1
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Xiong S, Li Y, Xiang Y, Peng N, Shen C, Cai Y, Song D, Zhang P, Wang X, Zeng X, Zhang X. Dysregulation of lncRNA and circRNA Expression in Mouse Testes after Exposure to Triptolide. Curr Drug Metab 2020; 20:665-673. [PMID: 31362668 PMCID: PMC7062010 DOI: 10.2174/1389200220666190729130020] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Revised: 07/05/2019] [Accepted: 07/15/2019] [Indexed: 02/07/2023]
Abstract
BACKGROUND Triptolide has been shown to exert various pharmacological effects on systemic autoimmune diseases and cancers. However, its severe toxicity, especially reproductive toxicity, prevents its widespread clinical use for people with fertility needs. Noncoding RNAs including lncRNAs and circRNAs are novel regulatory molecules that mediate a wide variety of physiological activities; they are crucial for spermatogenesis and their dysregulation might cause male infertility. However, whether they are involved in triptolide-induced reproductive toxicity is completely unknown. METHODS After exposure of mice to triptolide, the total RNAs were used to investigate lncRNA/circRNA/mRNA expression profiles by strand-specific RNA sequencing at the transcriptome level to help uncover RNA-related mechanisms in triptolide-induced toxicity. RESULTS Triptolide significantly decreased testicular weight, damaged testis and sperm morphology, and reduced sperm motility and density. Remarkable deformities in sperm head and tail were also found in triptolide-exposed mice. At the transcriptome level, the triptolide-treated mice exhibited aberrant expression profiles of lncRNAs/circRNAs/mRNAs. Gene Ontology and pathway analyses revealed that the functions of the differentially expressed lncRNA targets, circRNA cognate genes, and mRNAs were closely linked to many processes involved in spermatogenesis. In addition, some lncRNAs/circRNAs were greatly upregulated or inducibly expressed, implying their potential value as candidate markers for triptolide-induced male reproductive toxicity. CONCLUSION This study provides a preliminary database of triptolide-induced transcriptome, promotes understanding of the reproductive toxicity of triptolide, and highlights the need for research on increasing the medical efficacy of triptolide and decreasing its toxicity.
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Affiliation(s)
- Suping Xiong
- Institute of Life Science and School of Life Science, Nanchang University, Nanchang, China
| | - Yanting Li
- Institute of Life Science and School of Life Science, Nanchang University, Nanchang, China
| | - Yang Xiang
- Institute of Life Science and School of Life Science, Nanchang University, Nanchang, China
| | - Na Peng
- Institute of Life Science and School of Life Science, Nanchang University, Nanchang, China
| | - Chunmiao Shen
- Institute of Life Science and School of Life Science, Nanchang University, Nanchang, China
| | - Yanqiu Cai
- Institute of Life Science and School of Life Science, Nanchang University, Nanchang, China
| | - Dandan Song
- Institute of Life Science and School of Life Science, Nanchang University, Nanchang, China
| | - Peng Zhang
- Institute of Life Science and School of Life Science, Nanchang University, Nanchang, China
| | - Xiaolong Wang
- Traditional Chinese Medicine Department, Jilin Women and Children Health Hospital, Changchun, China
| | - Xuihui Zeng
- Institute of Life Science and School of Life Science, Nanchang University, Nanchang, China
| | - Xiaoning Zhang
- Institute of Life Science and School of Life Science, Nanchang University, Nanchang, China.,Medical School, Institute of Reproductive Medicine, Nantong University, Nantong, China
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2
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Capra E, Lazzari B, Turri F, Cremonesi P, Portela AMR, Ajmone-Marsan P, Stella A, Pizzi F. Epigenetic analysis of high and low motile sperm populations reveals methylation variation in satellite regions within the pericentromeric position and in genes functionally related to sperm DNA organization and maintenance in Bos taurus. BMC Genomics 2019; 20:940. [PMID: 31810461 PMCID: PMC6898967 DOI: 10.1186/s12864-019-6317-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 11/21/2019] [Indexed: 12/31/2022] Open
Abstract
Background Sperm epigenetics is an emerging area of study supported by observations reporting that abnormal sperm DNA methylation patterns are associated with infertility. Here, we explore cytosine-guanine dinucleotides (CpGs) methylation in high (HM) and low motile (LM) Bos taurus sperm populations separated by Percoll gradient. HM and LM methylation patterns were investigated by bisulfite sequencing. Results Comparison between HM and LM sperm populations revealed that methylation variation affects genes involved in chromatin organization. CpG Islands (CGIs), were highly remodelled. A high proportion of CGIs was found to be methylated at low/intermediate level (20–60%) and associated to the repetitive element BTSAT4 satellite. The low/intermediate level of methylation in BTSAT4 was stably maintained in pericentric regions of chromosomes. BTSAT4 was hypomethylated in HM sperm populations. Conclusions The characterization of the epigenome in HM and LM Bos taurus sperm populations provides a first step towards the understanding of the effect of methylation on sperm fertility. Methylation variation observed in HM and LM populations in genes associated to DNA structure remodelling as well as in a repetitive element in pericentric regions suggests that maintenance of chromosome structure through epigenetic regulation is probably crucial for correct sperm functionality.
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Affiliation(s)
- Emanuele Capra
- Istituto di Biologia e Biotecnologia Agraria, Consiglio Nazionale delle Ricerche, via Einstein, 26900, Lodi, Italy
| | - Barbara Lazzari
- Istituto di Biologia e Biotecnologia Agraria, Consiglio Nazionale delle Ricerche, via Einstein, 26900, Lodi, Italy
| | - Federica Turri
- Istituto di Biologia e Biotecnologia Agraria, Consiglio Nazionale delle Ricerche, via Einstein, 26900, Lodi, Italy
| | - Paola Cremonesi
- Istituto di Biologia e Biotecnologia Agraria, Consiglio Nazionale delle Ricerche, via Einstein, 26900, Lodi, Italy
| | | | - Paolo Ajmone-Marsan
- Department of Animal Science, Food and Nutrition - DIANA, Università Cattolica del Sacro Cuore, Piacenza, Italy.,Proteomics and Nutrigenomics Research Center - PRONUTRIGEN, Università Cattolica del Sacro Cuore, Piacenza, Italy
| | - Alessandra Stella
- Istituto di Biologia e Biotecnologia Agraria, Consiglio Nazionale delle Ricerche, via Einstein, 26900, Lodi, Italy
| | - Flavia Pizzi
- Istituto di Biologia e Biotecnologia Agraria, Consiglio Nazionale delle Ricerche, via Einstein, 26900, Lodi, Italy.
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3
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Koc G, Ozdemir AA, Girgin G, Akbal C, Kirac D, Avcilar T, Guney AI. Male infertility in Sertoli cell‐only syndrome: An investigation of autosomal gene defects. Int J Urol 2018; 26:292-298. [DOI: 10.1111/iju.13863] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 10/11/2018] [Indexed: 01/08/2023]
Affiliation(s)
- Gulsah Koc
- Department of Medical Biology and Genetics Faculty of Medicine Istanbul Aydin University Istanbul Turkey
| | - Abdullah A Ozdemir
- Department of Urology SBU Zeynep Kamil Women and Children's Diseases Education and Research Hospital Istanbul Turkey
| | - Gozde Girgin
- Department of Medical Genetics Faculty of Medicine Marmara University Istanbul Turkey
| | - Cem Akbal
- Department of Urology Faculty of Medicine Acibadem University Istanbul Turkey
| | - Deniz Kirac
- Department of Medical Biology Faculty of Medicine Yeditepe University Istanbul Turkey
| | - Tuba Avcilar
- Department of Medical Genetics Faculty of Medicine Marmara University Istanbul Turkey
| | - Ahmet I Guney
- Department of Medical Genetics Faculty of Medicine Marmara University Istanbul Turkey
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4
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Xue J, Gharaibeh RZ, Pietryk EW, Brouwer C, Tarantino LM, Valdar W, Ideraabdullah FY. Impact of vitamin D depletion during development on mouse sperm DNA methylation. Epigenetics 2018; 13:959-974. [PMID: 30239288 DOI: 10.1080/15592294.2018.1526027] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Suboptimal environmental conditions during development can substantially alter the epigenome. Stable environmentally-induced changes to the germline epigenome, in particular, have important implications for the health of the next generation. We showed previously that developmental vitamin D depletion (DVD) resulted in loss of DNA methylation at several imprinted loci over two generations. Here, we assessed the impact of DVD on genome-wide methylation in mouse sperm in order to characterize the number, extent and distribution of methylation changes in response to DVD and to find genes that may be susceptible to this prevalent environmental perturbation. We detected 15,827 loci that were differentially methylated in DVD mouse sperm vs. controls. Most epimutations (69%) were loss of methylation, and the extent of methylation change and number of CpGs affected in a region were associated with genic location and baseline methylation state. Methylation response to DVD at validated loci was only detected in offspring that exhibited a phenotypic response to DVD (increased body and testes weight) suggesting the two types of responses are linked, though a causal relationship is unclear. Epimutations localized to regions enriched for developmental and metabolic genes and pathway analyses showed enrichment for Cadherin, Wnt, PDGF and Integrin signaling pathways. These findings show for the first time that vitamin D status during development leads to substantial DNA methylation changes across the sperm genome and that locus susceptibility is linked to genomic and epigenomic context.
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Affiliation(s)
- Jing Xue
- a Department of Genetics, School of Medicine , University of North Carolina at Chapel Hill , Chapel Hill , NC , USA.,b Nutrition Research Institute , University of North Carolina at Chapel Hill , Kannapolis , NC , USA
| | - Raad Z Gharaibeh
- c Department of Bioinformatics and Genomics , University of North Carolina at Charlotte , Charlotte , NC , USA.,d UNC Charlotte Bioinformatics Service Division , North Carolina Research Campus , Kannapolis , NC , USA.,e Department of Medicine, Division of Gastroenterology , University of Florida , Gainesville , FL , USA
| | - Edward W Pietryk
- a Department of Genetics, School of Medicine , University of North Carolina at Chapel Hill , Chapel Hill , NC , USA.,b Nutrition Research Institute , University of North Carolina at Chapel Hill , Kannapolis , NC , USA
| | - Cory Brouwer
- c Department of Bioinformatics and Genomics , University of North Carolina at Charlotte , Charlotte , NC , USA.,d UNC Charlotte Bioinformatics Service Division , North Carolina Research Campus , Kannapolis , NC , USA
| | - Lisa M Tarantino
- b Nutrition Research Institute , University of North Carolina at Chapel Hill , Kannapolis , NC , USA.,f Department of Psychiatry, School of Medicine , University of North Carolina at Chapel Hill , Chapel Hill , NC , USA.,g Division of Pharmacotherapy and Experimental Therapeutics, Eshelman School of Pharmacy , University of North Carolina at Chapel Hill , Chapel Hill , NC , USA
| | - William Valdar
- b Nutrition Research Institute , University of North Carolina at Chapel Hill , Kannapolis , NC , USA.,h Lineberger Comprehensive Cancer Center , University of North Carolina at Chapel Hill , Chapel Hill , NC , USA
| | - Folami Y Ideraabdullah
- a Department of Genetics, School of Medicine , University of North Carolina at Chapel Hill , Chapel Hill , NC , USA.,b Nutrition Research Institute , University of North Carolina at Chapel Hill , Kannapolis , NC , USA.,i Department of Nutrition, Gillings School of Public Health , University of North Carolina at Chapel Hill , Chapel Hill , NC , USA
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5
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Uysal F, Akkoyunlu G, Ozturk S. DNA methyltransferases exhibit dynamic expression during spermatogenesis. Reprod Biomed Online 2016; 33:690-702. [PMID: 27687053 DOI: 10.1016/j.rbmo.2016.08.022] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 08/22/2016] [Accepted: 08/23/2016] [Indexed: 01/12/2023]
Abstract
DNA methylation is one of the epigenetic marks and plays critically important functions during spermatogenesis in mammals. DNA methylation is catalysed by DNA methyltransferase (DNMT) enzymes, which are responsible for the addition of a methyl group to the fifth carbon atom of the cytosine residues within cytosine-phosphate-guanine (CpG) and non-CpG dinucleotide sites. Structurally and functionally five different DNMT enzymes have been identified in mammals, including DNMT1, DNMT2, DNMT3A, DNMT3B and DNMT3L. These enzymes mainly play roles in two DNA methylation processes: maintenance and de novo. While DNMT1 is primarily responsible for maintenance methylation via transferring methyl groups to the hemi-methylated DNA strands following DNA replication, both DNMT3A and DNMT3B are capable of methylating unmodified cytosine residues, known as de novo methylation. However, DNMT3L indirectly participates in de novo methylation, and DNMT2 carries out methylation of the cytosine 38 in the anticodon loop of aspartic acid transfer RNA. To date, many studies have been performed to determine spatial and temporal expression levels and functional features of the DNMT in the male germ cells. This review article comprehensively discusses dynamic expression of the DNMT during spermatogenesis and their relationship with male infertility development in the light of existing investigations.
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Affiliation(s)
- Fatma Uysal
- Department of Histology and Embryology, Akdeniz University, School of Medicine, Campus 07070, Antalya, Turkey
| | - Gokhan Akkoyunlu
- Department of Histology and Embryology, Akdeniz University, School of Medicine, Campus 07070, Antalya, Turkey
| | - Saffet Ozturk
- Department of Histology and Embryology, Akdeniz University, School of Medicine, Campus 07070, Antalya, Turkey.
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6
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Ventura-Juncá P, Irarrázaval I, Rolle AJ, Gutiérrez JI, Moreno RD, Santos MJ. In vitro fertilization (IVF) in mammals: epigenetic and developmental alterations. Scientific and bioethical implications for IVF in humans. Biol Res 2015; 48:68. [PMID: 26683055 PMCID: PMC4684609 DOI: 10.1186/s40659-015-0059-y] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 11/30/2015] [Indexed: 01/06/2023] Open
Abstract
The advent of in vitro fertilization (IVF) in animals and humans implies an extraordinary change in the environment where the beginning of a new organism takes place. In mammals fertilization occurs in the maternal oviduct, where there are unique conditions for guaranteeing the encounter of the gametes and the first stages of development of the embryo and thus its future. During this period a major epigenetic reprogramming takes place that is crucial for the normal fate of the embryo. This epigenetic reprogramming is very vulnerable to changes in environmental conditions such as the ones implied in IVF, including in vitro culture, nutrition, light, temperature, oxygen tension, embryo-maternal signaling, and the general absence of protection against foreign elements that could affect the stability of this process. The objective of this review is to update the impact of the various conditions inherent in the use of IVF on the epigenetic profile and outcomes of mammalian embryos, including superovulation, IVF technique, embryo culture and manipulation and absence of embryo-maternal signaling. It also covers the possible transgenerational inheritance of the epigenetic alterations associated with assisted reproductive technologies (ART), including its phenotypic consequences as is in the case of the large offspring syndrome (LOS). Finally, the important scientific and bioethical implications of the results found in animals are discussed in terms of the ART in humans.
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Affiliation(s)
- Patricio Ventura-Juncá
- Bioethical Center and Department of Pediatrics, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile. .,Bioethics Center, Universidad Finis Terrae, Pedro de Valdivia 1509, Providencia, Región Metropolitana, 7501015, Santiago, Chile.
| | - Isabel Irarrázaval
- Bioethical Center and Department of Pediatrics, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile.
| | - Augusto J Rolle
- Bioethical Center and Department of Pediatrics, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile.
| | - Juan I Gutiérrez
- Bioethical Center and Department of Pediatrics, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile.
| | - Ricardo D Moreno
- Department of Physiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile. .,Department of Cellular and Molecular Biology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile.
| | - Manuel J Santos
- Bioethical Center and Department of Pediatrics, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile. .,Department of Cellular and Molecular Biology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile.
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7
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Epigenetic regulation of sox30 is associated with testis development in mice. PLoS One 2014; 9:e97203. [PMID: 24810894 PMCID: PMC4014610 DOI: 10.1371/journal.pone.0097203] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2014] [Accepted: 04/09/2014] [Indexed: 01/15/2023] Open
Abstract
DNA methylation is involved in tissue-specific and developmentally regulated gene expression. Here, we screened a novel methylation gene Sox30, whose methylation might contribute to its regulation and testis development in mice. Sox30 is a member of Sox transcription factors, and is considered to be involved in spermatogonial differentiation and spermatogenesis. However, the precise function and regulatory expression pattern remain unclear. In the present study, we found that Sox30 is highly expressed in adult testes but not in ovaries. Sox30 expression begins in early development, and in the testes, it is specifically increased coincidentally with development until adulthood. Moreover, Sox30 is expressed not only in testis germ cells, but also in sertoli cells. Sox30 is hypo-methylated in testis, epididymis and lung of adult mice, in which Sox30 is expressed. By contrast, Sox30 is hypermethylated in ovary, heart, brain, liver, kidney, spleen, pancreas, muscle, intestine, pituitary gland, blood and hippocampus of adult mice, in which the Sox30 is absent. Importantly, decreased methylation at CpG islands of Sox30 is observed in mouse developmental testes after birth, which is associated with enhanced Sox30 expression. However, the hypermethylated status of Sox30 is maintained in ovaries that does not express Sox30 during this period. Further, following demethylation treatment using 5-aza-dC, Sox30 expression is restored in GC2, TM3 and TM4 cell lines. This observation convincingly confirms that methylation really contributes to Sox30 silencing. In summary, we show that Sox30 expression is under the control of DNA methylation status, and this expression pattern is associated with testis development in mice.
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8
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Polymorphism in DNMT1 may modify the susceptibility to oligospermia. Reprod Biomed Online 2014; 28:644-9. [DOI: 10.1016/j.rbmo.2014.01.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Revised: 01/03/2014] [Accepted: 01/07/2014] [Indexed: 12/16/2022]
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9
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Reig-Viader R, Vila-Cejudo M, Vitelli V, Buscà R, Sabaté M, Giulotto E, Caldés MG, Ruiz-Herrera A. Telomeric Repeat-Containing RNA (TERRA) and Telomerase Are Components of Telomeres During Mammalian Gametogenesis1. Biol Reprod 2014; 90:103. [DOI: 10.1095/biolreprod.113.116954] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
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10
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Song N, Endo D, Koji T. Roles of epigenome in mammalian spermatogenesis. Reprod Med Biol 2013; 13:59-69. [PMID: 29699150 DOI: 10.1007/s12522-013-0167-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Accepted: 08/07/2013] [Indexed: 10/26/2022] Open
Abstract
Mammalian spermatogenesis is a successive process consisting of spermatogonial proliferation, spermatocytic meiosis, and spermiogenesis, representing the maturation of haploid spermatids. During the process, 25-75 % of the expected sperm yield is thought to be lost through apoptosis. In addition, spermatogenesis is considered to be a process undergoing successive heterochromatinization, finally reaching a complete condensed form in the sperm head. Thus, cell proliferation, differentiation and death may be strictly regulated by epigenetic factors in this process. This review describes the current understanding of the role of epigenome in spermatogenesis, especially focusing on the following aspects; DNA methylation, modification of histones, and small RNA function. These epigenetic factors affect each other and play a central role in events essential for spermatogenesis, fertilization and embryogenesis, through the regulation of gene expression, transposon activities, meiotic sex chromosome inactivation, histone remodeling and genome imprinting. Finally, a brief discussion of future avenues of study is highlighted.
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Affiliation(s)
- Ning Song
- Department of Histology and Cell Biology Nagasaki University Graduate School of Biomedical Sciences 1-12-4 Sakamoto 852-8523 Nagasaki Japan
| | - Daisuke Endo
- Department of Histology and Cell Biology Nagasaki University Graduate School of Biomedical Sciences 1-12-4 Sakamoto 852-8523 Nagasaki Japan
| | - Takehiko Koji
- Department of Histology and Cell Biology Nagasaki University Graduate School of Biomedical Sciences 1-12-4 Sakamoto 852-8523 Nagasaki Japan
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11
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El Hajj N, Haaf T. Epigenetic disturbances in in vitro cultured gametes and embryos: implications for human assisted reproduction. Fertil Steril 2013; 99:632-41. [PMID: 23357453 DOI: 10.1016/j.fertnstert.2012.12.044] [Citation(s) in RCA: 131] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Revised: 12/21/2012] [Accepted: 12/26/2012] [Indexed: 01/01/2023]
Abstract
Although assisted reproductive technology (ART) has become a routine practice for human infertility treatment, the etiology of the increased risks for perinatal problems in ART-conceived children is still poorly understood. Data from mouse experiments and the in vitro production of livestock provide strong evidence that imprint establishment in late oocyte stages and reprogramming of the two germline genomes for somatic development after fertilization are vulnerable to environmental cues. In vitro culture and maturation of oocytes, superovulation, and embryo culture all represent artificial intrusions upon the natural development, which can be expected to influence the epigenome of the resultant offspring. However, in this context it is difficult to define the normal range of epigenetic variation in humans from conception throughout life. With the notable exception of a few highly penetrant imprinting mutations, the phenotypic consequences of any observed epigenetic differences between ART and non-ART groups remain largely unclear. The periconceptional period is not only critical for embryonal, placental, and fetal development, as well as the outcome at birth, but suboptimal in vitro culture conditions may also lead to persistent changes in the epigenome influencing disease susceptibilities later in life. The epigenome appears to be most plastic in the late stages of oocyte and the early stages of embryo development; this plasticity steadily decreases during prenatal and postnatal life. Therefore, when considering the safety of human ART from an epigenetic point of view, our main concern should not be whether or not a few rare imprinting disorders are increased, but rather we must be aware of a functional link between interference with epigenetic reprogramming in very early development and adult disease.
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Affiliation(s)
- Nady El Hajj
- Institute of Human Genetics, Julius Maximilians University, Wuerzburg, Germany
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12
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DNA Hypomethylation and Hemimethylation in Cancer. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 754:31-56. [DOI: 10.1007/978-1-4419-9967-2_2] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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13
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Current advances in epigenetic modification and alteration during mammalian ovarian folliculogenesis. J Genet Genomics 2012; 39:111-23. [PMID: 22464470 DOI: 10.1016/j.jgg.2012.02.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Revised: 01/07/2012] [Accepted: 02/10/2012] [Indexed: 11/23/2022]
Abstract
During the growth and development of mammalian ovarian follicles, the activation and deactivation of mass genes are under the synergistic control of diverse modifiers through genetic and epigenetic events. Many factors regulate gene activity and functions through epigenetic modification without altering the DNA sequence, and the common mechanisms may include but are not limited to: DNA methylation, histone modifications (e.g., acetylation, deacetylation, phosphorylation, methylation, and ubiquitination), and RNA-associated silencing of gene expression by noncoding RNA. Over the past decade, substantial progress has been achieved in studies involving the epigenetic alterations during mammalian germ cell development. A number of candidate regulatory factors have been identified. This review focuses on the current available information of epigenetic alterations (e.g., DNA methylation, histone modification, noncoding-RNA-mediated regulation) during mammalian folliculogenesis and recounts when and how epigenetic patterns are differentially established, maintained, or altered in this process. Based on different types of epigenetic regulation, our review follows the temporal progression of events during ovarian folliculogenesis and describes the epigenetic changes and their contributions to germ cell-specific functions at each stage (i.e., primordial folliculogenesis (follicle formation), follicle maturation, and follicular atresia).
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Huang JX, Scott MB, Pu XY, Zhou-Cun A. Association between single-nucleotide polymorphisms of DNMT3L and infertility with azoospermia in Chinese men. Reprod Biomed Online 2011; 24:66-71. [PMID: 22116073 DOI: 10.1016/j.rbmo.2011.09.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Revised: 08/30/2011] [Accepted: 09/07/2011] [Indexed: 11/17/2022]
Abstract
The gene for DNA methyltransferase 3-like protein (DNMT3L) is essential for normal spermatogenesis and may be involved with spermatogenetic impairment and male infertility. To explore the possible association between the DNMT3L gene and male infertility, this study investigated allele, genotype and haplotype frequencies of three single nucleotide polymorphism (SNP) loci, rs2070565, rs2276248 and rs7354779, of DNMT3L in 233 infertile patients with azoospermia and 249 fertile controls from a population of Chinese men using polymerase chain reaction/restriction fragment length polymorphism. Results showed that the frequencies of allele A (20.6% versus 14.9%; P = 0.022) and the allele A carrier (GA + AA; 37.8% versus 28.1%; P = 0.027) in azoospermic patients were significantly higher than those in controls at the rs2070565 locus. The haplotype AAA frequency was significantly higher (18.1% versus 12.4%; P = 0.02) while the haplotype GAA frequency was significantly lower (53.2% versus 62.1%; P = 0.007) in infertile patients compared with fertile controls. These results indicated that SNP rs2070565, as well as haplotypes AAA and GAA, may be associated with male infertility and suggest that DNMT3L may contribute to azoospermia susceptibility in humans.
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Affiliation(s)
- Jian-Xi Huang
- Department of Biology, Dali College, Dali, Yunnan 671003, China
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15
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Rajender S, Avery K, Agarwal A. Epigenetics, spermatogenesis and male infertility. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2011; 727:62-71. [DOI: 10.1016/j.mrrev.2011.04.002] [Citation(s) in RCA: 206] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2010] [Revised: 04/07/2011] [Accepted: 04/08/2011] [Indexed: 12/31/2022]
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16
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El Hajj N, Zechner U, Schneider E, Tresch A, Gromoll J, Hahn T, Schorsch M, Haaf T. Methylation Status of Imprinted Genes and Repetitive Elements in Sperm DNA from Infertile Males. Sex Dev 2011; 5:60-9. [DOI: 10.1159/000323806] [Citation(s) in RCA: 96] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/13/2010] [Indexed: 01/19/2023] Open
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17
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Chmurzynska A. Fetal programming: link between early nutrition, DNA methylation, and complex diseases. Nutr Rev 2010; 68:87-98. [PMID: 20137054 DOI: 10.1111/j.1753-4887.2009.00265.x] [Citation(s) in RCA: 143] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Complex traits, including those involved in diet-related diseases, are determined by multiple genes and environmental influences. Factors influencing the development of complex traits should be expanded to include epigenetic factors, such as DNA methylation, which occurs in utero. Epigenetic factors regulate gene expression and thereby cell differentiation and organogenesis. The process of epigenotype establishment is sensitive to environmental conditions, with nutrition being one of the most important related factors. For example, DNA methylation depends on the availability of several nutrients including methionine and vitamins B(6), B(12), and folate. Epidemiological studies show that undernutrition during fetal life is associated with increased susceptibility to complex diseases. Numerous studies have been conducted on prenatal caloric and protein undernutrition. A reduction in the number of cells and changes in the structure and functioning of organs, as well as permanent changes in DNA methylation and gene expression, have been considered the molecular mechanisms responsible for metabolism programming.
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Affiliation(s)
- Agata Chmurzynska
- Department of Human Nutrition and Hygiene, Poznan University of Life Sciences, Wojska Polskiego 31, Poznan, Poland.
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Miller D, Brinkworth M, Iles D. Paternal DNA packaging in spermatozoa: more than the sum of its parts? DNA, histones, protamines and epigenetics. Reproduction 2010; 139:287-301. [PMID: 19759174 DOI: 10.1530/rep-09-0281] [Citation(s) in RCA: 262] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Haploid male germ cells package their DNA into a volume that is typically 10% or less that of a somatic cell nucleus. To achieve this remarkable level of compaction, spermatozoa replace most of their histones with smaller, highly basic arginine and (in eutherians) cysteine rich protamines. One reason for such a high level of compaction is that it may help optimise nuclear shape and hence support the gametes' swimming ability for the long journey across the female reproductive tract to the oocyte. Super-compaction of the genome may confer additional protection from the effects of genotoxic factors. However, many species including the human retain a fraction of their chromatin in the more relaxed nucleosomal configuration that appears to run counter to the ergonomic, toroidal and repackaging of sperm DNA. Recent research suggests that the composition of this 'residual' nucleosomal compartment, a generally overlooked feature of the male gamete, is far more significant and important than previously thought. In this respect, the transport and incorporation of modified paternal histones by the spermatozoon to the zygote has been demonstrated and indicates another potential paternal effect in the epigenetic reprogramming of the zygote following fertilisation that is independent of imprinting status. In this review, the most recent research into mammalian spermatozoal chromatin composition is discussed alongside evidence for conserved, non-randomly located nucleosomal domains in spermatozoal nuclei, all supporting the hypothesis that the spermatozoon delivers a novel epigenetic signature to the egg that may be crucial for normal development. We also provide some thoughts on why this signature may be required in early embryogenesis.
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Affiliation(s)
- David Miller
- Division of Reproduction and Early Development, Leeds Institute of Genetics, Health and Therapeutics, University of Leeds, Clarendon Way, Leeds LS2 9JT, UK.
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Dakshinamurthy AG, Ramesar R, Goldberg P, Blackburn JM. Infrequent and low expression of cancer-testis antigens located on the X chromosome in colorectal cancer: implications for immunotherapy in South African populations. Biotechnol J 2009; 3:1417-23. [PMID: 18956367 DOI: 10.1002/biot.200800144] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Cancer-testis (CT) antigens are a group of tumor antigens that are expressed in the testis and aberrantly in cancerous tissue but not in somatic tissues. The testis is an immune-privileged site because of the presence of a blood-testis barrier; as a result, CT antigens are considered to be essentially tumor specific and are attractive targets for immunotherapy. CT antigens are classified as the CT-X and the non-X CT antigens depending on the chromosomal location to which the genes are mapped. CT-X antigens are typically highly immunogenic and hence the first step towards tailored immunotherapy is to elucidate the expression profile of CT-X antigens in the respective tumors. In this study we investigated the expression profile of 16 CT-X antigen genes in 34 colorectal cancer (CRC) patients using reverse transcription-polymerase chain reaction. We observed that 12 of the 16 CT-X antigen genes studied did not show expression in any of the CRC samples analyzed. The other 4 CT-X antigen genes showed low frequency of expression and exhibited a highly variable expression profile when compared to other populations. Thus, our study forms the first report on the expression profile of CT-X antigen genes among CRC patients in the genetically diverse South African population. The results of our study suggest that genetic and ethnic variations in population might have a role in the expression of the CT-X antigen genes. Thus our results have significant implications for anti-CT antigen-based immunotherapy trials in this population.
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20
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Hara Y, Yamagata K, Oguchi K, Baba T. Nuclear localization of profilin III-ArpM1 complex in mouse spermiogenesis. FEBS Lett 2008; 582:2998-3004. [PMID: 18692047 DOI: 10.1016/j.febslet.2008.07.058] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2008] [Revised: 07/04/2008] [Accepted: 07/22/2008] [Indexed: 10/21/2022]
Abstract
Actin-related proteins (Arps) have been reported to be localized in the cell nucleus, and implicated in the regulation of chromatin and nuclear structure, as well as being involved in cytoplasmic functions. We demonstrate here that mouse ArpM1, which closely resembles the conventional actin, is expressed exclusively in the testis, particularly in haploid germ cells. ArpM1 protein first appears in the round spermatid and changes its localization dynamically in the nucleus during spermiogenesis. By co-immunoprecipitation analysis, profilin III was identified as ArpM1-interacting protein. Our findings suggest that the testis-specific profilin III-ArpM1 complex may be involved in conformational changes in the organization of the sperm-specific nucleus.
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Affiliation(s)
- Yuki Hara
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
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21
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Baumann C, Schmidtmann A, Muegge K, De La Fuente R. Association of ATRX with pericentric heterochromatin and the Y chromosome of neonatal mouse spermatogonia. BMC Mol Biol 2008; 9:29. [PMID: 18366812 PMCID: PMC2275742 DOI: 10.1186/1471-2199-9-29] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2007] [Accepted: 03/13/2008] [Indexed: 11/10/2022] Open
Abstract
Background Establishment of chromosomal cytosine methylation and histone methylation patterns are critical epigenetic modifications required for heterochromatin formation in the mammalian genome. However, the nature of the primary signal(s) targeting DNA methylation at specific genomic regions is not clear. Notably, whether histone methylation and/or chromatin remodeling proteins play a role in the establishment of DNA methylation during gametogenesis is not known. The chromosomes of mouse neonatal spermatogonia display a unique pattern of 5-methyl cytosine staining whereby centromeric heterochromatin is hypo-methylated whereas chromatids are strongly methylated. Thus, in order to gain some insight into the relationship between global DNA and histone methylation in the germ line we have used neonatal spermatogonia as a model to determine whether these unique chromosomal DNA methylation patterns are also reflected by concomitant changes in histone methylation. Results Our results demonstrate that histone H3 tri-methylated at lysine 9 (H3K9me3), a hallmark of constitutive heterochromatin, as well as the chromatin remodeling protein ATRX remained associated with pericentric heterochromatin regions in spite of their extensive hypo-methylation. This suggests that in neonatal spermatogonia, chromosomal 5-methyl cytosine patterns are regulated independently of changes in histone methylation, potentially reflecting a crucial mechanism to maintain pericentric heterochromatin silencing. Furthermore, chromatin immunoprecipitation and fluorescence in situ hybridization, revealed that ATRX as well as H3K9me3 associate with Y chromosome-specific DNA sequences and decorate both arms of the Y chromosome, suggesting a possible role in heterochromatinization and the predominant transcriptional quiescence of this chromosome during spermatogenesis. Conclusion These results are consistent with a role for histone modifications and chromatin remodeling proteins such as ATRX in maintaining transcriptional repression at constitutive heterochromatin domains in the absence of 5-methyl cytosine and provide evidence suggesting that the establishment and/or maintenance of repressive histone and chromatin modifications at pericentric heterochromatin following genome-wide epigenetic reprogramming in the germ line may precede the establishment of chromosomal 5-methyl cytosine patterns as a genomic silencing strategy in neonatal spermatogonia.
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Affiliation(s)
- Claudia Baumann
- Female Germ Cell Biology Group, Department of Clinical Studies, Center for Animal Transgenesis and Germ Cell Research, School of Veterinary Medicine, University of Pennsylvania, New Bolton Center, Kennett Square, PA 19348, USA.
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22
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Liang R, Yu WD, Du JB, Yang LJ, Yang JJ, Xu J, Shang M, Guo JZ. Cystathionine beta synthase participates in murine oocyte maturation mediated by homocysteine. Reprod Toxicol 2007; 24:89-96. [PMID: 17561372 DOI: 10.1016/j.reprotox.2007.04.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2006] [Revised: 03/25/2007] [Accepted: 04/09/2007] [Indexed: 01/12/2023]
Abstract
Our previous study demonstrated that cystathionine beta synthase (CBS) is highly expressed in the cumulus-oocyte complex during ovulation. However, the role of CBS during oocyte maturation remains uncertain. In this study, a small-interfering (si) RNA interference (siRNA) approach was used to investigate the potential role of CBS during oocyte maturation. Accompanied with a gradual increase of homocysteine, the introduction of CBS-siRNA into murine granulosa cells selectively depleted the corresponding target mRNA and protein for CBS as assessed by semi-quantitative reverse-transcriptase PCR (RT-PCR) and immunofluorescence staining. When fully grown, germinal vesicle (GV) oocytes matured in vitro for 16 h using medium from transfected granulosa cells, the functional suppression of CBS resulted in a significant increase in the rate of GV-arrested oocytes. The results of this study provide evidence that CBS participates in the process of oocyte maturation. Furthermore, this effect may be fulfilled by conditioning the level of homocysteine in the microenvironment of the oocyte.
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Affiliation(s)
- Rong Liang
- Department of Pediatrics, Peoples Hospital, Peking University, 11# South Street, Beijing, China
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23
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Yamazaki T, Yamagata K, Baba T. Time-lapse and retrospective analysis of DNA methylation in mouse preimplantation embryos by live cell imaging. Dev Biol 2007; 304:409-19. [PMID: 17274975 DOI: 10.1016/j.ydbio.2006.12.046] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2006] [Revised: 12/18/2006] [Accepted: 12/19/2006] [Indexed: 12/13/2022]
Abstract
Genome-wide change of DNA methylation in preimplantation embryos is known to be important for the nuclear reprogramming process. A synthetic RNA encoding enhanced green fluorescence protein fused to the methyl-CpG-binding domain and nuclear localization signal of human MBD1 was microinjected into metaphase II-arrested or fertilized oocytes, and the localization of methylated DNA was monitored by live cell imaging. Both the central part of decondensing sperm nucleus and the rim region of the nucleolus in the male pronucleus were highly DNA-methylated during pronuclear formation. The methylated paternal genome undergoing active DNA demethylation in the enlarging pronucleus was dispersed, assembled, and then migrated to the nucleolar rim. The female pronucleus contained methylated DNA predominantly in the nucleoplasm. When the localization of methylated DNA in preimplantation embryos was examined, a configurational change of methylated chromatin dramatically occurred during the transition of 2-cell to 4-cell embryos. Moreover, retrospective analysis demonstrated that a noticeable number of the oocytes reconstructed by round spermatid injection (ROSI) possess small, bright dots of methylated chromatin in the nucleoplasm of male pronucleus. These ROSI oocytes showed a significantly low rate of 2-cell formation, thus suggesting that the poor embryonic development of the ROSI oocytes may result from the abnormal localization of methylated chromatin.
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Affiliation(s)
- Taiga Yamazaki
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba Science City, Ibaraki 305-8572, Japan
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Galetzka D, Weis E, Tralau T, Seidmann L, Haaf T. Sex-specific windows for high mRNA expression of DNA methyltransferases 1 and 3A and methyl-CpG-binding domain proteins 2 and 4 in human fetal gonads. Mol Reprod Dev 2007; 74:233-41. [PMID: 16998846 DOI: 10.1002/mrd.20615] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
DNA methyltransferases (DNMTs) and 5-methyl-CpG-binding domain proteins (MBDs) are involved in the acquisition of parent-specific epigenetic modifications in human male and female germ cells. Reverse Northern blot analyses demonstrated sex-specific differences in mRNA expression for the maintenance DNMT1 and the de novo DNMT3A in developing testis and ovary. In fetal testis DNMT1 and DNMT3A expression peaked in mitotically arrested spermatogonia around 21 weeks gestation. In fetal ovary transcriptional upregulation of DNMT1 and DNMT3A occurred during a very brief period at 16 weeks gestation, when the oocytes proceeded through meiotic prophase. Fetal gonads showed several fold higher DNMT3A expression levels than fetal brain and adult tissues. The most abundant DNMT3A isoform in fetal testis and ovary was DNMT3A2, whereas in all other analyzed tissues DNMT3A1 predominated. The catalytically inactive DNMT3A3 isoform was also present at relatively high levels in developing gonads and may perform a regulatory function(s). In both male and female fetal gonads expression of genes for MBD2 and MBD4, which may be implicated in chromatin remodeling of methylated genomic DNA sequences, was tightly linked to DNMT expression. We propose that the sex-specific time windows for concomitant upregulation of DNMT1, DNMT3A, MBD2, and MBD4 are associated with prenatal remethylation of the human male and female germ line.
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Affiliation(s)
- Danuta Galetzka
- Institute for Human Genetics, Johannes Gutenberg University, Mainz, Germany
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Gure AO, Chua R, Williamson B, Gonen M, Ferrera CA, Gnjatic S, Ritter G, Simpson AJG, Chen YT, Old LJ, Altorki NK. Cancer-Testis Genes Are Coordinately Expressed and Are Markers of Poor Outcome in Non–Small Cell Lung Cancer. Clin Cancer Res 2005; 11:8055-62. [PMID: 16299236 DOI: 10.1158/1078-0432.ccr-05-1203] [Citation(s) in RCA: 267] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Cancer-testis genes mapping to the X chromosome have common expression patterns and show similar responses to modulators of epigenetic mechanisms. We asked whether cancer-testis gene expression occurred coordinately, and whether it correlated with variables of disease and clinical outcome of non-small cell lung cancer (NSCLC). EXPERIMENTAL DESIGN Tumors from 523 NSCLC patients undergoing surgery were evaluated for the expression of nine cancer-testis genes (NY-ESO-1, LAGE-1, MAGE-A1, MAGE-A3, MAGE-A4, MAGE-A10, CT7/MAGE-C1, SSX2, and SSX4) by semiquantitative PCR. Clinical data available for 447 patients were used to correlate cancer-testis expression to variables of disease and clinical outcome. RESULTS At least one cancer-testis gene was expressed by 90% of squamous carcinoma, 62% of bronchioloalveolar cancer, and 67% of adenocarcinoma samples. Statistically significant coexpression was observed for 34 of the 36 possible cancer-testis combinations. Cancer-testis gene expression, either cumulatively or individually, showed significant associations with male sex, smoking history, advanced tumor, nodal and pathologic stages, pleural invasion, and the absence of ground glass opacity. Cox regression analysis revealed the expression of NY-ESO-1 and MAGE-A3 as markers of poor prognosis, independent of confounding variables for adenocarcinoma of the lung. CONCLUSIONS Cancer-testis genes are coordinately expressed in NSCLC, and their expression is associated with advanced disease and poor outcome.
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Affiliation(s)
- Ali O Gure
- Ludwig Institute for Cancer Research, Memorial Sloan Kettering Cancer Center, New York, New York 10021, USA.
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Webster KE, O'Bryan MK, Fletcher S, Crewther PE, Aapola U, Craig J, Harrison DK, Aung H, Phutikanit N, Lyle R, Meachem SJ, Antonarakis SE, de Kretser DM, Hedger MP, Peterson P, Carroll BJ, Scott HS. Meiotic and epigenetic defects in Dnmt3L-knockout mouse spermatogenesis. Proc Natl Acad Sci U S A 2005; 102:4068-73. [PMID: 15753313 PMCID: PMC552976 DOI: 10.1073/pnas.0500702102] [Citation(s) in RCA: 207] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The production of mature germ cells capable of generating totipotent zygotes is a highly specialized and sexually dimorphic process. The transition from diploid primordial germ cell to haploid spermatozoa requires genome-wide reprogramming of DNA methylation, stage- and testis-specific gene expression, mitotic and meiotic division, and the histone-protamine transition, all requiring unique epigenetic control. Dnmt3L, a DNA methyltransferase regulator, is expressed during gametogenesis, and its deletion results in sterility. We found that during spermatogenesis, Dnmt3L contributes to the acquisition of DNA methylation at paternally imprinted regions, unique nonpericentric heterochromatic sequences, and interspersed repeats, including autonomous transposable elements. We observed retrotransposition of an LTR-ERV1 element in the DNA from Dnmt3L-/- germ cells, presumably as a result of hypomethylation. Later in development, in Dnmt3L-/- meiotic spermatocytes, we detected abnormalities in the status of biochemical markers of heterochromatin, implying aberrant chromatin packaging. Coincidentally, homologous chromosomes fail to align and form synaptonemal complexes, spermatogenesis arrests, and spermatocytes are lost by apoptosis and sloughing. Because Dnmt3L expression is restricted to gonocytes, the presence of defects in later stages reveals a mechanism whereby early genome reprogramming is linked inextricably to changes in chromatin structure required for completion of spermatogenesis.
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Affiliation(s)
- Kylie E Webster
- Genetics and Bioinformatics Division, The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3050, Australia
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