DOCSLIB.ORG

Glutamate Receptor, Ionotropic, Kainate 2 Silencing by DNA Hypermethylation Possesses Tumor Suppressor Function in Gastric Cancer

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Glutamate Receptor, Ionotropic, Kainate 2 Silencing by DNA Hypermethylation Possesses Tumor Suppressor Function in Gastric Cancer IJC International Journal of Cancer Glutamate receptor, ionotropic, kainate 2 silencing by DNA hypermethylation possesses tumor suppressor function in gastric cancer Chi-Sheng Wu1, Yen-Jung Lu2, Hsin-Pai Li1,3, Chuen Hsueh4, Chang-Yi Lu2, Yu-Wei Leu5, Hao-Ping Liu3, Kwang-Huei Lin1,3, Tim Hui-Ming Huang6 and Yu-Sun Chang1,3 1 Graduate Institute of Biomedical Sciences, Chang Gung University, Taoyuan, Taiwan 2 Institute of Microbiology and Immunology, National Yang-Ming University, Taipei, Taiwan 3 Molecular Medicine Research Center, Chang Gung University, Taoyuan, Taiwan 4 Department of Pathology, Chang Gung Memorial Hospital, Lin-Kou, Taoyuan, Taiwan 5 Department of Life Science, Institute of Molecular Biology, National Chung-Cheng University, Chia-Yi, Taiwan 6 Department of Molecular Virology, Immunology & Medical Genetics-Human Cancer Genetics, Ohio State University, OH Aberrant DNA methylation is considered a major mechanism for silencing tumor suppressor genes in gastric cancer. We used CpG microarray and differential methylation hybridization strategies to identify potential tumor suppressor genes and recovered glutamate receptor, ionotropic, kainate 2 (GRIK2) as a novel epigenetic target in gastric cancer. Additional experiments showed that the promoter region of GRIK2 was hypermethylated in 3 of the 4 tested gastric cancer cell lines, and its expression was restored by treatment of cells with the DNA methylation inhibitor, 50-aza-dC. In clinical samples, the GRIK2 promoter was differentially hypermethylated in tumor tissues compared with adjacent normal tissues (p < 0.001), and this methylation was inversely correlated with the expression level of GRIK2 mRNA (r 520.44). Functional studies further showed that GRIK2-expressing gastric cancer cell lines showed decreased colony formation and cell migration. Taken together, these results suggest that GRIK2 may play a tumor-suppressor role in gastric cancer. Future studies are warranted to examine whether DNA hypermethylation of the GRIK2 promoter can be used as a potential tumor marker for gastric cancer. Cancer Cell Biology Gastric cancer is one of the most common human cancers with chemotherapy is a common treatment for gastric cancer. worldwide and is a major upper gastrointestinal tract malig- Factors such as diet, tobacco use and Helicobacter pylori nant disease with poor prognosis for patients suffering from infection have been reported as the major risk factors for gas- more advanced stages of the disease.1 In the 2009 Taiwan tric carcinoma.2 Cancer Registry Report, this cancer was ranked as having the Numerous studies have sought to identify biomarkers ca- seventh highest incidence among cancers. Surgery combined pable of improving the prognosis for patients with gastric cancer.3 Similar to other cancers, the development of gastric cancer is a multistep process involving a variety of genetic Key words: gastric cancer, GRIK2, tumor suppressor gene, and epigenetic modifications. Some of the cellular molecules hypermethylation related to gastric cancer development and progression seem Additional Supporting Information may be found in the online to be regulated via DNA methylation.4 DNA methylation fre- version of this article quently occurs at CpG islands, which are short stretches of The first two authors contributed equally to this work. GC-rich sequences frequently located on promoters and in Grant sponsor: Ministry of Education, National Science Council; the first exon of genes.5 Such methylation can have a pro- Grant numbers: NSC 94-2314-B-182A-188, 94-3112-B-182-005, 95- found effect on the expression of tumor suppressor genes in 2320-B-182-001, 97-3112-B-182-008; Grant sponsor: Chang Gung various cancers. Therefore, aberrant DNA methylation of tu- Memorial Hospital, Taiwan; Grant numbers: CMRPD150961, mor suppressor genes may be useful as a good biomarker for CMRPG360221, CMRPG360262 cancers.6 In gastric cancer, genes such as p14ARF, p16INKaa,7 DOI: 10.1002/ijc.24958 MGMT, hMLH18 and APC9 reportedly play tumor-suppres- History: Received 23 Apr 2009; Accepted 29 Sep 2009; Online 12 sor roles and are regulated by DNA modification. During the Oct 2009 development of gastric cancer, it is believed that some tumor Correspondence to: Yu-Sun Chang, Chang Gung Molecular suppressor genes undergo DNA hypermethylation, leading to Medicine Research Center and Graduate Institute of Biomedical their decreased expression.10 Sciences, Chang Gung University, 259 Wen-Hwa 1st Road, Glutamate receptors are membrane proteins responsible Kwei-Shan, Taoyuan, 333 Taiwan, Tel: 886-3-211-8800 x5131; for mediating most excitatory neurotransmissions in the 886-3-211-8683, Fax: 886-3-211-8683, E-mail: [email protected] mammalian central nervous system (CNS).11 They are Int. J. Cancer: 126, 2542–2552 (2010) VC 2009 UICC Wu et al. 2543 Table 1. Clinical characteristics of gastric cancer samples Case no. Hypermethylated Hypomethylated p Gender Female 11 9 2 0.231 Male 16 9 7 Age (yr) <65 13 9 4 1 65 14 9 5 Depth of invasion (pT) T1, T2 8 5 3 1 T3, T4 19 13 6 Lymph node status (pN) N0 6 5 1 0.628 Non N0 21 13 8 Histological type Intestinal 11 6 5 0.393 Diffuse 14 10 4 Mix type 2 2 0 Helicobacter pylori infection Negative 21 15 6 0.367 Positive 6 3 3 Paired samples Adjacent normal 27 2 25 <0.0011 Tumor 27 18 9 Cancer Cell Biology P values were calculated using Pearson Chi-square test. 1statistically significant when <0.05. classified into 2 major groups: the metabotropic glutamate re- Although GRIK2 has been implicated in several neurologi- ceptor (mGlu) group, which is composed of mGlu1-8, and cal diseases, such as Huntington’s disease,19 autosomal reces- the ionotropic glutamate receptors, which include the N- sive mental retardation,20 autism21 and manic-depressive ill- 22 methyl-D-aspartate (NMDA), a-amino-3-hydroxy-5-methyl- ness, little is known about its role in tumor progression. A iso-xazole-4-propionate (AMPA) and kainate glutamate report by Sinclair et al. (2004) suggested that GRIK2 may be receptors. Glutamate receptor, ionotropic, kainate 2 (GluR6 a candidate tumor-suppressor gene for acute lymphocytic or GRIK2) is 1 of the 5 members of the kainate glutamate re- leukemia (ALL), but no subsequent study has examined the ceptor subgroup, which also includes GluR5-7, KA1 and relevant biological functions or regulation mechanisms. We KA2. Although kainate receptors are distributed throughout show for the first time that GRIK2 is regulated by DNA the CNS, their physiological significance is not yet known. methylation in gastric cancer and further report that colony GRIK2, located on chromosome 6q16.3-q21, is a 17-exon formation and cell migration are suppressed in gastric cancer gene12 that may be transcribed into at least 6 different splice cell lines expressing GRIK2, strongly indicating that GRIK2 is variants.13 Under physiological conditions, GRIK2 forms a a tumor-suppressor gene. homomeric receptor channel14 or a heteromeric receptor channel with GluR5.15 Recent studies have indicated that the Material and Methods ionotropic glutamate receptors, NMDA2A and NMDA2B, Cell culture, clinical samples and 50-aza-dC treatment may play tumor-suppressor functions in esophageal cancer,16 AGS cells cultured in Ham’s F12 medium containing 10% fe- gastric cancer17 and colorectal carcinoma.18 The expression tal bovine serum (FBS). TMC1 cells were maintained in level of these NMDA receptors is regulated at least in part RPMI medium containing 10% FBS. AZ521 and KATO III through changes in DNA methylation. However, no func- cells were kindly provided by Dr. Lin KH of Chang Gung tional analysis has suggested that kainate receptors may play University (Taiwan) and were cultured in RPMI containing a tumor-suppressor role or that their expression might be 10% FBS. Twenty-seven paired gastric cancer/normal adja- regulated by DNA methylation in cancer cells. cent tissue samples were collected from patients between Int. J. Cancer: 126, 2542–2552 (2010) VC 2009 UICC 2544 Glutamate receptor, ionotropic, kainate 2 silencing 2000 and 2003 and were obtained from the Chang Gung Me- Bisulfite treatment and bisulfite sequencing morial Hospital (CGMH) Tumor Bank (Taoyuan, Taiwan) Genomic DNA (1 lg) was modified by sodium bisulfite using (Table 1). Two normal adult stomach genomic DNA samples the EZ DNA methylation kit (Zymo Research, USA). The (N24 and N33) were purchased from BioChain Institute CpG islands of the GRIK2 promoter region were amplified (USA). This study was reviewed and approved by the institu- using primers 50-GTTTGGTAAAATTTTTGTTAGTAAAG-30 tional review board and ethics committee of CGMH. and 50-AATTCCTTAAAAATATCCAATCCAC-30. The PCR Informed consent was obtained from all patients and healthy products were cloned into a TA vector and sequenced. The controls. sequencing results were analyzed with the Vector NTI 9.0 One day before experiments, gastric cancer cell lines software (Invitrogen, USA). (AGS, AZ521 and TMC1) were seeded in 10-cm dishes at a confluence of 20–30% per dish. KATO III cells were seeded 0 Quantitative methylation-specific PCR in 25-T flasks at a density of 20–30% per flask. For 5 -aza-dC Bisulfite-modified DNA was subjected to real-time quantita- l 0 treatment, cells were treated with 5 M5-aza-dC (Sigma, tive methylation-specific PCR (Q-MSP) using a Bio-Rad iCy- USA) for 5 days. The culture medium was replaced every l  0 cler (Bio-Rad, USA). Each reaction contained 7.5 lof2 24 hr with fresh culture medium containing 5 -aza-dC. SYBR Green supermix (Bio-Rad), 0.2 lM of each primer and 10 ng of bisulfite-modified DNA in a total volume of 15 ll. Differential methylation hybridization and CpG microarray The reaction conditions consisted of 95C for 3 min, fol- Differential methylation hybridization (DMH) was performed lowed by 50 cycles of 95C for 15 sec, 60C for 20 sec, 72C 23 l as previously described.
Load more

Recommended publications
  • A Guide to Glutamate Receptors
    A guide to glutamate receptors 1 Contents Glutamate receptors . 4 Ionotropic glutamate receptors . 4 - Structure ........................................................................................................... 4 - Function ............................................................................................................ 5 - AMPA receptors ................................................................................................. 6 - NMDA receptors ................................................................................................. 6 - Kainate receptors ............................................................................................... 6 Metabotropic glutamate receptors . 8 - Structure ........................................................................................................... 8 - Function ............................................................................................................ 9 - Group I: mGlu1 and mGlu5. .9 - Group II: mGlu2 and mGlu3 ................................................................................. 10 - Group III: mGlu4, mGlu6, mGlu7 and mGlu8 ............................................................ 10 Protocols and webinars . 11 - Protocols ......................................................................................................... 11 - Webinars ......................................................................................................... 12 References and further reading . 13 Excitatory synapse pathway
    [Show full text]
  • Kainate Receptors in Health and Disease
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Elsevier - Publisher Connector Neuron Review Kainate Receptors in Health and Disease Juan Lerma1,* and Joana M. Marques1 1Instituto de Neurociencias, CSIC-UMH, San Juan de Alicante, 03550 Spain *Correspondence: [email protected] http://dx.doi.org/10.1016/j.neuron.2013.09.045 Our understanding of the molecular properties of kainate receptors and their involvement in synaptic phys- iology has progressed significantly over the last 30 years. A plethora of studies indicate that kainate receptors are important mediators of the pre- and postsynaptic actions of glutamate, although the mechanisms under- lying such effects are still often a topic for discussion. Three clear fields related to their behavior have emerged: there are a number of interacting proteins that pace the properties of kainate receptors; their activity is unconventional since they can also signal through G proteins, behaving like metabotropic recep- tors; they seem to be linked to some devastating brain diseases. Despite the significant progress in their importance in brain function, kainate receptors remain somewhat puzzling. Here we examine discoveries linking these receptors to physiology and their probable implications in disease, in particular mood disorders, and propose some ideas to obtain a deeper understanding of these intriguing proteins. A Historical Overview The absence of specific antibodies against different KAR Most excitatory synapses in the brain use the amino acid gluta- subunits has been a significant limitation in terms of exploring re- mate as a neurotransmitter. Since the excitatory properties of ceptor distribution. Thus, most of the information regarding their glutamate were postulated nearly 40 years ago, an extraordinary tissue expression comes from in situ hybridization studies that, wealth of data has accumulated on the types of synaptic re- although informative, cannot reveal the subcellular distribution sponses triggered by this neurotransmitter.
    [Show full text]
  • Sex Differences in Glutamate Receptor Gene Expression in Major Depression and Suicide
    Molecular Psychiatry (2015) 20, 1057–1068 © 2015 Macmillan Publishers Limited All rights reserved 1359-4184/15 www.nature.com/mp IMMEDIATE COMMUNICATION Sex differences in glutamate receptor gene expression in major depression and suicide AL Gray1, TM Hyde2,3, A Deep-Soboslay2, JE Kleinman2 and MS Sodhi1,4 Accumulating data indicate that the glutamate system is disrupted in major depressive disorder (MDD), and recent clinical research suggests that ketamine, an antagonist of the N-methyl-D-aspartate (NMDA) glutamate receptor (GluR), has rapid antidepressant efficacy. Here we report findings from gene expression studies of a large cohort of postmortem subjects, including subjects with MDD and controls. Our data reveal higher expression levels of the majority of glutamatergic genes tested in the dorsolateral prefrontal cortex (DLPFC) in MDD (F21,59 = 2.32, P = 0.006). Posthoc data indicate that these gene expression differences occurred mostly in the female subjects. Higher expression levels of GRIN1, GRIN2A-D, GRIA2-4, GRIK1-2, GRM1, GRM4, GRM5 and GRM7 were detected in the female patients with MDD. In contrast, GRM5 expression was lower in male MDD patients relative to male controls. When MDD suicides were compared with MDD non-suicides, GRIN2B, GRIK3 and GRM2 were expressed at higher levels in the suicides. Higher expression levels were detected for several additional genes, but these were not statistically significant after correction for multiple comparisons. In summary, our analyses indicate a generalized disruption of the regulation of the GluRs in the DLPFC of females with MDD, with more specific GluR alterations in the suicides and in the male groups.
    [Show full text]
  • Chapter Chapter 2
    Chapter Chapter 2 Attenuated AMPA receptor expression allows glioblastoma cell survival in glutamate-rich environment Dannis G. van Vuurden, Maryam Yazdani, Ingeborg Bosma, Richard A.J.F. Broekhuizen, Tjeerd J. Postma, Jan J. Heimans, Paul van der Valk, Eleonora Aronica, Bakhos A. Tannous, Thomas Würdinger, Gertjan J. L. Kaspers, Jacqueline Cloos PLoS ONE 2009; 4(6): e5953 23 Proefschrift1.indd 23 24-04-14 13:54 ABSTRACT Background: Glioblastoma multiforme (GBM) cells secrete large amounts of glutamate that can trigger AMPA-type glutamate receptors (AMPARs). This commonly results in Na+ and Ca2+-permeability and thereby in excitotoxic cell death of the surrounding neurons. Here we investigated how the GBM cells themselves survive in a glutamate-rich environment. Methods and Findings: In silico analysis of published reports shows down-regulation of all ionotropic glutamate receptors in GBM as compared to normal brain. In vitro, in all GBM samples tested, mRNA expression of AMPAR subunit GluR1, 2 and 4 was relatively low compared to adult and fetal total brain mRNA and adult cerebellum mRNA. These findings were in line with primary GBM samples, in which protein expression patterns were down- regulated as compared to the normal tissue. Furthermore, mislocalized expression of these receptors was found. Sequence analysis of GluR2 RNA in primary and established GBM cell lines showed that the GluR2 subunit was found to be partly unedited. Conclusions: Together with the lack of functional effect of AMPAR inhibition by NBQX our results suggest that down-regulation and non-functionality of AMPARs, enable GBM cells to survive in a high glutamate environment without going into excitotoxic cell death themselves.
    [Show full text]
  • Ion Channels
    UC Davis UC Davis Previously Published Works Title THE CONCISE GUIDE TO PHARMACOLOGY 2019/20: Ion channels. Permalink https://escholarship.org/uc/item/1442g5hg Journal British journal of pharmacology, 176 Suppl 1(S1) ISSN 0007-1188 Authors Alexander, Stephen PH Mathie, Alistair Peters, John A et al. Publication Date 2019-12-01 DOI 10.1111/bph.14749 License https://creativecommons.org/licenses/by/4.0/ 4.0 Peer reviewed eScholarship.org Powered by the California Digital Library University of California S.P.H. Alexander et al. The Concise Guide to PHARMACOLOGY 2019/20: Ion channels. British Journal of Pharmacology (2019) 176, S142–S228 THE CONCISE GUIDE TO PHARMACOLOGY 2019/20: Ion channels Stephen PH Alexander1 , Alistair Mathie2 ,JohnAPeters3 , Emma L Veale2 , Jörg Striessnig4 , Eamonn Kelly5, Jane F Armstrong6 , Elena Faccenda6 ,SimonDHarding6 ,AdamJPawson6 , Joanna L Sharman6 , Christopher Southan6 , Jamie A Davies6 and CGTP Collaborators 1School of Life Sciences, University of Nottingham Medical School, Nottingham, NG7 2UH, UK 2Medway School of Pharmacy, The Universities of Greenwich and Kent at Medway, Anson Building, Central Avenue, Chatham Maritime, Chatham, Kent, ME4 4TB, UK 3Neuroscience Division, Medical Education Institute, Ninewells Hospital and Medical School, University of Dundee, Dundee, DD1 9SY, UK 4Pharmacology and Toxicology, Institute of Pharmacy, University of Innsbruck, A-6020 Innsbruck, Austria 5School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, BS8 1TD, UK 6Centre for Discovery Brain Science, University of Edinburgh, Edinburgh, EH8 9XD, UK Abstract The Concise Guide to PHARMACOLOGY 2019/20 is the fourth in this series of biennial publications. The Concise Guide provides concise overviews of the key properties of nearly 1800 human drug targets with an emphasis on selective pharmacology (where available), plus links to the open access knowledgebase source of drug targets and their ligands (www.guidetopharmacology.org), which provides more detailed views of target and ligand properties.
    [Show full text]
  • Anti-GRIK2 / Gluk2 Antibody (ARG42640)
    Product datasheet [email protected] ARG42640 Package: 50 μl anti-GRIK2 / GluK2 antibody Store at: -20°C Summary Product Description Rabbit Polyclonal antibody recognizes GRIK2 / GluK2 Tested Reactivity Hu, Ms, Rat Tested Application IHC-P, WB Host Rabbit Clonality Polyclonal Isotype IgG Target Name GRIK2 / GluK2 Antigen Species Human Immunogen Synthetic peptide derived from Human GRIK2 / GluK2. Conjugation Un-conjugated Alternate Names GLUK6; Glutamate receptor ionotropic, kainate 2; GluK2; Excitatory amino acid receptor 4; GLUR6; GluR-6; EAA4; MRT6; GLR6; Glutamate receptor 6; GluR6 Application Instructions Application table Application Dilution IHC-P 1:50 - 1:200 WB 1:500 - 1:2000 Application Note * The dilutions indicate recommended starting dilutions and the optimal dilutions or concentrations should be determined by the scientist. Positive Control 293T Calculated Mw 103 kDa Observed Size ~ 97 kDa Properties Form Liquid Purification Affinity purified. Buffer PBS (pH 7.3), 0.02% Sodium azide, 50% Glycerol and 1% BSA. Preservative 0.02% Sodium azide Stabilizer 50% Glycerol and 1% BSA Storage instruction For continuous use, store undiluted antibody at 2-8°C for up to a week. For long-term storage, aliquot and store at -20°C. Storage in frost free freezers is not recommended. Avoid repeated freeze/thaw cycles. Suggest spin the vial prior to opening. The antibody solution should be gently mixed before use. www.arigobio.com 1/3 Note For laboratory research only, not for drug, diagnostic or other use. Bioinformation Gene Symbol GRIK2 Gene Full Name glutamate receptor, ionotropic, kainate 2 Background Glutamate receptors are the predominant excitatory neurotransmitter receptors in the mammalian brain and are activated in a variety of normal neurophysiologic processes.
    [Show full text]
  • The Glutamate Receptor Ion Channels
    0031-6997/99/5101-0007$03.00/0 PHARMACOLOGICAL REVIEWS Vol. 51, No. 1 Copyright © 1999 by The American Society for Pharmacology and Experimental Therapeutics Printed in U.S.A. The Glutamate Receptor Ion Channels RAYMOND DINGLEDINE,1 KARIN BORGES, DEREK BOWIE, AND STEPHEN F. TRAYNELIS Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia This paper is available online at http://www.pharmrev.org I. Introduction ............................................................................. 8 II. Gene families ............................................................................ 9 III. Receptor structure ...................................................................... 10 A. Transmembrane topology ............................................................. 10 B. Subunit stoichiometry ................................................................ 10 C. Ligand-binding sites located in a hinged clamshell-like gorge............................. 13 IV. RNA modifications that promote molecular diversity ....................................... 15 A. Alternative splicing .................................................................. 15 B. Editing of AMPA and kainate receptors ................................................ 17 V. Post-translational modifications .......................................................... 18 A. Phosphorylation of AMPA and kainate receptors ........................................ 18 B. Serine/threonine phosphorylation of NMDA receptors ..................................
    [Show full text]
  • Ligand-Gated Ion Channels
    S.P.H. Alexander et al. The Concise Guide to PHARMACOLOGY 2015/16: Ligand-gated ion channels. British Journal of Pharmacology (2015) 172, 5870–5903 THE CONCISE GUIDE TO PHARMACOLOGY 2015/16: Ligand-gated ion channels Stephen PH Alexander1, John A Peters2, Eamonn Kelly3, Neil Marrion3, Helen E Benson4, Elena Faccenda4, Adam J Pawson4, Joanna L Sharman4, Christopher Southan4, Jamie A Davies4 and CGTP Collaborators L 1 School of Biomedical Sciences, University of Nottingham Medical School, Nottingham, NG7 2UH, UK, N 2Neuroscience Division, Medical Education Institute, Ninewells Hospital and Medical School, University of Dundee, Dundee, DD1 9SY, UK, 3School of Physiology and Pharmacology, University of Bristol, Bristol, BS8 1TD, UK, 4Centre for Integrative Physiology, University of Edinburgh, Edinburgh, EH8 9XD, UK Abstract The Concise Guide to PHARMACOLOGY 2015/16 provides concise overviews of the key properties of over 1750 human drug targets with their pharmacology, plus links to an open access knowledgebase of drug targets and their ligands (www.guidetopharmacology.org), which provides more detailed views of target and ligand properties. The full contents can be found at http://onlinelibrary.wiley.com/ doi/10.1111/bph.13350/full. Ligand-gated ion channels are one of the eight major pharmacological targets into which the Guide is divided, with the others being: ligand-gated ion channels, voltage- gated ion channels, other ion channels, nuclear hormone receptors, catalytic receptors, enzymes and transporters. These are presented with nomenclature guidance and summary information on the best available pharmacological tools, alongside key references and suggestions for further reading. The Concise Guide is published in landscape format in order to facilitate comparison of related targets.
    [Show full text]
  • A Porcine Brain-Wide RNA Editing Landscape
    ARTICLE https://doi.org/10.1038/s42003-021-02238-3 OPEN A porcine brain-wide RNA editing landscape ✉ Jinrong Huang1,2,3 , Lin Lin 3,4, Zhanying Dong1, Ling Yang1, Tianyu Zheng1, Weiwang Gu5, Yan Zhang6, Tailang Yin6, Evelina Sjöstedt7,8, Jan Mulder7, Mathias Uhlén 7,8, Karsten Kristiansen 2, Lars Bolund1,3 & ✉ Yonglun Luo 1,3,4 Adenosine-to-inosine (A-to-I) RNA editing, catalyzed by ADAR enzymes, is an essential post-transcriptional modification. Although hundreds of thousands of RNA editing sites have been reported in mammals, brain-wide analysis of the RNA editing in the mammalian brain remains rare. Here, a genome-wide RNA-editing investigation is performed in 119 samples, representing 30 anatomically defined subregions in the pig brain. We identify a total of 682,037 A-to-I RNA editing sites of which 97% are not identified before. Within the pig 1234567890():,; brain, cerebellum and olfactory bulb are regions with most edited transcripts. The editing level of sites residing in protein-coding regions are similar across brain regions, whereas region-distinct editing is observed in repetitive sequences. Highly edited conserved recoding events in pig and human brain are found in neurotransmitter receptors, demonstrating the evolutionary importance of RNA editing in neurotransmission functions. Although potential data biases caused by age, sex or health status are not considered, this study provides a rich resource to better understand the evolutionary importance of post-transcriptional RNA editing. 1 Lars Bolund Institute of Regenerative Medicine, Qingdao-Europe Advanced Institute for Life Sciences, BGI-Qingdao, BGI-Shenzhen, Shenzhen, China. 2 Laboratory of Genomics and Molecular Biomedicine, Department of Biology, University of Copenhagen, Copenhagen, Denmark.
    [Show full text]
  • Converging Roles of Glutamate Receptors in Domestication and Prosociality
    bioRxiv preprint doi: https://doi.org/10.1101/439869; this version posted October 11, 2018. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. Converging roles of glutamate receptors in domestication and prosociality Thomas O’Rourke1,2 and Cedric Boeckx1,2,3 1Universitat de Barcelona 2Universitat de Barcelona Institute of Complex Systems 3ICREA October 10, 2018 Abstract Building on our previous work and expanding the range of species consid- ered, we highlight the prevalence of signals of positive selection on genes coding for glutamate receptors (most notably kainate and metabotropic receptors) in domesticated species and anatomically modern humans. Re- lying on their expression in the central nervous system and phenotypes associated with mutations in these genes, we claim that regulatory changes in kainate and metabotropic receptor genes have led to alterations in lim- bic function and Hypothalamic-Pituitary-Adrenal axis regulation, with potential implications for the emergence of unique social behaviors and communicative abilities in (self-)domesticated species. 1 Introduction Under one account of recent human evolution, selective pressures on prosocial behaviors led not only to a species-wide reduction in reactive aggression and the extension of our social interactions [1], but also left discernible physical mark- ers on the modern human phenotype, including our characteristically “gracile” anatomy [2, 3]. It has long been noted that these morphological differences resemble those of domesticated species when compared with their wild counterparts [4].
    [Show full text]
  • Association Between the Ionotropic Glutamate Receptor Kainate 3
    Molecular Psychiatry (2002) 7, 416–418 2002 Nature Publishing Group All rights reserved 1359-4184/02 $25.00 www.nature.com/mp ORIGINAL RESEARCH ARTICLE Association between the ionotropic glutamate receptor kainate 3 (GRIK3) ser310ala polymorphism and schizophrenia S Begni1, M Popoli2, S Moraschi1, S Bignotti3, GB Tura3 and M Gennarelli1 1Genetics Unit, IRCCS ‘S Giovanni di Dio’, Fatebenefratelli, 25123 Brescia, Italy; 2Center of Neuropharmacology, Institute of Pharmacological Sciences, University of Milan, 20133 Milan, Italy; 3Psychiatric Rehabilitation Unit, IRCCS ‘S Giovanni di Dio’, Fatebenefratelli, 25123 Brescia, Italy Keywords: association study; cSNP; expression; kainate through ionotropic glutamate receptors influences the receptor; neuronal plasticity regulation of transcriptional, translational and post- Schizophrenia is a severe psychiatric illness character- translational processes fundamental for the function of ised by disturbance of thought, hallucination and brain cells.3 delusions.1 Several studies have suggested that dys- One of the hypotheses about the molecular mech- functions in the glutamatergic transmission are linked anisms leading to schizophrenia is the presence of an to the pathogenesis of schizophrenia, and in particular excessive activation of glutamate receptors. An an excessive activation of glutamate receptors seems to increase in the basic metabolic activity along the gluta- be related to the disruption of neuronal ionic gradients matergic axons has been demonstrated by PET scan leading to excitotoxicity.2–7
    [Show full text]
  • Evidence for the Involvement of the Kainate Receptor Subunit Glur6 (GRIK2) in Mediating Behavioral Displays Related to Behaviora
    Molecular Psychiatry (2008) 13, 858–872 & 2008 Nature Publishing Group All rights reserved 1359-4184/08 $30.00 www.nature.com/mp ORIGINAL ARTICLE Evidence for the involvement of the kainate receptor subunit GluR6 (GRIK2) in mediating behavioral displays related to behavioral symptoms of mania G Shaltiel1, S Maeng1, O Malkesman1, B Pearson1, RJ Schloesser1, T Tragon1, M Rogawski2, M Gasior2, D Luckenbaugh1, G Chen1 and HK Manji1 1Laboratory of Molecular Pathophysiology, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA; 2Epilepsy Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA The glutamate receptor 6 (GluR6 or GRIK2, one of the kainate receptors) gene resides in a genetic linkage region (6q21) associated with bipolar disorder (BPD), but its function in affective regulation is unknown. Compared with wild-type (WT) and GluR5 knockout (KO) mice, GluR6 KO mice were more active in multiple tests and super responsive to amphetamine. In a battery of specific tests, GluR6 KO mice also exhibited less anxious or more risk-taking type behavior and less despair-type manifestations, and they also had more aggressive displays. Chronic treatment with lithium, a classic antimanic mood stabilizer, reduced hyperactivity, aggressive displays and some risk-taking type behavior in GluR6 KO mice. Hippocampal and prefrontal cortical membrane levels of GluR5 and KA-2 receptors were decreased in GluR6 KO mice, and chronic lithium treatment did not affect these decreases. The membrane levels of other glutamatergic receptors were not significantly altered by GluR6 ablation or chronic lithium treatment. Together, these biochemical and behavioral results suggest a unique role for GluR6 in controlling abnormalities related to the behavioral symptoms of mania, such as hyperactivity or psychomotor agitation, aggressiveness, driven or increased goal-directed pursuits, risk taking and supersensitivity to psychostimulants.
    [Show full text]