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Yang J, Ran K, Ma W, Chen Y, Chen Y, Zhang C, Ye H, Lu Y, Ran C. Degradation of Amyloid-β Species by Multi-Copper Oxidases. J Alzheimers Dis 2024; 101:525-539. [PMID: 39213075 DOI: 10.3233/jad-240625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
Background Reduction of the production of amyloid-β (Aβ) species has been intensively investigated as potential therapeutic approaches for Alzheimer's disease (AD). However, the degradation of Aβ species, another potential beneficial approach, has been far less explored. Objective To investigate the potential of multi-copper oxidases (MCOs) in degrading Aβ peptides and their potential benefits for AD treatment. Methods We investigated the degradation efficiency of MCOs by using electrophoresis and validated the ceruloplasmin (CP)-Aβ interaction using total internal reflection fluorescence microscopy, fluorescence photometer, and fluorescence polarization measurement. We also investigated the therapeutic effect of ascorbate oxidase (AO) by using induced pluripotent stem (iPS) neuron cells and electrophysiological analysis with brain slices. Results We discovered that CP, an important MCO in human blood, could degrade Aβ peptides. We also found that other MCOs could induce Aβ degradation as well. Remarkably, we revealed that AO had the strongest degrading effect among the tested MCOs. Using iPS neuron cells, we observed that AO could rescue neuron toxicity which induced by Aβ oligomers. In addition, our electrophysiological analysis with brain slices suggested that AO could prevent an Aβ-induced deficit in synaptic transmission in the hippocampus. Conclusions To the best of our knowledge, our report is the first to demonstrate that MCOs have a degrading function for peptides/proteins. Further investigations are warranted to explore the possible benefits of MCOs for future AD treatment.
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Affiliation(s)
- Jing Yang
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital/Harvard Medical School, Charlestown, Boston, MA, USA
- School of Engineering, China Pharmaceutical University, Nanjing, China
| | - Kathleen Ran
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital/Harvard Medical School, Charlestown, Boston, MA, USA
| | - Wenzhe Ma
- Department of System Biology, Harvard Medical School, Boston, MA, USA
| | - Yanshi Chen
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital/Harvard Medical School, Charlestown, Boston, MA, USA
| | - Yanxin Chen
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital/Harvard Medical School, Charlestown, Boston, MA, USA
| | - Can Zhang
- Department of Neurology, Genetics and Aging Research Unit, McCance Center for Brain Health, MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Hui Ye
- Department of Biology, Loyola University Chicago, IL, USA
| | - Ying Lu
- Department of System Biology, Harvard Medical School, Boston, MA, USA
| | - Chongzhao Ran
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital/Harvard Medical School, Charlestown, Boston, MA, USA
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Yang J, Ran K, Ma W, Chen L, Chen C, Zhang C, Ye H, Lu Y, Ran C. Degradation of amyloid beta species by multi-copper oxidases. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.02.547398. [PMID: 37461701 PMCID: PMC10350030 DOI: 10.1101/2023.07.02.547398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 07/24/2023]
Abstract
Reduction of the production of amyloid beta (Aβ) species has been intensively investigated as potential therapeutic approaches for Alzheimer's disease (AD). However, the degradation of Aβ species, another potential beneficial approach, has been far less explored. In this study, we discovered that ceruloplasmin (CP), an important multi-copper oxidase (MCO) in human blood, could degrade Aβ peptides. We also found that the presence of Vitamin C could enhance the degrading effect in a concentration-dependent manner. We then validated the CP-Aβ interaction using total internal reflection fluorescence (TIRF) microscopy, fluorescence photometer, and fluorescence polarization measurement. Based on the above discovery, we hypothesized that other MCOs had similar Aβ-degrading functions. Indeed, we found that other MCOs could induce Aβ degradation as well. Remarkably, we revealed that ascorbate oxidase (AO) had the strongest degrading effect among the tested MCOs. Using induced pluripotent stem (iPS) neuron cells, we observed that AO could rescue neuron toxicity which induced by Aβ oligomers. In addition, our electrophysiological analysis with brain slices suggested that AO could prevent an Ab-induced deficit in synaptic transmission in the hippocampus. To the best of our knowledge, our report is the first to demonstrate that MCOs have a degrading function for peptides/proteins. Further investigations are warranted to explore the possible benefits of MCOs for future AD treatment.
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Affiliation(s)
- Jing Yang
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital/Harvard Medical School, Room 2301, Building 149, Charlestown, Boston, Massachusetts 02129
- School of Engineering, China Pharmaceutical University, Nanjing, 210009, China
| | - Kathleen Ran
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital/Harvard Medical School, Room 2301, Building 149, Charlestown, Boston, Massachusetts 02129
| | - Wenzhe Ma
- Department of Systems Biology, Harvard Medical School, Boston, MA, United States
| | - Lucy Chen
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital/Harvard Medical School, Room 2301, Building 149, Charlestown, Boston, Massachusetts 02129
| | - Cindy Chen
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital/Harvard Medical School, Room 2301, Building 149, Charlestown, Boston, Massachusetts 02129
| | - Can Zhang
- Genetics and Aging Research Unit, McCance Center for Brain Health, MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Hui Ye
- Department of Biology, Loyola University Chicago, Chicago, IL, 60660
| | - Ying Lu
- Department of Systems Biology, Harvard Medical School, Boston, MA, United States
| | - Chongzhao Ran
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital/Harvard Medical School, Room 2301, Building 149, Charlestown, Boston, Massachusetts 02129
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Bagheri S, Rashno M, Salehi I, Karimi SA, Raoufi S, Komaki A. Geraniol improves passive avoidance memory and hippocampal synaptic plasticity deficits in a rat model of Alzheimer's disease. Eur J Pharmacol 2023; 951:175714. [PMID: 37054939 DOI: 10.1016/j.ejphar.2023.175714] [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: 01/12/2023] [Revised: 04/03/2023] [Accepted: 04/11/2023] [Indexed: 04/15/2023]
Abstract
Alzheimer's disease (AD) is the most progressive and irreversible neurodegenerative disease that leads to synaptic loss and cognitive decline. The present study was designed to evaluate the effects of geraniol (GR), a valuable acyclic monoterpene alcohol, with protective and therapeutic effects, on passive avoidance memory, hippocampal synaptic plasticity, and amyloid-beta (Aβ) plaques formation in an AD rat model induced by intracerebroventricular (ICV) microinjection of Aβ1-40. Seventy male Wistar rats were randomly into sham, control, control-GR (100 mg/kg; P.O. (orally), AD, GR-AD (100 mg/kg; P.O.; pretreatment), AD-GR (100 mg/kg; P.O.; treatment), and GR-AD-GR (100 mg/kg; P.O.; pretreatment & treatment). Administration of GR was continued for four consecutive weeks. Training for the passive avoidance test was carried out on the 36th day and a memory retention test was performed 24 h later. On day 38, hippocampal synaptic plasticity (long-term potentiation; LTP) was recorded in perforant path-dentate gyrus (PP-DG) synapses to assess field excitatory postsynaptic potentials (fEPSPs) slope and population spike (PS) amplitude. Subsequently, Aβ plaques were identified in the hippocampus by Congo red staining. The results showed that Aβ microinjection increased passive avoidance memory impairment, suppressed of hippocampal LTP induction, and enhanced of Aβ plaque formation in the hippocampus. Interestingly, oral administration of GR improved passive avoidance memory deficit, ameliorated hippocampal LTP impairment, and reduced Aβ plaque accumulation in the Aβ-infused rats. The results suggest that GR mitigates Aβ-induced passive avoidance memory impairment, possibly through alleviation of hippocampal synaptic dysfunction and inhibition of Aβ plaque formation.
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Affiliation(s)
- Shokufeh Bagheri
- Department of Neuroscience, School of Science and Advanced Technologies in Medicine, Hamadan University of Medical Sciences, Hamadan, Iran; Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Masome Rashno
- Asadabad School of Medical Sciences, Asadabad, Iran; Student Research Committee, Asadabad School of Medical Sciences, Asadabad, Iran
| | - Iraj Salehi
- Department of Neuroscience, School of Science and Advanced Technologies in Medicine, Hamadan University of Medical Sciences, Hamadan, Iran; Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Seyed Asaad Karimi
- Department of Neuroscience, School of Science and Advanced Technologies in Medicine, Hamadan University of Medical Sciences, Hamadan, Iran; Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Safoura Raoufi
- Department of Physiology, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Alireza Komaki
- Department of Neuroscience, School of Science and Advanced Technologies in Medicine, Hamadan University of Medical Sciences, Hamadan, Iran; Neurophysiology Research Center, Hamadan University of Medical Sciences, Hamadan, Iran. http://umsha.ac.ir
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4
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Prista von Bonhorst F, Gall D, Dupont G. Impact of β-Amyloids Induced Disruption of Ca2+ Homeostasis in a Simple Model of Neuronal Activity. Cells 2022; 11:cells11040615. [PMID: 35203266 PMCID: PMC8869902 DOI: 10.3390/cells11040615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 01/31/2022] [Accepted: 02/01/2022] [Indexed: 01/25/2023] Open
Abstract
Alzheimer’s disease is characterized by a marked dysregulation of intracellular Ca2+ homeostasis. In particular, toxic β-amyloids (Aβ) perturb the activities of numerous Ca2+ transporters or channels. Because of the tight coupling between Ca2+ dynamics and the membrane electrical activity, such perturbations are also expected to affect neuronal excitability. We used mathematical modeling to systematically investigate the effects of changing the activities of the various targets of Aβ peptides reported in the literature on calcium dynamics and neuronal excitability. We found that the evolution of Ca2+ concentration just below the plasma membrane is regulated by the exchanges with the extracellular medium, and is practically independent from the Ca2+ exchanges with the endoplasmic reticulum. Thus, disruptions of Ca2+ homeostasis interfering with signaling do not affect the electrical properties of the neurons at the single cell level. In contrast, the model predicts that by affecting the activities of L-type Ca2+ channels or Ca2+-activated K+ channels, Aβ peptides promote neuronal hyperexcitability. On the contrary, they induce hypo-excitability when acting on the plasma membrane Ca2+ ATPases. Finally, the presence of pores of amyloids in the plasma membrane can induce hypo- or hyperexcitability, depending on the conditions. These modeling conclusions should help with analyzing experimental observations in which Aβ peptides interfere at several levels with Ca2+ signaling and neuronal activity.
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Affiliation(s)
- Francisco Prista von Bonhorst
- Unit of Theoretical Chronobiology, Faculté des Sciences (CP231), Université Libre de Bruxelles (ULB), 1050 Brussels, Belgium;
| | - David Gall
- Research Laboratory in Human Reproduction, Faculté de Médecine (CP636), Université Libre de Bruxelles (ULB), 1070 Brussels, Belgium;
| | - Geneviève Dupont
- Unit of Theoretical Chronobiology, Faculté des Sciences (CP231), Université Libre de Bruxelles (ULB), 1050 Brussels, Belgium;
- Correspondence:
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Fernandez‐Perez EJ, Muñoz B, Bascuñan DA, Peters C, Riffo‐Lepe NO, Espinoza MP, Morgan PJ, Filippi C, Bourboulou R, Sengupta U, Kayed R, Epsztein J, Aguayo LG. Synaptic dysregulation and hyperexcitability induced by intracellular amyloid beta oligomers. Aging Cell 2021; 20:e13455. [PMID: 34409748 PMCID: PMC8441418 DOI: 10.1111/acel.13455] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 07/21/2021] [Accepted: 08/05/2021] [Indexed: 12/19/2022] Open
Abstract
Intracellular amyloid beta oligomer (iAβo) accumulation and neuronal hyperexcitability are two crucial events at early stages of Alzheimer's disease (AD). However, to date, no mechanism linking iAβo with an increase in neuronal excitability has been reported. Here, the effects of human AD brain-derived (h-iAβo) and synthetic (iAβo) peptides on synaptic currents and action potential firing were investigated in hippocampal neurons. Starting from 500 pM, iAβo rapidly increased the frequency of synaptic currents and higher concentrations potentiated the AMPA receptor-mediated current. Both effects were PKC-dependent. Parallel recordings of synaptic currents and nitric oxide (NO)-associated fluorescence showed that the increased frequency, related to pre-synaptic release, was dependent on a NO-mediated retrograde signaling. Moreover, increased synchronization in NO production was also observed in neurons neighboring those dialyzed with iAβo, indicating that iAβo can increase network excitability at a distance. Current-clamp recordings suggested that iAβo increased neuronal excitability via AMPA-driven synaptic activity without altering membrane intrinsic properties. These results strongly indicate that iAβo causes functional spreading of hyperexcitability through a synaptic-driven mechanism and offers an important neuropathological significance to intracellular species in the initial stages of AD, which include brain hyperexcitability and seizures.
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Affiliation(s)
| | - Braulio Muñoz
- Laboratory of NeurophysiologyDepartment of PhysiologyUniversidad de ConcepciónConcepciónChile
| | - Denisse A. Bascuñan
- Laboratory of NeurophysiologyDepartment of PhysiologyUniversidad de ConcepciónConcepciónChile
| | - Christian Peters
- Laboratory of NeurophysiologyDepartment of PhysiologyUniversidad de ConcepciónConcepciónChile
| | - Nicolas O. Riffo‐Lepe
- Laboratory of NeurophysiologyDepartment of PhysiologyUniversidad de ConcepciónConcepciónChile
| | - Maria P. Espinoza
- Laboratory of NeurophysiologyDepartment of PhysiologyUniversidad de ConcepciónConcepciónChile
| | - Peter J. Morgan
- Institute of Neurobiology of the Mediterranean Sea (INMED)Institut National de la Santé et de la Recherche Médicale (INSERM) U901, Aix-Marseille UniversitéMarseilleFrance
| | - Caroline Filippi
- Institute of Neurobiology of the Mediterranean Sea (INMED)Institut National de la Santé et de la Recherche Médicale (INSERM) U901, Aix-Marseille UniversitéMarseilleFrance
| | - Romain Bourboulou
- Institute of Neurobiology of the Mediterranean Sea (INMED)Institut National de la Santé et de la Recherche Médicale (INSERM) U901, Aix-Marseille UniversitéMarseilleFrance
| | - Urmi Sengupta
- Mitchell Center for Neurodegenerative DiseasesUniversity of Texas Medical BranchGalvestonTexasUSA
- Department of Neurology, Neuroscience and Cell BiologyUniversity of Texas Medical BranchGalvestonTexasUSA
| | - Rakez Kayed
- Mitchell Center for Neurodegenerative DiseasesUniversity of Texas Medical BranchGalvestonTexasUSA
- Department of Neurology, Neuroscience and Cell BiologyUniversity of Texas Medical BranchGalvestonTexasUSA
| | - Jérôme Epsztein
- Institute of Neurobiology of the Mediterranean Sea (INMED)Institut National de la Santé et de la Recherche Médicale (INSERM) U901, Aix-Marseille UniversitéMarseilleFrance
| | - Luis G. Aguayo
- Laboratory of NeurophysiologyDepartment of PhysiologyUniversidad de ConcepciónConcepciónChile
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6
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Wang ZJ, Zhao F, Wang CF, Zhang XM, Xiao Y, Zhou F, Wu MN, Zhang J, Qi JS, Yang W. Xestospongin C, a Reversible IP3 Receptor Antagonist, Alleviates the Cognitive and Pathological Impairments in APP/PS1 Mice of Alzheimer's Disease. J Alzheimers Dis 2020; 72:1217-1231. [PMID: 31683484 DOI: 10.3233/jad-190796] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Exaggerated Ca2+ signaling might be one of primary causes of neural dysfunction in Alzheimer's disease (AD). And the intracellular Ca2+ overload has been closely associated with amyloid-β (Aβ)-induced endoplasmic reticulum (ER) stress and memory impairments in AD. Here we showed for the first time the neuroprotective effects of Xestospongin C (XeC), a reversible IP3 receptor antagonist, on the cognitive behaviors and pathology of APP/PS1 AD mice. Male APP/PS1-AD mice (n = 20) were injected intracerebroventricularly with XeC (3μmol) via Alzet osmotic pumps for four weeks, followed by cognition tests, Aβ plaque examination, and ER stress-related protein measurement. The results showed that XeC pretreatment significantly improved the cognitive behavior of APP/PS1-AD mice, raising the spontaneous alteration accuracy in Y maze, decreasing the escape latency and increasing the target quadrant swimming time in Morris water maze; XeC pretreatment also reduced the number of Aβ plaques and the overexpression of ER stress proteins 78 kDa glucose-regulated protein (GRP-78), caspase-12, and CAAT/enhancer-binding protein (C/EBP) homologous protein (CHOP) in the hippocampus of APP/PS1 mice. In addition, in vitro experiments showed that XeC effectively ameliorated Aβ1 - 42-induced early neuronal apoptosis and intracellular Ca2+ overload in the primary hippocampal neurons. Taken together, IP3R-mediated Ca2+ disorder plays a key role in the cognitive deficits and pathological damages in AD mice. By targeting the IP3 R, XeC might be considered as a novel therapeutic strategy in AD.
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Affiliation(s)
- Zhao-Jun Wang
- Department of Physiology, Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, PR China
| | - Fang Zhao
- Department of Physiology, Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, PR China
| | - Chen-Fang Wang
- Department of Physiology, Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, PR China
| | - Xiu-Min Zhang
- Department of Physiology, Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, PR China
| | - Yi Xiao
- Department of Cardiology, the Third of Kunming People's Hospital, Yunnan, China
| | - Fang Zhou
- Department of Physiology, Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, PR China
| | - Mei-Na Wu
- Department of Physiology, Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, PR China
| | - Jun Zhang
- Department of Physiology, Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, PR China
| | - Jin-Shun Qi
- Department of Physiology, Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, PR China
| | - Wei Yang
- Department of Physiology, Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, PR China
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Liang J, Kulasiri D. What can computational modeling offer for studying the Ca 2+ dysregulation in Alzheimer's disease: current research and future directions. Neural Regen Res 2018; 13:1156-1158. [PMID: 30028315 PMCID: PMC6065234 DOI: 10.4103/1673-5374.235020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Ca2+ dysregulation is an early event observed in Alzheimer’s disease (AD) patients preceding the presence of its clinical symptoms. Dysregulation of neuronal Ca2+ will cause synaptic loss and neuronal death, eventually leading to memory impairments and cognitive decline. Treatments targeting Ca2+ signaling pathways are potential therapeutic strategies against AD. The complicated interactions make it challenging and expensive to study the underlying mechanisms as to how Ca2+ signaling contributes to the pathogenesis of AD. Computational modeling offers new opportunities to study the signaling pathway and test proposed mechanisms. In this mini-review, we present some computational approaches that have been used to study Ca2+ dysregulation of AD by simulating Ca2+ signaling at various levels. We also pointed out the future directions that computational modeling can be done in studying the Ca2+ dysregulation in AD.
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Affiliation(s)
- Jingyi Liang
- Centre for Advanced Computational Solutions (C-fACS), Lincoln University, Christchurch, New Zealand
| | - Don Kulasiri
- Centre for Advanced Computational Solutions (C-fACS), Lincoln University, Christchurch, New Zealand
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Hassan M, Abbas Q, Seo SY, Shahzadi S, Ashwal HA, Zaki N, Iqbal Z, Moustafa AA. Computational modeling and biomarker studies of pharmacological treatment of Alzheimer's disease (Review). Mol Med Rep 2018; 18:639-655. [PMID: 29845262 PMCID: PMC6059694 DOI: 10.3892/mmr.2018.9044] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 07/05/2017] [Indexed: 12/31/2022] Open
Abstract
Alzheimer's disease (AD) is a complex and multifactorial disease. In order to understand the genetic influence in the progression of AD, and to identify novel pharmaceutical agents and their associated targets, the present study discusses computational modeling and biomarker evaluation approaches. Based on mechanistic signaling pathway approaches, various computational models, including biochemical and morphological models, are discussed to explore the strategies that may be used to target AD treatment. Different biomarkers are interpreted on the basis of morphological and functional features of amyloid β plaques and unstable microtubule‑associated tau protein, which is involved in neurodegeneration. Furthermore, imaging and cerebrospinal fluids are also considered to be key methods in the identification of novel markers for AD. In conclusion, the present study reviews various biochemical and morphological computational models and biomarkers to interpret novel targets and agonists for the treatment of AD. This review also highlights several therapeutic targets and their associated signaling pathways in AD, which may have potential to be used in the development of novel pharmacological agents for the treatment of patients with AD. Computational modeling approaches may aid the quest for the development of AD treatments with enhanced therapeutic efficacy and reduced toxicity.
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Affiliation(s)
- Mubashir Hassan
- Department of Biology, College of Natural Sciences, Kongju National University, Gongju, Chungcheongnam 32588, Republic of Korea
- Institute of Molecular Science and Bioinformatics, Dyal Singh Trust Library, Lahore 54000, Pakistan
| | - Qamar Abbas
- Department of Physiology, University of Sindh, Jamshoro 76080, Pakistan
| | - Sung-Yum Seo
- Department of Biology, College of Natural Sciences, Kongju National University, Gongju, Chungcheongnam 32588, Republic of Korea
| | - Saba Shahzadi
- Institute of Molecular Science and Bioinformatics, Dyal Singh Trust Library, Lahore 54000, Pakistan
- Department of Bioinformatics, Virtual University Davis Road Campus, Lahore 54000, Pakistan
| | - Hany Al Ashwal
- College of Information Technology, United Arab Emirates University, Al-Ain 15551, United Arab Emirates
| | - Nazar Zaki
- College of Information Technology, United Arab Emirates University, Al-Ain 15551, United Arab Emirates
| | - Zeeshan Iqbal
- Institute of Molecular Science and Bioinformatics, Dyal Singh Trust Library, Lahore 54000, Pakistan
| | - Ahmed A. Moustafa
- School of Social Sciences and Psychology, Western Sydney University, Sydney, NSW 2751, Australia
- MARCS Institute for Brain, Behavior and Development, Western Sydney University, Sydney, NSW 2751, Australia
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9
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Yang J, Zhang X, Zhu Y, Lenczowski E, Tian Y, Yang J, Zhang C, Hardt M, Qiao C, Tanzi RE, Moore A, Ye H, Ran C. The double-edged role of copper in the fate of amyloid beta in the presence of anti-oxidants. Chem Sci 2017; 8:6155-6164. [PMID: 28989646 PMCID: PMC5627602 DOI: 10.1039/c7sc01787a] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Accepted: 06/19/2017] [Indexed: 12/13/2022] Open
Abstract
The biological fate of amyloid beta (Aβ) species is a fundamental question in Alzheimer's disease (AD) pathogenesis. The competition between clearance and aggregation of Aβs is critical for the onset of AD. Copper has been widely considered to be an inducer of harmful crosslinking of Aβs, and an important triggering factor for the onset of AD. In this report, however, we present data to show that copper can also be an inducer of Aβ degradation in the presence of a large excess of well-known intrinsic (such as dopamine) or extrinsic (such as vitamin C) anti-oxidants. The degraded fragments were identified using SDS-Page gels, and validated via nanoLC-MS/MS. A tentative mechanism for the degradation was proposed and validated with model peptides. In addition, we performed electrophysiological analysis to investigate the synaptic functions in brain slices, and found that in the presence of a significant excess of vitamin C, Cu(ii) could prevent an Aβ-induced deficit in synaptic transmission in the hippocampus. Collectively, our evidence strongly indicated that a proper combination of copper and anti-oxidants might have a positive effect on the prevention of AD. This double-edged function of copper in AD has been largely overlooked in the past. We believe that our report is very important for fully understanding the function of copper in AD pathology.
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Affiliation(s)
- Jing Yang
- Molecular Imaging Laboratory , MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging , Department of Radiology , Massachusetts General Hospital , Harvard Medical School , Room 2301, Building 149, Charlestown , Boston , Massachusetts 02129 , USA . .,College of Pharmaceutical Sciences , Soochow University , Suzhou , 215006 , China
| | - Xueli Zhang
- Molecular Imaging Laboratory , MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging , Department of Radiology , Massachusetts General Hospital , Harvard Medical School , Room 2301, Building 149, Charlestown , Boston , Massachusetts 02129 , USA . .,Center for Drug Discovery , School of Pharmacy , China Pharmaceutical University , Nanjing , 210009 , China
| | - Yiying Zhu
- Department of Applied Oral Sciences , The Forsyth Institute , Cambridge , MA 02142 , USA
| | - Emily Lenczowski
- Department of Biology , Loyola University Chicago , Chicago , IL 60660 , USA .
| | - Yanli Tian
- Molecular Imaging Laboratory , MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging , Department of Radiology , Massachusetts General Hospital , Harvard Medical School , Room 2301, Building 149, Charlestown , Boston , Massachusetts 02129 , USA . .,Department of Parasitology , Zhongshan School of Medicine , Sun Yat-Sen University , Guangzhou , 510080 , China
| | - Jian Yang
- Molecular Imaging Laboratory , MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging , Department of Radiology , Massachusetts General Hospital , Harvard Medical School , Room 2301, Building 149, Charlestown , Boston , Massachusetts 02129 , USA . .,Center for Drug Discovery , School of Pharmacy , China Pharmaceutical University , Nanjing , 210009 , China
| | - Can Zhang
- Alzheimer's Disease Research Unit , Department of Neurology , Massachusetts General Hospital , Building 114 , Charlestown , Massachusetts 02129 , USA
| | - Markus Hardt
- Department of Applied Oral Sciences , The Forsyth Institute , Cambridge , MA 02142 , USA
| | - Chunhua Qiao
- College of Pharmaceutical Sciences , Soochow University , Suzhou , 215006 , China
| | - Rudolph E Tanzi
- Alzheimer's Disease Research Unit , Department of Neurology , Massachusetts General Hospital , Building 114 , Charlestown , Massachusetts 02129 , USA
| | - Anna Moore
- Molecular Imaging Laboratory , MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging , Department of Radiology , Massachusetts General Hospital , Harvard Medical School , Room 2301, Building 149, Charlestown , Boston , Massachusetts 02129 , USA .
| | - Hui Ye
- Department of Biology , Loyola University Chicago , Chicago , IL 60660 , USA .
| | - Chongzhao Ran
- Molecular Imaging Laboratory , MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging , Department of Radiology , Massachusetts General Hospital , Harvard Medical School , Room 2301, Building 149, Charlestown , Boston , Massachusetts 02129 , USA .
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10
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Anwar H. Capturing intracellular Ca 2+ dynamics in computational models of neurodegenerative diseases. ACTA ACUST UNITED AC 2017; 19:37-42. [PMID: 28983320 DOI: 10.1016/j.ddmod.2017.02.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Many signaling pathways crucial for homeostatic regulation, synaptic plasticity, apoptosis and immune response depend on Ca2+. Ca2+ dysregulation disrupts normal function of neurons and neuronal networks. This causes severe motor and cognitive disabilities. Understanding how Ca2+ dysregulation triggers disease onset and progression, and affects downstream processes, can help identify targets for treatments. Because of intermingling of molecular pathways, dissecting the role of individual mechanisms and establishing causality is very challenging. Computational models provide a way to decipher these processes. I review some computational models with Ca2+ dynamics to illustrate their predictive power, and note where extending those models to capture multiscale interaction of Ca2+ dependent molecular pathways can be useful for therapeutic and drug discovery purposes.
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Affiliation(s)
- Haroon Anwar
- Department of Biological Sciences, New Jersey Institute of Technology, 100 Summit St, University Heights, Newark, NJ 07102, United States
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11
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Lloret‐Villas A, Varusai TM, Juty N, Laibe C, Le NovÈre N, Hermjakob H, Chelliah V. The Impact of Mathematical Modeling in Understanding the Mechanisms Underlying Neurodegeneration: Evolving Dimensions and Future Directions. CPT Pharmacometrics Syst Pharmacol 2017; 6:73-86. [PMID: 28063254 PMCID: PMC5321808 DOI: 10.1002/psp4.12155] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Revised: 10/14/2016] [Accepted: 10/30/2016] [Indexed: 12/14/2022] Open
Abstract
Neurodegenerative diseases are a heterogeneous group of disorders that are characterized by the progressive dysfunction and loss of neurons. Here, we distil and discuss the current state of modeling in the area of neurodegeneration, and objectively compare the gaps between existing clinical knowledge and the mechanistic understanding of the major pathological processes implicated in neurodegenerative disorders. We also discuss new directions in the field of neurodegeneration that hold potential for furthering therapeutic interventions and strategies.
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Affiliation(s)
- A Lloret‐Villas
- European Bioinformatics Institute (EMBL‐EBI), European Molecular Biology LaboratoryWellcome Trust Genome Campus, HinxtonCambridgeUK
| | - TM Varusai
- European Bioinformatics Institute (EMBL‐EBI), European Molecular Biology LaboratoryWellcome Trust Genome Campus, HinxtonCambridgeUK
| | - N Juty
- European Bioinformatics Institute (EMBL‐EBI), European Molecular Biology LaboratoryWellcome Trust Genome Campus, HinxtonCambridgeUK
| | - C Laibe
- European Bioinformatics Institute (EMBL‐EBI), European Molecular Biology LaboratoryWellcome Trust Genome Campus, HinxtonCambridgeUK
| | - N Le NovÈre
- Babraham Institute, Babraham Research CampusCambridgeUK
| | - H Hermjakob
- European Bioinformatics Institute (EMBL‐EBI), European Molecular Biology LaboratoryWellcome Trust Genome Campus, HinxtonCambridgeUK
| | - V Chelliah
- European Bioinformatics Institute (EMBL‐EBI), European Molecular Biology LaboratoryWellcome Trust Genome Campus, HinxtonCambridgeUK
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12
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Thummayot S, Tocharus C, Suksamrarn A, Tocharus J. Neuroprotective effects of cyanidin against Aβ-induced oxidative and ER stress in SK-N-SH cells. Neurochem Int 2016; 101:15-21. [PMID: 27697517 DOI: 10.1016/j.neuint.2016.09.016] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Revised: 09/10/2016] [Accepted: 09/12/2016] [Indexed: 11/29/2022]
Abstract
This study evaluated the mechanisms underlying the protective effect of cyanidin against Aβ25-35-induced neuronal cell death in SK-N-SH cells. Aβ25-35-induced neurotoxicity is characterized by a decrease in cell viability, inducing the expression of endoplasmic reticulum (ER) stress proteins; an increase in intracellular reactive oxygen species (ROS) production; and an increase in intracellular calcium release. Aβ25-35 also induces neuronal toxicity through the disturbance of ER calcium levels. Pretreatment with cyanidin significantly attenuated the Aβ25-35-induced loss of cell viability, reducing the expression of endoplasmic reticulum (ER) stress response proteins with regard to the down-regulation of the expression levels of 78 kDa glucose regulated protein (Grp78), phosphorylated forms of pancreatic ER elF2α kinase (PERK), eukaryotic initiation factor 2 α (eIF2α), and inositol-requiring enzyme 1 (IRE1), and the expression levels of X-box binding protein 1 (XBP-1), activating transcription factor 6 (ATF6), and CCAAT/enhancer binding protein homologous transcription factor (C/EBP) homologous protein (CHOP); decreased intracellular ROS production; decreased intracellular calcium release; and reduced down-regulation of the protein expression levels of calpain and cleaved caspase-12. This result suggests that cyanidin may be an alternative agent in preventing neurodegenerative diseases.
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Affiliation(s)
- Sarinthorn Thummayot
- Department of Anatomy, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Chainarong Tocharus
- Department of Anatomy, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Apichart Suksamrarn
- Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Ramkhamhaeng University, Bangkok 10240, Thailand
| | - Jiraporn Tocharus
- Department of Physiology, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand.
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13
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Wang X, Zhang XG, Zhou TT, Li N, Jang CY, Xiao ZC, Ma QH, Li S. Elevated Neuronal Excitability Due to Modulation of the Voltage-Gated Sodium Channel Nav1.6 by Aβ1-42. Front Neurosci 2016; 10:94. [PMID: 27013956 PMCID: PMC4783403 DOI: 10.3389/fnins.2016.00094] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 02/24/2016] [Indexed: 12/13/2022] Open
Abstract
Aberrant increases in neuronal network excitability may contribute to the cognitive deficits in Alzheimer's disease (AD). However, the mechanisms underlying hyperexcitability are not fully understood. Such overexcitation of neuronal networks has been detected in the brains of APP/PS1 mice. In the present study, using current-clamp recording techniques, we observed that 12 days in vitro (DIV) primary cultured pyramidal neurons from P0 APP/PS1 mice exhibited a more prominent action potential burst and a lower threshold than WT littermates. Moreover, after treatment with Aβ1−42 peptide, 12 DIV primary cultured neurons showed similar changes, to a greater degree than in controls. Voltage-clamp recordings revealed that the voltage-dependent sodium current density of neurons incubated with Aβ1−42 was significantly increased, without change in the voltage-dependent sodium channel kinetic characteristics. Immunohistochemistry and western blot results showed that, after treatment with Aβ1−42, expressions of Nav and Nav1.6 subtype increased in cultured neurons or APP/PS1 brains compared to control groups. The intrinsic neuronal hyperexcitability of APP/PS1 mice might thus be due to an increased expression of voltage-dependent sodium channels induced by Aβ1−42. These results may illuminate the mechanism of aberrant neuronal networks in AD.
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Affiliation(s)
- Xi Wang
- Department of Physiology, Dalian Medical University Dalian, China
| | - Xiao-Gang Zhang
- Department of Physiology, Dalian Medical University Dalian, China
| | - Ting-Ting Zhou
- Department of Neurology, the First Affiliated Hospital of Dalian Medical University Dalian, China
| | - Na Li
- Department of Physiology, Dalian Medical University Dalian, China
| | - Chun-Yan Jang
- Department of Physiology, Dalian Medical University Dalian, China
| | - Zhi-Cheng Xiao
- The Key Laboratory of Stem Cell and Regenerative Medicine, Kunming Medical College, Institute of Molecular and Clinical Medicine Kunming, China
| | - Quan-Hong Ma
- Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases, Institute of Neuroscience, Second Affiliated Hospital, Soochow University Suzhou, China
| | - Shao Li
- Department of Physiology, Dalian Medical University Dalian, China
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14
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Liang J, Kulasiri D, Samarasinghe S. Ca2+ dysregulation in the endoplasmic reticulum related to Alzheimer's disease: A review on experimental progress and computational modeling. Biosystems 2015; 134:1-15. [PMID: 25998697 DOI: 10.1016/j.biosystems.2015.05.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 05/12/2015] [Accepted: 05/12/2015] [Indexed: 12/12/2022]
Abstract
Alzheimer's disease (AD) is a devastating, incurable neurodegenerative disease affecting millions of people worldwide. Dysregulation of intracellular Ca(2+) signaling has been observed as an early event prior to the presence of clinical symptoms of AD and is believed to be a crucial factor contributing to its pathogenesis. The progressive and sustaining increase in the resting level of cytosolic Ca(2+) will affect downstream activities and neural functions. This review focuses on the issues relating to the increasing Ca(2+) release from the endoplasmic reticulum (ER) observed in AD neurons. Numerous research papers have suggested that the dysregulation of ER Ca(2+) homeostasis is associated with mutations in the presenilin genes and amyloid-β oligomers. These disturbances could happen at many different points in the signaling process, directly affecting ER Ca(2+) channels or interfering with related pathways, which makes it harder to reveal the underlying mechanisms. This review paper also shows that computational modeling is a powerful tool in Ca(2+) signaling studies and discusses the progress in modeling related to Ca(2+) dysregulation in AD research.
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Affiliation(s)
- Jingyi Liang
- Centre for Advanced Computational Solutions (C-fACS), Lincoln University, Christchurch, New Zealand; Department of Molecular Biosciences, Lincoln University, Christchurch, New Zealand
| | - Don Kulasiri
- Centre for Advanced Computational Solutions (C-fACS), Lincoln University, Christchurch, New Zealand; Department of Molecular Biosciences, Lincoln University, Christchurch, New Zealand.
| | - Sandhya Samarasinghe
- Centre for Advanced Computational Solutions (C-fACS), Lincoln University, Christchurch, New Zealand; Department of Informatics and Enabling Technologies, Lincoln University, Christchurch, New Zealand
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15
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Scala F, Fusco S, Ripoli C, Piacentini R, Li Puma DD, Spinelli M, Laezza F, Grassi C, D'Ascenzo M. Intraneuronal Aβ accumulation induces hippocampal neuron hyperexcitability through A-type K(+) current inhibition mediated by activation of caspases and GSK-3. Neurobiol Aging 2015; 36:886-900. [PMID: 25541422 PMCID: PMC4801354 DOI: 10.1016/j.neurobiolaging.2014.10.034] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2014] [Revised: 10/14/2014] [Accepted: 10/24/2014] [Indexed: 11/20/2022]
Abstract
Amyloid β-protein (Aβ) pathologies have been linked to dysfunction of excitability in neurons of the hippocampal circuit, but the molecular mechanisms underlying this process are still poorly understood. Here, we applied whole-cell patch-clamp electrophysiology to primary hippocampal neurons and show that intracellular Aβ42 delivery leads to increased spike discharge and action potential broadening through downregulation of A-type K(+) currents. Pharmacologic studies showed that caspases and glycogen synthase kinase 3 (GSK-3) activation are required for these Aβ42-induced effects. Extracellular perfusion and subsequent internalization of Aβ42 increase spike discharge and promote GSK-3-dependent phosphorylation of the Kv4.2 α-subunit, a molecular determinant of A-type K(+) currents, at Ser-616. In acute hippocampal slices derived from an adult triple-transgenic Alzheimer's mouse model, characterized by endogenous intracellular accumulation of Aβ42, CA1 pyramidal neurons exhibit hyperexcitability accompanied by increased phosphorylation of Kv4.2 at Ser-616. Collectively, these data suggest that intraneuronal Aβ42 accumulation leads to an intracellular cascade culminating into caspases activation and GSK-3-dependent phosphorylation of Kv4.2 channels. These findings provide new insights into the toxic mechanisms triggered by intracellular Aβ42 and offer potentially new therapeutic targets for Alzheimer's disease treatment.
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Affiliation(s)
- Federico Scala
- Institute of Human Physiology, Medical School, Università Cattolica, Rome, Italy
| | - Salvatore Fusco
- Institute of Human Physiology, Medical School, Università Cattolica, Rome, Italy
| | - Cristian Ripoli
- Institute of Human Physiology, Medical School, Università Cattolica, Rome, Italy
| | - Roberto Piacentini
- Institute of Human Physiology, Medical School, Università Cattolica, Rome, Italy
| | | | - Matteo Spinelli
- Institute of Human Physiology, Medical School, Università Cattolica, Rome, Italy
| | - Fernanda Laezza
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX, USA
| | - Claudio Grassi
- Institute of Human Physiology, Medical School, Università Cattolica, Rome, Italy.
| | - Marcello D'Ascenzo
- Institute of Human Physiology, Medical School, Università Cattolica, Rome, Italy.
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16
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Tuckwell HC, Penington NJ. Computational modeling of spike generation in serotonergic neurons of the dorsal raphe nucleus. Prog Neurobiol 2014; 118:59-101. [PMID: 24784445 DOI: 10.1016/j.pneurobio.2014.04.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Revised: 04/14/2014] [Accepted: 04/21/2014] [Indexed: 01/14/2023]
Abstract
Serotonergic neurons of the dorsal raphe nucleus, with their extensive innervation of limbic and higher brain regions and interactions with the endocrine system have important modulatory or regulatory effects on many cognitive, emotional and physiological processes. They have been strongly implicated in responses to stress and in the occurrence of major depressive disorder and other psychiatric disorders. In order to quantify some of these effects, detailed mathematical models of the activity of such cells are required which describe their complex neurochemistry and neurophysiology. We consider here a single-compartment model of these neurons which is capable of describing many of the known features of spike generation, particularly the slow rhythmic pacemaking activity often observed in these cells in a variety of species. Included in the model are 11 kinds of ion channels: a fast sodium current INa, a delayed rectifier potassium current IKDR, a transient potassium current IA, a slow non-inactivating potassium current IM, a low-threshold calcium current IT, two high threshold calcium currents IL and IN, small and large conductance potassium currents ISK and IBK, a hyperpolarization-activated cation current IH and a leak current ILeak. In Sections 3-8, each current type is considered in detail and parameters estimated from voltage clamp data where possible. Three kinds of model are considered for the BK current and two for the leak current. Intracellular calcium ion concentration Cai is an additional component and calcium dynamics along with buffering and pumping is discussed in Section 9. The remainder of the article contains descriptions of computed solutions which reveal both spontaneous and driven spiking with several parameter sets. Attention is focused on the properties usually associated with these neurons, particularly long duration of action potential, steep upslope on the leading edge of spikes, pacemaker-like spiking, long-lasting afterhyperpolarization and the ramp-like return to threshold after a spike. In some cases the membrane potential trajectories display doublets or have humps or notches as have been reported in some experimental studies. The computed time courses of IA and IT during the interspike interval support the generally held view of a competition between them in influencing the frequency of spiking. Spontaneous activity was facilitated by the presence of IH which has been found in these neurons by some investigators. For reasonable sets of parameters spike frequencies between about 0.6Hz and 1.2Hz are obtained, but frequencies as high as 6Hz could be obtained with special parameter choices. Topics investigated and compared with experiment include shoulders, notches, anodal break phenomena, the effects of noradrenergic input, frequency versus current curves, depolarization block, effects of cell size and the effects of IM. The inhibitory effects of activating 5-HT1A autoreceptors are also investigated. There is a considerable discussion of in vitro versus in vivo firing behavior, with focus on the roles of noradrenergic input, corticotropin-releasing factor and orexinergic inputs. Location of cells within the nucleus is probably a major factor, along with the state of the animal.
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Affiliation(s)
- Henry C Tuckwell
- Max Planck Institute for Mathematics in the Sciences, Inselstr. 22, 04103 Leipzig, Germany; School of Electrical and Electronic Engineering, University of Adelaide, Adelaide, South Australia 5005, Australia.
| | - Nicholas J Penington
- Department of Physiology and Pharmacology, State University of New York, Downstate Medical Center, Box 29, 450 Clarkson Avenue, Brooklyn, NY 11203-2098, USA; Program in Neural and Behavioral Science and Robert F. Furchgott Center for Neural and Behavioral Science, State University of New York, Downstate Medical Center, Box 29, 450 Clarkson Avenue, Brooklyn, NY 11203-2098, USA
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17
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Wilson NP, Gates B, Castellanos M. Modeling the short time-scale dynamics of β-amyloid–neuron interactions. J Theor Biol 2013; 331:28-37. [DOI: 10.1016/j.jtbi.2013.02.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2012] [Revised: 01/08/2013] [Accepted: 02/18/2013] [Indexed: 12/31/2022]
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18
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Nestor MW, Hoffman DA. Aberrant dendritic excitability: a common pathophysiology in CNS disorders affecting memory? Mol Neurobiol 2012; 45:478-87. [PMID: 22528602 PMCID: PMC3496255 DOI: 10.1007/s12035-012-8265-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2012] [Accepted: 03/29/2012] [Indexed: 01/13/2023]
Abstract
Discovering the etiology of pathophysiologies and aberrant behavior in many central nervous system (CNS) disorders has proven elusive because susceptibility to these diseases can be a product of multiple factors such as genetics, epigenetics, and environment. Advances in molecular biology and wide-scale genomics have shown that a large heterogeneity of genetic mutations are potentially responsible for the neuronal pathologies and dysfunctional behaviors seen in CNS disorders. Despite this seemingly complex array of genetic and physiological factors, many disorders of the CNS converge on common dysfunctions in memory. In this review, we propose that mechanisms underlying the development of many CNS disorders may share an underlying cause involving abnormal dendritic integration of synaptic signals. Through understanding the relationship between molecular genetics and dendritic computation, future research may uncover important links between neuronal physiology at the cellular level and higher-order circuit and network abnormalities observed in CNS disorders, and their subsequent affect on memory.
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Affiliation(s)
- Michael W. Nestor
- Molecular Neurophysiology and Biophysics Unit, LCSN, NICHD, NIH, 35 Lincoln Drive Room 3C-905, Bethesda, Maryland, 20892
| | - Dax A. Hoffman
- Molecular Neurophysiology and Biophysics Unit, LCSN, NICHD, NIH, 35 Lincoln Drive Room 3C-905, Bethesda, Maryland, 20892
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19
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Morphine protects against intracellular amyloid toxicity by inducing estradiol release and upregulation of Hsp70. J Neurosci 2012; 31:16227-40. [PMID: 22072674 DOI: 10.1523/jneurosci.3915-11.2011] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Certain experimental models support morphine can play a beneficial role against damage in the neuronal system. In this study, we find morphine as well as endomorphin-1 and endomorphin-2 can protect against intracellular amyloid β (iAβ) toxicity in human and rat primary neuronal cultures and in rat brains in vivo. Morphine reverses the electrophysiological changes induced by iAβ, including current density, resting membrane potential and capacitance. Also morphine improves the spatial memory performance in rats infected by iAβ packaged virus and in APP/PS1 mice in Morris water maze tests. Morphine protection is mediated through inducing estradiol release in hippocampal neurons measured by ELISA and liquid chromatography-mass spectrometry, possibly by increasing P450 cytochrome aromatase activity. Released estradiol induces upregulation of heat shock protein 70 (Hsp70). Hsp70 protects against intracellular amyloid toxicity by rescuing proteasomal activity which is impaired by iAβ. This is the first time, to our knowledge, that induction of estradiol release in hippocampal neurons by morphine is reported. Our data may contribute to both Alzheimer's disease therapy and pain clinics where morphine is widely used.
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20
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Orbán G, Völgyi K, Juhász G, Penke B, Kékesi KA, Kardos J, Czurkó A. Different electrophysiological actions of 24- and 72-hour aggregated amyloid-beta oligomers on hippocampal field population spike in both anesthetized and awake rats. Brain Res 2010; 1354:227-35. [DOI: 10.1016/j.brainres.2010.07.061] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2010] [Revised: 07/16/2010] [Accepted: 07/17/2010] [Indexed: 11/24/2022]
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21
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Morse TM, Carnevale NT, Mutalik PG, Migliore M, Shepherd GM. Abnormal Excitability of Oblique Dendrites Implicated in Early Alzheimer's: A Computational Study. Front Neural Circuits 2010; 4. [PMID: 20725509 PMCID: PMC2901152 DOI: 10.3389/fncir.2010.00016] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2009] [Accepted: 05/04/2010] [Indexed: 11/13/2022] Open
Abstract
The integrative properties of cortical pyramidal dendrites are essential to the neural basis of cognitive function, but the impact of amyloid beta protein (abeta) on these properties in early Alzheimer's is poorly understood. In animal models, electrophysiological studies of proximal dendrites have shown that abeta induces hyperexcitability by blocking A-type K+ currents (I(A)), disrupting signal integration. The present study uses a computational approach to analyze the hyperexcitability induced in distal dendrites beyond the experimental recording sites. The results show that back-propagating action potentials in the dendrites induce hyperexcitability and excessive calcium concentrations not only in the main apical trunk of pyramidal cell dendrites, but also in their oblique dendrites. Evidence is provided that these thin branches are particularly sensitive to local reductions in I(A). The results suggest the hypothesis that the oblique branches may be most vulnerable to disruptions of I(A) by early exposure to abeta, and point the way to further experimental analysis of these actions as factors in the neural basis of the early decline of cognitive function in Alzheimer's.
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Affiliation(s)
- Thomas M Morse
- Department of Neurobiology, Yale University School of Medicine New Haven, CT, USA
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22
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Pan YF, Chen XR, Wu MN, Ma CG, Qi JS. Arginine vasopressin prevents against Abeta(25-35)-induced impairment of spatial learning and memory in rats. Horm Behav 2010; 57:448-54. [PMID: 20138885 DOI: 10.1016/j.yhbeh.2010.01.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2009] [Revised: 01/19/2010] [Accepted: 01/31/2010] [Indexed: 11/29/2022]
Abstract
Amyloid beta protein (Abeta) is thought to be responsible for loss of memory in Alzheimer's disease (AD). A significant decrease in [Arg(8)]-vasopressin (AVP) has been found in the AD brain and in plasma; however, it is unclear whether this decrease in AVP is involved in Abeta-induced impairment of spatial cognition and whether AVP can protect against Abeta-induced deficits in cognitive function. The present study examined the effects of intracerebroventricular (i.c.v.) injection of AVP on spatial learning and memory in the Morris water maze test and investigated the potential protective function of AVP against Abeta-induced impairment in spatial cognition. The results were as follows: (1) i.c.v. injection of 25 nmol Abeta(25-35) resulted in a significant decline in spatial learning and memory; (2) 1 nmol and 10 nmol, but not 0.1 nmol, AVP injections markedly improved learning and memory; (3) pretreatment with 1 nmol or 10 nmol, but not 0.1 nmol, AVP effectively reversed the impairment in spatial learning and memory induced by Abeta(25-35); and (4) none of the drugs, including Abeta(25-35) and different concentrations of AVP, affected the vision or swimming speed of the rats. These results indicate that Abeta(25-35) could significantly impair spatial learning and memory in rats, and pretreatment with AVP centrally can enhance spatial learning and effectively prevent the behavioral impairment induced by neurotoxic Abeta(25-35). Thus, the present study provides further insight into the mechanisms by which Abeta impairs spatial learning and memory, suggesting that up-regulation of central AVP might be beneficial in the prevention and treatment of AD.
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Affiliation(s)
- Yan-Fang Pan
- Department of Physiology, Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, 030001, China
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23
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Opposite effects of low and high doses of Abeta42 on electrical network and neuronal excitability in the rat prefrontal cortex. PLoS One 2009; 4:e8366. [PMID: 20027222 PMCID: PMC2791225 DOI: 10.1371/journal.pone.0008366] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2009] [Accepted: 11/24/2009] [Indexed: 12/20/2022] Open
Abstract
Changes in neuronal synchronization have been found in patients and animal models of Alzheimer's disease (AD). Synchronized behaviors within neuronal networks are important to such complex cognitive processes as working memory. The mechanisms behind these changes are not understood but may involve the action of soluble beta-amyloid (Abeta) on electrical networks. In order to determine if Abeta can induce changes in neuronal synchronization, the activities of pyramidal neurons were recorded in rat prefrontal cortical (PFC) slices under calcium-free conditions using multi-neuron patch clamp technique. Electrical network activities and synchronization among neurons were significantly inhibited by low dose Abeta42 (1 nM) and initially by high dose Abeta42 (500 nM). However, prolonged application of high dose Abeta42 resulted in network activation and tonic firing. Underlying these observations, we discovered that prolonged application of low and high doses of Abeta42 induced opposite changes in action potential (AP)-threshold and after-hyperpolarization (AHP) of neurons. Accordingly, low dose Abeta42 significantly increased the AP-threshold and deepened the AHP, making neurons less excitable. In contrast, high dose Abeta42 significantly reduced the AP-threshold and shallowed the AHP, making neurons more excitable. These results support a model that low dose Abeta42 released into the interstitium has a physiologic feedback role to dampen electrical network activity by reducing neuronal excitability. Higher concentrations of Abeta42 over time promote supra-synchronization between individual neurons by increasing their excitability. The latter may disrupt frontal-based cognitive processing and in some cases lead to epileptiform discharges.
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24
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Kiyota T, Yamamoto M, Xiong H, Lambert MP, Klein WL, Gendelman HE, Ransohoff RM, Ikezu T. CCL2 accelerates microglia-mediated Abeta oligomer formation and progression of neurocognitive dysfunction. PLoS One 2009; 4:e6197. [PMID: 19593388 PMCID: PMC2703798 DOI: 10.1371/journal.pone.0006197] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2009] [Accepted: 06/01/2009] [Indexed: 01/14/2023] Open
Abstract
Background The linkages between neuroinflammation and Alzheimer's disease (AD) pathogenesis are well established. What is not, however, is how specific immune pathways and proteins affect the disease. To this end, we previously demonstrated that transgenic over-expression of CCL2 enhanced microgliosis and induced diffuse amyloid plaque deposition in Tg2576 mice. This rodent model of AD expresses a Swedish β-amyloid (Aβ) precursor protein mutant. Methodology/Principal Findings We now report that CCL2 transgene expression accelerates deficits in spatial and working memory and hippocampal synaptic transmission in β-amyloid precursor protein (APP) mice as early as 2–3 months of age. This is followed by increased numbers of microglia that are seen surrounding Aβ oligomers. CCL2 does not suppress Aβ degradation. Rather, CCL2 and tumor necrosis factor-α directly facilitated Aβ uptake, intracellular Aβ oligomerization, and protein secretion. Conclusions/Significance We posit that CCL2 facilitates Aβ oligomer formation in microglia and propose that such events accelerate memory dysfunction by affecting Aβ seeding in the brain.
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Affiliation(s)
- Tomomi Kiyota
- Center for Neurovirology and Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Masaru Yamamoto
- Center for Neurovirology and Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Huangui Xiong
- Center for Neurovirology and Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Mary P. Lambert
- Department of Neurobiology and Physiology, Northwestern University, Evanston, Illinois, United States of America
| | - William L. Klein
- Department of Neurobiology and Physiology, Northwestern University, Evanston, Illinois, United States of America
| | - Howard E. Gendelman
- Center for Neurovirology and Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Richard M. Ransohoff
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio, United States of America
| | - Tsuneya Ikezu
- Center for Neurovirology and Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- * E-mail:
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Jing W, Guo F, Cheng L, Zhang JF, Qi JS. Arginine vasopressin prevents amyloid beta protein-induced impairment of long-term potentiation in rat hippocampus in vivo. Neurosci Lett 2008; 450:306-10. [PMID: 19059464 DOI: 10.1016/j.neulet.2008.11.053] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2008] [Revised: 11/20/2008] [Accepted: 11/24/2008] [Indexed: 11/30/2022]
Abstract
Amyloid beta protein (Abeta) is thought to be responsible for the loss of memory in Alzheimer's disease (AD). A significant decrease in [Arg(8)]-vasopressin (AVP) in the AD brain has been found. However, it is unclear whether the decrease in AVP is involved in Abeta-induced impairment of memory and whether AVP can protect against Abeta-induced neurotoxicity. The present study examines the effects of intracerebroventricular (i.c.v.) injection of AVP on hippocampal long-term potentiation (LTP), a synaptic model of memory, and investigates the potential protective function of AVP in Abeta-induced LTP impairment. The results showed that (1) i.c.v. injection of different concentrations of AVP or Abeta(25-35) did not affect the baseline field excitatory postsynaptic potentials (fEPSPs); (2) AVP administration alone induced a significant increase in HFS-induced LTP, while Abeta(25-35) significantly suppressed HFS-induced LTP; (3) Abeta(25-35)-induced LTP suppression was significantly prevented by the pretreatment with AVP; (4) paired-pulse facilitation did not change after separate application or co-application of AVP and Abeta(25-35). These results indicate that AVP can potentiate hippocampal synaptic plasticity and dose-dependently prevent Abeta(25-35)-induced LTP impairment. Thus, the present study provides further insight into the mechanisms by which Abeta impairs synaptic plasticity and suggests an important approach in the treatment of AD.
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Affiliation(s)
- Wei Jing
- Department of Neurobiology and National Key Discipline of Physiology, Shanxi Medical University, 86 Xinjian South Road, Taiyuan, Shanxi 030001, China
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Abstract
The Alzheimer's disease related peptide amyloid beta (Abeta) might have a physiological role in upregulating K channel currents in neurones. Earlier studies used the human form of Abeta1-40 on rat neurones. We sought to confirm our hypothesis by use of rat Abeta, which has no Alzheimer's association. In rat cerebellar granule neurones and HEK293 cells expressing Kv4.2 subunits, whole-cell patch clamp of K currents revealed that preincubation of cells with recombinant human or rat Abeta1-40 (10 nM for 24 h) significantly increased K channel current density. This was accompanied by increased mRNA levels for Kv4.2. These data indicate that rodent and human Abeta are effective in modulating K currents. The effectiveness of nonaggregating rat Abeta also strongly supports a physiological role for the peptide.
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Ye H, Jalini S, Mylvaganam S, Carlen P. Activation of large-conductance Ca(2+)-activated K(+) channels depresses basal synaptic transmission in the hippocampal CA1 area in APP (swe/ind) TgCRND8 mice. Neurobiol Aging 2008; 31:591-604. [PMID: 18547679 DOI: 10.1016/j.neurobiolaging.2008.05.012] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2008] [Revised: 04/29/2008] [Accepted: 05/08/2008] [Indexed: 01/24/2023]
Abstract
Large-conductance Ca(2+)-activated K(+) (BK) channels regulate synaptic transmission by contributing to the repolarization phase of the action potential that invades the presynaptic terminal. BK channels are prone to activation under pathological conditions, such as brain ischemia and epilepsy. It is unclear if activation of these channels contributes to the depression of synaptic transmission observed in the early stage of Alzheimer's disease (AD). In this study, we recorded the field excitatory postsynaptic potentials (fEPSPs) in the hippocampus CA1 region of brain slices from 6 to 9 weeks (pre-plaque) TgCRND8 mice, a mouse model of Alzheimer's disease that harbors a double amyloid precursor mutation (KM670N/671L "Swedish" and V717F "Indiana"). Compared to age-matched controls, the fEPSPs in these animals are significantly depressed. This depression is largely mediated by the activation of presynaptic BK channels in the CA1 area. Both BK channel blockers (charybdotoxin and paxilline), and the fast binding calcium chelator, BAPTA-AM, enhance the fEPSP by deactivating the BK channels. Repetitive stimulation to the afferent pathway enhances fEPSP. This enhancement is more prominent when BK channel blockers are added in Tg slices, suggesting that repetitive stimulation further promotes BK channel activation in Tg slices. The potential candidates that mediate the activation of BK channels in these pre-plaque Alzheimer's disease model mice might involve impaired calcium homeostasis and AD related over-generation of reactive oxygen species.
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Affiliation(s)
- Hui Ye
- Toronto Western Research Institute, University Health Network, Canada.
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28
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Schmid AW, Freir DB, Herron CE. Inhibition of LTP in vivo by beta-amyloid peptide in different conformational states. Brain Res 2008; 1197:135-42. [DOI: 10.1016/j.brainres.2007.11.056] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2007] [Revised: 11/23/2007] [Accepted: 11/29/2007] [Indexed: 02/07/2023]
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29
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Sultana R, Butterfield DA. Alterations of some membrane transport proteins in Alzheimer's disease: role of amyloid β-peptide. ACTA ACUST UNITED AC 2008; 4:36-41. [DOI: 10.1039/b715278g] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Patel D, Good T. A rapid method to measure beta-amyloid induced neurotoxicity in vitro. J Neurosci Methods 2007; 161:1-10. [PMID: 17083984 DOI: 10.1016/j.jneumeth.2006.10.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2005] [Revised: 08/02/2006] [Accepted: 10/02/2006] [Indexed: 11/19/2022]
Abstract
Beta-amyloid (Abeta) is the primary protein component of senile plaques in Alzheimer's disease (AD) and is believed to be associated with neurotoxicity in the disease. Abeta-induced neurotoxicity is strongly dependent on its structure. The aggregation of the peptide from monomeric form to fibrils is a function of many variables including time. It is because of this dynamic nature of Abeta structure that there is a necessity for an in vitro toxicity assay that is rapid enough to eliminate or at least lower the possibility of Abeta structural changes during the time required for the assay. Here we describe a fast and sensitive method with which to assess Abeta-induced neurotoxicity in SH-SY5Y neuroblastoma cells. The method employs two-color flow cytometry using annexin-phycoerythrin, a marker for cell surface phosphatidylserine that typically indicates early stages of apoptosis, and 7-amino-actinomycin D, a membrane impermeant nucleic acid dye. We compare results using the two-color assay to those obtained using the propidium iodide toxicity assay and demonstrate comparability of results, but in 2h or less with the two-color assay as opposed to 24-48 h with the propidium iodide assay. The assay described could be a useful tool in evaluating the role of Abeta structure in biological activity of the peptide.
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Affiliation(s)
- Dhara Patel
- Department of Chemical and Biochemical Engineering, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA.
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Yun SH, Gamkrelidze G, Stine WB, Sullivan PM, Pasternak JF, LaDu MJ, Trommer BL. Amyloid-beta1-42 reduces neuronal excitability in mouse dentate gyrus. Neurosci Lett 2006; 403:162-5. [PMID: 16765515 PMCID: PMC3752836 DOI: 10.1016/j.neulet.2006.04.065] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2006] [Revised: 04/10/2006] [Accepted: 04/24/2006] [Indexed: 11/17/2022]
Abstract
Amyloid-beta (Abeta) is causally implicated in Alzheimer's disease and neuroplasticity failure has acquired validity as a possible mechanism of early AD pathogenesis. We have previously demonstrated that oligomeric Abeta(1-42) inhibits LTP in the dentate gyrus of rat hippocampal slices. We now show, using whole cell recordings in hippocampal granule cells, that oligomeric Abeta(1-42) decreases neuronal excitability. In particular, Abeta(1-42) application was associated with a decrease in the number of action potentials fired in response to current injection, and with an increase in the amplitude of the afterhyperpolarization. Reduced excitability may underlie the Abeta-mediated impairment in neuroplasticity, and ultimately may contribute to the memory loss in Alzheimer disease.
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Affiliation(s)
- Sung Hwan Yun
- Departments of Pediatrics and Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60614, United States
- Department of Pediatrics, Division of Neurology, Evanston Northwestern Healthcare, 2650 Ridge Avenue, Evanston IL 60201, United States
- ENH Research Institute, 1001 University Place Evanston, IL 60202, United States
| | - Georgi Gamkrelidze
- Department of Physiology and Neuroscience, New York University School of Medicine, New York, NY 10016, United States
| | - W. Blaine Stine
- ENH Research Institute, 1001 University Place Evanston, IL 60202, United States
| | - Patrick M. Sullivan
- Department of Medicine, Division of Neurology, Duke University, Durham, NC 27710, United States
| | - Joseph F. Pasternak
- Departments of Pediatrics and Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60614, United States
- Department of Pediatrics, Division of Neurology, Evanston Northwestern Healthcare, 2650 Ridge Avenue, Evanston IL 60201, United States
- ENH Research Institute, 1001 University Place Evanston, IL 60202, United States
| | - Mary Jo LaDu
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL 60612, United States
| | - Barbara L. Trommer
- Departments of Pediatrics and Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60614, United States
- Department of Pediatrics, Division of Neurology, Evanston Northwestern Healthcare, 2650 Ridge Avenue, Evanston IL 60201, United States
- ENH Research Institute, 1001 University Place Evanston, IL 60202, United States
- Corresponding author. Tel.: +1 847 570 2577; fax: +1 847 570 2073.
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Hölscher C. Development of beta-amyloid-induced neurodegeneration in Alzheimer's disease and novel neuroprotective strategies. Rev Neurosci 2006; 16:181-212. [PMID: 16323560 DOI: 10.1515/revneuro.2005.16.3.181] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Alzheimer's disease (AD) is a form of dementia in which people develop rapid neurodegeneration, complete loss of cognitive abilities, and are likely to die prematurely. At present, no treatment for AD is known. One of the hallmarks in the development of AD is the aggregation of amyloid protein fragments in the brain, and much evidence points towards beta-amyloid fragments being one of the main causes of the neurodegenerative processes. This review summarises the present concepts and theories on how AD develops, and lists the evidence that supports them. A cascade of biochemical events is initiated that ultimately leads to neuronal death involving an imbalance of intracellular calcium homeostasis via activation of calcium channels, intracellular calcium stores, and subsequent production of free radicals by calcium-sensitive enzymes. Secondary processes include inflammatory responses that produce more free radicals and the induction of apoptosis. Recently, several new strategies have been proposed to try to ameliorate the neurodegenerative developments associated with AD. These include the activation of neuronal growth factor receptors and insulin-like receptors, both of which have neuroprotective properties. Furthermore, the role of cholesterol and potential protective properties of cholesterol-lowering drugs are under intense investigation. Other promising strategies include the inhibition of beta- and gamma-secretases which produce beta-amyloid, activation of proteases that degrade beta-amyloid, glutamate receptor selective drugs, antioxidants, and metal chelating agents, all of which prevent formation of plaques. Novel drugs that act at different levels of the neurodegenerative processes show great promise to reduce neurodegeneration. They could help to prolong the time of unimpaired cognitive abilities of people who develop AD, allowing them to lead an independent life.
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Affiliation(s)
- Christian Hölscher
- School of Biomedical Sciences, University of Ulster, Coleraine, Northern Ireland.
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Chen C. β-Amyloid increases dendritic Ca2+ influx by inhibiting the A-type K+ current in hippocampal CA1 pyramidal neurons. Biochem Biophys Res Commun 2005; 338:1913-9. [PMID: 16289381 DOI: 10.1016/j.bbrc.2005.10.169] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2005] [Accepted: 10/25/2005] [Indexed: 10/25/2022]
Abstract
Accumulation of the beta-amyloid peptide (Abeta) is a primary event in the pathogenesis of Alzheimer's disease (AD). However, the mechanisms by which Abeta mediates neurotoxicity and initiates the degenerative processes of AD are still not clear. Recent evidence shows that voltage-gated K+ channels may be involved in Abeta-induced neurodegenerative processes. In particular, a transient A-type K+ current, with a linear increase in its density with distance from soma to distal dendrites in hippocampal CA1 pyramidal neurons, has been shown to contribute to dendritic membrane excitability. Here, I report that Abeta (1-42) inhibits the dendritic A-type K+ current in hippocampal CA1 pyramidal neurons, and this inhibition causes increases in back-propagating dendritic action potential amplitude and associated Ca2+ influx. These results suggest that the persistent inhibition of the A-type K+ current resulting from deposition of Abeta in dendritic arborization will induce a sustained increase in dendritic Ca2+ influx and lead to loss of Ca2+ homeostasis. This may be a component of the events that cause synaptic failure and initiate neuronal degenerative processes in the hippocampus.
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Affiliation(s)
- Chu Chen
- Neuroscience Center, School of Medicine, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA
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Wang SSS, Kazantzi V, Good TA. A Kinetic Analysis of the Mechanism of beta-Amyloid Induced G Protein Activation. J Theor Biol 2003; 221:269-78. [PMID: 12628233 DOI: 10.1006/jtbi.2003.3189] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
beta-Amyloid (A beta) is the primary protein component of senile plaques found in Alzheimer's disease. In an aggregated (amyloid fibril, protofibril, or low molecular weight oligomer) state, A beta has been consistently shown to be toxic to neurons, but the molecular mechanism of this toxicity is poorly understood. We have previously shown that A beta activates a G(i/o) protein, and that inhibition of this specific G protein activation attenuated A beta-induced cell toxicity. In the present study, we use a kinetic analysis to examine the mechanism of A beta-induced G protein activation. Using synthetic A beta(1-40) and phospholipid vesicles containing purified G(0)alpha subunits, we examined the relationship between A beta concentration, G(0)alpha subunit concentration, GTP concentration and rate of GTP hydrolysis experimentally. We found that at low concentrations of A beta (less than 10 microM), A beta increased the rate of GTP hydrolysis over the rate of hydrolysis in the absence of peptide, however, at high concentrations of A beta, significantly decreased rates of GTP hydrolysis were observed. We postulated several molecular level mechanisms for the observed rate behavior, from those mechanisms derived rate equations, and then tested the mechanisms against our experimental rate data. Based on our results, we identified a plausible mechanism for A beta-induced G protein activation which is consistent with available experimental data. This work demonstrates the utility of an engineering approach to examining steps in the mechanism of A beta-induced cell toxicity and could provide insight into our understanding of the mechanism of Alzheimer's disease.
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Affiliation(s)
- Steven S-S Wang
- Department of Chemical Engineering, Texas A>&M University, College Station, TX 77843-3122, USA
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35
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Wang SS, Rymer DL, Good TA. Reduction in cholesterol and sialic acid content protects cells from the toxic effects of beta-amyloid peptides. J Biol Chem 2001; 276:42027-34. [PMID: 11557751 DOI: 10.1074/jbc.m102834200] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
beta-Amyloid (Abeta) is the primary protein component of senile plaques associated with Alzheimer's disease and has been implicated in the neurotoxicity associated with the disease. A variety of evidence points to the importance of Abeta-membrane interactions in the mechanism of Abeta neurotoxicity and indicates that cholesterol and gangliosides are particularly important for Abeta aggregation and binding to membranes. We investigated the effects of cholesterol and sialic acid depletion on Abeta-induced GTPase activity in cells, a step implicated in the mechanism of Abeta toxicity, and Abeta-induced cell toxicity. Cholesterol reduction and depletion of membrane-associated sialic acid residues both significantly reduced the Abeta-induced GTPase activity. In addition, cholesterol and membrane-associated sialic acid residue depletion or inhibition of cholesterol and ganglioside synthesis protected PC12 cells from Abeta-induced toxicity. These results indicate the importance of Abeta-membrane interactions in the mechanism of Abeta toxicity. In addition, these results suggest that control of cellular cholesterol and/or ganglioside content may prove useful in the prevention or treatment of Alzheimer's disease.
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Affiliation(s)
- S S Wang
- Department of Chemical Engineering, Texas A & M University, College Station, Texas 77843-3122, USA
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36
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Kourie JI. Mechanisms of amyloid beta protein-induced modification in ion transport systems: implications for neurodegenerative diseases. Cell Mol Neurobiol 2001; 21:173-213. [PMID: 11569534 DOI: 10.1023/a:1010932603406] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
1. Alzheimer's disease (AD) is a neurodegenerative disorder that affects the cognitive function of the brain. Pathological changes in AD are characterized by the formation of amyloid plaques and neurofibrillary tangles as well as extensive neuronal loss. Abnormal proteolytic processing of amyloid precursor protein (APP) is the central step that leads to formation of amyloid plaque, neurofibrillary tangles, and neuronal loss. 2. The plaques, which accumulate extracellularly in the brain, are composed of aggregates and cause direct neurotoxic effects and/or increase neuronal vulnerability to excitotoxic insults. The aggregates consist of soluble pathologic amyloid beta peptides AbetaP[1-42] and AbetaP[1-43] and soluble nonpathologic AbetaP[1-40]. Both APP and AbetaP interact with ion transport systems. AbetaP induces a wide range of effects as the result of activating a cascade of mechanisms. 3. The major mechanisms proposed for AbetaP-induced cytotoxicity involve the loss of Ca2+ homeostasis and the generation of reactive oxygen species (ROS). The changes in Ca2+ homeostasis could be the result of (1) changes in endogenous ion transport systems, e.g. Ca2+ and K+ channels and Na+/K+-ATPase, and membrane receptor proteins, such as ligand-driven ion channels and G-protein-driven releases of second messengers, and (2) formation of heterogeneous ion channels. 4. The consequences of changes in Ca2+-homeostasis-induced generation of ROS are (a) direct modification of intrinsic ion transport systems and their regulatory mechanisms, and (b) indirect effects on ion transport systems via peroxidation of phospholipids in the membrane, inhibition of phosphorylation, and reduction of ATP levels and cytoplasmic pH. 5. We propose that in AD, AbetaP with its different conformations alters cell regulation by modifying several ion transport systems and also by forming heterogeneous ion channels. The changes in membrane transport systems are proposed as early steps in impairing neuronal function preceding plaque formation. We conclude that these changes damage the membrane by compromising its integrity and increasing its ion permeability. This mechanism of membrane damage is not only central for AD but also may explain other malfunctioned protein-processing-related pathologies.
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Affiliation(s)
- J I Kourie
- Department of Chemistry, The Faculties, The Australian National University, ACT, Canberra.
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Freir DB, Holscher C, Herron CE. Blockade of long-term potentiation by beta-amyloid peptides in the CA1 region of the rat hippocampus in vivo. J Neurophysiol 2001; 85:708-13. [PMID: 11160505 DOI: 10.1152/jn.2001.85.2.708] [Citation(s) in RCA: 124] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The effect of intracerebroventricular (icv) injections of beta-amyloid peptide fragments Abeta[15-25], Abeta[25-35], and Abeta[35-25] were examined on synaptic transmission and long-term potentiation (LTP) in the hippocampal CA1 region in vivo. Rats were anesthetized using urethan, and changes in synaptic efficacy were determined from the slope of the excitatory postsynaptic potential (EPSP). Baseline synaptic responses were monitored for 30 min prior to icv injection of Abeta peptides or vehicle. High-frequency stimulation (HFS) to induce LTP was applied to the Schaffer-collateral pathway 5 min or 1 h following the icv injection. HFS comprised 3 episodes of 10 stimuli at 200 Hz, 10 times, applied at 30-s intervals. Normal LTP measured 30 min following HFS, was produced following icv injection of vehicle (191 +/- 17%, mean +/- SE, n = 6) or Abeta[15-25; 100 nmol] (177 +/- 6%, n = 6) 1 h prior to HFS. LTP was, however, markedly reduced by Abeta[25-35; 10 nmol] (129 +/- 9%, n = 6, P < 0.001) and blocked by Abeta[25-35; 100 nmol] (99 +/- 6%, n = 6, P < 0.001). Injection of the reverse peptide, Abeta[35-25], also impaired LTP at concentrations of 10 nmol (136 +/- 3%, n = 6, P < 0.01) and 100 nmol (144 +/- 7, n = 8, P < 0.05). Using a different protocol, HFS was delivered 5 min following Abeta injections, and LTP was measured 1 h post HFS. Stable LTP was produced in the control group (188 +/- 15%, n = 7) and blocked by Abeta[25-35, 100 nmol] (108 +/- 15%, n = 6, P < 0.001). A lower dose of Abeta[25-35; 10 nmol] did not significantly impair LTP (176 +/- 30%, n = 4). The Abeta-peptides tested were also shown to have no significant effect on paired pulse facilitation (interstimulus interval of 50 ms), suggesting that neither presynaptic transmitter release or activity of interneurons in vivo are affected. The effects of Abeta on LTP are therefore likely to be mediated via a postsynaptic mechanism. This in vivo model of LTP is extremely sensitive to Abeta-peptides that can impair LTP in a time- ([25-35]) and concentration-dependent manner ([25-35] and [35-25]). These effects of Abeta-peptides may then contribute to the cognitive deficits associated with Alzheimer's disease.
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Affiliation(s)
- D B Freir
- Department of Human Anatomy and Physiology, University College Dublin, Dublin 2, Ireland
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38
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Chen ST, Wang JP, Chien CH, Shen CL. Differential expression of beta-amyloid precursor and Bcl-2 proto-oncogene proteins in the developing dog retina. Neurosci Res 1999; 35:265-71. [PMID: 10617317 DOI: 10.1016/s0168-0102(99)00096-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Previous studies of rat retinas have not only provided evidence that beta-amyloid precursor (APP) and B-cell lymphoma proto-oncogene (Bcl-2) proteins are colocalized in retinal Müller glial cells, but have also indicated that common mechanisms regulate their expression in these cells (Chen, S.T., Garey, L.J., Jen, L.S., 1994. Bcl-2 proto-oncogene protein immunoreactivity in normally developing and axotomised rat retinas. Neurosci. Lett. 172, 11 14; Chen, S.T., Gentleman, S.M., Garey, L.J., Jen, L.S., 1996. Distribution of beta-amyloid precursor and B-cell lymphoma proto-oncogene proteins in the rat retina after optic nerve transection or vascular lesion. J. Neuropathol. Exp. Neurol. 55, 1073-1082; Chen, S.T., Garey, L.J., Jen, L.S., 1997. Expression of beta-amyloid precursor protein immunoreactivity in the retina of the rat during normal development and after neonatal optic tract lesion. NeuroReport 8, 713-717). This investigation attempts to resolve whether or not the pattern observed in rats also applies to other higher mammalian species by examining the expression of immunoreactivity to APP and Bcl-2 in developing as well as mature dog retinas using immunocytochemical methods. Experimental results indicate that the immunoreactivity of both APP and Bcl-2 is located primarily in the inner retina, particularly in the ganglion cells and their axons in late fetal and neonatal stages. From the second postnatal week (the time of eye opening) onwards, immunoreactivity to APP, but not Bcl-2, is localized primarily in the endfeet and proximal part of the radial process of retinal Müller glial cells. Although the findings show both APP and Bcl-2 are expressed in ganglion cells and their processes suggest that the molecules have a role in the differentiation of neurons in the central nervous tissue, the lack of Bcl-2 in the Müller glial cells in dog retinas further suggests that the two molecules may have different biological roles with respect to glial function.
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Affiliation(s)
- S T Chen
- Department of Anatomy, National Cheng Kung University, Tainan City, Taiwan, ROC
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39
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Menschik ED, Finkel LH. Cholinergic neuromodulation and Alzheimer's disease: from single cells to network simulations. PROGRESS IN BRAIN RESEARCH 1999; 121:19-45. [PMID: 10551018 DOI: 10.1016/s0079-6123(08)63065-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- E D Menschik
- Institute of Neurological Sciences, University of Pennsylvania, Philadelphia 19104, USA.
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40
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Shao H, Jao S, Ma K, Zagorski MG. Solution structures of micelle-bound amyloid beta-(1-40) and beta-(1-42) peptides of Alzheimer's disease. J Mol Biol 1999; 285:755-73. [PMID: 9878442 DOI: 10.1006/jmbi.1998.2348] [Citation(s) in RCA: 247] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The amyloid beta-peptide is the major protein constituent of neuritic plaques in Alzheimer's disease. The beta-peptide varies slightly in length and exists in two predominant forms: (1) the shorter, 40 residue beta-(1-40), found mainly in cerebrovascular amyloid; and (2) the longer, 42 residue beta-(1-42), which is the major component in amyloid plaque core deposits. We report here that the sodium dodecyl sulphate (SDS) micelle, a membrane-mimicking system for biophysical studies, prevents aggregation of the beta-(1-40) and the beta-(1-42) into the neurotoxic amyloid-like, beta-pleated sheet structure, and instead encourages folding into predominantly alpha-helical structures at pH 7.2. Analysis of the nuclear Overhauser enhancement (NOE) and the alphaH NMR chemical shift data revealed no significant structural differences between the beta-(1-40) and the beta-(1-42). The NMR-derived, three-dimensional structure of the beta-(1-42) consists of an extended chain (Asp1-Gly9), two alpha-helices (Tyr10-Val24 and Lys28-Ala42), and a looped region (Gly25-Ser26-Asn27). The most stable alpha-helical regions reside at Gln15-Val24 and Lys28-Val36. The majority of the amide (NH) temperature coefficients were less than 5, indicative of predominately strong NH backbone bonding. The lack of a persistent region with consistently low NH coefficients, together with the rapid NH exchange rates in deuterated water and spin-labeled studies, suggests that the beta-peptide is located at the lipid-water interface of the micelle and does not become inbedded within the hydrophobic interior. This result has implications for the circulation of membrane-bound beta-peptide in biological fluids, and may also facilitate the design of amyloid inhibitors to prevent an alpha-helix-->beta-sheet conversion in Alzheimer's disease.
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Affiliation(s)
- H Shao
- Department of Chemistry, Case Western Reserve University, Cleveland, OH, 44106, USA
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41
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Hölscher C. Possible causes of Alzheimer's disease: amyloid fragments, free radicals, and calcium homeostasis. Neurobiol Dis 1998; 5:129-41. [PMID: 9848086 DOI: 10.1006/nbdi.1998.0193] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Alzheimer's disease (AD) is a form of dementia in which patients develop neurodegeneration and complete loss of cognitive abilities and die prematurely. No treatment is known for this condition. Evidence points toward beta-amyloid as one of the main causes for cytotoxic processes. The cascade of biochemical events that lead to neuronal death appears to be interference with intracellular calcium homeostasis via activation of calcium channels, intracellular calcium stores, and subsequent production of free radicals by calcium-sensitive enzymes. The glutamatergic system seems to be implicated in mediating the toxic processes. Several strategies promise amelioration of neurodegenerative developments as judging from in vitro experiments. Glutamate receptor-selective drugs, antioxidants, inhibitors of nitric oxide synthase, calcium channel antagonists, receptor or enzyme inhibitors, and growth factors promise help. Especially combinations of drugs that act at different levels might prolong patients' health.
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Affiliation(s)
- C Hölscher
- Department of Human Anatomy and Physiology, University College Dublin, Ireland
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