Read by QxMD icon Read


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
Gizem Bor, Jennifer Mytych, Jacek Zebrowski, Maciej Wnuk, Gülşah Şanlı-Mohamed
Although chitosan nanoparticles (CNs) became a promising tool for several biological and medical applications owing to their inherent biocompatibility and biodegradability features, studies regarding their effects on cytotoxic and cytostatic properties still remain insufficient. Therefore, in the present study, we decided to perform comprehensive analysis of the interactions between CNs-pKindling-Red-Mito (pDNA) and different cell line models derived from blood system and human solid tissues cancers. The resulting CNs-pDNA was investigated in terms of their cellular uptake, transfection efficiency, and physico-chemical, cytotoxic and cytostatic properties...
September 19, 2016: International Journal of Pharmaceutics
V V Ashapkin, L I Kutueva, B F Vanyushin
Dnmt2 is the most strongly conserved cytosine DNA methyltransferase in eukaryotes. It has been found in all organisms possessing methyltransferases of the Dnmt1 and Dnmt3 families, whereas in many others Dnmt2 is the sole cytosine DNA methyltransferase. The Dnmt2 molecule contains all conserved motifs of cytosine DNA methyltransferases. It forms 3D complexes with DNA very similar to those of bacterial DNA methyltransferases and performs cytosine methylation by a catalytic mechanism common to all cytosine DNA methyltransferases...
March 2016: Genetika
Hossein Ghanbarian, Nicole Wagner, Beatrice Polo, Delphine Baudouy, Jafar Kiani, Jean-François Michiels, François Cuzin, Minoo Rassoulzadegan, Kay-Dietrich Wagner
Dnmt2/Trdmt1 is a methyltransferase, which has been shown to methylate tRNAs. Deficient mutants were reported to exhibit various, seemingly unrelated, defects in development and RNA-mediated epigenetic heredity. Here we report a role in a distinct developmental regulation effected by a noncoding RNA. We show that Dnmt2-deficiency in mice results in cardiac hypertrophy. Echocardiographic measurements revealed that cardiac function is preserved notwithstanding the increased dimensions of the organ due to cardiomyocyte enlargement...
2016: PloS One
V V Ashapkin, L I Kutueva, B F Vanyushin
Expression and methylation patterns of genes encoding DNA methyltransferases and their functionally related proteins were studied in organs of Arabidopsis thaliana plants. Genes coding for the major maintenance-type DNA methyltransferases, MET1 and CMT3, and the major de novo-type DNA methyltransferase, DRM2, are actively expressed in all organs. Similar constitutively active expression was observed for genes encoding their functionally related proteins, a histone H3K9 methyltransferase KYP and a catalytically non-active protein DRM3...
February 2016: Biochemistry. Biokhimii︠a︡
Albert Jeltsch, Ann Ehrenhofer-Murray, Tomasz Jurkowski, Frank Lyko, Gunter Reuter, Serge Ankri, Wolfgang Nellen, Matthias Schaefer, Mark Helm
A group of homologous nucleic acid modification enzymes called Dnmt2, Trdmt1, Pmt1, DnmA, and Ehmet in different model organisms catalyze the transfer of a methyl group from the cofactor S-adenosyl-methionine (SAM) to the carbon-5 of cytosine residues. Originally considered as DNA MTases, these enzymes were shown to be tRNA methyltransferases about a decade ago. Between the presumed involvement in DNA modification-related epigenetics, and the recent foray into the RNA modification field, significant progress has characterized Dnmt2-related research...
May 27, 2016: RNA Biology
Hany Khalil, Mia Tazi, Kyle Caution, Amr Ahmed, Apurva Kanneganti, Kaivon Assani, Benjamin Kopp, Clay Marsh, Duaa Dakhlallah, Amal O Amer
Autophagy is a biological process characterized by self-digestion and involves induction of autophagosome formation, leading to degradation of autophagic cargo. Aging is associated with the reduction of autophagy activity leading to neurodegenerative disorders, chronic inflammation, and susceptibility to infection; however, the underlying mechanism is unclear. DNA methylation by DNA methyltransferases reduces the expression of corresponding genes. Since macrophages are major players in inflammation and defense against infection we determined the differences in methylation of autophagy genes in macrophages derived from young and aged mice...
May 3, 2016: Epigenetics: Official Journal of the DNA Methylation Society
Jennifer Mytych, Jacek Zebrowski, Anna Lewinska, Maciej Wnuk
It is widely accepted that silver nanoparticles (AgNPs) are toxic to biological systems. However, little is known about their actions at molecular level and the cytophysiological effects after AgNP removal. As nanoparticles are suggested a promising tool to transport drugs to the brain for use in neurological conditions, we used HT22 mouse hippocampal neuronal cells as a model to study AgNP-mediated effects after their removal from the cell culture medium. We selected a relatively low concentration of AgNPs, 5 μg/ml, treated the cells for 48 h, and evaluated AgNP-induced cytophysiological effects after 96 h of AgNP removal...
February 3, 2016: Molecular Neurobiology
Sanoji Wijenayake, Kenneth B Storey
Oxygen deprivation is a lethal stress that only a few animals can tolerate for extended periods. This study focuses on analyzing the role of DNA methylation in aiding natural anoxia tolerance in a champion vertebrate anaerobe, the red-eared slider turtle (Trachemys scripta elegans). We examined the relative expression and total enzymatic activity of four DNA methyltransferases (DNMT1, DNMT2, DNMT3a and DNMT3b), two methyl-binding domain proteins (MBD1 and MBD2), and relative genomic levels of 5-methylcytosine under control, 5 h anoxic, and 20 h anoxic conditions in liver, heart, and white skeletal muscle (n = 4, p < 0...
April 2016: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
Jennifer Mytych, Maciej Wnuk, Suresh I S Rattan
Nanodiamonds (ND) and silica nanoparticles (SiO2-NP) have been much investigated for their toxicity at high doses, little is known about their biological activity at low concentrations. Here we report the biphasic dose response of ND and SiO2-NP in modulating normal human facial skin fibroblasts (FSF1) in culture. ND and SiO2-NP at low concentration (up to 0.5 μg/ml) had beneficial effects on FSF1 in terms of increasing their proliferation and metabolic activity. Exposure of FSF1 cells to low levels of NP enhanced their wound healing ability in vitro and slowed down aging during serial passaging as measured by maintenance of youthful morphology, reduction in the rate of loss of telomeres, and the over all proliferative characteristics...
April 2016: Chemosphere
Deepshikha Arya, Sanjay Kapoor, Meenu Kapoor
DNA methyltransferase 2 (DNMT2) unlike other members of the cytosine DNA methyltransferase gene family has dual substrate specificity and it methylates cytosines in both the DNA and transfer RNA (tRNA). Its role in plants, however, has remained obscure to date. In this study, we demonstrate that DNMT2 from Physcomitrella patens accumulates in a temporal manner under salt and osmotic stress showing maximum accumulation during recovery, i.e. 24 h after plants are transferred to normal growth medium. Therefore, to study its role in stress tolerance, we generated PpDNMT2 targeted knockout plants (ppdnmt2ko)...
February 2016: FEBS Journal
Martin Müller, Mark Hartmann, Isabelle Schuster, Sebastian Bender, Kathrin L Thüring, Mark Helm, Jon R Katze, Wolfgang Nellen, Frank Lyko, Ann E Ehrenhofer-Murray
Dnmt2 enzymes are cytosine-5 methyltransferases that methylate C38 of several tRNAs. We report here that the activities of two Dnmt2 homologs, Pmt1 from Schizosaccharomyces pombe and DnmA from Dictyostelium discoideum, are strongly stimulated by prior queuosine (Q) modification of the substrate tRNA. In vivo tRNA methylation levels were stimulated by growth of cells in queuine-containing medium; in vitro Pmt1 activity was enhanced on Q-containing RNA; and queuine-stimulated in vivo methylation was abrogated by the absence of the enzyme that inserts queuine into tRNA, eukaryotic tRNA-guanine transglycosylase...
December 15, 2015: Nucleic Acids Research
Francesca Tuorto, Friederike Herbst, Nader Alerasool, Sebastian Bender, Oliver Popp, Giuseppina Federico, Sonja Reitter, Reinhard Liebers, Georg Stoecklin, Hermann-Josef Gröne, Gunnar Dittmar, Hanno Glimm, Frank Lyko
The Dnmt2 enzyme utilizes the catalytic mechanism of eukaryotic DNA methyltransferases to methylate several tRNAs at cytosine 38. Dnmt2 mutant mice, flies, and plants were reported to be viable and fertile, and the biological function of Dnmt2 has remained elusive. Here, we show that endochondral ossification is delayed in newborn Dnmt2-deficient mice, which is accompanied by a reduction of the haematopoietic stem and progenitor cell population and a cell-autonomous defect in their differentiation. RNA bisulfite sequencing revealed that Dnmt2 methylates C38 of tRNA Asp(GTC), Gly(GCC), and Val(AAC), thus preventing tRNA fragmentation...
September 14, 2015: EMBO Journal
Fatma Uysal, Gokhan Akkoyunlu, Saffet Ozturk
Epigenetic mechanisms play critical roles in oogenesis and early embryo development in mammals. One of these epigenetic mechanisms, DNA methylation is accomplished through the activities of DNA methyltransferases (DNMTs), which are responsible for adding a methyl group to the fifth carbon atom of the cytosine residues within cytosine-phosphate-guanine (CpG) and non-CpG dinuclotide sites. Five DNMT enzymes have been identified in mammals including DNMT1, DNMT2, DNMT3A, DNMT3B, and DNMT3L. They function in two different methylation processes: maintenance and de novo...
September 2015: Biochimie
Haiping Li, Fengmei Yang, Bo Gao, Zongtao Yu, Xiaobo Liu, Fei Xie, Jicai Zhang
PURPOSE: Our previous research identified that Hepatitis B virus (HBV) infection results in the increased methylation of p16; however, the mechanism(s) of the methylation changes observed following HBV infection are yet to be deduced. DNA methylation is governed by the interaction of DNA methyltransferases (DNMT). To investigate the expression of DNMT in cancerous tissue, cirrhotic tissues and non-cancerous tissue, we examined the relationship between HBV infection and DNMT expression...
2015: International Journal of Clinical and Experimental Medicine
Seon-Hee Kim, Hye-Jeong Cho, Woon-Mok Sohn, Chun-Seob Ahn, Yoon Kong, Hyun-Jong Yang, Young-An Bae
Despite recent reports regarding the biology of cytosine methylation in Schistosoma mansoni, the impact of the regulatory machinery remains unclear in diverse platyhelminthes. This ambiguity is reinforced by discoveries of DNA methyltransferase 2 (DNMT2)-only organisms and the substrate specificity of DNMT2 preferential to RNA molecules. Here, we characterized a novel DNA methyltransferase, named CsDNMT2, in a liver fluke Clonorchis sinensis. The protein exhibited structural properties conserved in other members of the DNMT2 family...
August 2015: Parasitology
John Wr Zinck, Margaret de Groh, Amanda J MacFarlane
BACKGROUND: Genetic variation can cause variable responses to environmental stimuli. A number of single-nucleotide polymorphisms (SNPs) have been associated with B vitamin status or chronic diseases related to vitamin B-12 and folate metabolism. OBJECTIVE: Our objective was to identify associations between common SNPs in genes related to folate and vitamin B-12 metabolism or associated with B vitamin-related chronic diseases and biomarkers of nutrient status in a population exposed to folic acid fortification...
June 2015: American Journal of Clinical Nutrition
Winfried Elhardt, Raghuvaran Shanmugam, Tomasz P Jurkowski, Albert Jeltsch
Methylation of tRNA is an important post-transcriptional modification and aberrations in tRNA modification has been implicated in cancer. The DNMT2 protein methylates C38 of tRNA-Asp and it has a role in cellular physiology and stress response and its expression levels are altered in cancer tissues. Here we studied whether DNMT2 somatic mutations found in cancer tissues affect the activity of the enzyme. We have generated 13 DNMT2 variants and purified the corresponding proteins. All proteins were properly folded as determined by circular dichroism spectroscopy...
May 2015: Biochimie
Anna Lewinska, Maciej Wnuk, Wioleta Grabowska, Tomasz Zabek, Ewelina Semik, Ewa Sikora, Anna Bielak-Zmijewska
It is widely accepted that abnormal accumulation of vascular smooth muscle cells (VSMCs) may promote atherosclerosis and post-angioplasty restenosis. The use of some plant polyphenols with potent antiproliferative activities may be considered as a therapeutic intervention to diminish/prevent the development of cardiovascular pathologies. In the present study, VSMC response to curcumin treatment was evaluated. 5 μM curcumin elicited a cytostatic effect, which was accompanied by protein carbonylation, oxidative DNA damage and changes in the nucleolar activity (the size and number of nucleoli, nucleolar protein levels and their localization)...
March 18, 2015: Toxicology Letters
Daniel P LePage, Kristin K Jernigan, Seth R Bordenstein
Wolbachia pipientis is a worldwide bacterial parasite of arthropods that infects germline cells and manipulates host reproduction to increase the ratio of infected females, the transmitting sex of the bacteria. The most common reproductive manipulation, cytoplasmic incompatibility (CI), is expressed as embryonic death in crosses between infected males and uninfected females. Specifically, Wolbachia modify developing sperm in the testes by unknown means to cause a post-fertilization disruption of the sperm chromatin that incapacitates the first mitosis of the embryo...
2014: PeerJ
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"