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German‐Castelan L, Shanks HRC, Gros R, Saito T, Saido TC, Saksida LM, Bussey TJ, Prado MAM, Schmitz TW, Prado VF. Sex-dependent cholinergic effects on amyloid pathology: A translational study. Alzheimers Dement 2024; 20:995-1012. [PMID: 37846816 PMCID: PMC10916951 DOI: 10.1002/alz.13481] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 08/05/2023] [Accepted: 08/17/2023] [Indexed: 10/18/2023]
Abstract
INTRODUCTION About two-thirds of Alzheimer's Disease (AD) patients are women, who exhibit more severe pathology and cognitive decline than men. Whether biological sex causally modulates the relationship between cholinergic signaling and amyloid pathology remains unknown. METHODS We quantified amyloid beta (Aβ) in male and female App-mutant mice with either decreased or increased cholinergic tone and examined the impact of ovariectomy and estradiol replacement in this relationship. We also investigated longitudinal changes in basal forebrain (cholinergic function) and Aβ in elderly individuals. RESULTS We show a causal relationship between cholinergic tone and amyloid pathology in males and ovariectomized female mice, which is decoupled in ovary-intact and ovariectomized females receiving estradiol. In elderly humans, cholinergic loss exacerbates Aβ. DISCUSSION Our findings emphasize the importance of reflecting human menopause in mouse models. They also support a role for therapies targeting estradiol and cholinergic signaling to reduce Aβ. HIGHLIGHTS Cholinergic tone regulates amyloid beta (Aβ) pathology in males and ovariectomized female mice. Estradiol uncouples the relationship between cholinergic tone and Aβ. In elderly humans, cholinergic loss correlates with increased Aβ in both sexes.
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Affiliation(s)
- Liliana German‐Castelan
- Robarts Research InstituteSchulich School of Medicine and DentistryUniversity of Western OntarioLondonOntarioCanada
- Neuroscience programSchulich School of Medicine and DentistryUniversity of Western OntarioLondonOntarioCanada
| | - Hayley R. C. Shanks
- Neuroscience programSchulich School of Medicine and DentistryUniversity of Western OntarioLondonOntarioCanada
| | - Robert Gros
- Robarts Research InstituteSchulich School of Medicine and DentistryUniversity of Western OntarioLondonOntarioCanada
- Department of MedicineSchulich School of Medicine & DentistryUniversity of Western OntarioLondonOntarioCanada
- Department of Physiology and PharmacologySchulich School of Medicine & DentistryUniversity of Western OntarioLondonOntarioCanada
| | - Takashi Saito
- Department of Neurocognitive ScienceInstitute of Brain ScienceNagoya City University Graduate School of Medical SciencesNagoyaJapan
- Laboratory for Proteolytic NeuroscienceRIKEN Center for Brain ScienceWako, SaitamaJapan
| | - Takaomi C. Saido
- Laboratory for Proteolytic NeuroscienceRIKEN Center for Brain ScienceWako, SaitamaJapan
| | - Lisa M. Saksida
- Robarts Research InstituteSchulich School of Medicine and DentistryUniversity of Western OntarioLondonOntarioCanada
- Neuroscience programSchulich School of Medicine and DentistryUniversity of Western OntarioLondonOntarioCanada
- Department of Physiology and PharmacologySchulich School of Medicine & DentistryUniversity of Western OntarioLondonOntarioCanada
- Western Institute for NeuroscienceUniversity of Western OntarioLondonOntarioCanada
| | - Timothy J. Bussey
- Robarts Research InstituteSchulich School of Medicine and DentistryUniversity of Western OntarioLondonOntarioCanada
- Neuroscience programSchulich School of Medicine and DentistryUniversity of Western OntarioLondonOntarioCanada
- Department of Physiology and PharmacologySchulich School of Medicine & DentistryUniversity of Western OntarioLondonOntarioCanada
- Western Institute for NeuroscienceUniversity of Western OntarioLondonOntarioCanada
| | - Marco A. M. Prado
- Robarts Research InstituteSchulich School of Medicine and DentistryUniversity of Western OntarioLondonOntarioCanada
- Neuroscience programSchulich School of Medicine and DentistryUniversity of Western OntarioLondonOntarioCanada
- Department of Physiology and PharmacologySchulich School of Medicine & DentistryUniversity of Western OntarioLondonOntarioCanada
- Western Institute for NeuroscienceUniversity of Western OntarioLondonOntarioCanada
- Department of Anatomy and Cell BiologySchulich School of Medicine & DentistryUniversity of Western OntarioLondonOntarioCanada
| | - Taylor W. Schmitz
- Robarts Research InstituteSchulich School of Medicine and DentistryUniversity of Western OntarioLondonOntarioCanada
- Neuroscience programSchulich School of Medicine and DentistryUniversity of Western OntarioLondonOntarioCanada
- Western Institute for NeuroscienceUniversity of Western OntarioLondonOntarioCanada
- Lawson Health Research InstituteSt. Joseph's HospitalLondonOntarioCanada
| | - Vania F. Prado
- Robarts Research InstituteSchulich School of Medicine and DentistryUniversity of Western OntarioLondonOntarioCanada
- Neuroscience programSchulich School of Medicine and DentistryUniversity of Western OntarioLondonOntarioCanada
- Department of Physiology and PharmacologySchulich School of Medicine & DentistryUniversity of Western OntarioLondonOntarioCanada
- Western Institute for NeuroscienceUniversity of Western OntarioLondonOntarioCanada
- Department of Anatomy and Cell BiologySchulich School of Medicine & DentistryUniversity of Western OntarioLondonOntarioCanada
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Li J, Li D, Zhou H, Wu G, He Z, Liao W, Li Y, Zhi Y. MicroRNA-338-5p alleviates neuronal apoptosis via directly targeting BCL2L11 in APP/PS1 mice. Aging (Albany NY) 2020; 12:20728-20742. [PMID: 33087587 PMCID: PMC7655176 DOI: 10.18632/aging.104005] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 08/01/2020] [Indexed: 12/30/2022]
Abstract
MicroRNAs have become pivotal modulators in the pathogenesis of Alzheimer’s disease. MiR-338-5p is associated with neuronal differentiation and neurogenesis, and expressed aberrantly in patients with cognitive dysfunction. However, its role and potential mechanism involved in Alzheimer’s disease remain to be elucidated. Herein, we showed that the expression of miR-338-5p decreased in APP/PS1 mice, accompanied by the elevation in the expression level of amyloid β, which indicated a reverse relationship between Alzheimer’s disease progression and miR-338-5p. In addition, lentiviral overexpression of miR-338-5p through intrahippocampal injection mitigated the amyloid plaque deposition and cognitive dysfunction in APP/PS1 mice, suggesting a protecting role of miR-338-5p against the development of Alzheimer’s disease. Moreover, miR-338-5p decelerated apoptotic loss of neurons in APP/PS1 mice. MiR-338-5p decreased neuronal apoptosis in vitro induced by amyloid β accumulation, which was attributed to the negative regulation of BCL2L11 by miR-338-5p, since the restoration of BCL2L11 eliminated the protective role of miR-338-5p against neuronal apoptosis. Taken together, all of these results may indicate miR-338-5p as an innovative modulator in the pathogenesis of Alzheimer’s disease, and also suggest that the protective effect of miR-338-5p on neuronal apoptosis may underlie its beneficial effect on APP/PS1 mice.
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Affiliation(s)
- Junhua Li
- Department of Anesthesiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, China.,Laboratory of RNA and Major Diseases of Brain and Hearts, Sun Yat-sen University, Guangzhou 510120, China.,Guangdong Province Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Danhua Li
- Department of Pediatrics, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, China.,Laboratory of RNA and Major Diseases of Brain and Hearts, Sun Yat-sen University, Guangzhou 510120, China
| | - Huatao Zhou
- Department of Cardiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, China.,Laboratory of RNA and Major Diseases of Brain and Hearts, Sun Yat-sen University, Guangzhou 510120, China
| | - Guiyun Wu
- Department of Anesthesiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, China.,Laboratory of RNA and Major Diseases of Brain and Hearts, Sun Yat-sen University, Guangzhou 510120, China
| | - Zhijie He
- Department of Intensive Care Unit, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, China
| | - Wenhua Liao
- Department of Intensive Care Unit, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, China
| | - Yujuan Li
- Department of Anesthesiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, China.,Laboratory of RNA and Major Diseases of Brain and Hearts, Sun Yat-sen University, Guangzhou 510120, China.,Guangdong Province Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Yaowei Zhi
- Department of Intensive Care Unit, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, China
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Parikh V, Bernard CS, Naughton SX, Yegla B. Interactions between Aβ oligomers and presynaptic cholinergic signaling: age-dependent effects on attentional capacities. Behav Brain Res 2014; 274:30-42. [PMID: 25101540 DOI: 10.1016/j.bbr.2014.07.046] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Revised: 07/14/2014] [Accepted: 07/25/2014] [Indexed: 12/24/2022]
Abstract
Substantial evidence suggests that cerebral deposition of the neurotoxic fibrillar form of amyloid precursor protein, β-amyloid (Aβ), plays a critical role in the pathogenesis of Alzheimer's disease (AD). Yet, many aspects of AD pathology including the cognitive symptoms and selective vulnerability of cortically projecting basal forebrain (BF) cholinergic neurons are not well explained by this hypothesis. Specifically, it is not clear why cognitive decline appears early when the loss of BF cholinergic neurons and plaque deposition are manifested late in AD. Soluble oligomeric forms of Aβ are proposed to appear early in the pathology and to be better predictors of synaptic loss and cognitive deficits. The present study was designed to examine the impact of Aβ oligomers on attentional functions and presynaptic cholinergic transmission in young and aged rats. Chronic intracranial infusions of Aβ oligomers produced subtle decrements in the ability of rats to sustain attentional performance with time on task, irrespective of the age of the animals. However, Aβ oligomers produced robust detrimental effects on performance under conditions of enhanced attentional load in aged animals. In vivo electrochemical recordings show reduced depolarization-evoked cholinergic signals in Aβ-infused aged rats. Moreover, soluble Aβ disrupted the capacity of cholinergic synapses to clear exogenous choline from the extracellular space in both young and aged rats, reflecting impairments in the choline transport process that is critical for acetylcholine (ACh) synthesis and release. Although aging per se reduced the cross-sectional area of BF cholinergic neurons and presynaptic cholinergic proteins in the cortex, attentional performance and ACh release remained unaffected in aged rats infused with the control peptide. Taken together, these data suggest that soluble Aβ may marginally influence attentional functions at young ages primarily by interfering with the choline uptake processes. However, age-related weakening of the cholinergic system may synergistically interact with these disruptive presynaptic mechanisms to make this neurotransmitter system vulnerable to the toxic effects of oligomeric Aβ in robustly impeding attentional capacities.
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Affiliation(s)
- Vinay Parikh
- Department of Psychology and Neuroscience Program, Temple University, Philadelphia, PA 19122, United States.
| | - Carcha S Bernard
- Department of Psychology and Neuroscience Program, Temple University, Philadelphia, PA 19122, United States
| | - Sean X Naughton
- Department of Psychology and Neuroscience Program, Temple University, Philadelphia, PA 19122, United States
| | - Brittney Yegla
- Department of Psychology and Neuroscience Program, Temple University, Philadelphia, PA 19122, United States
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Liu Z, Jiang M, Kang T, Miao D, Gu G, Song Q, Yao L, Hu Q, Tu Y, Pang Z, Chen H, Jiang X, Gao X, Chen J. Lactoferrin-modified PEG-co-PCL nanoparticles for enhanced brain delivery of NAP peptide following intranasal administration. Biomaterials 2013; 34:3870-81. [PMID: 23453061 DOI: 10.1016/j.biomaterials.2013.02.003] [Citation(s) in RCA: 117] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Accepted: 02/01/2013] [Indexed: 01/22/2023]
Abstract
Development of effective non-invasive drug delivery systems is of great importance to the treatment of Alzheimer's diseases and has made great progress in recent years. In this work, lactoferrin (Lf), a natural iron binding protein, whose receptor is highly expressed in both respiratory epithelial cells and neurons is here utilized to facilitate the nose-to-brain drug delivery of neuroprotection peptides. The Lf-conjugated PEG-PCL nanoparticle (Lf-NP) was constructed via a maleimide-thiol reaction with the Lf conjugation confirmed by CBQCA Protein Quantitation and XPS analysis. Other important parameters such as particle size distribution, zeta potential and in vitro release of fluorescent probes were also characterized. Compared with unmodified nanoparticles (NP), Lf-NP exhibited a significantly enhanced cellular accumulation in 16HBE14o-cells through both caveolae-/clathrin-mediated endocytosis and direct translocation. Following intranasal administration, Lf-NP facilitated the brain distribution of the coumarin-6 incorporated with the AUC0-8h in rat cerebrum (with hippocampus removed), cerebellum, olfactory tract, olfactory bulb and hippocampus 1.36, 1.53, 1.70, 1.57 and 1.23 times higher than that of coumarin-6 carried by NP, respectively. Using a neuroprotective peptide - NAPVSIPQ (NAP) as the model drug, the neuroprotective and memory improvement effect of Lf-NP was observed even at lower dose than that of NP in a Morris water maze experiment, which was also confirmed by the evaluation of acetylcholinesterase, choline acetyltransferase activity and neuronal degeneration in the mice hippocampus. In conclusion, Lf-NP may serve as a promising nose-to-brain drug delivery carrier especially for peptides and proteins.
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Affiliation(s)
- Zhongyang Liu
- Key Laboratory of Smart Drug Delivery, Ministry of Education & PLA, School of Pharmacy, Fudan University, Lane 826, Zhangheng Road, Shanghai 201203, PR China
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Eimer WA, Vassar R. Neuron loss in the 5XFAD mouse model of Alzheimer's disease correlates with intraneuronal Aβ42 accumulation and Caspase-3 activation. Mol Neurodegener 2013; 8:2. [PMID: 23316765 PMCID: PMC3552866 DOI: 10.1186/1750-1326-8-2] [Citation(s) in RCA: 267] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Accepted: 01/09/2013] [Indexed: 01/23/2023] Open
Abstract
Background Although the mechanism of neuron loss in Alzheimer’s disease (AD) is enigmatic, it is associated with cerebral accumulation of Aβ42. The 5XFAD mouse model of amyloid deposition expresses five familial AD (FAD) mutations that are additive in driving Aβ42 overproduction. 5XFAD mice exhibit intraneuronal Aβ42 accumulation at 1.5 months, amyloid deposition at 2 months, and memory deficits by 4 months of age. Results Here, we demonstrate by unbiased stereology that statistically significant neuron loss occurs by 9 months of age in 5XFAD mice. We validated two Aβ42-selective antibodies by immunostaining 5XFAD; BACE1−/− bigenic brain sections and then used these antibodies to show that intraneuronal Aβ42 and amyloid deposition develop in the same regions where neuron loss is observed in 5XFAD brain. In 5XFAD neuronal soma, intraneuronal Aβ42 accumulates in puncta that co-label for Transferrin receptor and LAMP-1, indicating endosomal and lysosomal localization, respectively. In addition, in young 5XFAD brains, we observed activated Caspase-3 in the soma and proximal dendrites of intraneuronal Aβ42-labeled neurons. In older 5XFAD brains, we found activated Caspase-3-positive punctate accumulations that co-localize with the neuronal marker class III β-tubulin, suggesting neuron loss by apoptosis. Conclusions Together, our results indicate a temporal sequence of intraneuronal Aβ42 accumulation, Caspase-3 activation, and neuron loss that implies a potential apoptotic mechanism of neuron death in the 5XFAD mouse.
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Affiliation(s)
- William A Eimer
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, 303 East Chicago Avenue, Chicago, IL 60611, USA
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Choi SJ, Jeong CH, Choi SG, Chun JY, Kim YJ, Lee J, Shin DH, Heo HJ. Zeatin prevents amyloid beta-induced neurotoxicity and scopolamine-induced cognitive deficits. J Med Food 2009; 12:271-7. [PMID: 19459726 DOI: 10.1089/jmf.2007.0678] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The antioxidative and protective effects of zeatin against amyloid beta-protein (Abeta)-induced neurotoxicity were investigated using PC12 cells. Zeatin showed antioxidative and cell protective effects against Abeta-induced neurotoxicity. In this study, we also evaluated the effect of zeatin on learning and memory capacity in vivo using ICR mice with amnesia induced by scopolamine (1 mg/kg of body weight). Zeatin, when administered to mice at 4.5 mg/kg of body weight, significantly ameliorated scopolamine-induced amnesia as measured in both the passive avoidance test and Y-maze test. Injecting mice with scopolamine impaired performance on the passive avoidance test (48 +/- 4.5% decrease) and on the Y-maze test (12 +/- 1.3% decrease). In contrast, mice treated with zeatin before scopolamine injections were protected from these changes (5-34% decrease in step-through latency; 1-4% decrease in alternation behavior). The present results suggest a possible chemopreventive role of zeatin in Alzheimer's disease.
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Affiliation(s)
- Soo Jung Choi
- Graduate School of Biotechnology, Korea University, Seoul, Republic of Korea
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Pre‐treatment with ebselen and vitamin E modulate acetylcholinesterase activity: interaction with demyelinating agents. Int J Dev Neurosci 2008; 27:73-80. [DOI: 10.1016/j.ijdevneu.2008.09.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2008] [Revised: 09/05/2008] [Accepted: 09/23/2008] [Indexed: 11/23/2022] Open
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Buntup D, Skare O, Solbu TT, Chaudhry FA, Storm-Mathisen J, Thangnipon W. Beta-amyloid 25-35 peptide reduces the expression of glutamine transporter SAT1 in cultured cortical neurons. Neurochem Res 2007; 33:248-56. [PMID: 18058230 PMCID: PMC2226019 DOI: 10.1007/s11064-007-9527-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2007] [Accepted: 10/05/2007] [Indexed: 01/31/2023]
Abstract
β-Amyloid (Aβ) peptides may cause malfunction and death of neurons in Alzheimer’s disease. We investigated the effect of Aβ on key transporters of amino acid neurotransmission in cells cultured from rat cerebral cortex. The cultures were treated with Aβ(25-35) at 3 and 10 μM for 12 and 24 h followed by quantitative analysis of immunofluorescence intensity. In mixed neuronal–glial cell cultures (from P1 rats), Aβ reduced the concentration of system A glutamine transporter 1 (SAT1), by up to 50% expressed relative to the neuronal marker microtubule-associated protein 2 (MAP2) in the same cell. No significant effects were detected on vesicular glutamate transporters VGLUT1 or VGLUT2 in neurons, or on glial system N glutamine transporter 1 (SN1). In neuronal cell cultures (from E18 rats), Aβ(25-35) did not reduce SAT1 immunoreactivity, suggesting that the observed effect depends on the presence of astroglia. The results indicate that Aβ may impair neuronal function and transmitter synthesis, and perhaps reduce excitotoxicity, through a reduction in neuronal glutamine uptake.
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Affiliation(s)
- Doungjai Buntup
- Neuro-Behavioural Biology Center, Institute of Science and Technology for Research and Development, Mahidol University, Salaya, Nakorn-pathom 73170, Thailand
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Mazzanti CM, Spanevello R, Ahmed M, Schmatz R, Mazzanti A, Salbego FZ, Graça DL, Sallis ESV, Morsch VM, Schetinger MRC. Cyclosporine A inhibits acetylcholinesterase activity in rats experimentally demyelinated with ethidium bromide. Int J Dev Neurosci 2007; 25:259-64. [PMID: 17467222 DOI: 10.1016/j.ijdevneu.2007.02.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2007] [Accepted: 02/27/2007] [Indexed: 10/23/2022] Open
Abstract
Cyclosporine A is the major immunosuppressive agent used for organ transplantation and for the treatment of a variety of autoimmune disorders such as multiple sclerosis. In this work, we investigated the effect of the cyclosporine A on the acetylcholinesterase activity in the cerebral cortex, striatum, hippocampus, hypothalamus, cerebellum and pons of the rats experimentally demyelinated by ethidium bromide. Rats were divided into four groups: I control (injected with saline), II (treated with cyclosporine A), III (injected with 0.1% ethidium bromide) and IV (injected with 0.1% the ethidium bromide and treated with cyclosporine A). The results showed a significant inhibition (p<0.05) of acetylcholinesterase activity in the groups II, III and IV in all brain structures analyzed. In the striatum, hippocampus, hypothalamus and pons the inhibition was greater (p<0.005) when ethidium bromide was associated with cyclosporine A. In conclusion, the present investigation demonstrated that cyclosporine A is an inhibitor of acetylcholinesterase activity and this effect is increased after an event of toxic demyelination of the central nervous system.
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Affiliation(s)
- Cinthia M Mazzanti
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcellos, 2600-Anexo, 90035-003 Porto Alegre, RS, Brazil
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Mazzanti CM, Spanevello RM, Obregon A, Pereira LB, Streher CA, Ahmed M, Mazzanti A, Graça DL, Morsch VM, Schetinger MRC. Ethidium bromide inhibits rat brain acetylcholinesterase activity in vitro. Chem Biol Interact 2006; 162:121-7. [PMID: 16839531 DOI: 10.1016/j.cbi.2006.05.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2006] [Revised: 05/19/2006] [Accepted: 05/22/2006] [Indexed: 11/21/2022]
Abstract
Ethidium bromide (EtBr), a fluorescent dark red compound and stain for double-stranded DNA and RNA was used to study acetylcholinesterase (AChE) activity in vitro together with kinetic parameters of this enzyme in the striatum (ST), hippocampus (HP), cerebral cortex (CC) and cerebellum (CB) of adult rats. AChE activity in vitro in the ST, HP, CC and CB was significantly reduced (p<0.05) in the presence of EtBr at concentrations of 0.00625, 0.0125, 0.025, 0.05 and 0.1 mM. For the analysis of the kinetic three concentrations of EtBr were tested (0.00625, 0.025 and 0.1 mM). An uncompetitive inhibition type was observed in the ST, HP and CC, whereas in the CB the inhibition type was mixed. These data indicate that EtBr should be considered a strong inhibitor of AChE activity demonstrating that there is an interaction between this compound and the cholinergic system.
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Affiliation(s)
- Cinthia M Mazzanti
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcellos, 2600-Anexo 90035-003, Porto Alegre, RS, Brazil
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Mazzanti CM, Spanevello RM, Pereira LB, Gonçalves JF, Kaizer R, Corrêa M, Ahmed M, Mazzanti A, Festugatto R, Graça DL, Morsch VM, Schetinger MRC. Acetylcholinesterase Activity in Rats Experimentally Demyelinated with Ethidium Bromide and Treated with Interferon Beta. Neurochem Res 2006; 31:1027-34. [PMID: 16871442 DOI: 10.1007/s11064-006-9112-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/05/2006] [Indexed: 10/24/2022]
Abstract
The ethidium bromide (EB) demyelinating model was associated with interferon beta (IFN-beta) to evaluate acetylcholinesterase (AChE) activity in the striatum (ST), hippocampus (HP), cerebral cortex (CC), cerebellum (CB), hypothalamus (HY), pons (PN) and synaptosomes from the CC. Rats were divided into four groups: I control (saline), II (IFN-beta), III (EB) and IV (EB and IFN-beta). After 7, 15 and 30 days rats (n = 6) were sacrificed, and the brain structures were removed for enzymatic assay. AChE activity was found to vary in all the brain structures in accordance with the day studied (7-15-30 days) (P < 0.05). In the group III, there was an inhibition of the AChE activity in the ST, CB, HY, HP and also in synaptosomes of the CC (P < 0.05). It was observed that IFN-beta per se was capable to significantly inhibit (P < 0.05) AChE activity in the ST, HP, HY and synaptosomes of the CC. Our results suggest that one of the mechanisms of action of IFN-beta is through the inhibition of AChE activity, and EB could be considered an inhibitor of AChE activity by interfering with cholinergic neurotransmission in the different brain regions.
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Affiliation(s)
- C M Mazzanti
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcellos, 2600-Anexo, 90035-003, Porto Alegre, RS, Brazil
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