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Mudyanselage AW, Wijamunige BC, Kocon A, Carter WG. Differentiated Neurons Are More Vulnerable to Organophosphate and Carbamate Neurotoxicity than Undifferentiated Neurons Due to the Induction of Redox Stress and Accumulate Oxidatively-Damaged Proteins. Brain Sci 2023; 13:brainsci13050728. [PMID: 37239200 DOI: 10.3390/brainsci13050728] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 04/21/2023] [Accepted: 04/25/2023] [Indexed: 05/28/2023] Open
Abstract
Organophosphate (OP) and carbamate pesticides are toxic to pests through targeted inhibition of acetylcholinesterase (AChE). However, OPs and carbamates may be harmful to non-target species including humans and could induce developmental neurotoxicity if differentiated or differentiating neurons are particularly vulnerable to neurotoxicant exposures. Hence, this study compared the neurotoxicity of OPs, chlorpyrifos-oxon (CPO), and azamethiphos (AZO) and the carbamate pesticide, aldicarb, to undifferentiated versus differentiated SH-SY5Y neuroblastoma cells. OP and carbamate concentration-response curves for cell viability were undertaken using 3-(4,5 dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assays and cellular bioenergetic capacity assessed via quantitation of cellular ATP levels. Concentration-response curves for inhibition of cellular AChE activity were also generated and the production of reactive oxygen species (ROS) was monitored using a 2',7'-dichlorofluorescein diacetate (DCFDA) assay. The OPs and aldicarb reduced cell viability, cellular ATP levels, and neurite outgrowth in a concentration-dependent fashion, from a threshold concentration of ≥10 µM. Neurotoxic potency was in the order AZO > CPO > aldicarb for undifferentiated cells but CPO > AZO > aldicarb for differentiated cells and this toxic potency of CPO reflected its more extensive induction of reactive oxygen species (ROS) and generation of carbonylated proteins that were characterized by western blotting. Hence, the relative neurotoxicity of the OPs and aldicarb in part reflects non-cholinergic mechanisms that are likely to contribute to developmental neurotoxicity.
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Affiliation(s)
- Anusha W Mudyanselage
- School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Uttoxeter Road, Derby DE22 3DT, UK
- Faculty of Agricultural Sciences, Sabaragamuwa University of Sri Lanka, Belihuloya 70140, Sri Lanka
| | - Buddhika C Wijamunige
- School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Uttoxeter Road, Derby DE22 3DT, UK
- Faculty of Agricultural Sciences, Sabaragamuwa University of Sri Lanka, Belihuloya 70140, Sri Lanka
| | - Artur Kocon
- School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Uttoxeter Road, Derby DE22 3DT, UK
| | - Wayne G Carter
- School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Uttoxeter Road, Derby DE22 3DT, UK
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Elmorsy E, Al-Ghafari A, Al Doghaither H, Salama M, Carter WG. An Investigation of the Neurotoxic Effects of Malathion, Chlorpyrifos, and Paraquat to Different Brain Regions. Brain Sci 2022; 12:brainsci12080975. [PMID: 35892416 PMCID: PMC9394375 DOI: 10.3390/brainsci12080975] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 07/16/2022] [Accepted: 07/21/2022] [Indexed: 02/04/2023] Open
Abstract
Acute or chronic exposures to pesticides have been linked to neurotoxicity and the potential development of neurodegenerative diseases (NDDs). This study aimed to consider the neurotoxicity of three widely utilized pesticides: malathion, chlorpyrifos, and paraquat within the hippocampus (HC), corpus striatum (CS), cerebellum (CER), and cerebral cortex (CC). Neurotoxicity was evaluated at relatively low, medium, and high pesticide dosages. All pesticides inhibited acetylcholinesterase (AChE) and neuropathy target esterase (NTE) in each of the brain regions, but esterase inhibition was greatest in the HC and CS. Each of the pesticides also induced greater disruption to cellular bioenergetics within the HC and CS, and this was monitored via inhibition of mitochondrial complex enzymes I and II, reduced ATP levels, and increased lactate production. Similarly, the HC and CS were more vulnerable to redox stress, with greater inhibition of the antioxidant enzymes catalase and superoxide dismutase and increased lipid peroxidation. All pesticides induced the production of nuclear Nrf2 in a dose-dependent manner. Collectively, these results show that pesticides disrupt cellular bioenergetics and that the HC and CS are more susceptible to pesticide effects than the CER and CC.
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Affiliation(s)
- Ekramy Elmorsy
- Department of Forensic Medicine and Clinical Toxicology, Faculty of Medicine, Mansoura University, Mansoura 35516, Egypt; (E.E.); (M.S.)
- Pathology Department, Faculty of Medicine, Northern Border University, Arar 91431, Saudi Arabia
- School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Derby DE22 3DT, UK
| | - Ayat Al-Ghafari
- Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (A.A.-G.); (H.A.D.)
- Scientific Research Center, Dar Al-Hekma University, Jeddah 22246, Saudi Arabia
| | - Huda Al Doghaither
- Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (A.A.-G.); (H.A.D.)
- Cancer and Mutagenesis Unit, King Fahd Medical Research Centre, King Abdulaziz University, Jeddah 22252, Saudi Arabia
| | - Mohamed Salama
- Department of Forensic Medicine and Clinical Toxicology, Faculty of Medicine, Mansoura University, Mansoura 35516, Egypt; (E.E.); (M.S.)
- Institute of Global Health and Human Ecology, The American University in Cairo (AUC), Cairo 11385, Egypt
| | - Wayne G. Carter
- School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Derby DE22 3DT, UK
- Correspondence: ; Tel.: +44-132-724-738
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Nwidu LL, Alikwe PCN, Elmorsy E, Carter WG. An Investigation of Potential Sources of Nutraceuticals from the Niger Delta Areas, Nigeria for Attenuating Oxidative Stress. MEDICINES 2019; 6:medicines6010015. [PMID: 30669529 PMCID: PMC6473651 DOI: 10.3390/medicines6010015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 01/14/2019] [Accepted: 01/15/2019] [Indexed: 12/21/2022]
Abstract
Background: Diets rich in fruits, vegetables, and medicinal plants possess antioxidants potentially capable of mitigating cellular oxidative stress. This study investigated the antioxidant, anti-acetylcholinesterase (AChE), and total phenolic and flavonoids contents (TPC/TFC) of dietary sources traditionally used for memory enhancing in Niger Delta, Nigeria. Methods:Dacroydes edulis methanolic seed extract (DEMSE), Cola lepidota methanolic seed extract (CLMSE), Terminalia catappa methanolic seed extract (TeCMSE), Tricosanthes cucumerina methanolic seed extract (TrCMSE), Tetrapleura tetraptera methanolic seed extract (TTMSE), and defatted Moringa oleifera methanolic seed extract (DMOMSE); Dennettia tripetala methanolic fruit extract (DTMFE), Artocarpus communis methanolic fruit extract (ACMFE), Gnetum africana methanolic leaf extract (GAMLE), Musa paradisiaca methanolic stembark extract (MPMSE), and Mangifera indica methanolic stembark extract (MIMSE) were evaluated for free radical scavenging antioxidant ability using 2,2-Diphenyl-1-picrylhydrazyl (DPPH), reducing power capacity (reduction of ferric iron to ferrous iron), AChE inhibitory potential by Ellman assay, and then TPC/TFC contents determined by estimating milli-equivalents of Gallic acid and Quercetin per gram, respectively. Results: The radical scavenging percentages were as follows: MIMSE (58%), MPMSE (50%), TrCMSE (42%), GAMLE (40%), CLMSE (40%), DMOMSE (38%), and DEMFE (37%) relative to β-tocopherol (98%). The highest iron reducing (antioxidant) capacity was by TrCMSE (52%), MIMSE (40%) and GAMLE (38%). Extracts of MIMSE, TrCMSE, DTMFE, TTMSE, and CLMSE exhibited concentration-dependent AChE inhibitory activity (p < 0.05–0.001). At a concentration of 200 µg/mL, the AChE inhibitory activity and IC50 (µg/mL) exhibited by the most potent extracts were: MIMSE (≈50%/111.9), TrCMSE (≈47%/201.2), DTMFE (≈32%/529.9), TTMSE (≈26%/495.4), and CLMSE (≈25%/438.4). The highest TPC were from MIMSE (156.2), TrCMSE (132.65), GAMLE (123.26), and CLMSE (119.63) in mg gallic acid equivalents/g, and for TFC were: MISME (87.35), GAMLE (73.26), ACMFE (69.54), CLMSE (68.35), and TCMSE2 (64.34) mg quercetin equivalents/gram. Conclusions: The results suggest that certain inedible and edible foodstuffs, most notably MIMSE, MPMSE, TrCMSE, GAMLE, and CLMSE may be beneficial to ameliorate the potentially damaging effects of redox stress.
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Affiliation(s)
- Lucky Legbosi Nwidu
- Department of Experimental Pharmacology and Toxicology, Faculty of Pharmaceutical Sciences, University of Port Harcourt, Port Harcourt PMB 5323, Rivers State, Nigeria.
- School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Derby DE22 3DT, UK.
| | - Philip Cheriose Nzien Alikwe
- Department of Animal Science, Niger Delta University, Wilberforce Island, Yenegoa PMB 071, Bayelsa State, Nigeria.
| | - Ekramy Elmorsy
- School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Derby DE22 3DT, UK.
- Department of Forensic Medicine and Clinical Toxicology, Faculty of Medicine, Mansoura University, Mansoura 35516, Egypt.
| | - Wayne Grant Carter
- School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Derby DE22 3DT, UK.
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Fang S, Tao Y, Zhang Y, Kong F, Wang Y. Effects of metalaxyl enantiomers stress on root activity and leaf antioxidant enzyme activities in tobacco seedlings. Chirality 2018; 30:469-474. [PMID: 29334408 DOI: 10.1002/chir.22810] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2017] [Revised: 11/17/2017] [Accepted: 12/04/2017] [Indexed: 11/11/2022]
Abstract
The objective of this experiment was to study the effects of metalaxyl enantiomers on the activity of roots and antioxidative enzymes in tobacco seedlings. Water culture experiment was conducted to analyze the effects of different concentrations of metalaxyl enantiomers (30 and 10 mg L-1 ) on root activity and leaf superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activities and malondialdehyde (MDA) content of tobacco seedlings. The results showed that metalaxyl significantly inhibited root activity and significantly improved leaf SOD, POD, and CAT activities and MDA content. A better physiological response in tobacco seedlings was observed at 30 mg L-1 than at 10 mg L-1 metalaxyl. The stereoselectivity for different enantiomers had no obvious effect on root activity and the leaf POD activity, but it affected significantly the SOD and CAT activities and MDA content. The SOD activity was promoted more by R-enantiomer than by S-enantiomer at 30 mg L-1 metalaxyl, and the same effect was observed on CAT activity from the beginning to the end of the stress period. The MDA content under the stress by R-enantiomer was higher than that under the stress by S-enantiomer at 10 mg L-1 metalaxyl.
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Affiliation(s)
- Song Fang
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences & Laboratory of Risk Assessment for Tobacco Products (Qingdao), Ministry of Agriculture, Qingdao, Shandong, China
| | - Yi Tao
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences & Laboratory of Risk Assessment for Tobacco Products (Qingdao), Ministry of Agriculture, Qingdao, Shandong, China
| | - Yizhi Zhang
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences & Laboratory of Risk Assessment for Tobacco Products (Qingdao), Ministry of Agriculture, Qingdao, Shandong, China
| | - Fanyu Kong
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences & Laboratory of Risk Assessment for Tobacco Products (Qingdao), Ministry of Agriculture, Qingdao, Shandong, China
| | - Yunbai Wang
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences & Laboratory of Risk Assessment for Tobacco Products (Qingdao), Ministry of Agriculture, Qingdao, Shandong, China
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Kadar A, de Sousa G, Peyre L, Wortham H, Doumenq P, Rahmani R. Evidence of in vitro metabolic interaction effects of a chlorfenvinphos, ethion and linuron mixture on human hepatic detoxification rates. CHEMOSPHERE 2017; 181:666-674. [PMID: 28476006 DOI: 10.1016/j.chemosphere.2017.04.116] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 04/12/2017] [Accepted: 04/23/2017] [Indexed: 06/07/2023]
Abstract
General population exposure to pesticides mainly occurs via food and water consumption. However, their risk assessment for regulatory purposes does not currently consider the actual co-exposure to multiple substances. To address this concern, relevant experimental studies are needed to fill the lack of data concerning effects of mixture on human health. For the first time, the present work evaluated on human microsomes and liver cells the combined metabolic effects of, chlorfenvinphos, ethion and linuron, three pesticides usually found in vegetables of the European Union. Concentrations of these substances were measured during combined incubation experiments, thanks to a new analytical methodology previously developed. The collected data allowed for calculation and comparison of the intrinsic hepatic clearance of each pesticide from different combinations. Finally, the results showed clear inhibitory effects, depending on the association of the chemicals at stake. The major metabolic inhibitor observed was chlorfenvinphos. During co-incubation, it was able to decrease the intrinsic clearance of both linuron and ethion. These latter also showed a potential for metabolic inhibition mainly cytochrome P450-mediated in all cases. Here we demonstrated that human detoxification from a pesticide may be severely hampered in case of co-occurrence of other pesticides, as it is the case for drugs interactions, thus increasing the risk of adverse health effects. These results could contribute to improve the current challenging risk assessment of human and animal dietary to environmental chemical mixtures.
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Affiliation(s)
- Ali Kadar
- Aix Marseille Univ, CNRS, LCE, Marseille, France; INRA, UMR 1331 TOXALIM, Laboratoire de Toxicologie Cellulaire et Moléculaire des Xénobiotiques, BP 167, 400 Route des Chappes, 06903, Sophia Antipolis Cedex, France.
| | - Georges de Sousa
- INRA, UMR 1331 TOXALIM, Laboratoire de Toxicologie Cellulaire et Moléculaire des Xénobiotiques, BP 167, 400 Route des Chappes, 06903, Sophia Antipolis Cedex, France
| | - Ludovic Peyre
- INRA, UMR 1331 TOXALIM, Laboratoire de Toxicologie Cellulaire et Moléculaire des Xénobiotiques, BP 167, 400 Route des Chappes, 06903, Sophia Antipolis Cedex, France
| | | | | | - Roger Rahmani
- INRA, UMR 1331 TOXALIM, Laboratoire de Toxicologie Cellulaire et Moléculaire des Xénobiotiques, BP 167, 400 Route des Chappes, 06903, Sophia Antipolis Cedex, France
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6
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Carter WG, Vigneswara V, Newlaczyl A, Wayne D, Ahmed B, Saddington S, Brewer C, Raut N, Gerdes HK, Erdozain AM, Tooth D, Bolt EL, Osna NA, Tuma DJ, Kharbanda KK. Isoaspartate, carbamoyl phosphate synthase-1, and carbonic anhydrase-III as biomarkers of liver injury. Biochem Biophys Res Commun 2015; 458:626-631. [PMID: 25684186 PMCID: PMC4355035 DOI: 10.1016/j.bbrc.2015.01.158] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 01/28/2015] [Indexed: 02/08/2023]
Abstract
We had previously shown that alcohol consumption can induce cellular isoaspartate protein damage via an impairment of the activity of protein isoaspartyl methyltransferase (PIMT), an enzyme that triggers repair of isoaspartate protein damage. To further investigate the mechanism of isoaspartate accumulation, hepatocytes cultured from control or 4-week ethanol-fed rats were incubated in vitro with tubercidin or adenosine. Both these agents, known to elevate intracellular S-adenosylhomocysteine levels, increased cellular isoaspartate damage over that recorded following ethanol consumption in vivo. Increased isoaspartate damage was attenuated by treatment with betaine. To characterize isoaspartate-damaged proteins that accumulate after ethanol administration, rat liver cytosolic proteins were methylated using exogenous PIMT and (3)H-S-adenosylmethionine and proteins resolved by gel electrophoresis. Three major protein bands of ∼ 75-80 kDa, ∼ 95-100 kDa, and ∼ 155-160 kDa were identified by autoradiography. Column chromatography used to enrich isoaspartate-damaged proteins indicated that damaged proteins from ethanol-fed rats were similar to those that accrued in the livers of PIMT knockout (KO) mice. Carbamoyl phosphate synthase-1 (CPS-1) was partially purified and identified as the ∼ 160 kDa protein target of PIMT in ethanol-fed rats and in PIMT KO mice. Analysis of the liver proteome of 4-week ethanol-fed rats and PIMT KO mice demonstrated elevated cytosolic CPS-1 and betaine homocysteine S-methyltransferase-1 when compared to their respective controls, and a significant reduction of carbonic anhydrase-III (CA-III) evident only in ethanol-fed rats. Ethanol feeding of rats for 8 weeks resulted in a larger (∼ 2.3-fold) increase in CPS-1 levels compared to 4-week ethanol feeding indicating that CPS-1 accumulation correlated with the duration of ethanol consumption. Collectively, our results suggest that elevated isoaspartate and CPS-1, and reduced CA-III levels could serve as biomarkers of hepatocellular injury.
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Affiliation(s)
- Wayne G Carter
- School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Derby, DE22 3DT, UK.
| | - Vasanthy Vigneswara
- School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Derby, DE22 3DT, UK
| | - Anna Newlaczyl
- School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Derby, DE22 3DT, UK
| | - Declan Wayne
- School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Derby, DE22 3DT, UK
| | - Bilal Ahmed
- School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Derby, DE22 3DT, UK
| | - Stephen Saddington
- School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Derby, DE22 3DT, UK
| | - Charlotte Brewer
- School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Derby, DE22 3DT, UK
| | - Nikhilesh Raut
- School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Derby, DE22 3DT, UK
| | - Henry K Gerdes
- School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Derby, DE22 3DT, UK
| | - Amaia M Erdozain
- School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Derby, DE22 3DT, UK; Department of Pharmacology, University of the Basque Country, and Centro de Investigación Biomédica en Red de Salud Mental, Spain
| | - David Tooth
- School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham, UK
| | - Edward L Bolt
- School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham, UK
| | - Natalie A Osna
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, NE, USA; Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, USA; Department of Biochemistry, University of Nebraska Medical Center, Omaha, NE, USA
| | - Dean J Tuma
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, NE, USA; Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, USA; Department of Biochemistry, University of Nebraska Medical Center, Omaha, NE, USA
| | - Kusum K Kharbanda
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, NE, USA; Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, USA; Department of Biochemistry, University of Nebraska Medical Center, Omaha, NE, USA
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7
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Amaraneni SR, Kumar S, Gourinath S. Biophysical aspects of lysozyme adduct with monocrotophos. Anal Bioanal Chem 2014; 406:5477-85. [DOI: 10.1007/s00216-014-7953-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Revised: 05/20/2014] [Accepted: 06/05/2014] [Indexed: 01/03/2023]
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Erdozain AM, Morentin B, Bedford L, King E, Tooth D, Brewer C, Wayne D, Johnson L, Gerdes HK, Wigmore P, Callado LF, Carter WG. Alcohol-related brain damage in humans. PLoS One 2014; 9:e93586. [PMID: 24699688 PMCID: PMC3974765 DOI: 10.1371/journal.pone.0093586] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Accepted: 03/04/2014] [Indexed: 12/02/2022] Open
Abstract
Chronic excessive alcohol intoxications evoke cumulative damage to tissues and organs. We examined prefrontal cortex (Brodmann’s area (BA) 9) from 20 human alcoholics and 20 age, gender, and postmortem delay matched control subjects. H & E staining and light microscopy of prefrontal cortex tissue revealed a reduction in the levels of cytoskeleton surrounding the nuclei of cortical and subcortical neurons, and a disruption of subcortical neuron patterning in alcoholic subjects. BA 9 tissue homogenisation and one dimensional polyacrylamide gel electrophoresis (PAGE) proteomics of cytosolic proteins identified dramatic reductions in the protein levels of spectrin β II, and α- and β-tubulins in alcoholics, and these were validated and quantitated by Western blotting. We detected a significant increase in α-tubulin acetylation in alcoholics, a non-significant increase in isoaspartate protein damage, but a significant increase in protein isoaspartyl methyltransferase protein levels, the enzyme that triggers isoaspartate damage repair in vivo. There was also a significant reduction in proteasome activity in alcoholics. One dimensional PAGE of membrane-enriched fractions detected a reduction in β-spectrin protein levels, and a significant increase in transmembranous α3 (catalytic) subunit of the Na+,K+-ATPase in alcoholic subjects. However, control subjects retained stable oligomeric forms of α-subunit that were diminished in alcoholics. In alcoholics, significant loss of cytosolic α- and β-tubulins were also seen in caudate nucleus, hippocampus and cerebellum, but to different levels, indicative of brain regional susceptibility to alcohol-related damage. Collectively, these protein changes provide a molecular basis for some of the neuronal and behavioural abnormalities attributed to alcoholics.
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Affiliation(s)
- Amaia M. Erdozain
- School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Derby, United Kingdom
- Department of Pharmacology, University of the Basque Country, and Centro de Investigación Biomédica en Red de Salud Mental, Spain
| | - Benito Morentin
- Section of Forensic Pathology, Basque Institute of Legal Medicine, Bilbao, Spain
| | - Lynn Bedford
- School of Life Sciences, University of Nottingham, Queen’s Medical Centre, Nottingham, United Kingdom
| | - Emma King
- School of Life Sciences, University of Nottingham, Queen’s Medical Centre, Nottingham, United Kingdom
| | - David Tooth
- School of Life Sciences, University of Nottingham, Queen’s Medical Centre, Nottingham, United Kingdom
| | - Charlotte Brewer
- School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Derby, United Kingdom
| | - Declan Wayne
- School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Derby, United Kingdom
| | - Laura Johnson
- School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Derby, United Kingdom
| | - Henry K. Gerdes
- School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Derby, United Kingdom
| | - Peter Wigmore
- School of Life Sciences, University of Nottingham, Queen’s Medical Centre, Nottingham, United Kingdom
| | - Luis F. Callado
- Department of Pharmacology, University of the Basque Country, and Centro de Investigación Biomédica en Red de Salud Mental, Spain
| | - Wayne G. Carter
- School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Derby, United Kingdom
- * E-mail:
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9
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Vigneswara V, Cass S, Wayne D, Bolt EL, Ray DE, Carter WG. Molecular ageing of alpha- and Beta-synucleins: protein damage and repair mechanisms. PLoS One 2013; 8:e61442. [PMID: 23630590 PMCID: PMC3632608 DOI: 10.1371/journal.pone.0061442] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Accepted: 03/14/2013] [Indexed: 11/19/2022] Open
Abstract
Abnormal α-synuclein aggregates are hallmarks of a number of neurodegenerative diseases. Alpha synuclein and β-synucleins are susceptible to post-translational modification as isoaspartate protein damage, which is regulated in vivo by the action of the repair enzyme protein L-isoaspartyl O-methyltransferase (PIMT). We aged in vitro native α-synuclein, the α-synuclein familial mutants A30P and A53T that give rise to Parkinsonian phenotypes, and β-synuclein, at physiological pH and temperature for a time course of up to 20 days. Resolution of native α-synuclein and β-synuclein by two dimensional techniques showed the accumulation of a number of post-translationally modified forms of both proteins. The levels of isoaspartate formed over the 20 day time course were quantified by exogenous methylation with PIMT using S-Adenosyl-L-[3H-methyl]methionine as a methyl donor, and liquid scintillation counting of liberated 3H-methanol. All α-synuclein proteins accumulated isoaspartate at ∼1% of molecules/day, ∼20 times faster than for β-synuclein. This disparity between rates of isoaspartate was confirmed by exogenous methylation of synucleins by PIMT, protein resolution by one-dimensional denaturing gel electrophoresis, and visualisation of 3H-methyl esters by autoradiography. Protein silver staining and autoradiography also revealed that α-synucleins accumulated stable oligomers that were resistant to denaturing conditions, and which also contained isoaspartate. Co-incubation of approximately equimolar β-synuclein with α-synuclein resulted in a significant reduction of isoaspartate formed in all α-synucleins after 20 days of ageing. Co-incubated α- and β-synucleins, or α, or β synucleins alone, were resolved by non-denaturing size exclusion chromatography and all formed oligomers of ∼57.5 kDa; consistent with tetramerization. Direct association of α-synuclein with β-synuclein in column fractions or from in vitro ageing co-incubations was demonstrated by their co-immunoprecipitation. These results provide an insight into the molecular differences between α- and β-synucleins during ageing, and highlight the susceptibility of α-synuclein to protein damage, and the potential protective role of β-synuclein.
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Affiliation(s)
- Vasanthy Vigneswara
- School of Biomedical Sciences, The University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom
| | - Simon Cass
- School of Biomedical Sciences, The University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom
| | - Declan Wayne
- School of Graduate Entry Medicine and Health, University of Nottingham Medical School, Royal Derby Hospital, Derby, United Kingdom
| | - Edward L. Bolt
- School of Biomedical Sciences, The University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom
| | - David E. Ray
- School of Biomedical Sciences, The University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom
| | - Wayne G. Carter
- School of Graduate Entry Medicine and Health, University of Nottingham Medical School, Royal Derby Hospital, Derby, United Kingdom
- * E-mail:
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Tarhoni MH, Vigneswara V, Smith M, Anderson S, Wigmore P, Lees JE, Ray DE, Carter WG. Detection, quantification, and microlocalisation of targets of pesticides using microchannel plate autoradiographic imagers. Molecules 2011; 16:8535-51. [PMID: 21989313 PMCID: PMC6264342 DOI: 10.3390/molecules16108535] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Revised: 09/30/2011] [Accepted: 09/30/2011] [Indexed: 12/12/2022] Open
Abstract
Organophosphorus (OP) compounds are a diverse chemical group that includes nerve agents and pesticides. They share a common chemical signature that facilitates their binding and adduction of acetylcholinesterase (AChE) within nerve synapses to induce cholinergic toxicity. However, this group diversity results in non-uniform binding and inactivation of other secondary protein targets, some of which may be adducted and protein activity influenced, even when only a relatively minor portion of tissue AChE is inhibited. The determination of individual OP protein binding targets has been hampered by the sensitivity of methods of detection and quantification of protein-pesticide adducts. We have overcome this limitation by the employment of a microchannel plate (MCP) autoradiographic detector to monitor a radiolabelled OP tracer compound. We preincubated rat thymus tissue in vitro with the OP pesticides, azamethiphos-oxon, chlorfenvinphos-oxon, chlorpyrifos-oxon, diazinon-oxon, and malaoxon, and then subsequently radiolabelled the free OP binding sites remaining with 3H-diisopropylfluorophosphate (3H-DFP). Proteins adducted by OP pesticides were detected as a reduction in 3H-DFP radiolabelling after protein separation by one dimensional polyacrylamide gel electrophoresis and quantitative digital autoradiography using the MCP imager. Thymus tissue proteins of molecular weights -28 kDa, 59 kDa, 66 kDa, and 82 kDa displayed responsiveness to adduction by this panel of pesticides. The 59 kDa protein target (previously putatively identified as carboxylesterase I) was only significantly adducted by chlorfenvinphos-oxon (p < 0.001), chlorpyrifos-oxon (p < 0.0001), and diazinon-oxon (p < 0.01), the 66 kDa protein target (previously identified as serum albumin) similarly only adducted by the same three pesticides (p < 0.0001), (p < 0.001), and (p < 0.01), and the 82 kDa protein target (previously identified as acyl peptide hydrolase) only adducted by chlorpyrifos-oxon (p < 0.0001) and diazinon-oxon (p < 0.001), when the average values of tissue AChE inhibition were 30%, 35%, and 32% respectively. The -28 kDa protein target was shown to be heterogeneous in nature and was resolved to reveal nineteen 3H-DFP radiolabelled protein spots by two dimensional polyacrylamide gel electrophoresis and MCP autoradiography. Some of these 3H-DFP proteins spots were responsive to adduction by preincubation with chlorfenvinphos-oxon. In addition, we exploited the useful spatial resolution of the MCP imager (-70 mm) to determine pesticide micolocalisation in vivo, after animal dosing and autoradiography of brain tissue sections. Collectively, MCP autoradiographic imaging provided a means to detect targets of OP pesticides, quantify their sensitivity of adduction relative to tissue AChE inhibition, and highlighted that these common pesticides exhibit specific binding character to protein targets, and therefore their toxicity will need to be evaluated on an individual compound basis. In addition, MCP autoradiography afforded a useful method of visualisation of the localisation of a small radiolabelled tracer within brain tissue.
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Affiliation(s)
- Mabruka H. Tarhoni
- School of Biomedical Sciences, University of Nottingham, Queen’s Medical Centre, Nottingham, Nottinghamshire NG7 2UH, UK; (M.H.T.); (V.V.); (P.W.); (D.E.R.)
| | - Vasanthy Vigneswara
- School of Biomedical Sciences, University of Nottingham, Queen’s Medical Centre, Nottingham, Nottinghamshire NG7 2UH, UK; (M.H.T.); (V.V.); (P.W.); (D.E.R.)
| | - Marie Smith
- School of Graduate Entry Medicine & Health, University of Nottingham Medical School, Royal Derby Hospital, Uttoxeter Road, Derby DE22 3DT, UK; (M.S.); (S.A.)
| | - Susan Anderson
- School of Graduate Entry Medicine & Health, University of Nottingham Medical School, Royal Derby Hospital, Uttoxeter Road, Derby DE22 3DT, UK; (M.S.); (S.A.)
| | - Peter Wigmore
- School of Biomedical Sciences, University of Nottingham, Queen’s Medical Centre, Nottingham, Nottinghamshire NG7 2UH, UK; (M.H.T.); (V.V.); (P.W.); (D.E.R.)
| | - John E. Lees
- BioImaging Unit, Space Research Centre, Department of Physics & Astronomy, University of Leicester, Leicester, LE1 7RH, UK;
| | - David E. Ray
- School of Biomedical Sciences, University of Nottingham, Queen’s Medical Centre, Nottingham, Nottinghamshire NG7 2UH, UK; (M.H.T.); (V.V.); (P.W.); (D.E.R.)
| | - Wayne G. Carter
- School of Biomedical Sciences, University of Nottingham, Queen’s Medical Centre, Nottingham, Nottinghamshire NG7 2UH, UK; (M.H.T.); (V.V.); (P.W.); (D.E.R.)
- School of Graduate Entry Medicine & Health, University of Nottingham Medical School, Royal Derby Hospital, Uttoxeter Road, Derby DE22 3DT, UK; (M.S.); (S.A.)
- Author to whom correspondence should be addressed; ; Tel: +44-0-1332-724738; Fax: +44-0-1332-724626
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