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Kristofikova Z, Ricny J, Soukup O, Korabecny J, Nepovimova E, Kuca K, Ripova D. Inhibitors of Acetylcholinesterase Derived from 7-Methoxytacrine and Their Effects on the Choline Transporter CHT1. Dement Geriatr Cogn Disord 2018; 43:45-58. [PMID: 27988521 DOI: 10.1159/000453256] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/08/2016] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Reversible acetylcholinesterase inhibitors are used in Alzheimer disease therapy. However, tacrine and its derivatives have severe side effects. Derivatives of the tacrine analogue 7-methoxytacrine (MEOTA) are less toxic. METHODS We evaluated new derivatives of 7-MEOTA (2 homodimers linked by 2 C4-C5 chains and 5 N-alkylated C4-C8 side chain derivatives) in vitro, using the rat hippocampal choline transporter CHT1. RESULTS Some derivatives were effective inhibitors of rat acetylcholinesterase and comparable with 7-MEOTA. All derivatives were able to inhibit CHT1, probably via quaternary ammonium, and this interaction could be involved in the enhancement of their detrimental side effects and/or in the attenuation of their promising effects. Under conditions of disrupted lipid rafts, the unfavorable effects of some derivatives were weakened. Only tacrine was probably able to stereospecifically interact with the naturally occurring amyloid-β isoform and to simultaneously stimulate CHT1. Some derivatives, when coincubated with amyloid β, did not influence CHT1. All derivatives also increased the fluidity of the cortical membranes. CONCLUSION The N-alkylated derivative of 7-MEOTA bearing from C4 side chains appears to be the most promising compound and should be evaluated in future in vivo research.
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Affiliation(s)
- Zdenka Kristofikova
- Alzheimer Disease Center, National Institute of Mental Health, Klecany, Czech Republic
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Cuddy LK, Seah C, Pasternak SH, Rylett RJ. Amino-Terminal β-Amyloid Antibody Blocks β-Amyloid-Mediated Inhibition of the High-Affinity Choline Transporter CHT. Front Mol Neurosci 2017; 10:361. [PMID: 29163036 PMCID: PMC5681948 DOI: 10.3389/fnmol.2017.00361] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 10/19/2017] [Indexed: 11/13/2022] Open
Abstract
Alzheimer's disease (AD) is a common age-related neurodegenerative disorder that is characterized by progressive cognitive decline. The deficits in cognition and attentional processing that are observed clinically in AD are linked to impaired function of cholinergic neurons that release the neurotransmitter acetylcholine (ACh). The high-affinity choline transporter (CHT) is present at the presynaptic cholinergic nerve terminal and is responsible for the reuptake of choline produced by hydrolysis of ACh following its release. Disruption of CHT function leads to decreased choline uptake and ACh synthesis, leading to impaired cholinergic neurotransmission. We report here that cell-derived β-amyloid peptides (Aβ) decrease choline uptake activity and cell surface CHT protein levels in SH-SY5Y neural cells. Moreover, we make the novel observation that the amount of CHT protein localizing to early endosomes and lysosomes is decreased significantly in cells that have been treated with cell culture medium that contains Aβ peptides released from neural cells. The Aβ-mediated loss of CHT proteins from lysosomes is prevented by blocking lysosomal degradation of CHT with the lysosome inhibitor bafilomycin A1 (BafA1). BafA1 also attenuated the Aβ-mediated decrease in CHT cell surface expression. Interestingly, however, lysosome inhibition did not block the effect of Aβ on CHT activity. Importantly, neutralizing Aβ using an anti-Aβ antibody directed at the N-terminal amino acids 1-16 of Aβ, but not by an antibody directed at the mid-region amino acids 22-35 of Aβ, attenuates the effect of Aβ on CHT activity and trafficking. This indicates that a specific N-terminal Aβ epitope, or specific conformation of soluble Aβ, may impair CHT activity. Therefore, Aβ immunotherapy may be a more effective therapeutic strategy for slowing the progression of cognitive decline in AD than therapies designed to promote CHT cell surface levels.
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Affiliation(s)
- Leah K Cuddy
- Molecular Medicine Research Laboratories, Robarts Research Institute, University of Western Ontario, London, ON, Canada.,Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada.,Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Claudia Seah
- Molecular Medicine Research Laboratories, Robarts Research Institute, University of Western Ontario, London, ON, Canada
| | - Stephen H Pasternak
- Molecular Medicine Research Laboratories, Robarts Research Institute, University of Western Ontario, London, ON, Canada.,Department of Clinical Neurological Sciences, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada
| | - R Jane Rylett
- Molecular Medicine Research Laboratories, Robarts Research Institute, University of Western Ontario, London, ON, Canada.,Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada
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Kristofikova Z, Ripova D, Hegnerová K, Sirova J, Homola J. Protein τ-Mediated Effects on Rat Hippocampal Choline Transporters CHT1 and τ-Amyloid β Interactions. Neurochem Res 2013; 38:1949-59. [DOI: 10.1007/s11064-013-1101-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Revised: 06/18/2013] [Accepted: 06/26/2013] [Indexed: 12/11/2022]
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Soukup O, Jun D, Tobin G, Kuca K. The summary on non-reactivation cholinergic properties of oxime reactivators: the interaction with muscarinic and nicotinic receptors. Arch Toxicol 2012. [PMID: 23179755 DOI: 10.1007/s00204-012-0977-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Organophosphorus inhibitors (OP) of acetylcholinesterase (AChE) represent a group of highly toxic compounds. The treatment of OP intoxication is, however, insufficiently ensured. Currently, two main categories of drugs-anticholinergics and oxime reactivators- are employed as antidotes. Oximes have been reported to act at several levels of the cholinergic transmission, and among the non-reactivation effects, the interaction with cholinergic receptors stands out. This review addresses issues correlated with non-reactivating effects of oxime reactivators with a special focus on the muscarinic and nicotinic receptors, but involvement of other cholinergic structures such as AChE and choline uptake carriers are discussed too. It can be concluded that the oxime reactivators show a variation in their antagonistic effect on the muscarinic and nicotinic receptors, which is likely to be of significance in the treatment of OP poisoning. In vitro data reported oximes to exert higher efficacy on the muscarinic M2 subtype than on the AChE. However, this effect seemed to be subtype specific since the antagonistic M3 effect was lower. Also, and importantly, the antimuscarinic effect was larger than that on nicotinic receptors. Even though atropine showed a much higher muscarinic antagonism, it is supposed that non-reactivation properties of oxime reactivators play a significant role in the treatment of OP poisoning.
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Affiliation(s)
- O Soukup
- Biomedical Research Center, University Hospital of Hradec Kralove, Sokolska 581, 50005 Hradec Kralove, Czech Republic
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Soukup O, Kristofikova Z, Jun D, Tambor V, Ripova D, Kuca K. The interaction of standard oxime reactivators with hemicholinium-3 sensitive choline carriers. Toxicol Lett 2012; 212:315-9. [DOI: 10.1016/j.toxlet.2012.05.027] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2012] [Revised: 05/28/2012] [Accepted: 05/30/2012] [Indexed: 11/29/2022]
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Krištofiková Z, Kříž Z, Řípová D, Koča J. Interactions of Amyloid β Peptide 1–40 and Cerebrosterol. Neurochem Res 2011; 37:604-13. [DOI: 10.1007/s11064-011-0650-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Revised: 10/31/2011] [Accepted: 11/03/2011] [Indexed: 01/07/2023]
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Nunes MA, Santos S, Cordeiro JM, Neves P, Silva VS, Sykes A, Morgado F, Dunant Y, Gonçalves PP. Acetylcholine release and choline uptake by cuttlefish (Sepia officinalis) optic lobe synaptosomes. THE BIOLOGICAL BULLETIN 2008; 214:1-5. [PMID: 18258770 DOI: 10.2307/25066654] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Acetylcholine (ACh), which is synthesized from choline (Ch), is believed to hold a central place in signaling mechanisms within the central nervous system (CNS) of cuttlefish (Sepia officinalis) and other coleoid cephalopods. Although the main elements required for cholinergic function have been identified in cephalopods, the transmembrane translocation events promoting the release of ACh and the uptake of Ch remain largely unsolved. The ACh release and Ch uptake were quantitatively studied through the use of in vitro chemiluminescence and isotopic methods on a subcellular fraction enriched in synaptic nerve endings (synaptosomes) isolated from cuttlefish optic lobe. The ACh release evoked by K+ depolarization was found to be very high (0.04 pmol ACh.s(-1).mg(-1) protein). In response to stimulation by veratridine, a secretagogue (a substance that induces secretion) that targets voltage-gated Na+ channels, the release rate and the total amount of ACh released were significantly lower, by 10-fold, than the response induced by KCl. The high-affinity uptake of choline was also very high (31 pmol Ch.min(-1).mg(-1) protein). The observed ACh release and Ch uptake patterns are in good agreement with published data on preparations characterized by high levels of ACh metabolism, adding further evidence that ACh acts as a neurotransmitter in cuttlefish optic lobe.
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Affiliation(s)
- M Alexandra Nunes
- CESAM, Departamento de Biologia, Universidade de Aveiro, 3810-193 Aveiro, Portugal
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Kristofiková Z, Kopecký V, Hofbauerová K, Hovorková P, Rípová D. Complex of Amyloid β Peptides with 24-Hydroxycholesterol and Its Effect on Hemicholinium-3 Sensitive Carriers. Neurochem Res 2007; 33:412-21. [PMID: 17717740 DOI: 10.1007/s11064-007-9443-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2007] [Accepted: 07/12/2007] [Indexed: 01/07/2023]
Abstract
Brains of Alzheimer disease patients in early stages of dementia contain an increased 24(S)-hydroxycholesterol (cerebrosterol)/cholesterol ratio when compared to controls. In this study, effects of amyloid beta peptides and of racemic 24-hydroxycholesterol were evaluated in vitro on undepleted or cholesterol-depleted hippocampal synaptosomes of young and old rats via a high-affinity choline transport and membrane anisotropy measurements. Depletion of membrane cholesterol decreased the transport of [3H]choline, increased the specific binding of [3H]hemicholinium-3 and decreased membrane anisotropy. However, less alterations were found in old when compared to young brains. 500 nM nonaggregated peptides were ineffective but aggregated fragment 1-42 evoked marked drops in the transport and anisotropy values on depleted synaptosomes. 50 microM 24-hydroxycholesterol inhibited choline transport on depleted synaptosomes but it did not influence membrane anisotropy. Peptides eliminated the actions of oxysterol on choline carriers in young but not in old rats. On the other hand, oxysterol eliminated the effects of peptides on membrane anisotropy. Our study suggests a possible role of membrane cholesterol in the regulation of choline carriers and supports data reporting a protective role of membrane cholesterol against toxic effects of amyloid beta peptides. Moreover, via Raman spectroscopy we demonstrate for the first time that peptides form a complex with 24-hydroxycholesterol.
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Affiliation(s)
- Zdena Kristofiková
- Alzheimer Disease Centre, Prague Psychiatric Centre, Ustavní 91, Prague 8 - Bohnice 181 03, Czech Republic.
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Silva VS, Nunes MA, Cordeiro JM, Calejo AI, Santos S, Neves P, Sykes A, Morgado F, Dunant Y, Gonçalves PP. Comparative effects of aluminum and ouabain on synaptosomal choline uptake, acetylcholine release and (Na+/K+)ATPase. Toxicology 2007; 236:158-77. [PMID: 17560001 DOI: 10.1016/j.tox.2007.04.017] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2007] [Revised: 03/16/2007] [Accepted: 04/10/2007] [Indexed: 11/25/2022]
Abstract
Closing the gap between adverse health effects of aluminum and its mechanisms of action still represents a huge challenge. Cholinergic dysfunction has been implicated in neuronal injury induced by aluminum. Previously reported data also indicate that in vivo and in vitro exposure to aluminum inhibits the mammalian (Na(+)/K(+))ATPase, an ubiquitous plasma membrane pump. This study was undertaken with the specific aim of determining whether in vitro exposure to AlCl(3) and ouabain, the foremost utilized selective inhibitor of (Na(+)/K(+))ATPase, induce similar functional modifications of cholinergic presynaptic nerve terminals, by comparing their effects on choline uptake, acetylcholine release and (Na(+)/K(+))ATPase activity, on subcellular fractions enriched in synaptic nerve endings isolated from rat brain, cuttlefish optic lobe and torpedo electric organ. Results obtained show that choline uptake by rat synaptosomes was inhibited by submillimolar AlCl(3), whereas the amount of choline taken up by synaptosomes isolated from cuttlefish and torpedo remained unchanged. Conversely, choline uptake was reduced by ouabain to a large extent in all synaptosomal preparations analyzed. In contrast to ouabain, which modified the K(+) depolarization evoked release of acetylcholine by rat, cuttlefish and torpedo synaptosomal fractions, AlCl(3) induced reduction of stimulated acetylcholine release was only observed when rat synaptosomes were challenged. Finally, it was observed that the aluminum effect on cuttlefish and torpedo synaptosomal (Na(+)/K(+))ATPase activity was slight when compared to its inhibitory action on mammalian (Na(+)/K(+))ATPase. In conclusion, inhibition of (Na(+)/K(+))ATPase by AlCl(3) and ouabain jeopardized the high-affinity (Na(+)-dependent, hemicholinium-3 sensitive) uptake of choline and the Ca(2+)-dependent, K(+) depolarization evoked release of acetylcholine by rat, cuttlefish and torpedo synaptosomal fractions. The effects of submillimolar AlCl(3) on choline uptake and acetylcholine release only resembled those of ouabain when rat synaptosomes were assayed. Therefore, important differences were found between the species regarding the cholinotoxic action of aluminum. The variability of (Na(+)/K(+))ATPase sensitivity to aluminum of cholinergic neurons might contribute to their differential susceptibility to this neurotoxic agent.
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Affiliation(s)
- Virgília S Silva
- CESAM, Departamento de Biologia, Universidade de Aveiro, 3810-193 Aveiro, Portugal
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Kristofiková Z, Rícný J, Kozmiková I, Rípová D, Zach P, Klaschka J. Sex-dependent Actions of Amyloid Beta Peptides on Hippocampal Choline Carriers of Postnatal Rats. Neurochem Res 2006; 31:351-60. [PMID: 16733811 DOI: 10.1007/s11064-005-9026-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
It is suggested that amyloid beta peptides (Abeta) play a role in the pathogenesis of Alzheimer disease but their physiological function is still unknown. However, low pM-nM concentrations mediate a hypofunction of a basal forebrain cholinergic system without marked signs of neurotoxicity. In this study, we compared in vitro effects of soluble nonaggregated human Abeta 1-40 and 1-42 either on synaptosomal hemicholinium-3 sensitive choline carriers or on membrane fluidity in hippocampi of male and female Wistar rats aged 7 and 14 days or 2-3 months. The results indicate age- and sex-dependent effects mediated by peptides at nM concentrations but no significant differences between both fragments. Namely, opposite actions were observed in 14-day (the increase in the choline uptake and membrane fluidity) when compared to 7-day old and adult males (the mild drops). Lineweaver-Burk plot analysis revealed that the enhancement of the high-affinity choline transport in 14-day old males occurs via alterations in K (M )and the change was accompanied by a mild increase in the specific binding of [3H]hemicholinium-3. On the other hand, no age-dependent differences were found in females. Rat Abeta 1-40 mediated similar effects on 14-day old rats as the corresponding human fragment. Moreover, higher levels of soluble peptides were detected in immature when compared to mature male brains by means of competitive ELISA. Our study indicates that Abeta could play a role in postnatal sexual differentiation of hippocampal cholinergic system.
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Affiliation(s)
- Z Kristofiková
- Prague Psychiatric Center, Ustavní 91, Prague 8, Bohnice, 181 03, Prague, Czech Republic.
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Kar S, Quirion R. Amyloid β peptides and central cholinergic neurons: functional interrelationship and relevance to Alzheimer's disease pathology. PROGRESS IN BRAIN RESEARCH 2004; 145:261-74. [PMID: 14650921 DOI: 10.1016/s0079-6123(03)45018-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Satyabrata Kar
- Douglas Hospital Research Center, Department of Psychiatry, McGill University, 6875 La Salle Blvd., Verdun, Montreal, QC H4H 1R3, Canada
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Auld DS, Kornecook TJ, Bastianetto S, Quirion R. Alzheimer's disease and the basal forebrain cholinergic system: relations to beta-amyloid peptides, cognition, and treatment strategies. Prog Neurobiol 2002; 68:209-45. [PMID: 12450488 DOI: 10.1016/s0301-0082(02)00079-5] [Citation(s) in RCA: 472] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Alzheimer's disease (AD) is the most common form of degenerative dementia and is characterized by progressive impairment in cognitive function during mid- to late-adult life. Brains from AD patients show several distinct neuropathological features, including extracellular beta-amyloid-containing plaques, intracellular neurofibrillary tangles composed of abnormally phosphorylated tau, and degeneration of cholinergic neurons of the basal forebrain. In this review, we will present evidence implicating involvement of the basal forebrain cholinergic system in AD pathogenesis and its accompanying cognitive deficits. We will initially discuss recent results indicating a link between cholinergic mechanisms and the pathogenic events that characterize AD, notably amyloid-beta peptides. Following this, animal models of dementia will be discussed in light of the relationship between basal forebrain cholinergic hypofunction and cognitive impairments in AD. Finally, past, present, and future treatment strategies aimed at alleviating the cognitive symptomatology of AD by improving basal forebrain cholinergic function will be addressed.
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Affiliation(s)
- Daniel S Auld
- Douglas Hospital Research Centre, 6875 Blvd Lasalle, Verdun, Que, Canada H4H 1R3
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Abstract
Choline has many physiological functions throughout the body that are dependent on its available local supply. However, since choline is a charged hydrophilic cation, transport mechanisms are required for it to cross biological membranes. Choline transport is required for cellular membrane construction and is the rate-limiting step for acetylcholine production. Transport mechanisms include: (1) sodium-dependent high-affinity uptake mechanism in synaptosomes, (2) sodium-independent low-affinity mechanism on cellular membranes, and (3) unique choline uptake mechanisms (e.g., blood-brain barrier choline transport). A comprehensive overview of choline transport studies is provided. This review article examines landmark and current choline transport studies, molecular mapping, and molecular identification of these carriers. Information regarding the choline-binding site is presented by reviewing choline structural analog (hemicholinium-3 and 15, and other nitrogen/methyl-hydroxyl compounds) inhibition studies. Choline transport in Alzheimer's disease, brain ischemic events, and aging is also discussed. Emphasis throughout the article is placed on targeting the choline transporter in disease and use of this carrier as a drug delivery vector.
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Affiliation(s)
- P R Lockman
- Department of Pharmaceutical Sciences, School of Pharmacy, Texas Tech University Health Sciences Center, Amarillo, Texas 79106-1712, USA
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Role of amyloid ? peptides in the regulation of central cholinergic function and its relevance to Alzheimer's disease pathology. Drug Dev Res 2002. [DOI: 10.1002/ddr.10080] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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