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Evaluation of Pulsed Electromagnetic Field Effects: A Systematic Review and Meta-Analysis on Highlights of Two Decades of Research In Vitro Studies. BIOMED RESEARCH INTERNATIONAL 2021; 2021:6647497. [PMID: 34368353 PMCID: PMC8342182 DOI: 10.1155/2021/6647497] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Revised: 05/30/2021] [Accepted: 06/27/2021] [Indexed: 12/13/2022]
Abstract
Pulsed electromagnetic field (PEMF) therapy is a type of physical stimulation that affects biological systems by producing interfering or coherent fields. Given that cell types are significantly distinct, which represents an important factor in stimulation, and that PEMFs can have different effects in terms of frequency and intensity, time of exposure, and waveform. This study is aimed at investigating if distinct positive and negative responses would correspond to specific characteristics of cells, frequency and flux density, time of exposure, and waveform. Necessary data were abstracted from the experimental observations of cell-based in vitro models. The observations were obtained from 92 publications between the years 1999 and 2019, which are available on PubMed and Web of Science databases. From each of the included studies, type of cells, pulse frequency of exposure, exposure flux density, and assayed cell responses were extracted. According to the obtained data, most of the experiments were carried out on human cells, and out of 2421 human cell experiments, cell changes were observed only in 51.05% of the data. In addition, the results pointed out the potential effects of PEMFs on some human cell types such as MG-63 human osteosarcoma cells (p value < 0.001) and bone marrow mesenchymal stem cells. However, human osteogenic sarcoma SaOS-2 (p < 0.001) and human adipose-derived mesenchymal stem cells (AD-MSCs) showed less sensitivity to PEMFs. Nevertheless, the evidence suggests that frequencies higher than 100 Hz, flux densities between 1 and 10 mT, and chronic exposure more than 10 days would be more effective in establishing a cellular response. This study successfully reported useful information about the role of cell type and signal characteristic parameters, which were of high importance for targeted therapies using PEMFs. Our findings would provide a deeper understanding about the effect of PEMFs in vitro, which could be useful as a reference for many in vivo experiments or preclinical trials.
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Abstract
Over the last three decades, evidence has emerged that low-intensity magnetic fields can influence biological systems. It is now well established that migratory birds have the capacity to detect the Earth's magnetic field; it has been reported that power lines are associated with childhood leukemia and that pulsed magnetic fields increase the production of reactive oxidative species (ROS) in cellular systems. Justifiably, studies in this field have been viewed with skepticism, as the underlying molecular mechanisms are unknown. In the accompanying paper, Sherrard and colleagues report that low-flux pulsed electromagnetic fields (PEMFs) result in aversive behavior in Drosophila larvae and ROS production in cell culture. They further report that these responses require the presence of cryptochrome, a putative magnetoreceptor. If correct, it is conceivable that carcinogenesis associated with power lines, PEMF-induced ROS generation, and animal magnetoreception share a common mechanistic basis.
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Affiliation(s)
- Lukas Landler
- Research Institute of Molecular Pathology, Vienna Biocentre, Vienna, Austria
| | - David A. Keays
- Research Institute of Molecular Pathology, Vienna Biocentre, Vienna, Austria
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Seo N, Lee SH, Ju KW, Woo J, Kim B, Kim S, Jahng JW, Lee JH. Low-frequency pulsed electromagnetic field pretreated bone marrow-derived mesenchymal stem cells promote the regeneration of crush-injured rat mental nerve. Neural Regen Res 2018; 13:145-153. [PMID: 29451219 PMCID: PMC5840980 DOI: 10.4103/1673-5374.224383] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Bone marrow-derived mesenchymal stem cells (BMSCs) have been shown to promote the regeneration of injured peripheral nerves. Pulsed electromagnetic field (PEMF) reportedly promotes the proliferation and neuronal differentiation of BMSCs. Low-frequency PEMF can induce the neuronal differentiation of BMSCs in the absence of nerve growth factors. This study was designed to investigate the effects of low-frequency PEMF pretreatment on the proliferation and function of BMSCs and the effects of low-frequency PEMF pre-treated BMSCs on the regeneration of injured peripheral nerve using in vitro and in vivo experiments. In in vitro experiments, quantitative DNA analysis was performed to determine the proliferation of BMSCs, and reverse transcription-polymerase chain reaction was performed to detect S100 (Schwann cell marker), glial fibrillary acidic protein (astrocyte marker), and brain-derived neurotrophic factor and nerve growth factor (neurotrophic factors) mRNA expression. In the in vivo experiments, rat models of crush-injured mental nerve established using clamp method were randomly injected with low-frequency PEMF pretreated BMSCs, unpretreated BMSCs or PBS at the injury site (1 × 106 cells). DiI-labeled BMSCs injected at the injury site were counted under the fluorescence microscope to determine cell survival. One or two weeks after cell injection, functional recovery of the injured nerve was assessed using the sensory test with von Frey filaments. Two weeks after cell injection, axonal regeneration was evaluated using histomorphometric analysis and retrograde labeling of trigeminal ganglion neurons. In vitro experiment results revealed that low-frequency PEMF pretreated BMSCs proliferated faster and had greater mRNA expression of growth factors than unpretreated BMSCs. In vivo experiment results revealed that compared with injection of unpretreated BMSCs, injection of low-frequency PEMF pretreated BMSCs led to higher myelinated axon count and axon density and more DiI-labeled neurons in the trigeminal ganglia, contributing to rapider functional recovery of injured mental nerve. These findings suggest that low-frequency PEMF pretreatment is a promising approach to enhance the efficacy of cell therapy for peripheral nerve injury repair.
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Affiliation(s)
- NaRi Seo
- Department of Oral and Maxillofacial Surgery, Graduate School of Dentistry, Seoul National University; Dental Research Institute, Seoul National University, Seoul, South Korea
| | - Sung-Ho Lee
- Department of Oral and Maxillofacial Surgery, Seoul National University Dental Hospital; Dental Research Institute, Seoul National University, Seoul, South Korea
| | - Kyung Won Ju
- Department of Oral and Maxillofacial Surgery, Seoul National University Dental Hospital; Dental Research Institute, Seoul National University, Seoul, South Korea
| | - JaeMan Woo
- Department of Oral and Maxillofacial Surgery, Seoul National University Dental Hospital, Seoul, South Korea
| | - BongJu Kim
- Clinical Translational Research Center for Dental Science (CTRC), Seoul National University Dental Hospital, Seoul, South Korea
| | - SoungMin Kim
- Department of Oral and Maxillofacial Surgery, Graduate School of Dentistry, Seoul National University; Department of Oral and Maxillofacial Surgery, Seoul National University Dental Hospital, Seoul, South Korea
| | - Jeong Won Jahng
- Dental Research Institute, Seoul National University, Seoul, South Korea
| | - Jong-Ho Lee
- Department of Oral and Maxillofacial Surgery, Graduate School of Dentistry, Seoul National University; Department of Oral and Maxillofacial Surgery, Seoul National University Dental Hospital; Dental Research Institute, Seoul National University; Clinical Translational Research Center for Dental Science (CTRC), Seoul National University Dental Hospital, Seoul, South Korea
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Hei WH, Byun SH, Kim JS, Kim S, Seo YK, Park JC, Kim SM, Jahng JW, Lee JH. Effects of electromagnetic field (PEMF) exposure at different frequency and duration on the peripheral nerve regeneration: in vitro and in vivo study. Int J Neurosci 2015; 126:739-48. [PMID: 26010211 DOI: 10.3109/00207454.2015.1054032] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE The purpose was to clarify the influence of frequency and exposure time of pulsed electromagnetic fields (PEMF) on the peripheral nerve regeneration. MATERIALS AND METHODS Immortalized rat Schwann cells (iSCs) (1 × 10(2)/well) were exposed at four different conditions in 1 mT (50 Hz 1 h/d, 50 Hz 12 h/d, 150 Hz 1 h/d and 150 Hz 12h/d). Cell proliferation, mRNA expression of S100 and brain-derived neurotrophic factor (BDNF) were analyzed. Sprague-Dawley rats (200-250 g) were divided into six groups (n = 10 each): control, sham, 50 Hz 1 h/d, 50 Hz 12 h/d, 150 Hz 1 h/d and 150 Hz 12 Hr/d. Mental nerve was crush-injured and exposed at four different conditions in 1 mT (50 Hz 1 Hr/d, 50 Hz 12 Hr/d, 150 Hz 1 h/d and 150 Hz 12 h/d). Nerve regeneration was evaluated with functional test, histomorphometry and retrograde labeling of trigeminal ganglion. RESULTS iSCs proliferation with 50 Hz, 1 h/d was increased from fourth to seventh day; mRNA expression of S100 and BDNF was significantly increased at the same condition from first week to third week (p < .05 vs. control); difference score was increased at the second and third week, and gap score was increased at the third under 50 Hz 1 h PEMF compared with control while other conditions showed no statistical meaning. Axon counts and retrograde labeled neurons were significantly increased under PEMF of four different conditions compared with control. Although there was no statistical difference, 50 Hz, 1 h PEMF showed highest regeneration ability than other conditions. CONCLUSION PEMF enhanced peripheral nerve regeneration, and that it may be due to cell proliferation and increase in BDNF and S100 gene expression.
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Affiliation(s)
- Wei-Hong Hei
- a Department of Oral and Maxillofacial Surgery, School of Dentistry , Seoul National University , Seoul , Korea
| | - Soo-Hwan Byun
- a Department of Oral and Maxillofacial Surgery, School of Dentistry , Seoul National University , Seoul , Korea
| | - Jong-Sik Kim
- b Department of Oral and Maxillofacial Surgery, Hallum Medical School , Sacred Kangdong hospital , Seoul , Korea
| | - Soochan Kim
- c Graduate School of Bio & Information Technology , Hankyong National University , Anseong-si, Kyonggi-do , Seoul , Korea
| | - Young-Kwon Seo
- d Research Institute of Biotechnology , Dongguk University , Seoul , Korea
| | - Joo-Cheol Park
- e Department of Oral Histology-Developmental Biology, School of Dentistry , Seoul National University , Seoul , Korea
| | - Soung-Min Kim
- a Department of Oral and Maxillofacial Surgery, School of Dentistry , Seoul National University , Seoul , Korea
| | - Jeong Won Jahng
- f Dental Research Institute , Seoul National University , Seoul , Korea
| | - Jong-Ho Lee
- a Department of Oral and Maxillofacial Surgery, School of Dentistry , Seoul National University , Seoul , Korea.,f Dental Research Institute , Seoul National University , Seoul , Korea
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Lekhraj R, Cynamon DE, DeLuca SE, Taub ES, Pilla AA, Casper D. Pulsed electromagnetic fields potentiate neurite outgrowth in the dopaminergic MN9D cell line. J Neurosci Res 2014; 92:761-71. [DOI: 10.1002/jnr.23361] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Revised: 11/07/2013] [Accepted: 12/06/2013] [Indexed: 11/09/2022]
Affiliation(s)
- Rukmani Lekhraj
- Department of Neurological Surgery; Montefiore Medical Center and the Albert Einstein College of Medicine; Bronx New York
| | - Deborah E. Cynamon
- Department of Neurological Surgery; Montefiore Medical Center and the Albert Einstein College of Medicine; Bronx New York
| | - Stephanie E. DeLuca
- Department of Neurological Surgery; Montefiore Medical Center and the Albert Einstein College of Medicine; Bronx New York
| | - Eric S. Taub
- Department of Neurological Surgery; Montefiore Medical Center and the Albert Einstein College of Medicine; Bronx New York
| | - Arthur A. Pilla
- Department of Biomedical Engineering; Columbia University; New York New York
- Department of Orthopedics; Mount Sinai School of Medicine; New York New York
| | - Diana Casper
- Department of Neurological Surgery; Montefiore Medical Center and the Albert Einstein College of Medicine; Bronx New York
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Cid MA, Ubeda A, Hernández-Bule ML, Martínez MA, Trillo MÁ. Antagonistic effects of a 50 Hz magnetic field and melatonin in the proliferation and differentiation of hepatocarcinoma cells. Cell Physiol Biochem 2012; 30:1502-16. [PMID: 23235525 DOI: 10.1159/000343338] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/21/2012] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND/AIMS Epidemiological and experimental evidence exists indicating that exposure to weak, extremely low frequency magnetic fields (ELF - MF) could affect cancer progression. It has been proposed that such hypothetical action could be mediated by MF-induced effects on the cellular response to melatonin (MEL), a potentially oncostatic neurohormone. The present study investigates the response of HepG2 cells to intermittent exposure to a 50 Hz, 10 µT MF, in the presence or absence of MEL at physiological (10 nM) or pharmacological doses (1 µM). METHODS The Trypan blue cell exclusion test, BrdU incorporation and PCNA expression assays were carried out to assess the cellular response in terms of viability and proliferation. In addition, albumin and alpha-fetoprotein, were analyzed as specific hepatocellular differentiation markers. RESULTS The results indicate that the MF exerts significant cytoproliferative and dedifferentiating effects that can be prevented by 10 nM MEL. Conversely, MEL exerts cytostatic and differentiating effects on HepG2 that are abolished by simultaneous exposure to MF. CONCLUSION As a whole, these results support the hypothesis that ELF - MF and MEL exert opposite, mutually counteracting effects on cell proliferation and differentiation.
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Affiliation(s)
- María Antonia Cid
- Dept. Investigación-BEM, Hospital Ramón y Cajal-IRYCIS, Madrid, Spain.
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Bistolfi F. Evidence of interlinks between bioelectromagnetics and biomechanics: from biophysics to medical physics. Phys Med 2012; 22:71-95. [PMID: 17664154 DOI: 10.1016/s1120-1797(06)80002-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2005] [Revised: 05/29/2006] [Accepted: 06/12/2006] [Indexed: 01/22/2023] Open
Abstract
A vast literature on electromagnetic and mechanical bioeffects at the bone and soft tissue level, as well as at the cellular level (osteoblasts, osteoclasts, keratinocytes, fibroblasts, chondrocytes, nerve cells, endothelial and muscle cells) has been reviewed and analysed in order to show the evident connections between both types of physical energies. Moreover, an intimate link between the two is suggested by transduction phenomena (electromagnetic-acoustic transduction and its reverse) occurring in living matter, as a sound biophysical literature has demonstrated. However, electromagnetic and mechanical signals are not always interchangeable, depending on their respective intensity. Calculations are reported in order to show in which cases (read: for which values of electric field in V/m and of mechanical pressure in Pa) a given electromagnetic or mechanical bioeffect is only due to the directly impinging energy or even to the indirect transductional energy. The relevance of the treated item for the applications of medical physics to regenerative medicine is stressed.
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Affiliation(s)
- F Bistolfi
- Radiotherapy Department, Galliera Hospital, Genova (Italy)
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Zhang D, Pan X, Ohno S, Osuga T, Sawada S, Sato K. No effects of pulsed electromagnetic fields on expression of cell adhesion molecules (integrin, CD44) and matrix metalloproteinase-2/9 in osteosarcoma cell lines. Bioelectromagnetics 2011; 32:463-73. [DOI: 10.1002/bem.20647] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2010] [Accepted: 12/20/2010] [Indexed: 11/09/2022]
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Zhang Y, Ding J, Duan W. A study of the effects of flux density and frequency of pulsed electromagnetic field on neurite outgrowth in PC12 cells. J Biol Phys 2010; 32:1-9. [PMID: 19669431 DOI: 10.1007/s10867-006-6901-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
The aim of this study was to investigate the influence of pulsed electromagnetic fields with various flux densities and frequencies on neurite outgrowth in PC12 rat pheochromocytoma cells. We have studied the percentage of neurite-bearing cells, average length of neurites and directivity of neurite outgrowth in PC12 cells cultured for 96 hours in the presence of nerve growth factor (NGF). PC12 cells were exposed to 50 Hz pulsed electromagnetic fields with a flux density of 1.37 mT, 0.19 mT and 0.016 mT respectively. The field was generated through a Helmholtz coil pair housed in one incubator and the control samples were placed in another identical incubator. It was found that exposure to both a relatively high flux density (1.37 mT) and a medium flux density (0.19 mT) inhibited the percentage of neurite-bearing cells and promoted neurite length significantly. Exposure to high flux density (1.37 mT) also resulted in nearly 20% enhancement of neurite directivity along the field direction. However, exposure to low flux density field (0.016 mT) had no detectable effect on neurite outgrowth. We also studied the effect of frequency at the constant flux density of 1.37 mT. In the range from 1 approximately 100 Hz, only 50 and 70 Hz pulse frequencies had significant effects on neurite outgrowth. Our study has shown that neurite outgrowth in PC12 cells is sensitive to flux density and frequency of pulsed electromagnetic field.
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Affiliation(s)
- Yang Zhang
- Department of Material Science, Faculty of Science, National University of Singapore, Singapore
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Santini MT, Rainaldi G, Indovina PL. Cellular effects of extremely low frequency (ELF) electromagnetic fields. Int J Radiat Biol 2009; 85:294-313. [PMID: 19399675 DOI: 10.1080/09553000902781097] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
PURPOSE The major areas of research that have characterised investigation of the impact of extremely low frequency (ELF) electromagnetic fields on living systems in the past 50 years are discussed. In particular, selected studies examining the role of these fields in cancer, their effects on immune and nerve cells, and the positive influence of these ELF fields on bone and nerve cells, wound healing and ischemia/reperfusion injury are explored. CONCLUSIONS The literature indicates that there is still no general agreement on the exact biological detrimental effects of ELF fields, on the physical mechanisms that may be behind these effects or on the extent to which these effects may be harmful to humans. Nonetheless, the majority of the in vitro experimental results indicate that ELF fields induce numerous types of changes in cells. Whether or not the perturbations observed at the cellular level can be directly extrapolated to negative effects in humans is still unknown. However, the myriad of effects that ELF fields have on biological systems should not be ignored when evaluating risk to humans from these fields and, consequently, in passing appropriate legislation to safeguard both the general public and professionally-exposed workers. With regard to the positive effects of these fields, the possibility of testing further their efficacy in therapeutic protocols should also not be overlooked.
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Affiliation(s)
- Maria T Santini
- Dipartimento di Ematologia, Oncologia e Medicina Molecolare, Istituto Superiore di Sanita, Viale Regina Elena, Rome.
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Continuous exposure to 900MHz GSM-modulated EMF alters morphological maturation of neural cells. Neurosci Lett 2009; 455:173-7. [PMID: 19429115 DOI: 10.1016/j.neulet.2009.03.061] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2009] [Revised: 03/02/2009] [Accepted: 03/19/2009] [Indexed: 11/22/2022]
Abstract
The effects of radiofrequency electromagnetic field (RF-EMF) exposure on neuronal phenotype maturation have been studied in two different in vitro models: murine SN56 cholinergic cell line and rat primary cortical neurons. The samples were exposed at a dose of 1W/kg at 900 MHz GSM modulated. The phenotype analysis was carried out at 48 and 72 h (24 and 48 h of SN56 cell line differentiation) or at 24, 72, 120 h (2, 4 and 6 days in vitro for cortical neurons) of exposure, on live and immunolabeled neurons, and included the morphological study of neurite emission, outgrowth and branching. Moreover, cortical neurons were studied to detect alterations in the expression pattern of cytoskeleton regulating factors, e.g. beta-thymosin, and of early genes, e.g. c-Fos and c-Jun through real-time PCR on mRNA extracted after 24h exposure to EMF. We found that RF-EMF exposure reduced the number of neurites generated by both cell systems, and this alteration correlates to increased expression of beta-thymosin mRNA.
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13
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Ahmed Z, Wieraszko A. The mechanism of magnetic field-induced increase of excitability in hippocampal neurons. Brain Res 2008; 1221:30-40. [DOI: 10.1016/j.brainres.2008.05.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2008] [Revised: 04/30/2008] [Accepted: 05/05/2008] [Indexed: 11/29/2022]
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Li GN, Hoffman-Kim D. Tissue-Engineered Platforms of Axon Guidance. TISSUE ENGINEERING PART B-REVIEWS 2008; 14:33-51. [DOI: 10.1089/teb.2007.0181] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Grace N. Li
- Department of Molecular Pharmacology, Physiology, and Biotechnology, Brown University, Providence, Rhode Island
| | - Diane Hoffman-Kim
- Department of Molecular Pharmacology, Physiology, and Biotechnology, Brown University, Providence, Rhode Island
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. ARS, . SNP, . HS. Effects of Electromagnetic Fields on Structure and Function of Rat Glioma Cell Line. ACTA ACUST UNITED AC 2006. [DOI: 10.3923/jm.2006.124.135] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Wieraszko A, Ahmed Z, Armani J, Maqsood N, Philips S, Raja H. Neurophysiological Effects Induced in the Nervous Tissue by Low-Frequency, Pulsed Magnetic Fields. ACTA ACUST UNITED AC 2005. [DOI: 10.1007/s10669-005-4277-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Wieraszko A. Amplification of evoked potentials recorded from mouse hippocampal slices by very low repetition rate pulsed magnetic fields. Bioelectromagnetics 2005; 25:537-44. [PMID: 15376238 DOI: 10.1002/bem.20044] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The influence of low repetition rate pulsed magnetic fields (LRMF) on the evoked potential (population spike) recorded from mouse hippocampal slices was investigated. LRMF were applied according to two protocols. In protocol A, LRMF applied with a constant strength (15 mT) and frequency ranging from 0.03 to 0.5 Hz resulted in an amplification of the potential. Although the frequency of 0.16 Hz was the most effective, enhancing the population spike by over 280%, it also caused an increase in spontaneous activity, seizures, and cessation of neuronal activity in 50% of the slices. In protocol B, LRMF were applied with a variable intensity (9-15 mT) and in cycles of different duration ranging from 5 to 20 min. While an increase in the amplitude of the population spike was observed in all slices exposed to LRMF applied according to protocol B, the longest exposure was the most effective. Neither seizures nor an increase in the spontaneous activity were observed in this group of the slices. These results support and extend our previous data and characterize further the relation between the pattern of applied magnetic fields and their influence on the nervous system.
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Affiliation(s)
- Andrzej Wieraszko
- Department of Biology/Program in Neuroscience, The College of Staten Island/CUNY, Staten Island, NY 10314, USA.
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Zhang Y, Ding J, Duan W, Fan W. Influence of pulsed electromagnetic field with different pulse duty cycles on neurite outgrowth in PC12 rat pheochromocytoma cells. Bioelectromagnetics 2005; 26:406-11. [PMID: 15887254 DOI: 10.1002/bem.20116] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The influence of low frequency (50 Hz repetition rate) pulsed electromagnetic field (EMF) on PC12 cell neurite outgrowth in vitro was investigated in this study. We studied the percentage of neurite bearing cells, average length of neurites, and directivity of neurite outgrowth in PC12 cells cultured for 96 h in the presence of nerve growth factor (NGF). PC12 cells were exposed in one incubator to pulsed EMF at 1.36 mT (peak value) generated by a pair of Helmholtz coils, and the control samples were placed in another identical incubator. We found that the pulse duty cycle had significant effect on neurite outgrowth. Low (10%) pulse on-time significantly inhibited the percentage of neurite bearing cells, but at the same time increased the average length of neurites, while 100% on-time (DC) had exactly the opposite effects. Furthermore, we found that neurites were prone to extend along the direction of pulsed EMF with 10% pulse on-time. Our studies show that neurite outgrowth in PC12 cells is sensitive to the pulse duty and this sensitivity was associated with NGF concentration.
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Affiliation(s)
- Y Zhang
- Department of Materials Science, National University of Singapore, Singapore
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Schimmelpfeng J, Weibezahn KF, Dertinger H. Quantification of NGF-dependent neuronal differentiation of PC-12 cells by means of neurofilament-L mRNA expression and neuronal outgrowth. J Neurosci Methods 2004; 139:299-306. [PMID: 15488244 DOI: 10.1016/j.jneumeth.2004.05.010] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2003] [Revised: 04/29/2004] [Accepted: 05/17/2004] [Indexed: 11/27/2022]
Abstract
We demonstrate that the degree of neuronal development of PC-12 cell differentiation can be quantified by the expression of neurofilament-L (NF-L) mRNA, when an optimal concentration of NGF (50 ng/ml) is used. During the first 7 days of NGF treatment, the relative amount of NF-L mRNA was found to increase continuously and to correlate with the outgrowth of neurites in a statistically significant way. Thus, mRNA expression is, under these conditions, a suitable means for reliably monitoring the differentiation of PC-12 cells as early as after 3 days of NGF treatment. The results obtained with 5 ng/ml NGF differ from those with 50 ng/ml: during the first 3 days of NGF treatment, neuronal outgrowth was less than with 50 ng/ml, although the NF-L mRNA levels did not depend significantly on NGF concentration. Beyond day 3, NF-L mRNA levels did not increase further at 5 ng/ml as opposed to 50 ng/ml NGF. These differences point to different signal transduction processes involved in neuronal differentiation at high and low NGF concentration. Expression of NF-L protein in response to NGF treatment was also demonstrated. In summary, our results stress that stable and sustained differentiation of PC-12 cells can only be achieved with 50 ng/ml NGF.
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Affiliation(s)
- J Schimmelpfeng
- Forschungszentrum Karlsruhe, Institute for Medical Engineering and Biophysics, P.O. Box 3640, D-76021 Karlsruhe, Germany.
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Hogan MV, Wieraszko A. An increase in cAMP concentration in mouse hippocampal slices exposed to low-frequency and pulsed magnetic fields. Neurosci Lett 2004; 366:43-7. [PMID: 15265587 DOI: 10.1016/j.neulet.2004.05.006] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2004] [Revised: 05/06/2004] [Accepted: 05/06/2004] [Indexed: 10/26/2022]
Abstract
Our previous studies revealed that magnetic fields amplified evoked potentials recorded from mouse hippocampal slices. In search for the mechanism of this effect, we evaluated the concentration of cAMP in slices exposed to low-frequency and pulsed magnetic fields. Low-frequency magnetic fields of 15 mT applied at 0.16 Hz for 30 min enhanced the concentration of cAMP almost three-fold. The concentration of cAMP continued to rise through the first hour after turning magnetic fields off, reaching almost a four-fold increase, and then returned to control levels at the end of the second hour. Neither static magnetic fields nor magnetic fields applied with the frequency of 0.5 Hz had any effect on cAMP concentration. The increase in cAMP levels was dependent on the strength of the magnetic field and required the presence of extracellular calcium. A pulsed magnetic field applied with variable intensity (9-15 mT) and in cycles lasting from 5 to 20 min doubled the cAMP concentration. These results support our previous electrophysiological observations and provide biochemical correlates for their interpretation.
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Affiliation(s)
- Michael V Hogan
- Clinical Laboratory Sciences, College of Allied Health Professions, University of South Alabama, SHAC 2309, 1504 Springhill Avenue, Mobile, AL 36604, USA
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Schimmelpfeng J, Weibezahn KF, Dertinger H. Neuronal outgrowth of PC-12 cells after combined treatment with nerve growth factor and a magnetic field: Influence of the induced electric field strength. Bioelectromagnetics 2004; 26:74-7. [PMID: 15605400 DOI: 10.1002/bem.20073] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
In view of possible therapeutic applications of magnetic fields, the effect of an enhancement of neuronal outgrowth at higher figures of flux density and induced field strength was investigated. On the average sinusoidal magnetic field treatment at 100 microTrms/50 Hz did not change nerve growth factor (NGF) induced neurite outgrowth to a statistically significant extent. These results suggest that further increasing the induced field strength by using either higher flux densities and/or more sophisticated wave forms might be necessary to cause the neuronal response of PC-12 cells, as seen in other experiments.
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Affiliation(s)
- J Schimmelpfeng
- Research Centre Karlsruhe, Institute for Medical Engineering and Biophysics, Karlsruhe, Germany.
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22
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Pirozzoli MC, Marino C, Lovisolo GA, Laconi C, Mosiello L, Negroni A. Effects of 50 Hz electromagnetic field exposure on apoptosis and differentiation in a neuroblastoma cell line. Bioelectromagnetics 2003; 24:510-6. [PMID: 12955756 DOI: 10.1002/bem.10130] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Experiments were carried out to assess whether a magnetic field of 50 Hz and 1 mT can influence apoptosis and proliferation in the human neuroblastoma cell line LAN-5. TUNEL assays and poly-ADP ribose polymerase (PARP) expression analysis were performed to test apoptosis induction, and the WST-1 assay was used to calculate the proliferation index in a long term exposure. No alterations were found in cellular ability to undergo programmed cell death, but a small increase in the proliferation index was evidenced after 7 days of continuous exposure. Also, a slight and transient increase of B-myb oncogene expression was detected after 5 days of exposure. Combined exposures of cells to EMF and to chemical agents which interfere with proliferation, such as the differentiative agent retinoic acid and the apoptotic inducer camptothecin, showed an antagonistic effect of magnetic fields against the differentiation of the LAN-5 cells and a protective effect towards apoptosis.
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Affiliation(s)
- M C Pirozzoli
- Ente Nuove tecnologie Energia e Ambiente (ENEA) Section of Toxicology and Biomedical Sciences, Rome, Italy
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23
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Volpe P. Interactions of zero-frequency and oscillating magnetic fields with biostructures and biosystems. Photochem Photobiol Sci 2003; 2:637-48. [PMID: 12859147 DOI: 10.1039/b212636b] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This review points to the investigations concerning the effects of zero-frequency (DC) and oscillating (AC) magnetic fields (MFs) on living matter, and especially those exerted by weak DC and low-frequency/low-intensity AC MFs. Starting from the analysis of observations on the action of natural magnetic storms (MSs) or periodic geomagnetic field (GMF) variations on bacteria, plants and animals, which led to an increasing interest in MFs in general, this survey pays particular attention to the background knowledge regarding the action of artificial MFs not only at the ionic, molecular or macromolecular levels, but also at the levels of subcellular regions, in vitro cycling cells, in situ functioning tissues or organs and total bodies or entire populations. The significance of some crucial findings concerning, for instance, the MF-dependence of the nuclear or cellular volumes, rate of cell proliferation vs. that of cell death, extent of necrosis vs. that of apoptosis and cell membrane fluidity, is judged by comparing the results obtained in a solenoid (SLD), where an MF can be added to a GMF, with those obtained in a magnetically shielded room (MSR), where the MFs can be partially attenuated or null. This comparative criterion is required because the differences detected in the behaviour of the experimental samples against that of the controls are rather small per se and also because the evaluation of the data often depends upon the peculiarity of the methodologies used. Therefore, only very small differences are observed in estimating the MF-dependence of the expression of a single gene or of the rates of total DNA replication, RNA transcription and protein translation. The review considers the MF-dependence of the interactions between host eukaryotic cells and infecting bacteria, while documentation of the harmful effects of the MFs on specific life processes is reported; cases of favourable action of the MFs on a number of biological functions are also evidenced. In the framework of studies on the origin and adaptation of life on Earth or in the Universe, theoretical insights paving the way to elucidate the mechanisms of the MF interactions with biostructures and biosystems are considered.
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Affiliation(s)
- Pietro Volpe
- Department of Biology, University of Rome Tor Vergata, Rome, Italy.
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Ikehara T, Park KH, Yamaguchi H, Hosokawa K, Houchi H, Azuma M, Minakuchi K, Kashimoto H, Kitamura M, Kinouchi Y, Yoshizaki K, Miyamoto H. Effects of a time varying strong magnetic field on release of cytosolic free Ca2+ from intracellular stores in cultured bovine adrenal chromaffin cells. Bioelectromagnetics 2002; 23:505-15. [PMID: 12224054 DOI: 10.1002/bem.10043] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
This study was made to explain the mechanisms for the effects of exposure to a time varying 1.51 T magnetic field on the intracellular Ca(2+) signaling pathway. The exposure inhibited an increase in intracellular Ca(2+) concentration ([Ca(2+)](i)) in bovine chromaffin cells induced by addition of bradykinin (BK) to a Ca(2+) free medium. The exposure did not change BK induced production of inositol 1,4,5-trisphosphate (IP(3)). [Ca(2+)](i) was markedly increased in IP(3) loaded cells, and this increase was inhibited by the magnetic field exposure. A similar increase in [Ca(2+)](i) by other drugs, which stimulated Ca(2+) release from intracellular Ca(2+) stores, was again inhibited by the same exposure. However, transmembrane Ca(2+) fluxes caused in the presence of thapsigargin were not inhibited by the magnetic field exposure in a Ca(2+) containing medium. Inhibition of the BK induced increase in [Ca(2+)](i) by the exposure for 30 min was mostly recovered 1 h after exposure ended. Our results reveal that the magnetic field exposure inhibits Ca(2+) release from intracellular Ca(2+) stores, but that BK bindings to BK receptors of the cell membrane and intracellular inositol IP(3) production are not influenced.
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Affiliation(s)
- Toshitaka Ikehara
- Department of Physiology, School of Medicine, The University of Tokushima, Kuramoto-cho, Tokushima 770-8503, Japan
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25
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Varani K, Gessi S, Merighi S, Iannotta V, Cattabriga E, Spisani S, Cadossi R, Borea PA. Effect of low frequency electromagnetic fields on A2A adenosine receptors in human neutrophils. Br J Pharmacol 2002; 136:57-66. [PMID: 11976268 PMCID: PMC1762120 DOI: 10.1038/sj.bjp.0704695] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The present study describes the effect of low frequency, low energy, pulsing electromagnetic fields (PEMFs) on A2A adenosine receptors in human neutrophils. Saturation experiments performed using a high affinity adenosine antagonist [3H]-ZM 241385 revealed a single class of binding sites in control and in PEMF-treated human neutrophils with similar affinity (KD=1.05+/-0.10 and 1.08+/-0.12 nM, respectively). Furthermore, after 1 h of exposure to PEMFs the receptor density was statistically increased (P<0.01) (Bmax =126+/-10 and 215+/-15 fmol mg-1 protein, respectively). The effect of PEMFs was specific to the A2A adenosine receptors. This effect was also intensity, time and temperature dependent. In the adenylyl cyclase assays the A2A receptor agonists, HE-NECA and NECA, increased cyclic AMP accumulation in untreated human neutrophils with an EC50 value of 43 (40 - 47) and 255 (228 - 284) nM, respectively. The capability of HE-NECA and NECA to stimulate cyclic AMP levels in human neutrophils was increased (P<0.01) after exposure to PEMFs with an EC50 value of 10(8 - 13) and 61(52 - 71) nM, respectively. In the superoxide anion (O2-) production assays HE-NECA and NECA inhibited the generation of O2- in untreated human neutrophils, with an EC50 value of 3.6(3.1 - 4.2) and of 23(20 - 27) nM, respectively. Moreover, in PEMF-treated human neutrophils, the same compounds show an EC50 value of 1.6(1.2 - 2.1) and of 6.0(4.7 - 7.5) nM respectively. These results indicate the presence of significant alterations in the expression and in the functionality of adenosine A2A receptors in human neutrophils treated with PEMFs.
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MESH Headings
- Binding, Competitive
- Cyclic AMP/biosynthesis
- Electromagnetic Fields
- Humans
- In Vitro Techniques
- Kinetics
- Neutrophils/metabolism
- Neutrophils/radiation effects
- Purinergic P1 Receptor Agonists
- Radioligand Assay
- Receptor, Adenosine A2A
- Receptors, Adrenergic, alpha-2/metabolism
- Receptors, Adrenergic, beta-2/metabolism
- Receptors, Opioid, kappa/metabolism
- Receptors, Opioid, mu/metabolism
- Receptors, Purinergic P1/metabolism
- Superoxides/metabolism
- Temperature
- Time Factors
- Up-Regulation
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Affiliation(s)
- Katia Varani
- Department of Clinical and Experimental Medicine, Pharmacology Unit, University of Ferrara, Ferrara, Italy
| | - Stefania Gessi
- Department of Clinical and Experimental Medicine, Pharmacology Unit, University of Ferrara, Ferrara, Italy
| | - Stefania Merighi
- Department of Clinical and Experimental Medicine, Pharmacology Unit, University of Ferrara, Ferrara, Italy
| | - Valeria Iannotta
- Department of Clinical and Experimental Medicine, Pharmacology Unit, University of Ferrara, Ferrara, Italy
| | - Elena Cattabriga
- Department of Clinical and Experimental Medicine, Pharmacology Unit, University of Ferrara, Ferrara, Italy
| | - Susanna Spisani
- Department of Biochemistry and Molecular Biology, University of Ferrara, Ferrara, Italy
| | | | - Pier Andrea Borea
- Department of Clinical and Experimental Medicine, Pharmacology Unit, University of Ferrara, Ferrara, Italy
- Author for correspondence:
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