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Scibetta S, Miceli M, Iuliano M, Stefanuto L, Carbone E, Piscopo P, Petrozza V, Romeo G, Mangino G, Calogero A, Gasperi T, Rosa P. In Vitro Evaluation of the Antioxidant Capacity of 3,3-Disubstituted-3H-benzofuran-2-one Derivatives in a Cellular Model of Neurodegeneration. Life (Basel) 2024; 14:422. [PMID: 38672695 PMCID: PMC11051253 DOI: 10.3390/life14040422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Revised: 03/18/2024] [Accepted: 03/19/2024] [Indexed: 04/28/2024] Open
Abstract
Oxidative stress represents a hallmark for many degenerative pathologies of the Central Nervous System. Throughout life, the constant pressure of noxious stimuli and/or episodes of traumatic events may expose the brain to a microenvironment where the non-balanced reactive oxygen species inevitably lead to neuronal loss and cognitive decline. HO-1, a 32 kDa heat-shock protein catalyzing the degradation of heme into carbon monoxide (CO), iron and biliverdin/bilirubin is considered one of the main antioxidant defense mechanisms playing pivotal roles in neuroprotection. Restoring the redox homeostasis is the goal of many natural or synthetic antioxidant molecules pursuing beneficial effects on brain functions. Here, we investigated the antioxidant capacity of four selected benzofuran-2-one derivatives in a cellular model of neurodegeneration represented by differentiated SH-SY5Y cells exposed to catechol-induced oxidative stress. Our main results highlight how all the molecules have antioxidant properties, especially compound 9, showing great abilities in reducing intracellular ROS levels and protecting differentiated SH-SY5Y cells from catechol-induced death. This compound above all seems to boost HO-1 mRNA and perinuclear HO-1 protein isoform expression when cells are exposed to the oxidative insult. Our findings open the way to consider benzofuran-2-ones as a novel and promising adjuvant antioxidant strategy for many neurodegenerative disorders.
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Affiliation(s)
- Sofia Scibetta
- Department of Medical-Surgical Sciences and Biotechnologies, University of Rome Sapienza, Polo Pontino, 04100 Latina, Italy; (S.S.); (M.I.); (V.P.); (G.R.); (G.M.); (A.C.)
| | - Martina Miceli
- Department of Science, University of Roma Tre, 00146 Rome, Italy; (M.M.); (L.S.)
| | - Marco Iuliano
- Department of Medical-Surgical Sciences and Biotechnologies, University of Rome Sapienza, Polo Pontino, 04100 Latina, Italy; (S.S.); (M.I.); (V.P.); (G.R.); (G.M.); (A.C.)
| | - Luca Stefanuto
- Department of Science, University of Roma Tre, 00146 Rome, Italy; (M.M.); (L.S.)
| | - Elena Carbone
- Department of Neuroscience, Italian National Institute of Health, 00161 Rome, Italy; (E.C.); (P.P.)
| | - Paola Piscopo
- Department of Neuroscience, Italian National Institute of Health, 00161 Rome, Italy; (E.C.); (P.P.)
| | - Vincenzo Petrozza
- Department of Medical-Surgical Sciences and Biotechnologies, University of Rome Sapienza, Polo Pontino, 04100 Latina, Italy; (S.S.); (M.I.); (V.P.); (G.R.); (G.M.); (A.C.)
- Istituto Chirurgico Ortopedico Traumatologico (ICOT), 04100 Latina, Italy
| | - Giovanna Romeo
- Department of Medical-Surgical Sciences and Biotechnologies, University of Rome Sapienza, Polo Pontino, 04100 Latina, Italy; (S.S.); (M.I.); (V.P.); (G.R.); (G.M.); (A.C.)
| | - Giorgio Mangino
- Department of Medical-Surgical Sciences and Biotechnologies, University of Rome Sapienza, Polo Pontino, 04100 Latina, Italy; (S.S.); (M.I.); (V.P.); (G.R.); (G.M.); (A.C.)
| | - Antonella Calogero
- Department of Medical-Surgical Sciences and Biotechnologies, University of Rome Sapienza, Polo Pontino, 04100 Latina, Italy; (S.S.); (M.I.); (V.P.); (G.R.); (G.M.); (A.C.)
- Istituto Chirurgico Ortopedico Traumatologico (ICOT), 04100 Latina, Italy
| | - Tecla Gasperi
- Department of Science, University of Roma Tre, 00146 Rome, Italy; (M.M.); (L.S.)
- National Institute of Biostructures and Biosystems (INBB), 00136 Rome, Italy
| | - Paolo Rosa
- Department of Medical-Surgical Sciences and Biotechnologies, University of Rome Sapienza, Polo Pontino, 04100 Latina, Italy; (S.S.); (M.I.); (V.P.); (G.R.); (G.M.); (A.C.)
- Istituto Chirurgico Ortopedico Traumatologico (ICOT), 04100 Latina, Italy
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Hamed M, Martyniuk CJ, Said REM, Soliman HAM, Badrey AEA, Hassan EA, Abdelhamid HN, Osman AGM, Sayed AEDH. Exposure to pyrogallol impacts the hemato-biochemical endpoints in catfish (Clarias gariepinus). ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 333:122074. [PMID: 37331582 DOI: 10.1016/j.envpol.2023.122074] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Revised: 06/13/2023] [Accepted: 06/16/2023] [Indexed: 06/20/2023]
Abstract
Pyrogallol is widely used in several industrial applications and can subsequently contaminate aquatic ecosystems. Here, we report for the first time the presence of pyrogallol in wastewater in Egypt. Currently, there is a complete lack of toxicity and carcinogenicity data for pyrogallol exposure in fish. To address this gap, both acute and sub-acute toxicity experiments were conducted to determine the toxicity of pyrogallol in catfish (Clarias gariepinus). Behavioral and morphological endpoints were evaluated, in addition to blood hematological endpoints, biochemical indices, electrolyte balance, and the erythron profile (poikilocytosis and nuclear abnormalities). In the acute toxicity assay, it was determined that the 96 h median-lethal concentration (96 h-LC50) of pyrogallol for catfish was 40 mg/L. In sub-acute toxicity experiment, fish divided into four groups; Group 1 was the control group. Group 2 was exposed to 1 mg/L of pyrogallol, Group 3 was exposed to 5 mg/L of pyrogallol, and Group 4 was exposed to 10 mg/L of pyrogallol. Fish showed morphological changes such as erosion of the dorsal and caudal fins, skin ulcers, and discoloration following exposure to pyrogallol for 96 h. Exposure to 1, 5, or 10 mg/L pyrogallol caused a significant decrease in hematological indices, including red blood cells (RBCs), hemoglobin, hematocrit, white blood cells (WBC), thrombocytes, and large and small lymphocytes in a dose-dependent manner. Several biochemical parameters (creatinine, uric acid, liver enzymes, lactate dehydrogenase, and glucose) were altered in a concentration dependent manner with short term exposures to pyrogallol. Pyrogallol exposure also caused a significant concentration-dependent rise in the percentage of poikilocytosis and nuclear abnormalities of RBCs in catfish. In conclusion, our data suggest that pyrogallol should be considered further in environmental risk assessments of aquatic species.
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Affiliation(s)
- Mohamed Hamed
- Department of Zoology, Faculty of Science, Al-Azhar University (Assiut Branch), Assiut, 71524, Egypt
| | - Christopher J Martyniuk
- Center for Environmental and Human Toxicology, Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, 32611, USA
| | - Rashad E M Said
- Department of Zoology, Faculty of Science, Al-Azhar University (Assiut Branch), Assiut, 71524, Egypt
| | - Hamdy A M Soliman
- Department of Zoology, Faculty of Science, Sohag University, Sohag, 8562, Egypt
| | - Ahmed E A Badrey
- Department of Zoology, Faculty of Science, Al-Azhar University (Assiut Branch), Assiut, 71524, Egypt
| | - Elhagag A Hassan
- Department of Botany and Microbiology, Faculty of Science, Assiut University, Assiut, 71516, Egypt
| | - Hani N Abdelhamid
- Advanced Multifunctional Materials Laboratory, Department of Chemistry, Assuit University, Assuit, 71515, Egypt; Nanotechnology Research Centre (NTRC), The British University in Egypt, El-Shorouk City, Suez Desert Road, P.O. Box 43, Cairo 11837, Egypt
| | - Alaa G M Osman
- Department of Zoology, Faculty of Science, Al-Azhar University (Assiut Branch), Assiut, 71524, Egypt
| | - Alaa El-Din H Sayed
- Department of Zoology, Faculty of Science, Assiut University, Assiut, 71516, Egypt; Molecular Biology Research & Studies Institute, Assiut University, 71516 Assiut, Egypt.
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Microglia Implicated in Tauopathy in the Striatum of Neurodegenerative Disease Patients from Genotype to Phenotype. Int J Mol Sci 2020; 21:ijms21176047. [PMID: 32842621 PMCID: PMC7503242 DOI: 10.3390/ijms21176047] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 08/19/2020] [Accepted: 08/20/2020] [Indexed: 12/12/2022] Open
Abstract
We found interactions between dopamine and oxidative damage in the striatum involved in advanced neurodegeneration, which probably change the microglial phenotype. We observed possible microglia dystrophy in the striatum of neurodegenerative brains. To investigate the interactions between oxidative damage and microglial phenotype, we quantified myeloperoxidase (MPO), poly (ADP-Ribose) (PAR), and triggering receptors expressed on myeloid cell 2 (TREM2) using enzyme-linked immunosorbent assay (ELISA). To test the correlations of microglia dystrophy and tauopathy, we quantified translocator protein (TSPO) and tau fibrils using autoradiography. We chose the caudate and putamen of Lewy body diseases (LBDs) (Parkinson’s disease, Parkinson’s disease dementia, and Dementia with Lewy body), Alzheimer’s disease (AD), and control brains and genotyped for TSPO, TREM2, and bridging integrator 1 (BIN1) genes using single nucleotide polymorphisms (SNP) assays. TREM2 gene variants were absent across all samples. However, associations between TSPO and BIN1 gene polymorphisms and TSPO, MPO, TREM2, and PAR level variations were found. PAR levels reduced significantly in the caudate of LBDs. TSPO density and tau fibrils decreased remarkably in the striatum of LBDs but increased in AD. Oxidative damage, induced by misfolded tau proteins and dopamine metabolism, causes microglia dystrophy or senescence during the late stage of LBDs. Consequently, microglia dysfunction conversely reduces tau propagation. The G allele of the BIN1 gene is a potential risk factor for tauopathy.
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Carregosa D, Carecho R, Figueira I, N Santos C. Low-Molecular Weight Metabolites from Polyphenols as Effectors for Attenuating Neuroinflammation. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:1790-1807. [PMID: 31241945 DOI: 10.1021/acs.jafc.9b02155] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Age-associated pathophysiological changes such as neurodegenerative diseases are multifactorial conditions with increasing incidence and no existing cure. The possibility of altering the progression and development of these multifactorial diseases through diet is an attractive approach with increasing supporting data. Epidemiological and clinical studies have highlighted the health potential of diets rich in fruits and vegetables. Such food sources are rich in (poly)phenols, natural compounds increasingly associated with health benefits, having the potential to prevent or retard the development of various diseases. However, absorption and the blood concentration of (poly)phenols is very low when compared with their corresponding (poly)phenolic metabolites. Therefore, these serum-bioavailable metabolites are much more promising candidates to overcome cellular barriers and reach target tissues, such as the brain. Bearing this in mind, it will be reviewed that the molecular mechanisms underlying (poly)phenolic metabolites effects, range from 0.1 to <50 μM and their role on neuroinflammation, a central hallmark in neurodegenerative diseases.
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Affiliation(s)
- Diogo Carregosa
- CEDOC, NOVA Medical School, Faculdade de Ciências Médicas , Universidade NOVA de Lisboa , Lisboa , Portugal
- iBET , Instituto de Biologia Experimental e Tecnológica , Avenida da República, Apartado 12 , 2781-901 Oeiras , Portugal
| | - Rafael Carecho
- CEDOC, NOVA Medical School, Faculdade de Ciências Médicas , Universidade NOVA de Lisboa , Lisboa , Portugal
- Instituto de Tecnologia Química e Biológica António Xavier , Universidade NOVA de Lisboa , Avenida da República , 2780-157 Oeiras , Portugal
| | - Inês Figueira
- iBET , Instituto de Biologia Experimental e Tecnológica , Avenida da República, Apartado 12 , 2781-901 Oeiras , Portugal
- Instituto de Tecnologia Química e Biológica António Xavier , Universidade NOVA de Lisboa , Avenida da República , 2780-157 Oeiras , Portugal
| | - Cláudia N Santos
- CEDOC, NOVA Medical School, Faculdade de Ciências Médicas , Universidade NOVA de Lisboa , Lisboa , Portugal
- iBET , Instituto de Biologia Experimental e Tecnológica , Avenida da República, Apartado 12 , 2781-901 Oeiras , Portugal
- Instituto de Tecnologia Química e Biológica António Xavier , Universidade NOVA de Lisboa , Avenida da República , 2780-157 Oeiras , Portugal
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Mitochondrial permeability transition pore is involved in oxidative burst and NETosis of human neutrophils. Biochim Biophys Acta Mol Basis Dis 2020; 1866:165664. [PMID: 31926265 DOI: 10.1016/j.bbadis.2020.165664] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 12/13/2019] [Accepted: 12/30/2019] [Indexed: 12/21/2022]
Abstract
Neutrophils release neutrophil extracellular traps (NETs) in response to numerous pathogenic microbes as the last suicidal resource (NETosis) in the fight against infection. Apart from the host defense function, NETs play an essential role in the pathogenesis of various autoimmune and inflammatory diseases. Therefore, understanding the molecular mechanisms of NETosis is important for regulating aberrant NET release. The initiation of NETosis after the recognition of pathogens by specific receptors is mediated by an increase in intracellular Ca2+ concentration, therefore, the use of Ca2+ ionophore A23187 can be considered a semi-physiological model of NETosis. Induction of NETosis by various stimuli depends on reactive oxygen species (ROS) produced by NADPH oxidase, however, NETosis induced by Ca2+ ionophores was suggested to be mediated by ROS produced in mitochondria (mtROS). Using the mitochondria-targeted antioxidant SkQ1 and specific inhibitors of NADPH oxidase, we showed that both sources of ROS, mitochondria and NADPH oxidase, are involved in NETosis induced by A23187 in human neutrophils. In support of the critical role of mtROS, SkQ1-sensitive NETosis was demonstrated to be induced by A23187 in neutrophils from patients with chronic granulomatous disease (CGD). We assume that Ca2+-triggered mtROS production contributes to NETosis either directly (CGD neutrophils) or by stimulating NADPH oxidase. The opening of the mitochondrial permeability transition pore (mPTP) in neutrophils treated by A23187 was revealed using the electron transmission microscopy as a swelling of the mitochondrial matrix. Using specific inhibitors, we demonstrated that the mPTP is involved in mtROS production, NETosis, and the oxidative burst induced by A23187.
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Yu CH, Cui NX, Wang Y, Wang Y, Liu WJ, Gong M, Zhao X, Rong L, Yi ZC. Changes in DNA methylation of erythroid-specific genes in K562 cells exposed to catechol in long term. Toxicol In Vitro 2017; 43:21-28. [PMID: 28552822 DOI: 10.1016/j.tiv.2017.05.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Revised: 05/08/2017] [Accepted: 05/25/2017] [Indexed: 12/11/2022]
Abstract
Catechol is one of phenolic metabolites of benzene that is a general occupational hazard and a ubiquitous environmental air pollutant. Catechol also occurs naturally in fruits, vegetables and cigarettes. Previous studies have revealed that 72h exposure to catechol improved hemin-induced erythroid differentiation of K562 cells accompanied with elevated methylation in erythroid specific genes. In present study, K562 cells were treated with 0, 10 or 20μM catechol for 1-4weeks, hemin-induced hemoglobin synthesis increased in a concentration- and time-dependent manner and the enhanced hemoglobin synthesis was relatively stable. The mRNA expression of α-, β- and γ-globin genes, erythroid heme synthesis enzymes PBGD and ALAS2, transcription factor GATA-1 and NF-E2 showed a significant increase in K562 cells exposed to 20μM catechol for 3w, and catechol enhanced hemin-induced mRNA expression of these genes. Quantitative MassARRAY methylation analysis also confirmed that the exposure to catechol changed DNA methylation levels at several CpG sites in several erythroid-specific genes and their far upstream of regulatory elements. These results demonstrated that long-term exposure to low concentration of catechol enhanced the hemin-induced erythroid differentiation of K562 cells, in which DNA methylation played a role by up-regulating erythroid specific genes.
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Affiliation(s)
- Chun-Hong Yu
- School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, China
| | - Ning-Xuan Cui
- School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, China
| | - Yan Wang
- School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, China
| | - Ying Wang
- School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, China
| | - Wen-Juan Liu
- School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, China
| | - Meng Gong
- School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, China
| | - Xiao Zhao
- School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, China
| | - Long Rong
- School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, China
| | - Zong-Chun Yi
- School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, China.
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Ibrahim WH, Habib HM, Kamal H, St Clair DK, Chow CK. Mitochondrial superoxide mediates labile iron level: evidence from Mn-SOD-transgenic mice and heterozygous knockout mice and isolated rat liver mitochondria. Free Radic Biol Med 2013; 65:143-149. [PMID: 23792772 DOI: 10.1016/j.freeradbiomed.2013.06.026] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2013] [Revised: 06/04/2013] [Accepted: 06/12/2013] [Indexed: 10/26/2022]
Abstract
Superoxide is the main reactive oxygen species (ROS) generated by aerobic cells primarily in mitochondria. It is also capable of producing other ROS and reactive nitrogen species (RNS). Moreover, superoxide has the potential to release iron from its protein complexes. Unbound or loosely bound cellular iron, known as labile iron, can catalyze the formation of the highly reactive hydroxyl radical. ROS/RNS can cause mitochondrial dysfunction and damage. Manganese superoxide dismutase (Mn-SOD) is the chief ROS-scavenging enzyme and thereby the primary antioxidant involved in protecting mitochondria from oxidative damage. To investigate whether mitochondrial superoxide mediates labile iron in vivo, the levels of labile iron were determined in the tissues of mice overexpressing Mn-SOD and heterozygous Mn-SOD-knockout mice. Furthermore, the effect of increased mitochondrial superoxide generation on labile iron levels was determined in isolated rat liver mitochondria exposed to various electron transport inhibitors. The results clearly showed that increased expression of Mn-SOD significantly lowered the levels of labile iron in heart, liver, kidney, and skeletal muscle, whereas decreased expression of Mn-SOD significantly increased the levels of labile iron in the same organs. In addition, the data showed that peroxidative damage to membrane lipids closely correlated with the levels of labile iron in various tissues and that altering the status of Mn-SOD did not alter the status of other antioxidant systems. Results also showed that increased ROS production in isolated liver mitochondria significantly increased the levels of mitochondrial labile iron. These findings constitute the first evidence suggesting that mitochondrial superoxide is capable of releasing iron from its protein complexes in vivo and that it could also release iron from protein complexes contained within the organelle.
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Affiliation(s)
- Wissam H Ibrahim
- Department of Nutrition and Health, College of Food and Agriculture, United Arab Emirates University, Al Ain, United Arab Emirates.
| | - Hosam M Habib
- Department of Nutrition and Health, College of Food and Agriculture, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Hina Kamal
- Department of Nutrition and Health, College of Food and Agriculture, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Daret K St Clair
- Graduate Center for Toxicology, University of Kentucky, Lexington, KY 40506, USA
| | - Ching K Chow
- Graduate Center for Nutritional Sciences, University of Kentucky, Lexington, KY 40506, USA
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Suriguga, Li XF, Li Y, Yu CH, Li YR, Yi ZC. The role of catechol-O-methyltransferase in catechol-enhanced erythroid differentiation of K562 cells. Toxicol Appl Pharmacol 2013; 273:635-43. [DOI: 10.1016/j.taap.2013.10.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Revised: 09/29/2013] [Accepted: 10/09/2013] [Indexed: 10/26/2022]
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Stokes SE, Winn LM. NF-κB Signaling Is Increased in HD3 Cells Following Exposure to 1,4-Benzoquinone: Role of Reactive Oxygen Species and p38-MAPK a. Toxicol Sci 2013; 137:303-10. [DOI: 10.1093/toxsci/kft256] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
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Li XF, Wu XR, Xue M, Wang Y, Wang J, Li Y, Suriguga, Zhang GY, Yi ZC. The role of DNA methylation in catechol-enhanced erythroid differentiation of K562 cells. Toxicol Appl Pharmacol 2012; 265:43-50. [DOI: 10.1016/j.taap.2012.09.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Revised: 08/06/2012] [Accepted: 09/20/2012] [Indexed: 12/17/2022]
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Kumar H, Lim HW, More SV, Kim BW, Koppula S, Kim IS, Choi DK. The role of free radicals in the aging brain and Parkinson's Disease: convergence and parallelism. Int J Mol Sci 2012; 13:10478-10504. [PMID: 22949875 PMCID: PMC3431873 DOI: 10.3390/ijms130810478] [Citation(s) in RCA: 141] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Revised: 08/08/2012] [Accepted: 08/13/2012] [Indexed: 02/08/2023] Open
Abstract
Free radical production and their targeted action on biomolecules have roles in aging and age-related disorders such as Parkinson's disease (PD). There is an age-associated increase in oxidative damage to the brain, and aging is considered a risk factor for PD. Dopaminergic neurons show linear fallout of 5-10% per decade with aging; however, the rate and intensity of neuronal loss in patients with PD is more marked than that of aging. Here, we enumerate the common link between aging and PD at the cellular level with special reference to oxidative damage caused by free radicals. Oxidative damage includes mitochondrial dysfunction, dopamine auto-oxidation, α-synuclein aggregation, glial cell activation, alterations in calcium signaling, and excess free iron. Moreover, neurons encounter more oxidative stress as a counteracting mechanism with advancing age does not function properly. Alterations in transcriptional activity of various pathways, including nuclear factor erythroid 2-related factor 2, glycogen synthase kinase 3β, mitogen activated protein kinase, nuclear factor kappa B, and reduced activity of superoxide dismutase, catalase and glutathione with aging might be correlated with the increased incidence of PD.
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Affiliation(s)
- Hemant Kumar
- Department of Biotechnology, Konkuk University, Chungju 380-704, Korea; E-Mails: (H.K.); (H.-W.L.); (S.V.M.); (B.-W.K.); (S.K.); (I.S.K.)
| | - Hyung-Woo Lim
- Department of Biotechnology, Konkuk University, Chungju 380-704, Korea; E-Mails: (H.K.); (H.-W.L.); (S.V.M.); (B.-W.K.); (S.K.); (I.S.K.)
| | - Sandeep Vasant More
- Department of Biotechnology, Konkuk University, Chungju 380-704, Korea; E-Mails: (H.K.); (H.-W.L.); (S.V.M.); (B.-W.K.); (S.K.); (I.S.K.)
| | - Byung-Wook Kim
- Department of Biotechnology, Konkuk University, Chungju 380-704, Korea; E-Mails: (H.K.); (H.-W.L.); (S.V.M.); (B.-W.K.); (S.K.); (I.S.K.)
| | - Sushruta Koppula
- Department of Biotechnology, Konkuk University, Chungju 380-704, Korea; E-Mails: (H.K.); (H.-W.L.); (S.V.M.); (B.-W.K.); (S.K.); (I.S.K.)
| | - In Su Kim
- Department of Biotechnology, Konkuk University, Chungju 380-704, Korea; E-Mails: (H.K.); (H.-W.L.); (S.V.M.); (B.-W.K.); (S.K.); (I.S.K.)
| | - Dong-Kug Choi
- Department of Biotechnology, Konkuk University, Chungju 380-704, Korea; E-Mails: (H.K.); (H.-W.L.); (S.V.M.); (B.-W.K.); (S.K.); (I.S.K.)
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Ji X, Huang L, Lin Q, Huang H. Characteristics and kinetics of iron release from the ferritin under the EGCG reduction. Biol Trace Elem Res 2012; 146:134-40. [PMID: 21984405 DOI: 10.1007/s12011-011-9225-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2011] [Accepted: 09/27/2011] [Indexed: 11/28/2022]
Abstract
The mechanism of iron release from ferritin in vivo is still unclear even though it represents a key step of the metabolism of iron in vivo. Here, both interaction intensity and binding stability between epigallocatechin gallate (EGCG) from tea and liver ferritin of Dasyatis akajei (DALF) were investigated using UV-visible, fluorescence and circular dichroism (CD) spectrometry, respectively. The results indicated that EGCG could reduce the iron within the ferritin shell directly in the absence of chemical reducers such as Na(2)S(2)O(4), but this process was strictly pH-dependent, and the rate of iron release is faster at low pH than at high pH. The kinetic study of iron release showed that this process fitted the law of zero order reaction, which differed from that of first order reaction by various chemical reducers such as Vitamin C. In addition, Both fluorescence and CD spectrometry were further used to study the reduction mechanism of iron release in vitro, showing that there was a slight conformation change of the ferritin shell during EGCG reduction because of a complex formation of DALF-EGCG. It appears that chemical reducers with large molecular sizes reduce the iron across the protein shell by the way of an electron transfer pathway (ETP). A novel pathway for iron release from DALF with EGCG reduction is suggested to explain for a reductive route of iron metabolism by biological reducers in vivo.
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Affiliation(s)
- Xuetao Ji
- Department of Biochemistry and Biotechnology, School of Life Sciences, Xiamen University, Xiamen, 361005, China
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Matić S, Stanić S, Bogojević D, Vidaković M, Grdović N, Arambašić J, Dinić S, Uskoković A, Poznanović G, Solujić S, Mladenović M, Marković J, Mihailović M. Extract of the plant Cotinus coggygria Scop. attenuates pyrogallol-induced hepatic oxidative stress in Wistar rats. Can J Physiol Pharmacol 2011; 89:401-11. [PMID: 21770795 DOI: 10.1139/y11-043] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
To examine the protective potential of the Cotinus coggygria Scop. methanol extract, Wistar rats were treated with the hepatotoxic compound pyrogallol, which possesses a potent ability to generate free radicals and induce oxidative stress. The ability of the extract to counteract the oxidative stress was examined in rats that were injected with the extract intraperitoneally (500 mg·(kg body weight)(-1)) either 2 or 12 h before the pyrogallol treatment. The extract possesses a reducing activity in vitro and an ability to chelate the ferrous ion both in vivo and in vitro. Application of the extract prior to pyrogallol treatment led to a decrease in the levels of thiobarbituric acid-reactive substances, aspartate aminotransferase, and alanine aminotransferase, increased activities of antioxidant enzymes and attenuation of DNA damage, as well as increased Akt activity and inhibition of NF-κB protein expression. Treatment with the extract 12 h prior to pyrogallol administration was more effective in suppressing pyrogallol-induced oxidative damage than the 2 h pretreatment. Extract administration promoted an increase in acute phase reactants haptoglobin and α(2)-macroglobulin that was short of a full-fledged acute phase response. Administration of the extract considerably improved the markers of oxidative stress, thus revealing a potential hepatoprotective activity. Our results suggest that Akt activation, NF-κB inhibition, and induction of the acute phase play important roles in mediating hepatic protection by the extract. The greater effectiveness of the 12 h pretreatment with extract points to the important role that preconditioning assumes in improving resistance to subsequent exposure to oxidative stress.
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Affiliation(s)
- Sanja Matić
- Department of Biology and Ecology, Faculty of Science, University of Kragujevac, Serbia.
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Verina T, Kiihl SF, Schneider JS, Guilarte TR. Manganese exposure induces microglia activation and dystrophy in the substantia nigra of non-human primates. Neurotoxicology 2011; 32:215-26. [PMID: 21112353 PMCID: PMC3057349 DOI: 10.1016/j.neuro.2010.11.003] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2010] [Revised: 11/18/2010] [Accepted: 11/19/2010] [Indexed: 11/19/2022]
Abstract
Chronic manganese (Mn) exposure produces neurological deficits including a form of parkinsonism that is different from Parkinson's disease (PD). In chronic Mn exposure, dopamine neurons in the substantia nigra (SN) do not degenerate but they appear to be dysfunctional. Further, previous studies have suggested that the substantia nigra pars reticulata (SNr) is affected by Mn. In the present study, we investigated whether chronic Mn exposure induces microglia activation in the substantia nigra pars compacta (SNc) and SNr in Cynomolgus macaques. Animals were exposed to different weekly doses of Mn (3.3-5.0, 5.0-6.7, 8.3-10 mg Mn/kg body weight) and microglia were examined in the substantia nigra using LN3 immunohistochemistry. We observed that in control animals, LN3 labeled microglia were characterized by a resting phenotype. However, in Mn-treated animals, microglia increased in number and displayed reactive changes with increasing Mn exposure. This effect was more prominent in the SNr than in the SNc. In the SNr of animals administered the highest Mn dose, microglia activation was the most advanced and included dystrophic changes. Reactive microglia expressed increased iNOS, L-ferritin, and intracellular ferric iron which were particularly prominent in dystrophic compartments. Our observations indicate that moderate Mn exposure produces structural changes on microglia, which may have significant consequences on their function.
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Affiliation(s)
- Tatyana Verina
- Department of Environmental Health Sciences, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD
| | - Samara F Kiihl
- Department of Biostatistics, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD
| | - Jay S Schneider
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA
| | - Tomás R Guilarte
- Department of Environmental Health Sciences, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD
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Kell DB. Towards a unifying, systems biology understanding of large-scale cellular death and destruction caused by poorly liganded iron: Parkinson's, Huntington's, Alzheimer's, prions, bactericides, chemical toxicology and others as examples. Arch Toxicol 2010; 84:825-89. [PMID: 20967426 PMCID: PMC2988997 DOI: 10.1007/s00204-010-0577-x] [Citation(s) in RCA: 286] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2010] [Accepted: 07/14/2010] [Indexed: 12/11/2022]
Abstract
Exposure to a variety of toxins and/or infectious agents leads to disease, degeneration and death, often characterised by circumstances in which cells or tissues do not merely die and cease to function but may be more or less entirely obliterated. It is then legitimate to ask the question as to whether, despite the many kinds of agent involved, there may be at least some unifying mechanisms of such cell death and destruction. I summarise the evidence that in a great many cases, one underlying mechanism, providing major stresses of this type, entails continuing and autocatalytic production (based on positive feedback mechanisms) of hydroxyl radicals via Fenton chemistry involving poorly liganded iron, leading to cell death via apoptosis (probably including via pathways induced by changes in the NF-κB system). While every pathway is in some sense connected to every other one, I highlight the literature evidence suggesting that the degenerative effects of many diseases and toxicological insults converge on iron dysregulation. This highlights specifically the role of iron metabolism, and the detailed speciation of iron, in chemical and other toxicology, and has significant implications for the use of iron chelating substances (probably in partnership with appropriate anti-oxidants) as nutritional or therapeutic agents in inhibiting both the progression of these mainly degenerative diseases and the sequelae of both chronic and acute toxin exposure. The complexity of biochemical networks, especially those involving autocatalytic behaviour and positive feedbacks, means that multiple interventions (e.g. of iron chelators plus antioxidants) are likely to prove most effective. A variety of systems biology approaches, that I summarise, can predict both the mechanisms involved in these cell death pathways and the optimal sites of action for nutritional or pharmacological interventions.
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Affiliation(s)
- Douglas B Kell
- School of Chemistry and the Manchester Interdisciplinary Biocentre, The University of Manchester, Manchester M1 7DN, UK.
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Mansoor S, Gupta N, Luczy-Bachman G, Limb GA, Kuppermann BD, Kenney MC. Protective effects of memantine and epicatechin on catechol-induced toxicity on Müller cells in vitro. Toxicology 2010; 271:107-14. [DOI: 10.1016/j.tox.2010.03.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2009] [Revised: 03/06/2010] [Accepted: 03/20/2010] [Indexed: 11/29/2022]
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Upadhyay G, Tiwari MN, Prakash O, Jyoti A, Shanker R, Singh MP. Involvement of multiple molecular events in pyrogallol-induced hepatotoxicity and silymarin-mediated protection: evidence from gene expression profiles. Food Chem Toxicol 2010; 48:1660-70. [PMID: 20362636 DOI: 10.1016/j.fct.2010.03.041] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2010] [Revised: 03/22/2010] [Accepted: 03/26/2010] [Indexed: 11/26/2022]
Abstract
In this study, the involvement of various molecular events in pyrogallol-mediated hepatotoxicity was deciphered by differential mRNA transcription profiles of control and pyrogallol treated mice liver. The modulatory effects of silymarin on pyrogallol-induced differentially expressed transcripts were also looked into. Swiss albino mice were treated with or without pyrogallol. In some set of experiments, mice were also treated with silymarin 2 h prior to pyrogallol. Total RNA was isolated from liver and polyadenylated RNA was reverse-transcribed into Cye 3 or Cye 5 labelled cDNA. Equal amounts of labelled cDNA from two different groups were mixed and hybridized with mouse 15 k array. The hybridized arrays were scanned, analyzed and the expression level of each transcript was calculated. The differential expression was validated by quantitative real time polymerase chain reaction. Comparative transcription pattern showed an alteration in the expression of 183 transcripts (150 up-regulated and 33 down-regulated) associated with oxidative stress, cell cycle, cytoskeletal network, cell-cell adhesion, extra-cellular matrix, inflammation, apoptosis, cell-signaling and intermediary metabolism in pyrogallol-exposed liver and silymarin pre-treatment modulated the expression of many of these transcripts. Results obtained thus suggest that pyrogallol induces multiple molecular events leading to hepatotoxicity and silymarin effectively counteracts pyrogallol-mediated alterations.
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Affiliation(s)
- Ghanshyam Upadhyay
- Indian Institute of Toxicology Research (Council of Scientific and Industrial Research), Lucknow, UP, India
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18
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Wang J, Ma H, Boor PJ, Sadagopa Ramanujam VM, Ansari G, Khan MF. Up-regulation of heme oxygenase-1 in rat spleen after aniline exposure. Free Radic Biol Med 2010; 48:513-8. [PMID: 19969074 PMCID: PMC2818702 DOI: 10.1016/j.freeradbiomed.2009.11.027] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2009] [Revised: 11/13/2009] [Accepted: 11/24/2009] [Indexed: 11/18/2022]
Abstract
The splenic toxicity of aniline is characterized by vascular congestion, hyperplasia, fibrosis, and the development of a variety of sarcomas in rats. However, the underlying mechanisms by which aniline elicits splenotoxic response are not well understood. Previously we have shown that aniline exposure causes oxidative damage to the spleen. To further explore the oxidative mechanism of aniline toxicity, we evaluated the potential contribution of heme oxygenase-1 (HO-1), which catalyzes heme degradation and releases free iron. Male SD rats were given 1 mmol/kg/day aniline in water by gavage for 1, 4, or 7 days, and respective controls received water only. Aniline exposure led to significant increases in HO-1 mRNA expression in the spleen (2-and 2.4-fold at days 4 and 7, respectively) with corresponding increases in protein expression, as confirmed by ELISA and Western blot analysis. Furthermore, immunohistochemical assessment of spleen showed stronger immunostaining for HO-1 in the spleens of rats treated for 7 days, confined mainly to the red pulp areas. No changes were observed in mRNA and protein levels of HO-1 after 1 day exposure. The increase in HO-1 expression was associated with increases in total iron (2.4-and 2.7-fold), free iron (1.9-and 3.5-fold), and ferritin levels (1.9-and 2.1-fold) at 4 and 7 days of aniline exposure. Our data suggest that HO-1 up-regulation in aniline-induced splenic toxicity could be a contributing pro-oxidant mechanism, mediated through iron release, and leading to oxidative damage.
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Affiliation(s)
- Jianling Wang
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, USA
| | - Huaxian Ma
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, USA
| | - Paul J. Boor
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, USA
| | - V. M. Sadagopa Ramanujam
- Department of Preventive Medicine and Community Health, University of Texas Medical Branch, Galveston, TX, USA
| | - G.A.S. Ansari
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, USA
| | - M. Firoze Khan
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, USA
- Address for Correspondence: M. Firoze Khan, Ph.D., Professor, Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555-0438, Tel: 409-772-6881, Fax: 409-747-1763,
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Pyrogallol-mediated toxicity and natural antioxidants: Triumphs and pitfalls of preclinical findings and their translational limitations. Chem Biol Interact 2010; 183:333-40. [DOI: 10.1016/j.cbi.2009.11.028] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2009] [Revised: 11/02/2009] [Accepted: 11/23/2009] [Indexed: 11/20/2022]
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Deng J, Cheng J, Liao X, Zhang T, Leng X, Zhao G. Comparative study on iron release from soybean (Glycine max) seed ferritin induced by anthocyanins and ascorbate. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2010; 58:635-41. [PMID: 19921836 DOI: 10.1021/jf903046u] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Anthocyanins have received much attentions due to their various activities. Phytoferritin represents a novel alternative for iron supplementation. In the present study, it was found that all tested anthocyanins such as cyanidin (Cy), delphinidin (Dp), delphinidin-3-O-glucoside (Dp3glc), malvidin (Mv), petunidin (Pt), and petunidin-3-O-glucoside (Pt3glc) had a strong interaction with SSF, respectively, resulting in iron release from soybean seed ferritin (SSF) just as for ascorbate. The order of iron release from SSF is as follows: Dp>Cy>Pt>Mv>Dp3glc>Pt3glc. Their ability to liberate iron from SSF is associated with the size of the molecules and the chemical structures but mainly depends on their chelating activity with Fe2+. Interestingly, these pigments inhibited SSF degradation during the iron release to different extents while ascorbate did not. The difference in protective effects on SFF between ascorbate and the anthocyanins is in good agreement with their different Fe2+-chelating activities.
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Affiliation(s)
- Jianjun Deng
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, People's Republic of China
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Jackson CS, Kodanko JJ. Iron-binding and mobilization from ferritin by polypyridyl ligands. Metallomics 2010; 2:407-11. [DOI: 10.1039/c003414b] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Barreto G, Madureira D, Capani F, Aon-Bertolino L, Saraceno E, Alvarez-Giraldez LD. The role of catechols and free radicals in benzene toxicity: an oxidative DNA damage pathway. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2009; 50:771-80. [PMID: 19449395 DOI: 10.1002/em.20500] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Benzene is a widespread volatile compound and an environmental contaminant. Since it causes important toxic effects in workers exposed to low levels, long-term exposure to this compound has been extensively studied. Leukemia, blood disorders, bone marrow depression, and some types of cancer are directly related to benzene-initiated toxicity. Bioactivation of benzene can lead to the formation of hazardous metabolites such as phenol, hydroquinone, and catechol. Catechol forms semiquinones and reactive quinones that are presumed to play an important role in the generation of reactive oxygen species (ROS). ROS formation can directly induce single and double strand breaks in the DNA, oxidized nucleotides, and hyper-recombination, and consequently produces deleterious genetic changes. In this review, we have addressed the cytotoxic effects of benzene and its main metabolite, catechol, focusing on the oxidative pathway and further DNA damage.
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Nurminskaya MV, Talbot CJ, Nurminsky DI, Beazley KE, Linsenmayer TF. Nuclear ferritin: a ferritoid-ferritin complex in corneal epithelial cells. Invest Ophthalmol Vis Sci 2009; 50:3655-61. [PMID: 19255152 DOI: 10.1167/iovs.08-3170] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Ferritin is an iron storage protein that is generally cytoplasmic. However, in embryonic avian corneal epithelial (CE) cells, the authors previously observed that the ferritin was predominantly nuclear. They also obtained evidence that this ferritin protects DNA from oxidative damage by UV light and hydrogen peroxide and that the nuclear localization involves a tissue-specific nuclear transporter, termed ferritoid. In the present investigation, the authors have determined additional properties of the nuclear ferritoid-ferritin complexes. METHODS For biochemical characterization, a combination of molecular sieve chromatography, immunoblotting, and nuclear-cytoplasmic fractionation was used; DNA binding was analyzed by electrophoretic mobility shift assay. RESULTS The CE nuclear ferritin complex has characteristics that differentiate it from a "typical" cytoplasmic ferritin, including the presence of ferritin and ferritoid subunits; a molecular weight of approximately 260 kDa, which is approximately half that of cytoplasmic ferritin; its iron content, which is below our limits of detection; and its ability to bind to DNA. CONCLUSIONS Within CE cell nuclei, ferritin and ferritoid are coassembled into stable complex(es) present in embryonic and adult corneas. Thus, ferritoid not only serves transiently as a nuclear transporter for ferritin, it remains as a component of a unique ferritoid-ferritin nuclear complex.
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Affiliation(s)
- Maria V Nurminskaya
- Department of Anatomy and Cell Biology, Tufts University, Boston, MA 02111, USA
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Lopes KO, Sparks DL, Streit WJ. Microglial dystrophy in the aged and Alzheimer's disease brain is associated with ferritin immunoreactivity. Glia 2008; 56:1048-60. [PMID: 18442088 DOI: 10.1002/glia.20678] [Citation(s) in RCA: 164] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Degeneration of microglial cells may be important for understanding the pathogenesis of aging-related neurodegeneration and neurodegenerative diseases. In this study, we analyzed the morphological characteristics of microglial cells in the nondemented and Alzheimer's disease (AD) human brain using ferritin immunohistochemistry. The central hypothesis was that expression of the iron storage protein ferritin increases the susceptibility of microglia to degeneration, particularly in the aged brain since senescent microglia might become less efficient in maintaining iron homeostasis and free iron can promote oxidative damage. In a primary set of 24 subjects (age range 34-97 years) examined, microglial cells immunoreactive for ferritin were found to constitute a subpopulation of the larger microglial pool labeled with an antibody for HLA-DR antigens. The majority of these ferritin-positive microglia exhibited aberrant morphological (dystrophic) changes in the aged and particularly in the AD brain. No spatial correlation was found between ferritin-positive dystrophic microglia and senile plaques in AD tissues. Analysis of a secondary set of human postmortem brain tissues with a wide range of postmortem intervals (PMI, average 10.94 +/- 5.69 h) showed that the occurrence of microglial dystrophy was independent of PMI and consequently not a product of tissue autolysis. Collectively, these results suggest that microglial involvement in iron storage and metabolism contributes to their degeneration, possibly through increased exposure of the cells to oxidative stress. We conclude that ferritin immunohistochemistry may be a useful method for detecting degenerating microglia in the human brain.
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Affiliation(s)
- Kryslaine O Lopes
- Department of Neuroscience, University of Florida College of Medicine, Gainesville, Florida 32610-0244, USA
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Barreto GES, dos Santos GS, Egito EST, El-Bachá RDS. Catechol inhibits FADH2-linked respiration in rat liver mitochondrial fraction. Acta Cir Bras 2007; 20 Suppl 1:72-7. [PMID: 16186974 DOI: 10.1590/s0102-86502005000700008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
PURPOSE The aim of this work was to investigate the hypothesis that catechol inhibits FADH -linked basal respiration in mitochondria isolated from rat liver homogenates. Moreover, catechol ability to induce peroxidation of biomolecules in liver nuclear fractions was also studied. METHODS Rat liver homogenates were incubated with 1mM 1,2-dihydroxybenzene (catechol) at pH 7.4 for up to 30 minutes. After that, mitochondrial fractions were isolated by differential centrifugation. Basal oxygen uptake was measured using a Clark-type electrode after the addition of 10 mM sodium succinate. Nuclear fractions were incubated in the presence of 1 mM catechol for 17 hours at room temperature and the peroxidation of biomolecules was investigated by the reaction with thiobarbituric acid, which was determined spectrophotometrically at 535 nm. RESULTS Catechol induced a time-dependent partial inhibition of FADH -linked basal mitochondrial respiration, however this substance was unable to induce a direct peroxidation of biomolecules in hepatic nuclear fractions. CONCLUSION Catechol produced an inhibition of basal respiration associated to FADH2 in isolated liver mitochondria that could lead to cytotoxicity, ROS generation and cell death.
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Affiliation(s)
- George Emílio Sampaio Barreto
- Laboratory of Dispersed Systems (LASID), Department of Pharmacy, Federal University of Rio Grande do Norte (UFRN), Natal, RN, Brazil
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Stockwin LH, Bumke MA, Yu SX, Webb SP, Collins JR, Hollingshead MG, Newton DL. Proteomic Analysis Identifies Oxidative Stress Induction by Adaphostin. Clin Cancer Res 2007; 13:3667-81. [PMID: 17575232 DOI: 10.1158/1078-0432.ccr-07-0025] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Activities distinct from inhibition of Bcr/abl have led to adaphostin (NSC 680410) being described as "a drug in search of a mechanism." In this study, proteomic analysis of adaphostin-treated myeloid leukemia cell lines was used to further elucidate a mechanism of action. EXPERIMENTAL DESIGN HL60 and K562 cells treated with adaphostin for 6, 12, or 24 h were analyzed using two-dimensional PAGE. Differentially expressed spots were excised, digested with trypsin, and analyzed by liquid chromatography-tandem mass spectrometry. The contribution of the redox-active hydroquinone group in adaphostin was also examined by carrying out proteomic analysis of HL60 cells treated with a simple hydroquinone (1,4-dihydroxybenzene) or H(2)O(2). RESULTS Analysis of adaphostin-treated cells identified 49 differentially expressed proteins, the majority being implicated in the response to oxidative stress (e.g., CALM, ERP29, GSTP1, PDIA1) or induction of apoptosis (e.g., LAMA, FLNA, TPR, GDIS). Interestingly, modulation of these proteins was almost fully prevented by inclusion of an antioxidant, N-acetylcysteine. Validation of the proteomic data confirmed GSTP1 as an adaphostin resistance gene. Subsequent analysis of HL60 cells treated with 1,4-dihydroxybenzene or H(2)O(2) showed similar increases in intracellular peroxides and an almost identical proteomic profiles to that of adaphostin treatment. Western blotting of a panel of cell lines identified Cu/Zn superoxide dismutase (SOD) as correlating with adaphostin resistance. The role of SOD as a second adaphostin resistance gene was confirmed by demonstrating that inhibition of SOD using diethyldithiocarbamate increased adaphostin sensitivity, whereas transfection of SOD I attenuated toxicity. Importantly, treatment with 1,4-dihydroxybenzene or H(2)O(2) replicated adaphostin-induced Bcr/abl polypeptide degradation, suggesting that kinase inhibition is a ROS-dependent phenomenon. CONCLUSION Adaphostin should be classified as a redox-active-substituted dihydroquinone.
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Affiliation(s)
- Luke H Stockwin
- Developmental Therapeutics Program, Science Applications International Corporation Frederick, Frederick, Maryland 21702, USA
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Cheng Z, Li Y. What is responsible for the initiating chemistry of iron-mediated lipid peroxidation: an update. Chem Rev 2007; 107:748-66. [PMID: 17326688 DOI: 10.1021/cr040077w] [Citation(s) in RCA: 139] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Zhiyong Cheng
- The Key Laboratory of Bioorganic & Molecular Engineering, College of Chemistry & Molecular Engineering, Peking University, Beijing, China 100871
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Koorts AM, Viljoen M. Ferritin and ferritin isoforms I: Structure-function relationships, synthesis, degradation and secretion. Arch Physiol Biochem 2007; 113:30-54. [PMID: 17522983 DOI: 10.1080/13813450701318583] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Ferritin is the intracellular protein responsible for the sequestration, storage and release of iron. Ferritin can accumulate up to 4500 iron atoms as a ferrihydrite mineral in a protein shell and releases these iron atoms when there is an increase in the cell's need for bioavailable iron. The ferritin protein shell consists of 24 protein subunits of two types, the H-subunit and the L-subunit. These ferritin subunits perform different functions in the mineralization process of iron. The ferritin protein shell can exist as various combinations of these two subunit types, giving rise to heteropolymers or isoferritins. Isoferritins are functionally distinct and characteristic populations of isoferritins are found depending on the type of cell, the proliferation status of the cell and the presence of disease. The synthesis of ferritin is regulated both transcriptionally and translationally. Translation of ferritin subunit mRNA is increased or decreased, depending on the labile iron pool and is controlled by an iron-responsive element present in the 5'-untranslated region of the ferritin subunit mRNA. The transcription of the genes for the ferritin subunits is controlled by hormones and cytokines, which can result in a change in the pool of translatable mRNA. The levels of intracellular ferritin are determined by the balance between synthesis and degradation. Degradation of ferritin in the cytosol results in complete release of iron, while degradation in secondary lysosomes results in the formation of haemosiderin and protection against iron toxicity. The majority of ferritin is found in the cytosol. However, ferritin with slightly different properties can also be found in organelles such as nuclei and mitochondria. Most of the ferritin produced intracellularly is harnessed for the regulation of iron bioavailability; however, some of the ferritin is secreted and internalized by other cells. In addition to the regulation of iron bioavailability ferritin may contribute to the control of myelopoiesis and immunological responses.
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Affiliation(s)
- A M Koorts
- Department of Physiology, School of Medicine, University of Pretoria, Pretoria, South Africa.
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Mehlhase J, Gieche J, Widmer R, Grune T. Ferritin levels in microglia depend upon activation: Modulation by reactive oxygen species. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2006; 1763:854-9. [PMID: 16777245 DOI: 10.1016/j.bbamcr.2006.04.012] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2006] [Revised: 04/14/2006] [Accepted: 04/19/2006] [Indexed: 11/20/2022]
Abstract
Iron is one of the trace elements playing a key role in the normal cellular metabolism. Since an excess of free iron is catalyzing the Fenton reaction, most of the intracellular iron is sequestered in the iron storage protein ferritin. The binding of iron into ferritin is well described for physiological conditions, however, under certain pathophysiological situations, the efficiency of this process is unknown. In the brain, microglial cells are among others the cell population most importantly responsible for the maintenance of the extracellular environment. These cells might undergo activation, and little is known about the expression of ferritin during activation of microglial cells. Therefore, we tested the microglial model cell line RAW264.7 for the expression of ferritin after LPS activation. A significant decrease in the levels of the ferritin H-chain during activation and a significant increase in the early recovery phase were found. We were able to demonstrate that reactive oxygen species are responsible for a suppression of the H-chain of ferritin, whereas iNOS expression and NO synthesis are counteracting the reactive oxygen species effect. The balance of reactive oxygen species and NO production are, therefore, determining expression levels of the ferritin H-chain during activation of microglial cells.
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Sturm B, Twaroch T, Knapitsch B, Czingraber S, Ternes N, Goldenberg H, Scheiber-Mojdehkar B. Differential response of iron metabolism to oxidative stress generated by antimycin A and nitrofurantoin. Biochimie 2005; 88:575-81. [PMID: 16644088 DOI: 10.1016/j.biochi.2005.08.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2005] [Revised: 08/01/2005] [Accepted: 08/30/2005] [Indexed: 10/25/2022]
Abstract
The close interrelationship of oxidative stress and iron is evident by the influence of intracellular reactive oxygen species on iron metabolism. Oxygen radicals can lead to release of iron from iron-sulfur proteins and ferritin, and can damage iron-containing enzymes such as mitochondrial aconitase. Treatment of HepG2 human hepatoma cells with antimycin A has two effects relating to iron depending on the concentrations of antimycin A: increase of the labile iron pool and stimulation of non-transferrin-bound iron uptake. Whereas the first could also be generated with nitrofurantoin, the stimulation of non-transferrin-bound iron uptake was only seen with antimycin A and needed considerably higher concentrations. Pretreatment of the cells with ebselen, which scavenges peroxides, reverted only the effect of nitrofurantoin on the labile iron pool. Depletion with iron chelators before or after treatment with antimycin A diminished the stimulation of non-transferrin-bound iron uptake. We conclude that the generation of oxygen radicals in the mitochondria leads to the liberation of iron from mitochondrial enzymes, which enters the labile iron pool. But high concentrations of antimycin A leading to the stimulation of non-transferrin-bound iron uptake is possibly not related to the inhibition of the respiratory chain.
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Affiliation(s)
- Brigitte Sturm
- Department of Medical Chemistry, Medical University of Vienna, Waehringerstrasse 10, 1090 Vienna, Austria
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Hose C, Kaur G, Sausville EA, Monks A. Transcriptional Profiling Identifies Altered Intracellular Labile Iron Homeostasis as a Contributing Factor to the Toxicity of Adaphostin: Decreased Vascular Endothelial Growth Factor Secretion Is Independent of Hypoxia-Inducible Factor-1 Regulation. Clin Cancer Res 2005; 11:6370-81. [PMID: 16144942 DOI: 10.1158/1078-0432.ccr-05-0291] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Adaphostin was developed as an inhibitor of the p210(bcr-abl) tyrosine kinase, but as its activity is not limited to tumor cell lines containing this translocation, transcriptional profiling was used as a tool to elucidate additional mechanisms responsible for adaphostin cytotoxicity. EXPERIMENTAL DESIGN Profiles of drug-induced transcriptional changes were measured in three hematopoietic cell lines following 1 and 10 micromol/L adaphostin for 2 to 6 hours and then confirmed with real-time reverse transcription-PCR (2-24 hours). These data indicated altered iron homeostasis, and this was confirmed experimentally. Alteration of vascular endothelial growth factor (VEGF) secretion through hypoxia-inducible factor-1 (HIF-1) regulation was also investigated. RESULTS Drug-induced genes included heat shock proteins and ubiquitins, but an intriguing response was the induction of ferritins. Measurement of the labile iron pool showed release of chelatable iron immediately after treatment with adaphostin and was quenched with the addition of an iron chelator. Pretreatment of cells with desferrioxamine and N-acetyl-cysteine reduced but did not ablate the sensitivity of the cells to adaphostin, and desferrioxamine was able to modulate adaphostin-induced activation of p38 and inactivation of AKT. VEGF secretion was shown to be reduced in cell lines after the addition of adaphostin but was not dependent on HIF-1. CONCLUSIONS Adaphostin-induced cytotoxicity is caused in part by a rapid release of free iron, leading to redox perturbations and cell death. Despite this, reduced VEGF secretion was found to be independent of regulation by the redox responsive transcription factor HIF-1. Thus, adaphostin remains an interesting agent with the ability to kill tumor cells directly and modulate angiogenesis.
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Affiliation(s)
- Curtis Hose
- SAIC Frederick, Inc., Screening Technologies Branch, Laboratory of Functional Genomics, National Cancer Institute Frederick, Frederick, Maryland 21702, USA
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Sánchez P, Gálvez N, Colacio E, Miñones E, Domínguez-Vera JM. Catechol releases iron(III) from ferritin by direct chelation without iron(II) production. Dalton Trans 2005:811-3. [PMID: 15702194 DOI: 10.1039/b416669h] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
It has been traditionally considered that catechols release iron from ferritin by reduction to iron(II), which diffuses through the ferritin channels into the intracellular milieu where it participates in the Fenton reaction, producing highly toxic hydroxyl radicals. However, in the present work we have proved that the mechanism of the release of iron from ferritin by catechol does not take place by iron(II) reduction but by direct iron(III) chelation and therefore without iron(II) production. A possible extension of these findings to other catechols is discussed on the basis of the stability with respect to the internal redox reaction of the iron(III)-catechol complexes.
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Affiliation(s)
- Purificación Sánchez
- Departamento de Química Inorgánica, Facultad de Ciencias, Universidad de Granada, 18071, Granada, Spain
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Abstract
Previous studies have shown that dietary vitamin E reduced generation and/or levels of superoxide. As superoxide has potential to release iron from its transport and storage proteins, and labile or available form of iron is capable of catalyzing the formation of reactive hydroxyl radicals, the effect of dietary vitamin E on labile iron pool was studied in rats. One-month-old Sprague-Dawley male and female rats were fed a basal vitamin E-deficient diet supplemented with 0, 20, 200, or 2,000 IU vitamin E/kg diet for 90 days. The levels of labile iron were measured in the liver, kidney, spleen, heart and skeletal muscle. Additionally, the levels of lipid peroxidation products were measured. The results showed that, except for labile iron in the heart of male rats, dietary vitamin E dose dependently reduced the levels of labile iron and lipid peroxidation products in all tissues of male and female rats. The findings suggest that dietary vitamin E may protect against oxidative tissue damage by reducing the generation and/or level of superoxide, which in turn attenuates the release of iron from its protein complexes.
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Affiliation(s)
- Wissam Ibrahim
- Graduate Center for Nutritional Sciences and Kentucky Agricultural Experiment Station, University of Kentucky, Lexington, 40506-0054, USA
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34
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Shackelford RE, Manuszak RP, Johnson CD, Hellrung DJ, Link CJ, Wang S. Iron chelators increase the resistance of Ataxia telangeictasia cells to oxidative stress. DNA Repair (Amst) 2004; 3:1263-72. [PMID: 15336622 DOI: 10.1016/j.dnarep.2004.01.015] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/12/2004] [Indexed: 10/26/2022]
Abstract
Ataxia telangeictasia (A-T) is an autosomal recessive disorder characterized by immune dysfunction, genomic instability, chronic oxidative damage, and increased cancer incidence. Previously, desferal was found to increase the resistance of A-T, but not normal cells to exogenous oxidative stress in the colony forming-efficiency assay, suggesting that iron metabolism is dysregulated in A-T. Since desferal both chelates iron and modulates gene expression, we tested the effects of apoferritin and the iron chelating flavonoid quercetin on A-T cell colony-forming ability. We demonstrate that apoferritin and quercetin increase the ability of A-T cells to form colonies. We also show that labile iron levels are significantly elevated in Atm-deficient mouse sera compared to syngeniec wild type mice. Our findings support a role for labile iron acting as a Fenton catalyst in A-T, contributing to the chronic oxidative stress seen in this disease. Our findings further suggest that iron chelators might promote the survival of A-T cells and hence, individuals with A-T.
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Al-Ghamdi SS, Chatterjee PK, Raftery MJ, Thiemermann C, Yaqoob MM. Role of cytochrome P4502E1 activation in proximal tubular cell injury induced by hydrogen peroxide. Ren Fail 2004; 26:103-10. [PMID: 15287192 DOI: 10.1081/jdi-120038483] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND There is now good evidence to suggest that cytochrome P450 (CYP450) may act as an iron-donating catalyst for the production of hydroxyl ion (OH*), which contributes to proximal tubular cell injury. However, it remains unclear which isoform of CYP450 is involved in this process. Cytochrome P4502E1 (CYP2E1) is a highly labile isoform which is not only involved in free radical generation, but has also been shown to be a source of iron in cisplatin-induced renal injury. This study investigates the role of CYP2E1 in the proximal tubular cell injury induced by hydrogen peroxide (H2O2). METHODS Porcine proximal tubular cells (LLC-PK1) were incubated with H2O2 (1 mM) for 4 h in the presence or absence of 0.1 mM of two CYP2E1 inhibitors; diallyl sulfide (DAS), or disulfiram (DSF), desferrioxamine (DFO) (0.1-0.4 mM), or catalase (CT) (78, 150, 300 U/mL). Cell death was determined by measuring LDH release. CYP2E1 activity was determined by p-nitrophenol hydroxylation after 2 h incubation with H2O2. RESULTS Exposure of LLC-PKI to H2O2 significantly increased cell death. CT, DFO, DAS and DSF significantly reduced H2O2-mediated cell death. Incubation with H2O2 increased CYP2EI activation in time- and dose-dependent manner, which was significantly reduced by CT, DFO, DAS and DSF. CONCLUSION We propose that CYP2E1 activation occurs possibly due to OH* and contributes to H2O2-mediated LLC-PK1 cell necrosis by acting as a source of iron and perpetuating the generation of OH* via the Fenton reaction. Inhibition of CYP2E1 may be a novel approach for the prevention of tubular injury caused by oxidative stress.
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Affiliation(s)
- Saeed S Al-Ghamdi
- Department of Experimental Medicine and Nephrology, St Bartholomew's and the Royal London School of Medicine and Dentistry, Queen Mary-University of London, London, UK.
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Shackelford RE, Manuszak RP, Johnson CD, Hellrung DJ, Steele TA, Link CJ, Wang S. Desferrioxamine treatment increases the genomic stability of Ataxia-telangiectasia cells. DNA Repair (Amst) 2003; 2:971-81. [PMID: 12967654 DOI: 10.1016/s1568-7864(03)00090-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Ataxia-telangiectasia (AT) is an autosomal recessive disorder characterized by genomic instability, chronic oxidative damage, and increased cancer incidence. Compared to normal cells, AT cells exhibit unusual sensitivity to exogenous oxidants, including t-butyl hydroperoxide (t-BOOH). Since ferritin releases labile iron under oxidative stress (which is chronic in AT) and labile iron mediates the toxic effects of t-butyl hydroperoxide, we hypothesized that chelation of intracellular labile iron would increase the genomic stability of AT cells, with and without exogenous oxidative stress. Here we report that desferrioxamine treatment increases the plating efficiency of AT, but not normal cells, in the colony forming-efficiency assay (a method often used to measure genomic stability). Additionally, desferrioxamine increases AT, but not normal cell resistance, to t-butyl hydroperoxide in this assay. Last, AT cells exhibit increased sensitivity to the toxic effects of FeCl(2) in the colony forming-efficiency assay and fail to demonstrate a FeCl(2)-induced G(2) checkpoint response when compared to normal cells. Our data indicates that: (1) chelation of labile iron increases genomic stability in AT cells, but not normal cells; and (2) AT cells exhibit deficits in their responses to iron toxicity. While preliminary, our findings suggest that AT might be, in part, a disorder of iron metabolism and treatment of individuals with AT with desferrioxamine might have clinical efficacy.
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Oakes KD, Van Der Kraak GJ. Utility of the TBARS assay in detecting oxidative stress in white sucker (Catostomus commersoni) populations exposed to pulp mill effluent. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2003; 63:447-63. [PMID: 12758008 DOI: 10.1016/s0166-445x(02)00204-7] [Citation(s) in RCA: 270] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Recent evidence indicates that contaminant-stimulated free radical production and resulting oxidative damage may be an important mechanism of toxicity in organisms exposed to water-borne contaminants. This study tested the hypothesis that increases in oxidative stress and associated biochemical alterations would be present in white sucker (Catostomus commersoni) living in an environment receiving pulp mill effluent. Consistent increases in liver TBARS and frequent increases in gonadal TBARS were observed immediately downstream of the pulp mill effluent discharge; observable effects were attenuated with distance until they were not significantly different from reference values. Increases detected with the TBARS assay were commensurate with increases detected using the lipid hydroperoxides assay, a mechanistically independent technique. Fish exposed to pulp mill effluent also exhibited significant increases in hepatic free iron and ascorbic acid and a reduced free radical scavenging capacity in the livers of fish downstream of the effluent discharge relative to reference fish. Increases in oxidative stress are not necessarily dependent on increases in lipid substrate or related to reductions in ascorbic acid. TBARS values similar to those observed in fish resident below pulp mill effluent discharges were observed in white sucker 2 h after intraperitoneal injection using 15 mg/kg body weight ferric nitrilotriacetate (Fe(3+) NTA) as a positive control. This study indicates oxidative stress could be a mechanism of toxicity in fish exposed to pulp mill effluent and demonstrates the utility of TBARS in delineating zones of exposure to pulp mill effluent.
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Affiliation(s)
- Ken D Oakes
- Department of Zoology, University of Guelph, Guelph, Ont., Canada N1G 2W1
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Kaur D, Yantiri F, Rajagopalan S, Kumar J, Mo JQ, Boonplueang R, Viswanath V, Jacobs R, Yang L, Beal MF, DiMonte D, Volitaskis I, Ellerby L, Cherny RA, Bush AI, Andersen JK. Genetic or pharmacological iron chelation prevents MPTP-induced neurotoxicity in vivo: a novel therapy for Parkinson's disease. Neuron 2003; 37:899-909. [PMID: 12670420 DOI: 10.1016/s0896-6273(03)00126-0] [Citation(s) in RCA: 480] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Studies on postmortem brains from Parkinson's patients reveal elevated iron in the substantia nigra (SN). Selective cell death in this brain region is associated with oxidative stress, which may be exacerbated by the presence of excess iron. Whether iron plays a causative role in cell death, however, is controversial. Here, we explore the effects of iron chelation via either transgenic expression of the iron binding protein ferritin or oral administration of the bioavailable metal chelator clioquinol (CQ) on susceptibility to the Parkinson's-inducing agent 1-methyl-4-phenyl-1,2,3,6-tetrapyridine (MPTP). Reduction in reactive iron by either genetic or pharmacological means was found to be well tolerated in animals in our studies and to result in protection against the toxin, suggesting that iron chelation may be an effective therapy for prevention and treatment of the disease.
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