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McCallum RT, Perreault ML. Glycogen Synthase Kinase-3: A Focal Point for Advancing Pathogenic Inflammation in Depression. Cells 2021; 10:cells10092270. [PMID: 34571919 PMCID: PMC8470361 DOI: 10.3390/cells10092270] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 08/26/2021] [Accepted: 08/28/2021] [Indexed: 01/03/2023] Open
Abstract
Increasing evidence indicates that the host immune response has a monumental role in the etiology of major depressive disorder (MDD), motivating the development of the inflammatory hypothesis of depression. Central to the involvement of chronic inflammation in MDD is a wide range of signaling deficits induced by the excessive secretion of pro-inflammatory cytokines and imbalanced T cell differentiation. Such signaling deficits include the glutamatergic, cholinergic, insulin, and neurotrophin systems, which work in concert to initiate and advance the neuropathology. Fundamental to the communication between such systems is the protein kinase glycogen synthase kinase-3 (GSK-3), a multifaceted protein critically linked to the etiology of MDD and an emerging target to treat pathogenic inflammation. Here, a consolidated overview of the widespread multi-system involvement of GSK-3 in contributing to the neuropathology of MDD will be discussed, with the feed-forward mechanistic links between all major neuronal signaling pathways highlighted.
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Affiliation(s)
- Ryan T. McCallum
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, ON N1G 2W1, Canada;
| | - Melissa L. Perreault
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, ON N1G 2W1, Canada;
- Collaborative Program in Neuroscience, University of Guelph, Guelph, ON N1G 2W1, Canada
- Correspondence: ; Tel.: +1-(519)-824-4120 (ext. 52013)
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2
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Locus Coeruleus Modulates Neuroinflammation in Parkinsonism and Dementia. Int J Mol Sci 2020; 21:ijms21228630. [PMID: 33207731 PMCID: PMC7697920 DOI: 10.3390/ijms21228630] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 11/10/2020] [Accepted: 11/11/2020] [Indexed: 12/11/2022] Open
Abstract
Locus Coeruleus (LC) is the main noradrenergic nucleus of the central nervous system, and its neurons widely innervate the whole brain. LC is severely degenerated both in Alzheimer’s disease (AD) and in Parkinson’s disease (PD), years before the onset of clinical symptoms, through mechanisms that differ among the two disorders. Several experimental studies have shown that noradrenaline modulates neuroinflammation, mainly by acting on microglia/astrocytes function. In the present review, after a brief introduction on the anatomy and physiology of LC, we provide an overview of experimental data supporting a pathogenetic role of LC degeneration in AD and PD. Then, we describe in detail experimental data, obtained in vitro and in vivo in animal models, which support a potential role of neuroinflammation in such a link, and the specific molecules (i.e., released cytokines, glial receptors, including pattern recognition receptors and others) whose expression is altered by LC degeneration and might play a key role in AD/PD pathogenesis. New imaging and biochemical tools have recently been developed in humans to estimate in vivo the integrity of LC, the degree of neuroinflammation, and pathology AD/PD biomarkers; it is auspicable that these will allow in the near future to test the existence of a link between LC-neuroinflammation and neurodegeneration directly in patients.
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3
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Macht VA, Woodruff JL, Maissy ES, Grillo CA, Wilson MA, Fadel JR, Reagan LP. Pyridostigmine bromide and stress interact to impact immune function, cholinergic neurochemistry and behavior in a rat model of Gulf War Illness. Brain Behav Immun 2019; 80:384-393. [PMID: 30953774 PMCID: PMC6790976 DOI: 10.1016/j.bbi.2019.04.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 04/02/2019] [Accepted: 04/03/2019] [Indexed: 02/06/2023] Open
Abstract
Gulf War Illness (GWI) is characterized by a constellation of symptoms that includes cognitive dysfunction. While the causes for GWI remain unknown, prophylactic use of the acetylcholinesterase inhibitor pyridostigmine bromide (PB) in combination with the stress of deployment has been proposed to be among the causes of the cognitive dysfunction in GWI. Mechanistically, clinical studies suggest that altered immune function may be an underlying factor in the neurochemical and neurobehavioral complications of GWI. Accordingly, the goal of this study was to determine how responses to an immune challenge (lipopolysaccharide; LPS) or stress impacts inflammation, acetylcholine (ACh) neurochemistry and behavior in an experimental model of GWI. Rats with a history of PB treatment exhibited potentiated increases in C-reactive protein levels in response to a submaximal LPS challenge compared to control rats, indicating that prior treatment with this cholinesterase inhibitor leads to exacerbated inflammatory responses to a subsequent immune challenge. ACh responses to LPS administration were decreased in the hippocampus, but not prefrontal cortex (PFC), in rats with a prior history of PB treatment or stress exposure. Additionally, ACh release in response to acute immobilization stress was attenuated in the PFC and hippocampus in these groups. These attenuated cholinergic responses were accompanied by impairments in contextual and cue-based fear learning. The results of this study suggest that stress and LPS challenges adversely affect central ACh neurochemistry in a rodent model of GWI and support the hypothesis that dysregulated immune responses are mechanistically linked to the neurological complications of GWI.
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Affiliation(s)
- V A Macht
- University of South Carolina School of Medicine, Department of Pharmacology, Physiology, & Neuroscience, Columbia, SC, United States; University of South Carolina, Department of Psychology, Columbia, SC, United States; Wm. Jennings Bryant Dorn VA Medical Center, Columbia, SC, United States.
| | - J L Woodruff
- University of South Carolina School of Medicine, Department of Pharmacology, Physiology, & Neuroscience, Columbia, SC, United States; Wm. Jennings Bryant Dorn VA Medical Center, Columbia, SC, United States
| | - E S Maissy
- University of South Carolina School of Medicine, Department of Pharmacology, Physiology, & Neuroscience, Columbia, SC, United States
| | - C A Grillo
- University of South Carolina School of Medicine, Department of Pharmacology, Physiology, & Neuroscience, Columbia, SC, United States; Wm. Jennings Bryant Dorn VA Medical Center, Columbia, SC, United States
| | - M A Wilson
- University of South Carolina School of Medicine, Department of Pharmacology, Physiology, & Neuroscience, Columbia, SC, United States; University of South Carolina, Department of Psychology, Columbia, SC, United States; Wm. Jennings Bryant Dorn VA Medical Center, Columbia, SC, United States
| | - J R Fadel
- University of South Carolina School of Medicine, Department of Pharmacology, Physiology, & Neuroscience, Columbia, SC, United States
| | - L P Reagan
- University of South Carolina School of Medicine, Department of Pharmacology, Physiology, & Neuroscience, Columbia, SC, United States; Wm. Jennings Bryant Dorn VA Medical Center, Columbia, SC, United States.
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4
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Laudisio A, Lo Monaco MR, Vetrano DL, Pisciotta MS, Brandi V, Gemma A, Fusco D, Bernabei R, Antonelli Incalzi R, Zuccalà G. Association of Pisa Syndrome With Mortality in Patients With Parkinson's Disease. J Am Med Dir Assoc 2019; 20:1037-1041.e1. [DOI: 10.1016/j.jamda.2019.01.141] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 01/22/2019] [Accepted: 01/23/2019] [Indexed: 01/05/2023]
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5
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Mohammadzadeh L, Abnous K, Razavi BM, Hosseinzadeh H. Crocin-protected malathion-induced spatial memory deficits by inhibiting TAU protein hyperphosphorylation and antiapoptotic effects. Nutr Neurosci 2019; 23:221-236. [DOI: 10.1080/1028415x.2018.1492772] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Leila Mohammadzadeh
- Department of Pharmacodynamics and Toxicology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Khalil Abnous
- Pharmaceutical Research Center, Department of Medicinal Chemistry, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Bibi Marjan Razavi
- Targeted Drug Delivery Research Center, Department of Pharmacodynamics and Toxicology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Hossein Hosseinzadeh
- Department of Pharmacodynamics and Toxicology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
- Pharmaceutical Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran
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6
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Vetreno RP, Crews FT. Adolescent binge ethanol-induced loss of basal forebrain cholinergic neurons and neuroimmune activation are prevented by exercise and indomethacin. PLoS One 2018; 13:e0204500. [PMID: 30296276 PMCID: PMC6175501 DOI: 10.1371/journal.pone.0204500] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2018] [Accepted: 09/10/2018] [Indexed: 12/31/2022] Open
Abstract
Basal forebrain cholinergic neurons mature in adolescence coinciding with development of adult cognitive function. Preclinical studies using the rodent model of adolescent intermittent ethanol (AIE; 5.0 g/kg, i.g., 2-days on/2-days off from postnatal day [P]25 to P55) reveal persistent increases of brain neuroimmune genes that are associated with cognitive dysfunction. Adolescent intermittent ethanol exposure also reduces basal forebrain expression of choline acetyltransferase (ChAT), an enzyme critical for acetylcholine synthesis in cholinergic neurons similar to findings in the post-mortem human alcoholic basal forebrain. We report here that AIE decreases basal forebrain ChAT+IR neurons in both adult female and male Wistar rats following early or late adolescent ethanol exposure. In addition, we find reductions in ChAT+IR somal size as well as the expression of the high-affinity nerve growth factor (NGF) receptor tropomyosin receptor kinase A (TrkA) and the low-affinity NGF receptor p75NTR, both of which are expressed on cholinergic neurons. The decrease in cholinergic neuron marker expression was accompanied by increased phosphorylation of NF-κB p65 (pNF-κB p65) consistent with increased neuroimmune signaling. Voluntary wheel running from P24 to P80 prevented AIE-induced cholinergic neuron shrinkage and loss of cholinergic neuron markers (i.e., ChAT, TrkA, and p75NTR) as well as the increase of pNF-κB p65 in the adult basal forebrain. Administration of the anti-inflammatory drug indomethacin (4.0 mg/kg, i.p prior to each ethanol exposure) during AIE also prevented the loss of basal forebrain cholinergic markers and the concomitant increase of pNF-κB p65. In contrast, treatment with the proinflammatory immune activator lipopolysaccharide (1.0 mg/kg, i.p. on P70) caused a loss of cholinergic neuron markers that was paralleled by increased pNF-κB p65 in the basal forebrain. These novel findings are consistent with AIE causing lasting activation of the neuroimmune system that contributes to the persistent loss of basal forebrain cholinergic neurons in adulthood.
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Affiliation(s)
- Ryan P. Vetreno
- The Bowles Center for Alcohol Studies, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- * E-mail:
| | - Fulton T. Crews
- The Bowles Center for Alcohol Studies, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
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7
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Gómez-Giménez B, Llansola M, Cabrera-Pastor A, Hernández-Rabaza V, Agustí A, Felipo V. Endosulfan and Cypermethrin Pesticide Mixture Induces Synergistic or Antagonistic Effects on Developmental Exposed Rats Depending on the Analyzed Behavioral or Neurochemical End Points. ACS Chem Neurosci 2018; 9:369-380. [PMID: 29094921 DOI: 10.1021/acschemneuro.7b00364] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Exposure to pesticides has been associated with neurodevelopmental toxicity. Usually people are exposed to mixtures of pesticides. However, most studies analyze the effects of individual pesticides. Developmental exposure to mixtures of pesticides may result in additive effects or in antagonistic or synergistic effects. The aim of this work was to compare the effects of developmental exposure of rats to cypermethrin or endosulfan with the effects of its mixture on cognitive and motor function and on some underlying mechanisms. Exposure to individual pesticides or the mixture was from gestational day 7 to postnatal day 21. We analyzed the effects, in males and females, on spatial learning and memory, associative learning, anxiety, motor coordination, and spontaneous motor activity. We also analyzed neuroinflammation and NMDA receptor subunits in hippocampus and extracellular GABA in cerebellum. Exposure to the mixture, but not to individual pesticides, impaired spatial memory in males, associative learning in females, and increased motor activity in males and females. This indicates a synergistic effect of cypermethrin and endolsufan exposure on these end points. In contrast, motor coordination was impaired by individual exposure to endosulfan or cypermethrin, associated with increased extracellular GABA in cerebellum, but these effects were prevented in rats exposed to the mixture, indicating an antagonistic effect of cypermethrin and endolsufan exposure on these end points. The results show different interaction modes (synergism or antagonism) of the pesticides, depending on the end point analyzed and the sex of the rats.
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Affiliation(s)
- Belén Gómez-Giménez
- Laboratorio
de Neurobiología, Centro Investigación Príncipe Felipe, Valencia 46012, Spain
| | - Marta Llansola
- Laboratorio
de Neurobiología, Centro Investigación Príncipe Felipe, Valencia 46012, Spain
| | - Andrea Cabrera-Pastor
- Laboratorio
de Neurobiología, Centro Investigación Príncipe Felipe, Valencia 46012, Spain
| | - Vicente Hernández-Rabaza
- Laboratorio
de Neurobiología, Centro Investigación Príncipe Felipe, Valencia 46012, Spain
- Department
of Biomedical Sciences, Cardenal Herrera University-CEU, CEU Universities, Avda del Pozo s/n, Alfara del Patriarca 46115, Spain
| | - Ana Agustí
- Laboratorio
de Neurobiología, Centro Investigación Príncipe Felipe, Valencia 46012, Spain
| | - Vicente Felipo
- Laboratorio
de Neurobiología, Centro Investigación Príncipe Felipe, Valencia 46012, Spain
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8
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Gómez-Giménez B, Llansola M, Hernández-Rabaza V, Cabrera-Pastor A, Malaguarnera M, Agusti A, Felipo V. Sex-dependent effects of developmental exposure to different pesticides on spatial learning. The role of induced neuroinflammation in the hippocampus. Food Chem Toxicol 2017; 99:135-148. [DOI: 10.1016/j.fct.2016.11.028] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 10/17/2016] [Accepted: 11/24/2016] [Indexed: 11/25/2022]
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9
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Pessah IN, Rogawski MA, Tancredi DJ, Wulff H, Zolkowska D, Bruun DA, Hammock BD, Lein PJ. Models to identify treatments for the acute and persistent effects of seizure-inducing chemical threat agents. Ann N Y Acad Sci 2016; 1378:124-136. [PMID: 27467073 DOI: 10.1111/nyas.13137] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 05/15/2016] [Accepted: 05/19/2016] [Indexed: 12/27/2022]
Abstract
Exposures to seizure-inducing chemical threat agents are a major public health concern. Of particular need is improved treatment to terminate convulsions and to prevent the long-term neurological sequelae in survivors. We are studying the organophosphorus cholinesterase inhibitor diisopropyl fluorophosphate (DFP) and the GABA receptor inhibitor tetramethylenedisulfotetramine (TETS), which arguably encompass the mechanistic spectrum of seizure-inducing chemical threats, with the goal of identifying therapeutic approaches with broad-spectrum efficacy. Research efforts have focused on developing translational models and translational diagnostic approaches, including (1) in vivo models of DFP- and TETS-induced seizures for studying neuropathological mechanisms and identifying treatment approaches; (2) in vivo imaging modalities for noninvasive longitudinal monitoring of neurological damage and response to therapeutic candidates; and (3) higher-throughput in vitro platforms for rapid screening of compounds to identify potential antiseizure and neuroprotective agents, as well as mechanistically relevant novel drug targets. This review summarizes our progress toward realizing these goals and discusses best practices and mechanistic insights derived from our modeling efforts.
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Affiliation(s)
- Isaac N Pessah
- Department of Molecular Biosciences, School of Veterinary Medicine
| | | | | | - Heike Wulff
- Department of Pharmacology, School of Medicine
| | | | - Donald A Bruun
- Department of Molecular Biosciences, School of Veterinary Medicine
| | - Bruce D Hammock
- Department of Entomology, College of Agricultural and Environmental Sciences, University of California, Davis, Davis, California
| | - Pamela J Lein
- Department of Molecular Biosciences, School of Veterinary Medicine.
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10
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Feinstein DL, Kalinin S, Braun D. Causes, consequences, and cures for neuroinflammation mediated via the locus coeruleus: noradrenergic signaling system. J Neurochem 2016; 139 Suppl 2:154-178. [PMID: 26968403 DOI: 10.1111/jnc.13447] [Citation(s) in RCA: 112] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Revised: 11/23/2015] [Accepted: 11/24/2015] [Indexed: 12/31/2022]
Abstract
Aside from its roles in as a classical neurotransmitter involved in regulation of behavior, noradrenaline (NA) has other functions in the CNS. This includes restricting the development of neuroinflammatory activation, providing neurotrophic support to neurons, and providing neuroprotection against oxidative stress. In recent years, it has become evident that disruption of physiological NA levels or signaling is a contributing factor to a variety of neurological diseases and conditions including Alzheimer's disease (AD) and Multiple Sclerosis. The basis for dysregulation in these diseases is, in many cases, due to damage occurring to noradrenergic neurons present in the locus coeruleus (LC), the major source of NA in the CNS. LC damage is present in AD, multiple sclerosis, and a large number of other diseases and conditions. Studies using animal models have shown that experimentally induced lesion of LC neurons exacerbates neuropathology while treatments to compensate for NA depletion, or to reduce LC neuronal damage, provide benefit. In this review, we will summarize the anti-inflammatory and neuroprotective actions of NA, summarize examples of how LC damage worsens disease, and discuss several approaches taken to treat or prevent reductions in NA levels and LC neuronal damage. Further understanding of these events will be of value for the development of treatments for AD, multiple sclerosis, and other diseases and conditions having a neuroinflammatory component. The classical neurotransmitter noradrenaline (NA) has critical roles in modulating behaviors including those involved in sleep, anxiety, and depression. However, NA can also elicit anti-inflammatory responses in glial cells, can increase neuronal viability by inducing neurotrophic factor expression, and can reduce neuronal damage due to oxidative stress by scavenging free radicals. NA is primarily produced by tyrosine hydroxylase (TH) expressing neurons in the locus coeruleus (LC), a relatively small brainstem nucleus near the IVth ventricle which sends projections throughout the brain and spinal cord. It has been known for close to 50 years that LC neurons are lost during normal aging, and that loss is exacerbated in neurological diseases including Parkinson's disease and Alzheimer's disease. LC neuronal damage and glial activation has now been documented in a variety of other neurological conditions and diseases, however, the causes of LC damage and cell loss remain largely unknown. A number of approaches have been developed to address the loss of NA and increased inflammation associated with LC damage, and several methods are being explored to directly minimize the extent of LC neuronal cell loss or function. In this review, we will summarize some of the consequences of LC loss, consider several factors that likely contribute to that loss, and discuss various ways that have been used to increase NA or to reduce LC damage. This article is part of the 60th Anniversary special issue.
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Affiliation(s)
- Douglas L Feinstein
- Department of Anesthesiology, University of Illinois, Chicago, IL, USA. .,Jesse Brown VA Medical Center, Chicago, IL, USA.
| | - Sergey Kalinin
- Department of Anesthesiology, University of Illinois, Chicago, IL, USA.,Jesse Brown VA Medical Center, Chicago, IL, USA
| | - David Braun
- Department of Anesthesiology, University of Illinois, Chicago, IL, USA.,Jesse Brown VA Medical Center, Chicago, IL, USA
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11
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Ledreux A, Boger HA, Hinson VK, Cantwell K, Granholm AC. BDNF levels are increased by aminoindan and rasagiline in a double lesion model of Parkinson׳s disease. Brain Res 2016; 1631:34-45. [PMID: 26607251 DOI: 10.1016/j.brainres.2015.11.028] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Revised: 11/13/2015] [Accepted: 11/16/2015] [Indexed: 01/12/2023]
Abstract
The anti-Parkinsonian drug rasagiline is a selective, irreversible inhibitor of monoamine oxidase and is used in the treatment of Parkinson׳s disease (PD). Its postulated neuroprotective effects may be attributed to MAO inhibition, or to its propargylamine moiety. The major metabolite of rasagiline, aminoindan, has shown promising neuroprotective properties in vitro but there is a paucity of studies investigating in vivo effects of this compound. Therefore, we examined neuroprotective effects of rasagiline and its metabolite aminoindan in a double lesion model of PD. Male Fisher 344 rats received i.p. injections of the noradrenergic neurotoxin DSP-4 and intra-striatal stereotaxic microinjections of the dopamine neurotoxin 6-OHDA. Saline, rasagiline or aminoindan (3mg/kg/day s.c.) were delivered via Alzet minipumps for 4 weeks. Rats were then tested for spontaneous locomotion and a novel object recognition task. Following behavioral testing, brain tissue was processed for ELISA measurements of growth factors and immunohistochemistry. Double-lesioned rats treated with rasagiline or aminoindan had reduced behavioral deficits, both in motor and cognitive tasks compared to saline-treated double-lesioned rats. BDNF levels were significantly increased in the hippocampus and striatum of the rasagiline- and aminoindan-lesioned groups compared to the saline-treated lesioned group. Double-lesioned rats treated with rasagiline or aminoindan exhibited a sparing in the mitochondrial marker Hsp60, suggesting mitochondrial involvement in neuroprotection. Tyrosine hydroxylase (TH) immunohistochemistry revealed a sparing of TH-immunoreactive terminals in double-lesioned rats treated with rasagiline or aminoindan in the striatum, hippocampus, and substantia nigra. These data provide evidence of neuroprotection by aminoindan and rasagiline via their ability to enhance BDNF levels.
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Affiliation(s)
- Aurélie Ledreux
- Department of Neurosciences and the Center on Aging, Medical University of South Carolina, Charleston, SC, USA
| | - Heather A Boger
- Department of Neurosciences and the Center on Aging, Medical University of South Carolina, Charleston, SC, USA
| | - Vanessa K Hinson
- Department of Neurology, Medical University of South Carolina, Charleston, SC, USA; Neurology Service, Ralph H. Johnson VA Medical Center, Charleston, SC, USA
| | - Kelsey Cantwell
- Psychology and Program in Neuroscience, College of Charleston, Charleston, SC, USA
| | - Ann-Charlotte Granholm
- Department of Neurosciences and the Center on Aging, Medical University of South Carolina, Charleston, SC, USA.
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12
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Mehan S, Kaur R, Khanna D, Kalra S, Parveen S. Precautionary Ellagic Acid Treatment Ameliorates Chronically Administered Scopolamine Induced Alzheimer's Type Memory and Cognitive Dysfunctions in Rats. ACTA ACUST UNITED AC 2015. [DOI: 10.5567/pharmacologia.2015.192.212] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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13
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Lv C, Li Q, Liu X, He B, Sui Z, Xu H, Yin Y, Liu R, Bi K. Determination of catecholamines and their metabolites in rat urine by ultra-performance liquid chromatography-tandem mass spectrometry for the study of identifying potential markers for Alzheimer's disease. JOURNAL OF MASS SPECTROMETRY : JMS 2015; 50:354-363. [PMID: 25800017 DOI: 10.1002/jms.3536] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Revised: 10/29/2014] [Accepted: 10/30/2014] [Indexed: 06/04/2023]
Abstract
In order to investigate the potential links between catecholamines (CAs) and Alzheimer's disease (AD), rapid and sensitive ultra-performance liquid chromatography (UPLC)-tandem mass spectrometry (MS/MS) methods in different ionization modes for the quantification of 14 CAs and their metabolites in rat urine without derivatization or complex sample pre-treatments were developed. After addition of the internal standard, isoproterenol, the urine samples were extracted by protein precipitation and separated on an Inertsil ODS-EP column (Shimadzu, Japan) at a flow of 1.0 ml min(-1). Tandem mass spectrometric detection was performed on a 4000Q UPLC-MS/MS in the multiple reaction monitoring mode with turbo ion spray source. Tyrosine, dopamine, noradrenaline, epinephrine, 3-methoxytyramine, normetanephrine and metanephrine were determined in positive mode, while 3,4-dihyroxy-L-phenylalanine (DOPA), 3,4-dihydroxyphenylacetic acid, DL-3,4-dihydroxymandelic acid, DL-3,4-dihydroxyphenyl glycol, homovanillic acid, DL-4-hydroxy-3-methoxymandelic acid and 4-hydroxy-3-methoxy-phenylglycol were determined in negative mode. The methods were examined and were found to be precise and accurate within the linearity range of the assays. The intra-day and inter-day precision and accuracy of the analytes were well within acceptance criteria (±15%). The mean extraction recoveries of analytes and internal standard were all more than 60%. The validated methods have been successfully applied to compare CAs profiles in normal and AD rats. The results indicated the urine levels of DL-3,4-dihydroxyphenyl glycol and 4-hydroxy-3-methoxy-phenylglycol in AD rats were significantly higher than those in the normal group, and the other CAs have an opposite performance. These may attribute to the difference of some enzyme activity between rats with AD and normal. Furthermore, this may be helpful in clinical diagnostics and monitor the efficacy of AD treatment.
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Affiliation(s)
- Chunxiao Lv
- School of Pharmacy, Shenyang Pharmaceutical University, Shenyang, 110016, China; National and Local United Engineering Laboratory for Key Technology of Chinese Material Medica Quality Control, Shenyang Pharmaceutical University, Shenyang, 110016, China
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14
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Abstract
To assess the consequences of locus ceruleus (LC) degeneration and subsequent noradrenaline (NA) deficiency in early Alzheimer's disease (AD), mice overexpressing mutant amyloid precursor protein and presenilin-1 (APP/PS1) were crossed with Ear2(-/-) mice that have a severe loss of LC neurons projecting to the hippocampus and neocortex. Testing spatial memory and hippocampal long-term potentiation revealed an impairment in APP/PS1 Ear2(-/-) mice, whereas APP/PS1 or Ear2(-/-) mice showed only minor changes. These deficits were associated with distinct synaptic changes including reduced expression of the NMDA 2A subunit and increased levels of NMDA receptor 2B in APP/PS1 Ear2(-/-) mice. Acute pharmacological replacement of NA by L-threo-DOPS partially restored phosphorylation of β-CaMKII and spatial memory performance in APP/PS1 Ear2(-/-) mice. These changes were not accompanied by altered APP processing or amyloid β peptide (Aβ) deposition. Thus, early LC degeneration and subsequent NA reduction may contribute to cognitive deficits via CaMKII and NMDA receptor dysfunction independent of Aβ and suggests that NA supplementation could be beneficial in treating AD.
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15
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Age and duration of inflammatory environment differentially affect the neuroimmune response and catecholaminergic neurons in the midbrain and brainstem. Neurobiol Aging 2013; 35:1065-73. [PMID: 24315728 DOI: 10.1016/j.neurobiolaging.2013.11.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Revised: 10/17/2013] [Accepted: 11/09/2013] [Indexed: 12/12/2022]
Abstract
Neuroinflammation and degeneration of ascending catecholaminergic systems occur early in the neurodegenerative process. Age and the duration of a pro-inflammatory environment induced by continuous intraventricular lipopolysaccharide (LPS) differentially affect the expression profile of pro- and anti-inflammatory genes and proteins as well as the number of activated microglia (express major histocompatibility complex II; MHC II) and the integrity and density of ascending catecholaminergic neural systems originating from the locus coeruleus (LC) and substantia nigra pars compacta (SNpc) in rats. LPS infusion increased gene expression and/or protein levels for both pro- and anti-inflammatory biomarkers. Although LPS infusion stimulated a robust increase in IL-1ß gene and protein expression, this increase was blunted with age. LPS infusion also increased the density of activated microglia cells throughout the midbrain and brainstem. Corresponding to the development of a pro-inflammatory environment, LC and SNpc neurons immunopositive for tyrosine-hydroxylase (the rate-limiting synthetic enzyme for dopamine and norepinephrine) decreased in number, along with a decrease in tyrosine-hydroxylase gene expression in the midbrain and/or brainstem region. Our data support the concept that continuous exposure to a pro-inflammatory environment drives exaggerated changes in the production and release of inflammatory mediators that interact with age to impair functional capacity of the SNpc and LC.
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Genotype-independent decrease in plasma dopamine beta-hydroxylase activity in Alzheimer's disease. Prog Neuropsychopharmacol Biol Psychiatry 2013; 44:94-9. [PMID: 23416088 PMCID: PMC3952071 DOI: 10.1016/j.pnpbp.2013.02.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Revised: 01/23/2013] [Accepted: 02/04/2013] [Indexed: 02/02/2023]
Abstract
The noradrenergic system is involved in the etiology and progression of Alzheimer's disease (AD) but its role is still unclear. Dopamine beta-hydroxylase (DBH) as a catecholamine-synthesizing enzyme plays a central role in noradrenaline (NA) synthesis and turnover. Plasma DBH (pDBH) activity shows wide inheritable interindividual variability that is under genetic control. The aim of this study was to determine pDBH activity, DBH (C-970T; rs1611115) and DBH (C1603T; rs6271) gene polymorphisms in 207 patients with AD and in 90 healthy age-matched controls. Plasma DBH activity was lower, particularly in the early stage of AD, compared to values in middle and late stages of the disease, as well as to control values. Two-way ANOVA revealed significant effect of both diagnosis and DBH (C-970T) or DBH (C1603T) genotypes on pDBH activity, but without significant diagnosis×genotype interaction. No association was found between AD and DBH C-970T (OR=1.08, 95% CI 1.13-4.37; p=0.779) and C1603T (OR=0.89; 95% CI 0.36-2.20; p=0.814) genotypes controlled for age, gender, and ApoE4 allele. The decrease in pDBH activity, found in early phase of AD suggests that alterations in DBH activity represent a compensatory mechanism for the loss of noradrenergic neurons, and that treatment with selective NA reuptake inhibitors may be indicated in early stages of AD to compensate for loss of noradrenergic activity in the locus coeruleus.
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Brothers HM, Bardou I, Hopp SC, Marchalant Y, Kaercher RM, Turner SM, Mitchem MR, Kigerl K, Wenk GL. Time-Dependent Compensatory Responses to Chronic Neuroinflammation in Hippocampus and Brainstem: The Potential Role of Glutamate Neurotransmission. ACTA ACUST UNITED AC 2013; 3:110. [PMID: 24600537 PMCID: PMC3939715 DOI: 10.4172/2161-0460.1000110] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Chronic neuroinflammation is characteristic of neurodegenerative diseases and is present during very early stages, yet significant pathology and behavioral deficits do not manifest until advanced age. We investigated the consequences of experimentally-induced chronic neuroinflammation within the hippocampus and brainstem of young (4 mo) F-344 rats. Lipopolysaccharide (LPS) was infused continuously into the IVth ventricle for 2, 4 or 8 weeks. The number of MHC II immunoreactive microglia in the brain continued to increase throughout the infusion period. In contrast, performance in the Morris water maze was impaired after 4 weeks but recovered by 8 weeks. Likewise, a transient loss of tyrosine hydroxylase immunoreactivity in the substantia nigra and locus coeruleus was observed after 2 weeks, but returned to control levels by 4 weeks of continuous LPS infusion. These data suggest that direct activation of microglia is sufficient to drive, but not sustain, spatial memory impairment and a decrease in tyrosine hydroxylase production in young rats. Our previous studies suggest that chronic neuroinflammation elevates extracellular glutamate and that this elevation underlies the spatial memory impairment. In the current study, increased levels of GLT1 and SNAP25 in the hippocampus corresponded with the resolution of performance deficit. Increased expression of SNAP25 is consistent with reduced glutamate release from axonal terminals while increased GLT1 is consistent with enhanced clearance of extracellular glutamate. These data demonstrate the capacity of the brain to compensate for the presence of chronic neuroinflammation, despite continued activation of microglia, through changes in the regulation of the glutamatergic system.
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Affiliation(s)
- Holly M Brothers
- Department of Psychology, Ohio State University, Columbus, OH, USA
| | - Isabelle Bardou
- Department of Psychology, Ohio State University, Columbus, OH, USA
| | - Sarah C Hopp
- Department of Neuroscience, Ohio State University, Columbus, OH, USA
| | | | | | - Sarah M Turner
- Department of Psychology, Ohio State University, Columbus, OH, USA
| | - Mollie R Mitchem
- Department of Psychology, Ohio State University, Columbus, OH, USA
| | - Kristina Kigerl
- Department of Neuroscience, Ohio State University, Columbus, OH, USA
| | - Gary L Wenk
- Department of Psychology, Ohio State University, Columbus, OH, USA
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18
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Van Dam D, De Deyn PP. Animal models in the drug discovery pipeline for Alzheimer's disease. Br J Pharmacol 2012; 164:1285-300. [PMID: 21371009 DOI: 10.1111/j.1476-5381.2011.01299.x] [Citation(s) in RCA: 152] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
With increasing feasibility of predicting conversion of mild cognitive impairment to dementia based on biomarker profiling, the urgent need for efficacious disease-modifying compounds has become even more critical. Despite intensive research, underlying pathophysiological mechanisms remain insufficiently documented for purposeful target discovery. Translational research based on valid animal models may aid in alleviating some of the unmet needs in the current Alzheimer's disease pharmaceutical market, which includes disease-modification, increased efficacy and safety, reduction of the number of treatment unresponsive patients and patient compliance. The development and phenotyping of animal models is indeed essential in Alzheimer's disease-related research as valid models enable the appraisal of early pathological processes - which are often not accessible in patients, and subsequent target discovery and evaluation. This review paper summarizes and critically evaluates currently available animal models, and discusses their value to the Alzheimer drug discovery pipeline. Models dealt with include spontaneous models in various species, including senescence-accelerated mice, chemical and lesion-induced rodent models, and genetically modified models developed in Drosophila melanogaster, Caenorhabditis elegans, Danio rerio and rodents. Although highly valid animal models exist, none of the currently available models recapitulates all aspects of human Alzheimer's disease, and one should always be aware of the potential dangers of uncritical extrapolating from model organisms to a human condition that takes decades to develop and mainly involves higher cognitive functions.
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Affiliation(s)
- Debby Van Dam
- Laboratory of Neurochemistry & Behaviour, Institute Born-Bunge, Department of Biomedical Sciences, University of Antwerp, Wilrijk (Antwerp), Belgium.
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Terry AV. Functional consequences of repeated organophosphate exposure: potential non-cholinergic mechanisms. Pharmacol Ther 2012; 134:355-65. [PMID: 22465060 DOI: 10.1016/j.pharmthera.2012.03.001] [Citation(s) in RCA: 159] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Accepted: 03/01/2012] [Indexed: 12/29/2022]
Abstract
The class of chemicals known as the "organophosphates" (OPs) comprises many of the most common agricultural and commercial pesticides that are used worldwide as well as the highly toxic chemical warfare agents. The mechanism of the acute toxicity of OPs in both target and non-target organisms is primarily attributed to inhibitory actions on various forms of cholinesterase leading to excessive peripheral and central cholinergic activity. However, there is now substantial evidence that this canonical (cholinesterase-based) mechanism cannot alone account for the wide-variety of adverse consequences of OP exposure that have been described, especially those associated with repeated exposures to levels that produce no overt signs of acute toxicity. This type of exposure has been associated with prolonged impairments in attention, memory, and other domains of cognition, as well as chronic illnesses where these symptoms are manifested (e.g., Gulf War Illness, Alzheimer's disease). Due to their highly reactive nature, it is not surprising that OPs might alter the function of a number of enzymes and proteins (in addition to cholinesterase). However, the wide variety of long-term neuropsychiatric symptoms that have been associated with OPs suggests that some basic or fundamental neuronal process was adversely affected during the exposure period. The purpose of this review is to discuss several non-cholinesterase targets of OPs that might affect such fundamental processes and includes cytoskeletal and motor proteins involved in axonal transport, neurotrophins and their receptors, and mitochondria (especially their morphology and movement in axons). Potential therapeutic implications of these OP interactions are also discussed.
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Affiliation(s)
- A V Terry
- Department of Pharmacology and Toxicology, Georgia Health Sciences University, Augusta, GA 30912, USA.
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20
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Yang C, Zhou JY, Zhong HJ, Wang HY, Yan J, Liu Q, Huang SN, Jiang JX. Exogenous Norepinephrine Correlates with Macrophage Endoplasmic Reticulum Stress Response in Association with XBP-1. J Surg Res 2011; 168:262-71. [DOI: 10.1016/j.jss.2009.10.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2009] [Revised: 09/10/2009] [Accepted: 10/01/2009] [Indexed: 01/29/2023]
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Cardiopulmonary arrest and resuscitation disrupts cholinergic anti-inflammatory processes: a role for cholinergic α7 nicotinic receptors. J Neurosci 2011; 31:3446-52. [PMID: 21368056 DOI: 10.1523/jneurosci.4558-10.2011] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Cardiac arrest is a leading cause of death worldwide. While survival rates following sudden cardiac arrest remain relatively low, recent advancements in patient care have begun to increase the proportion of individuals who survive cardiac arrest. However, many of these individuals subsequently develop physiological and psychiatric conditions that likely result from ongoing neuroinflammation and neuronal death. The present study was conducted to better understand the pathophysiological effects of cardiac arrest on neuronal cell death and inflammation, and their modulation by the cholinergic system. Using a well validated model of cardiac arrest, here we show that global cerebral ischemia increases microglial activation, proinflammatory cytokine mRNA expression (interleukin-1β, interleukin-6, tumor necrosis factor-α), and neuronal damage. Cardiac arrest also induces alterations in numerous cellular components of central cholinergic signaling, including a reduction in choline acetyltransferase enzymatic activity and the number of choline acetyltransferase-positive neurons, as well as, reduced acetylcholinesterase and vesicular acetylcholine transporter mRNA. However, treatment with a selective agonist of the α7 nicotinic acetylcholine receptor, the primary receptor mediating the cholinergic anti-inflammatory pathway, significantly decreases the neuroinflammation and neuronal damage resulting from cardiac arrest. These data suggest that global cerebral ischemia results in significant declines in central cholinergic signaling, which may in turn diminish the capacity of the cholinergic anti-inflammatory pathway to control inflammation. Furthermore, we provide evidence that pharmacological activation of α7 nicotinic acetylcholine receptors provide significant protection against ischemia-related cell death and inflammation within a clinically relevant time frame.
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Tanaka S, Kondo H, Kanda K, Ashino T, Nakamachi T, Sekikawa K, Iwakura Y, Shioda S, Numazawa S, Yoshida T. Involvement of interleukin-1 in lipopolysaccaride-induced microglial activation and learning and memory deficits. J Neurosci Res 2011; 89:506-14. [PMID: 21290410 DOI: 10.1002/jnr.22582] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2010] [Revised: 09/16/2010] [Accepted: 11/11/2010] [Indexed: 11/11/2022]
Abstract
We have developed an animal model of learning and memory impairment associated with activation of microglia in the mouse brain. Injection of lipopolysaccharide into the CA1 region of the mouse hippocampus resulted in an increased production of inflammatory cytokines, such as interleukin-1β. Immunostaining for interleukin-1β revealed an increase in the signal at 6 hr after lipopolysaccharide injection. Immunopositive cells for interleukin-1β were colocalized with those immunopositive for CD11b. When subacute lipopolysaccharide treatment (20 μg/2 μl/injection, bilaterally for 5 consecutive days) was performed, long-term activation of microglia and learning and memory deficits as evaluated using a step-through passive avoidance test were observed in the wild-type mice. Gene expression of the N-methyl-D-aspartate receptor NR1 and NR2A subunits was also decreased by the lipopolysaccharide treatment. In contrast, activation of microglia and the associated behavioral deficits were not observed in mice lacking interleukin-1α and -1β following the subacute lipopolysaccharide treatment, together with little change in the gene expression of NR1 and NR2A subunits. However, the subacute lipopolysaccharide treatment produced almost similar changes in those parameters in the tumor necrosis factor-α knockout mice as in the wild-type animals. The injection of interleukin-1β neutralizing antibody with lipopolysaccharide for 5 consecutive days resulted in the improvement of lipopolysaccharide-induced learning and memory deficits. These findings suggest that the expression of interleukin-1 plays an important role in lipopolysaccharide-induced activation of microglia and the associated functional deficits in learning and memory.
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Affiliation(s)
- S Tanaka
- Department of Biochemical Toxicology, School of Pharmacy, Showa University, Tokyo, Japan.
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23
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Rohlman DS, Anger WK, Lein PJ. Correlating neurobehavioral performance with biomarkers of organophosphorous pesticide exposure. Neurotoxicology 2010; 32:268-76. [PMID: 21182866 DOI: 10.1016/j.neuro.2010.12.008] [Citation(s) in RCA: 130] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2010] [Revised: 12/03/2010] [Accepted: 12/13/2010] [Indexed: 12/20/2022]
Abstract
There is compelling evidence that adverse neurobehavioral effects are associated with occupational organophosphorous pesticide (OP) exposure in humans. Behavioral studies of pesticide applicators, greenhouse workers, agricultural workers and farm residents exposed repeatedly over months or years to low levels of OPs reveal a relatively consistent pattern of neurobehavioral deficits. However, only two studies have demonstrated a link between neurobehavioral performance and current biomarkers of OP exposure including blood cholinesterase (ChE) activity and urinary levels of OP metabolites. A variety of reasons may explain why so few studies have reported such correlations, including differing individual and group exposure histories, differing methodologies for assessing behavior and exposure, and lack of a reliable index of exposure. Alternatively, these data may suggest that current biomarkers (ChE, urine metabolites) are neither predictive nor diagnostic of the neurobehavioral effects of chronic OP pesticide exposures. This review focuses on the evidence that neurobehavioral performance deficits are associated with occupational OP pesticide exposure and concludes that research needs to return to the basics and rigorously test the relationships between neurobehavioral performance and both current (ChE and urine metabolites) and novel (e.g., inflammation and oxidative stress) biomarkers using human and animal models. The results of such studies are critically important because OP pesticides are widely and extensively used throughout the world, including situations where exposure controls and personal protective equipment are not routinely used.
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Affiliation(s)
- Diane S Rohlman
- Center for Research on Occupational and Environmental Toxicology, Oregon Health & Science University, Portland, OR 97239, USA.
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Jardanhazi-Kurutz D, Kummer MP, Terwel D, Vogel K, Thiele A, Heneka MT. Distinct adrenergic system changes and neuroinflammation in response to induced locus ceruleus degeneration in APP/PS1 transgenic mice. Neuroscience 2010; 176:396-407. [PMID: 21129451 DOI: 10.1016/j.neuroscience.2010.11.052] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2010] [Revised: 11/23/2010] [Accepted: 11/24/2010] [Indexed: 02/07/2023]
Abstract
Degeneration of locus ceruleus (LC) neurons and subsequent reduction of norepinephrine (NE) in LC projection areas represent an early pathological indicator of Alzheimer's disease (AD). In order to study the effects of NE depletion on cortical and hippocampal adrenergic system changes, LC degeneration was induced in 3-month-old APP/PS1 mice by the neurotoxin N-(2-chloroethyl)-N-ethyl-bromo-benzylamine (dsp4). Dsp4 induced a widespread loss of norepinephrine transporter binding in multiple brain structures already at 4.5 months. This was accompanied by changes of α-1-, α-2-, and β-1-adreneroceptor binding sites as well as altered adrenoceptor mRNA expression. In parallel, we observed increased micro- and astrogliosis in cortical and hippocampal structures in dsp4-treated groups. In addition, the expression of the pro-inflammatory cytokines CCL2 and IL-1β were induced in both, dsp4-treated and APP/PS1-transgenic mice, whereas IL-1α was only up-regulated in dsp4-treated APP/PS1 mice. Concerning amyloid β (Aβ) deposition, we observed an elevation of Aβ1-42 levels in aged dsp4-treated APP/PS1 mice. These data support the hypothesis that LC degeneration leads to dysregulation of adrenergic receptors and exacerbation of Aβ-induced neuroinflammation, both of which are exploitable for early disease marker development.
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Affiliation(s)
- D Jardanhazi-Kurutz
- Global Drug Discovery, Bayer Schering Pharma AG, Berlin, Müllerstrasse 178, 13342 Berlin, Germany
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25
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Humpel C. Chronic mild cerebrovascular dysfunction as a cause for Alzheimer's disease? Exp Gerontol 2010; 46:225-32. [PMID: 21112383 PMCID: PMC3070802 DOI: 10.1016/j.exger.2010.11.032] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2010] [Revised: 11/17/2010] [Accepted: 11/19/2010] [Indexed: 02/08/2023]
Abstract
Alzheimer's disease (AD) is a progressive chronic disorder and is characterized by β-amyloid plaques and angiopathy, tau pathology, neuronal cell death, and inflammatory responses. The reasons for this disease are not known. This review proposes the hypothesis that a chronic mild longlasting cerebrovascular dysfunction could initiate a cascade of events leading to AD. It is suggested that (vascular) risk factors (e.g. hypercholesterolemia, type 2 diabetes, hyperhomocysteinemia) causes either damage of the cerebrovascular system including silent strokes or causes dysregulation of beta-amyloid clearance at the blood-brain barrier resulting in increased brain beta-amyloid. A cascade of subsequent downstream events may lead to disturbed metabolic changes, and neuroinflammation and tau pathology. The role of NGF on the cell death of cholinergic neurons is discussed. Additional risk factors (e.g. acidosis, metals) contribute to plaque development.
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Affiliation(s)
- Christian Humpel
- Laboratory of Psychiatry and Exp. Alzheimers Research, Department of Psychiatry and Psychotherapy, Innsbruck Medical University, Austria.
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26
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The dopamine β-hydroxylase -1021C/T polymorphism is associated with the risk of Alzheimer's disease in the Epistasis Project. BMC MEDICAL GENETICS 2010; 11:162. [PMID: 21070631 PMCID: PMC2994840 DOI: 10.1186/1471-2350-11-162] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/04/2010] [Accepted: 11/11/2010] [Indexed: 02/06/2023]
Abstract
Background The loss of noradrenergic neurones of the locus coeruleus is a major feature of Alzheimer's disease (AD). Dopamine β-hydroxylase (DBH) catalyses the conversion of dopamine to noradrenaline. Interactions have been reported between the low-activity -1021T allele (rs1611115) of DBH and polymorphisms of the pro-inflammatory cytokine genes, IL1A and IL6, contributing to the risk of AD. We therefore examined the associations with AD of the DBH -1021T allele and of the above interactions in the Epistasis Project, with 1757 cases of AD and 6294 elderly controls. Methods We genotyped eight single nucleotide polymorphisms (SNPs) in the three genes, DBH, IL1A and IL6. We used logistic regression models and synergy factor analysis to examine potential interactions and associations with AD. Results We found that the presence of the -1021T allele was associated with AD: odds ratio = 1.2 (95% confidence interval: 1.06-1.4, p = 0.005). This association was nearly restricted to men < 75 years old: odds ratio = 2.2 (1.4-3.3, 0.0004). We also found an interaction between the presence of DBH -1021T and the -889TT genotype (rs1800587) of IL1A: synergy factor = 1.9 (1.2-3.1, 0.005). All these results were consistent between North Europe and North Spain. Conclusions Extensive, previous evidence (reviewed here) indicates an important role for noradrenaline in the control of inflammation in the brain. Thus, the -1021T allele with presumed low activity may be associated with misregulation of inflammation, which could contribute to the onset of AD. We suggest that such misregulation is the predominant mechanism of the association we report here.
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27
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Rosales-Corral S, Reiter RJ, Tan DX, Ortiz GG, Lopez-Armas G. Functional aspects of redox control during neuroinflammation. Antioxid Redox Signal 2010; 13:193-247. [PMID: 19951033 DOI: 10.1089/ars.2009.2629] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Neuroinflammation is a CNS reaction to injury in which some severe pathologies, regardless of their origin, converge. The phenomenon emphasizes crosstalk between neurons and glia and reveals a complex interaction with oxidizing agents through redox sensors localized in enzymes, receptors, and transcription factors. When oxidizing pressures cause reversible molecular changes, such as minimal or transitory proinflammatory cytokine overproduction, redox couples provide a means of translating the presence of reactive oxygen or nitrogen species into useful signals in the cell. Additionally, thiol-based redox sensors convey information about localized changes in redox potential induced by physiologic or pathologic situations. They are susceptible to oxidative changes and become key events during neuroinflammation, altering the course of a signaling response or the behavior of specific transcription factors. When oxidative stress augments the pressure on the intracellular environment, the effective reduction potential of redox pairs diminishes, and cell signaling shifts toward proinflammatory and proapoptotic signals, creating a vicious cycle between oxidative stress and neuroinflammation. In addition, electrophilic compounds derived from the oxidative cascade react with key protein thiols and interfere with redox signaling. This article reviews the relevant functional aspects of redox control during the neuroinflammatory process.
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Affiliation(s)
- Sergio Rosales-Corral
- Lab. Desarrollo-Envejecimiento, Enfermedades Neurodegenerativas, División de Neurociencias, Centro de Investigación Biomédica de Occidente (CIBO) del Instituto Mexicano del Seguro Social (IMSS) , Guadalajara, Jalisco. Mexico.
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Konarski JZ, McIntyre RS, Kennedy SH, Rafi-Tari S, Soczynska JK, Ketter TA. Volumetric neuroimaging investigations in mood disorders: bipolar disorder versus major depressive disorder. Bipolar Disord 2008; 10:1-37. [PMID: 18199239 DOI: 10.1111/j.1399-5618.2008.00435.x] [Citation(s) in RCA: 208] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
BACKGROUND As patients with mood disorders manifest heterogeneity in phenomenology, pathophysiology, etiology, and treatment response, a biological classification of mental disease is urgently needed to advance research. Patient and methodological variability complicates the comparison of neuroimaging study results and limits heuristic model development and a biologically-based diagnostic schema. OBJECTIVE We have critically reviewed and compared the magnetic resonance neuroimaging literature to determine the degree and directionality of volumetric changes in brain regions putatively implicated in the pathophysiology of major depressive disorder (MDD) versus bipolar disorder (BD). METHODS A total of 140 published magnetic resonance imaging investigations evaluating subjects with BD or MDD were selected to provide a summary and interpretation of volumetric neuroimaging results in MDD and BD. Further commentary on the pathophysiological implications, and putative cellular and pharmacological mechanisms, is also provided. RESULTS While whole brain volumes of patients with mood disorders do not differ from those of healthy controls, regional deficits in the frontal lobe, particularly in the anterior cingulate and the orbitofrontal cortex, appear to consistently differentiate subjects with mood disorders from the general population. Preliminary findings also suggest that subcortical structures, particularly the striatum, amygdala, and hippocampus, may be differentially affected in MDD and BD. CONCLUSIONS Structural neuroimaging studies have consistently identified regional abnormalities in subjects with mood disorders. Future studies should strive to definitively establish the influence of age and medication.
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Affiliation(s)
- Jakub Z Konarski
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
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29
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Abstract
Recent advances in the understanding of the pathophysiological mechanisms underlying Alzheimer's disease have pointed to novel strategies for drug development. Animal models have contributed considerably to these advances, and will have a key role in the evaluation of therapeutics that could have the potential not just to alleviate the dementia associated with Alzheimer's disease, but to modify the disease process. Here, we summarize and critically evaluate current rodent models of dementia, and discuss their role in drug discovery and development.
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Affiliation(s)
- Debby Van Dam
- Laboratory of Neurochemistry and Behaviour, Institute Born-Bunge, Department of Biomedical Sciences, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium.
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30
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Haglund M, Sjöbeck M, Englund E. Locus ceruleus degeneration is ubiquitous in Alzheimer's disease: Possible implications for diagnosis and treatment. Neuropathology 2006; 26:528-32. [PMID: 17203588 DOI: 10.1111/j.1440-1789.2006.00725.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Degeneration of the locus ceruleus (LC) and decreased cortical levels of norepinephrine are common findings in Alzheimer's disease (AD), but their significance is unknown. Because the noradrenergic system is accessible to pharmacological intervention, the role of LC degeneration and noradrenergic dysfunction in the pathogenesis and clinical manifestations of AD needs clarification. Hypothetically, loss of noradrenergic innervation could cause microvascular dysfunction and manifest as ischemia. The objectives of this study were to develop a scale for assessment of LC degeneration and to determine whether degeneration of the LC correlates quantitatively with either duration of clinical dementia, overall severity of AD pathology or with measures of ischemic non-focal white matter disease (WMD) in AD. This report is a pathological follow-up of a clinical longitudinal dementia study of 66 consecutive cases of AD without admixture of vascular dementia (VaD) from the Lund Longitudinal Dementia Study, neuropathologically diagnosed between 1990 and 1999. Ten cases of VaD were included for comparative purposes. No correlation between degree of LC degeneration and duration of dementia, AD or WMD severity was found. LC degeneration was significantly more severe in the AD group than in the VaD group. Even though LC degeneration was not associated with WMD or the severity of AD pathology in this AD material, we suggest that clinical studies on the consequences of noradrenergic dysfunction are warranted. Treatment augmenting noradrenergic signaling is available and safe. The marked difference in the level of LC degeneration between AD and VaD cases suggests that LC degeneration could be used as a diagnostic marker of AD.
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Affiliation(s)
- Mattias Haglund
- Division of Neuropathology, Department of Pathology and Cytology, Lund University Hospital, Lund, Sweden.
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31
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Kalinin S, Feinstein DL, Xu HL, Huesa G, Pelligrino DA, Galea E. Degeneration of noradrenergic fibres from the locus coeruleus causes tight-junction disorganisation in the rat brain. Eur J Neurosci 2006; 24:3393-400. [PMID: 17229089 DOI: 10.1111/j.1460-9568.2006.05223.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Although functional studies demonstrate that noradrenaline controls the permeability of the blood-brain barrier, it has never been determined whether this neurotransmitter regulates the tight junction (TJ) assembly that confers the barrier property to brain microvessels. We thus tested in rats the effect of pharmacological depletion of noradrenaline with the noradrenergic toxin DSP4 (5 mg/kg) on the expression of the TJ proteins zonula occludens-1 (ZO1) and occludin. The effectiveness of the lesion was confirmed by tyrosine hydroxylase immunoreactivity, which showed noradrenergic fibre reduction accompanied by debris and swollen fibres in DSP4-treated brains. Noradrenergic fibre degeneration caused: (i) gliosis; (ii) disappearance of TJ proteins in vascular cell-to-cell contacts (49.9 and 38.3% reductions for occludin and ZO1, respectively); (iii) a 49.2% decrease in total ZO1 protein, measured by Western blot analysis, parallel to a 39.5% decrease in ZO1 mRNA, measured by real-time PCR; and (iv) a relative increase in the beta occludin isoform (62.9%), with no change in total occludin protein or mRNA. The expression of endothelial brain antigen, a marker of a functionally competent brain endothelium, was also reduced. We conclude that damage to the ascending fibres from the locus coeruleus caused TJ disruption and gliosis, a sign of inflammation. These results imply that the locus coeruleus degeneration reported in Alzheimer's and Parkinson's diseases may contribute to these disorders by causing blood-brain barrier dysfunction. Whether the vascular damage is the result of impaired noradrenergic transmission or secondary to the inflammatory reaction remains to be determined.
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Affiliation(s)
- Sergey Kalinin
- Department of Anaesthesiology, University of Illinois at Chicago, Illinois, USA
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Kaneko N, Okano H, Sawamoto K. Role of the cholinergic system in regulating survival of newborn neurons in the adult mouse dentate gyrus and olfactory bulb. Genes Cells 2006; 11:1145-59. [PMID: 16999735 DOI: 10.1111/j.1365-2443.2006.01010.x] [Citation(s) in RCA: 144] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Neurogenesis in the subgranular zone of the hippocampal dentate gyrus and olfactory bulbs continues into adulthood and has been implicated in the cognitive function of the adult brain. The basal forebrain cholinergic system has been suggested to play a role in regulating neurogenesis as well as learning and memory in these regions. Herein, we report that highly polysialylated neural cell adhesion molecule (PSA-NCAM)-positive immature cells as well as neuronal nuclei (NeuN)-positive mature neurons in the dentate gyrus and olfactory bulb express multiple acetylcholine receptor subunits and make contact with cholinergic fibers. To examine the function of acetylcholine in neurogenesis, we used donepezil (Aricept), a potent and selective acetylcholinesterase inhibitor that improves cognitive impairment in Alzheimer's disease. Intraperitoneal administrations of donepezil significantly enhanced the survival of newborn neurons, but not proliferation of neural progenitor cells in the subgranular zone or the subventricular zone of normal mice. Moreover, donepezil treatment reversed the chronic stress-induced decrease in neurogenesis. Taken together, these results suggest that activation of the cholinergic system promotes survival of newborn neurons in the adult dentate gyrus and olfactory bulb under both normal and stressed conditions.
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Affiliation(s)
- Naoko Kaneko
- Department of Physiology, Keio University School of Medicine, Tokyo 160-8582, Japan
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Griffin WST, Liu L, Li Y, Mrak RE, Barger SW. Interleukin-1 mediates Alzheimer and Lewy body pathologies. J Neuroinflammation 2006; 3:5. [PMID: 16542445 PMCID: PMC1435743 DOI: 10.1186/1742-2094-3-5] [Citation(s) in RCA: 179] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2005] [Accepted: 03/16/2006] [Indexed: 12/04/2022] Open
Abstract
Background Clinical and neuropathological overlap between Alzheimer's (AD) and Parkinson's disease (PD) is now well recognized. Such cases of concurrent AD and Lewy body disease (AD/LBD) show neuropathological changes that include Lewy bodies (α-synuclein aggregates), neuritic amyloid plaques, and neurofibrillary tangles (hyperphosphorylated tau aggregates). The co-occurrence of these clinical and neuropathological changes suggests shared pathogenic mechanisms in these diseases, previously assumed to be distinct. Glial activation, with overexpression of interleukin-1 (IL-1) and other proinflammatory cytokines, has been increasingly implicated in the pathogenesis of both AD and PD. Methods Rat primary cultures of microglia and cortical neurons were cultured either separately or as mixed cultures. Microglia or cocultures were treated with a secreted fragment (sAPPα) of the β-amyloid precursor protein (βAPP). Neurons were treated with IL-1β or conditioned medium from sAPPα-activated microglia, with or without IL-1 receptor antagonist. Slow-release pellets containing either IL-1β or bovine serum albumin (control) were implanted in cortex of rats, and mRNA for various neuropathological markers was analyzed by RT-PCR. Many of the same markers were assessed in tissue sections from human cases of AD/LBD. Results Activation of microglia with sAPPα resulted in a dose-dependent increase in secreted IL-1β. Cortical neurons treated with IL-1β showed a dose-dependent increase in sAPPα release, an effect that was enhanced in the presence of microglia. IL-1β also elevated the levels of α-synuclein, activated MAPK-p38, and phosphorylated tau; a concomitant decrease in levels of synaptophysin occurred. Delivery of IL-1β by slow-release pellets elevated mRNAs encoding α-synuclein, βAPP, tau, and MAPK-p38 compared to controls. Finally, human cases of AD/LBD showed colocalization of IL-1-expressing microglia with neurons that simultaneously overexpressed βAPP and contained both Lewy bodies and neurofibrillary tangles. Conclusion Our findings suggest that IL-1 drives production of substrates necessary for formation of the major neuropathological changes characteristic of AD/LBD.
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Affiliation(s)
- W Sue T Griffin
- Department of Geriatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA
- Department of Neurobiology & Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA
- Geriatric Research, Education and Clinical Center, Department of Veterans' Affairs Medical Center, Little Rock, Arkansas 72205, USA
- Mental Illness Research Education Center, Department of Veterans' Affairs Medical Center, Little Rock, Arkansas 72205, USA
| | - Ling Liu
- Department of Geriatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA
| | - Yuekui Li
- Department of Geriatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA
| | - Robert E Mrak
- Department of Pathology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA
- Department of Neurobiology & Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA
| | - Steven W Barger
- Department of Geriatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA
- Department of Neurobiology & Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA
- Geriatric Research, Education and Clinical Center, Department of Veterans' Affairs Medical Center, Little Rock, Arkansas 72205, USA
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Schliebs R. Basal forebrain cholinergic dysfunction in Alzheimer's disease--interrelationship with beta-amyloid, inflammation and neurotrophin signaling. Neurochem Res 2006; 30:895-908. [PMID: 16187224 DOI: 10.1007/s11064-005-6962-9] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/14/2005] [Indexed: 12/21/2022]
Abstract
Alzheimer's disease, the most common neurodegenerative disorder of senile dementia, is characterized by two major morpho-pathological hallmarks. Deposition of extracellular neuritic, beta-amyloid peptide-containing plaques (senile plaques) in cerebral cortical regions of Alzheimer patients is accompanied by the presence of intracellular neurofibrillary tangles in cerebral pyramidal neurons. Basal forebrain cholinergic dysfunction is also a consistent feature of Alzheimer's disease, which has been suggested to cause, at least partly, the cognitive deficits observed in patients with Alzheimer's disease. Impaired cortical cholinergic neurotransmission may also contribute to beta-amyloid plaque pathology in Alzheimer's disease by affecting expression and processing of the beta-amyloid precursor protein (APP). Vice versa, low level of soluble beta-amyloid has been observed to inhibit cholinergic synaptic function. Deposition of beta-amyloid plaques in Alzheimer's disease is also accompanied by a significant plaque-associated glial up-regulation of interleukin-1, which has been attributed to affect expression and metabolism of APP and to interfere with cholinergic transmission. Understanding the molecular mechanisms underlying the interrelationship between cortical cholinergic dysfunction, beta-amyloid formation and deposition, as well as local inflammatory upregulation, would allow to derive potential treatment strategies to pharmacologically intervene in the disease-causing signaling cascade.
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Affiliation(s)
- Reinhard Schliebs
- Paul Flechsig Institute for Brain Research, Department of Neurochemistry, University of Leipzig, Jahnallee 59, D-04109 Leipzig, Germany.
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Tanaka S, Ide M, Shibutani T, Ohtaki H, Numazawa S, Shioda S, Yoshida T. Lipopolysaccharide-induced microglial activation induces learning and memory deficits without neuronal cell deathin rats. J Neurosci Res 2006; 83:557-66. [PMID: 16429444 DOI: 10.1002/jnr.20752] [Citation(s) in RCA: 171] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We used lipopolysaccharide (LPS) to activate microglia that play an important role in the brain immune system. LPS injected into the rat hippocampus CA1 region activated microglial cells resulting in an increased production of interleukin (IL)-1beta and tumor necrosis factor (TNF)-alpha in the hippocampus during the initial stage of treatment. Immunostaining for IL-1beta was increased at 6 hr after LPS injection. IL-1beta-immunopositive cells were co-localized with immunostaining for CD11b. Subacute treatment with LPS by the same route for 5 days caused long-term activation of microglia and induced learning and memory deficits in animals when examined with a step-through passive avoidance test, but histochemical analysis showed that neuronal cell death was not observed under these experimental conditions. The increased expression of the heme oxygenase-1 (HO-1) gene, an oxidative stress maker, was observed. However, the genetic expression of brain-derived neurotrophic factor (BDNF) and its receptor, TrkB, decreased during the course of LPS treatment. We found decreases in [3H]MK801 binding in the hippocampus CA1 region by LPS-treatment for 5 days. The data shows that glutamatergic transmission was attenuated in the LPS-treated rats. These results suggest that long-term activation of microglia induced by LPS results in a decrease of glutamatergic transmission that leads to learning and memory deficits without neuronal cell death. The physiologic significance of these findings is discussed.
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Affiliation(s)
- Sachiko Tanaka
- Department of Biochemical Toxicology, School of Pharmaceutical Sciences, Tokyo, Japan.
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Blalock EM, Chen KC, Stromberg AJ, Norris CM, Kadish I, Kraner SD, Porter NM, Landfield PW. Harnessing the power of gene microarrays for the study of brain aging and Alzheimer's disease: statistical reliability and functional correlation. Ageing Res Rev 2005; 4:481-512. [PMID: 16257272 DOI: 10.1016/j.arr.2005.06.006] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2005] [Accepted: 06/17/2005] [Indexed: 11/15/2022]
Abstract
During normal brain aging, numerous alterations develop in the physiology, biochemistry and structure of neurons and glia. Aging changes occur in most brain regions and, in the hippocampus, have been linked to declining cognitive performance in both humans and animals. Age-related changes in hippocampal regions also may be harbingers of more severe decrements to come from neurodegenerative disorders such as Alzheimer's disease (AD). However, unraveling the mechanisms underlying brain aging, AD and impaired function has been difficult because of the complexity of the networks that drive these aging-related changes. Gene microarray technology allows massively parallel analysis of most genes expressed in a tissue, and therefore is an important new research tool that potentially can provide the investigative power needed to address the complexity of brain aging/neurodegenerative processes. However, along with this new analytic power, microarrays bring several major bioinformatics and resource problems that frequently hinder the optimal application of this technology. In particular, microarray analyses generate extremely large and unwieldy data sets and are subject to high false positive and false negative rates. Concerns also have been raised regarding their accuracy and uniformity. Furthermore, microarray analyses can result in long lists of altered genes, most of which may be difficult to evaluate for functional relevance. These and other problems have led to some skepticism regarding the reliability and functional usefulness of microarray data and to a general view that microarray data should be validated by an independent method. Given recent progress, however, we suggest that the major problem for current microarray research is no longer validity of expression measurements, but rather, the reliability of inferences from the data, an issue more appropriately redressed by statistical approaches than by validation with a separate method. If tested using statistically defined criteria for reliability/significance, microarray data do not appear a priori to require more independent validation than data obtained by any other method. In fact, because of added confidence from co-regulation, they may require less. In this article we also discuss our strategy of statistically correlating individual gene expression with biologically important endpoints designed to address the problem of evaluating functional relevance. We also review how work by ourselves and others with this powerful technology is leading to new insights into the complex processes of brain aging and AD, and to novel, more comprehensive models of aging-related brain change.
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Affiliation(s)
- E M Blalock
- Department of Molecular and Biomedical Pharmacology, University of Kentucky Medical Center, 800 Rose St. MS-309, Lexington, KY 40536-0084, USA.
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Thomas MS, Zhang W, Jordan PM, Saragovi HU, Taglialatela G. Signaling pathways mediating a selective induction of nitric oxide synthase II by tumor necrosis factor alpha in nerve growth factor-responsive cells. J Neuroinflammation 2005; 2:19. [PMID: 16144552 PMCID: PMC1242246 DOI: 10.1186/1742-2094-2-19] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2005] [Accepted: 09/06/2005] [Indexed: 01/08/2023] Open
Abstract
Background Inflammation and oxidative stress play a critical role in neurodegeneration associated with acute and chronic insults of the nervous system. Notably, affected neurons are often responsive to and dependent on trophic factors such as nerve growth factor (NGF). We previously showed in NGF-responsive PC12 cells that tumor necrosis factor alpha (TNFα) and NGF synergistically induce the expression of the free-radical producing enzyme inducible nitric oxide synthase (iNOS). We proposed that NGF-responsive neurons might be selectively exposed to iNOS-mediated oxidative damage as a consequence of elevated TNFα levels. With the aim of identifying possible therapeutic targets, in the present study we investigated the signaling pathways involved in NGF/TNFα-promoted iNOS induction. Methods Western blotting, RT-PCR, transcription factor-specific reporter gene systems, mutant cells lacking the low affinity p75NTR NGF receptor and transfections of TNFα/NGF chimeric receptors were used to investigate signalling events associated with NGF/TNFα-promoted iNOS induction in PC12 cells. Results Our results show that iNOS expression resulting from NGF/TNFα combined treatment can be elicited in PC12 cells. Mutant PC12 cells lacking p75NTR did not respond, suggesting that p75NTR is required to mediate iNOS expression. Furthermore, cells transfected with chimeric TNFα/NGF receptors demonstrated that the simultaneous presence of both p75NTR and TrkA signaling is necessary to synergize with TNFα to mediate iNOS expression. Lastly, our data show that NGF/TNFα-promoted iNOS induction requires activation of the transcription factor nuclear factor kappa B (NF-κB). Conclusion Collectively, our in vitro model suggests that cells bearing both the high and low affinity NGF receptors may display increased sensitivity to TNFα in terms of iNOS expression and therefore be selectively at risk during acute (e.g. neurotrauma) or chronic (e.g. neurodegenerative diseases) conditions where high levels of pro-inflammatory cytokines in the nervous system occur pathologically. Our results also suggest that modulation of NFκB-promoted transcription of selective genes could serve as a potential therapeutic target to prevent neuroinflammation-induced neuronal damage.
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Affiliation(s)
- Michael S Thomas
- Department of Neuroscience and Cell Biology, the University of Texas Medical Branch at Galveston, Texas - USA
| | - WenRu Zhang
- Department of Neuroscience and Cell Biology, the University of Texas Medical Branch at Galveston, Texas - USA
| | - Paivi M Jordan
- Department of Neuroscience and Cell Biology, the University of Texas Medical Branch at Galveston, Texas - USA
| | - H Uri Saragovi
- Department of Pharmacology and Therapeutics, McGill University, Montreal, QC, Canada
| | - Giulio Taglialatela
- Department of Neuroscience and Cell Biology, the University of Texas Medical Branch at Galveston, Texas - USA
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D'Intino G, Paradisi M, Fernandez M, Giuliani A, Aloe L, Giardino L, Calzà L. Cognitive deficit associated with cholinergic and nerve growth factor down-regulation in experimental allergic encephalomyelitis in rats. Proc Natl Acad Sci U S A 2005; 102:3070-5. [PMID: 15710875 PMCID: PMC548798 DOI: 10.1073/pnas.0500073102] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Clinical symptoms in multiple sclerosis include cognitive dysfunction. Difficulties in learning and remembering new information represent the most common cognitive deficit and are associated with a general and progressive brain pathology. Possible pathogenetic mechanisms for neuronal damage such as neuroprotective strategies are under active investigation also in experimental allergic encephalomyelitis, the most widely used experimental model for multiple sclerosis. In this paper we demonstrate that a selective deficit in learning and memory performance, as investigated by the Morris water maze test, is a consistent feature in rat encephalomyelitis, which correlates with a decline in choline acetyltransferase activity and nerve growth factor mRNA level in cerebral cortex, hippocampus, and basal forebrain. Treatment aimed to restore acetylcholine content through chronic administration of selective acetylcholinesterase inhibitors (rivastigmine and donepezil) restores cognitive performance, choline acetyltransferase activity, and nerve growth factor mRNA expression.
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Affiliation(s)
- Giulia D'Intino
- Department of Veterinary Morphophysiology and Animal Production, University of Bologna, 40064 Ozzano Emilia (Bologna), Italy
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Hunter CL, Bachman D, Granholm AC. Minocycline prevents cholinergic loss in a mouse model of Down's syndrome. Ann Neurol 2005; 56:675-88. [PMID: 15468085 DOI: 10.1002/ana.20250] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Individuals with Down's syndrome develop Alzheimer's-like pathologies comparatively early in life, including progressive degeneration of basal forebrain cholinergic neurons (BFCNs). Cholinergic hypofunction contributes to dementia-related cognitive decline and remains a target of therapeutic intervention for Alzheimer's disease. In light of this, partial trisomy 16 (Ts65Dn) mice have been developed to provide an animal model of Down's syndrome that exhibits progressive loss of BFCNs and cognitive ability. Another feature common to both Down's syndrome and Alzheimer's disease is neuroinflammation, which may exacerbate neurodegeneration, including cholinergic loss. Minocycline is a semisynthetic tetracycline with antiinflammatory properties that has demonstrated neuroprotective properties in certain disease models. Consistent with a role for inflammatory processes in BFCN degeneration, we have shown previously that minocycline protects BFCNs and improves memory in mice with acute, immunotoxic BFCN lesions. We now report that minocycline treatment inhibits microglial activation, prevents progressive BFCN decline, and markedly improves performance of Ts65Dn mice on a working and reference memory task. Minocycline is an established antiinflammatory and neuroprotective drug and may provide a novel approach to treat specific AD-like pathologies.
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Affiliation(s)
- Christopher L Hunter
- Medical University of South Carolina, Department of Neuroscience, and the Center on Aging, Charleston, SC 29425, USA
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Wenk GL, McGann-Gramling K, Hauss-Wegrzyniak B. The presence of the APP(swe) mutation in mice does not increase the vulnerability of cholinergic basal forebrain neurons to neuroinflammation. Neuroscience 2004; 125:769-76. [PMID: 15099690 DOI: 10.1016/j.neuroscience.2004.01.050] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/18/2004] [Indexed: 10/26/2022]
Abstract
Neuroinflammation, and elevated levels of inflammatory proteins, such as tumor necrosis factor-alpha, and the deposition of beta-amyloid may interact to contribute to the pathogenesis of Alzheimer's disease. We reproduced a component of the neuroinflammatory state within the basal forebrain cholinergic system, a region that is vulnerable to degeneration in Alzheimer's disease, of transgenic Tg2576 mice that express the Swedish double mutation of the human amyloid precursor protein (APPswe). We have previously shown that basal forebrain cholinergic neurons are selectively vulnerable to the consequences of neuroinflammation. In the current study, tumor necrosis factor-alpha was infused into the basal forebrain region of APPswe and nontransgenic control mice for 20 days with the expectation that the presence of the transgene would enhance the loss of cholinergic neurons. Chronic infusion of tumor necrosis factor-alpha significantly decreased cortical choline acetyltransferase activity, reduced the number of choline acetyltransferase-immunoreactive cells and increased the number of activated astrocytes and microglia within the basal forebrain. The presence of the APPswe gene did not enhance the vulnerability of forebrain cholinergic neurons to the chronic neuroinflammation. Furthermore, combined treatment of these mice with memantine demonstrated that the neurotoxic effects of tumor necrosis factor-alpha upon cholinergic cells did not require the activation of the N-methyl-d-aspartate receptors. In contrast, we have previously shown that memantine was able to provide neuroprotection to cholinergic forebrain neurons from the consequences of exposure to the inflammogen lipopolysaccharide. These results provide insight into the mechanism by which neuroinflammation may selectively target specific neural systems during the progression of Alzheimer's disease.
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Affiliation(s)
- G L Wenk
- Division of Neural Systems, Memory and Aging, University of Arizona, 350 Life Sciences North Building, Tucson, AZ 85724, USA.
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Rosi S, Ramirez-Amaya V, Hauss-Wegrzyniak B, Wenk GL. Chronic brain inflammation leads to a decline in hippocampal NMDA-R1 receptors. J Neuroinflammation 2004; 1:12. [PMID: 15285803 PMCID: PMC500869 DOI: 10.1186/1742-2094-1-12] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2004] [Accepted: 07/07/2004] [Indexed: 11/22/2022] Open
Abstract
Background Neuroinflammation plays a prominent role in the progression of Alzheimer's disease and may be responsible for degeneration in vulnerable regions such as the hippocampus. Neuroinflammation is associated with elevated levels of extracellular glutamate and potentially an enhanced stimulation of glutamate N-methyl-D-aspartate receptors. This suggests that neurons that express these glutamate receptors might be at increased risk of degeneration in the presence of chronic neuroinflammation. Methods We have characterized a novel model of chronic brain inflammation using a slow infusion of lipopolysaccharide into the 4th ventricle of rats. This model reproduces many of the behavioral, electrophysiological, neurochemical and neuropathological changes associated with Alzheimer's disease. Results The current study demonstrated that chronic neuroinflammation is associated with the loss of N-methyl-D-aspartate receptors, as determined both qualitatively by immunohistochemistry and quantitatively by in vitro binding studies using [3H]MK-801, within the hippocampus and entorhinal cortex. Conclusion The gradual loss of function of this critical receptor within the temporal lobe region may contribute to some of the cognitive deficits observed in patients with Alzheimer's disease.
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Affiliation(s)
- Susanna Rosi
- Arizona Research Laboratories, Division of Neural Systems, Memory & Aging; University of Arizona, Tucson, AZ, USA
| | - Victor Ramirez-Amaya
- Arizona Research Laboratories, Division of Neural Systems, Memory & Aging; University of Arizona, Tucson, AZ, USA
| | - Beatrice Hauss-Wegrzyniak
- Arizona Research Laboratories, Division of Neural Systems, Memory & Aging; University of Arizona, Tucson, AZ, USA
| | - Gary L Wenk
- Arizona Research Laboratories, Division of Neural Systems, Memory & Aging; University of Arizona, Tucson, AZ, USA
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Hunter CL, Quintero EM, Gilstrap L, Bhat NR, Granholm AC. Minocycline protects basal forebrain cholinergic neurons from mu p75-saporin immunotoxic lesioning. Eur J Neurosci 2004; 19:3305-16. [PMID: 15217386 DOI: 10.1111/j.0953-816x.2004.03439.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Two prominent characteristics of Alzheimer's disease are basal forebrain cholinergic degeneration and neuroinflammation characterized by glial activation and the release of pro-inflammatory cytokines. Mu p75- saporin (SAP) is a novel immunotoxin that mimics the selective loss of basal forebrain cholinergic neurons and induces cognitive impairment in mice. We report that cholinergic cell loss in the medial septal nucleus and ventral diagonal band after i.c.v. injection of mu p75-SAP is accompanied by simultaneous activation of microglia and astrocytes in the basal forebrain region as well as significant memory loss. Consistent with a role of glial cells in the pathology of Alzheimer's disease, minocycline, a second-generation tetracycline with known anti-inflammatory and neuroprotective properties, attenuated mu p75-SAP-induced cholinergic cell loss, glial activation and transcription of downstream pro-inflammatory mediators. In addition to neuroprotection, minocycline treatment mitigated the cognitive impairment that appears to be a functional consequence of mu p75-SAP lesioning. The current study demonstrates that glial-related inflammation plays a significant role in the selective neurotoxicity of mu p75-SAP, and suggests that minocycline may provide a viable therapeutic option for degenerating cholinergic systems.
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Affiliation(s)
- Christopher L Hunter
- Department of Physiology and Neuroscience and the Center on Aging, Medical University of South Carolina, 26 Bee street, Charleston, SC 29425, USA
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