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Panossian AG, Efferth T, Shikov AN, Pozharitskaya ON, Kuchta K, Mukherjee PK, Banerjee S, Heinrich M, Wu W, Guo D, Wagner H. Evolution of the adaptogenic concept from traditional use to medical systems: Pharmacology of stress- and aging-related diseases. Med Res Rev 2021; 41:630-703. [PMID: 33103257 PMCID: PMC7756641 DOI: 10.1002/med.21743] [Citation(s) in RCA: 140] [Impact Index Per Article: 46.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 08/26/2020] [Accepted: 10/11/2020] [Indexed: 12/14/2022]
Abstract
Adaptogens comprise a category of herbal medicinal and nutritional products promoting adaptability, resilience, and survival of living organisms in stress. The aim of this review was to summarize the growing knowledge about common adaptogenic plants used in various traditional medical systems (TMS) and conventional medicine and to provide a modern rationale for their use in the treatment of stress-induced and aging-related disorders. Adaptogens have pharmacologically pleiotropic effects on the neuroendocrine-immune system, which explain their traditional use for the treatment of a wide range of conditions. They exhibit a biphasic dose-effect response: at low doses they function as mild stress-mimetics, which activate the adaptive stress-response signaling pathways to cope with severe stress. That is in line with their traditional use for preventing premature aging and to maintain good health and vitality. However, the potential of adaptogens remains poorly explored. Treatment of stress and aging-related diseases require novel approaches. Some combinations of adaptogenic plants provide unique effects due to their synergistic interactions in organisms not obtainable by any ingredient independently. Further progress in this field needs to focus on discovering new combinations of adaptogens based on traditional medical concepts. Robust and rigorous approaches including network pharmacology and systems pharmacology could help in analyzing potential synergistic effects and, more broadly, future uses of adaptogens. In conclusion, the evolution of the adaptogenic concept has led back to basics of TMS and a new level of understanding of holistic approach. It provides a rationale for their use in stress-induced and aging-related diseases.
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Affiliation(s)
| | - Thomas Efferth
- Department of Pharmaceutical Biology, Institute of Pharmacy and BiochemistryJohannes Gutenberg UniversityMainzGermany
| | - Alexander N. Shikov
- Department of technology of dosage formsSaint‐Petersburg State Chemical‐Pharmaceutical UniversitySt. PetersburgRussia
| | - Olga N. Pozharitskaya
- Department of BiotechnologyMurmansk Marine Biological Institute of the Kola Science Center of the Russian Academy of Sciences (MMBI KSC RAS)MurmanskRussia
| | - Kenny Kuchta
- Department of Far Eastern Medicine, Clinic for Gastroenterology and Gastrointestinal OncologyUniversity Medical Center GöttingenGöttingenGermany
| | - Pulok K. Mukherjee
- Department of Pharmaceutical Technology, School of Natural Product StudiesJadavpur UniversityKolkataIndia
| | - Subhadip Banerjee
- Department of Pharmaceutical Technology, School of Natural Product StudiesJadavpur UniversityKolkataIndia
| | - Michael Heinrich
- Research Cluster Biodiversity and Medicines, UCL School of Pharmacy, Centre for Pharmacognosy and PhytotherapyUniversity of LondonLondonUK
| | - Wanying Wu
- Shanghai Research Center for TCM Modernization, Shanghai Institute of Materia MedicaChinese Academy of SciencesShanghaiChina
| | - De‐an Guo
- Shanghai Research Center for TCM Modernization, Shanghai Institute of Materia MedicaChinese Academy of SciencesShanghaiChina
| | - Hildebert Wagner
- Department of Pharmacy, Center for Pharma ResearchLudwig‐Maximilians‐Universität MünchenMunichGermany
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2
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Bastola T, Pariyar R, Jeon BM, Baek JI, Chang BY, Kim SC, Kim SY, Seo J. Protective effects of SGB121, ginsenoside F1-enriched ginseng extract, on scopolamine-induced cytotoxicity and memory impairments. J Funct Foods 2020. [DOI: 10.1016/j.jff.2020.104165] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
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3
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Griffith CM, Macklin LN, Cai Y, Sharp AA, Yan XX, Reagan LP, Strader AD, Rose GM, Patrylo PR. Impaired Glucose Tolerance and Reduced Plasma Insulin Precede Decreased AKT Phosphorylation and GLUT3 Translocation in the Hippocampus of Old 3xTg-AD Mice. J Alzheimers Dis 2020; 68:809-837. [PMID: 30775979 DOI: 10.3233/jad-180707] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Several studies have demonstrated that mouse models of Alzheimer's disease (AD) can exhibit impaired peripheral glucose tolerance. Further, in the APP/PS1 mouse model, this is observed prior to the appearance of AD-related neuropathology (e.g., amyloid-β plaques; Aβ) or cognitive impairment. In the current study, we examined whether impaired glucose tolerance also preceded AD-like changes in the triple transgenic model of AD (3xTg-AD). Glucose tolerance testing (GTT), insulin ELISAs, and insulin tolerance testing (ITT) were performed at ages prior to (1-3 months and 6-8 months old) and post-pathology (16-18 months old). Additionally, we examined for altered insulin signaling in the hippocampus. Western blots were used to evaluate the two-primary insulin signaling pathways: PI3K/AKT and MAPK/ERK. Since the PI3K/AKT pathway affects several downstream targets associated with metabolism (e.g., GSK3, glucose transporters), western blots were used to examine possible alterations in the expression, translocation, or activation of these targets. We found that 3xTg-AD mice display impaired glucose tolerance as early as 1 month of age, concomitant with a decrease in plasma insulin levels well prior to the detection of plaques (∼14 months old), aggregates of hyperphosphorylated tau (∼18 months old), and cognitive decline (≥18 months old). These alterations in peripheral metabolism were seen at all time points examined. In comparison, PI3K/AKT, but not MAPK/ERK, signaling was altered in the hippocampus only in 18-20-month-old 3xTg-AD mice, a time point at which there was a reduction in GLUT3 translocation to the plasma membrane. Taken together, our results provide further evidence that disruptions in energy metabolism may represent a foundational step in the development of AD.
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Affiliation(s)
- Chelsea M Griffith
- Department of Physiology, Southern Illinois University School of Medicine, Carbondale, IL, USA.,Center for Integrated Research in Cognitive and Neural Sciences, Southern Illinois University, Carbondale, IL, USA
| | - Lauren N Macklin
- Department of Physiology, Southern Illinois University School of Medicine, Carbondale, IL, USA.,Center for Integrated Research in Cognitive and Neural Sciences, Southern Illinois University, Carbondale, IL, USA
| | - Yan Cai
- Department of Anatomy and Neurobiology, Central South University Xiangya School of Medicine, Changsha, Hunan, China.,Key Laboratory of Hunan Province in Neurodegenerative Disorders, Changsha, Hunan, China
| | - Andrew A Sharp
- Department of Physiology, Southern Illinois University School of Medicine, Carbondale, IL, USA.,Department of Anatomy, Southern Illinois University School of Medicine, Carbondale, IL, USA.,Center for Integrated Research in Cognitive and Neural Sciences, Southern Illinois University, Carbondale, IL, USA
| | - Xiao-Xin Yan
- Department of Anatomy and Neurobiology, Central South University Xiangya School of Medicine, Changsha, Hunan, China.,Key Laboratory of Hunan Province in Neurodegenerative Disorders, Changsha, Hunan, China
| | - Lawrence P Reagan
- Department of Pharmacology, Physiology & Neuroscience, University of South Carolina, Columbia, SC, USA.,WJB Dorn Veterans Affairs Medical Center, Columbia, SC, USA
| | - April D Strader
- Department of Physiology, Southern Illinois University School of Medicine, Carbondale, IL, USA.,Center for Integrated Research in Cognitive and Neural Sciences, Southern Illinois University, Carbondale, IL, USA
| | - Gregory M Rose
- Department of Physiology, Southern Illinois University School of Medicine, Carbondale, IL, USA.,Department of Anatomy, Southern Illinois University School of Medicine, Carbondale, IL, USA.,Center for Integrated Research in Cognitive and Neural Sciences, Southern Illinois University, Carbondale, IL, USA
| | - Peter R Patrylo
- Department of Physiology, Southern Illinois University School of Medicine, Carbondale, IL, USA.,Department of Anatomy, Southern Illinois University School of Medicine, Carbondale, IL, USA.,Center for Integrated Research in Cognitive and Neural Sciences, Southern Illinois University, Carbondale, IL, USA
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4
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Effects of intrahippocampal injection of Leptin on seizure-induced cognitive impairment in male rats. LEARNING AND MOTIVATION 2020. [DOI: 10.1016/j.lmot.2020.101612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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5
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Osborne AJ, Pearson JF, Noble AJ, Gemmell NJ, Horwood LJ, Boden JM, Benton MC, Macartney-Coxson DP, Kennedy MA. Genome-wide DNA methylation analysis of heavy cannabis exposure in a New Zealand longitudinal cohort. Transl Psychiatry 2020; 10:114. [PMID: 32321915 PMCID: PMC7176736 DOI: 10.1038/s41398-020-0800-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 03/11/2020] [Accepted: 03/20/2020] [Indexed: 12/24/2022] Open
Abstract
Cannabis use is of increasing public health interest globally. Here we examined the effect of heavy cannabis use, with and without tobacco, on genome-wide DNA methylation in a longitudinal birth cohort (Christchurch Health and Development Study, CHDS). A total of 48 heavy cannabis users were selected from the CHDS cohort, on the basis of their adult exposure to cannabis and tobacco, and DNA methylation assessed from whole blood samples, collected at approximately age 28. Methylation in heavy cannabis users was assessed, relative to non-users (n = 48 controls) via the Illumina Infinium® MethylationEPIC BeadChip. We found the most differentially methylated sites in cannabis with tobacco users were in the AHRR and F2RL3 genes, replicating previous studies on the effects of tobacco. Cannabis-only users had no evidence of differential methylation in these genes, or at any other loci at the epigenome-wide significance level (P < 10-7). However, there were 521 sites differentially methylated at P < 0.001 which were enriched for genes involved in neuronal signalling (glutamatergic synapse and long-term potentiation) and cardiomyopathy. Further, the most differentially methylated loci were associated with genes with reported roles in brain function (e.g. TMEM190, MUC3L, CDC20 and SP9). We conclude that the effects of cannabis use on the mature human blood methylome differ from, and are less pronounced than, the effects of tobacco use, and that larger sample sizes are required to investigate this further.
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Affiliation(s)
- Amy J. Osborne
- grid.21006.350000 0001 2179 4063School of Biological Sciences, University of Canterbury, Christchurch, 8041 New Zealand
| | - John F. Pearson
- grid.29980.3a0000 0004 1936 7830Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch, 8011 New Zealand
| | - Alexandra J. Noble
- grid.21006.350000 0001 2179 4063School of Biological Sciences, University of Canterbury, Christchurch, 8041 New Zealand
| | - Neil J. Gemmell
- grid.29980.3a0000 0004 1936 7830Department of Anatomy, Otago School of Medical Sciences, University of Otago, Dunedin, 9054 New Zealand
| | - L. John Horwood
- grid.29980.3a0000 0004 1936 7830Department of Psychological Medicine, University of Otago Christchurch, Christchurch, 8011 New Zealand
| | - Joseph M. Boden
- grid.29980.3a0000 0004 1936 7830Department of Psychological Medicine, University of Otago Christchurch, Christchurch, 8011 New Zealand
| | - Miles C. Benton
- grid.419706.d0000 0001 2234 622XHuman Genomics, Institute of Environmental Science and Research, Kenepuru Science Centre, Porirua, 5240 New Zealand
| | - Donia P. Macartney-Coxson
- grid.419706.d0000 0001 2234 622XHuman Genomics, Institute of Environmental Science and Research, Kenepuru Science Centre, Porirua, 5240 New Zealand
| | - Martin A. Kennedy
- grid.29980.3a0000 0004 1936 7830Department of Pathology and Biomedical Science, University of Otago Christchurch, Christchurch, 8011 New Zealand
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6
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Jing D, Li D, Peng C, Chen Y, Behnisch T. Role of microtubules in late-associative plasticity of hippocampal Schaffer collateral-CA1 synapses in mice. Neurobiol Learn Mem 2019; 163:107038. [PMID: 31278986 DOI: 10.1016/j.nlm.2019.107038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 04/13/2019] [Accepted: 07/02/2019] [Indexed: 11/17/2022]
Abstract
The microtubule network represents a key scaffolding structure that forms part of the neuronal cytoskeleton and contributes to biomolecule exchange within neurons. However, researchers have not determined whether an intact microtubule network is required for late associative plasticity. Therefore, the late associative plasticity of field excitatory postsynaptic potentials from two synaptic inputs was analyzed. Synaptic potentiation was induced through alternating tetanization of hippocampal Schaffer-collateral CA1 synaptic populations in acute slices prepared from young-adult C57BL/6 mice. Vincristine was applied to depolymerize microtubules. Vincristine did not alter the phosphorylation levels of plasticity-related pre- or postsynaptic proteins but reduced the level of a protein marker of the ER-Golgi intermediate compartment (ERGIC-53/p58). Vincristine did not alter the magnitude or maintenance of the synaptic potentiation evoked by repeated tetanization (3 × 100 stimuli at 100 Hz) of one synaptic population. However, this synaptic potentiation was sensitive to the coapplication of a protein synthesis inhibitor, such as rapamycin, anisomycin or cycloheximide, indicating that protein synthesis has become essential in depolymerized microtubules during the first hour of the synaptic potentiation. The application of vincristine up to a 70 stimuli, 100 Hz tetanization of a second synaptic input prevented the transformation of short-term potentiation into long-term potentiation (LTP), further indicating that intact microtubules are required for the late associative properties of synaptic plasticity. Therefore, activity-dependent synaptic plasticity does not rely on microtubules within the first two hours after tetanization; however, the associative interaction of independent synaptic inputs relies on their proper function. In addition, either new protein synthesis or microtubule-based processes are sufficient to stabilize LTP within the first 3 h after tetanization, and a deficit in synaptic plasticity is only observable when both processes are blocked.
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Affiliation(s)
- Dongqing Jing
- Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, China
| | - Dongxue Li
- Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, China
| | - Cheng Peng
- Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, China
| | - Ying Chen
- Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, China
| | - Thomas Behnisch
- Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, China.
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7
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Li D, Jing D, Liu Z, Chen Y, Huang F, Behnisch T. Enhanced Expression of Secreted α-Klotho in the Hippocampus Alters Nesting Behavior and Memory Formation in Mice. Front Cell Neurosci 2019; 13:133. [PMID: 31001090 PMCID: PMC6454015 DOI: 10.3389/fncel.2019.00133] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 03/18/2019] [Indexed: 12/30/2022] Open
Abstract
The klotho gene family consists of α-, β-, and γ-Klotho, which encode type I single-pass transmembrane proteins with large extracellular domains. α-Klotho exists as a full-length membrane-bound and as a soluble form after cleavage of the extracellular domain. Due to gene splicing, a short extracellular Klotho form can be expressed and secreted. Inactivation of α-Klotho leads to a phenotype that resembles accelerated aging, as the expression level of the α-Klotho protein in the hippocampal formation of mice decreases with age. Here, we show that intrahippocampal viral expression of secreted human α-Klotho alters social behavior and memory formation. Interestingly, overexpression of secreted human α-Klotho in the CA1 changed the nest-building behavior and improved object recognition, object location and passive avoidance memory. Moreover, α-Klotho overexpression increased hippocampal synaptic transmission in response to standardized stimulation strengths, altered paired-pulse facilitation of synaptic transmission, and enhanced activity-dependent synaptic plasticity. These results indicate that memory formation benefits from an augmented level of secreted α-Klotho.
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Affiliation(s)
- Dongxue Li
- Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, China
| | - Dongqing Jing
- Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, China
| | - Ziyang Liu
- Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, China
| | - Ying Chen
- Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, China
| | - Fang Huang
- Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, China
| | - Thomas Behnisch
- Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, China
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8
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The passive avoidance memory improving effect of curcumin in young adult mice: Considering hippocampal MMP-2, MMP-9 and Akt/GSK3β. PHARMANUTRITION 2018. [DOI: 10.1016/j.phanu.2018.05.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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9
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Griffith CM, Eid T, Rose GM, Patrylo PR. Evidence for altered insulin receptor signaling in Alzheimer's disease. Neuropharmacology 2018; 136:202-215. [PMID: 29353052 DOI: 10.1016/j.neuropharm.2018.01.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 12/19/2017] [Accepted: 01/05/2018] [Indexed: 12/11/2022]
Abstract
Epidemiological data have shown that metabolic disease can increase the propensity for developing cognitive decline and dementia, particularly Alzheimer's disease (AD). While this interaction is not completely understood, clinical studies suggest that both hyper- and hypoinsulinemia are associated with an increased risk for developing AD. Indeed, insulin signaling is altered in post-mortem brain tissue from AD patients and treatments known to enhance insulin signaling can improve cognitive function. Further, clinical evidence has shown that AD patients and mouse models of AD often display alterations in peripheral metabolism. Since insulin is primarily derived from the periphery, it is likely that changes in peripheral insulin levels lead to alterations in central nervous system (CNS) insulin signaling and could contribute to cognitive decline and pathogenesis. Developing a better understanding of the relationship between alterations in peripheral metabolism and cognitive function might provide a foundation for the development of better treatment options for patients with AD. In this article we will begin to piece together the present data defining this relationship by briefly discussing insulin signaling in the periphery and CNS, its role in cognitive function, insulin's relationship to AD, peripheral metabolic alterations in mouse models of AD and how information from these models helps understand the mechanisms through which these changes potentially lead to impairments in insulin signaling in the CNS, and potential ways to target insulin signaling that could improve cognitive function in AD. This article is part of the Special Issue entitled 'Metabolic Impairment as Risk Factors for Neurodegenerative Disorders.'
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Affiliation(s)
- Chelsea M Griffith
- Department of Physiology, Southern Illinois University School of Medicine, Carbondale, IL 62901, USA; Center for Integrated Research in Cognitive and Neural Sciences, Southern Illinois University Carbondale, IL 62901, USA
| | - Tore Eid
- Department of Laboratory Medicine, Yale University School of Medicine, New Haven, CT 06510, USA; Department of Neurosurgery, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Gregory M Rose
- Department of Physiology, Southern Illinois University School of Medicine, Carbondale, IL 62901, USA; Department of Anatomy, Southern Illinois University School of Medicine, Carbondale, IL 62901, USA; Center for Integrated Research in Cognitive and Neural Sciences, Southern Illinois University Carbondale, IL 62901, USA
| | - Peter R Patrylo
- Department of Physiology, Southern Illinois University School of Medicine, Carbondale, IL 62901, USA; Department of Anatomy, Southern Illinois University School of Medicine, Carbondale, IL 62901, USA; Center for Integrated Research in Cognitive and Neural Sciences, Southern Illinois University Carbondale, IL 62901, USA.
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10
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Slouzkey I, Maroun M. PI3-kinase cascade has a differential role in acquisition and extinction of conditioned fear memory in juvenile and adult rats. ACTA ACUST UNITED AC 2016; 23:723-731. [PMID: 27918278 PMCID: PMC5110989 DOI: 10.1101/lm.041806.116] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 08/25/2016] [Indexed: 11/24/2022]
Abstract
The basolateral amygdala (BLA), medial prefrontal cortex (mPFC) circuit, plays a crucial role in acquisition and extinction of fear memory. Extinction of aversive memories is mediated, at least in part, by the phosphoinositide-3 kinase (PI3K)/Akt pathway in adult rats. There is recent interest in the neural mechanisms that mediate fear and extinction in juvenile animals and whether these mechanisms are distinctive from those in adult animals. In the present study, we examined (1) changes in phosphorylation of Akt in the BLA and mPFC after fear conditioning and extinction in juvenile and adult rats and (2) the effect of BLA and mPFC localized inhibition of the PI3K following acquisition and extinction of contextual fear memory. Our results show that Akt phosphorylation is increased following acquisition of contextual fear learning in the BLA but not in the mPFC in adult and juvenile rats. Extinction learning was not associated with changes in Akt phosphorylation. Although there were no differences in the pattern of phosphorylation of Akt either in adult or juvenile rats, microinjection of the PI3K inhibitor, LY294002, into the BLA or mPFC elicited differential effects on fear memory acquisition and extinction, depending on the site and timing of the microinjection, as well as on the age of the animal. These results suggest that PI3K/Akt has a differential role in formation, retrieval, and extinction of contextual fear memory in juvenile and adult animals, and point to developmental differences between adult and juvenile rats in mechanisms of extinction.
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Affiliation(s)
- Ilana Slouzkey
- Sagol Department of Neurobiology, Faculty of Natural Sciences, University of Haifa, Haifa 3498838, Israel
| | - Mouna Maroun
- Sagol Department of Neurobiology, Faculty of Natural Sciences, University of Haifa, Haifa 3498838, Israel
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11
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Wang J, Zhao J, Liu Z, Guo F, Wang Y, Wang X, Zhang R, Vreugdenhil M, Lu C. Acute Ethanol Inhibition of γ Oscillations Is Mediated by Akt and GSK3β. Front Cell Neurosci 2016; 10:189. [PMID: 27582689 PMCID: PMC4987361 DOI: 10.3389/fncel.2016.00189] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2016] [Accepted: 07/19/2016] [Indexed: 01/23/2023] Open
Abstract
Hippocampal network oscillations at gamma band frequency (γ, 30-80 Hz) are closely associated with higher brain functions such as learning and memory. Acute ethanol exposure at intoxicating concentrations (≥50 mM) impairs cognitive function. This study aimed to determine the effects and the mechanisms of acute ethanol exposure on γ oscillations in an in vitro model. Ethanol (25-100 mM) suppressed kainate-induced γ oscillations in CA3 area of the rat hippocampal slices, in a concentration-dependent, reversible manner. The ethanol-induced suppression was reduced by the D1R antagonist SCH23390 or the PKA inhibitor H89, was prevented by the Akt inhibitor triciribine or the GSk3β inhibitor SB415286, was enhanced by the NMDA receptor antagonist D-AP5, but was not affected by the MAPK inhibitor U0126 or PI3K inhibitor wortmanin. Our results indicate that the intracellular kinases Akt and GSk3β play a critical role in the ethanol-induced suppression of γ oscillations and reveal new cellular pathways involved in the ethanol-induced cognitive impairment.
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Affiliation(s)
- JianGang Wang
- Key Laboratory for the Brain Research of Henan Province, Xinxiang Medical UniversityXinxiang, China; Department of Pathophysiology, Xinxiang Medical UniversityXinxiang, China
| | - JingXi Zhao
- Key Laboratory for the Brain Research of Henan Province, Xinxiang Medical UniversityXinxiang, China; Psychiatric Hospital of Henan ProvinceXinxiang, China
| | - ZhiHua Liu
- Key Laboratory for the Brain Research of Henan Province, Xinxiang Medical UniversityXinxiang, China; Psychiatric Hospital of Henan ProvinceXinxiang, China
| | - FangLi Guo
- Key Laboratory for the Brain Research of Henan Province, Xinxiang Medical UniversityXinxiang, China; Department of Neurobiology and Physiology, Xinxiang Medical UniversityXinxiang, China
| | - Yali Wang
- Key Laboratory for the Brain Research of Henan Province, Xinxiang Medical UniversityXinxiang, China; Department of Neurobiology and Physiology, Xinxiang Medical UniversityXinxiang, China
| | - Xiaofang Wang
- Key Laboratory for the Brain Research of Henan Province, Xinxiang Medical University Xinxiang, China
| | - RuiLing Zhang
- Psychiatric Hospital of Henan Province Xinxiang, China
| | - Martin Vreugdenhil
- Department of Psychology, Xinxiang Medical UniversityHenan, China; Department of Health Sciences, Birmingham City UniversityBirmingham, UK
| | - Chengbiao Lu
- Key Laboratory for the Brain Research of Henan Province, Xinxiang Medical UniversityXinxiang, China; Psychiatric Hospital of Henan ProvinceXinxiang, China
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12
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Pen Y, Borovok N, Reichenstein M, Sheinin A, Michaelevski I. Membrane-tethered AKT kinase regulates basal synaptic transmission and early phase LTP expression by modulation of post-synaptic AMPA receptor level. Hippocampus 2016; 26:1149-67. [PMID: 27068236 DOI: 10.1002/hipo.22597] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/28/2016] [Indexed: 01/17/2023]
Abstract
The serine/threonine kinase AKT/PKB plays a fundamental role in a wide variety of neuronal functions, including neuronal cell development, axonal growth, and synaptic plasticity. Multiple evidence link AKT signaling pathways to regulation of late phase long-term synaptic plasticity, synaptogenesis, and spinogenesis, as well as long-term memory formation. Nevertheless, the downstream effectors mediating the effects of AKT on early phase long-term potentiation (eLTP) are currently unknown. Here we report that using different regimes of pharmacological activation and inhibition of AKT activity in acute hippocampal slices, we found that AKT regulates the post-synaptic expression of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPA) receptors affecting solely the expression of eLTP, with no effect on its induction and maintenance. We further show that both maintenance of basal synaptic activity and expression of eLTP require plasma membrane tethering by activated AKT and that basal synaptic activity may be regulated via the direct effects of AKT1 on the expression level of post-synaptic AMPA receptors bypassing the canonical AKT signaling. Finally, we establish that eLTP expression requires the involvement of both the canonical AKT signaling pathways and the direct effect of AKT1 on AMPA receptor activity/expression in the post-synaptic membrane. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Y Pen
- Department of Biochemistry and Molecular Biology, Tel Aviv University, Tel-Aviv, Israel
| | - N Borovok
- Department of Biochemistry and Molecular Biology, Tel Aviv University, Tel-Aviv, Israel
| | - M Reichenstein
- Department of Biochemistry and Molecular Biology, Tel Aviv University, Tel-Aviv, Israel
| | - A Sheinin
- Department of Biochemistry and Molecular Biology, Tel Aviv University, Tel-Aviv, Israel.,Sagol School of Neuroscience, Tel Aviv University, Tel-Aviv, Israel
| | - I Michaelevski
- Department of Biochemistry and Molecular Biology, Tel Aviv University, Tel-Aviv, Israel.,Sagol School of Neuroscience, Tel Aviv University, Tel-Aviv, Israel
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13
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Tong JQ, Zhang J, Hao M, Yang J, Han YF, Liu XJ, Shi H, Wu MN, Liu QS, Qi JS. Leptin attenuates the detrimental effects of β-amyloid on spatial memory and hippocampal later-phase long term potentiation in rats. Horm Behav 2015; 73:125-30. [PMID: 26135065 DOI: 10.1016/j.yhbeh.2015.06.013] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Revised: 04/21/2015] [Accepted: 06/25/2015] [Indexed: 12/26/2022]
Abstract
β-Amyloid (Aβ) is the main component of amyloid plaques developed in the brain of patients with Alzheimer's disease (AD). The increasing burden of Aβ in the cortex and hippocampus is closely correlated with memory loss and cognition deficits in AD. Recently, leptin, a 16kD peptide derived mainly from white adipocyte tissue, has been appreciated for its neuroprotective function, although less is known about the effects of leptin on spatial memory and synaptic plasticity. The present study investigated the neuroprotective effects of leptin against Aβ-induced deficits in spatial memory and in vivo hippocampal late-phase long-term potentiation (L-LTP) in rats. Y maze spontaneous alternation was used to assess short term working memory, and the Morris water maze task was used to assess long term reference memory. Hippocampal field potential recordings were performed to observe changes in L-LTP. We found that chronically intracerebroventricular injection of leptin (1μg) effectively alleviated Aβ1-42 (20μg)-induced spatial memory impairments of Y maze spontaneous alternation and Morris water maze. In addition, chronic administration of leptin also reversed Aβ1-42-induced suppression of in vivo hippocampal L-LTP in rats. Together, these results suggest that chronic leptin treatments reversed Aβ-induced deficits in learning and memory and the maintenance of L-LTP.
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Affiliation(s)
- Jia-Qing Tong
- Department of Neurobiology and National Key Discipline of Physiology, Shanxi Medical University, Taiyuan, Shanxi 030001, PR China; Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Jun Zhang
- Department of Neurobiology and National Key Discipline of Physiology, Shanxi Medical University, Taiyuan, Shanxi 030001, PR China
| | - Ming Hao
- Department of Neurobiology and National Key Discipline of Physiology, Shanxi Medical University, Taiyuan, Shanxi 030001, PR China
| | - Ju Yang
- Department of Neurobiology and National Key Discipline of Physiology, Shanxi Medical University, Taiyuan, Shanxi 030001, PR China
| | - Yu-Fei Han
- Department of Neurobiology and National Key Discipline of Physiology, Shanxi Medical University, Taiyuan, Shanxi 030001, PR China
| | - Xiao-Jie Liu
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Hui Shi
- Department of Neurobiology and National Key Discipline of Physiology, Shanxi Medical University, Taiyuan, Shanxi 030001, PR China
| | - Mei-Na Wu
- Department of Neurobiology and National Key Discipline of Physiology, Shanxi Medical University, Taiyuan, Shanxi 030001, PR China
| | - Qing-Song Liu
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Jin-Shun Qi
- Department of Neurobiology and National Key Discipline of Physiology, Shanxi Medical University, Taiyuan, Shanxi 030001, PR China.
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Phosphoinositide dynamics in the postsynaptic membrane compartment: Mechanisms and experimental approach. Eur J Cell Biol 2015; 94:401-14. [DOI: 10.1016/j.ejcb.2015.06.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
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15
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Amyloid-β pathology is attenuated by tauroursodeoxycholic acid treatment in APP/PS1 mice after disease onset. Neurobiol Aging 2014; 36:228-40. [PMID: 25443293 DOI: 10.1016/j.neurobiolaging.2014.08.034] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Revised: 07/31/2014] [Accepted: 08/12/2014] [Indexed: 01/06/2023]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder hallmarked by the accumulation of extracellular amyloid-β (Aβ) peptide and intraneuronal hyperphosphorylated tau, as well as chronic neuroinflammation. Tauroursodeoxycholic acid (TUDCA) is an endogenous anti-apoptotic bile acid with potent neuroprotective properties in several experimental models of AD. We have previously reported the therapeutic efficacy of TUDCA treatment before amyloid plaque deposition in APP/PS1 double-transgenic mice. In the present study, we evaluated the protective effects of TUDCA when administrated after the onset of amyloid pathology. APP/PS1 transgenic mice with 7 months of age were injected intraperitoneally with TUDCA (500 mg/kg) every 3 days for 3 months. TUDCA treatment significantly attenuated Aβ deposition in the brain, with a concomitant decrease in Aβ₁₋₄₀ and Aβ₁₋₄₂ levels. The amyloidogenic processing of amyloid precursor protein was also reduced, indicating that TUDCA interferes with Aβ production. In addition, TUDCA abrogated GSK3β hyperactivity, which is highly implicated in tau hyperphosphorylation and glial activation. This effect was likely dependent on the specific activation of the upstream kinase, Akt. Finally, TUDCA treatment decreased glial activation and reduced proinflammatory cytokine messenger RNA expression, while partially rescuing synaptic loss. Overall, our results suggest that TUDCA is a promising therapeutic strategy not only for prevention but also for treatment of AD after disease onset.
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Moosavi M, Zarifkar AH, Farbood Y, Dianat M, Sarkaki A, Ghasemi R. Agmatine protects against intracerebroventricular streptozotocin-induced water maze memory deficit, hippocampal apoptosis and Akt/GSK3β signaling disruption. Eur J Pharmacol 2014; 736:107-14. [DOI: 10.1016/j.ejphar.2014.03.041] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Revised: 02/13/2014] [Accepted: 03/17/2014] [Indexed: 01/09/2023]
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17
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Suárez LM, Bustamante J, Orensanz LM, Martín del Río R, Solís JM. Cooperation of taurine uptake and dopamine D1 receptor activation facilitates the induction of protein synthesis-dependent late LTP. Neuropharmacology 2014; 79:101-11. [DOI: 10.1016/j.neuropharm.2013.10.035] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Revised: 10/28/2013] [Accepted: 10/30/2013] [Indexed: 01/07/2023]
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18
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The role of γ-secretase in hippocampal synaptic transmission and activity-dependent synaptic plasticity. Neurosci Lett 2013; 554:16-21. [DOI: 10.1016/j.neulet.2013.08.056] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Revised: 08/08/2013] [Accepted: 08/27/2013] [Indexed: 11/23/2022]
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19
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Madathil SK, Carlson SW, Brelsfoard JM, Ye P, D’Ercole AJ, Saatman KE. Astrocyte-Specific Overexpression of Insulin-Like Growth Factor-1 Protects Hippocampal Neurons and Reduces Behavioral Deficits following Traumatic Brain Injury in Mice. PLoS One 2013; 8:e67204. [PMID: 23826235 PMCID: PMC3695083 DOI: 10.1371/journal.pone.0067204] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Accepted: 05/16/2013] [Indexed: 11/19/2022] Open
Abstract
Traumatic brain injury (TBI) survivors often suffer from long-lasting cognitive impairment that stems from hippocampal injury. Systemic administration of insulin-like growth factor-1 (IGF-1), a polypeptide growth factor known to play vital roles in neuronal survival, has been shown to attenuate posttraumatic cognitive and motor dysfunction. However, its neuroprotective effects in TBI have not been examined. To this end, moderate or severe contusion brain injury was induced in mice with conditional (postnatal) overexpression of IGF-1 using the controlled cortical impact (CCI) injury model. CCI brain injury produces robust reactive astrocytosis in regions of neuronal damage such as the hippocampus. We exploited this regional astrocytosis by linking expression of hIGF-1 to the astrocyte-specific glial fibrillary acidic protein (GFAP) promoter, effectively targeting IGF-1 delivery to vulnerable neurons. Following brain injury, IGF-1Tg mice exhibited a progressive increase in hippocampal IGF-1 levels which was coupled with enhanced hippocampal reactive astrocytosis and significantly greater GFAP levels relative to WT mice. IGF-1 overexpression stimulated Akt phosphorylation and reduced acute (1 and 3d) hippocampal neurodegeneration, culminating in greater neuron survival at 10d after CCI injury. Hippocampal neuroprotection achieved by IGF-1 overexpression was accompanied by improved motor and cognitive function in brain-injured mice. These data provide strong support for the therapeutic efficacy of increased brain levels of IGF-1 in the setting of TBI.
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Affiliation(s)
- Sindhu K. Madathil
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, Kentucky, United States of America
| | - Shaun W. Carlson
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, Kentucky, United States of America
| | - Jennifer M. Brelsfoard
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, Kentucky, United States of America
| | - Ping Ye
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - A. Joseph D’Ercole
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Kathryn E. Saatman
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, Kentucky, United States of America
- * E-mail:
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20
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Liang L, Fan L, Tao B, Yaster M, Tao YX. Protein kinase B/Akt is required for complete Freund's adjuvant-induced upregulation of Nav1.7 and Nav1.8 in primary sensory neurons. THE JOURNAL OF PAIN 2013; 14:638-47. [PMID: 23642408 DOI: 10.1016/j.jpain.2013.01.778] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2012] [Revised: 12/18/2012] [Accepted: 01/25/2013] [Indexed: 01/08/2023]
Abstract
UNLABELLED Voltage-gated sodium channels (Nav) are essential for the generation and conduction of action potentials. Peripheral inflammation increases the expression of Nav1.7 and Nav1.8 in dorsal root ganglion (DRG) neurons, suggesting that they participate in the induction and maintenance of chronic inflammatory pain. However, how Nav1.7 and Nav1.8 are regulated in the DRG under inflammatory pain conditions remains unclear. Using a complete Freund's adjuvant (CFA)-induced chronic inflammatory pain model and Western blot analysis, we found that phosphorylated Akt (p-Akt) was significantly increased in the ipsilateral L4/5 DRGs of rats on days 3 and 7 after intraplantar CFA injection. Immunohistochemistry showed that the percentage of p-Akt-positive neurons in the DRG was also significantly increased in the ipsilateral L4/5 DRGs at these time points. Moreover, CFA injection increased the colocalization of p-Akt with Nav1.7 and Nav1.8 in L4/5 DRG neurons. Pretreatment of rats with an intrathecal injection of Akt inhibitor IV blocked CFA-induced thermal hyperalgesia and CFA-induced increases in Nav1.7 and Nav1.8 in the L4/5 DRGs on day 7 after CFA injection. Our findings suggest that the Akt pathway participates in inflammation-induced upregulation of Nav1.7 and Nav1.8 expression in DRG neurons. This participation might contribute to the maintenance of chronic inflammatory pain. PERSPECTIVE This article presents that inhibition of Akt blocks CFA-induced thermal hyperalgesia and CFA-induced increases in dorsal root ganglion Nav1.7 and Nav1.8. These findings have potential implications for use of Akt inhibitors to prevent and/or treat persistent inflammatory pain.
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Affiliation(s)
- Lingli Liang
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
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21
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Panossian A, Hamm R, Kadioglu O, Wikman G, Efferth T. Synergy and Antagonism of Active Constituents of ADAPT-232 on Transcriptional Level of Metabolic Regulation of Isolated Neuroglial Cells. Front Neurosci 2013; 7:16. [PMID: 23430930 PMCID: PMC3576868 DOI: 10.3389/fnins.2013.00016] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Accepted: 02/01/2013] [Indexed: 12/16/2022] Open
Abstract
Gene expression profiling was performed on the human neuroglial cell line T98G after treatment with adaptogen ADAPT-232 and its constituents – extracts of Eleutherococcus senticosus root, Schisandra chinensis berry, and Rhodiola rosea root as well as several constituents individually, namely, eleutheroside E, schizandrin B, salidroside, triandrin, and tyrosol. A common feature for all tested adaptogens was their effect on G-protein-coupled receptor signaling pathways, i.e., cAMP, phospholipase C (PLC), and phosphatidylinositol signal transduction pathways. Adaptogens may reduce the cAMP level in brain cells by down-regulation of adenylate cyclase gene ADC2Y and up-regulation of phosphodiesterase gene PDE4D that is essential for energy homeostasis as well as for switching from catabolic to anabolic states and vice versa. Down-regulation of cAMP by adaptogens may decrease cAMP-dependent protein kinase A activity in various cells resulting in inhibition stress-induced catabolic transformations and saving of ATP for many ATP-dependant metabolic transformations. All tested adaptogens up-regulated the PLCB1 gene, which encodes phosphoinositide-specific PLC and phosphatidylinositol 3-kinases (PI3Ks), key players for the regulation of NF-κB-mediated defense responses. Other common targets of adaptogens included genes encoding ERα estrogen receptor (2.9–22.6 fold down-regulation), cholesterol ester transfer protein (5.1–10.6 fold down-regulation), heat shock protein Hsp70 (3.0–45.0 fold up-regulation), serpin peptidase inhibitor (neuroserpin), and 5-HT3 receptor of serotonin (2.2–6.6 fold down-regulation). These findings can be reconciled with the observed beneficial effects of adaptogens in behavioral, mental, and aging-associated disorders. Combining two or more active substances in one mixture significantly changes deregulated genes profiles: synergetic interactions result in activation of genes that none of the individual substances affected, while antagonistic interactions result in suppression some genes activated by individual substances. These interactions can have an influence on transcriptional control of metabolic regulation both on the cellular level and the level of the whole organism. Merging of deregulated genes array profiles and intracellular networks is specific to the new substance with unique pharmacological characteristics. Presumably, this phenomenon could be used to eliminate undesirable effects (e.g., toxic effects) and increase the selectivity of pharmacological intervention.
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22
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Durairajan SSK, Liu LF, Lu JH, Chen LL, Yuan Q, Chung SK, Huang L, Li XS, Huang JD, Li M. Berberine ameliorates β-amyloid pathology, gliosis, and cognitive impairment in an Alzheimer's disease transgenic mouse model. Neurobiol Aging 2012; 33:2903-19. [PMID: 22459600 DOI: 10.1016/j.neurobiolaging.2012.02.016] [Citation(s) in RCA: 183] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Accepted: 02/15/2012] [Indexed: 12/25/2022]
Abstract
The accumulation of β-amyloid (Aβ) peptide derived from abnormal processing of amyloid precursor protein (APP) is a common pathological hallmark of Alzheimer's disease (AD) brains. In this study, we evaluated the therapeutic effect of berberine (BBR) extracted from Coptis chinensis Franch, a Chinese medicinal herb, on the neuropathology and cognitive impairment in TgCRND8 mice, a well established transgenic mouse model of AD. Two-month-old TgCRND8 mice received a low (25 mg/kg per day) or a high dose of BBR (100 mg/kg per day) by oral gavage until 6 months old. BBR treatment significantly ameliorated learning deficits, long-term spatial memory retention, as well as plaque load compared with vehicle control treatment. In addition, enzyme-linked immunosorbent assay (ELISA) measurement showed that there was a profound reduction in levels of detergent-soluble and -insoluble β-amyloid in brain homogenates of BBR-treated mice. Glycogen synthase kinase (GSK)3, a major kinase involved in APP and tau phosphorylation, was significantly inhibited by BBR treatment. We also found that BBR significantly decreased the levels of C-terminal fragments of APP and the hyperphosphorylation of APP and tau via the Akt/glycogen synthase kinase 3 signaling pathway in N2a mouse neuroblastoma cells stably expressing human Swedish mutant APP695 (N2a-SwedAPP). Our results suggest that BBR provides neuroprotective effects in TgCRND8 mice through regulating APP processing and that further investigation of the BBR for therapeutic use in treating AD is warranted.
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23
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Costello DA, Claret M, Al-Qassab H, Plattner F, Irvine EE, Choudhury AI, Giese KP, Withers DJ, Pedarzani P. Brain deletion of insulin receptor substrate 2 disrupts hippocampal synaptic plasticity and metaplasticity. PLoS One 2012; 7:e31124. [PMID: 22383997 PMCID: PMC3287998 DOI: 10.1371/journal.pone.0031124] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2011] [Accepted: 01/03/2012] [Indexed: 01/17/2023] Open
Abstract
Objective Diabetes mellitus is associated with cognitive deficits and an increased risk of dementia, particularly in the elderly. These deficits and the corresponding neurophysiological structural and functional alterations are linked to both metabolic and vascular changes, related to chronic hyperglycaemia, but probably also defects in insulin action in the brain. To elucidate the specific role of brain insulin signalling in neuronal functions that are relevant for cognitive processes we have investigated the behaviour of neurons and synaptic plasticity in the hippocampus of mice lacking the insulin receptor substrate protein 2 (IRS-2). Research Design and Methods To study neuronal function and synaptic plasticity in the absence of confounding factors such as hyperglycaemia, we used a mouse model with a central nervous system- (CNS)-restricted deletion of IRS-2 (NesCreIrs2KO). Results We report a deficit in NMDA receptor-dependent synaptic plasticity in the hippocampus of NesCreIrs2KO mice, with a concomitant loss of metaplasticity, the modulation of synaptic plasticity by the previous activity of a synapse. These plasticity changes are associated with reduced basal phosphorylation of the NMDA receptor subunit NR1 and of downstream targets of the PI3K pathway, the protein kinases Akt and GSK-3β. Conclusions These findings reveal molecular and cellular mechanisms that might underlie cognitive deficits linked to specific defects of neuronal insulin signalling.
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Affiliation(s)
- Derek A. Costello
- Research Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
| | - Marc Claret
- Department of Medicine, University College London, London, United Kingdom
| | - Hind Al-Qassab
- Department of Medicine, University College London, London, United Kingdom
| | - Florian Plattner
- Wolfson Institute of Biomedical Research, University College London, London, United Kingdom
| | - Elaine E. Irvine
- Department of Medicine, University College London, London, United Kingdom
- Wolfson Institute of Biomedical Research, University College London, London, United Kingdom
- Metabolic Signalling Group, MRC Clinical Sciences Centre, Imperial College London, London, United Kingdom
| | - Agharul I. Choudhury
- Department of Medicine, University College London, London, United Kingdom
- Metabolic Signalling Group, MRC Clinical Sciences Centre, Imperial College London, London, United Kingdom
| | - K. Peter Giese
- Wolfson Institute of Biomedical Research, University College London, London, United Kingdom
| | - Dominic J. Withers
- Department of Medicine, University College London, London, United Kingdom
- Metabolic Signalling Group, MRC Clinical Sciences Centre, Imperial College London, London, United Kingdom
| | - Paola Pedarzani
- Research Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
- * E-mail:
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24
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Abstract
Synaptic plasticity, or changes in synaptic strength, is thought to underlie learning and memory. Imaging studies, mainly in brain slices, have revealed that long-term synaptic plasticity of excitatory synapses in hippocampal neurons is coupled with structural plasticity of dendritic spines, which is thought to be essential for inducing and regulating functional plasticity. Using pharmacological and genetic manipulation, the signalling network underlying structural plasticity has been extensively studied. Furthermore, the recent advent of fluorescence resonance energy transfer (FRET) imaging techniques has provided a readout of the dynamics of signal transduction in dendritic spines undergoing structural plasticity. These studies reveal the signalling pathways relaying Ca2+ to the functional and structural plasticity of dendritic spines.
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Affiliation(s)
- Michael Patterson
- Department of Neurobiology, Howard Hughes Medical Institute, Duke University Medical Center, Durham, NC 27710, USA
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25
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Moosavi M, Khales GY, Abbasi L, Zarifkar A, Rastegar K. Agmatine protects against scopolamine-induced water maze performance impairment and hippocampal ERK and Akt inactivation. Neuropharmacology 2012; 62:2018-23. [PMID: 22248637 DOI: 10.1016/j.neuropharm.2011.12.031] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Revised: 12/27/2011] [Accepted: 12/29/2011] [Indexed: 02/08/2023]
Abstract
Cholinergic brain activity plays a significant role in memory. Scopolamine a muscarinic cholinergic antagonist is known to induce impairment in Morris water maze performance, the task which is mainly dependent on the hippocampus. It is suggested that hippocampal ERK and Akt activation play roles in synaptic plasticity and some types of learning and memory. Agmatine, a polyamine derived from l-arginine decarboxylation, is recently shown to exert some neuroprotective effects. This study was aimed to investigate if agmatine could reverse scopolamine-induced memory impairment and possible hippocampal ERK and Akt activity alteration. Adult male Sprague-Dawley rats weighing 200-250 g were randomly assigned into 5 groups. The animals were trained for 3 days in Morris water maze and in day 4 their memory retention was assessed in probe trial which was consisted of a 60 s trial with no platform. Scopolamine (1 mg/kg/ip) or saline were injected 30 min and agmatine (20 or 40 mg/kg/ip) was administered 60 min before each session. The hippocampi were isolated after behavioral studies and western blotting studies on hippocampal lysates were done to determine the levels of activated ERK and Akt. Scopolamine treatment not only impaired water maze learning and memory, but also decreased the amount of phosphorylated (activated) ERK and Akt. Agmatine pre-treatment prevented both the learning impairment and hippocampal ERK and Akt inactivation induced by scopolamine. It seems that agmatine may act as a candidate substance against amnesia.
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Affiliation(s)
- Maryam Moosavi
- Shiraz Neuroscience Research Center and department of Physiology, Shiraz University of Medical Sciences, Zand Street, Shiraz, Iran.
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26
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Nonlethal aluminum maltolate can reduce brain-derived neurotrophic factor-induced Arc expression through interrupting the ERK signaling in SH-SY5Y neuroblastoma cells. Toxicol Lett 2011; 200:67-76. [DOI: 10.1016/j.toxlet.2010.10.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2010] [Revised: 10/22/2010] [Accepted: 10/25/2010] [Indexed: 11/20/2022]
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27
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Ye X, Carew TJ. Small G protein signaling in neuronal plasticity and memory formation: the specific role of ras family proteins. Neuron 2010; 68:340-61. [PMID: 21040840 PMCID: PMC3008420 DOI: 10.1016/j.neuron.2010.09.013] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/09/2010] [Indexed: 01/04/2023]
Abstract
Small G proteins are an extensive family of proteins that bind and hydrolyze GTP. They are ubiquitous inside cells, regulating a wide range of cellular processes. Recently, many studies have examined the role of small G proteins, particularly the Ras family of G proteins, in memory formation. Once thought to be primarily involved in the transduction of a variety of extracellular signals during development, it is now clear that Ras family proteins also play critical roles in molecular processing underlying neuronal and behavioral plasticity. We here review a number of recent studies that explore how the signaling of Ras family proteins contributes to memory formation. Understanding these signaling processes is of fundamental importance both from a basic scientific perspective, with the goal of providing mechanistic insights into a critical aspect of cognitive behavior, and from a clinical perspective, with the goal of providing effective therapies for a range of disorders involving cognitive impairments.
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Affiliation(s)
- Xiaojing Ye
- Department of Neurobiology and Behavior, Center for the Neurobiology of Learning and Memory, University of California, Irvine, CA 92697, USA
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28
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Marwarha G, Dasari B, Prabhakara JPR, Schommer J, Ghribi O. β-Amyloid regulates leptin expression and tau phosphorylation through the mTORC1 signaling pathway. J Neurochem 2010; 115:373-84. [PMID: 20670375 DOI: 10.1111/j.1471-4159.2010.06929.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
High levels of the adipocytokine leptin are associated with reduced risk of Alzheimer's disease. Leptin treatment also reduces β-amyloid (Aβ) levels in in vivo and in vitro models of Alzheimer's disease. Aβ and leptin interact with the Akt/mammalian target of rapamycin complex 1 (mTORC1) signaling pathway. Akt/mTORC1 activation reduces tau phosphorylation through the inhibition of the downstream enzyme GSK-3β. mTORC1 also regulates translation of many proteins including leptin. While Aβ has been shown to inactivate Akt, inhibit mTORC1, and facilitate the phosphorylation of tau, leptin activates both Akt and mTORC1 and reduces tau phosphorylation. However, the extent to which Aβ may modulate leptin expression and increase tau phosphorylation involving Akt/mTORC1 has not been determined. In this study, we show that incubation of organotypic slices from rabbit hippocampus with Aβ down-regulates leptin expression, inhibits Akt, activates GSK-3β, increases tau phosphorylation, and inactivates mTORC1. Leptin treatment reverses Aβ effects by alleviating Akt inhibition, preventing GSK-3β activation, reducing tau phosphorylation, and activating mTORC1. On the other hand, Rapamycin, an allosteric inhibitor of mTORC1, down-regulates leptin expression, increases tau phosphorylation, and does not affect Akt and GSK-3β. Our results demonstrate for the first time that Aβ regulates leptin expression and tau phosphorylation through mTORC1.
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Affiliation(s)
- Gurdeep Marwarha
- Department of Pharmacology, Physiology and Therapeutics, University of North Dakota School of Medicine and Health Sciences, Grand Forks, North Dakota 58202, USA
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29
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Hsu YY, Liu CM, Tsai HH, Jong YJ, Chen IJ, Lo YC. KMUP-1 attenuates serum deprivation-induced neurotoxicity in SH-SY5Y cells: roles of PKG, PI3K/Akt and Bcl-2/Bax pathways. Toxicology 2009; 268:46-54. [PMID: 19962417 DOI: 10.1016/j.tox.2009.11.021] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2009] [Revised: 11/04/2009] [Accepted: 11/27/2009] [Indexed: 11/19/2022]
Abstract
Aging populations with neurodegenerative disorders will gradually become a greater problem for society. Serum deprivation-induced cell death is recognized as one of the standard models for the study of neurotoxicity. Increasing evidence indicates that cGMP/PKG pathway may play a rescue role in serum deprivation-induced toxicity. The aim of this study was to investigate protective effects of KMUP-1, an enhancer of cGMP/PKG signaling on serum deprivation-induced neurotoxicity in SH-SY5Y neuroblastoma cells. Under normal serum condition, KMUP-1 enhanced protein expression of nNOS, PKG and sGCalpha1, increased intracellular cyclic GMP level, and attenuated PDE5 expression. KMUP-1 also increased expression of BDNF and Bcl-2, but it did not affect Bax expression. The phosphorylation of Akt and CREB induced by KMUP-1 was inhibited by tyrosine kinase (TrK) inhibitor K252a and phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002, respectively. Under serum deprivation condition, flow cytometric analysis using Annexin V showed KMUP-1 increased cell viability, but lacked protective effects in the presence of nitric oxide synthase inhibitor l-NAME, PKG inhibitor Rp-8-pCPT-cGMPS or LY294002. KMUP-1 not only enhanced expression of nNOS, sGCalpha1, PKG, p-CREB, p-Akt and Bcl-2, but also attenuated Bax expression in serum deprivation-treated cultures. In conclusion, cGMP/PKG, PI3K/Akt/CREB and Bcl-2/Bax signals play critical roles in the neuroprotective effects of KMUP-1 on serum deprivation-induced toxicity.
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Affiliation(s)
- Ya-Yun Hsu
- Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan
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Chen TJ, Wang DC, Chen SS. Amyloid-beta interrupts the PI3K-Akt-mTOR signaling pathway that could be involved in brain-derived neurotrophic factor-induced Arc expression in rat cortical neurons. J Neurosci Res 2009; 87:2297-307. [PMID: 19301428 DOI: 10.1002/jnr.22057] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The deposition of amyloid-beta (Abeta) contributes to the pathogenesis of Alzheimer's disease. Even at low levels, Abeta may interfere with various signaling cascades critical for the synaptic plasticity that underlies learning and memory. Brain-derived neurotrophic factor (BDNF) is well known to be capable of inducing the synthesis of activity-regulated cytoskeleton-associated protein (Arc), which plays a fundamental role in modulating synaptic plasticity. Our recent study has demonstrated that treatment of fibrillar Abeta at a nonlethal level was sufficient to impair BDNF-induced Arc expression in cultured rat cortical neurons. In this study, BDNF treatment alone induced the activation of the phosphatidylinositol 3-kinase-Akt-mammlian target of rapamycin (PI3K-Akt-mTOR) signaling pathway, the phosphorylation of eukaryotic initiation factor 4E binding protein (4EBP1) and p70 ribosomal S6 kinase (p70S6K), the dephosphorylation of eukaryotic elongation factor 2 (eEF2), and the expression of Arc. Interrupting the PI3K-Akt-mTOR signaling pathway by inhibitors prevented the effects of BDNF, indicating the involvement of this pathway in BDNF-induced 4EBP1 phosphorylation, p70S6K phosphorylation, eEF2 dephosphorylation, and Arc expression. Nonlethal Abeta pretreatment partially blocked these effects of BDNF. Double- immunofluorescent staining in rat cortical neurons further confirmed the coexistence of eEF2 dephosphorylation and Arc expression following BDNF treatment regardless of the presence of Abeta. These results reveal that, in cultured rat cortical neurons, Abeta interrupts the PI3K-Akt-mTOR signaling pathway that could be involved in BDNF-induced Arc expression. Moreover, this study also provides the first evidence that there is a close correlation between BDNF-induced eEF2 dephosphorylation and BDNF-induced Arc expression. (c) 2009 Wiley-Liss, Inc.
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Affiliation(s)
- Tsan-Ju Chen
- Department of Physiology, Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
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Zheng F, Soellner D, Nunez J, Wang H. The basal level of intracellular calcium gates the activation of phosphoinositide 3-kinase-Akt signaling by brain-derived neurotrophic factor in cortical neurons. J Neurochem 2008; 106:1259-74. [PMID: 18485103 DOI: 10.1111/j.1471-4159.2008.05478.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Brain-derived neurotrophic factor (BDNF) mediates survival and neuroplasticity through the activation of phosphoinositide 3-kinase-Akt pathway. Although previous studies suggested the roles of mitogen-activated protein kinase, phospholipase C-gamma-mediated intracellular calcium ([Ca2+]i) increase, and extracellular calcium influx in regulating Akt activation, the cellular mechanisms are largely unknown. We demonstrated that sub-nanomolar BDNF significantly induced Akt activation in developing cortical neurons. The TrkB-dependent Akt phosphorylation at S473 and T308 required only phosphoinositide 3-kinase, but not phospholipase C and mitogen-activated protein kinase activity. Blocking NMDA receptors, L-type voltage-gated calcium channels, and chelating extracellular calcium by EGTA failed to block BDNF-induced Akt phosphorylation. In contrast, chelating [Ca2+]i by 1,2-bis(o-aminophenoxy)ethane-N,N,N ',N '-tetraacetic acid-acetoxymethyl ester (BAPTA-AM) abolished Akt phosphorylation. Interestingly, sub-nanomolar BDNF did not stimulate [Ca2+]i increase under our culture conditions. Together with that NMDA- and membrane depolarization-induced [Ca2+]i increase did not activate Akt, we conclude that the basal level of [Ca2+]i gates BDNF function. Furthermore, inhibiting calmodulin by W13 suppressed Akt phosphorylation. On the other hand, inhibition of protein phosphatase 1 by okadaic acid and tautomycin rescued Akt phosphorylation in BAPTA-AM and W13-treated neurons. We further demonstrated that the phosphorylation of phosphoinositide-dependent kinase-1 did not correlate with Akt phosphorylation at T308. Our results suggested novel roles of basal [Ca2+]i, rather than activity-induced calcium elevation, in BDNF-Akt signaling.
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Affiliation(s)
- Fei Zheng
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA
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Tokuoka SM, Saiardi A, Nurrish SJ. The mood stabilizer valproate inhibits both inositol- and diacylglycerol-signaling pathways in Caenorhabditis elegans. Mol Biol Cell 2008; 19:2241-50. [PMID: 18287529 DOI: 10.1091/mbc.e07-09-0982] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The antiepileptic valproate (VPA) is widely used in the treatment of bipolar disorder, although the mechanism of its action in the disorder is unclear. We show here that VPA inhibits both inositol phosphate and diacylglycerol (DAG) signaling in Caenorhabditis elegans. VPA disrupts two behaviors regulated by the inositol-1,4,5-trisphosphate (IP(3)): defecation and ovulation. VPA also inhibits two activities regulated by DAG signaling: acetylcholine release and egg laying. The effects of VPA on DAG signaling are relieved by phorbol ester, a DAG analogue, suggesting that VPA acts to inhibit DAG production. VPA reduces levels of DAG and inositol-1-phosphate, but phosphatidylinositol-4,5-bisphosphate (PIP(2)) is slightly increased, suggesting that phospholipase C-mediated hydrolysis of PIP(2) to form DAG and IP(3) is defective in the presence of VPA.
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Affiliation(s)
- Suzumi M Tokuoka
- MRC Cell Biology Unit, MRC Laboratory for Molecular Cell Biology, Department of Neuroscience, Physiology, and Pharmacology, University College London, London WC1E 6BT, United Kingdom
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Frey S, Frey JU. 'Synaptic tagging' and 'cross-tagging' and related associative reinforcement processes of functional plasticity as the cellular basis for memory formation. PROGRESS IN BRAIN RESEARCH 2008; 169:117-43. [PMID: 18394471 DOI: 10.1016/s0079-6123(07)00007-6] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
We focus on new properties of cellular and network processes of memory formation involving 'synaptic tagging' and 'cross-tagging' during long-term potentiation (LTP) and long-term depression (LTD) as well as associative heterosynaptic interactions, the latter of which are characterized by a time-window of about 1h. About 20 years ago we showed for the first time that the maintenance of LTP, like memory storage, depends on intact protein synthesis and thus consists of at least two temporal phases. Later, similar properties for LTD were shown by our own and other laboratories. Here we describe the requirements for the induction of the transient early-LTP/LTD and of the protein synthesis-dependent late-LTP/LTD. Late-LTP/LTD depend on the associative activation of heterosynaptic inputs, i.e. the synergistic activation of glutamatergic and modulatory reinforcing inputs within specific, effective time-windows during their induction. The induction of late-LTP/LTD is characterized by novel, late-associative properties such as 'synaptic tagging', 'cross-tagging' and 'late-associative reinforcement'. All of these phenomena require the associative setting of synaptic tags as well as the availability of plasticity-related proteins (PRPs) and they are restricted to functional dendritic compartments, in general. 'Synaptic tagging' guarantees input specificity, 'cross-tagging' determines the interaction between LTP and LTD in a neuron, and thus both are required for the specific processing of afferent signals for the establishment of late-LTP/LTD. 'Late-associative reinforcement' describes a process where early-LTP/LTD by the co-activation of modulatory inputs can be transformed into late-LTP/LTD in activated synapses where a tag is set. Recent experiments in the freely moving rat revealed a number of modulatory brain structures involved in the transformation of early-plasticity events into long-lasting ones. Further to this, we have characterized time-windows and activation patterns to be effective in the reinforcement process. Studies using a combined electrophysiological and behavioural approach revealed the physiological relevance of these reinforcement processes, which is also supported by fMRI studies in humans, which led to the hypothesis outlined here on cellular and system memory-formation by late-associative heterosynaptic interactions at the cellular level during functional plasticity events.
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Affiliation(s)
- Sabine Frey
- Leibniz Institute for Neurobiology, Brenneckestrasse 6, D-39118 Magdeburg, Germany
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Smolen P. A model of late long-term potentiation simulates aspects of memory maintenance. PLoS One 2007; 2:e445. [PMID: 17505541 PMCID: PMC1865388 DOI: 10.1371/journal.pone.0000445] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2007] [Accepted: 04/25/2007] [Indexed: 11/21/2022] Open
Abstract
Late long-term potentiation (L-LTP) denotes long-lasting strengthening of synapses between neurons. L-LTP appears essential for the formation of long-term memory, with memories at least partly encoded by patterns of strengthened synapses. How memories are preserved for months or years, despite molecular turnover, is not well understood. Ongoing recurrent neuronal activity, during memory recall or during sleep, has been hypothesized to preferentially potentiate strong synapses, preserving memories. This hypothesis has not been evaluated in the context of a mathematical model representing ongoing activity and biochemical pathways important for L-LTP. In this study, ongoing activity was incorporated into two such models – a reduced model that represents some of the essential biochemical processes, and a more detailed published model. The reduced model represents synaptic tagging and gene induction simply and intuitively, and the detailed model adds activation of essential kinases by Ca2+. Ongoing activity was modeled as continual brief elevations of Ca2+. In each model, two stable states of synaptic strength/weight resulted. Positive feedback between synaptic weight and the amplitude of ongoing Ca2+ transients underlies this bistability. A tetanic or theta-burst stimulus switches a model synapse from a low basal weight to a high weight that is stabilized by ongoing activity. Bistability was robust to parameter variations in both models. Simulations illustrated that prolonged periods of decreased activity reset synaptic strengths to low values, suggesting a plausible forgetting mechanism. However, episodic activity with shorter inactive intervals maintained strong synapses. Both models support experimental predictions. Tests of these predictions are expected to further understanding of how neuronal activity is coupled to maintenance of synaptic strength. Further investigations that examine the dynamics of activity and synaptic maintenance can be expected to help in understanding how memories are preserved for up to a lifetime in animals including humans.
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Affiliation(s)
- Paul Smolen
- Department of Neurobiology and Anatomy, W.M. Keck Center for the Neurobiology of Learning and Memory, The University of Texas Medical School at Houston, Houston, Texas, United States of America.
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Malm TM, Iivonen H, Goldsteins G, Keksa-Goldsteine V, Ahtoniemi T, Kanninen K, Salminen A, Auriola S, Van Groen T, Tanila H, Koistinaho J. Pyrrolidine dithiocarbamate activates Akt and improves spatial learning in APP/PS1 mice without affecting beta-amyloid burden. J Neurosci 2007; 27:3712-21. [PMID: 17409235 PMCID: PMC6672417 DOI: 10.1523/jneurosci.0059-07.2007] [Citation(s) in RCA: 125] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Pyrrolidine dithiocarbamate (PDTC) is a clinically tolerated inhibitor of nuclear factor-kappaB (NF-kappaB), antioxidant and antiinflammatory agent, which provides protection in brain ischemia models. In neonatal hypoxia-ischemia model, PDTC activates Akt and reduces activation of glycogen synthase kinase 3beta (GSK-3beta). Because chronic inflammation, oxidative stress, and increased GSK-3beta activity are features of Alzheimer's disease (AD) pathology, we tested whether PDTC reduces brain pathology and improves cognitive function in a transgenic animal model of AD. A 7 month oral treatment with PDTC prevented the decline in cognition in AD mice without altering beta-amyloid burden or gliosis. Moreover, marked oxidative stress and activation of NF-kappaB were not part of the brain pathology. Instead, the phosphorylated form of GSK-3beta was decreased in the AD mouse brain, and PDTC treatment increased the phosphorylation of Akt and GSK-3beta. Also, PDTC treatment increased the copper concentration in the brain. In addition, PDTC rescued cultured hippocampal neurons from the toxicity of oligomeric Abeta and reduced tau phosphorylation in the hippocampus of AD mice. Finally, astrocytic glutamate transporter GLT-1, known to be regulated by Akt pathway, was decreased in the transgenic AD mice but upregulated back to the wild-type levels by PDTC treatment. Thus, PDTC may improve spatial learning in AD by interfering with Akt-GSK pathway both in neurons and astrocytes. Because PDTC is capable of transferring external Cu2+ into a cell, and, in turn, Cu2+ is able to activate Akt, we hypothesize that PDTC provides the beneficial effect in transgenic AD mice through Cu2+-activated Akt pathway.
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Affiliation(s)
| | | | | | | | | | | | - Antero Salminen
- Departments of Neuroscience and Neurology and
- Departments of Neurology and
| | | | | | - Heikki Tanila
- A. I. Virtanen Institute for Molecular Sciences and
- Departments of Neurology and
| | - Jari Koistinaho
- A. I. Virtanen Institute for Molecular Sciences and
- Oncology, Kuopio University Hospital, FIN-70211 Kuopio, Finland
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Horwood JM, Dufour F, Laroche S, Davis S. Signalling mechanisms mediated by the phosphoinositide 3-kinase/Akt cascade in synaptic plasticity and memory in the rat. Eur J Neurosci 2007; 23:3375-84. [PMID: 16820027 DOI: 10.1111/j.1460-9568.2006.04859.x] [Citation(s) in RCA: 226] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The phosphoinositide 3-kinase (PI3K)/Akt signalling cascade has classically been implicated in promoting cell survival but more recently has been shown to regulate a number of other cellular functions. In particular, studies have suggested that PI3K contributes to mechanisms associated with synaptic plasticity and memory processes but the function of this cascade in forms of synaptic plasticity, such as long-term potentiation, remains controversial and the PI3K substrates which mediate these effects are poorly understood. Here we report that the PI3K inhibitor LY294002 infused i.c.v. in vivo blocked maintenance of long-term potentiation induced in the dentate gyrus with a single tetanus to the perforant path but not with repeated tetani. This pattern of stimulation led to rapid and transient phosphorylation of the PI3K substrate Akt at Ser473 but not at Thr308. Functional readout of partial activation of Akt was demonstrated by an increase in phosphorylation of two downstream substrates, Forkhead (FKHR) and mammalian target of rapamycin (mTOR), in a delayed and prolonged manner at Akt-specific phosphorylation sites. LY294002 blocked phosphorylation of Akt and the prolonged phosphorylation of FKHR and mTOR but did not impair long-term potentiation-induced phosphorylation of extracellular receptor kinase. In addition, the same i.c.v. concentration of LY294002 impaired long-term consolidation of recognition memory but not short-term recognition memory or spatial learning and repeated training in the recognition memory task overcame the deficit in consolidation. These results suggest that activation of the PI3K/Akt pathway may contribute to the mechanisms of synaptic plasticity and memory consolidation by promoting cell survival via FKHR and protein synthesis via mTOR. Importantly, only partial activation of Akt at its Ser473 residue was necessary to mediate these effects.
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Affiliation(s)
- Jennifer M Horwood
- Laboratoire de Neurobiologie de l'Apprentissage, de la Mémoire et de la Communication, CNRS UMR 8620, Université Paris Sud, Bat. 446, 91405 Orsay, France
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37
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Raymond CR. LTP forms 1, 2 and 3: different mechanisms for the ‘long’ in long-term potentiation. Trends Neurosci 2007; 30:167-75. [PMID: 17292975 DOI: 10.1016/j.tins.2007.01.007] [Citation(s) in RCA: 142] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2006] [Revised: 12/21/2006] [Accepted: 01/31/2007] [Indexed: 11/23/2022]
Abstract
Long-term potentiation (LTP) of synaptic transmission is a primary experimental model of memory formation in neuronal circuits. Because of the intellectual appeal and scientific fecundity of the field, it is perhaps unsurprising that the literature on LTP contains many complex and often contradictory findings. Recognition that LTP is not a unitary phenomenon and mechanisms can differ between brain regions has resolved some controversy. However, further categorization can be made of mechanistically discrete forms of LTP at the same set of synapses. LTP1, LTP2 and LTP3 have previously been defined according to differences in the longevity and general molecular mechanisms of LTP. This review aims to reinvigorate and extend this concept as a useful framework to disentangle the mechanisms of LTP.
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Affiliation(s)
- Clarke R Raymond
- Division of Neuroscience, The John Curtin School of Medical Research, The Australian National University Canberra, ACT 0200, Australia.
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Abstract
Increasing evidence suggests that reactive oxygen species (ROS), such as superoxide and hydrogen peroxide, act as necessary signaling molecules in processes underlying cognition. Moreover, ROS have been shown to be necessary in molecular process underlying signal transduction, synaptic plasticity, and memory formation. Research from several laboratories suggests that NADPH oxidase is an important source of superoxide in the brain. Evidence is presented here to show that ROS are in fact important signaling molecules involved in synaptic plasticity and memory formation. Moreover, evidence that the NADPH oxidase complex is a key regulator of ROS generation in synaptic plasticity and memory formation is discussed. Understanding redox signaling in the brain, including the sources and molecular targets of ROS, are important for a full understanding of the signaling pathways that underlie synaptic plasticity and memory. Knowledge of ROS function in the brain also is critical for understanding aging and neurodegenerative diseases of the brain given that several of these disorders, including Alzheimer's disease and Parkinson disease, may be exacerbated by the unregulated generation of ROS.
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Affiliation(s)
- Kenneth T Kishida
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas, USA
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39
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Reymann KG, Frey JU. The late maintenance of hippocampal LTP: Requirements, phases, ‘synaptic tagging’, ‘late-associativity’ and implications. Neuropharmacology 2007; 52:24-40. [PMID: 16919684 DOI: 10.1016/j.neuropharm.2006.07.026] [Citation(s) in RCA: 223] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2006] [Revised: 07/14/2006] [Accepted: 07/17/2006] [Indexed: 11/28/2022]
Abstract
Our review focuses on the mechanisms which enable the late maintenance of hippocampal long-term potentiation (LTP; >3h), a phenomenon which is thought to underlie prolonged memory. About 20 years ago we showed for the first time that the maintenance of LTP - like memory storage--depends on intact protein synthesis and thus, consists of at least two temporal phases. Here we concentrate on mechanisms required for the induction of the transient early-LTP and of the protein synthesis-dependent late-LTP. Our group has shown that the induction of late-LTP requires the associative activation of heterosynaptic inputs, i.e. the synergistic activation of glutamatergic and modulatory, reinforcing inputs within specific, effective time windows. The induction of late-LTP is characterized by novel, late-associative properties such as 'synaptic tagging' and 'late-associative reinforcement'. Both phenomena require the associative setting of synaptic tags as well as the availability of plasticity-related proteins (PRPs) and they are restricted to functional dendritic compartments, in general. 'Synaptic tagging' guarantees input specificity and thus the specific processing of afferent signals for the establishment of late-LTP. 'Late-associative reinforcement' describes a process where early-LTP by the co-activation of modulatory inputs can be transformed into late-LTP in activated synapses where a tag is set. Recent evidence from behavioral experiments, which studied processes of emotional and cognitive reinforcement of LTP, point to the physiological relevance of the above mechanisms during cellular and system's memory formation.
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Affiliation(s)
- Klaus G Reymann
- Department for Neurophysiology, Leibniz Institute for Neurobiology, Brenneckestrasse 6, D-39118 Magdeburg, Germany
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40
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Karpova A, Mikhaylova M, Thomas U, Knöpfel T, Behnisch T. Involvement of protein synthesis and degradation in long-term potentiation of Schaffer collateral CA1 synapses. J Neurosci 2006; 26:4949-55. [PMID: 16672670 PMCID: PMC6674165 DOI: 10.1523/jneurosci.4573-05.2006] [Citation(s) in RCA: 141] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Expression of synaptic plasticity involves the translation of mRNA into protein and, probably, active protein degradation via the proteasome pathway. Here, we report on the rapid activation of synthesis and degradation of a probe protein with the induction of long-term potentiation (LTP) in the hippocampal Schaffer collateral CA1 pathway. The proteasome inhibitor MG132 significantly reduced the field EPSP slope potentiation and LTP maintenance without acutely affecting basal synaptic transmission. To visualize protein dynamics, CA1 pyramidal cells of hippocampal slices were transfected with Semliki Forest virus particles expressing a recombinant RNA. This RNA contained the coding sequence for a degradable green fluorescence protein with a nuclear localization signal (NLS-d1EGFP) followed by a 3'- untranslated region dendritic targeting sequence. NLS-d1EGFP fluorescence remained stable in the low-frequency test stimulation but increased with LTP induction in the cell body and in most dendritic compartments of CA1 neurons. Applying anisomycin, a protein synthesis inhibitor, caused NLS-d1EGFP levels to decline; a proteasome inhibitor MG132 reversed this effect. In the presence of anisomycin, LTP induction accelerated the degradation of NLS-d1EGFP. When both inhibitors were present, NLS-d1EGFP levels remained unaffected by LTP induction. Moreover, LTP-induced acceleration of NLS-d1EGFP synthesis was blocked by rapamycin, which is consistent with the involvement of dendritic mammalian target of rapamycin in LTP-triggered translational activity. Our results clearly demonstrate that LTP induction not only leads to a rapid increase in the rate of protein synthesis but also accelerates protein degradation via the proteasome system.
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Smolen P, Baxter DA, Byrne JH. A model of the roles of essential kinases in the induction and expression of late long-term potentiation. Biophys J 2006; 90:2760-75. [PMID: 16415049 PMCID: PMC1414565 DOI: 10.1529/biophysj.105.072470] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The induction of late long-term potentiation (L-LTP) involves complex interactions among second-messenger cascades. To gain insights into these interactions, a mathematical model was developed for L-LTP induction in the CA1 region of the hippocampus. The differential equation-based model represents actions of protein kinase A (PKA), MAP kinase (MAPK), and CaM kinase II (CAMKII) in the vicinity of the synapse, and activation of transcription by CaM kinase IV (CAMKIV) and MAPK. L-LTP is represented by increases in a synaptic weight. Simulations suggest that steep, supralinear stimulus-response relationships between stimuli (e.g., elevations in [Ca(2+)]) and kinase activation are essential for translating brief stimuli into long-lasting gene activation and synaptic weight increases. Convergence of multiple kinase activities to induce L-LTP helps to generate a threshold whereby the amount of L-LTP varies steeply with the number of brief (tetanic) electrical stimuli. The model simulates tetanic, -burst, pairing-induced, and chemical L-LTP, as well as L-LTP due to synaptic tagging. The model also simulates inhibition of L-LTP by inhibition of MAPK, CAMKII, PKA, or CAMKIV. The model predicts results of experiments to delineate mechanisms underlying L-LTP induction and expression. For example, the cAMP antagonist RpcAMPs, which inhibits L-LTP induction, is predicted to inhibit ERK activation. The model also appears useful to clarify similarities and differences between hippocampal L-LTP and long-term synaptic strengthening in other systems.
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Affiliation(s)
- Paul Smolen
- Department of Neurobiology and Anatomy, W.M. Keck Center for the Neurobiology of Learning and Memory, The University of Texas Medical School at Houston, USA
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