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Donders Z, Skorupska IJ, Willems E, Mussen F, Broeckhoven JV, Carlier A, Schepers M, Vanmierlo T. Beyond PDE4 inhibition: A comprehensive review on downstream cAMP signaling in the central nervous system. Biomed Pharmacother 2024; 177:117009. [PMID: 38908196 DOI: 10.1016/j.biopha.2024.117009] [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: 03/28/2024] [Revised: 05/27/2024] [Accepted: 06/17/2024] [Indexed: 06/24/2024] Open
Abstract
Cyclic adenosine monophosphate (cAMP) is a key second messenger that regulates signal transduction pathways pivotal for numerous biological functions. Intracellular cAMP levels are spatiotemporally regulated by their hydrolyzing enzymes called phosphodiesterases (PDEs). It has been shown that increased cAMP levels in the central nervous system (CNS) promote neuroplasticity, neurotransmission, neuronal survival, and myelination while suppressing neuroinflammation. Thus, elevating cAMP levels through PDE inhibition provides a therapeutic approach for multiple CNS disorders, including multiple sclerosis, stroke, spinal cord injury, amyotrophic lateral sclerosis, traumatic brain injury, and Alzheimer's disease. In particular, inhibition of the cAMP-specific PDE4 subfamily is widely studied because of its high expression in the CNS. So far, the clinical translation of full PDE4 inhibitors has been hampered because of dose-limiting side effects. Hence, focusing on signaling cascades downstream activated upon PDE4 inhibition presents a promising strategy, offering novel and pharmacologically safe targets for treating CNS disorders. Yet, the underlying downstream signaling pathways activated upon PDE(4) inhibition remain partially elusive. This review provides a comprehensive overview of the existing knowledge regarding downstream mediators of cAMP signaling induced by PDE4 inhibition or cAMP stimulators. Furthermore, we highlight existing gaps and future perspectives that may incentivize additional downstream research concerning PDE(4) inhibition, thereby providing novel therapeutic approaches for CNS disorders.
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Affiliation(s)
- Zoë Donders
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht 6229ER, the Netherlands; Department of Neuroscience, Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, Hasselt 3500, Belgium
| | - Iga Joanna Skorupska
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht 6229ER, the Netherlands; Department of Neuroscience, Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, Hasselt 3500, Belgium; Department of Cell Biology-Inspired Tissue Engineering, MERLN Institute for Technology-Inspired Regenerative Medicine, Maastricht 6629ER, the Netherlands
| | - Emily Willems
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht 6229ER, the Netherlands; Department of Neuroscience, Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, Hasselt 3500, Belgium
| | - Femke Mussen
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht 6229ER, the Netherlands; Department of Neuroscience, Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, Hasselt 3500, Belgium; Department of Immunology and Infection, Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, Hasselt 3500, Belgium
| | - Jana Van Broeckhoven
- Department of Immunology and Infection, Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, Hasselt 3500, Belgium; University MS Centre (UMSC) Hasselt - Pelt, Belgium
| | - Aurélie Carlier
- Department of Cell Biology-Inspired Tissue Engineering, MERLN Institute for Technology-Inspired Regenerative Medicine, Maastricht 6629ER, the Netherlands
| | - Melissa Schepers
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht 6229ER, the Netherlands; Department of Neuroscience, Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, Hasselt 3500, Belgium; University MS Centre (UMSC) Hasselt - Pelt, Belgium
| | - Tim Vanmierlo
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht 6229ER, the Netherlands; Department of Neuroscience, Biomedical Research Institute, Faculty of Medicine and Life Sciences, Hasselt University, Hasselt 3500, Belgium; University MS Centre (UMSC) Hasselt - Pelt, Belgium.
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Burrack N, Yitzhaky A, Mizrahi L, Wang M, Stern S, Hertzberg L. Altered Expression of PDE4 Genes in Schizophrenia: Insights from a Brain and Blood Sample Meta-Analysis and iPSC-Derived Neurons. Genes (Basel) 2024; 15:609. [PMID: 38790238 PMCID: PMC11121586 DOI: 10.3390/genes15050609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Revised: 05/03/2024] [Accepted: 05/05/2024] [Indexed: 05/26/2024] Open
Abstract
Schizophrenia symptomatology includes negative symptoms and cognitive impairment. Several studies have linked schizophrenia with the PDE4 family of enzymes due to their genetic association and function in cognitive processes such as long-term potentiation. We conducted a systematic gene expression meta-analysis of four PDE4 genes (PDE4A-D) in 10 brain sample datasets (437 samples) and three blood sample datasets (300 samples). Subsequently, we measured mRNA levels in iPSC-derived hippocampal dentate gyrus neurons generated from fibroblasts of three groups: healthy controls, healthy monozygotic twins (MZ), and their MZ siblings with schizophrenia. We found downregulation of PDE4B in brain tissues, further validated by independent data of the CommonMind consortium (515 samples). Interestingly, the downregulation signal was present in a subgroup of the patients, while the others showed no differential expression or even upregulation. Notably, PDE4A, PDE4B, and PDE4D exhibited upregulation in iPSC-derived neurons compared to healthy controls, whereas in blood samples, PDE4B was found to be upregulated while PDE4A was downregulated. While the precise mechanism and direction of altered PDE4 expression necessitate further investigation, the observed multilevel differential expression across the brain, blood, and iPSC-derived neurons compellingly suggests the involvement of PDE4 genes in the pathophysiology of schizophrenia.
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Affiliation(s)
- Nitzan Burrack
- Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva 84101, Israel;
- Clinical Research Center, Soroka University Medical Center, Beer-Sheva 84101, Israel
| | - Assif Yitzhaky
- Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Liron Mizrahi
- Sagol Department of Neurobiology, Faculty of Natural Sciences, University of Haifa, Haifa 3103301, Israel
| | - Meiyan Wang
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Shani Stern
- Sagol Department of Neurobiology, Faculty of Natural Sciences, University of Haifa, Haifa 3103301, Israel
| | - Libi Hertzberg
- Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100, Israel
- Shalvata Mental Health Center, Affiliated with the Faculty of Medicine, Tel-Aviv University, 13 Aliat Hanoar St., Hod Hasharon 45100, Israel
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Zhao H, Blokland A, Prickaerts J, Havekes R, Heckman PRA. Treatment with the selective PDE4B inhibitor A-33 or PDE4D inhibitor zatolmilast prevents sleep deprivation-induced deficits in spatial pattern separation. Behav Brain Res 2024; 459:114798. [PMID: 38056709 DOI: 10.1016/j.bbr.2023.114798] [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: 10/04/2023] [Revised: 11/22/2023] [Accepted: 12/01/2023] [Indexed: 12/08/2023]
Abstract
Sleep deprivation (SD) disrupts hippocampus-dependent memory, particularly in the dentate gyrus (DG) region, an area crucial for pattern separation. Previous research showed that non-selective phosphodiesterase type 4 (PDE4) inhibitors like roflumilast can alleviate these deficits. However, it remains unclear whether these outcomes are specific to a particular subfamily of PDE4. Hence, this study examined the specific impact of PDE4B inhibitor (A-33) and PDE4D inhibitor (zatolmilast) on spatial pattern separation in sleep deprived mice. Results demonstrated that SD impairs pattern separation, but both zatolmilast and A-33 alleviate these effects. However, A-33 impaired pattern separation in non-sleep deprived animals. The cognitive benefits of these inhibitors after SD may arise from alterations in relevant signaling pathways in the DG. This study provides initial evidence that inhibiting PDE4B or PDE4D holds promise for mitigating memory deficits due to SD.
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Affiliation(s)
- Hongyu Zhao
- Dept. Neuropsychology & Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, the Netherlands
| | - Arjan Blokland
- Dept. Neuropsychology & Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, the Netherlands
| | - Jos Prickaerts
- Dept. Psychiatry & Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, the Netherlands
| | - Robbert Havekes
- Neurobiology Expert Group, Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, Groningen, the Netherlands
| | - Pim R A Heckman
- Dept. Neuropsychology & Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, the Netherlands.
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Dominant-Negative Attenuation of cAMP-Selective Phosphodiesterase PDE4D Action Affects Learning and Behavior. Int J Mol Sci 2020; 21:ijms21165704. [PMID: 32784895 PMCID: PMC7460819 DOI: 10.3390/ijms21165704] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Revised: 07/26/2020] [Accepted: 08/06/2020] [Indexed: 12/22/2022] Open
Abstract
PDE4 cyclic nucleotide phosphodiesterases reduce 3′, 5′ cAMP levels in the CNS and thereby regulate PKA activity and the phosphorylation of CREB, fundamental to depression, cognition, and learning and memory. The PDE4 isoform PDE4D5 interacts with the signaling proteins β-arrestin2 and RACK1, regulators of β2-adrenergic and other signal transduction pathways. Mutations in PDE4D in humans predispose to acrodysostosis, associated with cognitive and behavioral deficits. To target PDE4D5, we developed mice that express a PDE4D5-D556A dominant-negative transgene in the brain. Male transgenic mice demonstrated significant deficits in hippocampus-dependent spatial learning, as assayed in the Morris water maze. In contrast, associative learning, as assayed in a fear conditioning assay, appeared to be unaffected. Male transgenic mice showed augmented activity in prolonged (2 h) open field testing, while female transgenic mice showed reduced activity in the same assay. Transgenic mice showed no demonstrable abnormalities in prepulse inhibition. There was also no detectable difference in anxiety-like behavior, as measured in the elevated plus-maze. These data support the use of a dominant-negative approach to the study of PDE4D5 function in the CNS and specifically in learning and memory.
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Amidfar M, de Oliveira J, Kucharska E, Budni J, Kim YK. The role of CREB and BDNF in neurobiology and treatment of Alzheimer's disease. Life Sci 2020; 257:118020. [PMID: 32603820 DOI: 10.1016/j.lfs.2020.118020] [Citation(s) in RCA: 194] [Impact Index Per Article: 48.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 06/23/2020] [Accepted: 06/23/2020] [Indexed: 12/28/2022]
Abstract
Alzheimer's disease (AD) is the most common form of dementia worldwide. β-amyloid peptide (Aβ) is currently assumed to be the main cause of synaptic dysfunction and cognitive impairments in AD, but the molecular signaling pathways underlying its neurotoxic consequences have not yet been completely explored. Additional investigations regarding these pathways will contribute to development of new therapeutic targets. In context, developing evidence suggest that Aβ decreases brain-derived neurotrophic factor (BDNF) mostly by lowering phosphorylated cyclic adenosine monophosphate (cAMP) response element binding protein (CREB) protein. In fact, it has been observed that brain or serum levels of BDNF appear to be beneficial markers for cognitive condition. In addition, the participation of transcription mediated by CREB has been widely analyzed in the memory process and AD development. Designing pharmacologic or genetic therapeutic approaches based on the targeting of CREB-BDNF signaling could be a promising treatment potential for AD. In this review, we summarize data demonstrating the role of CREB-BDNF signaling pathway in cognitive status and mediation of Aβ toxicity in AD. Finally, we also focus on the developing intervention methods for improvement of cognitive decline in AD based on targeting of CREB-BDNF pathway.
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Affiliation(s)
| | - Jade de Oliveira
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Ewa Kucharska
- Jesuit University Ignatianum in Krakow, Faculty of Education, Institute of Educational Sciences, Poland
| | - Josiane Budni
- Laboratório de Neurologia Experimental, Programa de Pós-Graduação em Ciências da Saúde, Universidade do Extremo Sul Catarinense (UNESC), Criciúma, SC, Brazil
| | - Yong-Ku Kim
- Departments of Psychiatry, College of Medicine, Korea University, Seoul, South Korea
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Tibbo AJ, Baillie GS. Phosphodiesterase 4B: Master Regulator of Brain Signaling. Cells 2020; 9:cells9051254. [PMID: 32438615 PMCID: PMC7291338 DOI: 10.3390/cells9051254] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 05/13/2020] [Accepted: 05/14/2020] [Indexed: 12/25/2022] Open
Abstract
Phosphodiesterases (PDEs) are the only superfamily of enzymes that have the ability to break down cyclic nucleotides and, as such, they have a pivotal role in neurological disease and brain development. PDEs have a modular structure that allows targeting of individual isoforms to discrete brain locations and it is often the location of a PDE that shapes its cellular function. Many of the eleven different families of PDEs have been associated with specific diseases. However, we evaluate the evidence, which suggests the activity from a sub-family of the PDE4 family, namely PDE4B, underpins a range of important functions in the brain that positions the PDE4B enzymes as a therapeutic target for a diverse collection of indications, such as, schizophrenia, neuroinflammation, and cognitive function.
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Campbell SL, van Groen T, Kadish I, Smoot LHM, Bolger GB. Altered phosphorylation, electrophysiology, and behavior on attenuation of PDE4B action in hippocampus. BMC Neurosci 2017; 18:77. [PMID: 29197324 PMCID: PMC5712142 DOI: 10.1186/s12868-017-0396-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2016] [Accepted: 11/28/2017] [Indexed: 01/19/2023] Open
Abstract
Background PDE4 cyclic nucleotide phosphodiesterases regulate 3′, 5′ cAMP abundance in the CNS and thereby regulate PKA activity and phosphorylation of CREB, which has been implicated in learning and memory, depression and other functions. The PDE4 isoform PDE4B1 also interacts with the DISC1 protein, implicated in neural development and behavioral disorders. The cellular functions of PDE4B1 have been investigated extensively, but its function(s) in the intact organism remained unexplored. Results To specifically disrupt PDE4B1, we developed mice that express a PDE4B1-D564A transgene in the hippocampus and forebrain. The transgenic mice showed enhanced phosphorylation of CREB and ERK1/2 in hippocampus. Hippocampal neurogenesis was increased in the transgenic mice. Hippocampal electrophysiological studies showed increased baseline synaptic transmission and enhanced LTP in male transgenic mice. Behaviorally, male transgenic mice showed increased activity in prolonged open field testing, but neither male nor female transgenic mice showed detectable anxiety-like behavior or antidepressant effects in the elevated plus-maze, tail-suspension or forced-swim tests. Neither sex showed any significant differences in associative fear conditioning or showed any demonstrable abnormalities in pre-pulse inhibition. Conclusions These data support the use of an isoform-selective approach to the study of PDE4B1 function in the CNS and suggest a probable role of PDE4B1 in synaptic plasticity and behavior. They also provide additional rationale and a refined approach to the development of small-molecule PDE4B1-selective inhibitors, which have potential functions in disorders of cognition, memory, mood and affect.
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Affiliation(s)
- Susan L Campbell
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA.,Center for Glial Biology in Health, Disease, and Cancer, Virginia Tech Carilion Research Institute, 2 Riverside Circle, Roanoke, VA, 24016, USA
| | - Thomas van Groen
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Inga Kadish
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Lisa High Mitchell Smoot
- Department of Medicine, University of Alabama at Birmingham, NP 2501, 1720 2nd Ave S, Birmingham, AL, 35294-3300, USA
| | - Graeme B Bolger
- Department of Pharmacology, University of Alabama at Birmingham, Birmingham, AL, 35294, USA. .,Department of Medicine, University of Alabama at Birmingham, NP 2501, 1720 2nd Ave S, Birmingham, AL, 35294-3300, USA. .,Center for Glial Biology in Health, Disease, and Cancer, Virginia Tech Carilion Research Institute, 2 Riverside Circle, Roanoke, VA, 24016, USA.
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8
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Vogel EW, Morales FN, Meaney DF, Bass CR, Morrison B. Phosphodiesterase-4 inhibition restored hippocampal long term potentiation after primary blast. Exp Neurol 2017; 293:91-100. [PMID: 28366471 PMCID: PMC6016024 DOI: 10.1016/j.expneurol.2017.03.025] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 03/08/2017] [Accepted: 03/30/2017] [Indexed: 01/03/2023]
Abstract
Due to recent military conflicts and terrorist attacks, blast-induced traumatic brain injury (bTBI) presents a health concern for military and civilian personnel alike. Although secondary blast (penetrating injury) and tertiary blast (inertia-driven brain deformation) are known to be injurious, the effects of primary blast caused by the supersonic shock wave interacting with the skull and brain remain debated. Our group previously reported that in vitro primary blast exposure reduced long-term potentiation (LTP), the electrophysiological correlate of learning and memory, in rat organotypic hippocampal slice cultures (OHSCs) and that primary blast affects key proteins governing LTP. Recent studies have investigated phosphodiesterase-4 (PDE4) inhibition as a therapeutic strategy for reducing LTP deficits following inertia-driven TBI. We investigated the therapeutic potential of PDE4 inhibitors, specifically roflumilast, to ameliorate primary blast-induced deficits in LTP. We found that roflumilast at concentrations of 1nM or greater prevented deficits in neuronal plasticity measured 24h post-injury. We also observed a therapeutic window of at least 6h, but <23h. Additionally, we investigated molecular mechanisms that could elucidate this therapeutic effect. Roflumilast treatment (1nM delivered 6h post-injury) significantly increased total AMPA glutamate receptor 1 (GluR1) subunit expression, phosphorylation of the GluR1 subunit at the serine-831 site, and phosphorylation of stargazin at the serine-239/240 site upon LTP induction, measured 24h following injury. Roflumilast treatment significantly increased PSD-95 regardless of LTP induction. These findings indicate that further investigation into the translation of PDE4 inhibition as a therapy following bTBI is warranted.
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Affiliation(s)
- Edward W Vogel
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA
| | - Fatima N Morales
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA
| | - David F Meaney
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Cameron R Bass
- Department of Biomedical Engineering, Duke University, Durham, NC 27705, USA
| | - Barclay Morrison
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA.
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Bolger GB. The PDE4 cAMP-Specific Phosphodiesterases: Targets for Drugs with Antidepressant and Memory-Enhancing Action. ADVANCES IN NEUROBIOLOGY 2017; 17:63-102. [PMID: 28956330 DOI: 10.1007/978-3-319-58811-7_4] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The PDE4 cyclic nucleotide phosphodiesterases are essential regulators of cAMP abundance in the CNS through their ability to regulate PKA activity, the phosphorylation of CREB, and other important elements of signal transduction. In pre-clinical models and in early-stage clinical trials, PDE4 inhibitors have been shown to have antidepressant and memory-enhancing activity. However, the development of clinically-useful PDE4 inhibitors for CNS disorders has been limited by variable efficacy and significant side effects. Recent structural studies have greatly enhanced our understanding of the molecular configuration of PDE4 enzymes, especially the "long" PDE4 isoforms that are abundant in the CNS. The new structural data provide a rationale for the development of a new generation of PDE4 inhibitors that specifically act on long PDE4 isoforms. These next generation PDE4 inhibitors may also be capable of targeting the interactions of select long forms with their "partner" proteins, such as RACK1, β-arrestin, and DISC1. They would therefore have the ability to affect cAMP levels in specific cellular compartments and target localized cellular functions, such as synaptic plasticity. These new agents might also be able to target PDE4 populations in select regions of the CNS that are implicated in learning and memory, affect, and cognition. Potential therapeutic uses of these agents could include affective disorders, memory enhancement, and neurogenesis.
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Affiliation(s)
- Graeme B Bolger
- Departments of Medicine and Pharmacology, University of Alabama at Birmingham, 1720 2nd Avenue South, NP 2501, Birmingham, AL, 35294-3300, USA.
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Ferulic acid prevents LPS-induced up-regulation of PDE4B and stimulates the cAMP/CREB signaling pathway in PC12 cells. Acta Pharmacol Sin 2016; 37:1543-1554. [PMID: 27665850 DOI: 10.1038/aps.2016.88] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 07/01/2016] [Indexed: 12/19/2022] Open
Abstract
AIM Phosphodiesterase 4 (PDE4) isozymes are involved in different functions, depending on their patterns of distribution in the brain. The PDE4 subtypes are distributed in different inflammatory cells, and appear to be important regulators of inflammatory processes. In this study we examined the effects of ferulic acid (FA), a plant component with strong anti-oxidant and anti-inflammatory activities, on lipopolysaccharide (LPS)-induced up-regulation of phosphodiesterase 4B (PDE4B) in PC12 cells, which in turn regulated cellular cAMP levels and the cAMP/cAMP response element binding protein (CREB) pathway in the cells. METHODS PC12 cells were treated with LPS (1 μg/mL) for 8 h, and the changes of F-actin were detected using laser scanning confocal microscopy. The levels of pro-inflammatory cytokines were measured suing ELISA kits, and PDE4B-specific enzymatic activity was assessed with a PDE4B assay kit. The mRNA levels of PDE4B were analyzed with Q-PCR, and the protein levels of CREB and phosphorylated CREB (pCREB) were determined using immunoblotting. Furthermore, molecular docking was used to identify the interaction between PDE4B2 and FA. RESULTS Treatment of PC12 cells with LPS induced thick bundles of actin filaments appearing in the F-actin cytoskeleton, which were ameliorated by pretreatment with FA (10-40 μmol/L) or with a PDE4B inhibitor rolipram (30 μmol/L). Pretreatment with FA dose-dependently inhibited the LPS-induced production of TNF-α and IL-1β in PC12 cells. Furthermore, pretreatment with FA dose-dependently attenuated the LPS-induced up-regulation of PDE4 activity in PC12 cells. Moreover, pretreatment with FA decreased LPS-induced up-regulation of the PDE4B mRNA, and reversed LPS-induced down-regulation of CREB and pCREB in PC12 cells. The molecular docking results revealed electrostatic and hydrophobic interactions between FA and PDE4B2. CONCLUSION The beneficial effects of FA in PC12 cells might be conferred through inhibition of LPS-induced up-regulation of PDE4B and stimulation of cAMP/CREB signaling pathway. Therefore, FA may be a potential therapeutic intervention for the treatment of neuroinflammatory diseases such as AD.
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Bolger GB. RACK1 and β-arrestin2 attenuate dimerization of PDE4 cAMP phosphodiesterase PDE4D5. Cell Signal 2016; 28:706-12. [PMID: 26257302 PMCID: PMC4744576 DOI: 10.1016/j.cellsig.2015.08.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 08/05/2015] [Indexed: 01/14/2023]
Abstract
PDE4 family cAMP-selective cyclic nucleotide phosphodiesterases are important in the regulation of cAMP abundance in numerous systems, and thereby play an important role in the regulation of PKA and EPAC activity and the phosphorylation of CREB. We have used the yeast 2-hybrid system to demonstrate recently that long PDE4 isoforms form homodimers, consistent with data obtained recently by structural studies. The long PDE4 isoform PDE4D5 interacts selectively with β-arrestin2, implicated in the regulation of G-protein-coupled receptors and other cell signaling components, and also with the β-propeller protein RACK1. In the present study, we use 2-hybrid approaches to demonstrate that RACK1 and β-arrestin2 inhibit the dimerization of PDE4D5. We also show that serine-to-alanine mutations at PKA and ERK1/2 phosphorylation sites on PDE4D5 detectably ablate dimerization. Conversely, phospho-mimic serine-to-aspartate mutations at the MK2 and oxidative stress kinase sites ablate dimerization. Analysis of PDE4D5 that is locked into the dimeric configuration by the formation of a trans disulfide bond between Ser261 and Ser602 shows that RACK1 interacts strongly with both the monomeric and dimeric forms, but that β-arrestin2 interacts exclusively with the monomeric form. This is consistent with the concept that β-arrestin2 can preferentially recruit the monomeric, or "open," form of PDE4D5 to β2-adrenergic receptors, where it can regulate cAMP signaling.
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Affiliation(s)
- Graeme B Bolger
- Departments of Medicine and Pharmacology, University of Alabama at Birmingham, Birmingham AL 35294, USA.
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12
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Pearse DD, Hughes ZA. PDE4B as a microglia target to reduce neuroinflammation. Glia 2016; 64:1698-709. [PMID: 27038323 DOI: 10.1002/glia.22986] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2016] [Revised: 03/08/2016] [Accepted: 03/11/2016] [Indexed: 12/12/2022]
Abstract
The importance of microglia in immune homeostasis within the brain is undisputed. Their role in a diversity of neurological and psychiatric diseases as well as CNS injury is the subject of much investigation. Cyclic adenosine monophosphate (AMP) is a critical regulator of microglia homeostasis; as the predominant negative modulator of cyclic AMP signaling within microglia, phosphodiesterase 4 (PDE4) represents a promising target for modulating immune function. PDE4 expression is regulated by inflammation, and in turn, PDE4 inhibition can alter microglia reactivity. As the prototypic PDE4 inhibitor, rolipram, was tested clinically in the 1980s, drug discovery and clinical development of PDE4 inhibitors have been severely hampered by tolerability issues involving nausea and emesis. The two PDE4 inhibitors approved for peripheral inflammatory disorders (roflumilast and apremilast) lack brain penetration and are dose-limited by side effects making them unsuitable for modulating microglial function. Subtype selective inhibitors targeting PDE4B are of high interest given the critical role PDE4B plays in immune function versus the association of PDE4D with nausea and emesis. The challenges and requirements for successful development of a novel brain-penetrant PDE4B inhibitor are discussed in the context of early clinical development strategies. Furthermore, the challenges of monitoring the state of microglia in vivo are highlighted, including a description of the currently available tools and their limitations. Continued drug discovery efforts to identify safe and well-tolerated, brain-penetrant PDE4 inhibitors are a reflection of the confidence in the rationale for modulation of this target to produce meaningful therapeutic benefit in a wide range of neurological conditions and injury. GLIA 2016;64:1698-1709.
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Affiliation(s)
- Damien D Pearse
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, Florida.,Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, Florida.,The Neuroscience Program, University of Miami Miller School of Medicine, Miami, Florida.,The Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, Florida.,Bruce W. Carter Department of Veterans Affairs Medical Center, Miami, Florida
| | - Zoë A Hughes
- Neuroscience and Pain Research Unit, Pfizer Global Research, Cambridge, Massachusetts
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13
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Umar T, Hoda N. Selective inhibitors of phosphodiesterases: therapeutic promise for neurodegenerative disorders. MEDCHEMCOMM 2015. [DOI: 10.1039/c5md00419e] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
PDE inhibitors: significant contributors to the treatment of neurodegenerative diseases.
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Affiliation(s)
- Tarana Umar
- Department of Chemistry
- Jamia Millia Islamia
- Central University
- New Delhi
- 110025 India
| | - Nasimul Hoda
- Department of Chemistry
- Jamia Millia Islamia
- Central University
- New Delhi
- 110025 India
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Richter W, Menniti FS, Zhang HT, Conti M. PDE4 as a target for cognition enhancement. Expert Opin Ther Targets 2013; 17:1011-27. [PMID: 23883342 DOI: 10.1517/14728222.2013.818656] [Citation(s) in RCA: 100] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
INTRODUCTION The second messengers cAMP and cGMP mediate fundamental aspects of brain function relevant to memory, learning, and cognitive functions. Consequently, cyclic nucleotide phosphodiesterases (PDEs), the enzymes that inactivate the cyclic nucleotides, are promising targets for the development of cognition-enhancing drugs. AREAS COVERED PDE4 is the largest of the 11 mammalian PDE families. This review covers the properties and functions of the PDE4 family, highlighting procognitive and memory-enhancing effects associated with their inactivation. EXPERT OPINION PAN-selective PDE4 inhibitors exert a number of memory- and cognition-enhancing effects and have neuroprotective and neuroregenerative properties in preclinical models. The major hurdle for their clinical application is to target inhibitors to specific PDE4 isoforms relevant to particular cognitive disorders to realize the therapeutic potential while avoiding side effects, in particular emesis and nausea. The PDE4 family comprises four genes, PDE4A-D, each expressed as multiple variants. Progress to date stems from characterization of rodent models with selective ablation of individual PDE4 subtypes, revealing that individual subtypes exert unique and non-redundant functions in the brain. Thus, targeting specific PDE4 subtypes, as well as splicing variants or conformational states, represents a promising strategy to separate the therapeutic benefits from the side effects of PAN-PDE4 inhibitors.
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Affiliation(s)
- Wito Richter
- University of California San Francisco, Department of Obstetrics, Gynecology and Reproductive Sciences, San Francisco, CA 94143-0556, USA.
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15
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Zhang H, Zhang SB, Zhang QQ, Liu M, He XY, Zou Z, Sun HJ, You ZD, Shi XY. Rescue of cAMP response element-binding protein signaling reversed spatial memory retention impairments induced by subanesthetic dose of propofol. CNS Neurosci Ther 2013; 19:484-93. [PMID: 23534694 DOI: 10.1111/cns.12088] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2012] [Revised: 02/08/2013] [Accepted: 02/12/2013] [Indexed: 12/14/2022] Open
Abstract
AIMS The intravenous anesthetic propofol caused episodic memory impairments in human. We hypothesized propofol caused episodic-like spatial memory retention but not acquisition impairments in rats and rescuing cAMP response element-binding protein (CREB) signaling using selective type IV phosphodiesterase (PDEIV) inhibitor rolipram reversed these effects. METHODS Male Sprague-Dawley rats were randomized into four groups: control; propofol (25 mg/kg, intraperitoneal); rolipram; and rolipram + propofol (pretreatment of rolipram 25 min before propofol, 0.3 mg/kg, intraperitoneal). Sedation and motor coordination were evaluated 5, 15, and 25 min after propofol injection. Invisible Morris water maze (MWM) acquisition and probe test (memory retention) were performed 5 min and 24 h after propofol injection. Visible MWM training was simultaneously performed to resist nonspatial effects. Hippocampal CREB signaling was detected 5 min, 50 min, and 24 h after propofol administration. RESULTS Rolipram did not change propofol-induced anesthetic/sedative states or impair motor skills. No difference was found on the latency to the platform during the visible MWM. Propofol impaired spatial memory retention but not acquisition. Rolipram reversed propofol-induced spatial memory impairments and suppression on cAMP levels, CaMKIIα and CREB phosphorylation, brain-derived neurotropic factor (BDNF) and Arc protein expression. CONCLUSIONS Propofol caused spatial memory retention impairments but not acquisition inability possibly by inhibiting CREB signaling.
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Affiliation(s)
- Hao Zhang
- Department of Anesthesiology and Neuroscience Research Center, Changzheng Hospital, Second Military Medical University, Shanghai, China
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16
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Kruse LS, Møller M, Kruuse C. Distribution of PDE8A in the nervous system of the Sprague-Dawley rat. J Chem Neuroanat 2011; 42:184-91. [DOI: 10.1016/j.jchemneu.2011.07.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Revised: 07/06/2011] [Accepted: 07/06/2011] [Indexed: 12/01/2022]
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Gourov AV. Synaptic instability in a neuronal population as an element of encoding information. Med Hypotheses 2011; 77:1094-7. [PMID: 21963190 DOI: 10.1016/j.mehy.2011.09.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2011] [Revised: 08/24/2011] [Accepted: 09/07/2011] [Indexed: 10/17/2022]
Abstract
An unexpected and novel finding is described and discussed here concerning the synaptic physiology of hippocampal slices during the period of recovery after brain dissection. Contrary to the common notion that the amplitude of synaptic responses recovers in a single exponential rising fashion, we found that synaptic response amplitude displayed an oscillatory pattern. The period of oscillation was of 6h and its frequency depended on the input frequency of stimulation. Based on these preliminary data we can make an assumption that the recovery-associated oscillatory behavior of synaptic responses may be hippocampus specific. These data suggest the existence of a previously undescribed element that modifies the electrical properties underlying the modulation of synaptic responses in a neuronal population. The article hypothesizes a mechanism for this phenomenon.
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Affiliation(s)
- Andrei V Gourov
- Department of Pathology, Downstate Medical Center, 450 Clarkson Avenue, Box 25, Brooklyn, NY 11203, USA.
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Johansson EM, Sanabra C, Cortés R, Vilaró MT, Mengod G. Lipopolysaccharide administration in vivo induces differential expression of cAMP-specific phosphodiesterase 4B mRNA splice variants in the mouse brain. J Neurosci Res 2011; 89:1761-72. [DOI: 10.1002/jnr.22707] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2011] [Revised: 05/06/2011] [Accepted: 05/10/2011] [Indexed: 01/13/2023]
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19
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Rutten K, Wallace TL, Works M, Prickaerts J, Blokland A, Novak TJ, Santarelli L, Misner DL. Enhanced long-term depression and impaired reversal learning in phosphodiesterase 4B-knockout (PDE4B-/-) mice. Neuropharmacology 2011; 61:138-47. [PMID: 21458469 DOI: 10.1016/j.neuropharm.2011.03.020] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2011] [Revised: 03/22/2011] [Accepted: 03/24/2011] [Indexed: 12/19/2022]
Abstract
3'-5'-Cyclic adenosine monophosphate (cAMP) is known to be an important regulator of synaptic plasticity. The effects of cAMP are mediated through downstream effectors such as protein kinase A (PKA), Ca(2+) and cAMP-response element binding protein (CREB). The phosphodiesterase 4 (PDE4) family of enzymes, which is comprised of four genes and at least 25 protein isoforms, mediates the hydrolysis of cAMP, yet little is presently known about the contribution of specific PDE4 isoforms to synaptic plasticity and cognitive behavior. The purpose of the present studies was to determine the contribution of the PDE4B gene in mediating synaptic plasticity and cognitive behavior. Electrophysiological recordings from hippocampal slice preparations of mice deficient in the PDE4B gene (PDE4B(-/-)) showed that knockout animals displayed markedly enhanced basal postsynaptic responses to stimulation and long-term depression as compared to wild-type littermates. Interestingly, no genotypic differences were noted in long-term potentiation experiments following several different induction protocols. On the behavioral level PDE4B(-/-) mice displayed impaired reversal learning in the Morris water maze compared to wild-type littermates, but no differences in acquisition and retention of spatial memory and fear conditioning. Taken together, these results suggest that the PDE4B gene may play a role in synaptic activity and long-term depression and is involved in spatial reversal memory. Our findings support the view that various PDE4 isoforms are non-redundant and have distinct neurological roles.
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Affiliation(s)
- Kris Rutten
- CNS Discovery Research, Roche Palo Alto, Palo Alto, CA, USA.
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20
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Navakkode S, Sajikumar S, Sacktor TC, Frey JU. Protein kinase Mzeta is essential for the induction and maintenance of dopamine-induced long-term potentiation in apical CA1 dendrites. Learn Mem 2010; 17:605-11. [PMID: 21084457 DOI: 10.1101/lm.1991910] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Dopaminergic D1/D5-receptor-mediated processes are important for certain forms of memory as well as for a cellular model of memory, hippocampal long-term potentiation (LTP) in the CA1 region of the hippocampus. D1/D5-receptor function is required for the induction of the protein synthesis-dependent maintenance of CA1-LTP (L-LTP) through activation of the cAMP/PKA-pathway. In earlier studies we had reported a synergistic interaction of D1/D5-receptor function and N-methyl-D-aspartate (NMDA)-receptors for L-LTP. Furthermore, we have found the requirement of the atypical protein kinase C isoform, protein kinase Mζ (PKMζ) for conventional electrically induced L-LTP, in which PKMζ has been identified as a LTP-specific plasticity-related protein (PRP) in apical CA1-dendrites. Here, we investigated whether the dopaminergic pathway activates PKMζ. We found that application of dopamine (DA) evokes a protein synthesis-dependent LTP that requires synergistic NMDA-receptor activation and protein synthesis in apical CA1-dendrites. We identified PKMζ as a DA-induced PRP, which exerted its action at activated synaptic inputs by processes of synaptic tagging.
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Affiliation(s)
- Sheeja Navakkode
- Department of Neurophysiology, Leibniz-Institute for Neurobiology, Brenneckestrasse 6, 39118 Magdeburg, Germany
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21
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Yang K, Trepanier CH, Li H, Beazely MA, Lerner EA, Jackson MF, MacDonald JF. Vasoactive intestinal peptide acts via multiple signal pathways to regulate hippocampal NMDA receptors and synaptic transmission. Hippocampus 2009; 19:779-89. [PMID: 19173226 DOI: 10.1002/hipo.20559] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Vasoactive intestinal peptide (VIP) is a 28-amino acid peptide, which belongs to a superfamily of structurally related peptide hormones including pituitary adenylate cyclase-activating polypeptide (PACAP). Although several studies have identified the involvement of PACAP in learning and memory, little work has been done to investigate such a role for VIP. At least three receptors for VIP have been identified including the PACAP receptor (PAC1-R) and the two VIP receptors (VPAC receptors). VIP can activate the PAC1-R only if it is used at relatively high concentrations (e.g., 100 nM); however, at lower concentrations (e.g., 1 nM) it is selective for the VPAC receptors. Our lab has showed that PAC1-R activation signals through PKC/CAKbeta/Src pathway to regulate NMDA receptors; however, there is little known about the potential regulation of NMDA receptors by VPAC receptors. Our studies demonstrated that application of 1 nM VIP enhanced NMDA currents by stimulating the VPAC receptors as the effect was blocked by VPAC receptor antagonist [Ac-Tyr(1), D-Phe(2)]GRF (1-29). This enhancement of NMDA currents was blocked by both Rp-cAMPS and PKI(14-22) (they are highly specific PKA inhibitors), but not by the specific PKC inhibitor, bisindolylmaleimide I. In addition, the VIP-induced enhancement of NMDA currents was accentuated by inhibition of phosphodiesterase 4, which inhibits the degradation of cAMP. This regulation of NMDA receptors also required the scaffolding protein AKAP. In contrast, the potentiation induced by high concentration of VIP (e.g., 100 nM) was mediated by PAC1-R as well as by Src kinase. Overall, these results show that VIP can regulate NMDA receptors through different receptors and signaling pathways.
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Affiliation(s)
- Kai Yang
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
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22
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Whitaker CM, Cooper NGF. The novel distribution of phosphodiesterase-4 subtypes within the rat retina. Neuroscience 2009; 163:1277-91. [PMID: 19638302 DOI: 10.1016/j.neuroscience.2009.07.045] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2009] [Revised: 07/21/2009] [Accepted: 07/21/2009] [Indexed: 01/01/2023]
Abstract
Phosphodiesterases (PDEs) are important regulators of signal transduction processes. While much is known about the function of cyclic GMP-specific PDEs in the retina, much less is known about the closely related, cyclic AMP-specific PDEs. The purpose of the present study is to characterize and localize PDE4 within the adult rat retina. We have used Western blotting, RT-PCR, and immunohistochemistry together with retrograde labeling to determine the presence and location of each PDE4 subtype. Western blot analysis revealed that multiple isoforms of PDE4A, B, and D subtypes are present within the retina, whereas the PDE4C subtype was absent. These data were confirmed by RT-PCR. Using immunohistochemistry we show that all three PDE4s are abundantly expressed within the retina where they all colocalize with retrograde-labeled retinal ganglion cells, as well as bipolar cells, horizontal cells, and cholinergic amacrine cells, whereas Müller cells lack PDE4 expression. Uniquely, PDE4B was expressed by the inner and outer segments of rod photoreceptors as well as their terminals within the outer plexiform layer. Collectively, our results demonstrate that PDE4s are abundantly expressed throughout the rodent retina and this study provides the framework for further functional studies.
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Affiliation(s)
- C M Whitaker
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, KY 40292, USA
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Selective phosphodiesterase inhibitors: a promising target for cognition enhancement. Psychopharmacology (Berl) 2009; 202:419-43. [PMID: 18709359 PMCID: PMC2704616 DOI: 10.1007/s00213-008-1273-x] [Citation(s) in RCA: 212] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2008] [Accepted: 07/23/2008] [Indexed: 12/15/2022]
Abstract
RATIONALE One of the major complaints most people face during aging is an impairment in cognitive functioning. This has a negative impact on the quality of daily life and is even more prominent in patients suffering from neurodegenerative and psychiatric disorders including Alzheimer's disease, schizophrenia, and depression. So far, the majority of cognition enhancers are generally targeting one particular neurotransmitter system. However, recently phosphodiesterases (PDEs) have gained increased attention as a potential new target for cognition enhancement. Inhibition of PDEs increases the intracellular availability of the second messengers cGMP and/or cAMP. OBJECTIVE The aim of this review was to provide an overview of the effects of phosphodiesterase inhibitors (PDE-Is) on cognition, the possible underlying mechanisms, and the relationship to current theories about memory formation. MATERIALS AND METHODS Studies of the effects of inhibitors of different PDE families (2, 4, 5, 9, and 10) on cognition were reviewed. In addition, studies related to PDE-Is and blood flow, emotional arousal, and long-term potentiation (LTP) were described. RESULTS PDE-Is have a positive effect on several aspects of cognition, including information processing, attention, memory, and executive functioning. At present, these data are likely to be explained in terms of an LTP-related mechanism of action. CONCLUSION PDE-Is are a promising target for cognition enhancement; the most suitable candidates appear to be PDE2-Is or PDE9-Is. The future for PDE-Is as cognition enhancers lies in the development of isoform-specific PDE-Is that have limited aversive side effects.
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Blokland A, Boess F. Use of behavioural and long-term potentiation models in the development of memory-improving drugs. Expert Opin Drug Discov 2008; 3:1067-80. [DOI: 10.1517/17460441.3.9.1067] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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25
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Fatemi SH, King DP, Reutiman TJ, Folsom TD, Laurence JA, Lee S, Fan YT, Paciga SA, Conti M, Menniti FS. PDE4B polymorphisms and decreased PDE4B expression are associated with schizophrenia. Schizophr Res 2008; 101:36-49. [PMID: 18394866 DOI: 10.1016/j.schres.2008.01.029] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2007] [Revised: 01/22/2008] [Accepted: 01/28/2008] [Indexed: 01/28/2023]
Abstract
Schizophrenia has a complex genetic underpinning and variations in a number of candidate genes have been identified that confer risk of developing the disorder. We report in the present studies that several single nucleotide polymorphisms (SNPs) and a two-SNP haplotype in PDE4B are associated with an increased incidence of schizophrenia in two large populations of Caucasian and African American patients. The SNPs in PDE4B associated with schizophrenia occur in intronic sequences in the vicinity of a critical splice junction that gives rise to the expression of PDE4B isoforms with distinct regulation and function. We also observed specific decreases in phosphodiesterase 4B (PDE4B) isoforms in brain tissue obtained postmortem from patients diagnosed with schizophrenia and bipolar disorder. PDE4B metabolically inactivates the second messenger cAMP to regulate intracellular signaling in neurons throughout the brain. Thus, the present observations suggest that dysregulation of intracellular signaling mediated by PDE4B is a significant factor in the cause and expression, respectively, of schizophrenia and bipolar disorder and that targeting PDE4B-regulated signaling pathways may yield new therapies to treat the totality of these disorders.
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Affiliation(s)
- S Hossein Fatemi
- Department of Psychiatry, University of Minnesota Medical School, MMC 392, Minneapolis, MN 55455, USA.
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26
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Reyes-Irisarri E, Pérez-Torres S, Miró X, Martínez E, Puigdomènech P, Palacios JM, Mengod G. Differential distribution of PDE4B splice variant mRNAs in rat brain and the effects of systemic administration of LPS in their expression. Synapse 2008; 62:74-9. [PMID: 17960764 DOI: 10.1002/syn.20459] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Phosphodiesterases (PDE) control intracellular cyclic adenosine monophosphate (cAMP) levels, which appear to play an important role in the regulation of inflammation. PDE4B is especially important in this process. Using in situ hybridization histochemistry we first mapped the expression sites of the four PDE4B splicing forms in rat brain. Using the systemic administration of the bacterial endotoxin lipopolysaccharide (LPS) as an inflammation model in rats, we found an increase in PDEB2 mRNA expression in choroid plexus. The differential expression of PDE4B spliced forms and the differential regulation of PDE4B2 in an inflammatory model further supports an involvement of this splicing variant in the inflammatory response.
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Affiliation(s)
- Elisabet Reyes-Irisarri
- Department of Neurochemistry, Institut d'Investigacions Biomèdiques de Barcelona, CSIC (IDIBAPS), Barcelona, Spain
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Sajikumar S, Navakkode S, Frey JU. Identification of compartment- and process-specific molecules required for "synaptic tagging" during long-term potentiation and long-term depression in hippocampal CA1. J Neurosci 2007; 27:5068-80. [PMID: 17494693 PMCID: PMC6672381 DOI: 10.1523/jneurosci.4940-06.2007] [Citation(s) in RCA: 146] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Protein synthesis-dependent forms of hippocampal long-term potentiation (late LTP) and long-term depression (late LTD) are prominent cellular mechanisms underlying memory formation. Recent data support the hypothesis that neurons store relevant information in dendritic functional compartments during late LTP and late LTD rather than in single synapses. It has been suggested that processes of "synaptic tagging" are restricted to such functional compartments. Here, we show that in addition to apical CA1 dendrites, synaptic tagging also takes place within basal CA1 dendritic compartments after LTP induction. We present data that tagging in the basal dendrites is restricted to these compartments. Plasticity-related proteins, partially nonspecific to the locally induced process, are synthesized in dendritic compartments and then captured by local, process-specific synaptic tags. We support these findings in two ways: (1) late LTP/LTD, locally induced in apical or basal (late LTP) dendrites of hippocampal CA1 neurons, does not spread to the basal or apical compartment, respectively; (2) the specificity of the synaptic plasticity event is achieved by the activation of process- and compartment-specific synaptic tag molecules. We have identified calcium/calmodulin-dependent protein kinase II as the first LTP-specific and extracellular signal-regulated kinase 1/2 as LTD-specific tag molecules in apical dendritic CA1 compartments, whereas either protein kinase A or protein kinase Mzeta mediates LTP-specific tags in basal dendrites.
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Affiliation(s)
- Sreedharan Sajikumar
- Leibniz Institute for Neurobiology, Department of Neurophysiology, 39118 Magdeburg, Germany
| | - Sheeja Navakkode
- Leibniz Institute for Neurobiology, Department of Neurophysiology, 39118 Magdeburg, Germany
| | - Julietta U. Frey
- Leibniz Institute for Neurobiology, Department of Neurophysiology, 39118 Magdeburg, Germany
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Menniti FS, Faraci WS, Schmidt CJ. Phosphodiesterases in the CNS: targets for drug development. Nat Rev Drug Discov 2006; 5:660-70. [PMID: 16883304 DOI: 10.1038/nrd2058] [Citation(s) in RCA: 304] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The therapeutic and commercial success of phosphodiesterase 5 inhibitors such as Viagra, Levitra and Cialis has sparked renewed interest in the phosphodiesterases as drug discovery targets. Virtually all the phosphodiesterases are expressed in the CNS, making this gene family a particularly attractive source of new targets for the treatment of psychiatric and neurodegenerative disorders. Significantly, all neurons express multiple phosphodiesterases, which differ in cyclic nucleotide specificity, affinity, regulatory control and subcellular compartmentalization. Therefore, phosphodiesterase inhibition represents a mechanism through which it could be possible to precisely modulate neuronal activity. In this article, we review the current state of the art in the burgeoning field of phosphodiesterase pharmacology in the CNS.
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Affiliation(s)
- Frank S Menniti
- Pfizer Global Research and Development, CNS Discovery, Groton, Connecticut 06340, USA
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29
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Navakkode S, Sajikumar S, Frey JU. Mitogen-activated protein kinase-mediated reinforcement of hippocampal early long-term depression by the type IV-specific phosphodiesterase inhibitor rolipram and its effect on synaptic tagging. J Neurosci 2006; 25:10664-70. [PMID: 16291939 PMCID: PMC6725844 DOI: 10.1523/jneurosci.2443-05.2005] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Rolipram, a selective inhibitor of cAMP-specific phosphodiesterase 4 (PDE4), has been shown to reinforce an early form of long-term potentiation (LTP) to a long-lasting LTP (late LTP). Furthermore, it was shown that the effects of rolipram-mediated reinforcement of LTP interacts with processes of synaptic tagging (Navakkode et al., 2004). Here we show in CA1 hippocampal slices from adult rats in vitro that rolipram also converted an early form of long-term depression (LTD) that normally decays within 2-3 h, to a long-lasting LTD (late LTD) if rolipram was applied during LTD-induction. Rolipram-reinforced LTD (RLTD) was NMDA receptor- and protein synthesis-dependent. Furthermore, it was dependent on the synergistic coactivation of dopaminergic D(1) and D(5) receptors. This let us speculate that RLTD resembles electrically induced, conventional CA1 late LTD, which is characterized by heterosynaptic processes and synaptic tagging. We therefore asked whether synaptic tagging occurs during RLTD. We found that early LTD in an S1 synaptic input was transformed into late LTD if early LTD was induced in a second independent S2 synaptic pathway during the inhibition of PDE by rolipram, supporting the interaction of processes of synaptic tagging during RLTD. Furthermore, application of PD 98059 (2'-amino-3'-methoxyflavone) or U0126 (1,4-diamino-2,3-dicyano-1,4-bis[2-aminophenylthio]butadiene), specific inhibitors of mitogen-activated protein kinases (MAPKs), prevented RLTD, suggesting a pivotal role of MAPK activation for RLTD. This MAPK activation was triggered during RLTD by the synergistic interaction of NMDA receptor- and D(1) and D(5) receptor-mediated Rap/B-Raf pathways, but not by the Ras/Raf-1 pathway in adult hippocampal CA1 neurons, as shown by the use of the pathway-specific inhibitors manumycin (Ras/Raf-1) and lethal toxin 82 (Rap/B-Raf).
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Affiliation(s)
- Sheeja Navakkode
- Department of Neurophysiology, Leibniz Institute for Neurobiology, D-39118 Magdeburg, Germany
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Sajikumar S, Navakkode S, Sacktor TC, Frey JU. Synaptic tagging and cross-tagging: the role of protein kinase Mzeta in maintaining long-term potentiation but not long-term depression. J Neurosci 2006; 25:5750-6. [PMID: 15958741 PMCID: PMC6724879 DOI: 10.1523/jneurosci.1104-05.2005] [Citation(s) in RCA: 141] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Protein kinase Mzeta (PKMzeta) is a persistently active protein kinase C isoform that is synthesized during long-term potentiation (LTP) and is critical for maintaining LTP. According to "synaptic tagging," newly synthesized, functionally important plasticity-related proteins (PRPs) may prolong potentiation not only at strongly tetanized pathways, but also at independent, weakly tetanized pathways if synaptic tags are set. We therefore investigated whether PKMzeta is involved in tagging and contributes to a sustained potentiation by providing strong and weak tetanization to two independent pathways and then disrupting the function of the kinase by a selective myristoylated zeta-pseudosubstrate inhibitory peptide. We found that persistent PKMzeta activity maintains potentiated responses, not only of the strongly tetanized pathway, but also of the weakly tetanized pathway. In contrast, an independent, nontetanized pathway was unaffected by the inhibitor, indicating that the function of PKMzeta was specific to the tagged synapses. To further delineate the specificity of the function of PKMzeta in synaptic tagging, we examined synaptic "cross-tagging," in which late LTP in one input can transform early into late long-term depression (LTD) in a separate input or, alternatively, late LTD in one input can transform early into late LTP in a second input, provided that the tags of the weak inputs are set. Although the PKMzeta inhibitor reversed late LTP, it did not prevent the persistent depression at the weakly stimulated, cross-tagged LTD input. Conversely, although the agent did not reverse late LTD, it blocked the persistent potentiation of weakly tetanized, cross-tagged synapses. Thus, PKMzeta is the first LTP-specific PRP and is critical for the transformation of early into late LTP during both synaptic tagging and cross-tagging.
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Affiliation(s)
- Sreedharan Sajikumar
- Department of Neurophysiology, Leibniz Institute for Neurobiology, D-39118 Magdeburg, Germany
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Ahmed T, Frey JU. Phosphodiesterase 4B (PDE4B) and cAMP-level regulation within different tissue fractions of rat hippocampal slices during long-term potentiation in vitro. Brain Res 2005; 1041:212-22. [PMID: 15829230 DOI: 10.1016/j.brainres.2005.02.023] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2004] [Revised: 02/02/2005] [Accepted: 02/07/2005] [Indexed: 12/14/2022]
Abstract
Molecular events associated with mnemonic processes and neuronal plasticity are postulated to result in functional changes in synaptic structure. One possible site is the post-synaptic density, where activity-dependent changes modulate signal transduction cascades. In this report, we detail spatial-temporal changes for phosphodiesterase 4B (PDE4B) proteins and their substrate cAMP within three neuronal fractions during early and late long-term potentiation (LTP). The cAMP-dependent protein kinase A cascade--which can be regulated by distinct PDE4B activity--is required for mnemonic processes as well as mechanisms of neuronal plasticity, such as those during the maintenance or late-LTP. Fluorescence in situ hybridization studies (FISH) identified no translocation of PDE4B3 from the soma after late-LTP induction indicating a subtle, local control of PDE4B activity. Protein changes were detected within the PSD-enriched fraction. From these results, we conclude that either the changes in PDE4B are due to modulation of pre-existing mRNA, or that the protein is specifically translocated to activated synaptic structures. Furthermore, we report late changes in cAMP levels in the somato-dendritic fraction and discuss this result with the increased PDE4B1/3 doublet in the PSD-enriched fraction.
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Affiliation(s)
- T Ahmed
- Department of Neurophysiology, Leibniz-Institute for Neurobiology, Brenneckestrasse 6, D-39118 Magdeburg, Germany
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Navakkode S, Sajikumar S, Frey JU. The type IV-specific phosphodiesterase inhibitor rolipram and its effect on hippocampal long-term potentiation and synaptic tagging. J Neurosci 2005; 24:7740-4. [PMID: 15342741 PMCID: PMC6729613 DOI: 10.1523/jneurosci.1796-04.2004] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We investigated the effects of rolipram, a selective cAMP phosphodiesterase (PDE) inhibitor, on late plastic events during functional CA1 plasticity in vitro in rat hippocampal slices. We present data showing that an early form of long-term potentiation (LTP) (early-LTP) that normally decays within 2-3 hr can be converted to a lasting LTP (late-LTP) if rolipram is applied during tetanization. This rolipram-reinforced LTP (RLTP) was NMDA receptor and protein synthesis dependent. cAMP formation in region CA1 during late-LTP requires dopaminergic receptor activity (Frey et al., 1989, 1990). Thus, we studied whether RLTP was influenced by inhibitors of the D(1)/D(5) receptor. Application of the specific D(1)/D(5) antagonist SCH23390 (0.1 microm) did not prevent RLTP, suggesting that the phosphodiesterase inhibitor acts downstream of the D(1)/D(5) receptors. We also studied whether rolipram can interact with processes of synaptic tagging, because RLTP was also dependent on protein synthesis, similar to late-LTP. Inhibition of PDE and subsequent induction of RLTP in one synaptic population were able to transform early-LTP into late-LTP in a second, independent synaptic population of the same neurons. This supports our hypothesis that cAMP-dependent processes are directly involved in the synthesis of plasticity-related proteins.
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Affiliation(s)
- Sheeja Navakkode
- Leibniz Institute for Neurobiology, Department of Neurophysiology, D-39118 Magdeburg, Germany
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Giorgi M, Modica A, Pompili A, Pacitti C, Gasbarri A. The induction of cyclic nucleotide phosphodiesterase 4 gene (PDE4D) impairs memory in a water maze task. Behav Brain Res 2004; 154:99-106. [PMID: 15302115 DOI: 10.1016/j.bbr.2004.01.024] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2003] [Revised: 01/26/2004] [Accepted: 01/28/2004] [Indexed: 10/26/2022]
Abstract
In this study, the effects on memory of intraperitoneal post-training administration of cyclic nucleotide phosphodiesterase (PDE) inhibitors, DC-TA 46 and rolipram, were tested using a visible/hidden-platform water maze task. The effects of these compounds on cyclic nucleotide levels in the hippocampal formation (HF) and striatum (CP) were also assessed, by enzymatic immunoassay (EIA). The results obtained from rats trained in the visible-platform task were not significantly different from controls. On the contrary, the animals trained in the hidden-platform water maze task showed a memory impairment, when injected with DC-TA 46 at maximal dose of 20mg/kg and with rolipram at 3 and 30 mg/kg doses. The effects of these drugs on cyclic nucleotide levels in HF and CP were observed at 30 min and at 24h after drug administration. Thirty minutes after drug injection, we observed an increase of cAMP level, both in HF and in CP. Twenty-four hours after the retention test, we observed that in CP the cAMP intracellular level remained high, while in the HF at effective doses both inhibitors induced cAMP PDE activity, determining a decrease of cyclic nucleotide. Semi-quantitative RT-PCR analysis, together with Western blot immunodetection, showed a mRNA and protein induction of PDE4D PDE isoforms, that may account for the increase of PDE activity observed. Our data suggest that, despite cyclic nucleotide increase at 30 min, the fundamental event causing memory impairment, came from the subsequent long time decrease of cAMP levels, due to the post-translational PDE4D induction.
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Affiliation(s)
- Mauro Giorgi
- Department of Basic and Applied Biology, University of L'Aquila, Via Vetoio, località Coppito, 67100 L'Aquila, Italy
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Zhang HT, Zhao Y, Huang Y, Dorairaj NR, Chandler LJ, O'Donnell JM. Inhibition of the phosphodiesterase 4 (PDE4) enzyme reverses memory deficits produced by infusion of the MEK inhibitor U0126 into the CA1 subregion of the rat hippocampus. Neuropsychopharmacology 2004; 29:1432-9. [PMID: 15114341 DOI: 10.1038/sj.npp.1300440] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Cyclic AMP-specific phosphodiesterase 4 (PDE4), which is an integral component of NMDA receptor-mediated cAMP signaling, is involved in the mediation of memory processes. Given that NMDA receptors also mediate MEK/mitogen-activated protein kinase (MAPK, ERK) signaling, which is involved in synaptic plasticity, and that some PDE4 subtypes are phosphorylated and regulated by ERK, it was of interest to determine if PDE4 is involved in MEK/ERK signaling-mediated memory. It was found that rolipram, a PDE4-selective inhibitor, reversed the amnesic effect in the radial-arm maze test of the MEK inhibitor U0126 administered into the CA1 subregion of the rat hippocampus. Consistent with this, rolipram, either by peripheral administration or direct intra-CA1 infusion, enhanced the retrieval of long-term memory impaired by intra-CA1 infusion of U0126 using the step-through inhibitory avoidance test. The same dose of rolipram did not affect U0126-induced reduction of phospho-ERK1/2 levels in the CA1 subregion. However, in primary cultures of rat cerebral cortical neurons, pretreatment with U0126 increased PDE4 activity; this was correlated with the U0126-induced reduction of phospho-ERK1/2 levels. These results suggest that MEK/ERK signaling plays an inhibitory role in regulating PDE4 activity in the brain; this may be a novel mechanism by which MEK/ERK signaling mediates memory. PDE4 is likely to be an important link between the cAMP/PKA and MEK/ERK signaling pathways in the mediation of memory.
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Affiliation(s)
- Han-Ting Zhang
- Department of Pharmacology, The University of Tennessee Health Science Center, Memphis, TN 38163, USA.
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Ahmed T, Frey S, Frey JU. Regulation of the phosphodiesterase PDE4B3-isotype during long-term potentiation in the area dentata in vivo. Neuroscience 2004; 124:857-67. [PMID: 15026126 DOI: 10.1016/j.neuroscience.2004.01.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/07/2004] [Indexed: 11/28/2022]
Abstract
Hippocampal long-term potentiation (LTP) is the most prominent cellular model underlying learning and memory formation. However, which cellular processes are involved in maintaining LTP remains largely unknown. We have previously detailed temporal modulations of cyclic adenosine monophosphate (cAMP) and a cAMP-specific phosphodiesterase, PDE4B3, after LTP-induction and its maintenance in hippocampal area CA1 in vitro. To test whether other hippocampal sub-structures are characterised by similar mechanisms, tissue from the area dentata of freely moving rats was analysed at different LTP-time points. The tissue was fractionated into three components, where PDE4B-levels and cAMP-concentrations were measured. In contrast with data obtained in area CA1, we now detail an LTP-specific translational, but not transcriptional regulation of PDE4B3 within the first 8 h after tetanization and present spatio-temporal changes of PDE4B proteins and cAMP that is LTP-specific.
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Affiliation(s)
- T Ahmed
- Leibniz-Institute for Neurobiology, Department of Neurophysiology, Brenneckestrasse 6, D-39118 Magdeburg, Germany
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O'Connor V, Genin A, Davis S, Karishma KK, Doyère V, De Zeeuw CI, Sanger G, Hunt SP, Richter-Levin G, Mallet J, Laroche S, Bliss TVP, French PJ. Differential Amplification of Intron-containing Transcripts Reveals Long Term Potentiation-associated Up-regulation of Specific Pde10A Phosphodiesterase Splice Variants. J Biol Chem 2004; 279:15841-9. [PMID: 14752115 DOI: 10.1074/jbc.m312500200] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We employed differential display of expressed mRNAs (Liang, P., and Pardee, A. B. (1992) Science 257, 967-971) to identify genes up-regulated after long term potentiation (LTP) induction in the hippocampus of awake adult rats. In situ hybridization confirmed the differential expression of five independently amplified clones representing two distinct transcripts, cl13/19/90 and cl95/96. Neither cl13/19/90 nor cl95/96 showed significant sequence homology to known transcripts (mRNA or expressed sequence tag) or to the mouse or human genome. However, comparison with the rat genome revealed that they are localized to a predicted intron of the phosphodiesterase Pde10A gene. cl13/19/90 and cl95/96 are likely to be part of the Pde10A primary transcript as, using reverse transcriptase-PCR, we could specifically amplify distinct introns of the Pde10A primary transcript, and in situ hybridization demonstrated that a subset of Pde10A splice variants are also up-regulated after LTP induction. These results indicate that amplification of a primary transcript can faithfully report gene activity and that differential display can be used to identify differential expression of RNA species other than mRNA. In transiently transfected Cos7 cells, Pde10A3 reduces the atrial natriuretic peptide-induced elevation in cGMP levels without affecting basal cGMP levels. This cellular function of LTP-associated Pde10A transcripts argues for a role of the cGMP/cGMP-dependent kinase pathway in long term synaptic plasticity.
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Affiliation(s)
- Vincent O'Connor
- School of Biological Sciences, University of Southampton, Southampton SO16 7PX, United Kingdom
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