1
|
López-Díaz B, Mercado-Sáenz S, Burgos-Molina AM, González-Vidal A, Sendra-Portero F, Ruiz-Gómez MJ. Genomic DNA damage induced by co-exposure to DNA damaging agents and pulsed magnetic field. Int J Radiat Biol 2022; 99:853-865. [PMID: 36069754 DOI: 10.1080/09553002.2022.2121873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
PURPOSE Many articles describe the effects of extremely low-frequency magnetic fields (MF) on DNA damage induction. However, the mechanism of MF interaction with living matter is not yet known with certainty. Some works suggest that MF could induce an increase in the efficacy of Reactive Oxygen Species (ROS) production. This work investigates whether pulsed MF exposure produces alterations in genomic DNA damage induced by co-exposure to DNA damaging agents (bleomycin and methyl methanesulfonate (MMS)). MATERIALS AND METHODS Genomic DNA, prepared from S. cerevisiae cultures, was exposed to pulsed MF (1.5 mT peak, 25 Hz) and MMS (0-1%) (15-60 minutes), and to MF and bleomycin (0-0.6 IU/ml) (24-72 hours). The damage induced to DNA was evaluated by electrophoresis and image analysis. RESULTS Pulsed MF induced an increment in the level of DNA damage produced by MMS and bleomycin in all groups at the exposure conditions assayed. CONCLUSIONS Pulsed MF could modulate the cytotoxic action of MMS and bleomycin. The observed effect could be the result of a multifactorial process influenced by the type of agent that damages DNA, the dose, and the duration of the exposure to the pulsed MF.
Collapse
Affiliation(s)
- Beatriz López-Díaz
- Departamento de Radiología y Medicina Física, Facultad de Medicina, Universidad de Málaga, Málaga, España
| | - Silvia Mercado-Sáenz
- Departamento de Radiología y Medicina Física, Facultad de Medicina, Universidad de Málaga, Málaga, España
| | - Antonio M Burgos-Molina
- Departamento de Radiología y Medicina Física, Facultad de Medicina, Universidad de Málaga, Málaga, España
| | - Alejandro González-Vidal
- Departamento de Radiología y Medicina Física, Facultad de Medicina, Universidad de Málaga, Málaga, España
| | - Francisco Sendra-Portero
- Departamento de Radiología y Medicina Física, Facultad de Medicina, Universidad de Málaga, Málaga, España
| | - Miguel J Ruiz-Gómez
- Departamento de Radiología y Medicina Física, Facultad de Medicina, Universidad de Málaga, Málaga, España
| |
Collapse
|
2
|
Nieminen V, Juntunen M, Naarala J, Luukkonen J. Static or 50 Hz magnetic fields at 100 μT do not modify the clonogenic survival of doxorubicin-treated MCF-7 cancer cells. Bioelectrochemistry 2022; 147:108196. [DOI: 10.1016/j.bioelechem.2022.108196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 06/20/2022] [Accepted: 06/23/2022] [Indexed: 11/02/2022]
|
3
|
Mustafa E, Makinistian L, Luukkonen J, Juutilainen J, Naarala J. Do 50/60 Hz magnetic fields influence oxidative or DNA damage responses in human SH-SY5Y neuroblastoma cells? Int J Radiat Biol 2022; 98:1581-1591. [PMID: 35320060 DOI: 10.1080/09553002.2022.2055803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Purpose: We investigated possible effects of 50 Hz and 60 Hz magnetic fields (MFs) on reactive oxygen species (ROS) production, DNA damage, DNA damage repair rate, as well as gene expression related to oxidative stress and DNA damage signaling.Materials and methods: Human SH-SY5Y neuroblastoma cells were sham-exposed or exposed to 100 µTRMS MFs for 24 h, then assayed or further treated with 100 µM menadione for 1 h before the assay. The levels of ROS and cytosolic superoxide anion (O2•-) were assayed fluorometrically. DNA damage and gene expression were assayed by comet assay and RT-qPCR, respectively. To examine whether MFs affected DNA damage repair rate, cells were allowed to repair their DNA for 1 or 2 h after menadione treatment and then assayed for DNA damage.Results: There was suggestive evidence of a general low-magnitude increase in the expression of ROS-related genes (primarily genes with antioxidant activity) when quantified immediately after MF exposure, suggesting a response to a small increase in ROS level. The possible upregulation of ROS-related genes is supported by the finding that the level of menadione-induced ROS was consistently decreased by 50 Hz MFs (not significantly by 60 Hz MFs) in several measurements 30 - 60 min after MF exposure. MF exposures did not affect cytosolic O2•- levels, DNA damage, or its repair rate. Changes in the expression of DNA damage-signaling genes in the MF-exposed cells did not exceed the expected rate of false positive findings. No firm evidence was found for differential effects from 50 Hz vs. 60 Hz MFs.Conclusions: While only weak effects were found on the endpoints measured, the results are consistent with MF effects on ROS signaling.
Collapse
Affiliation(s)
- Ehab Mustafa
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland
| | - Leonardo Makinistian
- Department of Physics and Institute of Applied Physics (INFAP), Universidad Nacional de San Luis-CONICET, San Luis, Argentina
| | - Jukka Luukkonen
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland
| | - Jukka Juutilainen
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland
| | - Jonne Naarala
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland
| |
Collapse
|
4
|
Luukkonen J, Höytö A, Sokka M, Syväoja J, Juutilainen J, Naarala J. Genomic instability induced by radiation-mimicking chemicals is not associated with persistent mitochondrial degeneration. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2022; 61:29-36. [PMID: 34331120 PMCID: PMC8897345 DOI: 10.1007/s00411-021-00927-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 06/21/2021] [Indexed: 06/13/2023]
Abstract
Ionizing radiation has been shown to cause induced genomic instability (IGI), which is defined as a persistently increased rate of genomic damage in the progeny of the exposed cells. In this study, IGI was investigated by exposing human SH-SY5Y neuroblastoma cells to hydroxyurea and zeocin, two chemicals mimicking different DNA-damaging effects of ionizing radiation. The aim was to explore whether IGI was associated with persistent mitochondrial dysfunction. Changes to mitochondrial function were assessed by analyzing mitochondrial superoxide production, mitochondrial membrane potential, and mitochondrial activity. The formation of micronuclei was used to determine immediate genetic damage and IGI. Measurements were performed either immediately, 8 days, or 15 days following exposure. Both hydroxyurea and zeocin increased mitochondrial superoxide production and affected mitochondrial activity immediately after exposure, and mitochondrial membrane potential was affected by zeocin, but no persistent changes in mitochondrial function were observed. IGI became manifested 15 days after exposure in hydroxyurea-exposed cells. In conclusion, immediate responses in mitochondrial function did not cause persistent dysfunction of mitochondria, and this dysfunction was not required for IGI in human neuroblastoma cells.
Collapse
Affiliation(s)
- Jukka Luukkonen
- Department of Environmental and Biological Sciences, University of Eastern Finland, Yliopistonranta 1, P.O. Box 1627, 70211, Kuopio, Finland.
| | - Anne Höytö
- Department of Environmental and Biological Sciences, University of Eastern Finland, Yliopistonranta 1, P.O. Box 1627, 70211, Kuopio, Finland
- STUK-Radiation and Nuclear Safety Authority, Helsinki, Finland
| | - Miiko Sokka
- Department of Environmental and Biological Sciences, University of Eastern Finland, Joensuu, Finland
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, USA
| | - Juhani Syväoja
- Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland
| | - Jukka Juutilainen
- Department of Environmental and Biological Sciences, University of Eastern Finland, Yliopistonranta 1, P.O. Box 1627, 70211, Kuopio, Finland
| | - Jonne Naarala
- Department of Environmental and Biological Sciences, University of Eastern Finland, Yliopistonranta 1, P.O. Box 1627, 70211, Kuopio, Finland
| |
Collapse
|
5
|
Mustafa E, Luukkonen J, Makkonen J, Naarala J. The duration of exposure to 50 Hz magnetic fields: Influence on circadian genes and DNA damage responses in murine hematopoietic FDC-P1 cells. Mutat Res 2021; 823:111756. [PMID: 34153743 DOI: 10.1016/j.mrfmmm.2021.111756] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 05/11/2021] [Accepted: 06/10/2021] [Indexed: 10/21/2022]
Abstract
We investigated the effects of 50 Hz extremely low-frequency magnetic fields (MFs) on gene expression related to the circadian rhythm or DNA damage signaling and whether these fields modify DNA damage repair rate after bleomycin treatment. Murine FDC-P1 hematopoietic cells were exposed for different durations (15 min, 2 h, 12 h, and 24 h) to either 200 μT MFs or sham-exposures. Cells were then collected for comet assay or real-time PCR to determine immediate DNA damage level and circadian rhythm gene expression, respectively. To assess DNA-damage signaling and DNA repair rate, the cells were subsequently treated with 20 μg/mL bleomycin for 1 h and then either assayed immediately or allowed to repair their DNA for 1 or 2 h. We found that circadian rhythm-related genes were upregulated after 12 h of MF exposure and downregulated after 24 h of MF exposure, but none of the affected genes were core genes controlling the circadian rhythm. In addition, we found that the repair rate for bleomycin-induced damage was only decreased after MF exposure for 24 h. In conclusion, our findings suggest that the effects of MFs are duration-dependent; they were observed predominantly after long exposures.
Collapse
Affiliation(s)
- Ehab Mustafa
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland.
| | - Jukka Luukkonen
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland.
| | - Jenny Makkonen
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland; Biosafe - Biological Safety Solutions, Kuopio, Finland.
| | - Jonne Naarala
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland.
| |
Collapse
|
6
|
Bertagna F, Lewis R, Silva SRP, McFadden J, Jeevaratnam K. Effects of electromagnetic fields on neuronal ion channels: a systematic review. Ann N Y Acad Sci 2021; 1499:82-103. [PMID: 33945157 DOI: 10.1111/nyas.14597] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 02/09/2021] [Accepted: 03/12/2021] [Indexed: 12/18/2022]
Abstract
Many aspects of chemistry and biology are mediated by electromagnetic field (EMF) interactions. The central nervous system (CNS) is particularly sensitive to EMF stimuli. Studies have explored the direct effect of different EMFs on the electrical properties of neurons in the last two decades, particularly focusing on the role of voltage-gated ion channels (VGCs). This work aims to systematically review published evidence in the last two decades detailing the effects of EMFs on neuronal ion channels as per the PRISM guidelines. Following a predetermined exclusion and inclusion criteria, 22 papers were included after searches on three online databases. Changes in calcium homeostasis, attributable to the voltage-gated calcium channels, were found to be the most commonly reported result of EMF exposure. EMF effects on the neuronal landscape appear to be diverse and greatly dependent on parameters, such as the field's frequency, exposure time, and intrinsic properties of the irradiated tissue, such as the expression of VGCs. Here, we systematically clarify how neuronal ion channels are particularly affected and differentially modulated by EMFs at multiple levels, such as gating dynamics, ion conductance, concentration in the membrane, and gene and protein expression. Ion channels represent a major transducer for EMF-related effects on the CNS.
Collapse
Affiliation(s)
- Federico Bertagna
- Leverhulme Quantum Biology Doctoral Training Centre, University of Surrey, Guildford, Surrey, UK.,School of Veterinary Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, UK
| | - Rebecca Lewis
- Leverhulme Quantum Biology Doctoral Training Centre, University of Surrey, Guildford, Surrey, UK.,School of Veterinary Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, UK
| | - S Ravi P Silva
- Leverhulme Quantum Biology Doctoral Training Centre, University of Surrey, Guildford, Surrey, UK.,Advanced Technology Institute, University of Surrey, Guildford, Surrey, UK
| | - Johnjoe McFadden
- Leverhulme Quantum Biology Doctoral Training Centre, University of Surrey, Guildford, Surrey, UK.,School of Biosciences and Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, UK
| | - Kamalan Jeevaratnam
- Leverhulme Quantum Biology Doctoral Training Centre, University of Surrey, Guildford, Surrey, UK.,School of Veterinary Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, UK
| |
Collapse
|
7
|
Brain-to-brain communication: the possible role of brain electromagnetic fields (As a Potential Hypothesis). Heliyon 2021; 7:e06363. [PMID: 33732922 PMCID: PMC7937662 DOI: 10.1016/j.heliyon.2021.e06363] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 12/29/2020] [Accepted: 02/22/2021] [Indexed: 11/23/2022] Open
Abstract
Up now, the communication between brains of different humans or animals has been confirmed and confined by the sensory medium and motor facilities of body. Recently, direct brain-to-brain communication (DBBC) outside the conventional five senses has been verified between animals and humans. Nevertheless, no empirical studies or serious discussion have been performed to elucidate the mechanism behind this process. The validation of DBBC has been documented via recording similar pattern of action potentials occurring in the brain cortex of two animals. With regard to action potentials in brain neurons, the magnetic field resulting from the action potentials created in neurons is one of the tools where the brain of one animal can affect the brain of another. It has been shown that different animals, even humans, have the power to understand the magnetic field. Cryptochrome, which exists in the retina and in different regions of the brain, has been confirmed to be able to perceive magnetic fields and convert magnetic fields to action potentials. Recently, iron particles (Fe3O4) believed to be functioning as magnets have been found in various parts of the brain, and are postulated as magnetic field receptors. Newly developed supersensitive magnetic sensors made of iron magnets that can sense the brain's magnetic field have suggested the idea that these Fe3O4 particles or magnets may be capable of perceiving the brain's extremely weak magnetic field. The present study suggests that it is possible the extremely week magnetic field in one animal's brain to transmit vital and accurate information to another animal's brain.
Collapse
|
8
|
Maldonado-Moreles A, Cordova-Fraga T, Bonilla-Jaime H, Lopez-Camacho PY, Basurto-Islas G. Low frequency vortex magnetic field reduces amyloid β aggregation, increase cell viability and protect from amyloid β toxicity. Electromagn Biol Med 2021; 40:191-200. [PMID: 33043710 DOI: 10.1080/15368378.2020.1830288] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 09/18/2020] [Indexed: 01/05/2023]
Abstract
Plaques formed by abnormal accumulation of amyloid β-peptide (Aβ) lead to onset of Alzheimer's disease (AD). Pharmacological treatments do not reduce Aβ aggregation neither restore learning and memory. Noninvasive techniques have emerged as an alternative to treat AD, such as stimulation with electromagnetic fields (EMF) that decrease Aβ deposition and reverses cognitive impairment in AD mice, even though some studies showed side effects on parallel magnetic fields stimulation. As a new approach of magnetic field (MF) stimulation, vortex magnetic fields (VMF) have been tested inducing a random movement of charged biomolecules in cells, promoting cell viability and apparently safer than parallel magnetic fields. In this study we demonstrate the effect of VMF on Aβ aggregation. The experimental strategy includes, i) design and construction of a coil capable to induce VMF, ii) evaluation of VMF stimulation on Aβ peptide induced-fibrils-formation, iii) evaluation of VMF stimulation on SH-SY5Y neuroblastoma cell line in the presence of Aβ peptide. We demonstrated for the first time that Aβ aggregation exposed to VMF during 24 h decreased ~ 86% of Aβ fibril formation compared to control. Likewise, VMF stimulation reduced Aβ fibrils-cytotoxicity and increase SH-SY5Y cell viability. These data establish the basis for future investigation that involve VMF as inhibitor of Aβ-pathology and indicate the therapeutic potential of VMF for AD treatment.
Collapse
Affiliation(s)
- Alejandro Maldonado-Moreles
- Doctorado en Ciencias Biologicas y de la Salud, Universidad Autonoma Metropolitana , Ciudad de México, México
| | | | - Herlinda Bonilla-Jaime
- Departamento de Biología de la Reproducción, Lab de Psicobiología, Universidad Autónoma Metropolitana Iztapalapa , Ciudad de México, México
| | - Perla Y Lopez-Camacho
- Departamento de Ciencias Naturales, Universidad Autónoma Metropolitana Cuajimalpa , Ciudad de México, México
| | | |
Collapse
|
9
|
Dural E, Shah UK, Pritchard D, Chapman KE, Doak SH, Jenkins GJS. The effect of chronic dosing and p53 status on the genotoxicity of pro-oxidant chemicals in vitro. Mutagenesis 2020; 35:479-489. [PMID: 33259605 DOI: 10.1093/mutage/geaa024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 09/07/2020] [Indexed: 11/12/2022] Open
Abstract
In this study, we have studied the cytotoxicity and genotoxic potency of 3 pro-oxidants; H2O2, menadione and KBrO3 in different dosing scenarios, namely acute (1-day dosing) and chronic (5-days). For this purpose, relative population doubling (RPD%) and mononucleated micronucleus (MN) test were used. TK6 cells and NH32 were employed in in vitro experiments. In the study, the total acute dose was divided into 5 days for each prooxidant chemicals by dose fractionation (1/5th per day) method. Acute dosing was compared to chronic dosing. The oxidative stress caused by the exposure of cells with pro-oxidant chemicals to the cells was determined by an optimized 2',7'-dichlorofluorescein diacetate (DCFHDA) test method. The antioxidant levels of the cell lines were altered with buthionine sulfoxide (BSO) and N-acetyl cysteine (NAC), and the effect of antioxidant capacity on the MN formation in the cells was observed with this method. In the case of H2O2 and menadione, fractional dosing has been observed to result in lower toxicity and lower genotoxicity. But in the case of KBrO3, unlike the other 2 pro-oxidants, higher MN induction was observed with fractionated doses. DCFHDA test clearly demonstrated ROS induction with H2O2 and menadione but not with KBrO3. Unexpectedly, DCFHDA test demonstrated that KBrO3 did not cause an increase ROS levels in both acute and chronic dosing, suggesting an alternative ROS induction mechanism. It was also observed that, treatment with BSO and NAC, caused increasing and decreasing of MN fold change respectively, allowing further ROS specific mechanisms to be explored. Hence, dose fractionation expectedly caused less MN, cytotoxicity and ROS formation with H2O2 and menadione exposure, but not with KBrO3. This implies a unique mechanism of action for KBrO3 induced genotoxicity. Chronic dosing in vitro may be a valuable approach allowing better understanding of how chemicals damage DNA and pose human hazards.
Collapse
Affiliation(s)
- Emrah Dural
- In vitro Toxicology Group, Institute of Life Science, College of Medicine, Swansea University, Swansea, U.K
- Sivas Cumhuriyet University, Department of Pharmaceutical Toxicology, Faculty of Pharmacy, Sivas, Turkey
| | - Ume-Kulsoom Shah
- In vitro Toxicology Group, Institute of Life Science, College of Medicine, Swansea University, Swansea, U.K
| | - Demi Pritchard
- In vitro Toxicology Group, Institute of Life Science, College of Medicine, Swansea University, Swansea, U.K
| | - Katherine Emma Chapman
- In vitro Toxicology Group, Institute of Life Science, College of Medicine, Swansea University, Swansea, U.K
| | - Shareen Heather Doak
- In vitro Toxicology Group, Institute of Life Science, College of Medicine, Swansea University, Swansea, U.K
| | - Gareth James Scott Jenkins
- In vitro Toxicology Group, Institute of Life Science, College of Medicine, Swansea University, Swansea, U.K
| |
Collapse
|
10
|
Feng Z, Sedeeq M, Daniel A, Corban M, Woolley KL, Condie R, Azimi I, Smith JA, Gueven N. Comparative In Vitro Toxicology of Novel Cytoprotective Short-Chain Naphthoquinones. Pharmaceuticals (Basel) 2020; 13:ph13080184. [PMID: 32784558 PMCID: PMC7463972 DOI: 10.3390/ph13080184] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 08/05/2020] [Indexed: 12/15/2022] Open
Abstract
Short-chain quinones (SCQs) have been identified as potential drug candidates against mitochondrial dysfunction, which largely depends on the reversible redox characteristics of the active quinone core. We recently identified 11 naphthoquinone derivatives, 1–11, from a library of SCQs that demonstrated enhanced cytoprotection and improved metabolic stability compared to the clinically used benzoquinone idebenone. Since the toxicity properties of our promising SCQs were unknown, this study developed multiplex methods and generated detailed toxicity profiles from 11 endpoint measurements using the human hepatocarcinoma cell line HepG2. Overall, the toxicity profiles were largely comparable across different assays, with simple standard assays showing increased sensitivity compared to commercial toxicity assays. Within the 11 naphthoquinones tested, the L-phenylalanine derivative 4 consistently demonstrated the lowest toxicity across all assays. The results of this study not only provide useful information about the toxicity features of SCQs but will also enable the progression of the most promising drug candidates towards their clinical use.
Collapse
Affiliation(s)
- Zikai Feng
- School of Pharmacy and Pharmacology, University of Tasmania, Hobart, TAS 7005, Australia; (M.S.); (A.D.); (M.C.); (I.A.)
- School of Natural Sciences, University of Tasmania, Hobart, TAS 7005, Australia; (K.L.W.); (R.C.); (J.A.S.)
- Correspondence: (Z.F.); (N.G.)
| | - Mohammed Sedeeq
- School of Pharmacy and Pharmacology, University of Tasmania, Hobart, TAS 7005, Australia; (M.S.); (A.D.); (M.C.); (I.A.)
| | - Abraham Daniel
- School of Pharmacy and Pharmacology, University of Tasmania, Hobart, TAS 7005, Australia; (M.S.); (A.D.); (M.C.); (I.A.)
| | - Monika Corban
- School of Pharmacy and Pharmacology, University of Tasmania, Hobart, TAS 7005, Australia; (M.S.); (A.D.); (M.C.); (I.A.)
| | - Krystel L. Woolley
- School of Natural Sciences, University of Tasmania, Hobart, TAS 7005, Australia; (K.L.W.); (R.C.); (J.A.S.)
| | - Ryan Condie
- School of Natural Sciences, University of Tasmania, Hobart, TAS 7005, Australia; (K.L.W.); (R.C.); (J.A.S.)
| | - Iman Azimi
- School of Pharmacy and Pharmacology, University of Tasmania, Hobart, TAS 7005, Australia; (M.S.); (A.D.); (M.C.); (I.A.)
| | - Jason A. Smith
- School of Natural Sciences, University of Tasmania, Hobart, TAS 7005, Australia; (K.L.W.); (R.C.); (J.A.S.)
| | - Nuri Gueven
- School of Pharmacy and Pharmacology, University of Tasmania, Hobart, TAS 7005, Australia; (M.S.); (A.D.); (M.C.); (I.A.)
- Correspondence: (Z.F.); (N.G.)
| |
Collapse
|
11
|
Kesari KK, Dhasmana A, Shandilya S, Prabhakar N, Shaukat A, Dou J, Rosenholm JM, Vuorinen T, Ruokolainen J. Plant-Derived Natural Biomolecule Picein Attenuates Menadione Induced Oxidative Stress on Neuroblastoma Cell Mitochondria. Antioxidants (Basel) 2020; 9:antiox9060552. [PMID: 32630418 PMCID: PMC7346164 DOI: 10.3390/antiox9060552] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Revised: 06/21/2020] [Accepted: 06/24/2020] [Indexed: 01/06/2023] Open
Abstract
Several bioactive compounds are in use for the treatment of neurodegenerative disorders, such as Alzheimer’s and Parkinson’s disease. Historically, willow (salix sp.) bark has been an important source of salisylic acid and other natural compounds with anti-inflammatory, antipyretic and analgesic properties. Among these, picein isolated from hot water extract of willow bark, has been found to act as a natural secondary metabolite antioxidant. The aim of this study was to investigate the unrevealed pharmacological action of picein. In silico studies were utilized to direct the investigation towards the neuroprotection abilities of picein. Our in vitro studies demonstrate the neuroprotective properties of picein by blocking the oxidative stress effects, induced by free radical generator 2-methyl-1,4-naphthoquinone (menadione, MQ), in neuroblastoma SH-SY5Y cells. Several oxidative stress-related parameters were evaluated to measure the protection for mitochondrial integrity, such as mitochondrial superoxide production, mitochondrial activity (MTT), reactive oxygen species (ROS) and live-cell imaging. A significant increase in the ROS level and mitochondrial superoxide production were measured after MQ treatment, however, a subsequent treatment with picein was able to mitigate this effect by decreasing their levels. Additionally, the mitochondrial activity was significantly decreased by MQ exposure, but a follow-up treatment with picein recovered the normal metabolic activity. In conclusion, the presented results demonstrate that picein can significantly reduce the level of MQ-induced oxidative stress on mitochondria, and thereby plays a role as a potent neuroprotectant.
Collapse
Affiliation(s)
- Kavindra Kumar Kesari
- Department of Applied Physics, Aalto University, 00076 Espoo, Finland;
- Correspondence: (K.K.K.); (T.V.); (J.R.)
| | - Anupam Dhasmana
- Department of Microbiology and Immunology, School of Medicine, University of Texas Rio Grande Valley, McAllen, TX 78539, USA;
- Department of Biosciences, Swami Rama Himalayan University, Dehradun 248016, India
| | - Shruti Shandilya
- Department of Applied Physics, Aalto University, 00076 Espoo, Finland;
| | - Neeraj Prabhakar
- Pharmaceutical Sciences Laboratory, Faculty of Science and Engineering, Åbo Akademi University, 20500 Turku, Finland; (N.P.); (J.M.R.)
| | - Ahmed Shaukat
- Department of Bioproducts and Biosystems, Aalto University, 00076 Espoo, Finland; (A.S.); (J.D.)
| | - Jinze Dou
- Department of Bioproducts and Biosystems, Aalto University, 00076 Espoo, Finland; (A.S.); (J.D.)
| | - Jessica M. Rosenholm
- Pharmaceutical Sciences Laboratory, Faculty of Science and Engineering, Åbo Akademi University, 20500 Turku, Finland; (N.P.); (J.M.R.)
| | - Tapani Vuorinen
- Department of Bioproducts and Biosystems, Aalto University, 00076 Espoo, Finland; (A.S.); (J.D.)
- Correspondence: (K.K.K.); (T.V.); (J.R.)
| | - Janne Ruokolainen
- Department of Applied Physics, Aalto University, 00076 Espoo, Finland;
- Correspondence: (K.K.K.); (T.V.); (J.R.)
| |
Collapse
|
12
|
Herrala M, Naarala J, Juutilainen J. Assessment of induced genomic instability in rat primary astrocytes exposed to intermediate frequency magnetic fields. ENVIRONMENTAL RESEARCH 2019; 173:112-116. [PMID: 30903815 DOI: 10.1016/j.envres.2019.03.033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 03/13/2019] [Accepted: 03/14/2019] [Indexed: 06/09/2023]
Abstract
We investigated whether exposure to intermediate frequency magnetic fields (IF MFs) could induce or enhance genomic instability in primary astrocytes. Rat primary astrocytes were exposed to vertical or horizontal 7.5 kHz, 300 μT MF for 24 h. To study possible combined effects with known genotoxic agents, the cells were exposed for 3 h to menadione or methyl methanesulfonate after the MF treatment. Induced genomic instability was evaluated 36 days after exposures using the Comet assay and flow cytometric scoring of micronuclei. Exposure to 7.5 kHz, 300 μT MF did not induce genomic instability alone or in combination with chemicals in measurements performed several cell generations after exposure.
Collapse
Affiliation(s)
- Mikko Herrala
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland.
| | - Jonne Naarala
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland
| | - Jukka Juutilainen
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland
| |
Collapse
|
13
|
Juutilainen J, Herrala M, Luukkonen J, Naarala J, Hore PJ. Magnetocarcinogenesis: is there a mechanism for carcinogenic effects of weak magnetic fields? Proc Biol Sci 2019; 285:rspb.2018.0590. [PMID: 29794049 DOI: 10.1098/rspb.2018.0590] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2018] [Accepted: 04/27/2018] [Indexed: 12/13/2022] Open
Abstract
Extremely low-frequency (ELF) magnetic fields have been classified as possibly carcinogenic, mainly based on rather consistent epidemiological findings suggesting a link between childhood leukaemia and 50-60 Hz magnetic fields from power lines. However, causality is not the only possible explanation for the epidemiological associations, as animal and in vitro experiments have provided only limited support for carcinogenic effects of ELF magnetic fields. Importantly, there is no generally accepted biophysical mechanism that could explain such effects. In this review, we discuss the possibility that carcinogenic effects are based on the radical pair mechanism (RPM), which seems to be involved in magnetoreception in birds and certain other animals, allowing navigation in the geomagnetic field. We review the current understanding of the RPM in magnetoreception, and discuss cryptochromes as the putative magnetosensitive molecules and their possible links to cancer-relevant biological processes. We then propose a hypothesis for explaining the link between ELF fields and childhood leukaemia, discuss the strengths and weaknesses of the current evidence, and make proposals for further research.
Collapse
Affiliation(s)
- Jukka Juutilainen
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland
| | - Mikko Herrala
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland
| | - Jukka Luukkonen
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland
| | - Jonne Naarala
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland
| | - P J Hore
- Department of Chemistry, University of Oxford, Oxford, UK
| |
Collapse
|
14
|
Consales C, Panatta M, Butera A, Filomeni G, Merla C, Carrì MT, Marino C, Benassi B. 50-Hz magnetic field impairs the expression of iron-related genes in the in vitro SOD1 G93A model of amyotrophic lateral sclerosis. Int J Radiat Biol 2019; 95:368-377. [PMID: 30513241 DOI: 10.1080/09553002.2019.1552378] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
PURPOSE We characterized the response to the extremely low frequency magnetic field (ELF-MF) in an in vitro model of familial Amyotrophic Lateral Sclerosis (fALS), carrying two mutant variants of the superoxide dismutase 1 (SOD1) gene. MATERIALS AND METHODS SH-SY5Y human neuroblastoma cells, stably over-expressing the wild type, the G93A or the H46R mutant SOD1 cDNA, were exposed to either the ELF-MF (50 Hz, 1 mT) or the sham control field, up to 72 h. Analysis of (i) viability, proliferation and apoptosis, (ii) reactive oxygen species generation, and (iii) assessment of the iron metabolism, were carried out in all clones in response to the MF exposure. RESULTS We report that 50-Hz MF exposure induces: (i) no change in proliferation and viability; (ii) no modulation of the intracellular superoxide and H2O2 levels; (iii) a significant deregulation in the expression of iron-related genes IRP1, MFRN1 and TfR1, this evidence being exclusive for the SOD1G93A clone and associated with a slight (p = .0512) difference in the total iron content. CONCLUSIONS 50-Hz MF affects iron homeostasis in the in vitro SOD1G93A ALS model.
Collapse
Affiliation(s)
- Claudia Consales
- a Department of Energy and Sustainable Economic Development , Division of Health Protection Technologies, ENEA-Italian National Agency for New Technologies , Rome , Italy
| | - Martina Panatta
- a Department of Energy and Sustainable Economic Development , Division of Health Protection Technologies, ENEA-Italian National Agency for New Technologies , Rome , Italy.,b Department of Chemistry and Biochemistry , University of Bern , Bern , Switzerland
| | - Alessio Butera
- a Department of Energy and Sustainable Economic Development , Division of Health Protection Technologies, ENEA-Italian National Agency for New Technologies , Rome , Italy
| | - Giuseppe Filomeni
- c Department of Biology , University of Rome Tor Vergata , Rome , Italy.,d Cell Stress and Survival Unit, Center for Autophagy, Recycling and Disease (CARD) , Danish Cancer Society Research Center , Copenhagen , Denmark
| | - Caterina Merla
- a Department of Energy and Sustainable Economic Development , Division of Health Protection Technologies, ENEA-Italian National Agency for New Technologies , Rome , Italy
| | | | - Carmela Marino
- a Department of Energy and Sustainable Economic Development , Division of Health Protection Technologies, ENEA-Italian National Agency for New Technologies , Rome , Italy
| | - Barbara Benassi
- a Department of Energy and Sustainable Economic Development , Division of Health Protection Technologies, ENEA-Italian National Agency for New Technologies , Rome , Italy
| |
Collapse
|
15
|
Benassi B, Santangeli S, Merla C, Tarantini L, Bollati V, Butera A, Marino C, Consales C. 50-Hz MF does not affect global DNA methylation of SH-SY5Y cells treated with the neurotoxin MPP . Bioelectromagnetics 2018; 40:33-41. [PMID: 30537234 DOI: 10.1002/bem.22158] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 10/23/2018] [Indexed: 01/08/2023]
Abstract
Exposure to extremely low frequency magnetic fields (ELF-MFs) has been associated with an increased risk of neurodegenerative disorders. The underlying mechanisms, however, are still debated. Since epigenetics play a key role in the neurodegenerative process, we investigated whether exposure to ELF-MF (50 Hz, 1 mT) might affect global DNA methylation of SH-SY5Y dopaminergic-like neuroblastoma cells. We assessed the percentage of 5-methylcytosine (5-mC) of three repetitive interspersed sequences (ALU, LINE-1, or SATα), through pyrosequencing analysis. We demonstrated that ELF exposure (up to 72 h) does not induce any change in the methylation pattern of ALU, LINE-1, and SATα in both proliferating and differentiated SH-SY5Y cells. Furthermore, when administered in combination with 1-methyl-4-phenylpyridinium (MPP+ ), a neurotoxin mimicking the Parkinson's Disease (PD) phenotype, ELF-MF exposure does not trigger any modulation in the percentage of 5-mC of the repetitive elements. Our findings demonstrate that exposure to 50-Hz MF does not affect global DNA methylation in proliferating and dopaminergic differentiated SH-SY5Y cells, either under basal culture conditions or under neurotoxic stress. Bioelectromagnetics. 40:33-41, 2019. © 2018 Bioelectromagnetics Society.
Collapse
Affiliation(s)
- Barbara Benassi
- Division of Health Protection Technologies, ENEA-Italian National Agency for New Technologies, Energy and Sustainable Economic Development, Rome, Italy
| | - Stefania Santangeli
- Department of Life and Environmental Sciences, "Marche Polytechnic" University, Ancona, Italy
| | - Caterina Merla
- Division of Health Protection Technologies, ENEA-Italian National Agency for New Technologies, Energy and Sustainable Economic Development, Rome, Italy
| | - Letizia Tarantini
- EPIGET-Epidemiology, Epigenetics and Toxicology Lab, Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Valentina Bollati
- EPIGET-Epidemiology, Epigenetics and Toxicology Lab, Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Alessio Butera
- Division of Health Protection Technologies, ENEA-Italian National Agency for New Technologies, Energy and Sustainable Economic Development, Rome, Italy.,Experimental Medicine and Surgery, University of Rome "Tor Vergata", Rome, Italy
| | - Carmela Marino
- Division of Health Protection Technologies, ENEA-Italian National Agency for New Technologies, Energy and Sustainable Economic Development, Rome, Italy
| | - Claudia Consales
- Division of Health Protection Technologies, ENEA-Italian National Agency for New Technologies, Energy and Sustainable Economic Development, Rome, Italy
| |
Collapse
|
16
|
Herrala M, Kumari K, Koivisto H, Luukkonen J, Tanila H, Naarala J, Juutilainen J. Genotoxicity of intermediate frequency magnetic fields in vitro and in vivo. ENVIRONMENTAL RESEARCH 2018; 167:759-769. [PMID: 30243651 DOI: 10.1016/j.envres.2018.09.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 09/05/2018] [Accepted: 09/07/2018] [Indexed: 06/08/2023]
Abstract
We assessed genotoxic effects of intermediate frequency magnetic fields (MF) in vitro and in vivo. Rat primary astrocytes were exposed for 24 h to a 7.5 kHz MF at a magnetic flux density of 30 or 300 µT. Male C57BL/6 J mice were exposed continuously for 5 weeks to a 7.5 kHz MF at 12 or 120 μT, and blood samples were collected for the genotoxicity assays. To evaluate possible co-genotoxicity, the in vitro experiments included combined exposure with menadione (an agent that induces mitochondrial superoxide production and DNA damage) and methyl methanesulfonate (an alkylating agent). DNA damage and DNA repair (in vitro) were measured using the alkaline Comet assay and formation of micronuclei was assessed microscopically (in vivo) or using flow cytometry (in vitro). The results did not support genotoxicity or co-genotoxicity of 7.5 kHz MFs at magnetic flux densities up to 300 µT in vitro or in vivo. On the contrary, there was some evidence that exposure to 7.5 kHz MFs might reduce the level of genetic damage. Strongest indication of any biological effects was obtained from measurements of relative cell number, which was significantly and consistently increased after MF exposure in all in vitro experiments. Health implications of this finding are unclear, but it suggests that 7.5 kHz MFs may stimulate cell proliferation or suppress cell death.
Collapse
Affiliation(s)
- Mikko Herrala
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland.
| | - Kajal Kumari
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland
| | | | - Jukka Luukkonen
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland
| | - Heikki Tanila
- A. I. Virtanen Institute, University of Eastern Finland, Kuopio, Finland
| | - Jonne Naarala
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland
| | - Jukka Juutilainen
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland
| |
Collapse
|
17
|
Herrala M, Mustafa E, Naarala J, Juutilainen J. Assessment of genotoxicity and genomic instability in rat primary astrocytes exposed to 872 MHz radiofrequency radiation and chemicals. Int J Radiat Biol 2018. [DOI: 10.1080/09553002.2018.1450534] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Mikko Herrala
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland
| | - Ehab Mustafa
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland
| | - Jonne Naarala
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland
| | - Jukka Juutilainen
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland
| |
Collapse
|
18
|
Consales C, Cirotti C, Filomeni G, Panatta M, Butera A, Merla C, Lopresto V, Pinto R, Marino C, Benassi B. Fifty-Hertz Magnetic Field Affects the Epigenetic Modulation of the miR-34b/c in Neuronal Cells. Mol Neurobiol 2017; 55:5698-5714. [PMID: 29039021 DOI: 10.1007/s12035-017-0791-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 09/26/2017] [Indexed: 12/24/2022]
Abstract
The exposure to extremely low-frequency magnetic fields (ELF-MFs) has been associated to increased risk of neurodegenerative diseases, although the underlying molecular mechanisms are still undefined. Since epigenetic modulation has been recently encountered among the key events leading to neuronal degeneration, we here aimed at assessing if the control of gene expression mediated by miRNAs, namely miRs-34, has any roles in driving neuronal cell response to 50-Hz (1 mT) magnetic field in vitro. We demonstrate that ELF-MFs drive an early reduction of the expression level of miR-34b and miR-34c in SH-SY5Y human neuroblastoma cells, as well as in mouse primary cortical neurons, by affecting the transcription of the common pri-miR-34. This modulation is not p53 dependent, but attributable to the hyper-methylation of the CpG island mapping within the miR-34b/c promoter. Incubation with N-acetyl-l-cysteine or glutathione ethyl-ester fails to restore miR-34b/c expression, suggesting that miRs-34 are not responsive to ELF-MF-induced oxidative stress. By contrast, we show that miRs-34 control reactive oxygen species production and affect mitochondrial oxidative stress triggered by ELF-MFs, likely by modulating mitochondria-related miR-34 targets identified by in silico analysis. We finally demonstrate that ELF-MFs alter the expression of the α-synuclein, which is specifically stimulated upon ELF-MFs exposure via both direct miR-34 targeting and oxidative stress. Altogether, our data highlight the potential of the ELF-MFs to tune redox homeostasis and epigenetic control of gene expression in vitro and shed light on the possible mechanism(s) producing detrimental effects and predisposing neurons to degeneration.
Collapse
Affiliation(s)
- Claudia Consales
- Division of Health Protection Technologies, ENEA-Italian National Agency for New Technologies, Energy and Sustainable Economic Development, ENEA-Casaccia, Via Anguillarese 301, 00123, Rome, Italy.
| | - Claudia Cirotti
- Department of Biology, University of Rome Tor Vergata, 00133, Rome, Italy
| | - Giuseppe Filomeni
- Department of Biology, University of Rome Tor Vergata, 00133, Rome, Italy.,Cell Stress and Survival Unit, Center for Autophagy, Recycling and Disease (CARD), Danish Cancer Society Research Center, 2100, Copenhagen, Denmark
| | - Martina Panatta
- Division of Health Protection Technologies, ENEA-Italian National Agency for New Technologies, Energy and Sustainable Economic Development, ENEA-Casaccia, Via Anguillarese 301, 00123, Rome, Italy
| | - Alessio Butera
- Division of Health Protection Technologies, ENEA-Italian National Agency for New Technologies, Energy and Sustainable Economic Development, ENEA-Casaccia, Via Anguillarese 301, 00123, Rome, Italy
| | - Caterina Merla
- Division of Health Protection Technologies, ENEA-Italian National Agency for New Technologies, Energy and Sustainable Economic Development, ENEA-Casaccia, Via Anguillarese 301, 00123, Rome, Italy.,Vectorology and Anticancer Therapies, UMR 8203, CNRS, Gustave Roussy, Univ. Paris-Sud, Université Paris-Saclay, 94805, Villejuif, France
| | - Vanni Lopresto
- Division of Health Protection Technologies, ENEA-Italian National Agency for New Technologies, Energy and Sustainable Economic Development, ENEA-Casaccia, Via Anguillarese 301, 00123, Rome, Italy
| | - Rosanna Pinto
- Division of Health Protection Technologies, ENEA-Italian National Agency for New Technologies, Energy and Sustainable Economic Development, ENEA-Casaccia, Via Anguillarese 301, 00123, Rome, Italy
| | - Carmela Marino
- Division of Health Protection Technologies, ENEA-Italian National Agency for New Technologies, Energy and Sustainable Economic Development, ENEA-Casaccia, Via Anguillarese 301, 00123, Rome, Italy
| | - Barbara Benassi
- Division of Health Protection Technologies, ENEA-Italian National Agency for New Technologies, Energy and Sustainable Economic Development, ENEA-Casaccia, Via Anguillarese 301, 00123, Rome, Italy.
| |
Collapse
|
19
|
Villarini M, Gambelunghe A, Giustarini D, Ambrosini MV, Fatigoni C, Rossi R, Dominici L, Levorato S, Muzi G, Piobbico D, Mariucci G. No evidence of DNA damage by co-exposure to extremely low frequency magnetic fields and aluminum on neuroblastoma cell lines. Mutat Res 2017; 823:11-21. [PMID: 28985943 DOI: 10.1016/j.mrgentox.2017.09.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Revised: 07/28/2017] [Accepted: 09/01/2017] [Indexed: 01/30/2023]
Abstract
Whether exposure to 50-60Hz extremely low frequency magnetic fields (ELF-MF) exerts neurotoxic effects is a debated issue. Analogously, the potential role of Aluminum (Al) in neurodegeneration is a matter of controversial debate. As all living organisms are exposed to ELF-MF and/or Al daily, we found investigating the early effects of co-exposure to ELF-MF and Al in SH-SY5Y and SK-N-BE-2 human neuroblastoma (NB) cells intriguing. SH-SY5Y5 and SK-N-BE-2 cells underwent exposure to 50Hz ELF-MF (0.01, 0.1 or 1mT) or AlCl3 (4 or 40μM) or co-exposure to 50Hz ELF-MF and AlCl3 for 1h continuously or 5h intermittently. The effects of the treatment were evaluated in terms of DNA damage, redox status changes and Hsp70 expression. The DNA damage was assessed by Comet assay; the cellular redox status was investigated by measuring the amount of reduced glutathione (GSH) and glutathione disulfide (GSSG) while the inducible Hsp70 expression was evaluated by western blot analysis and real-time RT-PCR. Neither exposure to ELF-MF or AlCl3 alone induced DNA damage, changes in GSH/GSSG ratio or variations in Hsp70 expression with respect to the controls in both NB cell lines. Similarly, co-exposure to ELF-MF and AlCl3 did not have any synergic toxic effects. The results of this in vitro study, which deals with the effects of co-exposure to 50Hz MF and Aluminum, seem to exclude that short-term exposure to ELF-MF in combination with Al can have harmful effects on human SH-SY5Y and SK-N-BE-2 cells.
Collapse
Affiliation(s)
- Milena Villarini
- Department of Pharmaceutical Sciences, University of Perugia, 06122 Perugia, Italy
| | | | - Daniela Giustarini
- Department of Life Sciences, Laboratory of Pharmacology and Toxicology, University of Siena, 53100 Siena, Italy
| | | | - Cristina Fatigoni
- Department of Pharmaceutical Sciences, University of Perugia, 06122 Perugia, Italy
| | - Ranieri Rossi
- Department of Life Sciences, Laboratory of Pharmacology and Toxicology, University of Siena, 53100 Siena, Italy
| | - Luca Dominici
- Department of Pharmaceutical Sciences, University of Perugia, 06122 Perugia, Italy
| | - Sara Levorato
- Department of Pharmaceutical Sciences, University of Perugia, 06122 Perugia, Italy
| | - Giacomo Muzi
- Department of Medicine, University of Perugia, 06132 Perugia, Italy
| | - Danilo Piobbico
- Department of Experimental Medicine, University of Perugia, 06132 Perugia, Italy
| | - Giuseppina Mariucci
- Department of Pharmaceutical Sciences, University of Perugia, 06122 Perugia, Italy.
| |
Collapse
|
20
|
Su L, Yimaer A, Wei X, Xu Z, Chen G. The effects of 50 Hz magnetic field exposure on DNA damage and cellular functions in various neurogenic cells. JOURNAL OF RADIATION RESEARCH 2017; 58:474-486. [PMID: 28369556 PMCID: PMC5570089 DOI: 10.1093/jrr/rrx012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Indexed: 05/15/2023]
Abstract
Epidemiological studies have indicated a possible association between extremely low-frequency magnetic field (ELF-MF) exposure and the risk of nervous system diseases. However, laboratory studies have not provided consistent results for clarifying this association, despite many years of studies. In this study, we have systematically investigated the effects of 50 Hz MF exposure on DNA damage and cellular functions in both neurogenic tumor cell lines (U251, A172, SH-SY5Y) and primary cultured neurogenic cells from rats (astrocytes, microglia, cortical neurons). The results showed that exposure to a 50 Hz MF at 2.0 mT for up to 24 h did not influence γH2AX foci formation (an early marker of DNA double-strand breaks) in any of six different neurogenic cells. Exposure to a 50 Hz MF did not affect cell cycle progression, cell proliferation or cell viability in neurogenic tumor U251, A172 or SH-SY5Y cells. Furthermore, the MF exposure for 24 h did not significantly affect the secretion of cytokines (TNF-α, IL-6 or IL-1β) in astrocytes or microglia, or the phagocytic activity of microglia. In addition, MF exposure for 1 h per day did not significantly influence expression levels of microtubule-associated protein tau, microtubule-associated protein 2, postsynaptic density 95 or gephyrin in cortical neurons, indicating an absence of effects of MF exposure on the development of cortical neurons. In conclusion, our data suggest that exposure to a 50 Hz MF at 2.0 mT did not elicit DNA damage effects or abnormal cellular functions in the neurogenic cells studied.
Collapse
Affiliation(s)
- Liling Su
- Bioelectromagnetics Laboratory, Zhejiang University School of Medicine, 866 Yuhangtang Road, Hangzhou 310058, China
- Department of Clinical Medicine, Jiangxi Medical College, 399 Zhimi Road, Shangrao 331000, China
| | - Aziguli Yimaer
- Bioelectromagnetics Laboratory, Zhejiang University School of Medicine, 866 Yuhangtang Road, Hangzhou 310058, China
| | - Xiaoxia Wei
- Bioelectromagnetics Laboratory, Zhejiang University School of Medicine, 866 Yuhangtang Road, Hangzhou 310058, China
| | - Zhengping Xu
- Bioelectromagnetics Laboratory, Zhejiang University School of Medicine, 866 Yuhangtang Road, Hangzhou 310058, China
- Institute of Environmental Health, Zhejiang University School of Public Health, 866 Yuhangtang Road, Hangzhou 310058, China
| | - Guangdi Chen
- Bioelectromagnetics Laboratory, Zhejiang University School of Medicine, 866 Yuhangtang Road, Hangzhou 310058, China
- Institute of Environmental Health, Zhejiang University School of Public Health, 866 Yuhangtang Road, Hangzhou 310058, China
- Corresponding author. Bioelectromagnetics Laboratory, Zhejiang University School of Medicine, 866 Yuhangtang Road, Hangzhou 310058, China. Tel: +86-571-88208169; Fax: +86-571-88208163;
| |
Collapse
|
21
|
Luukkonen J, Höytö A, Viluksela M, Juutilainen J, Naarala J. TCDD-induced mitochondrial superoxide production does not lead to mitochondrial degeneration or genomic instability in human SH-SY5Y neuroblastoma cells. Toxicol In Vitro 2017; 44:213-218. [PMID: 28673561 DOI: 10.1016/j.tiv.2017.06.030] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 05/30/2017] [Accepted: 06/29/2017] [Indexed: 01/18/2023]
Abstract
Several genotoxic and non-genotoxic agents have been reported to cause delayed genetic damage in the progeny of the exposed cells. Such induced genomic instability (IGI) may be a driving force in carcinogenesis, and it is thus highly important to understand the cellular events accompanying it. The aim of this study was to investigate whether 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) affects mitochondrial integrity and can consequently induce genomic instability. Mitochondrial integrity was evaluated by measuring mitochondrial superoxide production, mitochondrial membrane potential, and mitochondrial activity. Micronucleus formation was used to assess immediate genetic damage and IGI. The assays were performed either immediately, 8 or 15d after the exposure. Mitochondrial superoxide production was increased by TCDD immediately after the exposure. No consistent effects on mitochondrial integrity were observed at later time points, although slightly decreased mitochondrial membrane potential at 8d and increased mitochondrial superoxide potential production at 15 after exposure were observed in the TCDD-exposed cells. TCDD did not cause immediate genetic damage, and significant IGI was not observed. In conclusion, the present results suggest that immediate TCDD-induced increase in mitochondrial superoxide level does not lead to persistent loss of mitochondrial integrity or IGI in human SH-SY5Y neuroblastoma cells.
Collapse
Affiliation(s)
- Jukka Luukkonen
- University of Eastern Finland, Department of Environmental and Biological Sciences, Yliopistonranta 1, P.O. Box 1627, FI-70211 Kuopio, Finland.
| | - Anne Höytö
- University of Eastern Finland, Department of Environmental and Biological Sciences, Yliopistonranta 1, P.O. Box 1627, FI-70211 Kuopio, Finland
| | - Matti Viluksela
- University of Eastern Finland, Department of Environmental and Biological Sciences, Yliopistonranta 1, P.O. Box 1627, FI-70211 Kuopio, Finland; National Institute for Health and Welfare, Environmental Health Unit, Kuopio, Finland
| | - Jukka Juutilainen
- University of Eastern Finland, Department of Environmental and Biological Sciences, Yliopistonranta 1, P.O. Box 1627, FI-70211 Kuopio, Finland
| | - Jonne Naarala
- University of Eastern Finland, Department of Environmental and Biological Sciences, Yliopistonranta 1, P.O. Box 1627, FI-70211 Kuopio, Finland
| |
Collapse
|
22
|
Direction-Dependent Effects of Combined Static and ELF Magnetic Fields on Cell Proliferation and Superoxide Radical Production. BIOMED RESEARCH INTERNATIONAL 2017; 2017:5675086. [PMID: 28497056 PMCID: PMC5405400 DOI: 10.1155/2017/5675086] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 02/22/2017] [Accepted: 03/27/2017] [Indexed: 12/12/2022]
Abstract
Proliferation of human umbilical vein endothelial cells was stimulated by a nearly vertical 60 or 120 μT static magnetic field (MF) in comparison to cells that were shielded against MFs. When the static field was combined with an extremely low frequency (ELF) MF (18 Hz, 30 μT), proliferation was suppressed by a horizontal but not by a vertical ELF field. As these results suggested that the effects of an ELF MF depend on its direction in relation to the static MF, independent experiments were carried out to confirm such dependence using 50 Hz MFs and a different experimental model. Cytosolic superoxide level in rat glioma C6 cells exposed in the presence of a nearly vertical 33 μT static MF was increased by a horizontal 50 Hz, 30 μT MF, but not affected by a vertical 50 Hz MF. The results suggest that a weak ELF MF may interact with the static geomagnetic field in producing biological effects, but the effect depends on the relative directions of the static and ELF MFs.
Collapse
|
23
|
Höytö A, Herrala M, Luukkonen J, Juutilainen J, Naarala J. Cellular detection of 50 Hz magnetic fields and weak blue light: effects on superoxide levels and genotoxicity. Int J Radiat Biol 2017; 93:646-652. [PMID: 28264623 DOI: 10.1080/09553002.2017.1294275] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
PURPOSE We tested the hypothesis that the effects of 50 Hz magnetic fields (MFs) on superoxide levels and genotoxicity depend on the presence of blue light. MATERIALS AND METHODS Human SH-SY5Y neuroblastoma cells were exposed to a 50 Hz, 100 μT MF with or without non-phototoxic level of blue light for 24 h. We also studied whether these treatments alter responses to menadione, an agent that induces mitochondrial superoxide (O2• -) production and DNA damage. Micronuclei, proliferation, viability, cytosolic and mitochondrial O2• - levels were assessed. RESULTS MF (without blue light) increased cytosolic O2• - production and blue light suppressed this effect. Mitochondrial O2• - production was reduced by both MF and blue light, but these effects were not additive. Micronucleus frequency was not affected by blue light or MF alone, but blue light (significantly when combined with MF) enhanced menadione-induced micronuclei. CONCLUSIONS The original simple hypothesis (blue light is needed for MF effects) was not supported, but interaction of MF and blue light was nevertheless observed. The results are consistent with MF effects on light-independent radical reactions.
Collapse
Affiliation(s)
- Anne Höytö
- a Department of Environmental and Biological Sciences , University of Eastern Finland , Kuopio , Finland
| | - Mikko Herrala
- a Department of Environmental and Biological Sciences , University of Eastern Finland , Kuopio , Finland
| | - Jukka Luukkonen
- a Department of Environmental and Biological Sciences , University of Eastern Finland , Kuopio , Finland
| | - Jukka Juutilainen
- a Department of Environmental and Biological Sciences , University of Eastern Finland , Kuopio , Finland
| | - Jonne Naarala
- a Department of Environmental and Biological Sciences , University of Eastern Finland , Kuopio , Finland
| |
Collapse
|
24
|
Zeng Y, Shen Y, Hong L, Chen Y, Shi X, Zeng Q, Yu P. Effects of Single and Repeated Exposure to a 50-Hz 2-mT Electromagnetic Field on Primary Cultured Hippocampal Neurons. Neurosci Bull 2017; 33:299-306. [PMID: 28265899 DOI: 10.1007/s12264-017-0113-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2016] [Accepted: 01/10/2017] [Indexed: 11/29/2022] Open
Abstract
The prevalence of domestic and industrial electrical appliances has raised concerns about the health risk of extremely low-frequency magnetic fields (ELF-MFs). At present, the effects of ELF-MFs on the central nervous system are still highly controversial, and few studies have investigated its effects on cultured neurons. Here, we evaluated the biological effects of different patterns of ELF-MF exposure on primary cultured hippocampal neurons in terms of viability, apoptosis, genomic instability, and oxidative stress. The results showed that repeated exposure to 50-Hz 2-mT ELF-MF for 8 h per day after different times in culture decreased the viability and increased the production of intracellular reactive oxidative species in hippocampal neurons. The mechanism was potentially related to the up-regulation of Nox2 expression. Moreover, none of the repeated exposure patterns had significant effects on DNA damage, apoptosis, or autophagy, which suggested that ELF-MF exposure has no severe biological consequences in cultured hippocampal neurons.
Collapse
Affiliation(s)
- Ying Zeng
- Bioelectromagnetics Laboratory, Department of Occupational and Environmental Health, School of Public Health, Zhejiang University, Hangzhou, 310058, China
| | - Yunyun Shen
- Bioelectromagnetics Laboratory, Department of Occupational and Environmental Health, School of Public Health, Zhejiang University, Hangzhou, 310058, China.,Institute of Cognitive Neuroscience and Department of Psychology, Zhejiang Sci-Tech University, Hangzhou, 310018, China
| | - Ling Hong
- Bioelectromagnetics Laboratory, Department of Occupational and Environmental Health, School of Public Health, Zhejiang University, Hangzhou, 310058, China
| | - Yanfeng Chen
- Bioelectromagnetics Laboratory, Department of Occupational and Environmental Health, School of Public Health, Zhejiang University, Hangzhou, 310058, China
| | - Xiaofang Shi
- Department of Neurobiology, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Qunli Zeng
- Bioelectromagnetics Laboratory, Department of Occupational and Environmental Health, School of Public Health, Zhejiang University, Hangzhou, 310058, China.
| | - Peilin Yu
- Department of Toxicology, School of Public Health, Zhejiang University, Hangzhou, 310058, China.
| |
Collapse
|
25
|
Comparative study of human neuronal and glial cell sensitivity for in vitro neurogenotoxicity testing. Food Chem Toxicol 2017; 102:120-128. [PMID: 28174116 DOI: 10.1016/j.fct.2017.02.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 02/01/2017] [Accepted: 02/03/2017] [Indexed: 01/14/2023]
Abstract
Cell cultures from neuronal and glial origin have proven to be powerful tools for elucidating cellular and molecular mechanisms of nervous system development and physiology, and as neurotoxicity models to evaluate in vitro the possible effects of chemicals. But cellular heterogeneity of nervous system is considerable and these cells have been shown to respond diversely to neurotoxic insults, leading to disparate results from different studies. To shed more light on suitability of cellular models of nervous origin for neurotoxicity screening, the objective of this study was to compare the sensitivity to genetic damage induction of two nervous cell lines. To this aim, neurons (SH-SY5Y) and glial (A172) cells were treated with differently-acting genotoxic agents (bleomycin, actinomycin-D, methyl methanesulfonate, mitomycin C, and griseofulvin). After discarding cytotoxicity, genotoxicity was evaluated by a battery of assays encompassing detection of different genetic lesions. Results obtained showed that glial cells are generally more resistant to genotoxic damage induced by clastogenic agents, but more sensitive to aneugenic effects. These results highlight the need of proper design of in vitro neurotoxicology studies, especially for neurogenotoxicity screening, emphasizing the importance of employing more than one nervous cell type for testing the potential toxicity of a particular exposure.
Collapse
|
26
|
Kesari KK, Juutilainen J, Luukkonen J, Naarala J. Induction of micronuclei and superoxide production in neuroblastoma and glioma cell lines exposed to weak 50 Hz magnetic fields. J R Soc Interface 2016; 13:20150995. [PMID: 26791000 DOI: 10.1098/rsif.2015.0995] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Extremely low-frequency (ELF) magnetic fields (MF) have been associated with adverse health effects in epidemiological studies. However, there is no known mechanism for biological effects of weak environmental MFs. Previous studies indicate MF effects on DNA integrity and reactive oxygen species, but such evidence is limited to MFs higher (greater than or equal to 100 µT) than those generally found in the environment. Effects of 10 and 30 µT fields were studied in SH-SY5Y and C6 cells exposed to 50-Hz MFs for 24 h. Based on earlier findings, menadione (MQ) was used as a cofactor. Responses to MF were observed in both cell lines, but the effects differed between the cell lines. Micronuclei were significantly increased in SH-SY5Y cells at 30 µT. This effect was largest at the highest MQ dose used. Increased cytosolic and mitochondrial superoxide levels were observed in C6 cells. The effects on superoxide levels were independent of MQ, enabling further mechanistic studies without co-exposure to MQ. The micronucleus and mitochondrial superoxide data were consistent with a conventional rising exposure-response relationship. For cytosolic superoxide, the effect size was unexpectedly large at 10 µT. The results indicate that the threshold for biological effects of ELF MFs is 10 µT or less.
Collapse
Affiliation(s)
- Kavindra Kumar Kesari
- Department of Environmental Science, University of Eastern Finland, PO Box 1627, 70211 Kuopio, Finland
| | - Jukka Juutilainen
- Department of Environmental Science, University of Eastern Finland, PO Box 1627, 70211 Kuopio, Finland
| | - Jukka Luukkonen
- Department of Environmental Science, University of Eastern Finland, PO Box 1627, 70211 Kuopio, Finland
| | - Jonne Naarala
- Department of Environmental Science, University of Eastern Finland, PO Box 1627, 70211 Kuopio, Finland
| |
Collapse
|
27
|
Luukkonen J, Höytö A, Sokka M, Liimatainen A, Syväoja J, Juutilainen J, Naarala J. Modification of p21 level and cell cycle distribution by 50 Hz magnetic fields in human SH-SY5Y neuroblastoma cells. Int J Radiat Biol 2016; 93:240-248. [DOI: 10.1080/09553002.2017.1235298] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Jukka Luukkonen
- University of Eastern Finland, Department of Environmental and Biological Sciences, Yliopistonranta, Kuopio, Finland
| | - Anne Höytö
- University of Eastern Finland, Department of Environmental and Biological Sciences, Yliopistonranta, Kuopio, Finland
| | - Miiko Sokka
- University of Eastern Finland, Department of Environmental and Biological Sciences, Joensuu, Finland
| | - Anu Liimatainen
- University of Eastern Finland, Department of Environmental and Biological Sciences, Yliopistonranta, Kuopio, Finland
| | - Juhani Syväoja
- University of Eastern Finland, Institute of Biomedicine, Kuopio, Finland
| | - Jukka Juutilainen
- University of Eastern Finland, Department of Environmental and Biological Sciences, Yliopistonranta, Kuopio, Finland
| | - Jonne Naarala
- University of Eastern Finland, Department of Environmental and Biological Sciences, Yliopistonranta, Kuopio, Finland
| |
Collapse
|
28
|
Nakayama M, Nakamura A, Hondou T, Miyata H. Evaluation of cell viability, DNA single-strand breaks, and nitric oxide production in LPS-stimulated macrophage RAW264 exposed to a 50-Hz magnetic field. Int J Radiat Biol 2016; 92:583-9. [DOI: 10.1080/09553002.2016.1206224] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Maresuke Nakayama
- Department of Physics, Tohoku University, Aoba-ku Aramaki, Sendai, Miyagi, Japan
| | - Aya Nakamura
- Department of Physics, Tohoku University, Aoba-ku Aramaki, Sendai, Miyagi, Japan
| | - Tsuyoshi Hondou
- Department of Physics, Tohoku University, Aoba-ku Aramaki, Sendai, Miyagi, Japan
| | - Hidetake Miyata
- Department of Physics, Tohoku University, Aoba-ku Aramaki, Sendai, Miyagi, Japan
| |
Collapse
|
29
|
Kesari KK, Luukkonen J, Juutilainen J, Naarala J. Genomic instability induced by 50Hz magnetic fields is a dynamically evolving process not blocked by antioxidant treatment. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2015; 794:46-51. [PMID: 26653983 DOI: 10.1016/j.mrgentox.2015.10.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2015] [Revised: 10/07/2015] [Accepted: 10/12/2015] [Indexed: 11/26/2022]
Abstract
Increased level of micronuclei was observed in SH-SY5Y cells in a previous study at 8 and 15 days after exposure to extremely low frequency (ELF) magnetic fields (MF), indicating possible induction of genomic instability in the progeny of the exposed cells. The aim of this study was to further explore the induction of genomic instability by ELF MFs by increasing the follow-up time up to 45 days after exposure. Human SH-SY5Y neuroblastoma cells were exposed to a 50Hz, 100μT MF for 24h with or without co-exposure to menadione (MQ), a chemical agent that increases cellular superoxide production. Micronuclei, reactive oxygen species (ROS) and lipid peroxidation (LPO) were measured at 15, 30 and 45 days after exposure. To study the possible causal role of ROS in the delayed effects of MF, the antioxidant N-acetylcysteine (NAC) was administered before MF exposure. Consistently with the previous study, the level of micronuclei was statistically significantly elevated 15 days after exposure. A similar effect was observed at 30 days, but not at 45 days after exposure. The level of LPO was statically significantly decreased 30 and 45 days after exposure. Consistently with our previous findings, the MF effect did not depend on co-exposure to MQ. Treatment with NAC effectively decreased cellular ROS level and suppressed the effect of MQ on ROS, but it did not block the MF effect, indicating that increase in ROS is not needed as a causal link between MF exposure and induction of delayed effects. The results presented here are consistent with genomic instability that persists in the progeny of MF-exposed cells up to at least 30 days after exposure. Changes in LPO observed at 30 and 45 days after exposure indicates that the MF-initiated process may continue up to at least 45 days after exposure.
Collapse
Affiliation(s)
- Kavindra Kumar Kesari
- Department of Environmental Science, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland.
| | - Jukka Luukkonen
- Department of Environmental Science, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland
| | - Jukka Juutilainen
- Department of Environmental Science, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland
| | - Jonne Naarala
- Department of Environmental Science, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland
| |
Collapse
|
30
|
Woodbine L, Haines J, Coster M, Barazzuol L, Ainsbury E, Sienkiewicz Z, Jeggo P. The rate of X-ray-induced DNA double-strand break repair in the embryonic mouse brain is unaffected by exposure to 50 Hz magnetic fields. Int J Radiat Biol 2015; 91:495-9. [PMID: 25786477 PMCID: PMC4673581 DOI: 10.3109/09553002.2015.1021963] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Purpose: Following in utero exposure to low dose radiation (10–200 mGy), we recently observed a linear induction of DNA double-strand breaks (DSB) and activation of apoptosis in the embryonic neuronal stem/progenitor cell compartment. No significant induction of DSB or apoptosis was observed following exposure to magnetic fields (MF). In the present study, we exploited this in vivo system to examine whether exposure to MF before and after exposure to 100 mGy X-rays impacts upon DSB repair rates. Materials and methods: 53BP1 foci were quantified following combined exposure to radiation and MF in the embryonic neuronal stem/progenitor cell compartment. Embryos were exposed in utero to 50 Hz MF at 300 μT for 3 h before and up to 9 h after exposure to 100 mGy X-rays. Controls included embryos exposed to MF or X-rays alone plus sham exposures. Results: Exposure to MF before and after 100 mGy X-rays did not impact upon the rate of DSB repair in the embryonic neuronal stem cell compartment compared to repair rates following radiation exposure alone. Conclusions: We conclude that in this sensitive system MF do not exert any significant level of DNA damage and do not impede the repair of X-ray induced damage.
Collapse
Affiliation(s)
- Lisa Woodbine
- Genome Damage and Stability Centre, Life Sciences, University of Sussex , Brighton
| | | | | | | | | | | | | |
Collapse
|
31
|
Manzella N, Bracci M, Ciarapica V, Staffolani S, Strafella E, Rapisarda V, Valentino M, Amati M, Copertaro A, Santarelli L. Circadian gene expression and extremely low-frequency magnetic fields: an in vitro study. Bioelectromagnetics 2015; 36:294-301. [PMID: 25808738 DOI: 10.1002/bem.21915] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Accepted: 03/06/2015] [Indexed: 12/31/2022]
Abstract
It is well known that circadian clocks are mainly regulated by light targeting signaling pathways in the hypothalamic suprachiasmatic nucleus. However, an entrainment mediated by non-photic sensory stimuli was also suggested for peripheral clocks. Exposure to extremely low frequency (ELF) electromagnetic fields might affect circadian rhythmicity. The goal of this research was to investigate effects of ELF magnetic fields (ELF-MF) on circadian clock genes in a human fibroblast cell line. We found that an ELF-MF (0.1 mT, 50 Hz) exposure was capable of entraining expression of clock genes BMAL1, PER2, PER3, CRY1, and CRY2. Moreover, ELF-MF treatment induced an alteration in circadian clock gene expression previously entrained by serum shock stimulation. These results support the hypothesis that ELF-MF may be able to drive circadian physiologic processes by modulating peripheral clock gene expression.
Collapse
Affiliation(s)
- Nicola Manzella
- Occupational Medicine, Department of Clinical and Molecular Sciences, Polytechnic University of Marche, Ancona, Italy
| | | | | | | | | | | | | | | | | | | |
Collapse
|
32
|
An evaluation of genotoxicity in human neuronal-type cells subjected to oxidative stress under an extremely low frequency pulsed magnetic field. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2014; 775-776:31-7. [DOI: 10.1016/j.mrgentox.2014.10.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Revised: 10/03/2014] [Accepted: 10/08/2014] [Indexed: 12/28/2022]
|
33
|
Del Re B, Giorgi G. Cell-host, LINE and environment: Three players in search of a balance. Mob Genet Elements 2014; 3:e24040. [PMID: 23734298 PMCID: PMC3655780 DOI: 10.4161/mge.24040] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Revised: 02/13/2013] [Accepted: 02/18/2013] [Indexed: 12/19/2022] Open
Abstract
Long interspersed nuclear elements -1 (LINEs, L1s) are retroelements occupying almost 17% of the human genome. L1 retrotransposition can cause deleterious effects on the host-cell and it is generally inhibited by suppressive mechanisms, but it can occur in some specific cells during early development as well as in some tumor cells and in the presence of several environmental factors. In a recent publication we reported that extremely low frequency pulsed magnetic field can affect L1 retrotransposition in neuroblastoma cells. In this commentary we discuss the interaction between environment and L1 activity in the light of the new emerging paradigm of host-LINE relationship.
Collapse
Affiliation(s)
- Brunella Del Re
- Department of Pharmacy and Biotechnology; University of Bologna; Bologna, Italy
| | | |
Collapse
|
34
|
Reale M, Kamal MA, Patruno A, Costantini E, D'Angelo C, Pesce M, Greig NH. Neuronal cellular responses to extremely low frequency electromagnetic field exposure: implications regarding oxidative stress and neurodegeneration. PLoS One 2014; 9:e104973. [PMID: 25127118 PMCID: PMC4134243 DOI: 10.1371/journal.pone.0104973] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Accepted: 07/15/2014] [Indexed: 11/19/2022] Open
Abstract
Neurodegenerative diseases comprise both hereditary and sporadic conditions characterized by an identifying progressive nervous system dysfunction and distinctive neuopathophysiology. The majority are of non-familial etiology and hence environmental factors and lifestyle play key roles in their pathogenesis. The extensive use of and ever increasing worldwide demand for electricity has stimulated societal and scientific interest on the environmental exposure to low frequency electromagnetic fields (EMFs) on human health. Epidemiological studies suggest a positive association between 50/60-Hz power transmission fields and leukemia or lymphoma development. Consequent to the association between EMFs and induction of oxidative stress, concerns relating to development of neurodegenerative diseases, such as Alzheimer disease (AD), have been voiced as the brain consumes the greatest fraction of oxygen and is particularly vulnerable to oxidative stress. Exposure to extremely low frequency (ELF)-EMFs are reported to alter animal behavior and modulate biological variables, including gene expression, regulation of cell survival, promotion of cellular differentiation, and changes in cerebral blood flow in aged AD transgenic mice. Alterations in inflammatory responses have also been reported, but how these actions impact human health remains unknown. We hence evaluated the effects of an electromagnetic wave (magnetic field intensity 1mT; frequency, 50-Hz) on a well-characterized immortalized neuronal cell model, human SH-SY5Y cells. ELF-EMF exposure elevated the expession of NOS and O2−, which were countered by compensatory changes in antioxidant catylase (CAT) activity and enzymatic kinetic parameters related to CYP-450 and CAT activity. Actions of ELF-EMFs on cytokine gene expression were additionally evaluated and found rapidly modified. Confronted with co-exposure to H2O2-induced oxidative stress, ELF-EMF proved not as well counteracted and resulted in a decline in CAT activity and a rise in O2− levels. Together these studies support the further evaluation of ELF-EMF exposure in cellular and in vivo preclinical models to define mechanisms potentially impacted in humans.
Collapse
Affiliation(s)
- Marcella Reale
- Department of Experimental and Clinical Sciences, University “G. d'Annunzio, Chieti, Italy
- * E-mail: (MR); (NG)
| | - Mohammad A. Kamal
- King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia
| | - Antonia Patruno
- Department of Medicine and Aging Science, University 'G. d'Annunzio' of Chieti-Pescara, Chieti, Italy
| | - Erica Costantini
- Department of Experimental and Clinical Sciences, University “G. d'Annunzio, Chieti, Italy
| | - Chiara D'Angelo
- Department of Experimental and Clinical Sciences, University “G. d'Annunzio, Chieti, Italy
| | - Miko Pesce
- Department of Medicine and Aging Science, University 'G. d'Annunzio' of Chieti-Pescara, Chieti, Italy
| | - Nigel H. Greig
- Drug Design and Development Section, Translational Gerontology Branch, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, United States of America
- * E-mail: (MR); (NG)
| |
Collapse
|
35
|
Brisdelli F, Bennato F, Bozzi A, Cinque B, Mancini F, Iorio R. ELF-MF attenuates quercetin-induced apoptosis in K562 cells through modulating the expression of Bcl-2 family proteins. Mol Cell Biochem 2014; 397:33-43. [DOI: 10.1007/s11010-014-2169-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Accepted: 07/24/2014] [Indexed: 11/24/2022]
|
36
|
Huumonen K, Korkalainen M, Boman E, Heikkilä J, Höytö A, Lahtinen T, Luukkonen J, Viluksela M, Naarala J, Juutilainen J. Dose- and time-dependent changes of micronucleus frequency and gene expression in the progeny of irradiated cells: two components in radiation-induced genomic instability? Mutat Res 2014; 765:32-39. [PMID: 24797401 DOI: 10.1016/j.mrfmmm.2014.04.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Revised: 04/11/2014] [Accepted: 04/12/2014] [Indexed: 06/03/2023]
Abstract
Murine embryonic C3H/10T½ fibroblasts were exposed to X-rays at doses of 0.2, 0.5, 1, 2 or 5 Gy. To follow the development of radiation-induced genomic instability (RIGI), the frequency of micronuclei was measured with flow cytometry at 2 days after exposure and in the progeny of the irradiated cells at 8 and 15 days after exposure. Gene expression was measured at the same points in time by PCR arrays profiling the expression of 84 cancer-relevant genes. The micronucleus results showed a gradual decrease in the slope of the dose-response curve between days 2 and 15. The data were consistent with a model assuming two components in RIGI. The first component is characterized by dose-dependent increase in micronuclei. It may persist more than ten cell generations depending on dose, but eventually disappears. The second component is more persistent and independent of dose above a threshold higher than 0.2 Gy. Gene expression analysis 2 days after irradiation at 5 Gy showed consistent changes in genes that typically respond to DNA damage. However, the consistency of changes decreased with time, suggesting that non-specificity and increased heterogeneity of gene expression are characteristic to the second, more persistent component of RIGI.
Collapse
Affiliation(s)
- Katriina Huumonen
- University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, 70211 Kuopio, Finland
| | - Merja Korkalainen
- National Institute for Health and Welfare, Department of Environmental Health, P.O. Box 95, 70701 Kuopio, Finland
| | - Eeva Boman
- Kuopio University Hospital, Cancer Center, P.O. Box 1777, 70211 Kuopio, Finland
| | - Janne Heikkilä
- Kuopio University Hospital, Cancer Center, P.O. Box 1777, 70211 Kuopio, Finland
| | - Anne Höytö
- University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, 70211 Kuopio, Finland
| | - Tapani Lahtinen
- Kuopio University Hospital, Cancer Center, P.O. Box 1777, 70211 Kuopio, Finland
| | - Jukka Luukkonen
- University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, 70211 Kuopio, Finland
| | - Matti Viluksela
- National Institute for Health and Welfare, Department of Environmental Health, P.O. Box 95, 70701 Kuopio, Finland
| | - Jonne Naarala
- University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, 70211 Kuopio, Finland
| | - Jukka Juutilainen
- University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, 70211 Kuopio, Finland.
| |
Collapse
|
37
|
Jin YB, Choi SH, Lee JS, Kim JK, Lee JW, Hong SC, Myung SH, Lee YS. Absence of DNA damage after 60-Hz electromagnetic field exposure combined with ionizing radiation, hydrogen peroxide, or c-Myc overexpression. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2014; 53:93-101. [PMID: 24305851 DOI: 10.1007/s00411-013-0506-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Accepted: 11/25/2013] [Indexed: 06/02/2023]
Abstract
The principal objective of this study was to assess the DNA damage in a normal cell line system after exposure to 60 Hz of extremely low frequency magnetic field (ELF-MF) and particularly in combination with various external factors, via comet assays. NIH3T3 mouse fibroblast cells, WI-38 human lung fibroblast cells, L132 human lung epithelial cells, and MCF10A human mammary gland epithelial cells were exposed for 4 or 16 h to a 60-Hz, 1 mT uniform magnetic field in the presence or absence of ionizing radiation (IR, 1 Gy), H(2)O(2) (50 μM), or c-Myc oncogenic activation. The results obtained showed no significant differences between the cells exposed to ELF-MF alone and the unexposed cells. Moreover, no synergistic or additive effects were observed after 4 or 16 h of pre-exposure to 1 mT ELF-MF or simultaneous exposure to ELF-MF combined with IR, H(2)O(2), or c-Myc activation.
Collapse
Affiliation(s)
- Yeung Bae Jin
- Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup, Korea
| | | | | | | | | | | | | | | |
Collapse
|
38
|
Liu DD, Ren Z, Yang G, Zhao QR, Mei YA. Melatonin protects rat cerebellar granule cells against electromagnetic field-induced increases in Na(+) currents through intracellular Ca(2+) release. J Cell Mol Med 2014; 18:1060-70. [PMID: 24548607 PMCID: PMC4508145 DOI: 10.1111/jcmm.12250] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Accepted: 01/18/2014] [Indexed: 01/12/2023] Open
Abstract
Although melatonin (MT) has been reported to protect cells against oxidative damage induced by electromagnetic radiation, few reports have addressed whether there are other protective mechanisms. Here, we investigated the effects of MT on extremely low-frequency electromagnetic field (ELF-EMF)-induced Nav activity in rat cerebellar granule cells (GCs). Exposing cerebellar GCs to ELF-EMF for 60 min. significantly increased the Nav current (INa ) densities by 62.5%. MT (5 μM) inhibited the ELF-EMF-induced INa increase. This inhibitory effect of MT is mimicked by an MT2 receptor agonist and was eliminated by an MT2 receptor antagonist. The Nav channel steady-state activation curve was significantly shifted towards hyperpolarization by ELF-EMF stimulation but remained unchanged by MT in cerebellar GC that were either exposed or not exposed to ELF-EMF. ELF-EMF exposure significantly increased the intracellular levels of phosphorylated PKA in cerebellar GCs, and both MT and IIK-7 did not reduce the ELF-EMF-induced increase in phosphorylated PKA. The inhibitory effects of MT on ELF-EMF-induced Nav activity was greatly reduced by the calmodulin inhibitor KN93. Calcium imaging showed that MT did not increase the basal intracellular Ca(2+) level, but it significantly elevated the intracellular Ca(2+) level evoked by the high K(+) stimulation in cerebellar GC that were either exposed or not exposed to ELF-EMF. In the presence of ruthenium red, a ryanodine-sensitive receptor blocker, the MT-induced increase in intracellular calcium levels was reduced. Our data show for the first time that MT protects against neuronal INa that result from ELF-EMF exposure through Ca(2+) influx-induced Ca(2+) release.
Collapse
Affiliation(s)
- Dong-Dong Liu
- School of Life Sciences, Institutes of Brain Science and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, China
| | | | | | | | | |
Collapse
|
39
|
Okokon EO, Roivainen P, Kheifets L, Mezei G, Juutilainen J. Indoor transformer stations and ELF magnetic field exposure: use of transformer structural characteristics to improve exposure assessment. JOURNAL OF EXPOSURE SCIENCE & ENVIRONMENTAL EPIDEMIOLOGY 2014; 24:100-104. [PMID: 24022671 DOI: 10.1038/jes.2013.54] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Revised: 06/17/2013] [Accepted: 07/03/2013] [Indexed: 06/02/2023]
Abstract
Previous studies have shown that populations of multiapartment buildings with indoor transformer stations may serve as a basis for improved epidemiological studies on the relationship between childhood leukaemia and extremely-low-frequency (ELF) magnetic fields (MFs). This study investigated whether classification based on structural characteristics of the transformer stations would improve ELF MF exposure assessment. The data included MF measurements in apartments directly above transformer stations ("exposed" apartments) in 30 buildings in Finland, and reference apartments in the same buildings. Transformer structural characteristics (type and location of low-voltage conductors) were used to classify exposed apartments into high-exposure (HE) and intermediate-exposure (IE) categories. An exposure gradient was observed: both the time-average MF and time above a threshold (0.4 μT) were highest in the HE apartments and lowest in the reference apartments, showing a statistically significant trend. The differences between HE and IE apartments, however, were not statistically significant. A simulation exercise showed that the three-category classification did not perform better than a two-category classification (exposed and reference apartments) in detecting the existence of an increased risk. However, data on the structural characteristics of transformers is potentially useful for evaluating exposure-response relationship.
Collapse
Affiliation(s)
- Enembe Oku Okokon
- Department of Environmental Science, University of Eastern Finland, Kuopio, Finland
| | - Päivi Roivainen
- Department of Environmental Science, University of Eastern Finland, Kuopio, Finland
| | - Leeka Kheifets
- Department of Epidemiology, University of California, Los Angeles, Los Angeles, California, USA
| | - Gabor Mezei
- Electric Power Research Institute, Palo Alto, California, USA
| | - Jukka Juutilainen
- Department of Environmental Science, University of Eastern Finland, Kuopio, Finland
| |
Collapse
|
40
|
Luukkonen J, Liimatainen A, Juutilainen J, Naarala J. Induction of genomic instability, oxidative processes, and mitochondrial activity by 50Hz magnetic fields in human SH-SY5Y neuroblastoma cells. Mutat Res 2013; 760:33-41. [PMID: 24374227 DOI: 10.1016/j.mrfmmm.2013.12.002] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Revised: 12/13/2013] [Accepted: 12/19/2013] [Indexed: 11/26/2022]
Abstract
Epidemiological studies have suggested that exposure to 50Hz magnetic fields (MF) increases the risk of childhood leukemia, but there is no mechanistic explanation for carcinogenic effects. In two previous studies we have observed that a 24-h pre-exposure to MF alters cellular responses to menadione-induced DNA damage. The aim of this study was to investigate the cellular changes that must occur already during the first 24h of exposure to MF, and to explore whether the MF-induced changes in DNA damage response can lead to genomic instability in the progeny of the exposed cells. In order to answer these questions, human SH-SY5Y neuroblastoma cells were exposed to a 50-Hz, 100-μT MF for 24h, followed by 3-h exposure to menadione. The main finding was that MF exposure was associated with increased level of micronuclei, used as an indicator of induced genomic instability, at 8 and 15d after the exposures. Other delayed effects in MF-exposed cells included increased mitochondrial activity at 8d, and increased reactive oxygen species (ROS) production and lipid peroxidation at 15d after the exposures. Oxidative processes (ROS production, reduced glutathione level, and mitochondrial superoxide level) were affected by MF immediately after the exposure. In conclusion, the present results suggest that MF exposure disturbs oxidative balance immediately after the exposure, which might explain our previous findings on MF altered cellular responses to menadione-induced DNA damage. Persistently elevated levels of micronuclei were found in the progeny of MF-exposed cells, indicating induction of genomic instability.
Collapse
Affiliation(s)
- Jukka Luukkonen
- Department of Environmental Science, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland.
| | - Anu Liimatainen
- Department of Environmental Science, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland
| | - Jukka Juutilainen
- Department of Environmental Science, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland
| | - Jonne Naarala
- Department of Environmental Science, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland
| |
Collapse
|
41
|
He YL, Liu DD, Fang YJ, Zhan XQ, Yao JJ, Mei YA. Exposure to extremely low-frequency electromagnetic fields modulates Na+ currents in rat cerebellar granule cells through increase of AA/PGE2 and EP receptor-mediated cAMP/PKA pathway. PLoS One 2013; 8:e54376. [PMID: 23349866 PMCID: PMC3551899 DOI: 10.1371/journal.pone.0054376] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2012] [Accepted: 12/11/2012] [Indexed: 12/19/2022] Open
Abstract
Although the modulation of Ca2+ channel activity by extremely low-frequency electromagnetic fields (ELF-EMF) has been studied previously, few reports have addressed the effects of such fields on the activity of voltage-activated Na+ channels (Nav). Here, we investigated the effects of ELF-EMF on Nav activity in rat cerebellar granule cells (GCs). Our results reveal that exposing cerebellar GCs to ELF-EMF for 10–60 min significantly increased Nav currents (INa) by 30–125% in a time- and intensity-dependent manner. The Nav channel steady-state activation curve, but not the steady-state inactivation curve, was significantly shifted (by 5.2 mV) towards hyperpolarization by ELF-EMF stimulation. This phenomenon is similar to the effect of intracellular application of arachidonic acid (AA) and prostaglandin E2 (PGE2) on INa in cerebellar GCs. Increases in intracellular AA, PGE2 and phosphorylated PKA levels in cerebellar GCs were observed following ELF-EMF exposure. Western blottings indicated that the NaV 1.2 protein on the cerebellar GCs membrane was increased, the total expression levels of NaV 1.2 protein were not affected after exposure to ELF-EMF. Cyclooxygenase inhibitors and PGE2 receptor (EP) antagonists were able to eliminate this ELF-EMF-induced increase in phosphorylated PKA and INa. In addition, ELF-EMF exposure significantly enhanced the activity of PLA2 in cerebellar GCs but did not affect COX-1 or COX-2 activity. Together, these data demonstrate for the first time that neuronal INa is significantly increased by ELF-EMF exposure via a cPLA2 AA PGE2 EP receptors PKA signaling pathway.
Collapse
Affiliation(s)
- Yan-Lin He
- Institutes of Brain Science, School of Life Sciences and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, China
| | - Dong-Dong Liu
- Institutes of Brain Science, School of Life Sciences and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, China
| | - Yan-Jia Fang
- Institutes of Brain Science, School of Life Sciences and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, China
| | - Xiao-Qin Zhan
- Institutes of Brain Science, School of Life Sciences and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, China
| | - Jin-Jing Yao
- Institutes of Brain Science, School of Life Sciences and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, China
| | - Yan-Ai Mei
- Institutes of Brain Science, School of Life Sciences and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, China
- * E-mail:
| |
Collapse
|
42
|
Del Re B, Marcantonio P, Gavoçi E, Bersani F, Giorgi G. Assessing LINE-1 retrotransposition activity in neuroblastoma cells exposed to extremely low-frequency pulsed magnetic fields. Mutat Res 2012; 749:76-81. [PMID: 22981769 DOI: 10.1016/j.mrgentox.2012.07.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Revised: 06/05/2012] [Accepted: 07/25/2012] [Indexed: 06/01/2023]
Abstract
Mobile genetic elements represent an important source of mutation and genomic instability, and their activity can be influenced by several chemical and physical agents. In this research we address the question whether exposure to extremely low-frequency pulsed magnetic fields (EMF-PMF) could affect the mobility of the human LINE-1(RP) retrotransposon. To this purpose, an in vitro retrotransposition assay was used on human neuroblastoma BE(2) cells exposed for 48h to 1mT, 50Hz PMF, or sham-exposed. Moreover, since it is well known that retrotransposition causes DNA double-strand breaks (DSB), an estimation of γ-H2AX foci, which is a marker of DNA DSB, was carried out on PMF- and sham-exposed samples. The results show that PMF-exposed cells had a lower number of both retrotransposition events and DNA DSB compared with sham-exposed samples. These results suggest that exposure to PMF can interfere with retrotransposition activity by inducing a decrease of retrotransposition events.
Collapse
Affiliation(s)
- Brunella Del Re
- Department of Experimental Evolutionary Biology, University of Bologna, Bologna, Italy.
| | | | | | | | | |
Collapse
|
43
|
Consales C, Merla C, Marino C, Benassi B. Electromagnetic fields, oxidative stress, and neurodegeneration. Int J Cell Biol 2012; 2012:683897. [PMID: 22991514 PMCID: PMC3444040 DOI: 10.1155/2012/683897] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2012] [Revised: 06/19/2012] [Accepted: 06/19/2012] [Indexed: 12/21/2022] Open
Abstract
Electromagnetic fields (EMFs) originating both from both natural and manmade sources permeate our environment. As people are continuously exposed to EMFs in everyday life, it is a matter of great debate whether they can be harmful to human health. On the basis of two decades of epidemiological studies, an increased risk for childhood leukemia associated with Extremely Low Frequency fields has been consistently assessed, inducing the International Agency for Research on Cancer to insert them in the 2B section of carcinogens in 2001. EMFs interaction with biological systems may cause oxidative stress under certain circumstances. Since free radicals are essential for brain physiological processes and pathological degeneration, research focusing on the possible influence of the EMFs-driven oxidative stress is still in progress, especially in the light of recent studies suggesting that EMFs may contribute to the etiology of neurodegenerative disorders. This review synthesizes the emerging evidences about this topic, highlighting the wide data uncertainty that still characterizes the EMFs effect on oxidative stress modulation, as both pro-oxidant and neuroprotective effects have been documented. Care should be taken to avoid methodological limitations and to determine the patho-physiological relevance of any alteration found in EMFs-exposed biological system.
Collapse
Affiliation(s)
- Claudia Consales
- Unit of Radiation Biology and Human Health, ENEA-Casaccia, Rome 00123, Italy
| | | | | | - Barbara Benassi
- Unit of Radiation Biology and Human Health, ENEA-Casaccia, Rome 00123, Italy
| |
Collapse
|
44
|
Korkalainen M, Huumonen K, Naarala J, Viluksela M, Juutilainen J. Dioxin induces genomic instability in mouse embryonic fibroblasts. PLoS One 2012; 7:e37895. [PMID: 22666406 PMCID: PMC3362596 DOI: 10.1371/journal.pone.0037895] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2012] [Accepted: 04/30/2012] [Indexed: 12/04/2022] Open
Abstract
Ionizing radiation and certain other exposures have been shown to induce genomic instability (GI), i.e., delayed genetic damage observed many cell generations later in the progeny of the exposed cells. The aim of this study was to investigate induction of GI by a nongenotoxic carcinogen, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Mouse embryonic fibroblasts (C3H10T1/2) were exposed to 1, 10 or 100 nM TCDD for 2 days. Micronuclei (MN) and expression of selected cancer-related genes were assayed both immediately and at a delayed point in time (8 days). For comparison, similar experiments were done with cadmium, a known genotoxic agent. TCDD treatment induced an elevated frequency of MN at 8 days, but not directly after the exposure. TCDD-induced alterations in gene expression were also mostly delayed, with more changes observed at 8 days than at 2 days. Exposure to cadmium produced an opposite pattern of responses, with pronounced effects immediately after exposure but no increase in MN and few gene expression changes at 8 days. Although all responses to TCDD alone were delayed, menadione-induced DNA damage (measured by the Comet assay), was found to be increased directly after a 2-day TCDD exposure, indicating that the stability of the genome was compromised already at this time point. The results suggested a flat dose-response relationship consistent with dose-response data reported for radiation-induced GI. These findings indicate that TCDD, although not directly genotoxic, induces GI, which is associated with impaired DNA damage response.
Collapse
Affiliation(s)
- Merja Korkalainen
- Department of Environmental Health, National Institute for Health and Welfare, Kuopio, Finland
- * E-mail:
| | - Katriina Huumonen
- Department of Environmental Science, University of Eastern Finland, Kuopio, Finland
| | - Jonne Naarala
- Department of Environmental Science, University of Eastern Finland, Kuopio, Finland
| | - Matti Viluksela
- Department of Environmental Health, National Institute for Health and Welfare, Kuopio, Finland
| | - Jukka Juutilainen
- Department of Environmental Science, University of Eastern Finland, Kuopio, Finland
| |
Collapse
|
45
|
Yang L, Hao D, Wang M, Zeng Y, Wu S, Zeng Y. Cellular neoplastic transformation induced by 916 MHz microwave radiation. Cell Mol Neurobiol 2012; 32:1039-46. [PMID: 22395787 DOI: 10.1007/s10571-012-9821-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Accepted: 02/16/2012] [Indexed: 10/28/2022]
Abstract
There has been growing concern about the possibility of adverse health effects resulting from exposure to microwave radiations, such as those emitted by mobile phones. The purpose of this study was to investigate the cellular neoplastic transformation effects of electromagnetic fields. 916 MHz continuous microwave was employed in our study to simulate the electromagnetic radiation of mobile phone. NIH/3T3 cells were adopted in our experiment due to their sensitivity to carcinogen or cancer promoter in environment. They were divided randomly into one control group and three microwave groups. The three microwave groups were exposed to 916 MHz EMF for 2 h per day with power density of 10, 50, and 90 w/m(2), respectively, in which 10 w/m(2) was close to intensity near the antenna of mobile phone. The morphology and proliferation of NIH/3T3 cells were examined and furthermore soft agar culture and animal carcinogenesis assay were carried out to determine the neoplastic promotion. Our experiments showed NIH/3T3 cells changed in morphology and proliferation after 5-8 weeks exposure and formed clone in soft agar culture after another 3-4 weeks depending on the exposure intensity. In the animal carcinogenesis study, lumps developed on the back of SCID mice after being inoculated into exposed NIH/3T3 cells for more than 4 weeks. The results indicate that microwave radiation can promote neoplastic transformation of NIH/3T3cells.
Collapse
Affiliation(s)
- Lei Yang
- College of Life Science and Bioengineering, Beijing University of Technology, Chaoyang District, Beijing, People's Republic of China
| | | | | | | | | | | |
Collapse
|
46
|
Hong MN, Han NK, Lee HC, Ko YK, Chi SG, Lee YS, Gimm YM, Myung SH, Lee JS. Extremely low frequency magnetic fields do not elicit oxidative stress in MCF10A cells. JOURNAL OF RADIATION RESEARCH 2012; 53:79-86. [PMID: 22302048 DOI: 10.1269/jrr.11049] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The aim of this study was to determine whether extremely low frequency magnetic fields (ELF-MF) could affect intracellular reactive oxygen species (ROS) levels and antioxidant enzyme activity. After MCF10A human breast epithelial cells were exposed to 1 mT of 60 Hz ELF-MF for 4 hours, intracellular ROS level, superoxide dismutase (SOD) activity, and reduced to oxidized glutathione (GSH/GSSG) ratio were measured. The cells exposed to ELF-MF did not evidence statistically significant changes in the above-mentioned biological parameters as compared to either the incubator controls or sham-exposed cells. By way of contrast, the IR-exposed cells exhibited marked changes in ROS level, SOD activity, and GSH/GSSG ratio. When we assessed morphological changes and senescence-associated beta-galactosidase (SA-β-Gal) activity, only the IR-exposed cells were positive. According to our results, it could be concluded that ELF-MF has no effect on intracellular ROS level, SOD activity, and GSH/GSSG ratio under our exposure condition.
Collapse
Affiliation(s)
- Mi-Na Hong
- Division of Radiation Cancer Research, Korea Institute of Radiological & Medical Sciences, Seoul, Korea
| | | | | | | | | | | | | | | | | |
Collapse
|