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Yang LJ, Wu W, Jiang WR, Zhu CL, Yao ZH. Upregulation of RasGRF1 ameliorates spatial cognitive dysfunction in mice after chronic cerebral hypoperfusion. Aging (Albany NY) 2023; 15:2999-3020. [PMID: 37053022 DOI: 10.18632/aging.204654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 03/31/2023] [Indexed: 04/14/2023]
Abstract
Chronic cerebral hypoperfusion (CCH)-mediated cognitive impairment is a serious problem worldwide. However, given its complexity, the underlying mechanisms by which CCH induces cognitive dysfunction remain unclear, resulting in a lack of effective treatments. In this study, we aimed to determine whether changes in the expression of RasGRF1, an important protein associated with cognition and synaptic plasticity, underlie the associated impairments in cognition after CCH. We found that RasGRF1 levels markedly decreased following CCH. Through prediction and validation studies, we observed that miRNA-323-3p was upregulated after CCH and could bind to the 3'-untranslated region of Rasgrf1 mRNA and regulate its expression in vitro. Moreover, the inhibition of miRNA-323-3p upregulated Rasgrf1 expression in the hippocampus after CCH, which was reversed by Rasgrf1 siRNA. This suggests that miRNA-323-3p is an important regulator of Rasgrf1. The Morris water maze and Y maze tests showed that miRNA-323-3p inhibition and Rasgrf1 upregulation improved spatial learning and memory, and electrophysiological measurements revealed deficits in long-term potentiation after CCH that were reversed by Rasgrf1 upregulation. Dendritic spine density and mature mushroom spine density were also improved after miRNA-323-3p inhibition and Rasgrf1 upregulation. Furthermore, Rasgrf1 upregulation by miRNA-323-3p inhibition improved dendritic spine density and mature mushroom spine density and ameliorated the deterioration of synapses and postsynaptic density. Overall, RasGRF1 regulation attenuated cognitive impairment, helped maintain structural and functional synaptic plasticity, and prevented synapse deterioration after CCH. These results suggest that Rasgrf1 downregulation by miRNA-323-3p plays an important role in cognitive impairment after CCH. Thus, RasGRF1 and miRNA-323-3p may represent potential therapeutic targets for cognitive impairment after CCH.
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Affiliation(s)
- Li-Jie Yang
- Department of Geriatrics, Renmin Hospital of Wuhan University, Wuhan 430060, China
| | - Wei Wu
- Department of Clinical Laboratory, Renmin Hospital of Wuhan University, Wuhan 430060, China
| | - Wan-Rong Jiang
- Department of Geriatrics, Renmin Hospital of Wuhan University, Wuhan 430060, China
| | - Cheng-Liang Zhu
- Department of Clinical Laboratory, Renmin Hospital of Wuhan University, Wuhan 430060, China
| | - Zhao-Hui Yao
- Department of Geriatrics, Renmin Hospital of Wuhan University, Wuhan 430060, China
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Mice deficient in synaptic protease neurotrypsin show impaired spaced long-term potentiation and blunted learning-induced modulation of dendritic spines. Cell Mol Life Sci 2023; 80:82. [PMID: 36871239 PMCID: PMC9986217 DOI: 10.1007/s00018-023-04720-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 01/21/2023] [Accepted: 02/06/2023] [Indexed: 03/06/2023]
Abstract
Neurotrypsin (NT) is a neuronal trypsin-like serine protease whose mutations cause severe mental retardation in humans. NT is activated in vitro by Hebbian-like conjunction of pre- and postsynaptic activities, which promotes the formation of dendritic filopodia via proteolytic cleavage of the proteoglycan agrin. Here, we investigated the functional importance of this mechanism for synaptic plasticity, learning, and extinction of memory. We report that juvenile neurotrypsin-deficient (NT-/-) mice exhibit impaired long-term potentiation induced by a spaced stimulation protocol designed to probe the generation of new filopodia and their conversion into functional synapses. Behaviorally, juvenile NT-/- mice show impaired contextual fear memory and have a sociability deficit. The latter persists in aged NT-/- mice, which, unlike juvenile mice, show normal recall but impaired extinction of contextual fear memories. Structurally, juvenile mutants exhibit reduced spine density in the CA1 region, fewer thin spines, and no modulation in the density of dendritic spines following fear conditioning and extinction in contrast to wild-type littermates. The head width of thin spines is reduced in both juvenile and aged NT-/- mice. In vivo delivery of adeno-associated virus expressing an NT-generated fragment of agrin, agrin-22, but not a shorter agrin-15, elevates the spine density in NT-/- mice. Moreover, agrin-22 co-aggregates with pre- and postsynaptic markers and increases the density and size of presynaptic boutons and presynaptic puncta, corroborating the view that agrin-22 supports the synaptic growth.
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Eastman G, Sharlow ER, Lazo JS, Bloom GS, Sotelo-Silveira JR. Transcriptome and Translatome Regulation of Pathogenesis in Alzheimer's Disease Model Mice. J Alzheimers Dis 2022; 86:365-386. [PMID: 35034904 DOI: 10.3233/jad-215357] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Defining cellular mechanisms that drive Alzheimer's disease (AD) pathogenesis and progression will be aided by studies defining how gene expression patterns change during pre-symptomatic AD and ensuing periods of declining cognition. Previous studies have emphasized changes in transcriptome, but not translatome regulation, leaving the ultimate results of gene expression alterations relatively unexplored in the context of AD. OBJECTIVE To identify genes whose expression might be regulated at the transcriptome and translatome levels in AD, we analyzed gene expression in cerebral cortex of two AD model mouse strains, CVN (APPSwDI;NOS2 -/- ) and Tg2576 (APPSw), and their companion wild type (WT) strains at 6 months of age by tandem RNA-Seq and Ribo-Seq (ribosome profiling). METHODS Identical starting pools of bulk RNA were used for RNA-Seq and Ribo-Seq. Differential gene expression analysis was performed at the transcriptome, translatome, and translational efficiency levels. Regulated genes were functionally evaluated by gene ontology tools. RESULTS Compared to WT mice, AD model mice had similar levels of transcriptome regulation, but differences in translatome regulation. A microglial signature associated with early stages of Aβ accumulation was upregulated at both levels in CVN mice. Although the two mice strains did not share many regulated genes, they showed common regulated pathways related to AβPP metabolism associated with neurotoxicity and neuroprotection. CONCLUSION This work represents the first genome-wide study of brain translatome regulation in animal models of AD and provides evidence of a tight and early translatome regulation of gene expression controlling the balance between neuroprotective and neurodegenerative processes in brain.
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Affiliation(s)
- Guillermo Eastman
- Departamento de Genómica, Instituto de Investigaciones Biológicas Clemente Estable, Ministerio de Educación y Cultura, Montevideo, Uruguay.,Department of Biology, University of Virginia, Charlottesville, VA, USA
| | - Elizabeth R Sharlow
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA
| | - John S Lazo
- Department of Pharmacology, University of Virginia, Charlottesville, VA, USA.,Department of Chemistry, University of Virginia, Charlottesville, VA, USA
| | - George S Bloom
- Department of Biology, University of Virginia, Charlottesville, VA, USA.,Department of Cell Biology, University of Virginia, Charlottesville, VA, USA.,Department of Neuroscience, University of Virginia, Charlottesville, VA, USA
| | - José R Sotelo-Silveira
- Departamento de Genómica, Instituto de Investigaciones Biológicas Clemente Estable, Ministerio de Educación y Cultura, Montevideo, Uruguay.,Sección Biología Celular, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
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Ras inhibitor S-trans, trans-farnesylthiosalicylic acid enhances spatial memory and hippocampal long-term potentiation via up-regulation of NMDA receptor. Neuropharmacology 2018; 139:257-267. [PMID: 29578035 DOI: 10.1016/j.neuropharm.2018.03.026] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 03/19/2018] [Accepted: 03/21/2018] [Indexed: 11/22/2022]
Abstract
Statins by reducing farnesyl-pyrophosphate or farnesyl transferase inhibitors have been demonstrated to enhance spatial memory and long-term potentiation (LTP). The objective of this study was to investigate effects of the synthetic Ras inhibitor S-trans, trans-farnesylthiosalicylic acid (FTS) on spatial cognitive function in adult mice, synaptic plasticity in hippocampal CA1 regions, and NMDA receptor (NMDAr) activity of pyramidal cells. Here, we show that administering FTS (5 mg/kg, i.p.) enhanced spatial cognitive performance, as assessed via Morris water maze and Y-maze tests. Treating hippocampal slices with FTS (5 μM) for 2 h enhanced selectively NMDAr-dependent LTP without changing the synaptic properties. In comparison with the controls, the FTS-treated slices showed increases in the amplitude of NMDA-evoked currents (INMDA) and the phosphorylation of NMDAr GluN2A/GluN2B subunits and Src. The Src inhibitor PP2 blocked the enhancing effects of FTS on the activity and phosphorylation of NMDAr. In FTS-treated slices, basal levels of CaMKII, ERK2 and CREB phosphorylation did not differ significantly from those of controls; however, high-frequency stimulation-induced increases in CaMKII, ERK2 and CREB phosphorylation were more significant than in the controls, which were sensitive to PP2 and NMDAr antagonist MK801. Furthermore, the phosphorylation of AMPA receptor GluR1 during LTP was higher in FTS-treated slices compared with the control, which depended on Src and ERK1/2 signaling. The results indicate that the Ras inhibition by FTS can enhance NMDAr-dependent LTP by increasing Src activity to promote NMDAr GluN2A/GluN2B phosphorylation, which then leads to spatial memory potentiation.
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Minge D, Senkov O, Kaushik R, Herde MK, Tikhobrazova O, Wulff AB, Mironov A, van Kuppevelt TH, Oosterhof A, Kochlamazashvili G, Dityatev A, Henneberger C. Heparan Sulfates Support Pyramidal Cell Excitability, Synaptic Plasticity, and Context Discrimination. Cereb Cortex 2017; 27:903-918. [PMID: 28119345 PMCID: PMC5390399 DOI: 10.1093/cercor/bhx003] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Revised: 12/04/2016] [Accepted: 01/04/2017] [Indexed: 02/06/2023] Open
Abstract
Heparan sulfate (HS) proteoglycans represent a major component of the extracellular matrix and are critical for brain development. However, their function in the mature brain remains to be characterized. Here, acute enzymatic digestion of HS side chains was used to uncover how HSs support hippocampal function in vitro and in vivo. We found that long-term potentiation (LTP) of synaptic transmission at CA3-CA1 Schaffer collateral synapses was impaired after removal of highly sulfated HSs with heparinase 1. This reduction was associated with decreased Ca2+ influx during LTP induction, which was the consequence of a reduced excitability of CA1 pyramidal neurons. At the subcellular level, heparinase treatment resulted in reorganization of the distal axon initial segment, as detected by a reduction in ankyrin G expression. In vivo, digestion of HSs impaired context discrimination in a fear conditioning paradigm and oscillatory network activity in the low theta band after fear conditioning. Thus, HSs maintain neuronal excitability and, as a consequence, support synaptic plasticity and learning.
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Affiliation(s)
- Daniel Minge
- Institute of Cellular Neurosciences, University of Bonn Medical School, 53105 Bonn, Germany
| | - Oleg Senkov
- German Center for Neurodegenerative Diseases (DZNE), 39120 Magdeburg, Germany
| | - Rahul Kaushik
- German Center for Neurodegenerative Diseases (DZNE), 39120 Magdeburg, Germany
| | - Michel K. Herde
- Institute of Cellular Neurosciences, University of Bonn Medical School, 53105 Bonn, Germany
| | - Olga Tikhobrazova
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, 16163 Genova, Italy
- Department of Neurotechnology, Lobachevsky State University of Nizhny Novgorod, 603950 Nizhny Novgorod, Russia
| | - Andreas B. Wulff
- Institute of Cellular Neurosciences, University of Bonn Medical School, 53105 Bonn, Germany
| | - Andrey Mironov
- Department of Neurotechnology, Lobachevsky State University of Nizhny Novgorod, 603950 Nizhny Novgorod, Russia
- Central Research Laboratory, Nizhny Novgorod State Medical Academy, 603005 Nizhny Novgorod, Russia
| | - Toin H. van Kuppevelt
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Arie Oosterhof
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Gaga Kochlamazashvili
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, 16163 Genova, Italy
- Department of Molecular Pharmacology and Cell Biology, Leibniz-Institut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
| | - Alexander Dityatev
- German Center for Neurodegenerative Diseases (DZNE), 39120 Magdeburg, Germany
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, 16163 Genova, Italy
- Department of Neurotechnology, Lobachevsky State University of Nizhny Novgorod, 603950 Nizhny Novgorod, Russia
- Medizinische Fakultät, Otto-von-Guericke-Universität Magdeburg, 39120 Magdeburg, Germany
| | - Christian Henneberger
- Institute of Cellular Neurosciences, University of Bonn Medical School, 53105 Bonn, Germany
- German Center for Neurodegenerative Diseases (DZNE), 53175 Bonn, Germany
- Institute of Neurology, University College London, London WC1N 3BG, UK
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