151
|
Tarr JC, Turlington ML, Reid PR, Utley TJ, Sheffler DJ, Cho HP, Klar R, Pancani T, Klein M, Bridges T, Morrison R, Blobaum A, Xiang Z, Daniels JS, Niswender CM, Conn PJ, Wood MR, Lindsley CW. Targeting selective activation of M(1) for the treatment of Alzheimer's disease: further chemical optimization and pharmacological characterization of the M(1) positive allosteric modulator ML169. ACS Chem Neurosci 2012; 3:884-95. [PMID: 23173069 PMCID: PMC3503349 DOI: 10.1021/cn300068s] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 07/18/2012] [Indexed: 02/02/2023] Open
Abstract
The M(1) muscarinic acetylcholine receptor is thought to play an important role in memory and cognition, making it a potential target for the treatment of Alzheimer's disease (AD) and schizophrenia. Moreover, M(1) interacts with BACE1 and regulates its proteosomal degradation, suggesting selective M(1) activation could afford both palliative cognitive benefit as well as disease modification in AD. A key challenge in targeting the muscarinic acetylcholine receptors is achieving mAChR subtype selectivity. Our lab has previously reported the M(1) selective positive allosteric modulator ML169. Herein we describe our efforts to further optimize this lead compound by preparing analogue libraries and probing novel scaffolds. We were able to identify several analogues that possessed submicromolar potency, with our best example displaying an EC(50) of 310 nM. The new compounds maintained complete selectivity for the M(1) receptor over the other subtypes (M(2)-M(5)), displayed improved DMPK profiles, and potentiated the carbachol (CCh)-induced excitation in striatal MSNs. Selected analogues were able to potentiate CCh-mediated nonamyloidogenic APPsα release, further strengthening the concept that M(1) PAMs may afford a disease-modifying role in the treatment of AD.
Collapse
Affiliation(s)
- James C. Tarr
- Department
of Pharmacology, Department of Chemistry, Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt Specialized
Chemistry Center for Probe Development (MLPCN), and Vanderbilt Institute of Chemical
Biology/Chemical Synthesis Core, Vanderbilt
University Medical Center, Nashville, Tennessee 37232,
United States
| | - Mark L. Turlington
- Department
of Pharmacology, Department of Chemistry, Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt Specialized
Chemistry Center for Probe Development (MLPCN), and Vanderbilt Institute of Chemical
Biology/Chemical Synthesis Core, Vanderbilt
University Medical Center, Nashville, Tennessee 37232,
United States
| | - Paul R. Reid
- Department
of Pharmacology, Department of Chemistry, Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt Specialized
Chemistry Center for Probe Development (MLPCN), and Vanderbilt Institute of Chemical
Biology/Chemical Synthesis Core, Vanderbilt
University Medical Center, Nashville, Tennessee 37232,
United States
| | - Thomas J. Utley
- Department
of Pharmacology, Department of Chemistry, Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt Specialized
Chemistry Center for Probe Development (MLPCN), and Vanderbilt Institute of Chemical
Biology/Chemical Synthesis Core, Vanderbilt
University Medical Center, Nashville, Tennessee 37232,
United States
| | - Douglas J. Sheffler
- Department
of Pharmacology, Department of Chemistry, Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt Specialized
Chemistry Center for Probe Development (MLPCN), and Vanderbilt Institute of Chemical
Biology/Chemical Synthesis Core, Vanderbilt
University Medical Center, Nashville, Tennessee 37232,
United States
| | - Hyekyung P. Cho
- Department
of Pharmacology, Department of Chemistry, Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt Specialized
Chemistry Center for Probe Development (MLPCN), and Vanderbilt Institute of Chemical
Biology/Chemical Synthesis Core, Vanderbilt
University Medical Center, Nashville, Tennessee 37232,
United States
| | - Rebecca Klar
- Department
of Pharmacology, Department of Chemistry, Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt Specialized
Chemistry Center for Probe Development (MLPCN), and Vanderbilt Institute of Chemical
Biology/Chemical Synthesis Core, Vanderbilt
University Medical Center, Nashville, Tennessee 37232,
United States
| | - Tristano Pancani
- Department
of Pharmacology, Department of Chemistry, Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt Specialized
Chemistry Center for Probe Development (MLPCN), and Vanderbilt Institute of Chemical
Biology/Chemical Synthesis Core, Vanderbilt
University Medical Center, Nashville, Tennessee 37232,
United States
| | - Michael
T. Klein
- Department
of Pharmacology, Department of Chemistry, Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt Specialized
Chemistry Center for Probe Development (MLPCN), and Vanderbilt Institute of Chemical
Biology/Chemical Synthesis Core, Vanderbilt
University Medical Center, Nashville, Tennessee 37232,
United States
| | - Thomas
M. Bridges
- Department
of Pharmacology, Department of Chemistry, Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt Specialized
Chemistry Center for Probe Development (MLPCN), and Vanderbilt Institute of Chemical
Biology/Chemical Synthesis Core, Vanderbilt
University Medical Center, Nashville, Tennessee 37232,
United States
| | - Ryan
D. Morrison
- Department
of Pharmacology, Department of Chemistry, Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt Specialized
Chemistry Center for Probe Development (MLPCN), and Vanderbilt Institute of Chemical
Biology/Chemical Synthesis Core, Vanderbilt
University Medical Center, Nashville, Tennessee 37232,
United States
| | - Anna
L. Blobaum
- Department
of Pharmacology, Department of Chemistry, Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt Specialized
Chemistry Center for Probe Development (MLPCN), and Vanderbilt Institute of Chemical
Biology/Chemical Synthesis Core, Vanderbilt
University Medical Center, Nashville, Tennessee 37232,
United States
| | - Zixui Xiang
- Department
of Pharmacology, Department of Chemistry, Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt Specialized
Chemistry Center for Probe Development (MLPCN), and Vanderbilt Institute of Chemical
Biology/Chemical Synthesis Core, Vanderbilt
University Medical Center, Nashville, Tennessee 37232,
United States
| | - J. Scott Daniels
- Department
of Pharmacology, Department of Chemistry, Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt Specialized
Chemistry Center for Probe Development (MLPCN), and Vanderbilt Institute of Chemical
Biology/Chemical Synthesis Core, Vanderbilt
University Medical Center, Nashville, Tennessee 37232,
United States
| | - Colleen M. Niswender
- Department
of Pharmacology, Department of Chemistry, Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt Specialized
Chemistry Center for Probe Development (MLPCN), and Vanderbilt Institute of Chemical
Biology/Chemical Synthesis Core, Vanderbilt
University Medical Center, Nashville, Tennessee 37232,
United States
| | - P. Jeffrey Conn
- Department
of Pharmacology, Department of Chemistry, Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt Specialized
Chemistry Center for Probe Development (MLPCN), and Vanderbilt Institute of Chemical
Biology/Chemical Synthesis Core, Vanderbilt
University Medical Center, Nashville, Tennessee 37232,
United States
| | - Michael R. Wood
- Department
of Pharmacology, Department of Chemistry, Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt Specialized
Chemistry Center for Probe Development (MLPCN), and Vanderbilt Institute of Chemical
Biology/Chemical Synthesis Core, Vanderbilt
University Medical Center, Nashville, Tennessee 37232,
United States
| | - Craig W. Lindsley
- Department
of Pharmacology, Department of Chemistry, Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt Specialized
Chemistry Center for Probe Development (MLPCN), and Vanderbilt Institute of Chemical
Biology/Chemical Synthesis Core, Vanderbilt
University Medical Center, Nashville, Tennessee 37232,
United States
| |
Collapse
|
152
|
Inestrosa NC, Montecinos-Oliva C, Fuenzalida M. Wnt signaling: role in Alzheimer disease and schizophrenia. J Neuroimmune Pharmacol 2012; 7:788-807. [PMID: 23160851 DOI: 10.1007/s11481-012-9417-5] [Citation(s) in RCA: 131] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2012] [Accepted: 10/30/2012] [Indexed: 12/16/2022]
Abstract
Wnt signaling function starts during the development of the nervous system and is crucial for synaptic plasticity in the adult brain. Clearly Wnt effects in synaptic and plastic processes are relevant, however the implication of this pathway in the prevention of neurodegenerative diseases that produce synaptic impairment, is even more interesting. Several years ago our laboratory found a relationship between the loss of Wnt signaling and the neurotoxicity of the amyloid-β-peptide (Aβ), one of the main players in Alzheimer's disease (AD). Moreover, the activation of the Wnt signaling cascade prevents Aβ-dependent cytotoxic effects. In fact, disrupted Wnt signaling may be a direct link between Aβ-toxicity and tau hyperphosphorylation, ultimately leading to impaired synaptic plasticity and/or neuronal degeneration, indicating that a single pathway can account for both neuro-pathological lesions and altered synaptic function. These observations, suggest that a sustained loss of Wnt signaling function may be a key relevant factor in the pathology of AD. On the other hand, Schizophrenia remains one of the most debilitating and intractable illness in psychiatry. Since Wnt signaling is important in organizing the developing brain, it is reasonable to propose that defects in Wnt signaling could contribute to Schizophrenia, particularly since the neuro-developmental hypothesis of the disease implies subtle dys-regulation of brain development, including some core components of the Wnt signaling pathways such as GSK-3β or Disrupted in Schizophrenia-1 (DISC-1). This review focuses on the relationship between Wnt signaling and its potential relevance for the treatment of neurodegenerative and neuropsychiatric diseases including AD and Schizophrenia.
Collapse
Affiliation(s)
- Nibaldo C Inestrosa
- Centro de Envejecimiento y Regeneración (CARE), Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Alameda 340, 8331150, Santiago, Chile.
| | | | | |
Collapse
|
153
|
Damiano S, Petrozziello T, Ucci V, Amente S, Santillo M, Mondola P. Cu-Zn superoxide dismutase activates muscarinic acetylcholine M1 receptor pathway in neuroblastoma cells. Mol Cell Neurosci 2012; 52:31-7. [PMID: 23147108 DOI: 10.1016/j.mcn.2012.11.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Revised: 10/25/2012] [Accepted: 11/02/2012] [Indexed: 01/25/2023] Open
Abstract
Muscarinic receptors (mAChRs) control several neuronal functions and are widely expressed in the central nervous system (CNS): M1 subtype represents the predominant mAChR in the CNS. Previously, we showed that antioxidant enzyme Cu-Zn superoxide dismutase (SOD1) is secreted by many cellular lines and specifically interacts with cell surface membrane of human neuroblastoma SK-N-BE cells thus activating phospholipase C (PLC) transduction pathway and increasing intracellular calcium concentration ([Ca(2+)](i)). In addition, we demonstrated that a small amount of SOD1 is contained in large core dense vesicles and that it is secreted in response to depolarization induced by elevated extracellular K(+) concentration. In the present study, we investigated the involvement of muscarinic M1 receptors in SOD1-induced activation of PLC transduction pathway. We showed that, in SK-N-BE cells, SOD1 was able to activate muscarinic M1 receptor producing a phosphorylation of ERK 1/2 and Akt in dose- and time-dependent manner. Interestingly, in the presence of the M1 antagonist pirenzepine, ERK 1/2 and Akt phosphorylation induced by SOD1 was remarkably prevented. This effect was mimicked by knocking-down M1 receptor using two sequences of RNA silencing (siRNA). At functional level, siRNAs against M1 receptor were able to prevent the increase in [Ca(2+)](i) induced by SOD1. The same inhibitory effect on [Ca(2+)](i) changes was produced by the M1 antagonist pirenzepine. Collectively, the results of this study demonstrated that SOD1 could activate a transductional pathway through the involvement of M1 muscarinic receptor.
Collapse
Affiliation(s)
- Simona Damiano
- Dipartimento di Neuroscienze, Unità di Fisiologia Umana, Università degli Studi di Napoli Federico II, Napoli, Italy
| | | | | | | | | | | |
Collapse
|
154
|
Connor SA, Maity S, Roy B, Ali DW, Nguyen PV. Conversion of short-term potentiation to long-term potentiation in mouse CA1 by coactivation of -adrenergic and muscarinic receptors. Learn Mem 2012; 19:535-42. [DOI: 10.1101/lm.026898.112] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
155
|
Constitutive α- and β-secretase cleavages of the amyloid precursor protein are partially coupled in neurons, but not in frequently used cell lines. Neurobiol Dis 2012; 49:137-47. [PMID: 22940630 DOI: 10.1016/j.nbd.2012.08.011] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2012] [Revised: 07/20/2012] [Accepted: 08/16/2012] [Indexed: 11/21/2022] Open
Abstract
Proteolytic cleavage of the amyloid precursor protein (APP) by the two proteases α- and β-secretases controls the generation of the amyloid β peptide (Aβ), a key player in Alzheimer's disease pathogenesis. The α-secretase ADAM10 and the β-secretase BACE1 have opposite effects on Aβ generation and are assumed to compete for APP as a substrate, such that their cleavages are inversely coupled. This concept was mainly demonstrated in studies using activation or overexpression of α- and β-secretases. Here, we report that this inverse coupling is not seen to the same extent upon inhibition of the endogenous proteases. Genetic and pharmacological inhibition of ADAM10 and BACE1 revealed that the endogenous, constitutive α-secretase cleavage of APP is largely uncoupled from β-secretase cleavage and Aβ generation in neuroglioma H4 cells and in neuronally differentiated SH-SY5Y cells. In contrast, inverse coupling was observed in primary cortical neurons. However, this coupling was not bidirectional. Inhibition of BACE1 increased ADAM10 cleavage of APP, but a reduction of ADAM10 activity did not increase the BACE1 cleavage of APP in the neurons. Our analysis shows that the inverse coupling of the endogenous α- and β-secretase cleavages depends on the cellular model and suggests that a reduction of ADAM10 activity is unlikely to increase the AD risk through increased β-secretase cleavage.
Collapse
|
156
|
Narasingappa RB, Narasingapa RB, Javagal MR, Jargaval MR, Pullabhatla S, Htoo HH, Rao JKS, Hernandez JF, Govitrapong P, Vincent B. Activation of α-secretase by curcumin-aminoacid conjugates. Biochem Biophys Res Commun 2012; 424:691-6. [PMID: 22796219 DOI: 10.1016/j.bbrc.2012.07.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Accepted: 07/03/2012] [Indexed: 11/16/2022]
Abstract
The extracellular senile plaques observed in Alzheimer's disease (AD) patients are mainly composed of amyloid peptides produced from the β-amyloid precursor protein (βAPP) by β- and γ-secretases. A third non-amyloidogenic α-secretase activity performed by the disintegrins ADAM10 and ADAM17 occurs in the middle of the amyloid-β peptide Aβ and liberates the large sAPPα neuroprotective fragment. Since the activation of α-secretase recently emerged as a promising therapeutic approach to treat AD, the identification of natural compounds able to trigger this cleavage is highly required. Here we describe new curcumin-based modified compounds as α-secretase activators. We established that the aminoacid conjugates curcumin-isoleucine, curcumin-phenylalanine and curcumin-valine promote the constitutive α-secretase activity and increase ADAM10 immunoreactivity. Strickingly, experiments carried out under conditions mimicking the PKC/muscarinic receptor-regulated pathway display different patterns of activation by these compounds. Altogether, our data identified new lead natural compounds for the future development of powerful and stable α-secretase activators and established that some of these molecules are able to discriminate between the constitutive and regulated α-secretase pathways.
Collapse
Affiliation(s)
- Ramesh B Narasingappa
- Research Center for Neuroscience, Institute of Molecular Biosciences, Mahidol University, Nakhon Pathom 73170, Thailand
| | | | | | | | | | | | | | | | | | | |
Collapse
|
157
|
Claeysen S, Cochet M, Donneger R, Dumuis A, Bockaert J, Giannoni P. Alzheimer culprits: cellular crossroads and interplay. Cell Signal 2012; 24:1831-40. [PMID: 22627093 DOI: 10.1016/j.cellsig.2012.05.008] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2012] [Accepted: 05/09/2012] [Indexed: 12/22/2022]
Abstract
Alzheimer's disease (AD) is the primary cause of dementia in the elderly and one of the major health problems worldwide. Since its first description by Alois Alzheimer in 1907, noticeable but insufficient scientific comprehension of this complex pathology has been achieved. All the research that has been pursued takes origin from the identification of the pathological hallmarks in the forms of amyloid-β (Aβ) deposits (plaques), and aggregated hyperphosphorylated tau protein filaments (named neurofibrillary tangles). Since this discovery, many hypotheses have been proposed to explain the origin of the pathology. The "amyloid cascade hypothesis" is the most accredited theory. The mechanism suggested to be one of the initial causes of AD is an imbalance between the production and the clearance of Aβ peptides. Therefore, Amyloid Precursor Protein (APP) synthesis, trafficking and metabolism producing either the toxic Aβ peptide via the amyloidogenic pathway or the sAPPα fragment via the non amyloidogenic pathway have become appealing subjects of study. Being able to reduce the formation of the toxic Aβ peptides is obviously an immediate approach in the trial to prevent AD. The following review summarizes the most relevant discoveries in the field of the last decades.
Collapse
Affiliation(s)
- Sylvie Claeysen
- CNRS, UMR-5203, Institut de Génomique Fonctionnelle, F-34000 Montpellier, France.
| | | | | | | | | | | |
Collapse
|
158
|
Buiter HJ, Leysen JE, Schuit RC, Fisher A, Lammertsma AA, Windhorst AD. Radiosynthesis and biological evaluation of the M1 muscarinic acetylcholine receptor agonist ligand [11C]AF150(S). J Labelled Comp Radiopharm 2012. [DOI: 10.1002/jlcr.2932] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Hans J.C. Buiter
- Department of Nuclear Medicine & PET Research; VU University Medical Center; PO Box 7057; 1007 MB; Amsterdam; The Netherlands
| | - Josée E. Leysen
- Department of Nuclear Medicine & PET Research; VU University Medical Center; PO Box 7057; 1007 MB; Amsterdam; The Netherlands
| | - Robert C. Schuit
- Department of Nuclear Medicine & PET Research; VU University Medical Center; PO Box 7057; 1007 MB; Amsterdam; The Netherlands
| | - Abraham Fisher
- Israel Institute for Biological Research; Ness-Ziona; Israel
| | - Adriaan A. Lammertsma
- Department of Nuclear Medicine & PET Research; VU University Medical Center; PO Box 7057; 1007 MB; Amsterdam; The Netherlands
| | - Albert D. Windhorst
- Department of Nuclear Medicine & PET Research; VU University Medical Center; PO Box 7057; 1007 MB; Amsterdam; The Netherlands
| |
Collapse
|
159
|
Hunter S, Brayne C. Relationships between the amyloid precursor protein and its various proteolytic fragments and neuronal systems. Alzheimers Res Ther 2012; 4:10. [PMID: 22498202 PMCID: PMC3583130 DOI: 10.1186/alzrt108] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disease and in its familial form is associated with mutations in the amyloid precursor protein (APP) and the presenilins (PSs). Much data regarding the interactions of APP, its proteolytic fragments and PS have been generated, expanding our understanding of the roles of these proteins in mechanisms underlying cognitive function and revealing many complex relationships with wide ranging cellular systems. In this review, we examine the multiple interactions of APP and its proteolytic fragments with other neuronal systems in terms of feedback loops and use these relationships to build a map. We highlight the complexity involved in the APP proteolytic system and discuss alternative perspectives on the roles of APP and its proteolytic fragments in dynamic processes associated with disease progression in AD. We highlight areas where data are missing and suggest potential confounding factors. We suggest that a systems biology approach enhances representations of the data and may be more useful in modelling both normal cognition and disease processes.
Collapse
Affiliation(s)
- Sally Hunter
- Institute of Public Health, University of Cambridge, Forvie site, Robinson Way, Cambridge CB2 0SR, UK
| | - Carol Brayne
- Institute of Public Health, University of Cambridge, Forvie site, Robinson Way, Cambridge CB2 0SR, UK
| |
Collapse
|
160
|
M1 muscarinic acetylcholine receptor interacts with BACE1 and regulates its proteosomal degradation. Neurosci Lett 2012; 515:125-30. [PMID: 22450048 DOI: 10.1016/j.neulet.2012.03.026] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Revised: 03/08/2012] [Accepted: 03/09/2012] [Indexed: 01/31/2023]
Abstract
A prime culprit in the pathogenesis of Alzheimer's disease (AD) is overproduction/aggregation of β-amyloid (Aβ), which is derived from β-Amyloid Precursor Protein through sequential cleavages by β-site APP cleaving protein 1 (BACE1) and γ-secretase. The level/activity of BACE1 is elevated in sporadic AD and identification of proteins that affect BACE1 is important in AD research. Here we found that M1 Muscarinic acetylcholine receptor (M1 mAChR), an important G protein-coupled receptor involved in cholinergic neuronal activity, can interact with BACE1 and mediate its proteosomal degradation. Moreover, overexpression and downregulation of M1 mAChR can decrease and increase the levels of BACE1, as well as the generation of Aβ, respectively. These findings point to a novel coupling of BACE1 and M1 mAChR in AD and possibly schizophrenia.
Collapse
|
161
|
Puzzo D, Privitera L, Palmeri A. Hormetic effect of amyloid-β peptide in synaptic plasticity and memory. Neurobiol Aging 2012; 33:1484.e15-24. [PMID: 22284988 DOI: 10.1016/j.neurobiolaging.2011.12.020] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2011] [Revised: 11/23/2011] [Accepted: 12/19/2011] [Indexed: 02/09/2023]
Abstract
One of the hot topics in Alzheimer's disease research field is the "amyloid hypothesis" postulating that the increase and deposition of beta-amyloid peptides (Aβ) is the main pathogenetic factor. However, antiamyloid-based therapies have so far been a failure and, most importantly, growing evidences suggest that Aβ has important physiologic functions. Based on our previous findings demonstrating that low concentrations of Aβ enhanced both synaptic plasticity and memory, whereas high concentrations induced the well-known impairment of cognition, here we show that Aβ acts on hippocampal long-term potentiation and reference memory drawing biphasic dose-response curves. This phenomenon, characterized by low-dose stimulation and high-dose inhibition and represented by a U-shaped or inverted-U-shaped curve, resembles the characteristics of hormesis. The Aβ double role raises important issues on the use of Aβ level reducing agents in Alzheimer's disease.
Collapse
Affiliation(s)
- Daniela Puzzo
- Department of Bio-Medical Sciences, Section of Physiology, University of Catania, Catania, Italy.
| | | | | |
Collapse
|
162
|
Neuronal receptors as targets for the action of amyloid-beta protein (Aβ) in the brain. Expert Rev Mol Med 2012; 14:e2. [PMID: 22261393 DOI: 10.1017/s1462399411002134] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Accumulation of neurotoxic soluble amyloid-beta protein (Aβ) oligomers in the brains of patients with Alzheimer disease (AD) and their role in AD pathogenesis have emerged as topics of considerable interest in recent years. Soluble Aβ oligomers impair synaptic and neuronal function, leading to neurodegeneration that is clinically manifested by memory and cognitive dysfunction. The precise mechanisms whereby Aβ oligomers cause neurotoxicity remain unknown. Emerging insights into the mechanistic link between neuronal receptors and soluble Aβ oligomers highlight the potential role of these receptors in Aβ-mediated neurotoxicity in AD. The current review focuses on studies describing interactions between soluble Aβ oligomers and neuronal receptors, and their role in AD pathogenesis. Furthermore, these studies provide insight into potential therapies for AD using compounds directed at putative target receptors for the action of Aβ in the central nervous system. We focus on interactions of Aβ with subtypes of acetylcholine and glutamatergic receptors. Additionally, neuronal receptors such as insulin, amylin and receptor for advanced glycation end products could be potential targets for soluble Aβ-oligomer-mediated neurotoxicity. Aβ interactions with other receptors such as the p75 neurotrophin receptors, which are highly expressed on cholinergic basal forebrain neurons lost in AD, are also highlighted.
Collapse
|
163
|
Savelkoul PJM, Janickova H, Kuipers AAM, Hageman RJJ, Kamphuis PJ, Dolezal V, Broersen LM. A specific multi-nutrient formulation enhances M1 muscarinic acetylcholine receptor responses in vitro. J Neurochem 2012; 120:631-40. [PMID: 22146060 DOI: 10.1111/j.1471-4159.2011.07616.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Recent evidence indicates that supplementation with a specific combination of nutrients may affect cell membrane synthesis and composition. To investigate whether such nutrients may also modify the physical properties of membranes, and affect membrane-bound processes involved in signal transduction pathways, we studied the effects of nutrient supplementation on G protein-coupled receptor activation in vitro. In particular, we investigated muscarinic receptors, which are important for the progression of memory deterioration and pathology of Alzheimer's disease. Nerve growth factor differentiated pheochromocytoma cells that were supplemented with specific combinations of nutrients showed enhanced responses to muscarinic receptor agonists in a membrane potential assay. The largest effects were obtained with a combination of nutrients known as Fortasyn™ Connect, comprising docosahexaenoic acid, eicosapentaenoic acid, uridine monophosphate as a uridine source, choline, vitamin B6, vitamin B12, folic acid, phospholipids, vitamin C, vitamin E, and selenium. In subsequent experiments, it was shown that the effects of supplementation could not be attributed to single nutrients. In addition, it was shown that the agonist-induced response and the supplement-induced enhancement of the response were blocked with the muscarinic receptor antagonists atropine, telenzepine, and AF-DX 384. In order to determine whether the effects of Fortasyn™ Connect supplementation were receptor subtype specific, we investigated binding properties and activation of human muscarinic M1, M2 and M4 receptors in stably transfected Chinese hamster ovary cells after supplementation. Multi-nutrient supplementation did not change M1 receptor density in plasma membranes. However, M1 receptor-mediated G protein activation was significantly enhanced. In contrast, supplementation of M2- or M4-expressing cells did not affect receptor signaling. Taken together, these results indicate that a specific combination of nutrients acts synergistically in enhancing muscarinic M1 receptor responses, probably by facilitating receptor-mediated G protein activation.
Collapse
Affiliation(s)
- Paul J M Savelkoul
- Nutricia Advanced Medical Nutrition, Danone Research, Centre for Specialised Nutrition, Wageningen, The Netherlands.
| | | | | | | | | | | | | |
Collapse
|
164
|
Muñoz-Torrero D, Pera M, Relat J, Ratia M, Galdeano C, Viayna E, Sola I, Formosa X, Camps P, Badia A, Clos MV. Expanding the Multipotent Profile of Huprine-Tacrine Heterodimers as Disease-Modifying Anti-Alzheimer Agents. NEURODEGENER DIS 2012; 10:96-9. [DOI: 10.1159/000333225] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Accepted: 09/11/2011] [Indexed: 01/12/2023] Open
|
165
|
Smith Y, Wichmann T, Factor SA, DeLong MR. Parkinson's disease therapeutics: new developments and challenges since the introduction of levodopa. Neuropsychopharmacology 2012; 37:213-46. [PMID: 21956442 PMCID: PMC3238085 DOI: 10.1038/npp.2011.212] [Citation(s) in RCA: 156] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Revised: 07/28/2011] [Accepted: 07/29/2011] [Indexed: 12/13/2022]
Abstract
The demonstration that dopamine loss is the key pathological feature of Parkinson's disease (PD), and the subsequent introduction of levodopa have revolutionalized the field of PD therapeutics. This review will discuss the significant progress that has been made in the development of new pharmacological and surgical tools to treat PD motor symptoms since this major breakthrough in the 1960s. However, we will also highlight some of the challenges the field of PD therapeutics has been struggling with during the past decades. The lack of neuroprotective therapies and the limited treatment strategies for the nonmotor symptoms of the disease (ie, cognitive impairments, autonomic dysfunctions, psychiatric disorders, etc.) are among the most pressing issues to be addressed in the years to come. It appears that the combination of early PD nonmotor symptoms with imaging of the nigrostriatal dopaminergic system offers a promising path toward the identification of PD biomarkers, which, once characterized, will set the stage for efficient use of neuroprotective agents that could slow down and alter the course of the disease.
Collapse
Affiliation(s)
- Yoland Smith
- Yerkes National Primate Research Center, Emory University, Atlanta, GA 30322, USA.
| | | | | | | |
Collapse
|
166
|
Decker M, Holzgrabe U. M1 muscarinic cetylcholine receptor allosteric modulators as potential therapeutic opportunities for treating Alzheimer's disease. MEDCHEMCOMM 2012. [DOI: 10.1039/c2md20025b] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
|
167
|
Savonenko AV, Melnikova T, Hiatt A, Li T, Worley PF, Troncoso JC, Wong PC, Price DL. Alzheimer's therapeutics: translation of preclinical science to clinical drug development. Neuropsychopharmacology 2012; 37:261-77. [PMID: 21937983 PMCID: PMC3238084 DOI: 10.1038/npp.2011.211] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2011] [Revised: 08/16/2011] [Accepted: 08/16/2011] [Indexed: 12/15/2022]
Abstract
Over the past three decades, significant progress has been made in understanding the neurobiology of Alzheimer's disease. In recent years, the first attempts to implement novel mechanism-based treatments brought rather disappointing results, with low, if any, drug efficacy and significant side effects. A discrepancy between our expectations based on preclinical models and the results of clinical trials calls for a revision of our theoretical views and questions every stage of translation-from how we model the disease to how we run clinical trials. In the following sections, we will use some specific examples of the therapeutics from acetylcholinesterase inhibitors to recent anti-Aβ immunization and γ-secretase inhibition to discuss whether preclinical studies could predict the limitations in efficacy and side effects that we were so disappointed to observe in recent clinical trials. We discuss ways to improve both the predictive validity of mouse models and the translation of knowledge between preclinical and clinical stages of drug development.
Collapse
Affiliation(s)
- Alena V Savonenko
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| | | | | | | | | | | | | | | |
Collapse
|
168
|
Guillot-Sestier MV, Sunyach C, Ferreira ST, Marzolo MP, Bauer C, Thevenet A, Checler F. α-Secretase-derived fragment of cellular prion, N1, protects against monomeric and oligomeric amyloid β (Aβ)-associated cell death. J Biol Chem 2011; 287:5021-32. [PMID: 22184125 DOI: 10.1074/jbc.m111.323626] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
In physiological conditions, both β-amyloid precursor protein (βAPP) and cellular prion (PrP(c)) undergo similar disintegrin-mediated α-secretase cleavage yielding N-terminal secreted products referred to as soluble amyloid precursor protein-α (sAPPα) and N1, respectively. We recently demonstrated that N1 displays neuroprotective properties by reducing p53-dependent cell death both in vitro and in vivo. In this study, we examined the potential of N1 as a neuroprotector against amyloid β (Aβ)-mediated toxicity. We first show that both recombinant sAPPα and N1, but not its inactive parent fragment N2, reduce staurosporine-stimulated caspase-3 activation and TUNEL-positive cell death by lowering p53 promoter transactivation and activity in human cells. We demonstrate that N1 also lowers toxicity, cell death, and p53 pathway exacerbation triggered by Swedish mutated βAPP overexpression in human cells. We designed a CHO cell line overexpressing the London mutated βAPP (APP(LDN)) that yields Aβ oligomers. N1 protected primary cultured neurons against toxicity and cell death triggered by oligomer-enriched APP(LDN)-derived conditioned medium. Finally, we establish that N1 also protects neurons against oligomers extracted from Alzheimer disease-affected brain tissues. Overall, our data indicate that a cellular prion catabolite could interfere with Aβ-associated toxicity and that its production could be seen as a cellular protective mechanism aimed at compensating for an sAPPα deficit taking place at the early asymptomatic phase of Alzheimer disease.
Collapse
Affiliation(s)
- Marie-Victoire Guillot-Sestier
- Institut de Pharmacologie Moléculaire et Cellulaire, UMR6097 CNRS/Université de Nice-Sophia-Antipolis (UNSA), 660 route des Lucioles, Sophia-Antipolis, 06560 Valbonne, France
| | | | | | | | | | | | | |
Collapse
|
169
|
Fisher A. Cholinergic modulation of amyloid precursor protein processing with emphasis on M1 muscarinic receptor: perspectives and challenges in treatment of Alzheimer’s disease. J Neurochem 2011; 120 Suppl 1:22-33. [DOI: 10.1111/j.1471-4159.2011.07507.x] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
170
|
Abstract
'Secretase' is a generic term coined more than 20 years ago to refer to a group of proteases responsible for the cleavage of a vast number of membrane proteins. These endoproteolytic events result in the extracellular or intracellular release of soluble metabolites associated with a broad range of intrinsic physiological functions. α-Secretase refers to the activity targeting the amyloid precursor protein (APP) and generating sAPPα, a soluble extracellular fragment potentially associated with neurotrophic and neuroprotective functions. Several proteases from the a disintegrin and metalloproteinase (ADAM) family, including ADAM10 and ADAM17, have been directly or indirectly associated with the constitutive and regulated α-secretase activities. Recent evidence in primary neuronal cultures indicates that ADAM10 may represent the genuine constitutive α-secretase. Mainly because α-secretase cleaves APP within the sequence of Aβ, the core component of the cerebral amyloid plaques in Alzheimer's disease, α-secretase activation is considered to be of therapeutic value. In this article, we will provide a historical perspective on the characterization of α-secretase and review the recent literature on the identification and biology of the current α-secretase candidates.
Collapse
Affiliation(s)
- Valérie Vingtdeux
- Litwin-Zucker Research Center for the Study of Alzheimer's Disease, The Feinstein Institute for Medical Research, Manhasset, New York, USA
| | - Philippe Marambaud
- Litwin-Zucker Research Center for the Study of Alzheimer's Disease, The Feinstein Institute for Medical Research, Manhasset, New York, USA
| |
Collapse
|
171
|
Abstract
Alpha-secretase-mediated cleavage of the amyloid precursor protein (APP) releases the neuroprotective APP fragment sαAPP and prevents amyloid β peptide (Aβ) generation. Moreover, α-secretase-like cleavage of the Aβ transporter 'receptor for advanced glycation end products' counteracts the import of blood Aβ into the brain. Assuming that Aβ is responsible for the development of Alzheimer's disease (AD), activation of α-secretase should be preventive. α-Secretase-mediated APP cleavage can be activated via several G protein-coupled receptors and receptor tyrosine kinases. Protein kinase C, mitogen-activated protein kinases, phosphatidylinositol 3-kinase, cAMP and calcium are activators of receptor-induced α-secretase cleavage. Selective targeting of receptor subtypes expressed in brain regions affected by AD appears reasonable. Therefore, the PACAP receptor PAC1 and possibly the serotonin 5-HT(6) receptor subtype are promising targets. Activation of APP α-secretase cleavage also occurs upon blockade of cholesterol synthesis by statins or zaragozic acid A. Under physiological statin concentrations, the brain cholesterol content is not influenced. Statins likely inhibit Aβ production in the blood by α-secretase activation which is possibly sufficient to inhibit AD development. A disintegrin and metalloproteinase 10 (ADAM10) acts as α-secretase on APP. By targeting the nuclear retinoic acid receptor β, the expression of ADAM10 and non-amyloidogenic APP processing can be enhanced. Excessive activation of ADAM10 should be avoided because ADAM10 and also ADAM17 are not APP-specific. Both ADAM proteins cleave various substrates, and therefore have been associated with tumorigenesis and tumor progression.
Collapse
Affiliation(s)
- Rolf Postina
- Institute of Pharmacy and Biochemistry, Johannes Gutenberg University Mainz, Johann-Joachim-Becherweg 30, Mainz, Germany
| |
Collapse
|
172
|
Spines, plasticity, and cognition in Alzheimer's model mice. Neural Plast 2011; 2012:319836. [PMID: 22203915 PMCID: PMC3238410 DOI: 10.1155/2012/319836] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2011] [Accepted: 10/27/2011] [Indexed: 01/03/2023] Open
Abstract
The pathological hallmarks of Alzheimer's disease (AD)--widespread synaptic and neuronal loss and the pathological accumulation of amyloid-beta peptide (Aβ) in senile plaques, as well as hyperphosphorylated tau in neurofibrillary tangles--have been known for many decades, but the links between AD pathology and dementia and effective therapeutic strategies remain elusive. Transgenic mice have been developed based on rare familial forms of AD and frontotemporal dementia, allowing investigators to test in detail the structural, functional, and behavioral consequences of AD-associated pathology. Here, we review work on transgenic AD models that investigate the degeneration of dendritic spine structure, synaptic function, and cognition. Together, these data support a model of AD pathogenesis in which soluble Aβ initiates synaptic dysfunction and loss, as well as pathological changes in tau, which contribute to both synaptic and neuronal loss. These changes in synapse structure and function as well as frank synapse and neuronal loss contribute to the neural system dysfunction which causes cognitive deficits. Understanding the underpinnings of dementia in AD will be essential to develop and evaluate therapeutic approaches for this widespread and devastating disease.
Collapse
|
173
|
Lebois EP, Digby GJ, Sheffler DJ, Melancon BJ, Tarr JC, Cho HP, Miller NR, Morrison R, Bridges TM, Xiang Z, Daniels JS, Wood MR, Conn PJ, Lindsley CW. Development of a highly selective, orally bioavailable and CNS penetrant M1 agonist derived from the MLPCN probe ML071. Bioorg Med Chem Lett 2011; 21:6451-5. [PMID: 21930376 PMCID: PMC3190051 DOI: 10.1016/j.bmcl.2011.08.084] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Revised: 08/15/2011] [Accepted: 08/17/2011] [Indexed: 12/18/2022]
Abstract
Herein we report the discovery and SAR of a novel series of M(1) agonists based on the MLPCN probe, ML071. From this, VU0364572 emerged as a potent, orally bioavailable and CNS penetrant M(1) agonist with high selectivity, clean ancillary pharmacology and enantiospecific activity.
Collapse
Affiliation(s)
- Evan P. Lebois
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Gregory J. Digby
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Douglas J. Sheffler
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Bruce J. Melancon
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, TN 37232, USA
| | - James C. Tarr
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, TN 37232, USA
| | - Hyekyung P. Cho
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, TN 37232, USA
| | | | - Ryan Morrison
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, TN 37232, USA
| | - Thomas M. Bridges
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Zixiu Xiang
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - J. Scott Daniels
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, TN 37232, USA
| | - Michael R. Wood
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, TN 37232, USA
| | - P. Jeffrey Conn
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, TN 37232, USA
| | - Craig W. Lindsley
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, TN 37232, USA
| |
Collapse
|
174
|
Abstract
The concentration of amyloid-β (Aβ) within the brain extracellular space is one determinant of whether the peptide will aggregate into toxic species that are important in Alzheimer's disease (AD) pathogenesis. Some types of synaptic activity can regulate Aβ levels. Here we demonstrate two distinct mechanisms that are simultaneously activated by NMDA receptors and regulate brain interstitial fluid (ISF) Aβ levels in opposite directions in the living mouse. Depending on the dose of NMDA administered locally to the brain, ISF Aβ levels either increase or decrease. Low doses of NMDA increase action potentials and synaptic transmission which leads to an elevation in synaptic Aβ generation. In contrast, high doses of NMDA activate signaling pathways that lead to ERK (extracellular-regulated kinase) activation, which reduces processing of APP into Aβ. This depression in Aβ via APP processing occurs despite dramatically elevated synaptic activity. Both of these synaptic mechanisms are simultaneously active, with the balance between them determining whether ISF Aβ levels will increase or decrease. NMDA receptor antagonists increase ISF Aβ levels, suggesting that basal activity at these receptors normally suppresses Aβ levels in vivo. This has implications for understanding normal Aβ metabolism as well as AD pathogenesis.
Collapse
|
175
|
Alonso E, Vale C, Vieytes MR, Laferla FM, Giménez-Llort L, Botana LM. 13-Desmethyl spirolide-C is neuroprotective and reduces intracellular Aβ and hyperphosphorylated tau in vitro. Neurochem Int 2011; 59:1056-65. [PMID: 21907746 DOI: 10.1016/j.neuint.2011.08.013] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Revised: 08/10/2011] [Accepted: 08/17/2011] [Indexed: 12/22/2022]
Abstract
Spirolides are marine compounds of the cyclic imine group. Although the mechanism of action is not fully elucidated yet, cholinergic (muscarinic and nicotinic) receptors have been proposed as the main targets of these toxins. In this study we examined the effect of 13-desmethyl spirolide-C (SPX) on amyloid-beta (Aβ) accumulation and tau hyperphosphorylation in a neuronal model from triple transgenic mice (3xTg) for Alzheimer disease (AD). In vitro treatment of 3xTg cortical neurons with SPX reduced intracellular Aβ accumulation and the levels of phosphorylated tau. SPX treatment did not affect the steady-state levels of neither the M1 and M2 muscarinic nor the α7 nicotinic acetylcholine receptors (AChRs), while it decreased the amplitude of acetylcholine-evoked responses and increased ACh (acetylcholine) levels in 3xTg neurons. Additionally, SPX treatment decreased the levels of two protein kinases involved in tau phosphorylation, glycogen synthase kinase 3β (GSK-3β) and extracellular-regulated kinase (ERK). Also SPX abolished the glutamate-induced neurotoxicity in both control and 3xTg neurons. The results presented here constitute the first report indicating that exposure of 3xTg neurons to nontoxic concentrations of SPX produces a simultaneous reduction in the main pathological characteristics of AD. In spite of the few reports analyzing the mode of action of the toxin we suggest that SPX could ameliorate AD pathology increasing the intracellular ACh levels and simultaneously diminishing the levels of kinases involved in tau phosphorylation.
Collapse
Affiliation(s)
- Eva Alonso
- Departamento de Farmacología, Facultad de Veterinaria, Universidad de Santiago de Compostela, 27003 Lugo, Spain
| | | | | | | | | | | |
Collapse
|
176
|
Serotonin signaling is associated with lower amyloid-β levels and plaques in transgenic mice and humans. Proc Natl Acad Sci U S A 2011; 108:14968-73. [PMID: 21873225 DOI: 10.1073/pnas.1107411108] [Citation(s) in RCA: 245] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Aggregation of amyloid-β (Aβ) as toxic oligomers and amyloid plaques within the brain appears to be the pathogenic event that initiates Alzheimer's disease (AD) lesions. One therapeutic strategy has been to reduce Aβ levels to limit its accumulation. Activation of certain neurotransmitter receptors can regulate Aβ metabolism. We assessed the ability of serotonin signaling to alter brain Aβ levels and plaques in a mouse model of AD and in humans. In mice, brain interstitial fluid (ISF) Aβ levels were decreased by 25% following administration of several selective serotonin reuptake inhibitor (SSRI) antidepressant drugs. Similarly, direct infusion of serotonin into the hippocampus reduced ISF Aβ levels. Serotonin-dependent reductions in Aβ were reversed if mice were pretreated with inhibitors of the extracellular regulated kinase (ERK) signaling cascade. Chronic treatment with an SSRI, citalopram, caused a 50% reduction in brain plaque load in mice. To test whether serotonin signaling could impact Aβ plaques in humans, we retrospectively compared brain amyloid load in cognitively normal elderly participants who were exposed to antidepressant drugs within the past 5 y to participants who were not. Antidepressant-treated participants had significantly less amyloid load as quantified by positron emission tomography (PET) imaging with Pittsburgh Compound B (PIB). Cumulative time of antidepressant use within the 5-y period preceding the scan correlated with less plaque load. These data suggest that serotonin signaling was associated with less Aβ accumulation in cognitively normal individuals.
Collapse
|
177
|
Uwada J, Anisuzzaman ASM, Nishimune A, Yoshiki H, Muramatsu I. Intracellular distribution of functional M(1) -muscarinic acetylcholine receptors in N1E-115 neuroblastoma cells. J Neurochem 2011; 118:958-67. [PMID: 21740440 DOI: 10.1111/j.1471-4159.2011.07378.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Signaling by muscarinic agonists is thought to result from the activation of cell surface acetylcholine receptors (mAChRs) that transmit extracellular signals to intracellular systems. In N1E-115 neuroblastoma cells, we detected both plasma membrane and intracellular M(1) -mAChRs using both biochemical and pharmacological methods. In intact cells, both plasma membrane and intracellular M(1) -mAChRs were detected by the hydrophobic ligand probe, 1-quinuclidinyl-[phenyl-4-(3) H]-benzilate ([(3) H]-QNB) whereas the hydrophilic probe, 1-[N-methyl-(3) H] scopolamine ([(3) H]-NMS), detected only cell surface receptors. These probes detected comparable numbers of receptors in isolated membrane preparations. Immunohistochemical studies with M(1) -mAChR antibody also detected both cell-surface and intracellular M(1) -mAChRs. Carbachol-stimulated phosphatidylinositol hydrolysis and Ca(2+) mobilization were completely inhibited by a cell-impermeable M(1) antagonist, muscarinic toxin -7 and the G(q/11) inhibitor YM-254890. However, carbachol-stimulated extracellular-regulated kinase 1/2 activation was unaffected by muscarinic toxin-7, but was blocked by the cell-permeable antagonist, pirenzepine. extracellular regulated kinase 1/2 phosphorylation was resistant to blockade of G(q/11) (YM-254890) and protein kinase C (bisindolylmaleimide I). Our data suggest that the geographically distinct M(1) -mAChRs (cell surface versus intracellular) can signal via unique signaling pathways that are differentially sensitive to cell-impermeable versus cell-permeable antagonists. Our data are of potential physiological relevance to signaling that affects both cognitive and neurodegenerative processes.
Collapse
Affiliation(s)
- Junsuke Uwada
- Division of Pharmacology, Department of Biochemistry and Bioinformative Sciences, and Organization for Life Science Advancement Programs, School of Medicine, University of Fukui, Eiheiji, Fukui, Japan
| | | | | | | | | |
Collapse
|
178
|
Medeiros R, Kitazawa M, Caccamo A, Baglietto-Vargas D, Estrada-Hernandez T, Cribbs DH, Fisher A, LaFerla FM. Loss of muscarinic M1 receptor exacerbates Alzheimer's disease-like pathology and cognitive decline. THE AMERICAN JOURNAL OF PATHOLOGY 2011; 179:980-91. [PMID: 21704011 PMCID: PMC3157199 DOI: 10.1016/j.ajpath.2011.04.041] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2011] [Revised: 03/29/2011] [Accepted: 04/22/2011] [Indexed: 02/03/2023]
Abstract
Alzheimer's disease (AD) is pathologically characterized by tau-laden neurofibrillary tangles and β-amyloid deposits. Dysregulation of cholinergic neurotransmission has been implicated in AD pathogenesis, contributing to the associated memory impairments; yet, the exact mechanisms remain to be defined. Activating the muscarinic acetylcholine M(1) receptors (M(1)Rs) reduces AD-like pathological features and enhances cognition in AD transgenic models. To elucidate the molecular mechanisms by which M(1)Rs affect AD pathophysiological features, we crossed the 3xTgAD and transgenic mice expressing human Swedish, Dutch, and Iowa triple-mutant amyloid precursor protein (Tg-SwDI), two widely used animal models, with the M(1)R(-/-) mice. Our data show that M(1)R deletion in the 3xTgAD and Tg-SwDI mice exacerbates the cognitive impairment through mechanisms dependent on the transcriptional dysregulation of genes required for memory and through acceleration of AD-related synaptotoxicity. Ablating the M(1)R increased plaque and tangle levels in the brains of 3xTgAD mice and elevated cerebrovascular deposition of fibrillar Aβ in Tg-SwDI mice. Notably, tau hyperphosphorylation and potentiation of amyloidogenic processing in the mice with AD lacking M(1)R were attributed to changes in the glycogen synthase kinase 3β and protein kinase C activities. Finally, deleting the M(1)R increased the astrocytic and microglial response associated with Aβ plaques. Our data highlight the significant role that disrupting the M(1)R plays in exacerbating AD-related cognitive decline and pathological features and provide critical preclinical evidence to justify further development and evaluation of selective M(1)R agonists for treating AD.
Collapse
Affiliation(s)
- Rodrigo Medeiros
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, California
- Department of Neurobiology and Behavior, University of California, Irvine, California
| | - Masashi Kitazawa
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, California
- Department of Neurobiology and Behavior, University of California, Irvine, California
| | - Antonella Caccamo
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, California
- Department of Neurobiology and Behavior, University of California, Irvine, California
| | - David Baglietto-Vargas
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, California
- Department of Neurobiology and Behavior, University of California, Irvine, California
| | - Tatiana Estrada-Hernandez
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, California
- Department of Neurobiology and Behavior, University of California, Irvine, California
| | - David H. Cribbs
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, California
- Department of Neurology, University of California, Irvine, California
| | - Avraham Fisher
- Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Frank M. LaFerla
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, California
- Department of Neurobiology and Behavior, University of California, Irvine, California
| |
Collapse
|
179
|
Affiliation(s)
- Jesús Avila
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Nicolás Cabrera 1, Universidad Autónoma de Madrid, Campus, Cantoblanco, 28049 Madrid, Spain and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Valderrebollo 5, 28031 Madrid, Spain
| |
Collapse
|
180
|
Cole SL, Vassar R. The Basic Biology of BACE1: A Key Therapeutic Target for Alzheimer's Disease. Curr Genomics 2011; 8:509-30. [PMID: 19415126 PMCID: PMC2647160 DOI: 10.2174/138920207783769512] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2007] [Revised: 12/27/2007] [Accepted: 12/27/2007] [Indexed: 11/22/2022] Open
Abstract
Alzheimer’s disease (AD) is an intractable, neurodegenerative disease that appears to be brought about by both genetic and non-genetic factors. The neuropathology associated with AD is complex, although amyloid plaques composed of the β-amyloid peptide (Aβ) are hallmark neuropathological lesions of AD brain. Indeed, Aβ plays an early and central role in this disease. β-site amyloid precursor protein (APP) cleaving enzyme 1 (BACE1) is the initiating enzyme in Aβ genesis and BACE1 levels are elevated under a variety of conditions. Given the strong correlation between Aβ and AD, and the elevation of BACE1 in this disease, this enzyme is a prime drug target for inhibiting Aβ production in AD. However, nine years on from the initial identification of BACE1, and despite intense research, a number of key questions regarding BACE1 remain unanswered. Indeed, drug discovery and development for AD continues to be challenging. While current AD therapies temporarily slow cognitive decline, treatments that address the underlying pathologic mechanisms of AD are completely lacking. Here we review the basic biology of BACE1. We pay special attention to recent research that has provided some answers to questions such as those involving the identification of novel BACE1 substrates, the potential causes of BACE1 elevation and the putative function of BACE1 in health and disease. Our increasing understanding of BACE1 biology should aid the development of compounds that interfere with BACE1 expression and activity and may lead to the generation of novel therapeutics for AD.
Collapse
Affiliation(s)
- S L Cole
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, 303 E. Chicago Avenue, Chicago, IL 60611, USA
| | | |
Collapse
|
181
|
Wang D, Yang L, Su J, Niu Y, Lei X, Xiong J, Cao X, Hu Y, Mei B, Hu JF. Attenuation of neurodegenerative phenotypes in Alzheimer-like presenilin 1/presenilin 2 conditional double knockout mice by EUK1001, a promising derivative of xanomeline. Biochem Biophys Res Commun 2011; 410:229-34. [DOI: 10.1016/j.bbrc.2011.05.120] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Accepted: 05/21/2011] [Indexed: 12/22/2022]
|
182
|
Cisse M, Braun U, Leitges M, Fisher A, Pages G, Checler F, Vincent B. ERK1-independent α-secretase cut of β-amyloid precursor protein via M1 muscarinic receptors and PKCα/ε. Mol Cell Neurosci 2011; 47:223-32. [PMID: 21570469 DOI: 10.1016/j.mcn.2011.04.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2011] [Revised: 03/17/2011] [Accepted: 04/26/2011] [Indexed: 10/18/2022] Open
|
183
|
Alonso E, Vale C, Vieytes MR, Laferla FM, Giménez-Llort L, Botana LM. The cholinergic antagonist gymnodimine improves Aβ and tau neuropathology in an in vitro model of Alzheimer disease. Cell Physiol Biochem 2011; 27:783-94. [PMID: 21691095 DOI: 10.1159/000330086] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/29/2011] [Indexed: 12/13/2022] Open
Abstract
Gymnodimine (GYM) is a marine phycotoxin with a macrocyclic imine structure, isolated from extracts of the dinoflagellate Karenia selliformis known to act as a cholinergic antagonist with subtype selectivity. However, no data on the chronic effects of this compound has been reported so far. In this work, we evaluated the effect of long term exposure of cortical neurons to gymnodimine in the progress of Alzheimer disease (AD) pathology in vitro. Treatment of cortical neurons with 50 nM gymnodimine decreased the intracellular amyloid beta (Aβ) accumulation and the levels of the hyperphosphorylated isoforms of tau protein recognized by AT8 and AT100 antibodies. These results are suggested to be mediated by the increase in the inactive isoform of the glycogen synthase kinase-3 (phospho GSK-3 Ser9), the decrease in the levels of the active isoform of the ERK1/2 kinase and the increase in acetylcholine (Ach) synthesis elicited by long term exposure of cortical neurons to the toxin. Moreover, gymnodimine decreased glutamate-induced neurotoxicity in vitro. Altogether these results indicate that the marine phycotoxin gymnodimine may constitute a valuable tool for the development of drugs to treat neurodegenerative diseases.
Collapse
Affiliation(s)
- Eva Alonso
- Departamento de Farmacología, Facultad de Veterinaria, Universidad de Santiago de Compostela, 27003 Lugo, Spain
| | | | | | | | | | | |
Collapse
|
184
|
Abstract
Alzheimer's disease is associated with synapse loss, memory dysfunction, and pathological accumulation of amyloid-β (Aβ) in plaques. However, an exclusively pathological role for Aβ is being challenged by new evidence for an essential function of Aβ at the synapse. Aβ protein exists in different assembly states in the central nervous system and plays distinct roles ranging from synapse and memory formation to memory loss and neuronal cell death. Aβ is present in the brain of symptom-free people where it likely performs important physiological roles. New evidence indicates that synaptic activity directly evokes the release of Aβ at the synapse. At physiological levels, Aβ is a normal, soluble product of neuronal metabolism that regulates synaptic function beginning early in life. Monomeric Aβ40 and Aβ42 are the predominant forms required for synaptic plasticity and neuronal survival. With age, some assemblies of Aβ are associated with synaptic failure and Alzheimer's disease pathology, possibly targeting the N-methyl-D-aspartic acid receptor through the nicotinic acetylcholine receptor, mitochondrial Aβ alcohol dehydrogenase, and cyclophilin D. But emerging data suggests a distinction between age effects on the target response in contrast to the assembly state or the accumulation of the peptide. Both aging and Aβ independently decrease neuronal plasticity. Our laboratory has reported that Aβ, glutamate, and lactic acid are each increasingly toxic with neuron age. The basis of the age-related toxicity partly resides in age-related mitochondrial dysfunction and an oxidative shift in mitochondrial and cytoplasmic redox potential. In turn, signaling through phosphorylated extracellular signal-regulated protein kinases is affected along with an age-independent increase in phosphorylated cAMP response element-binding protein. This review examines the long-awaited functional impact of Aβ on synaptic plasticity.
Collapse
Affiliation(s)
- Mordhwaj S Parihar
- School of Studies in Biotechnology & Zoology, Vikram University, Ujjain, MP, India
| | | |
Collapse
|
185
|
Rat D, Schmitt U, Tippmann F, Dewachter I, Theunis C, Wieczerzak E, Postina R, van Leuven F, Fahrenholz F, Kojro E. Neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP) slows down Alzheimer's disease-like pathology in amyloid precursor protein-transgenic mice. FASEB J 2011; 25:3208-18. [PMID: 21593432 PMCID: PMC3157688 DOI: 10.1096/fj.10-180133] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP) has neuroprotective and neurotrophic properties and is a potent α-secretase activator. As PACAP peptides and their specific receptor PAC1 are localized in central nervous system areas affected by Alzheimer's disease (AD), this study aims to examine the role of the natural peptide PACAP as a valuable approach in AD therapy. We investigated the effect of PACAP in the brain of an AD transgenic mouse model. The long-term intranasal daily PACAP application stimulated the nonamyloidogenic processing of amyloid precursor protein (APP) and increased expression of the brain-derived neurotrophic factor and of the antiapoptotic Bcl-2 protein. In addition, it caused a strong reduction of the amyloid β-peptide (Aβ) transporter receptor for advanced glycation end products (RAGE) mRNA level. PACAP, by activation of the somatostatin-neprilysin cascade, also enhanced expression of the Aβ-degrading enzyme neprilysin in the mouse brain. Furthermore, daily PAC1-receptor activation via PACAP resulted in an increased mRNA level of both the PAC1 receptor and its ligand PACAP. Our behavioral studies showed that long-term PACAP treatment of APP[V717I]-transgenic mice improved cognitive function in animals. Thus, nasal application of PACAP was effective, and our results indicate that PACAP could be of therapeutic value in treating AD.—Rat, D., Schmitt, U., Tippmann, F., Dewachter, I., Theunis, C., Wieczerzak, E, Postina, R., van Leuven, F., Fahrenholz, F., Kojro, E. Neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP) slows down Alzheimer's disease-like pathology in amyloid precursor protein-transgenic mice.
Collapse
Affiliation(s)
- Dorothea Rat
- Institute of Pharmacy and Biochemistry, Johannes Gutenberg University, Mainz, Germany.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
186
|
Bordji K, Becerril-Ortega J, Buisson A. Synapses, NMDA receptor activity and neuronal Aβ production in Alzheimer's disease. Rev Neurosci 2011; 22:285-94. [PMID: 21568789 DOI: 10.1515/rns.2011.029] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
A direct relationship has been established between synaptic activity and amyloid-β secretion. Dysregulation of neuronal calcium homeostasis was shown to increase production of amyloid-β, contributing to the initiation of Alzheimer's disease. Among the different routes of Ca(2+) entry, N-methyl-d-aspartate (NMDA) receptors, a subtype of ionotropic glutamate receptors, are especially involved in this process because of their ability to gate high levels of Ca(2+) influx. These receptors have been extensively studied for their crucial roles in synaptic plasticity that underlies learning and memory but also in neurotoxicity occurring during acute brain injuries and neurodegenerative diseases. For one decade, several studies provided evidence that NMDA receptor activation could have distinct consequences on neuronal fate, depending on their location. Synaptic NMDA receptor activation is neuroprotective, whereas extrasynaptic NMDA receptors trigger neuronal death and/or neurodegenerative processes. Recent data suggest that chronic activation of extrasynaptic NMDA receptors leads to a sustained neuronal amyloid-β release and could be involved in the pathogenesis of Alzheimer's disease. Thus, as for other neurological diseases, therapeutic targeting of extrasynaptic NMDA receptors could be a promising strategy. Following this concept, memantine, unlike other NMDA receptor antagonists was shown, to preferentially target the extrasynaptic NMDA receptor signaling pathways, while relatively sparing normal synaptic activity. This molecular mechanism could therefore explain why memantine is, to date, the only clinically approved NMDA receptor antagonist for the treatment of dementia.
Collapse
Affiliation(s)
- Karim Bordji
- Groupement d'Intérêt Public Cyceron, Centre National de la Recherche Scientifique, UMR 6232-Centre d'Imagerie Neurosciences et d'Applications aux Pathologies, Bd Becquerel, F-14074 Caen, France.
| | | | | |
Collapse
|
187
|
Shin J. Towards development of drugs targeting both amyloid and tau pathologies of Alzheimer's disease. Int J Geriatr Psychiatry 2011; 26:546-8. [PMID: 21446001 DOI: 10.1002/gps.2543] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
188
|
Obulesu M, Venu R, Somashekhar R. Tau mediated neurodegeneration: an insight into Alzheimer's disease pathology. Neurochem Res 2011; 36:1329-35. [PMID: 21509508 DOI: 10.1007/s11064-011-0475-5] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/07/2011] [Indexed: 12/13/2022]
Abstract
Extracellular accumulations of Aβ, hyperphosphorylation of tau and intracellular neurofibrillary tangle formation have been the hallmarks of Alzheimer's Disease (AD). Although tau and its phosphorylation play a pivotal role in the normal physiology yet its hyperphosphorylation has been a pathological manifestation in neurodegenerative disorders like AD. In this review physiology of tau, its phosphorylation, hyperphosphorylation with the intervention of various kinases, aggregation and formation of paired helical filaments has been discussed. A brief account of various animal models employed to study the pathological manifestation of tau in AD and therapeutic strategies streamlined to counter the tau induced pathology has been given. The reasons for the failure to have suitable animal model to study AD pathology and recent success in achieving this has been included. The role of caspase cascade in tau cleavage has been emphasized. The summary of current studies on tau and the need for future studies has been accentuated.
Collapse
Affiliation(s)
- M Obulesu
- Department of Biotechnology, Rayalaseema University, Kurnool, India.
| | | | | |
Collapse
|
189
|
Green KN, Khashwji H, Estrada T, Laferla FM. ST101 induces a novel 17 kDa APP cleavage that precludes Aβ generation in vivo. Ann Neurol 2011; 69:831-44. [PMID: 21416488 DOI: 10.1002/ana.22325] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2010] [Revised: 10/25/2010] [Accepted: 11/02/2010] [Indexed: 11/07/2022]
Abstract
OBJECTIVE Inhibiting Aβ generation is a prime therapeutic goal for preventing or treating Alzheimer disease. Here we sought to identify any disease-modifying properties of an azaindolizinone derivative, spiro[imidazo[1,2-a]pyridine-3,2-idan]-2(3H)-one (ST101 or ZSET1446). METHODS The effects of ST101 were studied in 3xTg-AD mice and young cynomolgus monkeys using a combination of biochemical and histological analyses. RESULTS Here we describe that ST101 induces cleavage of APP protein at a novel site, generating a 17 kDa C-terminal fragment. This 17 kDa APP cleavage product does not appear to be a substrate for either α- or β-secretase, and thus bypasses generation of Aβ. ST101 is orally active, efficacious at low doses, improves memory function, and robustly reduces brain Aβ in transgenic mice and nonhuman primates. INTERPRETATION Using rodent and nonhuman primate models, we show that ST101 represents a novel class of small molecules that reduce central nervous system levels of Aβ by inducing an alternate pathway of APP cleavage.
Collapse
Affiliation(s)
- Kim N Green
- From the Department of Neurobiology and Behavior Institute for Memory Impairments and Neurological Disorders, University of California at Irvine, Irvine, CA 92697-4545, USA.
| | | | | | | |
Collapse
|
190
|
Fiedler MJ, Nathanson MH. The type I inositol 1,4,5-trisphosphate receptor interacts with protein 4.1N to mediate neurite formation through intracellular Ca waves. Neurosignals 2011; 19:75-85. [PMID: 21389686 PMCID: PMC3124450 DOI: 10.1159/000324507] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2010] [Accepted: 01/25/2011] [Indexed: 01/07/2023] Open
Abstract
Ca2+ waves are an important mechanism for encoding Ca2+ signaling information, but the molecular basis for wave formation and how this regulates neuronal function is not entirely understood. Using nerve growth factor-differentiated PC12 cells as a model system, we investigated the interaction between the type I inositol 1,4,5-trisphosphate receptor (IP3R1) and the cytoskeletal linker, protein 4.1N, to examine the relationship between Ca2+ wave formation and neurite development. This was examined using RNAi and overexpressed dominant negative binding regions of each protein. Confocal microscopy was used to monitor neurite formation and Ca2+ waves. Knockdown of IP3R1 or 4.1N attenuated neurite formation, as did binding regions of IP3R1 and 4.1N, which colocalized with endogenous 4.1N and IP3R1, respectively. Upon stimulation with the IP3-producing agonist carbachol, both RNAi and dominant negative molecules shifted signaling events from waves to homogeneous patterns of Ca2+ release. These findings provide evidence that IP3R1 localization, via protein 4.1N, is necessary for Ca2+ wave formation, which in turn mediates neurite formation.
Collapse
Affiliation(s)
- Michael J Fiedler
- Cell Biology Department, Yale University, New Haven, CT 06520-8019, USA
| | | |
Collapse
|
191
|
Morais K, Hayashi M, Bruni F, Lopes-Ferreira M, Camargo A, Ulrich H, Lameu C. Bj-PRO-5a, a natural angiotensin-converting enzyme inhibitor, promotes vasodilatation mediated by both bradykinin B2 and M1 muscarinic acetylcholine receptors. Biochem Pharmacol 2011; 81:736-42. [DOI: 10.1016/j.bcp.2010.12.016] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2010] [Revised: 11/12/2010] [Accepted: 12/16/2010] [Indexed: 11/24/2022]
|
192
|
Bartko SJ, Vendrell I, Saksida LM, Bussey TJ. A computer-automated touchscreen paired-associates learning (PAL) task for mice: impairments following administration of scopolamine or dicyclomine and improvements following donepezil. Psychopharmacology (Berl) 2011; 214:537-48. [PMID: 21086119 DOI: 10.1007/s00213-010-2050-1] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2010] [Accepted: 10/13/2010] [Indexed: 10/18/2022]
Abstract
RATIONALE Performance on the Cambridge Neuropsychological Test Automated Battery touchscreen paired-associates learning (PAL) test is predictive of Alzheimer's disease and impaired in schizophrenia and chronic drug users. An automated computer touchscreen PAL task for rats has been previously established. A pharmacologically validated PAL task for mice would be a highly valuable tool, which could be useful for a number of experimental aims including drug discovery. OBJECTIVES This study sought to investigate the effects of systemic administration of cholinergic agents on task performance in C57Bl/6 mice. METHODS Scopolamine hydrobromide (0.02, 0.2, and 2.0 mg/kg), dicyclomine hydrochloride (M(1) receptor antagonist; 2.0, 4.0, and 8.0 mg/kg), and donepezil hydrochloride (cholinesterase inhibitor; 0.03, 0.1, and 0.3 mg/kg) were administered post-acquisition in C57Bl/6 mice performing the PAL task. RESULTS Scopolamine (0.2 and 2.0 mg/kg) and dicyclomine (at all administered doses) significantly impaired PAL performance. A significant facilitation in PAL was revealed in mice following donepezil administration (0.3 mg/kg). CONCLUSIONS The present study shows that mice can acquire the rodent PAL task and that the cholinergic system is important for PAL task performance. M(1) receptors in particular are likely implicated in normal performance of PAL. The finding that mouse PAL can detect both impairments and improvements indicates that this task could prove to be a highly valuable tool for a number of experimental aims including drug discovery.
Collapse
Affiliation(s)
- Susan J Bartko
- Department of Experimental Psychology, University of Cambridge, Downing St., Cambridge, CB2 3EB, UK.
| | | | | | | |
Collapse
|
193
|
Scarr E. Muscarinic receptors: their roles in disorders of the central nervous system and potential as therapeutic targets. CNS Neurosci Ther 2011; 18:369-79. [PMID: 22070219 DOI: 10.1111/j.1755-5949.2011.00249.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Phylogenetically, acetylcholine is an ancient neurochemical. Therefore, it is not surprising that cholinergic neurons project extensively throughout the central nervous system, innervating a wide range of structures within the brain. In fact, acetylcholine is involved in processes that underpin some of our most basic central functions. Both muscarinic and nicotinic receptor families, which mediate cholinergic transmission, have been implicated in the pathophysiology of psychiatric and neurological disorders. The question that remains to be definitively answered is whether or not these receptors are viable targets for the development of future therapeutic agents.
Collapse
Affiliation(s)
- Elizabeth Scarr
- Department of Psychiatry, University of Melbourne, Victoria, Australia.
| |
Collapse
|
194
|
Terry AV, Callahan PM, Hall B, Webster SJ. Alzheimer's disease and age-related memory decline (preclinical). Pharmacol Biochem Behav 2011; 99:190-210. [PMID: 21315756 DOI: 10.1016/j.pbb.2011.02.002] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2010] [Revised: 01/21/2011] [Accepted: 02/01/2011] [Indexed: 01/05/2023]
Abstract
An unfortunate result of the rapid rise in geriatric populations worldwide is the increasing prevalence of age-related cognitive disorders such as Alzheimer's disease (AD). AD is a devastating neurodegenerative illness that is characterized by a profound impairment of cognitive function, marked physical disability, and an enormous economic burden on the afflicted individual, caregivers, and society in general. The rise in elderly populations is also resulting in an increase in individuals with related (potentially treatable) conditions such as "Mild Cognitive Impairment" (MCI) which is characterized by a less severe (but abnormal) level of cognitive impairment and a high-risk for developing dementia. Even in the absence of a diagnosable disorder of cognition (e.g., AD and MCI), the perception of increased forgetfulness and declining mental function is a clear source of apprehension in the elderly. This is a valid concern given that even a modest impairment of cognitive function is likely to be associated with significant disability in a rapidly evolving, technology-based society. Unfortunately, the currently available therapies designed to improve cognition (i.e., for AD and other forms of dementia) are limited by modest efficacy and adverse side effects, and their effects on cognitive function are not sustained over time. Accordingly, it is incumbent on the scientific community to develop safer and more effective therapies that improve and/or sustain cognitive function in the elderly allowing them to remain mentally active and productive for as long as possible. As diagnostic criteria for memory disorders evolve, the demand for pro-cognitive therapeutic agents is likely to surpass AD and dementia to include MCI and potentially even less severe forms of memory decline. The purpose of this review is to provide an overview of the contemporary therapeutic targets and preclinical pharmacologic approaches (with representative drug examples) designed to enhance memory function.
Collapse
Affiliation(s)
- Alvin V Terry
- Department of Pharmacology and Toxicology and Small Animal Behavior Core, Medical College of Georgia, Augusta, GA 30912, USA.
| | | | | | | |
Collapse
|
195
|
Thathiah A, De Strooper B. The role of G protein-coupled receptors in the pathology of Alzheimer's disease. Nat Rev Neurosci 2011; 12:73-87. [DOI: 10.1038/nrn2977] [Citation(s) in RCA: 212] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|
196
|
Sy M, Kitazawa M, LaFerla F. The 3xTg-AD Mouse Model: Reproducing and Modulating Plaque and Tangle Pathology. NEUROMETHODS 2011. [DOI: 10.1007/978-1-60761-898-0_24] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
|
197
|
Lichtenthaler SF. ADAM10: potential ‘molecular scissors’ for the treatment of Alzheimer’s disease. FUTURE NEUROLOGY 2011. [DOI: 10.2217/fnl.10.75] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- Stefan F Lichtenthaler
- DZNE – German Center for Neurodegenerative Diseases, 80336 Munich, Germany and Adolf-Butenandt-Institute, Biochemistry, Ludwig Maximilians University, 80336 Munich, Germany
| |
Collapse
|
198
|
Piau A, Nourhashémi F, Hein C, Caillaud C, Vellas B. Progress in the development of new drugs in Alzheimer's disease. J Nutr Health Aging 2011; 15:45-57. [PMID: 21267520 DOI: 10.1007/s12603-011-0012-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Alzheimer's disease (AD) is an age-related neurodegenerative disease with a global prevalence estimated at 26.55 million in 2006. During the past decades, several agents have been approved that enhance cognition of AD patients. However, the effectiveness of these treatments are limited or controversial and they do not modify disease progression. Recent advances in understanding AD pathogenesis have led to the development of numerous compounds that might modify the disease process. AD is mainly characterized neuropathologically by the presence of two kinds of protein aggregates: extracellular plaques of Abeta-peptide and intracellular neurofibrillary tangles. Abeta and tau could interfere in an original way contributing to a cascade of events leading to neuronal death and transmitter deficits. Investigation for novel therapeutic approaches targeting the presumed underlying pathogenic mechanisms is major focus of research. Antiamyloid agents targeting production, accumulation, clearance, or toxicity associated with Abeta peptide, are some approaches under investigation to limit extracellular plaques of Abeta-peptide accumulation. We can state as an example: Abeta passive and active immunization, secretases modulation, Abeta degradation enhancement, or antiaggregation and antifibrillization agents. Tau-related therapies are also under clinical investigation but few compounds are available. Another alternative approach under development is neuroprotective agents such as antioxidants, anti-inflammatory drugs, compounds acting against glutamate mediated neurotoxicity. Neurorestorative approaches through neurotrophin or cell therapy also represent a minor avenue in AD research. Finally, statins, receptor for advanced glycation end products inhibitors, thiazolidinediones, insulin, and hormonal therapies are some other ways of research for a therapeutic approach of Alzheimer's disease. Taking into account AD complexity, it becomes clear that polypharmacology with drugs targeting different sites could be the future treatment approach and a majority of the recent drugs under evaluation seems to act on multiple targets. This article exposes general classes of disease-modifying therapies under investigation.
Collapse
|
199
|
Enhanced striatal cholinergic neuronal activity mediates L-DOPA-induced dyskinesia in parkinsonian mice. Proc Natl Acad Sci U S A 2010; 108:840-5. [PMID: 21187382 DOI: 10.1073/pnas.1006511108] [Citation(s) in RCA: 143] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Treatment of Parkinson disease (PD) with L-3,4-dihydroxyphenylalanine (L-DOPA) dramatically relieves associated motor deficits, but L-DOPA-induced dyskinesias (LID) limit the therapeutic benefit over time. Previous investigations have noted changes in striatal medium spiny neurons, including abnormal activation of extracellular signal-regulated kinase1/2 (ERK). Using two PD models, the traditional 6-hydroxydopamine toxic lesion and a genetic model with nigrostriatal dopaminergic deficits, we found that acute dopamine challenge induces ERK activation in medium spiny neurons in denervated striatum. After repeated L-DOPA treatment, however, ERK activation diminishes in medium spiny neurons and increases in striatal cholinergic interneurons. ERK activation leads to enhanced basal firing rate and stronger excitatory responses to dopamine in striatal cholinergic neurons. Pharmacological blockers of ERK activation inhibit L-DOPA-induced changes in ERK phosphorylation, neuronal excitability, and the behavioral manifestation of LID. In addition, a muscarinic receptor antagonist reduces LID. These data indicate that increased dopamine sensitivity of striatal cholinergic neurons contributes to the expression of LID, which suggests novel therapeutic targets for LID.
Collapse
|
200
|
Buchanan KA, Petrovic MM, Chamberlain SE, Marrion NV, Mellor JR. Facilitation of long-term potentiation by muscarinic M(1) receptors is mediated by inhibition of SK channels. Neuron 2010; 68:948-63. [PMID: 21145007 PMCID: PMC3003154 DOI: 10.1016/j.neuron.2010.11.018] [Citation(s) in RCA: 144] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/01/2010] [Indexed: 12/01/2022]
Abstract
Muscarinic receptor activation facilitates the induction of synaptic plasticity and enhances cognitive function. However, the specific muscarinic receptor subtype involved and the critical intracellular signaling pathways engaged have remained controversial. Here, we show that the recently discovered highly selective allosteric M(1) receptor agonist 77-LH-28-1 facilitates long-term potentiation (LTP) induced by theta burst stimulation at Schaffer collateral synapses in the hippocampus. Similarly, release of acetylcholine by stimulation of cholinergic fibers facilitates LTP via activation of M(1) receptors. N-methyl-D-aspartate receptor (NMDAR) opening during theta burst stimulation was enhanced by M(1) receptor activation, indicating this is the mechanism for LTP facilitation. M(1) receptors were found to enhance NMDAR activation by inhibiting SK channels that otherwise act to hyperpolarize postsynaptic spines and inhibit NMDAR opening. Thus, we describe a mechanism where M(1) receptor activation inhibits SK channels, allowing enhanced NMDAR activity and leading to a facilitation of LTP induction in the hippocampus.
Collapse
Affiliation(s)
- Katherine A. Buchanan
- Medical Research Council Centre for Synaptic Plasticity, School of Physiology and Pharmacology, University of Bristol, University Walk, Bristol BS8 1TD, UK
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, UK
| | - Milos M. Petrovic
- Medical Research Council Centre for Synaptic Plasticity, School of Physiology and Pharmacology, University of Bristol, University Walk, Bristol BS8 1TD, UK
| | - Sophie E.L. Chamberlain
- Medical Research Council Centre for Synaptic Plasticity, School of Physiology and Pharmacology, University of Bristol, University Walk, Bristol BS8 1TD, UK
| | - Neil V. Marrion
- Medical Research Council Centre for Synaptic Plasticity, School of Physiology and Pharmacology, University of Bristol, University Walk, Bristol BS8 1TD, UK
| | - Jack R. Mellor
- Medical Research Council Centre for Synaptic Plasticity, School of Physiology and Pharmacology, University of Bristol, University Walk, Bristol BS8 1TD, UK
| |
Collapse
|