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Pal G, Mishra HP, Suvvari TK, Tanwar A, Ghosh T, Verma P, Pal A, Patial K, Mahapatra C, Amanullah NA, Shukoor SA, Kamal S, Rohil V. Oxidative Stress in Wistar Rats Under Acute Restraint Stress and Its Modulation by Antioxidants and Nitric Oxide Modulators. Cureus 2023; 15:e43333. [PMID: 37701013 PMCID: PMC10493075 DOI: 10.7759/cureus.43333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/11/2023] [Indexed: 09/14/2023] Open
Abstract
BACKGROUND Several pathogenic conditions leading to morbidity, including cancer, aging, diabetes, reperfusion injury, cardiovascular disease, and neurological disorders, are known to be exacerbated by oxidative stress. Antioxidant therapy is effective in the treatment of such disorders and appears to be a potential therapeutic technique to reduce oxidative stress. The aim of our study is to investigate the antioxidant effects of L-ascorbic acid and nitric oxide (NO) modulators on rats suffering from oxidative stress induced by acute restraint stress (RSx1). METHODOLOGY In this in vivo study, Wistar rats were subjected to one hour of restraint stress on day 21 to induce oxidative stress. Superoxide dismutase (SOD), total antioxidant capacity (TAC), catalase, glutathione (GSH), and malondialdehyde (MDA) were used to assess the antioxidant effects. IBM Corp. Released 2013. IBM SPSS Statistics for Windows, Version 22.0. Armonk, NY: IBM Corp. was used for data analysis. RESULTS Compared to vehicle groups, acute restraint stress (RSx1) dramatically increased MDA levels while decreasing GSH, SOD, total antioxidant capacity, and catalase. L-NAME, 7-NI, AG (50 mg/kg each), and L-ascorbic acid (200 mg/kg) reversed the changes in SOD, MDA, GSH, total antioxidant capacity, and catalase levels. The NO precursor L-arginine (1000 mg/kg) and NO synthase inhibitors followed the same trend. CONCLUSION Our study findings highlight the complex role of antioxidants and NO modulators in the pathogenesis of diseases, as evidenced by the reversal of oxidative stress indicators. Antioxidant therapy, with its potential to mitigate oxidative stress, emerges as a viable treatment option for a range of pathological conditions associated with oxidative stress.
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Affiliation(s)
- Giridhari Pal
- Pharmacology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, IND
| | - Hara Prasad Mishra
- Clinical Trial, All India Institute of Medical Sciences, New Delhi, Delhi, IND
- Pharmacology and Therapeutics, University College of Medical Sciences, University of Delhi, Delhi, IND
| | - Tarun Kumar Suvvari
- Medicine and Surgery, Squad Medicine and Research (SMR), Visakhapatnam, IND
- General Medicine, Rangaraya Medical College, Kakinada, IND
| | - Anshul Tanwar
- Pharmacology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, IND
| | - Tamoghna Ghosh
- Medicine, All India Institute of Medical Sciences, New Delhi, Delhi, IND
| | - Pankaj Verma
- Pharmacology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, IND
| | - Abhilasha Pal
- Zoology, Miranda House, University of Delhi, Delhi, IND
| | - Kuldeep Patial
- Sleep Medicine Division, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, IND
| | | | - Nidhal A Amanullah
- Psychiatry and Behavioral Sciences, Sree Ramakrishna Mission Hospital, Thiruvananthapuram, IND
| | - Sara A Shukoor
- Psychiatry, Government Medical College Trivandrum, Trivandrum, IND
| | - Sibin Kamal
- Pain and Palliative Medicine, IQRAA International Hospital & Research Centre, Kandhla, IND
| | - Vishwajeet Rohil
- Biochemistry, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, IND
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Pérez R, Burgos V, Marín V, Camins A, Olloquequi J, González-Chavarría I, Ulrich H, Wyneke U, Luarte A, Ortiz L, Paz C. Caffeic Acid Phenethyl Ester (CAPE): Biosynthesis, Derivatives and Formulations with Neuroprotective Activities. Antioxidants (Basel) 2023; 12:1500. [PMID: 37627495 PMCID: PMC10451560 DOI: 10.3390/antiox12081500] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2023] [Revised: 06/21/2023] [Accepted: 06/27/2023] [Indexed: 08/27/2023] Open
Abstract
Neurodegenerative disorders are characterized by a progressive process of degeneration and neuronal death, where oxidative stress and neuroinflammation are key factors that contribute to the progression of these diseases. Therefore, two major pathways involved in these pathologies have been proposed as relevant therapeutic targets: The nuclear transcription factor erythroid 2 (Nrf2), which responds to oxidative stress with cytoprotecting activity; and the nuclear factor NF-κB pathway, which is highly related to the neuroinflammatory process by promoting cytokine expression. Caffeic acid phenethyl ester (CAPE) is a phenylpropanoid naturally found in propolis that shows important biological activities, including neuroprotective activity by modulating the Nrf2 and NF-κB pathways, promoting antioxidant enzyme expression and inhibition of proinflammatory cytokine expression. Its simple chemical structure has inspired the synthesis of many derivatives, with aliphatic and/or aromatic moieties, some of which have improved the biological properties. Moreover, new drug delivery systems increase the bioavailability of these compounds in vivo, allowing its transcytosis through the blood-brain barrier, thus protecting brain cells from the increased inflammatory status associated to neurodegenerative and psychiatric disorders. This review summarizes the biosynthesis and chemical synthesis of CAPE derivatives, their miscellaneous activities, and relevant studies (from 2010 to 2023), addressing their neuroprotective activity in vitro and in vivo.
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Affiliation(s)
- Rebeca Pérez
- Laboratory of Natural Products & Drug Discovery, Center CEBIM, Department of Basic Sciences, Faculty of Medicine, Universidad de La Frontera, Temuco 4780000, Chile; (R.P.); (V.M.)
| | - Viviana Burgos
- Departamento de Ciencias Biológicas y Químicas, Facultad de Recursos Naturales, Universidad Católica de Temuco, Rudecindo Ortega, Temuco 4780000, Chile;
| | - Víctor Marín
- Laboratory of Natural Products & Drug Discovery, Center CEBIM, Department of Basic Sciences, Faculty of Medicine, Universidad de La Frontera, Temuco 4780000, Chile; (R.P.); (V.M.)
| | - Antoni Camins
- Department of Pharmacology, Toxicology and Therapeutic Chemistry, Faculty of Pharmacy and Food Sciences, Universitat de Barcelona, 08028 Barcelona, Spain;
- Institut de Neurociències (UBNeuro), Universitat de Barcelona, 08028 Barcelona, Spain
- Biomedical Research Networking Centre in Neurodegenerative Diseases (CIBERNED), 28031 Madrid, Spain
| | - Jordi Olloquequi
- Department of Biochemistry and Physiology, Faculty of Pharmacy and Food Sciences, Universitat de Barcelona, 08028 Barcelona, Spain;
- Institute of Biomedical Sciences, Faculty of Health Sciences, Universidad Autónoma de Chile, Talca 3460000, Chile
| | - Iván González-Chavarría
- Departamento de Fisiopatología, Facultad de Ciencias Biológicas Universidad de Concepción, Concepción 4030000, Chile;
| | - Henning Ulrich
- Department of Biochemistry, Instituto de Química, Universidad de São Paulo, Av. Prof. Lineu Prestes 748, São Paulo 05508-000, SP, Brazil;
| | - Ursula Wyneke
- Facultad de Medicina, Universidad de Los Andes, Santiago 111711, Chile; (U.W.)
- Center of Interventional Medicine for Precision and Advanced Cellular Therapy (IMPACT), Santiago 7620001, Chile
| | - Alejandro Luarte
- Facultad de Medicina, Universidad de Los Andes, Santiago 111711, Chile; (U.W.)
- Center of Interventional Medicine for Precision and Advanced Cellular Therapy (IMPACT), Santiago 7620001, Chile
| | - Leandro Ortiz
- Instituto de Ciencias Químicas, Facultad de Ciencias, Universidad Austral de Chile, Casilla 567, Valdivia 5110566, Chile;
| | - Cristian Paz
- Laboratory of Natural Products & Drug Discovery, Center CEBIM, Department of Basic Sciences, Faculty of Medicine, Universidad de La Frontera, Temuco 4780000, Chile; (R.P.); (V.M.)
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Chauhan S, Behl T, Sehgal A, Singh S, Sharma N, Gupta S, Albratty M, Najmi A, Meraya AM, Alhazmi HA. Understanding the Intricate Role of Exosomes in Pathogenesis of Alzheimer's Disease. Neurotox Res 2022; 40:1758-1773. [PMID: 36564606 DOI: 10.1007/s12640-022-00621-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 12/06/2022] [Accepted: 12/08/2022] [Indexed: 12/25/2022]
Abstract
Alzheimer's disease causes loss of memory and deterioration of mental abilities is utmost predominant neurodegenerative disease accounting 70-80% cases of dementia. The appearance of plaques of amyloid-β and neurofibrillary tangles in the brain post-mortems of Alzheimer's patients established them as key participants in the etiology of Alzheimer's disease. Exosomes exist as extracellular vesicles of nano-size which are present throughout the body. Exosomes are known to spread toxic hyperphosphorylated tau and amyloid-β between the cells and are linked to the loss of neurons by inducing apoptosis. Exosomes have progressed from cell trashcans to multifunctional organelles which are involved in various functions like internalisation and transmission of macromolecules such as lipids, proteins, and nucleic acids. This review covers current findings on relationship of exosomes in biogenesis and angiogenesis of Alzheimer's disease and functions of exosomes in the etiology of AD. Furthermore, the roles of exosomes in development, diagnosis, treatment, and its importance as therapeutic targets and biomarkers for Alzheimer's disease have also been highlighted.
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Affiliation(s)
- Simran Chauhan
- Chitkara College of Pharmacy, Chitkara University, Punjab, 140401, India
| | - Tapan Behl
- School of Health Sciences, University of Petroleum and Energy Studies, Uttarakhand, Dehradun, 248007, India.
| | - Aayush Sehgal
- GHG Khalsa College of Pharmacy, Sadhar, Ludhiana, Punjab, Gurusar, 141104, India
| | - Sukhbir Singh
- Department of Pharmaceutics, MM College of Pharmacy, Maharishi Markandeshwar (Deemed to be University), Haryana, Mullana-Ambala, 133207, India.
| | - Neelam Sharma
- Department of Pharmaceutics, MM College of Pharmacy, Maharishi Markandeshwar (Deemed to be University), Haryana, Mullana-Ambala, 133207, India
| | - Sumeet Gupta
- Department of Pharmacology, MM College of Pharmacy, Maharishi Markandeshwar (Deemed to be University), Haryana, Mullana-Ambala, 133207, India
| | - Mohammed Albratty
- Department of Pharmaceutical Chemistry and Pharmacognosy, College of Pharmacy, Jazan University, Jazan, 45142, Saudi Arabia
| | - Asim Najmi
- Department of Pharmaceutical Chemistry and Pharmacognosy, College of Pharmacy, Jazan University, Jazan, 45142, Saudi Arabia
| | - Abdulkarim M Meraya
- Pharmacy Practice Research Unit, Department of Clinical Pharmacy, Jazan Uniersity, Jazan, 45124, Saudi Arabia
| | - Hassan A Alhazmi
- Department of Pharmaceutical Chemistry, College of Pharmacy, Jzan University, Jazan, 45142, Saudi Arabia
- Substance Abuse and Toxicology Research Centre, Jzan University, Jazan, 45142, Saudi Arabia
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Vaghef L, Farajdokht F, Erfani M, Majdi A, Sadigh-Eteghad S, Karimi P, Sandoghchian Shotorbani S, Seyedi Vafaee M, Mahmoudi J. Cerebrolysin attenuates ethanol-induced spatial memory impairments through inhibition of hippocampal oxidative stress and apoptotic cell death in rats. Alcohol 2019; 79:127-135. [PMID: 30981808 DOI: 10.1016/j.alcohol.2019.03.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 03/23/2019] [Accepted: 03/27/2019] [Indexed: 02/07/2023]
Abstract
The present study investigates the potential neuroprotective effect of cerebrolysin (CBL), a combination of neurotrophic factors, on the cognitive and biochemical alterations induced by chronic ethanol administration in rats. The animals were divided into five groups as follows: control; ethanol (4 g/kg, for 30 days) plus normal saline (Ethanol + NS); ethanol plus CBL 1 mL/kg (Ethanol + CBL 1), ethanol plus CBL 2.5 mL/kg (Ethanol + CBL 2.5); and ethanol plus CBL 5 mL/kg (Ethanol + CBL 5). The Morris water maze (MWM) test was performed to assess cognitive impairment. The status of the lipid peroxidation marker MDA, antioxidant capacity, as well as alterations of the apoptotic factors such as Bcl-2, BAX, and cleaved caspase-9 and -3, were evaluated in the hippocampus. The results showed that CBL treatment not only normalized the increased MDA levels in the alcoholic rats and enhanced antioxidant defense, but also reduced the Bax/Bcl-2 ratio and cleaved caspase-9 and -3 in the hippocampus. These results were parallel with improvement in spatial memory performance in the MWM test. The findings of the present study provide evidence for the promising therapeutic effect of CBL in chronic ethanol consumption through counteracting oxidative stress and apoptosis markers.
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Banu R, Gerding J, Franklin C, Sikazwe D, Horton W, Török M, Davis J, Cheng KH, Nakazwe M, Mochona B. 4,5-Dimethoxy-2-nitrobenzohydrazides and 1-(1-Benzylpiperidin-4-yl)ethan-1-ones as Potential Antioxidant/Cholinergic Endowed Small Molecule Leads. Sci Pharm 2017; 86:scipharm86010002. [PMID: 29267246 PMCID: PMC5874532 DOI: 10.3390/scipharm86010002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Revised: 12/13/2017] [Accepted: 12/13/2017] [Indexed: 11/16/2022] Open
Abstract
The objective of this research is to generate leads for developing our ultimate poly-active molecules with utility in central nervous system (CNS) diseases. Indeed, poly-active molecules capable of mitigating brain free radical damage while enhancing acetylcholine signaling (via cholinesterase inhibition) are still being sought for combating Alzheimer's disease (AD). We differentiate "poly-active" agents from "multi-target" ones by defining them as single molecular entities designed to target only specific contributory synergistic pharmacologies in a disease. For instance, in AD, free radicals either initiate or act in synergy with other pharmacologies, leading to disease worsening. For this preliminary report, a total of 14 (i.e., 4,5-dimethoxy-2-nitrobenzohydrazide plus 1-(1-benzylpiperidin-4-yl)ethan-1-one) derivatives were synthesized and screened, in silico and in vitro, for their ability to scavenge free radicals and inhibit acetylcholinesterase (AChE)/butyrylcholinesterase (BuChE) enzymes. Overall, six derivatives (4a, 4d, 4e, 4f, 4g, 9b) exhibited potent (>30%) antioxidant properties in the oxygen radical absorbance capacity (ORAC) assay. The antioxidant values were either comparable or more potent than the comparator molecules (ascorbic acid, resveratrol, and trolox). Only three compounds (4d, 9a, 9c) yielded modest AChE/BuChE inhibitions (>10%). Please note that a SciFinder substance data base search confirmed that most of the compounds reported herein are new, except 9a and 9c which are also commercially available.
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Affiliation(s)
- Rukhsar Banu
- Pharmaceutical Sciences Department, Feik School of Pharmacy, University of the Incarnate Word, San Antonio, TX 78209, USA.
| | - Jason Gerding
- Pharmaceutical Sciences Department, Feik School of Pharmacy, University of the Incarnate Word, San Antonio, TX 78209, USA.
| | - Cynthia Franklin
- Pharmaceutical Sciences Department, Feik School of Pharmacy, University of the Incarnate Word, San Antonio, TX 78209, USA.
| | - Donald Sikazwe
- Pharmaceutical Sciences Department, Feik School of Pharmacy, University of the Incarnate Word, San Antonio, TX 78209, USA.
| | - William Horton
- Department of Chemistry, University of Massachusetts Boston, Boston, MA 02125, USA.
| | - Marianna Török
- Department of Chemistry, University of Massachusetts Boston, Boston, MA 02125, USA.
| | - Julian Davis
- Chemistry Department, School of Mathematics, Science and Engineering, University of the Incarnate Word, San Antonio, TX 78209, USA.
| | - Kwan H Cheng
- Department of Physics and Astronomy and Neuroscience Program, Trinity University, San Antonio, TX 78212, USA.
| | - Muziya Nakazwe
- Anatomy and Physiology Department, School of Osteopathic Medicine, University of the Incarnate Word, San Antonio, TX 78209, USA.
| | - Bereket Mochona
- Department of Chemistry, Florida A&M University, Tallahassee, FL 32307, USA.
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Tian L, Hui CW, Bisht K, Tan Y, Sharma K, Chen S, Zhang X, Tremblay ME. Microglia under psychosocial stressors along the aging trajectory: Consequences on neuronal circuits, behavior, and brain diseases. Prog Neuropsychopharmacol Biol Psychiatry 2017; 79:27-39. [PMID: 28095309 DOI: 10.1016/j.pnpbp.2017.01.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Revised: 12/30/2016] [Accepted: 01/13/2017] [Indexed: 12/18/2022]
Abstract
Mounting evidence indicates the importance of microglia for proper brain development and function, as well as in complex stress-related neuropsychiatric disorders and cognitive decline along the aging trajectory. Considering that microglia are resident immune cells of the brain, a homeostatic maintenance of their effector functions that impact neuronal circuitry, such as phagocytosis and secretion of inflammatory factors, is critical to prevent the onset and progression of these pathological conditions. However, the molecular mechanisms by which microglial functions can be properly regulated under healthy and pathological conditions are still largely unknown. We aim to summarize recent progress regarding the effects of psychosocial stress and oxidative stress on microglial phenotypes, leading to neuroinflammation and impaired microglia-synapse interactions, notably through our own studies of inbred mouse strains, and most importantly, to discuss about promising therapeutic strategies that take advantage of microglial functions to tackle such brain disorders in the context of adult psychosocial stress or aging-induced oxidative stress.
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Affiliation(s)
- Li Tian
- Neuroscience Center, University of Helsinki, Viikinkaari 4, Helsinki FIN-00014, Finland; Psychiatry Research Center, Beijing Huilongguan Hospital, Peking University, Beijing, China.
| | - Chin Wai Hui
- Axe Neurosciences, Centre de recherche du CHU de Québec, Québec, Canada
| | - Kanchan Bisht
- Axe Neurosciences, Centre de recherche du CHU de Québec, Québec, Canada
| | - Yunlong Tan
- Psychiatry Research Center, Beijing Huilongguan Hospital, Peking University, Beijing, China
| | - Kaushik Sharma
- Axe Neurosciences, Centre de recherche du CHU de Québec, Québec, Canada
| | - Song Chen
- Psychiatry Research Center, Beijing Huilongguan Hospital, Peking University, Beijing, China; Beijing Key Laboratory of Mental Disorders and Center of Schizophrenia, Beijing Institute for Brain Disorders, Beijing Anding Hospital, Capital Medical University, China
| | - Xiangyang Zhang
- Psychiatry Research Center, Beijing Huilongguan Hospital, Peking University, Beijing, China; Department of Psychiatry and Behavioral Sciences, The University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Marie-Eve Tremblay
- Axe Neurosciences, Centre de recherche du CHU de Québec, Québec, Canada.
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Tamm C, Ceccatelli S. Mechanistic insight into neurotoxicity induced by developmental insults. Biochem Biophys Res Commun 2017; 482:408-418. [DOI: 10.1016/j.bbrc.2016.10.087] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Accepted: 10/23/2016] [Indexed: 12/31/2022]
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Shao Y, Figeys D, Ning Z, Mailloux R, Chan HM. Methylmercury can induce Parkinson's-like neurotoxicity similar to 1-methyl-4- phenylpyridinium: a genomic and proteomic analysis on MN9D dopaminergic neuron cells. J Toxicol Sci 2016; 40:817-28. [PMID: 26558463 DOI: 10.2131/jts.40.817] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Exposure to environmental chemicals has been implicated as a possible risk factor for the development of neurodegenerative diseases. Our previous study showed that methylmercury (MeHg) exposure can disrupt synthesis, uptake and metabolism of dopamine similar to 1-methyl-4-phenylpyridinium (MPP(+)). The objective of this study was to investigate the effects of MeHg exposure on gene and protein profiles in a dopaminergic MN9D cell line. MN9D cells were treated with MeHg (1-5 μM) and MPP(+) (10-40 μM) for 48 hr. Real-time PCR Parkinson's disease (PD) arrays and high-performance liquid chromatography/electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS) were performed for the analysis. PD PCR array results showed that 19% genes were significantly changed in the 2.5 μM MeHg treated cells, and 39% genes were changed in the 5 μM MeHg treated cells. In comparison, MPP(+) treatment (40 µM) resulted in significant changes in 25% genes. A total of 15 common genes were altered by both MeHg and MPP(+), and dopaminergic signaling transduction was the most affected pathway. Proteomic analysis identified a total of 2496 proteins, of which 188, 233 and 395 proteins were differentially changed by 1 μM and 2.5 μM MeHg, and MPP(+) respectively. A total of 61 common proteins were changed by both MeHg and MPP(+) treatment. The changed proteins were mainly involved in energetic generation-related metabolism pathway (propanoate metabolism, pyruvate metabolism and fatty acid metabolism), oxidative phosphorylation, proteasome, PD and other neurodegenerative disorders. A total of 7 genes/proteins including Ube2l3 (Ubiquitin-conjugating enzyme E2 L3) and Th (Tyrosine 3-monooxygenase) were changed in both genomic and proteomic analysis. These results suggest that MeHg and MPP(+) share many similar signaling pathways leading to the pathogenesis of PD and other neurodegenerative diseases.
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Affiliation(s)
- Yueting Shao
- Natural Resources and Environmental Studies Program, University of Northern British Columbia, Canada
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Hodjat M, Rezvanfar MA, Abdollahi M. A systematic review on the role of environmental toxicants in stem cells aging. Food Chem Toxicol 2015; 86:298-308. [PMID: 26582272 DOI: 10.1016/j.fct.2015.11.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Revised: 10/29/2015] [Accepted: 11/02/2015] [Indexed: 12/19/2022]
Abstract
Stem cells are an important target for environmental toxicants. As they are the main source for replenishing of organs in the body, any changes in their normal function could affect the regenerative potential of organs, leading to the appearance of age-related disease and acceleration of the aging process. Environmental toxicants could exert their adverse effect on stem cell function via multiple cellular and molecular mechanisms, resulting in changes in the stem cell differentiation fate and cell transformation, and reduced self-renewal capacity, as well as induction of stress-induced cellular senescence. The present review focuses on the effect of environmental toxicants on stem cell function associated with the aging process. We categorized environmental toxicants according to their preferred molecular mechanism of action on stem cells, including changes in genomic, epigenomic, and proteomic levels and enhancing oxidative stress. Pesticides, tobacco smoke, radiation and heavy metals are well-studied toxicants that cause stem cell dysfunction via induction of oxidative stress. Transgenerational epigenetic changes are the most important effects of a variety of toxicants on germ cells and embryos that are heritable and could affect health in the next several generations. A better understanding of the underlying mechanisms of toxicant-induced stem cell aging will help us to develop therapeutic intervention strategies against environmental aging. Meanwhile, more efforts are required to find the direct in vivo relationship between adverse effect of environmental toxicants and stem cell aging, leading to organismal aging.
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Affiliation(s)
- Mahshid Hodjat
- Department of Toxicology and Pharmacology, Faculty of Pharmacy, and Pharmaceutical Sciences Research Center (PSRC), Endocrinology & Metabolism Research Center (EMRC), Toxicology & Poisoning Research Center (TPRC), Tehran University of Medical Sciences (TUMS), Tehran 1417614411, Iran
| | - Mohammad Amin Rezvanfar
- Department of Toxicology and Pharmacology, Faculty of Pharmacy, and Pharmaceutical Sciences Research Center (PSRC), Endocrinology & Metabolism Research Center (EMRC), Toxicology & Poisoning Research Center (TPRC), Tehran University of Medical Sciences (TUMS), Tehran 1417614411, Iran
| | - Mohammad Abdollahi
- Department of Toxicology and Pharmacology, Faculty of Pharmacy, and Pharmaceutical Sciences Research Center (PSRC), Endocrinology & Metabolism Research Center (EMRC), Toxicology & Poisoning Research Center (TPRC), Tehran University of Medical Sciences (TUMS), Tehran 1417614411, Iran.
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Zhang Z, Ma W, Wang L, Gong H, Tian Y, Zhang J, Liu J, Lu H, Chen X, Liu Y. Activation of Type 4 Metabotropic Glutamate Receptor Attenuates Oxidative Stress-Induced Death of Neural Stem Cells with Inhibition of JNK and p38 MAPK Signaling. Stem Cells Dev 2015; 24:2709-22. [PMID: 26176363 DOI: 10.1089/scd.2015.0067] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Promoting both endogenous and exogenous neural stem cells' (NSCs) survival in the hostile host environments is essential to cell replacement therapy for central nervous system (CNS) disorders. Type 4 metabotropic glutamate receptor (mGluR4), one of the members of mGluRs, has been shown to protect neurons from acute and chronic excitotoxic insults in various brain damages. The present study investigated the preventive effects of mGluR4 on NSC injury induced by oxidative stress. Under challenge with H2O2, loss of cell viability was observed in cultured rat NSCs, and treatment with selective mGluR4 agonist VU0155041 conferred protective effects against the loss of cellular viability in a concentration-dependent manner, as shown by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Pretreatment of VU0155041 (30 μM) also inhibited the excessive NSC death induced by H2O2, and group III mGluRs antagonist (RS)-a-methylserine-O-phosphate (MSOP) or gene-targeted knockdown abolished the protective action of mGluR4, indicated by propidium iodide-Hoechst and terminal deoxynucleotidyl transferase-mediated UTP nick end labeling (TUNEL) staining. Western blot assay demonstrated that mGluR4 activation reversed the decreased procaspase-8/9/3and the destructed Bcl-2/Bax expressing balance, and likewise, MSOP and mGluR4 knockdown abrogated the action of mGluR4 activity. Furthermore, inhibition of JNK and p38 mitogen-activated protein kinases (MAPKs) were observed after mGluR4 activation, and as paralleling control, JNK-specific inhibitor SP600125 and p38-specific inhibitor SB203580 significantly rescued the H2O2-mediated NSC apoptosis and cleavage of procaspase-3. We suggest that activation of mGluR4 prevents oxidative stress-induced NSC death and apoptotic-associated protein activities with involvement of inhibiting the JNK and p38 pathways in cell culture. Our findings may help to develop strategies for enhancing the resided and transplanted NSC survival after oxidative stress insult of CNS.
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Affiliation(s)
- Zhichao Zhang
- 1 Institute of Neurobiology, Xi'an Jiaotong University Health Science Center , Xi'an, Shaanxi, China
| | - Wen Ma
- 1 Institute of Neurobiology, Xi'an Jiaotong University Health Science Center , Xi'an, Shaanxi, China
| | - Li Wang
- 2 Department of Obstetrics and Gynecology, The Affiliated Hospital of Xi'an Medical College , Xi'an, Shaanxi, China
| | - Hanshi Gong
- 1 Institute of Neurobiology, Xi'an Jiaotong University Health Science Center , Xi'an, Shaanxi, China
| | - Yumei Tian
- 3 Xi'an Mental Health Center , Xi'an, Shaanxi, China
| | - Jianshui Zhang
- 1 Institute of Neurobiology, Xi'an Jiaotong University Health Science Center , Xi'an, Shaanxi, China
| | - Jianxin Liu
- 1 Institute of Neurobiology, Xi'an Jiaotong University Health Science Center , Xi'an, Shaanxi, China
| | - Haixia Lu
- 1 Institute of Neurobiology, Xi'an Jiaotong University Health Science Center , Xi'an, Shaanxi, China
| | - Xinlin Chen
- 1 Institute of Neurobiology, Xi'an Jiaotong University Health Science Center , Xi'an, Shaanxi, China
| | - Yong Liu
- 1 Institute of Neurobiology, Xi'an Jiaotong University Health Science Center , Xi'an, Shaanxi, China
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Bose R, Spulber S, Kilian P, Heldring N, Lönnerberg P, Johnsson A, Conti M, Hermanson O, Ceccatelli S. Tet3 mediates stable glucocorticoid-induced alterations in DNA methylation and Dnmt3a/Dkk1 expression in neural progenitors. Cell Death Dis 2015; 6:e1793. [PMID: 26086966 PMCID: PMC4669838 DOI: 10.1038/cddis.2015.159] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Revised: 04/28/2015] [Accepted: 05/13/2015] [Indexed: 12/15/2022]
Abstract
Developmental exposure to excess glucocorticoids (GCs) has harmful neurodevelopmental effects, which include persistent alterations in the differentiation potential of embryonic neural stem cells (NSCs). The mechanisms, however, are largely unknown. Here, we investigated the effects of dexamethasone (Dex, a synthetic GC analog) by MeDIP-like genome-wide analysis of differentially methylated DNA regions (DMRs) in NSCs isolated from embryonic rat cortices. We found that Dex-induced genome-wide DNA hypomethylation in the NSCs in vitro. Similarly, in utero exposure to Dex resulted in global DNA hypomethylation in the cerebral cortex of 3-day-old mouse pups. Dex-exposed NSCs displayed stable changes in the expression of the DNA methyltransferase Dnmt3a, and Dkk1, an essential factor for neuronal differentiation. These alterations were dependent on Tet3 upregulation. In conclusion, we propose that GCs elicit strong and persistent effects on DNA methylation in NSCs with Tet3 playing an essential role in the regulation of Dnmt3a and Dkk1. Noteworthy is the occurrence of similar changes in Dnmt3a and Dkk1 gene expression after exposure to excess GC in vivo.
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Affiliation(s)
- R Bose
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - S Spulber
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - P Kilian
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - N Heldring
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - P Lönnerberg
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - A Johnsson
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - M Conti
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - O Hermanson
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - S Ceccatelli
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
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12
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Phosphoproteomic profiling of selenate-treated Alzheimer's disease model cells. PLoS One 2014; 9:e113307. [PMID: 25485856 PMCID: PMC4259334 DOI: 10.1371/journal.pone.0113307] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Accepted: 10/21/2014] [Indexed: 11/19/2022] Open
Abstract
The reversible phosphorylation of proteins regulates most biological processes, while abnormal phosphorylation is a cause or consequence of many diseases including Alzheimer's disease (AD). One of the hallmarks of AD is the formation of neurofibrillary tangles (NFTs), which is composed of hyperphosphorylated tau proteins. Sodium selenate has been recently found to reduce tau hyperphosphorylation and NFTs formation, and to improve spatial learning and motor performance in AD mice. In the current study, the phosphoproteomics of N2aSW cells treated with selenate were investigated. To avoid missing low-abundance phosphoproteins, both the total proteins of cells and the phosphor-enriched proteins were extracted and subjected to the two-dimensional gel electrophoresis with Pro-Q diamond staining and then LC-MS/MS analysis. A total of 65 proteins were altered in phosphorylation level, of which 39 were up-regulated and 26 were down-regulated. All identified phosphoproteins were bioinformatically annotated according to their physiochemical features, subcellular location, and biological function. Most of these significantly changed phosphoproteins are involved in crucial neural processes such as protesome activity, oxidative stress, cysteine and methionine metabolism, and energy metabolism. Furthermore, decreases were found in homocysteine, phosphor-tau and amyloid β upon selenate treatment. Our results suggest that selenate may intervene in the pathological process of AD by altering the phosphorylation of some key proteins involved in oxidative stress, energy metabolism and protein degradation, thus play important roles in maintaining redox homeostasis, generating ATP, and clearing misfolded proteins and aggregates. The present paper provides some new clues to the mechanism of selenate in AD prevention.
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Choi NY, Choi H, Park HH, Lee EH, Yu HJ, Lee KY, Joo Lee Y, Koh SH. Neuroprotective effects of amlodipine besylate and benidipine hydrochloride on oxidative stress-injured neural stem cells. Brain Res 2014; 1551:1-12. [PMID: 24440775 DOI: 10.1016/j.brainres.2014.01.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 12/11/2013] [Accepted: 01/07/2014] [Indexed: 12/19/2022]
Abstract
Hypertension is associated with oxidative stress. Amlodipine besylate (AB) and benidipine hydrochloride (BH), which are Ca(2+) antagonists, have been reported to reduce oxidative stress. In this study, we examined the neuroprotective effects of AB and BH on oxidative stress-injured neural stem cells (NSCs), with a focus on the phosphatidylinositol 3-kinase (PI3K) pathway and the extracellular signal-regulated kinase (ERK) pathway. After treatment with H2O2, the viability of NSCs decreased in a concentration-dependent manner; however, co-treatment with AB or BH restored the viability of H2O2-injured NSCs. H2O2 increased free radical production and apoptosis in NSCs, whereas co-treatment with AB or BH attenuated these effects. To evaluate the effects of AB or BH on the H2O2-inhibited proliferation of NSCs, we performed BrdU labeling and colony formation assays and found that NSC proliferation decreased upon H2O2 treatment but that combined treatment with AB or BH restored this proliferation. Western blot analysis showed that AB and BH increased the expression of cell survival-related proteins that were linked with the PI3K and ERK pathways but decreased the expression of cell death-related proteins. To investigate whether the PI3K and ERK pathways were directly involved in the neuroprotective effects of AB and BH on H2O2-treated NSCs, NSCs were pretreated with the PI3K inhibitor, LY294002, or the ERK inhibitor, FR180204, which significantly blocked the effects of AB and BH. Together, our results suggest that AB and BH restore the H2O2-inhibited viability and proliferation of NSCs by inhibiting oxidative stress and by activating the PI3K and ERK pathways.
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Affiliation(s)
- Na-Young Choi
- Department of Neurology, Hanyang University College of Medicine, Seoul, Republic of Korea; Department of Translational Medicine, Hanyang University Graduate School of Biomedical Science & Engineering, Seoul, Republic of Korea
| | - Hojin Choi
- Department of Neurology, Hanyang University College of Medicine, Seoul, Republic of Korea
| | - Hyun-Hee Park
- Department of Neurology, Hanyang University College of Medicine, Seoul, Republic of Korea
| | - Eun-Hye Lee
- Department of Neurology, Hanyang University College of Medicine, Seoul, Republic of Korea; Department of Translational Medicine, Hanyang University Graduate School of Biomedical Science & Engineering, Seoul, Republic of Korea
| | - Hyun-Jeung Yu
- Department of Neurology, Bundang Jesaeng Hospital, Gyeonggi Province, Republic of Korea
| | - Kyu-Yong Lee
- Department of Neurology, Hanyang University College of Medicine, Seoul, Republic of Korea
| | - Young Joo Lee
- Department of Neurology, Hanyang University College of Medicine, Seoul, Republic of Korea
| | - Seong-Ho Koh
- Department of Neurology, Hanyang University College of Medicine, Seoul, Republic of Korea; Department of Translational Medicine, Hanyang University Graduate School of Biomedical Science & Engineering, Seoul, Republic of Korea.
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14
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A Framework to Examine the Role of Epigenetics in Health Disparities among Native Americans. Nurs Res Pract 2013; 2013:410395. [PMID: 24386563 PMCID: PMC3872279 DOI: 10.1155/2013/410395] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 11/06/2013] [Accepted: 11/19/2013] [Indexed: 12/29/2022] Open
Abstract
Background. Native Americans disproportionately experience adverse childhood experiences (ACEs) as well as health disparities, including high rates of posttraumatic stress, depression, and substance abuse. Many ACEs have been linked to methylation changes in genes that regulate the stress response, suggesting that these molecular changes may underlie the risk for psychiatric disorders related to ACEs. Methods. We reviewed published studies to provide evidence that ACE-related methylation changes contribute to health disparities in Native Americans. This framework may be adapted to understand how ACEs may result in health disparities in other racial/ethnic groups. Findings. Here we provide evidence that links ACEs to methylation differences in genes that regulate the stress response. Psychiatric disorders are also associated with methylation differences in endocrine, immune, and neurotransmitter genes that serve to regulate the stress response and are linked to psychiatric symptoms and medical morbidity. We provide evidence linking ACEs to these epigenetic modifications, suggesting that ACEs contribute to the vulnerability for developing psychiatric disorders in Native Americans. Conclusion. Additional studies are needed to better understand how ACEs contribute to health and well-being. These studies may inform future interventions to address these serious risks and promote the health and well-being of Native Americans.
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Schiavone S, Jaquet V, Trabace L, Krause KH. Severe life stress and oxidative stress in the brain: from animal models to human pathology. Antioxid Redox Signal 2013; 18:1475-90. [PMID: 22746161 PMCID: PMC3603496 DOI: 10.1089/ars.2012.4720] [Citation(s) in RCA: 204] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2012] [Revised: 06/25/2012] [Accepted: 07/01/2012] [Indexed: 12/27/2022]
Abstract
SIGNIFICANCE Severe life stress (SLS), as opposed to trivial everyday stress, is defined as a serious psychosocial event with the potential of causing an impacting psychological traumatism. RECENT ADVANCES Numerous studies have attempted to understand how the central nervous system (CNS) responds to SLS. This response includes a variety of morphological and neurochemical modifications; among them, oxidative stress is almost invariably observed. Oxidative stress is defined as disequilibrium between oxidant generation and the antioxidant response. CRITICAL ISSUES In this review, we discuss how SLS leads to oxidative stress in the CNS, and how the latter impacts pathophysiological outcomes. We also critically discuss experimental methods that measure oxidative stress in the CNS. The review covers animal models and human observations. Animal models of SLS include sleep deprivation, maternal separation, and social isolation in rodents, and the establishment of hierarchy in non-human primates. In humans, SLS, which is caused by traumatic events such as child abuse, war, and divorce, is also accompanied by oxidative stress in the CNS. FUTURE DIRECTIONS The outcome of SLS in humans ranges from resilience, over post-traumatic stress disorder, to development of chronic mental disorders. Defining the sources of oxidative stress in SLS might in the long run provide new therapeutic avenues.
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Affiliation(s)
- Stefania Schiavone
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland.
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Childhood adversity and DNA methylation of genes involved in the hypothalamus-pituitary-adrenal axis and immune system: whole-genome and candidate-gene associations. Dev Psychopathol 2013; 24:1417-25. [PMID: 23062307 DOI: 10.1017/s0954579412000806] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
In recent years, translational research involving humans and animals has uncovered biological and physiological pathways that explain associations between early adverse circumstances and long-term mental and physical health outcomes. In this article, we summarize the human and animal literature demonstrating that epigenetic alterations in key biological systems, the hypothalamus-pituitary-adrenal axis and immune system, may underlie such disparities. We review evidence suggesting that changes in DNA methylation profiles of the genome may be responsible for the alterations in hypothalamus-pituitary-adrenal axis and immune system trajectories. Using some preliminary data, we demonstrate how explorations of genome-wide and candidate-gene DNA methylation profiles may inform hypotheses and guide future research efforts in these areas. We conclude our article by discussing the many important future directions, merging perspectives from developmental psychology, molecular genetics, neuroendocrinology, and immunology, that are essential for furthering our understanding of how early adverse circumstances may shape developmental trajectories, particularly in the areas of stress reactivity and physical or mental health.
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17
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Madkour NK. Beneficial role of celery oil in lowering the di(2-ethylhexyl) phthalate-induced testicular damage. Toxicol Ind Health 2012; 30:861-72. [DOI: 10.1177/0748233712464808] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Di(2-ethylhexyl) phthalate (DEHP), the most abundant phthalate in the environment, is known to be a reproductive toxicant. Considering the therapeutic significance of medicinal plants, this study was conducted to evaluate the effects of administration of celery oil on DEHP-induced testicular toxicity. The experiment was carried out for 8 weeks on 36 male rats that were divided equally into six groups. Group 1 was kept as normal control (given vehicle), while rats of group 2 were administered orally 200 mg/kg/day of celery oil. Groups 3 and 5 were orally given 500 and 1000 mg DEHP/kg/day, respectively. Groups 4 and 6 were treated with similar doses of DEHP as in groups 3 and 5 plus celery oil (200 mg/kg/day). Body and testicular weights, sperm parameters, serum hormones (testosterone, follicle-stimulating hormone, luteinizing hormone and estradiol), antioxidant enzymes (superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT)) and expression of cytochrome P450 aromatase (CYP19) messenger RNA (mRNA) were investigated at the end of 8th week. Treatment with DEHP alone resulted in a significant decrease in body and testicular weights, sperm parameters and serum hormone levels when compared with control. On the other hand, testicular antioxidant enzymes showed a significant dose-dependent increase. The expression of CYP19 mRNA was significantly reduced by increasing the doses of DEHP. Administration of celery oil along with DEHP partially prevented the decrease in body and testicular weights and enhanced epididymal sperm count, serum hormone levels and the expression of CYP19 mRNA along with diminution in the activities of SOD, GPx and CAT enzymes. The obtained results showed that the celery improved the testicular alterations induced by DEHP in albino rats.
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Affiliation(s)
- Naglaa K Madkour
- Department of Zoology, Women College for Arts, Education and Science, Ain Shams University, Cairo, Egypt
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18
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Giardino G, Fusco A, Romano R, Gallo V, Maio F, Esposito T, Palamaro L, Parenti G, Salerno MC, Vajro P, Pignata C. Betamethasone therapy in ataxia telangiectasia: unraveling the rationale of this serendipitous observation on the basis of the pathogenesis. Eur J Neurol 2012; 20:740-7. [PMID: 23121321 DOI: 10.1111/ene.12024] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2012] [Accepted: 09/20/2012] [Indexed: 11/30/2022]
Abstract
Ataxia telangiectasia (A-T) is a rare autosomal recessive disorder characterized by progressive neurological dysfunction. To date, only supportive care aimed to halt the progressive neurodegeneration is available for the treatment. Recently, an improvement of neurological signs during short-term treatment with betamethasone has been reported. To date, the molecular and biochemical mechanisms by which the steroid produces such effects have not yet been elucidated. Therefore, a review of the literature was carried out to define the potential molecular and functional targets of the steroid effects in A-T. Glucocorticoids (GCs) are capable of diffusing into the CNS by crossing the blood-brain barrier (BBB) where they exert effects on the suppression of inflammation or as antioxidant. GCs have been shown to protect post-mitotic neurons from apoptosis. Eventually, GCs may also modulate synaptic plasticity. A better understanding of the mechanisms of action of GCs in the brain is needed, because in A-T during the initial phase of cell loss the neurological impairment may be rescued by interfering in the biochemical pathways. This would open a new window of intervention in this so far incurable disease.
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Affiliation(s)
- G Giardino
- Department of Pediatrics, Federico II University, Naples, Italy
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19
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Endocrine-disrupting chemicals: associated disorders and mechanisms of action. JOURNAL OF ENVIRONMENTAL AND PUBLIC HEALTH 2012; 2012:713696. [PMID: 22991565 PMCID: PMC3443608 DOI: 10.1155/2012/713696] [Citation(s) in RCA: 334] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Revised: 05/10/2012] [Accepted: 05/10/2012] [Indexed: 12/21/2022]
Abstract
The incidence and/or prevalence of health problems associated with endocrine-disruption have increased. Many chemicals have endocrine-disrupting properties, including bisphenol A, some organochlorines, polybrominated flame retardants, perfluorinated substances, alkylphenols, phthalates, pesticides, polycyclic aromatic hydrocarbons, alkylphenols, solvents, and some household products including some cleaning products, air fresheners, hair dyes, cosmetics, and sunscreens. Even some metals were shown to have endocrine-disrupting properties. Many observations suggesting that endocrine disruptors do contribute to cancer, diabetes, obesity, the metabolic syndrome, and infertility are listed in this paper. An overview is presented of mechanisms contributing to endocrine disruption. Endocrine disruptors can act through classical nuclear receptors, but also through estrogen-related receptors, membrane-bound estrogen-receptors, and interaction with targets in the cytosol resulting in activation of the Src/Ras/Erk pathway or modulation of nitric oxide. In addition, changes in metabolism of endogenous hormones, cross-talk between genomic and nongenomic pathways, cross talk with estrogen receptors after binding on other receptors, interference with feedback regulation and neuroendocrine cells, changes in DNA methylation or histone modifications, and genomic instability by interference with the spindle figure can play a role. Also it was found that effects of receptor activation can differ in function of the ligand.
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20
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Childhood adversity and epigenetic modulation of the leukocyte glucocorticoid receptor: preliminary findings in healthy adults. PLoS One 2012; 7:e30148. [PMID: 22295073 PMCID: PMC3266256 DOI: 10.1371/journal.pone.0030148] [Citation(s) in RCA: 371] [Impact Index Per Article: 30.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Accepted: 12/13/2011] [Indexed: 11/20/2022] Open
Abstract
Background A history of early adverse experiences is an important risk factor for adult psychopathology. Changes in stress sensitivity and functioning of the hypothalamic-pituitary-adrenal (HPA) axis may underlie the association between stress and risk for psychiatric disorders. Preclinical work in rodents has linked low levels of maternal care to increased methylation of the promoter region of the glucocorticoid receptor (GR) gene, as well as to exaggerated hormonal and behavioral responses to stress. Recent studies have begun to examine whether early-life stress leads to epigenetic modifications of the GR gene in humans. Methods We examined the degree of methylation of a region of the promoter of the human GR gene (NR3C1) in leukocyte DNA from 99 healthy adults. Participants reported on their childhood experiences of parental behavior, parental death or desertion, and childhood maltreatment. On a separate day, participants completed the dexamethasone/corticotropin-releasing hormone (Dex/CRH) test, a standardized neuroendocrine challenge test. Results Disruption or lack of adequate nurturing, as measured by parental loss, childhood maltreatment, and parental care, was associated with increased NR3C1 promoter methylation (p<.05). In addition, NR3C1 promoter methylation was linked to attenuated cortisol responses to the Dex/CRH test (p<.05). Conclusions These findings suggest that childhood maltreatment or adversity may lead to epigenetic modifications of the human GR gene. Alterations in methylation of this gene could underlie the associations between childhood adversity, alterations in stress reactivity, and risk for psychopathology.
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Mutsaers HAM, Tofighi R. Dexamethasone enhances oxidative stress-induced cell death in murine neural stem cells. Neurotox Res 2012; 22:127-37. [PMID: 22237944 DOI: 10.1007/s12640-012-9308-9] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Revised: 12/19/2011] [Accepted: 01/02/2012] [Indexed: 11/25/2022]
Abstract
Glucocorticoids (GCs) are essential for normal brain development; however, there is consistent evidence that prenatal exposure of the fetal brain to excess GCs permanently modifies the phenotype of neuronal cells. In this paper, the murine-derived multipotent stem cell line C17.2 was used, as an in vitro model, to investigate the impact of GCs on neural stem cell survival. Our results indicate that dexamethasone (Dex) increases the sensitivity of murine neural stem cells (NSCs) to 2,3-methoxy-1,4-naphthoquinone-induced apoptosis, and this effect could be blocked by the glucocorticoid-receptor (GR) antagonist mifepristone, strongly suggesting the involvement of the GR. Furthermore, our results show that Dex decreases cell number and induces a G1-arrest. We hypothesized that the mitochondria are the main target of Dex. Interestingly, after treatment with Dex, 72% of the investigated genes involved in the mitochondrial respiratory chain are down-regulated, as well as 29% of the genes encoding for antioxidant enzymes. In conclusion, using the C17.2 cell line as a model to study developmental neurotoxicity in vitro, we have shown that GCs can increase cellular sensitivity to oxidative stress and alter the phenotype of NCSs.
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Affiliation(s)
- Henricus A M Mutsaers
- Department of Neuroscience, Karolinska Institutet, P.O. Box 210, 171177 Stockholm, Sweden.
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22
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Godefroy D, Gosselin RD, Yasutake A, Fujimura M, Combadière C, Maury-Brachet R, Laclau M, Rakwal R, Melik-Parsadaniantz S, Bourdineaud JP, Rostène W. The chemokine CCL2 protects against methylmercury neurotoxicity. Toxicol Sci 2011; 125:209-18. [PMID: 21976372 DOI: 10.1093/toxsci/kfr252] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Industrial pollution due to heavy metals such as mercury is a major concern for the environment and public health. Mercury, in particular methylmercury (MeHg), primarily affects brain development and neuronal activity, resulting in neurotoxic effects. Because chemokines can modulate brain functions and are involved in neuroinflammatory and neurodegenerative diseases, we tested the possibility that the neurotoxic effect of MeHg may interfere with the chemokine CCL2. We have used an original protocol in young mice using a MeHg-contaminated fish-based diet for 3 months relevant to human MeHg contamination. We observed that MeHg induced in the mice cortex a decrease in CCL2 concentrations, neuronal cell death, and microglial activation. Knock-out (KO) CCL2 mice fed with a vegetal control food already presented a decrease in cortical neuronal cell density in comparison with wild-type animals under similar diet conditions, suggesting that the presence of CCL2 is required for normal neuronal survival. Moreover, KO CCL2 mice showed a pronounced neuronal cell death in response to MeHg. Using in vitro experiments on pure rat cortical neurons in culture, we observed by blockade of the CCL2/CCR2 neurotransmission an increased neuronal cell death in response to MeHg neurotoxicity. Furthermore, we showed that sod genes are upregulated in brain of wild-type mice fed with MeHg in contrast to KO CCL2 mice and that CCL2 can blunt in vitro the decrease in glutathione levels induced by MeHg. These original findings demonstrate that CCL2 may act as a neuroprotective alarm system in brain deficits due to MeHg intoxication.
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Affiliation(s)
- David Godefroy
- INSERM UMRS 968, Institut de la Vision, Université Pierre et Marie Curie Paris 6, 75012 Paris, France
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Sokolowski K, Falluel-Morel A, Zhou X, DiCicco-Bloom E. Methylmercury (MeHg) elicits mitochondrial-dependent apoptosis in developing hippocampus and acts at low exposures. Neurotoxicology 2011; 32:535-44. [PMID: 21741406 DOI: 10.1016/j.neuro.2011.06.003] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2011] [Revised: 05/20/2011] [Accepted: 06/15/2011] [Indexed: 01/20/2023]
Abstract
The developing brain is particularly sensitive to environmental teratogens, such as methylmercury (MeHg), which may induce cell death. Although several mechanisms of MeHg-induced apoptosis have been defined in culture models, pathways mediating caspase-3 activation in vivo remain unclear, especially in the developing hippocampus. To explore apoptotic mechanisms, Sprague-Dawley rats were exposed to 5 μg/g MeHg or PBS vehicle on postnatal day 7 (P7) and the hippocampus was assessed at various times for levels of apoptotic proteins. MeHg induced a 38% increase in Bax protein and an increase in cytosolic cytochrome c at 4h, followed by later increases in caspase-9 (40% at 12h; 33% at 24h) and caspase-8 (33% at 24h), compared to controls. MeHg also induced an increase in executioner caspase-3, a protease activated by both mitochondrial-dependent caspase-9 and mitochondrial-independent caspase-8. To further define pathways, we used a forebrain culture model and found that the MeHg-induced increases in caspase-3 and caspase-8 were completely blocked by a caspase-9-specific inhibitor, while caspase-9 induction was unperturbed by the caspase-8 inhibitor. These observations suggest that MeHg acts primarily through the mitochondrial-dependent cascade to activate caspase-3 in forebrain precursors, a pathway that may contribute to previously documented neurotoxicity in developing hippocampus. In turn, using the endpoint protein, caspase-3, as a sensitive marker for neural injury, we were able to detect hippocampal cell death in vivo at ten-fold lower levels of MeHg exposure (0.6 μg/g) than previously reported. Thus mitochondrial-dependent cell death in the hippocampus may serve as a sensitive index for teratogenic insults to the developing brain.
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Affiliation(s)
- Katie Sokolowski
- Joint Graduate Program in Toxicology, Graduate School of Biomedical Sciences at Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA
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Tofighi R, Moors M, Bose R, Ibrahim WNW, Ceccatelli S. Neural stem cells for developmental neurotoxicity studies. Methods Mol Biol 2011; 758:67-80. [PMID: 21815059 DOI: 10.1007/978-1-61779-170-3_5] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The developing nervous system is particularly susceptible to toxicants, and exposure during development may result in long-lasting neurological impairments. The damage can range from subtle to severe, and it may impose substantial burdens on affected individuals, their families, and society. Given the little information available on developmental neurotoxicity (DNT) and the growing number of chemicals that need to be tested, new testing strategies and approaches are necessary to identify developmental neurotoxic agents with speed, reliability, and respect for animal welfare. So far, there are no validated alternative methods for DNT testing. Recently, neural stem/progenitor cells have been proposed as relevant models for alternative DNT testing. In this chapter, we provide detailed protocols for culturing neural stem cells (NSCs), in vitro experimental models, including primary cultures of rat and human embryonic NSCs, rat and mouse adult NSCs, as well as the mouse NSC line C17.2 that we have implemented and successfully used for neurotoxicity studies.
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Affiliation(s)
- Roshan Tofighi
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden.
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Glucocorticoids induce long-lasting effects in neural stem cells resulting in senescence-related alterations. Cell Death Dis 2010; 1:e92. [PMID: 21368868 PMCID: PMC3032322 DOI: 10.1038/cddis.2010.60] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Alterations in intrauterine programming occurring during critical periods of development have adverse consequences for whole-organ systems or individual tissue functions in later life. In this paper, we show that rat embryonic neural stem cells (NSCs) exposed to the synthetic glucocorticoid dexamethasone (Dex) undergo heritable alterations, possibly through epigenetic mechanisms. Exposure to Dex results in decreased NSC proliferation, with no effects on survival or differentiation, and changes in the expression of genes associated with cellular senescence and mitochondrial functions. Dex upregulates cell cycle-related genes p16 and p21 in a glucocorticoid receptor(GR)-dependent manner. The senescence-associated markers high mobility group (Hmg) A1 and heterochromatin protein 1 (HP1) are also upregulated in Dex-exposed NSCs, whereas Bmi1 (polycomb ring finger oncogene) and mitochondrial genes Nd3 (NADH dehydrogenase 3) and Cytb (cytochrome b) are downregulated. The concomitant decrease in global DNA methylation and DNA methyltransferases (Dnmts) suggests the occurrence of epigenetic changes. All these features are retained in daughter NSCs (never directly exposed to Dex) and are associated with a higher susceptibility to oxidative stress, as shown by the increased occurrence of apoptotic cell death on exposure to the redox-cycling reactive oxygen species (ROS) generator 2,3-dimethoxy-1-naphthoquinone (DMNQ). Our study provides novel evidence for programming effects induced by glucocorticoids (GCs) on NSCs and supports the idea that fetal exposure to endogenous or exogenous GCs is likely to result in long-term consequences that may predispose to neurodevelopmental and/or neurodegenerative disorders.
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Mabandla MV, Russell VA. Voluntary exercise reduces the neurotoxic effects of 6-hydroxydopamine in maternally separated rats. Behav Brain Res 2010; 211:16-22. [PMID: 20206210 PMCID: PMC2862124 DOI: 10.1016/j.bbr.2010.02.045] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2009] [Revised: 02/23/2010] [Accepted: 02/23/2010] [Indexed: 11/28/2022]
Abstract
Maternal separation has been associated with development of anxiety-like behaviour and learning impairments in adult rats. This has been linked to changes in brain morphology observed after exposure to high levels of circulating glucocorticoids during the stress-hyporesponsive period (P4-P14). In the present study, adult rats that had been subjected to maternal separation (180 min/day for 14 days) during the stress-hyporesponsive period, received unilateral infusions of a small dose of 6-hydroxydopamine (6-OHDA, 5 microg/4 microl saline) into the medial forebrain bundle. The results showed that voluntary exercise had a neuroprotective effect in both non-stressed and maternally separated rats in that there was a decrease in forelimb akinesia (step test) and limb use asymmetry (cylinder test). Maternal separation increased forelimb akinesia and forelimb use asymmetry and reduced the beneficial effect of exercise on forelimb akinesia. It also reduced exploratory behaviour, consistent with anxiety-like behaviour normally associated with maternal separation. Exercise appeared to reduce dopamine neuron destruction in the lesioned substantia nigra when expressed as a percentage of the non-lesioned hemisphere. However, this appeared to be due to a compensatory decrease in completely stained tyrosine hydroxylase-positive neurons in the contralateral, non-lesioned substantia nigra. In agreement with reports that maternal separation increases the 6-OHDA-induced loss of dopamine terminals in the striatum, there was a small increase in dopamine neuron destruction when expressed as a percentage of the non-lesioned hemisphere but there was no difference in dopamine cell number, suggesting that exposure to maternal separation did not exacerbate dopamine cell loss.
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Affiliation(s)
- Musa Vuyisile Mabandla
- Department of Human Physiology, School of Medical Sciences, Faculty of Health Sciences, University of KwaZulu-Natal, Durban 4000, South Africa.
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Effects of chronic restraint stress and 17-β-estradiol replacement on oxidative stress in the spinal cord of ovariectomized female rats. Neurochem Res 2010; 35:1700-7. [PMID: 20632091 DOI: 10.1007/s11064-010-0232-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/08/2010] [Indexed: 01/02/2023]
Abstract
Previous studies have shown sex-specific oxidative changes in spinal cord of rats submitted to chronic stress, which may be due to gonadal hormones. Here, we assessed total radical-trapping potential (TRAP), superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities and lipid peroxidation (evaluated by the TBARS test) in the spinal cord of ovariectomized (OVX) female rats. Female rats were subjected to OVX, and half of the animals received estradiol replacement. Animals were subdivided into controls and chronically stressed (for 40 days). Our findings demonstrate that chronic stress decreased TRAP, and increased SOD activity in spinal cord homogenates from ovariectomized female rats and had no effect on GPx activity. On the other hand, groups receiving 17β-estradiol replacement presented a decreased GPx activity, but no alteration in TRAP and in SOD activity. No differences in the TBARS test were found in any of the groups analyzed. In conclusion, our results support the idea that chronic stress induces an imbalance between SOD and GPx activities, additionally decreasing TRAP. Estradiol replacement did not reverse the effects of chronic stress, but induced a decrease in GPx activity. Therefore, estradiol replacement in ovariectomized chronically stressed rats could make the spinal cord more susceptible to oxidative injury.
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Tyrka AR, Price LH, Kao HT, Porton B, Marsella SA, Carpenter LL. Childhood maltreatment and telomere shortening: preliminary support for an effect of early stress on cellular aging. Biol Psychiatry 2010; 67:531-4. [PMID: 19828140 PMCID: PMC2853238 DOI: 10.1016/j.biopsych.2009.08.014] [Citation(s) in RCA: 240] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2009] [Revised: 08/11/2009] [Accepted: 08/11/2009] [Indexed: 12/23/2022]
Abstract
BACKGROUND Psychological stress and trauma are risk factors for several medical and psychiatric illnesses. Recent studies have implicated advanced cellular aging as a potential mechanism of this association. Telomeres, DNA repeats that cap the ends of chromosomes and promote stability, shorten progressively with each cell division; their length is a marker of biological aging. Based on previous evidence linking psychosocial stress to shorter telomere length, this study was designed to evaluate the effect of childhood adversity on telomere length. METHODS Thirty-one adults with no current or past major Axis I psychiatric disorder participated. Subjects reported on their history of childhood maltreatment and telomere length was measured from DNA extracted from frozen whole blood using quantitative polymerase chain reaction. RESULTS Participants reporting a history of childhood maltreatment had significantly shorter telomeres than those who did not report a history of maltreatment. This finding was not due to effects of age, sex, smoking, body mass index, or other demographic factors. Analysis of subscales showed that both physical neglect and emotional neglect were significantly linked to telomere length. CONCLUSIONS These results extend previous reports linking shortened leukocyte telomere length and caregiver stress to more remote stressful experiences in childhood and suggest that childhood maltreatment could influence cellular aging.
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Affiliation(s)
- Audrey R. Tyrka
- Mood Disorders Research Program, Butler Hospital, Providence RI 02906, Department of Psychiatry and Human Behavior, Warren Alpert Medical School of Brown University
| | - Lawrence H Price
- Mood Disorders Research Program, Butler Hospital, Providence RI 02906, Department of Psychiatry and Human Behavior, Warren Alpert Medical School of Brown University
| | - Hung-Teh Kao
- Department of Psychiatry and Human Behavior, Warren Alpert Medical School of Brown University, Laboratory of Molecular Psychiatry, Butler Hospital, Providence RI 02906
| | - Barbara Porton
- Department of Psychiatry and Human Behavior, Warren Alpert Medical School of Brown University, Laboratory of Molecular Psychiatry, Butler Hospital, Providence RI 02906
| | - Sarah A Marsella
- Mood Disorders Research Program, Butler Hospital, Providence RI 02906
| | - Linda L Carpenter
- Mood Disorders Research Program, Butler Hospital, Providence RI 02906, Department of Psychiatry and Human Behavior, Warren Alpert Medical School of Brown University
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Russo I, Cosentino C, Del Giudice E, Broccoletti T, Amorosi S, Cirillo E, Aloj G, Fusco A, Costanzo V, Pignata C. In ataxia-teleangiectasia betamethasone response is inversely correlated to cerebellar atrophy and directly to antioxidative capacity. Eur J Neurol 2009; 16:755-9. [PMID: 19475758 DOI: 10.1111/j.1468-1331.2009.02600.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND AND PURPOSE Ataxia-telangiectasia (A-T) is a rare autosomal recessive disorder caused by alterations of the A-T mutated (ATM) gene. Although A-T is a non-curable disease, we, previously, documented a clear improvement of cerebellar functions during a short-term betamethasone trial. The aim of this study was to define the underlying biochemical mechanism. METHODS In six A-T patients receiving a short-term steroid therapy, intracellular glutathione (GSH) levels were evaluated with a colorimetric assay. The lipid peroxidation level and reactive oxygen species (ROS) production were evaluated using commercial assays. All the parameters were compared with the improvement of cerebellar functions expressed as delta (Delta) of the Scale for the Assessment and Rating of Ataxia (SARA). RESULTS We observed an inverse correlation between Delta SARA and the severity of cerebellar atrophy and between the latter and basal GSH values. Four of the five patients with the highest Delta SARA also had the highest GSH values. Moreover, even though basal ROS values were comparable in patients and controls, in the only patient studied at different time-points of therapy, a remarkable reduction in ROS levels was documented. CONCLUSION We suggest that antioxidative mechanisms play a role in favouring the improvement of cerebellar functions observed in A-T patients receiving a short-term betamethasone trial.
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Affiliation(s)
- I Russo
- Department of Pediatrics, "Federico II" University, Naples, Italy
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Mechanisms regulating the susceptibility of hematopoietic malignancies to glucocorticoid-induced apoptosis. Adv Cancer Res 2009; 101:127-248. [PMID: 19055945 DOI: 10.1016/s0065-230x(08)00406-5] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Glucocorticoids (GCs) are commonly used in the treatment of hematopoietic malignancies owing to their ability to induce apoptosis of these cancerous cells. Whereas some types of lymphoma and leukemia respond well to this drug, others are resistant. Also, GC-resistance gradually develops upon repeated treatments ultimately leading to refractory relapsed disease. Understanding the mechanisms regulating GC-induced apoptosis is therefore uttermost important for designing novel treatment strategies that overcome GC-resistance. This review discusses updated data describing the complex regulation of the cell's susceptibility to apoptosis triggered by GCs. We address both the genomic and nongenomic effects involved in promoting the apoptotic signals as well as the resistance mechanisms opposing these signals. Eventually we address potential strategies of clinical relevance that sensitize GC-resistant lymphoma and leukemia cells to this drug. The major target is the nongenomic signal transduction machinery where the interplay between protein kinases determines the cell fate. Shifting the balance of the kinome towards a state where Glycogen synthase kinase 3alpha (GSK3alpha) is kept active, favors an apoptotic response. Accumulating data show that it is possible to therapeutically modulate GC-resistance in patients, thereby improving the response to GC therapy.
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Ferraro L, Tomasini MC, Tanganelli S, Mazza R, Coluccia A, Carratù MR, Gaetani S, Cuomo V, Antonelli T. Developmental exposure to methylmercury elicits early cell death in the cerebral cortex and long-term memory deficits in the rat. Int J Dev Neurosci 2008; 27:165-74. [PMID: 19084587 DOI: 10.1016/j.ijdevneu.2008.11.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2008] [Revised: 11/05/2008] [Accepted: 11/12/2008] [Indexed: 01/24/2023] Open
Abstract
Experiments were performed to assess the neurotoxic effects induced by prenatal acute treatment with methylmercury on cortical neurons. To this purpose, primary neuronal cultures were obtained from cerebral cortex of neonatal rats born to dams treated with methylmercury (4 and 8 mg/kg by gavage) on gestational day 15, the developmental stage critical for cortical neuron proliferation. Prenatal exposure to methylmercury 8 mg/kg significantly reduced cell viability and caused either apoptotic or necrotic neuronal death. Moreover, this exposure level resulted in abnormal neurite outgrowth and retraction or collapse of some neurites, caused by a dissolution of microtubules. The severe and early cortical neuron damage induced by methylmercury 8 mg/kg treatment correlated with long term memory impairment, since adult rats (90 days of age) born to dams treated with this dose level showed a significant deficit in the retention performance when subjected to a passive avoidance task. Prenatal exposure to methylmercury 4 mg/kg significantly increased the neuronal vulnerability to a neurotoxic insult. This was determined by measuring the increment of chromatin condensation induced by glutamate, at a concentration (30 microM) able to induce an excitotoxic damage. This exposure level eliciting apoptotic death did not result in cognitive dysfunctions. In conclusion, the methylmercury-induced disruption of glutamate pathway during critical windows of brain development may interfere with cell fate and proliferation resulting in a more or less severe cortical lesions associated or not with loss of function later in life, depending on the exposure levels. Therefore, the early biochemical effects and long-term behavioral changes elicited by high methylmercury levels suggest that the developing brain is impaired in its ability to recover following toxic insult, and the initial effects on cortical neurons may lead to permanent cognitive dysfunctions.
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Affiliation(s)
- Luca Ferraro
- Department of Clinical and Experimental Medicine, University of Ferrara, Ferrara, Italy.
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Casaccia-Bonnefil P, Pandozy G, Mastronardi F. Evaluating epigenetic landmarks in the brain of multiple sclerosis patients: a contribution to the current debate on disease pathogenesis. Prog Neurobiol 2008; 86:368-78. [PMID: 18930111 DOI: 10.1016/j.pneurobio.2008.09.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2008] [Accepted: 09/05/2008] [Indexed: 12/31/2022]
Abstract
The evidence suggesting a role of epigenetics in the definition of complex trait diseases is rapidly increasing. The gender prevalence of multiple sclerosis, the low level concordance in homozygous twins and the linkage to several genetic loci, suggest an epigenetic component to the definition of this demyelinating disorder. While the immune etio-pathogenetic mechanism of disease progression has been well characterized, still relatively little is known about the initial events contributing to onset and progression of the demyelinating lesion. This article addresses the challenging question of whether loss of the mechanisms of epigenetic regulation of gene expression in the myelinating cells may contribute to the pathogenesis of multiple sclerosis, by affecting the repair process and by modulating the levels of enzymes involved in neo-epitope formation. The role of altered post-translational modifications of nucleosomal histones and DNA methylation in white matter oligodendroglial cells are presented in terms of pathogenetic concepts and the relevance to therapeutic intervention is then discussed.
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Affiliation(s)
- Patrizia Casaccia-Bonnefil
- Department of Neuroscience, Mount Sinai School of Medicine, One Gustave Levy Place, New York, NY10029, USA.
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