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De novo DNA Methylation

Yasuhiro Kyono, Laurent M Sachs, Patrice Bilesimo, Luan Wen, Robert J Denver
Thyroid hormone (TH) is essential for normal development in vertebrates. In amphibians, TH controls metamorphosis by inducing tissue-specific gene regulation programs. A hallmark of TH action is the modification of chromatin structure, which underlies changes in gene transcription. We found that mRNA for the de novo DNA methyltransferase (DNMT) dnmt3a, but not dnmt1, increased in the brain of Xenopus tadpoles during metamorphosis in parallel with plasma [TH]. Addition of 3,5,3`-triiodothyronine (T3) to the rearing water caused a time-dependent increase in dnmt3a mRNA in tadpole brain, tail and hind limb...
October 25, 2016: Endocrinology
Sasha Kay, Daniel Skowronski, Brendan G Hunt
DNA methylation is accomplished in animals by two classes of enzymes known as DNA methyltransferases, DNMT3 and DNMT1, which perform de novo methylation and maintenance methylation, respectively. Several studies of hymenopteran eusocial insects suggest that DNA methylation is capable of influencing developmental plasticity. However, fundamental questions remain about the patterning of DNA methylation during the course of insect development. In this study, we performed quantitative real-time PCR (qPCR) on transcripts from the single-copy orthologs of DNMT1 and DNMT3 in the red imported fire ant, Solenopsis invicta...
October 24, 2016: Insect Science
Allison B Norvil, Christopher J Petell, Lama Abdullah Alabdi, Lanchen Wu, Sandra Rossie, Humaira Gowher
The catalytic domains of the de novo DNA methyltransferases, Dnmt3a-C and Dnmt3b-C are highly homologous. However their unique biochemical properties could potentially contribute to differences in the substrate preferences or biological functions of these enzymes. Dnmt3a-C forms tetramers through interactions at the dimer interface, which also promote multimerization on DNA and cooperativity. Similar to processive enzymes, cooperativity allows Dnmt3a-C to methylate multiple sites on the same DNA molecule, however it is unclear whether Dnmt3b-C methylates DNA by cooperative or processive mechanism...
October 21, 2016: Biochemistry
Yan Long, Wen-Bin Tsai, Jeffrey T Chang, Marcos Estecio, Medhi Wangpaichitr, Naramol Savaraj, Lynn G Feun, Helen H W Chen, Macus Tien Kuo
Many human tumors require extracellular arginine (Arg) for growth because the key enzyme for de novo biosynthesis of Arg, argininosuccinate synthetase 1 (ASS1), is silenced. These tumors are sensitive to Arg-starvation therapy using pegylated arginine deiminase (ADI-PEG20) which digests extracellular Arg. Many previous studies reported that ASS1 silencing is due to epigenetic inactivation of ASS1 expression by DNA methylation, and that the demethylation agent 5-aza-deoxycytidine (Aza-dC) can induce ASS1 expression...
September 28, 2016: Oncotarget
Francesca Megiorni, Simona Camero, Simona Ceccarelli, Heather P McDowell, Olga Mannarino, Francesco Marampon, Barry Pizer, Rajeev Shukla, Antonio Pizzuti, Cinzia Marchese, Anna Clerico, Carlo Dominici
Aberrant DNA methylation has been frequently observed in many human cancers, including rhabdomyosarcoma (RMS), the most common soft tissue sarcoma in children. To date, the expression and function of the de novo DNA methyltransferase (DNMT) 3B in RMS have not yet been investigated. Our study show for the first time a significant up-regulation of DNMT3B levels in 14 RMS tumour samples and 4 RMS cell lines in comparison to normal skeletal muscle. Transfection of RD and TE671 cells, two in vitro models of embryonal RMS (ERMS), with a synthetic DNMT3B siRNA decreased cell proliferation by arresting cell cycle at G1 phase, as demonstrated by the reduced expression of Cyclin B1, Cyclin D1 and Cyclin E2, and by the concomitant up-regulation of the checkpoint regulators p21 and p27...
October 15, 2016: Oncotarget
Takamasa Hirano, Hidetoshi Hasuwa, Haruhiko Siomi
The mouse testis has served as a popular model system to study a wide range of biological processes, including germ cell development, meiosis, epigenetic changes of chromatin, transposon silencing, and small RNA-mediated epigenetic modifications. PIWI-interacting RNAs (piRNAs) are a class of small RNAs that are almost exclusively expressed in animal gonads. They repress transposons by forming effector complexes with PIWI proteins to maintain genome integrity of the germline. Here we describe detailed procedures of how to produce monoclonal antibodies against a mouse nuclear PIWI protein, MIWI2, which functions in de novo DNA methylation of target transposon loci...
2017: Methods in Molecular Biology
Jennifer Dorts, Elodie Falisse, Emilie Schoofs, Enora Flamion, Patrick Kestemont, Frédéric Silvestre
DNA methylation, a well-studied epigenetic mark, is important for gene regulation in adulthood and for development. Using genetic and epigenetic approaches, the present study aimed at evaluating the effects of heat stress and copper exposure during zebrafish early embryogenesis when patterns of DNA methylation are being established, a process called reprogramming. Embryos were exposed to 325 μg Cu/L from fertilization (<1 h post fertilization - hpf) to 4 hpf at either 26.5 °C or 34 °C, followed by incubation in clean water at 26...
October 12, 2016: Scientific Reports
Ferdinand von Meyenn, Rebecca V Berrens, Simon Andrews, Fátima Santos, Amanda J Collier, Felix Krueger, Rodrigo Osorno, Wendy Dean, Peter J Rugg-Gunn, Wolf Reik
Primordial germ cell (PGC) development is characterized by global epigenetic remodeling, which resets genomic potential and establishes an epigenetic ground state. Here we recapitulate PGC specification in vitro from naive embryonic stem cells and characterize the early events of epigenetic reprogramming during the formation of the human and mouse germline. Following rapid de novo DNA methylation during priming to epiblast-like cells, methylation is globally erased in PGC-like cells. Repressive chromatin marks (H3K9me2/3) and transposable elements are enriched at demethylation-resistant regions, while active chromatin marks (H3K4me3 or H3K27ac) are more prominent at regions that demethylate faster...
October 10, 2016: Developmental Cell
Norio Asou
Current treatment of acute myeloid leukemia (AML) still relies on intensive chemotherapy and allogeneic hematopoietic stem cell transplantation (HSCT). AML is a heterogeneous neoplasm characterized by distinct chromosomal and genetic abnormalities. Recent comprehensive gene analyses have highlighted distinct genetic subgroups that are associated with different responses to chemotherapy. Therefore, the molecular landscape of AML is fundamental to the development of novel therapeutic approaches and provides opportunities for individualization of therapy...
2016: [Rinshō Ketsueki] the Japanese Journal of Clinical Hematology
Ying Wang, George L Sen
In this issue of Cell Stem Cell, Rinaldi et al. (2016) find an unexpected role for the de novo DNA methyltransferases Dnmt3a and Dnmt3b in the regulation of enhancers. Their findings provide new insight into how regulation of enhancer activity through DNA methylation can have dramatic consequences on epidermal stem cell fate decisions.
October 6, 2016: Cell Stem Cell
Fatma Uysal, Gokhan Akkoyunlu, Saffet Ozturk
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...
September 12, 2016: Reproductive Biomedicine Online
X Shawn Liu, Hao Wu, Xiong Ji, Yonatan Stelzer, Xuebing Wu, Szymon Czauderna, Jian Shu, Daniel Dadon, Richard A Young, Rudolf Jaenisch
Mammalian DNA methylation is a critical epigenetic mechanism orchestrating gene expression networks in many biological processes. However, investigation of the functions of specific methylation events remains challenging. Here, we demonstrate that fusion of Tet1 or Dnmt3a with a catalytically inactive Cas9 (dCas9) enables targeted DNA methylation editing. Targeting of the dCas9-Tet1 or -Dnmt3a fusion protein to methylated or unmethylated promoter sequences caused activation or silencing, respectively, of an endogenous reporter...
September 22, 2016: Cell
Angelo Amabile, Alessandro Migliara, Paola Capasso, Mauro Biffi, Davide Cittaro, Luigi Naldini, Angelo Lombardo
Gene silencing is instrumental to interrogate gene function and holds promise for therapeutic applications. Here, we repurpose the endogenous retroviruses' silencing machinery of embryonic stem cells to stably silence three highly expressed genes in somatic cells by epigenetics. This was achieved by transiently expressing combinations of engineered transcriptional repressors that bind to and synergize at the target locus to instruct repressive histone marks and de novo DNA methylation, thus ensuring long-term memory of the repressive epigenetic state...
September 22, 2016: Cell
Kathleen R Stewart, Lenka Veselovska, Gavin Kelsey
Epigenetic modifications established during gametogenesis regulate transcription and other nuclear processes in gametes, but also have influences in the zygote, embryo and postnatal life. This is best understood for DNA methylation which, established at discrete regions of the oocyte and sperm genomes, governs genomic imprinting. In this review, we describe how imprinting has informed our understanding of de novo DNA methylation mechanisms, highlight how recent genome-wide profiling studies have provided unprecedented insights into establishment of the sperm and oocyte methylomes and consider the fate and function of gametic methylation and other epigenetic modifications after fertilization...
October 2016: Epigenomics
Kanako Kojima-Kita, Satomi Kuramochi-Miyagawa, Ippei Nagamori, Narumi Ogonuki, Atsuo Ogura, Hidetoshi Hasuwa, Takashi Akazawa, Norimitsu Inoue, Toru Nakano
During the development of mammalian embryonic germ cells, global demethylation and de novo DNA methylation take place. In mouse embryonic germ cells, two PIWI family proteins, MILI and MIWI2, are essential for the de novo DNA methylation of retrotransposons, presumably through PIWI-interacting RNAs (piRNAs). Although piRNA-associated MIWI2 has been reported to play critical roles in the process, its molecular mechanisms have remained unclear. To identify the mechanism, transgenic mice were produced; they contained a fusion protein of MIWI2 and a zinc finger (ZF) that recognized the promoter region of a type A LINE-1 gene...
September 13, 2016: Cell Reports
Clayton B Woodcock, Egor A Ulashchik, Nikolai E Poopeiko, Vadim Shmanai, Norbert O Reich, Mikhail S Shchepinov
The human DNA methyltransferase 3A (DNMT 3A) is responsible for de novo epigenetic regulation which is essential for mammalian viability and a contributing cause of diverse human diseases. All DNA cytosine C5 methyltransferases follow a broadly conserved catalytic mechanism. We investigated whether C5 -elimination contributes to the rate limiting step in catalysis of DNMT3A and the bacterial M.HhaI by using deuterium substitutions of C5 and C6 hydrogens. This substitution caused a 1.59-1.83 fold change in the rate of catalysis suggesting that -elimination is partially rate limiting for both enzymes...
September 5, 2016: Chembiochem: a European Journal of Chemical Biology
C Stirzaker, J Z Song, W Ng, Q Du, N J Armstrong, W J Locke, A L Statham, H French, R Pidsley, F Valdes-Mora, E Zotenko, S J Clark
Cancer is characterised by DNA hypermethylation and gene silencing of CpG island-associated promoters, including tumour-suppressor genes. The methyl-CpG-binding domain (MBD) family of proteins bind to methylated DNA and can aid in the mediation of gene silencing through interaction with histone deacetylases and histone methyltransferases. However, the mechanisms responsible for eliciting CpG island hypermethylation in cancer, and the potential role that MBD proteins play in modulation of the methylome remain unclear...
September 5, 2016: Oncogene
Hye-Young Min, Su-Chan Lee, Jong Kyu Woo, Hyun Jin Jung, Kwan Hee Park, Hae Min Jeong, Seung Yeob Hyun, Jaebeom Cho, Wooin Lee, Ji Eun Park, So Jung Kwon, Hyo-Jong Lee, Xiao Ni, Young Kee Shin, Faye M Johnson, Madeleine Duvic, Ho-Young Lee
PURPOSE: Histone deacetylase inhibitors (HDIs) are promising anticancer therapies; however, drug resistance limits their efficacy. Here, we investigated the molecular mechanisms underlying HDI resistance, focusing on the mechanism of HDI-mediated induction of insulin-like growth factor 2 (IGF2) based on our previous study. EXPERIMENTAL DESIGN: The methylation status of CCCTC binding factor (CTCF)-binding sites in the IGF2/H19 imprinting control region (ICR) were determined by methylation-specific PCR and bisulfite sequencing...
August 31, 2016: Clinical Cancer Research: An Official Journal of the American Association for Cancer Research
Brian H Ladle, Kun-Po Li, Maggie J Phillips, Alexandra B Pucsek, Azeb Haile, Jonathan D Powell, Elizabeth M Jaffee, David A Hildeman, Christopher J Gamper
DNMT3a is a de novo DNA methyltransferase expressed robustly after T-cell activation that regulates plasticity of CD4(+) T-cell cytokine expression. Here we show that DNMT3a is critical for directing early CD8(+) T-cell effector and memory fate decisions. Whereas effector function of DNMT3a knockout T cells is normal, they develop more memory precursor and fewer terminal effector cells in a T-cell intrinsic manner compared with wild-type animals. Rather than increasing plasticity of differentiated effector CD8(+) T cells, loss of DNMT3a biases differentiation of early effector cells into memory precursor cells...
September 20, 2016: Proceedings of the National Academy of Sciences of the United States of America
Gudrun Valgerdur Skuladottir, Emil Karl Nilsson, Jessica Mwinyi, Helgi Birgir Schiöth
BACKGROUND: Sleep deprivation has been associated with obesity among adults, and accumulating data suggests that stearoyl-CoA desaturase 1 (SCD1) expression has a relevant impact on fatty acid (FA) composition of lipid pools and obesity. The aim of this study was to investigate the effect of one-night total sleep deprivation (TSD) on DNA methylation in the 5'-prime region of SCD1, and whether detected changes in DNA methylation are associated with SCD activity indices (product to precursor FA ratios; 16:1n-7/16:0 and 18:1n-9/18:0) derived from serum phospholipids (PL)...
2016: Lipids in Health and Disease
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