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Green R, Rubenstein J, Popoli R, Capulong R, Till C. Sex-specific neurotoxic effects of early-life exposure to fluoride: A review of the epidemiologic and animal literature. CURR EPIDEMIOL REP 2020; 7:263-273. [PMID: 33816056 PMCID: PMC8011433 DOI: 10.1007/s40471-020-00246-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/21/2020] [Indexed: 12/13/2022]
Abstract
PURPOSE OF REVIEW A growing body of evidence suggests adverse neurodevelopmental effects of early-life exposure to fluoride that may differ depending on timing of exposure and sex of the exposed. We conducted a literature search to identify the animal and human epidemiologic studies that examined sex-specific neurodevelopmental differences in response to prenatal and postnatal exposure to fluoride. RECENT FINDINGS Six of 138 animal studies and 15 of 106 human epidemiologic studies tested for sex-specific effects. Prenatal exposure to fluoride was associated with a male susceptibility to adverse behavioural effects in four of six animal studies and lower IQ in one of three prospective cohort studies. The body of evidence examining sex-effects associated with postnatal fluoride exposure was scarce, and many animal and cross-sectional human studies were considered to have a high risk of bias. SUMMARY Compared to females, male offspring appear to be more sensitive to prenatal, but not postnatal, exposure to fluoride. We discuss several sex-specific mechanisms and emphasize the need for future research.
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Affiliation(s)
- R. Green
- York University, Department of Psychology, 4700 Keele St
| | - J. Rubenstein
- York University, Department of Psychology, 4700 Keele St
| | - R. Popoli
- York University, Department of Psychology, 4700 Keele St
| | - R. Capulong
- York University, Department of Psychology, 4700 Keele St
| | - C. Till
- York University, Department of Psychology, 4700 Keele St
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Gu X, Huang X, Li D, Bi N, Yu X, Wang HL. Nuclear accumulation of histone deacetylase 4 (HDAC4) by PP1-mediated dephosphorylation exerts neurotoxicity in Pb-exposed neural cells. Neurotoxicology 2020; 81:395-405. [PMID: 33080273 DOI: 10.1016/j.neuro.2020.10.006] [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: 05/12/2020] [Revised: 10/13/2020] [Accepted: 10/13/2020] [Indexed: 10/23/2022]
Abstract
Lead (Pb) is an environmental contaminant that primarily affects the central nervous system, particularly the developing brain. Recently, increasing evidence indicates the important roles of histone deacetylases (HDACs) in Pb-induced neurotoxicity. However, the precise molecular mechanisms involving HDAC4 remains unknown. The purpose of this study was to investigate the role of HDAC4 in Pb-induced neurotoxicity both in vivo and in vitro. In vitro study, PC12 cells were exposed to Pb (10 μM) for 24 h, then the mRNA and protein levels of HDAC4 were analyzed. In vivo study, pregnant rats and their female offspring were treated with lead (50 ppm) until postnatal day 30. Then the pups were sacrificed and the mRNA and protein levels of HDAC4 in the hippocampus were analyzed. The results showed that HDAC4 was significantly increased in both PC12 cells and rat hippocampus upon Pb exposure. Blockade of HDAC4 with either LMK-235 (an inhibitor of HDAC4) or shHDAC4 (HDAC4-knocking down plasmid) ameliorated the Pb-induced neurite outgrowth deficits. Interestingly, HDAC4 was aberrantly accumulated in the nucleus upon Pb exposure. By contrast, blocking the HDAC4 shuffling from the cytosol to the nucleus with ΔNLS2-HDAC4 (the cytosol-localized HDAC4 mutant) was able to rescue the neuronal impairment. In addition, Pb increased PP1 (protein phosphatase 1) expression which in turn influenced the subcellular localization of HDAC4 by dephosphorylation of specific serine/threonine residues. What's more, blockade of PP1 with PP1-knocking down construct (shPP1) ameliorated Pb-induced neurite outgrowth deficits. Taken together, nuclear accumulation of HDAC4 by PP1-mediated dephosphorylation involved in Pb-induced neurotoxicity. This study might provide a promising molecular target for medical intervention with environmental cues.
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Affiliation(s)
- Xiaozhen Gu
- School of Food and Biological Engineering, Hefei University of Technology, No. 193 of Tunxi Road, Baohe District, 230009, Hefei, China
| | - Xiyao Huang
- School of Food and Biological Engineering, Hefei University of Technology, No. 193 of Tunxi Road, Baohe District, 230009, Hefei, China
| | - Danyang Li
- School of Food and Biological Engineering, Hefei University of Technology, No. 193 of Tunxi Road, Baohe District, 230009, Hefei, China
| | - Nanxi Bi
- School of Food and Biological Engineering, Hefei University of Technology, No. 193 of Tunxi Road, Baohe District, 230009, Hefei, China
| | - Xi Yu
- School of Food and Biological Engineering, Hefei University of Technology, No. 193 of Tunxi Road, Baohe District, 230009, Hefei, China
| | - Hui-Li Wang
- School of Food and Biological Engineering, Hefei University of Technology, No. 193 of Tunxi Road, Baohe District, 230009, Hefei, China.
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Farruggio S, Raina G, Cocomazzi G, Librasi C, Mary D, Gentilli S, Grossini E. Genistein improves viability, proliferation and mitochondrial function of cardiomyoblasts cultured in physiologic and peroxidative conditions. Int J Mol Med 2019; 44:2298-2310. [DOI: 10.3892/ijmm.2019.4365] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 08/02/2019] [Indexed: 11/06/2022] Open
Affiliation(s)
- Serena Farruggio
- Laboratory of Physiology and Experimental Surgery, Department of Translational Medicine, AGING Project, University of East Piedmont, I‑28100 Novara, Italy
| | - Giulia Raina
- Laboratory of Physiology and Experimental Surgery, Department of Translational Medicine, AGING Project, University of East Piedmont, I‑28100 Novara, Italy
| | - Grazia Cocomazzi
- Laboratory of Physiology and Experimental Surgery, Department of Translational Medicine, AGING Project, University of East Piedmont, I‑28100 Novara, Italy
| | - Carlotta Librasi
- Laboratory of Physiology and Experimental Surgery, Department of Translational Medicine, AGING Project, University of East Piedmont, I‑28100 Novara, Italy
| | - David Mary
- Laboratory of Physiology and Experimental Surgery, Department of Translational Medicine, AGING Project, University of East Piedmont, I‑28100 Novara, Italy
| | - Sergio Gentilli
- General Surgery Unit, Department of Health of Sciences, University of East Piedmont; University Hospital Company Major of Charity, I‑28100 Novara, Italy
| | - Elena Grossini
- Laboratory of Physiology and Experimental Surgery, Department of Translational Medicine, AGING Project, University of East Piedmont, I‑28100 Novara, Italy
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Beckwith TJ, Dietrich KN, Wright JP, Altaye M, Cecil KM. Reduced regional volumes associated with total psychopathy scores in an adult population with childhood lead exposure. Neurotoxicology 2018; 67:1-26. [PMID: 29634994 PMCID: PMC6054826 DOI: 10.1016/j.neuro.2018.04.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 04/03/2018] [Accepted: 04/04/2018] [Indexed: 01/05/2023]
Abstract
Childhood lead exposure has been correlated to acts of delinquency and criminal behavior; however, little research has been conducted to examine its potential long term influence on behavioral factors such as personality, specifically psychopathic personality. Neuroimaging studies have demonstrated that the effects of childhood lead exposure persist into adulthood, with structural abnormalities found in gray and white matter regions involved in behavioral decision making. The current study examined whether measurements of adult psychopathy were associated with neuroanatomical differences in structural brain volumes for a longitudinal cohort with measured childhood lead exposure. We hypothesized that increased total psychopathy scores and increased blood lead concentration at 78 months of age (PbB78) would be inversely associated with volumetric measures of gray and white matter brain structures responsible for executive and emotional processing. Analyses did not display a direct effect between total psychopathy score and gray matter volume; however, reduced white matter volume in the cerebellum and brain stem in relation to increased total psychopathy scores was observed. An interaction between sex and total psychopathy score was also detected. Females displayed increased gray matter volume in the frontal, temporal, and parietal lobes associated with increased total psychopathy score, but did not display any white matter volume differences. Males primarily displayed reductions in frontal gray and white matter brain volume in relation to increased total psychopathy scores. Additionally, reduced gray and white matter volume was associated with increased blood lead levels in the frontal lobes; reduced white matter volume was also observed in the parietal and temporal lobes. Females demonstrated gray and white matter volume loss associated with increased PbB78 values in the right temporal lobe, as well as reduced gray matter volume in the frontal lobe. Males displayed reduced white matter volumes associated with increased PbB78 values in the frontal, temporal, and parietal lobes. Comparison of the two primary models revealed a volumetric decrease in the white matter of the left prefrontal cortex associated with increased total psychopathy scores and increased blood lead concentration in males. The results of this study suggested that increased psychopathy scores in this cohort may be attributable to the neuroanatomical abnormalities observed and that childhood lead exposure may be influential to these outcomes.
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Affiliation(s)
- Travis J Beckwith
- Imaging Research Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States.
| | - Kim N Dietrich
- Department of Environmental Health, Division of Epidemiology and Biostatistics, University of Cincinnati College of Medicine, Cincinnati, OH, United States
| | - John P Wright
- School of Criminal Justice, University of Cincinnati, Cincinnati, OH, United States
| | - Mekibib Altaye
- Division of Biostatistics and Epidemiology, Cincinnati Children's Hospital Medical Center Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, United States
| | - Kim M Cecil
- Imaging Research Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States; Department of Environmental Health, Division of Epidemiology and Biostatistics, University of Cincinnati College of Medicine, Cincinnati, OH, United States; Department of Radiology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH, United States
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5
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Xue WZ, Gu X, Wu Y, Li D, Xu Y, Wang HL. Multiple regulatory aspects of histone methyltransferase EZH2 in Pb-induced neurotoxicity. Oncotarget 2017; 8:85169-85184. [PMID: 29156711 PMCID: PMC5689601 DOI: 10.18632/oncotarget.19615] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2016] [Accepted: 07/06/2017] [Indexed: 12/02/2022] Open
Abstract
Pb is a pervasive environmental threat to human health. Although remarkable progress has been made in its neurotoxicity, the precise molecular mechanisms underlying this widespread toxicant still remain elusive. In this study, the detailed roles of EZH2, a transcriptional repressor, in the regulation of Pb-led neurotoxicity were investigated, highlighting its sub-functionalization, compartmentalization, functional chaperones and downstream partners. Based on the findings, EZH2’s protein levels were significantly reduced in response to Pb treatment; EZH2’s gain-of-function trials recovered the dampened neurite outgrowth; EZH2’ recruitment to ploycomb complex, as well as its interaction with cytosolic Vav1, was altered in a distinct manner, suggesting that EZH2’s multiple roles were markedly redistributed in this context; EZH2’s cytosolic and nuclear presence differed in their respective response towards Pb treatment; EZH2 directly occupied the promoters of EGR2, NGFR and CaMKK2, genes responsible for various nerve functions and repair mechanisms, and essentially contributed to their aberrant expression. It indicated that EZH2 mediated the dynamic changes of a cascade of key molecules and consequently the related neurological impairments. In summary, EZH2 emerges as a central player to regulate Pb-led neurotoxicity in a transcriptionally dependent and independent manner, and thereby provided a promising molecular target for medical intervention.
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Affiliation(s)
- Wei-Zhen Xue
- School of Food Science and Engineering, Hefei University of Technology, Hefei, Anhui 230009, PR China
| | - Xiaozhen Gu
- School of Food Science and Engineering, Hefei University of Technology, Hefei, Anhui 230009, PR China
| | - Yulan Wu
- School of Food Science and Engineering, Hefei University of Technology, Hefei, Anhui 230009, PR China
| | - Danyang Li
- School of Food Science and Engineering, Hefei University of Technology, Hefei, Anhui 230009, PR China
| | - Yi Xu
- School of Food Science and Engineering, Hefei University of Technology, Hefei, Anhui 230009, PR China
| | - Hui-Li Wang
- School of Food Science and Engineering, Hefei University of Technology, Hefei, Anhui 230009, PR China
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Hu XM, Li XQ, Li XT. The Tau-Induced Reduction of mRNA Levels of Kv Channels in Human Neuroblastoma SK-N-SH Cells. J Mol Neurosci 2015; 58:306-11. [PMID: 26576773 DOI: 10.1007/s12031-015-0683-6] [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: 01/04/2015] [Accepted: 11/09/2015] [Indexed: 11/25/2022]
Abstract
Previous findings indicated that microtubule-binding protein tau and voltage-gated K(+) (Kv) channels exhibit a regulatory role in cell proliferation. However, the possible interaction of tau with Kv channels remained obscure. In this report, transfection of tau plasmids into human neuroblastoma SK-N-SH cells caused a significant reduction in the messenger RNA (mRNA) levels of several Kv channels, including Kv2.1, Kv3.1, Kv5.1, Kv9.2, and KCNH4. Correspondingly, the Kv currents recorded using patch-clamp techniques were substantially declined in the tau-transfected SK-N-SH cells. Moreover, tau induction and treatment with the Kv channel blocker TEA (tetraethylammonium) were able to improve proliferation rates of SK-N-SH cells by 43.1 and 66.2%, respectively. These data suggested that the tau-mediated alteration of Kv channels could be involved in its action on neural proliferation.
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Affiliation(s)
- Xi-Mu Hu
- Graduate Institute of South-Central University for Nationalities, Wuhan, 430074, China
| | - Xiao-Qing Li
- Graduate Institute of South-Central University for Nationalities, Wuhan, 430074, China
| | - Xian-Tao Li
- Department of Neurobiology, College of Life Sciences, South-Central University for Nationalities, Wuhan, 430074, China.
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The role of Nrf2 in protection against Pb-induced oxidative stress and apoptosis in SH-SY5Y cells. Food Chem Toxicol 2015; 86:191-201. [PMID: 26498409 DOI: 10.1016/j.fct.2015.10.009] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 10/06/2015] [Accepted: 10/16/2015] [Indexed: 11/21/2022]
Abstract
Lead exerts severe adverse effects on the nervous system in which oxidative stress might mediate impairments. In this study, we focused on Nrf2, which has been identified to significantly influence the protection of a cellular system against many xenobiotic compounds. We found that PbAc exhibited neurotoxicity mainly through oxidant-based processes and could be inhibited by NAC and DPI in SH-SY5Y cells. As a defense response, Nrf2 was activated when exposed to PbAc, thereby inducing a rapid increase in Nrf2 nuclear accumulation, as well as Nrf2-ARE binding activities in a ROS-dependent manner. Analysis of Nrf2-regulated gene expression and protein showed that PbAc could induce the mRNA transcription of HO-1, GSTα1, GCLM, GCLC, and NQO1, as well as the protein expression of HO-1 and γ-GCS. The responses of these genes to PbAc were regulated by Nrf2. Silencing Nrf2 expression in SH-SY5Y cells inhibited PbAc-induced gene transcription and protein expression. Overexpression of Nrf2 led to decreased ROS production and cell apoptosis, as well as increased cell viability under PbAc exposure. These results indicated that the Nrf2-ARE system exhibited a protective role in Pb-induced neurotoxicity, providing potential therapeutic strategies for the prevention and treatment of Pb-related diseases.
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8
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Protective actions of 17β-estradiol and progesterone on oxidative neuronal injury induced by organometallic compounds. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2015; 2015:343706. [PMID: 25815107 PMCID: PMC4359856 DOI: 10.1155/2015/343706] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/28/2014] [Accepted: 02/06/2015] [Indexed: 01/10/2023]
Abstract
Steroid hormones synthesized in and secreted from peripheral endocrine glands pass through the blood-brain barrier and play a role in the central nervous system. In addition, the brain possesses an inherent endocrine system and synthesizes steroid hormones known as neurosteroids. Increasing evidence shows that neuroactive steroids protect the central nervous system from various harmful stimuli. Reports show that the neuroprotective actions of steroid hormones attenuate oxidative stress. In this review, we summarize the antioxidative effects of neuroactive steroids, especially 17β-estradiol and progesterone, on neuronal injury in the central nervous system under various pathological conditions, and then describe our recent findings concerning the neuroprotective actions of 17β-estradiol and progesterone on oxidative neuronal injury induced by organometallic compounds, tributyltin, and methylmercury.
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9
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Parajuli RP, Fujiwara T, Umezaki M, Watanabe C. Impact of caste on the neurodevelopment of young children from birth to 36 months of age: a birth cohort study in Chitwan Valley, Nepal. BMC Pediatr 2014; 14:56. [PMID: 24571600 PMCID: PMC3941607 DOI: 10.1186/1471-2431-14-56] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Accepted: 02/13/2014] [Indexed: 12/27/2022] Open
Abstract
Background Caste, a proxy of socioeconomic position, can influence the neurodevelopment of children through several pathways, including exposure to toxic elements. Studies from developing countries where caste is represented by prevailing caste groups and people are highly exposed to toxic elements can provide useful insights into the mechanisms of neurodevelopmental inequities among children. This study aims to investigate the impact of caste on the neurodevelopment of children from birth to 36 months of age in Chitwan Valley, Nepal, where people are exposed to high levels of arsenic (As) and lead (Pb). Methods Participants (N = 94) were mother-infant pairs from the Chitwan district in Nepal. The neurodevelopment of the infants was assessed using the Brazelton Neonatal Behavioral Assessment Scale, Third Edition, (NBAS III) at birth and the Bayley Scales of Infant Development, Second Edition, (BSID II) at ages 6, 24, and 36 months. Caste was categorized based on surname, which, in Nepal generally refers to one of four caste groups. We also measured the concentrations of As and Pb in cord blood. Results Caste was positively associated with the state regulation cluster score of the NBAS III at birth after adjustment for covariates (p for trend < 0.01). Adding cord blood As levels attenuated the association (p for trend = 0.12). With regard to neurodevelopment at six months of age, the third-ranked caste group scored higher than the first-ranked caste group on the Mental Development Index (MDI) of the BSID II (coefficient = 3.7; 95% confidence interval (CI) = 1.3 to 6.0). This difference remained significant after adjustment for cord blood As levels and other covariates was made (coefficient = 3.9; 95% CI = 1.2 to 6.7). The remaining clusters of the NBAS III and BSID II at 6, 24, and 36 months were not significantly associated with caste group. Conclusions Caste was positively associated with the state regulation cluster score of NBAS III at birth. This association was partially mediated by cord blood As levels. However, the negative impact of caste on neurodevelopment disappeared as the children grew. Furthermore, an inverse association between caste and MDI at six months of age was observed. Additional studies are needed to elucidate the mechanism of how caste affects neurodevelopment.
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Affiliation(s)
| | - Takeo Fujiwara
- Department of Social Medicine, National Research Institute for Child Health and Development, 2-10-1 Okura, Setagaya-ku, 157-8535 Tokyo, Japan.
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Gargouri M, Magné C, Dauvergne X, Ksouri R, El Feki A, Metges MAG, Talarmin H. Cytoprotective and antioxidant effects of the edible halophyte Sarcocornia perennis L. (swampfire) against lead-induced toxicity in renal cells. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2013; 95:44-51. [PMID: 23755863 DOI: 10.1016/j.ecoenv.2013.05.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2013] [Revised: 05/08/2013] [Accepted: 05/10/2013] [Indexed: 06/02/2023]
Abstract
Lead (Pb) exposure is considered as a risk factor responsible for renal impairment in humans. On the other hand, the halophyte Sarcocornia perennis is a fresh vegetable crop suitable for leafy vegetable production. This study was designed to evaluate the in vitro protective activity of S. perennis against lead-induced damages in HEK293 kidney cells. Morphological and biochemical indicators were used to assess cytotoxicity and oxidative damages caused by Pb treatment on the cells. Our results showed that lead induced (1) a decrease in cell viability (MTT), (2) cell distortion and cohesion loss, (3) superoxide anion production and lipid peroxidation. Conversely, addition of S. perennis extract to the lead-containing medium alleviated every above syndrome. Thus, cell survival was increased and the production of reactive oxygen species caused by Pb treatment was inhibited. Taken together, our study revealed that S. perennis has potent cytoprotective effect against Pb-induced toxicity in HEK 293 cell. Such action would proceed through the decrease in ROS levels and resulting oxidative stress, which suggests a potential interest of this halophyte in the treatment of oxidative-stress related diseases.
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Affiliation(s)
- Manel Gargouri
- Laboratoire d'Ecophysiologie Animale, Faculté des Sciences de Sfax, Sfax, Tunisia.
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Senut MC, Cingolani P, Sen A, Kruger A, Shaik A, Hirsch H, Suhr ST, Ruden D. Epigenetics of early-life lead exposure and effects on brain development. Epigenomics 2013; 4:665-74. [PMID: 23244311 DOI: 10.2217/epi.12.58] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The epigenetic machinery plays a pivotal role in the control of many of the body's key cellular functions. It modulates an array of pliable mechanisms that are readily and durably modified by intracellular or extracellular factors. In the fast-moving field of neuroepigenetics, it is emerging that faulty epigenetic gene regulation can have dramatic consequences on the developing CNS that can last a lifetime and perhaps even affect future generations. Mounting evidence suggests that environmental factors can impact the developing brain through these epigenetic mechanisms and this report reviews and examines the epigenetic effects of one of the most common neurotoxic pollutants of our environment, which is believed to have no safe level of exposure during human development: lead.
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Affiliation(s)
- Marie-Claude Senut
- Institute of Environmental Health Sciences, CS Mott Center for Human Health & Development & Department of Obstetrics & Gynecology, Wayne State University, Detroit, MI 48201, USA
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Xing W, Li SL, Chen ZY. Lead acetate induces cell apoptosis and promotes caspase-3 expression in human liver cell line L-02. Shijie Huaren Xiaohua Zazhi 2011; 19:2426-2431. [DOI: 10.11569/wcjd.v19.i23.2426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the impact of lead acetate on cell apoptosis and caspase-3 expression in human liver cell line L-02.
METHODS: After L-02 cells were treated with different concentrations (0, 2.5, 40, 100, 200, 400 μmol/L) of lead acetate for 24 or 48 h, the proliferation of L-02 cells was assayed by MTT assay; cell morphological changes were observed after Hoechest33258 staining; and the expression of caspase-3 mRNA and protein was determined by RT-PCR and Western blot.
RESULTS: Compared to the normal control group, the proliferation of L-02 cells was significantly inhibited after treatment with different concentrations of lead acetate for 24 or 48 h (24 h: 0.4678 ± 0.0438, 0.4686 ± 0.0733, 0.4500 ± 0.0712, 0.4244 ± 0.0407, 0.3998 ± 0.0499 vs 0.5234 ± 0.0589; 48 h: 0.4290 ± 0.0607, 0.4184 ± 0.0296, 0.4032 ± 0.0499, 0.3856 ± 0.0386, 0.3750 ± 0.0149 vs 0.5300 ± 0.0397, all P < 0.05 or 0.01). Significant morphological changes were noted in cells treated with lead acetate for 48 h. Compared to the normal control group, the levels of caspase-3 mRNA increased significantly in a dose-dependent manner in L-02 cells treated with lead acetate (1.0912 ± 0.0769, 1.2874 ± 0.144, 1.4536 ± 0.1046, 1.6986 ± 0.1371, 1.9882 ± 0.0925 vs 0.8438 ± 0.0933, all P < 0.01). Additionally, the expression levels of caspase-3 protein also significantly increased after treatment with lead acetate.
CONCLUSION: Lead acetate inhibits proliferation and induces apoptosis of L-02 cells possibly via a mechanism associated with the activation of caspase-3.
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Chen T, Li YY, Zhang JL, Xu B, Lin Y, Wang CX, Guan WC, Wang YJ, Xu SQ. Protective effect of C(60) -methionine derivate on lead-exposed human SH-SY5Y neuroblastoma cells. J Appl Toxicol 2010; 31:255-61. [PMID: 20878908 DOI: 10.1002/jat.1588] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2009] [Revised: 06/10/2010] [Accepted: 07/26/2010] [Indexed: 01/24/2023]
Abstract
Oxidative stress has been considered as one of the possible mechanisms leading to the neurotoxicity of lead. One of the effective ways to prevent cellular damage after lead exposure is using antioxidants. In this paper, a novel C(60) -methionine derivate (FMD), a fullerene molecule modified with methionine, was synthesized. The protective effect of FMD on lead-exposed human SH-SY5Y neuroblastoma cells was investigated. In this research, after incubating with 500 µm Pb acetate alone for 72 h, the cells had undergone a series of biological changes including viability loss, apoptotic death, the depletion of glutathione (GSH), the peroxidation of membrane lipid and DNA damage. Pretreatment with FMD before lead exposure could improve cell survival, increase the GSH level, reduce malondialdehyde content and attenuate DNA damage without obvious toxicity. In addition, the protective effects of FMD were proven to be greater than those of other two C(60) -amino acid derivates, β-alanine C(60) derivate and cystine C(60) derivate, which have been confirmed in our previous work to be able to protect rat pheochromocytoma PC12 cells from hydrogen dioxide-induced oxidative injuries. These observations suggest that FMD may serve as a potential antioxidative and neuroprotective agent in the prevention of lead intoxication.
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Affiliation(s)
- Tian Chen
- School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China
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14
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Brubaker CJ, Dietrich KN, Lanphear BP, Cecil KM. The influence of age of lead exposure on adult gray matter volume. Neurotoxicology 2010; 31:259-66. [PMID: 20226811 DOI: 10.1016/j.neuro.2010.03.004] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2010] [Revised: 02/08/2010] [Accepted: 03/03/2010] [Indexed: 12/12/2022]
Abstract
Childhood lead exposure is associated with decreased cognitive abilities and executive functioning localized within the prefrontal cortex. Several studies have observed stronger associations between blood lead measurements obtained later in life than earlier measures, but there are no imaging studies investigating the developmental trajectory of blood lead levels taken during childhood on adult gray matter volume. In this study, we recruited 157 adults (20.8+/-1.5 years of age) from the Cincinnati Lead Study to undergo high resolution volumetric magnetic resonance imaging. Adjusted voxel-wise regression analyses were performed for associations between adult gray matter volume loss and yearly mean blood lead levels from 1 to 6 years of age in the entire cohort and by sex. We observed significant inverse associations between gray matter volume loss and annual mean blood lead levels from 3 to 6 years of age. The extent of prefrontal gray matter associated with yearly mean blood lead levels increased with advancing age of the subjects. The inverse associations between gray matter volume loss and yearly mean blood lead measurements were more pronounced in the frontal lobes of men than women. Analysis of women yielded significantly weaker associations between yearly mean blood lead levels and gray matter volume at all ages than either men or the combined cohort of men and women together. These results suggest that blood lead concentrations obtained during later childhood demonstrate greater loss in gray matter volume than childhood mean or maximum values. The relationship between childhood blood lead levels and gray matter volume loss was predominantly observed in the frontal lobes of males. This study demonstrates that maximum blood lead levels do not fully account for gray matter changes associated with childhood lead exposure, particularly in the frontal lobes of young men.
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Affiliation(s)
- Christopher J Brubaker
- Cincinnati Children's Environmental Health Center, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH, USA
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Protective effects of pre-germinated brown rice diet on low levels of Pb-induced learning and memory deficits in developing rat. Chem Biol Interact 2010; 184:484-91. [PMID: 20138853 DOI: 10.1016/j.cbi.2010.01.043] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2009] [Revised: 01/28/2010] [Accepted: 01/28/2010] [Indexed: 11/23/2022]
Abstract
Lead (Pb) is a known neurotoxicant in humans and experimental animals. Numerous studies have provided evidence that humans, especially young children, and animals chronically intoxicated with low levels of Pb show learning and memory impairments. Unfortunately, Pb-poisoning cases continue to occur in many countries. Because the current treatment options are very limited, there is a need for alternative methods to attenuate Pb toxicity. In this study, the weaning (postnatal day 21, PND21) rats were randomly divided into five groups: the control group (AIN-93G diet, de-ionized water), the lead acetate (PbAC) group (AIN-93G diet, 2g/L PbAC in de-ionized water), the lead acetate+WR group (white rice diet, 2g/L PbAC in de-ionized water; PbAC+WR), the lead acetate+BR group (brown rice diet, 2g/L PbAC in de-ionized water; PbAC+BR) and the lead acetate+PR group (pre-germinated brown rice diet, 2g/L PbAC in de-ionized water; PbAC+PR). The animals received the different diets until PND60, and then the experiments were terminated. The protective effects of pre-germinated brown rice (PR) on Pb-induced learning and memory impairment in weaning rats were assessed by the Morris water maze and one-trial-learning passive avoidance test. The anti-oxidative effects of feeding a PR diet to Pb-exposed rats were evaluated. The levels of reactive oxygen species (ROS) were determined by flow cytometry. The levels of 8-hydroxy-2-deoxyguanosine (8-OHdG), gamma-aminobutyric acid (GABA) and glutamate were determined by HPLC. Our data showed that feeding a PR diet decreased the accumulation of lead and decreased Pb-induced learning and memory deficits in developing rats. The mechanisms might be related to the anti-oxidative effects and large amount of GABA in PR. Our study provides a regimen to reduce Pb-induced toxicity, especially future learning and memory deficits in the developing brain.
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Lee KH, Lee SK, Kim HS, Cho EJ, Joo HK, Lee EJ, Lee JY, Park MS, Chang SJ, Cho CH, Park JB, Jeon BH. Overexpression of Ref-1 Inhibits Lead-induced Endothelial Cell Death via the Upregulation of Catalase. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2009; 13:431-6. [PMID: 20054488 DOI: 10.4196/kjpp.2009.13.6.431] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2009] [Revised: 11/09/2009] [Accepted: 11/10/2009] [Indexed: 11/15/2022]
Abstract
The role of apurinic/apyrimidinic endonuclease1/redox factor-1 (Ref-1) on the lead (Pb)-induced cellular response was investigated in the cultured endothelial cells. Pb caused progressive cellular death in endothelial cells, which occurred in a concentration- and time-dependent manner. However, Ref-1 overexpression with AdRef-1 significantly inhibited Pb-induced cell death in the endothelial cells. Also the overexpression of Ref-1 significantly suppressed Pb-induced superoxide and hydrogen peroxide elevation in the endothelial cells. Pb exposure induced the downregulation of catalase, it was inhibited by the Ref-1 overexpression in the endothelial cells. Taken together, our data suggests that the overexpression of Ref-1 inhibited Pb-induced cell death via the upregulation of catalase in the cultured endothelial cells.
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Affiliation(s)
- Kwon Ho Lee
- Department of Physiology, School of Medicine, Chungnam National University, Daejeon 301-131, Korea
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17
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Gu C, Chen S, Xu X, Zheng L, Li Y, Wu K, Liu J, Qi Z, Han D, Chen G, Huo X. Lead and cadmium synergistically enhance the expression of divalent metal transporter 1 protein in central nervous system of developing rats. Neurochem Res 2009; 34:1150-6. [PMID: 19083094 DOI: 10.1007/s11064-008-9891-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/26/2008] [Indexed: 02/05/2023]
Abstract
Divalent metal transporter 1 (DMT1) can transport a large range of ions, including toxic lead (Pb) and cadmium (Cd), across membranes. In this study, a total of 24 rats were divided into four groups for intragastrical perfusion treatment: control, Pb alone, Cd alone, and Pb + Cd. Pb and Cd contents in blood were detected, and the mRNA and protein levels of DMT1 were analyzed in the cerebellum, cortex, and hippocampus. Both Pb and Cd levels were elevated in all groups perfused with Pb and/or Cd, except for Pb level in the Cd-alone group (P < 0.05). The mRNA level of DMT1 did not differ among the four groups (P > 0.05). However, the DMT1 protein expression was significantly increased by 0.9-, 1.0-, and 1.1-fold in cerebellum, cortex, and hippocampus of the Pb + Cd group than in controls, respectively. Pb and Cd exposure can synergistically induce DMT1 protein synthesis and has implications for transportation of toxic ions in the developing rat's brain.
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Affiliation(s)
- Chengwu Gu
- Analytical Cytology Laboratory, Shantou University Medical College, Shantou, People's Republic of China
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18
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Jiang YM, Long LL, Zhu XY, Zheng H, Fu X, Ou SY, Wei DL, Zhou HL, Zheng W. Evidence for altered hippocampal volume and brain metabolites in workers occupationally exposed to lead: a study by magnetic resonance imaging and (1)H magnetic resonance spectroscopy. Toxicol Lett 2008; 181:118-25. [PMID: 18692119 DOI: 10.1016/j.toxlet.2008.07.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2008] [Revised: 07/05/2008] [Accepted: 07/05/2008] [Indexed: 11/28/2022]
Abstract
Environmental and occupational exposure to lead (Pb) remains to be a major public health issue. The purpose of this cross-sectional study was to use non-invasive magnetic resonance imaging (MRI) and proton magnetic resonance spectroscopy ((1)H MRS) techniques to investigate whether chronic exposure to Pb in an occupational setting altered brain structure and function of Pb-exposed workers. The Pb-exposed group consisted of 15 workers recruited from either a Pb-smelting factory or a Pb-battery manufacturer. The control group had 19 healthy volunteers who had no history of Pb exposure in working environment or at home. The average airborne Pb concentrations in fume and dust were 0.43 and 0.44 mg/m(3), respectively, in the smeltery, and 0.10 and 1.06 mg/m(3), respectively, in the Pb battery workshop. The average blood Pb concentrations (BPb) in Pb-exposed and control workers were 63.5 and 8.7 microg/dL, respectively. The MRI examination showed that brain hippocampal volume among Pb-exposed workers was significantly diminished in comparison to age-matched control subjects (p < 0.01), although the extent of this reduction was relatively small (5-6% of the control values). Linear regression analyses revealed significant inverse associations between BPb and the decreased hippocampal volume on both sides of brain hemisphere. Among five brain metabolites investigated by MRS, i.e., N-acetyl-aspartate (NAA), creatine (Cr), choline (Cho), inosine (mI), glutamate/glutamine (Glx) and lipids (Lip), a significant decrease in NAA/Cr ratio (7% of controls, p < 0.05) and a remarkable increase in Lip/Cr ratio (40%, p < 0.01) were observed in the brains of Pb-exposed workers as compared to controls. Furthermore, the increased Lip/Cr ratio was significantly associated with BPb (r = 0.46, p < 0.01). Taken together, this study suggests that occupational exposure to Pb may cause subtle structural and functional alteration in human brains. The MRI and MRS brain imaging techniques can be used as the non-invasive means to evaluate Pb-induced neurotoxicity.
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Affiliation(s)
- Yue-Ming Jiang
- Department of Occupational Health and Toxicology, Guangxi Medical University, Nanning, Guangxi, China
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