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Khodasevich D, Smith AR, Huen K, Eskenazi B, Cardenas A, Holland N. Comparison of DNA methylation measurements from EPIC BeadChip and SeqCap targeted bisulphite sequencing in PON1 and nine additional candidate genes. Epigenetics 2022; 17:1944-1955. [PMID: 35786310 DOI: 10.1080/15592294.2022.2091818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Epigenome-wide association studies (EWAS) are widely implemented in epidemiology, and the Illumina HumanMethylationEPIC BeadChip (EPIC) DNA microarray is the most-used technology. Recently, next-generation sequencing (NGS)-based methods, which assess DNA methylation at single-base resolution, have become more affordable and technically feasible. While the content of microarray technology is fixed, NGS-based approaches, such as the Roche Nimblegen, SeqCap Epi Enrichment System (SeqCap), offer the flexibility of targeting most CpGs in a gene. With the current usage of microarrays and emerging NGS-based technologies, it is important to establish whether data generated from the two platforms are comparable. We harnessed 112 samples from the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) birth cohort study and compared DNA methylation between the EPIC microarray and SeqCap for PON1 and nine additional candidate genes, by evaluating epigenomic coverage and correlations. We conducted multivariable linear regression and principal component analyses to assess the ability of the EPIC array and SeqCap to detect biological differences in gene methylation by the PON1-108 single nucleotide polymorphism. We found an overall high concordance (r = 0.84) between SeqCap and EPIC DNA methylation, among highly methylated and minimally methylated regions. However, substantial disagreement was present between the two methods in moderately methylated regions, with SeqCap measurements exhibiting greater within-site variation. Additionally, SeqCap did not capture PON1 SNP associated differences in DNA methylation that were evident with the EPIC array. Our findings indicate that microarrays perform well for analysing DNA methylation in large cohort studies but with limited coverage.
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Affiliation(s)
- Dennis Khodasevich
- Division of Environmental Health Sciences, Children's Environmental Health Laboratory, School of Public Health, University of California, Berkeley, CA, USA
| | - Anna R Smith
- Division of Environmental Health Sciences, Children's Environmental Health Laboratory, School of Public Health, University of California, Berkeley, CA, USA.,Center for Computational Biology, University of California, Berkeley, CA, USA
| | - Karen Huen
- Division of Environmental Health Sciences, Children's Environmental Health Laboratory, School of Public Health, University of California, Berkeley, CA, USA
| | - Brenda Eskenazi
- Center for Children's Environmental Health, School of Public Health, University of California, Berkeley, CA, USA
| | - Andres Cardenas
- Division of Environmental Health Sciences, Children's Environmental Health Laboratory, School of Public Health, University of California, Berkeley, CA, USA.,Center for Computational Biology, University of California, Berkeley, CA, USA
| | - Nina Holland
- Division of Environmental Health Sciences, Children's Environmental Health Laboratory, School of Public Health, University of California, Berkeley, CA, USA
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2
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Mosca A, Del Casale A, Borro M, Gentile G, Pomes LM, Padovano A, Fiaschè F, Pinzone V, Rapinesi C, Zoppi T, Brugnoli R, Sani G, Kotzalidis GD, Girardi P, Ferracuti S, Simmaco M, Pompili M. PON1 polymorphisms can predict generalized anxiety and depressed mood in patients with multiple chemical sensitivity. Per Med 2021; 18:255-267. [PMID: 33728967 DOI: 10.2217/pme-2019-0141] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Background: Multiple chemical sensitivity (MCS) is a chronic condition with somatic, cognitive and affective symptoms that follow contact with chemical agents at usually non toxic concentrations. We aimed to assess the role of genetic polymorphisms involved in oxidative stress on anxiety and depression in MCS. Materials & methods: Our study investigated the CAT rs1001179, MPO rs2333227, PON1 rs662 and PON1 rs705379 polymorphisms in MCS. Results: The AG genotype of the PON1 rs662 and the TT and CT genotypes of the PON1 rs705379 were involved in anxiety and depression. Discussion: These results are in line with existing evidence of PON1 involvement in MCS and suggest a further role of this gene in the exhibition of anxiety and depression in this disease.
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Affiliation(s)
- Alessio Mosca
- Department of Neuroscience, Mental Health, & Sensory Organs (NESMOS), Faculty of Medicine & Psychology, Sapienza University, Rome, Italy
| | - Antonio Del Casale
- Department of Dynamic & Clinical Psychology, & Health Studies, Faculty of Medicine & Psychology, Sapienza University, Rome, Italy.,Unit of Psychiatry, 'Sant'Andrea' University Hospital, Rome, Italy
| | - Marina Borro
- Department of Neuroscience, Mental Health, & Sensory Organs (NESMOS), Faculty of Medicine & Psychology, Sapienza University, Rome, Italy.,Unit of Laboratory & Advanced Molecular Diagnostics, 'Sant'Andrea' University Hospital, Rome, Italy
| | - Giovanna Gentile
- Department of Neuroscience, Mental Health, & Sensory Organs (NESMOS), Faculty of Medicine & Psychology, Sapienza University, Rome, Italy.,Unit of Laboratory & Advanced Molecular Diagnostics, 'Sant'Andrea' University Hospital, Rome, Italy
| | - Leda Marina Pomes
- Department of Neuroscience, Mental Health, & Sensory Organs (NESMOS), Faculty of Medicine & Psychology, Sapienza University, Rome, Italy.,Unit of Laboratory & Advanced Molecular Diagnostics, 'Sant'Andrea' University Hospital, Rome, Italy
| | - Alessio Padovano
- Department of Neuroscience, Mental Health, & Sensory Organs (NESMOS), Faculty of Medicine & Psychology, Sapienza University, Rome, Italy.,Unit of Psychiatry, 'Sant'Andrea' University Hospital, Rome, Italy
| | - Federica Fiaschè
- Department of Neuroscience, Mental Health, & Sensory Organs (NESMOS), Faculty of Medicine & Psychology, Sapienza University, Rome, Italy.,Unit of Psychiatry, 'Sant'Andrea' University Hospital, Rome, Italy
| | - Vito Pinzone
- Department of Neuroscience, Mental Health, & Sensory Organs (NESMOS), Faculty of Medicine & Psychology, Sapienza University, Rome, Italy.,Unit of Psychiatry, 'Sant'Andrea' University Hospital, Rome, Italy
| | - Chiara Rapinesi
- Department of Neuroscience, Mental Health, & Sensory Organs (NESMOS), Faculty of Medicine & Psychology, Sapienza University, Rome, Italy
| | - Teodolinda Zoppi
- Department of Neuroscience, Mental Health, & Sensory Organs (NESMOS), Faculty of Medicine & Psychology, Sapienza University, Rome, Italy.,Unit of Psychiatry, 'Sant'Andrea' University Hospital, Rome, Italy
| | - Roberto Brugnoli
- Department of Neuroscience, Mental Health, & Sensory Organs (NESMOS), Faculty of Medicine & Psychology, Sapienza University, Rome, Italy.,Unit of Psychiatry, 'Sant'Andrea' University Hospital, Rome, Italy
| | - Gabriele Sani
- Institute of Psychiatry & Psychology, Department of Geriatrics, Neuroscience & Orthopedics, Fondazione Policlinico Universitario IRCCS "A. Gemelli", Università Cattolica del Sacro Cuore, Rome, Italy
| | - Georgios Demetrios Kotzalidis
- Department of Neuroscience, Mental Health, & Sensory Organs (NESMOS), Faculty of Medicine & Psychology, Sapienza University, Rome, Italy
| | - Paolo Girardi
- Department of Neuroscience, Mental Health, & Sensory Organs (NESMOS), Faculty of Medicine & Psychology, Sapienza University, Rome, Italy.,Unit of Psychiatry, 'Sant'Andrea' University Hospital, Rome, Italy
| | - Stefano Ferracuti
- Department of Human Neuroscience, Sapienza University; Unit of Risk Management, 'Sant'Andrea' University Hospital, Rome, Italy
| | - Maurizio Simmaco
- Department of Neuroscience, Mental Health, & Sensory Organs (NESMOS), Faculty of Medicine & Psychology, Sapienza University, Rome, Italy.,Unit of Laboratory & Advanced Molecular Diagnostics, 'Sant'Andrea' University Hospital, Rome, Italy
| | - Maurizio Pompili
- Department of Neuroscience, Mental Health, & Sensory Organs (NESMOS), Faculty of Medicine & Psychology, Sapienza University, Rome, Italy.,Unit of Psychiatry, 'Sant'Andrea' University Hospital, Rome, Italy
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3
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Darney K, Kasteel EEJ, Buratti FM, Turco L, Vichi S, Béchaux C, Roudot AC, Kramer NI, Testai E, Dorne JLCM, Di Consiglio E, Lautz LS. Bayesian meta-analysis of inter-phenotypic differences in human serum paraoxonase-1 activity for chemical risk assessment. ENVIRONMENT INTERNATIONAL 2020; 138:105609. [PMID: 32114288 DOI: 10.1016/j.envint.2020.105609] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 02/19/2020] [Accepted: 02/22/2020] [Indexed: 06/10/2023]
Abstract
Human variability in paraoxonase-1 (PON1) activities is driven by genetic polymorphisms that affect the internal dose of active oxons of organophosphorus (OP) insecticides. Here, an extensive literature search has been performed to collect human genotypic frequencies (i.e. L55M, Q192R, and C-108T) in subgroups from a range of geographical ancestry and PON1 activities in three probe substrates (paraoxon, diazoxon and phenyl acetate). Bayesian meta-analyses were performed to estimate variability distributions for PON1 activities and PON1-related uncertainty factors (UFs), while integrating quantifiable sources of inter-study, inter-phenotypic and inter-individual differences. Inter-phenotypic differences were quantified using the population with high PON1 activity as the reference group. Results from the meta-analyses provided PON1 variability distributions and these can be implemented in generic physiologically based kinetic models to develop quantitative in vitro in vivo extrapolation models. PON1-related UFs in the Caucasian population were above the default toxicokinetic UF of 3.16 for two specific genotypes namely -108CC using diazoxon as probe substrate and, -108CT, -108TT, 55MM and 192QQ using paraoxon as probe substrate. However, integration of PON1 genotypic frequencies and activity distributions showed that all UFs were within the default toxicokinetic UF. Quantitative inter-individual differences in PON1 activity are important for chemical risk assessment particularly with regards to the potential sensitivity to organophosphates' toxicity.
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Affiliation(s)
- K Darney
- Risk Assessment Department, French Agency for Food, Environmental and Occupational Health & Safety (ANSES), 14 rue Pierre et Marie Curie, Maisons-Alfort F-94700, France
| | - E E J Kasteel
- Institute for Risk Assessment Sciences, Utrecht University, 3508 TD Utrecht, the Netherlands
| | - F M Buratti
- Department of Environment and Health, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy
| | - L Turco
- Department of Environment and Health, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy
| | - S Vichi
- Department of Environment and Health, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy
| | - C Béchaux
- Risk Assessment Department, French Agency for Food, Environmental and Occupational Health & Safety (ANSES), 14 rue Pierre et Marie Curie, Maisons-Alfort F-94700, France
| | - A C Roudot
- Laboratoire des Interactions Epithéliums Neurones, Université Bretagne Loire (UBL), UFR Sciences et Techniques, 6 Av. Victor Le Gorgeu, CS93837, Cedex 3, Brest 29238, France
| | - N I Kramer
- Institute for Risk Assessment Sciences, Utrecht University, 3508 TD Utrecht, the Netherlands
| | - E Testai
- Department of Environment and Health, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy
| | - J L C M Dorne
- European Food Safety Authority, 1a, Via Carlo Magno 1A, 43126 Parma, Italy
| | - E Di Consiglio
- Department of Environment and Health, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy
| | - L S Lautz
- Risk Assessment Department, French Agency for Food, Environmental and Occupational Health & Safety (ANSES), 14 rue Pierre et Marie Curie, Maisons-Alfort F-94700, France.
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4
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Idrees M, Siddiq AR, Ajmal M, Akram M, Khalid RR, Hussain A, Qamar R, Bokhari H. Decreased serum PON1 arylesterase activity in familial hypercholesterolemia patients with a mutated LDLR gene. Genet Mol Biol 2018; 41:570-577. [PMID: 30044465 PMCID: PMC6136370 DOI: 10.1590/1678-4685-gmb-2016-0287] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 01/16/2018] [Indexed: 01/17/2023] Open
Abstract
Paraoxonase 1 (PON1) is a serum enzyme associated with high density lipoprotein (HDL) regulation through its paraoxonase and arylesterase activity. PON1 inhibits the oxidation of HDL and low density lipoprotein (LDL), and is involved in the pathogenesis of a variety of diseases including atherosclerosis. Conversely, mutations in the low density lipoprotein receptor (LDLR) result in failure of receptor mediated endocytosis of LDL leading to its elevated plasma levels and onset of familial hypercholesterolemia (FH). In the current study we investigated the role of PON1 polymorphisms rs662; c.575A > G (p.Gln192Arg) and rs854560; c.163T > A (p.Leu55Met) in a large family having FH patients harboring a functional mutation in LDLR. Genotypes were revealed by RFLP, followed by confirmation through Sanger sequencing. PON1 activity was measure by spectrophotometry. Our results show significantly reduced serum paraoxonase and arylesterase activities in FH patients compared with the healthy individuals of the family (p < 0.05). PON1 QQ192 genotype showed a significantly higher association with FH (p=0.0002). PON1 Q192 isoform was associated with reduced serum paraoxonase activity by in silico analysis and PON1 R192 exhibited higher serum paraoxonase and arylesterase activity than the other polymorphs. Our results highlight that the combination of LDLR mutations and PON1 MMQQ genotypes may lead to severe cardiac events.
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Affiliation(s)
- Muhammad Idrees
- COMSAT Institute of Information Tecnology, Islamabad, Pakistan
| | | | - Muhammad Ajmal
- COMSAT Institute of Information Tecnology, Islamabad, Pakistan
| | - Muhammad Akram
- COMSAT Institute of Information Tecnology, Islamabad, Pakistan
| | | | - Alamdar Hussain
- COMSAT Institute of Information Tecnology, Islamabad, Pakistan
| | - Raheel Qamar
- COMSAT Institute of Information Tecnology, Islamabad, Pakistan
| | - Habib Bokhari
- COMSAT Institute of Information Tecnology, Islamabad, Pakistan
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5
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Mohamed Safwat S, Manal El-Sayed Abd ES, Mahmoud LS, Marwa M F, Aya Shawky K. PON1 Inter-individual Enzymatic activity variation as a predictor of OPC toxicity in agricultural workers presented to PCCASU, Egypt. ANNALS OF ENVIRONMENTAL SCIENCE AND TOXICOLOGY 2018; 2:068-073. [DOI: 10.17352/aest.000014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
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6
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García-González I, Mendoza-Alcocer R, Pérez-Mendoza GJ, Rubí-Castellanos R, González-Herrera L. Distribution of genetic variants of oxidative stress metabolism genes: Paraoxonase 1 (PON1) and Glutathione S-transferase (GSTM1/GSTT1) in a population from Southeastern Mexico. Ann Hum Biol 2016; 43:554-562. [PMID: 26620773 DOI: 10.3109/03014460.2015.1126353] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND Paraoxonase 1 (PON1) and glutathione S-transferases (GSTs) are involved in the biotransformation of xenobiotics. Variation in the enzyme concentration and activity suggests individual differences for the degree of protection against oxidative stress. AIM This study analysed the distribution of SNPs Q192R, L55M (PON1) and variants in GSTM1 and GSTT1 genes in a population from Southeastern Mexico. SUBJECTS AND METHODS One hundred and fifty-one Mexican Mestizo healthy volunteers were included. PON1 polymorphisms were determined by Taqman allele discrimination real time-PCR, whereas GSTM1 and GSTT1 genes were determined with a multiplex PCR-based method. RESULTS All genotypes were in Hardy-Weinberg equilibrium, except for GSTM1. The genotypic distributions of Q192R and L55M were 22% QQ, 48% QR, 30% RR, 62% LL, 34% LM and 4% MM, respectively, whereas the allele frequencies were 0.46 (Q), 0.54 (R), 0.79 (L) and 0.21 (M). The most frequent haplotype was R/L (46.7%). It was found that 31% and 9% of the individuals had the GSTM1 and GSTT1 null genotype, respectively. The frequency of the combined null genotype GSTM1*0/GSTT1*0 was 4.64%. CONCLUSION The results showed that the frequencies of polymorphisms of PON1, GSTM1 and GSTT1 in the Yucatán population differ to those observed in other ethnic groups and provide useful data for epidemiological studies.
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Affiliation(s)
- I García-González
- a Laboratorio de Genética , Centro de Investigaciones Regionales 'Dr. Hideyo Noguchi', Universidad Autónoma de Yucatán . Mérida, Yucatán , Mexico and
| | - R Mendoza-Alcocer
- b Centro Estatal de la Transfusión Sanguínea, Secretaria de Salud de Yucatán , Mérida, Yucatán , Mexico
| | - G J Pérez-Mendoza
- a Laboratorio de Genética , Centro de Investigaciones Regionales 'Dr. Hideyo Noguchi', Universidad Autónoma de Yucatán . Mérida, Yucatán , Mexico and
| | - R Rubí-Castellanos
- a Laboratorio de Genética , Centro de Investigaciones Regionales 'Dr. Hideyo Noguchi', Universidad Autónoma de Yucatán . Mérida, Yucatán , Mexico and
| | - L González-Herrera
- a Laboratorio de Genética , Centro de Investigaciones Regionales 'Dr. Hideyo Noguchi', Universidad Autónoma de Yucatán . Mérida, Yucatán , Mexico and
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7
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Lozano-Paniagua D, Gómez-Martín A, Gil F, Parrón T, Alarcón R, Requena M, Lacasaña M, Hernández AF. Activity and determinants of cholinesterases and paraoxonase-1 in blood of workers exposed to non-cholinesterase inhibiting pesticides. Chem Biol Interact 2016; 259:160-167. [PMID: 27062891 DOI: 10.1016/j.cbi.2016.04.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 03/27/2016] [Accepted: 04/04/2016] [Indexed: 11/19/2022]
Abstract
Pesticide exposure has been associated with different adverse health effects which may be modulated to some extent by paraoxonase-1 (PON1) activity and genetic polymorphisms. This study assessed seasonal variations in PON1 activity (using paraoxon -POase-, phenylacetate -AREase-, diazoxon -DZOase- and dihydrocoumarin -DHCase- as substrates), erythrocyte acetylcholinesterase (AChE) and plasma cholinesterase (using butyrylthiocholine -BuChE- and benzoylcholine -BeChE- as substrates. The study population consisted of intensive agriculture workers regularly exposed to pesticides other than organophosphates and non-exposed controls from Almería (Southeastern Spain). The effect of common genetic polymorphisms of PON1 and BCHE on paraoxonase-1 and cholinesterase activities toward different substrates was also assessed. Linear mixed models were used to compare esterase activities in agricultural workers and control subjects over the two study periods (high and low exposure to pesticides). The significant decrease in AChE and increase in BuChE and BeChE activities observed in workers with respect to control subjects was attributed to pesticide exposure. Workers also had higher levels of AREase, DZOase and, to a lesser extent, of POase, but showed decreased DHCase activity. While PON1 Q192R and PON1 -108C/T gene polymorphisms were significantly associated with all PON1 activities, PON1 L55M showed a significant association with AREase, DZOase and DHCase. BCHE-K (Karlow variant) was significantly associated with lower BeChE activity (but not with BuChE) and BCHE-A (atypical variant) showed no significant association with any cholinesterase activity. These findings suggest that increased PON1, BuChE and BeChE activities in exposed workers might result from an adaptive response against pesticide exposure to compensate for adverse effects at the biochemical level. This response appears to be modulated by PON1 and BCHE gene polymorphisms.
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Affiliation(s)
- David Lozano-Paniagua
- Dept. Legal Medicine and Toxicology, University of Granada School of Medicine, Spain
| | - Antonio Gómez-Martín
- Pfizer-University of Granada-Junta de Andalucía Centre for Genomics and Oncological Research (GENYO), Spain
| | - Fernando Gil
- Dept. Legal Medicine and Toxicology, University of Granada School of Medicine, Spain
| | | | | | - Mar Requena
- University of Almería School of Health Sciences, Spain
| | - Marina Lacasaña
- Escuela Andaluza de Salud Pública, Spain; CIBERESP, Spain; ibs.GRANADA, Spain
| | - Antonio F Hernández
- Dept. Legal Medicine and Toxicology, University of Granada School of Medicine, Spain.
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8
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Afolabi OK, Wusu AD, Ogunrinola OO, Abam EO, Babayemi DO, Dosumu OA, Onunkwor OB, Balogun EA, Odukoya OO, Ademuyiwa O. Paraoxonase 1 activity in subchronic low-level inorganic arsenic exposure through drinking water. ENVIRONMENTAL TOXICOLOGY 2016; 31:154-162. [PMID: 25082665 DOI: 10.1002/tox.22030] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Revised: 07/12/2014] [Accepted: 07/13/2014] [Indexed: 06/03/2023]
Abstract
Epidemiological evidences indicate close association between inorganic arsenic exposure via drinking water and cardiovascular diseases. While the exact mechanism of this arsenic-mediated increase in cardiovascular risk factors remains enigmatic, epidemiological studies indicate a role for paraoxonase 1 (PON1) in cardiovascular diseases. To investigate the association between inorganic arsenic exposure and cardiovascular diseases, rats were exposed to sodium arsenite (trivalent; 50, 100, and 150 ppm As) and sodium arsenate (pentavalent; 100, 150, and 200 ppm As) in their drinking water for 12 weeks. PON1 activity towards paraoxon (PONase) and phenylacetate (AREase) in plasma, lipoproteins, hepatic, and brain microsomal fractions were determined. Inhibition of PONase and AREase in plasma and HDL characterized the effects of the two arsenicals. While the trivalent arsenite inhibited PONase by 33% (plasma) and 46% (HDL), respectively, the pentavalent arsenate inhibited the enzyme by 41 and 34%, respectively. AREase activity was inhibited by 52 and 48% by arsenite, whereas the inhibition amounted to 72 and 67%, respectively by arsenate. The pattern of inhibition in plasma and HDL indicates that arsenite induced a dose-dependent inhibition of PONase whereas arsenate induced a dose-dependent inhibition of AREase. In the VLDL + LDL, arsenate inhibited PONase and AREase while arsenite inhibited PONase. In the hepatic and brain microsomal fractions, only the PONase enzyme was inhibited by the two arsenicals. The inhibition was more pronounced in the hepatic microsomes where a 70% inhibition was observed at the highest dose of pentavalent arsenic. Microsomal cholesterol was increased by the two arsenicals resulting in increased cholesterol/phospholipid ratios. Our findings indicate that decreased PON1 activity observed in arsenic exposure may be an incipient biochemical event in the cardiovascular effects of arsenic. Modulation of PON1 activity by arsenic may also be mediated through changes in membrane fluidity brought about by changes in the concentration of cholesterol in the microsomes.
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Affiliation(s)
- Olusegun K Afolabi
- Department of Biochemistry, Federal University of Agriculture, Abeokuta, Nigeria
- Department of Biochemistry, Ladoke Akintola University of Technology, Ogbomosho, Nigeria
| | - Adedoja D Wusu
- Department of Biochemistry, Federal University of Agriculture, Abeokuta, Nigeria
- Department of Biochemistry, Lagos State University, Ojoo, Nigeria
| | - Olufunmilayo O Ogunrinola
- Department of Biochemistry, Federal University of Agriculture, Abeokuta, Nigeria
- Department of Biochemistry, Lagos State University, Ojoo, Nigeria
| | - Esther O Abam
- Department of Biochemistry, Federal University of Agriculture, Abeokuta, Nigeria
| | - David O Babayemi
- Department of Biochemistry, Federal University of Agriculture, Abeokuta, Nigeria
| | - Oluwatosin A Dosumu
- Department of Biochemistry, Federal University of Agriculture, Abeokuta, Nigeria
| | - Okechukwu B Onunkwor
- Department of Biochemistry, Federal University of Agriculture, Abeokuta, Nigeria
| | - Elizabeth A Balogun
- Department of Biochemistry, Federal University of Agriculture, Abeokuta, Nigeria
- Department of Biochemistry, University of Ilorin, Nigeria
| | - Olusegun O Odukoya
- Department of Chemistry, Federal University of Agriculture, Abeokuta, Nigeria
| | - Oladipo Ademuyiwa
- Department of Biochemistry, Federal University of Agriculture, Abeokuta, Nigeria
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9
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Arbel Y, Shenhar-Tsarfaty S, Waiskopf N, Finkelstein A, Halkin A, Revivo M, Berliner S, Herz I, Shapira I, Keren G, Soreq H, Banai S. Decline in serum cholinesterase activities predicts 2-year major adverse cardiac events. Mol Med 2014; 20:38-45. [PMID: 24395570 PMCID: PMC3951463 DOI: 10.2119/molmed.2013.00139] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2013] [Accepted: 12/19/2013] [Indexed: 01/17/2023] Open
Abstract
Parasympathetic activity influences long-term outcome in patients with cardiovascular disease, but the underlying mechanism(s) linking parasympathetic activity and the occurrence of major adverse cardiovascular events (MACEs) are incompletely understood. The aim of this pilot study was to evaluate the association between serum cholinesterase activities as parasympathetic biomarkers and the risk for the occurrence of MACEs. Cholinergic status was determined by measuring the cumulative capacity of serum acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) to hydrolyze the AChE substrate acetylthiocholine. Cholinergic status was evaluated in randomly selected patients undergoing cardiac catheterization. The patients were divided into two groups of 100 patients in each group, with or without occurrence of MACEs during a follow-up period of 40 months. Cox regression models adjusted for potential clinical, metabolic and inflammatory confounders served to evaluate association with clinical outcome. We found that patients with MACE presented lower cholinergic status and AChE values at catheterization (1,127 ± 422 and 359 ± 153 nmol substrate hydrolyzed per minute per milliliter, respectively) than no-MACE patients (1,760 ± 546 and 508 ± 183 nmol substrate hydrolyzed per minute per milliliter, p < 0.001 and p < 0.001, respectively), whose levels were comparable to those of matched healthy controls (1,622 ± 303 and 504 ± 126 nmol substrate hydrolyzed per minute per milliliter, respectively). In a multivariate analysis, patients with AChE or total cholinergic status values below median showed conspicuously elevated risk for MACE (hazard ratio 1.85 [95% confidence interval [CI] 1.09-3.15, p = 0.02] and 2.21 [95% CI 1.22-4.00, p = 0.009]) compared with those above median, even after adjusting for potential confounders. We conclude that parasympathetic dysfunction expressed as reduced serum AChE and AChE activities in patients compared to healthy controls can together reflect impaired parasympathetic activity. This impairment predicts the risk of MACE up to 40 months in such patients. Monitoring these parasympathetic parameters might help in the risk stratification of patients with cardiovascular disease.
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Affiliation(s)
- Yaron Arbel
- Department of Cardiology, Tel Aviv Medical Center, affiliated with the Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Shani Shenhar-Tsarfaty
- Department of Biological Chemistry, The Life Sciences Institute and the Edmond and Lily Safra Center of Brain Science, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Nir Waiskopf
- Department of Biological Chemistry, The Life Sciences Institute and the Edmond and Lily Safra Center of Brain Science, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Ariel Finkelstein
- Department of Cardiology, Tel Aviv Medical Center, affiliated with the Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Amir Halkin
- Department of Cardiology, Tel Aviv Medical Center, affiliated with the Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Miri Revivo
- Department of Cardiology, Tel Aviv Medical Center, affiliated with the Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Shlomo Berliner
- Internal Medicine “E,” Tel Aviv Medical Center, affiliated with the Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Itzhak Herz
- Department of Cardiology, Tel Aviv Medical Center, affiliated with the Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Itzhak Shapira
- Department of Cardiology, Tel Aviv Medical Center, affiliated with the Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Gad Keren
- Department of Cardiology, Tel Aviv Medical Center, affiliated with the Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Hermona Soreq
- Department of Biological Chemistry, The Life Sciences Institute and the Edmond and Lily Safra Center of Brain Science, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Shmuel Banai
- Department of Cardiology, Tel Aviv Medical Center, affiliated with the Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
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Shenhar-Tsarfaty S, Waiskopf N, Ofek K, Shopin L, Usher S, Berliner S, Shapira I, Bornstein NM, Ritov Y, Soreq H, Ben Assayag E. Atherosclerosis and arteriosclerosis parameters in stroke patients associate with paraoxonase polymorphism and esterase activities. Eur J Neurol 2013; 20:891-8. [PMID: 23305304 DOI: 10.1111/ene.12074] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Accepted: 11/12/2012] [Indexed: 11/29/2022]
Abstract
BACKGROUND AND PURPOSE Polymorphic paraoxonase (PON1) variants can variably prevent low- and high-density lipoprotein oxidation, but their role in provoking atherosclerosis remained unclear. We addressed this issue by profiling PON1 polymorphisms and enzymatic activities, and assessing atherosclerosis and cerebral arteriosclerosis severity in post-stroke patients. METHODS Carotid artery intima-media-thickness (IMT), cerebral white matter lesions (WML), serum PON1 -108C/T, Q192R and L55M polymorphisms, and PON and acetylcholinesterase (AChE) enzyme activities were determined in 237 patients. RESULTS Genetic variation at the PON1 locus showed a strong influence on PON1 activity in ischaemic stroke patients, but lacked direct influence on IMT. Stroke patients with PON1 QQ192 or MM55 genotypes demonstrated lower PON and arylesterase activities at both Day 1 and 12 months post-stroke than patients with either RQ/RR192 or LM/LL55 genotypes (P < 0.001). Furthermore, patients with carotid atherosclerosis and/or cerebral arteriosclerosis expressed as IMT, carotid plaques and WML had lower 12 months PON1 activity than patients without (P = 0.02, P = 0.027 and P = 0.001, respectively), and PON and AChE hydrolysis rates were more tightly correlated in patients carrying the PON1 192R compared with the 192QQ allele, in a gene dose-dependent manner (P < 0.001). CONCLUSION Our findings show inverse PON1 activity-carotid atherosclerosis and -cerebral arteriosclerosis association in stroke patients: the lower the PON1 activity the more progressed is the atherosclerotic process and the weaker is the association with AChE activity. Extending previous PON1 genetic studies in stroke populations, our study emphasizes the PON1 activity as a potential anti-atherogenic element and proposes involvement of cholinesterase activities in its effects.
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Affiliation(s)
- S Shenhar-Tsarfaty
- The Institute of Life Sciences and the Edmond and Lily Safra Center of Brain Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
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11
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Gonzalez V, Huen K, Venkat S, Pratt K, Xiang P, Harley KG, Kogut K, Trujillo CM, Bradman A, Eskenazi B, Holland NT. Cholinesterase and paraoxonase (PON1) enzyme activities in Mexican-American mothers and children from an agricultural community. JOURNAL OF EXPOSURE SCIENCE & ENVIRONMENTAL EPIDEMIOLOGY 2012; 22:641-8. [PMID: 22760442 PMCID: PMC4123814 DOI: 10.1038/jes.2012.61] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Accepted: 03/29/2012] [Indexed: 05/30/2023]
Abstract
Exposure to organophosphate and carbamate pesticides can lead to neurotoxic effects through inhibition of cholinesterase enzymes. The paraoxonase (PON1) enzyme can detoxify oxon derivatives of some organophosphates. Lower PON1, acetylcholinesterase, and butyrylcholinesterase activities have been reported in newborns relative to adults, suggesting increased susceptibility to organophosphate exposure in young children. We determined PON1, acetylcholinesterase, and butyrylcholinesterase activities in Mexican-American mothers and their 9-year-old children (n=202 pairs) living in an agricultural community. We used Wilcoxon signed-rank tests to compare enzymatic activities among mothers and their children, and analysis of variance to identify factors associated with enzyme activities. Substrate-specific PON1 activities were slightly lower in children than their mothers; however, these differences were only statistically significant for the paraoxon substrate. We observed significantly lower acetylcholinesterase but higher butyrylcholinesterase levels in children compared with their mothers. Mean butyrylcholinesterase levels were strongly associated with child obesity status (body mass index Z scores >95%). We observed highly significant correlations among mother-child pairs for each of the enzymatic activities analyzed; however, PON1 activities did not correlate with acetylcholinesterase or butyrylcholinesterase activities. Our findings suggest that by age 9 years, PON1 activities approach adult levels, and host factors including sex and obesity may affect key enzymes involved in pesticide metabolism.
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Affiliation(s)
- Veronica Gonzalez
- Center for Environmental Research and Children's Health, 50 University Hall, School of Public Health, University of California, Berkeley, California 94720-7360, USA
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Lane RM, He Y. Butyrylcholinesterase genotype and gender influence Alzheimer's disease phenotype. Alzheimers Dement 2012; 9:e1-73. [PMID: 22402324 DOI: 10.1016/j.jalz.2010.12.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2010] [Revised: 09/04/2010] [Accepted: 12/02/2010] [Indexed: 10/28/2022]
Abstract
Retrospective data are presented to support a spectrum of early Alzheimer's disease (AD) along a continuum defined by gender and genotype. The putative neurodegenerative mechanisms driving distinct phenotypes at each end of the spectrum are glial hypoactivity associated with early failure of synaptic cholinergic neurotransmission and glial overactivation associated with loss of neural network connectivity due to accelerated age-related breakdown of myelin. In early AD, male butyrylcholinesterase K-variant carriers with one or two apolipoprotein ɛ4 alleles have prominent medial temporal atrophy, synaptic failure, cognitive decline, and accumulation of aggregated beta-amyloid peptide. Increasing synaptic acetylcholine in damaged but still functional cholinergic synapses improves cognitive symptoms, whereas increasing the ability of glia to support synapses and to clear beta-amyloid peptide might be disease-modifying. Conversely, chronic glial overactivation can also drive degenerative processes and in butyrylcholinesterase K-variant negative females generalized glial overactivation may be the main driver from mild cognitive impairment to AD. Females are more likely than males to have accelerated age-related myelin breakdown, more widespread white matter loss, loss of neural network connectivity, whole brain atrophy, and functional decline. Increasing extracellular acetylcholine levels blocks glial activation, reduces myelin loss and damage to neural network connectivity, and is disease-modifying. Between extremes characterized by gender, genotype, and age, pathophysiology may be mixed and this spectrum may explain much of the heterogeneity of amnestic mild cognitive impairment. Preservation of the functional integrity of the neural network may be an important component of strengthening cognitive reserve and significantly delaying the onset and progression of dementia, particularly in females. Prospective confirmation of these hypotheses is required. Implications for future research and therapeutic opportunities are discussed.
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Affiliation(s)
- Roger M Lane
- Bristol-Myers Squibb Global Clinical Research, Wallingford, CT, USA.
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Klimkowicz-Mrowiec A, Marona M, Spisak K, Jagiella J, Wolkow P, Szczudlik A, Slowik A. Paraoxonase 1 gene polymorphisms do not influence the response to treatment in Alzheimer's disease. Dement Geriatr Cogn Disord 2012; 32:26-31. [PMID: 21829028 DOI: 10.1159/000330343] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/22/2011] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Acetylcholinesterase inhibitors (AChEIs) are the treatment of choice for patients with Alzheimer's disease (AD). However, their efficacy is moderate and differs from patient to patient. Recent studies suggest that the Q192R variant of the paraoxonase 1 gene (PON1) might affect individual susceptibility to these drugs. METHODS We investigated the influence of 3 single nucleotide polymorphisms (SNPs) in PON1 (rs 662, rs 854560, rs 705381) and the APOE common polymorphism in 101 Polish patients with late-onset AD in response to treatment with AChEIs. RESULTS No significant differences were observed between carriers and non-carriers of the PON1 SNPs or the APOE common polymorphism in terms of treatment response. These results did not change after stratification of APOE status. CONCLUSION Our results suggest that both the investigated PON1 and APOE common SNPs do not influence treatment response to AChEIs in patients with AD.
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Affiliation(s)
- A Klimkowicz-Mrowiec
- Department of Neurology, University Hospital, Cracow, Poland. Aleksandra.Klimkowicz @ mp.pl
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14
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Klimkowicz-Mrowiec A, Marona M, Wolkow P, Witkowski A, Maruszak A, Styczynska M, Barcikowska M, Szczudlik A, Slowik A. Paraoxonase gene polymorphism and the risk for Alzheimer's disease in the polish population. Dement Geriatr Cogn Disord 2011; 31:417-23. [PMID: 21757906 DOI: 10.1159/000329571] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/20/2011] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The relationship between different paraoxonase (PON) gene polymorphisms and the risk of Alzheimer's disease (AD) was studied several times and the results were controversial. METHODS We investigated the association of 4 single-nucleotide polymorphisms (SNPs) of the PON1 (M55L; Q192R; -161C/T) and the PON2 (C311S) genes that were shown to affect the risk of sporadic AD. We studied 360 Caucasian cases with late-onset AD and 354 nondemented controls. RESULTS No significant differences were observed between the studied PON SNPs and AD risk. The results did not change after stratification of the apolipoprotein E status. Meta-analyses of studies in Caucasians assessing the associations between the PON1 M55L, -161C/T and Q192R SNPs and the risk of AD were performed, and no associations were found. CONCLUSION Our results suggest that the studied PON1 and PON2 polymorphisms are not associated with late-onset AD.
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Affiliation(s)
- A Klimkowicz-Mrowiec
- Department of Neurology, School of Medicine, Jagiellonian University, ul. Botaniczna 3, Cracow, Poland.
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15
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Matthews AR, Sutter ME, Rentz DE. Serum paraoxonase-1 (PON-1) genotype and exposure to organophosphorous insectides--is there a high-risk population? J Med Toxicol 2011; 7:243-7. [PMID: 21786069 DOI: 10.1007/s13181-011-0166-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
The Health Studies Branch (HSB) is responsible for responding to domestic and international requests for assistance with suspected and known environmental-associated public health threats as well as pursuing original environmental research. The HSB employs personnel with a wide variety of educational backgrounds and professional training including epidemiology, medicine, toxicology, statistics, and other environmental public health-related disciplines. This wide range of expertise is necessary to address the broad scope of potential environmental health threats. HSB scientists conduct studies on environmental exposures. Recent examples include the following: mercury exposure in children living in large urban areas, exposure to brevetoxins and microcystins arising from harmful algal blooms, and occupational exposures to pesticides. This article will present a brief description of an ongoing study of insecticide exposure and paraoxonase-1 (PON-1) genotype in banana plantation workers in Chinandega, Nicaragua. We will then discuss the enzyme PON-1 and its potential role in organophosphate insecticide metabolism and toxicity.
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Affiliation(s)
- Andre R Matthews
- US Centers for Disease Control and Prevention, Division of Environmental Health and Hazard Effects, Health Studies Branch, National Center for Environmental Health, Atlanta, GA, USA
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16
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Silveyra MX, García-Ayllón MS, Serra-Basante C, Mazzoni V, García-Gutierrez MS, Manzanares J, Culvenor JG, Sáez-Valero J. Changes in acetylcholinesterase expression are associated with altered presenilin-1 levels. Neurobiol Aging 2011; 33:627.e27-37. [PMID: 21621296 DOI: 10.1016/j.neurobiolaging.2011.04.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2010] [Revised: 02/10/2011] [Accepted: 04/02/2011] [Indexed: 12/21/2022]
Abstract
We have previously identified presenilin-1 (PS1), the active component of the γ-secretase complex, as an interacting protein of the amyloid-associated enzyme acetylcholinesterase (AChE). In this study, we have explored the consequences of AChE-PS1 interactions. Treatment of SH-SY5Y cells with the AChE-inhibitor tacrine decreased PS1 levels, in parallel with increase in the secretion of amyloid precursor protein APPα, whereas the cholinergic agonist carbachol had no effect on PS1. AChE knockdown with siRNA also decreased PS1 levels, while AChE overexpression exerted opposing effect. AChE-deficient also had decreased PS1. Mice administered with tacrine or donepezil displayed lower levels of brain PS1. However, sustained AChE inhibition failed to exert long-term effect on PS1. This limited duration of response may be due to AChE upregulation caused by chronic inhibition. Finally, we exposed SH-SY5Y cells to β-amyloid (Aβ)42 which triggered elevation of both AChE and PS1 levels. The Aβ42-induced PS1 increase was abolished by siRNA AChE pretreatment, suggesting that AChE may participate in the pathological feedback loop between PS1 and Aβ. Our results provide insight into AChE-amyloid interrelationships.
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Affiliation(s)
- María-Ximena Silveyra
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-CSIC, Sant Joan d'Alacant, Alicante, Spain
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Effects of physostigmine on microcirculatory alterations during experimental endotoxemia. Shock 2011; 35:537-8; author reply 538. [PMID: 21499071 DOI: 10.1097/shk.0b013e318207dd20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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18
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Berg RMG, Ofek K, Qvist T, Tofteng F, Soreq H, Møller K. Cholinesterase modulations in patients with acute bacterial meningitis. Scandinavian Journal of Clinical and Laboratory Investigation 2011; 71:350-2. [PMID: 21303225 DOI: 10.3109/00365513.2011.558107] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
BACKGROUND The circulating cholinesterases acetyl- and butyrylcholinesterase may be suppressed and subsequently released from the brain in acute bacterial meningitis. METHODS We report serum activities of acetylcholinesterase and butyrylcholinesterase in paired arterial and jugular venous samples from seven patients with acute bacterial meningitis and eight healthy controls. Paraoxonase 1, which protects these enzymes from oxidative inactivation, was also measured. FINDINGS AND CONCLUSION Acetyl- and butyrylcholinesterase activities were lower in patients, independently of changes in paraoxonase 1. Arterial and jugular venous enzyme activities were similar both in patients and controls, suggesting that no cerebral release was present.
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Biochemical, environmental, and genetic factors associated with paraoxonase (PON1) activity. Biochem Genet 2011; 49:364-8. [PMID: 21258965 DOI: 10.1007/s10528-010-9413-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2010] [Accepted: 09/28/2010] [Indexed: 10/18/2022]
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Jonathan C, Shani ST, Nir W, Reut Y, Einor BA, Shlomo B, Hermona S. Serum AChE Activities Predict Exercise Heart Rate Parameters of Asymptomatic Individuals. ACTA ACUST UNITED AC 2010. [DOI: 10.4236/nm.2010.12007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Leduc V, Théroux L, Dea D, Robitaille Y, Poirier J. Involvement of paraoxonase 1 genetic variants in Alzheimer’s disease neuropathology. Eur J Neurosci 2009; 30:1823-30. [DOI: 10.1111/j.1460-9568.2009.06983.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Ginsberg G, Neafsey P, Hattis D, Guyton KZ, Johns DO, Sonawane B. Genetic polymorphism in paraoxonase 1 (PON1): Population distribution of PON1 activity. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART B, CRITICAL REVIEWS 2009; 12:473-507. [PMID: 20183530 DOI: 10.1080/10937400903158409] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Paraoxonase-1 (PON1) is a serum esterase that hydrolyzes the activated oxon form of several organophosphates. The central role of PON1 in detoxification of organophosphate (OP) pesticides was demonstrated in knockout mouse studies, suggesting that human variability in PON1 needs to be considered in health risk assessments involving exposure to these pesticides. The current analysis focused on two genetic loci in which polymorphisms demonstrated to affect PON1 activity. Detailed kinetic studies and population studies found that the *192Q (wild type) allele is more active toward some substrates (such as sarin, soman, and diazoxon) and less active toward others (such as paraoxon or chlorpyrifos) relative to the variant *192R allele. Another allele that affects activity is *55M; PON1 enzyme quantity, rather than specific activity or substrate preference, is altered. The *192R variant occurs commonly with a frequency of 25-64% across the populations analyzed. The *55M allele is less common, occurring in 5-40% of individuals depending upon the ethnic group studied. These activity and allele frequency data were incorporated into Monte Carlo simulations in which the frequency of both variant alleles was simultaneously modeled in Caucasian, African American, and Japanese populations. The resulting Monte Carlo activity distributions were bimodal for the substrate paraoxon with approximately fourfold differences between low- and high-activity modal medians. Differences in activity between total population median and 1st percentile were five- to sixfold. When sarin metabolic variability was simulated, the population distributions were unimodal. However, there was an even greater degree of interindividual variability (median to 1st percentile difference >20-fold). These results show that the combined effects of two PON1 allelic variants yielded a population distribution that is associated with a considerable degree of interindividual variability in enzyme activity. This indicates that assessments involving PON1 substrates need to evaluate polymorphism-related variability in enzyme activity to display the distribution of internal doses and adverse responses. This may best be achieved via physiologically based pharmacokinetic (PBPK) models that input PON1 activity distributions, such as those generated in this analysis, to simulate the range of oxon internal doses possible across the population.
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Affiliation(s)
- Gary Ginsberg
- Connecticut Department of Public Health, Hartford, 06134, USA.
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Beseler CL, Stallones L, Hoppin JA, Alavanja MCR, Blair A, Keefe T, Kamel F. Depression and pesticide exposures among private pesticide applicators enrolled in the Agricultural Health Study. ENVIRONMENTAL HEALTH PERSPECTIVES 2008; 116:1713-9. [PMID: 19079725 PMCID: PMC2599768 DOI: 10.1289/ehp.11091] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2007] [Accepted: 09/09/2008] [Indexed: 05/03/2023]
Abstract
BACKGROUND We evaluated the relationship between diagnosed depression and pesticide exposure using information from private pesticide applicators enrolled in the Agricultural Health Study between 1993 and 1997 in Iowa and North Carolina. METHODS There were 534 cases who self-reported a physician-diagnosed depression and 17,051 controls who reported never having been diagnosed with depression and did not feel depressed more than once a week in the past year. Lifetime pesticide exposure was categorized in three mutually exclusive groups: low (< 226 days, the reference group), intermediate (226-752 days), and high (> 752 days). Two additional measures represented acute high-intensity pesticide exposures: an unusually high pesticide exposure event (HPEE) and physician-diagnosed pesticide poisoning. Logistic regression analyses were performed relating pesticide exposure to depression. RESULTS After adjusting for state, age, education, marital status, doctor visits, alcohol use, smoking, solvent exposure, not currently having crops or animals, and ever working a job off the farm, pesticide poisoning was more strongly associated with depression [odds ratio (OR) = 2.57; 95% confidence interval (CI), 1.74-3.79] than intermediate (OR = 1.07; 95% CI, 0.87-1.31) or high (OR = 1.11; 95% CI, 0.87-1.42) cumulative exposure or an HPEE (OR = 1.65; 95% CI, 1.33-2.05). In analysis of a subgroup without a history of acute poisoning, high cumulative exposure was significantly associated with depression (OR = 1.54; 95% CI, 1.16-2.04). CONCLUSION These findings suggest that both acute high-intensity and cumulative pesticide exposure may contribute to depression in pesticide applicators. Our study is unique in reporting that depression is also associated with chronic pesticide exposure in the absence of a physician-diagnosed poisoning.
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Affiliation(s)
- Cheryl L Beseler
- Colorado Injury Control Research Center, Department of Psychology, Colorado State University, Fort Collins, CO, USA.
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Shaked I, Zimmerman G, Soreq H. Stress-induced Alternative Splicing Modulations in Brain and Periphery. Ann N Y Acad Sci 2008; 1148:269-81. [DOI: 10.1196/annals.1410.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Venkatesh S, Zachariah A, Oommen A. Myofibril Membranes in Relation to the Neuromuscular Weakness of Acute Monocrotophos Poisoning. Toxicol Mech Methods 2008; 16:419-26. [DOI: 10.1080/15376520600685813] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Leduc V, Poirier J. Polymorphisms at the paraoxonase 1 L55M and Q192R loci affect the pathophysiology of Alzheimer's disease: emphasis on the cholinergic system and beta-amyloid levels. NEURODEGENER DIS 2008; 5:225-7. [PMID: 18322397 DOI: 10.1159/000113709] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Paraoxonase 1 (PON1) functions to protect the cholinergic system against nerve gases and the organophosphate family of pesticides. Recent studies have shown that polymorphisms at the PON1 L55M and Q192R loci might affect individual susceptibility to experience-derived and environmental events such as the exposure to inhibitors of cholinesterase (ChEIs). OBJECTIVE ChEI therapy being the treatment of choice for mild-to-moderate Alzheimer's disease (AD) patients, we determined whether genetic variations in the PON1 loci are associated with AD risk and whether they affect brain choline acetyltransferase (CHAT) activity, nicotinic receptor density, and beta-amyloid (Abeta) levels in different regions of AD and age-matched control subjects. METHODS This pilot genetic study used a small cohort of brains from autopsy-confirmed AD patients and age-matched controls from the Douglas Hospital Brain Bank, Quebec, Canada. RESULTS The frequency of the M55M genotype at the PON1 L55M locus was found to be significantly increased in AD patients relative to age-matched controls (p < 0.05). Significant associations were observed between the PON1 L55M and Q192R polymorphisms and frontal cortex Abeta levels as well as CHAT activity and nicotinic receptor density in the temporal cortex. CONCLUSIONS Our results suggest a prominent role for PON1 in the pathophysiology of common AD with a marked impact on the cholinergic system and Abeta levels in the brain.
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Affiliation(s)
- Valerie Leduc
- Douglas Mental Health University Institute, Verdun, Que., Canada
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Shapira-Lichter I, Beilin B, Ofek K, Bessler H, Gruberger M, Shavit Y, Seror D, Grinevich G, Posner E, Reichenberg A, Soreq H, Yirmiya R. Cytokines and cholinergic signals co-modulate surgical stress-induced changes in mood and memory. Brain Behav Immun 2008; 22:388-98. [PMID: 17959355 DOI: 10.1016/j.bbi.2007.09.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2007] [Revised: 09/11/2007] [Accepted: 09/13/2007] [Indexed: 11/30/2022] Open
Abstract
Inflammatory cytokines and the cholinergic system have been implicated in the effects of stressors on mood and memory; however, the underlying mechanisms involved and the potential interrelationships between these pathways remain unclear. To address these questions, we administered neuropsychological tests to 33 generally healthy surgery patients who donated blood samples several days prior to undergoing moderate surgery (baseline), on the morning of the surgery (i.e., a psychological stressor), and one day after surgery. Eighteen control subjects were similarly tested. Serum levels of inflammatory cytokines, acetylcholinesterase (AChE) activity, and the stressor-inducible AChE-R variant were measured. An elevation in anxiety levels, an increase in depressed mood, and a decline in declarative memory were observed on the morning of the surgery, prior to any medical intervention, and were exacerbated one day after surgery. The surgical stressor-induced elevated IL-1 beta levels, which contributed to the increased depressed mood and to the post-surgery increase in AChE-R expression. The latter increase, which was also predicted by pre-surgery AChE-R and post-surgery mood disturbances, was associated with exacerbated memory impairments induced by surgery. In addition, elevated levels of AChE-R on the morning of the surgery predicted the post-surgery elevation in IL-6 levels, which was associated with amelioration of the memory impairments induced by surgery. Taken together, these findings suggest that exposure to a surgical stressor induces a reciprocal up-regulation of AChE-R and pro-inflammatory cytokines, which are involved in regulating the surgery-induced mood and memory disturbances.
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Farchi N, Ofek K, Podoly E, Dong H, Xiang YY, Diamant S, Livnah O, Li J, Hochner B, Lu WY, Soreq H. Peripheral site acetylcholinesterase blockade induces RACK1-associated neuronal remodeling. NEURODEGENER DIS 2007; 4:171-84. [PMID: 17596712 DOI: 10.1159/000101842] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Peripheral anionic site (PAS) blockade of acetylcholinesterase (AChE) notably affects neuronal activity and cyto-architecture, however, the mechanism(s) involved are incompletely understood. OBJECTIVE We wished to specify the PAS extracellular effects on specific AChE mRNA splice variants, delineate the consequent cellular remodeling events, and explore the inhibitory effects on interchanging RACK1 interactions. METHODS We exposed rat hippocampal cultured neurons to BW284C51, the peripheral anionic site inhibitor of AChE, and to the non-selective AChE active site inhibitor, physostigmine for studying the neuronal remodeling of AChE mRNA expression and trafficking. RESULTS BW284C51 induced overexpression of both AChE splice variants, yet promoted neuritic translocation of the normally rare AChE-R, and retraction of AChE-S mRNA in an antisense-suppressible manner. BW284C51 further caused modest decreases in the expression of the scaffold protein RACK1 (receptor for activated protein kinase betaII), followed by drastic neurite retraction of both RACK1 and the AChE homologue neuroligin1, but not the tubulin-associated MAP2 protein. Accompanying BW284C51 effects involved decreases in the Fyn kinase and membrane insertion of the glutamate receptor NR2B variant and impaired glutamatergic activities of treated cells. Intriguingly, molecular modeling suggested that direct, non-catalytic competition with Fyn binding by the RACK1-interacting AChE-R variant may be involved. CONCLUSIONS Our findings highlight complex neuronal AChE-R/RACK1 interactions and are compatible with the hypothesis that peripheral site AChE inhibitors induce RACK1-mediated neuronal remodeling, promoting suppressed glutamatergic neurotransmission.
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MESH Headings
- Acetylcholinesterase/genetics
- Acetylcholinesterase/metabolism
- Alternative Splicing
- Animals
- Benzenaminium, 4,4'-(3-oxo-1,5-pentanediyl)bis(N,N-dimethyl-N-2-propenyl-), Dibromide/pharmacology
- Cells, Cultured
- Cholinesterase Inhibitors/pharmacology
- Cricetinae
- Cricetulus
- Embryo, Mammalian
- Excitatory Postsynaptic Potentials/drug effects
- Excitatory Postsynaptic Potentials/physiology
- Excitatory Postsynaptic Potentials/radiation effects
- Gene Expression Regulation, Enzymologic/drug effects
- Hippocampus/cytology
- Models, Molecular
- Nerve Tissue Proteins/metabolism
- Neurons/cytology
- Neurons/drug effects
- Neurons/physiology
- Patch-Clamp Techniques/methods
- Physostigmine/pharmacology
- RNA, Messenger/biosynthesis
- Rats
- Receptors for Activated C Kinase
- Receptors, Cell Surface/metabolism
- Receptors, Glutamate/drug effects
- Receptors, Glutamate/metabolism
- Reverse Transcriptase Polymerase Chain Reaction/methods
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Affiliation(s)
- Noa Farchi
- Department of Neurobiology, Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
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30
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Sirivarasai J, Kaojarern S, Yoovathaworn K, Sura T. Paraoxonase (PON1) polymorphism and activity as the determinants of sensitivity to organophosphates in human subjects. Chem Biol Interact 2007; 168:184-92. [PMID: 17532308 DOI: 10.1016/j.cbi.2007.04.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2007] [Revised: 04/12/2007] [Accepted: 04/12/2007] [Indexed: 10/23/2022]
Abstract
Paraoxonase (PON1) plays an important role in mechanism of organophosphorus compound (OP) toxicity, as seen both in vitro and in vivo studies. Polymorphisms of PON1 gene at coding and promoter regions have also been to affect on the hydrolytic activity and PON1 level. The objectives of this study were to determine PON1 polymorphism and activity in an OP-exposed population and the effects on inhibition of cholinesterase activity. The studied population consisted of control (n=30) and exposed groups (n=90). All enzyme activities (AChE, BuChE, paraoxonase, arylesterase and diazonase) were measured once for control group and two periods of exposure for exposed group. Three polymorphisms of PON1 (Q192R, L55M and T-108C) were identified only in the exposed subjects. The results demonstrated that AChE activity in both high (345.5 microkat/gHb) and low exposure periods (496.9 microkat/gHb) of the exposed group were significantly different from control group (649.7 microkat/gHb, p<0.01). For BuChE activity, the exposed group also showed the statistically lower level in both periods (high exposure period: 62.17 microkat/L and low exposure period: 81.84 microkat/L) than those in the control group (93.35 microkat/L). Serum paraoxonase activity was significantly different among individual genotypes, RR>QR>RR, LL>LM and -108CC>-108CT>-108TT, but this was not found for those of arylesterase and diazonase activities. Q192R and L55M as well as Q192R and T-108C also presented substantial linkage disequilibrium. Further analysis was performed with haplotypes and various enzyme activities. AChE activity was not affected by haplotypes. Individuals with "211" haplotype showed significantly higher paraoxonase activity and BuChE activity than other haplotypes but not in diazonase activity. In conclusion, PON1 gene exhibited a wide variation in enzyme activities both within and between genotypes which implied insights of a potentially difference in sensitivity to OP toxicity.
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Affiliation(s)
- Jintana Sirivarasai
- Division of Clinical Pharmacology and Toxicology, Department of Medicine, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok 10400, Thailand.
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31
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Evron T, Moyal-Segal LB, Lamm N, Geffen A, Soreq H. RNA-targeted suppression of stress-induced allostasis in primate spinal cord neurons. NEURODEGENER DIS 2006; 2:16-27. [PMID: 16908999 DOI: 10.1159/000086427] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2005] [Accepted: 04/21/2005] [Indexed: 01/01/2023] Open
Abstract
Peripheral acetylcholine levels notably control the synthesis in macrophages of pro-inflammatory cytokines; however, it remains unclear whether this peripheral regulatory pathway affects central nervous system neurons. To explore the interrelationship between neuronal cholinergic homeostasis and peripheral inflammatory responses in primates, we used spinal cord sections from cynomolgus monkeys after 7 days oral or intravenous treatment with Monarsen oligonucleotide. Monarsen is an antisense oligonucleotide 3'-protected by 2'-oxymethylation, which was proved to induce selective destruction of the stress-induced acetylcholinesterase splice variant AChE-R mRNA. Handling stress predictably suppressed neuronal choline acetyl transferase (ChAT) and the vesicular acetylcholine transporter (VAChT) in all treated monkeys. In Monarsen-treated animals, we further observed suppression of stress-induced increases in plasma AChE activities. Corresponding decreases in AChE-R mRNA were seen in spinal cord neurons, associated with parallel decline patterns in the mRNA encoding for the splice factor SC35 (the levels of which co-increase with those of AChE-R) as well as in the neuronal pro-inflammatory interleukins IL-1beta and IL-6. The antisense effects showed direct dose dependence and were inversely associated with neuronal cell size. These findings suggest a causal association between neuronal cholinergic allostasis and inflammatory reactions in primates and support the peripheral use of RNA-targeted intervention with AChE-R accumulation for the management of both stress and inflammatory responses.
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Affiliation(s)
- Tama Evron
- Department of Biological Chemistry, Institute of Life Sciences, and the Israel Center of Neuronal Computation, The Hebrew University of Jerusalem, Jerusalem, Israel
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32
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Wolff MS. Endocrine Disruptors: Challenges for Environmental Research in the 21st Century. Ann N Y Acad Sci 2006; 1076:228-38. [PMID: 17119205 DOI: 10.1196/annals.1371.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
During the past 10 years, there has been a worldwide decline in the use and human exposure to many chemicals, including pesticides and persistent organic pollutants (POPs). However, a new generation of chemicals that have endocrine disrupting (ED) potential have emerged. Their presence in the environment and concomitant levels in humans are prevalent, although the sources of these contemporary-use industrial chemicals are not entirely identified. They include the phthalates, alkylphenols, brominated diphenyl ethers, and perfluorinated organics (PFOCs). The alkylphenols, especially bisphenol A, are potent EDs. Levels vary by geography, race/ethnicity, age and gender, and human health effects are just beginning to be assessed. This article discusses the toxicology, human exposure, and potential health effects of EDs that are likely to be important in the 21st century.
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Affiliation(s)
- Mary S Wolff
- Department of Community and Preventive Medicine, Mount Sinai School of Medicine, New York, NY 10029, USA.
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33
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Abstract
Much has been learned in recent years about the genetics of familial Parkinson's disease. However, far less is known about those malfunctioning genes which contribute to the emergence and/or progression of the vast majority of cases, the 'sporadic Parkinson's disease', which is the focus of our current review. Drastic differences in the reported prevalence of Parkinson's disease in different continents and countries suggest ethnic and/or environmental-associated multigenic contributions to this disease. Numerous association studies showing variable involvement of multiple tested genes in these distinct locations support this notion. Also, variable increases in the risk of Parkinson's disease due to exposure to agricultural insecticides indicate complex gene-environment interactions, especially when genes involved in protection from oxidative stress are explored. Further consideration of the brain regions damaged in Parkinson's disease points at the age-vulnerable cholinergic-dopaminergic balance as being involved in the emergence of sporadic Parkinson's disease in general and in the exposure-induced risks in particular. More specifically, the chromosome 7 ACHE/PON1 locus emerges as a key region controlling this sensitive balance, and animal model experiments are compatible with this concept. Future progress in the understanding of the genetics of sporadic Parkinson's disease depends on globally coordinated, multileveled studies of gene-environment interactions.
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Affiliation(s)
- Liat Benmoyal-Segal
- Department of Biological Chemistry, The Life Sciences Institute, Jerusalem, Israel
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34
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Browne RO, Moyal-Segal LB, Zumsteg D, David Y, Kofman O, Berger A, Soreq H, Friedman A. Coding region paraoxonase polymorphisms dictate accentuated neuronal reactions in chronic, sub-threshold pesticide exposure. FASEB J 2006; 20:1733-5. [PMID: 16807370 DOI: 10.1096/fj.05-5576fje] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Organophosphate pesticides (OPs), known inhibitors of acetylcholinesterase (AChE), are used extensively throughout the world. Recent studies have focused on the ACHE/PON1 locus as a determinant of inherited susceptibility to environmental OP exposure. To explore the relationship of the corresponding gene-environment interactions with brain activity, we integrated neurophysiologic, neuropsychological, biochemical, and genetic methods. Importantly, we found that subthreshold OP exposure leads to discernible physiological consequences that are significantly influenced by inherited factors. Cortical EEG analyses by LORETA revealed significantly decreased theta activity in the hippocampus, parahippocampal regions, and the cingulate cortex, as well as increased beta activity in the prefrontal cortex of exposed individuals-areas known to play a role in cholinergic-associated cognitive functions. Through neuropsychological testing, we identified an appreciable deficit in the visual recall in exposed individuals. Other neuropsychological tests revealed no significant differences between exposed and non-exposed individuals, attesting to the specificity of our findings. Biochemical analyses of blood samples revealed increases in paraoxonase and arylesterase activities and reduced serum acetylcholinesterase activity in chronically exposed individuals. Notably, specific paraoxonase genotypes were found to be associated with these exposure-related changes in blood enzyme activities and abnormal EEG patterns. Thus, gene-environment interactions involving the ACHE/PON1 locus may be causally involved in determining the physiological response to OP exposure.
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Affiliation(s)
- R Orie Browne
- Department of Physiology, Soroka University Medical Center, The Hebrew University of Jerusalem, Jerusalem, Israel
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35
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Zimmerman G, Soreq H. Termination and beyond: acetylcholinesterase as a modulator of synaptic transmission. Cell Tissue Res 2006; 326:655-69. [PMID: 16802134 DOI: 10.1007/s00441-006-0239-8] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2006] [Accepted: 05/05/2006] [Indexed: 11/28/2022]
Abstract
Termination of synaptic transmission by neurotransmitter hydrolysis is a substantial characteristic of cholinergic synapses. This unique termination mechanism makes acetylcholinesterase (AChE), the enzyme in charge of executing acetylcholine breakdown, a key component of cholinergic signaling. AChE is now known to exist not as a single entity, but rather as a combinatorial complex of protein products. The diverse AChE molecular forms are generated by a single gene that produces over ten different transcripts by alternative splicing and alternative promoter choices. These transcripts are translated into six different protein subunits. Mature AChE proteins are found as soluble monomers, amphipatic dimers, or tetramers of these subunits and become associated to the cellular membrane by specialized anchoring molecules or members of other heteromeric structural components. A substantial increasing body of research indicates that AChE functions in the central nervous system go far beyond the termination of synaptic transmission. The non-enzymatic neuromodulatory functions of AChE affect neurite outgrowth and synaptogenesis and play a major role in memory formation and stress responses. The structural homology between AChE and cell adhesion proteins, together with the recently discovered protein partners of AChE, predict the future unraveling of the molecular pathways underlying these multileveled functions.
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Affiliation(s)
- Gabriel Zimmerman
- The Institute of Life Sciences and the Interdisciplinary Center for Neural Computation (ICNC), The Hebrew University of Jerusalem, Jerusalem 91904, Israel
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36
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Meshorer E, Soreq H. Virtues and woes of AChE alternative splicing in stress-related neuropathologies. Trends Neurosci 2006; 29:216-24. [PMID: 16516310 DOI: 10.1016/j.tins.2006.02.005] [Citation(s) in RCA: 141] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2005] [Revised: 01/18/2006] [Accepted: 02/14/2006] [Indexed: 12/15/2022]
Abstract
The ACh hydrolyzing enzyme acetylcholinesterase (AChE) is a combinatorial series of proteins with variant N and C termini generated from alternate promoter usage and 3' alternative splicing. Neuronal AChE variants show indistinguishable enzymatic activity yet differ in their expression, multimeric assembly and membrane-association patterns. Differentially induced under stress, they show distinct non-hydrolytic properties and interact with different protein partners. Recent findings suggest that transcriptional and post-transcriptional regulation of AChE pre-mRNA is a neuroprotection strategy but might involve long-term damage. Specifically, variant-specific causal involvement of AChE in the progression of both neurodegenerative diseases (e.g. Alzheimer's and Parkinson's diseases) and neuromuscular syndromes (e.g. myasthenia gravis) raises the possibility that future therapeutic drugs might target specific AChE variant(s) or the corresponding RNA transcripts.
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Affiliation(s)
- Eran Meshorer
- National Cancer Institute, National Institutes of Health, Building 41, 41 Library Drive, Bethesda, MD 20892, USA.
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