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Berteli TS, Wang F, Navarro PA, Kohlrausch FB, Keefe DL. A pilot study of LINE-1 copy number and telomere length with aging in human sperm. J Assist Reprod Genet 2023:10.1007/s10815-023-02857-1. [PMID: 37382785 PMCID: PMC10371944 DOI: 10.1007/s10815-023-02857-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 06/03/2023] [Indexed: 06/30/2023] Open
Abstract
PURPOSE Unlike other cells in the body, in sperm, telomere length (TL) increases with age. TL can regulate nearby genes, and the subtelomeric region is rich in retrotransposons. We hypothesized that age-related telomere lengthening in sperm might suppress Long Interspersed Element 1 (LINE-1/L1), the only competent retrotransposon in humans. METHODS We measured L1 copy number (L1-CN) and sperm telomere length (STL) from young and older men to evaluate the relationship between age, TL and L1-CN. We also evaluated L1-CN and TL in individual sperm to determine whether these variables influence sperm morphology. STL was assayed by Multiplex quantitative polymerase chain reaction method (mmqPCR) and L1-CN by Quantitative polymerase chain reaction (qPCR). RESULTS We found that STL increased, and L1-CN decreased significantly with paternal age. STL in normal single sperm was significantly higher than in abnormal sperm. L1-CN did not differ between normal and abnormal sperm. Furthermore, morphologically normal sperm have longer telomeres than abnormal sperm. CONCLUSIONS Elongation of telomeres in the male germline could repress retrotransposition, which tends to increase with cellular aging. More studies in larger cohorts across a wide age span are needed to confirm our conclusions and explore their biological and clinical significance.
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Affiliation(s)
- Thalita S Berteli
- Department of Obstetrics and Gynecology, Langone Medical Center, New York University, 462, 1st Avenue, New York, NY, 10016, USA.
- Human Reproduction Division, Department of Gynecology and Obstetrics, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil.
| | - Fang Wang
- Department of Obstetrics and Gynecology, Langone Medical Center, New York University, 462, 1st Avenue, New York, NY, 10016, USA
| | - Paula A Navarro
- Human Reproduction Division, Department of Gynecology and Obstetrics, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil
| | - Fabiana B Kohlrausch
- Department of Obstetrics and Gynecology, Langone Medical Center, New York University, 462, 1st Avenue, New York, NY, 10016, USA
- Human Genetics Laboratory, Fluminense Federal University, Niteroi, RJ, Brazil
| | - David L Keefe
- Department of Obstetrics and Gynecology, Langone Medical Center, New York University, 462, 1st Avenue, New York, NY, 10016, USA
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Impact of superovulation and in vitro fertilization on LINE-1 copy number and telomere length in C57BL/6 J mice blastocysts. Mol Biol Rep 2022; 49:4909-4917. [PMID: 35316424 DOI: 10.1007/s11033-022-07351-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 03/09/2022] [Indexed: 12/09/2022]
Abstract
OBJECTIVE Millions of babies have been conceived by IVF, yet debate about its safety to offspring continues. We hypothesized that superovulation and in vitro fertilization (IVF) promote genomic changes, including altered telomere length (TL) and activation of the retrotransposon LINE-1 (L1), and tested this hypothesis in a mouse model. MATERIAL AND METHODS Experimental study analyzing TL and L1 copy number in C57BL/6 J mouse blastocysts in vivo produced from natural mating cycles (N), in vivo produced following superovulation (S), or in vitro produced following superovulation (IVF). We also examined the effects of prolonged culture on TL and L1 copy number in the IVF group comparing blastocysts cultured 96 h versus blastocysts cultured 120 h. TL and L1 copy number were measured by Real Time PCR. RESULTS TL in S (n = 77; Mean: 1.50 ± 1.15; p = 0.0007) and IVF (n = 82; Mean: 1.72 ± 1.44; p < 0.0001) exceeded that in N (n = 16; Mean: 0.61 ± 0.27). TL of blastocysts cultured 120 h (n = 15, Mean: 2.14 ± 1.05) was significantly longer than that of embryos cultured for 96 h (n = 67, Mean: 1.63 ± 1.50; p = 0.0414). L1 copy number of blastocysts cultured for 120 h (n = 15, Mean: 1.71 ± 1.49) exceeded that of embryos cultured for 96 h (n = 67, Mean: 0.95 ± 1.03; p = 0.0162). CONCLUSIONS Intriguingly ovarian stimulation, alone or followed by IVF, produced embryos with significantly longer telomeres compared to in vivo, natural cycle-produced embryos. The significance of this enriched telomere endowment for the health and longevity of offspring born from IVF merit future studies.
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Liu H, Shen E, Wu H, Ma W, Chen H, Lin Y. Trans-kingdom expression of an insect endogenous microRNA in rice enhances resistance to striped stem borer Chilo suppressalis. PEST MANAGEMENT SCIENCE 2022; 78:770-777. [PMID: 34704657 DOI: 10.1002/ps.6690] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 10/27/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND The striped stem borer (SSB), Chilo suppressalis Walker, is a major pest of rice worldwide. Breeding of transgenic rice expressing Bacillus thuringiensis (Bt) toxins is a powerful strategy to control SSB. However, pests may evolve certain resistance to Bt toxins in transgenic plants. Hence, new controlling strategies must be continuously developed. RESULTS We successfully generated SSB-resistant rice (csu-53) expressing the artificial microRNA (amiRNA) of SSB endogenous miRNA (csu-novel-miR53) through the RNAi-based technology. Feeding assays demonstrated that csu-53 rice inhibited larval growth, delayed pupation time, and reduced pupal weight and eclosion rate of SSB larva. In a 10-day feeding experiment, the miRNA mimic of csu-novel-miR53 also suppressed larval growth and more importantly increased larval mortality. Transcriptome analysis identified 28 differentially expressed unigenes (DEGs) in the midgut between SSB larvae fed on csu-53 rice and the wild type. One DEG (DN90065_c0_g12) validated by qRT-PCR had a predicted target site of csu-novel-miR53. In addition, in vitro double-stranded RNA synthesis and further feeding assay proved that DN90065_c0_g12 is most likely the target of csu-novel-miR53. CONCLUSION amiRNA-mediated strategy can be applied to the development of insect-resistant crops, and the novel amiRNA csu-novel-miR53 of SSB has important application potential in developing SSB resistant rice. © 2021 Society of Chemical Industry.
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Affiliation(s)
- Haoju Liu
- National Key Laboratory of Crop Genetic Improvement, National Centre of Plant Gene Research, Wuhan, China
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Enlong Shen
- National Key Laboratory of Crop Genetic Improvement, National Centre of Plant Gene Research, Wuhan, China
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Hao Wu
- National Key Laboratory of Crop Genetic Improvement, National Centre of Plant Gene Research, Wuhan, China
- Henry Fok School of Biology and Agriculture, Shaoguan University, Shaoguan, China
| | - Weihua Ma
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Hao Chen
- National Key Laboratory of Crop Genetic Improvement, National Centre of Plant Gene Research, Wuhan, China
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Yongjun Lin
- National Key Laboratory of Crop Genetic Improvement, National Centre of Plant Gene Research, Wuhan, China
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
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Kohlrausch FB, Berteli TS, Wang F, Navarro PA, Keefe DL. Control of LINE-1 Expression Maintains Genome Integrity in Germline and Early Embryo Development. Reprod Sci 2021; 29:328-340. [PMID: 33481218 DOI: 10.1007/s43032-021-00461-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 01/06/2021] [Indexed: 11/28/2022]
Abstract
Maintenance of genome integrity in the germline and in preimplantation embryos is crucial for mammalian development. Epigenetic remodeling during primordial germ cell (PGC) and preimplantation embryo development may contribute to genomic instability in these cells, since DNA methylation is an important mechanism to silence retrotransposons. Long interspersed elements 1 (LINE-1 or L1) are the most common autonomous retrotransposons in mammals, corresponding to approximately 17% of the human genome. Retrotransposition events are more frequent in germ cells and in early stages of embryo development compared with somatic cells. It has been shown that L1 activation and expression occurs in germline and is essential for preimplantation development. In this review, we focus on the role of L1 retrotransposon in mouse and human germline and early embryo development and discuss the possible relationship between L1 expression and genomic instability during these stages. Although several studies have addressed L1 expression at different stages of development, the developmental consequences of this expression remain poorly understood. Future research is still needed to highlight the relationship between L1 retrotransposition events and genomic instability during germline and early embryo development.
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Affiliation(s)
- Fabiana B Kohlrausch
- Department of Obstetrics and Gynecology, New York University Langone Medical Center, 462 1st Avenue, New York, NY, 10016, USA.,Departamento de Biologia Geral, Instituto de Biologia, Universidade Federal Fluminense, Niterói, RJ, Brazil
| | - Thalita S Berteli
- Department of Obstetrics and Gynecology, New York University Langone Medical Center, 462 1st Avenue, New York, NY, 10016, USA.,Departamento de Ginecologia e Obstetrícia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Fang Wang
- Department of Obstetrics and Gynecology, New York University Langone Medical Center, 462 1st Avenue, New York, NY, 10016, USA
| | - Paula A Navarro
- Departamento de Ginecologia e Obstetrícia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - David L Keefe
- Department of Obstetrics and Gynecology, New York University Langone Medical Center, 462 1st Avenue, New York, NY, 10016, USA.
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Shalini V, Bhaduri U, Ravikkumar AC, Rengarajan A, Satyanarayana RMR. Genome-wide occupancy reveals the localization of H1T2 (H1fnt) to repeat regions and a subset of transcriptionally active chromatin domains in rat spermatids. Epigenetics Chromatin 2021; 14:3. [PMID: 33407810 PMCID: PMC7788777 DOI: 10.1186/s13072-020-00376-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 11/23/2020] [Indexed: 11/10/2022] Open
Abstract
Background H1T2/H1FNT is a germ cell-specific linker histone variant expressed during spermiogenesis specifically in round and elongating spermatids. Infertile phenotype of homozygous H1T2 mutant male mice revealed the essential function of H1T2 for the DNA condensation and histone-to-protamine replacement in spermiogenesis. However, the mechanism by which H1T2 imparts the inherent polarity within spermatid nucleus including the additional protein partners and the genomic domains occupied by this linker histone are unknown. Results Sequence analysis revealed the presence of Walker motif, SR domains and putative coiled-coil domains in the C-terminal domain of rat H1T2 protein. Genome-wide occupancy analysis using highly specific antibody against the CTD of H1T2 demonstrated the binding of H1T2 to the LINE L1 repeat elements and to a significant percentage of the genic regions (promoter-TSS, exons and introns) of the rat spermatid genome. Immunoprecipitation followed by mass spectrometry analysis revealed the open chromatin architecture of H1T2 occupied chromatin encompassing the H4 acetylation and other histone PTMs characteristic of transcriptionally active chromatin. In addition, the present study has identified the interacting protein partners of H1T2-associated chromatin mainly as nucleo-skeleton components, RNA-binding proteins and chaperones. Conclusions Linker histone H1T2 possesses unique domain architecture which can account for the specific functions associated with chromatin remodeling events facilitating the initiation of histone to transition proteins/protamine transition in the polar apical spermatid genome. Our results directly establish the unique function of H1T2 in nuclear shaping associated with spermiogenesis by mediating the interaction between chromatin and nucleo-skeleton, positioning the epigenetically specialized chromatin domains involved in transcription coupled histone replacement initiation towards the apical pole of round/elongating spermatids.
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Affiliation(s)
- Vasantha Shalini
- From the Chromatin Biology Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P.O., Bangalore, 560064, India
| | - Utsa Bhaduri
- From the Chromatin Biology Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P.O., Bangalore, 560064, India.,Department of Life Sciences, University of Trieste, Trieste, Italy.,European Union's H2020 TRIM-NET ITN, Marie Sklodowska-Curie Actions (MSCA), Leiden, The Netherlands
| | - Anjhana C Ravikkumar
- From the Chromatin Biology Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P.O., Bangalore, 560064, India
| | - Anusha Rengarajan
- From the Chromatin Biology Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P.O., Bangalore, 560064, India
| | - Rao M R Satyanarayana
- From the Chromatin Biology Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P.O., Bangalore, 560064, India.
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Wang X, Shi J, Cai G, Zheng E, Liu D, Wu Z, Li Z. Overexpression of MBD3 Improves Reprogramming of Cloned Pig Embryos. Cell Reprogram 2019; 21:221-228. [PMID: 31393170 DOI: 10.1089/cell.2019.0008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Methyl-CpG-binding domain protein 3 (MBD3) is a core component of the nucleosome remodeling and deacetylase (NuRD) complex, which is crucial for pluripotent stem cell differentiation and embryonic development. MBD3 was shown to play important roles in transcription factor-induced somatic cell reprogramming. Expression level of MBD3 was demonstrated to be higher in somatic cell nuclear transfer-generated cloned pig embryos than in fertilization-derived porcine embryos. However, the functions of MBD3 in nuclear transfer-mediated somatic cell reprogramming are unknown. In this study, MBD3 was overexpressed in cloned pig embryos, and the effects of MBD3 overexpression on gene transcription, DNA methylation, and in vitro developmental competence of cloned pig embryos were analyzed. Results indicated that overexpression of MBD3 in cloned pig embryos not only increased blastocyst rate and number of cells per blastocyst but also upregulated mRNA expression levels and decreased the DNA methylation of NANOG, OCT4, and LINE1 genes to the levels close to those in in vivo fertilization-produced pig embryos. These findings suggest that overexpression of MBD3 improves reprogramming of cloned pig embryos.
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Affiliation(s)
- Xingwang Wang
- National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Junsong Shi
- Guangdong Wen's Breeding Swine Company, Yunfu, Guangdong, China
| | - Gengyuan Cai
- National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Enqin Zheng
- National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Dewu Liu
- National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Zhenfang Wu
- National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Zicong Li
- National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agricultural University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, China
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7
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Miousse IR, Chang J, Shao L, Pathak R, Nzabarushimana É, Kutanzi KR, Landes RD, Tackett AJ, Hauer-Jensen M, Zhou D, Koturbash I. Inter-Strain Differences in LINE-1 DNA Methylation in the Mouse Hematopoietic System in Response to Exposure to Ionizing Radiation. Int J Mol Sci 2017; 18:ijms18071430. [PMID: 28677663 PMCID: PMC5535921 DOI: 10.3390/ijms18071430] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 06/28/2017] [Accepted: 06/30/2017] [Indexed: 12/15/2022] Open
Abstract
Long Interspersed Nuclear Element 1 (LINE-1) retrotransposons are the major repetitive elements in mammalian genomes. LINE-1s are well-accepted as driving forces of evolution and critical regulators of the expression of genetic information. Alterations in LINE-1 DNA methylation may lead to its aberrant activity and are reported in virtually all human cancers and in experimental carcinogenesis. In this study, we investigated the endogenous DNA methylation status of the 5′ untranslated region (UTR) of LINE-1 elements in the bone marrow hematopoietic stem cells (HSCs), hematopoietic progenitor cells (HPCs), and mononuclear cells (MNCs) in radioresistant C57BL/6J and radiosensitive CBA/J mice and in response to ionizing radiation (IR). We demonstrated that basal levels of DNA methylation within the 5′-UTRs of LINE-1 elements did not differ significantly between the two mouse strains and were negatively correlated with the evolutionary age of LINE-1 elements. Meanwhile, the expression of LINE-1 elements was higher in CBA/J mice. At two months after irradiation to 0.1 or 1 Gy of 137Cs (dose rate 1.21 Gy/min), significant decreases in LINE-1 DNA methylation in HSCs were observed in prone to radiation-induced carcinogenesis CBA/J, but not C57BL/6J mice. At the same time, no residual DNA damage, increased ROS, or changes in the cell cycle were detected in HSCs of CBA/J mice. These results suggest that epigenetic alterations may potentially serve as driving forces of radiation-induced carcinogenesis; however, future studies are needed to demonstrate the direct link between the LINE-1 DNA hypomethylation and radiation carcinogenesis.
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Affiliation(s)
- Isabelle R Miousse
- Department of Environmental and Occupational Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Jianhui Chang
- Department of Pharmaceutical Sciences, Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Lijian Shao
- Department of Pharmaceutical Sciences, Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Rupak Pathak
- Department of Pharmaceutical Sciences, Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Étienne Nzabarushimana
- Department of Bioinformatics, School of Informatics and Computing, Indiana University, Bloomington, IN 47408, USA.
| | - Kristy R Kutanzi
- Department of Environmental and Occupational Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Reid D Landes
- Department of Biostatistics, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Alan J Tackett
- Department of Biochemistry, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Martin Hauer-Jensen
- Department of Pharmaceutical Sciences, Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Daohong Zhou
- Department of Pharmaceutical Sciences, Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Igor Koturbash
- Department of Environmental and Occupational Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
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Giorgi G, Pirazzini C, Bacalini MG, Giuliani C, Garagnani P, Capri M, Bersani F, Del Re B. Assessing the combined effect of extremely low-frequency magnetic field exposure and oxidative stress on LINE-1 promoter methylation in human neural cells. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2017; 56:193-200. [PMID: 28258386 DOI: 10.1007/s00411-017-0683-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 01/11/2017] [Indexed: 06/06/2023]
Abstract
Extremely low frequency magnetic fields (ELF-MF) have been classified as "possibly carcinogenic", but their genotoxic effects are still unclear. Recent findings indicate that epigenetic mechanisms contribute to the genome dysfunction and it is well known that they are affected by environmental factors. To our knowledge, to date the question of whether exposure to ELF-MF can influence epigenetic modifications has been poorly addressed. In this paper, we investigated whether exposure to ELF-MF alone and in combination with oxidative stress (OS) can affect DNA methylation, which is one of the most often studied epigenetic modification. To this end, we analyzed the DNA methylation levels of the 5'untranslated region (5'UTR) of long interspersed nuclear element-1s (LINE-1 or L1), which are commonly used to evaluate the global genome methylation level. Human neural cells (BE(2)C) were exposed for 24 and 48 h to extremely low frequency pulsed magnetic field (PMF; 50 Hz, 1 mT) in combination with OS. The methylation levels of CpGs located in L1 5'UTR region were measured by MassARRAY EpiTYPER. The results indicate that exposures to the single agents PMF and OS induced weak decreases and increases of DNA methylation levels at different CpGs. However, the combined exposure to PMF and OS lead to significant decrease of DNA methylation levels at different CpG sites. Most of the changes were transient, suggesting that cells can restore homeostatic DNA methylation patterns. The results are discussed and future research directions outlined.
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Affiliation(s)
- Gianfranco Giorgi
- Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, via Selmi 3, 40126, Bologna, Italy
| | - Chiara Pirazzini
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), University of Bologna, via S. Giacomo 12, 40126, Bologna, Italy
| | - Maria Giulia Bacalini
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), University of Bologna, via S. Giacomo 12, 40126, Bologna, Italy
| | - Cristina Giuliani
- Department of Biological, Geological and Environmental Sciences (BiGeA), Centre for Genome Biology, University of Bologna, via Selmi 3, 40126, Bologna, Italy
| | - Paolo Garagnani
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), University of Bologna, via S. Giacomo 12, 40126, Bologna, Italy
- CIG-Interdepartmental Centre "L. Galvani" for Bioinformatics, Biophysics and Biocomplexity, Piazza di Porta San Donato 1, 40126, Bologna, Italy
| | - Miriam Capri
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), University of Bologna, via S. Giacomo 12, 40126, Bologna, Italy
- CIG-Interdepartmental Centre "L. Galvani" for Bioinformatics, Biophysics and Biocomplexity, Piazza di Porta San Donato 1, 40126, Bologna, Italy
| | - Ferdinando Bersani
- DIFA Department of Physics and Astronomy, University of Bologna, via Berti Pichat 6/2, 40127, Bologna, Italy
| | - Brunella Del Re
- Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, via Selmi 3, 40126, Bologna, Italy.
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9
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Emerging cardiac non-coding landscape: The importance of meta-analysis. Biochimie 2017; 133:87-94. [DOI: 10.1016/j.biochi.2016.12.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Accepted: 12/26/2016] [Indexed: 11/23/2022]
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10
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11
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The Fine LINE: Methylation Drawing the Cancer Landscape. BIOMED RESEARCH INTERNATIONAL 2015; 2015:131547. [PMID: 26448926 PMCID: PMC4584040 DOI: 10.1155/2015/131547] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Revised: 11/17/2014] [Accepted: 11/25/2014] [Indexed: 01/08/2023]
Abstract
LINE-1 (L1) is the most abundant mammalian transposable element that comprises nearly 20% of the genome, and nearly half of the mammalian genome has stemmed from L1-mediated mobilization. Expression and retrotransposition of L1 are suppressed by complex mechanisms, where the key role belongs to DNA methylation. Alterations in L1 methylation may lead to aberrant expression of L1 and have been described in numerous diseases. Accumulating evidence clearly indicates that loss of global DNA methylation observed in cancer development and progression is tightly associated with hypomethylation of L1 elements. Significant progress achieved in the last several years suggests that such parameters as L1 methylation status can be potentially utilized as clinical biomarkers for determination of the disease stage and in predicting the disease-free survival in cancer patients. In this paper, we summarize the current knowledge on L1 methylation, with specific emphasis given to success and challenges on the way of introduction of L1 into clinical practice.
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12
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Weirick T, Militello G, Müller R, John D, Dimmeler S, Uchida S. The identification and characterization of novel transcripts from RNA-seq data. Brief Bioinform 2015; 17:678-85. [PMID: 26283677 DOI: 10.1093/bib/bbv067] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Indexed: 11/12/2022] Open
Abstract
Owing greatly to the advancement of next-generation sequencing (NGS), the amount of NGS data is increasing rapidly. Although there are many NGS applications, one of the most commonly used techniques 'RNA sequencing (RNA-seq)' is rapidly replacing microarray-based techniques in laboratories around the world. As more and more of such techniques are standardized, allowing technicians to perform these experiments with minimal hands-on time and reduced experimental/operator-dependent biases, the bottleneck of such techniques is clearly visible; that is, data analysis. Further complicating the matter, increasing evidence suggests most of the genome is transcribed into RNA; however, the majority of these RNAs are not translated into proteins. These RNAs that do not become proteins are called 'noncoding RNAs (ncRNAs)'. Although some time has passed since the discovery of ncRNAs, their annotations remain poor, making analysis of RNA-seq data challenging. Here, we examine the current limitations of RNA-seq analysis using case studies focused on the detection of novel transcripts and examination of their characteristics. Finally, we validate the presence of novel transcripts using biological experiments, showing novel transcripts can be accurately identified when a series of filters is applied. In conclusion, novel transcripts that are identified from RNA-seq must be examined carefully before proceeding to biological experiments.
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13
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Chandrashekar DS, Dey P, Acharya KK. GREAM: A Web Server to Short-List Potentially Important Genomic Repeat Elements Based on Over-/Under-Representation in Specific Chromosomal Locations, Such as the Gene Neighborhoods, within or across 17 Mammalian Species. PLoS One 2015. [PMID: 26208093 PMCID: PMC4514817 DOI: 10.1371/journal.pone.0133647] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Background Genome-wide repeat sequences, such as LINEs, SINEs and LTRs share a considerable part of the mammalian nuclear genomes. These repeat elements seem to be important for multiple functions including the regulation of transcription initiation, alternative splicing and DNA methylation. But it is not possible to study all repeats and, hence, it would help to short-list before exploring their potential functional significance via experimental studies and/or detailed in silico analyses. Result We developed the ‘Genomic Repeat Element Analyzer for Mammals’ (GREAM) for analysis, screening and selection of potentially important mammalian genomic repeats. This web-server offers many novel utilities. For example, this is the only tool that can reveal a categorized list of specific types of transposons, retro-transposons and other genome-wide repetitive elements that are statistically over-/under-represented in regions around a set of genes, such as those expressed differentially in a disease condition. The output displays the position and frequency of identified elements within the specified regions. In addition, GREAM offers two other types of analyses of genomic repeat sequences: a) enrichment within chromosomal region(s) of interest, and b) comparative distribution across the neighborhood of orthologous genes. GREAM successfully short-listed a repeat element (MER20) known to contain functional motifs. In other case studies, we could use GREAM to short-list repetitive elements in the azoospermia factor a (AZFa) region of the human Y chromosome and those around the genes associated with rat liver injury. GREAM could also identify five over-represented repeats around some of the human and mouse transcription factor coding genes that had conserved expression patterns across the two species. Conclusion GREAM has been developed to provide an impetus to research on the role of repetitive sequences in mammalian genomes by offering easy selection of more interesting repeats in various contexts/regions. GREAM is freely available at http://resource.ibab.ac.in/GREAM/.
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Affiliation(s)
- Darshan Shimoga Chandrashekar
- Institute of Bioinformatics and Applied Biotechnology (IBAB), Biotech Park, Electronic City, Bengaluru (Bangalore), 560100, Karnataka state, India
- Manipal University, Manipal, 576104, Karnataka state, India
| | - Poulami Dey
- Institute of Bioinformatics and Applied Biotechnology (IBAB), Biotech Park, Electronic City, Bengaluru (Bangalore), 560100, Karnataka state, India
- Manipal University, Manipal, 576104, Karnataka state, India
| | - Kshitish K. Acharya
- Institute of Bioinformatics and Applied Biotechnology (IBAB), Biotech Park, Electronic City, Bengaluru (Bangalore), 560100, Karnataka state, India
- Shodhaka Life Sciences Pvt. Ltd., IBAB, Biotech Park, Bengaluru (Bangalore), 560100, Karnataka state, India
- * E-mail:
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Miousse IR, Chalbot MCG, Lumen A, Ferguson A, Kavouras IG, Koturbash I. Response of transposable elements to environmental stressors. MUTATION RESEARCH. REVIEWS IN MUTATION RESEARCH 2015; 765:19-39. [PMID: 26281766 PMCID: PMC4544780 DOI: 10.1016/j.mrrev.2015.05.003] [Citation(s) in RCA: 93] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Revised: 05/27/2015] [Accepted: 05/28/2015] [Indexed: 12/21/2022]
Abstract
Transposable elements (TEs) comprise a group of repetitive sequences that bring positive, negative, as well as neutral effects to the host organism. Earlier considered as "junk DNA," TEs are now well-accepted driving forces of evolution and critical regulators of the expression of genetic information. Their activity is regulated by epigenetic mechanisms, including methylation of DNA and histone modifications. The loss of epigenetic control over TEs, exhibited as loss of DNA methylation and decondensation of the chromatin structure, may result in TEs reactivation, initiation of their insertional mutagenesis (retrotransposition) and has been reported in numerous human diseases, including cancer. Accumulating evidence suggests that these alterations are not the simple consequences of the disease, but often may drive the pathogenesis, as they can be detected early during disease development. Knowledge derived from the in vitro, in vivo, and epidemiological studies, clearly demonstrates that exposure to ubiquitous environmental stressors, many of which are carcinogens or suspected carcinogens, are capable of causing alterations in methylation and expression of TEs and initiate retrotransposition events. Evidence summarized in this review suggests that TEs are the sensitive endpoints for detection of effects caused by such environmental stressors, as ionizing radiation (terrestrial, space, and UV-radiation), air pollution (including particulate matter [PM]-derived and gaseous), persistent organic pollutants, and metals. Furthermore, the significance of these effects is characterized by their early appearance, persistence and presence in both, target organs and peripheral blood. Altogether, these findings suggest that TEs may potentially be introduced into safety and risk assessment and serve as biomarkers of exposure to environmental stressors. Furthermore, TEs also show significant potential to become invaluable surrogate biomarkers in clinic and possible targets for therapeutic modalities for disease treatment and prevention.
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Affiliation(s)
- Isabelle R Miousse
- Department of Environmental and Occupational Health, Fay W. Boozman College of Public Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Marie-Cecile G Chalbot
- Department of Environmental and Occupational Health, Fay W. Boozman College of Public Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Annie Lumen
- Division of Biochemical Toxicology, National Center for Toxicological Research, US Food and Drug Administration, Jefferson, AR 72079, USA.
| | - Alesia Ferguson
- Department of Environmental and Occupational Health, Fay W. Boozman College of Public Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Ilias G Kavouras
- Department of Environmental and Occupational Health, Fay W. Boozman College of Public Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Igor Koturbash
- Department of Environmental and Occupational Health, Fay W. Boozman College of Public Health, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
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15
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Miller D. Confrontation, Consolidation, and Recognition: The Oocyte's Perspective on the Incoming Sperm. Cold Spring Harb Perspect Med 2015; 5:a023408. [PMID: 25957313 PMCID: PMC4526728 DOI: 10.1101/cshperspect.a023408] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
From the oocyte's perspective, the incoming sperm poses a significant challenge. Despite (usually) arising from a male of the same species, the sperm is a "foreign" body that may carry with it additional, undesirable factors such as transposable elements (mainly retroposons) into the egg. These factors can arise either during spermatogenesis or while the sperm is moving through the epididymis or the female genital tract. Furthermore, in addition to the paternal genome, the sperm also carries its own complex repertoire of RNAs into the egg that includes mRNAs, lncRNAs, and sncRNAs. Last, the paternal genome itself is efficiently packaged into a protamine (nucleo-toroid) and histone (nucleosome)-based chromatin scaffold within which much of the RNA is embedded. Taken together, the sperm delivers a far more complex package to the egg than was originally thought. Understanding this complexity, at both the compositional and structural level, depends largely on investigating sperm chromatin from both the genomic (DNA packaging) and epigenomic (RNA carriage and extant histone modifications) perspectives. Why this complexity has arisen and its likely purpose requires us to look more closely at what happens in the oocyte when the sperm gains entry and the processes that then take place preparing the paternal (and maternal) genomes for syngamy.
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Affiliation(s)
- David Miller
- Institute of Cardiovascular and Metabolic Medicine (LICAMM), LIGHT Laboratories, University of Leeds, Leeds, LS2 9JT West Yorkshire, United Kingdom
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Kejnovsky E, Lexa M. Quadruplex-forming DNA sequences spread by retrotransposons may serve as genome regulators. Mob Genet Elements 2014; 4:e28084. [PMID: 24616836 DOI: 10.4161/mge.28084] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Accepted: 02/03/2014] [Indexed: 02/02/2023] Open
Abstract
Transposable elements (TEs) are ubiquitous genome inhabitants in eukaryotes. Increasing evidence shows that TEs are involved in regulatory networks of eukaryotic cells and contribute to genome evolution. Recently, we reported that many plant long-terminal repeat (LTR) retrotransposons contain DNA quadruplex-forming sequences at precise positions inside their LTRs and that quadruplexes are better preserved in evolutionary younger elements. As quadruplexes can modulate molecular processes, quadruplexes found at specific distances upstream and downstream from the endogenous TE promoter can affect transcription of the element. Moreover, quadruplexes found in solo LTRs, as well as in 3' ends of 5'-truncated copies of LINE-1 elements, can affect expression of neighboring genes. Here, we propose that this way retrotransposons can serve as vehicles for spread of DNA quadruplexes. Quadruplexes can thus fulfill a dual regulatory role-to influence both the retrotransposons carrying them and the neighboring host genes, e.g., by direct effect on transcription or by modifying the local chromatin state. Additionally, four-stranded DNA structures may serve as hotspots for recombination-based genome rearrangements.
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Affiliation(s)
- Eduard Kejnovsky
- Department of Plant Developmental Genetics; Institute of Biophysics ASCR; Brno, Czech Republic ; Laboratory of Genome Dynamics; CEITEC-Central European Institute of Technology; Masaryk University; Brno, Czech Republic
| | - Matej Lexa
- Laboratory of Genome Dynamics; CEITEC-Central European Institute of Technology; Masaryk University; Brno, Czech Republic ; Faculty of Informatics; Masaryk University; Brno, Czech Republic
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