo from fertilization through the first rounds of cellular differentiation. The male and female pronuclei of the zygote showed similar staining levels, and these remained elevated over the next three cell cycles. The inner cells of the morula showed a progressive reduction in global levels of both 5meC and 5hmC and further losses occurred in the pluripotent inner cell mass (ICM) of the blastocyst. This was accompanied by undetectable levels of DNA methyltransferase of each class in the nuclei of the ICM, while DNA methyltransferase 3B was elevated in the hypermethylated nuclei of the trophectoderm (TE). Segregation of the ICM into hypoblast and epiblast was accompanied by increased levels in the hypoblast compared with the epiblast. Blastocyst outgrowth in vitro is a model for implantation and showed that a demethylated state persisted in the epiblast while the hypoblast had higher levels of both 5meC and 5hmC staining. The high levels of 5meC and 5hmC evident in the TE persisted in trophoblast and trophoblast giant cells after attachment of the blastocyst to the substratum in vitro. This study shows that global cytosine hypomethylation and hypohydroxymethylation accompanied the formation of the pluripotent ICM and this persisted into the epiblast after blastocyst outgrowth, and each differentiated lineage formed in the early embryo showed higher global levels of 5meC and 5hmC.
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Affiliation(s)
- Y Li
- Centre for Developmental and Regenerative MedicineKolling Institute for Medical Research, Sydney Medical School, University of Sydney, Sydney, New South Wales 2065, Australia
| | - Michelle K Y Seah
- Centre for Developmental and Regenerative MedicineKolling Institute for Medical Research, Sydney Medical School, University of Sydney, Sydney, New South Wales 2065, Australia
| | - C O'Neill
- Centre for Developmental and Regenerative MedicineKolling Institute for Medical Research, Sydney Medical School, University of Sydney, Sydney, New South Wales 2065, Australia
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15
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Kamat PK, Kalani A, Tyagi SC, Tyagi N. Hydrogen Sulfide Epigenetically Attenuates Homocysteine-Induced Mitochondrial Toxicity Mediated Through NMDA Receptor in Mouse Brain Endothelial (bEnd3) Cells. J Cell Physiol 2015; 230:378-94. [PMID: 25056869 DOI: 10.1002/jcp.24722] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Accepted: 07/18/2014] [Indexed: 01/08/2023]
Abstract
Previously we have shown that homocysteine (Hcy) caused oxidative stress and altered mitochondrial function. Hydrogen sulfide (H2S) has potent anti-inflammatory, anti-oxidative, and anti-apoptotic effects. Therefore, in the present study we examined whether H2S ameliorates Hcy-induced mitochondrial toxicity which led to endothelial dysfunction in part, by epigenetic alterations in mouse brain endothelial cells (bEnd3). The bEnd3 cells were exposed to 100 μM Hcy treatment in the presence or absence of 30 μM NaHS (donor of H2S) for 24 h. Hcy-activate NMDA receptor and induced mitochondrial toxicity by increased levels of Ca(2+), NADPH-oxidase-4 (NOX-4) expression, mitochondrial dehydrogenase activity and decreased the level of nitrate, superoxide dismutase (SOD-2) expression, mitochondria membrane potentials, ATP production. To confirm the role of epigenetic, 5'-azacitidine (an epigenetic modulator) treatment was given to the cells. Pretreatment with NaHS (30 μM) attenuated the Hcy-induced increased expression of DNMT1, DNMT3a, Ca(2+), and decreased expression of DNMT3b in bEND3 cells. Furthermore, NaHS treatment also mitigated mitochondrial oxidative stress (NOX4, ROS, and NO) and restored ATP that indicates its protective effects against mitochondrial toxicity. Additional, NaHS significantly alleviated Hcy-induced LC3-I/II, CSE, Atg3/7, and low p62 expression which confirm its effect on mitophagy. Likewise, NaHS also restored level of eNOS, CD31, VE-cadherin and ET-1 and maintains endothelial function in Hcy treated cells. Molecular inhibition of NMDA receptor by using small interfering RNA showed protective effect whereas inhibition of H2S production by propargylglycine (PG) (inhibitor of enzyme CSE) showed mitotoxic effect. Taken together, results demonstrate that, administration of H2S protected the cells from HHcy-induced mitochondrial toxicity and endothelial dysfunction.
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Affiliation(s)
- Pradip K Kamat
- Department of Physiology and Biophysics, School of Medicine, University of Louisville, Louisville, Kentucky
| | - Anuradha Kalani
- Department of Physiology and Biophysics, School of Medicine, University of Louisville, Louisville, Kentucky
| | - Suresh C Tyagi
- Department of Physiology and Biophysics, School of Medicine, University of Louisville, Louisville, Kentucky
| | - Neetu Tyagi
- Department of Physiology and Biophysics, School of Medicine, University of Louisville, Louisville, Kentucky
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16
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Uysal F, Akkoyunlu G, Ozturk S. Dynamic expression of DNA methyltransferases (DNMTs) in oocytes and early embryos. Biochimie 2015; 116:103-13. [PMID: 26143007 DOI: 10.1016/j.biochi.2015.06.019] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 06/26/2015] [Indexed: 11/26/2022]
Abstract
Epigenetic mechanisms play critical roles in oogenesis and early embryo development in mammals. One of these epigenetic mechanisms, DNA methylation is accomplished through the activities of DNA methyltransferases (DNMTs), which are responsible for adding a methyl group to the fifth carbon atom of the cytosine residues within cytosine-phosphate-guanine (CpG) and non-CpG dinuclotide sites. Five DNMT enzymes have been identified in mammals including DNMT1, DNMT2, DNMT3A, DNMT3B, and DNMT3L. They function in two different methylation processes: maintenance and de novo. For maintenance methylation, DNMT1 preferentially transfers methyl groups to the hemi-methylated DNA strands following DNA replication. However, for de novo methylation activities both DNMT3A and DNMT3B function in the methylation of the unmodified cytosine residues. Although DNMT3L indirectly contributes to de novo methylation process, DNMT2 enables the methylation of the cytosine 38 in the anticodon loop of aspartic acid transfer RNA and does not methylate DNA. In this review article, we have evaluated and discussed the existing published studies to characterize the spatial and temporal expression patterns of the DNMTs in mouse, bovine and human oocytes and early embryos. We have also reviewed the effects of in vitro culture conditions (serum abundance and glucose concentration), aging, superovulation, vitrification, and somatic cell nuclear transfer technology on the dynamics of DNMTs.
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Affiliation(s)
- Fatma Uysal
- Department of Histology and Embryology, Akdeniz University, School of Medicine, Antalya, Turkey
| | - Gokhan Akkoyunlu
- Department of Histology and Embryology, Akdeniz University, School of Medicine, Antalya, Turkey
| | - Saffet Ozturk
- Department of Histology and Embryology, Akdeniz University, School of Medicine, Antalya, Turkey.
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Koppes E, Himes KP, Chaillet JR. Partial Loss of Genomic Imprinting Reveals Important Roles for Kcnq1 and Peg10 Imprinted Domains in Placental Development. PLoS One 2015; 10:e0135202. [PMID: 26241757 PMCID: PMC4524636 DOI: 10.1371/journal.pone.0135202] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 07/19/2015] [Indexed: 01/24/2023] Open
Abstract
Mutations in imprinted genes or their imprint control regions (ICRs) produce changes in imprinted gene expression and distinct abnormalities in placental structure, indicating the importance of genomic imprinting to placental development. We have recently shown that a very broad spectrum of placental abnormalities associated with altered imprinted gene expression occurs in the absence of the oocyte-derived DNMT1o cytosine methyltransferase, which normally maintains parent-specific imprinted methylation during preimplantation. The absence of DNMT1o partially reduces inherited imprinted methylation while retaining the genetic integrity of imprinted genes and their ICRs. Using this novel system, we undertook a broad and inclusive approach to identifying key ICRs involved in placental development by correlating loss of imprinted DNA methylation with abnormal placental phenotypes in a mid-gestation window (E12.5-E15.5). To these ends we measured DNA CpG methylation at 15 imprinted gametic differentially methylated domains (gDMDs) that overlap known ICRs using EpiTYPER-mass array technology, and linked these epigenetic measurements to histomorphological defects. Methylation of some imprinted gDMDs, most notably Dlk1, was nearly normal in mid-gestation DNMT1o-deficient placentas, consistent with the notion that cells having lost methylation on these DMDs do not contribute significantly to placental development. Most imprinted gDMDs however showed a wide range of methylation loss among DNMT1o-deficient placentas. Two striking associations were observed. First, loss of DNA methylation at the Peg10 imprinted gDMD associated with decreased embryonic viability and decreased labyrinthine volume. Second, loss of methylation at the Kcnq1 imprinted gDMD was strongly associated with trophoblast giant cell (TGC) expansion. We conclude that the Peg10 and Kcnq1 ICRs are key regulators of mid-gestation placental function.
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Affiliation(s)
- Erik Koppes
- Magee-Womens Research Institute, Program in Integrative Molecular Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Katherine P. Himes
- Magee-Womens Research Institute, Department of Obstetrics, Gynecology and Reproductive Sciences, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - J. Richard Chaillet
- Magee-Womens Research Institute, Department of Obstetrics, Gynecology and Reproductive Sciences, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
- * E-mail:
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18
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Benkhalifa M, Madkour A, Louanjli N, Bouamoud N, Saadani B, Kaarouch I, Chahine H, Sefrioui O, Merviel P, Copin H. From global proteome profiling to single targeted molecules of follicular fluid and oocyte: contribution to embryo development and IVF outcome. Expert Rev Proteomics 2015; 12:407-23. [DOI: 10.1586/14789450.2015.1056782] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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19
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Himes KP, Young A, Koppes E, Stolz D, Barak Y, Sadovsky Y, Chaillet JR. Loss of inherited genomic imprints in mice leads to severe disruption in placental lipid metabolism. Placenta 2015; 36:389-96. [PMID: 25662615 PMCID: PMC4359963 DOI: 10.1016/j.placenta.2015.01.012] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 12/29/2014] [Accepted: 01/22/2015] [Indexed: 11/16/2022]
Abstract
INTRODUCTION Monoallelic expression of imprinted genes is necessary for placental development and normal fetal growth. Differentially methylated domains (DMDs) largely determine the parental-specific monoallelic expression of imprinted genes. Maternally derived DNA (cytosine-5-) -methyltransferase 1o (DNMT1o) maintains DMDs during the eight-cell stage of development. DNMT1o-deficient mouse placentas have a generalized disruption of genomic imprints. Previous studies have demonstrated that DNMT1o deficiency alters placental morphology and broadens the embryonic weight distribution in late gestation. Lipids are critical for fetal growth. Thus, we assessed the impact of disrupted imprinting on placental lipids. METHODS Lipids were quantified from DNMT1o-deficient mouse placentas and embryos at E17.5 using a modified Folch method. Expression of select genes critical for lipid metabolism was quantified with RT-qPCR. Mitochondrial morphology was assessed by TEM and mitochondrial aconitase and cytoplasmic citrate concentrations quantified. DMD methylation was determined by EpiTYPER. RESULTS We found that DNMT1o deficiency is associated with increased placental triacylglycerol levels. Neither fetal triacylglycerol concentrations nor expression of select genes that mediate placental lipid transport were different from wild type. Placental triacylglycerol accumulation was associated with impaired beta-oxidation and abnormal citrate metabolism with decreased mitochondrial aconitase activity and increased cytoplasmic citrate concentrations. Loss of methylation at the MEST DMD was strongly associated with placental triacylglycerol accumulation. DISCUSSION A generalized disruption of genomic imprints leads to triacylglycerol accumulation and abnormal mitochondrial function. This could stem directly from a loss of methylation at a given DMD, such as MEST, or represent a consequence of abnormal placental development.
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Affiliation(s)
- K P Himes
- Magee-Womens Research Institute, Department of Obstetrics, Gynecology and Reproductive Sciences, University of Pittsburgh School of Medicine, 204 Craft Avenue, Pittsburgh, PA 15213, USA.
| | - A Young
- Magee-Womens Research Institute, Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, 204 Craft Avenue, Pittsburgh, PA 15213, USA.
| | - E Koppes
- Magee-Womens Research Institute, Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, 204 Craft Avenue, Pittsburgh, PA 15213, USA.
| | - D Stolz
- Department of Cell Biology, Center for Biologic Imaging, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA.
| | - Y Barak
- Magee-Womens Research Institute, Department of Obstetrics, Gynecology and Reproductive Sciences, University of Pittsburgh School of Medicine, 204 Craft Avenue, Pittsburgh, PA 15213, USA; Magee-Womens Research Institute, Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, 204 Craft Avenue, Pittsburgh, PA 15213, USA.
| | - Y Sadovsky
- Magee-Womens Research Institute, Department of Obstetrics, Gynecology and Reproductive Sciences, University of Pittsburgh School of Medicine, 204 Craft Avenue, Pittsburgh, PA 15213, USA; Magee-Womens Research Institute, Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, 204 Craft Avenue, Pittsburgh, PA 15213, USA.
| | - J R Chaillet
- Magee-Womens Research Institute, Department of Obstetrics, Gynecology and Reproductive Sciences, University of Pittsburgh School of Medicine, 204 Craft Avenue, Pittsburgh, PA 15213, USA.
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20
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McGraw S, Zhang JX, Farag M, Chan D, Caron M, Konermann C, Oakes CC, Mohan KN, Plass C, Pastinen T, Bourque G, Chaillet JR, Trasler JM. Transient DNMT1 suppression reveals hidden heritable marks in the genome. Nucleic Acids Res 2015; 43:1485-97. [PMID: 25578964 PMCID: PMC4330356 DOI: 10.1093/nar/gku1386] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Genome-wide demethylation and remethylation of DNA during early embryogenesis is essential for development. Imprinted germline differentially methylated domains (gDMDs) established by sex-specific methylation in either male or female germ cells, must escape these dynamic changes and sustain precise inheritance of both methylated and unmethylated parental alleles. To identify other, gDMD-like sequences with the same epigenetic inheritance properties, we used a modified embryonic stem (ES) cell line that emulates the early embryonic demethylation and remethylation waves. Transient DNMT1 suppression revealed gDMD-like sequences requiring continuous DNMT1 activity to sustain a highly methylated state. Remethylation of these sequences was also compromised in vivo in a mouse model of transient DNMT1 loss in the preimplantation embryo. These novel regions, possessing heritable epigenetic features similar to imprinted-gDMDs are required for normal physiological and developmental processes and when disrupted are associated with disorders such as cancer and autism spectrum disorders. This study presents new perspectives on DNA methylation heritability during early embryo development that extend beyond conventional imprinted-gDMDs.
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Affiliation(s)
- Serge McGraw
- Departments of Pediatrics, Human Genetics and Pharmacology & Therapeutics, McGill University and the Research Institute of the McGill University Health Centre at the Montreal Children's Hospital, Montreal, QC H3Z 2Z3, Canada
| | - Jacques X Zhang
- Departments of Pediatrics, Human Genetics and Pharmacology & Therapeutics, McGill University and the Research Institute of the McGill University Health Centre at the Montreal Children's Hospital, Montreal, QC H3Z 2Z3, Canada
| | - Mena Farag
- Departments of Pediatrics, Human Genetics and Pharmacology & Therapeutics, McGill University and the Research Institute of the McGill University Health Centre at the Montreal Children's Hospital, Montreal, QC H3Z 2Z3, Canada
| | - Donovan Chan
- Departments of Pediatrics, Human Genetics and Pharmacology & Therapeutics, McGill University and the Research Institute of the McGill University Health Centre at the Montreal Children's Hospital, Montreal, QC H3Z 2Z3, Canada
| | - Maxime Caron
- Department of Human Genetics, McGill University and Genome Quebec Innovation Centre, Montreal, QC H3A 1A4, Canada
| | - Carolin Konermann
- Division of Epigenomics and Cancer Risk Factors, German Cancer Research Center, Heidelberg 69120, Germany
| | - Christopher C Oakes
- Division of Epigenomics and Cancer Risk Factors, German Cancer Research Center, Heidelberg 69120, Germany
| | - K Naga Mohan
- Department of Biological Sciences, Birla Institute of Technology and Science Pilani, Hyderabad 500 078, India
| | - Christoph Plass
- Division of Epigenomics and Cancer Risk Factors, German Cancer Research Center, Heidelberg 69120, Germany
| | - Tomi Pastinen
- Department of Human Genetics, McGill University and Genome Quebec Innovation Centre, Montreal, QC H3A 1A4, Canada
| | - Guillaume Bourque
- Department of Human Genetics, McGill University and Genome Quebec Innovation Centre, Montreal, QC H3A 1A4, Canada
| | - J Richard Chaillet
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA 15213-3005, USA
| | - Jacquetta M Trasler
- Departments of Pediatrics, Human Genetics and Pharmacology & Therapeutics, McGill University and the Research Institute of the McGill University Health Centre at the Montreal Children's Hospital, Montreal, QC H3Z 2Z3, Canada
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21
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The DNMT1 intrinsically disordered domain regulates genomic methylation during development. Genetics 2014; 199:533-41. [PMID: 25533200 DOI: 10.1534/genetics.114.173609] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The DNMT1 cytosine methyltransferase enzyme contains a large ∼300-aa intrinsically disordered domain (IDD) that we previously showed regulated DNA methylation patterns in mouse ES cells. Here we generated seven mouse lines with different mutations in the IDD. Homozygous mutant mice of five lines developed normally, with normal levels of methylation on both imprinted and nonimprinted DNA sequences. The other two lines, however, had alterations in imprinted and/or nonimprinted (global) DNA methylation appearing during embryonic development. Embryos of one line expressing a DNMT1 variant containing a 6-aa rat orthologous sequence in the IDD maintained imprinted methylation, showed very reduced levels of global methylation and occasionally completed fetal development. These in vivo studies demonstrate that at least two DNMT1-dependent methylation processes can be distinguished during fetal development. One process maintains the bulk of genomic methylation on nonimprinted sequences. The other process maintains methylation on a much smaller class of sequences including but not limited to gametic differentially methylated domains (gDMDs) that transmit essential imprinted parent-specific methylation for embryonic development.
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22
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Zhang B, Denomme MM, White CR, Leung KY, Lee MB, Greene NDE, Mann MRW, Trasler JM, Baltz JM. Both the folate cycle and betaine-homocysteine methyltransferase contribute methyl groups for DNA methylation in mouse blastocysts. FASEB J 2014; 29:1069-79. [PMID: 25466894 DOI: 10.1096/fj.14-261131] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The embryonic pattern of global DNA methylation is first established in the inner cell mass (ICM) of the mouse blastocyst. The methyl donor S-adenosylmethionine (SAM) is produced in most cells through the folate cycle, but only a few cell types generate SAM from betaine (N,N,N-trimethylglycine) via betaine-homocysteine methyltransferase (BHMT), which is expressed in the mouse ICM. Here, mean ICM cell numbers decreased from 18-19 in controls to 11-13 when the folate cycle was inhibited by the antifolate methotrexate and to 12-14 when BHMT expression was knocked down by antisense morpholinos. Inhibiting both pathways, however, much more severely affected ICM development (7-8 cells). Total SAM levels in mouse blastocysts decreased significantly only when both pathways were inhibited (from 3.1 to 1.6 pmol/100 blastocysts). DNA methylation, detected as 5-methylcytosine (5-MeC) immunofluorescence in isolated ICMs, was minimally affected by inhibition of either pathway alone but decreased by at least 45-55% when both BHMT and the folate cycle were inhibited simultaneously. Effects on cell numbers and 5-MeC levels in the ICM were completely rescued by methionine (immediate SAM precursor) or SAM. Both the folate cycle and betaine/BHMT appear to contribute to a methyl pool required for normal ICM development and establishing initial embryonic DNA methylation.
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Affiliation(s)
- Baohua Zhang
- *Ottawa Hospital Research Institute, Ottawa, Ontario, Canada; Departments of Obstetrics and Gynecology, and Cellular and Molecular Medicine, University of Ottawa Faculty of Medicine, Ottawa, Ontario, Canada; Department of Obstetrics and Gynecology, and Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada; Children's Health Research Institute, London, Ontario, Canada; Developmental Biology and Cancer Program, University College London Institute of Child Health, London, United Kingdom; Research Institute of the McGill University Health Centre, Montréal Children's Hospital, Montréal, Quebec, Canada; and Departments of Human Genetics, Pediatrics, and Pharmacology and Therapeutics, McGill University, Montréal, Quebec, Canada
| | - Michelle M Denomme
- *Ottawa Hospital Research Institute, Ottawa, Ontario, Canada; Departments of Obstetrics and Gynecology, and Cellular and Molecular Medicine, University of Ottawa Faculty of Medicine, Ottawa, Ontario, Canada; Department of Obstetrics and Gynecology, and Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada; Children's Health Research Institute, London, Ontario, Canada; Developmental Biology and Cancer Program, University College London Institute of Child Health, London, United Kingdom; Research Institute of the McGill University Health Centre, Montréal Children's Hospital, Montréal, Quebec, Canada; and Departments of Human Genetics, Pediatrics, and Pharmacology and Therapeutics, McGill University, Montréal, Quebec, Canada
| | - Carlee R White
- *Ottawa Hospital Research Institute, Ottawa, Ontario, Canada; Departments of Obstetrics and Gynecology, and Cellular and Molecular Medicine, University of Ottawa Faculty of Medicine, Ottawa, Ontario, Canada; Department of Obstetrics and Gynecology, and Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada; Children's Health Research Institute, London, Ontario, Canada; Developmental Biology and Cancer Program, University College London Institute of Child Health, London, United Kingdom; Research Institute of the McGill University Health Centre, Montréal Children's Hospital, Montréal, Quebec, Canada; and Departments of Human Genetics, Pediatrics, and Pharmacology and Therapeutics, McGill University, Montréal, Quebec, Canada
| | - Kit-Yi Leung
- *Ottawa Hospital Research Institute, Ottawa, Ontario, Canada; Departments of Obstetrics and Gynecology, and Cellular and Molecular Medicine, University of Ottawa Faculty of Medicine, Ottawa, Ontario, Canada; Department of Obstetrics and Gynecology, and Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada; Children's Health Research Institute, London, Ontario, Canada; Developmental Biology and Cancer Program, University College London Institute of Child Health, London, United Kingdom; Research Institute of the McGill University Health Centre, Montréal Children's Hospital, Montréal, Quebec, Canada; and Departments of Human Genetics, Pediatrics, and Pharmacology and Therapeutics, McGill University, Montréal, Quebec, Canada
| | - Martin B Lee
- *Ottawa Hospital Research Institute, Ottawa, Ontario, Canada; Departments of Obstetrics and Gynecology, and Cellular and Molecular Medicine, University of Ottawa Faculty of Medicine, Ottawa, Ontario, Canada; Department of Obstetrics and Gynecology, and Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada; Children's Health Research Institute, London, Ontario, Canada; Developmental Biology and Cancer Program, University College London Institute of Child Health, London, United Kingdom; Research Institute of the McGill University Health Centre, Montréal Children's Hospital, Montréal, Quebec, Canada; and Departments of Human Genetics, Pediatrics, and Pharmacology and Therapeutics, McGill University, Montréal, Quebec, Canada
| | - Nicholas D E Greene
- *Ottawa Hospital Research Institute, Ottawa, Ontario, Canada; Departments of Obstetrics and Gynecology, and Cellular and Molecular Medicine, University of Ottawa Faculty of Medicine, Ottawa, Ontario, Canada; Department of Obstetrics and Gynecology, and Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada; Children's Health Research Institute, London, Ontario, Canada; Developmental Biology and Cancer Program, University College London Institute of Child Health, London, United Kingdom; Research Institute of the McGill University Health Centre, Montréal Children's Hospital, Montréal, Quebec, Canada; and Departments of Human Genetics, Pediatrics, and Pharmacology and Therapeutics, McGill University, Montréal, Quebec, Canada
| | - Mellissa R W Mann
- *Ottawa Hospital Research Institute, Ottawa, Ontario, Canada; Departments of Obstetrics and Gynecology, and Cellular and Molecular Medicine, University of Ottawa Faculty of Medicine, Ottawa, Ontario, Canada; Department of Obstetrics and Gynecology, and Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada; Children's Health Research Institute, London, Ontario, Canada; Developmental Biology and Cancer Program, University College London Institute of Child Health, London, United Kingdom; Research Institute of the McGill University Health Centre, Montréal Children's Hospital, Montréal, Quebec, Canada; and Departments of Human Genetics, Pediatrics, and Pharmacology and Therapeutics, McGill University, Montréal, Quebec, Canada
| | - Jacquetta M Trasler
- *Ottawa Hospital Research Institute, Ottawa, Ontario, Canada; Departments of Obstetrics and Gynecology, and Cellular and Molecular Medicine, University of Ottawa Faculty of Medicine, Ottawa, Ontario, Canada; Department of Obstetrics and Gynecology, and Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada; Children's Health Research Institute, London, Ontario, Canada; Developmental Biology and Cancer Program, University College London Institute of Child Health, London, United Kingdom; Research Institute of the McGill University Health Centre, Montréal Children's Hospital, Montréal, Quebec, Canada; and Departments of Human Genetics, Pediatrics, and Pharmacology and Therapeutics, McGill University, Montréal, Quebec, Canada
| | - Jay M Baltz
- *Ottawa Hospital Research Institute, Ottawa, Ontario, Canada; Departments of Obstetrics and Gynecology, and Cellular and Molecular Medicine, University of Ottawa Faculty of Medicine, Ottawa, Ontario, Canada; Department of Obstetrics and Gynecology, and Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada; Children's Health Research Institute, London, Ontario, Canada; Developmental Biology and Cancer Program, University College London Institute of Child Health, London, United Kingdom; Research Institute of the McGill University Health Centre, Montréal Children's Hospital, Montréal, Quebec, Canada; and Departments of Human Genetics, Pediatrics, and Pharmacology and Therapeutics, McGill University, Montréal, Quebec, Canada
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Petrussa L, Van de Velde H, De Rycke M. Dynamic regulation of DNA methyltransferases in human oocytes and preimplantation embryos after assisted reproductive technologies. Mol Hum Reprod 2014; 20:861-74. [PMID: 24994815 DOI: 10.1093/molehr/gau049] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
DNA methylation is a key epigenetic modification which is essential for normal embryonic development. Major epigenetic reprogramming takes place during gametogenesis and in the early embryo; the complex DNA methylation patterns are established and maintained by DNA methyltransferases (DNMTs). However, the influence of assisted reproductive technologies (ART) on DNA methylation reprogramming enzymes has predominantly been studied in mice and less so in human oocytes and embryos. The expression and localization patterns of the four known DNMTs were analysed in human oocytes and IVF/ICSI embryos by immunocytochemistry and compared between a reference group of good quality fresh embryos and groups of abnormally developing embryos or embryo groups after cryopreservation. In humans, DNMT1o rather than DNMT1s seems to be the key player for maintaining methylation in early embryos. DNMT3b, rather than DNMT3a and DNMT3L, appears to ensure global DNA remethylation in the blastocysts before implantation. DNMT3L, an important regulator of maternal imprint methylation in mouse, was not detected in human oocytes (GV, MI and MII stage). Our study confirms the existence of species differences for mammalian DNA methylation enzymes. In poor quality fresh embryos, the switch towards nuclear DNMT3b expression was delayed and nuclear DNMT1, DNMT1s and DNMT3b expression was less common. Compared with the reference embryos, a smaller number of cryopreserved embryos showed nuclear DNMT1, while a delayed switch to nuclear DNMT3b and an extended DNMT1s temporal expression pattern were also observed. The spatial and temporal expression patterns of DNMTs seem to be disturbed in abnormally developing embryos and in embryos that have been cryopreserved. Further research must be performed in order to understand whether the potentially disturbed embryonic DNMT expression after cryopreservation has any long-term developmental consequences.
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Affiliation(s)
- Laetitia Petrussa
- Department of Reproduction and Genetics (REGE), Vrije Universiteit Brussel (VUB), Laarbeeklaan 103, 1090 Brussels, Belgium
| | - Hilde Van de Velde
- Department of Reproduction and Genetics (REGE), Vrije Universiteit Brussel (VUB), Laarbeeklaan 103, 1090 Brussels, Belgium Centre for Reproductive Medicine (CRM), Universitair Ziekenhuis Brussel (UZ Brussel), Laarbeeklaan 101, 1090 Brussels, Belgium
| | - Martine De Rycke
- Department of Reproduction and Genetics (REGE), Vrije Universiteit Brussel (VUB), Laarbeeklaan 103, 1090 Brussels, Belgium Centre for Medical Genetics (CMG), Universitair Ziekenhuis Brussel (UZ Brussel), Laarbeeklaan 101, 1090 Brussels, Belgium
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24
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Azzi S, Blaise A, Steunou V, Harbison MD, Salem J, Brioude F, Rossignol S, Habib WA, Thibaud N, Neves CD, Jule ML, Brachet C, Heinrichs C, Bouc YL, Netchine I. Complex tissue-specific epigenotypes in Russell-Silver Syndrome associated with 11p15 ICR1 hypomethylation. Hum Mutat 2014; 35:1211-20. [PMID: 25044976 DOI: 10.1002/humu.22623] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Accepted: 07/02/2014] [Indexed: 01/13/2023]
Abstract
Russell-Silver Syndrome (RSS) is a prenatal and postnatal growth retardation syndrome caused mainly by 11p15 ICR1 hypomethylation. Clinical presentation is heterogeneous in RSS patients with 11p15 ICR1 hypomethylation. We previously identified a subset of RSS patients with 11p15 ICR1 and multilocus hypomethylation. Here, we examine the relationships between IGF2 expression, 11p15 ICR1 methylation, and multilocus imprinting defects in various cell types from 39 RSS patients with 11p15 ICR1 hypomethylation in leukocyte DNA. 11p15 ICR1 hypomethylation was more pronounced in leukocytes than in buccal mucosa cells. Skin fibroblast IGF2 expression was correlated with the degree of ICR1 hypomethylation. Different tissue-specific multilocus methylation defects coexisted in 38% of cases, with some loci hypomethylated and others hypermethylated within the same cell type in some cases. Our new results suggest that tissue-specific epigenotypes may lead to clinical heterogeneity in RSS.
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Affiliation(s)
- Salah Azzi
- INSERM, UMR_S 938, CDR Saint-Antoine, Paris, F-75012, France; Sorbonne Universités, UPMC Univ Paris 06, UMR_S 938, CDR Saint-Antoine, Paris, F-75012, France; APHP, Armand Trousseau Hospital, Pediatric Endocrinology, Paris, France
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25
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Chavez SL, McElroy SL, Bossert NL, De Jonge CJ, Rodriguez MV, Leong DE, Behr B, Westphal LM, Reijo Pera RA. Comparison of epigenetic mediator expression and function in mouse and human embryonic blastomeres. Hum Mol Genet 2014; 23:4970-84. [PMID: 24821703 PMCID: PMC4140471 DOI: 10.1093/hmg/ddu212] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A map of human embryo development that combines imaging, molecular, genetic and epigenetic data for comparisons to other species and across pathologies would be greatly beneficial for basic science and clinical applications. Here, we compared mRNA and protein expression of key mediators of DNA methylation and histone modifications between mouse and human embryos, embryos from fertile/infertile couples, and following growth factor supplementation. We observed that individual mouse and human embryos are characterized by similarities and distinct differences in DNA methylation and histone modification patterns especially at the single-cell level. In particular, while mouse embryos first exhibited sub-compartmentalization of different histone modifications between blastomeres at the morula stage and cell sub-populations in blastocysts, differential histone modification expression was detected between blastomeres earlier in human embryos at the four- to eight-cell stage. Likewise, differences in epigenetic mediator expression were also observed between embryos from fertile and infertile couples, which were largely equalized in response to growth factor supplementation, suggesting that select growth factors might prevent alterations in epigenetic profiles during prolonged embryo culture. Finally, we determined that reduced expression via morpholino technologies of a single histone-modifying enzyme, Rps6ka4/Msk2, resulted in cleavage-stage arrest as assessed by time-lapse imaging and was associated with aneuploidy generation. Taken together, data document differences in epigenetic patterns between species with implications for fertility and suggest functional roles for individual epigenetic factors during pre-implantation development.
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Affiliation(s)
- Shawn L Chavez
- Center for Reproductive and Stem Cell Biology, Institute for Stem Cell Biology and Regenerative Medicine, Department of Obstetrics and Gynecology and Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Sohyun L McElroy
- Center for Reproductive and Stem Cell Biology, Institute for Stem Cell Biology and Regenerative Medicine, Department of Obstetrics and Gynecology and Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Nancy L Bossert
- Reproductive Medicine Center, University of Minnesota, Minneapolis, MN 55414, USA
| | | | - Maria Vera Rodriguez
- Center for Reproductive and Stem Cell Biology, Institute for Stem Cell Biology and Regenerative Medicine, Department of Obstetrics and Gynecology and Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA Iviomics, Valencia, Spain
| | - Denise E Leong
- Center for Reproductive and Stem Cell Biology, Institute for Stem Cell Biology and Regenerative Medicine, Department of Obstetrics and Gynecology and Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Barry Behr
- Department of Obstetrics and Gynecology and
| | | | - Renee A Reijo Pera
- Center for Reproductive and Stem Cell Biology, Institute for Stem Cell Biology and Regenerative Medicine, Department of Obstetrics and Gynecology and Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA
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26
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Kappen C, Salbaum JM. Gene expression in teratogenic exposures: a new approach to understanding individual risk. Reprod Toxicol 2014; 45:94-104. [PMID: 24491834 DOI: 10.1016/j.reprotox.2013.12.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Revised: 11/21/2013] [Accepted: 12/18/2013] [Indexed: 12/29/2022]
Abstract
The phenomenon of partial or incomplete penetrance is common to many paradigms of exposure to teratogens, where only some of the exposed individuals exhibit developmental defects. We here argue that the most widely used experimental approaches in reproductive toxicology do not take partial penetrance into account, and are thus likely to miss differences between affected and unaffected individuals that contribute to susceptibility for teratogenesis. We propose that focus on the variation between exposed individuals could help to discover factors that may play a causative role for abnormal developmental processes that occur with incomplete penetrance.
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Affiliation(s)
- Claudia Kappen
- Department of Developmental Biology, Pennington Biomedical Research Center, Louisiana State University System, 6400 Perkins Road, Baton Rouge, LA 70808, United States.
| | - J Michael Salbaum
- Laboratory of Regulation of Gene Expression, Pennington Biomedical Research Center, Louisiana State University System, 6400 Perkins Road, Baton Rouge, LA 70808, United States
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27
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McGraw S, Oakes CC, Martel J, Cirio MC, de Zeeuw P, Mak W, Plass C, Bartolomei MS, Chaillet JR, Trasler JM. Loss of DNMT1o disrupts imprinted X chromosome inactivation and accentuates placental defects in females. PLoS Genet 2013; 9:e1003873. [PMID: 24278026 PMCID: PMC3836718 DOI: 10.1371/journal.pgen.1003873] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Accepted: 08/28/2013] [Indexed: 01/04/2023] Open
Abstract
The maintenance of key germline derived DNA methylation patterns during preimplantation development depends on stores of DNA cytosine methyltransferase-1o (DNMT1o) provided by the oocyte. Dnmt1omat−/− mouse embryos born to Dnmt1Δ1o/Δ1o female mice lack DNMT1o protein and have disrupted genomic imprinting and associated phenotypic abnormalities. Here, we describe additional female-specific morphological abnormalities and DNA hypomethylation defects outside imprinted loci, restricted to extraembryonic tissue. Compared to male offspring, the placentae of female offspring of Dnmt1Δ1o/Δ1o mothers displayed a higher incidence of genic and intergenic hypomethylation and more frequent and extreme placental dysmorphology. The majority of the affected loci were concentrated on the X chromosome and associated with aberrant biallelic expression, indicating that imprinted X-inactivation was perturbed. Hypomethylation of a key regulatory region of Xite within the X-inactivation center was present in female blastocysts shortly after the absence of methylation maintenance by DNMT1o at the 8-cell stage. The female preponderance of placental DNA hypomethylation associated with maternal DNMT1o deficiency provides evidence of additional roles beyond the maintenance of genomic imprints for DNA methylation events in the preimplantation embryo, including a role in imprinted X chromosome inactivation. During oocyte growth and maturation, vital proteins and enzymes are produced to ensure that, when fertilized, a healthy embryo will arise. When this natural process is interrupted, one or more of these essential elements can fail to be produced thus compromising the health of the future embryo. We are using a mouse model, lacking an enzyme (DNMT1o) produced in the oocyte and only required post-fertilization in the early embryo for the maintenance of inherited DNA methylation marks. Here, we reveal that oocytes lacking DNMT1o, when fertilized, generated conceptuses with a wide variety of placental abnormalities. These placental abnormalities were more frequent and severe in females, and showed specific genomic regions constantly deprived of their normal methylation marks. The affected genomic regions were concentrated on the X chromosome. Interestingly, we also found that a region important for the regulation of the X chromosome inactivation process was hypomethylated in female blastocysts and was associated with sex-specific abnormalities in the placenta, relaxation of imprinted X chromosome inactivation, and disruption of DNA methylation later in development. Our findings provide a novel unanticipated role for DNA methylation events taking place within the first few days of life specifically in female preimplantation embryos.
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Affiliation(s)
- Serge McGraw
- Departments of Pharmacology & Therapeutics, Pediatrics and Human Genetics, Research Institute at The Montreal Children's Hospital of the McGill University Health Centre, McGill University, Montreal, Quebec, Canada
| | - Christopher C. Oakes
- Department of Epigenomics and Cancer Risk Factors, The German Cancer Research Center, Heidelberg, Baden-Württemberg, Germany
| | - Josée Martel
- Departments of Pharmacology & Therapeutics, Pediatrics and Human Genetics, Research Institute at The Montreal Children's Hospital of the McGill University Health Centre, McGill University, Montreal, Quebec, Canada
| | - M. Cecilia Cirio
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Pauline de Zeeuw
- Departments of Pharmacology & Therapeutics, Pediatrics and Human Genetics, Research Institute at The Montreal Children's Hospital of the McGill University Health Centre, McGill University, Montreal, Quebec, Canada
| | - Winifred Mak
- Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Christoph Plass
- Department of Epigenomics and Cancer Risk Factors, The German Cancer Research Center, Heidelberg, Baden-Württemberg, Germany
| | - Marisa S. Bartolomei
- Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - J. Richard Chaillet
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Jacquetta M. Trasler
- Departments of Pharmacology & Therapeutics, Pediatrics and Human Genetics, Research Institute at The Montreal Children's Hospital of the McGill University Health Centre, McGill University, Montreal, Quebec, Canada
- * E-mail:
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28
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Denomme MM, Mann MRW. Maternal control of genomic imprint maintenance. Reprod Biomed Online 2013; 27:629-36. [PMID: 24125946 DOI: 10.1016/j.rbmo.2013.06.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Revised: 06/03/2013] [Accepted: 06/12/2013] [Indexed: 11/17/2022]
Abstract
Genomic imprinting is a specialized transcriptional phenomenon that employs epigenetic mechanisms to facilitate parental-specific expression. Perturbations in parental epigenetic asymmetry can lead to the development of imprinting disorders, such as Beckwith-Wiedemann syndrome and Angelman syndrome. DNA methylation is one of the most widely studied epigenetic marks that characterizes imprinted regions. During gametogenesis and early embryogenesis, imprinted methylation undergoes a cycle of erasure, acquisition and maintenance. Gamete and embryo manipulations for the purpose of assisted reproduction are performed during these reprogramming events and may lead to their disruption. Recent studies point to the role of maternal-effect proteins in imprinted gene regulation. Studies are now required to increase understanding of how these factors regulate genomic imprinting as well as how assisted reproduction technologies may alter their function.
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Affiliation(s)
- Michelle M Denomme
- Department of Obstetrics and Gynecology, University of Western Ontario, Schulich School of Medicine and Dentistry, London, Ontario, Canada; Department of Biochemistry, University of Western Ontario, Schulich School of Medicine and Dentistry, London, Ontario, Canada; Children's Health Research Institute, London, Ontario, Canada N6C 2V5
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29
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McGraw S, Shojaei Saadi HA, Robert C. Meeting the methodological challenges in molecular mapping of the embryonic epigenome. Mol Hum Reprod 2013; 19:809-27. [PMID: 23783346 DOI: 10.1093/molehr/gat046] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The past decade of life sciences research has been driven by progress in genomics. Many voices are already proclaiming the post-genomics era, in which phenomena other than sequence polymorphism influence gene expression and also explain complex phenotypes. One of these burgeoning fields is the study of the epigenome. Although the mechanisms by which chromatin structure and reorganization as well as cytosine methylation influence gene expression are not fully understood, they are being invoked to explain the now-accepted long-term impact of the environment on gene expression, which appears to be a factor in the development of numerous diseases. Such studies are particularly relevant in early embryonic development, during which waves of epigenetic reprogramming are known to have profound impacts. Since gametes and zygotes are in the process of resetting the genome in order to create embryonic stem cells that will each differentiate to create one of many specific tissue types, this phase of life is now viewed as a window of susceptibility to epigenetic reprogramming errors. Epigenetics could explain the influence of factors such as the nutritional/metabolic status of the mother or the artificial environment of assisted reproductive technologies. However, the peculiar nature of early embryos in addition to their scarcity poses numerous technological challenges that are slowly being overcome. The principal subject of this article is to review the suitability of various current and emerging technological platforms to study oocytes and early embryonic epigenome with more emphasis on studying DNA methylation. Furthermore, the constraint of samples size, inherent to the study of preimplantation embryo development, was put in perspective with the various molecular platforms described.
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Affiliation(s)
- Serge McGraw
- Department of Human Genetics, Montreal Children's Hospital Research Institute, McGill University, Montréal, QC H3Z 2Z3, Canada
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30
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Ge ZJ, Liang XW, Guo L, Liang QX, Luo SM, Wang YP, Wei YC, Han ZM, Schatten H, Sun QY. Maternal diabetes causes alterations of DNA methylation statuses of some imprinted genes in murine oocytes. Biol Reprod 2013; 88:117. [PMID: 23515675 DOI: 10.1095/biolreprod.112.105981] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Maternal diabetes has adverse effects not only on oocyte quality but also on embryo development. However, it is still unknown whether the DNA imprinting in oocytes is altered by diabetes. By using streptozotocin (STZ)-induced and nonobese diabetic (NOD) mouse models we investigated the effect of maternal diabetes on DNA methylation of imprinted genes in oocytes. Mice which were judged as being diabetic 4 days after STZ injection were used for experiments. In superovulated oocytes of diabetic mice, the methylation pattern of Peg3 differential methylation regions (DMR) was affected in a time-dependent manner, and evident demethylation was observed on Day 35 after STZ injection. The expression level of DNA methyltransferases (DNMTs) was also decreased in a time-dependent manner in diabetic oocytes. However, the methylation patterns of H19 and Snrpn DMRs were not significantly altered by maternal diabetes, although there were some changes in Snrpn. In NOD mice, the methylation pattern of Peg3 was similar to that of STZ-induced mice. Embryo development was adversely affected by maternal diabetes; however, no evident imprinting abnormality was observed in oocytes from female offspring derived from a diabetic mother. These results indicate that maternal diabetes has adverse effects on DNA methylation of maternally imprinted gene Peg3 in oocytes of a diabetic female in a time-dependent manner, but methylation in offspring's oocytes is normal.
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Affiliation(s)
- Zhao-Jia Ge
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
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31
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Ko YG, Yun J, Park HJ, Tanaka S, Shiota K, Cho JH. Dynamic methylation pattern of the methyltransferase1o (Dnmt1o) 5'-flanking region during mouse oogenesis and spermatogenesis. Mol Reprod Dev 2013; 80:212-22. [PMID: 23325669 DOI: 10.1002/mrd.22153] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Accepted: 01/09/2013] [Indexed: 12/30/2022]
Abstract
DNA methyltransferase1o (Dnmt1o), which is specific to oocyte and preimplantation embryo, plays a role in maintaining DNA methylation in mammalian cells. Here, we investigated the methylation status of CpGs sites in the Dnmt1o 5'-flanking region in germ cells at different stages of oogenesis or spermatogenesis. The methylation levels of the CpG sites at the 5'-flanking regions were hypermethylated in growing oocytes of all follicular stages, while the oocytes in meiotic metaphase II (MII) were demethylated. The methylation pattern within the CpGs sites in the 5'-flanking region, however, was dramatically changed during spermatogenesis. We observed that there was significant non-CpG methylation both in MII oocytes and spermatocytes. Although a low methylation level in non-CpG sites was observed in primary and secondary oocytes, the CpA site of position 25 and CpT site of position 29 within the no-CpG region in the 5'-flanking region of Dnmt1o was highly methylated in MII oocytes. During spermatogenesis, the low degree of methylation at CpG sites in spermatocytes increased to a higher degree in sperm, while the high ratio of methylation in non-CpG sites in spermatocytes decreased. Together, germ cells showed inverted methylation patterns between CpG and non-CpG sites in the Dnmt1o 5'-upstream region, and the methylation pattern during oogenesis did not drastically change, remaining generally hypomethylated at the MII stage.
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Affiliation(s)
- Yeoung-Gyu Ko
- Animal Genetic Resources Station, National Institute of Animal Science, RDA, Namwon, Korea.
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Abstract
Zusammenfassung
Bei allen derzeit bekannten Imprintingerkrankungen wurde über eine Assoziation mit molekularen Veränderungen an krankheitsspezifischen chromosomalen Loci berichtet. Die locusspezifische Zuordnung einiger dieser Krankheitsbilder wird erschwert durch den Nachweis so genannter Multilocusmethylierungsdefekte (MLMD): Dabei besteht nicht nur an krankheitsspezifischen geprägten Genorten eine aberrante Methylierung, sondern auch an anderen Loci. Klinisch zeigt sich mehrheitlich die Symptomatik nur einer Imprintingerkrankung, in einzelnen Fällen überlappen sich jedoch verschiedene Krankheitsbilder. Umgekehrt wurden auch Fälle mit gleichartigem MLMD-Muster, aber unterschiedlichen Krankheitsbildern beschrieben. Zur Abklärung von MLMD sollten daher Testverfahren eingesetzt werden, die auf Methylierungsveränderungen an verschiedenen geprägten Loci ausgerichtet sind. Aber auch bei der MLMD-Testung ist eine eindeutige Unterscheidung des zugrunde liegenden Mutationstyps als Basis für eine gezielte genetische Beratung erforderlich.
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Mohan KN, Chaillet JR. Cell and molecular biology of DNA methyltransferase 1. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2013; 306:1-42. [PMID: 24016522 DOI: 10.1016/b978-0-12-407694-5.00001-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The DNA cytosine methyltransferase 1 (DNMT1) is a ubiquitous nuclear enzyme that catalyzes the well-established reaction of placing methyl groups on the unmethylated cytosines in methyl-CpG:CpG base pairs in the hemimethylated DNA formed by methylated parent and unmethylated daughter strands. This activity regenerates fully methylated methyl-CpG:methyl-CpG pairs. Despite the straightforward nature of its catalytic activity, detailed biochemical, genetic, and developmental studies revealed intricate details of the central regulatory role of DNMT1 in governing the epigenetic makeup of the nuclear genome. DNMT1 mediates demethylation and also participates in seemingly wide cellular functions unrelated to maintenance DNA methylation. This review brings together mechanistic details of maintenance methylation by DNMT1, its regulation at transcriptional and posttranscriptional levels, and the seemingly unexpected functions of DNMT1 in the context of DNA methylation which is central to epigenetic changes that occur during development and the process of cell differentiation.
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Affiliation(s)
- K Naga Mohan
- Department of Biological Sciences, Birla Institute of Technology and Science Pilani, Hyderabad Campus, Hyderabad, Andhra Pradesh, India
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34
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Wilkins JF. Phenotypic Plasticity, Pleiotropy, and the Growth-First Theory of Imprinting. ENVIRONMENTAL EPIGENOMICS IN HEALTH AND DISEASE 2013. [DOI: 10.1007/978-3-642-36827-1_4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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35
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Generalized disruption of inherited genomic imprints leads to wide-ranging placental defects and dysregulated fetal growth. Dev Biol 2012; 373:72-82. [PMID: 23085235 DOI: 10.1016/j.ydbio.2012.10.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2012] [Revised: 10/02/2012] [Accepted: 10/08/2012] [Indexed: 01/21/2023]
Abstract
Monoallelic expression of imprinted genes, including ones solely expressed in the placenta, is essential for normal placental development and fetal growth. To better understand the role of placental imprinting in placental development and fetal growth, we examined conceptuses developing in the absence of maternally derived DNA (cytosine-5-)-methyltransferase 1o (DNMT1o). Absence of DNMT1o results in the partial loss of methylation at imprinted differentially methylated domain (DMD) sequences in the embryo and the placenta. Mid-gestation E9.5 DNMT1o-deficient placentas exhibited structural abnormalities of all tissue layers. At E17.5, all examined placentas had aberrant placental morphology, most notably in the spongiotrophoblast and labyrinth layers. Abnormalities included an expanded volume fraction of spongiotrophoblast tissue with extension of the spongiotrophoblast layer into the labyrinth. Many mutant placentas also demonstrated migration abnormalities of glycogen cells. Additionally, the volume fraction of the labyrinth was reduced, as was the surface area for maternal fetal gas exchange. Despite these placental morphologic abnormalities, approximately one-half of DNMT1o-deficient fetuses survived to late gestation (E17.5). Furthermore, DNMT1o-deficient placentas supported a broad range of fetal growth. The ability of some DNMT1o-deficient and morphologically abnormal placentas to support fetal growth in excess of wild type demonstrates the importance of differential methylation of DMDs and proper imprinting of discrete gene clusters to placental morphogenesis and fetal growth.
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36
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Denomme MM, Mann MRW. Genomic imprints as a model for the analysis of epigenetic stability during assisted reproductive technologies. Reproduction 2012; 144:393-409. [DOI: 10.1530/rep-12-0237] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Gamete and early embryo development are important stages when genome-scale epigenetic transitions are orchestrated. The apparent lack of remodeling of differential imprinted DNA methylation during preimplantation development has lead to the argument that epigenetic disruption by assisted reproductive technologies (ARTs) is restricted to imprinted genes. We contend that aberrant imprinted methylation arising from assisted reproduction or infertility may be an indicator of more global epigenetic instability. Here, we review the current literature on the effects of ARTs, including ovarian stimulation,in vitrooocyte maturation, oocyte cryopreservation, IVF, ICSI, embryo culture, and infertility on genomic imprinting as a model for evaluating epigenetic stability. Undoubtedly, the relationship between impaired fertility, ARTs, and epigenetic stability is unquestionably complex. What is clear is that future studies need to be directed at determining the molecular and cellular mechanisms giving rise to epigenetic errors.
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37
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Eggermann T, Leisten I, Binder G, Begemann M, Spengler S. Disturbed methylation at multiple imprinted loci: an increasing observation in imprinting disorders. Epigenomics 2012; 3:625-37. [PMID: 22126250 DOI: 10.2217/epi.11.84] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The widely accepted association between aberrant methylation at specific imprinted loci and distinct imprinting disorders has recently been brought into question by the identification of methylation defects at multiple loci (multilocus methylation defect [MLMD]). Strikingly, in different imprinting disorders, the same MLMD patterns can be observed. The cause for this ambiguous epigenotype-phenotype correlation is currently unknown. Future strategies to solve this enigma have to include all levels of imprinting regulation, ranging from DNA methylation to chromatin organization, as any disturbance of the balanced interaction between the different players in imprinting regulation might cause disturbed expression of imprinted factors. The molecular analysis of MLMD will help in discovering these interactions and contribute to the understanding of genomic imprinting and its disturbances.
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Affiliation(s)
- Thomas Eggermann
- Institute of Human Genetics, RWTH Aachen, Pauwelsstr. 30, D-52074 Aachen, Germany.
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38
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Genomic imprinting: recognition and marking of imprinted loci. Curr Opin Genet Dev 2011; 22:72-8. [PMID: 22195775 DOI: 10.1016/j.gde.2011.12.001] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Revised: 11/30/2011] [Accepted: 12/01/2011] [Indexed: 11/21/2022]
Abstract
Genomic imprinting is an epigenetic process resulting in the monoallelic parent-of-origin-specific expression of a subset of genes in the mammalian genome. The parental alleles are differentially marked by DNA methylation during gametogenesis when the genomes are in separate compartments. How methylation machinery recognizes and differentially modifies these imprinted regions in germ cells remains a key question in the field. While studies have focused on determining a sequence signature that alone could distinguish imprinted regions from the rest of the genome, recent reports do not support such a hypothesis. Rather, it is becoming clear that features such as transcription, histone modifications and higher order chromatin are employed either individually or in combination to set up parental imprints.
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Bartolomei MS, Ferguson-Smith AC. Mammalian genomic imprinting. Cold Spring Harb Perspect Biol 2011; 3:cshperspect.a002592. [PMID: 21576252 DOI: 10.1101/cshperspect.a002592] [Citation(s) in RCA: 362] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Normal mammalian development requires a maternal and paternal contribution, which is attributed to imprinted genes, or genes that are expressed from a single parental allele. Approximately 100 imprinted genes have been reported in mammals thus far. Imprinted genes are controlled by cis-acting regulatory elements, termed imprinting control regions (ICRs), which have parental-specific epigenetic modifications, including DNA methylation. ICRs are methylated by de novo DNA methyltransferases during germline development; these parental-specific modifications must be maintained following fertilization when the genome is extensively reprogrammed. Many imprinted genes reside in ∼1-megabase clusters, with two major mechanisms of imprinting regulation currently recognized, CTCF-dependent insulators and long noncoding RNAs. Unclustered imprinted genes are generally regulated by germline-derived differential promoter methylation. Here, we describe the identification and functions of imprinted genes, cis-acting control sequences, trans-acting factors, and imprinting mechanisms in clusters. Finally, we define questions that require more extensive research.
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Affiliation(s)
- Marisa S Bartolomei
- Department of Cell and Developmental Biology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19063, USA.
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Affiliation(s)
- Diane E. Handy
- Cardiovascular Division, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA
| | - Rita Castro
- Cardiovascular Division, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA
- Metabolism & Genetics Group, Research Institute for Medicines and Pharmaceutical Sciences (iMed.UL), Faculty of Pharmacy, University of Lisbon, Portugal
| | - Joseph Loscalzo
- Cardiovascular Division, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA
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D'Aiuto L, Di Maio R, Mohan KN, Minervini C, Saporiti F, Soreca I, Greenamyre JT, Chaillet JR. Mouse ES cells overexpressing DNMT1 produce abnormal neurons with upregulated NMDA/NR1 subunit. Differentiation 2011; 82:9-17. [PMID: 21492995 DOI: 10.1016/j.diff.2011.03.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2010] [Revised: 03/23/2011] [Accepted: 03/24/2011] [Indexed: 10/18/2022]
Abstract
High levels of DNA methyltransferase 1 (DNMT1), hypermethylation, and downregulation of GAD(67) and reelin have been described in GABAergic interneurons of patients with schizophrenia (SZ) and bipolar (BP) disorders. However, overexpression of DNMT1 is lethal, making it difficult to assess the direct effect of high levels of DNMT1 on neuronal development in vivo. We therefore used Dnmt1(tet/tet) mouse ES cells that overexpress DNMT1 as an in vitro model to investigate the impact of high levels of DNMT1 on neuronal differentiation. Although there is down-regulation of DNMT1 during early stages of differentiation in wild type and Dnmt1(tet/tet) ES cell lines, neurons derived from Dnmt1(tet/tet) cells showed abnormal dendritic arborization and branching. The Dnmt1(tet/tet) neuronal cells also showed elevated levels of functional N-methyl d-aspartate receptor (NMDAR), a feature also reported in some neurological and neurodegenerative disorders. Considering the roles of reelin and GAD(67) in neuronal networking and excitatory/inhibitory balance, respectively, we studied methylation of these genes' promoters in Dnmt1(tet/tet) ES cells and neurons. Both reelin and GAD(67) promoters were not hypermethylated in the Dnmt1(tet/tet) ES cells and neurons, suggesting that overexpression of DNMT1 may not directly result in methylation-mediated repression of these two genes. Taken together, our results suggest that overexpression of DNMT1 in ES cells results in an epigenetic change prior to the onset of differentiation. This epigenetic change in turn results in abnormal neuronal differentiation and upregulation of functional NMDA receptor.
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Affiliation(s)
- Leonardo D'Aiuto
- Department of Microbiology and Molecular Genetics, Magee-Womens Research Institute, University of Pittsburgh, 204 Craft Avenue, Pittsburgh, PA 15213, USA.
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Abstract
DMAP1 (DNMT1-associated protein 1) is a member of the TIP60-p400 complex that maintains embryonic stem (ES) cell pluripotency and a complex containing the somatic form of DNA methyltransferase 1 (DNMT1s). DMAP1 interacts with DNMT1s through a domain that is absent in Dnmt1(V)(/)(V) mice expressing just the oocyte form (DNMT1o). A Dmap1-null allele was generated to study the role of DMAP1 in development. Consistent with the phenotypes of loss of other members of the TIP60-p400 complex, Dmap1(-/-) mice died during preimplantation in both Dnmt1(+/+) and Dnmt1(V)(/)(V) backgrounds. Unexpectedly, in the Dnmt1(V)(/)(V) background, Dmap1(+/-) parents produced mainly Dmap1(+/-) mice. Most Dmap1(+/+) progeny died during midgestation, with loss of DNA methylation on imprinted genes, suggesting that DMAP1 influences maintenance methylation mediated by DNMT1o. In this regard, a DMAP1-DNMT1o complex was detected in ES cells when DNMT1o was stably expressed but not when transiently expressed, indicating a novel interaction between DMAP1 and DNMT1o. These results suggest that DMAP1-DNMT1s and DMAP1-DNMT1o interactions are essential for normal development and that DMAP1-DNMT1o complexes are not readily formed in the embryo. Therefore, DMAP1 mediates distinct preimplantation epigenetic reprogramming processes: TIP60-p400 nucleosome remodeling and DNMT1 maintenance methylation.
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Kcnq1ot1: a chromatin regulatory RNA. Semin Cell Dev Biol 2011; 22:343-50. [PMID: 21345374 DOI: 10.1016/j.semcdb.2011.02.020] [Citation(s) in RCA: 139] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2010] [Revised: 02/12/2011] [Accepted: 02/14/2011] [Indexed: 01/12/2023]
Abstract
There is a growing interest for noncoding RNA (ncRNA)-mediated epigenetic regulation of transcription in diverse biological functions. Recent evidence suggests that a subset of long ncRNA epigenetically regulate the transcription of multiple genes in chromosomal domains via interaction with chromatin. Kcnq1ot1 is one such long chromatin-interacting ncRNA that silences multiple genes in the Kcnq1 domain by establishing a repressive higher order chromatin structure. This is done by the recruitment of chromatin and DNA-modifying proteins. This review looks at recent evidence supporting the notion that Kcnq1ot1-mediated silencing is a multilayered pathway. Comparing the mode of action of Kcnq1ot1 with other well-investigated chromatin regulatory long ncRNAs, such as Xist, HOTAIR and Airn, revealed that chromatin regulatory ncRNAs share common epigenetic pathways in the silencing of multiple genes.
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Obata Y, Hiura H, Fukuda A, Komiyama J, Hatada I, Kono T. Epigenetically immature oocytes lead to loss of imprinting during embryogenesis. J Reprod Dev 2011; 57:327-34. [PMID: 21289466 DOI: 10.1262/jrd.10-145a] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Loss of imprinting (LOI) is occasionally observed in human imprinting disorders. However, the process behind the LOI is not fully understood. To gain a better understanding, we produced embryos and pups from mouse oocytes that lacked a complete methylation imprint using a method that involved transferring the nuclei of growing oocytes into the cytoplasm of enucleated fully grown oocytes following in vitro fertilization (IVF). We then analyzed the imprinting statuses. Our findings show that the incomplete methylation imprint derived from growing oocytes results in epigenetic mosaicism or a loss of methylation imprint (LOM) at maternal alleles in embryos. In some embryos, both hypo- and hypermethylated maternal Kcnq1ot1 alleles were detected, whereas either hypo- or hypermethylated maternal Kcnq1ot1 alleles were detected in others. Such tendencies were also observed at the Igf2r and Mest loci. Gene expression levels of imprinted genes were linked with their methylation statuses in some but not all embryos. Possible explanations of the inconsistency between the data from DNA methylation and gene expression include epigenetic mosaicism in embryos. Pups were successfully produced from growing oocytes at a quite low frequency. They exhibited an obese phenotype and LOI with respect to Igf2r, Snrpn and Mest. Our finding suggests the possibility that LOI/LOM at maternal alleles in human concepti could be derived from epigenetically immature/mutated oocytes.
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Affiliation(s)
- Yayoi Obata
- Department of BioScience, Tokyo University of Agriculture, Tokyo, Japan.
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Robins JC, Marsit CJ, Padbury JF, Sharma SS. Endocrine disruptors, environmental oxygen, epigenetics and pregnancy. Front Biosci (Elite Ed) 2011; 3:690-700. [PMID: 21196344 DOI: 10.2741/e279] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The placenta and its myriad functions are central to successful reproductive outcomes. These functions can be influenced by the environment encountered throughout pregnancy, thereby altering the appropriate genetic programming needed to allow for sustained pregnancy and appropriate fetal development. This altered programming may result from epigenetic alterations related to environmental exposures. Epigenetic alterations are now being linked to several important reproductive outcomes, including early pregnancy loss, intrauterine growth restriction, congenital syndromes, preterm birth, and preeclampsia. The diversity of environmental exposures linked to adverse reproductive effects continues to grow. Much attention has focused on the role of endocrine disruptors in infertility, but recent work suggests that these chemicals may also have adverse effects in pregnancy and development. Environmental oxygen is also critical in pregnancy success. There are clear links between altered oxygen levels and placentation amongst other effects. As research continues to enhance our understanding of the molecular processes including epigenetic regulation that influence pregnancy, it will be critical to specifically examine how the environment, broadly defined, may play a role in altering these critical functions.
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Affiliation(s)
- Jared C Robins
- Division of Reproductive Endocrinology and Infertility, Women and Infants Hospital of Rhode Island, Providence, RI, USA
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Weaver JR, Sarkisian G, Krapp C, Mager J, Mann MRW, Bartolomei MS. Domain-specific response of imprinted genes to reduced DNMT1. Mol Cell Biol 2010; 30:3916-28. [PMID: 20547750 PMCID: PMC2916450 DOI: 10.1128/mcb.01278-09] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2009] [Revised: 10/21/2009] [Accepted: 06/08/2010] [Indexed: 11/20/2022] Open
Abstract
Imprinted genes are expressed in a monoallelic, parent-of-origin-specific manner. Clusters of imprinted genes are regulated by imprinting control regions (ICRs) characterized by DNA methylation of one allele. This methylation is critical for imprinting; a reduction in the DNA methyltransferase DNMT1 causes a widespread loss of imprinting. To better understand the role of DNA methylation in the regulation of imprinting, we characterized the effects of Dnmt1 mutations on the expression of a panel of imprinted genes in the embryo and placenta. We found striking differences among imprinted domains. The Igf2 and Peg3 domains showed imprinting perturbations with both null and partial loss-of-function mutations, and both domains had pairs of coordinately regulated genes with opposite responses to loss of DNMT1 function, suggesting these domains employ similar regulatory mechanisms. Genes in the Kcnq1 domain were less sensitive to the absence of DNMT1. Cdkn1c exhibited imprinting perturbations only in null mutants, while Kcnq1 and Ascl2 were largely unaffected by a loss of DNMT1 function. These results emphasize the critical role for DNA methylation in imprinting and reveal the different ways it controls gene expression.
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Affiliation(s)
- Jamie R. Weaver
- Department of Cell and Developmental Biology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104
| | - Garnik Sarkisian
- Department of Cell and Developmental Biology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104
| | - Christopher Krapp
- Department of Cell and Developmental Biology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104
| | - Jesse Mager
- Department of Cell and Developmental Biology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104
| | - Mellissa R. W. Mann
- Department of Cell and Developmental Biology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104
| | - Marisa S. Bartolomei
- Department of Cell and Developmental Biology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104
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Yurttas P, Morency E, Coonrod SA. Use of proteomics to identify highly abundant maternal factors that drive the egg-to-embryo transition. Reproduction 2010; 139:809-23. [DOI: 10.1530/rep-09-0538] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
As IVF becomes an increasingly popular method for human reproduction, it is more critical than ever to understand the unique molecular composition of the mammalian oocyte. DNA microarray studies have successfully provided valuable information regarding the identity and dynamics of factors at the transcriptional level. However, the oocyte transcribes and stores a large amount of material that plays no obvious role in oogenesis, but instead is required to regulate embryogenesis. Therefore, an accurate picture of the functional state of the oocyte requires both transcriptional profiling and proteomics. Here, we summarize our previous studies of the oocyte proteome, and present new panels of oocyte proteins that we recently identified in screens of metaphase II-arrested mouse oocytes. Importantly, our studies indicate that several abundant oocyte proteins are not, as one might predict, ubiquitous housekeeping proteins, but instead are unique to the oocyte. Furthermore, mouse studies indicate that a number of these factors arise from maternal effect genes (MEGs). One of the identified MEG proteins, peptidylarginine deiminase 6, localizes to and is required for the formation of a poorly characterized, highly abundant cytoplasmic structure: the oocyte cytoplasmic lattices. Additionally, a number of other MEG-derived abundant proteins identified in our proteomic screens have been found by others to localize to another unique oocyte feature: the subcortical maternal complex. Based on these observations, we put forth the hypothesis that the mammalian oocyte contains several unique storage structures, which we have named maternal effect structures, that facilitate the oocyte-to-embryo transition.
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Imprinting and epigenetic changes in the early embryo. Mamm Genome 2009; 20:532-43. [PMID: 19760320 DOI: 10.1007/s00335-009-9225-2] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2009] [Accepted: 06/18/2009] [Indexed: 10/20/2022]
Abstract
Imprinted genes are epigenetically regulated so that only one allele is expressed in a parent-of-origin-dependent manner. Although they represent a small subset of the mammalian genome, imprinted genes are essential for normal development. The regulatory mechanisms underlying imprinting are complex and have been the subject of extensive investigation. DNA methylation is the best-established epigenetic mark that is critical for the allele-specific expression of imprinted genes. This mark must be correctly established in the germline, maintained throughout life, and erased and reestablished in the germline the next generation. These events coincide with the genome-wide epigenetic reprogramming that occurs during gametogenesis and early embryogenesis; therefore, the establishment and maintenance of DNA methylation must be tightly regulated. Studies on enzymes that participate in both de novo methylation and its maintenance (i.e., the DNMT family) have provided information on how methylation influences imprinting. However, many aspects of the regulation of DNA methylation are unknown, including how methylation complexes are targeted and the molecular mechanisms underlying DNA demethylation. In this review we focus on the epigenetic changes that occur in the germline and early embryo, with an emphasis on imprinting. We summarize recent findings on factors influencing DNA methylation establishment, maintenance, and erasure that have further elucidated the mechanisms of imprinting, while highlighting topics that require further investigation.
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Abstract
Genomic imprinting refers to an epigenetic mark that distinguishes parental alleles and results in a monoallelic, parental-specific expression pattern in mammals. Few phenomena in nature depend more on epigenetic mechanisms while at the same time evading them. The alleles of imprinted genes are marked epigenetically at discrete elements termed imprinting control regions (ICRs) with their parental origin in gametes through the use of DNA methylation, at the very least. Imprinted gene expression is subsequently maintained using noncoding RNAs, histone modifications, insulators, and higher-order chromatin structure. Avoidance is manifest when imprinted genes evade the genome-wide reprogramming that occurs after fertilization and remain marked with their parental origin. This review summarizes what is known about the establishment and maintenance of imprinting marks and discusses the mechanisms of imprinting in clusters. Additionally, the evolution of imprinted gene clusters is described. While considerable information regarding epigenetic control of imprinting has been obtained recently, much remains to be learned.
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Affiliation(s)
- Marisa S Bartolomei
- Department of Cell and Developmental Biology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA.
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