On the potential role of active DNA demethylation in establishing epigenetic states associated with neural plasticity and memory

2013 ◽  
Vol 105 ◽  
pp. 125-132 ◽  
Author(s):  
Xiang Li ◽  
Wei Wei ◽  
Vikram S. Ratnu ◽  
Timothy W. Bredy
Keyword(s):  
Neural Plasticity ◽  
Potential Role ◽  
Dna Demethylation ◽  
Active Dna Demethylation

scholarly journals Vitamin C Transporters and Their Implications in Carcinogenesis

Nutrients ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3869
Author(s):  
Kinga Linowiecka ◽  
Marek Foksinski ◽  
Anna A. Brożyna
Keyword(s):  
Vitamin C ◽  
Cancer Biology ◽  
Redox Homeostasis ◽  
Regulation Of Gene Expression ◽  
Dna Demethylation ◽  
Altered Expression ◽  
Tet Proteins ◽  
Active Dna Demethylation ◽  
Hypoxic State

Vitamin C is implicated in various bodily functions due to its unique properties in redox homeostasis. Moreover, vitamin C also plays a great role in restoring the activity of 2-oxoglutarate and Fe2+ dependent dioxygenases (2-OGDD), which are involved in active DNA demethylation (TET proteins), the demethylation of histones, and hypoxia processes. Therefore, vitamin C may be engaged in the regulation of gene expression or in a hypoxic state. Hence, vitamin C has acquired great interest for its plausible effects on cancer treatment. Since its conceptualization, the role of vitamin C in cancer therapy has been a controversial and disputed issue. Vitamin C is transferred to the cells with sodium dependent transporters (SVCTs) and glucose transporters (GLUT). However, it is unknown whether the impaired function of these transporters may lead to carcinogenesis and tumor progression. Notably, previous studies have identified SVCTs’ polymorphisms or their altered expression in some types of cancer. This review discusses the potential effects of vitamin C and the impaired SVCT function in cancers. The variations in vitamin C transporter genes may regulate the active transport of vitamin C, and therefore have an impact on cancer risk, but further studies are needed to thoroughly elucidate their involvement in cancer biology.

scholarly journals L-Theanine Activates the Browning of White Adipose Tissue through the AMPK/α-Ketoglutarate/Prdm16 Axis and Ameliorates Diet-induced Obesity in Mice

2021 ◽  
Author(s):  
Wan-Qiu Peng ◽  
Gang Xiao ◽  
Bai-Yu Li ◽  
Ying-Ying Guo ◽  
Liang Guo ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
White Adipose Tissue ◽  
Intraperitoneal Administration ◽  
Dna Demethylation ◽  
Active Dna Demethylation ◽  
Diet Induced Obesity ◽  
Elevated Expression ◽  
Obesity In Mice

L-Theanine is a nonprotein amino acid with much beneficial efficacy. We found that intraperitoneal treatment of the mice with L-Theanine(100mg/kg/day) enhanced adaptive thermogenesis and induced the browning of inguinal white adipose tissue (iWAT) with elevated expression of Prdm16, Ucp1 and other thermogenic genes. Meanwhile, administration of the mice with L-Theanine increased energy expenditure. In vitro studies indicated that L-Theanine induced the development of brown-like features in adipocytes. The shRNA-mediated depletion of Prdm16 blunted the role of L-Theanine in promoting the brown-like phenotypes in adipocytes and in the iWAT of mice. L-Theanine treatment enhanced AMPKα phosphorylation both in adipocytes and in iWAT. Knockdown of AMPKα ablolished L-Theanine-induced upregulation of Prdm16 and adipocytes browning. L-Theanine increased the α-ketoglutarate (α-KG) level in adipocytes, which may increase the transcription of Prdm16 by inducing active DNA demethylation on its promoter. AMPK activation was required for L-Theanine-induced increase of α-KG and DNA demethylation on Prdm16 promoter. Moreover, intraperitoneal administration with L-Theanine ameliorated obesity, improved glucose tolerance and insulin sensitivity, and reduced plasma triglyceride, total cholesterol and free fatty acid in the high fat diet-fed mice. Our results suggest a potential role of L-Theanine in combating diet-induced obesity in mice, which may involve L-Theanine-induced browning of white adipose tissue.

scholarly journals DNA Demethylation Pathways: Recent Insights

2013 ◽  
Vol 5 ◽  
pp. GEG.S12143 ◽  
Author(s):  
Cong-jun Li
Keyword(s):  
Dna Methylation ◽  
Mammalian Cells ◽  
De Novo ◽  
Dna Demethylation ◽  
Epigenetic Mark ◽  
Sequencing Technologies ◽  
Active Dna Demethylation ◽  
Mammalian Genomes ◽  
Genome Context

DNA methylation is a major epigenetic regulatory mechanism for gene expression and cell differentiation. Until recently, it was still unclear how unmethylated regions in mammalian genomes are protected from de novo methylation and whether or not active demethylating activity is involved. Even the role of molecules and the mechanisms underlying the processes of active demethylation itself is blurred. Emerging sequencing technologies have led to recent insights into the dynamic distribution of DNA methylation during development and the role of this epigenetic mark within a distinct genome context, such as the promoters, exons, or imprinted control regions. This review summarizes recent insights on the dynamic nature of DNA methylation and demethylation, as well as the mechanisms regulating active DNA demethylation in mammalian cells, which have been fundamental research interests in the field of epigenomics.

scholarly journals Male fertility in Arabidopsis requires active DNA demethylation of genes that control pollen tube function

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Souraya Khouider ◽  
Filipe Borges ◽  
Chantal LeBlanc ◽  
Alexander Ungru ◽  
Arp Schnittger ◽  
...  
Keyword(s):  
Pollen Tube ◽  
Male Fertility ◽  
Essential Role ◽  
Dna Demethylation ◽  
Dna Glycosylases ◽  
Active Dna Demethylation ◽  
Molecular Determinants ◽  
Tube Function ◽  
Mutant Pollen

AbstractActive DNA demethylation is required for sexual reproduction in plants but the molecular determinants underlying this epigenetic control are not known. Here, we show in Arabidopsis thaliana that the DNA glycosylases DEMETER (DME) and REPRESSOR OF SILENCING 1 (ROS1) act semi-redundantly in the vegetative cell of pollen to demethylate DNA and ensure proper pollen tube progression. Moreover, we identify six pollen-specific genes with increased DNA methylation as well as reduced expression in dme and dme;ros1. We further show that for four of these genes, reinstalling their expression individually in mutant pollen is sufficient to improve male fertility. Our findings demonstrate an essential role of active DNA demethylation in regulating genes involved in pollen function.

scholarly journals L-Theanine Activates the Browning of White Adipose Tissue through the AMPK/α-Ketoglutarate/Prdm16 Axis and Ameliorates Diet-induced Obesity in Mice

2021 ◽  
Author(s):  
Wan-Qiu Peng ◽  
Gang Xiao ◽  
Bai-Yu Li ◽  
Ying-Ying Guo ◽  
Liang Guo ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
White Adipose Tissue ◽  
Intraperitoneal Administration ◽  
Dna Demethylation ◽  
Active Dna Demethylation ◽  
Diet Induced Obesity ◽  
Elevated Expression ◽  
Obesity In Mice

L-Theanine is a nonprotein amino acid with much beneficial efficacy. We found that intraperitoneal treatment of the mice with L-Theanine(100mg/kg/day) enhanced adaptive thermogenesis and induced the browning of inguinal white adipose tissue (iWAT) with elevated expression of Prdm16, Ucp1 and other thermogenic genes. Meanwhile, administration of the mice with L-Theanine increased energy expenditure. In vitro studies indicated that L-Theanine induced the development of brown-like features in adipocytes. The shRNA-mediated depletion of Prdm16 blunted the role of L-Theanine in promoting the brown-like phenotypes in adipocytes and in the iWAT of mice. L-Theanine treatment enhanced AMPKα phosphorylation both in adipocytes and in iWAT. Knockdown of AMPKα ablolished L-Theanine-induced upregulation of Prdm16 and adipocytes browning. L-Theanine increased the α-ketoglutarate (α-KG) level in adipocytes, which may increase the transcription of Prdm16 by inducing active DNA demethylation on its promoter. AMPK activation was required for L-Theanine-induced increase of α-KG and DNA demethylation on Prdm16 promoter. Moreover, intraperitoneal administration with L-Theanine ameliorated obesity, improved glucose tolerance and insulin sensitivity, and reduced plasma triglyceride, total cholesterol and free fatty acid in the high fat diet-fed mice. Our results suggest a potential role of L-Theanine in combating diet-induced obesity in mice, which may involve L-Theanine-induced browning of white adipose tissue.

scholarly journals Active DNA demethylation regulates tracheary element differentiation in Arabidopsis

2020 ◽  
Vol 6 (26) ◽  
pp. eaaz2963
Author(s):  
Wei Lin ◽  
Linhua Sun ◽  
Run-Zhou Huang ◽  
Wenjie Liang ◽  
Xinyu Liu ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Tracheary Element ◽  
Dna Demethylation ◽  
Epigenetic Mechanism ◽  
Dna Glycosylases ◽  
Tracheary Element Differentiation ◽  
Xylem Development ◽  
Active Dna Demethylation ◽  
Genomic Regions

DNA demethylation is important for the erasure of DNA methylation. The role of DNA demethylation in plant development remains poorly understood. Here, we found extensive DNA demethylation in the CHH context around pericentromeric regions and DNA demethylation in the CG, CHG, and CHH contexts at discrete genomic regions during ectopic xylem tracheary element (TE) differentiation. While loss of pericentromeric methylation occurs passively, DNA demethylation at a subset of regions relies on active DNA demethylation initiated by DNA glycosylases ROS1, DML2, and DML3. The ros1 and rdd mutations impair ectopic TE differentiation and xylem development in the young roots of Arabidopsis seedlings. Active DNA demethylation targets and regulates many genes for TE differentiation. The defect of xylem development in rdd is proposed to be caused by dysregulation of multiple genes. Our study identifies a role of active DNA demethylation in vascular development and reveals an epigenetic mechanism for TE differentiation.

O-GlcNAcylation and chromatin remodeling in mammals: an up-to-date overview

2017 ◽  
Vol 45 (2) ◽  
pp. 323-338 ◽  
Author(s):  
Maïté Leturcq ◽  
Tony Lefebvre ◽  
Anne-Sophie Vercoutter-Edouart
Keyword(s):  
Chromatin Remodeling ◽  
Dna Demethylation ◽  
Post Translational Modifications ◽  
Cellular Models ◽  
Active Dna Demethylation ◽  
Chromatin Regulators ◽  
Lysine Specific Demethylase ◽  
The Stability ◽  
Glcnac Transferase

Post-translational modifications of histones and the dynamic DNA methylation cycle are finely regulated by a myriad of chromatin-binding factors and chromatin-modifying enzymes. Epigenetic modifications ensure local changes in the architecture of chromatin, thus controlling in fine the accessibility of the machinery of transcription, replication or DNA repair to the chromatin. Over the past decade, the nutrient-sensor enzyme O-GlcNAc transferase (OGT) has emerged as a modulator of chromatin remodeling. In mammals, OGT acts either directly through dynamic and reversible O-GlcNAcylation of histones and chromatin effectors, or in an indirect manner through its recruitment into chromatin-bound multiprotein complexes. In particular, there is an increasing amount of evidence of a cross-talk between OGT and the DNA dioxygenase ten–eleven translocation proteins that catalyze active DNA demethylation. Conversely, the stability of OGT itself can be controlled by the histone lysine-specific demethylase 2 (LSD2). Finally, a few studies have explored the role of O-GlcNAcase (OGA) in chromatin remodeling. In this review, we summarize the recent findings on the link between OGT, OGA and chromatin regulators in mammalian cellular models, and discuss their relevance in physiological and pathological conditions.

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