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Huang Y, Zhang F, Zhang Y, Chen R, Lü X. Combination of gene/protein and metabolite multiomics to reveal biomarkers of nickel ion cytotoxicity and the underlying mechanism. Regen Biomater 2024; 11:rbae079. [PMID: 39022125 PMCID: PMC11254314 DOI: 10.1093/rb/rbae079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Revised: 06/11/2024] [Accepted: 06/19/2024] [Indexed: 07/20/2024] Open
Abstract
Biomarkers have been applied for toxicity assessment of biomaterials due to their advantages. However, research on biomarkers for biomaterials is still in its early stages. There is a lack of integrated analysis in biomarker research based on multiomics studies. Herein, we report a new approach for combining of gene/protein and metabolite multiomics to reveal biomarkers of nickel ion (Ni2+) cytotoxicity and the underlying mechanism. Firstly, differentially expressed genes and proteins were compared to screen gene/protein pairs exhibiting consistent differential expression within the same Ni2+-treated groups. Next, metabolic pathway analysis was carried out to reveal pathways in which gene/protein pairs and metabolites showed upstream and downstream relationships. Important networks composed of gene/protein pairs, metabolites and metabolic pathways and candidate biomarkers were subsequently identified. Through expression level and function validation, the gene/protein/metabolite biomarkers were confirmed, and the underlying mechanism was revealed: Ni2+ influenced the expression of the Rrm2 gene biomarker, which subsequently affected the expression of the RRM2 protein biomarker. These changes in turn impacted the levels of uric acid and uridine metabolite biomarkers, ultimately inhibiting DNA synthesis, suppressing cell proliferation, increasing intracellular ROS levels and reducing ATP content.
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Affiliation(s)
- Yan Huang
- State Key Laboratory of Digital Medical Engineering, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
| | - Fudan Zhang
- State Key Laboratory of Digital Medical Engineering, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
| | - Yajing Zhang
- State Key Laboratory of Digital Medical Engineering, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
| | - Rong Chen
- State Key Laboratory of Digital Medical Engineering, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
| | - Xiaoying Lü
- State Key Laboratory of Digital Medical Engineering, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
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2
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Potential and Limits of Kidney Cells for Evaluation of Renal Excretion. Pharmaceuticals (Basel) 2021; 14:ph14090908. [PMID: 34577608 PMCID: PMC8464824 DOI: 10.3390/ph14090908] [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: 04/25/2021] [Revised: 08/27/2021] [Accepted: 08/31/2021] [Indexed: 12/02/2022] Open
Abstract
A large number of therapeutic drugs, herbal components and their metabolites are excreted by the kidneys. Therefore, generally applied models for estimating renal excretion, including freshly isolated rat proximal tubule cells, cultured tubule cells and immortalized kidney cell lines MDCKII, NRK-52E, IHKE-1 and Caki-1, were investigated regarding their predictive potential for active renal transport. Cultured proximal tubule cells showed an epithelial cell-like morphology and formed tight monolayers. However, mRNA expression analyses and immunohistochemical studies revealed patterns of tight junction proteins that were notably different from freshly isolated cells and distinct from those in vivo. High levels of mannitol permeation were found in NRK-52E, IHKE-1 and Caki-1 cells, suggesting that they are not suitable for bidirectional transport studies. Cultured cells and freshly isolated cells also differed in proximal tubule markers and transport proteins, indicating that cultured primary cells were in a state of dedifferentiation. Cell lines MDCKII, NRK-52E, IHKE-1 and Caki-1 did not accurately reflect the characteristics of proximal tubules. The expression patterns of marker and transport proteins differed from freshly isolated primary cells. In summary, each of these models has profound disadvantages to consider when adopting them reliable models for the in vivo situation. Thus, they should not be used alone but only in combination.
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Ojeda AS, Ford SD, Gallucci RM, Ihnat MA, Philp RP. Geochemical characterization and renal cell toxicity of water-soluble extracts from U.S. Gulf Coast lignite. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2019; 41:1037-1053. [PMID: 30276587 DOI: 10.1007/s10653-018-0196-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 09/21/2018] [Indexed: 06/08/2023]
Abstract
An assortment of organic material can leach from lignite (low-rank coal) in water, and the water-soluble fraction from lignite has been associated with adverse health effects in areas of the Balkans. Recent efforts have been made to evaluate this hypothesis in other areas where lignite is in contact with groundwater like in the U.S. Gulf Coast region. In this study, five Gulf Coast lignite samples were extracted with water, and the water-soluble portion of the coal was then characterized by total organic carbon, UV-Vis spectroscopy, and gas chromatography/mass spectrometry. Additionally, human kidney cells (HK-2) were exposed to water-soluble extracts of Gulf Coast lignite to assess toxicity. Cell viability was measured, and a dose-response curve was used to generate IC50 values that ranged from 490 to 3000 ppm. The most toxic extract (Dolet Hills) was from Louisiana where lignite-derived organic material has been previously linked to high incidence of renal pelvic cancer. Concentrations of nephrotoxic metals (As, Cd, Co, Cu, Hg, Pb, V, Zn) were screened and were below those considered toxic to renal cells. We conclude that leachates from lignite do indeed have toxic affects on cultured human renal cells. Although the IC50 values are higher than the concentration of organic matter in the local groundwater, typically < 5 ppm, the effects of long-term low-level exposure is not known.
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Affiliation(s)
- A S Ojeda
- Department of Geology and Geophysics, The University of Oklahoma, Norman, OK, 73019, USA.
| | - S D Ford
- Department of Pharmaceutical Sciences, College of Pharmacy, The University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| | - R M Gallucci
- Department of Pharmaceutical Sciences, College of Pharmacy, The University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| | - M A Ihnat
- Department of Pharmaceutical Sciences, College of Pharmacy, The University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| | - R P Philp
- Department of Geology and Geophysics, The University of Oklahoma, Norman, OK, 73019, USA
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Handl J, Čapek J, Majtnerová P, Petira F, Hauschke M, Roušarová E, Roušar T. Transient increase in cellular dehydrogenase activity after cadmium treatment precedes enhanced production of reactive oxygen species in human proximal tubular kidney cells. Physiol Res 2019; 68:481-490. [PMID: 30904015 DOI: 10.33549/physiolres.934121] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Cadmium is a heavy metal causing toxicity especially in kidney cells. The toxicity is linked also with enhanced oxidative stress leading to cell death. On the other hand, our recent experiments have shown that an increase of total intracellular dehydrogenases activity can also occur in kidney cells before declining until cell death. The aim of the present study, therefore, was to evaluate this transient enhancement in cell viability after cadmium treatment. The human kidney HK-2 cell line was treated with CdCl(2) at concentrations 0-200 microM for 2-24 h and intracellular dehydrogenase activity was tested. In addition, we measured reactive oxygen species (ROS) production, glutathione levels, mitochondrial membrane potential, and C-Jun-N-terminal kinase (JNK) activation. We found that significantly increased dehydrogenase activity could occur in cells treated with 25, 100, and 200 microM CdCl(2). Moreover, the results showed an increase in ROS production linked with JNK activation following the enhancement of dehydrogenase activity. Other tests detected no relationship with the increased in intracellular dehydrogenase activity. Hence, the transient increase in dehydrogenase activity in HK-2 cells preceded the enhancement of ROS production and our finding provides new evidence in cadmium kidney toxicity.
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Affiliation(s)
- J Handl
- Department of Biological and Biochemical Sciences, Faculty of Chemical Technology, University of Pardubice, Pardubice, Czech Republic.
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5
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Abreu PL, Ferreira LMR, Cunha-Oliveira T, Alpoim MC, Urbano AM. HSP90: A Key Player in Metal-Induced Carcinogenesis? HEAT SHOCK PROTEINS 2019. [DOI: 10.1007/978-3-030-23158-3_11] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Intrauterine Exposure to Cadmium Reduces HIF-1 DNA-Binding Ability in Rat Fetal Kidneys. TOXICS 2018; 6:toxics6030053. [PMID: 30177602 PMCID: PMC6161213 DOI: 10.3390/toxics6030053] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 08/07/2018] [Accepted: 08/29/2018] [Indexed: 02/06/2023]
Abstract
During embryonic development, some hypoxia occurs due to incipient vascularization. Under hypoxic conditions, gene expression is mainly controlled by hypoxia-inducible factor 1 (HIF-1). The activity of this transcription factor can be altered by the exposure to a variety of compounds; among them is cadmium (Cd), a nephrotoxic heavy metal capable of crossing the placenta and reaching fetal kidneys. The goal of the study was to determine Cd effects on HIF-1 on embryonic kidneys. Pregnant Wistar rats were exposed to a mist of isotonic saline solution or CdCl₂ (DDel = 1.48 mg Cd/kg/day), from gestational day (GD) 8 to 20. Embryonic kidneys were obtained on GD 21 for RNA and protein extraction. Results show that Cd exposure had no effect on HIF-1α and prolyl hydroxylase 2 protein levels, but it reduced HIF-1 DNA-binding ability, which was confirmed by a decrease in vascular endothelial growth factor (VEGF) mRNA levels. In contrast, the protein levels of VEGF were not changed, which suggests the activation of additional regulatory mechanisms of VEGF protein expression to ensure proper kidney development. In conclusion, Cd exposure decreases HIF-1-binding activity, posing a risk on renal fetal development.
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Karri V, Kumar V, Ramos D, Oliveira E, Schuhmacher M. An in vitro cytotoxic approach to assess the toxicity of heavy metals and their binary mixtures on hippocampal HT-22 cell line. Toxicol Lett 2018; 282:25-36. [DOI: 10.1016/j.toxlet.2017.10.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 09/24/2017] [Accepted: 10/02/2017] [Indexed: 12/23/2022]
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Prozialeck WC, Lamar PC, Edwards JR. Effects of sub-chronic Cd exposure on levels of copper, selenium, zinc, iron and other essential metals in rat renal cortex. Toxicol Rep 2016; 3:740-746. [PMID: 28959600 PMCID: PMC5616073 DOI: 10.1016/j.toxrep.2016.09.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 09/09/2016] [Accepted: 09/11/2016] [Indexed: 02/04/2023] Open
Abstract
Cd (Cd) is a nephrotoxic environmental pollutant that causes generalized proximal tubule dysfunction. Even though the specific mechanisms by which Cd damages the kidney have yet to be fully elucidated, there is evidence to suggest that some of these nephrotoxic effects may result from the ability of Cd to alter the levels and function of metals such as Cu, Se, Zn and Fe within the kidney. In order to further explore this issue, we examined the effects of subchronic Cd exposure on tissue levels of a panel of metals (Ca, Cu, Fe, K, Mg, Na, Se and Zn) in the rat renal cortex. Adult male Sprague-Dawley rats were treated with CdCl2 (0.6 mg Cd/kg body weight in isotonic saline by subcutaneous injection, 5 days per week for 6, 9 or 12 weeks). At each time point, 24 h urine samples were collected and assayed for levels of protein, creatinine, β2 microglobulin and cystatin C. Samples of renal cortex were removed and assayed for levels of the metals of interest by inductively-coupled mass spectrometry at Michigan State University. Results showed that at 9 and 12 weeks, Cd caused significant increases in urine volume and urinary protein with no change in creatinine excretion. Increases in the excretion of the urinary biomarkers β2 microglobulin and cystatin C were evident after 6 weeks of Cd exposure. Results of the metal analyses showed that Cd caused significant increases in tissue levels of Cu and Se at all of the time points examined. Tissue levels of Zn were transiently elevated at 6 weeks but declined to control levels at 9 and 12 weeks. Cd caused a significant decrease in levels of Fe at 9 and 12 weeks. Cd had no effects on any of the other metals. Tissue levels of Cd were 530 ± 52, 863 ± 23, 837 ± 23 ppm dry weight at 6, 9 and 12 weeks, respectively. These results indicate that the early stages of Cd nephrotoxicity are associated with alterations in renal tissue levels of Cu, Se, Zn and Fe. The fact that the changes in levels of the metals occurred during the early stages of Cd toxicity raises the possibility that the alterations in renal cortical metal content may play some role in the pathophysiology or Cd-induced injury.
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Affiliation(s)
- Walter C Prozialeck
- Department of Pharmacology, Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, IL 60515, United States
| | - Peter C Lamar
- Department of Pharmacology, Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, IL 60515, United States
| | - Joshua R Edwards
- Department of Pharmacology, Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, IL 60515, United States
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Yan SH, Zhao NW, Jiang WM, Wang XT, Zhang SQ, Zhu XX, Zhang CB, Gao YH, Gao F, Liu FM, Fang ZY. Hsp90β is involved in the development of high salt-diet-induced nephropathy via interaction with various signalling proteins. Open Biol 2016; 6:150159. [PMID: 27248656 PMCID: PMC4852449 DOI: 10.1098/rsob.150159] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2015] [Accepted: 03/19/2016] [Indexed: 12/23/2022] Open
Abstract
A high-salt diet often leads to a local intrarenal increase in renal hypoxia and oxidative stress, which are responsible for an excess production of pathogenic substances. Here, Wistar Kyoto/spontaneous hypertensive (WKY/SHR) rats fed a high-salt diet developed severe proteinuria, resulting from pronounced renal inflammation, fibrosis and tubular epithelial cell apoptosis. All these were mainly non-pressure-related effects. Hsp90β, TGF-β, HIF-1α, TNF-α, IL-6 and MCP-1 were shown to be highly expressed in response to salt loading. Next, we found that Hsp90β might play the key role in non-pressure-related effects of salt loading through a series of cellular signalling events, including the NF-κB, p38 activation and Bcl-2 inactivation. Hsp90β was previously proven to regulate the upstream mediators in multiple cellular signalling cascades through stabilizing and maintaining their activities. In our study, 17-dimethylaminoethylamino-17-demethoxygeldanamycin (17-DMAG) or Hsp90β knockdown dramatically alleviated the high-salt-diet-induced proteinuria and renal damage without altering blood pressure significantly, when it reversed activations of NF-κB, mTOR and p38 signalling cascades. Meanwhile, Co-IP results demonstrated that Hsp90β could interact with and stabilize TAK1, AMPKα, IKKα/β, HIF-1α and Raptor, whereas Hsp90β inhibition disrupted this process. In addition, Hsp90β inhibition-mediated renal improvements also accompanied the reduction of renal oxidative stress. In conclusion, salt loading indeed exhibited non-pressure-related impacts on proteinuria and renal dysfunction in WKY/SHR rats. Hsp90β inhibition caused the destabilization of upstream mediators in various pathogenic signalling events, thereby effectively ameliorating this nephropathy owing to renal hypoxia and oxidative stress.
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Affiliation(s)
- Shi-hai Yan
- Affiliated Hospital of Nanjing University of Chinese Medicine, Jiangsu Province Hospital of TCM, Nanjing, People's Republic of China
| | - Ning-wei Zhao
- Affiliated Hospital of Nanjing University of Chinese Medicine, Jiangsu Province Hospital of TCM, Nanjing, People's Republic of China Shimadzu Biomedical Research Laboratory, Shanghai, People's Republic of China
| | - Wei-min Jiang
- Affiliated Hospital of Nanjing University of Chinese Medicine, Jiangsu Province Hospital of TCM, Nanjing, People's Republic of China
| | - Xin-tong Wang
- Affiliated Hospital of Nanjing University of Chinese Medicine, Jiangsu Province Hospital of TCM, Nanjing, People's Republic of China
| | - Si-qi Zhang
- Affiliated Hospital of Nanjing University of Chinese Medicine, Jiangsu Province Hospital of TCM, Nanjing, People's Republic of China
| | - Xuan-xuan Zhu
- Affiliated Hospital of Nanjing University of Chinese Medicine, Jiangsu Province Hospital of TCM, Nanjing, People's Republic of China
| | - Chun-bing Zhang
- Affiliated Hospital of Nanjing University of Chinese Medicine, Jiangsu Province Hospital of TCM, Nanjing, People's Republic of China
| | - Yan-hong Gao
- Nanjing Normal University, Nanjing, People's Republic of China
| | - Feng Gao
- Affiliated Hospital of Nanjing University of Chinese Medicine, Jiangsu Province Hospital of TCM, Nanjing, People's Republic of China
| | - Fu-ming Liu
- Affiliated Hospital of Nanjing University of Chinese Medicine, Jiangsu Province Hospital of TCM, Nanjing, People's Republic of China
| | - Zhu-yuan Fang
- Affiliated Hospital of Nanjing University of Chinese Medicine, Jiangsu Province Hospital of TCM, Nanjing, People's Republic of China
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Lee JY, Tokumoto M, Fujiwara Y, Hasegawa T, Seko Y, Shimada A, Satoh M. Accumulation of p53 via down-regulation of UBE2D family genes is a critical pathway for cadmium-induced renal toxicity. Sci Rep 2016; 6:21968. [PMID: 26912277 PMCID: PMC4766413 DOI: 10.1038/srep21968] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 02/03/2016] [Indexed: 12/19/2022] Open
Abstract
Chronic cadmium (Cd) exposure can induce renal toxicity. In Cd renal toxicity, p53 is thought to be involved. Our previous studies showed that Cd down-regulated gene expression of the UBE2D (ubiquitin-conjugating enzyme E2D) family members. Here, we aimed to define the association between UBE2D family members and p53-dependent apoptosis in human proximal tubular cells (HK-2 cells) treated with Cd. Cd increased intracellular p53 protein levels and decreased UBE2D2 and UBE2D4 gene expression via inhibition of YY1 and FOXF1 transcription factor activities. Double knockdown of UBE2D2 and UBE2D4 caused an increase in p53 protein levels, and knockdown of p53 attenuated not only Cd-induced apoptosis, but also Cd-induced apoptosis-related gene expression (BAX and PUMA). Additionally, the mice exposed to Cd for 6 months resulted in increased levels of p53 and induction of apoptosis in proximal tubular cells. These findings suggest that down-regulation of UBE2D family genes followed by accumulation of p53 in proximal tubular cells is an important mechanism for Cd-induced renal toxicity.
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Affiliation(s)
- Jin-Yong Lee
- Laboratory of Pharmaceutical Health Sciences, School of Pharmacy, Aichi Gakuin University, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya, Aichi 464-8650, Japan
| | - Maki Tokumoto
- Laboratory of Pharmaceutical Health Sciences, School of Pharmacy, Aichi Gakuin University, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya, Aichi 464-8650, Japan
| | - Yasuyuki Fujiwara
- Laboratory of Pharmaceutical Health Sciences, School of Pharmacy, Aichi Gakuin University, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya, Aichi 464-8650, Japan.,Department of Environmental Health, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan
| | - Tatsuya Hasegawa
- Department of Environmental Biochemistry, Mount Fuji Research Institute, 5597-1 Kenmarubi, Kamiyoshida, Fujiyoshida, Yamanashi 403-0005, Japan
| | - Yoshiyuki Seko
- Department of Environmental Biochemistry, Mount Fuji Research Institute, 5597-1 Kenmarubi, Kamiyoshida, Fujiyoshida, Yamanashi 403-0005, Japan
| | - Akinori Shimada
- Laboratory of Pathology, Department of Medical Technology, School of Life and Environmental Science, Azabu University, 1-17-71 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5201, Japan
| | - Masahiko Satoh
- Laboratory of Pharmaceutical Health Sciences, School of Pharmacy, Aichi Gakuin University, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya, Aichi 464-8650, Japan
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Adebambo OA, Ray PD, Shea D, Fry RC. Toxicological responses of environmental mixtures: Environmental metal mixtures display synergistic induction of metal-responsive and oxidative stress genes in placental cells. Toxicol Appl Pharmacol 2015; 289:534-41. [PMID: 26472158 DOI: 10.1016/j.taap.2015.10.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Revised: 09/24/2015] [Accepted: 10/09/2015] [Indexed: 11/18/2022]
Abstract
Exposure to elevated levels of the toxic metals inorganic arsenic (iAs) and cadmium (Cd) represents a major global health problem. These metals often occur as mixtures in the environment, creating the potential for interactive or synergistic biological effects different from those observed in single exposure conditions. In the present study, environmental mixtures collected from two waste sites in China and comparable mixtures prepared in the laboratory were tested for toxicogenomic response in placental JEG-3 cells. These cells serve as a model for evaluating cellular responses to exposures during pregnancy. One of the mixtures was predominated by iAs and one by Cd. Six gene biomarkers were measured in order to evaluate the effects from the metal mixtures using dose and time-course experiments including: heme oxygenase 1 (HO-1) and metallothionein isoforms (MT1A, MT1F and MT1G) previously shown to be preferentially induced by exposure to either iAs or Cd, and metal transporter genes aquaporin-9 (AQP9) and ATPase, Cu(2+) transporting, beta polypeptide (ATP7B). There was a significant increase in the mRNA expression levels of ATP7B, HO-1, MT1A, MT1F, and MT1G in mixture-treated cells compared to the iAs or Cd only-treated cells. Notably, the genomic responses were observed at concentrations significantly lower than levels found at the environmental collection sites. These data demonstrate that metal mixtures increase the expression of gene biomarkers in placental JEG-3 cells in a synergistic manner. Taken together, the data suggest that toxic metals that co-occur may induce detrimental health effects that are currently underestimated when analyzed as single metals.
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Affiliation(s)
| | - Paul D Ray
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, United States
| | - Damian Shea
- Department of Biological Sciences, North Carolina State University, United States
| | - Rebecca C Fry
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, United States.
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12
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Clarke R, Connolly L, Frizzell C, Elliott CT. Challenging conventional risk assessment with respect to human exposure to multiple food contaminants in food: A case study using maize. Toxicol Lett 2015. [PMID: 26196220 DOI: 10.1016/j.toxlet.2015.07.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Mycotoxins and heavy metals are ubiquitous in the environment and contaminate many foods. The widespread use of pesticides in crop production to control disease contributes further to the chemical contamination of foods. Thus multiple chemical contaminants threaten the safety of many food commodities; hence the present study used maize as a model crop to identify the severity in terms of human exposure when multiple contaminants are present. High Content Analysis (HCA) measuring multiple endpoints was used to determine cytotoxicity of complex mixtures of mycotoxins, heavy metals and pesticides. Endpoints included nuclear intensity (NI), nuclear area (NA), plasma membrane permeability (PMP), mitochondrial membrane potential (MMP) and mitochondrial mass (MM). At concentrations representing legal limits of each individual contaminant in maize (3ng/ml ochratoxin A (OTA), 1μg/ml fumonisin B1 (FB1), 2ng/ml aflatoxin B1 (AFB1), 100ng/ml cadmium (Cd), 150ng/ml arsenic (As), 50ng/ml chlorpyrifos (CP) and 5μg/ml pirimiphos methyl (PM), the mixtures (tertiary mycotoxins plus Cd/As) and (tertiary mycotoxins plus Cd/As/CP/PM) were cytotoxic for NA and MM endpoints with a difference of up to 13.6% (p≤0.0001) and 12% (p≤0.0001) respectively from control values. The most cytotoxic mixture was (tertiary mycotoxins plus Cd/As/CP/PM) across all 4 endpoints (NA, NI, MM and MMP) with increases up to 61.3%, 23.0%, 61.4% and 36.3% (p≤0.0001) respectively. Synergy was evident for two endpoints (NI and MM) at concentrations contaminating maize above legal limits, with differences between expected and measured values of (6.2-12.4% (p≤0.05-p≤0.001) and 4.5-12.3% (p≤0.05-p≤0.001) for NI and MM, respectively. The study introduces for the first time, a holistic approach to identify the impact in terms of toxicity to humans when multiple chemical contaminants are present in foodstuffs. Governmental regulatory bodies must begin to contemplate how to safeguard the population when such mixtures of contaminants are found in foods and this study starts to address this critical issue.
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Affiliation(s)
- R Clarke
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Ireland.
| | - L Connolly
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Ireland
| | - C Frizzell
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Ireland
| | - C T Elliott
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Ireland
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Khamis I, Heikkila JJ. Enhanced HSP30 and HSP70 accumulation in Xenopus cells subjected to concurrent sodium arsenite and cadmium chloride stress. Comp Biochem Physiol C Toxicol Pharmacol 2013; 158:165-72. [PMID: 23919948 DOI: 10.1016/j.cbpc.2013.07.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Revised: 07/26/2013] [Accepted: 07/26/2013] [Indexed: 01/31/2023]
Abstract
Heat shock proteins (HSPs) are molecular chaperones that aid in protein folding, translocation and in preventing stress-induced protein aggregation. The present study examined the effect of simultaneous sodium arsenite and cadmium chloride treatment on the pattern of HSP30 and HSP70 accumulation in A6 kidney epithelial cells of the frog, Xenopus laevis. Immunoblot analysis revealed that HSP30 and HSP70 accumulation in concurrent stressor treatments were significantly higher than the sum of HSP30 or HSP70 accumulation in individual treatments. This finding suggested a synergistic action between sodium arsenite and cadmium chloride. KNK437 inhibitor studies indicated that the combined stressor-induced accumulation of HSPs may be regulated, at least in part, at the level of transcription. Immunocytochemistry revealed that simultaneous treatment of cells with the two stressors induced HSP30 accumulation primarily in the cytoplasm in a punctate pattern with some dysregulation of F-actin structure. Increased ubiquitinated protein accumulation was observed with combined sodium arsenite and cadmium chloride treatment compared to individual stressors suggesting an impairment of the ubiquitin proteasome degradation system. The addition of a mild heat shock further enhanced the accumulation of HSP30 and HSP70 in response to relatively low concentrations of sodium arsenite plus cadmium chloride.
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Affiliation(s)
- Imran Khamis
- Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1, Canada
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14
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Toxicogenomic approaches for understanding molecular mechanisms of heavy metal mutagenicity and carcinogenicity. Int J Hyg Environ Health 2013; 216:587-98. [PMID: 23540489 DOI: 10.1016/j.ijheh.2013.02.010] [Citation(s) in RCA: 101] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Revised: 02/26/2013] [Accepted: 02/26/2013] [Indexed: 12/24/2022]
Abstract
Heavy metals that are harmful to humans include arsenic, cadmium, chromium, lead, mercury, and nickel. Some metals or their related compounds may even cause cancer. However, the mechanism underlying heavy metal-induced cancer remains unclear. Increasing data show a link between heavy metal exposure and aberrant changes in both genetic and epigenetic factors via non-targeted multiple toxicogenomic technologies of the transcriptome, proteome, metabolome, and epigenome. These modifications due to heavy metal exposure might provide a better understanding of environmental disorders. Such informative changes following heavy metal exposure might also be useful for screening of biomarker-monitored exposure to environmental pollutants and/or predicting the risk of disease. We summarize advances in high-throughput toxicogenomic-based technologies and studies related to exposure to individual heavy metal and/or mixtures and propose the underlying mechanism of action and toxicant signatures. Integrative multi-level expression analysis of the toxicity of heavy metals via system toxicology-based methodologies combined with statistical and computational tools might clarify the biological pathways involved in carcinogenic processes. Although standard in vitro and in vivo endpoint testing of mutagenicity and carcinogenicity are considered a complementary approach linked to disease, we also suggest that further evaluation of prominent biomarkers reflecting effects, responses, and disease susceptibility might be diagnostic. Furthermore, we discuss challenges in toxicogenomic applications for toxicological studies of metal mixtures and epidemiological research. Taken together, this review presents toxicogenomic data that will be useful for improvement of the knowledge of carcinogenesis and the development of better strategies for health risk assessment.
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Bidmon B, Kratochwill K, Rusai K, Kuster L, Herzog R, Eickelberg O, Aufricht C. Increased immunogenicity is an integral part of the heat shock response following renal ischemia. Cell Stress Chaperones 2012; 17:385-97. [PMID: 22180342 PMCID: PMC3312958 DOI: 10.1007/s12192-011-0314-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2010] [Revised: 11/29/2011] [Accepted: 11/30/2011] [Indexed: 11/25/2022] Open
Abstract
Renal ischemia increases tubular immunogenicity predisposing to increased risk of kidney allograft rejection. Ischemia-reperfusion not only disrupts cellular homeostasis but also induces the cytoprotective heat shock response that also plays a major role in cellular immune and defense processes. This study therefore tested the hypothesis that upregulation of renal tubular immunogenicity is an integral part of the heat shock response after renal ischemia. Expressions of 70 kDa heat shock protein (Hsp70), major histocompatibility complex (MHC) class II, and intercellular adhesion molecule-1 (ICAM-1) were assessed in normal rat kidney (NRK) cells following ATP depletion (antimycin A for 3 h) and heat (42°C for 24 h). In vitro, transient Hsp70 transfection and heat shock factor-1 (HSF-1) transcription factor decoy treatment were performed. In vivo, ischemic renal cortex was investigated in Sprague-Dawley rats following unilateral renal artery clamping for 45 min and 24 h recovery. Upregulation of Hsp70 was closely and significantly correlated with upregulation of MHC class II and/or ICAM-1 following ATP depletion and heat injury. Bioinformatics analysis searching the TRANSFAC database predicted HSF-1 binding sites in these genes. HSF-1 decoy significantly reduced the expression of immunogenicity markers in stressed NRK cells. In the in vivo rat model of renal ischemia, concordant upregulation of MHC class II molecules and Hsp70 suggests biological relevance of this link. The results demonstrate that upregulation of renal tubular immunogenicity is an integral part of the heat shock response after renal ischemia. Bioinformatic analysis predicted a molecular link to tubular immunogenicity at the level of the transcription factor HSF-1 that was experimentally verified by HSF-1 decoy treatment. Future studies in HSF-1 knockout mice are needed.
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Affiliation(s)
- Bettina Bidmon
- Department of Pediatrics, Medical University Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Klaus Kratochwill
- Department of Pediatrics, Medical University Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Krisztina Rusai
- Department of Pediatrics, Medical University Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Lilian Kuster
- Department of Pediatrics, Medical University Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Rebecca Herzog
- Department of Pediatrics, Medical University Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Oliver Eickelberg
- Comprehensive Pneumology Center, University Hospital, Helmholtz Zentrum München, University of Munich, Max-Lebsche-Platz 31, 81377 Munich, Germany
| | - Christoph Aufricht
- Department of Pediatrics, Medical University Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
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Stacchiotti A, Morandini F, Bettoni F, Schena I, Lavazza A, Grigolato PG, Apostoli P, Rezzani R, Aleo MF. Stress proteins and oxidative damage in a renal derived cell line exposed to inorganic mercury and lead. Toxicology 2009; 264:215-24. [PMID: 19720107 DOI: 10.1016/j.tox.2009.08.014] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2009] [Revised: 08/21/2009] [Accepted: 08/21/2009] [Indexed: 10/20/2022]
Abstract
A close link between stress protein up-regulation and oxidative damage may provide a novel therapeutic tool to counteract nephrotoxicity induced by toxic metals in the human population, mainly in children, of industrialized countries. Here we analysed the time course of the expression of several heat shock proteins, glucose-regulated proteins and metallothioneins in a rat proximal tubular cell line (NRK-52E) exposed to subcytotoxic doses of inorganic mercury and lead. Concomitantly, we used morphological and biochemical methods to evaluate metal-induced cytotoxicity and oxidative damage. In particular, as biochemical indicators of oxidative stress we detected reactive oxygen species (ROS) and nitrogen species (RNS), total glutathione (GSH) and glutathione-S-transferase (GST) activity. Our results clearly demonstrated that mercury increases ROS and RNS levels and the expressions of Hsp25 and inducible Hsp72. These findings are corroborated by evident mitochondrial damage, apoptosis or necrosis. By contrast, lead is unable to up-regulate Hsp72 but enhances Grp78 and activates nuclear Hsp25 translocation. Furthermore, lead causes endoplasmic reticulum (ER) stress, vacuolation and nucleolar segregation. Lastly, both metals stimulate the over-expression of MTs, but with a different time course. In conclusion, in NRK-52E cell line the stress response is an early and metal-induced event that correlates well with the direct oxidative damage induced by mercury. Indeed, different chaperones are involved in the specific nephrotoxic mechanism of these environmental pollutants and work together for cell survival.
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Affiliation(s)
- Alessandra Stacchiotti
- Human Anatomy Unit, Department of Biomedical Sciences and Biotechnology, School of Medicine, University of Brescia, Italy
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Simultaneous exposure of Xenopus A6 kidney epithelial cells to concurrent mild sodium arsenite and heat stress results in enhanced hsp30 and hsp70 gene expression and the acquisition of thermotolerance. Comp Biochem Physiol A Mol Integr Physiol 2009; 153:417-24. [DOI: 10.1016/j.cbpa.2009.03.024] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2008] [Revised: 03/26/2009] [Accepted: 03/31/2009] [Indexed: 01/09/2023]
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Ling XP, Zhu JY, Huang L, Huang HQ. Proteomic changes in response to acute cadmium toxicity in gill tissue of Paralichthys olivaceus. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2009; 27:212-218. [PMID: 21783942 DOI: 10.1016/j.etap.2008.10.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2008] [Revised: 10/07/2008] [Accepted: 10/17/2008] [Indexed: 05/31/2023]
Abstract
In the present study, we developed a two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) technique for examining the response of the proteome from gill tissue of Paralichthys olivaceus (POGT) to acute cadmium (AC) toxicity. Approximately 700 protein spots were detected from the gill sample when applying a 600μg protein 2D-PAGE gel in the pH range 5.0-8.0, and approximately 400 of these were identified by peptide mass fingerprinting (PMF) and database search. Compared to a control sample, significant changes were visualized in 18 protein spots exposed to seawater cadmium acute toxicity at 10.0ppm for 24h. Among these spots, two were up-regulated, one was down-regulated, seven showed low expression, and eight showed high expression. The collected spots were further identified by PMF and database search. Ten of the 18 proteins identified on the 2D-PAGE gel, including heat shock protein 70 and calcium-binding protein, demonstrated a synchronous response to AC, and we suggest that the variable levels and trends of these spots on the gel might be utilized as biomarker profiles to investigate cadmium contamination levels in seawater and to evaluate the degree of risk of human fatalities. The experimental results emphasize that the application of multiple biomarkers has an advantage over single biomarkers for monitoring levels of heavy metal contamination in seawater.
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Affiliation(s)
- Xue-Ping Ling
- Department of Biochemistry and Biotechnology, School of Life Sciences, Xiamen University, Xiamen 361005, China; Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
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Ivanina AV, Cherkasov AS, Sokolova IM. Effects of cadmium on cellular protein and glutathione synthesis and expression of stress proteins in eastern oysters, Crassostrea virginica Gmelin. ACTA ACUST UNITED AC 2008; 211:577-86. [PMID: 18245635 DOI: 10.1242/jeb.011262] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Cadmium (Cd) is an important toxicant in estuarine and coastal environments that can strongly affect energy balance of aquatic organisms by increasing the organism's basal energy demand and reducing its aerobic capacity. Mechanisms of cadmium-induced increase in basal metabolic costs are not well understood and may involve elevated detoxification costs due to the synthesis of cellular protective proteins and glutathione. We studied the short-term effects of cadmium exposure (4 h) on protein and glutathione (GSH) synthesis and expression of stress proteins (heat shock proteins HSP60, HSP70 and HSP90) and metallothioneins in isolated gill and hepatopancreas cells of the eastern oyster, Crassostrea virginica. Our study showed that exposure to cadmium resulted in a dose-dependent increase in the rate of protein synthesis in oyster cells, which reached 150% of the control at the highest tested Cd level (2000 micromol l(-1)). GSH synthesis was significantly inhibited by the highest Cd concentrations, especially in hepatopancreas, which resulted in a slight but significant decrease in the total GSH concentrations. Elevated protein synthesis was associated with the increased expression of metallothioneins and heat shock proteins. Interestingly, stress protein response differed considerably between gill and hepatopancreas cells. In hepatopancreas, expression of metallothionein mRNA (measured by real-time PCR) increased 2-8-fold in response to Cd exposure, whereas no significant increase in metallothionein expression was found in Cd-exposed gill cells. By contrast, HSP60 and HSP70 protein levels increased significantly in Cd-exposed gill cells (by 1.5-2-fold) but not in hepatopancreas. No change in HSP90 expression was detected in response to Cd exposure in oyster cells. These data indicate that metallothionein expression may provide sufficient protection against Cd-induced damage to intracellular proteins in hepatopancreas, alleviating the need for overexpression of molecular chaperones. By contrast, Cd detoxification mechanisms such as inducible metallothioneins and GSH appear to be insufficient to fully prevent protein damage in gill cells, thus necessitating induction of HSPs as a secondary line of cellular defense. Therefore, gills are likely to be among the most Cd-sensitive tissues in oysters, which may have important implications for impaired oxygen uptake contributing to energy misbalance and reduced aerobic scope in Cd-exposed oysters.
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Affiliation(s)
- Anna V Ivanina
- Biology Department, University of North Carolina at Charlotte, 9201 University City Blvd, Charlotte, NC 28223, USA
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Wang G, Fowler BA. Roles of biomarkers in evaluating interactions among mixtures of lead, cadmium and arsenic. Toxicol Appl Pharmacol 2008; 233:92-9. [PMID: 18325558 DOI: 10.1016/j.taap.2008.01.017] [Citation(s) in RCA: 147] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2007] [Accepted: 01/25/2008] [Indexed: 11/25/2022]
Abstract
Human exposure to environmental chemicals is most correctly characterized as exposure to mixtures of these agents. The metals/metalloids, lead (Pb), cadmium (Cd), and arsenic (As), are among the leading toxic agents detected in the environment. Exposure to these elements, particularly at chronic low dose levels, is still a major public health concern. Concurrent exposure to Pb, Cd, or As may produce additive or synergistic interactions or even new effects that are not seen in single component exposures. Evaluating these interactions on a mechanistic basis is essential for risk assessment and management of metal/metalloid mixtures. This paper will review a number of individual studies that addressed interactions of these metals/metalloids in both experimental and human exposure studies with particular emphasis on biomarkers. In general, co-exposure to metal/metalloid mixtures produced more severe effects at both relatively high dose and low dose levels in a biomarker-specific manner. These effects were found to be mediated by dose, duration of exposure and genetic factors. While traditional endpoints, such as morphological changes and biochemical parameters for target organ toxicity, were effective measures for evaluating the toxicity of high dose metal/metalloid mixtures, biomarkers for oxidative stress, altered heme biosynthesis parameters, and stress proteins showed clear responses in evaluating toxicity of low dose metal/metalloid mixtures. Metallothionein, heat shock proteins, and glutathione are involved in regulating interactive effects of metal/metalloid mixtures at low dose levels. These findings suggest that further studies on interactions of these metal/metalloid mixtures utilizing biomarker endpoints are highly warranted.
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Affiliation(s)
- Gensheng Wang
- Department of Experimental Radiation Oncology, U.T.M.D. Anderson Cancer Center, Houston, TX 77030, USA.
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Gottschalg E, Moore NE, Ryan AK, Travis LC, Waller RC, Pratt S, Atmaca M, Kind CN, Fry JR. Phenotypic anchoring of arsenic and cadmium toxicity in three hepatic-related cell systems reveals compound- and cell-specific selective up-regulation of stress protein expression: implications for fingerprint profiling of cytotoxicity. Chem Biol Interact 2006; 161:251-61. [PMID: 16729991 DOI: 10.1016/j.cbi.2006.04.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2006] [Revised: 04/04/2006] [Accepted: 04/05/2006] [Indexed: 10/24/2022]
Abstract
Exposure of cells to toxic chemicals is known to up-regulate the expression of a number of stress proteins (SPs), including metallothionein (MT) and members of the heat shock protein (HSP) family, and this response may allow the development of a fingerprint profile to identify mechanisms of toxicity in an in vitro toxicology setting. To test this hypothesis, three hepatic-derived cell culture systems (rat hepatoma FGC4 cell line, rat hepatocytes, human hepatoma HepG2 cell line) were exposed to cadmium (as CdCl2) and arsenic (as NaAsO2), two compounds believed to exert their toxicity through an oxidative stress mechanism, under conditions of phenotypic anchoring defined as minimal and mild toxicity (approximately 5 and 25% reduction in neutral red uptake, respectively). The expression of six SPs--MT, HSP25/27, HSP40, HSP60, HSP70, and HSP90--was then determined by ELISA. Expression of four of these SPs--MT, HSP25/27, HSP40 and HSP70--was up-regulated in at least one experimental condition. However, the patterns of expression of these four SPs varied across the experimental conditions, according to differences in toxicant concentration and/or level of toxicity, cell-type and toxicant itself. This lack of uniformity in response of a focussed set of mechanistically defensible targets suggests that similar problems may emerge when using more global approaches based on genomics and proteomics, in which problems of redundancy in targets and uncertain mechanistic relevance will be greater.
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Affiliation(s)
- Elke Gottschalg
- School of Biomedical Sciences, Medical School (E Floor), Queen's Medical Centre, Nottingham NG7 2UH, UK
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Yu Z, Yang X, Wang K. Metal ions induced heat shock protein response by elevating superoxide anion level in HeLa cells transformed by HSE-SEAP reporter gene. Toxicology 2006; 223:1-8. [PMID: 16595161 DOI: 10.1016/j.tox.2006.02.021] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2005] [Revised: 02/24/2006] [Accepted: 02/27/2006] [Indexed: 10/24/2022]
Abstract
The aim of this work is to define the relationship between heat shock protein (HSP) and reactive oxygen species (ROS) in the cells exposed to different concentrations of metal ions, and to evaluate a new method for tracing the dynamic levels of cellular reactive oxygen species using a HSE-SEAP reporter gene. The expression of heat shock protein was measured using a secreted alkaline phosphatase (SEAP) reporter gene transformed into HeLa cell strain, the levels of superoxide anion (O(2)(-)) and hydrogen peroxide (H(2)O(2)) were determined by NBT reduction assay and DCFH staining flow cytometry (FCM), respectively. The experimental results demonstrated that the expression of heat shock protein induced by metal ions was linearly related to the cellular superoxide anion level before cytotoxic effects were observed, but not related to the cellular hydrogen peroxide level. The experimental results suggested that metal ions might induce heat shock protein by elevating cellular superoxide anion level, and thus the expression of heat shock protein indicated by the HSE-SEAP reporter gene can be an effective model for monitoring the dynamic level of superoxide anion and early metal-induced oxidative stress/cytotoxicity.
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Affiliation(s)
- Zhanjiang Yu
- Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing 100083, PR China
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23
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Giuliani R, Bettoni F, Leali D, Morandini F, Apostoli P, Grigolato P, Cesana BM, Aleo MF. Focal adhesion molecules as potential target of lead toxicity in NRK-52E cell line. FEBS Lett 2005; 579:6251-8. [PMID: 16253243 DOI: 10.1016/j.febslet.2005.09.097] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2005] [Revised: 09/20/2005] [Accepted: 09/26/2005] [Indexed: 10/25/2022]
Abstract
In this study, we investigated the influence of inorganic lead (Pb(II)), an environmental pollutant having nephrotoxic action, on the focal adhesion (FA) organization of a rat kidney epithelial cell line (NRK-52E). In particular, we evaluated the effects of the metal on the recruitment of paxillin, focal adhesion kinase, vinculin and cytoskeleton proteins at the FAs complexes. We provided evidences that, in proliferating NRK-52E cell cultures, low concentrations of Pb(II) affect the cell adhesive ability and stimulate the disassembly of FAs, thus inhibiting the integrin-activated signalling. These effects appeared to be strictly associated to the Pb-induced arrest of cell cycle at G0/G1 phase also proved in this cell line.
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Affiliation(s)
- Roberta Giuliani
- Unit of Biochemistry, School of Medicine, University of Brescia, Italy
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Bonham RT, Fine MR, Pollock FM, Shelden EA. Hsp27, Hsp70, and metallothionein in MDCK and LLC-PK1 renal epithelial cells: effects of prolonged exposure to cadmium. Toxicol Appl Pharmacol 2003; 191:63-73. [PMID: 12915104 DOI: 10.1016/s0041-008x(03)00226-6] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Cadmium is a widely distributed industrial and environmental toxin. The principal target organ of chronic sublethal cadmium exposure is the kidney. In renal epithelial cells, acute high-dose cadmium exposure induces differential expression of proteins, including heat shock proteins. However, few studies have examined heat shock protein expression in cells after prolonged exposure to cadmium at sublethal concentrations. Here, we assayed total cell protein, neutral red uptake, cell death, and levels of metallothionein and heat shock proteins Hsp27 and inducible Hsp70 in cultures of MDCK and LLC-PK1 renal epithelial cells treated with cadmium for 3 days. Treatment with cadmium at concentrations equal to or greater than 10 microM (LLC-PK1) or 25 microM (MDCK) reduced measures of cell vitality and induced cell death. However, a concentration-dependent increase in Hsp27 was detected in both cell types treated with as little as 5 microM cadmium. Accumulation of Hsp70 was correlated only with cadmium treatment at concentrations also causing cell death. Metallothionein was maximally detected in cells treated with cadmium at concentrations that did not reduce cell vitality, and further increases were not detected at greater concentrations. These results reveal that heat shock proteins accumulate in renal epithelial cells during prolonged cadmium exposure, that cadmium induces differential expression of heat shock protein in epithelial cells, and that protein expression patterns in epithelial cells are specific to the cadmium concentration and degree of cellular injury. A potential role for Hsp27 in the cellular response to sublethal cadmium-induced injury is also implicated by our results.
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Affiliation(s)
- Rita T Bonham
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
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