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Greig NH, Sambamurti K, Lahiri DK, Becker RE. Amyloid-β precursor protein synthesis inhibitors for Alzheimer's disease treatment. Ann Neurol 2014; 76:629-30. [PMID: 25146731 DOI: 10.1002/ana.24254] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Revised: 07/01/2014] [Accepted: 08/21/2014] [Indexed: 12/25/2022]
Affiliation(s)
- Nigel H Greig
- Drug Design and Development Section, Translational Gerontology Branch, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, MD
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Chen J, Pan H, Chen C, Wu W, Iskandar K, He J, Piermartiri T, Jacobowitz DM, Yu QS, McDonough JH, Greig NH, Marini AM. (-)-Phenserine attenuates soman-induced neuropathology. PLoS One 2014; 9:e99818. [PMID: 24955574 PMCID: PMC4067273 DOI: 10.1371/journal.pone.0099818] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 05/15/2014] [Indexed: 11/18/2022] Open
Abstract
Organophosphorus (OP) nerve agents are deadly chemical weapons that pose an alarming threat to military and civilian populations. The irreversible inhibition of the critical cholinergic degradative enzyme acetylcholinesterase (AChE) by OP nerve agents leads to cholinergic crisis. Resulting excessive synaptic acetylcholine levels leads to status epilepticus that, in turn, results in brain damage. Current countermeasures are only modestly effective in protecting against OP-induced brain damage, supporting interest for evaluation of new ones. (-)-Phenserine is a reversible AChE inhibitor possessing neuroprotective and amyloid precursor protein lowering actions that reached Phase III clinical trials for Alzheimer's Disease where it exhibited a wide safety margin. This compound preferentially enters the CNS and has potential to impede soman binding to the active site of AChE to, thereby, serve in a protective capacity. Herein, we demonstrate that (-)-phenserine protects neurons against soman-induced neuronal cell death in rats when administered either as a pretreatment or post-treatment paradigm, improves motoric movement in soman-exposed animals and reduces mortality when given as a pretreatment. Gene expression analysis, undertaken to elucidate mechanism, showed that (-)-phenserine pretreatment increased select neuroprotective genes and reversed a Homer1 expression elevation induced by soman exposure. These studies suggest that (-)-phenserine warrants further evaluation as an OP nerve agent protective strategy.
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Affiliation(s)
- Jun Chen
- Neurology Department, Uniformed Services University of Health Sciences, Bethesda, Maryland, United States of America
| | - Hongna Pan
- Neurology Department, Uniformed Services University of Health Sciences, Bethesda, Maryland, United States of America
| | - Cynthia Chen
- Neurology Department, Uniformed Services University of Health Sciences, Bethesda, Maryland, United States of America
| | - Wei Wu
- Neurology Department, Uniformed Services University of Health Sciences, Bethesda, Maryland, United States of America
| | - Kevin Iskandar
- Neurology Department, Uniformed Services University of Health Sciences, Bethesda, Maryland, United States of America
| | - Jeffrey He
- Neurology Department, Uniformed Services University of Health Sciences, Bethesda, Maryland, United States of America
| | - Tetsade Piermartiri
- Neurology Department, Uniformed Services University of Health Sciences, Bethesda, Maryland, United States of America
| | - David M. Jacobowitz
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Qian-Sheng Yu
- Drug Design & Development Section, Translational Gerontology Branch, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, United States of America
| | - John H. McDonough
- Pharmacology Branch, Research Division, US Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, Maryland, United States of America
| | - Nigel H. Greig
- Drug Design & Development Section, Translational Gerontology Branch, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, United States of America
| | - Ann M. Marini
- Neurology Department, Uniformed Services University of Health Sciences, Bethesda, Maryland, United States of America
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Asuni AA, Guridi M, Pankiewicz JE, Sanchez S, Sadowski MJ. Modulation of amyloid precursor protein expression reduces β-amyloid deposition in a mouse model. Ann Neurol 2014; 75:684-99. [PMID: 24687915 DOI: 10.1002/ana.24149] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2013] [Revised: 03/18/2014] [Accepted: 03/22/2014] [Indexed: 12/17/2022]
Abstract
OBJECTIVE Proteolytic cleavage of the amyloid precursor protein (APP) generates β-amyloid (Aβ) peptides. Prolonged accumulation of Aβ in the brain underlies the pathogenesis of Alzheimer disease (AD) and is regarded as a principal target for development of disease-modifying therapeutics. METHODS Using Chinese hamster ovary (CHO) APP751SW cells, we identified and characterized effects of 2-([pyridine-2-ylmethyl]-amino)-phenol (2-PMAP) on APP steady-state level and Aβ production. Outcomes of 2-PMAP treatment on Aβ accumulation and associated memory deficit were studied in APPSW /PS1dE9 AD transgenic model mice. RESULTS In CHO APP751SW cells, 2-PMAP lowered the steady-state APP level and inhibited Aβx-40 and Aβx-42 production in a dose-response manner with a minimum effective concentration ≤ 0.5μM. The inhibitory effect of 2-PMAP on translational efficiency of APP mRNA into protein was directly confirmed using a 35S-methionine/cysteine metabolic labeling technique, whereas APP mRNA level remained unaltered. Administration of 2-PMAP to APPSW /PS1dE9 mice reduced brain levels of full-length APP and its C-terminal fragments and lowered levels of soluble Aβx-40 and Aβx-42 . Four-month chronic treatment of APPSW /PS1dE9 mice revealed no observable toxicity and improved animals' memory performance. 2-PMAP treatment also caused significant reduction in brain Aβ deposition determined by both unbiased quantification of Aβ plaque load and biochemical analysis of formic acid-extracted Aβx-40 and Aβx-42 levels and the level of oligomeric Aβ. INTERPRETATION We demonstrate the potential of modulating APP steady-state expression level as a safe and effective approach for reducing Aβ deposition in AD transgenic model mice.
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Affiliation(s)
- Ayodeji A Asuni
- Department of Neurology, New York University School of Medicine, New York, NY
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Alzheimer's disease therapeutics targeted to the control of amyloid precursor protein translation: maintenance of brain iron homeostasis. Biochem Pharmacol 2014; 88:486-94. [PMID: 24513321 DOI: 10.1016/j.bcp.2014.01.032] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Revised: 01/16/2014] [Accepted: 01/22/2014] [Indexed: 11/20/2022]
Abstract
The neurotoxicity of amyloid beta (Aβ), a major cleavage product of the amyloid precursor protein (APP), is enhanced by iron, as found in the amyloid plaques of Alzheimer's disease (AD) patients. By contrast, the long-known neuroprotective activity of APP is evident after α-secretase cleavage of the precursor to release sAPPα, and depends on the iron export actions of APP itself. The latter underlie its neurotrophic and protective effects in facilitating the homeostatic actions of ferroportin mediated-iron export. Thus APP-dependent iron export may alleviate oxidative stress by minimizing labile iron thus protecting neurons from iron overload during stroke and hemorrhage. Consistent with this, altered phosphorylation of iron-regulatory protein-1 (IRP1) and its signaling processes play a critical role in modulating APP translation via the 5' untranslated region (5'UTR) of its transcript. The APP 5'UTR region encodes a functional iron-responsive element (IRE) RNA stem loop that represents a potential target for modulating APP production. Targeted regulation of APP gene expression via the modulation of 5'UTR sequence function represents a novel approach for the potential treatment of AD since altering APP translation can be used to improve both the protective brain iron balance and provide anti-amyloid efficacy. Approved drugs including paroxetine and desferrioxamine and several novel compounds have been identified that suppress abnormal metal-promoted Aβ accumulation with a subset of these acting via APP 5'UTR-dependent mechanisms to modulate APP translation and cleavage to generate the non-toxic sAPPα.
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Badin AS, Eraifej J, Greenfield S. High-resolution spatio-temporal bioactivity of a novel peptide revealed by optical imaging in rat orbitofrontal cortex in vitro: Possible implications for neurodegenerative diseases. Neuropharmacology 2013; 73:10-8. [DOI: 10.1016/j.neuropharm.2013.05.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 04/12/2013] [Accepted: 05/08/2013] [Indexed: 11/26/2022]
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Greig NH, Reale M, Tata AM. New pharmacological approaches to the cholinergic system: an overview on muscarinic receptor ligands and cholinesterase inhibitors. RECENT PATENTS ON CNS DRUG DISCOVERY 2013; 8:123-41. [PMID: 23597304 PMCID: PMC5831731 DOI: 10.2174/1574889811308020003] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Revised: 04/13/2013] [Accepted: 04/13/2013] [Indexed: 12/27/2022]
Abstract
The cholinergic system is expressed in neuronal and in non-neuronal tissues. Acetylcholine (ACh), synthesized in and out of the nervous system can locally contribute to modulation of various cell functions (e.g. survival, proliferation). Considering that the cholinergic system and its functions are impaired in a number of disorders, the identification of new pharmacological approaches to regulate cholinergic system components appears of great relevance. The present review focuses on recent pharmacological drugs able to modulate the activity of cholinergic receptors and thereby, cholinergic function, with an emphasis on the muscarinic receptor subtype, and additionally covers the cholinesterases, the main enzymes involved in ACh hydrolysis. The presence and function of muscarinic receptor subtypes both in neuronal and non-neuronal cells has been demonstrated using extensive pharmacological data emerging from studies on transgenic mice. The possible involvement of ACh in different pathologies has been proposed in recent years and is becoming an important area of study. Although the lack of selective muscarinic receptor ligands has for a long time limited the definition of therapeutic treatment based on muscarinic receptors as targets, some muscarinic ligands such as cevimeline (patents US4855290; US5571918) or xanomeline (patent, US5980933) have been developed and used in pre-clinical or in clinical studies for the treatment of nervous system diseases (Alzheimer' and Sjogren's diseases). The present review focuses on the potential implications of muscarinic receptors in different pathologies, including tumors. Moreover, the future use of muscarinic ligands in therapeutic protocols in cancer therapy will be discussed, considering that some muscarinic antagonists currently used in the treatment of genitourinary disease (e.g. darifenacin, patent, US5096890; US6106864) have also been demonstrated to arrest tumor progression in nude mice. The involvement of muscarinic receptors in nociception also is over-viewed. In fact, muscarinic agonists such as vedaclidine, CMI-936 and CMI-1145 have been demonstrated to have analgesic effects in animal models comparable or more pronounced to those produced by morphine or opiates. Likewise, the crucial role of cholinesterases (acetylcholinesterase and butirylcholinesterase) in neural transmission is discussed, as large number of drugs inhibiting cholinesterase activity have become of increasing relevance particularly for the treatment of neurodegenerative disorders. Herein we summarize the current knowledge of the cholinesterase inhibitors with particular attention to recent patents for Alzheimer's disease drugs.
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Affiliation(s)
- Nigel H. Greig
- Drug Design and Development Section, Translational Gerontology Branch, Intramural Research Program, National Institute on Aging, Baltimore, MD, USA
| | - Marcella Reale
- Department of Experimental and Clinical Sciences, University G. D'Annunzio, Chieti, Italy
| | - Ada Maria Tata
- Dept. of Biology and Biotechnologies Charles Darwin, Sapienza Università di Roma, Research Center of Neurobiology Daniel Bovet, Roma, Italy
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Bandyopadhyay S, Cahill C, Balleidier A, Huang C, Lahiri DK, Huang X, Rogers JT. Novel 5' untranslated region directed blockers of iron-regulatory protein-1 dependent amyloid precursor protein translation: implications for down syndrome and Alzheimer's disease. PLoS One 2013; 8:e65978. [PMID: 23935819 PMCID: PMC3729844 DOI: 10.1371/journal.pone.0065978] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2013] [Accepted: 04/30/2013] [Indexed: 11/19/2022] Open
Abstract
We reported that iron influx drives the translational expression of the neuronal amyloid precursor protein (APP), which has a role in iron efflux. This is via a classic release of repressor interaction of APP mRNA with iron-regulatory protein-1 (IRP1) whereas IRP2 controls the mRNAs encoding the L- and H-subunits of the iron storage protein, ferritin. Here, we identified thirteen potent APP translation blockers that acted selectively towards the uniquely configured iron-responsive element (IRE) RNA stem loop in the 5' untranslated region (UTR) of APP mRNA. These agents were 10-fold less inhibitory of 5'UTR sequences of the related prion protein (PrP) mRNA. Western blotting confirmed that the 'ninth' small molecule in the series selectively reduced neural APP production in SH-SY5Y cells at picomolar concentrations without affecting viability or the expression of α-synuclein and ferritin. APP blocker-9 (JTR-009), a benzimidazole, reduced the production of toxic Aβ in SH-SY5Y neuronal cells to a greater extent than other well tolerated APP 5'UTR-directed translation blockers, including posiphen, that were shown to limit amyloid burden in mouse models of Alzheimer's disease (AD). RNA binding assays demonstrated that JTR-009 operated by preventing IRP1 from binding to the IRE in APP mRNA, while maintaining IRP1 interaction with the H-ferritin IRE RNA stem loop. Thus, JTR-009 constitutively repressed translation driven by APP 5'UTR sequences. Calcein staining showed that JTR-009 did not indirectly change iron uptake in neuronal cells suggesting a direct interaction with the APP 5'UTR. These studies provide key data to develop small molecules that selectively reduce neural APP and Aβ production at 10-fold lower concentrations than related previously characterized translation blockers. Our data evidenced a novel therapeutic strategy of potential impact for people with trisomy of the APP gene on chromosome 21, which is a phenotype long associated with Down syndrome (DS) that can also cause familial Alzheimer's disease.
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Affiliation(s)
- Sanghamitra Bandyopadhyay
- Neurochemistry Laboratory, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, United States of America
| | - Catherine Cahill
- Neurochemistry Laboratory, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, United States of America
- Department of Pediatrics, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, United States of America
| | - Amelie Balleidier
- Neurochemistry Laboratory, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, United States of America
| | - Conan Huang
- Neurochemistry Laboratory, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, United States of America
| | - Debomoy K. Lahiri
- Laboratory of Molecular Neurogenetics, Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Xudong Huang
- Neurochemistry Laboratory, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, United States of America
| | - Jack T. Rogers
- Neurochemistry Laboratory, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, United States of America
- * E-mail:
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Age-dependent neuroplasticity mechanisms in Alzheimer Tg2576 mice following modulation of brain amyloid-β levels. PLoS One 2013; 8:e58752. [PMID: 23554921 PMCID: PMC3598857 DOI: 10.1371/journal.pone.0058752] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Accepted: 02/05/2013] [Indexed: 11/19/2022] Open
Abstract
The objective of this study was to investigate the effects of modulating brain amyloid-β (Aβ) levels at different stages of amyloid pathology on synaptic function, inflammatory cell changes and hippocampal neurogenesis, i.e. processes perturbed in Alzheimer's disease (AD). Young (4- to 6-month-old) and older (15- to 18-month-old) APP(SWE) transgenic (Tg2576) mice were treated with the AD candidate drug (+)-phenserine for 16 consecutive days. We found significant reductions in insoluble Aβ1-42 levels in the cortices of both young and older transgenic mice, while significant reductions in soluble Aβ1-42 levels and insoluble Aβ1-40 levels were only found in animals aged 15-18 months. Autoradiography binding with the amyloid ligand Pittsburgh Compound B ((3)H-PIB) revealed a trend for reduced fibrillar Aβ deposition in the brains of older phenserine-treated Tg2576 mice. Phenserine treatment increased cortical synaptophysin levels in younger mice, while decreased interleukin-1β and increased monocyte chemoattractant protein-1 and tumor necrosis factor-alpha levels were detected in the cortices of older mice. The reduction in Aβ1-42 levels was associated with an increased number of bromodeoxyuridine-positive proliferating cells in the hippocampi of both young and older Tg2576 mice. To determine whether the increased cell proliferation was accompanied by increased neuronal production, the endogenous early neuronal marker doublecortin (DCX) was examined in the dentate gyrus (DG) using immunohistochemical detection. Although no changes in the total number of DCX(+)-expressing neurons were detected in the DG in Tg2576 mice at either age following (+)-phenserine treatment, dendritic arborization was increased in differentiating neurons in young Tg2576 mice. Collectively, these findings indicate that reducing Aβ1-42 levels in Tg2576 mice at an early pathological stage affects synaptic function by modulating the maturation and plasticity of newborn neurons in the brain. In contrast, lowering Aβ levels in Tg2576 mice when Aβ plaque pathology is prominent mainly alters the levels of proinflammatory cytokines and chemokines.
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Lilja AM, Luo Y, Yu QS, Röjdner J, Li Y, Marini AM, Marutle A, Nordberg A, Greig NH. Neurotrophic and neuroprotective actions of (-)- and (+)-phenserine, candidate drugs for Alzheimer's disease. PLoS One 2013; 8:e54887. [PMID: 23382994 PMCID: PMC3559887 DOI: 10.1371/journal.pone.0054887] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2012] [Accepted: 12/17/2012] [Indexed: 12/11/2022] Open
Abstract
Neuronal dysfunction and demise together with a reduction in neurogenesis are cardinal features of Alzheimer’s disease (AD) induced by a combination of oxidative stress, toxic amyloid-β peptide (Aβ) and a loss of trophic factor support. Amelioration of these was assessed with the Aβ lowering AD experimental drugs (+)-phenserine and (−)-phenserine in neuronal cultures, and actions in mice were evaluated with (+)-phenserine. Both experimental drugs together with the metabolite N1-norphenserine induced neurotrophic actions in human SH-SY5Y cells that were mediated by the protein kinase C (PKC) and extracellular signal–regulated kinases (ERK) pathways, were evident in cells expressing amyloid precursor protein Swedish mutation (APPSWE), and retained in the presence of Aβ and oxidative stress challenge. (+)-Phenserine, together with its (−) enantiomer as well as its N1- and N8-norphenserine and N1,N8-bisnorphenserine metabolites, likewise provided neuroprotective activity against oxidative stress and glutamate toxicity via the PKC and ERK pathways. These neurotrophic and neuroprotective actions were evident in primary cultures of subventricular zone (SVZ) neural progenitor cells, whose neurosphere size and survival were augmented by (+)-phenserine. Translation of these effects in vivo was assessed in wild type and AD APPswe transgenic (Tg2576) mice by doublecortin (DCX) immunohistochemical analysis of neurogenesis in the SVZ, which was significantly elevated by 16 day systemic (+)-phenserine treatment, in the presence of a (+)-phenserine-induced elevation in brain- derived neurotrophic factor (BDNF).
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Affiliation(s)
- Anna M. Lilja
- Alzheimer Neurobiology Center, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden
- Drug Design and Development Section, Laboratory of Neurosciences, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, United States of America
- * E-mail: (AL); (NHG)
| | - Yu Luo
- Department of Neurological Surgery, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
| | - Qian-sheng Yu
- Drug Design and Development Section, Laboratory of Neurosciences, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, United States of America
| | - Jennie Röjdner
- Alzheimer Neurobiology Center, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden
- Department of Geriatric Medicine, Karolinska University Hospital Huddinge, Stockholm, Sweden
| | - Yazhou Li
- Drug Design and Development Section, Laboratory of Neurosciences, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, United States of America
| | - Ann M. Marini
- Department of Neurology and Neuroscience Program, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Amelia Marutle
- Alzheimer Neurobiology Center, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden
| | - Agneta Nordberg
- Alzheimer Neurobiology Center, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden
- Department of Geriatric Medicine, Karolinska University Hospital Huddinge, Stockholm, Sweden
| | - Nigel H. Greig
- Drug Design and Development Section, Laboratory of Neurosciences, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, United States of America
- * E-mail: (AL); (NHG)
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Becker RE, Greig NH. Fire in the ashes: can failed Alzheimer's disease drugs succeed with second chances? Alzheimers Dement 2013; 9:50-7. [PMID: 22465172 PMCID: PMC5176356 DOI: 10.1016/j.jalz.2012.01.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Revised: 11/12/2011] [Accepted: 01/02/2012] [Indexed: 11/18/2022]
Abstract
BACKGROUND Since Cognex, more than 200 Alzheimer's disease (AD) drug candidates have failed. Investigations have identified vulnerabilities of these AD drug developments to methodological errors. (-)-Phenserine has been discussed as possibly failing due to flawed methods and practices in development. METHODS We analyzed documentation of (-)-phenserine's development for vulnerabilities to errors and designed interventions for a redevelopment that could provide fair or unbiased assessments of (-)-phenserine target engagement, target relevance for human diseases, and adequate presumptive evidence of efficacy as a therapeutic for one or more diagnoses to justify registration-required clinical trials. RESULTS Similar to studies of 40 other AD developments, with (-)-phenserine, we found little evidence of preemptive interventions against potentially invalidating errors, grounds to judge progress in development through stages as not scientifically justifiable, and variance excess and placebo group improvements as capable of accounting for outcomes from various studies in the development. We propose to compare a redevelopment resourced to counter these deficiencies with the original development as historical control to evaluate further our hypothesis that errors in development accounted for the (-)-phenserine failure, specifically, and other AD drug failures, potentially. CONCLUSIONS We find support for our earlier proposal that (-)-phenserine did not fail, but the methods of development did fail, to provide conditions where efficacy could be tested. We propose that redevelopment under conditions aimed to correct methodological deficiencies common in AD drug developments will successfully test efficacy for (-)-phenserine and hopefully lead to a disease-modifying addition to the AD therapeutic armamentarium.
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Maccecchini ML, Chang MY, Pan C, John V, Zetterberg H, Greig NH. Posiphen as a candidate drug to lower CSF amyloid precursor protein, amyloid-β peptide and τ levels: target engagement, tolerability and pharmacokinetics in humans. J Neurol Neurosurg Psychiatry 2012; 83:894-902. [PMID: 22791904 PMCID: PMC3415310 DOI: 10.1136/jnnp-2012-302589] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
AIM A first in human study to evaluate tolerability and pharmacokinetics followed by an early proof of mechanism (POM) study to determine whether the small orally, available molecule, Posiphen tartrate (Posiphen), lowers secreted (s) amyloid-β precursor protein (APP) α and -β, amyloid-β peptide (Aβ), tau (τ) and inflammatory markers in CSF of patients with mild cognitive impairment (MCI). STUDY DESIGN Posiphen single and multiple ascending dose phase 1 randomised, double blind, placebo-controlled safety, tolerance, pharmacokinetic studies were undertaken in a total of 120 healthy volunteers to define a dose that was then used in a small non-randomised study of five MCI subjects, used as their own controls, to define target engagement. MAIN OUTCOME MEASURES Pharmacodynamic: sAPPα, sAPPβ, Aβ(42), τ (total (t) and phosphorylated (p)) and inflammatory marker levels were time-dependently measured over 12 h and compared prior to and following 10 days of oral Posiphen treatment in four MCI subjects who completed the study. Pharmacokinetic: plasma and CSF drug and primary metabolite concentrations with estimated brain levels extrapolated from steady-state drug administration in rats. RESULTS Posiphen proved well tolerated and significantly lowered CSF levels of sAPPα, sAPPβ, t-τ, p-τ and specific inflammatory markers, and demonstrated a trend to lower CSF Aβ(42). CONCLUSIONS These results confirm preclinical POM studies, demonstrate that pharmacologically relevant drug/metabolite levels reach brain and support the continued clinical optimisation and evaluation of Posiphen for MCI and Alzheimer's disease.
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Bailey JA, Lahiri DK. Chromatographic separation of reaction products from the choline acetyltransferase and carnitine acetyltransferase assay: differential ChAT and CrAT activity in brain extracts from Alzheimer's disease versus controls. J Neurochem 2012; 122:672-80. [PMID: 22607230 DOI: 10.1111/j.1471-4159.2012.07793.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Choline acetyltransferase (ChAT) catalyzes the reaction between choline and acetylcoenzyme A (AcCoA) to form acetylcholine (ACh) in nerve terminals. ACh metabolism has implications in numerous aspects of physiology and varied disease states, such as Alzheimer's disease. Therefore a specific, sensitive, and reliable method for detecting ChAT enzyme activity is of great utility in a number of situations. Using an existing radionuclide-based enzyme activity assay, we have observed detectable ChAT signals from non-cholinergic cells, suggesting a contaminant in the assay producing an artifactual signal. Previous reports have suggested that L-acetylcarnitine (LAC) contaminates many assays of ChAT activity, because of difficulties in separating LAC from ACh by organic extraction. To determine the source of this hypothesized artifact and to rectify the problem, we have developed a paper chromatography-based assay for the detection of acetylcholine and other contaminating reaction products of this assay, including LAC. Our first goal was to develop a simple and economical method for resolving and verifying the identities of various reaction products or contaminants that could be performed in most laboratories without specialized equipment. Our second goal was to apply this separation method in postmortem human brain tissue samples. Our assay successfully detected several contaminants, especially in assays using brain tissue, and allowed the separation of the intended ACh product from these contaminants. We further demonstrate that this assay can be used to measure carnitine acetyltransferase (CrAT) activity in the same samples, and assays comparing ChAT and CrAT show that CrAT is highly active in neuronal tissues and in neuronal cell cultures relative to ChAT. Thus, the simple chromatography-based assay we describe allows the measurement of specific reaction products separated from contaminants using commonly available and inexpensive materials. Further, we show that ChAT activity is significantly reduced in brain extracts from Alzheimer's disease compared to controls.
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Affiliation(s)
- Jason A Bailey
- Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, IN, USA
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Tabrez S, Jabir NR, Shakil S, Greig NH, Alam Q, Abuzenadah AM, Damanhouri GA, Kamal MA. A synopsis on the role of tyrosine hydroxylase in Parkinson's disease. CNS & NEUROLOGICAL DISORDERS DRUG TARGETS 2012; 11:395-409. [PMID: 22483313 PMCID: PMC4978221 DOI: 10.2174/187152712800792785] [Citation(s) in RCA: 102] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2012] [Revised: 02/12/2012] [Accepted: 02/18/2012] [Indexed: 12/14/2022]
Abstract
Parkinson's disease (PD) is a common chronic progressive neurodegenerative disorder in elderly people. A consistent neurochemical abnormality in PD is degeneration of dopaminergic neurons in substantia nigra pars compacta, leading to a reduction of striatal dopamine (DA) levels. As tyrosine hydroxylase (TH) catalyses the formation of L-dihydroxyphenylalanine (L-DOPA), the rate-limiting step in the biosynthesis of DA, the disease can be considered as a TH-deficiency syndrome of the striatum. Problems related to PD usually build up when vesicular storage of DA is altered by the presence of either α-synuclein protofibrils or oxidative stress. Phosphorylation of three physiologically-regulated specific sites of N-terminal domain of TH is vital in regulating its kinetic and protein interaction. The concept of physiological significance of TH isoforms is another interesting aspect to be explored further for a comprehensive understanding of its role in PD. Thus, a logical and efficient strategy for PD treatment is based on correcting or bypassing the enzyme deficiency by the treatment with L-DOPA, DA agonists, inhibitors of DA metabolism or brain grafts with cells expressing a high level of TH. Neurotrophic factors are also attracting the attention of neuroscientists because they provide the essential neuroprotective and neurorestorative properties to the nigrostriatal DA system. PPAR-γ, a key regulator of immune responses, is likewise a promising target for the treatment of PD, which can be achieved by the use of agonists with the potential to impact the expression of pro- and anti-inflammatory cytokines at the transcriptional level in immune cells via expression of TH. Herein, we review the primary biochemical and pathological features of PD, and describe both classical and developing approaches aimed to ameliorate disease symptoms and its progression.
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Affiliation(s)
- Shams Tabrez
- King Fahd Medical Research Center, King Abdulaziz University, P. O. Box 80216, Jeddah 21589, Saudi Arabia
| | - Nasimudeen R. Jabir
- King Fahd Medical Research Center, King Abdulaziz University, P. O. Box 80216, Jeddah 21589, Saudi Arabia
| | - Shazi Shakil
- King Fahd Medical Research Center, King Abdulaziz University, P. O. Box 80216, Jeddah 21589, Saudi Arabia
| | - Nigel H. Greig
- Drug Design & Development Section, Laboratory of Neurosciences, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Qamre Alam
- King Fahd Medical Research Center, King Abdulaziz University, P. O. Box 80216, Jeddah 21589, Saudi Arabia
| | - Adel M. Abuzenadah
- King Fahd Medical Research Center, King Abdulaziz University, P. O. Box 80216, Jeddah 21589, Saudi Arabia
| | - Ghazi A. Damanhouri
- King Fahd Medical Research Center, King Abdulaziz University, P. O. Box 80216, Jeddah 21589, Saudi Arabia
| | - Mohammad A. Kamal
- King Fahd Medical Research Center, King Abdulaziz University, P. O. Box 80216, Jeddah 21589, Saudi Arabia
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Mikkilineni S, Cantuti-Castelvetri I, Cahill CM, Balliedier A, Greig NH, Rogers JT. The anticholinesterase phenserine and its enantiomer posiphen as 5'untranslated-region-directed translation blockers of the Parkinson's alpha synuclein expression. PARKINSON'S DISEASE 2012; 2012:142372. [PMID: 22693681 PMCID: PMC3368596 DOI: 10.1155/2012/142372] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Accepted: 02/29/2012] [Indexed: 12/15/2022]
Abstract
There is compelling support for limiting expression of alpha-synuclein (α-syn) in the brains of Parkinson's disease (PD) patients. An increase of SNCA gene copy number can genetically cause familial PD where increased dose of this pathogenic protein correlates with severity of symptoms (triplication of the SNCA gene causes dementia in PD patients). Gene promoter polymorphisms were shown to increase α-synuclein expression as a risk for PD. Cholinesterase inhibitors can clinically slow cognitive decline in the later stages of PD etiology similar to their widespread use in Alzheimer's disease (AD). Pertinent to this, we identified that the well-tolerated anticholinesterase, phenserine, blocked neural SNCA mRNA translation and tested for targeting via its 5'untranslated region (5'UTR) in a manner similar to its action to limit the expression of the AD-specific amyloid precursor protein (APP). Posiphen, its better-tolerated (+) enantiomer (devoid of anticholinesterase action), repressed neural α-synuclein translation. Primary metabolic analogs of posiphen were, likewise, characterized using primary fetal neurons grown ex vivo from the brains of Parkinson's transgenic mice expressing the human SNCA gene.
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Affiliation(s)
- Sohan Mikkilineni
- Neurochemistry Laboratory, Massachusetts General Hospital (East), CNY2, 149, 13th Street, Charlestown, MA 02129, USA
| | | | - Catherine M. Cahill
- Neurochemistry Laboratory, Massachusetts General Hospital (East), CNY2, 149, 13th Street, Charlestown, MA 02129, USA
| | - Amelie Balliedier
- Neurochemistry Laboratory, Massachusetts General Hospital (East), CNY2, 149, 13th Street, Charlestown, MA 02129, USA
| | - Nigel H. Greig
- Drug Design and Development Section, Laboratory of Neurosciences, Intramural Research Program, National Institute on Aging, Baltimore, MD 21224, USA
| | - Jack T. Rogers
- Neurochemistry Laboratory, Massachusetts General Hospital (East), CNY2, 149, 13th Street, Charlestown, MA 02129, USA
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Banks WA. Drug delivery to the brain in Alzheimer's disease: consideration of the blood-brain barrier. Adv Drug Deliv Rev 2012; 64:629-39. [PMID: 22202501 DOI: 10.1016/j.addr.2011.12.005] [Citation(s) in RCA: 124] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Revised: 12/09/2011] [Accepted: 12/09/2011] [Indexed: 12/21/2022]
Abstract
The successful treatment of Alzheimer's disease (AD) will require drugs that can negotiate the blood-brain barrier (BBB). However, the BBB is not simply a physical barrier, but a complex interface that is in intimate communication with the rest of the central nervous system (CNS) and influenced by peripheral tissues. This review examines three aspects of the BBB in AD. First, it considers how the BBB may be contributing to the onset and progression of AD. In this regard, the BBB itself is a therapeutic target in the treatment of AD. Second, it examines how the BBB restricts drugs that might otherwise be useful in the treatment of AD and examines strategies being developed to deliver drugs to the CNS for the treatment of AD. Third, it considers how drug penetration across the AD BBB may differ from the BBB of normal aging. In this case, those differences can complicate the treatment of CNS diseases such as depression, delirium, psychoses, and pain control in the AD population.
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Affiliation(s)
- William A Banks
- Geriatric Research, Education, and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA , USA.
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Ray B, Chauhan NB, Lahiri DK. The "aged garlic extract:" (AGE) and one of its active ingredients S-allyl-L-cysteine (SAC) as potential preventive and therapeutic agents for Alzheimer's disease (AD). Curr Med Chem 2012; 18:3306-13. [PMID: 21728972 DOI: 10.2174/092986711796504664] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2011] [Accepted: 05/27/2011] [Indexed: 01/04/2023]
Abstract
Alzheimer's disease (AD) is the most common form of dementia in the older people and 7(th) leading cause of death in the United States. Deposition of amyloid-beta (Aβ) plaques, hyperphosphorylation of microtubule associated protein tau (MAPT), neuroinflammation and cholinergic neuron loss are the major hallmarks of AD. Deposition of Aβ peptides, which takes place years before the clinical onset of the disease can trigger hyperphophorylation of tau proteins and neuroinflammation, and the latter is thought to be primarily involved in neuronal and synaptic damage seen in AD. To date, four cholinesterase inhibitors or ChEI (tacrine, rivastigmine, donepezil and galantamine) and a partial NMDA receptor antagonist (memantine) are the only approved treatment options for AD. However, these drugs fail to completely cure the disease, which warrants a search for newer class of targets that would eventually lead to effective drugs for the treatment of AD. In addition to selected pharmacological agents, botanical and medicinal plant extracts are also being investigated. Apart from its culinary use, garlic (Allium sativum) is being used to treat several ailments like cancer and diabetes. Herein we have discussed the effects of a specific 'Aged Garlic Extract' (AGE) and one of its active ingredients, S-allyl-L-cysteine (SAC) in restricting several pathological cascades related to the synaptic degeneration and neuroinflammatory pathways associated with AD. Thus, based on the reported positive preliminary results reviewed herein, further research is required to develop the full potential of AGE and/or SAC into an effective preventative strategy for AD.
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Affiliation(s)
- B Ray
- Department of Psychiatry, Indiana University School of Medicine, 791Union Drive, Indianapolis IN 46202, USA
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Araujo JA, Greig NH, Ingram DK, Sandin J, de Rivera C, Milgram NW. Cholinesterase inhibitors improve both memory and complex learning in aged beagle dogs. J Alzheimers Dis 2012; 26:143-55. [PMID: 21593569 DOI: 10.3233/jad-2011-110005] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Similar to patients with Alzheimer's disease (AD), dogs exhibit age-dependent cognitive decline, amyloid-β (Aβ) pathology, and evidence of cholinergic hypofunction. The present study sought to further investigate the role of cholinergic hypofunction in the canine model by examining the effect of the cholinesterase inhibitors phenserine and donepezil on performance of two tasks, a delayed non-matching-to-position task (DNMP) designed to assess working memory, and an oddity discrimination learning task designed to assess complex learning, in aged dogs. Phenserine (0.5 mg/kg; PO) significantly improved performance on the DNMP at the longest delay compared to wash-out and partially attenuated scopolamine-induced deficits (15 μg/kg; SC). Phenserine also improved learning on a difficult version of an oddity discrimination task compared to placebo, but had no effect on an easier version. We also examined the effects of three doses of donepezil (0.75, 1.5, and 6 mg/kg; PO) on performance of the DNMP. Similar to the results with phenserine, 1.5 mg/kg of donepezil improved performance at the longest delay compared to baseline and wash-out, indicative of memory enhancement. These results further extend the findings of cholinergic hypofunction in aged dogs and provide pharmacological validation of the canine model with a cholinesterase inhibitor approved for use in AD. Collectively, these studies support utilizing the aged dog in future screening of therapeutics for AD, as well as for investigating the links among cholinergic function, Aβ pathology, and cognitive decline.
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Affiliation(s)
- Joseph A Araujo
- Department of Pharmacology, University of Toronto, Toronto, ON, Canada.
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Abstract
Alzheimer's disease (AD) is a chronic neurodegenerative disease with well-defined pathophysiological mechanisms, mostly affecting medial temporal lobe and associative neocortical structures. Neuritic plaques and neurofibrillary tangles represent the pathological hallmarks of AD, and are respectively related to the accumulation of the amyloid-beta peptide (Aβ) in brain tissues, and to cytoskeletal changes that arise from the hyperphosphorylation of microtubule-associated Tau protein in neurons. According to the amyloid hypothesis of AD, the overproduction of Aβ is a consequence of the disruption of homeostatic processes that regulate the proteolytic cleavage of the amyloid precursor protein (APP). Genetic, age-related and environmental factors contribute to a metabolic shift favoring the amyloidogenic processing of APP in detriment of the physiological, secretory pathway. Aβ peptides are generated by the successive cleavage of APP by beta-secretase (BACE-1) and gamma-secretase, which has been recently characterized as part of the presenilin complex. Among several beta-amyloid isoforms that bear subtle differences depending on the number of C-terminal amino acids, Aβ (1-42) plays a pivotal role in the pathogenesis of AD. The neurotoxic potential of the Aβ peptide results from its biochemical properties that favor aggregation into insoluble oligomers and protofibrils. These further originate fibrillary Aβ species that accumulate into senile and neuritic plaques. These processes, along with a reduction of Aβ clearance from the brain, leads to the extracellular accumulation of Aβ, and the subsequent activation of neurotoxic cascades that ultimately lead to cytoskeletal changes, neuronal dysfunction and cellular death. Intracerebral amyloidosis develops in AD patients in an age-dependent manner, but recent evidence indicate that it may be observed in some subjects as early as in the third or fourth decades of life, with increasing magnitude in late middle age, and highest estimates in old age. According to recent propositions, three clinical phases of Alzheimer's disease may be defined: (i) pre-symptomatic (or pre-clinical) AD, which may last for several years or decades until the overproduction and accumulation of Aβ in the brain reaches a critical level that triggers the amyloid cascade; (ii) pre-dementia phase of AD (compatible with the definition of progressive, amnestic mild cognitive impairment), in which early-stage pathology is present, ranging from mild neuronal dystrophy to early-stage Braak pathology, and may last for several years according to individual resilience and brain reserve; (iii) clinically defined dementia phase of AD, in which cognitive and functional impairment is severe enough to surmount the dementia threshold; at this stage there is significant accumulation of neuritic plaques and neurofibrillary tangles in affected brain areas, bearing relationship with the magnitude of global impairment. New technologies based on structural and functional neuroimaging, and on the biochemical analysis of cerebrospinal fluid may depict correlates of intracerebral amyloidosis in individuals with mild, pre-dementia symptoms. These methods are commonly referred to as AD-related biomarkers, and the combination of clinical and biological information yields good diagnostic accuracy to identify individuals at high risk of AD. In other words, the characterization of pathogenic Aβ by means of biochemical analysis of biological fluids or by molecular neuroimaging are presented as diagnostic tools to help identify AD cases at the earliest stages of the disease process. The relevance of this early diagnosis of AD relies on the hypothesis that pharmacological interventions with disease-modifying compounds are more likely to produce clinically relevant benefits if started early enough in the continuum towards dementia. Therapies targeting the modification of amyloid-related cascades may be viewed as promising strategies to attenuate or even to prevent dementia. Therefore, the cumulative knowledge on the pathogenesis of AD derived from basic science models will hopefully be translated into clinical practice in the forthcoming years.
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Affiliation(s)
- Vanessa J De-Paula
- Laboratory of Neuroscience (LIM 27), Department and Institute of Psychiatry, Faculty of Medicine, University of Sao Paulo, Rua Dr. Ovídio Pires de Campos 785, Terceiro Andar-Ala Norte, 05403-010, São Paulo-SP, Brazil,
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Schammel AW, Chiou G, Garg NK. Synthesis of (+)-Phenserine Using an Interrupted Fischer Indolization Reaction. J Org Chem 2011; 77:725-8. [DOI: 10.1021/jo202078z] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Alex W. Schammel
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles,
California 90095, United States
| | - Grace Chiou
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles,
California 90095, United States
| | - Neil K. Garg
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles,
California 90095, United States
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García-Ayllón MS, Small DH, Avila J, Sáez-Valero J. Revisiting the Role of Acetylcholinesterase in Alzheimer's Disease: Cross-Talk with P-tau and β-Amyloid. Front Mol Neurosci 2011; 4:22. [PMID: 21949503 PMCID: PMC3171929 DOI: 10.3389/fnmol.2011.00022] [Citation(s) in RCA: 159] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2011] [Accepted: 08/24/2011] [Indexed: 11/29/2022] Open
Abstract
A common feature in the Alzheimer’s disease (AD) brain is the presence of acetylcholinesterase (AChE) which is commonly associated with β-amyloid plaques and neurofibrillary tangles (NFT). Although our understanding of the relationship between AChE and the pathological features of AD is incomplete, increasing evidence suggests that both β-amyloid protein (Aβ) and abnormally hyperphosphorylated tau (P-tau) can influence AChE expression. We also review recent findings which suggest the possible role of AChE in the development of a vicious cycle of Aβ and P-tau dysregulation and discuss the limited and temporary effect of therapeutic intervention with AChE inhibitors.
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71
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Bailey JA, Ray B, Greig NH, Lahiri DK. Rivastigmine lowers Aβ and increases sAPPα levels, which parallel elevated synaptic markers and metabolic activity in degenerating primary rat neurons. PLoS One 2011; 6:e21954. [PMID: 21799757 PMCID: PMC3142110 DOI: 10.1371/journal.pone.0021954] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2011] [Accepted: 06/15/2011] [Indexed: 01/20/2023] Open
Abstract
Overproduction of amyloid-β (Aβ) protein in the brain has been hypothesized as the primary toxic insult that, via numerous mechanisms, produces cognitive deficits in Alzheimer's disease (AD). Cholinesterase inhibition is a primary strategy for treatment of AD, and specific compounds of this class have previously been demonstrated to influence Aβ precursor protein (APP) processing and Aβ production. However, little information is available on the effects of rivastigmine, a dual acetylcholinesterase and butyrylcholinesterase inhibitor, on APP processing. As this drug is currently used to treat AD, characterization of its various activities is important to optimize its clinical utility. We have previously shown that rivastigmine can preserve or enhance neuronal and synaptic terminal markers in degenerating primary embryonic cerebrocortical cultures. Given previous reports on the effects of APP and Aβ on synapses, regulation of APP processing represents a plausible mechanism for the synaptic effects of rivastigmine. To test this hypothesis, we treated degenerating primary cultures with rivastigmine and measured secreted APP (sAPP) and Aβ. Rivastigmine treatment increased metabolic activity in these cultured cells, and elevated APP secretion. Analysis of the two major forms of APP secreted by these cultures, attributed to neurons or glia based on molecular weight showed that rivastigmine treatment significantly increased neuronal relative to glial secreted APP. Furthermore, rivastigmine treatment increased α-secretase cleaved sAPPα and decreased Aβ secretion, suggesting a therapeutic mechanism wherein rivastigmine alters the relative activities of the secretase pathways. Assessment of sAPP levels in rodent CSF following once daily rivastigmine administration for 21 days confirmed that elevated levels of APP in cell culture translated in vivo. Taken together, rivastigmine treatment enhances neuronal sAPP and shifts APP processing toward the α-secretase pathway in degenerating neuronal cultures, which mirrors the trend of synaptic proteins, and metabolic activity.
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Affiliation(s)
- Jason A. Bailey
- Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Balmiki Ray
- Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Nigel H. Greig
- Laboratory of Neuroscience, Intramural Research Program, National Institute of Aging, National Institutes of Health, Baltimore Maryland, United States of America
| | - Debomoy K. Lahiri
- Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
- Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
- * E-mail:
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72
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Silveyra MX, García-Ayllón MS, Serra-Basante C, Mazzoni V, García-Gutierrez MS, Manzanares J, Culvenor JG, Sáez-Valero J. Changes in acetylcholinesterase expression are associated with altered presenilin-1 levels. Neurobiol Aging 2011; 33:627.e27-37. [PMID: 21621296 DOI: 10.1016/j.neurobiolaging.2011.04.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2010] [Revised: 02/10/2011] [Accepted: 04/02/2011] [Indexed: 12/21/2022]
Abstract
We have previously identified presenilin-1 (PS1), the active component of the γ-secretase complex, as an interacting protein of the amyloid-associated enzyme acetylcholinesterase (AChE). In this study, we have explored the consequences of AChE-PS1 interactions. Treatment of SH-SY5Y cells with the AChE-inhibitor tacrine decreased PS1 levels, in parallel with increase in the secretion of amyloid precursor protein APPα, whereas the cholinergic agonist carbachol had no effect on PS1. AChE knockdown with siRNA also decreased PS1 levels, while AChE overexpression exerted opposing effect. AChE-deficient also had decreased PS1. Mice administered with tacrine or donepezil displayed lower levels of brain PS1. However, sustained AChE inhibition failed to exert long-term effect on PS1. This limited duration of response may be due to AChE upregulation caused by chronic inhibition. Finally, we exposed SH-SY5Y cells to β-amyloid (Aβ)42 which triggered elevation of both AChE and PS1 levels. The Aβ42-induced PS1 increase was abolished by siRNA AChE pretreatment, suggesting that AChE may participate in the pathological feedback loop between PS1 and Aβ. Our results provide insight into AChE-amyloid interrelationships.
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Affiliation(s)
- María-Ximena Silveyra
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Sant Joan d'Alacant, Alicante, Spain
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73
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Winblad B, Giacobini E, Frölich L, Friedhoff LT, Bruinsma G, Becker RE, Greig NH. Phenserine efficacy in Alzheimer's disease. J Alzheimers Dis 2011; 22:1201-8. [PMID: 20930279 DOI: 10.3233/jad-2010-101311] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
To gather preliminary evidence in Alzheimer's disease (AD) for the efficacy of phenserine, a non-competitive acetylcholinesterase inhibitor that has independent modulatory effects on amyloid-β generation, a 12-week comparison of patients receiving phenserine (10 and 15 mg BID) or placebo was conducted under double-blind conditions. Patients who completed 12 weeks of the double-blind before others were continued in the double-blind to determine longer-term treatment effects. At 12 weeks, mean ADAS-cog (AD assessment scale-cognitive) changes from baseline were -2.5 and -1.9 for high-dose phenserine (n=83) and placebo (n=81) groups, respectively, a non-statistically significant improvement for the high-dose phenserine group relative to placebo. CIBIC+ (clinician's interview based impression of change + caregiver's input) values for the high-dose and placebo groups were similar at 12 weeks. For patients who received more than 12 weeks of therapy, the ADAS-cog changes were -3.18 and -0.66 for the high-dose phenserine (n=52) and placebo (n=63) groups, respectively, a difference achieving statistical significance (p=0.0286). After 12 weeks, CIBIC+ values were 3.59 and 3.95 for the high-dose (n=54) and placebo (n=66) groups respectively (p=0.0568). These results from this short-term study are consistent with phenserine potentially benefiting mild to moderate Alzheimer's disease symptomatically but do not address possible amyloid metabolic mediated effects on disease processes in AD.
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Affiliation(s)
- Bengt Winblad
- Alzheimer's Disease Research Center, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
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74
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Rogers JT, Mikkilineni S, Cantuti-Castelvetri I, Smith DH, Huang X, Bandyopadhyay S, Cahill CM, Maccecchini ML, Lahiri DK, Greig NH. The alpha-synuclein 5'untranslated region targeted translation blockers: anti-alpha synuclein efficacy of cardiac glycosides and Posiphen. J Neural Transm (Vienna) 2011; 118:493-507. [PMID: 21221670 PMCID: PMC6625511 DOI: 10.1007/s00702-010-0513-5] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Accepted: 10/15/2010] [Indexed: 12/24/2022]
Abstract
Increased brain α-synuclein (SNCA) protein expression resulting from gene duplication and triplication can cause a familial form of Parkinson's disease (PD). Dopaminergic neurons exhibit elevated iron levels that can accelerate toxic SNCA fibril formation. Examinations of human post mortem brain have shown that while mRNA levels for SNCA in PD have been shown to be either unchanged or decreased with respect to healthy controls, higher levels of insoluble protein occurs during PD progression. We show evidence that SNCA can be regulated via the 5'untranslated region (5'UTR) of its transcript, which we modeled to fold into a unique RNA stem loop with a CAGUGN apical loop similar to that encoded in the canonical iron-responsive element (IRE) of L- and H-ferritin mRNAs. The SNCA IRE-like stem loop spans the two exons that encode its 5'UTR, whereas, by contrast, the H-ferritin 5'UTR is encoded by a single first exon. We screened a library of 720 natural products (NPs) for their capacity to inhibit SNCA 5'UTR driven luciferase expression. This screen identified several classes of NPs, including the plant cardiac glycosides, mycophenolic acid (an immunosuppressant and Fe chelator), and, additionally, posiphen was identified to repress SNCA 5'UTR conferred translation. Western blotting confirmed that Posiphen and the cardiac glycoside, strophanthidine, selectively blocked SNCA expression (~1 μM IC(50)) in neural cells. For Posiphen this inhibition was accelerated in the presence of iron, thus providing a known APP-directed lead with potential for use as a SNCA blocker for PD therapy. These are candidate drugs with the potential to limit toxic SNCA expression in the brains of PD patients and animal models in vivo.
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Affiliation(s)
- Jack T Rogers
- Neurochemistry Laboratory, Psychiatry-Neuroscience, Massachusetts General Hospital, Charlestown, MA 02129, USA.
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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.
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76
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Ji W, Ha I. Drug development for Alzheimer's disease: recent progress. Exp Neurobiol 2010; 19:120-31. [PMID: 22110351 PMCID: PMC3214787 DOI: 10.5607/en.2010.19.3.120] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2010] [Accepted: 12/28/2010] [Indexed: 12/31/2022] Open
Abstract
Alzheimer's disease, the most common cause of dementia, is characterized by two major pathological hallmarks: amyloid plaques and neurofibrillary tangles. Based on these two indicators, an amyloid cascade hypothesis was proposed, and accordingly, most current therapeutic approaches are now focused on the removal of β-amyloid peptides (Aβ from the brain. Additionally, strategies for blocking tau hyperphosphorylation and aggregation have been suggested, including the development of drugs that can block the formation of tangles. However, there are no true disease-modifying drugs in the current market, though many drugs based on theories other than Aβ and tau pathology are under development. The purpose of this review was to provide information on the current development of AD drugs and to discuss the issues related to drug development.
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Affiliation(s)
- Wonjin Ji
- Institute for Brain Science and Technology (IBST)/Graduate Program in Neuroscience, Inje University, Busan 614-735, Korea
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77
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Abstract
In Alzheimer disease (AD), which is the most common cause of dementia, the underlying disease pathology most probably precedes the onset of cognitive symptoms by many years. Thus, efforts are underway to find early diagnostic markers as well as disease-modifying treatments for this disorder. PET enables various brain systems to be monitored in living individuals. In patients with AD, PET can be used to investigate changes in cerebral glucose metabolism, various neurotransmitter systems, neuroinflammation, and the protein aggregates that are characteristic of the disease, notably the amyloid deposits. These investigations are helping to further our understanding of the complex pathophysiological mechanisms that underlie AD, as well as aiding the early and differential diagnosis of the disease in the clinic. In the future, PET studies will also be useful for identifying new therapeutic targets and monitoring treatment outcomes. Amyloid imaging could be useful as early diagnostic marker of AD and for selecting patients for anti-amyloid-beta therapy, while cerebral glucose metabolism could be a suitable PET marker for monitoring disease progression. For the near future, multitracer PET studies are unlikely to be used routinely in the clinic for AD, being both burdensome and expensive; however, such studies are very informative in a research context.
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Affiliation(s)
- Agneta Nordberg
- Division of Alzheimer Neurobiology, Department of Neurobiology, Care Sciences and Society, Karolinska Institute, Karolinska University Hospital Huddinge, Novum, Stockholm, Sweden.
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78
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Alley GM, Bailey JA, Chen D, Ray B, Puli LK, Tanila H, Banerjee PK, Lahiri DK. Memantine lowers amyloid-beta peptide levels in neuronal cultures and in APP/PS1 transgenic mice. J Neurosci Res 2010; 88:143-54. [PMID: 19642202 DOI: 10.1002/jnr.22172] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Memantine is a moderate-affinity, uncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist that stabilizes cognitive, functional, and behavioral decline in patients with moderate to severe Alzheimer's disease (AD). In AD, the extracellular deposition of fibrillogenic amyloid-beta peptides (Abeta) occurs as a result of aberrant processing of the full-length Abeta precursor protein (APP). Memantine protects neurons from the neurotoxic effects of Abeta and improves cognition in transgenic mice with high brain levels of Abeta. However, it is unknown how memantine protects cells against neurodegeneration and affects APP processing and Abeta production. We report the effects of memantine in three different systems. In human neuroblastoma cells, memantine, at therapeutically relevant concentrations (1-4 muM), decreased levels of secreted APP and Abeta(1-40). Levels of the potentially amylodogenic Abeta(1-42) were undetectable in these cells. In primary rat cortical neuronal cultures, memantine treatment lowered Abeta(1-42) secretion. At the concentrations used, memantine treatment was not toxic to neuroblastoma or primary cultures and increased cell viability and/or metabolic activity under certain conditions. In APP/presenilin-1 (PS1) transgenic mice exhibiting high brain levels of Abeta(1-42), oral dosing of memantine (20 mg/kg/day for 8 days) produced a plasma drug concentration of 0.96 microM and significantly reduced the cortical levels of soluble Abeta(1-42). The ratio of Abeta(1-40)/Abeta(1-42) increased in treated mice, suggesting effects on the gamma-secretase complex. Thus, memantine reduces the levels of Abeta peptides at therapeutic concentrations and may inhibit the accumulation of fibrillogenic Abeta in mammalian brains. Memantine's ability to preserve neuronal cells against neurodegeneration, to increase metabolic activity, and to lower Abeta level has therapeutic implications for neurodegenerative disorders.
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Affiliation(s)
- George M Alley
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, USA
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79
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The role of positron emission tomography imaging of β-amyloid in patients with Alzheimer's disease. Nucl Med Commun 2010; 31:4-11. [DOI: 10.1097/mnm.0b013e32833019f3] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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80
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Ray B, Banerjee PK, Greig NH, Lahiri DK. Memantine treatment decreases levels of secreted Alzheimer's amyloid precursor protein (APP) and amyloid beta (A beta) peptide in the human neuroblastoma cells. Neurosci Lett 2009; 470:1-5. [PMID: 19948208 DOI: 10.1016/j.neulet.2009.11.016] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2009] [Revised: 11/04/2009] [Accepted: 11/05/2009] [Indexed: 01/05/2023]
Abstract
Memantine, an uncompetitive NMDA receptor antagonist, is a FDA-approved drug used for the treatment of moderate-to-severe Alzheimer's disease (AD). Several studies have documented protective roles of memantine against amyloid beta (A beta) peptide-mediated damage to neurons in both in vitro and in vivo models. Memantine is also effective in reducing amyloid burden in the brain of APP transgenic mice. However, the exact mechanism by which memantine provides protection against A beta-mediated neurodegenerative cascade, including APP metabolism, remains to be elucidated. Herein, we investigated the effect of memantine on levels of the secreted form of A beta precursor protein (APP), secreted A beta and cell viability markers under short/acute conditions. We treated neuronal SK-N-SH cells with 10 microM memantine and measured levels of secreted total APP (sAPP), APP alpha isoform and A beta((1-40)) in a time dependent manner for up to 24h. Memantine significantly decreased the levels of the secreted form of sAPP, sAPP alpha and A beta((1-40)) compared to vehicle treated cells. This change started as early as 8h and continued for up to 24h of drug treatment. Unlike sAPP, a slight non-significant increase in total intracellular APP level was observed in 24-h treated memantine cells. Taken together, these results suggest a role for memantine in the transport or trafficking of APP molecules away from the site of their proteolytic cleavage by the secretase enzymes. Such a novel property of memantine warrants further study to define its therapeutic utility.
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Affiliation(s)
- Balmiki Ray
- Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN 46202, USA
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81
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Bailey JA, Lahiri DK. A novel effect of rivastigmine on pre-synaptic proteins and neuronal viability in a neurodegeneration model of fetal rat primary cortical cultures and its implication in Alzheimer's disease. J Neurochem 2009; 112:843-53. [PMID: 19912467 DOI: 10.1111/j.1471-4159.2009.06490.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Alzheimer's disease (AD) is characterized by deposition of amyloid-beta peptide plaque, disrupted amyloid-beta-precursor protein (APP) metabolism, hyperphosphorylation of Tau leading to neurofibrillary tangles and associated neurotoxicity. Moreover, there is synaptic loss in AD, which occurs early and may precede frank amyloidosis. The central cholinergic system is especially vulnerable to the toxic events associated with AD, and reduced acetylcholine levels in specific brain regions is thought to be central to memory deficits in AD. First-generation cholinesterase inhibitors have provided only symptomatic relief to patients with AD by prolonging the action of remaining acetylcholine with little or no change in the course of the disease. Some second-generation cholinesterase inhibitors are multifunctional drugs that may provide more than purely palliative results. To evaluate the effects of the dual acetylcholinesterase and butyrylcholinesterase inhibitor rivastigmine on key aspects of AD, embryonic day 16 rat primary cortical cultures were treated with rivastigmine under media conditions observed to induce time-dependent neurodegeneration. Samples were subjected to western blotting and immunocytochemistry techniques to determine what influence this drug may have on synaptic proteins and neuronal morphology. There was a strong increase in relative cell viability associated with rivastigmine treatment. Significant dose-dependent increases were observed in the levels of synaptic markers synaptosomal-associated protein of 25 kDa (SNAP-25) and synaptophysin, as well as the neuron-specific form of enolase. Together with an observed enhancement of neuronal morphology, our results suggest a rivastigmine-mediated novel neuroprotective and/or neurorestorative effects involving the synapse. Our observations may explain the potential for rivastigmine to alter the course of AD, and warrant further investigations into using butyrylcholinesterase inhibition as a therapeutic strategy for AD, especially with regard to restoration of synaptic function.
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Affiliation(s)
- Jason A Bailey
- Laboratory of Molecular Neurogenetics, Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN 46202, USA
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82
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Marks N, Berg MJ. BACE and gamma-secretase characterization and their sorting as therapeutic targets to reduce amyloidogenesis. Neurochem Res 2009; 35:181-210. [PMID: 19760173 DOI: 10.1007/s11064-009-0054-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2009] [Accepted: 08/21/2009] [Indexed: 10/20/2022]
Abstract
Secretases are named for enzymes processing amyloid precursor protein (APP), a prototypic type-1 membrane protein. This led directly to discovery of novel Aspartyl proteases (beta-secretases or BACE), a tetramer complex gamma-secretase (gamma-SC) containing presenilins, nicastrin, aph-1 and pen-2, and a new role for metalloprotease(s) of the ADAM family as a alpha-secretases. Recent advances in defining pathways that mediate endosomal-lysosomal-autophagic-exosomal trafficking now provide targets for new drugs to attenuate abnormal production of fibril forming products characteristic of AD. A key to success includes not only characterization of relevant secretases but mechanisms for sorting and transport of key metabolites to abnormal vesicles or sites for assembly of fibrils. New developments we highlight include an important role for an 'early recycling endosome' coated in retromer complex containing lipoprotein receptor LRP-II (SorLA) for switching APP to a non-amyloidogenic pathway for alpha-secretases processing, or to shuttle APP to a 'late endosome compartment' to form Abeta or AICD. LRP11 (SorLA) is of particular importance since it decreases in sporadic AD whose etiology otherwise is unknown.
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Affiliation(s)
- Neville Marks
- Center for Neurochemistry, Nathan S Kline Institute for Psychiatric Research, 140 Old Orangeburg Road, Orangeburg, NY 10962, USA.
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83
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Ray B, Bailey JA, Sarkar S, Lahiri DK. Molecular and immunocytochemical characterization of primary neuronal cultures from adult rat brain: Differential expression of neuronal and glial protein markers. J Neurosci Methods 2009; 184:294-302. [PMID: 19720084 DOI: 10.1016/j.jneumeth.2009.08.018] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2009] [Revised: 08/12/2009] [Accepted: 08/22/2009] [Indexed: 11/30/2022]
Abstract
Neurobiological studies using primary neuronal cultures commonly employ fetal-derived neurons, but much less often adult brain-derived neurons. Our goal is to perform morphological and molecular characterization of primary neuronal cultures from adult rat brain, including the relative expression of neuronal and glial cell markers at different time points. We tested the hypothesis that long-term neuronal viability is compatible with glial proliferation in adult neuron culture. We examined neuron culture from adult rat brain, which was maintained at steady state up to 24 days, and characterized them on the basis of cellular, molecular and biochemical properties at different time points of the culture. We identified neuronal and glial cells by both immunocytochemical and western immunoblotting techniques using NSE and Tau as neuronal markers and GFAP as glial protein marker, which revealed the presence of predominantly neuronal cells in the initial phase of the culture and a rise in glial cells from day 12 onwards. Notably, neuronal cells were preserved in the culture along with the glial cells even at day 24. Transfection of the cultured cells with a GFP expression vector and plasmids containing a luciferase reporter gene under the control of two different gene promoters demonstrated DNA transfectability. Taken together, these results suggest a differential expression of neuronal and glial cells at different time points and long-term neuronal viability in the presence of glial proliferation. Such adult neurons serve as a suitable system for the application of neurodegeneration models and for drug target discovery in various brain disorders including Alzheimer's disease.
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Affiliation(s)
- Balmiki Ray
- Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, 791 Union Drive, Indianapolis, IN 46202, USA
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84
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Ray B, Lahiri DK. Neuroinflammation in Alzheimer's disease: different molecular targets and potential therapeutic agents including curcumin. Curr Opin Pharmacol 2009; 9:434-44. [DOI: 10.1016/j.coph.2009.06.012] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2009] [Revised: 06/10/2009] [Accepted: 06/12/2009] [Indexed: 12/30/2022]
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85
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Jakob-Roetne R, Jacobsen H. Alzheimer's disease: from pathology to therapeutic approaches. Angew Chem Int Ed Engl 2009; 48:3030-59. [PMID: 19330877 DOI: 10.1002/anie.200802808] [Citation(s) in RCA: 486] [Impact Index Per Article: 32.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Mind how you go: The current strategies for the development of therapies for Alzheimer's disease are very diverse. Particular attention is given to the search for inhibitors (see picture for two examples) of the proteolytic enzyme beta- and gamma-secretase, which inhibits the cleavage of the amyloid precursor proteins into amyloid beta peptides, from which the disease-defining deposits of plaque in the brains of Alzheimer's patients originates.Research on senile dementia and Alzheimer's disease covers an extremely broad range of scientific activities. At the recent international meeting of the Alzheimer's Association (ICAD 2008, Chicago) more than 2200 individual scientific contributions were presented. The aim of this Review is to give an overview of the field and to outline its main areas, starting from behavioral abnormalities and visible pathological findings and then focusing on the molecular details of the pathology. The "amyloid hypothesis" of Alzheimer's disease is given particular attention, since the majority of the ongoing therapeutic approaches are based on its theoretical framework.
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Affiliation(s)
- Roland Jakob-Roetne
- F.Hoffmann-La Roche AG, Medicinal Chemistry, Bldg 92/8.10B, 4070 Basel, Switzerland.
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86
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Sabbagh MN. Drug development for Alzheimer's disease: where are we now and where are we headed? THE AMERICAN JOURNAL OF GERIATRIC PHARMACOTHERAPY 2009; 7:167-85. [PMID: 19616185 PMCID: PMC2948028 DOI: 10.1016/j.amjopharm.2009.06.003] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 06/10/2009] [Indexed: 01/14/2023]
Abstract
OBJECTIVE The aim of this article was to provide a survey of the clinical development of pharmacotherapy for Alzheimer's disease (AD). METHODS A search of PubMed to identify pertinent English-language literature was conducted using the terms Alzheimer's disease AND clinical trials (2003-2008), dementia AND prevention AND clinical trials (2003-2008), and the chemical names of all compounds mentioned in articles on new drugs for AD published since 2005. www.ClinicalTrials.gov was searched for relevant trials. Abstracts of the 2008 International Conference on Alzheimer's Disease (ICAD) were reviewed for relevance, as were pharmaceutical company and AD advocacy Web sites. Articles selected for review were primary reports of data from preclinical studies and clinical trials. RESULTS A large number of drugs with differing targets and mechanisms of action are under development for the treatment of AD. Phase III trials of Ginkgo biloba, NSAIDs, phenserine, statins, tarenflurbil, tramiprosate, and xaliproden have been completed, none of them demonstrating adequate efficacy. Encouraging results from completed Phase II trials of dimebon, huperzine A, intravenous immunoglobulin, and methylthioninium chloride were reported at ICAD 2008. Nineteen compounds are currently in Phase II trials, and 3 compounds (AN1792, lecozotan SR, and SGS742) failed at this stage of development. CONCLUSIONS Despite disappointing results from recently completed Phase III trials of several novel compounds, the extent and breadth of activity at all phases of clinical development suggest that new pharmacotherapeutic options for the treatment of AD will become available within the next decade.
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Affiliation(s)
- Marwan N Sabbagh
- The Cleo Roberts Center for Clinical Research, Banner-Sun Health Research Institute, Sun City, AZ 85351, USA.
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87
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Jakob-Roetne R, Jacobsen H. Die Alzheimer-Demenz: von der Pathologie zu therapeutischen Ansätzen. Angew Chem Int Ed Engl 2009. [DOI: 10.1002/ange.200802808] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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88
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Physiological and pathological role of alpha-synuclein in Parkinson's disease through iron mediated oxidative stress; the role of a putative iron-responsive element. Int J Mol Sci 2009; 10:1226-60. [PMID: 19399246 PMCID: PMC2672027 DOI: 10.3390/ijms10031226] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2008] [Revised: 03/03/2009] [Accepted: 03/11/2009] [Indexed: 12/16/2022] Open
Abstract
Parkinson’s disease (PD) is the second most common progressive neurodegenerative disorder after Alzheimer’s disease (AD) and represents a large health burden to society. Genetic and oxidative risk factors have been proposed as possible causes, but their relative contribution remains unclear. Dysfunction of alpha-synuclein (α-syn) has been associated with PD due to its increased presence, together with iron, in Lewy bodies. Brain oxidative damage caused by iron may be partly mediated by α-syn oligomerization during PD pathology. Also, α-syn gene dosage can cause familial PD and inhibition of its gene expression by blocking translation via a newly identified Iron Responsive Element-like RNA sequence in its 5’-untranslated region may provide a new PD drug target.
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89
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Bartolini M, Greig NH, Yu QS, Andrisano V. Immobilized butyrylcholinesterase in the characterization of new inhibitors that could ease Alzheimer's disease. J Chromatogr A 2008; 1216:2730-8. [PMID: 18950780 DOI: 10.1016/j.chroma.2008.09.100] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2008] [Revised: 09/26/2008] [Accepted: 09/29/2008] [Indexed: 11/28/2022]
Abstract
Focus of this work was the development and characterization of a new immobilized enzyme reactor (IMER) containing human recombinant butyrylcholinesterase (rBChE) for the on-line kinetic characterization of specific, pseudo-irreversible and brain-targeted BChE inhibitors as potential drug candidates for Alzheimer's disease (AD). Specifically, a rBChE-IMER containing 0.99 U of covalently bound target enzyme was purposely developed and inserted into a HPLC system connected to a UV-vis detector. Selected reversible cholinesterase inhibitors, (-)-phenserine and (-)-cymserine analogues, were then kinetically characterized by rBChE-IMER, and by classical in solution assays and their carbamoylation and decarbamoylation constants were determined. The results support the elucidation of the potency, inhibition duration, mode of action and specific structure/activity relations of these agents and allow cross-validation of the two assay techniques.
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Affiliation(s)
- Manuela Bartolini
- Department of Pharmaceutical Sciences, Via Belmeloro 6, University of Bologna, 40126 Bologna, Italy
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90
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Kadir A, Andreasen N, Almkvist O, Wall A, Forsberg A, Engler H, Hagman G, Lärksäter M, Winblad B, Zetterberg H, Blennow K, Långström B, Nordberg A. Effect of phenserine treatment on brain functional activity and amyloid in Alzheimer's disease. Ann Neurol 2008; 63:621-31. [DOI: 10.1002/ana.21345] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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91
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Nordberg A. Amyloid imaging in Alzheimer's disease. Neuropsychologia 2008; 46:1636-41. [DOI: 10.1016/j.neuropsychologia.2008.03.020] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2007] [Revised: 03/16/2008] [Accepted: 03/20/2008] [Indexed: 11/29/2022]
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92
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Kamal MA, Qu X, Yu QS, Tweedie D, Holloway HW, Li Y, Tan Y, Greig NH. Tetrahydrofurobenzofuran cymserine, a potent butyrylcholinesterase inhibitor and experimental Alzheimer drug candidate, enzyme kinetic analysis. J Neural Transm (Vienna) 2008; 115:889-98. [PMID: 18235987 DOI: 10.1007/s00702-008-0022-y] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2007] [Accepted: 01/14/2008] [Indexed: 12/29/2022]
Abstract
Synaptic loss, particularly related to the forebrain cholinergic system, is considered to be an early event that leads to Alzheimer's disease (AD) and has led to the development of acetylcholinesterase inhibitors (AChE-Is) as the mainstay of treatment for several degenerative disorders that culminate in dementia. The primary dose-limiting toxicities of all clinically available AChE-Is are, similar to useful actions on cognition, cholinergically mediated and they ultimately limit the value of this drug class in achieving anything but symptomatic improvements. In addition, AChE levels in brain areas associated with AD decline with disease progression, which likely ultimately limits the therapeutic utility of this drug class. New research indicates that selective inhibition of butyrylcholinesterase (BuChE), a closely related enzyme that is markedly elevated in AD brain, increases acetylcholine (ACh) and augments cognition in rodents free of the characteristic undesirable actions of AChE-Is. BuChE inhibition hence represents an innovative treatment approach for AD, and agents are currently being synthesized to optimally achieve this. The novel compound, tetrahydrofurobenzofuran cymserine (THFBFC), is derived from our effort to produce a potent and BuChE-selective inhibitor as a candidate to test the hypothesis that BuChE-Is would be efficacious and better tolerated than AChE-Is in AD. Herein, we applied innovative enzyme kinetic analyses to characterize the quantitative interaction of THFBFC with human BuChE. These provided values for the agent's IC(50), together with specific new kinetic constants, such as K (T50), K (T1/2), R (I), (o)K (RT), (o)P(max), K(PT) and PT(1/2), to aid define target concentrations for clinical translation. Additional classical kinetic parameters, including K(i), K(m)or K(s), k(cat) or V(max) and V (mi) were also determined. THFBFC proved to be a potent competitive inhibitor of human BuChE and, like its isomer dihydrobenzodioxepine cymserine, is a potentially interesting AD drug candidate.
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Affiliation(s)
- Mohammad A Kamal
- Department of Medical and Molecular BioSciences, Faculty of Science, University of Technology Sydney, Sydney, NSW, Australia.
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93
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Marks N, Berg MJ. Neurosecretases provide strategies to treat sporadic and familial Alzheimer disorders. Neurochem Int 2008; 52:184-215. [PMID: 17719698 DOI: 10.1016/j.neuint.2007.06.020] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2007] [Revised: 06/05/2007] [Indexed: 12/30/2022]
Abstract
Recent discoveries on neurosecretases and their trafficking to release fibril-forming neuropeptides or other products, are of interest to pathology, cell signaling and drug discovery. Nomenclature arose from the use of amyloid precursor protein (APP) as a prototypic type-1 substrate leading to the isolation of beta-secretase (BACE), multimeric complexes (gamma-secretase, gamma-SC) for intramembranal cleavage, and attributing a new function to well-characterized metalloproteases of the ADAM family (alpha-secretase) for normal APP turnover. While purified alpha/beta-secretases facilitate drug discovery, gamma-SC presents greater challenges for characterization and mechanisms of catalysis. The review comments on links between mutation or polymorphisms in relation to enzyme mechanisms and disease. The association between lipoprotein receptor LRP11 variants and sporadic Alzheimer's disease (SAD) offers scope to integrate components of pre- and post-Golgi membranes, or brain clathrin-coated vesicles within pathways for trafficking as targets for intervention. The presence of APP and metabolites in brain clathrin-coated vesicles as significant cargo with lipoproteins and adaptors focuses attention as targets for therapeutic intervention. This overview emphasizes the importance to develop new therapies targeting neurosecretases to treat a major neurological disorder that has vast economic and social implications.
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Affiliation(s)
- Neville Marks
- Center for Neurochemistry, Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY 10962, United States.
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Walker D, Lue LF. Anti-inflammatory and immune therapy for Alzheimer's disease: current status and future directions. Curr Neuropharmacol 2007; 5:232-43. [PMID: 19305740 PMCID: PMC2644496 DOI: 10.2174/157015907782793667] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2007] [Revised: 03/30/2007] [Accepted: 04/12/2007] [Indexed: 12/12/2022] Open
Abstract
From the initial characterizations of inflammatory responses in Alzheimer's disease (AD) affected brains, namely the demonstration of activated microglia and reactive astrocytes, complement system activation, increased production of proinflammatory cytokines, and evidence for microglial-produced neurotoxins, there was hope that reducing inflammation might be a feasible treatment for this memory-robbing disease. This hope was supported by a number of epidemiology studies demonstrating that patients who took non-steroidal anti-inflammatory drugs had significantly lower risk of developing AD. However, clinical trials of anti-inflammatories have not shown effectiveness, and in recent years, the concept of immune therapy has become a treatment option as animal studies and clinical trials with Abeta vaccines have demonstrated enhanced amyloid removal through stimulation of microglial phagocytosis.This review will examine the current status of whether inhibiting inflammation is a valid therapeutic target for treating AD; what lessons have come from the clinical trials; what new pathways and classes of agents are being considered; and how this field of research can progress towards new therapeutics. We will examine a number of agents that have shown effectiveness in reducing inflammation amongst other demonstrated mechanisms of action. The major focus of much AD drug discovery has been in identifying agents that have anti-amyloid properties; however, a number of these agents were first identified for their anti-inflammatory properties. As drug development and clinical testing is a costly and lengthy endeavor, sound justification of new therapeutic targets is required. Possible future directions for AD anti-inflammatory or immune clearance therapy will be discussed based on recent experimental data.
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Affiliation(s)
- Douglas Walker
- Laboratory of Neuroinflammation, Sun Health Research Institute, Sun City, Arizona, USA.
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95
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Abstract
Phenserine, a derivative of physostigmine, was first described as an inhibitor of acetylcholinesterase (AChE) and was shown to improve cognition in various experimental paradigms in rodents and dogs. It was clinically tested for Alzheimer's disease, with moderate success in initial Phase II studies. Phenserine deserves attention for an additional quality of action: in addition to inhibiting AChE, it modulates the amount of beta-amyloid precursor protein (APP) in neuronal cell culture by reducing APP translation. This effect probably involves interaction of phenserine with a regulatory element in the 5'-untranslated region of the APP gene that controls APP expression. Phenserine apparently reduces translational efficiency of APP mRNA into protein, a process that may involve an interaction with iron and/or an iron-responsive element. As a consequence, phenserine reduces beta-amyloid peptide (Abeta) formation in vitro and in vivo. Phenserine is also unique because of differing actions of its enantiomers: (-)-phenserine is the active enantiomer for inhibition of AChE, whereas (+)-phenserine ('posiphen') has weak activity as an AChE inhibitor and can be dosed much higher. Both enantiomers are equipotent in downregulating APP expression. (+)-Posiphen may be a promising drug, either alone or in combination with (-)-phenserine, to attenuate the progression of Alzheimer's disease.
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Affiliation(s)
- Jochen Klein
- University of Frankfurt College of Pharmacy, Biocenter N260, Frankfurt, Germany.
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Utsuki T, Uchimura N, Irikura M, Moriuchi H, Holloway HW, Yu QS, Spangler EL, Mamczarz J, Ingram DK, Irie T, Greig NH. Preclinical Investigation of the Topical Administration of Phenserine: Transdermal Flux, Cholinesterase Inhibition, and Cognitive Efficacy. J Pharmacol Exp Ther 2007; 321:353-61. [PMID: 17255466 DOI: 10.1124/jpet.106.118000] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Phenserine (PS) was designed as a selective acetylcholinesterase (AChE) inhibitor, with a tartrate form (PST) for oral administration in mild to moderate Alzheimer's disease (AD). Recent phase 3 trials of PST in Europe indicate that any clinically relevant activity of PST may be limited by its duration of action. Like many oral drugs, bioavailability and plasma concentrations of PST are regulated by hepatic and gastrointestinal first-pass effects. To minimize the kinetic limitations of first-pass metabolism, transdermal formulations of PS and PST (ointment/patch) were developed and characterized in vitro and in vivo. Initial in vitro kinetic characterization of PS or PST formulations used a diffusion cell chamber and skin samples isolated from hairless mice. Liquid paraffin and fatty alcohol/propylene glycol (FAPG) were found to be suitable vehicles for ointment formulation. Addition of a penetration enhancer, 1-[2-(decylthio)ethyl]-azacyclopentane-2-one (HPE-101), improved stratum corneum permeability. Application of the optimal formulation of PS/HPE-101/FAPG to the shaved back of rats resulted in significantly lowered plasma and brain AChE activities and improved cognitive performance in animals with scopolamine-induced cognitive impairment. These results suggest that the transdermal application of AChE inhibitors may represent an effective therapeutic strategy for AD. Particular benefits over oral therapies might include avoiding first-pass metabolic effects and improved dosing compliance.
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Affiliation(s)
- Tadanobu Utsuki
- Drug Design and Development Section, Laboratory of Neurosciences, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, USA
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H. Greig N, Luo W, Yu QS, W. Holloway H, Tweedie D, Parrish D, Brossi A. Syntheses and Anticholinesterase Activities of Novel 3-Aminocarbonylmethylene-3-methyl-2,3-dihydrobenzofuran-5-yl Carbamates. HETEROCYCLES 2007. [DOI: 10.3987/com-07-11136] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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