1
|
Ashraf A, Michaelides C, Walker TA, Ekonomou A, Suessmilch M, Sriskanthanathan A, Abraha S, Parkes A, Parkes HG, Geraki K, So PW. Regional Distributions of Iron, Copper and Zinc and Their Relationships With Glia in a Normal Aging Mouse Model. Front Aging Neurosci 2019; 11:351. [PMID: 31920630 PMCID: PMC6930884 DOI: 10.3389/fnagi.2019.00351] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Accepted: 12/02/2019] [Indexed: 01/08/2023] Open
Abstract
Microglia and astrocytes can quench metal toxicity to maintain tissue homeostasis, but with age, increasing glial dystrophy alongside metal dyshomeostasis may predispose the aged brain to acquire neurodegenerative diseases. The aim of the present study was to investigate age-related changes in brain metal deposition along with glial distribution in normal C57Bl/6J mice aged 2-, 6-, 19- and 27-months (n = 4/age). Using synchrotron-based X-ray fluorescence elemental mapping, we demonstrated age-related increases in iron, copper, and zinc in the basal ganglia (p < 0.05). Qualitative assessments revealed age-associated increases in iron, particularly in the basal ganglia and zinc in the white matter tracts, while copper showed overt enrichment in the choroid plexus/ventricles. Immunohistochemical staining showed augmented numbers of microglia and astrocytes, as a function of aging, in the basal ganglia (p < 0.05). Moreover, qualitative analysis of the glial immunostaining at the level of the fimbria and ventral commissure, revealed increments in the number of microglia but decrements in astroglia, in older aged mice. Upon morphological evaluation, aged microglia and astroglia displayed enlarged soma and thickened processes, reminiscent of dystrophy. Since glial cells have major roles in metal metabolism, we performed linear regression analysis and found a positive association between iron (R2 = 0.57, p = 0.0008), copper (R2 = 0.43, p = 0.0057), and zinc (R2 = 0.37, p = 0.0132) with microglia in the basal ganglia. Also, higher levels of iron (R2 = 0.49, p = 0.0025) and zinc (R2 = 0.27, p = 0.040) were correlated to higher astroglia numbers. Aging was accompanied by a dissociation between metal and glial levels, as we found through the formulation of metal to glia ratios, with regions of basal ganglia being differentially affected. For example, iron to astroglia ratio showed age-related increases in the substantia nigra and globus pallidus, while the ratio was decreased in the striatum. Meanwhile, copper and zinc to astroglia ratios showed a similar regional decline. Our findings suggest that inflammation at the choroid plexus, part of the blood-cerebrospinal-fluid barrier, prompts accumulation of, particularly, copper and iron in the ventricles, implying a compromised barrier system. Moreover, age-related glial dystrophy/senescence appears to disrupt metal homeostasis, likely due to induced oxidative stress, and hence increase the risk of neurodegenerative diseases.
Collapse
Affiliation(s)
- Azhaar Ashraf
- Department of Neuroimaging, Institute of Psychiatry, Psychology, and Neuroscience, King's College London, London, United Kingdom
| | - Christos Michaelides
- Department of Neuroimaging, Institute of Psychiatry, Psychology, and Neuroscience, King's College London, London, United Kingdom
| | - Thomas A Walker
- Department of Neuroimaging, Institute of Psychiatry, Psychology, and Neuroscience, King's College London, London, United Kingdom
| | - Antigoni Ekonomou
- Department of Neuroimaging, Institute of Psychiatry, Psychology, and Neuroscience, King's College London, London, United Kingdom
| | - Maria Suessmilch
- Department of Neuroimaging, Institute of Psychiatry, Psychology, and Neuroscience, King's College London, London, United Kingdom
| | - Achvini Sriskanthanathan
- Department of Neuroimaging, Institute of Psychiatry, Psychology, and Neuroscience, King's College London, London, United Kingdom
| | - Semhar Abraha
- Department of Neuroimaging, Institute of Psychiatry, Psychology, and Neuroscience, King's College London, London, United Kingdom
| | - Adam Parkes
- Department of Neuroimaging, Institute of Psychiatry, Psychology, and Neuroscience, King's College London, London, United Kingdom
| | - Harold G Parkes
- Department of Neuroimaging, Institute of Psychiatry, Psychology, and Neuroscience, King's College London, London, United Kingdom
| | - Kalotina Geraki
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, United Kingdom
| | - Po-Wah So
- Department of Neuroimaging, Institute of Psychiatry, Psychology, and Neuroscience, King's College London, London, United Kingdom
| |
Collapse
|
2
|
Li CR, Li SL, Yang ZY. Development of a coumarin-furan conjugate as Zn 2+ ratiometric fluorescent probe in ethanol-water system. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2017; 174:214-222. [PMID: 27915158 DOI: 10.1016/j.saa.2016.11.034] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Revised: 11/18/2016] [Accepted: 11/19/2016] [Indexed: 06/06/2023]
Abstract
In this study, a novel coumarin-derived compound bearing the furan moiety called 7-diethylamino-3-formylcoumarin (2'-furan formyl) hydrazone (1) has been designed, synthesized and evaluated as a Zn2+ ratiometric fluorescent probe in ethanol-water system. This probe 1 showed good selectivity and high sensitivity towards Zn2+ over other metal ions investigated, and a decrease in fluorescence emission intensity at 511nm accompanied by an enhancement in fluorescence emission intensity at 520nm of this probe 1 was observed in the presence of Zn2+ in ethanol-water (V : V=9 : 1) solution, which provided ratiometric fluorescence detection of Zn2+. Additionally, the ratiometric fluorescence response of 1 to Zn2+ was nearly completed within 0.5min, which suggested that this probe 1 could be utilized for sensing and monitoring Zn2+ in environmental and biological systems for real-time detection.
Collapse
Affiliation(s)
- Chao-Rui Li
- College of Chemistry and Chemical Engineering, State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, PR China
| | - Si-Liang Li
- College of Chemistry and Chemical Engineering, State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, PR China; School of Petrochemical Engineering, Lanzhou University of Technology, Lanzhou 730050, PR China
| | - Zheng-Yin Yang
- College of Chemistry and Chemical Engineering, State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, PR China.
| |
Collapse
|
3
|
Lichten LA, Ryu MS, Guo L, Embury J, Cousins RJ. MTF-1-mediated repression of the zinc transporter Zip10 is alleviated by zinc restriction. PLoS One 2011; 6:e21526. [PMID: 21738690 PMCID: PMC3124522 DOI: 10.1371/journal.pone.0021526] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Accepted: 06/01/2011] [Indexed: 12/11/2022] Open
Abstract
The regulation of cellular zinc uptake is a key process in the overall mechanism governing mammalian zinc homeostasis and how zinc participates in cellular functions. We analyzed the zinc transporters of the Zip family in both the brain and liver of zinc-deficient animals and found a large, significant increase in Zip10 expression. Additionally, Zip10 expression decreased in response to zinc repletion. Moreover, isolated mouse hepatocytes, AML12 hepatocytes, and Neuro 2A cells also respond differentially to zinc availability in vitro. Measurement of Zip10 hnRNA and actinomycin D inhibition studies indicate that Zip10 was transcriptionally regulated by zinc deficiency. Through luciferase promoter constructs and ChIP analysis, binding of MTF-1 to a metal response element located 17 bp downstream of the transcription start site was shown to be necessary for zinc-induced repression of Zip10. Furthermore, zinc-activated MTF-1 causes down-regulation of Zip10 transcription by physically blocking Pol II movement through the gene. Lastly, ZIP10 is localized to the plasma membrane of hepatocytes and neuro 2A cells. Collectively, these results reveal a novel repressive role for MTF-1 in the regulation of the Zip10 zinc transporter expression by pausing Pol II transcription. ZIP10 may have roles in control of zinc homeostasis in specific sites particularly those of the brain and liver. Within that context ZIP10 may act as an important survival mechanism during periods of zinc inadequacy.
Collapse
Affiliation(s)
- Louis A. Lichten
- Center for Nutritional Sciences, Food Science and Human Nutrition Department, College of Agricultural and Life Sciences, University of Florida, Gainesville, Florida, United States of America
| | - Moon-Suhn Ryu
- Center for Nutritional Sciences, Food Science and Human Nutrition Department, College of Agricultural and Life Sciences, University of Florida, Gainesville, Florida, United States of America
| | - Liang Guo
- Center for Nutritional Sciences, Food Science and Human Nutrition Department, College of Agricultural and Life Sciences, University of Florida, Gainesville, Florida, United States of America
| | - Jennifer Embury
- Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Robert J. Cousins
- Center for Nutritional Sciences, Food Science and Human Nutrition Department, College of Agricultural and Life Sciences, University of Florida, Gainesville, Florida, United States of America
- Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, Florida, United States of America
| |
Collapse
|
4
|
Gutiérrez L, Sabaratnam N, Aktar R, Bettedi L, Mandilaras K, Missirlis F. Zinc accumulation in heterozygous mutants of fumble, the pantothenate kinase homologue of Drosophila. FEBS Lett 2010; 584:2942-6. [PMID: 20493851 DOI: 10.1016/j.febslet.2010.05.029] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2010] [Accepted: 05/14/2010] [Indexed: 11/15/2022]
Abstract
Coenzyme A (CoA) functions in the intracellular trafficking of acetyl groups. In humans, mutations in the pantothenate kinase-2 gene, which encodes a key enzyme in CoA biosynthesis, are associated with neurodegeneration and premature death. Diagnosis is based on iron accumulation in the globus pallidus observed by magnetic resonance imaging. We investigated the elemental composition of the fumble mutant, a model of the human disease. Surprisingly, flies carrying a fumble loss-of-function allele had a three-fold increase in total zinc levels per dry weight when compared to control strains, but no change in total iron, copper or manganese levels. Accordingly, zinc supplementation had an adverse impact on the development of fumble mutant larvae, but zinc chelation failed to protect.
Collapse
Affiliation(s)
- Lucia Gutiérrez
- School of Biological and Chemical Sciences, Queen Mary University of London, London, UK
| | | | | | | | | | | |
Collapse
|
5
|
Sims RE, Woodhall GL, Wilson CL, Stanford IM. Functional characterization of GABAergic pallidopallidal and striatopallidal synapses in the rat globus pallidus in vitro. Eur J Neurosci 2009; 28:2401-8. [PMID: 19087170 DOI: 10.1111/j.1460-9568.2008.06546.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
As a central integrator of basal ganglia function, the external segment of the globus pallidus (GP) plays a critical role in the control of voluntary movement. Driven by intrinsic mechanisms and excitatory glutamatergic inputs from the subthalamic nucleus, GP neurons receive GABAergic inhibitory input from the striatum (Str-GP) and from local collaterals of neighbouring pallidal neurons (GP-GP). Here we provide electrophysiological evidence for functional differences between these two inhibitory inputs. The basic synaptic characteristics of GP-GP and Str-GP GABAergic synapses were studied using whole-cell recordings with paired-pulse and train stimulation protocols and variance-mean (VM) analysis. We found (i) IPSC kinetics are consistent with local collaterals innervating the soma and proximal dendrites of GP neurons whereas striatal inputs innervate more distal regions. (ii) Compared to GP-GP synapses Str-GP synapses have a greater paired-pulse ratio, indicative of a lower probability of release. This was confirmed using VM analysis. (iii) In response to 20 and 50 Hz train stimulation, GP-GP synapses are weakly facilitatory in 1 mM external calcium and depressant in 2.4 mM calcium. This is in contrast to Str-GP synapses which display facilitation under both conditions. This is the first quantitative study comparing the properties of GP-GP and Str-GP synapses. The results are consistent with the differential location of these inhibitory synapses and subtle differences in their release probability which underpin stable GP-GP responses and robust short-term facilitation of Str-GP responses. These fundamental differences may provide the physiological basis for functional specialization.
Collapse
Affiliation(s)
- Robert E Sims
- Biomedical Sciences, School of Life and Health Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK
| | | | | | | |
Collapse
|