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Chen L, Christenson Wick Z, Vetere LM, Vaughan N, Jurkowski A, Galas A, Diego KS, Philipsberg PA, Soler I, Feng Y, Cai DJ, Shuman T. Progressive Excitability Changes in the Medial Entorhinal Cortex in the 3xTg Mouse Model of Alzheimer's Disease Pathology. J Neurosci 2023; 43:7441-7454. [PMID: 37714705 PMCID: PMC10621765 DOI: 10.1523/jneurosci.1204-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 09/07/2023] [Accepted: 09/08/2023] [Indexed: 09/17/2023] Open
Abstract
Alzheimer's disease (AD) is a chronic neurodegenerative disorder characterized by memory loss and progressive cognitive impairments. In mouse models of AD pathology, studies have found neuronal and synaptic deficits in hippocampus, but less is known about changes in medial entorhinal cortex (MEC), which is the primary spatial input to the hippocampus and an early site of AD pathology. Here, we measured neuronal intrinsic excitability and synaptic activity in MEC layer II (MECII) stellate cells, MECII pyramidal cells, and MEC layer III (MECIII) excitatory neurons at 3 and 10 months of age in the 3xTg mouse model of AD pathology, using male and female mice. At 3 months of age, before the onset of memory impairments, we found early hyperexcitability in intrinsic properties of MECII stellate and pyramidal cells, but this was balanced by a relative reduction in synaptic excitation (E) compared with inhibition (I; E/I ratio), suggesting intact homeostatic mechanisms regulating MECII activity. Conversely, MECIII neurons had reduced intrinsic excitability at this early time point with no change in synaptic E/I ratio. By 10 months of age, after the onset of memory deficits, neuronal excitability of MECII pyramidal cells and MECIII excitatory neurons was largely normalized in 3xTg mice. However, MECII stellate cells remained hyperexcitable, and this was further exacerbated by an increased synaptic E/I ratio. This observed combination of increased intrinsic and synaptic hyperexcitability suggests a breakdown in homeostatic mechanisms specifically in MECII stellate cells at this postsymptomatic time point, which may contribute to the emergence of memory deficits in AD.SIGNIFICANCE STATEMENT AD causes cognitive deficits, but the specific neural circuits that are damaged to drive changes in memory remain unknown. Using a mouse model of AD pathology that expresses both amyloid and tau transgenes, we found that neurons in the MEC have altered excitability. Before the onset of memory impairments, neurons in layer 2 of MEC had increased intrinsic excitability, but this was balanced by reduced inputs onto the cell. However, after the onset of memory impairments, stellate cells in MEC became further hyperexcitable, with increased excitability exacerbated by increased synaptic inputs. Thus, it appears that MEC stellate cells are uniquely disrupted during the progression of memory deficits and may contribute to cognitive deficits in AD.
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Affiliation(s)
- Lingxuan Chen
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York 10029
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, California 92697
| | - Zoé Christenson Wick
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York 10029
| | - Lauren M Vetere
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York 10029
| | - Nick Vaughan
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York 10029
| | - Albert Jurkowski
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York 10029
- Hunter College, City University of New York, New York, New York 10065
| | - Angelina Galas
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York 10029
- New York University, New York, New York 10012
| | - Keziah S Diego
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York 10029
| | - Paul A Philipsberg
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York 10029
| | - Ivan Soler
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York 10029
| | - Yu Feng
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York 10029
| | - Denise J Cai
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York 10029
| | - Tristan Shuman
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York 10029
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2
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Chen L, Wick ZC, Vetere LM, Vaughan N, Jurkowski A, Galas A, Diego KS, Philipsberg P, Cai DJ, Shuman T. Progressive excitability changes in the medial entorhinal cortex in the 3xTg mouse model of Alzheimer's disease pathology. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.30.542838. [PMID: 37398359 PMCID: PMC10312508 DOI: 10.1101/2023.05.30.542838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Alzheimer's disease (AD) is a chronic neurodegenerative disorder that is characterized by memory loss and progressive cognitive impairments. In mouse models of AD pathology, studies have found neuronal and synaptic deficits in the hippocampus, but less is known about what happens in the medial entorhinal cortex (MEC), which is the primary spatial input to the hippocampus and an early site of AD pathology. Here, we measured the neuronal intrinsic excitability and synaptic activity in MEC layer II (MECII) stellate cells, MECII pyramidal cells, and MEC layer III (MECIII) excitatory neurons at early (3 months) and late (10 months) time points in the 3xTg mouse model of AD pathology. At 3 months of age, prior to the onset of memory impairments, we found early hyperexcitability in MECII stellate and pyramidal cells' intrinsic properties, but this was balanced by a relative reduction in synaptic excitation (E) compared to inhibition (I), suggesting intact homeostatic mechanisms regulating activity in MECII. Conversely, MECIII neurons had reduced intrinsic excitability at this early time point with no change in the synaptic E/I ratio. By 10 months of age, after the onset of memory deficits, neuronal excitability of MECII pyramidal cells and MECIII excitatory neurons was largely normalized in 3xTg mice. However, MECII stellate cells remained hyperexcitable and this was further exacerbated by an increased synaptic E/I ratio. This observed combination of increased intrinsically and synaptically generated excitability suggests a breakdown in homeostatic mechanisms specifically in MECII stellate cells at this post-symptomatic time point. Together, these data suggest that the breakdown in homeostatic excitability mechanisms in MECII stellate cells may contribute to the emergence of memory deficits in AD.
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Affiliation(s)
- Lingxuan Chen
- Icahn School of Medicine at Mount Sinai, New York NY
- University of California Irvine, Irvine CA
| | | | | | - Nick Vaughan
- Icahn School of Medicine at Mount Sinai, New York NY
| | - Albert Jurkowski
- Icahn School of Medicine at Mount Sinai, New York NY
- CUNY Hunter College, New York NY
| | - Angelina Galas
- Icahn School of Medicine at Mount Sinai, New York NY
- New York University, New York NY
| | | | | | - Denise J. Cai
- Icahn School of Medicine at Mount Sinai, New York NY
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3
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Bigi A, Cascella R, Fani G, Bernacchioni C, Cencetti F, Bruni P, Chiti F, Donati C, Cecchi C. Sphingosine 1-phosphate attenuates neuronal dysfunction induced by amyloid-β oligomers through endocytic internalization of NMDA receptors. FEBS J 2023; 290:112-133. [PMID: 35851748 PMCID: PMC10087929 DOI: 10.1111/febs.16579] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 05/24/2022] [Accepted: 07/18/2022] [Indexed: 01/14/2023]
Abstract
Soluble oligomers arising from the aggregation of the amyloid beta peptide (Aβ) have been identified as the main pathogenic agents in Alzheimer's disease (AD). Prefibrillar oligomers of the 42-residue form of Aβ (Aβ42 O) show membrane-binding capacity and trigger the disruption of Ca2+ homeostasis, a causative event in neuron degeneration. Since bioactive lipids have been recently proposed as potent protective agents against Aβ toxicity, we investigated the involvement of sphingosine 1-phosphate (S1P) signalling pathway in Ca2+ homeostasis in living neurons exposed to Aβ42 O. We show that both exogenous and endogenous S1P rescued neuronal Ca2+ dyshomeostasis induced by toxic Aβ42 O in primary rat cortical neurons and human neuroblastoma SH-SY5Y cells. Further analysis revealed a strong neuroprotective effect of S1P1 and S1P4 receptors, and to a lower extent of S1P3 and S1P5 receptors, which activate the Gi -dependent signalling pathways, thus resulting in the endocytic internalization of the extrasynaptic GluN2B-containing N-methyl-D-aspartate receptors (NMDARs). Notably, the S1P beneficial effect can be sustained over time by sphingosine kinase-1 overexpression, thus counteracting the down-regulation of the S1P signalling induced by Aβ42 O. Our findings disclose underlying mechanisms of S1P neuronal protection against harmful Aβ42 O, suggesting that S1P and its signalling axis can be considered promising targets for therapeutic approaches for AD.
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Affiliation(s)
- Alessandra Bigi
- Department of Experimental and Clinical Biomedical Sciences, University of Florence, Italy
| | - Roberta Cascella
- Department of Experimental and Clinical Biomedical Sciences, University of Florence, Italy
| | - Giulia Fani
- Department of Experimental and Clinical Biomedical Sciences, University of Florence, Italy
| | - Caterina Bernacchioni
- Department of Experimental and Clinical Biomedical Sciences, University of Florence, Italy
| | - Francesca Cencetti
- Department of Experimental and Clinical Biomedical Sciences, University of Florence, Italy
| | - Paola Bruni
- Department of Experimental and Clinical Biomedical Sciences, University of Florence, Italy
| | - Fabrizio Chiti
- Department of Experimental and Clinical Biomedical Sciences, University of Florence, Italy
| | - Chiara Donati
- Department of Experimental and Clinical Biomedical Sciences, University of Florence, Italy
| | - Cristina Cecchi
- Department of Experimental and Clinical Biomedical Sciences, University of Florence, Italy
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4
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Alexandersen CG, de Haan W, Bick C, Goriely A. A multi-scale model explains oscillatory slowing and neuronal hyperactivity in Alzheimer's disease. J R Soc Interface 2023; 20:20220607. [PMID: 36596460 PMCID: PMC9810432 DOI: 10.1098/rsif.2022.0607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Alzheimer's disease is the most common cause of dementia and is linked to the spreading of pathological amyloid-β and tau proteins throughout the brain. Recent studies have highlighted stark differences in how amyloid-β and tau affect neurons at the cellular scale. On a larger scale, Alzheimer's patients are observed to undergo a period of early-stage neuronal hyperactivation followed by neurodegeneration and frequency slowing of neuronal oscillations. Herein, we model the spreading of both amyloid-β and tau across a human connectome and investigate how the neuronal dynamics are affected by disease progression. By including the effects of both amyloid-β and tau pathology, we find that our model explains AD-related frequency slowing, early-stage hyperactivation and late-stage hypoactivation. By testing different hypotheses, we show that hyperactivation and frequency slowing are not due to the topological interactions between different regions but are mostly the result of local neurotoxicity induced by amyloid-β and tau protein.
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Affiliation(s)
| | - Willem de Haan
- Alzheimer Center Amsterdam, Department of Neurology, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam UMC, Amsterdam, The Netherlands
| | - Christian Bick
- Mathematical Institute, University of Oxford, Oxford, UK,Department of Mathematics, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands,Amsterdam Neuroscience—Systems and Network Neuroscience, Amsterdam, The Netherlands
| | - Alain Goriely
- Mathematical Institute, University of Oxford, Oxford, UK
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5
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Panda SP, Dhurandhar Y, Agrawal M. The interplay of epilepsy with impaired mitophagy and autophagy linked dementia (MAD): A review of therapeutic approaches. Mitochondrion 2022; 66:27-37. [PMID: 35842181 DOI: 10.1016/j.mito.2022.07.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 06/21/2022] [Accepted: 07/10/2022] [Indexed: 12/28/2022]
Abstract
The duration and, age of dementia have been linked to a higher risk of seizures. The exact mechanism that drives epileptogenesis in impaired mitophagy and autophagy linked dementia (MAD) is fully defined after reviewing the Scopus, Publon, and Pubmed databases. The epileptogenesis in patients with Alzheimer's disease dementia (ADD) and Parkinson's disease dementia (PDD) is due to involvement of amyloid plaques (Aβ), phosphorylated tau (pTau), Parkin, NF-kB and NLRP3 inflammasome. Microglia, the prime protective and inflammatory cells in the brain exert crosstalk between mitophagy and inflammation. Several researchers believed that the inflammatory brain cells microglia could be a therapeutic target for the treatment of a MAD associated epilepsy. There are conventional antiepileptic drugs such as gabapentin, lamotrigine, phenytoin sodium, carbamazepine, oxcarbazepine, felbamate, lamotrigine, valproate sodium, and topiramate are prescribed by a psychiatrist to suppress seizure frequency. Also, the conventional drugs generate serious adverse effects and synergises dementia characteristics. The adverse effect of carbamazepine is neurotoxic and also, damages haemopoietic system and respiratory tract. The phenytoin treatment causes cerebellar defect and anemia. Dementia and epilepsy have a complicated relationship, thus targeting mitophagy for cure of epileptic dementia makes sense. Complementary and alternative medicine (CAM) is one of the rising strategies by many patients of the world, not only to suppress seizure frequency but also to mitigate dementia characteristics of patients. Therefore our present review focus on the interplay between epilepsy and MAD and their treatment with CAM approaches.
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Affiliation(s)
- Siva Prasad Panda
- Institute of Pharmaceutical Research, GLA University, Mathura, Uttar Pradesh, India.
| | - Yogita Dhurandhar
- Institute of Pharmaceutical Research, GLA University, Mathura, Uttar Pradesh, India.
| | - Mehak Agrawal
- Institute of Pharmaceutical Research, GLA University, Mathura, Uttar Pradesh, India.
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6
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Takasu K, Niidome K, Hasegawa M, Ogawa K. Histone Deacetylase Inhibitor Improves the Dysfunction of Hippocampal Gamma Oscillations and Fast Spiking Interneurons in Alzheimer's Disease Model Mice. Front Mol Neurosci 2021; 14:782206. [PMID: 35027883 PMCID: PMC8751405 DOI: 10.3389/fnmol.2021.782206] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 11/01/2021] [Indexed: 12/05/2022] Open
Abstract
The hippocampal gamma oscillation is important for cognitive function, and its deficit is related to cognitive impairment in Alzheimer's disease (AD). Recently, it has been recognized that post-translational modification via histone acetylation is a fundamental molecular mechanism for regulating synaptic plasticity and cognitive function. However, little is known regarding the regulation of hippocampal gamma oscillation by histone acetylation. We investigated whether histone acetylation regulated kainate-induced gamma oscillations and their important regulator, fast-spiking interneurons, using acute hippocampal slices of AD model mice (PSAPP transgenic mice). We found a decrease in kainate-induced gamma oscillations in slices from PSAPP mice, accompanied with the increased activity of fast spiking interneurons in basal state and the decreased activity in activated state. The histone deacetylase (HDAC) inhibitor (SAHA, named vorinostat) restored deficits of gamma oscillation in PSAPP mice, accompanied with rescue of activity of fast spiking interneurons in basal and activated state. The effect of SAHA was different from that of the clinical AD drug donepezil, which rescued only function of fast spiking interneurons in basal state. Besides, activator of nuclear receptor family 4a (NR4a) receptor (cytosporone B), as one of the epigenetic modification related to HDAC inhibition, rescued the deficits in gamma oscillations in PSAPP mice. These results suggested a novel mechanism in which HDAC inhibition improved impairment of gamma oscillations in PSAPP mice by restoring the activity of fast spiking interneurons both in basal and activated state. The reversal of gamma oscillation deficits by HDAC inhibition and/or NR4a activation appears to be a potential therapeutic target for treating cognitive impairment in AD patients.
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Affiliation(s)
| | | | | | - Koichi Ogawa
- Pain and Neuroscience, Drug Discovery and Disease Research Laboratory, Shionogi & Co., Ltd., Osaka, Japan
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7
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Cano A, Fonseca E, Ettcheto M, Sánchez-López E, de Rojas I, Alonso-Lana S, Morató X, Souto EB, Toledo M, Boada M, Marquié M, Ruíz A. Epilepsy in Neurodegenerative Diseases: Related Drugs and Molecular Pathways. Pharmaceuticals (Basel) 2021; 14:1057. [PMID: 34681281 PMCID: PMC8538968 DOI: 10.3390/ph14101057] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 10/14/2021] [Accepted: 10/14/2021] [Indexed: 12/17/2022] Open
Abstract
Epilepsy is a chronic disease of the central nervous system characterized by an electrical imbalance in neurons. It is the second most prevalent neurological disease, with 50 million people affected around the world, and 30% of all epilepsies do not respond to available treatments. Currently, the main hypothesis about the molecular processes that trigger epileptic seizures and promote the neurotoxic effects that lead to cell death focuses on the exacerbation of the glutamate pathway and the massive influx of Ca2+ into neurons by different factors. However, other mechanisms have been proposed, and most of them have also been described in other neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, Huntington's disease, or multiple sclerosis. Interestingly, and mainly because of these common molecular links and the lack of effective treatments for these diseases, some antiseizure drugs have been investigated to evaluate their therapeutic potential in these pathologies. Therefore, in this review, we thoroughly investigate the common molecular pathways between epilepsy and the major neurodegenerative diseases, examine the incidence of epilepsy in these populations, and explore the use of current and innovative antiseizure drugs in the treatment of refractory epilepsy and other neurodegenerative diseases.
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Affiliation(s)
- Amanda Cano
- Ace Alzheimer Center Barcelona, Universitat Internacional de Catalunya (UIC), 08029 Barcelona, Spain; (I.d.R.); (S.A.-L.); (X.M.); (M.B.); (M.M.); (A.R.)
- Biomedical Research Networking Centre in Neurodegenerative Diseases (CIBERNED), 28031 Madrid, Spain; (M.E.); (E.S.-L.)
- Department of Pharmacy, Pharmaceutical Technology and Physical Chemistry, Faculty of Pharmacy and Food Sciences, University of Barcelona, 08028 Barcelona, Spain
- Institute of Nanoscience and Nanotechnology (IN2UB), 08028 Barcelona, Spain
| | - Elena Fonseca
- Epilepsy Unit, Neurology Department, Vall d’Hebron University Hospital, 08035 Barcelona, Spain; (E.F.); (M.T.)
- Research Group on Status Epilepticus and Acute Seizures, Vall d’Hebron Institut de Recerca (VHIR), Vall d’Hebron Barcelona Hospital Campus, 08035 Barcelona, Spain
| | - Miren Ettcheto
- Biomedical Research Networking Centre in Neurodegenerative Diseases (CIBERNED), 28031 Madrid, Spain; (M.E.); (E.S.-L.)
- Department of Pharmacology, Toxicology and Therapeutic Chemistry, Faculty of Pharmacy and Food Sciences, University of Barcelona, 08028 Barcelona, Spain
- Institute of Neurosciences (UBNeuro), University of Barcelona, 08007 Barcelona, Spain
| | - Elena Sánchez-López
- Biomedical Research Networking Centre in Neurodegenerative Diseases (CIBERNED), 28031 Madrid, Spain; (M.E.); (E.S.-L.)
- Department of Pharmacy, Pharmaceutical Technology and Physical Chemistry, Faculty of Pharmacy and Food Sciences, University of Barcelona, 08028 Barcelona, Spain
- Institute of Nanoscience and Nanotechnology (IN2UB), 08028 Barcelona, Spain
| | - Itziar de Rojas
- Ace Alzheimer Center Barcelona, Universitat Internacional de Catalunya (UIC), 08029 Barcelona, Spain; (I.d.R.); (S.A.-L.); (X.M.); (M.B.); (M.M.); (A.R.)
- Biomedical Research Networking Centre in Neurodegenerative Diseases (CIBERNED), 28031 Madrid, Spain; (M.E.); (E.S.-L.)
| | - Silvia Alonso-Lana
- Ace Alzheimer Center Barcelona, Universitat Internacional de Catalunya (UIC), 08029 Barcelona, Spain; (I.d.R.); (S.A.-L.); (X.M.); (M.B.); (M.M.); (A.R.)
| | - Xavier Morató
- Ace Alzheimer Center Barcelona, Universitat Internacional de Catalunya (UIC), 08029 Barcelona, Spain; (I.d.R.); (S.A.-L.); (X.M.); (M.B.); (M.M.); (A.R.)
| | - Eliana B. Souto
- Department of Pharmaceutical Technology, Faculty of Pharmacy, University of Coimbra, 3004-531 Coimbra, Portugal;
- Centre of Biological Engineering (CEB), University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
| | - Manuel Toledo
- Epilepsy Unit, Neurology Department, Vall d’Hebron University Hospital, 08035 Barcelona, Spain; (E.F.); (M.T.)
- Research Group on Status Epilepticus and Acute Seizures, Vall d’Hebron Institut de Recerca (VHIR), Vall d’Hebron Barcelona Hospital Campus, 08035 Barcelona, Spain
| | - Mercè Boada
- Ace Alzheimer Center Barcelona, Universitat Internacional de Catalunya (UIC), 08029 Barcelona, Spain; (I.d.R.); (S.A.-L.); (X.M.); (M.B.); (M.M.); (A.R.)
- Biomedical Research Networking Centre in Neurodegenerative Diseases (CIBERNED), 28031 Madrid, Spain; (M.E.); (E.S.-L.)
| | - Marta Marquié
- Ace Alzheimer Center Barcelona, Universitat Internacional de Catalunya (UIC), 08029 Barcelona, Spain; (I.d.R.); (S.A.-L.); (X.M.); (M.B.); (M.M.); (A.R.)
- Biomedical Research Networking Centre in Neurodegenerative Diseases (CIBERNED), 28031 Madrid, Spain; (M.E.); (E.S.-L.)
| | - Agustín Ruíz
- Ace Alzheimer Center Barcelona, Universitat Internacional de Catalunya (UIC), 08029 Barcelona, Spain; (I.d.R.); (S.A.-L.); (X.M.); (M.B.); (M.M.); (A.R.)
- Biomedical Research Networking Centre in Neurodegenerative Diseases (CIBERNED), 28031 Madrid, Spain; (M.E.); (E.S.-L.)
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8
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Errico S, Ramshini H, Capitini C, Canale C, Spaziano M, Barbut D, Calamai M, Zasloff M, Oropesa-Nuñez R, Vendruscolo M, Chiti F. Quantitative Measurement of the Affinity of Toxic and Nontoxic Misfolded Protein Oligomers for Lipid Bilayers and of its Modulation by Lipid Composition and Trodusquemine. ACS Chem Neurosci 2021; 12:3189-3202. [PMID: 34382791 PMCID: PMC8414483 DOI: 10.1021/acschemneuro.1c00327] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Accepted: 07/29/2021] [Indexed: 12/13/2022] Open
Abstract
Many neurodegenerative diseases are associated with the self-assembly of peptides and proteins into fibrillar aggregates. Soluble misfolded oligomers formed during the aggregation process, or released by mature fibrils, play a relevant role in neurodegenerative processes through their interactions with neuronal membranes. However, the determinants of the cytotoxicity of these oligomers are still unclear. Here we used liposomes and toxic and nontoxic oligomers formed by the same protein to measure quantitatively the affinity of the two oligomeric species for lipid membranes. To this aim, we quantified the perturbation to the lipid membranes caused by the two oligomers by using the fluorescence quenching of two probes embedded in the polar and apolar regions of the lipid membranes and a well-defined protein-oligomer binding assay using fluorescently labeled oligomers to determine the Stern-Volmer and dissociation constants, respectively. With both approaches, we found that the toxic oligomers have a membrane affinity 20-25 times higher than that of nontoxic oligomers. Circular dichroism, intrinsic fluorescence, and FRET indicated that neither oligomer type changes its structure upon membrane interaction. Using liposomes enriched with trodusquemine, a potential small molecule drug known to penetrate lipid membranes and make them refractory to toxic oligomers, we found that the membrane affinity of the oligomers was remarkably lower. At protective concentrations of the small molecule, the binding of the oligomers to the lipid membranes was fully prevented. Furthermore, the affinity of the toxic oligomers for the lipid membranes was found to increase and slightly decrease with GM1 ganglioside and cholesterol content, respectively, indicating that physicochemical properties of lipid membranes modulate their affinity for misfolded oligomeric species.
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Affiliation(s)
- Silvia Errico
- Department
of Experimental and Clinical Biomedical Sciences, Section of Biochemistry, University of Florence, Florence 50134, Italy
- Centre
for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom
| | - Hassan Ramshini
- Department
of Experimental and Clinical Biomedical Sciences, Section of Biochemistry, University of Florence, Florence 50134, Italy
- Department
of Biology, Payame Noor University, Tehran 19395-4697, Islamic Republic of Iran
| | - Claudia Capitini
- European
Laboratory for Non-linear Spectroscopy (LENS), Sesto Fiorentino 50019, Italy
- Department
of Physics and Astronomy, University of
Florence, Sesto
Fiorentino 50019, Italy
| | - Claudio Canale
- Department
of Physics, University of Genoa, Genoa 16146, Italy
| | - Martina Spaziano
- Department
of Experimental and Clinical Biomedical Sciences, Section of Biochemistry, University of Florence, Florence 50134, Italy
| | - Denise Barbut
- Enterin
Inc., 2005 Market Street, Philadelphia, Pennsylvania 19103, United States
| | - Martino Calamai
- European
Laboratory for Non-linear Spectroscopy (LENS), Sesto Fiorentino 50019, Italy
- National
Institute of Optics, National Research Council
of Italy (CNR), Florence 50125, Italy
| | - Michael Zasloff
- Enterin
Inc., 2005 Market Street, Philadelphia, Pennsylvania 19103, United States
- MedStar-Georgetown
Transplant Institute, Georgetown University
School of Medicine, Washington D.C. 20007, United States
| | - Reinier Oropesa-Nuñez
- Department
of Materials Science and Engineering, Uppsala
University, Uppsala SE-751 03, Sweden
| | - Michele Vendruscolo
- Centre
for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom
| | - Fabrizio Chiti
- Department
of Experimental and Clinical Biomedical Sciences, Section of Biochemistry, University of Florence, Florence 50134, Italy
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9
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Fani G, Mannini B, Vecchi G, Cascella R, Cecchi C, Dobson CM, Vendruscolo M, Chiti F. Aβ Oligomers Dysregulate Calcium Homeostasis by Mechanosensitive Activation of AMPA and NMDA Receptors. ACS Chem Neurosci 2021; 12:766-781. [PMID: 33538575 PMCID: PMC7898266 DOI: 10.1021/acschemneuro.0c00811] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 01/25/2021] [Indexed: 12/15/2022] Open
Abstract
Alzheimer's disease, which is the most common form of dementia, is characterized by the aggregation of the amyloid β peptide (Aβ) and by an impairment of calcium homeostasis caused by excessive activation of glutamatergic receptors (excitotoxicity). Here, we studied the effects on calcium homeostasis caused by the formation of Aβ oligomeric assemblies. We found that Aβ oligomers cause a rapid influx of calcium ions (Ca2+) across the cell membrane by rapidly activating extrasynaptic N-methyl-d-aspartate (NMDA) receptors and, to a lower extent, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors. We also observed, however, that misfolded oligomers do not interact directly with these receptors. Further experiments with lysophosphatidylcholine and arachidonic acid, which cause membrane compression and stretch, respectively, indicated that these receptors are activated through a change in membrane tension induced by the oligomers and transmitted mechanically to the receptors via the lipid bilayer. Indeed, lysophosphatidylcholine is able to neutralize the oligomer-induced activation of the NMDA receptors, whereas arachidonic acid activates the receptors similarly to the oligomers with no additive effects. An increased rotational freedom observed for a fluorescent probe embedded within the membrane in the presence of the oligomers also indicates a membrane stretch. These results reveal a mechanism of toxicity of Aβ oligomers in Alzheimer's disease through the perturbation of the mechanical properties of lipid membranes sensed by NMDA and AMPA receptors.
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Affiliation(s)
- Giulia Fani
- Department
of Experimental and Clinical Biomedical Sciences, Section of Biochemistry, University of Florence, Viale Morgagni 50, 50134 Florence, Italy
- Centre
for Misfolding Diseases, Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, U.K.
| | - Benedetta Mannini
- Centre
for Misfolding Diseases, Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, U.K.
| | - Giulia Vecchi
- Centre
for Misfolding Diseases, Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, U.K.
| | - Roberta Cascella
- Department
of Experimental and Clinical Biomedical Sciences, Section of Biochemistry, University of Florence, Viale Morgagni 50, 50134 Florence, Italy
| | - Cristina Cecchi
- Department
of Experimental and Clinical Biomedical Sciences, Section of Biochemistry, University of Florence, Viale Morgagni 50, 50134 Florence, Italy
| | - Christopher M. Dobson
- Centre
for Misfolding Diseases, Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, U.K.
| | - Michele Vendruscolo
- Centre
for Misfolding Diseases, Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, U.K.
| | - Fabrizio Chiti
- Department
of Experimental and Clinical Biomedical Sciences, Section of Biochemistry, University of Florence, Viale Morgagni 50, 50134 Florence, Italy
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10
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Harris SS, Wolf F, De Strooper B, Busche MA. Tipping the Scales: Peptide-Dependent Dysregulation of Neural Circuit Dynamics in Alzheimer’s Disease. Neuron 2020; 107:417-435. [DOI: 10.1016/j.neuron.2020.06.005] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 04/24/2020] [Accepted: 06/01/2020] [Indexed: 02/07/2023]
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11
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Aceto G, Re A, Mattera A, Leone L, Colussi C, Rinaudo M, Scala F, Gironi K, Barbati SA, Fusco S, Green T, Laezza F, D'Ascenzo M, Grassi C. GSK3β Modulates Timing-Dependent Long-Term Depression Through Direct Phosphorylation of Kv4.2 Channels. Cereb Cortex 2020; 29:1851-1865. [PMID: 29790931 DOI: 10.1093/cercor/bhy042] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 01/15/2018] [Accepted: 02/07/2018] [Indexed: 12/31/2022] Open
Abstract
Spike timing-dependent plasticity (STDP) is a form of activity-dependent remodeling of synaptic strength that underlies memory formation. Despite its key role in dictating learning rules in the brain circuits, the molecular mechanisms mediating STDP are still poorly understood. Here, we show that spike timing-dependent long-term depression (tLTD) and A-type K+ currents are modulated by pharmacological agents affecting the levels of active glycogen-synthase kinase 3 (GSK3) and by GSK3β knockdown in layer 2/3 of the mouse somatosensory cortex. Moreover, the blockade of A-type K+ currents mimics the effects of GSK3 up-regulation on tLTD and occludes further changes in synaptic strength. Pharmacological, immunohistochemical and biochemical experiments revealed that GSK3β influence over tLTD induction is mediated by direct phosphorylation at Ser-616 of the Kv4.2 subunit, a molecular determinant of A-type K+ currents. Collectively, these results identify the functional interaction between GSK3β and Kv4.2 channel as a novel mechanism for tLTD modulation providing exciting insight into the understanding of GSK3β role in synaptic plasticity.
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Affiliation(s)
- Giuseppe Aceto
- Institute of Human Physiology, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Agnese Re
- Institute of Cell Biology and Neurobiology, National Research Council, Rome, Italy
| | - Andrea Mattera
- Institute of Human Physiology, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Lucia Leone
- Institute of Human Physiology, Università Cattolica del Sacro Cuore, Rome, Italy.,Fondazione Policlinico Universitario A Gemelli, IRCCS, Rome, Italy
| | - Claudia Colussi
- Institute of Cell Biology and Neurobiology, National Research Council, Rome, Italy
| | - Marco Rinaudo
- Institute of Human Physiology, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Federico Scala
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Katia Gironi
- Institute of Human Physiology, Università Cattolica del Sacro Cuore, Rome, Italy
| | | | - Salvatore Fusco
- Institute of Human Physiology, Università Cattolica del Sacro Cuore, Rome, Italy.,Fondazione Policlinico Universitario A Gemelli, IRCCS, Rome, Italy
| | - Thomas Green
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX, USA
| | - Fernanda Laezza
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX, USA
| | - Marcello D'Ascenzo
- Institute of Human Physiology, Università Cattolica del Sacro Cuore, Rome, Italy.,Fondazione Policlinico Universitario A Gemelli, IRCCS, Rome, Italy
| | - Claudio Grassi
- Institute of Human Physiology, Università Cattolica del Sacro Cuore, Rome, Italy.,Fondazione Policlinico Universitario A Gemelli, IRCCS, Rome, Italy
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12
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Epilepsy and Alzheimer’s Disease: Potential mechanisms for an association. Brain Res Bull 2020; 160:107-120. [DOI: 10.1016/j.brainresbull.2020.04.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 04/05/2020] [Accepted: 04/10/2020] [Indexed: 12/16/2022]
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13
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Alcantara-Gonzalez D, Villasana-Salazar B, Peña-Ortega F. Single amyloid-beta injection exacerbates 4-aminopyridine-induced seizures and changes synaptic coupling in the hippocampus. Hippocampus 2019; 29:1150-1164. [PMID: 31381216 DOI: 10.1002/hipo.23129] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 05/12/2019] [Accepted: 06/05/2019] [Indexed: 11/09/2022]
Abstract
Accumulation of amyloid-beta (Aβ) in temporal lobe structures, including the hippocampus, is related to a variety of Alzheimer's disease symptoms and seems to be involved in the induction of neural network hyperexcitability and even seizures. Still, a direct evaluation of the pro-epileptogenic effects of Aβ in vivo, and of the underlying mechanisms, is missing. Thus, we tested whether the intracisternal injection of Aβ modulates 4-aminopyridine (4AP)-induced epileptiform activity, hippocampal network function, and its synaptic coupling. When tested 3 weeks after its administration, Aβ (but not its vehicle) reduces the latency for 4AP-induced seizures, increases the number of generalized seizures, exacerbates the time to fully recover from seizures, and favors seizure-induced death. These pro-epileptogenic effects of Aβ correlate with a reduction in the power of the spontaneous hippocampal network activity, involving all frequency bands in vivo and only the theta band (4-10 Hz) in vitro. The pro-epileptogenic effects of Aβ also correlate with a reduction of the Schaffer-collateral CA1 synaptic coupling in vitro, which is exacerbated by the sequential bath application of 4-AP and Aβ. In summary, Aβ produces long-lasting pro-epileptic effects that can be due to alterations in the hippocampal circuit, impacting its coordinated network activity and its synaptic efficiency. It is likely that normalizing synaptic coupling and/or coordinated neural network activity (i.e., theta activity) may contribute not only to improve cognitive function in Alzheimer's disease but also to avoid hyperexcitation in conditions of amyloidosis.
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Affiliation(s)
- David Alcantara-Gonzalez
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, Qro, Mexico
| | - Benjamín Villasana-Salazar
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, Qro, Mexico
| | - Fernando Peña-Ortega
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, Qro, Mexico
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14
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Colvin BA, Rogers VA, Kulas JA, Ridgway EA, Amtashar FS, Combs CK, Nichols MR. The conformational epitope for a new Aβ42 protofibril-selective antibody partially overlaps with the peptide N-terminal region. J Neurochem 2017; 143:736-749. [PMID: 28881033 DOI: 10.1111/jnc.14211] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 08/09/2017] [Accepted: 08/29/2017] [Indexed: 01/01/2023]
Abstract
Aggregation and accumulation of amyloid-β peptide (Aβ) is a key component of Alzheimer's disease (AD). While monomeric Aβ appears to be benign, oligomers adopt a biologically detrimental structure. These soluble structures can be detected in AD brain tissue by antibodies that demonstrate selectivity for aggregated Aβ. Protofibrils are a subset of soluble oligomeric Aβ species and are described as small (< 100 nm) curvilinear assemblies enriched in β-sheet structure. Our own in vitro studies demonstrate that microglial cells are much more sensitive to soluble Aβ42 protofibrils compared to Aβ42 monomer or insoluble Aβ42 fibrils. Protofibrils interact with microglia, trigger Toll-like receptor signaling, elicit cytokine transcription and expression, and are rapidly taken up by the cells. Because of the importance of this Aβ species, we sought to develop an antibody that selectively recognizes protofibrils over other Aβ species. Immunization of rabbits with isolated Aβ42 protofibrils generated a high-titer anti serum with a strong affinity for Aβ42 protofibrils. The antiserum, termed AbSL, was selective for Aβ42 protofibrils over Aβ42 monomers and Aβ42 fibrils. AbSL did not react with amyloid precursor protein and recognized distinct pathological features in AD transgenic mouse brain slices. Competition studies with an Aβ antibody that targets residues 1-16 indicated that the conformational epitope for AbSL involved the N-terminal region of protofibrils in some manner. The newly developed antibody may have potential diagnostic and therapeutic uses in AD tissue and patients, and targeting of protofibrils in AD may have beneficial effects. Read the Editorial Highlight for this article on page 621. Cover Image for this issue: doi. 10.1111/jnc.13827.
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Affiliation(s)
- Benjamin A Colvin
- Department of Chemistry and Biochemistry, University of Missouri-St. Louis, St. Louis, Missouri, USA
| | - Victoria A Rogers
- Department of Chemistry and Biochemistry, University of Missouri-St. Louis, St. Louis, Missouri, USA
| | - Joshua A Kulas
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, North Dakota, USA
| | - Elizabeth A Ridgway
- Department of Chemistry and Biochemistry, University of Missouri-St. Louis, St. Louis, Missouri, USA
| | - Fatima S Amtashar
- Department of Chemistry and Biochemistry, University of Missouri-St. Louis, St. Louis, Missouri, USA
| | - Colin K Combs
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, North Dakota, USA
| | - Michael R Nichols
- Department of Chemistry and Biochemistry, University of Missouri-St. Louis, St. Louis, Missouri, USA
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15
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Colvin BA, Rogers VA, Kulas JA, Ridgway EA, Amtashar FS, Combs CK, Nichols MR. The conformational epitope for a new Aβ42 protofibril-selective antibody partially overlaps with the peptide N-terminal region. J Neurochem 2017. [PMID: 28881033 DOI: 10.1111/jnc.13827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Aggregation and accumulation of amyloid-β peptide (Aβ) is a key component of Alzheimer's disease (AD). While monomeric Aβ appears to be benign, oligomers adopt a biologically detrimental structure. These soluble structures can be detected in AD brain tissue by antibodies that demonstrate selectivity for aggregated Aβ. Protofibrils are a subset of soluble oligomeric Aβ species and are described as small (< 100 nm) curvilinear assemblies enriched in β-sheet structure. Our own in vitro studies demonstrate that microglial cells are much more sensitive to soluble Aβ42 protofibrils compared to Aβ42 monomer or insoluble Aβ42 fibrils. Protofibrils interact with microglia, trigger Toll-like receptor signaling, elicit cytokine transcription and expression, and are rapidly taken up by the cells. Because of the importance of this Aβ species, we sought to develop an antibody that selectively recognizes protofibrils over other Aβ species. Immunization of rabbits with isolated Aβ42 protofibrils generated a high-titer anti serum with a strong affinity for Aβ42 protofibrils. The antiserum, termed AbSL, was selective for Aβ42 protofibrils over Aβ42 monomers and Aβ42 fibrils. AbSL did not react with amyloid precursor protein and recognized distinct pathological features in AD transgenic mouse brain slices. Competition studies with an Aβ antibody that targets residues 1-16 indicated that the conformational epitope for AbSL involved the N-terminal region of protofibrils in some manner. The newly developed antibody may have potential diagnostic and therapeutic uses in AD tissue and patients, and targeting of protofibrils in AD may have beneficial effects. Read the Editorial Highlight for this article on page 621. Cover Image for this issue: doi. 10.1111/jnc.13827.
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Affiliation(s)
- Benjamin A Colvin
- Department of Chemistry and Biochemistry, University of Missouri-St. Louis, St. Louis, Missouri, USA
| | - Victoria A Rogers
- Department of Chemistry and Biochemistry, University of Missouri-St. Louis, St. Louis, Missouri, USA
| | - Joshua A Kulas
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, North Dakota, USA
| | - Elizabeth A Ridgway
- Department of Chemistry and Biochemistry, University of Missouri-St. Louis, St. Louis, Missouri, USA
| | - Fatima S Amtashar
- Department of Chemistry and Biochemistry, University of Missouri-St. Louis, St. Louis, Missouri, USA
| | - Colin K Combs
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, North Dakota, USA
| | - Michael R Nichols
- Department of Chemistry and Biochemistry, University of Missouri-St. Louis, St. Louis, Missouri, USA
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16
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Papazoglou A, Soos J, Lundt A, Wormuth C, Ginde VR, Müller R, Henseler C, Broich K, Xie K, Ehninger D, Haenisch B, Weiergräber M. Gender-Specific Hippocampal Dysrhythmia and Aberrant Hippocampal and Cortical Excitability in the APPswePS1dE9 Model of Alzheimer's Disease. Neural Plast 2016; 2016:7167358. [PMID: 27840743 PMCID: PMC5093295 DOI: 10.1155/2016/7167358] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 09/07/2016] [Accepted: 09/19/2016] [Indexed: 12/26/2022] Open
Abstract
Alzheimer's disease (AD) is a multifactorial disorder leading to progressive memory loss and eventually death. In this study an APPswePS1dE9 AD mouse model has been analyzed using implantable video-EEG radiotelemetry to perform long-term EEG recordings from the primary motor cortex M1 and the hippocampal CA1 region in both genders. Besides motor activity, EEG recordings were analyzed for electroencephalographic seizure activity and frequency characteristics using a Fast Fourier Transformation (FFT) based approach. Automatic seizure detection revealed severe electroencephalographic seizure activity in both M1 and CA1 deflection in APPswePS1dE9 mice with gender-specific characteristics. Frequency analysis of both surface and deep EEG recordings elicited complex age, gender, and activity dependent alterations in the theta and gamma range. Females displayed an antithetic decrease in theta (θ) and increase in gamma (γ) power at 18-19 weeks of age whereas related changes in males occurred earlier at 14 weeks of age. In females, theta (θ) and gamma (γ) power alterations predominated in the inactive state suggesting a reduction in atropine-sensitive type II theta in APPswePS1dE9 animals. Gender-specific central dysrhythmia and network alterations in APPswePS1dE9 point to a functional role in behavioral and cognitive deficits and might serve as early biomarkers for AD in the future.
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Affiliation(s)
- Anna Papazoglou
- Department of Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte (BfArM)), Bonn, Germany
| | - Julien Soos
- Department of Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte (BfArM)), Bonn, Germany
- German Center for Neurodegenerative Diseases (Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE)), Bonn, Germany
| | - Andreas Lundt
- Department of Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte (BfArM)), Bonn, Germany
| | - Carola Wormuth
- Department of Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte (BfArM)), Bonn, Germany
| | - Varun Raj Ginde
- Department of Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte (BfArM)), Bonn, Germany
- German Center for Neurodegenerative Diseases (Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE)), Bonn, Germany
| | - Ralf Müller
- Department of Psychiatry and Psychotherapy, University of Cologne, Cologne, Germany
| | - Christina Henseler
- Department of Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte (BfArM)), Bonn, Germany
| | - Karl Broich
- Department of Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte (BfArM)), Bonn, Germany
| | - Kan Xie
- German Center for Neurodegenerative Diseases (Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE)), Bonn, Germany
| | - Dan Ehninger
- German Center for Neurodegenerative Diseases (Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE)), Bonn, Germany
| | - Britta Haenisch
- German Center for Neurodegenerative Diseases (Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE)), Bonn, Germany
| | - Marco Weiergräber
- Department of Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte (BfArM)), Bonn, Germany
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17
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Nichols MR, Colvin BA, Hood EA, Paranjape GS, Osborn DC, Terrill-Usery SE. Biophysical Comparison of Soluble Amyloid-β(1–42) Protofibrils, Oligomers, and Protofilaments. Biochemistry 2015; 54:2193-204. [DOI: 10.1021/bi500957g] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Michael R. Nichols
- Department of Chemistry and
Biochemistry and Center for Nanoscience, University of Missouri—St. Louis, One University Boulevard, St. Louis, Missouri 63121, United States
| | - Benjamin A. Colvin
- Department of Chemistry and
Biochemistry and Center for Nanoscience, University of Missouri—St. Louis, One University Boulevard, St. Louis, Missouri 63121, United States
| | - Elizabeth A. Hood
- Department of Chemistry and
Biochemistry and Center for Nanoscience, University of Missouri—St. Louis, One University Boulevard, St. Louis, Missouri 63121, United States
| | - Geeta S. Paranjape
- Department of Chemistry and
Biochemistry and Center for Nanoscience, University of Missouri—St. Louis, One University Boulevard, St. Louis, Missouri 63121, United States
| | - David C. Osborn
- Department of Chemistry and
Biochemistry and Center for Nanoscience, University of Missouri—St. Louis, One University Boulevard, St. Louis, Missouri 63121, United States
| | - Shana E. Terrill-Usery
- Department of Chemistry and
Biochemistry and Center for Nanoscience, University of Missouri—St. Louis, One University Boulevard, St. Louis, Missouri 63121, United States
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18
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Ping Y, Hahm ET, Waro G, Song Q, Vo-Ba DA, Licursi A, Bao H, Ganoe L, Finch K, Tsunoda S. Linking aβ42-induced hyperexcitability to neurodegeneration, learning and motor deficits, and a shorter lifespan in an Alzheimer's model. PLoS Genet 2015; 11:e1005025. [PMID: 25774758 PMCID: PMC4361604 DOI: 10.1371/journal.pgen.1005025] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 01/25/2015] [Indexed: 11/19/2022] Open
Abstract
Alzheimer's disease (AD) is the most prevalent form of dementia in the elderly. β-amyloid (Aβ) accumulation in the brain is thought to be a primary event leading to eventual cognitive and motor dysfunction in AD. Aβ has been shown to promote neuronal hyperactivity, which is consistent with enhanced seizure activity in mouse models and AD patients. Little, however, is known about whether, and how, increased excitability contributes to downstream pathologies of AD. Here, we show that overexpression of human Aβ42 in a Drosophila model indeed induces increased neuronal activity. We found that the underlying mechanism involves the selective degradation of the A-type K+ channel, Kv4. An age-dependent loss of Kv4 leads to an increased probability of AP firing. Interestingly, we find that loss of Kv4 alone results in learning and locomotion defects, as well as a shortened lifespan. To test whether the Aβ42-induced increase in neuronal excitability contributes to, or exacerbates, downstream pathologies, we transgenically over-expressed Kv4 to near wild-type levels in Aβ42-expressing animals. We show that restoration of Kv4 attenuated age-dependent learning and locomotor deficits, slowed the onset of neurodegeneration, and partially rescued premature death seen in Aβ42-expressing animals. We conclude that Aβ42-induced hyperactivity plays a critical role in the age-dependent cognitive and motor decline of this Aβ42-Drosophila model, and possibly in AD.
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Affiliation(s)
- Yong Ping
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, China
| | - Eu-Teum Hahm
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States of America
| | - Girma Waro
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States of America
| | - Qian Song
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, China
| | - Dai-An Vo-Ba
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States of America
| | - Ashley Licursi
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States of America
| | - Han Bao
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Shanghai Jiao Tong University, Shanghai, China
| | - Logan Ganoe
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States of America
| | - Kelly Finch
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States of America
| | - Susan Tsunoda
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States of America
- * E-mail:
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19
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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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20
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Minniti AN, Arrazola MS, Bravo-Zehnder M, Ramos F, Inestrosa NC, Aldunate R. The protein oxidation repair enzyme methionine sulfoxide reductase a modulates Aβ aggregation and toxicity in vivo. Antioxid Redox Signal 2015; 22:48-62. [PMID: 24988428 PMCID: PMC4270145 DOI: 10.1089/ars.2013.5803] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
AIMS To examine the role of the enzyme methionine sulfoxide reductase A-1 (MSRA-1) in amyloid-β peptide (Aβ)-peptide aggregation and toxicity in vivo, using a Caenorhabditis elegans model of the human amyloidogenic disease inclusion body myositis. RESULTS MSRA-1 specifically reduces oxidized methionines in proteins. Therefore, a deletion of the msra-1 gene was introduced into transgenic C. elegans worms that express the Aβ-peptide in muscle cells to prevent the reduction of oxidized methionines in proteins. In a constitutive transgenic Aβ strain that lacks MSRA-1, the number of amyloid aggregates decreases while the number of oligomeric Aβ species increases. These results correlate with enhanced synaptic dysfunction and mislocalization of the nicotinic acetylcholine receptor ACR-16 at the neuromuscular junction (NMJ). INNOVATION This approach aims at modulating the oxidation of Aβ in vivo indirectly by dismantling the methionine sulfoxide repair system. The evidence presented here shows that the absence of MSRA-1 influences Aβ aggregation and aggravates locomotor behavior and NMJ dysfunction. The results suggest that therapies which boost the activity of the Msr system could have a beneficial effect in managing amyloidogenic pathologies. CONCLUSION The absence of MSRA-1 modulates Aβ-peptide aggregation and increments its deleterious effects in vivo.
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Affiliation(s)
- Alicia N Minniti
- 1 Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile , Santiago, Chile
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21
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Terrill-Usery SE, Mohan MJ, Nichols MR. Amyloid-β(1-42) protofibrils stimulate a quantum of secreted IL-1β despite significant intracellular IL-1β accumulation in microglia. Biochim Biophys Acta Mol Basis Dis 2014; 1842:2276-85. [PMID: 25125050 DOI: 10.1016/j.bbadis.2014.08.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Revised: 07/25/2014] [Accepted: 08/04/2014] [Indexed: 12/22/2022]
Abstract
Neuroinflammation is a characteristic feature of the Alzheimer's disease (AD) brain. Significant inflammatory markers such as activated microglia and cytokines can be found surrounding the extracellular senile plaques predominantly composed of amyloid-β protein (Aβ). Several innate immune pathways, including Toll-like receptors (TLRs) and the NLRP3 inflammasome, have been implicated in AD inflammation. Aβ plays a primary role in activating these pathways which likely contributes to the progressive neurodegeneration in AD. In order to better understand the complexities of this interaction we investigated the inflammatory response of primary microglia to Aβ(1-42) protofibrils. Aβ(1-42) protofibrils triggered a time- and MyD88-dependent process that produced tumor necrosis factor alpha (TNFα) and interleukin-1β (IL-1β) mRNA, and intracellular pro and mature forms of IL-1β protein. The accumulation of both IL-1β forms indicated that Aβ(1-42) protofibrils were able to prime and activate the NLRP3 inflammasome. Surprisingly, Aβ-induced accumulation of intracellular mature IL-1β did not translate into greater IL-1β secretion. Instead, we found that Aβ elicited a quantized burst of secreted IL-1β and this process occurred even prior to Aβ priming of the microglia suggesting a basal level of either pro or mature IL-1β in the cultured primary microglia. The IL-1β secretion burst was rapid but not sustained, yet could be re-evoked with additional Aβ stimulation. The findings from this study demonstrated multiple sites of IL-1β regulation by Aβ(1-42) protofibrils including TLR/MyD88-mediated priming, NLRP3 inflammasome activation, and modulation of the IL-1β secretory process. These results underscore the wide-ranging effects of Aβ on the innate immune response.
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Affiliation(s)
- Shana E Terrill-Usery
- Department of Chemistry and Biochemistry and Center for Nanoscience University of Missouri-St. Louis, St. Louis, MO, USA
| | - Michael J Mohan
- Department of Chemistry and Biochemistry and Center for Nanoscience University of Missouri-St. Louis, St. Louis, MO, USA
| | - Michael R Nichols
- Department of Chemistry and Biochemistry and Center for Nanoscience University of Missouri-St. Louis, St. Louis, MO, USA.
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22
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Cochran JN, Hall AM, Roberson ED. The dendritic hypothesis for Alzheimer's disease pathophysiology. Brain Res Bull 2014; 103:18-28. [PMID: 24333192 PMCID: PMC3989444 DOI: 10.1016/j.brainresbull.2013.12.004] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2013] [Revised: 11/28/2013] [Accepted: 12/02/2013] [Indexed: 01/02/2023]
Abstract
Converging evidence indicates that processes occurring in and around neuronal dendrites are central to the pathogenesis of Alzheimer's disease. These data support the concept of a "dendritic hypothesis" of AD, closely related to the existing synaptic hypothesis. Here we detail dendritic neuropathology in the disease and examine how Aβ, tau, and AD genetic risk factors affect dendritic structure and function. Finally, we consider potential mechanisms by which these key drivers could affect dendritic integrity and disease progression. These dendritic mechanisms serve as a framework for therapeutic target identification and for efforts to develop disease-modifying therapeutics for Alzheimer's disease.
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Affiliation(s)
- J Nicholas Cochran
- Center for Neurodegeneration and Experimental Therapeutics, Departments of Neurology and Neurobiology, University of Alabama at Birmingham, Birmingham, AL 35294, United States
| | - Alicia M Hall
- Center for Neurodegeneration and Experimental Therapeutics, Departments of Neurology and Neurobiology, University of Alabama at Birmingham, Birmingham, AL 35294, United States
| | - Erik D Roberson
- Center for Neurodegeneration and Experimental Therapeutics, Departments of Neurology and Neurobiology, University of Alabama at Birmingham, Birmingham, AL 35294, United States.
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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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Paranjape GS, Terrill SE, Gouwens LK, Ruck BM, Nichols MR. Amyloid-β(1-42) protofibrils formed in modified artificial cerebrospinal fluid bind and activate microglia. J Neuroimmune Pharmacol 2012; 8:312-22. [PMID: 23242692 DOI: 10.1007/s11481-012-9424-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Accepted: 11/20/2012] [Indexed: 11/24/2022]
Abstract
Soluble aggregated forms of amyloid-β protein (Aβ) have garnered significant attention recently for their role in Alzheimer's disease (AD). Protofibrils are a subset of these soluble species and are considered intermediates in the aggregation pathway to mature Aβ fibrils. Biological studies have demonstrated that protofibrils exhibit both toxic and inflammatory activities. It is important in these in vitro studies to prepare protofibrils using solution conditions that are appropriate for cellular studies as well as conducive to biophysical characterization of protofibrils. Here we describe the preparation and characterization of Aβ(1-42) protofibrils in modified artificial cerebrospinal fluid (aCSF) and demonstrate their prominent binding and activation of microglial cells. A simple phosphate/bicarbonate buffer system was prepared that maintained the ionic strength and cell compatibility of F-12 medium but did not contain numerous supplements that interfere with spectroscopic analyses of Aβ protofibrils. Reconstitution of Aβ(1-42) in aCSF and isolation with size exclusion chromatography (SEC) revealed curvilinear β-sheet protofibrils <100 nm in length and hydrodynamic radii of 21 nm. Protofibril concentration determination by BCA assay, which was not possible in F-12 medium, was more accurately measured in aCSF. Protofibrils formed and isolated in aCSF, but not monomers, markedly stimulated TNFα production in BV-2 and primary microglia and bound in significant amounts to microglial membranes. This report demonstrates the suitability of a modified aCSF system for preparing SEC-isolated Aβ(1-42) protofibrils and underscores the unique ability of protofibrils to functionally interact with microglia.
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Affiliation(s)
- Geeta S Paranjape
- Department of Chemistry and Biochemistry and Center for Nanoscience, University of Missouri-St. Louis, St. Louis, MO, USA
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25
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Lioudyno MI, Broccio M, Sokolov Y, Rasool S, Wu J, Alkire MT, Liu V, Kozak JA, Dennison PR, Glabe CG, Lösche M, Hall JE. Effect of synthetic aβ peptide oligomers and fluorinated solvents on Kv1.3 channel properties and membrane conductance. PLoS One 2012; 7:e35090. [PMID: 22563377 PMCID: PMC3338507 DOI: 10.1371/journal.pone.0035090] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2011] [Accepted: 03/12/2012] [Indexed: 01/07/2023] Open
Abstract
The impact of synthetic amyloid β (1–42) (Aβ1–42) oligomers on biophysical properties of voltage-gated potassium channels Kv 1.3 and lipid bilayer membranes (BLMs) was quantified for protocols using hexafluoroisopropanol (HFIP) or sodium hydroxide (NaOH) as solvents prior to initiating the oligomer formation. Regardless of the solvent used Aβ1–42 samples contained oligomers that reacted with the conformation-specific antibodies A11 and OC and had similar size distributions as determined by dynamic light scattering. Patch-clamp recordings of the potassium currents showed that synthetic Aβ1–42 oligomers accelerate the activation and inactivation kinetics of Kv 1.3 current with no significant effect on current amplitude. In contrast to oligomeric samples, freshly prepared, presumably monomeric, Aβ1–42 solutions had no effect on Kv 1.3 channel properties. Aβ1–42 oligomers had no effect on the steady-state current (at −80 mV) recorded from Kv 1.3-expressing cells but increased the conductance of artificial BLMs in a dose-dependent fashion. Formation of amyloid channels, however, was not observed due to conditions of the experiments. To exclude the effects of HFIP (used to dissolve lyophilized Aβ1–42 peptide), and trifluoroacetic acid (TFA) (used during Aβ1–42 synthesis), we determined concentrations of these fluorinated compounds in the stock Aβ1–42 solutions by 19F NMR. After extensive evaporation, the concentration of HFIP in the 100× stock Aβ1–42 solutions was ∼1.7 μM. The concentration of residual TFA in the 70× stock Aβ1–42 solutions was ∼20 μM. Even at the stock concentrations neither HFIP nor TFA alone had any effect on potassium currents or BLMs. The Aβ1–42 oligomers prepared with HFIP as solvent, however, were more potent in the electrophysiological tests, suggesting that fluorinated compounds, such as HFIP or structurally-related inhalational anesthetics, may affect Aβ1–42 aggregation and potentially enhance ability of oligomers to modulate voltage-gated ion channels and biological membrane properties.
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Affiliation(s)
- Maria I. Lioudyno
- Department of Physiology and Biophysics, University of California Irvine, Irvine, Calfornia, United States of America
| | - Matteo Broccio
- Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - Yuri Sokolov
- Department of Physiology and Biophysics, University of California Irvine, Irvine, Calfornia, United States of America
| | - Suhail Rasool
- Department of Molecular Biology and Biochemistry, University of California Irvine, Irvine, California, United States of America
| | - Jessica Wu
- Department of Molecular Biology and Biochemistry, University of California Irvine, Irvine, California, United States of America
| | - Michael T. Alkire
- Department of Anesthesiology and Perioperative Care, University of California Irvine, Irvine, California, United States of America
| | - Virginia Liu
- Department of Physiology and Biophysics, University of California Irvine, Irvine, Calfornia, United States of America
- Department of Anesthesiology and Perioperative Care, University of California Irvine, Irvine, California, United States of America
| | - J. Ashot Kozak
- Department of Neuroscience, Cell biology, and Physiology, Wright State University, Dayton, Ohio, United States of America
| | - Philip R. Dennison
- Department of Chemistry, University of California Irvine, Irvine, California, United States of America
| | - Charles G. Glabe
- Department of Molecular Biology and Biochemistry, University of California Irvine, Irvine, California, United States of America
| | - Mathias Lösche
- Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
- Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland, United States of America
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - James E. Hall
- Department of Physiology and Biophysics, University of California Irvine, Irvine, Calfornia, United States of America
- * E-mail:
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26
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Paranjape GS, Gouwens LK, Osborn DC, Nichols MR. Isolated amyloid-β(1-42) protofibrils, but not isolated fibrils, are robust stimulators of microglia. ACS Chem Neurosci 2012; 3:302-11. [PMID: 22860196 DOI: 10.1021/cn2001238] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2011] [Accepted: 01/09/2012] [Indexed: 12/22/2022] Open
Abstract
Senile plaques composed of amyloid-β protein (Aβ) are an unshakable feature of the Alzheimer's disease (AD) brain. Although there is significant debate on the role of the plaques in AD progression, there is little disagreement on their role in stimulating a robust inflammatory response within the context of the disease. Significant inflammatory markers such as activated microglia and cytokines are observed almost exclusively surrounding the plaques. However, recent evidence suggests that the plaque exterior may contain a measurable level of soluble Aβ aggregates. The observations that microglia activation in vivo is selectively stimulated by distinct Aβ deposits led us to examine what specific form of Aβ is the most effective proinflammatory mediator in vitro. We report here that soluble prefibrillar species of Aβ(1-42) were better than fibrils at inducing microglial tumor necrosis factor α (TNFα) production in either BV-2 and primary murine microglia. Reconstitution of Aβ(1-42) in NaOH followed by dilution into F-12 media and isolation with size exclusion chromatography (SEC) revealed classic curvilinear β-sheet protofibrils 100 nm in length. The protofibrils, but not monomers, markedly activated BV-2 microglia. Comparisons were also made between freshly isolated protofibrils and Aβ(1-42) fibrils prepared from SEC-purified monomer. Surprisingly, while isolated fibrils had a much higher level of thioflavin T fluorescence per mole, they were not effective at stimulating either primary or BV-2 murine microglia compared to protofibrils. Furthermore, SEC-isolated Aβ(1-40) protofibrils exhibited significantly less activity than concentration-matched Aβ(1-42). This report is the first to demonstrate microglial activation by SEC-purified protofibrils, and the overall findings indicate that small, soluble Aβ(1-42) protofibrils induce much greater microglial activation than mature insoluble fibrils.
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Affiliation(s)
- Geeta S. Paranjape
- Department of Chemistry and Biochemistry and Center
for Nanoscience, University of Missouri—St. Louis, St. Louis, Missouri 63121, United States
| | - Lisa K. Gouwens
- Department of Chemistry and Biochemistry and Center
for Nanoscience, University of Missouri—St. Louis, St. Louis, Missouri 63121, United States
| | - David C. Osborn
- Department of Chemistry and Biochemistry and Center
for Nanoscience, University of Missouri—St. Louis, St. Louis, Missouri 63121, United States
| | - Michael R. Nichols
- Department of Chemistry and Biochemistry and Center
for Nanoscience, University of Missouri—St. Louis, St. Louis, Missouri 63121, United States
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27
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Garrido-Sanabria ER, Perez-Cordova MG, Colom LV. Differential expression of voltage-gated K+ currents in medial septum/diagonal band complex neurons exhibiting distinct firing phenotypes. Neurosci Res 2011; 70:361-9. [PMID: 21624401 PMCID: PMC3150140 DOI: 10.1016/j.neures.2011.05.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2010] [Revised: 04/22/2011] [Accepted: 05/09/2011] [Indexed: 01/28/2023]
Abstract
The medial septum/diagonal band complex (MSDB) controls hippocampal excitability, rhythms and plastic processes. Medial septal neuronal populations display heterogeneous firing patterns. In addition, some of these populations degenerate during age-related disorders (e.g. cholinergic neurons). Thus, it is particularly important to examine the intrinsic properties of theses neurons in order to create new agents that effectively modulate hippocampal excitability and enhance memory processes. Here, we have examined the properties of voltage-gated, K(+) currents in electrophysiologically-identified neurons. These neurons were taken from young rat brain slices containing the MS/DB complex. Whole-cell, patch recordings of outward currents were obtained from slow firing, fast-spiking, regular-firing and burst-firing neurons. Slow firing neurons showed depolarization-activated K(+) current peaks and densities larger than in other neuronal subtypes. Slow firing total current exhibited an inactivating A-type current component that activates at subthreshold depolarization and was reliably blocked by high concentrations of 4-AP. In addition, slow firing neurons expressed a low-threshold delayed rectifier K(+) current component with slow inactivation and intermediate sensitivity to tetraethylammonium. Fast-spiking neurons exhibited the smaller I(K) and I(A) current densities. Burst and regular firing neurons displayed an intermediate firing phenotype with I(K) and I(A) current densities that were larger than the ones observed in fast-spiking neurons but smaller than the ones observed in slow-firing neurons. In addition, the prevalence of each current differed among electrophysiological groups with slow firing and regular firing neurons expressing mostly I(A) and fast spiking and bursting neurons exhibiting mostly delayer rectifier K(+) currents with only minimal contributions of the I(A). The pharmacological or genetic modulations of these currents constitute an important target for the treatment of age-related disorders.
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Affiliation(s)
- Emilio R. Garrido-Sanabria
- Department of Biological Sciences, The Center for Biomedical Studies, The University of Texas at Brownsville, 80 Fort Brown, Brownsville, Texas 78520
| | - Miriam G. Perez-Cordova
- Department of Biological Sciences, The Center for Biomedical Studies, The University of Texas at Brownsville, 80 Fort Brown, Brownsville, Texas 78520
| | - Luis V. Colom
- Department of Biological Sciences, The Center for Biomedical Studies, The University of Texas at Brownsville, 80 Fort Brown, Brownsville, Texas 78520
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28
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Brown JT, Chin J, Leiser SC, Pangalos MN, Randall AD. Altered intrinsic neuronal excitability and reduced Na+ currents in a mouse model of Alzheimer's disease. Neurobiol Aging 2011; 32:2109.e1-14. [PMID: 21794952 DOI: 10.1016/j.neurobiolaging.2011.05.025] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2010] [Revised: 04/20/2011] [Accepted: 05/30/2011] [Indexed: 01/13/2023]
Abstract
Transgenic mice that overproduce beta-amyloid (Aβ) peptides can exhibit central nervous system network hyperactivity. Patch clamp measurements from CA1 pyramidal cells of PSAPP and wild type mice were employed to investigate if altered intrinsic excitability could contribute to such network hyperfunction. At approximately 10 months, when PSAPP mice have a substantial central nervous system Aβ load, resting potential and input resistance were genotype-independent. However, PSAPP mice exhibited a substantially more prominent action potential (AP) burst close to the onset of weak depolarizing current stimuli. The spike afterdepolarization (ADP) was also larger in PSAPP mice. The rate of rise, width and height of APs were reduced in PSAPP animals; AP threshold was unaltered. Voltage-clamp recordings from nucleated macropatches revealed that somatic Na(+) current density was depressed by approximately 50% in PSAPP mice. K(+) current density was unaltered. All genotype-related differences were absent in PSAPP mice aged 5-7 weeks which lack a substantial Aβ load. We conclude that intrinsic neuronal hyperexcitability and changes to AP waveforms may contribute to neurophysiological deficits that arise as a consequence of Aβ accumulation.
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Affiliation(s)
- Jon T Brown
- Pfizer Applied Neurophysiology Group, University of Bristol School of Physiology and Pharmacology, Bristol, UK
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29
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Santos SF, Pierrot N, Octave JN. Network excitability dysfunction in Alzheimer's disease: insights from in vitro and in vivo models. Rev Neurosci 2010; 21:153-71. [PMID: 20879690 DOI: 10.1515/revneuro.2010.21.3.153] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
UNLABELLED Recent reports have drawn attention to dysfunctions of intrinsic neuronal excitability and network activity in Alzheimer disease (AD). Here we review the possible causes of these basic dysfunctions and implications for AD, based on in vitro and in vivo findings. We then review the current therapeutic approaches particularly linked to the issue of neuronal excitability in AD. CONCLUSION AD is a complex, neurodegenerative disorder. Hippocampal synaptic dysfunction is an early feature of the degenerative process that is clearly linked to memory impairment, the first and major symptom of AD. A growing body of evidence points toward a dysfunction of neuronal networks. Intrinsic neuronal excitability, mainly through profound dysregulation of calcium homeostasis, appears to be largely affected. Consequently, neuronal communication is disturbed. Such cellular defects might underlie cognitive manifestations like fluctuations in cognitive impairment and might also explain several observations obtained with EEG, MEG, MRI, or PET studies, leading to the concept of a disconnection syndrome in AD.
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Affiliation(s)
- Susana Ferrao Santos
- Université catholique de Louvain, Institute of Neuroscience, B-1200 Brussels, Belgium.
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30
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Jan A, Hartley DM, Lashuel HA. Preparation and characterization of toxic Abeta aggregates for structural and functional studies in Alzheimer's disease research. Nat Protoc 2010; 5:1186-209. [PMID: 20539293 DOI: 10.1038/nprot.2010.72] [Citation(s) in RCA: 198] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The amyloid cascade hypothesis, supported by strong evidence from genetics, pathology and studies using animal models, implicates amyloid-beta (Abeta) oligomerization and fibrillogenesis as central causative events in the pathogenesis of Alzheimer's disease (AD). Today, significant efforts in academia, biotechnology and the pharmaceutical industry are devoted to identifying the mechanisms by which the process of Abeta aggregation contributes to neurodegeneration in AD and to the identity of the toxic Abeta species. In this paper, we describe methods and detailed protocols for reproducibly preparing Abeta aggregates of defined size distribution and morphology, including monomers, protofibrils and fibrils, using size exclusion chromatography. In addition, we describe detailed biophysical procedures for elucidating the structural features, aggregation kinetics and toxic properties of the different Abeta aggregation states, with special emphasis on protofibrillar intermediates. The information provided by this approach allows for consistent correlation between the properties of the aggregates and their toxicity toward primary neurons and/or cell lines. A better understanding of the molecular and structural basis of Abeta aggregation and toxicity is crucial for the development of effective strategies aimed at prevention and/or treatment of AD. Furthermore, the identification of specific aggregation states, which correlate with neurodegeneration in AD, could lead to the development of diagnostic tools to detect and monitor disease progression. The procedures described can be performed in as little as 1 day, or may take longer, depending on the exact toxicity assays used.
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Affiliation(s)
- Asad Jan
- Laboratory of Molecular Neurobiology and Neuroproteomics, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
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31
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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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32
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Peña F, Ordaz B, Balleza-Tapia H, Bernal-Pedraza R, Márquez-Ramos A, Carmona-Aparicio L, Giordano M. Beta-amyloid protein (25-35) disrupts hippocampal network activity: role of Fyn-kinase. Hippocampus 2010; 20:78-96. [PMID: 19294646 DOI: 10.1002/hipo.20592] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Early cognitive deficit characteristic of early Alzheimer's disease seems to be produced by the soluble forms of beta-amyloid protein. Such cognitive deficit correlates with neuronal network dysfunction that is reflected as alterations in the electroencephalogram of both Alzheimer patients and transgenic murine models of such disease. Correspondingly, recent studies have demonstrated that chronic exposure to betaAP affects hippocampal oscillatory properties. However, it is still unclear if such neuronal network dysfunction results from a direct action of betaAP on the hippocampal circuit or it is secondary to the chronic presence of the protein in the brain. Therefore, we aimed to explore the effect of acute exposure to betaAP(25-35) on hippocampal network activity both in vitro and in vivo, as well as on intrinsic and synaptic properties of hippocampal neurons. We found that betaAP(25-35), reversibly, affects spontaneous hippocampal population activity in vitro. Such effect is not produced by the inverse sequence betaAP(35-25) and is reproduced by the full-length peptide betaAP(1-42). Correspondingly betaAP(25-35), but not the inverse sequence betaAP(35-25), reduces theta-like activity recorded from the hippocampus in vivo. The betaAP(25-35)-induced disruption in hippocampal network activity correlates with a reduction in spontaneous neuronal activity and synaptic transmission, as well as with an inhibition in the subthreshold oscillations produced by pyramidal neurons in vitro. Finally, we studied the involvement of Fyn-kinase on the betaAP(25-35)-induced disruption in hippocampal network activity in vitro. Interestingly, we found that such phenomenon is not observed in slices obtained from Fyn-knockout mice. In conclusion, our data suggest that betaAP acutely affects proper hippocampal function through a Fyn-dependent mechanism. We propose that such alteration might be related to the cognitive impairment observed, at least, during the early phases of Alzheimer's disease.
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Affiliation(s)
- Fernando Peña
- Departamento de Farmacobiología, Centro de Investigación y de Estudios Avanzados Sede Sur, México, D.F., México.
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Dendritic vulnerability in neurodegenerative disease: insights from analyses of cortical pyramidal neurons in transgenic mouse models. Brain Struct Funct 2010; 214:181-99. [PMID: 20177698 DOI: 10.1007/s00429-010-0244-2] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2009] [Accepted: 02/05/2010] [Indexed: 12/27/2022]
Abstract
In neurodegenerative disorders, such as Alzheimer's disease, neuronal dendrites and dendritic spines undergo significant pathological changes. Because of the determinant role of these highly dynamic structures in signaling by individual neurons and ultimately in the functionality of neuronal networks that mediate cognitive functions, a detailed understanding of these changes is of paramount importance. Mutant murine models, such as the Tg2576 APP mutant mouse and the rTg4510 tau mutant mouse have been developed to provide insight into pathogenesis involving the abnormal production and aggregation of amyloid and tau proteins, because of the key role that these proteins play in neurodegenerative disease. This review showcases the multidimensional approach taken by our collaborative group to increase understanding of pathological mechanisms in neurodegenerative disease using these mouse models. This approach includes analyses of empirical 3D morphological and electrophysiological data acquired from frontal cortical pyramidal neurons using confocal laser scanning microscopy and whole-cell patch-clamp recording techniques, combined with computational modeling methodologies. These collaborative studies are designed to shed insight on the repercussions of dystrophic changes in neocortical neurons, define the cellular phenotype of differential neuronal vulnerability in relevant models of neurodegenerative disease, and provide a basis upon which to develop meaningful therapeutic strategies aimed at preventing, reversing, or compensating for neurodegenerative changes in dementia.
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34
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Randall AD, Witton J, Booth C, Hynes-Allen A, Brown JT. The functional neurophysiology of the amyloid precursor protein (APP) processing pathway. Neuropharmacology 2010; 59:243-67. [PMID: 20167227 DOI: 10.1016/j.neuropharm.2010.02.011] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2010] [Accepted: 02/11/2010] [Indexed: 01/12/2023]
Abstract
Amyloid beta (Abeta) peptides derived from proteolytic cleavage of amyloid precursor protein (APP) are thought to be a pivotal toxic species in the pathogenesis of Alzheimer's disease (AD). Furthermore, evidence has been accumulating that components of APP processing pathway are involved in non-pathological normal function of the CNS. In this review we aim to cover the extensive body of research aimed at understanding how components of this pathway contribute to neurophysiological function of the CNS in health and disease. We briefly outline changes to clinical neurophysiology seen in AD patients before discussing functional changes in mouse models of AD which range from changes to basal synaptic transmission and synaptic plasticity through to abnormal synchronous network activity. We then describe the various neurophysiological actions that are produced by application of exogenous Abeta in various forms, and finally discuss a number or other neurophysiological aspects of the APP pathway, including functional activities of components of secretase complexes other than Abeta production.
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Affiliation(s)
- A D Randall
- MRC Centre for Synaptic Plasticity, Department of Anatomy, University of Bristol School of Medical Sciences, Bristol, UK.
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35
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Tabaton M, Zhu X, Perry G, Smith MA, Giliberto L. Signaling effect of amyloid-beta(42) on the processing of AbetaPP. Exp Neurol 2009; 221:18-25. [PMID: 19747481 DOI: 10.1016/j.expneurol.2009.09.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2009] [Revised: 09/01/2009] [Accepted: 09/02/2009] [Indexed: 12/28/2022]
Abstract
The effects of amyloid-beta are extremely complex. Current work in the field of Alzheimer disease is focusing on discerning the impact between the physiological signaling effects of soluble low molecular weight amyloid-beta species and the more global cellular damage that could derive from highly concentrated and/or aggregated amyloid. Being able to dissect the specific signaling events, to understand how soluble amyloid-beta induces its own production by up-regulating BACE1 expression, could lead to new tools to interrupt the distinctive feedback cycle with potential therapeutic consequences. Here we describe a positive loop that exists between the secretases that are responsible for the generation of the amyloid-beta component of Alzheimer disease. According to our hypothesis, in familial Alzheimer disease, the primary overproduction of amyloid-beta can induce BACE1 transcription and drive a further increase of amyloid-beta precursor protein processing and resultant amyloid-beta production. In sporadic Alzheimer disease, many factors, among them oxidative stress and inflammation, with consequent induction of presenilins and BACE1, would activate a loop and proceed with the generation of amyloid-beta and its signaling role onto BACE1 transcription. This concept of a signaling effect by and feedback on the amyloid-beta precursor protein will likely shed light on how amyloid-beta generation, oxidative stress, and secretase functions are intimately related in sporadic Alzheimer disease.
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Affiliation(s)
- Massimo Tabaton
- Departments of Neuroscience, Ophthalmology, and Genetics, University of Genova, Genova, Italy.
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36
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Minkeviciene R, Rheims S, Dobszay MB, Zilberter M, Hartikainen J, Fülöp L, Penke B, Zilberter Y, Harkany T, Pitkänen A, Tanila H. Amyloid beta-induced neuronal hyperexcitability triggers progressive epilepsy. J Neurosci 2009; 29:3453-62. [PMID: 19295151 PMCID: PMC6665248 DOI: 10.1523/jneurosci.5215-08.2009] [Citation(s) in RCA: 487] [Impact Index Per Article: 32.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2008] [Revised: 01/05/2009] [Accepted: 02/08/2009] [Indexed: 11/21/2022] Open
Abstract
Alzheimer's disease is associated with an increased risk of unprovoked seizures. However, the underlying mechanisms of seizure induction remain elusive. Here, we performed video-EEG recordings in mice carrying mutant human APPswe and PS1dE9 genes (APdE9 mice) and their wild-type littermates to determine the prevalence of unprovoked seizures. In two recording episodes at the onset of amyloid beta (Abeta) pathogenesis (3 and 4.5 months of age), at least one unprovoked seizure was detected in 65% of APdE9 mice, of which 46% had multiple seizures and 38% had a generalized seizure. None of the wild-type mice had seizures. In a subset of APdE9 mice, seizure phenotype was associated with a loss of calbindin-D28k immunoreactivity in dentate granular cells and ectopic expression of neuropeptide Y in mossy fibers. In APdE9 mice, persistently decreased resting membrane potential in neocortical layer 2/3 pyramidal cells and dentate granule cells underpinned increased network excitability as identified by patch-clamp electrophysiology. At stimulus strengths evoking single-component EPSPs in wild-type littermates, APdE9 mice exhibited decreased action potential threshold and burst firing of pyramidal cells. Bath application (1 h) of Abeta1-42 or Abeta25-35 (proto-)fibrils but not oligomers induced significant membrane depolarization of pyramidal cells and increased the activity of excitatory cell populations as measured by extracellular field recordings in the juvenile rodent brain, confirming the pathogenic significance of bath-applied Abeta (proto-)fibrils. Overall, these data identify fibrillar Abeta as a pathogenic entity powerfully altering neuronal membrane properties such that hyperexcitability of pyramidal cells culminates in epileptiform activity.
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Affiliation(s)
| | - Sylvain Rheims
- Faculté de Sciences de Luminy, Aix Marseille Université, and
| | - Marton B. Dobszay
- Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, S-17177 Stockholm, Sweden
| | - Misha Zilberter
- Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, S-17177 Stockholm, Sweden
| | | | | | - Botond Penke
- Supramolecular and Nanostructured Materials Research Group of the Hungarian Academy of Science, University of Szeged, H-6720 Szeged, Hungary
| | - Yuri Zilberter
- Institut National de la Santé et de la Recherche Médicale, Institut de Neurobiologie de la Méditerranée U901, F-13000 Marseille, France
- Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, S-17177 Stockholm, Sweden
| | - Tibor Harkany
- Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, S-17177 Stockholm, Sweden
- Institute of Medical Sciences, College of Life Sciences & Medicine, University of Aberdeen, Aberdeen, AB25 2ZD, United Kingdom
| | - Asla Pitkänen
- A. I. Virtanen Institute, University of Kuopio, and
- Department of Neurology, Kuopio University Hospital, FIN-70211 Kuopio, Finland
| | - Heikki Tanila
- A. I. Virtanen Institute, University of Kuopio, and
- Department of Neurology, Kuopio University Hospital, FIN-70211 Kuopio, Finland
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37
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Rahimi F, Shanmugam A, Bitan G. Structure-function relationships of pre-fibrillar protein assemblies in Alzheimer's disease and related disorders. Curr Alzheimer Res 2008; 5:319-41. [PMID: 18537546 DOI: 10.2174/156720508784533358] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Several neurodegenerative diseases, including Alzheimer's, Parkinson's, Huntington's and prion diseases, are characterized pathognomonically by the presence of intra- and/or extracellular lesions containing proteinaceous aggregates, and by extensive neuronal loss in selective brain regions. Related non-neuropathic systemic diseases, e.g., light-chain and senile systemic amyloidoses, and other organ-specific diseases, such as dialysis-related amyloidosis and type-2 diabetes mellitus, also are characterized by deposition of aberrantly folded, insoluble proteins. It is debated whether the hallmark pathologic lesions are causative. Substantial evidence suggests that these aggregates are the end state of aberrant protein folding whereas the actual culprits likely are transient, pre-fibrillar assemblies preceding the aggregates. In the context of neurodegenerative amyloidoses, the proteinaceous aggregates may eventuate as potentially neuroprotective sinks for the neurotoxic, oligomeric protein assemblies. The pre-fibrillar, oligomeric assemblies are believed to initiate the pathogenic mechanisms that lead to synaptic dysfunction, neuronal loss, and disease-specific regional brain atrophy. The amyloid beta-protein (Abeta), which is believed to cause Alzheimer's disease (AD), is considered an archetypal amyloidogenic protein. Intense studies have led to nominal, functional, and structural descriptions of oligomeric Abeta assemblies. However, the dynamic and metastable nature of Abeta oligomers renders their study difficult. Different results generated using different methodologies under different experimental settings further complicate this complex area of research and identification of the exact pathogenic assemblies in vivo seems daunting. Here we review structural, functional, and biological experiments used to produce and study pre-fibrillar Abeta assemblies, and highlight similar studies of proteins involved in related diseases. We discuss challenges that contemporary researchers are facing and future research prospects in this demanding yet highly important field.
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Affiliation(s)
- F Rahimi
- Department of Neurology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095-7334, USA
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38
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Minkeviciene R, Ihalainen J, Malm T, Matilainen O, Keksa-Goldsteine V, Goldsteins G, Iivonen H, Leguit N, Glennon J, Koistinaho J, Banerjee P, Tanila H. Age-related decrease in stimulated glutamate release and vesicular glutamate transporters in APP/PS1 transgenic and wild-type mice. J Neurochem 2008; 105:584-94. [DOI: 10.1111/j.1471-4159.2007.05147.x] [Citation(s) in RCA: 135] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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39
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Hartley DM, Zhao C, Speier AC, Woodard GA, Li S, Li Z, Walz T. Transglutaminase induces protofibril-like amyloid beta-protein assemblies that are protease-resistant and inhibit long-term potentiation. J Biol Chem 2008; 283:16790-800. [PMID: 18397883 DOI: 10.1074/jbc.m802215200] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
An increasing body of evidence suggests that soluble assemblies of amyloid beta-protein (Abeta) play an important role in the initiation of Alzheimer disease (AD). In vitro studies have found that synthetic Abeta can form soluble aggregates through self-assembly, but this process requires Abeta concentrations 100- to 1000-fold greater than physiological levels. Tissue transglutaminase (TGase) has been implicated in neurodegeneration and can cross-link Abeta. Here we show that TGase induces rapid aggregation of Abeta within 0.5-30 min, which was not observed with chemical cross-linkers. Both Abeta40 and Abeta42 are good substrates for TGase but show different aggregation patterns. Guinea pig and human TGase induced similar Abeta aggregation patterns, and oligomerization was observed with Abeta40 concentrations as low as 50 nm. The formed Abeta40 species range from 5 to 6 nm spheres to curvilinear structures of the same width, but up to 100 nm in length, that resemble the previously described self-assembled Abeta protofibrils. TGase-induced Abeta40 assemblies are resistant to a 1-h incubation with either neprilysin or insulin degrading enzyme, whereas the monomer is rapidly degraded by both proteases. In support of these species being pathological, TGase-induced Abeta40 assemblies (100 nm) inhibited long term potentiation recorded in the CA1 region of mouse hippocampus slices. Our data suggest that TGase can contribute to AD by initiating Abeta oligomerization and aggregation at physiological levels, by reducing the clearance of Abeta due to the generation of protease-resistant Abeta species, and by forming Abeta assemblies that inhibit processes involved in memory and learning. Our data suggest that TGase might constitute a specific therapeutic target for slowing or blocking the progression of AD.
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Affiliation(s)
- Dean M Hartley
- Department of Neurological Sciences, Rush University Medical Center, Chicago, Illinois 60612, USA.
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40
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Li S, Feig LA, Hartley DM. A brief, but repeated, swimming protocol is sufficient to overcome amyloid beta-protein inhibition of hippocampal long-term potentiation. Eur J Neurosci 2007; 26:1289-98. [PMID: 17767506 DOI: 10.1111/j.1460-9568.2007.05760.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Alzheimer's disease starts as an almost imperceptible malady, first observed clinically as a mild memory problem. Accumulating genetic and biochemical data have suggested that amyloid beta-protein (Abeta) plays an important role in this memory loss, and Abeta has been shown to suppress long-term potentiation (LTP), a cellular model for memory and learning. Here we show that a very brief (3 min) swimming, twice daily for 2 weeks, rescues LTP inhibition in the CA1 region of hippocampal slices caused by Abeta(42) or Abeta(40) carrying the Arctic mutation using a theta burst stimulation (TBS) protocol. Whereas the input-output curve was not affected, the paired-pulse ratio was reduced in mice receiving our repeated swimming protocol, suggesting a possible involvement of presynaptic facilitation. Similar to swimming, Abeta's inhibition of LTP could be rescued with the adenylyl cyclase, forskolin. Interestingly, this swimming protocol produced conditions in which a weak-TBS could invoke LTP not observed in naïve mice, which again was mimicked by forskolin. In contrast, the protein kinase A (PKA) inhibitor, H89, blocked both the forskolin and swimming potentiation of LTP; these data implicate cAMP/PKA signaling in the protective effect of swimming and mediating Abeta' detrimental effects. Our data add a new simple behavior paradigm that shows the importance of an environmental factor in reversing the pathophysiological effects of Abeta, and suggest new therapeutic avenues.
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Affiliation(s)
- Shaomin Li
- Department of Biochemistry, Tufts University School of Medicine, 136 Harrison Ave., Boston, MA 02111, USA
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41
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Abstract
Converging lines of evidence suggest that progressive accumulation of the amyloid beta-protein (A beta) plays a central role in the genesis of Alzheimer's disease, but it was long assumed that A beta had to be assembled into extracellular amyloid fibrils to exert its cytotoxic effects. Over the past decade, data have emerged from the use of synthetic A beta peptides, cell culture models, beta-amyloid precursor protein transgenic mice and human brain to suggest that pre-fibrillar, diffusible assemblies of A beta are also deleterious. Although the precise molecular identity of these soluble toxins remains unsettled, accumulating evidence suggests that soluble forms of A beta are indeed the proximate effectors of synapse loss and neuronal injury. Here we review recent progress in understanding the role of soluble oligomers in Alzheimer's disease.
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Affiliation(s)
- Dominic M Walsh
- Laboratory for Neurodegenerative Research, The Conway Institute, University College Dublin, Belfield, Dublin, Republic of Ireland.
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42
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Abstract
The interaction of Abeta with synaptosomal plasma membranes decreases membrane fluidity. Using model membrane/liposome systems the interaction of Abeta with specific lipids (e.g. phospholipids, gangliosides, cholesterol) has been defined. The formation of the beta-sheet structure of Abeta when undergoing peptide aggregation is important for Abeta's membrane perturbing properties. This effect can be correlated with the peptide length of Abeta, the longer Abeta1-42 having the greatest effect on membrane fluidity and on neurotoxicity.
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Affiliation(s)
- Gunter P Eckert
- Department of Pharmacology, ZAFES, Biocenter University of Frankfurt, Germany
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43
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Kidd JF, Sattelle DB. The effects of amyloid peptides on A-type K(+) currents of Drosophila larval cholinergic neurons: modeled actions on firing properties. INVERTEBRATE NEUROSCIENCE 2006; 6:207-13. [PMID: 17106756 DOI: 10.1007/s10158-006-0034-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2006] [Accepted: 10/09/2006] [Indexed: 10/24/2022]
Abstract
In a previous paper we described the actions of beta-amyloid on an A-type K(+) current from Drosophila 3(rd) Instar larval neurons. The results were a depolarizing shift in the steady-state voltage dependence of inactivation and an increase in the rate of recovery from inactivation of the current. In this work we have used the simulation program NEURON to construct a model cell. We then use the model to predict the effects of changing the A-type K(+) current as was observed in the amyloid treated neurons on the firing properties of the cell. We show that changing the steady-state voltage dependence of inactivation of the current to a more depolarized level as observed in experiments in beta-amyloid treated neurons causes an increase in the threshold for the initiation of repetitive firing. However, increasing the rate of recovery from inactivation had no effect. Changing both properties simultaneously had no additional effect over changing the voltage dependence of inactivation alone. Thus, a change in the steady-state properties of the A-type K(+ )current as seen in the amyloid-treated Drosophila cholinergic neurons is sufficient to alter the firing properties of the modeled cell.
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Affiliation(s)
- Jackie F Kidd
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford, OX1 3PT, UK.
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44
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Monien BH, Apostolova LG, Bitan G. Early diagnostics and therapeutics for Alzheimer's disease--how early can we get there? Expert Rev Neurother 2006; 6:1293-306. [PMID: 17009917 PMCID: PMC2715564 DOI: 10.1586/14737175.6.9.1293] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Alzheimer's disease (AD) is a major threat for the rapidly aging world population. AD is the leading cause of dementia and a major cause of death in developed countries. The disease puts a tremendous practical, emotional and financial burden on individuals and governments. Clinicians and researchers in the AD field face great challenges: the pathophysiological processes that cause AD are not well understood, definite diagnosis of AD requires autopsy, and therapeutic options are limited to treating the symptoms rather than the cause of the disease. Nevertheless, new insights into the earliest events that lead to development of AD increase hope that reliable diagnostics and efficacious therapies may emerge.
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Affiliation(s)
- Bernhard H Monien
- Department of Neurology, David Geffen School of Medicine, University of California at Los Angeles, Neuroscience Research Building 1, Room 455, 635 Charles E. Young Drive South, Los Angeles, CA 90095-7334, USA, Tel.: +1 310 206 2300, Fax: +1 310 206 1700,
| | - Liana G Apostolova
- Tichi Wilkerson-Kassel Dementia Scholar, UCLA Alzheimer’s Disease Center, 10911 Weyburn Ave., 2nd Floor, Los Angeles, CA 90095-7226, USA, Tel.: +1 310 794 2551, Fax: +1 310 794 3148,
| | - Gal Bitan
- Department of Neurology, David Geffen School of Medicine, University of California at Los Angeles, Neuroscience Research Building 1, Room 451, 635 Charles E. Young Drive South, Los Angeles, CA 90095-7334, USA, Tel.: +1 310 206 2082, Fax: +1 310 206 1700,
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45
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Effects of lithium chloride on outward potassium currents in acutely isolated hippocampal CA1 pyramidal neurons. CHINESE SCIENCE BULLETIN-CHINESE 2006. [DOI: 10.1007/s11434-006-2076-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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46
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Zhang CF, Yang P. Zinc-induced aggregation of Abeta (10-21) potentiates its action on voltage-gated potassium channel. Biochem Biophys Res Commun 2006; 345:43-9. [PMID: 16674922 DOI: 10.1016/j.bbrc.2006.04.044] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2006] [Accepted: 04/15/2006] [Indexed: 11/18/2022]
Abstract
Zinc may play an important role in the pathogenesis of Alzheimer's disease (AD) through influencing the conformation and neurotoxicity of amyloid beta-proteins (Abeta). Zn(2+) induces rapid aggregation of synthetic or endogenous Abeta in a pH-dependent fashion. Here we show for the first time that Zn(2+)-induced aggregation of Abeta (10-21) potentiates its action on outward potassium currents in hippocampal CA1 pyramidal neurons. Using the whole-cell voltage-clamp technique, we showed that Abeta (10-21) blocked the fast-inactivating outward potassium current (I(A)) in a concentration- and aggregation-dependent manner, but with no effect on the delayed rectifier potassium current (I(K)). Both the unaggregated and aggregated forms of Abeta (10-21) significantly shifted the activation curve and the inactivation curve of I(A) to more negative potentials. But the aggregated form has more effects than the unaggregated form. These data indicated that aggregation of amyloid fragments by zinc ions is required in order to obtain full modulatory effects on potassium channel currents.
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Affiliation(s)
- Chao-Feng Zhang
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Molecular Science, Shanxi University, Taiyuan 030006, China
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47
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Qin Y, Qi JS, Qiao JT. Apolipoprotein E4 suppresses delayed-rectifier potassium channels in membrane patches excised from hippocampal neurons. Synapse 2006; 59:82-91. [PMID: 16270302 DOI: 10.1002/syn.20201] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Recent studies show a clear association between Alzheimer's disease (AD) and the apolipoprotein E epsilon 4 allele (APOE4). The mechanisms underlying apoE4-mediated detrimental effects have not been well-clarified. The present study investigates possible effects of apoE4 on the delayed-rectifier potassium (IK) channels in inside-out membrane patches excised from rat hippocampal neurons. Acute application of apoE4 (0.5 microM) to the inside of the membrane patches markedly and reversibly suppressed the single IK channel activities. The average open probability and open frequency of IK channels decreased by (92.6+/-7.1)% and (88.6+/-3.2)%, respectively. The mean open time of IK channels decreased by (81.6+/-6.7)%, and the mean closed-time of them increased by 6.9+/-1.9 fold. Meanwhile, the mean current amplitude of IK channels was not significantly affected. In contrast, application of apolipoprotein A (apoA, 0.5 microM), another member of apolipoprotein family with similar molecular weight and amino acid sequence to apoE4, did not exhibit any effects on IK currents. These results indicate that apoE4 molecules can rapidly suppress the activities of IK channels in hippocampal neurons when they act on the inner side of the neuronal membrane. We propose that the overproduction of apoE4 in neurons may suppress normal IK channel activities and thus be responsible for the late-developed neuronal damages related to the pathogenesis of AD.
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Affiliation(s)
- Ying Qin
- Department of Neurobiology, Shanxi Medical University, Taiyuan, Shanxi 030001, People's Republic of China
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48
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Niemi K, Baumann MH, Kovanen PT, Eklund KK. Serum amyloid A (SAA) activates human mast cells which leads into degradation of SAA and generation of an amyloidogenic SAA fragment. Biochim Biophys Acta Mol Basis Dis 2006; 1762:424-30. [PMID: 16483749 DOI: 10.1016/j.bbadis.2006.01.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2005] [Revised: 01/05/2006] [Accepted: 01/05/2006] [Indexed: 12/27/2022]
Abstract
Serum amyloid A (SAA) is a precursor for the amyloid A in AA type of amyloidosis. Distribution of mast cells in tissues is similar to the distribution of amyloid deposits in secondary AA-amyloidosis. Therefore, we studied whether mast cells could be involved in SAA metabolism. Human mast cell line (HMC-1) cells were cultured with recombinant human apoSAA (rhSAA), and the production of tumour necrosis factor (TNF)-alpha and interleukin (IL)-1 beta was determined by ELISA. RhSAA and human SAA (huSAA) were incubated with human chymase, tryptase or with intact human mast cell (huMC) in cultures, and degradation of SAA was followed by gel electrophoresis, liquid chromatography and mass spectrometry. SAA induced dose-dependent production of TNF-alpha and IL-1 beta in HMC-1 cells. Tryptase, chymase, and huMC granules degraded efficiently the SAA protein. Degradation of SAA by tryptase, but not by chymase, released a highly amyloidogenic N-terminal fragment of SAA. Finally, incubation of huMC with rhSAA alone resulted in degradation of SAA and formation of protofibrillar intermediates. These results suggest a pathogenic role for mast cells in AA-amyloidosis.
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Affiliation(s)
- Katri Niemi
- Protein Chemistry Unit, Institute of Biomedicine and Neuroscience Research Program, University of Helsinki, Haartmaninkatu 8, 00290 Helsinki, Finland.
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49
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Peña F, Gutiérrez-Lerma A, Quiroz-Baez R, Arias C. The role of beta-amyloid protein in synaptic function: implications for Alzheimer's disease therapy. Curr Neuropharmacol 2006; 4:149-63. [PMID: 18615129 PMCID: PMC2430670 DOI: 10.2174/157015906776359531] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2005] [Revised: 10/25/2005] [Accepted: 01/05/2006] [Indexed: 12/16/2022] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder characterized by progressive and irreversible loss of memory and other cognitive functions. Substantial evidence based on genetic, neuropathological and biochemical data has established the central role of beta-amyloid protein (betaAP) in this pathology. Although the precise etiology of AD is not well understood yet, strong evidence for some of the molecular events that lead to progressive brain dysfunction and neurodegeneration in AD has been afforded by identification of biochemical pathways implicated in the generation of betaAP, development of transgenic models exhibiting progressive disease pathology and by data on the effects of betaAP at the neuronal network level. However, the mechanisms by which betaAP causes cognitive decline have not been determined, nor is it clear if the degree of dementia correlates in time with the degree of neuronal loss. Hence, it is of interest to understand the biochemical processes involved in the mechanisms of betaAP-induced neurotoxicity and the mechanisms involved in electrophysiological effects of this protein on different parameters of synaptic transmission and on neuronal firing properties. In this review we analyze recent evidence suggesting a complex role of betaAP in the molecular events that lead to progressive loss of function and eventually to neurodegeneration in AD as well as the therapeutic implications based on betaAP metabolism inhibition.
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Affiliation(s)
- F Peña
- Departamento de Farmacobiología, Cinvestav-Coapa, México D.F. 14330, México.
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50
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Losic D, Martin LL, Mechler A, Aguilar MI, Small DH. High resolution scanning tunnelling microscopy of the beta-amyloid protein (Abeta1-40) of Alzheimer's disease suggests a novel mechanism of oligomer assembly. J Struct Biol 2006; 155:104-10. [PMID: 16650774 DOI: 10.1016/j.jsb.2006.02.013] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2005] [Revised: 02/21/2006] [Accepted: 02/24/2006] [Indexed: 10/24/2022]
Abstract
The aggregation of the beta-amyloid protein (Abeta) is an important step in the pathogenesis of Alzheimer's disease. There is increasing evidence that lower molecular weight oligomeric forms of Abeta may be the most toxic species in vivo. However, little is known about the structure of Abeta oligomers. In this study, scanning tunnelling microscopy (STM) was used to examine the structure of Abeta monomers, dimers and oligomers. Abeta1-40 was visualised by STM on a surface of atomically flat gold. At low concentrations (0.5 microM) small globular structures were observed. High resolution STM of these structures revealed them to be monomers of Abeta. The monomers measured approximately 3-4 nm in diameter. Internal structure was seen in many of the monomers consistent with a conformation in which the polypeptide chain is folded into 3 or 4 domains. Oligomers were seen after ageing the Abeta solution for 24 h. The oligomers were also 3-4 nm in width and appeared to be formed by the end-to-end association of monomers with the polypeptide chain oriented at 90 degrees to the axis of the oligomer. The results suggest that the oligomer formation can proceed through a mechanism involving the linear association of monomers.
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Affiliation(s)
- Dusan Losic
- Department of Biochemistry and Molecular Biology, Monash University, Vic. 3800, Australia
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