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Margolis ET, Gabard-Durnam LJ. Prenatal influences on postnatal neuroplasticity: Integrating DOHaD and sensitive/critical period frameworks to understand biological embedding in early development. INFANCY 2024. [PMID: 38449347 DOI: 10.1111/infa.12588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2023] [Revised: 01/26/2024] [Accepted: 02/13/2024] [Indexed: 03/08/2024]
Abstract
Early environments can have significant and lasting effects on brain, body, and behavior across the lifecourse. Here, we address current research efforts to understand how experiences impact neurodevelopment with a new perspective integrating two well-known conceptual frameworks - the Developmental Origins of Health and Disease (DOHaD) and sensitive/critical period frameworks. Specifically, we consider how prenatal experiences characterized in the DOHaD model impact two key neurobiological mechanisms of sensitive/critical periods for adapting to and learning from the postnatal environment. We draw from both animal and human research to summarize the current state of knowledge on how particular prenatal substance exposures (psychoactive substances and heavy metals) and nutritional profiles (protein-energy malnutrition and iron deficiency) each differentially impact brain circuits' excitation/GABAergic inhibition balance and myelination. Finally, we highlight new research directions that emerge from this integrated framework, including testing how prenatal environments alter sensitive/critical period timing and learning and identifying potential promotional/buffering prenatal exposures to impact postnatal sensitive/critical periods. We hope this integrative framework considering prenatal influences on postnatal neuroplasticity will stimulate new research to understand how early environments have lasting consequences on our brains, behavior, and health.
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Affiliation(s)
- Emma T Margolis
- Department of Psychology, Northeastern University, Boston, Massachusetts, USA
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2
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Naffaa V, Magny R, Regazzetti A, Van Steenwinckel J, Gressens P, Laprévote O, Auzeil N, Schang AL. Shift in phospholipid and fatty acid contents accompanies brain myelination. Biochimie 2022; 203:20-31. [DOI: 10.1016/j.biochi.2022.08.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 08/11/2022] [Accepted: 08/15/2022] [Indexed: 11/02/2022]
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Lead exposure of rats during and after pregnancy induces anti-myelin proteolytic activity: a potential mechanism for lead-induced neurotoxicity. Toxicology 2022; 472:153179. [DOI: 10.1016/j.tox.2022.153179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 04/01/2022] [Accepted: 04/10/2022] [Indexed: 11/21/2022]
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Naffaa V, Hochar I, Lama C, Magny R, Regazzetti A, Gressens P, Laprévote O, Auzeil N, Schang AL. Bisphenol A Impairs Lipid Remodeling Accompanying Cell Differentiation in the Oligodendroglial Cell Line Oli-Neu. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27072274. [PMID: 35408676 PMCID: PMC9000593 DOI: 10.3390/molecules27072274] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 03/11/2022] [Accepted: 03/25/2022] [Indexed: 12/04/2022]
Abstract
In the central nervous system, the process of myelination involves oligodendrocytes that wrap myelin around axons. Myelin sheaths are mainly composed of lipids and ensure efficient conduction of action potentials. Oligodendrocyte differentiation is an essential preliminary step to myelination which, in turn, is a key event of neurodevelopment. Bisphenol A (BPA), a ubiquitous endocrine disruptor, is suspected to disrupt this developmental process and may, thus, contribute to several neurodevelopmental disorders. In this study, we assessed the effect of BPA on oligodendrocyte differentiation through a comprehensive analysis of cell lipidome by UHPLC-HRMS. For this purpose, we exposed the oligodendroglial cell line Oli-neu to several BPA concentrations for 72 h of proliferation and another 72 h of differentiation. In unexposed cells, significant changes occurred in lipid distribution during Oli-neu differentiation, including an increase in characteristic myelin lipids, sulfatides, and ethanolamine plasmalogens, and a marked remodeling of phospholipid subclasses and fatty acid contents. Moreover, BPA induced a decrease in sulfatide and phosphatidylinositol plasmalogen contents and modified monounsaturated/polyunsaturated fatty acid relative contents in phospholipids. These effects counteracted the lipid remodeling accompanying differentiation and were confirmed by gene expression changes. Altogether, our results suggest that BPA disrupts lipid remodeling accompanying early oligodendrocyte differentiation.
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Affiliation(s)
- Vanessa Naffaa
- CiTCoM, CNRS, Université Paris Cité, 75006 Paris, France; (V.N.); (I.H.); (C.L.); (R.M.); (A.R.); (O.L.); (N.A.)
| | - Isabelle Hochar
- CiTCoM, CNRS, Université Paris Cité, 75006 Paris, France; (V.N.); (I.H.); (C.L.); (R.M.); (A.R.); (O.L.); (N.A.)
| | - Chéryane Lama
- CiTCoM, CNRS, Université Paris Cité, 75006 Paris, France; (V.N.); (I.H.); (C.L.); (R.M.); (A.R.); (O.L.); (N.A.)
| | - Romain Magny
- CiTCoM, CNRS, Université Paris Cité, 75006 Paris, France; (V.N.); (I.H.); (C.L.); (R.M.); (A.R.); (O.L.); (N.A.)
- INSERM UMR 968, CNRS UMR 7210, Institut de la Vision, IHU ForeSight, Sorbonne Université UM80, 75012 Paris, France
| | - Anne Regazzetti
- CiTCoM, CNRS, Université Paris Cité, 75006 Paris, France; (V.N.); (I.H.); (C.L.); (R.M.); (A.R.); (O.L.); (N.A.)
| | - Pierre Gressens
- NeuroDiderot, Inserm, Université Paris Cité, 75019 Paris, France;
| | - Olivier Laprévote
- CiTCoM, CNRS, Université Paris Cité, 75006 Paris, France; (V.N.); (I.H.); (C.L.); (R.M.); (A.R.); (O.L.); (N.A.)
- Hôpital Européen Georges Pompidou, AP-HP, Service de Biochimie, 75015 Paris, France
| | - Nicolas Auzeil
- CiTCoM, CNRS, Université Paris Cité, 75006 Paris, France; (V.N.); (I.H.); (C.L.); (R.M.); (A.R.); (O.L.); (N.A.)
| | - Anne-Laure Schang
- UMR 1153 CRESS, Université Paris Cité, 75004 Paris, France
- Correspondence:
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Takeuchi H, Taki Y, Nouchi R, Yokoyama R, Kotozaki Y, Nakagawa S, Sekiguchi A, Iizuka K, Hanawa S, Araki T, Miyauchi CM, Sakaki K, Nozawa T, Ikeda S, Yokota S, Daniele M, Sassa Y, Kawashima R. Lead exposure is associated with functional and microstructural changes in the healthy human brain. Commun Biol 2021; 4:912. [PMID: 34312468 PMCID: PMC8313694 DOI: 10.1038/s42003-021-02435-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Accepted: 07/06/2021] [Indexed: 02/07/2023] Open
Abstract
Lead is a toxin known to harm many organs in the body, particularly the central nervous system, across an individual's lifespan. To date, no study has yet investigated the associations between body lead level and the microstructural properties of gray matter areas, and brain activity during attention-demanding tasks. Here, utilizing data of diffusion tensor imaging, functional magnetic resonance imaging and cognitive measures among 920 typically developing young adults, we show greater hair lead levels are weakly but significantly associated with (a) increased working memory-related activity in the right premotor and pre-supplemental motor areas, (b) lower fractional anisotropy (FA) in white matter areas near the internal capsule, (c) lower mean diffusivity (MD) in the dopaminergic system in the left hemisphere and other widespread contingent areas, and (d) greater MD in the white matter area adjacent to the right fusiform gyrus. Higher lead levels were also weakly but significantly associated with lower performance in tests of high-order cognitive functions, such as the psychometric intelligence test, greater impulsivity measures, and higher novelty seeking and extraversion. These findings reflect the weak effect of daily lead level on the excitability and microstructural properties of the brain, particularly in the dopaminergic system.
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Affiliation(s)
- Hikaru Takeuchi
- grid.69566.3a0000 0001 2248 6943Division of Developmental Cognitive Neuroscience, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| | - Yasuyuki Taki
- grid.69566.3a0000 0001 2248 6943Division of Developmental Cognitive Neuroscience, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan ,grid.69566.3a0000 0001 2248 6943Division of Medical Neuroimaging Analysis, Department of Community Medical Supports, Tohoku Medical Megabank Organization, Tohoku University, Sendai, Japan ,grid.69566.3a0000 0001 2248 6943Department of Radiology and Nuclear Medicine, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| | - Rui Nouchi
- grid.69566.3a0000 0001 2248 6943Creative Interdisciplinary Research Division, Frontier Research Institute for Interdisciplinary Science, Tohoku University, Sendai, Japan ,grid.69566.3a0000 0001 2248 6943Human and Social Response Research Division, International Research Institute of Disaster Science, Tohoku University, Sendai, Japan ,grid.69566.3a0000 0001 2248 6943Department of Advanced Brain Science, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| | - Ryoichi Yokoyama
- grid.31432.370000 0001 1092 3077School of Medicine, Kobe University, Kobe, Japan
| | - Yuka Kotozaki
- grid.411582.b0000 0001 1017 9540Division of Clinical research, Medical-Industry Translational Research Center, Fukushima Medical University School of Medicine, Fukushima, Japan
| | - Seishu Nakagawa
- grid.69566.3a0000 0001 2248 6943Department of Human Brain Science, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan ,grid.412755.00000 0001 2166 7427Division of Psychiatry, Tohoku Medical and Pharmaceutical University, Sendai, Japan
| | - Atsushi Sekiguchi
- grid.69566.3a0000 0001 2248 6943Division of Medical Neuroimaging Analysis, Department of Community Medical Supports, Tohoku Medical Megabank Organization, Tohoku University, Sendai, Japan ,grid.419280.60000 0004 1763 8916Department of Behavioral Medicine, National Institute of Mental Health, National Center of Neurology and Psychiatry, Tokyo, Japan
| | - Kunio Iizuka
- grid.69566.3a0000 0001 2248 6943Department of Psychiatry, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Sugiko Hanawa
- grid.69566.3a0000 0001 2248 6943Department of Human Brain Science, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| | | | - Carlos Makoto Miyauchi
- grid.69566.3a0000 0001 2248 6943Department of Advanced Brain Science, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| | - Kohei Sakaki
- grid.69566.3a0000 0001 2248 6943Department of Advanced Brain Science, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| | - Takayuki Nozawa
- grid.32197.3e0000 0001 2179 2105Research Institute for the Earth Inclusive Sensing, Tokyo Institute of Technology, Tokyo, Japan
| | - Shigeyuki Ikeda
- grid.69566.3a0000 0001 2248 6943Department of Ubiquitous Sensing, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| | - Susum Yokota
- grid.177174.30000 0001 2242 4849Division for Experimental Natural Science, Faculty of Arts and Science, Kyushu University, Fukuoka, Japan
| | - Magistro Daniele
- grid.12361.370000 0001 0727 0669Department of Sport Science, School of Science and Technology, Nottingham Trent University, Nottingham, UK
| | - Yuko Sassa
- grid.69566.3a0000 0001 2248 6943Division of Developmental Cognitive Neuroscience, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| | - Ryuta Kawashima
- grid.69566.3a0000 0001 2248 6943Division of Developmental Cognitive Neuroscience, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan ,grid.69566.3a0000 0001 2248 6943Department of Advanced Brain Science, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan ,grid.69566.3a0000 0001 2248 6943Department of Human Brain Science, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
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Naffaa V, Laprévote O, Schang AL. Effects of endocrine disrupting chemicals on myelin development and diseases. Neurotoxicology 2020; 83:51-68. [PMID: 33352275 DOI: 10.1016/j.neuro.2020.12.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 12/10/2020] [Accepted: 12/16/2020] [Indexed: 12/14/2022]
Abstract
In the central and peripheral nervous systems, myelin is essential for efficient conduction of action potentials. During development, oligodendrocytes and Schwann cells differentiate and ensure axon myelination, and disruption of these processes can contribute to neurodevelopmental disorders. In adults, demyelination can lead to important disabilities, and recovery capacities by remyelination often decrease with disease progression. Among environmental chemical pollutants, endocrine disrupting chemicals (EDCs) are of major concern for human health and are notably suspected to participate in neurodevelopmental and neurodegenerative diseases. In this review, we have combined the current knowledge on EDCs impacts on myelin including several persistent organic pollutants, bisphenol A, triclosan, heavy metals, pesticides, and nicotine. Besides, we presented several other endocrine modulators, including pharmaceuticals and the phytoestrogen genistein, some of which are candidates for treating demyelinating conditions but could also be deleterious as contaminants. The direct impacts of EDCs on myelinating cells were considered as well as their indirect consequences on myelin, particularly on immune mechanisms associated with demyelinating conditions. More studies are needed to describe the effects of these compounds and to further understand the underlying mechanisms in relation to the potential for endocrine disruption.
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Affiliation(s)
- Vanessa Naffaa
- Université de Paris, UMR 8038 (CiTCoM), CNRS, Faculté de Pharmacie de Paris, 4 avenue de l'Observatoire, 75006 Paris, France.
| | - Olivier Laprévote
- Université de Paris, UMR 8038 (CiTCoM), CNRS, Faculté de Pharmacie de Paris, 4 avenue de l'Observatoire, 75006 Paris, France; Hôpital Européen Georges Pompidou, AP-HP, Service de Biochimie, 20 rue Leblanc, 75015 Paris, France.
| | - Anne-Laure Schang
- Université de Paris, UMR 1153 (CRESS), Faculté de Pharmacie de Paris, 4 avenue de l'Observatoire, 75006 Paris, France.
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7
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Kraft AD. The use of glial data in human health assessments of environmental contaminants. Toxicology 2015; 333:127-136. [PMID: 25912087 DOI: 10.1016/j.tox.2015.04.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Revised: 04/10/2015] [Accepted: 04/21/2015] [Indexed: 11/27/2022]
Abstract
Central nervous system (CNS) glia (i.e., astrocytes, microglia, and oligodendrocytes) are essential for maintaining neuronal homeostasis, and they orchestrate an organized cellular response to CNS injury. In addition to their beneficial roles, studies have demonstrated that disrupted glial function can have disastrous consequences on neuronal health. While effects on neuron-supportive glia are important to consider when evaluating neurotoxicity risk, interpreting glial changes is not always straightforward, particularly when attempting to discern pro-neurotoxic phenotypes from homeostatic processes or adaptive responses. To better understand how glia have been characterized and used in human health assessments of environmental contaminants (e.g., chemicals), an evaluation of all finalized assessments conducted by the U.S. Environmental Protection Agency's influential Integrated Risk Information System (IRIS) program between 1987 and 2013 was performed. Human health assessments to date have placed a clear emphasis on the neuronal cell response to potential toxicants, although more recent assessments increasingly include descriptions of glial changes. However, these descriptions are generally brief and non-specific, and they primarily consist of documenting gliosis following overt neuronal injury. As research interest in this topic continues to increase, methods for evaluating changes in glia continue to be expanded and refined, and assessors' confidence in the reliability of these data is likely to rise. Thus, glial data are anticipated to have an increasingly influential impact on the interpretation of neurotoxicity risk and underlying mechanisms. As our understanding of the complex roles these cells play grows, this knowledge is expected to support the inclusion of more extensive and specific descriptions of glial changes, including informed interpretations of the potential impact on CNS health, in future human health assessments.
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Affiliation(s)
- Andrew D Kraft
- National Center for Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, 1200 Pennsylvania Ave., N.W., Mail Code 8623P, Washington, D.C. 20460, United States.
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Rai NK, Ashok A, Rai A, Tripathi S, Nagar GK, Mitra K, Bandyopadhyay S. Exposure to As, Cd and Pb-mixture impairs myelin and axon development in rat brain, optic nerve and retina. Toxicol Appl Pharmacol 2013; 273:242-58. [DOI: 10.1016/j.taap.2013.05.003] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2012] [Revised: 04/13/2013] [Accepted: 05/03/2013] [Indexed: 01/25/2023]
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9
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Liu W, Deng Y, Liu Y, Gong W, Deng W. Stem Cell Models for Drug Discovery and Toxicology Studies. J Biochem Mol Toxicol 2013; 27:17-27. [DOI: 10.1002/jbt.21470] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2012] [Revised: 11/29/2012] [Accepted: 12/01/2012] [Indexed: 12/15/2022]
Affiliation(s)
- Wenwei Liu
- Medical College; Hubei University of Arts and Science; Xiangyang; Hubei; People's Republic of China
| | - Yaguang Deng
- Medical College; Hubei University of Arts and Science; Xiangyang; Hubei; People's Republic of China
| | | | - Wenrong Gong
- Medical College; Hubei University of Arts and Science; Xiangyang; Hubei; People's Republic of China
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Wang H, Ji YL, Wang Q, Zhao XF, Ning H, Liu P, Zhang C, Yu T, Zhang Y, Meng XH, Xu DX. Maternal lead exposure during lactation persistently impairs testicular development and steroidogenesis in male offspring. J Appl Toxicol 2012; 33:1384-94. [DOI: 10.1002/jat.2795] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2012] [Revised: 06/06/2012] [Accepted: 06/06/2012] [Indexed: 11/12/2022]
Affiliation(s)
- Hua Wang
- Department of Toxicology, School of Public Health; Anhui Medical University; Hefei 230032 China
| | - Yan-Li Ji
- Department of Toxicology, School of Public Health; Anhui Medical University; Hefei 230032 China
| | - Qun Wang
- Department of Toxicology, School of Public Health; Anhui Medical University; Hefei 230032 China
| | - Xian-Feng Zhao
- Department of Toxicology, School of Public Health; Anhui Medical University; Hefei 230032 China
| | - Huan Ning
- Department of Toxicology, School of Public Health; Anhui Medical University; Hefei 230032 China
| | - Ping Liu
- Department of Toxicology, School of Public Health; Anhui Medical University; Hefei 230032 China
| | - Cheng Zhang
- Department of Toxicology, School of Public Health; Anhui Medical University; Hefei 230032 China
| | - Tao Yu
- Department of Toxicology, School of Public Health; Anhui Medical University; Hefei 230032 China
| | - Ying Zhang
- Department of Toxicology, School of Public Health; Anhui Medical University; Hefei 230032 China
| | - Xiu-Hong Meng
- Department of Toxicology, School of Public Health; Anhui Medical University; Hefei 230032 China
| | - De-Xiang Xu
- Department of Toxicology, School of Public Health; Anhui Medical University; Hefei 230032 China
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11
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Kamal M, Fathy MM, Taher E, Hasan M, Tolba M. Assessment of the role of paraoxonase gene polymorphism (Q192R) and paraoxonase activity in the susceptibility to atherosclerosis among lead-exposed workers. Ann Saudi Med 2011; 31:481-7. [PMID: 21911985 PMCID: PMC3183682 DOI: 10.4103/0256-4947.84625] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND AND OBJECTIVE Lead exposure is a well known cause of cardiovascular damage, including atherosclerosis. Paraoxonase 1 (PON1), a high-density lipoprotein-associated antioxidant enzyme, is capable of hydrolyzing oxidized lipids and thus it protects against atherosclerosis. The mechanism by which heavy metals inhibit serum PON1 activity is still not clear. Our aim was to detect the association between lead exposure and serum PON1 activity and lipid profile and also to study the polymorphism of the PON1 gene. DESIGN AND SETTING A case-control, cross-sectional study conducted from June 2008 until May 2009. SUBJECTS AND METHODS Male workers (n=100) in a lead battery manufactory were recruited for this study. They were compared with 100 male age-matched workers not exposed to lead (control group). Serum lipid profile, paraoxonase activity and lead were measured in blood samples. The DNA was extracted for detecting the Q192R polymorphism of the PON1 gene by polymerase chain reaction followed by restriction fragment length polymorphism. RESULTS There was significant difference in triglycerides, total cholesterol and high-density lipoprotein cholesterol (HDL-C) (P=.01, .05 and .04, respectively) between cases and controls. Multiple linear regression analysis showed that blood lead levels were significantly associated with decreased serum paraoxonase activity (P=.03) in lead workers. The paraoxonase genotype QR was the most prevalent in 34/53 subjects (64%) among the lead-exposed groups, while the genotype QQ was more prevalent in the control group, in 15/25 subjects (60%), with a significant difference between the control and other groups (P<.05). CONCLUSION Lead exposure is associated with increased triglycerides, total cholesterol and low-density lipoprotein cholesterol and decreased HDL-C. Because of the protective role of PON1 in the development of atherosclerosis, a decrease in serum PON1 activity due to lead exposure may render individuals more susceptible to atherosclerosis.
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Affiliation(s)
- Manal Kamal
- Department of Clinical and Chemical Pathology, Community Medicine, Cairo University, Egypt.
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Cecil KM, Dietrich KN, Altaye M, Egelhoff JC, Lindquist DM, Brubaker CJ, Lanphear BP. Proton magnetic resonance spectroscopy in adults with childhood lead exposure. ENVIRONMENTAL HEALTH PERSPECTIVES 2011; 119:403-8. [PMID: 20947467 PMCID: PMC3060006 DOI: 10.1289/ehp.1002176] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2010] [Accepted: 10/13/2010] [Indexed: 05/04/2023]
Abstract
BACKGROUND Childhood lead exposure adversely affects neurodevelopment. However, few studies have examined changes in human brain metabolism that may underlie known adverse cognitive and behavioral outcomes. OBJECTIVE We examined the association between mean childhood blood lead levels and in vivo brain metabolite concentrations as adults, determined by proton magnetic resonance spectroscopy (MRS) in a birth cohort with documented low-to-moderate lead exposure. METHODS Adult participants from the Cincinnati Lead Study [n = 159; mean age (± SD), 20.8 ± 0.9 years] completed a quantitative, short-echo proton MRS protocol evaluating seven regions to determine brain concentrations of N-acetyl aspartate (NAA), creatine and phosphocreatine (Cr), cholines (Cho), myo-inositol, and a composite of glutamate and glutamine (GLX). Correlation and multiple linear regression analyses were conducted. RESULTS Mean childhood blood lead levels were associated with regionally specific brain metabolite concentrations adjusted for age at imaging and Full-Scale intelligence quotient. Adjusted analyses estimated for a unit (micrograms per deciliter) increase in mean childhood blood lead concentrations, a decrease of NAA and Cr concentration levels in the basal ganglia, a decrease of NAA and a decrease of Cho concentration levels in the cerebellar hemisphere, a decrease of GLX concentration levels in vermis, a decrease of Cho and a decrease of GLX concentration levels in parietal white matter, and a decrease of Cho concentration levels in frontal white matter. CONCLUSIONS Gray-matter NAA reductions associated with increasing childhood blood lead levels suggest that sustained childhood lead exposure produces an irreversible pattern of neuronal dysfunction, whereas associated white-matter choline declines indicate a permanent alteration to myelin architecture.
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Affiliation(s)
- Kim M Cecil
- Cincinnati Children's Environmental Health Center at Cincinnati Children's Hospital Medical Center, Ohio 45229, USA.
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13
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Effects of early low-level lead exposure on human brain structure, organization and functions. J Dev Orig Health Dis 2010. [DOI: 10.1017/s2040174410000486] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Advanced neuroimaging techniques offer unique insights into how childhood lead exposure impacts the brain. Volumetric magnetic resonance imaging affords anatomical information about the size of global, regional and subcomponent structures within the brain. Diffusion tensor imaging provides information about white matter architecture by quantitatively describing how water molecules diffuse within it. Proton magnetic resonance spectroscopy generates quantitative measures of neuronal, axonal and glial elements via concentration levels of select metabolites. Functional magnetic resonance imaging infers neuronal activity associated with a given task performed. Employing these techniques in the study of the Cincinnati Lead Study, a relatively homogeneous birth cohort longitudinally monitored for over 30 years, one can non-invasively and quantitatively explore how childhood lead exposure is associated with adult brain structure, organization and function. These studies yield important findings how environmental lead exposure impacts human health.
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14
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Effects of blood lead concentration on intelligence and personality in school children. Mol Cell Toxicol 2010. [DOI: 10.1007/s13273-010-0003-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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15
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Brubaker CJ, Schmithorst VJ, Haynes EN, Dietrich KN, Egelhoff JC, Lindquist DM, Lanphear BP, Cecil KM. Altered myelination and axonal integrity in adults with childhood lead exposure: a diffusion tensor imaging study. Neurotoxicology 2009; 30:867-75. [PMID: 19619581 DOI: 10.1016/j.neuro.2009.07.007] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2009] [Revised: 06/29/2009] [Accepted: 07/02/2009] [Indexed: 11/27/2022]
Abstract
Childhood lead exposure is associated with adverse cognitive, neurobehavioral and motor outcomes, suggesting altered brain structure and function. The purpose of this work was to assess the long-term impact of childhood lead exposure on white matter integrity in young adults. We hypothesized that childhood lead exposure would alter adult white matter architecture via deficits in axonal integrity and myelin organization. Adults (22.9+/-1.5 years, range 20.0-26.1 years) from the Cincinnati Lead Study were recruited to undergo a study employing diffusion tensor imaging (DTI). The anatomic regions of association between water diffusion characteristics in white matter and mean childhood blood lead level were determined for 91 participants (52 female). Fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) were measured on an exploratory voxel-wise basis. In adjusted analyses, mean childhood blood lead levels were associated with decreased FA throughout white matter. Regions of the corona radiata demonstrated highly significant lead-associated decreases in FA and AD and increases in MD and RD. The genu, body, and splenium of the corpus callosum demonstrated highly significant lead-associated decreases in RD, smaller and less significant decreases in MD, and small areas with increases in AD. The results of this analysis suggest multiple insults appear as distinct patterns of white matter diffusion abnormalities in the adult brain. Neurotoxic insults from the significant lead burden the participants experienced throughout childhood affect neural elements differently and may be related to the developmental stage of myelination at periods of exposure. This study indicates that childhood lead exposure is associated with a significant and persistent impact on white matter microstructure as quantified with diffusivity changes suggestive of altered myelination and axonal integrity.
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Affiliation(s)
- Christopher J Brubaker
- Cincinnati Children's Environmental Health Center at the Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
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16
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Ademuyiwa O, Agarwal R, Chandra R, Behari JR. Lead-induced phospholipidosis and cholesterogenesis in rat tissues. Chem Biol Interact 2009; 179:314-20. [DOI: 10.1016/j.cbi.2008.10.057] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2008] [Revised: 10/30/2008] [Accepted: 10/31/2008] [Indexed: 10/21/2022]
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Dąbrowska-Bouta B, Strużyńska L, Walski M, Rafałowska U. Myelin glycoproteins targeted by lead in the rodent model of prolonged exposure. Food Chem Toxicol 2008; 46:961-6. [DOI: 10.1016/j.fct.2007.10.024] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2007] [Revised: 09/19/2007] [Accepted: 10/22/2007] [Indexed: 11/25/2022]
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18
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Grizzo LT, Cordellini S. Perinatal lead exposure affects nitric oxide and cyclooxygenase pathways in aorta of weaned rats. Toxicol Sci 2008; 103:207-14. [PMID: 18234738 DOI: 10.1093/toxsci/kfn018] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Perinatal Pb exposure may modulate arterial tone through nitric oxide (NO) and cyclooxygenase products. To investigate this, Wistar dams received 1000 ppm of Pb or sodium acetate (control) in drinking water during pregnancy and lactation. Curves were constructed in phenylephrine-precontracted intact and/or denuded rings of thoracic aortas of weaned (23-day-old) male pups from their responses to N(omega)-nitro-L-arginine methyl ester (L-NAME, NO synthase inhibitor) and ACh in the absence or presence of indomethacin (10(-5)M, cyclooxygenase inhibitor) or L-NAME (3 x 10(-7)M and 3 x 10(-4)M). Blood lead concentration and systolic blood pressure (SBP) were higher in intoxicated than control pups (blood lead microg/dl: control < 3.0, Pb 58.7 +/- 6.5*; SBP mmHg: control 111.4 +/- 2.3, Pb 135.5 +/- 2.4*). In L-NAME-treated rings maximal responses increased in Pb-exposed rats, and were higher in intact than in denuded aortas (contraction [% of phenylephrine] intact: control 184.3 +/- 23.7, Pb 289.1 +/- 18.3*; denuded: control 125.1 +/- 4.5, Pb 154.8 +/- 13.3*). ACh-induced relaxation in intact aortas from Pb-exposed rats presented rightward shift in L-NAME presence (EC50 x 10(-7)M: control 1.32 [0.33-5.18], Pb 4.88 [3.56-6.69]*) but moved left under indomethacin (EC50 x 10(-7)M: control 8.95 [3.47-23.07], Pb 0.97 [0.38-2.43]*). *p < 0.05 significant relative to the respective control; N = 7-9. Endothelium removal abolished ACh-induced relaxation. Perinatal Pb exposure caused hypertension associated with alterations in the production and/or release of basal and stimulated endothelium-derived relaxing factors-NO and constricting cyclooxygenase products. These findings may help explain the contribution of NO and cyclooxygenase products to the etiology and/or maintenance of Pb-induced hypertension and could ultimately lead to therapeutic advantages in plumbism.
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Affiliation(s)
- Larissa Tercilia Grizzo
- Departamento de Farmacologia, Instituto de Biociências, São Paulo State University-UNESP, Distrito de Rubião Júnior s/n, 18618-000 Botucatu, SP, Brazil
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19
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Li Z, Dong T, Pröschel C, Noble M. Chemically diverse toxicants converge on Fyn and c-Cbl to disrupt precursor cell function. PLoS Biol 2007; 5:e35. [PMID: 17298174 PMCID: PMC1790953 DOI: 10.1371/journal.pbio.0050035] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2006] [Accepted: 12/04/2006] [Indexed: 12/29/2022] Open
Abstract
Identification of common mechanistic principles that shed light on the action of the many chemically diverse toxicants to which we are exposed is of central importance in understanding how toxicants disrupt normal cellular function and in developing more effective means of protecting against such effects. Of particular importance is identifying mechanisms operative at environmentally relevant toxicant exposure levels. Chemically diverse toxicants exhibit striking convergence, at environmentally relevant exposure levels, on pathway-specific disruption of receptor tyrosine kinase (RTK) signaling required for cell division in central nervous system (CNS) progenitor cells. Relatively small toxicant-induced increases in oxidative status are associated with Fyn kinase activation, leading to secondary activation of the c-Cbl ubiquitin ligase. Fyn/c-Cbl pathway activation by these pro-oxidative changes causes specific reductions, in vitro and in vivo, in levels of the c-Cbl target platelet-derived growth factor receptor-α and other c-Cbl targets, but not of the TrkC RTK (which is not a c-Cbl target). Sequential Fyn and c-Cbl activation, with consequent pathway-specific suppression of RTK signaling, is induced by levels of methylmercury and lead that affect large segments of the population, as well as by paraquat, an organic herbicide. Our results identify a novel regulatory pathway of oxidant-mediated Fyn/c-Cbl activation as a shared mechanism of action of chemically diverse toxicants at environmentally relevant levels, and as a means by which increased oxidative status may disrupt mitogenic signaling. These results provide one of a small number of general mechanistic principles in toxicology, and the only such principle integrating toxicology, precursor cell biology, redox biology, and signaling pathway analysis in a predictive framework of broad potential relevance to the understanding of pro-oxidant–mediated disruption of normal development. Chemically different toxins (lead, methylmercury, and paraquat) each cause the intracellular environment to become more oxidized, and thereby activate a common pathway that suppresses signaling from growth factor receptors that may be associated with developmental impairments. Discovering general principles underlying the effects of toxicant exposure on biological systems is one of the central challenges of toxicological research. We have discovered a previously unrecognized regulatory pathway on which chemically diverse toxicants converge, at environmentally relevant exposure levels, to disrupt the function of progenitor cells of the developing central nervous system. We found that the ability of low levels of methylmercury, lead, and paraquat to make progenitor cells more oxidized causes activation of an enzyme called Fyn kinase. Activated Fyn then activates another enzyme (c-Cbl) that modifies specific proteins—receptors that are required for cell division and survival—to initiate the proteins' degradation. By enhancing degradation of these receptors, their downstream signaling functions are repressed. Analysis of developmental exposure to methylmercury provided evidence that this same pathway is activated in vivo by environmentally relevant toxicant levels. The remarkable sensitivity of progenitor cells to low levels of toxicant exposure, and the discovery of the redox/Fyn/c-Cbl pathway as a mechanism by which small increases in oxidative status can markedly alter cell function, provide a novel and specific means by which exposure to chemically diverse toxicants might perturb normal development. In addition, the principles revealed in our studies appear likely to have broad applicability in understanding the regulation of cell function by alterations in redox balance, regardless of how they might be generated.
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Affiliation(s)
- Zaibo Li
- Department of Biomedical Genetics, University of Rochester Medical Center, Rochester, New York, United States of America
| | - Tiefei Dong
- Department of Biomedical Genetics, University of Rochester Medical Center, Rochester, New York, United States of America
| | - Chris Pröschel
- Department of Biomedical Genetics, University of Rochester Medical Center, Rochester, New York, United States of America
| | - Mark Noble
- Department of Biomedical Genetics, University of Rochester Medical Center, Rochester, New York, United States of America
- * To whom correspondence should be addressed. E-mail:
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Ademuyiwa O, Ugbaja RN, Idumebor F, Adebawo O. Plasma lipid profiles and risk of cardiovascular disease in occupational lead exposure in Abeokuta, Nigeria. Lipids Health Dis 2005; 4:19. [PMID: 16191200 PMCID: PMC1253530 DOI: 10.1186/1476-511x-4-19] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2005] [Accepted: 09/28/2005] [Indexed: 12/05/2022] Open
Abstract
In order to investigate the effects of lead exposure on risk of cardiovascular disease during occupational exposure to this metal, plasma cholesterol and its fractions as high-density liporotein (HDL), low-density liporotein (LDL) and triglyceride were determined in various artisans in Abeokuta, Nigeria who have been shown to be occupationally exposed to lead and these were related to blood lead levels. Increased risk of cardiovascular disease was observed in the artisans. Total cholesterol in the artisans was between 1.5 and 2.0 times higher in the artisans than that present in controls while LDL cholesterol was between 1.6 and 2.4 times higher in the artisans when compared with control subjects [p < 0.001]. HDL cholesterol and triglyceride levels were not affected [p > 0.05]. A significant positive correlation was observed between blood lead and total cholesterol on one hand [r = 0.372; p = 3.0 × 10-5] and blood lead and LDL cholesterol on the other hand [r = 0.283; p = 0.001]. LDL/HDL cholesterol ratio was also higher in the artisans when compared with control. Blood pressure (systolic and diastolic) and other anthropometric parameters were not significantly different between the artisans and the control subjects [p > 0.05]. Results suggest that lead exposure increases cholesterol synthesis and transport to peripheral tissues whereas reverse cholesterol transport to the liver is not affected.
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Affiliation(s)
- Oladipo Ademuyiwa
- Department of Biochemistry, University of Agriculture, Abeokuta, Nigeria
| | | | - Florence Idumebor
- Department of Biochemistry, University of Agriculture, Abeokuta, Nigeria
| | - Olugbenga Adebawo
- Department of Biochemistry, Olabisi Onabanjo University, Ikenne, Nigeria
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Abstract
The developing nervous system has been long recognized as a primary target for a variety of toxicants. To date, most efforts to understand the impact of neurotoxic agents on the brain have focused primarily on neurons and to a lesser degree astroglia as cellular targets. The role of oligodendroglia, the myelin-forming cells in the central nervous system (CNS), in developmental neurotoxicity has been emphasized only in recent years. Oligodendrocytes originate from migratory, mitotic progenitors that mature progressively into postmitotic myelinating cells. During differentiation, oligodendroglial lineage cells pass through a series of distinct phenotypic stages that are characterized by different proliferative capacities and migratory abilities, as well as dramatic changes in morphology with sequential expression of unique developmental markers. In recent years, it has become appreciated that oligodendrocyte lineage cells have important functions other than those related to myelin formation and maintenance, including participation in neuronal survival and development, as well as neurotransmission and synaptic function. Substantial knowledge has accumulated on the control of oligodendroglial survival, migration, proliferation, and differentiation, as well as the cellular and molecular events involved in oligodendroglial development and myelin formation. Recently, studies have been initiated to address the role of oligodendrocyte lineage cells in neurotoxic processes. This article examines recent progress in oligodendroglial biology, focuses attention on the characteristic features of the oligodendrocyte developmental lineage as a model system for neurotoxicological studies, and explores the role of oligodendrocyte lineage cells in developmental neurotoxicity. The potential role of oligodendroglia in environmental lead neurotoxicity is presented to exemplify this thesis.
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Affiliation(s)
- Wenbin Deng
- Department of Biochemistry and Microbiology, Rutgers University, 76 Lipman Drive, New Brunswick, NJ 08901-8525, USA
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Dominguéz C, Solé E, Fortuny A. In vitro lead-induced cell toxicity and cytoprotective activity of fetal calf serum in human fibroblasts. Mol Cell Biochem 2002; 237:47-53. [PMID: 12236586 DOI: 10.1023/a:1016547519763] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The underlying mechanisms by which lead ions produce their deleterious effects prior to the onset of clinical symptoms are incompletely understood. This study aimed to assess lead-induced cell toxicity mechanisms by focusing on the effects of the metal on cell growth, DNA synthesis, cellular ATP, intracellular hexosaminidase activity and lysosomal function, and examine the possible cytoprotective role of fetal calf serum (FCS). Several human dermal cultured fibroblast lines were exposed to Pb (400 microM) for 1-6 days with 2, 5, and 10% FCS. The earliest toxic effect of Pb was significant inhibition of DNA synthesis after 24 h direct exposure; this harmful effect was not progressive during the first 3 days, but worsened clearly on the 4th day regardless of the FCS concentration. Atime-dependent depletion of intracellularATP content was also caused by ionic lead, thereby compromising the cell energy charge which precedes cell death. Fibroblast growth was progressively and significantly inhibited from day 2 onwards; the greatest noxious effect was observed in the presence of 2% FCS: 49% reduction in cell proliferation after 5 days. Lead salts produced loss of cell adhesion to the culture dish which worsened from the 2nd day and was more pronounced when FCS in growth medium was decreased. Toxic actions on lysosomal membrane integrity provoked a decrease in neutral red uptake (NRU) which was exposure time-dependent and more marked with 2% FCS. In contrast, increased relative NRU (to 20% at 4 days), suggestive of endocytosis-induced lysosome enlargement, was observed in Pb-exposed cells. Intracellular hexosaminidase activity was not negatively affected until 5 days after exposure to Pb salts. FCS had a significant cytoprotective effect on Pb-induced toxicity.
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Affiliation(s)
- Carmen Dominguéz
- Biochemistry and Molecular Biology Center, Vall d 'Hebron Hospitals, Barcelona, Spain.
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Deng W, Poretz RD. Protein kinase C activation is required for the lead-induced inhibition of proliferation and differentiation of cultured oligodendroglial progenitor cells. Brain Res 2002; 929:87-95. [PMID: 11852034 DOI: 10.1016/s0006-8993(01)03385-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Lead (Pb) is a common neurotoxicant of major public health concern. Previous studies revealed that cultured oligodendrocyte progenitor cells (OPCs) are highly vulnerable to Pb toxicity. The present study examines the effect of Pb on the survival, proliferation and differentiation of OPCs in vitro. Dose-response studies showed that> or = l5-10 microM Pb is cytotoxic to OPCs within 24 h. However, 1 microM of Pb was found to inhibit the proliferation and differentiation of OPCs without affecting cell viability. Pb markedly decreased the proliferative capability of OPCs and inhibited cell-intrinsic lineage progression of OPCs at a late progenitor stage. The Pb-induced decrease of proliferation and differentiation was abolished by inhibition of protein kinase C (PKC) with bisindolylmaleimide I, while the effect of the PKC-activating agent phorbol-12,13-didecanoate was potentiated by Pb. Furthermore, Pb exposure of OPCs caused the translocation of PKC from the cytoplasm to membrane without an increase in total cellular PKC enzymic activity. These results indicate that Pb inhibits the proliferation and differentiation of oligodendrocyte lineage cells in vitro through a mechanism requiring PKC activation.
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Affiliation(s)
- Wenbin Deng
- Department of Biochemistry and Microbiology, Rutgers University, 76 Lipman Drive, New Brunswick, NJ 08901, USA
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24
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Deng W, McKinnon RD, Poretz RD. Lead exposure delays the differentiation of oligodendroglial progenitors in vitro. Toxicol Appl Pharmacol 2001; 174:235-44. [PMID: 11485384 DOI: 10.1006/taap.2001.9219] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Lead (Pb) is an environmental neurotoxicant that can cause hypo- and demyelination. Oligodendrocytes (OLs), the myelin-forming cells in the central nervous system, may be a possible target for Pb toxicity. The present study describes the effect of Pb on the maturation of rat OL progenitor (OP) cells and the developmental expression of myelin-specific galactolipids. Dose-response studies showed that OP cultures were more sensitive to Pb than mature OLs. Pb delayed the differentiation of OL progenitors, as demonstrated by cell morphology and immunostaining with a panel of stage-specific differentiation markers. Pb given prior to and during differentiation caused a decrease in the biosynthesis of galactolipids in both undifferentiated and differentiated OLs, as detected by metabolic radiolabeling with 3H-D-galactose. While the ratios of galacto/gluco-cerebrosides, hydroxy fatty acid/nonhydroxy fatty acid galactolipids, and galactocerebrosides/sulfatides increased in control cultures during cell differentiation, Pb treatment prevented these changes. The results suggest that chronic Pb exposure may impact brain development by interfering with the timely developmental maturation of OL progenitors.
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Affiliation(s)
- W Deng
- Department of Biochemistry and Microbiology, Rutgers University, 76 Lipman Drive, New Brunswick, New Jersey 08901, USA
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Deng W, Poretz RD. Lead alters the developmental profile of the galactolipid metabolic enzymes in cultured oligodendrocyte lineage cells. Neurotoxicology 2001; 22:429-37. [PMID: 11577801 DOI: 10.1016/s0161-813x(01)00048-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Lead is a neurotoxicant that can cause myelin deficits. Galactolipids are expressed during differentiation of oligodendrocyte lineage cells and accumulate in myelin. To examine the impact of lead on oligodendroglial differentiation, galactolipid metabolism in cultured oligodendrocyte lineage cells exposed to the metal was studied. Oligodendrocyte progenitor cells obtained from newborn rat pups were exposed to 1 microM lead acetate for 24 h prior to maintenance of the cells in medium containing the metal salt for 0, 2, or 6 days of differentiation. Lead caused approximately 50% reduction in levels of the galactolipid biosynthetic transferases, UDP-galactose:ceramide galactosyltransferase and 3'-phosphoadenosine-5'-phosphosulfate:galactocerebroside sulfotransferase, as compared to sodium-treated controls, in cultures of oligodendrocyte lineage cells following 2 days of differentiation. The activities of the galactolipid catabolic hydrolases, galactocerebroside-beta-galactosidase and arylsulfatase A, were reduced by 20%. Following 6 days of differentiation, lead-exposed cells exhibited levels of all the enzymes, except for arylsulfatase A, similar to those of the control cells. These results are consistent with the lead-induced delay of oligodendrocyte differentiation, as evidenced by the emergence of stage-specific immunochemical markers and the observed change in the developmental activity profile of 2',3'-cyclic nucleotide 3'-phosphohydrolase. The activity of arylsulfatase A in lead-treated 6-day oligodendrocytes was significantly less than that found in control cultures. This effect is consistent with the lead-induced reduction of arylsulfatase A in human fibroblasts caused by mis-sorting the newly-synthesized enzyme. The perturbation of galactolipid metabolism by lead during developmental maturation of oligodendrocytes may represent a contributing mechanism for lead-induced neurotoxicity.
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Affiliation(s)
- W Deng
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, NJ 08901-8525, USA
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