1
|
van Wijk KJ, Bentolila S, Leppert T, Sun Q, Sun Z, Mendoza L, Li M, Deutsch EW. Detection and editing of the updated Arabidopsis plastid- and mitochondrial-encoded proteomes through PeptideAtlas. PLANT PHYSIOLOGY 2024; 194:1411-1430. [PMID: 37879112 DOI: 10.1093/plphys/kiad572] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 09/12/2023] [Accepted: 09/23/2023] [Indexed: 10/27/2023]
Abstract
Arabidopsis (Arabidopsis thaliana) ecotype Col-0 has plastid and mitochondrial genomes encoding over 100 proteins. Public databases (e.g. Araport11) have redundancy and discrepancies in gene identifiers for these organelle-encoded proteins. RNA editing results in changes to specific amino acid residues or creation of start and stop codons for many of these proteins, but the impact of RNA editing at the protein level is largely unexplored due to the complexities of detection. Here, we assembled the nonredundant set of identifiers, their correct protein sequences, and 452 predicted nonsynonymous editing sites of which 56 are edited at lower frequency. We then determined accumulation of edited and/or unedited proteoforms by searching ∼259 million raw tandem MS spectra from ProteomeXchange, which is part of PeptideAtlas (www.peptideatlas.org/builds/arabidopsis/). We identified all mitochondrial proteins and all except 3 plastid-encoded proteins (NdhG/Ndh6, PsbM, and Rps16), but no proteins predicted from the 4 ORFs were identified. We suggest that Rps16 and 3 of the ORFs are pseudogenes. Detection frequencies for each edit site and type of edit (e.g. S to L/F) were determined at the protein level, cross-referenced against the metadata (e.g. tissue), and evaluated for technical detection challenges. We detected 167 predicted edit sites at the proteome level. Minor frequency sites were edited at low frequency at the protein level except for cytochrome C biogenesis 382 at residue 124 (Ccb382-124). Major frequency sites (>50% editing of RNA) only accumulated in edited form (>98% to 100% edited) at the protein level, with the exception of Rpl5-22. We conclude that RNA editing for major editing sites is required for stable protein accumulation.
Collapse
Affiliation(s)
- Klaas J van Wijk
- Section of Plant Biology, School of Integrative Plant Sciences (SIPS), Cornell University, Ithaca, NY 14853, USA
| | - Stephane Bentolila
- Department of Molecular Biology & Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Tami Leppert
- Institute for Systems Biology (ISB), Seattle, WA 98109, USA
| | - Qi Sun
- Computational Biology Service Unit, Cornell University, Ithaca, NY 14853, USA
| | - Zhi Sun
- Institute for Systems Biology (ISB), Seattle, WA 98109, USA
| | - Luis Mendoza
- Institute for Systems Biology (ISB), Seattle, WA 98109, USA
| | - Margaret Li
- Institute for Systems Biology (ISB), Seattle, WA 98109, USA
| | - Eric W Deutsch
- Institute for Systems Biology (ISB), Seattle, WA 98109, USA
| |
Collapse
|
2
|
Suzuki A, Hara H, Kimura H. Role of the AMPA receptor in antidepressant effects of ketamine and potential of AMPA receptor potentiators as a novel antidepressant. Neuropharmacology 2023; 222:109308. [PMID: 36341809 DOI: 10.1016/j.neuropharm.2022.109308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Revised: 10/19/2022] [Accepted: 10/24/2022] [Indexed: 11/06/2022]
Abstract
Ketamine exerts rapid and long-lasting antidepressant effects in patients with treatment-resistant depression. However, its clinical use is limited by its undesirable psychotomimetic side effects. Accumulating evidence from preclinical studies has shown that the antidepressant effects of ketamine are dependent on α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPA-R) activation, which triggers activation of the mechanistic target of rapamycin pathway and brain-derived neurotrophic factor release. Thus, AMPA-R has emerged as a promising new target for novel antidepressants with a rapid onset of action. However, almost all known AMPA-R potentiators carry the risk of a narrow bell-shaped dose-response curve and a poor safety margin against seizures. Our data suggest that agonistic activity is not only related to the risks of bell-shaped dose-response curves and seizures but also to the reduced synaptic transmission and procognitive effects of AMPA-R potentiators. In this review, we describe our original screening approach that led to the discovery of an investigational AMPA-R potentiator with low agonistic activity, TAK-653. We further review the in vitro and in vivo profiles of TAK-653, including its procognitive and antidepressant-like effects, as well as its safety profile, in comparison with known AMPA-R potentiators with agonistic activity and AMPA, an AMPA-R agonist. The low agnostic activity of TAK-653 may overcome limitations of known AMPA-R potentiators. This article is part of the Special Issue on 'Ketamine and its Metabolites'.
Collapse
Affiliation(s)
- Atsushi Suzuki
- Neuroscience Drug Discovery Unit, Research, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-chome, Fujisawa, Kanagawa, 251-8555, Japan
| | - Hiroe Hara
- Neuroscience Drug Discovery Unit, Research, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-chome, Fujisawa, Kanagawa, 251-8555, Japan
| | - Haruhide Kimura
- Neuroscience Drug Discovery Unit, Research, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-chome, Fujisawa, Kanagawa, 251-8555, Japan.
| |
Collapse
|
3
|
Detection technologies for RNA modifications. Exp Mol Med 2022; 54:1601-1616. [PMID: 36266445 PMCID: PMC9636272 DOI: 10.1038/s12276-022-00821-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 04/21/2022] [Accepted: 05/18/2022] [Indexed: 12/29/2022] Open
Abstract
To date, more than 170 chemical modifications have been characterized in RNA, providing a new layer of gene expression regulation termed the 'epitranscriptome'. RNA modification detection methods and tools advance the functional studies of the epitranscriptome. According to the detection throughput and principles, existing RNA modification detection technologies can be categorized into four classes, including quantification methods, locus-specific detection methods, next-generation sequencing-based detection technologies and nanopore direct RNA sequencing-based technologies. In this review, we summarize the current knowledge about these RNA modification detection technologies and discuss the challenges for the existing detection tools, providing information for a comprehensive understanding of the epitranscriptome.
Collapse
|
4
|
Bazard P, Pineros J, Acosta AA, Thivierge M, Paganella LR, Zucker S, Mannering FL, Modukuri S, Zhu X, Frisina RD, Ding B. Post-Translational Modifications and Age-related Hearing Loss. Hear Res 2022; 426:108625. [DOI: 10.1016/j.heares.2022.108625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 08/21/2022] [Accepted: 09/23/2022] [Indexed: 11/04/2022]
|
5
|
Royo M, Escolano BA, Madrigal MP, Jurado S. AMPA Receptor Function in Hypothalamic Synapses. Front Synaptic Neurosci 2022; 14:833449. [PMID: 35173598 PMCID: PMC8842481 DOI: 10.3389/fnsyn.2022.833449] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Accepted: 01/03/2022] [Indexed: 12/15/2022] Open
Abstract
AMPA receptors (AMPARs) are critical for mediating glutamatergic synaptic transmission and plasticity, thus playing a major role in the molecular machinery underlying cellular substrates of memory and learning. Their expression pattern, transport and regulatory mechanisms have been extensively studied in the hippocampus, but their functional properties in other brain regions remain poorly understood. Interestingly, electrophysiological and molecular evidence has confirmed a prominent role of AMPARs in the regulation of hypothalamic function. This review summarizes the existing evidence on AMPAR-mediated transmission in the hypothalamus, where they are believed to orchestrate the role of glutamatergic transmission in autonomous, neuroendocrine function, body homeostasis, and social behavior.
Collapse
|
6
|
Soundararajan R, Varanasi SM, Patil SS, Srinivas S, Hernández-Cuervo H, Czachor A, Bulkhi A, Fukumoto J, Galam L, Lockey RF, Kolliputi N. Lung fibrosis is induced in ADAR2 overexpressing mice via HuR-induced CTGF signaling. FASEB J 2022; 36:e22143. [PMID: 34985777 PMCID: PMC10395739 DOI: 10.1096/fj.202101511r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 12/17/2021] [Accepted: 12/20/2021] [Indexed: 11/11/2022]
Abstract
Adenosine deaminase acting on RNA 2 (ADAR2), an RNA editing enzyme is involved in a site-selective modification of adenosine (A) to inosine (I) in double-stranded RNA (dsRNA). Its role in the lungs is unknown. The phenotypic characterization of Adarb1 mice that lacked ADAR2 auto-regulation due to the deletion of editing complementary sequence (ΔECS mice) determined the functional role of ADAR2 in the lungs. ADAR2 protein expression increased in the ΔECS mice. These mice display immune cell infiltration and alveolar disorganization. The lung wet by dry ratio indicates there is no lung edema in ΔECS mice. Bronchoalveolar lavage (BAL) analysis of ΔECS mice reveals a significant increase in neutrophils. Interestingly, ΔECS mice spontaneously develop lung fibrosis as indicated by Sirius red staining of collagen fibers in the lung sections and a significant increase in hydroxyproline level in their lungs. ADAR2 expression increased significantly in a bleomycin mouse model, implicating a role of ADAR2 in lung fibrosis. Furthermore, there is a likely possibility that the genetically modified ΔECS mice does not model the physiological or pathophysiological process of lung fibrosis. Nevertheless, this model is useful in interrogating the role of ADAR2 in the lungs. The Ctgf mRNA and connective tissue growth factor (CTGF) protein significantly increased in ΔECS lungs and occurs in bronchial epithelial cells. There is a significant increase in Human antigen R (ELAVL1; HuR) protein levels in ΔECS lungs and suggests a role in stabilizing Ctgf mRNA. Lung mechanics such as total respiratory resistance, Newtonian resistance and tissue damping were increased, whereas inspiratory capacity was decreased in the ΔECS mice. Taken together, these data indicate that overexpression of ADAR2 causes spontaneous lung fibrosis via HuR-mediated CTGF signaling and implicate a role for ADAR2 auto-regulation in lung homeostasis. The identification of ADAR2 target genes in ΔECS mice would facilitate a mechanistic understanding of the role of ADAR2 in the lungs and provide a therapeutic strategy for lung fibrosis.
Collapse
Affiliation(s)
- Ramani Soundararajan
- Division of Allergy and Immunology, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| | - Sai Manasa Varanasi
- Division of Allergy and Immunology, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| | - Sahebgowda Sidramagowda Patil
- Division of Allergy and Immunology, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| | - Sriraja Srinivas
- Division of Allergy and Immunology, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA.,Department of Drug Discovery and Development, Auburn University, Auburn, Alabama, USA
| | - Helena Hernández-Cuervo
- Division of Allergy and Immunology, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA.,Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| | - Alexander Czachor
- Division of Allergy and Immunology, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA.,Department of Medicine, Jagiellonian University Medical College, Kraków, Poland
| | - Adeeb Bulkhi
- Division of Allergy and Immunology, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA.,Department of Internal Medicine, College of Medicine, Umm Al Qura University, Makkah, Saudi Arabia
| | - Jutaro Fukumoto
- Division of Allergy and Immunology, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| | - Lakshmi Galam
- Division of Allergy and Immunology, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| | - Richard F Lockey
- Division of Allergy and Immunology, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| | - Narasaiah Kolliputi
- Division of Allergy and Immunology, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA
| |
Collapse
|
7
|
Owens MC, Zhang C, Liu KF. Recent technical advances in the study of nucleic acid modifications. Mol Cell 2021; 81:4116-4136. [PMID: 34480848 DOI: 10.1016/j.molcel.2021.07.036] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 07/20/2021] [Accepted: 07/28/2021] [Indexed: 12/30/2022]
Abstract
Enzyme-mediated chemical modifications of nucleic acids are indispensable regulators of gene expression. Our understanding of the biochemistry and biological significance of these modifications has largely been driven by an ever-evolving landscape of technologies that enable accurate detection, mapping, and manipulation of these marks. Here we provide a summary of recent technical advances in the study of nucleic acid modifications with a focus on techniques that allow accurate detection and mapping of these modifications. For each modification discussed (N6-methyladenosine, 5-methylcytidine, inosine, pseudouridine, and N4-acetylcytidine), we begin by introducing the "gold standard" technique for its mapping and detection, followed by a discussion of techniques developed to address any shortcomings of the gold standard. By highlighting the commonalities and differences of these techniques, we hope to provide a perspective on the current state of the field and to lay out a guideline for development of future technologies.
Collapse
Affiliation(s)
- Michael C Owens
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Celia Zhang
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Kathy Fange Liu
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
| |
Collapse
|
8
|
Coombs ID, Cull-Candy SG. Single-channel mechanisms underlying the function, diversity and plasticity of AMPA receptors. Neuropharmacology 2021; 198:108781. [PMID: 34480912 DOI: 10.1016/j.neuropharm.2021.108781] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Revised: 08/18/2021] [Accepted: 08/31/2021] [Indexed: 12/29/2022]
Abstract
The functional properties of AMPA receptors shape many of the essential features of excitatory synaptic signalling in the brain, including high-fidelity point-to-point transmission and long-term plasticity. Understanding the behaviour and regulation of single AMPAR channels is fundamental in unravelling how central synapses carry, process and store information. There is now an abundance of data on the importance of alternative splicing, RNA editing, and phosphorylation of AMPAR subunits in determining central synaptic diversity. Furthermore, auxiliary subunits have emerged as pivotal players that regulate AMPAR channel properties and add further diversity. Single-channel studies have helped reveal a fascinating picture of the unique behaviour of AMPAR channels - their concentration-dependent single-channel conductance, the basis of their multiple-conductance states, and the influence of auxiliary proteins in controlling many of their gating and conductance properties. Here we summarize basic hallmarks of AMPAR single-channels, in relation to function, diversity and plasticity. We also present data that reveal an unexpected feature of AMPAR sublevel behaviour. This article is part of the special Issue on 'Glutamate Receptors - AMPA receptors'.
Collapse
Affiliation(s)
- Ian D Coombs
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, WC1E 6BT, UK.
| | - Stuart G Cull-Candy
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, WC1E 6BT, UK.
| |
Collapse
|
9
|
Guo C, Ma YY. Calcium Permeable-AMPA Receptors and Excitotoxicity in Neurological Disorders. Front Neural Circuits 2021; 15:711564. [PMID: 34483848 PMCID: PMC8416103 DOI: 10.3389/fncir.2021.711564] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 07/23/2021] [Indexed: 12/13/2022] Open
Abstract
Excitotoxicity is one of the primary mechanisms of cell loss in a variety of diseases of the central and peripheral nervous systems. Other than the previously established signaling pathways of excitotoxicity, which depend on the excessive release of glutamate from axon terminals or over-activation of NMDA receptors (NMDARs), Ca2+ influx-triggered excitotoxicity through Ca2+-permeable (CP)-AMPA receptors (AMPARs) is detected in multiple disease models. In this review, both acute brain insults (e.g., brain trauma or spinal cord injury, ischemia) and chronic neurological disorders, including Epilepsy/Seizures, Huntington’s disease (HD), Parkinson’s disease (PD), Alzheimer’s disease (AD), amyotrophic lateral sclerosis (ALS), chronic pain, and glaucoma, are discussed regarding the CP-AMPAR-mediated excitotoxicity. Considering the low expression or absence of CP-AMPARs in most cells, specific manipulation of the CP-AMPARs might be a more plausible strategy to delay the onset and progression of pathological alterations with fewer side effects than blocking NMDARs.
Collapse
Affiliation(s)
- Changyong Guo
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Yao-Ying Ma
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, United States.,Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, United States
| |
Collapse
|
10
|
Drug-Evoked Synaptic Plasticity of Excitatory Transmission in the Ventral Tegmental Area. Cold Spring Harb Perspect Med 2021; 11:cshperspect.a039701. [PMID: 32341062 DOI: 10.1101/cshperspect.a039701] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Cocaine leads to a strong euphoria, which is at the origin of its recreational use. Past the acute effects, the drug leaves traces in the brain that persist long after it has been cleared from the body. These traces eventually shape behavior such that drug use may become compulsive, and addiction develops. Here, we discuss cocaine-evoked synaptic plasticity of glutamatergic transmission onto dopamine (DA) neurons of the ventral tegmental area (VTA) as one of the earliest traces after a first injection of cocaine. We review the literature that has examined the induction requirements, as well as the expression mechanism of this form of plasticity, and ask the question about its functional significance.
Collapse
|
11
|
Levi O, Arava YS. RNA modifications as a common denominator between tRNA and mRNA. Curr Genet 2021; 67:545-551. [PMID: 33683402 DOI: 10.1007/s00294-021-01168-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 02/23/2021] [Accepted: 02/25/2021] [Indexed: 12/27/2022]
Abstract
Recent studies underscore RNA modifications as a novel mechanism to coordinate expression and function of different genes. While modifications on the sugar or base moieties of tRNA are well known, their roles in mRNA regulation are only starting to emerge. Interestingly, some modifications are present in both tRNA and mRNA, and here we discuss the functional significance of these common features. We describe key modifications that are present in both RNA types, elaborate on proteins that interact with them, and indicate recent works that identify roles in communicating tRNA processes and mRNA regulation. We propose that as tools are developed, the shortlist of features that are common between types of RNA will greatly expand and proteins that interact with them will be identified. In conclusion, the presence of the same modification in both RNA types provides an intersect between tRNA processes and mRNA regulation and implies a novel mechanism for connecting diverse cellular processes.
Collapse
Affiliation(s)
- Ofri Levi
- Faculty of Biology, Technion-Israel Institute of Technology, 3200003, Haifa, Israel
| | - Yoav S Arava
- Faculty of Biology, Technion-Israel Institute of Technology, 3200003, Haifa, Israel.
| |
Collapse
|
12
|
Abstract
RNA editing is an RNA modification that alters the RNA sequence relative to its genomic blueprint. The most common type of RNA editing is A-to-I editing by double-stranded RNA-specific adenosine deaminase (ADAR) enzymes. Editing of a protein-coding region within the RNA molecule may result in non-synonymous substitutions, leading to a modified protein product. These editing sites, also known as "recoding" sites, contribute to the complexity and diversification of the proteome. Recent computational transcriptomic studies have identified thousands of recoding sites in multiple species, many of which are conserved within (but not usually across) lineages and have functional and evolutionary importance. In this chapter we describe the recoding phenomenon across species, consider its potential utility for diversity and adaptation, and discuss its evolution.
Collapse
|
13
|
Nakahama T, Kawahara Y. Adenosine-to-inosine RNA editing in the immune system: friend or foe? Cell Mol Life Sci 2020; 77:2931-2948. [PMID: 31996954 PMCID: PMC11104962 DOI: 10.1007/s00018-020-03466-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 12/27/2019] [Accepted: 01/14/2020] [Indexed: 12/19/2022]
Abstract
Our body expresses sensors to detect pathogens through the recognition of expressed molecules, including nucleic acids, lipids, and proteins, while immune tolerance prevents an overreaction with self and the development of autoimmune disease. Adenosine (A)-to-inosine (I) RNA editing, catalyzed by adenosine deaminases acting on RNA (ADARs), is a post-transcriptional modification that can potentially occur at over 100 million sites in the human genome, mainly in Alu repetitive elements that preferentially form a double-stranded RNA (dsRNA) structure. A-to-I conversion within dsRNA, which may induce a structural change, is required to escape from the host immune system, given that endogenous dsRNAs transcribed from Alu repetitive elements are potentially recognized by melanoma differentiation-associated protein 5 (MDA5) as non-self. Of note, loss-of-function mutations in the ADAR1 gene cause Aicardi-Goutières syndrome, a congenital autoimmune disease characterized by encephalopathy and a type I interferon (IFN) signature. However, the loss of ADAR1 in cancer cells with an IFN signature induces lethality via the activation of protein kinase R in addition to MDA5. This makes cells more sensitive to immunotherapy, highlighting the opposing immune status of autoimmune diseases (overreaction) and cancer (tolerance). In this review, we provide an overview of insights into two opposing aspects of RNA editing that functions as a modulator of the immune system in autoimmune diseases and cancer.
Collapse
Affiliation(s)
- Taisuke Nakahama
- Department of RNA Biology and Neuroscience, Graduate School of Medicine, Osaka University, Suita, Osaka, 565-0871, Japan
| | - Yukio Kawahara
- Department of RNA Biology and Neuroscience, Graduate School of Medicine, Osaka University, Suita, Osaka, 565-0871, Japan.
| |
Collapse
|
14
|
Maroofian R, Sedmík J, Mazaheri N, Scala M, Zaki MS, Keegan LP, Azizimalamiri R, Issa M, Shariati G, Sedaghat A, Beetz C, Bauer P, Galehdari H, O'Connell MA, Houlden H. Biallelic variants in ADARB1, encoding a dsRNA-specific adenosine deaminase, cause a severe developmental and epileptic encephalopathy. J Med Genet 2020; 58:495-504. [PMID: 32719099 PMCID: PMC8327408 DOI: 10.1136/jmedgenet-2020-107048] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 05/20/2020] [Accepted: 06/05/2020] [Indexed: 11/08/2022]
Abstract
BACKGROUND Adenosine-to-inosine RNA editing is a co-transcriptional/post-transcriptional modification of double-stranded RNA, catalysed by one of two active adenosine deaminases acting on RNA (ADARs), ADAR1 and ADAR2. ADARB1 encodes the enzyme ADAR2 that is highly expressed in the brain and essential to modulate the function of glutamate and serotonin receptors. Impaired ADAR2 editing causes early onset progressive epilepsy and premature death in mice. In humans, ADAR2 dysfunction has been very recently linked to a neurodevelopmental disorder with microcephaly and epilepsy in four unrelated subjects. METHODS We studied three children from two consanguineous families with severe developmental and epileptic encephalopathy (DEE) through detailed physical and instrumental examinations. Exome sequencing (ES) was used to identify ADARB1 mutations as the underlying genetic cause and in vitro assays with transiently transfected cells were performed to ascertain the impact on ADAR2 enzymatic activity and splicing. RESULTS All patients showed global developmental delay, intractable early infantile-onset seizures, microcephaly, severe-to-profound intellectual disability, axial hypotonia and progressive appendicular spasticity. ES revealed the novel missense c.1889G>A, p.(Arg630Gln) and deletion c.1245_1247+1 del, p.(Leu415PhefsTer14) variants in ADARB1 (NM_015833.4). The p.(Leu415PhefsTer14) variant leads to incorrect splicing resulting in frameshift with a premature stop codon and loss of enzyme function. In vitro RNA editing assays showed that the p.(Arg630Gln) variant resulted in a severe impairment of ADAR2 enzymatic activity. CONCLUSION In conclusion, these data support the pathogenic role of biallelic ADARB1 variants as the cause of a distinctive form of DEE, reinforcing the importance of RNA editing in brain function and development.
Collapse
Affiliation(s)
- Reza Maroofian
- Department of Neuromuscular Disorders, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
| | - Jiří Sedmík
- CEITEC, Masaryk University, Kamenice 735/5, A35, Brno 62500, Czech Republic
| | - Neda Mazaheri
- Department of Genetics, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran
| | - Marcello Scala
- Department of Neuromuscular Disorders, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK.,Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, Università degli Studi di Genova, Genova, Italy
| | - Maha S Zaki
- Clinical Genetics Department, Human Genetics and Genome Research Division, National Research Centre, Cairo, Egypt
| | - Liam P Keegan
- CEITEC, Masaryk University, Kamenice 735/5, A35, Brno 62500, Czech Republic
| | - Reza Azizimalamiri
- Department of Paediatric Neurology, Golestan, Medical, Educational, and Research Center, Ahvaz Jundishapur University of Medical Sciences, Behbahan, Iran
| | - Mahmoud Issa
- Clinical Genetics Department, Human Genetics and Genome Research Division, National Research Centre, Cairo, Egypt
| | - Gholamreza Shariati
- Department of Medical Genetics, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Behbahan, Iran
| | - Alireza Sedaghat
- Health Research Institute, Diabetes Research Center, Ahvaz Jundishapur University of medical Sciences, Ahvaz, Iran
| | | | | | - Hamid Galehdari
- Department of Genetics, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran
| | - Mary A O'Connell
- CEITEC, Masaryk University, Kamenice 735/5, A35, Brno 62500, Czech Republic
| | - Henry Houlden
- Department of Neuromuscular Disorders, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK
| |
Collapse
|
15
|
Charsouei S, Jabalameli MR, Karimi-Moghadam A. Molecular insights into the role of AMPA receptors in the synaptic plasticity, pathogenesis and treatment of epilepsy: therapeutic potentials of perampanel and antisense oligonucleotide (ASO) technology. Acta Neurol Belg 2020; 120:531-544. [PMID: 32152997 DOI: 10.1007/s13760-020-01318-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2019] [Accepted: 02/27/2020] [Indexed: 02/07/2023]
Abstract
Glutamate is considered as the predominant excitatory neurotransmitter in the mammalian central nervous systems (CNS). Alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) are the main glutamate-gated ionotropic channels that mediate the majority of fast synaptic excitation in the brain. AMPARs are highly dynamic that constitutively move into and out of the postsynaptic membrane. Changes in the postsynaptic number of AMPARs play a key role in controlling synaptic plasticity and also brain functions such as memory formation and forgetting development. Impairments in the regulation of AMPAR function, trafficking, and signaling pathway may also contribute to neuronal hyperexcitability and epileptogenesis process, which offers AMPAR as a potential target for epilepsy therapy. Over the last decade, various types of AMPAR antagonists such as perampanel and talampanel have been developed to treat epilepsy, but they usually show limited efficacy at low doses and produce unwanted cognitive and motor side effects when administered at higher doses. In the present article, the latest findings in the field of molecular mechanisms controlling AMPAR biology, as well as the role of these mechanism dysfunctions in generating epilepsy will be reviewed. Also, a comprehensive summary of recent findings from clinical trials with perampanel, in treating epilepsy, glioma-associated epilepsy and Parkinson's disease is provided. Finally, antisense oligonucleotide therapy as an alternative strategy for the efficient treatment of epilepsy is discussed.
Collapse
Affiliation(s)
- Saeid Charsouei
- Department of Neurology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, IR, Iran
| | - M Reza Jabalameli
- Department of Genetics, Albert Einstein College of Medicine, 1301 Morris Park Avenue, Bronx, NY, 10461, USA
| | - Amin Karimi-Moghadam
- Division of Genetics, Department of Biology, Faculty of Science, University of Isfahan, Isfahan, IR, Iran.
| |
Collapse
|
16
|
Modulation of ADAR mRNA expression in patients with congenital heart defects. PLoS One 2019; 14:e0200968. [PMID: 31039163 PMCID: PMC6490900 DOI: 10.1371/journal.pone.0200968] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2018] [Accepted: 04/05/2019] [Indexed: 12/26/2022] Open
Abstract
Adenosine (A) to inosine (I) RNA editing is a hydrolytic deamination reaction catalyzed by the adenosine deaminase (ADAR) enzyme acting on double-stranded RNA. This posttranscriptional process diversifies a plethora of transcripts, including coding and noncoding RNAs. Interestingly, few studies have been carried out to determine the role of RNA editing in vascular disease. The aim of this study was to determine the potential role of ADARs in congenital heart disease. Strong downregulation of ADAR2 and increase in ADAR1 expression was observed in blood samples from congenital heart disease (CHD) patients. The decrease in expression of ADAR2 was in line with its downregulation in ventricular tissues of dilated cardiomyopathy patients. To further decipher the plausible regulatory pathway of ADAR2 with respect to heart physiology, miRNA profiling of ADAR2 was performed on tissues from ADAR2-/- mouse hearts. Downregulation of miRNAs (miR-29b, miR-405, and miR-19) associated with cardiomyopathy and cardiac fibrosis was observed. Moreover, the upregulation of miR-29b targets COL1A2 and IGF1, indicated that ADAR2 might be involved in cardiac myopathy. The ADAR2 target vascular development associated protein-coding gene filamin B (FLNB) was selected. The editing levels of FLNB were dramatically reduced in ADAR2-/- mice; however, no observable changes in FLNB expression were noted in ADAR2-/- mice compared to wild-type mice. This study proposes that sufficient ADAR2 enzyme activity might play a vital role in preventing cardiovascular defects.
Collapse
|
17
|
Abstract
C-to-U RNA editing enzymatically converts the base C to U in RNA molecules and could lead to nonsynonymous changes when occurring in coding regions. Hundreds to thousands of coding sites were recently found to be C-to-U edited or editable in humans, but the biological significance of this phenomenon is elusive. Here, we test the prevailing hypothesis that nonsynonymous editing is beneficial because it provides a means for tissue- or time-specific regulation of protein function that may be hard to accomplish by mutations due to pleiotropy. The adaptive hypothesis predicts that the fraction of sites edited and the median proportion of RNA molecules edited (i.e., editing level) are both higher for nonsynonymous than synonymous editing. However, our empirical observations are opposite to these predictions. Furthermore, the frequency of nonsynonymous editing, relative to that of synonymous editing, declines as genes become functionally more important or evolutionarily more constrained, and the nonsynonymous editing level at a site is negatively correlated with the evolutionary conservation of the site. Together, these findings refute the adaptive hypothesis; they instead indicate that the reported C-to-U coding RNA editing is mostly slightly deleterious or neutral, probably resulting from off-target activities of editing enzymes. Along with similar conclusions on the more prevalent A-to-I editing and m6A modification of coding RNAs, our study suggests that, at least in humans, most events of each type of posttranscriptional coding RNA modification likely manifest cellular errors rather than adaptations, demanding a paradigm shift in the research of posttranscriptional modification.
Collapse
Affiliation(s)
- Zhen Liu
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China.,Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI
| | - Jianzhi Zhang
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI
| |
Collapse
|
18
|
Jiang Y, Wang Z, Chen X, Wang W, Wang X. ADAR1 silencing-induced HUVEC apoptosis is mediated by FGFR2 under hypoxia stress. Drug Des Devel Ther 2018; 12:4181-4189. [PMID: 30573948 PMCID: PMC6292393 DOI: 10.2147/dddt.s181312] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Background The adenosine deaminase acting on RNA 1 (ADAR1) specifically deaminates adenosine to inosine in double-stranded RNA (dsRNA). Emerging evidence indicated that under hypoxia condition, such as tumor microenvironment, ADAR1 level was increased. Interestingly, we found FGFR2 was also increased under hypoxia stress. The purpose of this study was to investigate the regulation mechanism of ADAR1 and the potential role of ADAR1–FGFR2 axis in cell proliferation and apoptosis. Methods Using human umbilical vein endothelial cells as cellular model, we explored the function of ADAR1 in regulating cell survival. Results We found manipulation of FGFR2 activity could override the cellular effect of ADAR1, suggesting FGFR2 could be a potential effector of ADAR1. Moreover, our results revealed that PI3K-Akt pathway was involved in ADAR1–FGFR2 axis-induced cell proliferation. Conclusion In summary, this study supported the notion that ADAR1 could play a role in tumor cell proliferation, which was mediated by FGFR2.
Collapse
Affiliation(s)
- Yun Jiang
- Department of Cardiology, The Eighth People's Hospital of Shanghai, Shanghai 200233, China,
| | - Zhancheng Wang
- Department of Cardiology, The Eighth People's Hospital of Shanghai, Shanghai 200233, China,
| | - Xu Chen
- Department of Cardiology, The Eighth People's Hospital of Shanghai, Shanghai 200233, China,
| | - Wei Wang
- Department of Cardiology, The Eighth People's Hospital of Shanghai, Shanghai 200233, China,
| | - Xiaowei Wang
- Shanghai Weiang Info Tech Ltd., Shanghai 200233, China
| |
Collapse
|
19
|
Abstract
RNA-guided programmable nucleases from CRISPR systems generate precise breaks in DNA or RNA at specified positions. In cells, this activity can lead to changes in DNA sequence or RNA transcript abundance. Base editing is a newer genome-editing approach that uses components from CRISPR systems together with other enzymes to directly install point mutations into cellular DNA or RNA without making double-stranded DNA breaks. DNA base editors comprise a catalytically disabled nuclease fused to a nucleobase deaminase enzyme and, in some cases, a DNA glycosylase inhibitor. RNA base editors achieve analogous changes using components that target RNA. Base editors directly convert one base or base pair into another, enabling the efficient installation of point mutations in non-dividing cells without generating excess undesired editing by-products. In this Review, we summarize base-editing strategies to generate specific and precise point mutations in genomic DNA and RNA, highlight recent developments that expand the scope, specificity, precision and in vivo delivery of base editors and discuss limitations and future directions of base editing for research and therapeutic applications.
Collapse
Affiliation(s)
- Holly A Rees
- Merkin Institute of Transformative Technologies in Healthcare, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - David R Liu
- Merkin Institute of Transformative Technologies in Healthcare, Broad Institute of MIT and Harvard, Cambridge, MA, USA.
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA.
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA.
| |
Collapse
|
20
|
Ayuob NN, Balgoon MJ. Histological and molecular techniques utilized to investigate animal models of depression. An updated review. Microsc Res Tech 2018; 81:1143-1153. [PMID: 30168883 DOI: 10.1002/jemt.23105] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 06/25/2018] [Accepted: 07/16/2018] [Indexed: 12/30/2022]
Abstract
This review aimed to summarize the different histopathological techniques and procedures utilized during investigating the different animal models of depression in order to explore the pathophysiological aspect of depression and testing the efficacy of the antidepressant drugs or new treatments. This will be helpful while designing researches aiming to achieve these objectives. It was found that the major obstacle during investigating the animal models of depression was the restricted availability of validated animal models. The chronic stress models have face, construct, and predictive validity. It was found that the histological techniques used in investigating the animal models of depression that was described in the literatures fall under three categories; the light microscopic, the electron microscopic and the molecular biological studies. The light microscope studies were performed using the routine histological staining and immunohistochemical technique that aimed to describe the hippocampal histopathological changes induced by depression. Establishment of a preclinical behavioral science laboratory is highly recommended. It will encourage and support the conduction of high quality, multidisciplinary researches targeting anxiety and other psychiatric disorders and will indirectly improve the health care provided to the psychiatric patients. RESEARCH HIGHLIGHTS: Chronic stress models are valid ones. Light microscope was utilized to examine the routinely or immunohistochemically stained sections in hippocampus of animal models of depression while electron microscope was utilized to examine its ultrastructure.
Collapse
Affiliation(s)
- Nasra Naeim Ayuob
- Department of Anatomy, Faculty of Medicine, King Abdulaziz University, Saudi Arabia.,Histology Department, Faculty of Medicine, Mansoura University, Egypt
| | - Maha Jameal Balgoon
- Department of Biochemistry, Faculty of Science, King Abdulaziz University, Saudi Arabia
| |
Collapse
|
21
|
Pre- and postsynaptic ionotropic glutamate receptors in the auditory system of mammals. Hear Res 2018; 362:1-13. [DOI: 10.1016/j.heares.2018.02.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 02/16/2018] [Accepted: 02/21/2018] [Indexed: 01/22/2023]
|
22
|
Li J, Xie J, Liu S, Li X, Zhang D, Wang X, Jiang J, Hu W, Zhang Y, Jin B, Zhuang R, Yin W. ADAR1 attenuates allogeneic graft rejection by suppressing miR‐21 biogenesis in macrophages and promoting M2 polarization. FASEB J 2018; 32:5162-5173. [DOI: 10.1096/fj.201701449r] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Junjie Li
- Department of Emergency School of Basic Medical SciencesFourth Military Medical UniversityXi'anChina
| | - Jiangang Xie
- Department of Emergency School of Basic Medical SciencesFourth Military Medical UniversityXi'anChina
- Department of Plastic SurgeryXijing HospitalSchool of Basic Medical SciencesFourth Military Medical UniversityXi'anChina
| | - Shanshou Liu
- Department of Emergency School of Basic Medical SciencesFourth Military Medical UniversityXi'anChina
| | - Xiao Li
- Department of Hepatobiliary SurgerySchool of Basic Medical SciencesFourth Military Medical UniversityXi'anChina
| | - Dongliang Zhang
- Department of Plastic SurgeryXijing HospitalSchool of Basic Medical SciencesFourth Military Medical UniversityXi'anChina
- Transplant Immunology Laboratory and School of Basic Medical SciencesFourth Military Medical UniversityXi'anChina
| | - Xianqi Wang
- Department of Emergency School of Basic Medical SciencesFourth Military Medical UniversityXi'anChina
| | - Jinquan Jiang
- Department of Emergency School of Basic Medical SciencesFourth Military Medical UniversityXi'anChina
| | - Wei Hu
- Transplant Immunology Laboratory and School of Basic Medical SciencesFourth Military Medical UniversityXi'anChina
- Department of ImmunologySchool of Basic Medical SciencesFourth Military Medical UniversityXi'anChina
| | - Yuan Zhang
- Transplant Immunology Laboratory and School of Basic Medical SciencesFourth Military Medical UniversityXi'anChina
| | - Boquan Jin
- Department of ImmunologySchool of Basic Medical SciencesFourth Military Medical UniversityXi'anChina
| | - Ran Zhuang
- Transplant Immunology Laboratory and School of Basic Medical SciencesFourth Military Medical UniversityXi'anChina
- Department of ImmunologySchool of Basic Medical SciencesFourth Military Medical UniversityXi'anChina
| | - Wen Yin
- Department of Emergency School of Basic Medical SciencesFourth Military Medical UniversityXi'anChina
| |
Collapse
|
23
|
Ye LQ, Zhao H, Zhou HJ, Ren XD, Liu LL, Otecko NO, Wang ZB, Yang MM, Zeng L, Hu XT, Yao YG, Zhang YP, Wu DD. The RNA editome of Macaca mulatta and functional characterization of RNA editing in mitochondria. Sci Bull (Beijing) 2017; 62:820-830. [PMID: 36659315 DOI: 10.1016/j.scib.2017.05.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 05/09/2017] [Accepted: 05/16/2017] [Indexed: 01/21/2023]
Abstract
RNA editing was first discovered in mitochondrial RNA molecular. However, whether adenosine-to-inosine (A-to-I) RNA editing has functions in nuclear genes involved in mitochondria remains elusive. Here, we retrieved 707,246 A-to-I RNA editing sites in Macaca mulatta leveraging massive transcriptomes of 30 different tissues and genomes of nine tissues, together with the reported data, and found that A-to-I RNA editing occurred frequently in nuclear genes that have functions in mitochondria. The mitochondrial structure, the level of ATP production, and the expression of some key genes involved in mitochondrial function were dysregulated after knocking down the expression of ADAR1 and ADAR2, the key genes encoding the enzyme responsible for RNA editing. When investigating dynamic changes of RNA editing during brain development, an amino-acid-changing RNA editing site (I234/V) in MFN1, a mediator of mitochondrial fusion, was identified to be significantly correlated with age, and could influence the function of MFN1. When studying transcriptomes of brain disorder, we found that dysregulated RNA editing sites in autism were also enriched within genes having mitochondrial functions. These data indicated that RNA editing had a significant function in mitochondria via their influence on nuclear genes.
Collapse
Affiliation(s)
- Ling-Qun Ye
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China; Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming 650204, China
| | - Hui Zhao
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650091, China
| | - He-Jiang Zhou
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China; CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China
| | - Xiao-Die Ren
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China; Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming 650204, China
| | - Lin-Lin Liu
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650091, China
| | - Newton O Otecko
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China; Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming 650204, China
| | - Zheng-Bo Wang
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China
| | - Min-Min Yang
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China
| | - Lin Zeng
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China; Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming 650204, China
| | - Xin-Tian Hu
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China; Kunming Primate Research Center of the Chinese Academy of Sciences, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China
| | - Yong-Gang Yao
- Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China; Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming 650204, China; Kunming Primate Research Center of the Chinese Academy of Sciences, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China; CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China
| | - Ya-Ping Zhang
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China; Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming 650204, China.
| | - Dong-Dong Wu
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China; Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming 650204, China; Kunming Primate Research Center of the Chinese Academy of Sciences, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China.
| |
Collapse
|
24
|
Greger IH, Watson JF, Cull-Candy SG. Structural and Functional Architecture of AMPA-Type Glutamate Receptors and Their Auxiliary Proteins. Neuron 2017; 94:713-730. [DOI: 10.1016/j.neuron.2017.04.009] [Citation(s) in RCA: 169] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 04/04/2017] [Accepted: 04/05/2017] [Indexed: 12/20/2022]
|
25
|
RNA Editing, ADAR1, and the Innate Immune Response. Genes (Basel) 2017; 8:genes8010041. [PMID: 28106799 PMCID: PMC5295035 DOI: 10.3390/genes8010041] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 01/03/2017] [Accepted: 01/11/2017] [Indexed: 01/14/2023] Open
Abstract
RNA editing, particularly A-to-I RNA editing, has been shown to play an essential role in mammalian embryonic development and tissue homeostasis, and is implicated in the pathogenesis of many diseases including skin pigmentation disorder, autoimmune and inflammatory tissue injury, neuron degeneration, and various malignancies. A-to-I RNA editing is carried out by a small group of enzymes, the adenosine deaminase acting on RNAs (ADARs). Only three members of this protein family, ADAR1-3, exist in mammalian cells. ADAR3 is a catalytically null enzyme and the most significant function of ADAR2 was found to be in editing on the neuron receptor GluR-B mRNA. ADAR1, however, has been shown to play more significant roles in biological and pathological conditions. Although there remains much that is not known about how ADAR1 regulates cellular function, recent findings point to regulation of the innate immune response as an important function of ADAR1. Without appropriate RNA editing by ADAR1, endogenous RNA transcripts stimulate cytosolic RNA sensing receptors and therefore activate the IFN-inducing signaling pathways. Overactivation of innate immune pathways can lead to tissue injury and dysfunction. However, obvious gaps in our knowledge persist as to how ADAR1 regulates innate immune responses through RNA editing. Here, we review critical findings from ADAR1 mechanistic studies focusing on its regulatory function in innate immune responses and identify some of the important unanswered questions in the field.
Collapse
|
26
|
Guerra GP, Rubin MA, Mello CF. Modulation of learning and memory by natural polyamines. Pharmacol Res 2016; 112:99-118. [PMID: 27015893 DOI: 10.1016/j.phrs.2016.03.023] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2016] [Revised: 03/09/2016] [Accepted: 03/11/2016] [Indexed: 01/08/2023]
Abstract
Spermine and spermidine are natural polyamines that are produced mainly via decarboxylation of l-ornithine and the sequential transfer of aminopropyl groups from S-adenosylmethionine to putrescine by spermidine synthase and spermine synthase. Spermine and spermidine interact with intracellular and extracellular acidic residues of different nature, including nucleic acids, phospholipids, acidic proteins, carboxyl- and sulfate-containing polysaccharides. Therefore, multiple actions have been suggested for these polycations, including modulation of the activity of ionic channels, protein synthesis, protein kinases, and cell proliferation/death, within others. In this review we summarize these neurochemical/neurophysiological/morphological findings, particularly those that have been implicated in the improving and deleterious effects of spermine and spermidine on learning and memory of naïve animals in shock-motivated and nonshock-motivated tasks, from a historical perspective. The interaction with the opioid system, the facilitation and disruption of morphine-induced reward and the effect of polyamines and putative polyamine antagonists on animal models of cognitive diseases, such as Alzheimer's, Huntington, acute neuroinflammation and brain trauma are also reviewed and discussed. The increased production of polyamines in Alzheimer's disease and the biphasic nature of the effects of polyamines on memory and on the NMDA receptor are also considered. In light of the current literature on polyamines, which include the description of an inborn error of the metabolism characterized by mild-to moderate mental retardation and polyamine metabolism alterations in suicide completers, we can anticipate that polyamine targets may be important for the development of novel strategies and approaches for understanding the etiopathogenesis of important central disorders and their pharmacological treatment.
Collapse
Affiliation(s)
- Gustavo Petri Guerra
- Department of Food Technology, Federal Technological University of Paraná, Campus Medianeira, Medianeira, PR 85884-000, Brazil
| | - Maribel Antonello Rubin
- Department of Biochemistry, Center of Exact and Natural Sciences, Federal University of Santa Maria (UFSM), Santa Maria, RS 97105-900, Brazil.
| | - Carlos Fernando Mello
- Department of Physiology and Pharmacology, Center of Health Sciences, Federal University of Santa Maria (UFSM), Santa Maria, RS 97105-900, Brazil.
| |
Collapse
|
27
|
Plasticity in the Neonatal Brain following Hypoxic-Ischaemic Injury. Neural Plast 2016; 2016:4901014. [PMID: 27047695 PMCID: PMC4800097 DOI: 10.1155/2016/4901014] [Citation(s) in RCA: 117] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 01/12/2016] [Accepted: 02/07/2016] [Indexed: 12/03/2022] Open
Abstract
Hypoxic-ischaemic damage to the developing brain is a leading cause of child death, with high mortality and morbidity, including cerebral palsy, epilepsy, and cognitive disabilities. The developmental stage of the brain and the severity of the insult influence the selective regional vulnerability and the subsequent clinical manifestations. The increased susceptibility to hypoxia-ischaemia (HI) of periventricular white matter in preterm infants predisposes the immature brain to motor, cognitive, and sensory deficits, with cognitive impairment associated with earlier gestational age. In term infants HI causes selective damage to sensorimotor cortex, basal ganglia, thalamus, and brain stem. Even though the immature brain is more malleable to external stimuli compared to the adult one, a hypoxic-ischaemic event to the neonate interrupts the shaping of central motor pathways and can affect normal developmental plasticity through altering neurotransmission, changes in cellular signalling, neural connectivity and function, wrong targeted innervation, and interruption of developmental apoptosis. Models of neonatal HI demonstrate three morphologically different types of cell death, that is, apoptosis, necrosis, and autophagy, which crosstalk and can exist as a continuum in the same cell. In the present review we discuss the mechanisms of HI injury to the immature brain and the way they affect plasticity.
Collapse
|
28
|
Huntley MA, Lou M, Goldstein LD, Lawrence M, Dijkgraaf GJP, Kaminker JS, Gentleman R. Complex regulation of ADAR-mediated RNA-editing across tissues. BMC Genomics 2016; 17:61. [PMID: 26768488 PMCID: PMC4714477 DOI: 10.1186/s12864-015-2291-9] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 12/11/2015] [Indexed: 01/28/2023] Open
Abstract
Background RNA-editing is a tightly regulated, and essential cellular process for a properly functioning brain. Dysfunction of A-to-I RNA editing can have catastrophic effects, particularly in the central nervous system. Thus, understanding how the process of RNA-editing is regulated has important implications for human health. However, at present, very little is known about the regulation of editing across tissues, and individuals. Results Here we present an analysis of RNA-editing patterns from 9 different tissues harvested from a single mouse. For comparison, we also analyzed data for 5 of these tissues harvested from 15 additional animals. We find that tissue specificity of editing largely reflects differential expression of substrate transcripts across tissues. We identified a surprising enrichment of editing in intronic regions of brain transcripts, that could account for previously reported higher levels of editing in brain. There exists a small but remarkable amount of editing which is tissue-specific, despite comparable expression levels of the edit site across multiple tissues. Expression levels of editing enzymes and their isoforms can explain some, but not all of this variation. Conclusions Together, these data suggest a complex regulation of the RNA-editing process beyond transcript expression levels. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-2291-9) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Melanie A Huntley
- Department of Bioinformatics and Computational Biology, Genentech Inc., 1 DNA Way, South San Francisco, USA.
| | - Melanie Lou
- Department of Bioinformatics and Computational Biology, Genentech Inc., 1 DNA Way, South San Francisco, USA.
| | - Leonard D Goldstein
- Department of Bioinformatics and Computational Biology, Genentech Inc., 1 DNA Way, South San Francisco, USA.
| | - Michael Lawrence
- Department of Bioinformatics and Computational Biology, Genentech Inc., 1 DNA Way, South San Francisco, USA.
| | - Gerrit J P Dijkgraaf
- Department of Molecular Oncology, Genentech Inc., 1 DNA Way, South San Francisco, USA.
| | - Joshua S Kaminker
- Department of Bioinformatics and Computational Biology, Genentech Inc., 1 DNA Way, South San Francisco, USA.
| | - Robert Gentleman
- Department of Bioinformatics and Computational Biology, Genentech Inc., 1 DNA Way, South San Francisco, USA.
| |
Collapse
|
29
|
Wu DD, Ye LQ, Li Y, Sun YB, Shao Y, Chen C, Zhu Z, Zhong L, Wang L, Irwin DM, Zhang YE, Zhang YP. Integrative analyses of RNA editing, alternative splicing, and expression of young genes in human brain transcriptome by deep RNA sequencing. J Mol Cell Biol 2015; 7:314-25. [DOI: 10.1093/jmcb/mjv043] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 04/16/2015] [Indexed: 12/31/2022] Open
|
30
|
Frésard L, Leroux S, Roux PF, Klopp C, Fabre S, Esquerré D, Dehais P, Djari A, Gourichon D, Lagarrigue S, Pitel F. Genome-Wide Characterization of RNA Editing in Chicken Embryos Reveals Common Features among Vertebrates. PLoS One 2015; 10:e0126776. [PMID: 26024316 PMCID: PMC4449034 DOI: 10.1371/journal.pone.0126776] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2014] [Accepted: 04/07/2015] [Indexed: 12/15/2022] Open
Abstract
RNA editing results in a post-transcriptional nucleotide change in the RNA sequence that creates an alternative nucleotide not present in the DNA sequence. This leads to a diversification of transcription products with potential functional consequences. Two nucleotide substitutions are mainly described in animals, from adenosine to inosine (A-to-I) and from cytidine to uridine (C-to-U). This phenomenon is described in more details in mammals, notably since the availability of next generation sequencing technologies allowing whole genome screening of RNA-DNA differences. The number of studies recording RNA editing in other vertebrates like chicken is still limited. We chose to use high throughput sequencing technologies to search for RNA editing in chicken, and to extend the knowledge of its conservation among vertebrates. We performed sequencing of RNA and DNA from 8 embryos. Being aware of common pitfalls inherent to sequence analyses that lead to false positive discovery, we stringently filtered our datasets and found fewer than 40 reliable candidates. Conservation of particular sites of RNA editing was attested by the presence of 3 edited sites previously detected in mammals. We then characterized editing levels for selected candidates in several tissues and at different time points, from 4.5 days of embryonic development to adults, and observed a clear tissue-specificity and a gradual increase of editing level with time. By characterizing the RNA editing landscape in chicken, our results highlight the extent of evolutionary conservation of this phenomenon within vertebrates, attest to its tissue and stage specificity and provide support of the absence of non A-to-I events from the chicken transcriptome.
Collapse
Affiliation(s)
- Laure Frésard
- INRA, Génétique, Physiologie et Systèmes d’Elevage, Castanet-Tolosan, France
- Université de Toulouse, INP, ENSAT, Génétique, Physiologie et Systèmes d’Elevage, Castanet-Tolosan, France
- Université de Toulouse, INP, ENVT, Génétique, Physiologie et Systèmes d’Elevage, Toulouse, France
| | - Sophie Leroux
- INRA, Génétique, Physiologie et Systèmes d’Elevage, Castanet-Tolosan, France
- Université de Toulouse, INP, ENSAT, Génétique, Physiologie et Systèmes d’Elevage, Castanet-Tolosan, France
- Université de Toulouse, INP, ENVT, Génétique, Physiologie et Systèmes d’Elevage, Toulouse, France
| | - Pierre-François Roux
- Agrocampus Ouest, Physiologie, Environnement et Génétique pour l'Animal et les Systèmes d'Élevage, Rennes, France
- INRA, Physiologie, Environnement et Génétique pour l'Animal et les Systèmes d'Élevage, Rennes, France
| | - Christophe Klopp
- INRA, Sigenae Biométrie et Intelligence Artificielle, Castanet-Tolosan, France
| | - Stéphane Fabre
- INRA, Génétique, Physiologie et Systèmes d’Elevage, Castanet-Tolosan, France
- Université de Toulouse, INP, ENSAT, Génétique, Physiologie et Systèmes d’Elevage, Castanet-Tolosan, France
- Université de Toulouse, INP, ENVT, Génétique, Physiologie et Systèmes d’Elevage, Toulouse, France
| | - Diane Esquerré
- INRA, Génétique, Physiologie et Systèmes d’Elevage, Castanet-Tolosan, France
- Université de Toulouse, INP, ENSAT, Génétique, Physiologie et Systèmes d’Elevage, Castanet-Tolosan, France
- Université de Toulouse, INP, ENVT, Génétique, Physiologie et Systèmes d’Elevage, Toulouse, France
- INRA, GeT-PlaGe Genotoul, Castanet-Tolosan, France
| | - Patrice Dehais
- INRA, Génétique, Physiologie et Systèmes d’Elevage, Castanet-Tolosan, France
- Université de Toulouse, INP, ENSAT, Génétique, Physiologie et Systèmes d’Elevage, Castanet-Tolosan, France
- Université de Toulouse, INP, ENVT, Génétique, Physiologie et Systèmes d’Elevage, Toulouse, France
- INRA, Sigenae Biométrie et Intelligence Artificielle, Castanet-Tolosan, France
| | - Anis Djari
- INRA, Génétique, Physiologie et Systèmes d’Elevage, Castanet-Tolosan, France
- Université de Toulouse, INP, ENSAT, Génétique, Physiologie et Systèmes d’Elevage, Castanet-Tolosan, France
- Université de Toulouse, INP, ENVT, Génétique, Physiologie et Systèmes d’Elevage, Toulouse, France
- INRA, Sigenae Biométrie et Intelligence Artificielle, Castanet-Tolosan, France
| | - David Gourichon
- INRA, Pôle d'Expérimentation Avicole de Tours, Nouzilly, France
| | - Sandrine Lagarrigue
- Agrocampus Ouest, Physiologie, Environnement et Génétique pour l'Animal et les Systèmes d'Élevage, Rennes, France
- INRA, Physiologie, Environnement et Génétique pour l'Animal et les Systèmes d'Élevage, Rennes, France
- * E-mail: (FP); (SL)
| | - Frédérique Pitel
- INRA, Génétique, Physiologie et Systèmes d’Elevage, Castanet-Tolosan, France
- Université de Toulouse, INP, ENSAT, Génétique, Physiologie et Systèmes d’Elevage, Castanet-Tolosan, France
- Université de Toulouse, INP, ENVT, Génétique, Physiologie et Systèmes d’Elevage, Toulouse, France
- * E-mail: (FP); (SL)
| |
Collapse
|
31
|
|
32
|
George CX, John L, Samuel CE. An RNA editor, adenosine deaminase acting on double-stranded RNA (ADAR1). J Interferon Cytokine Res 2015; 34:437-46. [PMID: 24905200 DOI: 10.1089/jir.2014.0001] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Adenosine deaminase acting on RNA1 (ADAR1) catalyzes the C6 deamination of adenosine (A) to produce inosine (I) in regions of RNA with double-stranded (ds) character. This process is known as A-to-I RNA editing. Alternative promoters drive the expression of the Adar1 gene and alternative splicing gives rise to transcripts that encode 2 ADAR1 protein size isoforms. ADAR1 p150 is an interferon (IFN)-inducible dsRNA adenosine deaminase found in the cytoplasm and nucleus, whereas ADAR1 p110 is constitutively expressed and nuclear in localization. Dependent on the duplex structure of the dsRNA substrate, deamination of adenosine by ADAR can be either highly site-selective or nonspecific. A-to-I editing can alter the stability of RNA structures and the coding of RNA as I is read as G instead of A by ribosomes during mRNA translation and by polymerases during RNA replication. A-to-I editing is of broad physiologic significance. Both the production and the action of IFNs, and hence the subsequent interaction of viruses with their hosts, are among the processes affected by A-to-I editing.
Collapse
Affiliation(s)
- Cyril X George
- Department of Molecular, Cellular and Developmental Biology, University of California , Santa Barbara, California
| | | | | |
Collapse
|
33
|
Rajić V, Debeljak M, Goričar K, Jazbec J. Polymorphisms in GRIA1 gene are a risk factor for asparaginase hypersensitivity during the treatment of childhood acute lymphoblastic leukemia. Leuk Lymphoma 2015; 56:3103-8. [PMID: 25697915 DOI: 10.3109/10428194.2015.1020802] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
l-asparaginase is an effective antineoplastic agent used in chemotherapy of acute lymphoblastic leukemia. The drug effect may be compromised by an elicited immune response, resulting in the production of anti-asparaginase antibodies causing an anaphylactic reaction or silent inactivation of the enzyme. To elucidate possible genetic predisposition for inter-individual differences in asparaginase hypersensitivity, we studied single nucleotide polymorphisms (SNPs) in the GRIA1 gene in 146 pediatric patients treated with l-asparaginase. Allergic reaction to l-asparaginase occurred in 49.3% of patients. We observed a statistically significant association between SNPs in the GRIA1 gene and the occurrence of asparaginase allergy: rs4958351 with p = 0.003, rs4958676 with p = 0.005, rs6889909 with p = 0.005, rs6890057 with p = 0.005 and rs10070447 with p = 0.006. We found a statistically significant correlation between asparaginase allergy and event-free survival (p-value 0.005).
Collapse
Affiliation(s)
- Vladan Rajić
- a Department of Hematology and Oncology , University Children's Hospital , Ljubljana , Slovenia
| | - Maruša Debeljak
- b Unit of Special Laboratory Diagnostics, Centre for Medical Genetics, University Medical Centre Ljubljana , Ljubljana , Slovenia
| | - Katja Goričar
- c Institute of Biochemistry, Medical Faculty, University of Ljubljana , Ljubljana , Slovenia
| | - Janez Jazbec
- a Department of Hematology and Oncology , University Children's Hospital , Ljubljana , Slovenia
| |
Collapse
|
34
|
Molecular mechanisms contributing to TARP regulation of channel conductance and polyamine block of calcium-permeable AMPA receptors. J Neurosci 2014; 34:11673-83. [PMID: 25164663 DOI: 10.1523/jneurosci.0383-14.2014] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Many properties of fast synaptic transmission in the brain are influenced by transmembrane AMPAR regulatory proteins (TARPs) that modulate the pharmacology and gating of AMPA-type glutamate receptors (AMPARs). Although much is known about TARP influence on AMPAR pharmacology and kinetics through their modulation of the extracellular ligand-binding domain (LBD), less is known about their regulation of the ion channel region. TARP-induced modifications in AMPAR channel behavior include increased single-channel conductance and weakened block of calcium-permeable AMPARs (CP-AMPARs) by endogenous intracellular polyamines. To investigate how TARPs modify ion flux and channel block, we examined the action of γ-2 (stargazin) on GluA1 and GluA4 CP-AMPARs. First, we compared the permeation of organic cations of different sizes. We found that γ-2 increased the permeability of several cations but not the estimated AMPAR pore size, suggesting that TARP-induced relief of polyamine block does not reflect altered pore diameter. Second, to determine whether residues in the TARP intracellular C-tail regulate polyamine block and channel conductance, we examined various γ-2 C-tail mutants. We identified the membrane proximal region of the C terminus as crucial for full TARP-attenuation of polyamine block, whereas complete deletion of the C-tail markedly enhanced the TARP-induced increase in channel conductance; thus, the TARP C-tail influences ion permeation. Third, we identified a site in the pore-lining region of the AMPAR, close to its Q/R site, that is crucial in determining the TARP-induced changes in single-channel conductance. This conserved residue represents a site of TARP action, independent of the AMPAR LBD.
Collapse
|
35
|
Alexander SPH, Benson HE, Faccenda E, Pawson AJ, Sharman JL, Spedding M, Peters JA, Harmar AJ. The Concise Guide to PHARMACOLOGY 2013/14: ligand-gated ion channels. Br J Pharmacol 2014; 170:1582-606. [PMID: 24528238 PMCID: PMC3892288 DOI: 10.1111/bph.12446] [Citation(s) in RCA: 113] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The Concise Guide to PHARMACOLOGY 2013/14 provides concise overviews of the key properties of over 2000 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.12444/full. Ligand-gated ion channels are one of the seven major pharmacological targets into which the Guide is divided, with the others being G protein-coupled receptors, ion channels, catalytic receptors, nuclear hormone receptors, transporters and enzymes. These are presented with nomenclature guidance and summary information on the best available pharmacological tools, alongside key references and suggestions for further reading. A new landscape format has easy to use tables comparing related targets. It is a condensed version of material contemporary to late 2013, which is presented in greater detail and constantly updated on the website www.guidetopharmacology.org, superseding data presented in previous Guides to Receptors and Channels. It is produced in conjunction with NC-IUPHAR and provides the official IUPHAR classification and nomenclature for human drug targets, where appropriate. It consolidates information previously curated and displayed separately in IUPHAR-DB and the Guide to Receptors and Channels, providing a permanent, citable, point-in-time record that will survive database updates.
Collapse
Affiliation(s)
- Stephen P H Alexander
- School of Life Sciences, University of Nottingham Medical School, Nottingham, NG7 2UH, UK
| | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Baicalin reverse AMPA receptor expression and neuron apoptosis in chronic unpredictable mild stress rats. Biochem Biophys Res Commun 2014; 451:467-72. [DOI: 10.1016/j.bbrc.2014.07.041] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Accepted: 07/07/2014] [Indexed: 11/18/2022]
|
37
|
Rivera-Cervantes MC, Castañeda-Arellano R, Castro-Torres RD, Gudiño-Cabrera G, Feria y Velasco AI, Camins A, Beas-Zárate C. P38 MAPK inhibition protects against glutamate neurotoxicity and modifies NMDA and AMPA receptor subunit expression. J Mol Neurosci 2014; 55:596-608. [PMID: 25172309 DOI: 10.1007/s12031-014-0398-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Accepted: 08/05/2014] [Indexed: 11/28/2022]
Abstract
NMDA and AMPA receptors are thought to be responsible for Ca(++) influx during glutamate-induced excitotoxicity and, therefore, hippocampal neuronal death. We assessed whether excitotoxicity induced by neonatal treatment with monosodium glutamate in rats at postnatal age of 1, 3, 5, and 7 modifies the hippocampal expression of the NMDAR subunit NR1 and the AMPAR subunits GluR1/GluR2 at postnatal days 8, 10, 12, and 14. We also assessed the involvement of MAPK signaling by using the p38 inhibitor SB203580. Our results showed that monosodium glutamate induces neuronal death and alters the expression of the subunits evaluated in the hippocampus at all ages studied, which could be prevented by SB203580 treatment.Furthermore, expression of the NRSF gene silencing factor also increased in response to excitotoxicity, suggesting a relationship in suppressing GluR2-expression, which was regulated by the p38-MAPK pathway inhibitor SB203580. This result suggests that selectively blocking the pro-death signaling pathway may reduce neuronal death in some neurodegenerative diseases in which these neurotoxic processes are present and produce major clinical benefits in the treatment of these pathologies.
Collapse
|
38
|
O'Leary T, Williams AH, Franci A, Marder E. Cell types, network homeostasis, and pathological compensation from a biologically plausible ion channel expression model. Neuron 2014; 82:809-21. [PMID: 24853940 DOI: 10.1016/j.neuron.2014.04.002] [Citation(s) in RCA: 174] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/26/2013] [Indexed: 01/06/2023]
Abstract
How do neurons develop, control, and maintain their electrical signaling properties in spite of ongoing protein turnover and perturbations to activity? From generic assumptions about the molecular biology underlying channel expression, we derive a simple model and show how it encodes an "activity set point" in single neurons. The model generates diverse self-regulating cell types and relates correlations in conductance expression observed in vivo to underlying channel expression rates. Synaptic as well as intrinsic conductances can be regulated to make a self-assembling central pattern generator network; thus, network-level homeostasis can emerge from cell-autonomous regulation rules. Finally, we demonstrate that the outcome of homeostatic regulation depends on the complement of ion channels expressed in cells: in some cases, loss of specific ion channels can be compensated; in others, the homeostatic mechanism itself causes pathological loss of function.
Collapse
Affiliation(s)
- Timothy O'Leary
- Volen Center and Biology Department, Brandeis University, Waltham, MA 02454, USA.
| | - Alex H Williams
- Volen Center and Biology Department, Brandeis University, Waltham, MA 02454, USA
| | - Alessio Franci
- Department of Electrical Engineering and Computer Science, University of Liège, 10 Grande Traverse, Liège B 4000, Belgium; Department of Engineering, University of Cambridge, Trumpington Street, Cambridge CB2 1PZ, UK
| | - Eve Marder
- Volen Center and Biology Department, Brandeis University, Waltham, MA 02454, USA.
| |
Collapse
|
39
|
Lohmann C, Kessels HW. The developmental stages of synaptic plasticity. J Physiol 2014; 592:13-31. [PMID: 24144877 PMCID: PMC3903349 DOI: 10.1113/jphysiol.2012.235119] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Accepted: 10/16/2013] [Indexed: 01/17/2023] Open
Abstract
The brain is programmed to drive behaviour by precisely wiring the appropriate neuronal circuits. Wiring and rewiring of neuronal circuits largely depends on the orchestrated changes in the strengths of synaptic contacts. Here, we review how the rules of synaptic plasticity change during development of the brain, from birth to independence. We focus on the changes that occur at the postsynaptic side of excitatory glutamatergic synapses in the rodent hippocampus and neocortex. First we summarize the current data on the structure of synapses and the developmental expression patterns of the key molecular players of synaptic plasticity, N-methyl-d-aspartate (NMDA) and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors, as well as pivotal kinases (Ca(2+)/calmodulin-dependent protein kinase II, protein kinase A, protein kinase C) and phosphatases (PP1, PP2A, PP2B). In the second part we relate these findings to important characteristics of the emerging network. We argue that the concerted and gradual shifts in the usage of plasticity molecules comply with the changing need for (re)wiring neuronal circuits.
Collapse
Affiliation(s)
- Christian Lohmann
- C. Lohmann and H. W. Kessels: The Netherlands Institute for Neuroscience, the Royal Academy of Arts and Sciences, Meibergdreef 47, 1105 BA, Amsterdam, the Netherlands. Emails: ,
| | | |
Collapse
|
40
|
Li X, Overton IM, Baines RA, Keegan LP, O'Connell MA. The ADAR RNA editing enzyme controls neuronal excitability in Drosophila melanogaster. Nucleic Acids Res 2013; 42:1139-51. [PMID: 24137011 PMCID: PMC3902911 DOI: 10.1093/nar/gkt909] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
RNA editing by deamination of specific adenosine bases to inosines during pre-mRNA processing generates edited isoforms of proteins. Recoding RNA editing is more widespread in Drosophila than in vertebrates. Editing levels rise strongly at metamorphosis, and Adar5G1 null mutant flies lack editing events in hundreds of CNS transcripts; mutant flies have reduced viability, severely defective locomotion and age-dependent neurodegeneration. On the other hand, overexpressing an adult dADAR isoform with high enzymatic activity ubiquitously during larval and pupal stages is lethal. Advantage was taken of this to screen for genetic modifiers; Adar overexpression lethality is rescued by reduced dosage of the Rdl (Resistant to dieldrin), gene encoding a subunit of inhibitory GABA receptors. Reduced dosage of the Gad1 gene encoding the GABA synthetase also rescues Adar overexpression lethality. Drosophila Adar5G1 mutant phenotypes are ameliorated by feeding GABA modulators. We demonstrate that neuronal excitability is linked to dADAR expression levels in individual neurons; Adar-overexpressing larval motor neurons show reduced excitability whereas Adar5G1 null mutant or targeted Adar knockdown motor neurons exhibit increased excitability. GABA inhibitory signalling is impaired in human epileptic and autistic conditions, and vertebrate ADARs may have a relevant evolutionarily conserved control over neuronal excitability.
Collapse
Affiliation(s)
- Xianghua Li
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine at the University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, Scotland, UK, Faculty of Life Sciences, University of Manchester, Oxford Road, Manchester M13 9PT, UK and Department of Molecular Biosciences, The Wenner Gren Institute, Stockholm University, Svante Arrhenius väg 20C, 106 91 Stockholm, Sweden
| | | | | | | | | |
Collapse
|
41
|
Lüscher C. Cocaine-evoked synaptic plasticity of excitatory transmission in the ventral tegmental area. Cold Spring Harb Perspect Med 2013; 3:a012013. [PMID: 23637310 DOI: 10.1101/cshperspect.a012013] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Cocaine leads to a strong euphoria, which is at the origin of its recreational use. Past the acute effects, the drug leaves traces in the brain that persist long after it has been cleared from the body. These traces eventually shape behavior such that drug use may become compulsive and addiction develops. Here we discuss cocaine-evoked synaptic plasticity of glutamatergic transmission onto dopamine (DA) neurons of the ventral tegmental area (VTA) as one of the earliest traces after a first injection of cocaine. We review the literature that has examined the induction requirements as well as the expression mechanism of this form of plasticity and ask the question about its functional significance.
Collapse
Affiliation(s)
- Christian Lüscher
- Department of Basic Neurosciences, University of Geneva, Geneva, Switzerland.
| |
Collapse
|
42
|
Russo I, Bonini D, Via LL, Barlati S, Barbon A. AMPA receptor properties are modulated in the early stages following pilocarpine-induced status epilepticus. Neuromolecular Med 2013; 15:324-38. [PMID: 23494293 DOI: 10.1007/s12017-013-8221-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2012] [Accepted: 02/08/2013] [Indexed: 01/28/2023]
Abstract
Glutamate over-activation and the consequent neuronal excitotoxicity have been identified as crucial players in brain dysfunctions such as status epilepticus (SE). Owing to the central function of 2-amino-3-(hydroxyl-5-methylisoxazole-4-yl) propionic acid receptors (AMPARs) in fast excitatory neurotransmission, these receptors have been recognized to play a prominent role in the development and generation of epileptic seizure. This study was undertaken to investigate both the early changes that affect glutamatergic neurons in the rat cerebral cortex and hippocampus and the level and channel properties of AMPARs in response to SE. The results obtained after 3 h of pilocarpine (PILO)-induced SE showed a disorganization of glutamatergic neurons in the CA3 and a thinner neuronal cell layer in the dentate gyrus (DG) region as compared with controls. A significant increase in AMPAR GluA2 protein expression, a decrease in GluA1, GluA3, and GluA4 expression, and a reduction in the phosphorylation of Ser831-GluA1 and Ser880-GluA2 were also observed. In addition, we report a downregulation of R/G editing levels and of Flip splicing isoforms, with a prominent effect on the hippocampus of PILO-treated rats. Our results suggest the presence of an attenuation of AMPARs' post-synaptic excitatory response to glutamate after PILO treatment, thus conferring neuronal protection from the excitotoxic conditions observed in the SE. This study suggests a role for AMPARs in alterations of the glutamatergic pathway during the onset and early progression of epilepsy, thus indicating additional targets for potential therapeutic interventions.
Collapse
Affiliation(s)
- Isabella Russo
- Division of Biology and Genetics, Department of Biomedical Sciences and Biotechnology and National Institute of Neuroscience, University of Brescia, Viale Europa 11, 25123 Brescia, Italy
| | | | | | | | | |
Collapse
|
43
|
Casillas-Espinosa PM, Powell KL, O'Brien TJ. Regulators of synaptic transmission: roles in the pathogenesis and treatment of epilepsy. Epilepsia 2013; 53 Suppl 9:41-58. [PMID: 23216578 DOI: 10.1111/epi.12034] [Citation(s) in RCA: 103] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Synaptic transmission is the communication between a presynaptic and a postsynaptic neuron, and the subsequent processing of the signal. These processes are complex and highly regulated, reflecting their importance in normal brain functioning and homeostasis. Sustaining synaptic transmission depends on the continuing cycle of synaptic vesicle formation, release, and endocytosis, which requires proteins such as dynamin, syndapin, synapsin, and synaptic vesicle protein 2A. Synaptic transmission is regulated by diverse mechanisms, including presynaptic modulators of synaptic vesicle formation and release, postsynaptic receptors and signaling, and modulators of neurotransmission. Neurotransmitters released presynaptically can bind to their postsynaptic receptors, the inhibitory γ-aminobutyric acid (GABA)ergic receptors or the excitatory glutamate receptors. Once released, glutamate activates a variety of postsynaptic receptors including α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), N-methyl-D-aspartate (NMDA), kainate, and metabotropic receptors. The activation of the receptors triggers downstream signaling cascades generating a vast array of effects, which can be modulated by a numerous auxiliary regulatory subunits. Moreover, different neuropeptides such as neuropeptide Y, brain-derived neurotrophic factor (BDNF), somatostatin, ghrelin, and galanin, act as regulators of diverse synaptic functions and along with the classic neurotransmitters. Abnormalities in the regulation of synaptic transmission play a critical role in the pathogenesis of numerous brain diseases, including epilepsy. This review focuses on the different mechanisms involved in the regulation of synaptic transmission, which may play a role in the pathogenesis of epilepsy: the presynaptic modulators of synaptic vesicle formation and release, postsynaptic receptors, and modulators of neurotransmission, including the mechanism by which drugs can modulate the frequency and severity of epileptic seizures.
Collapse
Affiliation(s)
- Pablo M Casillas-Espinosa
- The Departments of Medicine and Neurology, The Royal Melbourne Hospital, The Melbourne Brain Centre, The University of Melbourne, Parkville, Victoria, Australia
| | | | | |
Collapse
|
44
|
Lanore F, Labrousse VF, Szabo Z, Normand E, Blanchet C, Mulle C. Deficits in morphofunctional maturation of hippocampal mossy fiber synapses in a mouse model of intellectual disability. J Neurosci 2012; 32:17882-93. [PMID: 23223307 PMCID: PMC6621665 DOI: 10.1523/jneurosci.2049-12.2012] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2012] [Revised: 10/16/2012] [Accepted: 10/18/2012] [Indexed: 01/04/2023] Open
Abstract
The grik2 gene, coding for the kainate receptor subunit GluK2 (formerly GluR6), is associated with autism spectrum disorders and intellectual disability. Here, we tested the hypothesis that GluK2 could play a role in the appropriate maturation of synaptic circuits involved in learning and memory. We show that both the functional and morphological maturation of hippocampal mossy fiber to CA3 pyramidal cell (mf-CA3) synapses is delayed in mice deficient for the GluK2 subunit (GluK2⁻/⁻). In GluK2⁻/⁻ mice this deficit is manifested by a transient reduction in the amplitude of AMPA-EPSCs at a critical time point of postnatal development, whereas the NMDA component is spared. By combining multiple probability peak fluctuation analysis and immunohistochemistry, we have provided evidence that the decreased amplitude reflects a decrease in the quantal size per mf-CA3 synapse and in the number of active synaptic sites. Furthermore, we analyzed the time course of structural maturation of CA3 synapses by confocal imaging of YFP-expressing cells followed by tridimensional (3D) anatomical reconstruction of thorny excrescences and presynaptic boutons. We show that major changes in synaptic structures occur subsequently to the sharp increase in synaptic transmission, and more importantly that the course of structural maturation of synaptic elements is impaired in GluK2⁻/⁻ mice. This study highlights how a mutation in a gene linked to intellectual disability in the human may lead to a transient reduction of synaptic strength during postnatal development, impacting on the proper formation of neural circuits linked to memory.
Collapse
MESH Headings
- Animals
- Animals, Outbred Strains
- Disease Models, Animal
- Excitatory Amino Acid Agonists/pharmacology
- Excitatory Postsynaptic Potentials/genetics
- Excitatory Postsynaptic Potentials/physiology
- Intellectual Disability/genetics
- Intellectual Disability/metabolism
- Intellectual Disability/pathology
- Intellectual Disability/physiopathology
- Mice
- Mice, Knockout
- Mossy Fibers, Hippocampal/drug effects
- Mossy Fibers, Hippocampal/growth & development
- Mossy Fibers, Hippocampal/pathology
- Mossy Fibers, Hippocampal/physiopathology
- N-Methylaspartate/pharmacology
- Presynaptic Terminals/pathology
- Receptors, Kainic Acid/agonists
- Receptors, Kainic Acid/genetics
- Receptors, Kainic Acid/physiology
- Synapses/pathology
- alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid/pharmacology
- GluK2 Kainate Receptor
Collapse
Affiliation(s)
- Frederic Lanore
- Interdisciplinary Institute for Neuroscience, University of Bordeaux, and
- CNRS UMR 5297, F-33000 Bordeaux, France
| | - Virginie F. Labrousse
- Interdisciplinary Institute for Neuroscience, University of Bordeaux, and
- CNRS UMR 5297, F-33000 Bordeaux, France
| | - Zsolt Szabo
- Interdisciplinary Institute for Neuroscience, University of Bordeaux, and
- CNRS UMR 5297, F-33000 Bordeaux, France
| | - Elisabeth Normand
- Interdisciplinary Institute for Neuroscience, University of Bordeaux, and
- CNRS UMR 5297, F-33000 Bordeaux, France
| | - Christophe Blanchet
- Interdisciplinary Institute for Neuroscience, University of Bordeaux, and
- CNRS UMR 5297, F-33000 Bordeaux, France
| | - Christophe Mulle
- Interdisciplinary Institute for Neuroscience, University of Bordeaux, and
- CNRS UMR 5297, F-33000 Bordeaux, France
| |
Collapse
|
45
|
Ion Channels. Mol Pharmacol 2012. [DOI: 10.1002/9781118451908.ch4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
|
46
|
Balik A, Penn AC, Nemoda Z, Greger IH. Activity-regulated RNA editing in select neuronal subfields in hippocampus. Nucleic Acids Res 2012; 41:1124-34. [PMID: 23172290 PMCID: PMC3553983 DOI: 10.1093/nar/gks1045] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
RNA editing by adensosine deaminases is a widespread mechanism to alter genetic information in metazoa. In addition to modifications in non-coding regions, editing contributes to diversification of protein function, in analogy to alternative splicing. However, although splicing programs respond to external signals, facilitating fine tuning and homeostasis of cellular functions, a similar regulation has not been described for RNA editing. Here, we show that the AMPA receptor R/G editing site is dynamically regulated in the hippocampus in response to activity. These changes are bi-directional, reversible and correlate with levels of the editase Adar2. This regulation is observed in the CA1 hippocampal subfield but not in CA3 and is thus subfield/celltype-specific. Moreover, alternative splicing of the flip/flop cassette downstream of the R/G site is closely linked to the editing state, which is regulated by Ca2+. Our data show that A-to-I RNA editing has the capacity to tune protein function in response to external stimuli.
Collapse
Affiliation(s)
- Ales Balik
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, CB2 0QH, UK
| | | | | | | |
Collapse
|
47
|
La Via L, Bonini D, Russo I, Orlandi C, Barlati S, Barbon A. Modulation of dendritic AMPA receptor mRNA trafficking by RNA splicing and editing. Nucleic Acids Res 2012; 41:617-31. [PMID: 23166306 PMCID: PMC3592400 DOI: 10.1093/nar/gks1223] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
RNA trafficking to dendrites and local translation are crucial processes for superior neuronal functions. To date, several α-amino-3-hydroxy-5-methyl-4-isoxazolepropionate receptor (AMPAR) mRNAs have been detected in dendrites and are subject to local protein synthesis. Here, we report the presence of all AMPAR GluA1-4 mRNAs in hippocampal and cortical rat synaptic spines by synaptoneurosomes analysis. In particular, we showed that dendritic AMPAR mRNAs are present in the Flip versions in the cortex and hippocampus. To further confirm these data, we demonstrate, using in situ hybridization, the dendritic localization of the GluA2 Flip isoform in vitro and in vivo, whereas the Flop variant is restricted mainly to the soma. In addition, we report that dendritic AMPA mRNAs are edited at low levels at their R/G sites; this result was also supported with transfection experiments using chimeric GluA2 DNA vectors, showing that transcripts carrying an unedited nucleotide at the R/G site, in combination with the Flip exon, are more efficiently targeted to dendrites when compared with the edited-Flip versions. Our data show that post-transcriptional regulations such as RNA splicing, editing and trafficking might be mutually coordinated and that the localization of different AMPAR isoforms in dendrites might play a functional role in the regulation of neuronal transmission.
Collapse
Affiliation(s)
- Luca La Via
- Department of Biomedical Sciences and Biotechnology, Division of Biology and Genetics, National Institute of Neuroscience, University of Brescia, Viale Europa 11, Brescia 25123, Italy
| | | | | | | | | | | |
Collapse
|
48
|
Czöndör K, Thoumine O. Biophysical mechanisms regulating AMPA receptor accumulation at synapses. Brain Res Bull 2012; 93:57-68. [PMID: 23174308 DOI: 10.1016/j.brainresbull.2012.11.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Accepted: 11/05/2012] [Indexed: 11/25/2022]
Abstract
Controlling the number of AMPA receptors at synapses is fundamental for fast synaptic transmission as well as for long term adaptations in synaptic strength. In this review, we examine the biophysical mechanisms implicated in regulating AMPAR levels at the cell surface and at synapses. We first describe the structure and function of AMPARs, as well as their interactions with various proteins regulating their traffic and function. Second we review the vesicular trafficking mechanism involving exocytosis and endocytosis, by which AMPARs reach the cell surface and are internalized, respectively. Third, we examine the properties of lateral diffusion of AMPARs and their trapping at post-synaptic densities. Finally, we discuss how these two parallel mechanisms are integrated in time and space to control changes in synaptic AMPAR levels in response to plasticity protocols. This review highlights the important role of the extra-synaptic AMPAR pool, which makes an obligatory link between vesicular trafficking and trapping or release at synapses.
Collapse
|
49
|
Steinman RA, Yang Q, Gasparetto M, Robinson LJ, Liu X, Lenzner DE, Hou J, Smith C, Wang Q. Deletion of the RNA-editing enzyme ADAR1 causes regression of established chronic myelogenous leukemia in mice. Int J Cancer 2012; 132:1741-50. [PMID: 22987615 DOI: 10.1002/ijc.27851] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Accepted: 08/24/2012] [Indexed: 01/26/2023]
Abstract
Patients with chronic myelogenous leukemia (CML) respond well to tyrosine kinase inhibitors (TKIs) of the Bcr-Abl oncoprotein. However, intolerance and resistance to these agents remains a challenge, and TKIs are unable to eradicate rare leukemia-initiating cells. Leukemia treatment would benefit from a better understanding of molecular signals that are necessary for the survival of leukemia-initiating cells but dispensable for normal hematopoietic stem cells. Leukemia-initiating cells in CML can arise from myeloid progenitor cells, a population that we have reported in normal hematopoiesis to depend on the RNA-editing enzyme adenosine deaminase acting on RNA-1 (ADAR1). We now report that Bcr-Abl transformed leukemic cells were ADAR1-dependent in a conditional ADAR1 knockout mouse model. ADAR1 deletion reversed leukocytosis and splenomegaly, and preferentially depleted primitive Lin-Sca+Kit+ (LSK) leukemic cells but not LSK cells lacking the leukemic oncoprotein. ADAR1 deletion ultimately normalized the peripheral white blood count, eliminating leukemic cells as assessed by PCR. These results uncover a novel requirement for ADAR1 in myeloid leukemic cells and indicate that ADAR1 may comprise a new molecular target for CML-directed therapeutics.
Collapse
Affiliation(s)
- Richard A Steinman
- Department of Medicine, Division of Hematology and Oncology, University of Pittsburgh, Pittsburgh, PA, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
50
|
Hayashi M, Suzuki T. Dyschromatosis symmetrica hereditaria. J Dermatol 2012; 40:336-43. [DOI: 10.1111/j.1346-8138.2012.01661.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2012] [Accepted: 07/10/2012] [Indexed: 11/28/2022]
Affiliation(s)
- Masahiro Hayashi
- Department of Dermatology; Yamagata University Faculty of Medicine; Yamagata; Japan
| | - Tamio Suzuki
- Department of Dermatology; Yamagata University Faculty of Medicine; Yamagata; Japan
| |
Collapse
|