1
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Green JR, Mahalingaiah PKS, Gopalakrishnan SM, Liguori MJ, Mittelstadt SW, Blomme EAG, Van Vleet TR. Off-target pharmacological activity at various kinases: Potential functional and pathological side effects. J Pharmacol Toxicol Methods 2023; 123:107468. [PMID: 37553032 DOI: 10.1016/j.vascn.2023.107468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 06/16/2023] [Accepted: 08/01/2023] [Indexed: 08/10/2023]
Abstract
In drug discovery, during the lead optimization and candidate characterization stages, novel small molecules are frequently evaluated in a battery of in vitro pharmacology assays to identify potential unintended, off-target interactions with various receptors, transporters, ion channels, and enzymes, including kinases. Furthermore, these screening panels may also provide utility at later stages of development to provide a mechanistic understanding of unexpected safety findings. Here, we present a compendium of the most likely functional and pathological outcomes associated with interaction(s) to a panel of 95 kinases based on an extensive curation of the scientific literature. This panel of kinases was designed by AbbVie based on safety-related data extracted from the literature, as well as from over 20 years of institutional knowledge generated from discovery efforts. For each kinase, the scientific literature was reviewed using online databases and the most often reported functional and pathological effects were summarized. This work should serve as a practical guide for small molecule drug discovery scientists and clinical investigators to predict and/or interpret adverse effects related to pharmacological interactions with these kinases.
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Affiliation(s)
- Jonathon R Green
- Departments of Preclinical Safety, AbbVie, 1 North Waukegan Road, North Chicago, IL 60064, United States.
| | | | - Sujatha M Gopalakrishnan
- Drug Discovery Science and Technology, AbbVie, 1 North Waukegan Road, North Chicago, IL 60064, United States
| | - Michael J Liguori
- Departments of Preclinical Safety, AbbVie, 1 North Waukegan Road, North Chicago, IL 60064, United States
| | - Scott W Mittelstadt
- Departments of Preclinical Safety, AbbVie, 1 North Waukegan Road, North Chicago, IL 60064, United States
| | - Eric A G Blomme
- Departments of Preclinical Safety, AbbVie, 1 North Waukegan Road, North Chicago, IL 60064, United States
| | - Terry R Van Vleet
- Departments of Preclinical Safety, AbbVie, 1 North Waukegan Road, North Chicago, IL 60064, United States
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2
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Wilson BAP, Li N, Martinez Fiesco JA, Dalilian M, Wang D, Smith EA, Wamiru A, Shah R, Goncharova EI, Beutler JA, Grkovic T, Zhang P, O’Keefe BR. Biochemical Discovery, Intracellular Evaluation, and Crystallographic Characterization of Synthetic and Natural Product Adenosine 3',5'-Cyclic Monophosphate-Dependent Protein Kinase A (PKA) Inhibitors. ACS Pharmacol Transl Sci 2023; 6:633-650. [PMID: 37082750 PMCID: PMC10111623 DOI: 10.1021/acsptsci.3c00010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Indexed: 04/22/2023]
Abstract
The recent demonstration that adenosine 3',5'-cyclic monophosphate (cAMP)-dependent protein kinase A (PKA) plays an oncogenic role in a number of important cancers has led to a renaissance in drug development interest targeting this kinase. We therefore have established a suite of biochemical, cell-based, and structural biology assays for identifying and evaluating new pharmacophores for PKA inhibition. This discovery process started with a 384-well high-throughput screen of more than 200,000 substances, including fractionated natural product extracts. Identified active compounds were further prioritized in biochemical, biophysical, and cell-based assays. Priority lead compounds were assessed in detail to fully characterize several previously unrecognized PKA pharmacophores including the generation of new X-ray crystallography structures demonstrating unique interactions between PKA and bound inhibitor molecules.
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Affiliation(s)
- Brice A. P. Wilson
- Molecular
Targets Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Ning Li
- Center
for Structural Biology, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Juliana A. Martinez Fiesco
- Center
for Structural Biology, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Masoumeh Dalilian
- Molecular
Targets Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
- Basic
Science Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, United States
| | - Dongdong Wang
- Molecular
Targets Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Emily A. Smith
- Molecular
Targets Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
- Basic
Science Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, United States
| | - Antony Wamiru
- Molecular
Targets Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
- Basic
Science Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland 21702, United States
| | - Rohan Shah
- Molecular
Targets Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Ekaterina I. Goncharova
- Molecular
Targets Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
- Advanced
Biomedical Computational Science, Frederick
National Laboratory for Cancer Research, Frederick, Maryland 21702, United States
| | - John A. Beutler
- Molecular
Targets Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Tanja Grkovic
- Molecular
Targets Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
- Natural
Products Branch, Developmental Therapeutics Program, Division of Cancer
Treatment and Diagnosis, National Cancer
Institute, Frederick, Maryland 21702, United States
| | - Ping Zhang
- Center
for Structural Biology, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
| | - Barry R. O’Keefe
- Molecular
Targets Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702, United States
- Natural
Products Branch, Developmental Therapeutics Program, Division of Cancer
Treatment and Diagnosis, National Cancer
Institute, Frederick, Maryland 21702, United States
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3
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Timmermann A, Tascio D, Jabs R, Boehlen A, Domingos C, Skubal M, Huang W, Kirchhoff F, Henneberger C, Bilkei-Gorzo A, Seifert G, Steinhäuser C. Dysfunction of NG2 glial cells affects neuronal plasticity and behavior. Glia 2023; 71:1481-1501. [PMID: 36802096 DOI: 10.1002/glia.24352] [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: 12/01/2022] [Revised: 01/18/2023] [Accepted: 01/19/2023] [Indexed: 02/20/2023]
Abstract
NG2 glia represents a distinct type of macroglial cells in the CNS and is unique among glia because they receive synaptic input from neurons. They are abundantly present in white and gray matter. While the majority of white matter NG2 glia differentiates into oligodendrocytes, the physiological impact of gray matter NG2 glia and their synaptic input are still ill defined. Here, we asked whether dysfunctional NG2 glia affect neuronal signaling and behavior. We generated mice with inducible deletion of the K+ channel Kir4.1 in NG2 glia and performed comparative electrophysiological, immunohistochemical, molecular and behavioral analyses. Kir4.1 was deleted at postnatal day 23-26 (recombination efficiency about 75%) and mice were investigated 3-8 weeks later. Notably, these mice with dysfunctional NG2 glia demonstrated improved spatial memory as revealed by testing new object location recognition while working and social memory remained unaffected. Focussing on the hippocampus, we found that loss of Kir4.1 potentiated synaptic depolarizations of NG2 glia and stimulated the expression of myelin basic protein while proliferation and differentiation of hippocampal NG2 glia remained largely unaffected. Mice with targeted deletion of the K+ channel in NG2 glia showed impaired long-term potentiation at CA3-CA1 synapses, which could be fully rescued by extracellular application of a TrkB receptor agonist. Our data demonstrate that proper NG2 glia function is important for normal brain function and behavior.
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Affiliation(s)
- Aline Timmermann
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Dario Tascio
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Ronald Jabs
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Anne Boehlen
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Catia Domingos
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Magdalena Skubal
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Wenhui Huang
- Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, Homburg, Germany
| | - Frank Kirchhoff
- Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, Homburg, Germany
| | - Christian Henneberger
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany.,German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.,Institute of Neurology, University College London, London, UK
| | - Andras Bilkei-Gorzo
- Institute of Molecular Psychiatry, Medical Faculty, University of Bonn, Bonn, Germany
| | - Gerald Seifert
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Christian Steinhäuser
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
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4
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Wang B, Zhao M, Su Z, Jin B, Yang X, Zhang C, Guo B, Li J, Hong W, Liu J, Zhao Y, Hou Y, Lai F, Zhang W, Qin L, Zhang W, Luo J, Zheng R. RIIβ-PKA in GABAergic Neurons of Dorsal Median Hypothalamus Governs White Adipose Browning. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2205173. [PMID: 36529950 PMCID: PMC9929258 DOI: 10.1002/advs.202205173] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 11/18/2022] [Indexed: 06/17/2023]
Abstract
The RIIβ subunit of cAMP-dependent protein kinase A (PKA) is expressed in the brain and adipose tissue. RIIβ-knockout mice show leanness and increased UCP1 in brown adipose tissue. The authors have previously reported that RIIβ reexpression in hypothalamic GABAergic neurons rescues the leanness. However, whether white adipose tissue (WAT) browning contributes to the leanness and whether RIIβ-PKA in these neurons governs WAT browning are unknown. Here, this work reports that RIIβ-KO mice exhibit a robust WAT browning. RIIβ reexpression in dorsal median hypothalamic GABAergic neurons (DMH GABAergic neurons) abrogates WAT browning. Single-cell sequencing, transcriptome sequencing, and electrophysiological studies show increased GABAergic activity in DMH GABAergic neurons of RIIβ-KO mice. Activation of DMH GABAergic neurons or inhibition of PKA in these neurons elicits WAT browning and thus lowers body weight. These findings reveal that RIIβ-PKA in DMH GABAergic neurons regulates WAT browning. Targeting RIIβ-PKA in DMH GABAergic neurons may offer a clinically useful way to promote WAT browning for treating obesity and other metabolic disorders.
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Affiliation(s)
- Bingwei Wang
- Department of AnatomyHistology and EmbryologySchool of Basic Medical SciencesPeking UniversityBeijing100191P. R. China
| | - Miao Zhao
- Department of AnatomyHistology and EmbryologySchool of Basic Medical SciencesPeking UniversityBeijing100191P. R. China
| | - Zhijie Su
- Department of AnatomyHistology and EmbryologySchool of Basic Medical SciencesPeking UniversityBeijing100191P. R. China
| | - Baohua Jin
- Department of PharmacologyInstitution of Chinese Integrative MedicineHebei Medical UniversityShijiazhuang050017P. R. China
| | - Xiaoning Yang
- Department of AnatomyHistology and EmbryologySchool of Basic Medical SciencesPeking UniversityBeijing100191P. R. China
| | - Chenyu Zhang
- Department of AnatomyHistology and EmbryologySchool of Basic Medical SciencesPeking UniversityBeijing100191P. R. China
| | - Bingbing Guo
- Department of AnatomyHistology and EmbryologySchool of Basic Medical SciencesPeking UniversityBeijing100191P. R. China
| | - Jiebo Li
- Institute of Medical PhotonicsBeijing Advanced Innovation Center for Biomedical EngineeringSchool of Biological Science and Medical EngineeringBeihang UniversityBeijing100191P. R. China
| | - Weili Hong
- Institute of Medical PhotonicsBeijing Advanced Innovation Center for Biomedical EngineeringSchool of Biological Science and Medical EngineeringBeihang UniversityBeijing100191P. R. China
| | - Jiarui Liu
- Department of AnatomyHistology and EmbryologySchool of Basic Medical SciencesPeking UniversityBeijing100191P. R. China
| | - Yun Zhao
- Department of AnatomyHistology and EmbryologySchool of Basic Medical SciencesPeking UniversityBeijing100191P. R. China
| | - Yujia Hou
- Department of AnatomyHistology and EmbryologySchool of Basic Medical SciencesPeking UniversityBeijing100191P. R. China
| | - Futing Lai
- Department of AnatomyHistology and EmbryologySchool of Basic Medical SciencesPeking UniversityBeijing100191P. R. China
| | - Wei Zhang
- Department of PharmacologyInstitution of Chinese Integrative MedicineHebei Medical UniversityShijiazhuang050017P. R. China
| | - Lihua Qin
- Department of AnatomyHistology and EmbryologySchool of Basic Medical SciencesPeking UniversityBeijing100191P. R. China
| | - Weiguang Zhang
- Department of AnatomyHistology and EmbryologySchool of Basic Medical SciencesPeking UniversityBeijing100191P. R. China
| | - Jianyuan Luo
- Department of Medical GeneticsSchool of Basic Medical SciencesPeking UniversityBeijing100191P. R. China
- Department of Biochemistry and Molecular BiologySchool of Basic Medical SciencesPeking UniversityBeijing100191P. R. China
| | - Ruimao Zheng
- Department of AnatomyHistology and EmbryologySchool of Basic Medical SciencesPeking UniversityBeijing100191P. R. China
- Neuroscience Research InstituteKey Laboratory for Neuroscience of Ministry of EducationKey Laboratory for Neuroscience of National Health Commission of the People's Republic of ChinaPeking UniversityBeijing100191P. R. China
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5
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PKA Cβ: a forgotten catalytic subunit of cAMP-dependent protein kinase opens new windows for PKA signaling and disease pathologies. Biochem J 2021; 478:2101-2119. [PMID: 34115095 DOI: 10.1042/bcj20200867] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 04/30/2021] [Accepted: 05/05/2021] [Indexed: 12/17/2022]
Abstract
3',5'-cyclic adenosine monophosphate (cAMP) dependent protein kinase or protein kinase A (PKA) has served as a prototype for the large family of protein kinases that are crucially important for signal transduction in eukaryotic cells. The PKA catalytic subunits are encoded by the two major genes PRKACA and PRKACB, respectively. The PRKACA gene encodes two known splice variants, the ubiquitously expressed Cα1 and the sperm-specifically expressed Cα2. In contrast, the PRKACB gene encodes several splice variants expressed in a highly cell and tissue-specific manner. The Cβ proteins are called Cβ1, Cβ2, Cβ3, Cβ4 and so-called abc variants of Cβ3 and Cβ4. Whereas Cβ1 is ubiquitously expressed, Cβ2 is enriched in immune cells and the Cβ3, Cβ4 and their abc variants are solely expressed in neuronal cells. All Cα and Cβ splice variants share a kinase-conserved catalytic core and a C-terminal tail encoded by exons 2 through 10 in the PRKACA and PRKACB genes, respectively. All Cα and Cβ splice variants with the exception of Cα1 and Cβ1 are hyper-variable at the N-terminus. Here, we will discuss how the PRKACA and PRKACB genes have developed as paralogs that encode distinct and functionally non-redundant proteins. The fact that Cα and Cβ splice variant mutations are associated with numerous diseases further opens new windows for PKA-induced disease pathologies.
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6
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Baro Graf C, Ritagliati C, Stival C, Luque GM, Gentile I, Buffone MG, Krapf D. Everything you ever wanted to know about PKA regulation and its involvement in mammalian sperm capacitation. Mol Cell Endocrinol 2020; 518:110992. [PMID: 32853743 DOI: 10.1016/j.mce.2020.110992] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 08/11/2020] [Accepted: 08/12/2020] [Indexed: 12/29/2022]
Abstract
The 3', 5'-cyclic adenosine monophosphate (cAMP) dependent protein kinase (PKA) is a tetrameric holoenzyme comprising a set of two regulatory subunits (PKA-R) and two catalytic (PKA-C) subunits. The PKA-R subunits act as sensors of cAMP and allow PKA-C activity. One of the first signaling events observed during mammalian sperm capacitation is PKA activation. Thus, understanding how PKA activity is restricted in space and time is crucial to decipher the critical steps of sperm capacitation. It is widely accepted that PKA specificity depends on several levels of regulation. Anchoring proteins play a pivotal role in achieving proper localization signaling, subcellular targeting and cAMP microdomains. These multi-factorial regulation steps are necessary for a precise spatio-temporal activation of PKA. Here we discuss recent understanding of regulatory mechanisms of PKA in mammalian sperm, such as post-translational modifications, in the context of its role as the master orchestrator of molecular events conducive to capacitation.
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Affiliation(s)
- Carolina Baro Graf
- Laboratory of Cell Signal Transduction Networks, Instituto de Biología Molecular y Celular de Rosario (IBR), CONICET-UNR, Rosario, Argentina; Laboratorio de Medicina Reproductiva (LMR), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Carla Ritagliati
- Laboratory of Cell Signal Transduction Networks, Instituto de Biología Molecular y Celular de Rosario (IBR), CONICET-UNR, Rosario, Argentina
| | - Cintia Stival
- Laboratory of Cell Signal Transduction Networks, Instituto de Biología Molecular y Celular de Rosario (IBR), CONICET-UNR, Rosario, Argentina
| | - Guillermina M Luque
- Laboratory of Cellular and Molecular Reproductive Biology, Instituto de Biología y Medicina Experimental (IBYME), CONICET, Buenos Aires, Argentina
| | - Iñaki Gentile
- Laboratory of Cell Signal Transduction Networks, Instituto de Biología Molecular y Celular de Rosario (IBR), CONICET-UNR, Rosario, Argentina
| | - Mariano G Buffone
- Laboratory of Cellular and Molecular Reproductive Biology, Instituto de Biología y Medicina Experimental (IBYME), CONICET, Buenos Aires, Argentina
| | - Dario Krapf
- Laboratory of Cell Signal Transduction Networks, Instituto de Biología Molecular y Celular de Rosario (IBR), CONICET-UNR, Rosario, Argentina; Laboratorio de Medicina Reproductiva (LMR), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina.
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7
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Kelly MP, Heckman PRA, Havekes R. Genetic manipulation of cyclic nucleotide signaling during hippocampal neuroplasticity and memory formation. Prog Neurobiol 2020; 190:101799. [PMID: 32360536 DOI: 10.1016/j.pneurobio.2020.101799] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 03/14/2020] [Accepted: 03/26/2020] [Indexed: 12/12/2022]
Abstract
Decades of research have underscored the importance of cyclic nucleotide signaling in memory formation and synaptic plasticity. In recent years, several new genetic techniques have expanded the neuroscience toolbox, allowing researchers to measure and modulate cyclic nucleotide gradients with high spatiotemporal resolution. Here, we will provide an overview of studies using genetic approaches to interrogate the role cyclic nucleotide signaling plays in hippocampus-dependent memory processes and synaptic plasticity. Particular attention is given to genetic techniques that measure real-time changes in cyclic nucleotide levels as well as newly-developed genetic strategies to transiently manipulate cyclic nucleotide signaling in a subcellular compartment-specific manner with high temporal resolution.
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Affiliation(s)
- Michy P Kelly
- Department of Pharmacology, Physiology & Neuroscience, University of South Carolina School of Medicine, 6439 Garners Ferry Rd, VA Bldg1, 3(rd) Fl, D-12, Columbia, 29209, SC, USA.
| | - Pim R A Heckman
- Neurobiology Expertise Group, Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, Nijenborgh 7, 9747 AG Groningen, the Netherlands.
| | - Robbert Havekes
- Neurobiology Expertise Group, Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, Nijenborgh 7, 9747 AG Groningen, the Netherlands.
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8
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Argyrousi EK, Heckman PRA, Prickaerts J. Role of cyclic nucleotides and their downstream signaling cascades in memory function: Being at the right time at the right spot. Neurosci Biobehav Rev 2020; 113:12-38. [PMID: 32044374 DOI: 10.1016/j.neubiorev.2020.02.004] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 01/23/2020] [Accepted: 02/03/2020] [Indexed: 01/23/2023]
Abstract
A plethora of studies indicate the important role of cAMP and cGMP cascades in neuronal plasticity and memory function. As a result, altered cyclic nucleotide signaling has been implicated in the pathophysiology of mnemonic dysfunction encountered in several diseases. In the present review we provide a wide overview of studies regarding the involvement of cyclic nucleotides, as well as their upstream and downstream molecules, in physiological and pathological mnemonic processes. Next, we discuss the regulation of the intracellular concentration of cyclic nucleotides via phosphodiesterases, the enzymes that degrade cAMP and/or cGMP, and via A-kinase-anchoring proteins that refine signal compartmentalization of cAMP signaling. We also provide an overview of the available data pointing to the existence of specific time windows in cyclic nucleotide signaling during neuroplasticity and memory formation and the significance to target these specific time phases for improving memory formation. Finally, we highlight the importance of emerging imaging tools like Förster resonance energy transfer imaging and optogenetics in detecting, measuring and manipulating the action of cyclic nucleotide signaling cascades.
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Affiliation(s)
- Elentina K Argyrousi
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, 6200 MD, the Netherlands
| | - Pim R A Heckman
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, 6200 MD, the Netherlands
| | - Jos Prickaerts
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, 6200 MD, the Netherlands.
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9
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Khorasani A, Abbasnejad M, Esmaeili-Mahani S. Phytohormone abscisic acid ameliorates cognitive impairments in streptozotocin-induced rat model of Alzheimer's disease through PPARβ/δ and PKA signaling. Int J Neurosci 2019; 129:1053-1065. [PMID: 31215291 DOI: 10.1080/00207454.2019.1634067] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Aim: Alzheimer's disease (AD) is characterized by oxidative stress, neuroinflammation and progressive cognitive decline. Abscisic acid (ABA) is produced in a variety of mammalian tissues, including brain. It has anti-inflammatory and antioxidant effects and elicits a positive effect on spatial learning and memory performance. Here, the possible protective effect of ABA was evaluated in streptozotocin (STZ)-induced AD rat model which were injected intracerebroventriculary (i.c.v.) with STZ (3 mg/kg). Material and Methods: The STZ-treated animals received ABA (10 μg/rat, i.c.v.), ABA plus PPARβ/δ receptor antagonist (GSK0660, 80 nM/rat) or ABA plus selective inhibitor of PKA (KT5720, 0.5 μg/rat) for 14 d. Learning and memory were determined using Morris water maze (MWM) and passive avoidance (PA) tests. Results: The data showed that STZ produced a significant learning and memory deficit in both MWM and PA tests. ABA significantly prevented the learning and memory impairment in STZ-treated rats. However, ABA effects were blocked by GSK0660 and KT5720. Conclusion: The data indicated that ABA attenuates STZ-induced learning and memory impairment and PPAR-β/δ receptors and PKA signaling are involved, at least in part, in the ABA mechanism.
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Affiliation(s)
- Ali Khorasani
- Department of Biology, Faculty of Sciences, Shahid Bahonar University of Kerman , Kerman , Iran.,Laboratory of Molecular Neuroscience, Kerman Neuroscience Research Center (KNRC), Institute of neuropharmacology, Kerman University of Medical Sciences , Kerman , Iran
| | - Mehdi Abbasnejad
- Department of Biology, Faculty of Sciences, Shahid Bahonar University of Kerman , Kerman , Iran.,Laboratory of Molecular Neuroscience, Kerman Neuroscience Research Center (KNRC), Institute of neuropharmacology, Kerman University of Medical Sciences , Kerman , Iran
| | - Saeed Esmaeili-Mahani
- Department of Biology, Faculty of Sciences, Shahid Bahonar University of Kerman , Kerman , Iran.,Laboratory of Molecular Neuroscience, Kerman Neuroscience Research Center (KNRC), Institute of neuropharmacology, Kerman University of Medical Sciences , Kerman , Iran
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10
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Espiard S, Knape MJ, Bathon K, Assié G, Rizk-Rabin M, Faillot S, Luscap-Rondof W, Abid D, Guignat L, Calebiro D, Herberg FW, Stratakis CA, Bertherat J. Activating PRKACB somatic mutation in cortisol-producing adenomas. JCI Insight 2018; 3:98296. [PMID: 29669941 DOI: 10.1172/jci.insight.98296] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 03/20/2018] [Indexed: 12/13/2022] Open
Abstract
Mutations in the gene encoding the protein kinase A (PKA) catalytic subunit α have been found to be responsible for cortisol-producing adenomas (CPAs). In this study, we identified by whole-exome sequencing the somatic mutation p.S54L in the PRKACB gene, encoding the catalytic subunit β (Cβ) of PKA, in a CPA from a patient with severe Cushing syndrome. Bioluminescence resonance energy transfer and surface plasmon resonance assays revealed that the mutation hampers formation of type I holoenzymes and that these holoenzymes were highly sensitive to cAMP. PKA activity, measured both in cell lysates and with recombinant proteins, based on phosphorylation of a synthetic substrate, was higher under basal conditions for the mutant enzyme compared with the WT, while maximal activity was lower. These data suggest that at baseline the PRKACB p.S54L mutant drove the adenoma cells to higher cAMP signaling activity, probably contributing to their autonomous growth. Although the role of PRKACB in tumorigenesis has been suggested, we demonstrated for the first time to our knowledge that a PRKACB mutation can lead to an adrenal tumor. Moreover, this observation describes another mechanism of PKA pathway activation in CPAs and highlights the particular role of residue Ser54 for the function of PKA.
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Affiliation(s)
- Stéphanie Espiard
- Cochin Institute, Paris Descartes University, CNRS (UMR 8104)/Inserm (U1016), Paris, France.,Section on Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, Maryland, USA
| | - Matthias J Knape
- University of Kassel, Department of Biochemistry, Kassel, Germany
| | - Kerstin Bathon
- Institute of Pharmacology and Toxicology and Bio-Imaging Center/Rudolf Virchow Center, University of Würzburg, Würzburg, Germany
| | - Guillaume Assié
- Cochin Institute, Paris Descartes University, CNRS (UMR 8104)/Inserm (U1016), Paris, France.,Center for Rare Adrenal Diseases, Endocrinology Department, Cochin Hospital, Assistance Publique Hôpitaux de Paris, Paris, France
| | - Marthe Rizk-Rabin
- Cochin Institute, Paris Descartes University, CNRS (UMR 8104)/Inserm (U1016), Paris, France
| | - Simon Faillot
- Cochin Institute, Paris Descartes University, CNRS (UMR 8104)/Inserm (U1016), Paris, France
| | - Windy Luscap-Rondof
- Cochin Institute, Paris Descartes University, CNRS (UMR 8104)/Inserm (U1016), Paris, France
| | - Daniel Abid
- University of Kassel, Department of Biochemistry, Kassel, Germany
| | - Laurence Guignat
- Center for Rare Adrenal Diseases, Endocrinology Department, Cochin Hospital, Assistance Publique Hôpitaux de Paris, Paris, France
| | - Davide Calebiro
- Institute of Pharmacology and Toxicology and Bio-Imaging Center/Rudolf Virchow Center, University of Würzburg, Würzburg, Germany.,Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom.,Centre of Membrane Proteins and Receptors (COMPARE), Universities of Birmingham and Nottingham, United Kingdom
| | | | - Constantine A Stratakis
- Section on Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, Maryland, USA
| | - Jérôme Bertherat
- Cochin Institute, Paris Descartes University, CNRS (UMR 8104)/Inserm (U1016), Paris, France.,Center for Rare Adrenal Diseases, Endocrinology Department, Cochin Hospital, Assistance Publique Hôpitaux de Paris, Paris, France
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11
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Uddin R, Singh SM. Gene Network Construction from Microarray Data Identifies a Key Network Module and Several Candidate Hub Genes in Age-Associated Spatial Learning Impairment. Front Syst Neurosci 2017; 11:75. [PMID: 29066959 PMCID: PMC5641338 DOI: 10.3389/fnsys.2017.00075] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Accepted: 09/22/2017] [Indexed: 01/06/2023] Open
Abstract
As humans age many suffer from a decrease in normal brain functions including spatial learning impairments. This study aimed to better understand the molecular mechanisms in age-associated spatial learning impairment (ASLI). We used a mathematical modeling approach implemented in Weighted Gene Co-expression Network Analysis (WGCNA) to create and compare gene network models of young (learning unimpaired) and aged (predominantly learning impaired) brains from a set of exploratory datasets in rats in the context of ASLI. The major goal was to overcome some of the limitations previously observed in the traditional meta- and pathway analysis using these data, and identify novel ASLI related genes and their networks based on co-expression relationship of genes. This analysis identified a set of network modules in the young, each of which is highly enriched with genes functioning in broad but distinct GO functional categories or biological pathways. Interestingly, the analysis pointed to a single module that was highly enriched with genes functioning in “learning and memory” related functions and pathways. Subsequent differential network analysis of this “learning and memory” module in the aged (predominantly learning impaired) rats compared to the young learning unimpaired rats allowed us to identify a set of novel ASLI candidate hub genes. Some of these genes show significant repeatability in networks generated from independent young and aged validation datasets. These hub genes are highly co-expressed with other genes in the network, which not only show differential expression but also differential co-expression and differential connectivity across age and learning impairment. The known function of these hub genes indicate that they play key roles in critical pathways, including kinase and phosphatase signaling, in functions related to various ion channels, and in maintaining neuronal integrity relating to synaptic plasticity and memory formation. Taken together, they provide a new insight and generate new hypotheses into the molecular mechanisms responsible for age associated learning impairment, including spatial learning.
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Affiliation(s)
- Raihan Uddin
- Department of Biology, University of Western Ontario, London, ON, Canada
| | - Shiva M Singh
- Department of Biology, University of Western Ontario, London, ON, Canada
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12
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Moen LV, Sener Z, Volchenkov R, Svarstad AC, Eriksen AM, Holen HL, Skålhegg BS. Ablation of the Cβ2 subunit of PKA in immune cells leads to increased susceptibility to systemic inflammation in mice. Eur J Immunol 2017; 47:1880-1889. [PMID: 28837222 DOI: 10.1002/eji.201646809] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 06/30/2017] [Accepted: 08/14/2017] [Indexed: 11/06/2022]
Abstract
Protein kinase A (PKA) is a holoenzyme composed of a regulatory subunit dimer and two catalytic subunits and regulates numerous cellular functions including immune cell activity. There are two major catalytic subunit genes, PRKACA and PRKACB encoding the catalytic subunits Cα and Cβ. The PRKACB gene encodes several splice variants including Cβ2, which is enriched in T-, B- and natural killer cells. Cβ2 is significantly larger (46 kDa) than any other C splice variant. In this study we characterized mice ablated for the Cβ2 protein demonstrating a significantly reduced cAMP-induced catalytic activity of PKA in the spleenocytes, lymphocytes and thymocytes. We also observed a significantly increased number of CD62L-expressing CD4+ and CD8+ T cells in LNs, accompanied by increased susceptibility to systemic inflammation by the Cβ2 ablated mice. The latter was reflected in an elevated sensitivity to collagen-induced arthritis (CIA), as well as higher concentration of TNF-α and lower concentration of IL-10 in response to LPS challenges. We suggest a role of Cβ2 in regulating innate as well as adaptive immune sensitivity in vivo.
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Affiliation(s)
- Line Victoria Moen
- Department of Nutrition, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Zeynep Sener
- Department of Nutrition, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Roman Volchenkov
- Department of Nutrition, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway.,Rheumatech AS, Oslo, Norway
| | - Anja Camilla Svarstad
- Department of Nutrition, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Aud Marit Eriksen
- Department of Nutrition, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | | | - Bjørn S Skålhegg
- Department of Nutrition, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
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13
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Calcium-Permeable AMPA Receptors Mediate the Induction of the Protein Kinase A-Dependent Component of Long-Term Potentiation in the Hippocampus. J Neurosci 2016; 36:622-31. [PMID: 26758849 DOI: 10.1523/jneurosci.3625-15.2016] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED Two forms of NMDA receptor (NMDAR)-dependent long-term potentiation (LTP) at hippocampal CA1 synapses can be distinguished based on their sensitivity to inhibitors of protein kinase A (PKA). The PKA-dependent form requires multiple episodes of high-frequency stimulation (HFS) or theta burst stimuli (TBS) with a spacing between episodes in the order of minutes. To investigate the mechanism by which spaced episodes induce the PKA-dependent form of LTP, we have compared, in interleaved experiments, spaced (s) and compressed (c) TBS protocols in the rat CA1 synapses. We find that LTP induced by sTBS, but not that induced by cTBS, involves the insertion of calcium-permeable (CP) AMPARs, as assessed using pharmacological and electrophysiological criteria. Furthermore, a single TBS when paired with rolipram [4-(3-(cyclopentyloxy)-4-methoxyphenyl)pyrrolidin-2-one], to activate PKA, generates an LTP that also involves the insertion of CP-AMPARs. These data demonstrate that the involvement of CP-AMPARs in LTP is critically determined by the timing of the induction trigger and is associated specifically with the PKA-dependent form of LTP. SIGNIFICANCE STATEMENT Long-term potentiation is a family of synaptic mechanisms that are believed to be important for learning and memory. Two of the most extensively studied forms are triggered by the synaptic activation of NMDA receptors and expressed by changes in AMPA receptor function. They can be distinguished on the basis of their requirement for activation of a protein kinase, PKA. We show that the PKA-dependent form also involves the transient insertion of calcium-permeable AMPA receptors. These results have implications for relating synaptic plasticity to learning and memory and suggest a specific linkage between PKA activation and the rapid synaptic insertion of calcium-permeable AMPA receptors during long-term potentiation.
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14
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Turnham RE, Scott JD. Protein kinase A catalytic subunit isoform PRKACA; History, function and physiology. Gene 2015; 577:101-8. [PMID: 26687711 DOI: 10.1016/j.gene.2015.11.052] [Citation(s) in RCA: 125] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 11/17/2015] [Accepted: 11/23/2015] [Indexed: 01/01/2023]
Abstract
Our appreciation of the scope and influence of second messenger signaling has its origins in pioneering work on the cAMP-dependent protein kinase. Also called protein kinase A (PKA), this holoenzyme exists as a tetramer comprised of a regulatory (R) subunit dimer and two catalytic (C) subunits. Upon binding of two molecules of the second messenger cAMP to each R subunit, a conformational change in the PKA holoenzyme occurs to release the C subunits. These active kinases phosphorylate downstream targets to propagate cAMP responsive cell signaling events. This article focuses on the discovery, structure, cellular location and physiological effects of the catalytic subunit alpha of protein kinase A (encoded by the gene PRKACA). We also explore the potential role of this essential gene as a molecular mediator of certain disease states.
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Affiliation(s)
- Rigney E Turnham
- Howard Hughes Medical Institute, Department of Pharmacology, Box 357750, University of Washington School of Medicine, 1959 Pacific St. NE, Seattle, WA 98195, United States
| | - John D Scott
- Howard Hughes Medical Institute, Department of Pharmacology, Box 357750, University of Washington School of Medicine, 1959 Pacific St. NE, Seattle, WA 98195, United States.
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15
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Angelakos CC, Abel T. Molecular Genetic Strategies in the Study of Corticohippocampal Circuits. Cold Spring Harb Perspect Biol 2015; 7:a021725. [PMID: 26134320 DOI: 10.1101/cshperspect.a021725] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The first reproductively viable genetically modified mice were created in 1982 by Richard Palmiter and Ralph Brinster (Palmiter RD, Brinster RL, Hammer RE, Trumbauer ME, Rosenfeld MG, Birnberg NC, Evans RM. 1982. Dramatic growth of mice that develop from eggs microinjected with metallothionein-growth hormone fusion genes. Nature 300: 611-615). In the subsequent 30 plus years, numerous ground-breaking technical advancements in genetic manipulation have paved the way for improved spatially and temporally targeted research. Molecular genetic studies have been especially useful for probing the molecules and circuits underlying how organisms learn and remember—one of the most interesting and intensively investigated questions in neuroscience research. Here, we discuss selected genetic tools, focusing on corticohippocampal circuits and their implications for understanding learning and memory.
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Affiliation(s)
| | - Ted Abel
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6018
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16
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Roat TC, dos Santos-Pinto JRA, Dos Santos LD, Santos KS, Malaspina O, Palma MS. Modification of the brain proteome of Africanized honeybees (Apis mellifera) exposed to a sub-lethal doses of the insecticide fipronil. ECOTOXICOLOGY (LONDON, ENGLAND) 2014; 23:1659-1670. [PMID: 25139030 DOI: 10.1007/s10646-014-1305-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/06/2014] [Indexed: 06/03/2023]
Abstract
Fipronil is a phenylpyrazole insecticide that is widely used in Brazilian agriculture for pest control. Although honeybees are not targets of fipronil, studies indicate that this pesticide can be harmful to honeybees. To assess the effects of fipronil in the brain of Africanized Apis mellifera workers, this study focused on the toxico-proteome profiling of the brain of newly emerged and aged honeybee workers that were exposed to a sub-lethal dose (10 pg fipronil per day. i.e. (1)/100 of LD50/bee/day during 5 days) of the insecticide. Proteomic analysis identified 25 proteins that were differentially up-regulated or down-regulated when the fipronil-exposed and non-exposed groups were compared. These proteins are potentially related to pathogen susceptibility, neuronal chemical stress, neuronal protein misfolding, and occurrence of apoptosis, ischemia, visual impairment, damaged synapse formation, brain degeneration, memory and learning impairment. The exposure of honeybees to a very low dose of fipronil, even for a short period of time (5 days), was sufficient to cause a series of important neuroproteomic changes in the brains of honeybees.
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Affiliation(s)
- T C Roat
- Institute of Biosciences of Rio Claro, Department of Biology, Center of the Study of Social Insects, University of São Paulo State (UNESP), Avenida 24-A, N.1515-Bela Vista, Rio Claro, SP, Brazil,
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17
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Wong TH, Chiu WZ, Breedveld GJ, Li KW, Verkerk AJMH, Hondius D, Hukema RK, Seelaar H, Frick P, Severijnen LA, Lammers GJ, Lebbink JHG, van Duinen SG, Kamphorst W, Rozemuller AJ, Bakker EB, Neumann M, Willemsen R, Bonifati V, Smit AB, van Swieten J. PRKAR1B mutation associated with a new neurodegenerative disorder with unique pathology. ACTA ACUST UNITED AC 2014; 137:1361-73. [PMID: 24722252 DOI: 10.1093/brain/awu067] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Pathological accumulation of intermediate filaments can be observed in neurodegenerative disorders, such as Alzheimer's disease, frontotemporal dementia and Parkinson's disease, and is also characteristic of neuronal intermediate filament inclusion disease. Intermediate filaments type IV include three neurofilament proteins (light, medium and heavy molecular weight neurofilament subunits) and α-internexin. The phosphorylation of intermediate filament proteins contributes to axonal growth, and is regulated by protein kinase A. Here we describe a family with a novel late-onset neurodegenerative disorder presenting with dementia and/or parkinsonism in 12 affected individuals. The disorder is characterized by a unique neuropathological phenotype displaying abundant neuronal inclusions by haematoxylin and eosin staining throughout the brain with immunoreactivity for intermediate filaments. Combining linkage analysis, exome sequencing and proteomics analysis, we identified a heterozygous c.149T>G (p.Leu50Arg) missense mutation in the gene encoding the protein kinase A type I-beta regulatory subunit (PRKAR1B). The pathogenicity of the mutation is supported by segregation in the family, absence in variant databases, and the specific accumulation of PRKAR1B in the inclusions in our cases associated with a specific biochemical pattern of PRKAR1B. Screening of PRKAR1B in 138 patients with Parkinson's disease and 56 patients with frontotemporal dementia did not identify additional novel pathogenic mutations. Our findings link a pathogenic PRKAR1B mutation to a novel hereditary neurodegenerative disorder and suggest an altered protein kinase A function through a reduced binding of the regulatory subunit to the A-kinase anchoring protein and the catalytic subunit of protein kinase A, which might result in subcellular dislocalization of the catalytic subunit and hyperphosphorylation of intermediate filaments.
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Affiliation(s)
- Tsz Hang Wong
- 1 Department of Neurology, Erasmus Medical Centre, 3015 CE Rotterdam, The Netherlands
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18
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Zhang M, Wang H. Mice overexpressing type 1 adenylyl cyclase show enhanced spatial memory flexibility in the absence of intact synaptic long-term depression. Learn Mem 2013; 20:352-7. [PMID: 23772089 PMCID: PMC3687257 DOI: 10.1101/lm.030114.112] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
There is significant interest in understanding the contribution of intracellular signaling and synaptic substrates to memory flexibility, which involves new learning and suppression of obsolete memory. Here, we report that enhancement of Ca2+-stimulated cAMP signaling by overexpressing type 1 adenylyl cyclase (AC1) facilitated long-term potentiation (LTP) but impaired long-term depression (LTD) at the hippocampal Shaffer collateral-CA1 synapses. However, following the induction of LTP, low-frequency stimulation caused comparable synaptic depotentiation in both wild type and AC1 transgenic (AC1 TG) mice. Although previous studies have suggested the function of LTD in spatial memory flexibility, AC1 TG mice showed not only better initial learning in the Morris water maze, but also faster acquisition and increased ratio of new memory formation to old memory retention during the reversal platform training. In the memory extinction test, which requires suppression of old memory without involving the acquisition of the new platform information, AC1 TG and wild type mice showed comparable performance. Our results demonstrate new functions of Ca2+-stimulated AC1, and also suggest that certain aspects of hippocampus-dependent behavioral flexibility may not require intact LTD.
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Affiliation(s)
- Ming Zhang
- Department of Physiology, Neuroscience Program, Michigan State University, East Lansing, Michigan 48824, USA
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19
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Abstract
Exposure to various forms of stress is a common daily occurrence in the lives of most individuals, with both positive and negative effects on brain function. The impact of stress is strongly influenced by the type and duration of the stressor. In its acute form, stress may be a necessary adaptive mechanism for survival and with only transient changes within the brain. However, severe and/or prolonged stress causes overactivation and dysregulation of the hypothalamic pituitary adrenal (HPA) axis thus inflicting detrimental changes in the brain structure and function. Therefore, chronic stress is often considered a negative modulator of the cognitive functions including the learning and memory processes. Exposure to long-lasting stress diminishes health and increases vulnerability to mental disorders. In addition, stress exacerbates functional changes associated with various brain disorders including Alzheimer’s disease and Parkinson’s disease. The primary purpose of this paper is to provide an overview for neuroscientists who are seeking a concise account of the effects of stress on learning and memory and associated signal transduction mechanisms. This review discusses chronic mental stress and its detrimental effects on various aspects of brain functions including learning and memory, synaptic plasticity, and cognition-related signaling enabled via key signal transduction molecules.
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20
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The role of phosphodiesterases in hippocampal synaptic plasticity. Neuropharmacology 2013; 74:86-95. [PMID: 23357335 DOI: 10.1016/j.neuropharm.2013.01.011] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Revised: 01/08/2013] [Accepted: 01/12/2013] [Indexed: 01/19/2023]
Abstract
Phosphodiesterases (PDEs) degrade cyclic nucleotides, signalling molecules that play important roles in synaptic plasticity and memory. Inhibition of PDEs may therefore enhance synaptic plasticity and memory as a result of elevated levels of these signalling molecules, and this has led to interest in PDE inhibitors as cognitive enhancers. The development of new mouse models in which PDE subtypes have been selectively knocked out and increasing selectivity of PDE antagonists means that this field is currently expanding. Roles for PDE2, 4, 5 and 9 in synaptic plasticity have so far been demonstrated and we review these studies here in the context of cyclic nucleotide signalling more generally. The role of other PDE families in synaptic plasticity has not yet been investigated, and this area promises to advance our understanding of cyclic nucleotide signalling in synaptic plasticity in the future. This article is part of the Special Issue entitled 'Glutamate Receptor-Dependent Synaptic Plasticity'.
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21
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Plasticity of metabotropic glutamate receptor-dependent long-term depression in the anterior cingulate cortex after amputation. J Neurosci 2012; 32:11318-29. [PMID: 22895715 DOI: 10.1523/jneurosci.0146-12.2012] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Long-term depression (LTD) is a key form of synaptic plasticity important in learning and information storage in the brain. It has been studied in various cortical regions, including the anterior cingulate cortex (ACC). ACC is a crucial cortical region involved in such emotion-related physiological and pathological conditions as fear memory and chronic pain. In the present study, we used a multielectrode array system to map cingulate LTD in a spatiotemporal manner within the ACC. We found that low-frequency stimulation (1 Hz, 15 min) applied onto deep layer V induced LTD in layers II/III and layers V/VI. Cingulate LTD requires activation of metabotropic glutamate receptors (mGluRs), while L-type voltage-gated calcium channels and NMDA receptors also contribute to its induction. Peripheral amputation of the distal tail impaired ACC LTD, an effect that persisted for at least 2 weeks. The loss of LTD was rescued by priming ACC slices with activation of mGluR1 receptors by coapplying (RS)-3,5-dihydroxyphenylglycine and MPEP, a form of metaplasticity that involved the activation of protein kinase C. Our results provide in vitro evidence of the spatiotemporal properties of ACC LTD in adult mice. We demonstrate that tail amputation causes LTD impairment within the ACC circuit and that this can be rescued by activation of mGluR1.
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22
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Nashawi H, Bartl T, Bartl P, Novotny L, Oriowo M, Kombian S. TH-9 (a theophylline derivative) induces long-lasting enhancement in excitatory synaptic transmission in the rat hippocampus that is occluded by frequency-dependent plasticity in vitro. Neuroscience 2012; 220:70-84. [DOI: 10.1016/j.neuroscience.2012.06.028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Revised: 06/10/2012] [Accepted: 06/11/2012] [Indexed: 11/24/2022]
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23
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Keil MF, Briassoulis G, Gokarn N, Nesterova M, Wu T, Stratakis CA. Anxiety phenotype in mice that overexpress protein kinase A. Psychoneuroendocrinology 2012; 37:836-43. [PMID: 22024111 PMCID: PMC3320692 DOI: 10.1016/j.psyneuen.2011.09.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2011] [Revised: 09/07/2011] [Accepted: 09/29/2011] [Indexed: 01/13/2023]
Abstract
The role of cyclic adenosine monophosphate/protein kinase A (cAMP/PKA) signaling in the molecular pathways involved in fear and memory is well established. Prior studies in our lab reported that transgenic mice with an inactivating mutation in Prkar1a gene (codes for the 1-alpha regulatory subunit (R1α) of PKA) exhibited behavioral abnormalities including anxiety and depression. In the present study, we examined the role of altered PKA signaling on anxiety-like behaviors in Prkar1a(+/-) mice compared to wild-type (WT) littermates. The elevated plus maze (EPM) and marble bury (MB) tests were used to assess anxiety-like behavior. The hotplate test was performed to evaluate analgesia. We further examined the impact of the Prkar1a inactivating mutation on PKA activity in specific nuclei of the brain associated with anxiety-like behavior. Results for the MB test showed a genotype effect, with increased anxiety-like behavior in Prkar1a(+/-) mice, compared to WT littermates (p<0.05). MANOVA analysis showed a significant genotype difference in anxiety-like behavior in the EPM between WT and Prkar1a(+/-) mice on combined dependent variables (open arm time and open to total time ratio; p<0.05). Results of hotplate testing showed no genotype effect however; the expected sex difference was noted. Analysis of PKA activity showed the loss of one Prkar1a allele led to an increase in basal and cAMP-stimulated kinase activity in both the basolateral and central amygdala. These results suggest that the alteration in PKA signaling in Prkar1a(+/-) mice is not a ubiquitous effect; and supports the importance of cAMP/PKA pathway in neurobiological processes involved in anxiety and fear sensitization.
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Affiliation(s)
- Margaret F. Keil
- Section on Endocrinology and Genetics, Program in Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health, Bethesda, MD 20892
- Graduate School of Nursing, Uniformed Services University of the Health Sciences, Bethesda, MD 20814
| | - George Briassoulis
- Section on Endocrinology and Genetics, Program in Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health, Bethesda, MD 20892
| | - Nirmal Gokarn
- Section on Endocrinology and Genetics, Program in Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health, Bethesda, MD 20892
| | - Maria Nesterova
- Section on Endocrinology and Genetics, Program in Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health, Bethesda, MD 20892
| | - T.John Wu
- Department of Obstetrics and Gynecology and Program in Neuroscience, Uniformed Services University of the Health Sciences, Bethesda, MD 20814
| | - Constantine A. Stratakis
- Section on Endocrinology and Genetics, Program in Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health, Bethesda, MD 20892
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24
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Banday AR, Azim S, Tabish M. Identification and expression analysis of three novel splice variants of protein kinase A catalytic β subunit gene in the mouse using combinatorial in silico and molecular biology approaches. FEBS J 2012; 279:572-85. [DOI: 10.1111/j.1742-4658.2011.08446.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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25
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Brown JA, Diggs-Andrews KA, Gianino SM, Gutmann DH. Neurofibromatosis-1 heterozygosity impairs CNS neuronal morphology in a cAMP/PKA/ROCK-dependent manner. Mol Cell Neurosci 2012; 49:13-22. [PMID: 21903164 PMCID: PMC3237958 DOI: 10.1016/j.mcn.2011.08.008] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Revised: 08/17/2011] [Accepted: 08/19/2011] [Indexed: 11/19/2022] Open
Abstract
Children with the neurofibromatosis-1 (NF1) cancer predisposition syndrome exhibit numerous clinical problems that reflect defective central nervous system (CNS) neuronal function, including learning disabilities, attention deficit disorder, and seizures. These clinical features result from reduced NF1 protein (neurofibromin) expression in NF1+/- (NF1 heterozygosity) brain neurons. Previous studies have shown that mouse CNS neurons are sensitive to the effects of reduced Nf1 expression and exhibit shorter neurite lengths, smaller growth cone areas, and attenuated survival, reflecting attenuated neurofibromin cAMP regulation. In striking contrast, Nf1+/- peripheral nervous system (PNS) neurons are nearly indistinguishable from their wild-type counterparts, and complete neurofibromin loss leads to increased neurite lengths and survival in a RAS/Akt-dependent fashion. To gain insights into the differential responses of CNS and PNS neurons to reduced neurofibromin function, we designed a series of experiments to define the molecular mechanism(s) underlying the unique CNS neuronal sensitivity to Nf1 heterozygosity. First, Nf1 heterozygosity decreases cAMP levels in CNS, but not in PNS, neurons. Second, CNS neurons exhibit Nf1 gene-dependent increases in RAS pathway signaling, but no further decreases in cAMP levels were observed in Nf1-/- CNS neurons relative to their Nf1+/- counterparts. Third, neurofibromin regulates CNS neurite length and growth cone areas in a cAMP/PKA/Rho/ROCK-dependent manner in vitro and in vivo. Collectively, these findings establish cAMP/PKA/Rho/ROCK signaling as the responsible axis underlying abnormal Nf1+/- CNS neuronal morphology with important implications for future preclinical and clinical studies aimed at improving cognitive and behavioral deficits in mice and children with reduced brain neuronal NF1 gene expression.
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Affiliation(s)
- Jacquelyn A Brown
- Department of Neurology, Washington University School of Medicine, St. Louis, MO, USA
| | - Kelly A Diggs-Andrews
- Department of Neurology, Washington University School of Medicine, St. Louis, MO, USA
| | - Scott M Gianino
- Department of Neurology, Washington University School of Medicine, St. Louis, MO, USA
| | - David H Gutmann
- Department of Neurology, Washington University School of Medicine, St. Louis, MO, USA.
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26
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Bidirectional synaptic plasticity and spatial memory flexibility require Ca2+-stimulated adenylyl cyclases. J Neurosci 2011; 31:10174-83. [PMID: 21752993 DOI: 10.1523/jneurosci.0009-11.2011] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
When certain memory becomes obsolete, effective suppression of the previously established memory is essential for animals to adapt to the changing environment. At the cellular level, reversal of synaptic potentiation may be important for neurons to acquire new information and to prevent synaptic saturation. Here, we investigated the function of Ca(2+)-stimulated cAMP signaling in the regulation of bidirectional synaptic plasticity and spatial memory formation in double knock-out mice (DKO) lacking both type 1 and 8 adenylyl cyclases (ACs). In anesthetized animals, the DKO mutants showed defective long-term potentiation (LTP) after a single high-frequency stimulation (HFS) or two spaced HFSs at 100 Hz. However, DKO mice showed normal LTP after a single HFS at 200 Hz or two compressed HFSs at 100 Hz. Interestingly, reversal of synaptic potentiation as well as de novo synaptic depression was impaired in DKO mice. In the Morris water maze, DKO mice showed defective acquisition and memory retention, although the deficits could be attenuated by overtraining or compressed trainings with a shorter intertrial interval. In the reversal platform test, DKO animals were impaired in both relearning and old memory suppression. Furthermore, the extinction of the old spatial memory was not efficient in DKO mice. These data demonstrate that Ca(2+)-stimulated AC activity is important not only for LTP and spatial memory formation but also for the suppression of both previously established synaptic potentiation and old spatial memory.
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Yin Z, Pringle DR, Jones GN, Kelly KM, Kirschner LS. Differential role of PKA catalytic subunits in mediating phenotypes caused by knockout of the Carney complex gene Prkar1a. Mol Endocrinol 2011; 25:1786-93. [PMID: 21852354 DOI: 10.1210/me.2011-1008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The Carney complex is an inherited tumor predisposition caused by activation of the cAMP-dependent protein kinase [protein kinase A (PKA)] resulting from mutation of the PKA-regulatory subunit gene PRKAR1A. Myxomas and tumors in cAMP-responsive tissues are cardinal features of this syndrome, which is unsurprising given the important role played by PKA in modulating cell growth and function. Previous studies demonstrated that cardiac-specific knockout of Prkar1a causes embryonic heart failure and myxomatous degeneration in the heart, whereas limited Schwann cell-specific knockout of the gene causes schwannoma formation. In this study, we sought to determine the role of PKA activation in this phenotype by using genetic means to reduce PKA enzymatic activity. To accomplish this goal, we introduced null alleles of the PKA catalytic subunits Prkaca (Ca) or Prkacb (Cb) into the Prkar1a-cardiac knockout (R1a-CKO) or limited Schwann cell knockout (R1a-TEC3KO) line. Heterozygosity for Prkaca rescued the embryonic lethality of the R1a-CKO, although mice had a shorter than normal lifespan and died from cardiac failure with atrial thrombosis. In contrast, heterozygosity for Prkacb only enabled the mice to survive 1 extra day during embryogenesis. Biochemical analysis indicated that reduction of Ca markedly reduced PKA activity in embryonic hearts, whereas reduction of Cb had minimal effects. In R1a-TEC3KO mice, tumorigenesis was completely suppressed by a heterozygosity for Prkaca, and by more than 80% by heterozygosity for Prkacb. These data suggest that both developmental and tumor phenotypes caused by Prkar1a mutation result from excess PKA activity due to PKA-Ca.
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Affiliation(s)
- Zhirong Yin
- Department of Molecular Virology, Immunology, and Medical Genetics, Ohio State University, Columbus, Ohio 43210, USA
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Vetter MM, Zenn HM, Méndez E, van den Boom H, Herberg FW, Skålhegg BS. The testis-specific Cα2 subunit of PKA is kinetically indistinguishable from the common Cα1 subunit of PKA. BMC BIOCHEMISTRY 2011; 12:40. [PMID: 21812984 PMCID: PMC3163529 DOI: 10.1186/1471-2091-12-40] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/02/2011] [Accepted: 08/03/2011] [Indexed: 11/22/2022]
Abstract
Background The two variants of the α-form of the catalytic (C) subunit of protein kinase A (PKA), designated Cα1 and Cα2, are encoded by the PRKACA gene. Whereas Cα1 is ubiquitous, Cα2 expression is restricted to the sperm cell. Cα1 and Cα2 are encoded with different N-terminal domains. In Cα1 but not Cα2 the N-terminal end introduces three sites for posttranslational modifications which include myristylation at Gly1, Asp-specific deamidation at Asn2 and autophosphorylation at Ser10. Previous reports have implicated specific biological features correlating with these modifications on Cα1. Since Cα2 is not modified in the same way as Cα1 we tested if they have distinct biochemical activities that may be reflected in different biological properties. Results We show that Cα2 interacts with the two major forms of the regulatory subunit (R) of PKA, RI and RII, to form cAMP-sensitive PKAI and PKAII holoenzymes both in vitro and in vivo as is also the case with Cα1. Moreover, using Surface Plasmon Resonance (SPR), we show that the interaction patterns of the physiological inhibitors RI, RII and PKI were comparable for Cα2 and Cα1. This is also the case for their potency to inhibit catalytic activities of Cα2 and Cα1. Conclusion We conclude that the regulatory complexes formed with either Cα1 or Cα2, respectively, are indistinguishable.
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Affiliation(s)
- Maike M Vetter
- Department of Nutrition, Institute of Basic Medical Sciences, University of Oslo, Pb 1046 Blindern, Oslo, Norway
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Dwivedi Y, Pandey GN. Elucidating biological risk factors in suicide: role of protein kinase A. Prog Neuropsychopharmacol Biol Psychiatry 2011; 35:831-41. [PMID: 20817068 PMCID: PMC3026860 DOI: 10.1016/j.pnpbp.2010.08.025] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2010] [Revised: 08/17/2010] [Accepted: 08/26/2010] [Indexed: 01/19/2023]
Abstract
Suicide is a major public health concern. Although there have been several studies of suicidal behavior that focused on the roles of psychosocial and sociocultural factors, these factors are of too little predictive value to be clinically useful. Therefore, research on the biological perspective of suicide has gained a stronghold and appears to provide a promising approach to identify biological risk factors associated with suicidal behavior. Recent studies demonstrate that an alteration in synaptic and structural plasticity is key to affective illnesses and suicide. Signal transduction molecules play an important role in such plastic events. Protein kinase A (PKA) is a crucial enzyme in the adenylyl cyclase signal transduction pathway and is involved in regulating gene transcription, cell survival, and plasticity. In this review, we critically and comprehensively discuss the role of PKA in suicidal behavior. Because stress is an important component of suicide, we also discuss whether stress affects PKA and how this may be associated with suicidal behavior. In addition, we also discuss the functional significance of the findings regarding PKA by describing the role of important PKA substrates (i.e., Rap1, cyclic adenosine monophosphate response element binding protein, and target gene brain-derived neurotrophic factor). These studies suggest the interesting possibility that PKA and related signaling molecules may serve as important neurobiological factors in suicide and may be relevant in target-specific therapeutic interventions for these disorders.
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Affiliation(s)
- Yogesh Dwivedi
- The Psychiatric Institute, Department of Psychiatry, University of Illinois at Chicago, 1601 West Taylor Street, Chicago, IL 60612, USA.
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Serafini G, Pompili M, Innamorati M, Giordano G, Tatarelli R, Lester D, Girardi P, Dwivedi Y. Glycosides, depression and suicidal behaviour: the role of glycoside-linked proteins. Molecules 2011; 16:2688-713. [PMID: 21441870 PMCID: PMC6259655 DOI: 10.3390/molecules16032688] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2010] [Revised: 03/17/2011] [Accepted: 03/18/2011] [Indexed: 01/19/2023] Open
Abstract
Nowadays depression and suicide are two of the most important worldwide public health problems. Although their specific molecular mechanisms are still largely unknown, glycosides can play a fundamental role in their pathogenesis. These molecules act presumably through the up-regulation of plasticity-related proteins: probably they can have a presynaptic facilitatory effect, through the activation of several intracellular signaling pathways that include molecules like protein kinase A, Rap-1, cAMP, cADPR and G proteins. These proteins take part in a myriad of brain functions such as cell survival and synaptic plasticity. In depressed suicide victims, it has been found that their activity is strongly decreased, primarily in hippocampus and prefrontal cortex. These studies suggest that glycosides can regulate neuroprotection through Rap-1 and other molecules, and may play a crucial role in the pathophysiology of depression and suicide.
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Affiliation(s)
- Gianluca Serafini
- Department of Neuroscience, Mental Health and Sensory Functions, "Sapienza" University of Rome, Suicide Prevention Center, Sant'Andrea Hospital, Via Grottarossa 1035-1039, 00189 Rome, Italy.
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31
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Jones GN, Pringle DR, Yin Z, Carlton MM, Powell KA, Weinstein MB, Toribio RE, La Perle KMD, Kirschner LS. Neural crest-specific loss of Prkar1a causes perinatal lethality resulting from defects in intramembranous ossification. Mol Endocrinol 2010; 24:1559-68. [PMID: 20534695 DOI: 10.1210/me.2009-0439] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The cranial neural crest (CNC) undergoes complex molecular and morphological changes during embryogenesis in order to form the vertebrate skull, and nearly three quarters of all birth defects result from defects in craniofacial development. The molecular events leading to CNC differentiation have been extensively studied; however, the role of the cAMP-dependent protein kinase [protein kinase A (PKA)] during craniofacial development has only been described in palate formation. Here, we provide evidence that strict PKA regulation in postmigratory CNC cells is essential during craniofacial bone development. Selective inactivation of Prkar1a, a regulatory subunit of the PKA holoenzyme, in the CNC results in perinatal lethality caused by dysmorphic craniofacial development and subsequent asphyxiation. Additionally, aberrant differentiation of CNC mesenchymal cells results in anomalous intramembranous ossification characterized by formation of cartilaginous islands in some areas and osteolysis of bony trabeculae with fibrous connective tissue stabilization in others. Genetic interaction studies revealed that genetic reduction of the PKA catalytic subunit C(alpha) was able to rescue the phenotype, whereas reduction in Cbeta had no effect. Overall, these observations provide evidence of the essential role of proper regulation of PKA during the ossification of the bones of the skull. This knowledge may have implications for the understanding and treatment of craniofacial birth defects.
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Affiliation(s)
- Georgette N Jones
- Department of Molecular Virology, The Ohio State University, Columbus, Ohio 43210, USA
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32
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Activation of the hedgehog-signaling pathway in human cancer and the clinical implications. Oncogene 2009; 29:469-81. [PMID: 19935712 DOI: 10.1038/onc.2009.392] [Citation(s) in RCA: 247] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The hedgehog pathway, initially discovered by two Nobel laureates Drs E Wieschaus and C Nusslein-Volhard in Drosophila, is a major regulator for cell differentiation, tissue polarity and cell proliferation. Studies from many laboratories reveal activation of this pathway in a variety of human cancer, including basal cell carcinomas (BCCs), medulloblastomas, leukemia, gastrointestinal, lung, ovarian, breast and prostate cancers. It is thus believed that targeted inhibition of hedgehog signaling may be effective in treatment and prevention of human cancer. Even more exciting is the discovery and synthesis of specific signaling antagonists for the hedgehog pathway, which have significant clinical implications in novel cancer therapeutics. In this review, we will summarize major advances in the last 2 years in our understanding of hedgehog signaling activation in human cancer, interactions between hedgehog signaling and other pathways in carcinogenesis, potential antagonists for hedgehog signaling inhibition and their clinical implications for human cancer treatment.
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Rivard RL, Birger M, Gaston KJ, Howe AK. AKAP-independent localization of type-II protein kinase A to dynamic actin microspikes. ACTA ACUST UNITED AC 2009; 66:693-709. [PMID: 19536823 DOI: 10.1002/cm.20399] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Regulation of the cyclic AMP-dependent protein kinase (PKA) in subcellular space is required for cytoskeletal dynamics and chemotaxis. Currently, spatial regulation of PKA is thought to require the association of PKA regulatory (R) subunits with A-kinase anchoring proteins (AKAPs). Here, we show that the regulatory RIIalpha subunit of PKA associates with dynamic actin microspikes in an AKAP-independent manner. Both endogenous RIIalpha and a GFP-RIIalpha fusion protein co-localize with F-actin in microspikes within hippocampal neuron growth cones and the leading edge lamellae of NG108-15 cells. Live-cell imaging demonstrates that RIIalpha-associated microspikes are highly dynamic and that the coupling of RIIalpha to actin is tight, as the movement of both actin and RIIalpha are immediately and coincidently stopped by low-dose cytochalasin D. Importantly, co-localization of RIIalpha and actin in these structures is resistant to displacement by a cell-permeable disrupter of PKA-AKAP interactions. Biochemical fractionation confirms that a substantial pool of PKA RIIalpha is associated with the detergent-insoluble cytoskeleton and is resistant to extraction by a peptide inhibitor of AKAP interactions. Finally, mutation of the AKAP-binding domain of RIIalpha fails to disrupt its association with actin microspikes. These data provide the first demonstration of the physical association of a kinase with such dynamic actin structures, as well as the first demonstration of the ability of type-II PKA to localize to discrete subcellular structures independently of canonical AKAP function. This association is likely to be important for microfilament dynamics and cell migration and may prime the investigation of novel mechanisms for localizing PKA activity.
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Affiliation(s)
- Robert L Rivard
- Department of Pharmacology, University of Vermont College of Medicine, Burlington, VT 05405, USA
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A systematic investigation of the protein kinases involved in NMDA receptor-dependent LTD: evidence for a role of GSK-3 but not other serine/threonine kinases. Mol Brain 2009; 2:22. [PMID: 19583853 PMCID: PMC2715398 DOI: 10.1186/1756-6606-2-22] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2009] [Accepted: 07/07/2009] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND The signalling mechanisms involved in the induction of N-methyl-D-aspartate (NMDA) receptor-dependent long-term depression (LTD) in the hippocampus are poorly understood. Numerous studies have presented evidence both for and against a variety of second messengers systems being involved in LTD induction. Here we provide the first systematic investigation of the involvement of serine/threonine (ser/thr) protein kinases in NMDAR-LTD, using whole-cell recordings from CA1 pyramidal neurons. RESULTS Using a panel of 23 inhibitors individually loaded into the recorded neurons, we can discount the involvement of at least 57 kinases, including PKA, PKC, CaMKII, p38 MAPK and DYRK1A. However, we have been able to confirm a role for the ser/thr protein kinase, glycogen synthase kinase 3 (GSK-3). CONCLUSION The present study is the first to investigate the role of 58 ser/thr protein kinases in LTD in the same study. Of these 58 protein kinases, we have found evidence for the involvement of only one, GSK-3, in LTD.
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Funderud A, Aas-Hanssen K, Aksaas AK, Hafte TT, Corthay A, Munthe LA, Orstavik S, Skålhegg BS. Isoform-specific regulation of immune cell reactivity by the catalytic subunit of protein kinase A (PKA). Cell Signal 2008; 21:274-81. [PMID: 19000925 DOI: 10.1016/j.cellsig.2008.10.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2008] [Revised: 10/22/2008] [Accepted: 10/22/2008] [Indexed: 10/21/2022]
Abstract
There are two major genes encoding the catalytic subunits of protein kinase A, Calpha and Cbeta. The functional significance of these isoforms is enigmatic. Lymphoid cells of the immune system express both Calpha and Cbeta. In this study we tested the role of Calpha and Cbeta in regulating immune cell reactivity to antigens using mice carrying a targeted disruption of the Calpha and Cbeta gene respectively. Calpha and Cbeta ablation both resulted in a 50% reduction in PKA-specific kinase activity and the level of PKA type I but not PKA type II. Moreover, despite that C subunit ablation did not affect immune cell development and homeostasis, Calpha but not Cbeta ablation augmented expression of the activation marker CD69 on lymphocytes. CD69 induction coincided with immune cell hyperresponsiveness and was associated with reduced sensitivity to cAMP-mediated inhibition of anti-CD3 induced T cell proliferation. Our results imply that Calpha is required for normal immune cell reactivity and demonstrates isoform-specific effects and non-redundant functions of C subunit isoforms expressed in the same cell.
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Affiliation(s)
- Ane Funderud
- Department of Nutrition, Institute of Basic Medical Sciences, University of Oslo, Norway
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36
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Yang Y, Takeuchi K, Rodenas-Ruano A, Takayasu Y, Bennett MVL, Zukin RS. Developmental switch in requirement for PKA RIIbeta in NMDA-receptor-dependent synaptic plasticity at Schaffer collateral to CA1 pyramidal cell synapses. Neuropharmacology 2008; 56:56-65. [PMID: 18789341 DOI: 10.1016/j.neuropharm.2008.08.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2008] [Revised: 08/01/2008] [Accepted: 08/01/2008] [Indexed: 11/24/2022]
Abstract
The cAMP/protein kinase A (PKA) signaling cascade is crucial for synaptic plasticity in a wide variety of species. PKA regulates Ca2+ permeation through NMDA receptors (NMDARs) and induction of NMDAR-dependent synaptic plasticity at the Schaffer collateral to CA1 pyramidal cell synapse. Whereas the role of PKA in induction of NMDAR-dependent LTP at CA1 synapses is established, the identity of PKA isoforms involved in this phenomenon is less clear. Here we report that protein synthesis-independent NMDAR-dependent LTP at the Schaffer collateral-CA1 synapse in the hippocampus is deficient, but NMDAR-dependent LTD is normal, in young (postnatal day 10 (P10)-P14) mice lacking PKA RIIbeta, the PKA regulatory protein that links PKA to NMDARs at synaptic sites. In contrast, in young adult (P21-P28) mice lacking PKA RIIbeta, LTP is normal and LTD is abolished. These findings indicate that distinct PKA isoforms may subserve distinct forms of synaptic plasticity and are consistent with a developmental switch in the signaling cascades required for LTP induction.
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Affiliation(s)
- Yupeng Yang
- Dominick P. Purpura Department of Neuroscience, Kennedy Center Room 602B, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
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Abstract
The hedgehog (Hh) pathway, initially discovered in Drosophila by two Nobel laureates, Dr. Eric Wieschaus and Dr. Christiane Nusslein-Volhard, is a major regulator for cell differentiation, tissue polarity and cell proliferation. Studies from many laboratories, including ours, reveal activation of this pathway in most basal cell carcinomas and in approximately 30% of extracutaneous human cancers, including medulloblastomas, gastrointestinal, lung, breast and prostate cancers. Thus, it is believed that targeted inhibition of Hh signaling may be effective in treating and preventing many types of human cancers. Even more exciting is the discovery and synthesis of specific signaling antagonists for the Hh pathway, which have significant clinical implications in novel cancer therapeutics. This review discusses the major advances in the current understanding of Hh signaling activation in different types of human cancers, the molecular basis of Hh signaling activation, the major antagonists for Hh signaling inhibition and their potential clinical application in human cancer therapy.
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Affiliation(s)
- Jingwu Xie
- Department of Pharmacology and Toxicology, Sealy Center for Cancer Cell Biology, University of Texas at Galveston, Galveston, Texas 77555-1048, USA.
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Galpha(i2) inhibition of adenylate cyclase regulates presynaptic activity and unmasks cGMP-dependent long-term depression at Schaffer collateral-CA1 hippocampal synapses. Learn Mem 2008; 15:261-70. [PMID: 18391187 DOI: 10.1101/lm.810208] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Cyclic AMP signaling plays a central role in regulating activity at a number of synapses in the brain. We showed previously that pairing activation of receptors that inhibit adenylate cyclase (AC) and reduce the concentration of cyclic AMP, with elevation of the concentration of cyclic GMP is sufficient to elicit a presynaptically expressed form of LTD at Schaffer collateral-CA1 synapses in the hippocampus. To directly test the role of AC inhibition and G-protein signaling in LTD at these synapses, we utilized transgenic mice that express a mutant, constitutively active inhibitory G protein, Galpha(i2), in principal neurons of the forebrain. Transgene expression of Galpha(i2) markedly enhanced LTD and impaired late-phase LTP at Schaffer collateral synapses, with no associated differences in input/output relations, paired-pulse facilitation, or NMDA receptor-gated conductances. When paired with application of a type V phosphodiesterase inhibitor to elevate the concentration of intracellular cyclic GMP, constitutively active Galpha(i2) expression converted the transient depression normally caused by this treatment to an LTD that persisted after the drug was washed out. Moreover, this effect could be mimicked in control slices by pairing type V phosphodiesterase inhibitor application with application of a PKA inhibitor. Electrophysiological recordings of spontaneous excitatory postsynaptic currents and two-photon visualization of vesicular release using FM1-43 revealed that constitutively active Galpha(i2) tonically reduced basal release probability from the rapidly recycling vesicle pool of Schaffer collateral terminals. Our findings support the hypothesis that inhibitory G-protein signaling acts presynaptically to regulate release, and, when paired with elevations in the concentration of cyclic GMP, converts a transient cyclic GMP-induced depression into a long-lasting decrease in release.
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Dwivedi Y, Pandey GN. Adenylyl cyclase-cyclicAMP signaling in mood disorders: role of the crucial phosphorylating enzyme protein kinase A. Neuropsychiatr Dis Treat 2008; 4:161-76. [PMID: 18728821 PMCID: PMC2515915 DOI: 10.2147/ndt.s2380] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Mood disorders are among the most prevalent and recurrent forms of psychiatric illnesses. In the last decade, there has been increased understanding of the biological basis of mood disorders. In fact, novel mechanistic concepts of the neurobiology of unipolar and bipolar disorders are evolving based on recent pre-clinical and clinical studies, most of which now focus on the role of signal transduction mechanisms in these psychiatric illnesses. Particular investigative emphasis has been given to the role of phosphorylating enzymes, which are crucial in regulating gene expression and neuronal and synaptic plasticity. Among the most important phosphorylating enzyme is protein kinase A (PKA), a component of adenylyl cyclase-cyclic adenosine monophosphate (AC-cAMP) signaling system. In this review, we critically and comprehensively discuss the role of various components of AC-cAMP signaling in mood disorders, with a special focus on PKA, because of the interesting observation that have been made about its involvement in unipolar and bipolar disorders. We also discuss the functional significance of the findings regarding PKA by discussing the role of important PKA substrates, namely, Rap-1, cyclicAMP-response element binding protein, and brain-derived neurotrophic factor. These studies suggest the interesting possibility that PKA and related signaling molecules may serve as important neurobiological factors in mood disorders and may be relevant in target-specific therapeutic interventions for these disorders.
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Affiliation(s)
- Yogesh Dwivedi
- Psychiatric Institute, Department of Psychiatry, College of Medicine, University of Illinois at Chicago Chicago, Illinois 60612, USA.
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Matsubara Y, Kikuchi S, Sugimoto M, Oka K, Tomita M. Algebraic method for the analysis of signaling crosstalk. ARTIFICIAL LIFE 2008; 14:81-94. [PMID: 18171132 DOI: 10.1162/artl.2008.14.1.81] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
A unified mathematical description that expresses the characteristics of whole systems is necessary for an understanding of signal transduction cascades. In this study we explore an algebraic method, named extreme signaling flow, enhanced from the concept of extreme pathway, to analyze signal transduction systems. This method enables us to represent the long-term potentiation (LTP) and the long-term depression (LTD) of hippocampal neuronal plasticity in an integrated simulation model. The model is validated by comparing the results of redundancy, reaction participation, and in silico knockout analysis with biological knowledge available from the literature. The following properties are assumed in these computational analyses: (1) LTP is fault-tolerant under network modification, (2) protein kinase C and MAPK have numerous routes to LTP induction, (3) calcium-calmodulin kinase II has a few routes to LTP induction, and (4) calcineurin has many routes to LTD induction. These results demonstrate that our approach produces an integrated framework for analyzing properties of large-scale systems with complicated signal transduction.
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Affiliation(s)
- Yoshiya Matsubara
- Institute for Advanced Biosciences, Keio University, Endo 5322, Fujisawa, Kanagawa, 252-8520, Japan
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Liang Z, Liu F, Grundke-Iqbal I, Iqbal K, Gong CX. Down-regulation of cAMP-dependent protein kinase by over-activated calpain in Alzheimer disease brain. J Neurochem 2007; 103:2462-70. [PMID: 17908236 PMCID: PMC2262109 DOI: 10.1111/j.1471-4159.2007.04942.x] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Impaired cognition and memory may be associated with down-regulation of cAMP-response element-binding protein (CREB) in the brain in patients with Alzheimer disease, but the molecular mechanism leading to the down-regulation is not understood. In this study, we found a selective reduction in the levels of the regulatory subunits (RIIalpha and RIIbeta) and the catalytic subunit (Cbeta) as well as the enzymatic activity of cAMP-dependent protein kinase (PKA), which is the major positive regulator of CREB. We also observed that PKA subunits were proteolyzed by calpain and the levels of PKA subunits correlated negatively with calpain activation in the human brain. These findings led us to propose that in the brain in patients with Alzheimer disease, over-activation of calpain because of calcium dysregulation causes increased degradation and thus decreased activity of PKA, which, in turn, contributes to down-regulation of CREB and impaired cognition and memory.
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Affiliation(s)
- Zhihou Liang
- Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York, USA
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Kemp A, Manahan-Vaughan D. -Adrenoreceptors Comprise a Critical Element in Learning-Facilitated Long-Term Plasticity. Cereb Cortex 2007; 18:1326-34. [PMID: 17906333 DOI: 10.1093/cercor/bhm164] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
A novel spatial environment consists of several different types of information that may be encoded by cellular information storage mechanisms such as long-term potentiation (LTP) and long-term depression (LTD). Arousal, mediated, for example, by activation of the noradrenergic system, is a critical factor in information acquisition and may enhance the encoding of novel spatial information. Using electrophysiological recordings of hippocampal responses in freely moving rats during spatial learning, we investigated the role of the beta-adrenoreceptor in Schaeffer collateral-CA1 synaptic plasticity. We found that novel exploration of spatial context facilitates induction of LTD that is inhibited by intracerebroventricular application of the beta-adrenoreceptor antagonist, propranolol. Long-lasting homosynaptic LTD, that was electrically induced by low-frequency stimulation, was unaffected by the antagonist. Although application of a beta-adrenoreceptor agonist (isoproterenol) did not affect electrically induced LTD, agonist application facilitated short-term depression (STD) into LTD and mimicked the augmentation, through spatial exploration, of STD into LTD. Exploration of a novel empty environment facilitated LTP that was prevented by application of propranolol. These results suggest that beta-adrenoreceptors may facilitate encoding of spatial information through synaptic plasticity in the hippocampus and that noradrenaline is a key factor in effective information acquisition.
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Affiliation(s)
- Anne Kemp
- Learning and Memory Research, Medical Faculty, Ruhr University Bochum, 44780 Bochum, Germany
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Cai Q, Pan PY, Sheng ZH. Syntabulin-kinesin-1 family member 5B-mediated axonal transport contributes to activity-dependent presynaptic assembly. J Neurosci 2007; 27:7284-96. [PMID: 17611281 PMCID: PMC6794594 DOI: 10.1523/jneurosci.0731-07.2007] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The mechanism by which microtubule-based axonal transport regulates activity-dependent presynaptic plasticity in developing neurons remains mostly unknown. Our previous studies established that syntabulin is an adaptor capable of conjoining the kinesin family member 5B (KIF5B) motor and syntaxin-1. We now report that the complex of syntaxin-1-syntabulin-KIF5B mediates axonal transport of the active zone (AZ) components essential for presynaptic assembly. Syntabulin associates with AZ precursor carriers and colocalizes and comigrates with green fluorescent protein (GFP)-Bassoon-labeled AZ transport cargos within developing axons. Knock-down of syntabulin or disruption of the syntaxin-1-syntabulin-KIF5B complex impairs the anterograde transport of GFP-Bassoon out of the soma and reduces the axonal densities of synaptic vesicle (SV) clusters and FM4-64 [N-(3-triethylammoniumpropyl)-4-(p-dibutylaminostyryl)pyridinium, dibromide] loading. Furthermore, syntabulin loss of function results in a reduction in both the amplitude of postsynaptic currents and the frequency of asynchronous quantal events, and abolishes the activity-induced recruitment of new GFP-Bassoon into the axons and subsequent coclustering with SVs. Consequently, syntabulin loss of function blocks the formation of new presynaptic boutons during activity-dependent synaptic plasticity in developing neurons. These studies establish that a kinesin motor-adaptor complex is critical for the anterograde axonal transport of AZ components, thus contributing to activity-dependent presynaptic assembly during neuronal development.
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Affiliation(s)
- Qian Cai
- Synaptic Function Unit, The Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892-3701
| | - Ping-Yue Pan
- Synaptic Function Unit, The Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892-3701
| | - Zu-Hang Sheng
- Synaptic Function Unit, The Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892-3701
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44
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Yi JJ, Ehlers MD. Emerging roles for ubiquitin and protein degradation in neuronal function. Pharmacol Rev 2007; 59:14-39. [PMID: 17329546 DOI: 10.1124/pr.59.1.4] [Citation(s) in RCA: 178] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Alterations in cellular structure and synapse composition are central to proper nervous system function. Recent work has identified the ubiquitin-proteasome system (UPS) as a key regulator of neuronal biology. The UPS is essential for the growth and development of immature neurons and is a critical mediator of synaptic adaptability in mature neurons. Furthermore, proteinaceous deposits that accumulate in diverse neurodegenerative disorders are enriched in components of the UPS, suggesting that UPS dysfunction may be pivotal for pathogenesis. Here, we summarize existing knowledge about the role of the UPS in brain function, highlighting recent work delineating its importance in neuronal development, plasticity, and degeneration.
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Affiliation(s)
- Jason J Yi
- Program in Cell and Molecular Biology, Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA
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Abstract
Depression is a condition with a complex biologic pattern in etiology. Environmental stressors modulate subsequent vulnerability to depression. In particular, early adversity seems to induce heightened reactivity to stress through several possible mechanisms, both biologic and psychologic. This increased reactivity results in an enhancement of biologic stress-response mechanisms, especially the HPA axis. Regulators of this system, particularly signal transduction pathways involving PKA and PKC, may be important in the regulation of key genes in this system including genes for GR, BDNF, and trk-b. This system potentially is vulnerable to ROS and therefore, indirectly, to the effects of cytokines. Finally, some of these effects may be controlled by chemical modification of DNA, specifically, methylation of promoters or other gene regions. This modification is a mechanism by which long-term biologic change can be induced by environmental stressors. The brain is homeostatic, and it is possible that alterations at multiple points in this system may induce dysregulation and, as a result, vulnerability to stress. Therefore, a person may be vulnerable to depression, which may be a final common "pathway" for this family of conditions. Individuals may very considerably with regard to the locus of the problem, however. For example, functional variants in a set of genes might predispose some people to depression; others may have epigenetic imprinting; and yet different causes may be at work in others. Although this mix is complicated, it can be unraveled. Doing so could lead to the development of novel interventions that could target specific points of vulnerability, allowing an improved matching of patient to treatment based on differential abnormalities at the cellular level.
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Affiliation(s)
- Richard C Shelton
- Department of Psychiatry, Vanderbilt University Medical Center, 1500 21st Avenue, South, Suite 2200, Nashville, TN 37212, USA.
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Pöschel B, Stanton PK. Comparison of cellular mechanisms of long-term depression of synaptic strength at perforant path-granule cell and Schaffer collateral-CA1 synapses. PROGRESS IN BRAIN RESEARCH 2007; 163:473-500. [PMID: 17765734 DOI: 10.1016/s0079-6123(07)63026-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
This chapter compares the cellular mechanisms that have been implicated in the induction and expression of long-term depression (LTD) at Schaffer collateral-CA1 synapses to perforant path-dentate gyrus (DG) synapses. In general, Schaffer collateral LTD and long-term potentiation (LTP) both appear to be a complex combination of many alterations in synaptic transmission that occur at both presynaptic and postsynaptic sites, while at perforant path synapses, most evidence has focused on postsynaptic long-term alterations. Within the DG, the medial perforant path is far more studied than lateral perforant path synapses, where most evidence relates to the induction of heterosynaptic LTD at lateral perforant path synapses when LTP is induced in the medial perforant path. Of course, there remain many other classes of synapses in the DG where synaptic plasticity, including LTD, have been largely neglected. It is clear that a better understanding of the range of DG loci where long-lasting activity-dependent plasticity, both LTD and LTP, are expressed will be essential to improve our understanding of the cognitive roles of such DG plasticity.
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Affiliation(s)
- Beatrice Pöschel
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY 10595, USA
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Abstract
A number of neuronal functions, including synaptic plasticity, depend on proper regulation of synaptic proteins, many of which can be rapidly regulated by phosphorylation. Neuronal activity controls the function of these synaptic proteins by exquisitely regulating the balance of various protein kinase and protein phosphatase activity. Recent understanding of synaptic plasticity mechanisms underscores important roles that these synaptic phosphoproteins play in regulating both pre- and post-synaptic functions. This review will focus on key postsynaptic phosphoproteins that have been implicated to play a role in synaptic plasticity.
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Affiliation(s)
- Hey-Kyoung Lee
- Department of Biology, Neuroscience and Cognitive Science (NACS) Program, University of Maryland, College Park, MD 20742, USA.
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Funderud A, Henanger HH, Hafte TT, Amieux PS, Ørstavik S, Skålhegg BS. Identification, cloning and characterization of a novel 47 kDa murine PKA C subunit homologous to human and bovine Cbeta2. BMC BIOCHEMISTRY 2006; 7:20. [PMID: 16889664 PMCID: PMC1557514 DOI: 10.1186/1471-2091-7-20] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/04/2006] [Accepted: 08/04/2006] [Indexed: 11/24/2022]
Abstract
Background Two main genes encoding the catalytic subunits Cα and Cβ of cyclic AMP dependent protein kinase (PKA) have been identified in all vertebrates examined. The murine, bovine and human Cβ genes encode several splice variants, including the splice variant Cβ2. In mouse Cβ2 has a relative molecular mass of 38 kDa and is only expressed in the brain. In human and bovine Cβ2 has a relative molecular mass of 47 kDa and is mainly expressed in lymphoid tissues. Results We identified a novel 47 kDa splice variant encoded by the mouse Cβ gene that is highly expressed in lymphoid cells. Cloning, expression, and production of a sequence-specific antiserum and characterization of PKA catalytic subunit activities demonstrated the 47 kDa protein to be a catalytically active murine homologue of human and bovine Cβ2. Based on the present results and the existence of a human brain-specifically expressed Cβ splice variant designated Cβ4 that is identical to the former mouse Cβ2 splice variant, the mouse splice variant has now been renamed mouse Cβ4. Conclusion Murine lymphoid tissues express a protein that is a homologue of human and bovine Cβ2. The murine Cβ gene encodes the splice variants Cβ1, Cβ2, Cβ3 and Cβ4, as is the case with the human Cβ gene.
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Affiliation(s)
- Ane Funderud
- Department of Nutrition Research, Institute of Basic Medical Sciences, University of Oslo, PO Box 1046 Blindern, 0317 Oslo, Norway
| | - Heidi H Henanger
- Department of Nutrition Research, Institute of Basic Medical Sciences, University of Oslo, PO Box 1046 Blindern, 0317 Oslo, Norway
| | - Tilahun T Hafte
- Department of Nutrition Research, Institute of Basic Medical Sciences, University of Oslo, PO Box 1046 Blindern, 0317 Oslo, Norway
| | - Paul S Amieux
- Department of Pharmacology, University of Washington School of Medicine, PO Box 357750, Seattle, WA 98195-7750, USA
| | - Sigurd Ørstavik
- Department of Nutrition Research, Institute of Basic Medical Sciences, University of Oslo, PO Box 1046 Blindern, 0317 Oslo, Norway
| | - Bjørn S Skålhegg
- Department of Nutrition Research, Institute of Basic Medical Sciences, University of Oslo, PO Box 1046 Blindern, 0317 Oslo, Norway
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Watson RF, Abdel-Majid RM, Barnett MW, Willis BS, Katsnelson A, Gillingwater TH, McKnight GS, Kind PC, Neumann PE. Involvement of protein kinase A in patterning of the mouse somatosensory cortex. J Neurosci 2006; 26:5393-401. [PMID: 16707791 PMCID: PMC6675315 DOI: 10.1523/jneurosci.0750-06.2006] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Patterning of the mouse somatosensory cortex is unusually evident because of the presence of a "barrel field." Presynaptic serotonin and postsynaptic glutamate receptors regulate barrel formation, but little is known of the intracellular signaling pathways through which they act. To determine whether protein kinase A (PKA) plays a role in the development of the barrel field, we examined five viable PKA subunit-specific knock-out (KO) mouse lines for barrel field abnormalities. Barrels are present in these mice, but those lacking the RIIbeta subunit display significantly reduced contrast between the cell densities of barrel hollows and sides compared with wild-type animals. Thalamocortical afferent segregation in the posterior medial barrel subfield appeared normal, suggesting a postsynaptic site of gene action for the RIIbeta protein. Immunoelectron microscopy confirmed that RIIbeta was selectively localized to dendrites and dendritic spines. Mice lacking RIIbeta show reduced glutamate receptor A (GluRA) subunit insertion into the postsynaptic density in postnatal day 7 somatosensory cortex; however, GluRA KO mice developed normal barrels. Our results clearly demonstrate a role for postsynaptic PKA signaling pathways in barrel differentiation. They also demonstrate a clear dissociation between the regulation of GluRA trafficking by PKA and its role in barrel formation. Finally, although a role for PKA downstream of cAMP cannot be ruled out, these data suggest that PKA may not be the principle downstream target because none of the mutants showed a barrelless phenotype similar to that observed in adenylate cyclase type 1 KO mice. These results give insight into activity-dependent mechanisms that regulate barrel formation.
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Inan M, Lu HC, Albright MJ, She WC, Crair MC. Barrel map development relies on protein kinase A regulatory subunit II beta-mediated cAMP signaling. J Neurosci 2006; 26:4338-49. [PMID: 16624954 PMCID: PMC6674004 DOI: 10.1523/jneurosci.3745-05.2006] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The cellular and molecular mechanisms mediating the activity-dependent development of brain circuitry are still incompletely understood. Here, we examine the role of cAMP-dependent protein kinase [protein kinase A (PKA)] signaling in cortical development and plasticity, focusing on its role in thalamocortical synapse and barrel map development. We provide direct evidence that PKA activity mediates barrel map formation using knock-out mice that lack type IIbeta regulatory subunits of PKA (PKARIIbeta). We show that PKARIIbeta-mediated PKA function is required for proper dendritogenesis and the organization of cortical layer IV neurons into barrels, but not for the development and plasticity of thalamocortical afferent clustering into a barrel pattern. We localize PKARIIbeta function to postsynaptic processes in barrel cortex and show that postsynaptic PKA targets, but not presynaptic PKA targets, have decreased phosphorylation in pkar2b knock-out (PKARIIbeta(-/-)) mice. We also show that long-term potentiation at TC synapses and the associated developmental increase in AMPA receptor function at these synapses, which normally occurs as barrels form, is absent in PKARIIbeta(-/-) mice. Together, these experiments support an activity-dependent model for barrel map development in which the selective addition and elimination of thalamocortical synapses based on Hebbian mechanisms for synapse formation is mediated by a cAMP/PKA-dependent pathway that relies on PKARIIbeta function.
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