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Tanaka-Kanegae R, Kimura H, Hamada K. Oral Administration of Egg- and Soy-Derived Lysophosphatidylcholine Mitigated Acetylcholine Depletion in the Brain of Scopolamine-Treated Rats. Nutrients 2023; 15:3618. [PMID: 37630808 PMCID: PMC10458616 DOI: 10.3390/nu15163618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Revised: 08/04/2023] [Accepted: 08/09/2023] [Indexed: 08/27/2023] Open
Abstract
Enzyme-modified lecithin that contains lysophosphatidylcholine (LPC) is generally recognized as safe. However, its potential as a functional ingredient has been less investigated than other choline (Ch)-containing compounds, such as glycerophosphocholine (GPC). Reports on the possibility of LPC functioning as a cholinergic precursor in vivo and on its kinetics are limited to docosahexaenoic acid-bound LPC. Herein, three experiments were performed to investigate these processes in scopolamine (SCO)-treated rats. First, an egg-derived LPC reagent was orally administered to rats, and brain acetylcholine (ACh), Ch, plasma Ch, and LPC were measured. Second, soy- and rapeseed-derived enzyme-modified lecithins and GPC were administered for comparison. Third, soy-derived enzyme-modified lecithins with different fat contents were administered for comparison. The LPC reagent mitigated SCO-induced ACh depletion at 500 mg/kg body weight and increased plasma Ch, but not LPC, concentrations. Additionally, soy-derived LPC-containing food additive counteracted brain ACh depletion similarly to GPC. Interestingly, plasma Ch and linoleoyl-LPC levels were higher when soy-derived LPC with a higher fat content was administered, whereas the plasma levels of palmitoyl-LPC decreased and those of total LPC remained constant. In conclusion, egg- and soy-derived LPC species function as cholinergic precursors in vivo, and future studies should explore this potential.
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Affiliation(s)
- Ryohei Tanaka-Kanegae
- Saga Nutraceuticals Research Institute, Otsuka Pharmaceutical Co., Ltd. 5006-5 Aza Higashiyama, Yoshinogari-cho, Kanzaki-gun, Omagari, Saga 842-0195, Japan
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2
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Lu J, Drobyshevsky A, Lu L, Yu Y, Caplan MS, Claud EC. Microbiota from Preterm Infants Who Develop Necrotizing Enterocolitis Drives the Neurodevelopment Impairment in a Humanized Mouse Model. Microorganisms 2023; 11:1131. [PMID: 37317106 PMCID: PMC10224461 DOI: 10.3390/microorganisms11051131] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 04/22/2023] [Accepted: 04/24/2023] [Indexed: 06/16/2023] Open
Abstract
Necrotizing enterocolitis (NEC) is the leading basis for gastrointestinal morbidity and poses a significant risk for neurodevelopmental impairment (NDI) in preterm infants. Aberrant bacterial colonization preceding NEC contributes to the pathogenesis of NEC, and we have demonstrated that immature microbiota in preterm infants negatively impacts neurodevelopment and neurological outcomes. In this study, we tested the hypothesis that microbial communities before the onset of NEC drive NDI. Using our humanized gnotobiotic model in which human infant microbial samples were gavaged to pregnant germ-free C57BL/6J dams, we compared the effects of the microbiota from preterm infants who went on to develop NEC (MNEC) to the microbiota from healthy term infants (MTERM) on brain development and neurological outcomes in offspring mice. Immunohistochemical studies demonstrated that MNEC mice had significantly decreased occludin and ZO-1 expression compared to MTERM mice and increased ileal inflammation marked by the increased nuclear phospho-p65 of NFκB expression, revealing that microbial communities from patients who developed NEC had a negative effect on ileal barrier development and homeostasis. In open field and elevated plus maze tests, MNEC mice had worse mobility and were more anxious than MTERM mice. In cued fear conditioning tests, MNEC mice had worse contextual memory than MTERM mice. MRI revealed that MNEC mice had decreased myelination in major white and grey matter structures and lower fractional anisotropy values in white matter areas, demonstrating delayed brain maturation and organization. MNEC also altered the metabolic profiles, especially carnitine, phosphocholine, and bile acid analogs in the brain. Our data demonstrated numerous significant differences in gut maturity, brain metabolic profiles, brain maturation and organization, and behaviors between MTERM and MNEC mice. Our study suggests that the microbiome before the onset of NEC has negative impacts on brain development and neurological outcomes and can be a prospective target to improve long-term developmental outcomes.
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Affiliation(s)
- Jing Lu
- Department of Pediatrics, Division of Biological Sciences, Pritzker School of Medicine, University of Chicago, Chicago, IL 60637, USA
| | | | - Lei Lu
- Department of Pediatrics, Division of Biological Sciences, Pritzker School of Medicine, University of Chicago, Chicago, IL 60637, USA
| | - Yueyue Yu
- Department of Pediatrics, Division of Biological Sciences, Pritzker School of Medicine, University of Chicago, Chicago, IL 60637, USA
| | - Michael S. Caplan
- Department of Pediatrics, NorthShore University HealthSystem, Evanston, IL 60202, USA
| | - Erika C. Claud
- Department of Pediatrics, Division of Biological Sciences, Pritzker School of Medicine, University of Chicago, Chicago, IL 60637, USA
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3
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Secades JJ, Gareri P. Citicoline: pharmacological and clinical review, 2022 update. Rev Neurol 2022; 75:S1-S89. [PMID: 36544369 PMCID: PMC10548481 DOI: 10.33588/rn.75s05.2022311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Indexed: 12/24/2022]
Abstract
This review is based on the previous one published in 2016 (Secades JJ. Citicoline: pharmacological and clinical review, 2016 update. Rev Neurol 2016; 63 (Supl 3): S1-S73), incorporating 176 new references, having all the information available in the same document to facilitate the access to the information in one document. This review is focused on the main indications of the drug, as acute stroke and its sequelae, including the cognitive impairment, and traumatic brain injury and its sequelae. There are retrieved the most important experimental and clinical data in both indications.
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Affiliation(s)
- Julio J. Secades
- Medical Department. Grupo Ferrer, S.A.
Barcelona, SpainMedical DepartmentGrupo Ferrer, S.A.BarcelonaSpain
| | - Pietro Gareri
- Center for Cognitive Disorders and Dementia -
Catanzaro Lido. ASP Catanzaro. Catanzaro, ItalyCenter for Cognitive Disorders and Dementia -
Catanzaro LidoCenter for Cognitive Disorders and Dementia -
Catanzaro LidoCatanzaroItaly
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4
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Tanaka-Kanegae R, Hamada K. A novel in vitro assay model developed to measure both extracellular and intracellular acetylcholine levels for screening cholinergic agents. PLoS One 2021; 16:e0258420. [PMID: 34637466 PMCID: PMC8509891 DOI: 10.1371/journal.pone.0258420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 09/27/2021] [Indexed: 11/24/2022] Open
Abstract
Background Cholinergic neurons utilize choline (Ch) to synthetize acetylcholine (ACh) and contain a high-affinity Ch transporter, Ch acetyltransferase (ChAT), ACh receptors, and acetylcholinesterase (AChE). As the depletion or malfunction of each component of the cholinergic system has been reported in patients with dementia, many studies have sought to evaluate whether treatment candidates affect each of the cholinergic components. The associated changes in the cholinergic components may be reflected by intra- or extra-cellular ACh levels, with an increase in extracellular ACh levels occurring following AChE inhibition. We hypothesized that increases in intracellular ACh levels can be more sensitively detected than those in extracellular ACh levels, thereby capturing subtle effects in the cholinergic components other than AChE. The objective of this study was to test this hypothesis. Methods We developed an in vitro model to measure both extracellular and intracellular ACh levels using the human cholinergic neuroblastoma cell line, LA-N-2, which have been reported to express Ch transporter, ChAT, muscarinic ACh receptor (mAChR), and AChE. With this model, we evaluated several drug compounds and food constituents reported to improve cholinergic function through various mechanisms. In addition, we conducted western blotting to identify the subtype of mAChR that is expressed on the cell line. Results Our cell-based assay system was capable of detecting increases in extracellular ACh levels induced by an AChE inhibitor at relatively high doses, as well as increases in intracellular ACh levels following the administration of lower AChE-inhibitor doses and an mAChR agonist. Moreover, increases in intracellular ACh levels were observed even after treatment with food constituents that have different mechanisms of action, such as Ch provision and ChAT activation. In addition, we revealed that LA-N-2 cells expressed mAChR M2. Conclusion The findings support our hypothesis and indicate that the developed assay model can broadly screen compounds from drugs to food ingredients, with varying strengths and mechanisms of action, to develop treatments for ACh-relevant phenomena, including dementia and aging-related cognitive decline.
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Affiliation(s)
- Ryohei Tanaka-Kanegae
- Saga Nutraceuticals Research Institute, Otsuka Pharmaceutical Co., Ltd., Saga, Japan
- * E-mail:
| | - Koichiro Hamada
- Saga Nutraceuticals Research Institute, Otsuka Pharmaceutical Co., Ltd., Saga, Japan
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5
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Niesyto K, Neugebauer D. Synthesis and Characterization of Ionic Graft Copolymers: Introduction and In Vitro Release of Antibacterial Drug by Anion Exchange. Polymers (Basel) 2020; 12:E2159. [PMID: 32971814 PMCID: PMC7570301 DOI: 10.3390/polym12092159] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 09/17/2020] [Accepted: 09/20/2020] [Indexed: 11/16/2022] Open
Abstract
Amphiphilic graft copolymers based on [2-(methacryloyloxy)ethyl]trimethyl- ammonium chloride (TMAMA) were obtained for the delivery of pharmaceutical ionic drugs, such as p-aminosalicylate (PAS) and clavunate (CLV) anions. The side chains were attached by grafting from a multifunctional macroinitiator via atom transfer radical polymerization (ATRP) to get polymers with different grafting degrees and ionic content. The self-assembling ability, confirmed by determining the critical micelle concentration (CMC) through interfacial tension (IFT) with the use of goniometry, was reduced after ion exchange (CMC twice higher than for chloride anions contained copolymers 0.005-0.026 mg/mL). Similarly, the hydrophilicity level (adjusted by the content of ionic fraction) evaluated by the water contact angle (WCA) of the polymer film surfaces was decreased with the increase of trimethylammonium units (68°-44°) and after introduction of pharmaceutical anions. The exchange of Cl- onto PAS- and CLV- in the polymer matrix was yielded at 31%-64% and 79%-100%, respectively. The exchange onto phosphate anions to release the drug was carried out (PAS: 20%-42%, 3.1-8.8 μg/mL; CLV: 25%-73%, 11-31 μg/mL from 1 mg of drug conjugates). Because of the bacteriostatic activity of PAS and the support of the action of the antibiotics by CLV, the designed water-soluble systems could be alternatives for the treatment of bacterial infections, including pneumonia and tuberculosis.
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Affiliation(s)
| | - Dorota Neugebauer
- Department of Physical Chemistry and Technology of Polymers, Faculty of Chemistry, Silesian University of Technology, 44-100 Gliwice, Poland;
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Zhou C, He M, Peng C, Yu J, Li Z, Zhou M, Li Y, Yang S, Ouyang H, Feng Y. Pharmacokinetic and Lipidomic Assessment of the In Vivo Effects of Parishin A-Isorhynchophylline in Rat Migraine Models. JOURNAL OF ANALYTICAL METHODS IN CHEMISTRY 2020; 2020:9101598. [PMID: 32695549 PMCID: PMC7362284 DOI: 10.1155/2020/9101598] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 03/27/2020] [Indexed: 06/11/2023]
Abstract
Migraine is a chronic brain disease that leads to periodic neurological attacks. Parishin A and isorhynchophylline (PI) is the active monomer component extracted from the traditional antimigraine Chinese medicinal combination of Gastrodia and Uncaria, respectively. In this study, using high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) technology, we performed pharmacokinetic and lipidomic study on migraine model rats after administration of PI. For the detection of the compounds in plasma, AB Sciex Triple Quad™ 4500 was applied for quantitative analysis, and the COSMOSIL C18 column (2.1 × 100 mm, 2.6 μm) was used for separation. Isorhynchophylline (ISO: m/z 384.8-241.2) and its main metabolite rhynchophylline (RHY: m/z 384.8-160.2) were simultaneously detected under positive ion modes. Besides, parishin A (PA: m/z 995.1-726.9) and its main metabolite gastrodin (GAS: m/z 331.1-123.0) were simultaneously detected with negative ion modes. For the analysis of endogenous lipid components, Dionex Ultimate 3000 (UHPLC) Thermo Orbitrap Elite was applied for the detection, and the Waters UPLCRBEH C18 column (1.7 μm 100 ∗ 2.1 mm) was used for separation. Chloroform/methanol (2 : 1, v : v) was used for extraction. The results demonstrated that PI exists significant difference in metabolism between single- and coadministration and can regulate lipid levels associated with migraine.
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Affiliation(s)
- Chaoqun Zhou
- Jiangxi University of Traditional Chinese Medicine, Nanchang, China
| | - Mingzhen He
- Jiangxi University of Traditional Chinese Medicine, Nanchang, China
- State Key Laboratory of Innovative Drug and Efficient Energy-Saving Pharmaceutical Equipment, Nanchang, China
| | - Chunyan Peng
- Jiangxi University of Traditional Chinese Medicine, Nanchang, China
| | - Jianjun Yu
- Jiangxi University of Traditional Chinese Medicine, Nanchang, China
| | - Zhifeng Li
- Jiangxi University of Traditional Chinese Medicine, Nanchang, China
- State Key Laboratory of Innovative Drug and Efficient Energy-Saving Pharmaceutical Equipment, Nanchang, China
| | - Maofu Zhou
- Jiangxi University of Traditional Chinese Medicine, Nanchang, China
| | - Yan Li
- Jiangxi University of Traditional Chinese Medicine, Nanchang, China
| | - Shilin Yang
- State Key Laboratory of Innovative Drug and Efficient Energy-Saving Pharmaceutical Equipment, Nanchang, China
| | - Hui Ouyang
- Jiangxi University of Traditional Chinese Medicine, Nanchang, China
| | - Yulin Feng
- Jiangxi University of Traditional Chinese Medicine, Nanchang, China
- State Key Laboratory of Innovative Drug and Efficient Energy-Saving Pharmaceutical Equipment, Nanchang, China
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Ronowska A, Szutowicz A, Bielarczyk H, Gul-Hinc S, Klimaszewska-Łata J, Dyś A, Zyśk M, Jankowska-Kulawy A. The Regulatory Effects of Acetyl-CoA Distribution in the Healthy and Diseased Brain. Front Cell Neurosci 2018; 12:169. [PMID: 30050410 PMCID: PMC6052899 DOI: 10.3389/fncel.2018.00169] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 05/31/2018] [Indexed: 12/25/2022] Open
Abstract
Brain neurons, to support their neurotransmitter functions, require a several times higher supply of glucose than non-excitable cells. Pyruvate, the end product of glycolysis, through pyruvate dehydrogenase complex reaction, is a principal source of acetyl-CoA, which is a direct energy substrate in all brain cells. Several neurodegenerative conditions result in the inhibition of pyruvate dehydrogenase and decrease of acetyl-CoA synthesis in mitochondria. This attenuates metabolic flux through TCA in the mitochondria, yielding energy deficits and inhibition of diverse synthetic acetylation reactions in all neuronal sub-compartments. The acetyl-CoA concentrations in neuronal mitochondrial and cytoplasmic compartments are in the range of 10 and 7 μmol/L, respectively. They appear to be from 2 to 20 times lower than acetyl-CoA Km values for carnitine acetyltransferase, acetyl-CoA carboxylase, aspartate acetyltransferase, choline acetyltransferase, sphingosine kinase 1 acetyltransferase, acetyl-CoA hydrolase, and acetyl-CoA acetyltransferase, respectively. Therefore, alterations in acetyl-CoA levels alone may significantly change the rates of metabolic fluxes through multiple acetylation reactions in brain cells in different physiologic and pathologic conditions. Such substrate-dependent alterations in cytoplasmic, endoplasmic reticulum or nuclear acetylations may directly affect ACh synthesis, protein acetylations, and gene expression. Thereby, acetyl-CoA may regulate the functional and adaptative properties of neuronal and non-neuronal brain cells. The excitotoxicity-evoked intracellular zinc excess hits several intracellular targets, yielding the collapse of energy balance and impairment of the functional and structural integrity of postsynaptic cholinergic neurons. Acute disruption of brain energy homeostasis activates slow accumulation of amyloid-β1-42 (Aβ). Extra and intracellular oligomeric deposits of Aβ affect diverse transporting and signaling pathways in neuronal cells. It may combine with multiple neurotoxic signals, aggravating their detrimental effects on neuronal cells. This review presents evidences that changes of intraneuronal levels and compartmentation of acetyl-CoA may contribute significantly to neurotoxic pathomechanisms of different neurodegenerative brain disorders.
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Affiliation(s)
- Anna Ronowska
- Department of Laboratory Medicine, Faculty of Medicine, Medical University of Gdańsk, Gdańsk, Poland
| | - Andrzej Szutowicz
- Department of Laboratory Medicine, Faculty of Medicine, Medical University of Gdańsk, Gdańsk, Poland
| | - Hanna Bielarczyk
- Department of Laboratory Medicine, Faculty of Medicine, Medical University of Gdańsk, Gdańsk, Poland
| | - Sylwia Gul-Hinc
- Department of Laboratory Medicine, Faculty of Medicine, Medical University of Gdańsk, Gdańsk, Poland
| | - Joanna Klimaszewska-Łata
- Department of Laboratory Medicine, Faculty of Medicine, Medical University of Gdańsk, Gdańsk, Poland
| | - Aleksandra Dyś
- Department of Laboratory Medicine, Faculty of Medicine, Medical University of Gdańsk, Gdańsk, Poland
| | - Marlena Zyśk
- Department of Laboratory Medicine, Faculty of Medicine, Medical University of Gdańsk, Gdańsk, Poland
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8
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Aytan N, Choi JK, Carreras I, Crabtree L, Nguyen B, Lehar M, Blusztajn JK, Jenkins BG, Dedeoglu A. Protective effects of 7,8-dihydroxyflavone on neuropathological and neurochemical changes in a mouse model of Alzheimer's disease. Eur J Pharmacol 2018; 828:9-17. [PMID: 29510124 DOI: 10.1016/j.ejphar.2018.02.045] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 02/13/2018] [Accepted: 02/28/2018] [Indexed: 12/26/2022]
Abstract
Interest in brain-derived neurotrophic factor (BDNF) was greatly enhanced when it was recognized that its expression is reduced in neurodegenerative disorders, especially in Alzheimer's disease (AD). BDNF signaling through the TrkB receptor has a central role in promoting synaptic transmission, synaptogenesis, and facilitating synaptic plasticity making the BDNF-TrkB signaling pathway an attractive candidate for targeted therapies. Here we investigated the early effect of the small molecule TrkB agonist, 7,8 dihydroxyflavone (7,8-DHF), on AD-related pathology, dendritic arborization, synaptic density, and neurochemical changes in the 5xFAD mouse model of AD. We treated 5xFAD mice with 7,8-DHF for 2 months beginning at 1 month of age. We found that, in this model of AD, 7,8-DHF treatment decreased cortical Aβ plaque deposition and protected cortical neurons against reduced dendritic arbor complexity but had no significant impact on the density of dendritic spines. In addition 7,8-DHF treatment protected against hippocampal increase in the level of choline-containing compounds and glutamate loss, but had no significant impact on hippocampal neurogenesis.
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Affiliation(s)
- Nurgul Aytan
- Department of Veterans Affairs, VA Boston Healthcare System, Boston, MA 02130, USA; Department of Neurology Boston University School of Medicine, Boston, MA 02118, USA; Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA.
| | - Ji-Kyung Choi
- Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA.
| | - Isabel Carreras
- Department of Veterans Affairs, VA Boston Healthcare System, Boston, MA 02130, USA; Department of Biochemistry Boston University School of Medicine, Boston, MA 02118, USA.
| | - Leah Crabtree
- Department of Veterans Affairs, VA Boston Healthcare System, Boston, MA 02130, USA; Department of Neurology Boston University School of Medicine, Boston, MA 02118, USA; University of Exeter Medical School, Devon EX4 4QJ, UK.
| | - Brian Nguyen
- Department of Veterans Affairs, VA Boston Healthcare System, Boston, MA 02130, USA; Department of Neurology Boston University School of Medicine, Boston, MA 02118, USA.
| | - Margaret Lehar
- Department of Veterans Affairs, VA Boston Healthcare System, Boston, MA 02130, USA; Department of Neurology Boston University School of Medicine, Boston, MA 02118, USA.
| | | | - Bruce G Jenkins
- Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA.
| | - Alpaslan Dedeoglu
- Department of Veterans Affairs, VA Boston Healthcare System, Boston, MA 02130, USA; Department of Neurology Boston University School of Medicine, Boston, MA 02118, USA; Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA.
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9
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Yan H, Zhang E, Feng C, Zhao X. Role of A3 adenosine receptor in diabetic neuropathy. J Neurosci Res 2016; 94:936-46. [PMID: 27319979 DOI: 10.1002/jnr.23774] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 05/02/2016] [Accepted: 05/02/2016] [Indexed: 12/11/2022]
Affiliation(s)
- Heng Yan
- Department of Anesthesiology; The Second Hospital of Shandong University; Jinan Shandong China
| | - Enshui Zhang
- Department of Orthopedics; Jinan Central Hospital Affiliated to Shandong University; Jinan Shandong China
| | - Chang Feng
- Department of Anesthesiology; The Second Hospital of Shandong University; Jinan Shandong China
| | - Xin Zhao
- Department of Anesthesiology; The Second Hospital of Shandong University; Jinan Shandong China
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10
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Janes K, Symons-Liguori AM, Jacobson KA, Salvemini D. Identification of A3 adenosine receptor agonists as novel non-narcotic analgesics. Br J Pharmacol 2016; 173:1253-67. [PMID: 26804983 DOI: 10.1111/bph.13446] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Revised: 11/09/2015] [Accepted: 11/22/2015] [Indexed: 12/26/2022] Open
Abstract
Chronic pain negatively impacts the quality of life in a variety of patient populations. The current therapeutic repertoire is inadequate in managing patient pain and warrants the development of new therapeutics. Adenosine and its four cognate receptors (A1 , A2A , A2B and A3 ) have important roles in physiological and pathophysiological states, including chronic pain. Preclinical and clinical studies have revealed that while adenosine and agonists of the A1 and A2A receptors have antinociceptive properties, their therapeutic utility is limited by adverse cardiovascular side effects. In contrast, our understanding of the A3 receptor is only in its infancy, but exciting preclinical observations of A3 receptor antinociception, which have been bolstered by clinical trials of A3 receptor agonists in other disease states, suggest pain relief without cardiovascular side effects and with sufficient tolerability. Our goal herein is to briefly discuss adenosine and its receptors in the context of pathological pain and to consider the current data regarding A3 receptor-mediated antinociception. We will highlight recent findings regarding the impact of the A3 receptor on pain pathways and examine the current state of selective A3 receptor agonists used for these studies. The adenosine-to-A3 receptor pathway represents an important endogenous system that can be targeted to provide safe, effective pain relief from chronic pain.
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Affiliation(s)
- K Janes
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, St. Louis, MO, USA
| | - A M Symons-Liguori
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, St. Louis, MO, USA
| | - K A Jacobson
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - D Salvemini
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, St. Louis, MO, USA
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High maternal choline consumption during pregnancy and nursing alleviates deficits in social interaction and improves anxiety-like behaviors in the BTBR T+Itpr3tf/J mouse model of autism. Behav Brain Res 2015; 278:210-20. [DOI: 10.1016/j.bbr.2014.09.043] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Revised: 09/23/2014] [Accepted: 09/28/2014] [Indexed: 12/26/2022]
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12
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Janes K, Esposito E, Doyle T, Cuzzocrea S, Tosh DK, Jacobson KA, Salvemini D. A3 adenosine receptor agonist prevents the development of paclitaxel-induced neuropathic pain by modulating spinal glial-restricted redox-dependent signaling pathways. Pain 2014; 155:2560-2567. [PMID: 25242567 DOI: 10.1016/j.pain.2014.09.016] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 09/03/2014] [Accepted: 09/12/2014] [Indexed: 10/24/2022]
Abstract
Chemotherapy-induced peripheral neuropathy accompanied by chronic neuropathic pain is the major dose-limiting toxicity of several anticancer agents including the taxane paclitaxel (Taxol). A critical mechanism underlying paclitaxel-induced neuropathic pain is the increased production of peroxynitrite in spinal cord generated in response to activation of the superoxide-generating enzyme, NADPH oxidase. Peroxynitrite in turn contributes to the development of neuropathic pain by modulating several redox-dependent events in spinal cord. We recently reported that activation of the Gi/Gq-coupled A3 adenosine receptor (A3AR) with selective A3AR agonists (ie, IB-MECA) blocked the development of chemotherapy induced-neuropathic pain evoked by distinct agents, including paclitaxel, without interfering with anticancer effects. The mechanism or mechanisms of action underlying these beneficial effects has yet to be explored. We now demonstrate that IB-MECA attenuates the development of paclitaxel-induced neuropathic pain by inhibiting the activation of spinal NADPH oxidase and two downstream redox-dependent systems. The first relies on inhibition of the redox-sensitive transcription factor (NFκB) and mitogen activated protein kinases (ERK and p38) resulting in decreased production of neuroexcitatory/proinflammatory cytokines (TNF-α, IL-1β) and increased formation of the neuroprotective/anti-inflammatory IL-10. The second involves inhibition of redox-mediated posttranslational tyrosine nitration and modification (inactivation) of glia-restricted proteins known to play key roles in regulating synaptic glutamate homeostasis: the glutamate transporter GLT-1 and glutamine synthetase. Our results unravel a mechanistic link into biomolecular signaling pathways employed by A3AR activation in neuropathic pain while providing the foundation to consider use of A3AR agonists as therapeutic agents in patients with chemotherapy-induced peripheral neuropathy.
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Affiliation(s)
- Kali Janes
- Department of Pharmacological and Physiological Science, Saint Louis University School of Medicine, 1402 South Grand Blvd, St Louis, MO 63104, USA Department of Clinical and Experimental Medicine and Pharmacology, University of Messina, Messina 98122, Italy Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0810, USA
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13
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Scholey AB, Camfield DA, Hughes ME, Woods W, K Stough CK, White DJ, Gondalia SV, Frederiksen PD. A randomized controlled trial investigating the neurocognitive effects of Lacprodan® PL-20, a phospholipid-rich milk protein concentrate, in elderly participants with age-associated memory impairment: the Phospholipid Intervention for Cognitive Ageing Reversal (PLICAR): study protocol for a randomized controlled trial. Trials 2013; 14:404. [PMID: 24279904 PMCID: PMC4220811 DOI: 10.1186/1745-6215-14-404] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 11/11/2013] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Age-related cognitive decline (ARCD) is of major societal concern in an ageing population, with the development of dietary supplements providing a promising avenue for amelioration of associated deficits. Despite initial interest in the use of phospholipids (PLs) for ARCD, in recent years there has been a hiatus in such research. Because of safety concerns regarding PLs derived from bovine cortex, and the equivocal efficacy of soybean-derived PLs, there is an important need for the development of new PL alternatives. Phospholipids derived from milk proteins represent one potential candidate treatment. METHODS In order to reduce the effects of age-associated memory impairment (AAMI) the Phospholipid Intervention for Cognitive Ageing Reversal (PLICAR) was developed to test the efficacy of a milk protein concentrate rich in natural, non-synthetic milk phospholipids (Lacprodan® PL-20). PLICAR is a randomized, double-blind, placebo-controlled parallel-groups study where 150 (N = 50/group) AAMI participants aged > 55 years will be randomized to receive a daily supplement of Lacprodan® PL-20 or one of two placebos (phospholipid-free milk protein concentrate or inert rice starch) over a 6-month (180-day) period. Participants will undergo testing at baseline, 90 days and 180 days. The primary outcome is a composite memory score from the Rey Auditory Verbal Learning Test. Secondary outcomes include cognitive (verbal learning, working memory, prospective and retrospective memory, processing speed and attention), mood (depression, anxiety, stress and visual analogue scales), cardiovascular (blood pressure, blood velocity and pulse wave pressure), gastrointestinal microbiota and biochemical measures (oxidative stress, inflammation, B vitamins and Homocysteine, glucoregulation and serum choline). Allelic differences in the Apolipoprotein E and (APOE) and Methylenetetrahydrofolate reductase (MTHFR) gene will be included for subgroup analysis. A subset (N = 60; 20/group)) will undergo neuroimaging using functional magnetic resonance imaging (fMRI) and magnetoencephalography (MEG) in order to further explore in vivo central mechanisms of action of Lacprodan® PL-20. This study will enable evaluation of the efficacy of milk-derived phospholipids for AAMI, and their mechanisms of action. TRIAL REGISTRATION The trial is jointly funded by Arla Foods and Swinburne University of Technology, currently recruiting and is registered on the Australian New Zealand Clinical Trials Registry as ACTRN12613000347763.
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Affiliation(s)
- Andrew B Scholey
- Centre for Human Psychopharmacology, Swinburne University of Technology, Melbourne 3122, Victoria, Australia.
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14
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Tuboly E, Szabó A, Garab D, Bartha G, Janovszky Á, Erős G, Szabó A, Mohácsi Á, Szabó G, Kaszaki J, Ghyczy M, Boros M. Methane biogenesis during sodium azide-induced chemical hypoxia in rats. Am J Physiol Cell Physiol 2012; 304:C207-14. [PMID: 23174561 DOI: 10.1152/ajpcell.00300.2012] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Previous studies demonstrated methane generation in aerobic cells. Our aims were to investigate the methanogenic features of sodium azide (NaN(3))-induced chemical hypoxia in the whole animal and to study the effects of l-α-glycerylphosphorylcholine (GPC) on endogenous methane production and inflammatory events as indicators of a NaN(3)-elicited mitochondrial dysfunction. Group 1 of Sprague-Dawley rats served as the sham-operated control; in group 2, the animals were treated with NaN(3) (14 mg·kg(-1)·day(-1) sc) for 8 days. In group 3, the chronic NaN(3) administration was supplemented with daily oral GPC treatment. Group 4 served as an oral antibiotic-treated control (rifaximin, 10 mg·kg(-1)·day(-1)) targeting the intestinal bacterial flora, while group 5 received this antibiotic in parallel with NaN(3) treatment. The whole body methane production of the rats was measured by means of a newly developed method based on photoacoustic spectroscopy, the microcirculation of the liver was observed by intravital videomicroscopy, and structural changes were assessed via in vivo fluorescent confocal laser-scanning microscopy. NaN(3) administration induced a significant inflammatory reaction and methane generation independently of the methanogenic flora. After 8 days, the hepatic microcirculation was disturbed and the ATP content was decreased, without major structural damage. Methane generation, the hepatic microcirculatory changes, and the increased tissue myeloperoxidase and xanthine oxidoreductase activities were reduced by GPC treatment. In conclusion, the results suggest that methane production in mammals is connected with hypoxic events associated with a mitochondrial dysfunction. GPC is protective against the inflammatory consequences of a hypoxic reaction that might involve cellular or mitochondrial methane generation.
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Affiliation(s)
- Eszter Tuboly
- Institute of Surgical Research, Faculty of Medicine, University of Szeged, Szeged, Hungary
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15
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Batra V, Kislay B, Devasagayam TPA. Interaction between total body gamma-irradiation and choline deficiency triggers immediate modulation of choline and choline-containing moieties. Int J Radiat Biol 2011; 87:1196-207. [PMID: 21923302 DOI: 10.3109/09553002.2011.624153] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE The objective of this study was to examine the effect of 60Co-gamma (γ) radiation on acute phase modulation, if any, of choline and choline-containing moieties in choline-deficient subjects. Corresponding results could provide information that might be useful in the management of adverse effects of γ-radiation. MATERIALS AND METHODS Male Swiss mice maintained on a choline-sufficient diet (CSD) and choline-free diet (CFD) based on AIN-93M formula, were subjected to whole body γ-irradiation (2-6 Gy). Liver, serum and brain samples from each group were then tested for: (i) Alterations in choline and choline-containing moieties such as phosphatidylcholine (PC) and sphingomyeline (SM); and (ii) modulation of choline profile modulating enzymes such as phospholipase D (PLD) and total sphingomyelinase (t-SMase). Liver and brain samples were also subjected to histo-pathological examinations. RESULTS No significant changes were observed in folate, choline, choline-containing moieties and choline-modulating enzymes in choline-sufficient mice. In contrast, interaction between cytotoxic effects of γ-radiation and choline deficiency modulated choline and choline-containing moieties. Feeding CFD reduced hepatic concentrations of choline, PC and SM whereas PLD and t-SMase activities were significantly raised. The decrease in liver choline and choline-containing moieties was accompanied by an increase in blood choline concentration. Despite choline deficiency, the level of choline and acetylcholine synthesizing enzyme choline acetyltransfease (ChAT) significantly increased in the brain. CONCLUSIONS We propose that choline deprivation and γ-radiation interact to modulate choline reserves of hepatic tissue, which might release choline to blood. Our studies also clearly showed that interaction between choline deficiency and γ-radiation might substantially enhance liver adipogenesis.
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Affiliation(s)
- Vipen Batra
- Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai, India.
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16
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Kawaguchi M, Okabe T, Okudaira S, Hanaoka K, Fujikawa Y, Terai T, Komatsu T, Kojima H, Aoki J, Nagano T. Fluorescence probe for lysophospholipase C/NPP6 activity and a potent NPP6 inhibitor. J Am Chem Soc 2011; 133:12021-30. [PMID: 21721554 DOI: 10.1021/ja201028t] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Nucleotide pyrophosphatases/phosphodiesterases (NPPs) are ubiquitous membrane-associated or secreted ectoenzymes that have a role in regulating extracellular nucleotide and phospholipid metabolism. Among the members of the NPP family, NPP1 and -3 act on nucleotides such as ATP, while NPP2, -6, and -7 act on phospholipids such as lysophosphatidylcholine and sphingomyelin. NPP6, a recently characterized NPP family member, is a choline-specific glycerophosphodiester phosphodiesterase, but its functions remain to be analyzed, partly due to the lack of highly sensitive activity assay systems and practical inhibitors. Here we report synthesis of novel NPP6 fluorescence probes, TG-mPC and its analogues TG-mPC(3)C, TG-mPC(5)C, TG-mPENE, TG-mPEA, TG-mPhos, TG-mPA, TG-mPMe, and TG-mPPr. Among the seven NPPs, only NPP6 hydrolyzed TG-mPC, TG-mPC(3)C, and TG-mPENE. TG-mPC was hydrolyzed in the cell lysate from NPP6-transfected cells, but not control cells, showing that it is suitable for use in cell-based NPP6 assays. We also examined the usefulness of TG-mPC as a fluorescence imaging probe. We further applied TG-mPC to carry out high-throughput NPP6 inhibitor screening and found several NPP6-selective inhibitors in a library of about 80,000 compounds. Through structure-activity relationship (SAR) analysis, we identified a potent and selective NPP6 inhibitor with an IC(50) value of 0.21 μM. Our NPP6-selective fluorescence probe, TG-mPC, and the inhibitor are expected to be useful to elucidate the biological function of NPP6.
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Affiliation(s)
- Mitsuyasu Kawaguchi
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Tokyo 113-0033, Japan
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Mustafa I, Elkamel A, Ibrahim G, Chen P, Elnashaie S. Effect of choline and acetate substrates on bifurcation and chaotic behavior of acetylcholine neurocycle and Alzheimer's and Parkinson's diseases. Chem Eng Sci 2009. [DOI: 10.1016/j.ces.2009.01.027] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Oral phosphatidylcholine pretreatment decreases ischemia-reperfusion-induced methane generation and the inflammatory response in the small intestine. Shock 2009; 30:596-602. [PMID: 18461026 DOI: 10.1097/shk.0b013e31816f204a] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We have shown that phosphatidylcholine (PC) metabolites may have a function in counteracting the production of reactive oxygen species (ROS), and that this mechanism can lead to the generation of methane from choline. The aims were to establish whether the dietary administration of PC can protect the reperfused small bowel mucosa by its acting as an anti-inflammatory agent and to investigate this possibility in association with in vivo methane generation. Group 1 (n = 5) of anesthetized dogs served as sham-operated controls, whereas in groups 2 (n = 6) and 3 (n = 6), complete small intestinal ischemia was induced by occluding the superior mesenteric artery for 60 min. Groups 1 and 2 were fed with normal laboratory chow for 1 week before the experiments, whereas the animals in group 3 received a special diet containing 1% soybean PC. The intramucosal pH and the difference of the arterial and local PCO2 (PCO2 gap) were detected by indirect tonometry. Intestinal superoxide production and myeloperoxidase (MPO) activity (a marker of tissue leukocyte infiltration) were ascertained on ileal biopsy samples 180 min after reperfusion. The content of methane in the exhaled air was determined by gas chromatography. I/R was characterized by significant tissue acidosis with ROS generation and elevated MPO activity. These changes were accompanied by increased methane production in the exhaled air during reoxygenation. The PC-enriched diet prevented the decrease in intramucosal pH, diminished the intestinal superoxide generation and the MPO activity, and significantly decreased the exhaled methane concentration. The increased dietary uptake of PC exerts an anti-inflammatory influence in the gastrointestinal tract. Exhaled methane is linked to abnormal ROS generation; a decreased methane production is associated with significantly reduced inflammatory activation during I/R.
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Krzystanek E, Krzystanek M, Opala G, Trzeciak HI, Siuda J, Małecki A. Platelet phospholipase A2 activity in patients with Alzheimer’s disease, vascular dementia and ischemic stroke. J Neural Transm (Vienna) 2007; 114:1033-9. [PMID: 17447002 DOI: 10.1007/s00702-007-0669-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2006] [Accepted: 02/18/2007] [Indexed: 11/26/2022]
Abstract
Phospholipase A(2) (E.C. 3.1.1.4, PLA(2)) plays an essential role in metabolism of membrane phospholipids, it is related to inflammatory reactions, secretion of amyloid precursor protein and activation of NMDA receptor after ischemia. In the present study we investigated PLA(2) activity in platelets from 37 Alzheimer's disease (AD) patients, 32 vascular dementia (VaD) patients and 32 individuals with ischemic stroke as compared to 27 healthy elderly controls. PLA(2) activity was determined using radiometric assay. Mean platelet PLA(2) activity was increased in individuals with Alzheimer's disease (p < 0.001). In VaD group the enzyme activity was between the values in AD and controls, these differences being significant from both groups. In the group of patients with ischemic stroke mean PLA(2) activity was higher either 48 h after the stroke or 7 days later (in both cases p < 0.001). The results may be particularly interesting in light of the fact, that inhibitors of PLA(2) activity are known.
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Affiliation(s)
- E Krzystanek
- Department of Late Age Neurology, Silesian Medical University, Katowice, Poland.
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20
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Bazalakova MH, Wright J, Schneble EJ, McDonald MP, Heilman CJ, Levey AI, Blakely RD. Deficits in acetylcholine homeostasis, receptors and behaviors in choline transporter heterozygous mice. GENES BRAIN AND BEHAVIOR 2006; 6:411-24. [PMID: 17010154 DOI: 10.1111/j.1601-183x.2006.00269.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Cholinergic neurons elaborate a hemicholinium-3 (HC-3) sensitive choline transporter (CHT) that mediates presynaptic, high-affinity choline uptake (HACU) in support of acetylcholine (ACh) synthesis and release. Homozygous deletion of CHT (-/-) is lethal shortly after birth (Ferguson et al. 2004), consistent with CHT as an essential component of cholinergic signaling, but precluding functional analyses of CHT contributions in adult animals. In contrast, CHT+/- mice are viable, fertile and display normal levels of synaptosomal HACU, yet demonstrate reduced CHT protein and increased sensitivity to HC-3, suggestive of underlying cholinergic hypofunction. We find that CHT+/- mice are equivalent to CHT+/+ siblings on measures of motor co-ordination (rotarod), general activity (open field), anxiety (elevated plus maze, light/dark paradigms) and spatial learning and memory (Morris water maze). However, CHT+/- mice display impaired performance as a result of physical challenge in the treadmill paradigm, as well as reduced sensitivity to challenge with the muscarinic receptor antagonist scopolamine in the open field paradigm. These behavioral alterations are accompanied by significantly reduced brain ACh levels, elevated choline levels and brain region-specific decreased expression of M1 and M2 muscarinic acetylcholine receptors. Our studies suggest that CHT hemizygosity results in adequate baseline ACh stores, sufficient to sustain many phenotypes, but normal sensitivities to physical and/or pharmacological challenge require full cholinergic signaling capacity.
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Affiliation(s)
- M H Bazalakova
- Neuroscience Graduate Program, MSTP, Vanderbilt University School of Medicine, Vanderbilt University, Nashville, TN 37242-8548, USA
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Matthies DS, Fleming PA, Wilkes DM, Blakely RD. The Caenorhabditis elegans choline transporter CHO-1 sustains acetylcholine synthesis and motor function in an activity-dependent manner. J Neurosci 2006; 26:6200-12. [PMID: 16763028 PMCID: PMC6675188 DOI: 10.1523/jneurosci.5036-05.2006] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Cholinergic neurotransmission supports motor, autonomic, and cognitive function and is compromised in myasthenias, cardiovascular diseases, and neurodegenerative disorders. Presynaptic uptake of choline via the sodium-dependent, hemicholinium-3-sensitive choline transporter (CHT) is believed to sustain acetylcholine (ACh) synthesis and release. Analysis of this hypothesis in vivo is limited in mammals because of the toxicity of CHT antagonists and the early postnatal lethality of CHT-/- mice (Ferguson et al., 2004). In Caenorhabditis elegans, in which cholinergic signaling supports motor activity and mutant alleles impacting ACh secretion and response can be propagated, we investigated the contribution of CHT (CHO-1) to facets of cholinergic neurobiology. Using the cho-1 promoter to drive expression of a translational, green fluorescent protein-CHO-1 fusion (CHO-1:GFP) in wild-type and kinesin (unc-104) mutant backgrounds, we establish in the living nematode that the transporter localizes to cholinergic synapses, and likely traffics on synaptic vesicles. Using embryonic primary cultures, we demonstrate that CHO-1 mediates hemicholinium-3-sensitive, high-affinity choline uptake that can be enhanced with depolarization in a Ca(2+)-dependent manner supporting ACh synthesis. Although homozygous cho-1 null mutants are viable, they possess 40% less ACh than wild-type animals and display stress-dependent defects in motor activity. In a choline-free liquid environment, cho-1 mutants demonstrate premature paralysis relative to wild-type animals. Our findings establish a requirement for presynaptic choline transport activity in vivo in a model amenable to a genetic dissection of CHO-1 regulation.
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Cai D, Netzer WJ, Zhong M, Lin Y, Du G, Frohman M, Foster DA, Sisodia SS, Xu H, Gorelick FS, Greengard P. Presenilin-1 uses phospholipase D1 as a negative regulator of beta-amyloid formation. Proc Natl Acad Sci U S A 2006; 103:1941-6. [PMID: 16449386 PMCID: PMC1413665 DOI: 10.1073/pnas.0510708103] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Presenilin (PS1/PS2) is a major component of gamma-secretase, the activity that mediates proteolysis of beta-amyloid precursor protein to generate beta-amyloid (Abeta). Here we demonstrate that PS1, through its loop region, binds to phospholipase D1 (PLD1), thereby recruiting it to the Golgi/trans-Golgi network. Overexpression of wild-type PLD1 reduces Abeta generation. Conversely, down-regulation of endogenous PLD1 by small hairpin RNA elevates Abeta production. The Abeta-lowering effect of PLD1 is independent of its ability to promote vesicular budding of beta-amyloid precursor protein. The data indicate that overexpression of PLD1 decreases, and down-regulation of PLD1 increases, the catalytic activity, and the association of the subunits, of gamma-secretase.
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Affiliation(s)
- Dongming Cai
- *Laboratory of Molecular and Cellular Neuroscience, and Fisher Center for Research on Alzheimer Disease, The Rockefeller University, 1230 York Avenue, New York, NY 10021
| | - William J. Netzer
- *Laboratory of Molecular and Cellular Neuroscience, and Fisher Center for Research on Alzheimer Disease, The Rockefeller University, 1230 York Avenue, New York, NY 10021
| | - Minghao Zhong
- Department of Biological Sciences, Hunter College of City University of New York, New York, NY 10021
| | - Yixin Lin
- Ciphergen Biosystems Inc., 6611 Dumbarton Circle, Fremont, CA 94555
| | - Guangwei Du
- Department of Pharmacology and the Center for Developmental Genetics, University Medical Center at Stony Brook, Stony Brook, NY 11794
| | - Michael Frohman
- Department of Pharmacology and the Center for Developmental Genetics, University Medical Center at Stony Brook, Stony Brook, NY 11794
| | - David A. Foster
- Department of Biological Sciences, Hunter College of City University of New York, New York, NY 10021
| | - Sangram S. Sisodia
- Department of Neurobiology, Pharmacology, and Physiology, University of Chicago, Chicago, IL 60637
| | - Huaxi Xu
- Center for Neurosciences and Aging, Burnham Institute for Medical Research, 10901 North Torrey Pines Road, La Jolla, CA 92037; and
| | - Fred S. Gorelick
- *Laboratory of Molecular and Cellular Neuroscience, and Fisher Center for Research on Alzheimer Disease, The Rockefeller University, 1230 York Avenue, New York, NY 10021
- **Department of Internal Medicine, Veterans Affairs Connecticut Healthcare System and Yale University, West Haven, CT 06516
| | - Paul Greengard
- *Laboratory of Molecular and Cellular Neuroscience, and Fisher Center for Research on Alzheimer Disease, The Rockefeller University, 1230 York Avenue, New York, NY 10021
- ††To whom correspondence should be addressed. E-mail:
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Cai D, Zhong M, Wang R, Netzer WJ, Shields D, Zheng H, Sisodia SS, Foster DA, Gorelick FS, Xu H, Greengard P. Phospholipase D1 corrects impaired betaAPP trafficking and neurite outgrowth in familial Alzheimer's disease-linked presenilin-1 mutant neurons. Proc Natl Acad Sci U S A 2006; 103:1936-40. [PMID: 16449385 PMCID: PMC1413666 DOI: 10.1073/pnas.0510710103] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Presenilins (PS1/PS2) regulate proteolysis of beta-amyloid precursor protein (betaAPP) and affect its intracellular trafficking. Here, we demonstrate that a PS1-interacting protein, phospholipase D1 (PLD1), affects intracellular trafficking of betaAPP. Overexpression of PLD1 in PS1wt cells promotes generation of betaAPP-containing vesicles from the trans-Golgi network. Conversely, inhibition of PLD1 activity by 1-butanol decreases betaAPP trafficking in both wt and PS1-deficient cells. The subcellular localization of PLD1 is altered, and PLD enzymatic activity is reduced in cells expressing familial Alzheimer's disease (FAD) PS1 mutations compared with PS1wt cells. Overexpression of wt, but not catalytically inactive, PLD1 increases budding of betaAPP-containing vesicles from the trans-Golgi network in FAD mutant cells. Surface delivery of betaAPP is also increased by PLD1 in these cells. The impaired neurite outgrowth capacity in FAD mutant neurons was corrected by introducing PLD1 into these cells. The results indicate that PLD1 may represent a therapeutic target for rescuing compromised neuronal function in AD.
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Affiliation(s)
- Dongming Cai
- *Laboratory of Molecular and Cellular Neuroscience, and Fisher Center for Research on Alzheimer Disease, The Rockefeller University, 1230 York Avenue, New York, NY 10021
| | - Minghao Zhong
- Department of Biological Sciences, Hunter College of City University of New York, New York, NY 10021
| | - Runsheng Wang
- Huffington Center on Aging, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030
| | - William J. Netzer
- *Laboratory of Molecular and Cellular Neuroscience, and Fisher Center for Research on Alzheimer Disease, The Rockefeller University, 1230 York Avenue, New York, NY 10021
| | - Dennis Shields
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, New York, NY 10461
| | - Hui Zheng
- Huffington Center on Aging, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030
| | - Sangram S. Sisodia
- Department of Neurobiology, Pharmacology, and Physiology, University of Chicago, Chicago, IL 60637
| | - David A. Foster
- Department of Biological Sciences, Hunter College of City University of New York, New York, NY 10021
| | - Fred S. Gorelick
- *Laboratory of Molecular and Cellular Neuroscience, and Fisher Center for Research on Alzheimer Disease, The Rockefeller University, 1230 York Avenue, New York, NY 10021
- Department of Internal Medicine, Veterans Affairs Connecticut Healthcare System and Yale University, West Haven, CT 06516; and
| | - Huaxi Xu
- *Laboratory of Molecular and Cellular Neuroscience, and Fisher Center for Research on Alzheimer Disease, The Rockefeller University, 1230 York Avenue, New York, NY 10021
- **Center for Neurosciences and Aging, Burnham Institute for Medical Research, 10901 North Torrey Pines Road, La Jolla, CA 92037
- To whom correspondence may be addressed. E-mail:
or
| | - Paul Greengard
- *Laboratory of Molecular and Cellular Neuroscience, and Fisher Center for Research on Alzheimer Disease, The Rockefeller University, 1230 York Avenue, New York, NY 10021
- To whom correspondence may be addressed. E-mail:
or
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Abstract
Ten years after the isoforms of mammalian phospholipase D (PLD), PLD1 and 2, were cloned, their roles in the brain remain speculative but several lines of evidence now implicate these enzymes in basic cell functions such as vesicular trafficking as well as in brain development. Many mitogenic factors, including neurotransmitters and growth factors, activate PLD in neurons and astrocytes. Activation of PLD downstream of protein kinase C seems to be a required step for astroglial proliferation. The characteristic disruption of the PLD signaling pathway by ethanol probably contributes to the delay of brain growth in fetal alcohol syndrome. The post-natal increase of PLD activities concurs with synapto- and myelinogenesis in the brain and PLD is apparently involved in neurite formation. In the adult and aging brain, PLD activity has antiapoptotic properties suppressing ceramide formation. Increased PLD activities in acute and chronic neurodegeneration as well as in inflammatory processes are evidently due to astrogliosis and may be associated with protective responses of tissue repair and remodeling. ARF-regulated PLD participates in receptor endocytosis as well as in exocytosis of neurotransmitters where PLD seems to favor vesicle fusion by modifications of the shape and charge of lipid membranes. Finally, PLD activities contribute free choline for the synthesis of acetylcholine in the brain. Novel tools such as RNA interference should help to further elucidate the roles of PLD isoforms in brain physiology and pathology.
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Affiliation(s)
- Jochen Klein
- Department of Pharmaceutical Sciences, School of Pharmacy, Texas Tech University Health Science Center, Amarillo, Texas 79106, USA.
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Murai S, Saito H, Shirato R, Tamura H, Yamada A, Kato H. An improved method for assaying phosphatidylcholine in mouse tissue. J Pharmacol Toxicol Methods 2005; 50:223-9. [PMID: 15519909 DOI: 10.1016/j.vascn.2004.06.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2004] [Accepted: 06/03/2004] [Indexed: 10/26/2022]
Abstract
INTRODUCTION To measure levels of phosphatidylcholine (PtdCh) in various mouse tissues, we developed a rapid and precise method using high-performance liquid chromatography (HPLC) with electrochemical detection (ECD) and an immobilized enzyme column. To generate an example data set, the effect of methoxamine (an alpha1-adrenergic agonist) on the PtdCh levels was examined by this method in the artery and the submandibular gland of the mouse in vivo. METHODS Under our modifications of the method of Zapata et al. [J. Neurosci. 18 (1998) 3597], the mixture of lipophilic choline metabolites (PtdCh, lyso-PtdCh, and sphingomyelin) extracted by chloroform from the tissue homogenate was dried without prior separation and hydrolyzed with free choline by a 1-N perchloric acid solution containing ethylhomocholine (an internal standard for choline assay) at 90 degrees C for 1 h. Subsequently, the hydrolyzed mixture was injected directly into the HPLC system for PtdCh assay. RESULTS The present method permitted PtdCh assay within 5 min in one chromatographic run. Recovery of an authentic PtdCh sample was 99% (n = 10). The within-run coefficients of variation for choline derived from PtdCh in the same tissue samples were 0.6% (n = 10) and 1.3% (n = 30). Under the present method, the lowest and highest PtdCh values in tissue samples were about 2 micromol/g (eye ball) and 29 micromol/g (spinal cord), respectively. Methoxamine significantly decreased PtdCh levels and increased free choline levels in mouse artery and submandibular gland. DISCUSSION Under the present sample processing procedure, the choline values originating from lyso-PtdCh and sphingomyelin were much less than those originating from PtdCh hydrolysis. Thus, it was possible to inject the hydrolyzed mixture directly into the HPLC system for PtdCh assay. Since the present method provides simple, rapid, and highly reliable PtdCh determination, it is suitable for routine assay of PtdCh in a large number of samples.
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Affiliation(s)
- Shigeo Murai
- Department of Pharmacology, School of Dentistry, Iwate Medical University, Morioka, 020-8505, Japan
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Lecomte MJ, De Gois S, Guerci A, Ravassard P, Faucon Biguet N, Mallet J, Berrard S. Differential expression and regulation of the high-affinity choline transporter CHT1 and choline acetyltransferase in neurons of superior cervical ganglia. Mol Cell Neurosci 2005; 28:303-13. [PMID: 15691711 DOI: 10.1016/j.mcn.2004.09.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2004] [Revised: 09/17/2004] [Accepted: 09/22/2004] [Indexed: 11/21/2022] Open
Abstract
Previous studies revealed that leukemia inhibitory factor (LIF) and retinoic acid (RA) induce a noradrenergic to cholinergic switch in cultured sympathetic neurons of superior cervical ganglia (SCG) by up-regulating the coordinate expression of choline acetyltransferase (ChAT) and the vesicular acetylcholine transporter. Here, we examined the effect of both factors on high-affinity choline uptake (HACU) and on expression of the high-affinity choline transporter CHT1. We found that HACU and CHT1-mRNA levels are up-regulated by LIF and down-regulated by RA in these neurons. Thus, in contrast to LIF, RA differentially regulates the expression of the presynaptic cholinergic proteins. Moreover, we showed that untreated SCG neurons express HACU and CHT1-mRNAs at much higher levels than ChAT activity and transcripts. In intact SCG, CHT1-mRNAs are abundant and synthesized by the noradrenergic neurons themselves. This study provides the first example of CHT1 expression in neurons which do not use acetylcholine as neurotransmitter.
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Affiliation(s)
- Marie-José Lecomte
- Laboratoire de la Neurotransmission et des Processus Neurodégénératifs, CNRS, UMR 7091, Bâtiment CERVI, Hôpital de la Pitié-Salpêtrière, 83 boulevard de l'Hôpital, 75013 Paris, France
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27
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Brandon EP, Mellott T, Pizzo DP, Coufal N, D'Amour KA, Gobeske K, Lortie M, López-Coviella I, Berse B, Thal LJ, Gage FH, Blusztajn JK. Choline transporter 1 maintains cholinergic function in choline acetyltransferase haploinsufficiency. J Neurosci 2004; 24:5459-66. [PMID: 15201317 PMCID: PMC6729318 DOI: 10.1523/jneurosci.1106-04.2004] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Choline acetyltransferase (ChAT), the enzyme that synthesizes the neurotransmitter acetylcholine (ACh), is thought to be present in kinetic excess in cholinergic neurons. The rate-limiting factor in ACh production is the provision of choline to ChAT. Cholinergic neurons are relatively unique in their expression of the choline transporter 1 (CHT1), which exhibits high-affinity for choline and catalyzes its uptake from the extracellular space to the neuron. Multiple lines of evidence indicate that the activity of CHT1 is a key determinant of choline supply for ACh synthesis. We examined the interaction of ChAT and ChT activity using mice heterozygous for a null mutation in the Chat gene (Chat+/-). In these mice, brain ChAT activity was reduced by 40-50% relative to the wild type, but brain ACh levels as well as ACh content and depolarization-evoked ACh release in hippocampal slices were normal. However, the amount of choline taken up by CHT1 and ACh synthesized de novo from choline transported by CHT1 in hippocampal slices, as well as levels of CHT1 mRNA in the septum and CHT1 protein in several regions of the CNS, were 50-100% higher in Chat+/- than in Chat+/+ mice. Thus, haploinsufficiency of ChAT leads to an increased expression of CHT1. Increased ChT activity may compensate for the reduced ChAT activity in Chat+/- mice, contributing to the maintenance of apparently normal cholinergic function as reflected by normal performance of these mice in several behavioral assays.
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Affiliation(s)
- Eugene P Brandon
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, California 92037, USA
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Ferguson SM, Bazalakova M, Savchenko V, Tapia JC, Wright J, Blakely RD. Lethal impairment of cholinergic neurotransmission in hemicholinium-3-sensitive choline transporter knockout mice. Proc Natl Acad Sci U S A 2004; 101:8762-7. [PMID: 15173594 PMCID: PMC423269 DOI: 10.1073/pnas.0401667101] [Citation(s) in RCA: 125] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Presynaptic acetylcholine (ACh) synthesis and release is thought to be sustained by a hemicholinium-3-sensitive choline transporter (CHT). We disrupted the murine CHT gene and examined CHT-/- and +/- animals for evidence of impaired cholinergic neurotransmission. Although morphologically normal at birth, CHT-/- mice become immobile, breathe irregularly, appear cyanotic, and die within an hour. Hemicholinium-3-sensitive choline uptake and subsequent ACh synthesis are specifically lost in CHT-/- mouse brains. Moreover, we observe a time-dependent loss of spontaneous and evoked responses at CHT-/- neuromuscular junctions. Consistent with deficits in synaptic ACh availability, we also observe developmental alterations in neuromuscular junction morphology reminiscent of changes in mutants lacking ACh synthesis. Adult CHT+/- mice overcome reductions in CHT protein levels and sustain choline uptake activity at wild-type levels through posttranslational mechanisms. Our results demonstrate that CHT is an essential and regulated presynaptic component of cholinergic signaling and indicate that CHT warrants consideration as a candidate gene for disorders characterized by cholinergic hypofunction.
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Affiliation(s)
- Shawn M Ferguson
- Neuroscience Graduate Program, Vanderbilt University, Nashville, TN 37232, USA
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29
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Schueler UH, Kolter T, Kaneski CR, Blusztajn JK, Herkenham M, Sandhoff K, Brady RO. Toxicity of glucosylsphingosine (glucopsychosine) to cultured neuronal cells: a model system for assessing neuronal damage in Gaucher disease type 2 and 3. Neurobiol Dis 2004; 14:595-601. [PMID: 14678774 DOI: 10.1016/j.nbd.2003.08.016] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Patients with Gaucher disease have been classified as type 1 nonneuronopathic, type 2 acute neuronopathic, and type 3 chronic neuronopathic phenotypes. Increased quantities of glucocerebroside and glucosylsphingosine (glucopsychosine) are present in the brain of type 2 and type 3 Gaucher patients. Galactosylsphingosine has previously been shown to be neurotoxic in globoid cell leukodystrophy (Krabbe disease). To determine whether glucosylsphingosine is also neurotoxic, we examined its effect on cultured cholinergic neuron-like LA-N-2 cells. When these cells were exposed to 1, 5, or 10 microM glucosylsphingosine for a period of 18 h, they became shriveled, neurite outgrowth was suppressed, and the activities of the lysosomal enzymes glucocerebrosidase, sphingomyelinase, and beta-galactosidase were reduced in a dose-dependent manner. Acetylcholine in cells exposed to glucosylsphingosine also declined. Cells switched to glucosylsphingosine-free medium partially recovered. The data suggest that accumulation of glucosylsphingosine contributes to neuronal dysfunction and destruction in patients with neuronopathic Gaucher disease.
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Affiliation(s)
- U H Schueler
- Developmental and Metabolic Neurology Branch, NINDS, NIH, DHHS, Bethesda, MD 20892, USA.
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30
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Meck WH, Williams CL. Metabolic imprinting of choline by its availability during gestation: implications for memory and attentional processing across the lifespan. Neurosci Biobehav Rev 2003; 27:385-99. [PMID: 12946691 DOI: 10.1016/s0149-7634(03)00069-1] [Citation(s) in RCA: 225] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A growing body of research supports the view that choline is an essential nutrient during early development that has long-lasting effects on memory and attentional processes throughout the lifespan. This review describes the known effects of alterations in dietary choline availability both in adulthood and during early development. Although modest effects of choline on cognitive processes have been reported when choline is administered to adult animals, we have found that the perinatal period is a critical time for cholinergic organization of brain function. Choline supplementation during this period increases memory capacity and precision of the young adult and appears to prevent age-related memory and attentional decline. Deprivation of choline during early development leads to compromised cognitive function and increased decline with age. We propose that this organizational effect of choline availability may be due to relatively permanent alterations in the functioning of the cholinergic synapse, which we have called 'metabolic imprinting'.
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Affiliation(s)
- Warren H Meck
- Department of Psychological and Brain Sciences, Duke University, 9 Flowers Drive, Box 90086, Durham, NC 27708-0086, USA.
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31
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Ryu GR, Kim MJ, Song CH, Sim SS, Min DS, Rhie DJ, Yoon SH, Hahn SJ, Kim MS, Jo YH. Site-Specific Distribution of Phospholipase D Isoforms in the Rat Pancreas. Acta Histochem Cytochem 2003. [DOI: 10.1267/ahc.36.51] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- Gyeong Ryul Ryu
- Department of Physiology, College of Medicine, The Catholic University of Korea
| | - Myung-Jun Kim
- Department of Physiology, College of Medicine, The Catholic University of Korea
| | - Chan-Hee Song
- Department of Physiology, College of Medicine, The Catholic University of Korea
| | - Sang Soo Sim
- Department of Pathophysiology, College of Pharmacy, Chung Ang University
| | - Do Sik Min
- Department of Physiology, College of Medicine, The Catholic University of Korea
| | - Duck-Joo Rhie
- Department of Physiology, College of Medicine, The Catholic University of Korea
| | - Shin Hee Yoon
- Department of Physiology, College of Medicine, The Catholic University of Korea
| | - Sang June Hahn
- Department of Physiology, College of Medicine, The Catholic University of Korea
| | - Myung-Suk Kim
- Department of Physiology, College of Medicine, The Catholic University of Korea
| | - Yang-Hyeok Jo
- Department of Physiology, College of Medicine, The Catholic University of Korea
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Chen J, Dohi S, Tan Z, Banno Y, Nozawa Y. The inhibitory effect of local anesthetics on bradykinin-induced phospholipase D activation in rat pheochromocytoma PC12 cells. Anesth Analg 2002; 95:88-97, table of contents. [PMID: 12088949 DOI: 10.1097/00000539-200207000-00016] [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: 11/25/2022]
Abstract
UNLABELLED Bradykinin induces activation of phospholipase D (PLD) via B(2) receptors in neuronal cells. To demonstrate molecular mechanism(s) of local anesthetics, we examined whether and how local anesthetics affect bradykinin-induced PLD activation in PC12 cells. Using [(3)H]Palmitic acid-labeled PC12 cells stimulated with bradykinin, formation of [(3)H]phosphatidylbutanol was measured as a variable of PLD activity. Bradykinin-stimulated PLD activity seemed to peak at 2 min. Procaine, lidocaine, ropivacaine, bupivacaine, and tetracaine suppressed the bradykinin-induced PLD activation. We chose tetracaine, the most potent drug among the local anesthetics tested, to examine how local anesthetics affect phospholipase C, protein tyrosine kinase, and extracellular signal-regulated kinase, which are the molecules upstream of PLD. Tetracaine at clinically relevant concentrations (1 approximately 10 x 10(-4) M) inhibited the bradykinin-induced PLD activation in a dose- and time-dependent manner, but neither tetrodotoxin nor nifedipine affected the PLD activation. Tetracaine (5 x 10(-4) M) slightly potentiated brady-kinin-induced phospholipase C activation. Bradykinin-stimulated protein tyrosine-phosphorylation and extracellular signal-regulated kinase activation were not affected by tetracaine. Tetracaine significantly decreased PLD activity of membrane fraction in PC12 cells. These results indicate that local anesthetics depress bradykinin-induced lipid signaling pathway(s) and may provide some clues to understanding the molecular mechanisms of these drugs for anesthesia or analgesia. IMPLICATIONS Local anesthetics depressed the bradykinin-induced activation of phospholipase D (PLD) in PC12 cells. The effects of tetracaine, the most potent among the anesthetics tested, on the bradykinin-induced intracellular signaling molecules were examined. The bradykinin-induced PLD activation could be one of the potential intracellular signaling molecular sites of local anesthetic action.
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Affiliation(s)
- Jinen Chen
- Department of Anesthesiology, Gifu University School of Medicine, Tsukusamachi-40, Gifu City, Gifu 400-8705, Japan
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Zhao D, Frohman MA, Blusztajn JK. Generation of choline for acetylcholine synthesis by phospholipase D isoforms. BMC Neurosci 2001; 2:16. [PMID: 11734063 PMCID: PMC60648 DOI: 10.1186/1471-2202-2-16] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2001] [Accepted: 10/19/2001] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND In cholinergic neurons, the hydrolysis of phosphatidylcholine (PC) by a phospholipase D (PLD)-type enzyme generates some of the precursor choline used for the synthesis of the neurotransmitter acetylcholine (ACh). We sought to determine the molecular identity of the relevant PLD using murine basal forebrain cholinergic SN56 cells in which the expression and activity of the two PLD isoforms, PLD1 and PLD2, were experimentally modified. ACh levels were examined in cells incubated in a choline-free medium, to ensure that their ACh was synthesized entirely from intracellular choline. RESULTS PLD2, but not PLD1, mRNA and protein were detected in these cells and endogenous PLD activity and ACh synthesis were stimulated by phorbol 12-myristate 13-acetate (PMA). Introduction of a PLD2 antisense oligonucleotide into the cells reduced PLD2 mRNA and protein expression by approximately 30%. The PLD2 antisense oligomer similarly reduced basal- and PMA-stimulated PLD activity and ACh levels. Overexpression of mouse PLD2 by transient transfection increased basal- (by 74%) and PMA-stimulated (by 3.2-fold) PLD activity. Moreover, PLD2 transfection increased ACh levels by 26% in the absence of PMA and by 2.1-fold in the presence of PMA. Overexpression of human PLD1 by transient transfection increased PLD activity by 4.6-fold and ACh synthesis by 2.3-fold in the presence of PMA as compared to controls. CONCLUSIONS These data identify PLD2 as the endogenous enzyme that hydrolyzes PC to generate choline for ACh synthesis in cholinergic cells, and indicate that in a model system choline generated by PLD1 may also be used for this purpose.
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Affiliation(s)
- Di Zhao
- Departments of Pathology and Laboratory Medicine, Boston University, School of Medicine, Boston, MA, USA
| | - Michael A Frohman
- Department of Pharmacology and the Center for Developmental Genetics, SUNY at Stony Brook, Stony Brook, New York, USA
| | - Jan Krzysztof Blusztajn
- Departments of Pathology and Laboratory Medicine, Boston University, School of Medicine, Boston, MA, USA
- Department of Psychiatry, Boston University School of Medicine, Boston, MA, USA
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Murai S, Saito H, Shirato R, Kawaguchi T. An improved method for assaying phosphocholine and glycerophosphocholine in mouse tissue. J Pharmacol Toxicol Methods 2001; 46:103-9. [PMID: 12481847 DOI: 10.1016/s1056-8719(02)00165-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
INTRODUCTION To measure the levels of phosphocholine (PCh) and glycerophosphocholine (GPCh) in the tissues and organs of mice, we developed a simple and rapid method using high-performance liquid chromatography (HPLC) with electrochemical detection (ECD) and an immobilized enzyme column. METHODS Under our modifications of the separation procedure of Klein et al. [Neurochem. Int. 2 (1993) 293], PCh and GPCh in the hydrophilic phase of the homogenate samples were selectively hydrolyzed into free choline by alkaline phosphatase and a 0.4-N perchloric acid solution, respectively, and the resulting hydrolyzed mixtures were directly injected into the HPLC system for analysis. RESULTS The present method permits PCh or GPCh assay within 5 min in one chromatographic run. Recoveries from tissue samples were 97% for PCh and 101% for GPCh. The percentages of the crossover reaction to the authentic PCh and GPCh were 0.4% and 3.8%, respectively. The within-run coefficients of variation for choline derived from PCh and GPCh in the tissue samples were 1.2% and 1.4%, respectively. DISCUSSION The method is effective and has been applied to the measurement of PCh and GPCh levels in several tissues of mice.
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Affiliation(s)
- S Murai
- Department of Pharmacology, School of Dentistry, Iwate Medical University, Morioka 020-8505, Japan.
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Leng Y, Chase TN, Bennett MC. Muscarinic receptor stimulation induces translocation of an alpha-synuclein oligomer from plasma membrane to a light vesicle fraction in cytoplasm. J Biol Chem 2001; 276:28212-8. [PMID: 11337491 DOI: 10.1074/jbc.m011121200] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The close correspondence between the distribution of brain alpha-synuclein and that of muscarinic M1 and M3 receptors suggests a role for this protein in cholinergic transmission. We thus examined the effect of muscarinic stimulation on alpha-synuclein in SH-SY5Y, a human dopaminergic cell line that expresses this protein. Under basal conditions, alpha-synuclein was detected in all subcellular compartments isolated as follows: plasma membrane, cytoplasm, nucleus, and two vesicle fractions. The lipid fractions contained only a 45-kDa alpha-synuclein oligomer, whereas the cytoplasmic and nuclear fractions contained both the oligomer and the monomer. This finding suggests alpha-synuclein exists physiologically as a lipid-bound oligomer and a soluble monomer. Muscarinic stimulation by carbachol reduced the alpha-synuclein oligomer in plasma membrane over a 30-min period, with a concomitant increase of both the oligomer and the monomer in the cytoplasmic fraction. The oligomer was associated with a light vesicle fraction in cytoplasm that contains uncoated endocytotic vesicles. The carbachol-induced alteration of alpha-synuclein was blocked by atropine. Translocation of the alpha-synuclein oligomer in response to carbachol stimulation corresponds closely with the time course of ligand-stimulated muscarinic receptor endocytosis. The data suggest that the muscarine receptor stimulated release of the alpha-synuclein oligomer from plasma membrane, and its subsequent association with the endocytotic vesicle fraction may have a role in muscarine receptor endocytosis. We propose that its function may be a transient release of membrane-bound phospholipase D2 from alpha-synuclein inhibition, thus allowing this lipase to participate in muscarinic receptor endocytosis.
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Affiliation(s)
- Y Leng
- Experimental Therapeutics Branch, NINDS, National Institutes of Health, Bethesda, Maryland 20892, USA
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Lee M, Jo Y, Chun M, Chung J, Kim M, Min D. Immunohistochemical localization of phospholipase D1 in rat central nervous system. Brain Res 2000; 864:52-9. [PMID: 10793186 DOI: 10.1016/s0006-8993(00)02134-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Phospholipase D (PLD) is one of the intracellular signal transduction enzymes and plays an important role in a variety of cellular functions. We investigated the distribution of PLD isozyme, PLD1 in the rat brain and spinal cord using an immunological approach. Western blot analysis showed the presence of PLD1 protein in all tissues studied, with significantly higher levels in the brainstem and spinal cord, which was correlated with the results obtained from PLD activity assay. Prominent and specific signals of PLD1 were observed in many functionally diverse brain areas, including the olfactory bulb, medial septum-diagonal band complex, cerebral cortex, brainstem, cerebellum, and spinal cord. In the brainstem, the red nucleus, substantia nigra, interpeduncular nucleus, cranial motor nuclei (trigeminal motor, abducent, facial, and hypoglossal), sensory cranial nerve nuclei (spinal trigeminal, vestibular, and cochlear), as well as nuclei of the reticular formation, all showed intense immunoreactivity. Purkinje cells and deep cerebellar nuclei of the cerebellum were also labeled intensely. However, no significant labeling was found in the thalamus, epithalamus, and basal ganglia. Although many of the PLD1 immunoreactive cells were neurons, PLD1 was also expressed in glial cells such as presumed astrocytes and tanycytes. These findings suggest that PLD1 may play an important role in the central nervous system of the adult rat.
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Affiliation(s)
- M Lee
- Department of Anatomy, College of Medicine, The Catholic University of Korea, 505 Banpo-dong, Socho-gu, 137-701, Seoul, South Korea
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Abstract
Previous studies have shown that NMDA evokes a calcium-dependent and region-specific increase in extracellular choline that is associated with a reduction of membrane phosphatidylcholine and precedes neuronal cell death. We investigated, using in vivo microdialysis, the contribution of high-affinity choline uptake on the increase in extracellular choline evoked by NMDA. Dialysis was performed in the presence of Neostigmine (0.5 microM), an acetylcholinesterase inhibitor, in prefrontal cortex or hippocampus of freely moving rats. Drugs were administered through the dialysis probe. In cholinergic denervation experiments, rats were subjected to sham or AMPA-induced lesion of cholinergic nuclei at least 2 weeks before microdialysis. Excitotoxic lesion of the medial septum / ventral diagonal band nuclei reduced hippocampal choline acetyltransferase activity by 74%, [(3)H]hemicholinium-3 binding by 32%, and completely abolished potassium-evoked acetylcholine release. Despite this reduction of presynaptic cholinergic function, perfusion of NMDA (300 microM) by retrodialysis produced an increase in hippocampal extracellular choline (249 +/- 22% of basal levels) that was similar to that observed in sham controls (301 +/- 35%). Inhibition of choline uptake with hemicholinium-3 in nonlesioned rats produced a sustained increase in dialysate choline (163 +/- 8%) and reduced acetylcholine to 33 +/- 2% of basal levels, consistent with a depletion of the acetylcholine pool due to precursor deficit. Simultaneous perfusion of hemicholinium-3 and NMDA produced a synergistic increase in dialysate choline (664 +/- 95% of basal levels), indicating that part of the choline released by NMDA is taken up. In contrast, NMDA antagonized the decrease of acetylcholine produced by hemicholinium-3. These results show that NMDA-evoked choline release is not mediated by inhibition of high-affinity choline uptake and indicate that choline released by NMDA can be used to sustain acetylcholine synthesis when there is a precursor deficit secondary to uptake inhibition.
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Affiliation(s)
- A Zapata
- Neurobiology Unit, Institut d'Investigacions Biomèdiques de Barcelona, Consejo Superior de Investigaciones Científicas, IDIBAPS, Barcelona, Spain
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Abstract
The synthesis, storage and release of acetylcholine (ACh) requires the expression of several specialized proteins, including choline acetyltransferase (ChAT) and the vesicular ACh transporter (VAChT). The VAChT gene is located within the first intron of the ChAT gene. This unique genomic organization permits coordinated activation of expression of the two genes by extracellular factors. Much less is known about factors that reduce the expression of the cholinergic phenotype. A cholinergic deficit is one of the primary features of Alzheimer's disease (AD), and AD brains are characterized by amyloid deposits composed primarily of A beta peptides. Although A beta peptides are neurotoxic, part of the cholinergic deficit in AD could be attributed to the suppression of cholinergic markers in the absence of cell death. Indeed, we and others demonstrated that synthetic A beta peptides, at submicromolar concentrations that cause no cytotoxicity, reduce the expression of cholinergic markers in neuronal cells. Another feature of AD is abnormal phospholipid turnover, which might be related to the progressive accumulation of apolipoprotein E (apoE) within amyloid plaques, leading perhaps to the reduction of apoE content in the CSF of AD patients. ApoE is a component of very low density lipoproteins (VLDL). As a first step in investigating a potential neuroprotective function of apoE, we determined the effects of VLDL on ACh content in neuronal cells. We found that VLDL increases ACh levels, and that it can partially offset the anticholinergic actions of A beta peptides.
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Affiliation(s)
- J K Blusztajn
- Department of Pathology and Laboratory Medicine, Boston University School of Medicine, MA 02118, USA.
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Liscovitch M, Czarny M, Fiucci G, Tang X. Phospholipase D: molecular and cell biology of a novel gene family. Biochem J 2000. [PMID: 10642495 DOI: 10.1042/0264-6021:3450401] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Interaction of extracellular-signal molecules with cell-surface receptors often activates a phospholipase D (PLD)-mediated hydrolysis of phosphatidylcholine and other phospholipids, generating phosphatidic acid. The activation of PLD is believed to play an important role in the regulation of cell function and cell fate. Multiple PLD activities were characterized in eukaryotic cells, and, more recently, several PLD genes have been cloned. A PLD gene superfamily, defined by a number of structural domains and sequence motifs, also includes phosphatidyltransferases and certain phosphodiesterases. Among the eukaryotic PLD genes are those from mammals, nematodes, fungi and plants. The present review focuses on the structure, localization, regulation and possible functions of cloned mammalian and yeast PLDs. In addition, an overview of plant PLD genes, and of several distinct PLD activities that have not yet been cloned, is provided. Emerging evidence from recent work employing new molecular tools indicates that different PLD isoforms are localized in distinct cellular organelles, where they are likely to serve diverse functions in signal transduction, membrane vesicle trafficking and cytoskeletal dynamics.
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Affiliation(s)
- M Liscovitch
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot 76100, Israel.
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40
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Utal AK, Coleman PD. Non-HPLC separation of water-soluble choline metabolites by two-dimensional high voltage electrophoresis and thin layer chromatography. J Neurosci Methods 1999; 90:13-21. [PMID: 10517269 DOI: 10.1016/s0165-0270(99)00059-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
In cholinergic neurons choline is directed to three main pathways; (1) conversion to phosphorylcholine (PCh) and cytidine diphosphate choline (CDP-choline) for the synthesis of phosphatidylcholine, (2) acylation to the neurotransmitter acetylcholine and (3) oxidation to betaine for the formation of methionine. Thus, the distribution of choline among the different metabolites is important for a better understanding of the regulation of these pathways in neurons. A non-HPLC method for the simultaneous separation of five choline metabolites found in neurons is described. High voltage electrophoresis (HVE) was combined with thin layer chromatography (TLC) to separate choline, PCh, CDP-choline, acetylcholine and betaine. This method is useful in studying the distribution of choline among its different metabolites in radiotracer experiments. Aqueous metabolites from leukemia inhibitory factor treated LA-N-2 cells labeled with [methyl-3H]choline were separated by HVE followed by TLC in the same dimension. Although the separation appeared to be complete, some 'tailing' by PCh significantly elevated the radioactivity measured in CDP-choline. This tailing of PCh was confirmed by subjecting radiolabeled PCh alone to this multiple separation method. Contamination of CDP-choline by PCh was eliminated by subjecting the samples to HVE followed by TLC in the second dimension. This two-dimensional approach was consistently reproducible and achieved excellent resolution of all five metabolites. In addition, this technique also resolved a sixth choline-containing metabolite, glycerophosphorylcholine (GPC), a breakdown product of phosphatidylcholine.
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Affiliation(s)
- A K Utal
- Department of Neurobiology and Anatomy, University of Rochester School of Medicine and Dentistry, NY 14642, USA.
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Mamoon AM, Smith J, Baker RC, Farley JM. Activation of muscarinic receptors in porcine airway smooth muscle elicits a transient increase in phospholipase D activity. J Biomed Sci 1999; 6:97-105. [PMID: 10087440 DOI: 10.1007/bf02256440] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
Phospholipase D (PLD) is a phosphodiesterase that catalyses hydrolysis of phosphatidylcholine to produce phosphatidic acid and choline. In the presence of ethanol, PLD also catalyses the formation of phosphatidylethanol, which is a unique characteristic of this enzyme. Muscarinic receptor-induced changes in the activity of PLD were investigated in porcine tracheal smooth muscle by measuring the formation of [3H]phosphatidic acid ([3H]PA) and [3H]phosphatidylethanol ([3H]PEth) after labeling the muscle strips with [3H]palmitic acid. The cholinergic receptor agonist acetylcholine (Ach) significantly but transiently increased formation of both [3H]PA and [3H]PEth in a concentration-dependent manner (>105-400% vs. controls in the presence of 10(-6) to 10(-4) M Ach) when pretreated with 100 mM ethanol. The Ach receptor-mediated increase in PLD activity was inhibited by atropine (10(-6) M), indicating that activation of PLD occurred via muscarinic receptors. Activation of protein kinase C (PKC) by phorbol-12-myristate-13-acetate (PMA) increased PLD activity that was effectively blocked by the PKC inhibitors calphostin C (10(-8) to 10(-6) M) and GFX (10(-8) to 10(-6) M). Ach-induced increases in PLD activity were also significantly, but incompletely, inhibited by both GFX and calphostin C. From the present data, we conclude that in tracheal smooth muscle, muscarinic acetylcholine receptor-induced PLD activation is transient in nature and coupled to these receptors via PKC. However, PKC activation is not solely responsible for Ach-induced activation of PLD in porcine tracheal smooth muscle.
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Affiliation(s)
- A M Mamoon
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Miss., USA
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42
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Abstract
The contributions of several Ca(2+)-dependent processes to neurotoxicity were examined in primary cultures of rat cortical neurons. The Ca2+ ionophore ionomycin induced a rapid loss of axonal morphology and concomitant release of inositol phosphates that preceded morphological alterations of neuronal cell bodies, choline and arachidonate release, and protein degradation. These events were followed by a degree of neuronal lysis proportional to the external Ca2+ concentration and exposure time. The phospholipase inhibitor neomycin decreased both arachidonate release and the phospholipid hydrolysis catalysed by phospholipases C and D. Proteolysis was abated by the protease inhibitor leupeptin, but not by lysosomal proteolysis inhibitors. Neuronal lysis was inhibited partially by either leupeptin or neomycin and almost completely by both in combination. However, neither agent, alone or in combination, affected the morphological derangements. The diacylglycerol lipase inhibitor RHC-80267 reduced arachidonate release, but not neuronal lysis. Phospholipase A2 inhibitors had no effect on either arachidonate release or lysis. Treatment of mixed cultures of neurons and glia with a Ca(2+)-dependent glutamate challenge caused similar morphological changes and a delayed neuronal lysis that was also diminished by leupeptin and neomycin, but not by inhibitors of lysosomal proteolysis. These data describe several distinct stages of Ca(2+)-dependent injury to cortical neurons, a key feature of which is the stimulation of protease, and phospholipase C and D activities. The initial stage is characterized by a rapid loss of axonal morphology and increased phosphatidylinositol hydrolysis. An intermediate stage involves changes in cell body morphology plus the degradation of neuronal protein and phosphatidylcholine. In a later stage, the loss of plasma membrane integrity denotes neuronal death.
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Affiliation(s)
- M R Castillo
- Department of Biomedical Sciences, College of Pharmacy, University of Rhode Island, Kingston 02881, USA
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Zhao D, Berse B, Holler T, Cermak JM, Blusztajn JK. Developmental changes in phospholipase D activity and mRNA levels in rat brain. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 1998; 109:121-7. [PMID: 9729325 DOI: 10.1016/s0165-3806(98)00071-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Phospholipase D (PLD) activity and PLD1 mRNA levels were determined in rat brain at ages ranging from embryonic day (E) 19 to postnatal day (P) 49. Basal, oleate-, and phosphatidylinositol-4, 5-bisphosphate-stimulated PLD activity increased between E19 and P24 by approximately 3-fold and remained unaltered thereafter. A similar developmental pattern of mRNA levels of PLD1 isoform was found by Northern blotting. The development of PLD correlates with synaptogenesis and myelination suggesting that the enzyme might have an important function in these processes.
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Affiliation(s)
- D Zhao
- Department of Pathology and Laboratory Medicine, Boston University School of Medicine, 85 East Newton Street, room M1009, Boston, MA 02118, USA
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44
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Abstract
NMDA receptor-induced excitotoxicity has been hypothesized to mediate abnormal choline (Cho) metabolism that is involved in alterations in membrane permeability and cell death in certain neurodegenerative disorders. To determine whether NMDA receptor overactivation modulates choline metabolism in vivo, we investigated the effects of NMDA on interstitial choline concentrations using microdialysis. Perfusion of NMDA by retrodialysis increased dialysate choline (approximately 400%) and reduced dialysate acetylcholine (Ach) (approximately 40%). Choline levels remained increased for at least 2.5 hr, but acetylcholine returned to pretreatment values 75 min after NMDA perfusion. The NMDA-evoked increase in dialysate choline was calcium and concentration dependent and was prevented with 1 mM AP-5, a competitive NMDA antagonist, but was not altered by mepacrine, a phospholipase A2 inhibitor. NMDA increased extracellular choline levels four- to fivefold in prefrontal cortex and hippocampus, produced a slight increase in neostriatum, and did not modify dialysate choline in cerebellum. Perfusion with NMDA for 2 hr produced a delayed, but not acute, reduction in choline acetyltransferase activity in the area surrounding the dialysis probe. Consistent with a lack of acute cholinergic neurotoxicity evoked by this treatment, basal acetylcholine levels were unaltered by 2 hr of continuous NMDA perfusion. Prolonged NMDA perfusion produced a 34% decrease in phosphatidylcholine content in the lipid fraction of the tissue surrounding the dialysis probe. These results show that NMDA modulates choline metabolism, eliciting a receptor-mediated, calcium-dependent, and region-specific increase in extracellular choline from membrane phospholipids that is not mediated by phospholipase A2 and precedes delayed excitotoxic neuronal cell death.
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45
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Zapata A, Capdevila JL, Trullas R. Region-specific and calcium-dependent increase in dialysate choline levels by NMDA. J Neurosci 1998; 18:3597-605. [PMID: 9570791 PMCID: PMC6793164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/1998] [Revised: 03/04/1998] [Accepted: 03/05/1998] [Indexed: 02/07/2023] Open
Abstract
NMDA receptor-induced excitotoxicity has been hypothesized to mediate abnormal choline (Cho) metabolism that is involved in alterations in membrane permeability and cell death in certain neurodegenerative disorders. To determine whether NMDA receptor overactivation modulates choline metabolism in vivo, we investigated the effects of NMDA on interstitial choline concentrations using microdialysis. Perfusion of NMDA by retrodialysis increased dialysate choline (approximately 400%) and reduced dialysate acetylcholine (Ach) (approximately 40%). Choline levels remained increased for at least 2.5 hr, but acetylcholine returned to pretreatment values 75 min after NMDA perfusion. The NMDA-evoked increase in dialysate choline was calcium and concentration dependent and was prevented with 1 mM AP-5, a competitive NMDA antagonist, but was not altered by mepacrine, a phospholipase A2 inhibitor. NMDA increased extracellular choline levels four- to fivefold in prefrontal cortex and hippocampus, produced a slight increase in neostriatum, and did not modify dialysate choline in cerebellum. Perfusion with NMDA for 2 hr produced a delayed, but not acute, reduction in choline acetyltransferase activity in the area surrounding the dialysis probe. Consistent with a lack of acute cholinergic neurotoxicity evoked by this treatment, basal acetylcholine levels were unaltered by 2 hr of continuous NMDA perfusion. Prolonged NMDA perfusion produced a 34% decrease in phosphatidylcholine content in the lipid fraction of the tissue surrounding the dialysis probe. These results show that NMDA modulates choline metabolism, eliciting a receptor-mediated, calcium-dependent, and region-specific increase in extracellular choline from membrane phospholipids that is not mediated by phospholipase A2 and precedes delayed excitotoxic neuronal cell death.
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Affiliation(s)
- A Zapata
- Neurobiology Unit, Institut d'Investigacions Biomèdiques de Barcelona, Consejo Superior de Investigaciones Científicas, 08034 Barcelona, Spain
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46
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Johnson PI, Blusztajn JK. Sexually dimorphic activation of liver and brain phosphatidylethanolamine N-methyltransferase by dietary choline deficiency. Neurochem Res 1998; 23:583-7. [PMID: 9566595 DOI: 10.1023/a:1022470301550] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Phosphatidylethanolamine N-methyltransferase (PEMT) activity was measured by a radioenzymatic assay in homogenates of brain and liver obtained from Sprague Dawley rats fed a choline-free or control (0.3 g/kg of choline chloride) diet for seven days. Choline deficiency increased PEMT activity in the liver of male rats by 34% but had no effect on hepatic PEMT in females. In contrast, brain PEMT activity was increased in brain of choline deficient females (by 49%) but was unaltered in males. Activation of the PE methylation pathway in female brain may constitute a compensatory mechanism to sustain PC synthesis during choline deficiency.
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Affiliation(s)
- P I Johnson
- Department of Pathology and Laboratory Medicine, Boston University School of Medicine, MA 02118, USA
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47
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Cermak JM, Holler T, Jackson DA, Blusztajn JK. Prenatal availability of choline modifies development of the hippocampal cholinergic system. FASEB J 1998; 12:349-57. [PMID: 9506479 DOI: 10.1096/fasebj.12.3.349] [Citation(s) in RCA: 95] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Choline supplementation during fetal development [embryonic days (E) 11-17] permanently enhances memory performance in rats. To characterize the neurochemical mechanisms that may mediate this effect, we investigated the development of indices of the cholinergic system in the hippocampus: choline acetyltransferase (ChAT), acetylcholinesterase (AChE), synthesis of acetylcholine (ACh) from choline transported by high-affinity choline uptake (HACU), and potassium-evoked ACh release. During E11-E17, Sprague-Dawley pregnant rats consumed 0 [choline-deficient (ChD)], 1.3 [control (ChC)], and 4.6 [choline-supplemented (ChS)] mmol/(kg x day) of choline, respectively. On postnatal days 17 and 27, hippocampi of the ChD animals had the highest AChE and ChAT activities, and increased synthesis of ACh from choline transported by HACU, concomitant with reductions of tissue ACh content relative to the ChC and ChS rats and an inability to sustain depolarization-evoked ACh release relative to the ChS animals. In contrast, AChE and ChAT activities, and ACh synthesized from choline transported by HACU, were lowest in ChS rats whereas depolarization-evoked ACh release was the highest. This pattern of changes suggests that the hippocampus of the ChD animals is characterized by fast ACh recycling and efficient choline reutilization for ACh synthesis, presumably to maintain adequate ACh release despite the decrease of the ACh pool, whereas in the ChS animals ACh turnover and choline recycling is slower while the evoked release of ACh is high. Together, the data show a complex adaptive response of the hippocampal cholinergic system to prenatal choline availability and provide a novel example of developmental plasticity in the nervous system governed by the supply of a single nutrient.
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Affiliation(s)
- J M Cermak
- Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Massachusetts 02118, USA
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48
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Poirier J. Apolipoprotein E in the brain and its role in Alzheimer's disease. J Psychiatry Neurosci 1996; 21:128-34. [PMID: 8820179 PMCID: PMC1188752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Recent evidence indicates that apolipoprotein E (apoE) plays a central role in the brain response to injury. The coordinated expression of apoE and its main receptor, the apoE/apoB (LDL) receptor, appears to regulate the transport of cholesterol and phospholipids during the different phases of the reinnervation process. The recent discovery that a peculiar form of apoE, the apoE4, is strongly linked to both sporadic and familial late onset Alzheimer's disease (AD) raises the possibility that a dysfunction of the lipid transport system associated with compensatory sprouting and synaptic remodelling could be central to the AD process. The role of apoE in the central nervous system (CNS) is particularly important in relation to the function of the cholinergic system which relies to a certain extent on the integrity of phospholipid homeostasis in neurons. Recent evidence suggests that apoE4 allele has a direct impact on cholinergic function in AD.
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Affiliation(s)
- J Poirier
- Douglas Hospital Research Centre, Verdun, Quebec, Canada
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49
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Marshall DL, De Micheli E, Bogdanov MB, Wurtman RJ. Effects of ethanolamine (Etn) administration on Etn and choline (Ch) levels in plasma, brain extracellular fluid (ECF) and brain tissue, and on brain phospholipid levels in rats: an in vivo study. NEUROSCIENCE RESEARCH COMMUNICATIONS 1996; 18:87-96. [PMID: 11540106 DOI: 10.1002/(sici)1520-6769(199603)18:2<87::aid-nrc144>3.0.co;2-c] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The sources and fates of brain ethanolamine (Etn) are poorly known and the effects of its administration have not been investigated, even though cortical levels are known to be reduced in certain neurodegenerative diseases. We studied the effect of different Etn doses (10(-3), 5 x 10(-3) and 10(-2) mol/kg, i. p.) on its and choline's (Ch) levels in arterial plasma and brain extracellular fluid (ECF) of awake rats. We also studied its effects on brain levels of Etn, Ch, and their respective major phospholipids. Etn administration caused dose dependent increases in Etn levels within both plasma and brain ECF. For the 10(-2) mol/kg dose, Etn levels were significantly (p<0.01) greater than pre-injection values in both the plasma and ECF. Whole brain Etn and phosphatidylethanolamine were also significantly (p<0.05) increased by 10(-2) mol/kg Etn. Exogenous Etn significantly (p<0.05) increased Ch levels in plasma and whole brain; Etn also increased brain ECF Ch levels. Our data show for the first time that circulating Etn can act as a source of brain Ch. Metabolic pathways that might mediate the increases in Etn and Ch are discussed, as are possible mechanisms of the decreases in brain Eth seen in Alzheimer's disease.
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Affiliation(s)
- D L Marshall
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge 02139-4307, USA
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50
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Klein J, Lindmar R, Löffelholz K. Muscarinic activation of phosphatidylcholine hydrolysis. PROGRESS IN BRAIN RESEARCH 1996; 109:201-8. [PMID: 9009708 DOI: 10.1016/s0079-6123(08)62103-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- J Klein
- Department of Pharmacology, University of Mainz, Germany
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