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Zarate N, Gundry K, Yu D, Casby J, Eberly LE, Öz G, Gomez-Pastor R. Neurochemical correlates of synapse density in a Huntington's disease mouse model. J Neurochem 2023; 164:226-241. [PMID: 36272099 PMCID: PMC9892354 DOI: 10.1111/jnc.15714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 10/01/2022] [Accepted: 10/18/2022] [Indexed: 02/04/2023]
Abstract
Striatal medium spiny neurons are highly susceptible in Huntington's disease (HD), resulting in progressive synaptic perturbations that lead to neuronal dysfunction and death. Non-invasive imaging techniques, such as proton magnetic resonance spectroscopy (1 H-MRS), are used in HD mouse models and patients with HD to monitor neurochemical changes associated with neuronal health. However, the association between brain neurochemical alterations and synaptic dysregulation remains unknown, limiting our ability to monitor potential treatments that may affect synapse function. We conducted in vivo longitudinal 1 H-MRS in the striatum followed by ex vivo analyses of excitatory synapse density of two synaptic circuits disrupted in HD, thalamo-striatal (T-S), and cortico-striatal (C-S) pathways, to assess the relationship between neurochemical alterations and changes in synapse density. We used the zQ175(Tg/0) HD mouse model as well as zQ175 mice lacking one allele of CK2α'(zQ175(Tg/0) :CK2α'(+/-) ), a kinase previously shown to regulate synapse function in HD. Longitudinal analyses of excitatory synapse density showed early and sustained reduction in T-S synapses in zQ175 mice, preceding C-S synapse depletion, which was rescued in zQ175:CK2α'(+/-) . Changes in T-S and C-S synapses were accompanied by progressive alterations in numerous neurochemicals between WT and HD mice. Linear regression analyses showed C-S synapse number positively correlated with 1 H-MRS-measured levels of GABA, while T-S synapse number positively correlated with levels of phosphoethanolamine and negatively correlated with total creatine levels. These associations suggest that these neurochemical concentrations measured by 1 H-MRS may facilitate monitoring circuit-specific synaptic dysfunction in the zQ175 mouse model and in other HD pre-clinical studies.
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Affiliation(s)
- Nicole Zarate
- Department of Neuroscience, Medical School, University of Minnesota, Minneapolis, MN, United States
| | - Katherine Gundry
- Center for Magnetic Resonance Research, Department of Radiology, Medical School, University of Minnesota, Minneapolis, MN, United States
| | - Dahyun Yu
- Department of Neuroscience, Medical School, University of Minnesota, Minneapolis, MN, United States
| | - Jordan Casby
- Department of Pharmacology, Medical School, University of Minnesota, Minneapolis, MN, United States
| | - Lynn E Eberly
- Center for Magnetic Resonance Research, Department of Radiology, Medical School, University of Minnesota, Minneapolis, MN, United States.,Division of Biostatistics, School of Public Health, University of Minnesota, Minneapolis, Minnesota
| | - Gülin Öz
- Center for Magnetic Resonance Research, Department of Radiology, Medical School, University of Minnesota, Minneapolis, MN, United States
| | - Rocio Gomez-Pastor
- Department of Neuroscience, Medical School, University of Minnesota, Minneapolis, MN, United States
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Bertoglio D, Zajicek F, Lombaerde SD, Miranda A, Stroobants S, Wang Y, Dominguez C, Munoz-Sanjuan I, Bard J, Liu L, Verhaeghe J, Staelens S. Validation, kinetic modeling, and test-retest reproducibility of [ 18F]SynVesT-1 for PET imaging of synaptic vesicle glycoprotein 2A in mice. J Cereb Blood Flow Metab 2022; 42:1867-1878. [PMID: 35570828 PMCID: PMC9536120 DOI: 10.1177/0271678x221101648] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Alterations in synaptic vesicle glycoprotein 2 A (SV2A) have been associated with several neuropsychiatric and neurodegenerative disorders. Therefore, SV2A positron emission tomography (PET) imaging may provide a unique tool to investigate synaptic density dynamics during disease progression and after therapeutic intervention. This study aims to extensively characterize the novel radioligand [18F]SynVesT-1 for preclinical applications. In C57Bl/6J mice (n = 39), we assessed the plasma profile of [18F]SynVesT-1, validated the use of a noninvasive image-derived input function (IDIF) compared to an arterial input function (AIF), performed a blocking study with levetiracetam (50 and 200 mg/kg, i.p.) to verify the specificity towards SV2A, examined kinetic models for volume of distribution (VT) quantification, and explored test-retest reproducibility of [18F]SynVesT-1 in the central nervous system (CNS). Plasma availability of [18F]SynVesT-1 decreased rapidly (13.4 ± 1.5% at 30 min post-injection). VT based on AIF and IDIF showed excellent agreement (r2 = 0.95, p < 0.0001) and could be reliably estimated with a 60-min acquisition. The blocking study resulted in a complete blockade with no suitable reference region. Test-retest analysis indicated good reproducibility (mean absolute variability <10%). In conclusion, [18F]SynVesT-1 is selective for SV2A with optimal kinetics representing a candidate tool to quantify CNS synaptic density non-invasively.
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Affiliation(s)
- Daniele Bertoglio
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Antwerp, Belgium
| | - Franziska Zajicek
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Antwerp, Belgium
| | - Stef De Lombaerde
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Antwerp, Belgium.,Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium
| | - Alan Miranda
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Antwerp, Belgium
| | - Sigrid Stroobants
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Antwerp, Belgium.,Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium
| | - Yuchuan Wang
- CHDI Management/CHDI Foundation, Los Angeles, California, USA
| | - Celia Dominguez
- CHDI Management/CHDI Foundation, Los Angeles, California, USA
| | | | - Jonathan Bard
- CHDI Management/CHDI Foundation, Los Angeles, California, USA
| | - Longbin Liu
- CHDI Management/CHDI Foundation, Los Angeles, California, USA
| | - Jeroen Verhaeghe
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Antwerp, Belgium
| | - Steven Staelens
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Antwerp, Belgium
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Jagtap S, Potdar C, Yadav R, Pal PK, Datta I. Dopaminergic Neurons Differentiated from LRRK2 I1371V-Induced Pluripotent Stem Cells Display a Lower Yield, α-Synuclein Pathology, and Functional Impairment. ACS Chem Neurosci 2022; 13:2632-2645. [PMID: 36006382 DOI: 10.1021/acschemneuro.2c00297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Being a large multidomain protein, LRRK2 has several confirmed pathological mutant variants for PD, and the incidence of these variants shows ethnicity biases. I1371V, a mutation in the GTPase domain, has been reported in East-Asian populations, but there are no studies reported on dopaminergic (DA) neurons differentiated from this variant. The aim here was to assess the yield, function, and α-synuclein pathology of DA neurons differentiated from LRRK2 I1371V iPSCs. FACS analysis of neural progenitors (NPs) showed a comparable immunopositive population of cells for neural and glial progenitor markers nestin and S100β; however, NPs from I1371V iPSCs showed lower clonogenic and proliferative capacities than healthy control NPs as determined by the neurosphere assay and Ki67 expression. Floor plate cells obtained from I1371V NPs primed with FGF8 showed distinctly lower immunopositivity for FOXA2 and CLIC5 than healthy control FPCs and similar DOC2B expression. On SHH addition, a similar mature neuronal population was obtained from both groups; however, the yield of TH-immunopositive cells was significantly lower in I1371V, with lower expression of mature DA neuronal markers En1, Nurr1, and DAT. Vesicular dopamine release and intracellular Ca2+ response with KCl stimulation were lower in I1371V DA neurons, along with a significantly reduced expression of resting vesicle marker VMAT2. A concurrently lower expression of PSD95/Syn-I immunopositive puncta was observed in I1371V differentiated cells. Further, higher phosphorylation of α-synuclein and aggregation of oligomeric α-synuclein in I1371V DA neurons were observed. Our data demonstrated conclusively for the first time that mutations in the I1371V allele of LRRK2 showed developmental deficit from the FPC stage and generated a lower yield/number of TH-immunopositive neurons with impairment in their function and synapse density along with increased α-synuclein pathology.
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Affiliation(s)
- Soham Jagtap
- Department of Biophysics, National Institute of Mental Health and Neurosciences, Institute of National Importance, Bengaluru 560029, Karnataka, India
| | - Chandrakanta Potdar
- Department of Biophysics, National Institute of Mental Health and Neurosciences, Institute of National Importance, Bengaluru 560029, Karnataka, India
| | - Ravi Yadav
- Department of Neurology, National Institute of Mental Health and Neurosciences, Institute of National Importance, Bengaluru 560029, Karnataka, India
| | - Pramod Kumar Pal
- Department of Neurology, National Institute of Mental Health and Neurosciences, Institute of National Importance, Bengaluru 560029, Karnataka, India
| | - Indrani Datta
- Department of Biophysics, National Institute of Mental Health and Neurosciences, Institute of National Importance, Bengaluru 560029, Karnataka, India
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Liu Y, Chen C, Liu Y, Li W, Wang Z, Sun Q, Zhou H, Chen X, Yu Y, Wang Y, Abumaria N. TRPM7 Is Required for Normal Synapse Density, Learning, and Memory at Different Developmental Stages. Cell Rep 2019; 23:3480-3491. [PMID: 29924992 DOI: 10.1016/j.celrep.2018.05.069] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 01/29/2018] [Accepted: 05/18/2018] [Indexed: 10/28/2022] Open
Abstract
The TRPM7 chanzyme contributes to several biological and pathological processes in different tissues. However, its role in the CNS under physiological conditions remains unclear. Here, we show that TRPM7 knockdown in hippocampal neurons reduces structural synapse density. The synapse density is rescued by the α-kinase domain in the C terminus but not by the ion channel region of TRPM7 or by increasing extracellular concentrations of Mg2+ or Zn2+. Early postnatal conditional knockout of TRPM7 in mice impairs learning and memory and reduces synapse density and plasticity. TRPM7 knockdown in the hippocampus of adult rats also impairs learning and memory and reduces synapse density and synaptic plasticity. In knockout mice, restoring expression of the α-kinase domain in the brain rescues synapse density/plasticity and memory, probably by interacting with and phosphorylating cofilin. These results suggest that brain TRPM7 is important for having normal synaptic and cognitive functions under physiological, non-pathological conditions.
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Affiliation(s)
- Yuqiang Liu
- Department of Neurology, Huashan Hospital, and Institutes of Brain Science, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200032, China
| | - Cui Chen
- Department of Neurology, Huashan Hospital, and Institutes of Brain Science, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200032, China
| | - Yunlong Liu
- School of Medicine, Tsinghua University, Beijing 100084, China
| | - Wei Li
- Department of Neurology, Huashan Hospital, and Institutes of Brain Science, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200032, China
| | - Zhihong Wang
- Department of Neurology, Huashan Hospital, and Institutes of Brain Science, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200032, China
| | - Qifeng Sun
- School of Medicine, Tsinghua University, Beijing 100084, China
| | - Hang Zhou
- School of Medicine, Tsinghua University, Beijing 100084, China
| | - Xiangjun Chen
- Department of Neurology, Huashan Hospital, and Institutes of Brain Science, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200032, China
| | - Yongchun Yu
- Department of Neurology, Huashan Hospital, and Institutes of Brain Science, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200032, China
| | - Yun Wang
- Department of Neurology, Huashan Hospital, and Institutes of Brain Science, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200032, China
| | - Nashat Abumaria
- Department of Neurology, Huashan Hospital, and Institutes of Brain Science, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200032, China; Department of Laboratory Animal Science, Shanghai Medical College, Fudan University, Shanghai 200032, China.
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5
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le Feber J, Dummer A, Hassink GC, van Putten MJAM, Hofmeijer J. Evolution of Excitation-Inhibition Ratio in Cortical Cultures Exposed to Hypoxia. Front Cell Neurosci 2018; 12:183. [PMID: 30018536 PMCID: PMC6037832 DOI: 10.3389/fncel.2018.00183] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Accepted: 06/11/2018] [Indexed: 11/24/2022] Open
Abstract
In the core of a brain infarct, neuronal death occurs within minutes after loss of perfusion. In the penumbra, a surrounding area with some residual perfusion, neurons initially remain structurally intact, but hypoxia-induced synaptic failure impedes neuronal activity. Penumbral activity may recover or further deteriorate, reflecting cell death. Mechanisms leading to either outcome remain ill-understood, but may involve changes in the excitation to inhibition (E/I) ratio. The E/I ratio is determined by structural (relative densities of excitatory and inhibitory synapses) and functional factors (synaptic strengths). Clinical studies demonstrated excitability alterations in regions surrounding the infarct core. These may be related to structural E/I changes, but the effects of hypoxia /ischemia on structural connectivity have not yet been investigated, and the role of structural connectivity changes in excitability alterations remains unclear. We investigated the evolution of the structural E/I ratio and associated network excitability in cortical cultures exposed to severe hypoxia of varying duration. 6–12 h of hypoxia reduced the total synaptic density. In particular, the inhibitory synaptic density dropped significantly, resulting in an elevated E/I ratio. Initially, this does not lead to increased excitability due to hypoxia-induced synaptic failure. Increased excitability becomes apparent upon reoxygenation after 6 or 12 h, but not after 24 h. After 24 h of hypoxia, structural patterns of vesicular glutamate stainings change. This possibly reflects disassembly of excitatory synapses, and may account for the irreversible reduction of activity and stimulus responses seen after 24 h.
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Affiliation(s)
- Joost le Feber
- Clinical Neurophysiology, TechMed Centre, University of Twente, Enschede, Netherlands
| | - Anneloes Dummer
- Clinical Neurophysiology, TechMed Centre, University of Twente, Enschede, Netherlands
| | - Gerco C Hassink
- Clinical Neurophysiology, TechMed Centre, University of Twente, Enschede, Netherlands.,Biomedical Signals and Systems, TechMed Centre, University of Twente, Enschede, Netherlands
| | - Michel J A M van Putten
- Clinical Neurophysiology, TechMed Centre, University of Twente, Enschede, Netherlands.,Department of Clinical Neurophysiology, Medisch Spectrum Twente, Enschede, Netherlands
| | - Jeannette Hofmeijer
- Clinical Neurophysiology, TechMed Centre, University of Twente, Enschede, Netherlands.,Department of Neurology, Rijnstate Hospital, Arnhem, Netherlands
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Dong H, Yuede CM, Coughlan CA, Murphy KM, Csernansky JG. Effects of donepezil on amyloid-beta and synapse density in the Tg2576 mouse model of Alzheimer's disease. Brain Res 2009; 1303:169-78. [PMID: 19799879 PMCID: PMC2789417 DOI: 10.1016/j.brainres.2009.09.097] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2009] [Revised: 09/22/2009] [Accepted: 09/24/2009] [Indexed: 10/20/2022]
Abstract
Donepezil, an acetylcholinesterase inhibitor, is an approved drug for the treatment of Alzheimer's disease (AD). Although extensive studies have demonstrated the symptomatic efficacy of donepezil treatment in patients with AD, the effects of donepezil, if any, on the AD process are not known. In this study, we sought to determine whether long-term administration of donepezil would slow amyloid plaque deposition or confer neuronal protection in a mouse model of AD. We used quantitative light and electron microscopy to investigate the effects of long-term administration (from 3 to 9 months of age for 6 months of treatment) of donepezil (1, 2, 4 mg/kg, in drinking water) on tissue amyloid-beta (Abeta) protein, plaque deposition, synaptic protein (synaptophysin), and synapse density in the hippocampus of Tg2576 mice. Administration of the 4 mg/kg dose of donepezil, as compared to vehicle and lower doses of donepezil, significantly reduced brain tissue soluble Abeta(1-40) and Abeta(1-42), Abeta plaque number, and burden at the study end point in Tg2576 mice. The dose of 4 mg/kg of donepezil also significantly increased synaptic density in the molecular layer of the dentate gyrus in Tg2576 mice. However, a significant change of the synaptophysin-positive bouton in the hippocampus was not observed. These results suggest that a higher dose of donepezil may have a measurable impact on tissue level of Abeta protein and plaque deposition and may prevent synapse loss in the Tg2576 mouse model of AD.
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Affiliation(s)
- Hongxin Dong
- Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
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Dong H, Yuede CM, Coughlan C, Lewis B, Csernansky JG. Effects of memantine on neuronal structure and conditioned fear in the Tg2576 mouse model of Alzheimer's disease. Neuropsychopharmacology 2008; 33:3226-36. [PMID: 18418360 PMCID: PMC2664647 DOI: 10.1038/npp.2008.53] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Memantine, an uncompetitive NMDA receptor antagonist used for the treatment of Alzheimer's disease (AD), has been hypothesized to have neuroprotective properties. However, the similarity of its mechanism of action to other NMDA receptor antagonists has led to concerns that it may also have neurotoxic effects. To assess both the neuroprotective and neurotoxic potential of memantine in a mouse model of AD (Tg2576 mice), we used quantitative light and electron microscopy to investigate the effects of long-term (6 months) administration of memantine (5, 10 and 20 mg/kg) on plaque deposition and neuronal morphology in the hippocampus and overlying cortex. A fear-conditioning paradigm was used to evaluate the behavioral consequences of any observed changes in structure. Administration of the two higher doses of memantine (10 and 20 mg/kg) was associated with a significant decrease in beta-amyloid (Abeta) plaque deposition, increases in synaptic density and the appearance of degenerating axons; the latter two effects were independent of genotype. Administration of the lowest dose of memantine (5 mg/kg) was associated with a significant decrease in Abeta plaque deposition and a significant increase in synaptic density, but not a significant increase in degenerating axons. However, memantine did not significantly improve behavioral deficits associated with genotype in a fear-conditioning paradigm at any dose. These results suggest that chronic memantine administration may have both neuroprotective and neurotoxic effects in a mouse model of AD.
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Affiliation(s)
- Hongxin Dong
- Department of Psychiatry, Washington University School of Medicine, St Louis, MO, USA
| | - Carla M Yuede
- Department of Psychiatry, Washington University School of Medicine, St Louis, MO, USA
| | - Carolyn Coughlan
- Department of Psychiatry, Washington University School of Medicine, St Louis, MO, USA
| | - Brian Lewis
- Department of Psychiatry, Washington University School of Medicine, St Louis, MO, USA
| | - John G Csernansky
- Department of Psychiatry, Washington University School of Medicine, St Louis, MO, USA,Department of Anatomy and Neurobiology, Washington University School of Medicine, St Louis, MO, USA,Correspondence: Dr JG Csernansky, Department of Psychiatry, Washington University School of Medicine, 660 South Euclid Avenue, Campus Box 8134, St Louis, MO 63110, USA, Tel: +1 314 747 2160, Fax: + 1 314 747 2182, E-mail:
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