Pulsed or continuous electromagnetic field induce p53/p21-mediated apoptotic signaling pathway in mouse spermatogenic cells in vitro and thus may affect male fertility

1,2-Dichloroethane induces testicular pyroptosis by activating piR-mmu-1019957/IRF7 pathway and the protective effects of melatonin

1,2-Dichloroethane (1,2-DCE) is a prevalent environmental contaminant, and our study revealed its induction of testicular toxicity in mice upon subacute exposure. Melatonin, a prominent secretory product of the pineal gland, has been shown to offer protection against pyroptosis in male reproductive toxicity. However, the exact mechanism underlying 1,2-DCE-induced testicular toxicity and the comprehensive extent of melatonin's protective effects in this regard remain largely unexplored. Therefore, we sequenced testis piRNAs in mice exposed to environmentally relevant concentrations of 1,2-DCE by 28-day dynamic inhalation, and investigated the role of key piRNAs using GC-2 spd cells. Our results showed that 1,2-DCE induced mouse testicular damage and GC-2 spd cell pyroptosis. 1,2-DCE upregulated the expression of pyroptosis-correlated proteins in both mouse testes and GC-2 spd cells. 1,2-DCE exposure caused pore formation on cellular membranes and lactate dehydrogenase leakage in GC-2 spd cells. Additionally, we identified three upregulated piRNAs in 1,2-DCE-exposed mouse testes, among which piR-mmu-1019957 induced pyroptosis in GC-2 spd cells, and its inhibition alleviated 1,2-DCE-induced pyroptosis. PiR-mmu-1019957 mimic and 1,2-DCE treatment activated the expression of interferon regulatory factor 7 (IRF7) in GC-2 spd cells. IRF7 knockdown reversed 1,2-DCE-induced cellular pyroptosis, and overexpression of piR-mmu-1019957 did not promote pyroptosis when IRF7 was inhibited. Notably, melatonin reversed 1,2-DCE-caused testicular toxicity, cellular pyroptosis, and upregulated piR-mmu-1019957 and IRF7. Collectively, our findings indicated that melatonin mitigates this effect, suggesting its potential as a therapeutic intervention against 1,2-DCE-induced male reproductive toxicity in clinical practice.

Effect of extremely low frequency electromagnetic field on the pathogenicity of Magnaporthe oryzae

Numerous works have reported that extremely low frequency electromagnetic fields (ELF-EMFs) were associated with human health; however, little is known about their effects on the occurrence of agricultural diseases. In this study, Magnaporthe oryzae was used as a model organism, and its pathogenicity under 50 Hz, 3 mT ELF-EMF was studied. Our results showed that the pathogenicity, growth rate, and conidia generation of M. oryzae were enhanced under ELF-EMF exposure. In addition, M. oryzae exposed to ELF-EMF showed enhanced tolerance to cell wall-perturbing agents sodium lauryl sulphate, and increased expression of cell wall integrity-related genes, including RAC1, CDC42, RHO2, and NOX2. In addition, the level of reactive oxygen species (ROS) and the expression level of ROS scavenger system-related gene MoAP1 increased in ELF-EMF-exposed samples, whereas the total antioxidant capacity and the activities of superoxide dismutase and catalase did not change. Results of our study demonstrated that exposure to 50 Hz, 3 mT ELF-EMF enhanced the infection ability of M. oryzae, which present new important challenges for understanding the effect of ELF-EMF exposure on farmland ecology, especially on agricultural diseases.

Genomic DNA damage induced by co-exposure to DNA damaging agents and pulsed magnetic field

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.

Genotoxic effects of electromagnetic field radiations from mobile phones

The use of wireless communication technology in mobile phones has revolutionized modern telecommunication and mobile phones have become so popular that their number exceeds the global population. Electromagnetic field radiations (EMR) are an integral part of wireless technology, which are emitted by mobile phones, mobile tower antennas, electric power stations, transmission lines, radars, microwave ovens, television sets, refrigerators, diagnostic, therapeutic, and other electronic devices. Manmade EMR sources have added to the existing burden of natural EMR human exposure arising from the Sun, cosmos, atmospheric discharges, and thunder storms. EMR including radiofrequency waves (RF) and extremely low-frequency radiation (ELF) has generated great interest as their short-term exposure causes headache, fatigue, tinnitus, concentration problems, depression, memory loss, skin irritation, sleep disorders, nausea, cardiovascular effects, chest pain, immunity, and hormonal disorders in humans, whereas long-term exposure to EMR leads to the development of cancer. The review has been written by collecting the information using various search engines including google scholar, PubMed, SciFinder, Science direct, EMF-portal, saferemr, and other websites from the internet. The main focus of this review is to delineate the mutagenic and genotoxic effects of EMR in humans and mammals. Numerous investigations revealed that exposure in the range of 0-300 GHz EMR is harmless as it did not increase micronuclei and chromosome aberrations. On the contrary, several other studies have demonstrated that exposure to EMR is genotoxic and mutagenic as it increases the frequency of micronuclei, chromosome aberrations, DNA adducts, DNA single and double strand breaks at the molecular level in vitro and in vivo. The EMR exposure induces reactive oxygen species and changes the fidelity of genes involved in signal transduction, cytoskeleton formation, and cellular metabolism.

Exposure of S. cerevisiae to pulsed magnetic field during chronological aging could induce genomic DNA damage

This study evaluates the DNA damage induced by pulsed magnetic field (MF) on S. cerevisiae cells exposed during chronological aging. Samples were exposed to 25 Hz pulsed MF (1.5mT, 8 h/day) while cells were aging chronologically. Clonogenic drop test was used to study cellular survival and the mutation frequency was evaluated by scoring the spontaneous revertant mutants. DNA damage analysis was performed after aging by electrophoresis and image analysis. Yeast cells aged during 40 days of exposure showing that pulsed MF exposure induced a premature aging. In addition, a gradual increase in spontaneous mutants was found in pulsed MF samples in relation to unexposed controls. An increase in DNA degradation, over the background level in relation to controls, was observed at the end of the exposure period. In conclusion, exposure of S. cerevisiae cells to pulsed MF during chronological aging could induce genomic DNA damage.

An overview of the biological effects of extremely low frequency electromagnetic fields combined with ionizing radiation

By growing the electrical power networks and electronic devices, electromagnetic fields (EMF) have become an inseparable part of the modern world. Considering the inevitable exposure to a various range of EMFs, especially at extremely low frequencies (ELF-EMF), investigating the biological effects of ELF-EMFs on biological systems became a global issue. The possible adverse consequences of these exposures were studied, along with their potential therapeutic capabilities. Also, their biological impacts in combination with other chemical and physical agents, specifically ionizing radiation (IR), as a co-carcinogen or as adjuvant therapy in combination with radiotherapy were explored. Here, we review the results of several in-vitro and in-vivo studies and discuss some proposed possible mechanisms of ELF-EMFs' actions in combination with IR. The results of these experiments could be fruitful to develop more precise safety standards for environmental ELF-EMFs exposures. Furthermore, it could evaluate the therapeutic capacities of ELF-EMFs alone or as an improver of radiotherapy.

The effect of electromagnetic field (EMF) exposure on synthesis and release of steroid hormones by the porcine conceptuses during the peri-implantation period

CONTEXT

Electrical devices and power systems are the sources of EM-waves which propagate everywhere in the environment.

AIMS

The study aimed to determine whether EMF induced changes in the steroidogenesis of conceptuses and whether progesterone (P4 ) may be a possible protectant against the effects of EMF radiation.

METHODS

The entire porcine conceptuses were collected during the peri-implantation period (days 15-16 of pregnancy), divided into fragments (100mg) and treated in vitro with EMF (50Hz or 120Hz, 2 or 4h exposure), and examined to determine of CYP17A1 , HSD3B1 , CYP19A3 , and HSD17B4 mRNA transcript and encoded protein abundance and the release of steroid hormones. Selected fragments of conceptuses were treated with P4 .

KEY RESULTS

In conceptuses incubated without P4 , EMF at 120Hz decreased androstenedione (A4 ) and testosterone (T) release after 2h and increased oestrone (E1 ) release at 50Hz and 120Hz after 4h exposure. In P4 -treated conceptuses, EMF (50 and 120Hz, 4h exposure) decreased CYP19A3 mRNA transcript abundance, and increased (120Hz, 2h exposure) oestradiol-17β (E2 ) release.

CONCLUSIONS

The EMF radiation alters androgen and oestrogen synthesis and release from the conceptuses of pigs during the peri-implantation period. The P4 exerts protective effects on androgens and E1 release but it sensitises the conceptuses when comes to the mechanism of oestrogen synthesis and release during EMF radiation.

IMPLICATIONS

The effect of EMF radiation on the steroidogenic pathway in conceptuses may induce disturbances in their proper development and implantation.

Cancer on-target: Selective enhancement of 3-bromopyruvate action by an electromagnetic field in vitro

Cancer is one of the leading causes of death in the modern world. Nowadays, most often treatment methods used in clinical oncology are drug therapies applied as monotherapy or combined therapy. Additionally, recent studies focus on developing approaches with the use of a drug in combination with other factors, not only chemical, to improve the probability and magnitude of therapeutic responses and reduce the possibility of chemoresistance. Such a promising factor seems to be an electromagnetic field (EMF) application. Here, we tested the effect of continuous or pulsed EMF on human cancer cells of different origin treated or not with 3-bromopyruvate, a small and powerful alkylating agent with a broad spectrum of anticancer activities. We provide strong evidence suggesting that ELF-EMF potentiates the anti-cancer activity of 3BP in human cancer cells through inhibition of TNFα secretion leading to irreversible p21/p27-dependent G2/M cell cycle arrest and finally cancer cell death. Our findings suggest a novel approach combining pharmacotherapy with ELF-EMF. In conclusion, electromagnetic field seems to be a potential modulator of anti-cancer efficacy of 3BP while combined therapy offers off-target activity. These features contribute to the development of innovative therapeutic strategies for cancer treatment.

Radiofrequency Electromagnetic Field Exposure and Apoptosis: A Scoping Review of In Vitro Studies on Mammalian Cells

In the last decades, experimental studies have been carried out to investigate the effects of radiofrequency (RF, 100 kHz–300 GHz) electromagnetic fields (EMF) exposure on the apoptotic process. As evidence-based critical evaluation of RF and apoptosis in vitro is lacking, we performed a scoping literature review with the aim of systematically mapping the research performed in this area and identifying gaps in knowledge. Eligible for inclusion were in vitro studies assessing apoptosis in mammalian cells exposed to RF-EMF, which met basic quality criteria (sham control, at least three independent experiments, appropriate dosimetry analysis and temperature monitoring). We conducted a systematic literature review and charted data in order to overview the main characteristics of included studies. From the 4362 papers retrieved with our search strategy, 121 were pertinent but, among them, only 42 met basic quality criteria. We pooled data with respect to exposure (frequency, exposure level and duration) and biological parameters (cell type, endpoint), and highlighted some qualitative trends with respect to the detection of significant effect of RF-EMF on the apoptotic process. We provided a qualitative picture of the evidence accumulated so far, and highlighted that the quality of experimental methodology still needs to be highly improved.

The guardians of germ cells; Sertoli-derived exosomes against electromagnetic field-induced oxidative stress in mouse spermatogonial stem cells

Nowadays, prolonged exposure to electromagnetic fields (EMF) has raised public concern about the detrimental potential of EMF on spermatogonial stem cells (SSCs) and spermatogenesis. Recent studies introduced the fundamental role of Sertoli cell paracrine signaling in the regulation of SSCs maintenance and differentiation in fertility preservation. Thus we investigated the therapeutic effect of Sertoli-derived exosomes (Sertoli-EXOs) as powerful paracrine mediators in SSCs subjected to EMF and its underlying mechanisms. SSCs and Sertoli cells were isolated from neonate mice testis, and identified by their specific markers. Then SSCs were exposed to 50 Hz EMF with intensity of 2.5 mT (1 h for 5 days) and supplemented with exosomes that were isolated from pre-pubertal Sertoli cells. Sertoli-EXOs were characterized and the uptake was observed by PKH26 labeling. The cell viability, colonization efficiency, reactive oxygen species (ROS) balance, cell cycle arrest and apoptosis induction were then analysed. SSCs were confirmed by immunocytochemistry (Oct4, Plzf) and Sertoli cells were identified through Sox9 and vimentin expression by immunocytochemistry and Real-time PCR (qRT-PCR), respectively. Our results demonstrated the detrimental effect of EMF via ROS accumulation that reduced the expression of catalase antioxidant, cell viability and colonization of SSCs. Also, AO/PI and flow cytometry analysis demonstrated the elevation of apoptosis in SSCs exposed to EMF in comparison with control. qRT-PCR data confirmed the up-regulation of apoptotic gene (Caspase-3) and down-regulation of SSCs specific gene (GFRα1). Consequently, the administration of Sertoli-EXOs exerted ameliorative effect on SSCs and significantly improved these changes through the regulation of oxidative stress. These findings suggest that Sertoli-EXOs have positive impact on SSCs exposed to EMF and can be useful in further investigation of Sertoli-EXOs as a novel therapeutic agent which may recover the deregulated SSCs microenvironment and spermatogenesis after exposure to EMF.

Evaluation of Pulsed Electromagnetic Field Effects: A Systematic Review and Meta-Analysis on Highlights of Two Decades of Research In Vitro Studies

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.

Mkrn2 deficiency induces teratozoospermia and male infertility through p53/PERP-mediated apoptosis in testis

The apoptosis that occurs in the immature testis under physiological conditions is necessary for male germ cell development, whereas improper activation of apoptosis can impair spermatogenesis and cause defects in reproduction. We previously demonstrated that in mice, the makorin-2 (Mkrn2) gene is expressed exclusively in the testis and its deletion leads to male infertility. To understand the potential molecular mechanism, in this study, we found that levels of apoptosis in the testis were abnormally high in the absence of Mkrn2. To identify specific gene(s) involved, we performed digital gene expression profiling (DGE) and pathway analysis via gene set enrichment analysis (GSEA) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) database, and we found that MKRN2 inhibits p53 apoptosis effector related to PMP22 (PERP) expression and that levels of the protein in sperm samples have an inverse correlation with infertility levels. GSEA additionally indicated that PERP is a negative regulator of spermatogenesis and that its ectopic expression induces male infertility. Further, Gene Expression Omnibus (GEO) dataset analysis showed that p53, upstream of PERP, was upregulated in oligoasthenoteratozoospermia (OAT). These observations suggest that Mkrn2 is crucial for protecting germ cells from excessive apoptosis and implicate Mkrn2-based suppression of the p53/PERP signaling pathway in spermatogenesis and male fertility.

Melatonin: a Potential Shield against Electromagnetic Waves

Melatonin, a vital hormone synthesized by the pineal gland, has been implicated in various physiological functions and in circadian rhythm regulation. Its role in the protection against the non-ionizing electromagnetic field (EMF), known to disrupt the body's oxidative/anti-oxidative balance, has been called into question due to inconsistent results observed across studies. This review provides the current state of knowledge on the interwoven relationship between melatonin, EMF, and oxidative stress. Based on synthesized evidence, we present a model that best describes the mechanisms underlying the protective effects of melatonin against RF/ELF-EMF induced oxidative stress. We show that the free radical scavenger activity of melatonin is enabled through reduction of the radical pair singlet-triplet conversion rate and the concentration of the triplet products. Moreover, this review aims to highlight the potential therapeutic benefits of melatonin against the detrimental effects of EMF, in general, and electromagnetic hypersensitivity (EHS), in particular.

An upward 9.4 T static magnetic field inhibits DNA synthesis and increases ROS-P53 to suppress lung cancer growth

•

Upward 9.4 T SMF exposure for 88 h significantly inhibited A549 tumor growth in mice.

•

9.4 T SMF treatment for 88 h had no severe impairment to the mice key organs or blood cell count.

•

Upward 9.4 T SMF treatment for 24 h caused A549 DNA synthesis inhibition.

•

Upward 9.4 T SMF treatment for 24 h significantly increased ROS and P53 levels, and caused G2 cell cycle arrest.

Studies have shown that 9.4 Tesla (9.4 T) high-field magnetic resonance imaging (MRI) has obvious advantages in improving image resolution and capacity, but their safety issues need to be further validated before their clinical approval. Meanwhile, emerging experimental evidences show that moderate to high intensity Static Magnetic Fields (SMFs) have some anti-cancer effects.

We examined the effects of two opposite SMF directions on lung cancer bearing mice and found when the lung cancer cell-bearing mice were treated with 9.4 T SMFs for 88 h in total, the upward 9.4 T SMF significantly inhibited A549 tumor growth (tumor growth inhibition=41%), but not the downward 9.4 T SMF. In vitro cellular analysis shows that 9.4 T upward SMF treatment for 24 h not only inhibited A549 DNA synthesis, but also significantly increased ROS and P53 levels, and arrested G2 cell cycle. Moreover, the 9.4 T SMF-treatments for 88 h had no severe impairment to the key organs or blood cell count of the mice.

Our findings demonstrated the safety of 9.4 T SMF long-term exposure for their future applications in MRI, and revealed the anti-cancer potential of the upward direction 9.4 T SMF.

Manmade Electromagnetic Fields and Oxidative Stress-Biological Effects and Consequences for Health

Concomitant with the ever-expanding use of electrical appliances and mobile communication systems, public and occupational exposure to electromagnetic fields (EMF) in the extremely-low-frequency and radiofrequency range has become a widely debated environmental risk factor for health. Radiofrequency (RF) EMF and extremely-low-frequency (ELF) MF have been classified as possibly carcinogenic to humans (Group 2B) by the International Agency for Research on Cancer (IARC). The production of reactive oxygen species (ROS), potentially leading to cellular or systemic oxidative stress, was frequently found to be influenced by EMF exposure in animals and cells. In this review, we summarize key experimental findings on oxidative stress related to EMF exposure from animal and cell studies of the last decade. The observations are discussed in the context of molecular mechanisms and functionalities relevant to health such as neurological function, genome stability, immune response, and reproduction. Most animal and many cell studies showed increased oxidative stress caused by RF-EMF and ELF-MF. In order to estimate the risk for human health by manmade exposure, experimental studies in humans and epidemiological studies need to be considered as well.

Histone H3 methylation orchestrates transcriptional program in mouse spermatogenic cell line

Changes in histone modifications always correlate with altered transcriptional activities of genes. Recent studies have shown that the mutation of certain lysine residues to methionine in the histone variant H3.3 can act as a valuable tool to reduce specific H3 methylation levels. In our study, we used the mouse spermatogenic cell line GC-2 as a model to generate cells stably expressing H3.3 K4, H3.3 K9, H3.3 K27, and H3.3 K36M. The expression of these H3.3 K-to-M mutants influenced the expression of different subsets of genes, and a total of 891 differentially expressed genes were identified through global gene expression profiling. Moreover, the H3.3 K-to-M transgenes, especially H3.3 K36M, impacted the expression of endogenous retrovirus ERVK. This study gives a global view of how different H3 modifications regulate transcriptomes in spermatogenic cell lines, and identifies potential targets of H3 modifications in male germ line.

Apoptotic Effect of 1800 MHz Electromagnetic Radiation on NIH/3T3 Cells

To investigate the effect of 1800 MHz electromagnetic radiation (EMR) on apoptosis, we exposed NIH/3T3 cells at 1800 MHz with a specific absorption rate (SAR) of 2 W/kg intermittently for 12, 24, 36, and 48 h. After exposure, Cell Counting Kit-8 (CCK-8) and flow cytometry were used to detect cell viability and apoptosis; the expression of p53, a molecule with the key role in apoptosis, was measured by real-time qPCR, western blot, and immunofluorescence; and images of the structure of the mitochondria, directly reflecting apoptosis, were captured by electron microscopy. The results showed that the viability of cells in the 12, 36, and 48 h exposure groups significantly decreased compared with the sham groups; after 48 h of exposure, the percentage of late apoptotic cells in the exposure group was significantly higher. Real-time qPCR results showed that p53 mRNA in the 48 h exposure group was 1.4-fold of that in the sham group; significant differences of p53 protein fluorescence expression were observed between the exposure groups and the sham groups after 24 h and 48 h. The mitochondrial swelling and vesicular morphology were found in the electron microscopy images after 48 h exposure. These findings demonstrated 1800 MHz, SAR 2 W/kg EMR for 48 h may cause apoptosis in NIH/3T3 cells and that this apoptosis might be attributed to mitochondrial damage and upregulation of p53 expression.

CT2A Cell Viability Modulated by Electromagnetic Fields at Extremely Low Frequency under No Thermal Effects

The effects produced by electromagnetic fields (EMFs) on human beings at extremely low frequencies (ELFs) have being investigated in the past years, across in vitro studies, using different cell lines. Nevertheless, the effects produced on cells are not clarified, and the cellular mechanisms and cell-signaling processes involved are still unknown. This situation has resulted in a division among the scientific community about the adequacy of the recommended level of exposure. In this sense, we consider that it is necessary to develop long-term exposure studies and check if the recommended levels of EMFs are under thermal effects. Hence, we exposed CT2A cells to different EMFs at different ELFs at short and long times. Our results showed frequency dependence in CT2A exposed during 24 h to a small EMF of 30 μT equal to those originated by the Earth and frequency dependence after the exposure during seven days to an EMF of 100 µT at different ELFs. Particularly, our results showed a remarkable cell viability decrease of CT2A cells exposed to EMFs of 30 Hz. Nevertheless, after analyzing the thermal effects in terms of HSP90 expression, we did not find thermal damages related to the differences in cell viability, so other crucial cellular mechanism should be involved.

Exposure to Static and Extremely-Low Frequency Electromagnetic Fields and Cellular Free Radicals

This paper summarizes studies on changes in cellular free radical activities from exposure to static and extremely-low frequency (ELF) electromagnetic fields (EMF), particularly magnetic fields. Changes in free radical activities, including levels of cellular reactive oxygen (ROS)/nitrogen (RNS) species and endogenous antioxidant enzymes and compounds that maintain physiological free radical concentrations in cells, is one of the most consistent effects of EMF exposure. These changes have been reported to affect many physiological functions such as DNA damage; immune response; inflammatory response; cell proliferation and differentiation; wound healing; neural electrical activities; and behavior. An important consideration is the effects of EMF-induced changes in free radicals on cell proliferation and differentiation. These cellular processes could affect cancer development and proper growth and development in organisms. On the other hand, they could cause selective killing of cancer cells, for instance, via the generation of the highly cytotoxic hydroxyl free radical by the Fenton Reaction. This provides a possibility of using these electromagnetic fields as a non-invasive and low side-effect cancer therapy. Static- and ELF-EMF probably play important roles in the evolution of living organisms. They are cues used in many critical survival functions, such as foraging, migration, and reproduction. Living organisms can detect and respond immediately to low environmental levels of these fields. Free radical processes are involved in some of these mechanisms. At this time, there is no credible hypothesis or mechanism that can adequately explain all the observed effects of static- and ELF-EMF on free radical processes. We are actually at the impasse that there are more questions than answers.

Entry-Prohibited Effect of kHz Pulsed Magnetic Field Upon Interaction Between SPIO Nanoparticles and Mesenchymal Stem Cells

OBJECTIVE

The interaction between superparamagnetic iron oxide (SPIO) nanoparticles and mesenchymal stem cells (MSCs) in the presence of pulsed magnetic field (PMF) has become an important area of research in recent years.

METHODS

A parameter-adjustable pulsed magnetic field was developed based on the principle of insulated gate bipolar translator transistor-controlled discharge of large capacitances. The internalizations of SPIO nanoparticles by MSCs were investigated under the treatment of PMF in both intermittent stimulation mode and continuous stimulation mode.

RESULTS

The intensities and frequencies of pulsed magnetic field can be adjustable in the range of 1.9-4.6 mT and 3-5 kHz, respectively. This PMF was safe to the MSCs. However, the uptake of SPIO nanoparticles by MSCs was significantly prohibited under the treatment of kHz-ranged PMF while the 10 Hz PMF enhanced the cellular uptake of nanoparticles. This phenomenon was relative with the magnetic effect of the PMF with different frequency.

CONCLUSION

The PMF can be used to effectively regulate the cellular uptake of SPIO nanoparticles and the mechanism lies in the magnetic effect.

SIGNIFICANCE

The interaction between SPIO nanoparticles and the MSCs is a fundamental and important issue for nanomedicine and stem cell research. Our results demonstrate that the external magnetic field can be used to regulate their interaction. We believe that this safe, facile, and flexible method will greatly promote the development and clinical translation of regenerative medicine and nanomedicine.

Geobacter sulfurreducens-inoculated bioelectrochemical system reveals the potential of metabolic current in defining the effect of extremely low-frequency electromagnetic field on living cells

The effect of extremely low-frequency electromagnetic fields (ELF-EMFs) on human health has become a worldwide concern, and no molecule/factor has been established as a measurable indicator of this effect. Diseases related to ELF-EMF are generally accompanied with energy metabolic dysfunction, and the energy in metabolism often flows in terms of electrons in all living cells. Hence, this study specifically investigated the relationship between metabolic current and ELF-EMF. By applying 0-128 Gauss ELF-EMFs to Geobacter sulfurreducens-inoculated bioelectrochemical systems, we found that metabolic current was increased and oscillated in ELF-EMF-exposed G. sulfurreducens. All effects were exposure dose dependent. Moreover, the oscillation amplitude varied linearly with the ELF-EMF strength. These results reveal that metabolic current can be used as a dosimetric indicator of the effect of ELF-EMF on living organisms, including human beings.

A comprehensive overview on utilizing electromagnetic fields in bone regenerative medicine

Stem cells are one of the most important sources to develope  a new strategy for repairing bone lesions through tissue engineering. Osteogenic differentiation of stem cells can be affected by various factors such as biological, chemical, physiological, and physical ones. The application of ELF-EMFs has been the subject of many research in bone tissue engineering and evidence suggests that this exogenous physical stimulus can promote osteogenic differentiation in several types of  cells. The purpose of this paper is to review the current knowledge on the effects of EMFs on stem cells in bone tissue engineering studies. We recapitulated and analyzed 39 articles that were focused on the application of EMFs for bone tissue engineering purposes. We tabulated scattered information from these articles for easy use and tried to provide an overview of conducted research and identify the knowledge gaps in the field.

Role of Mitochondria in the Oxidative Stress Induced by Electromagnetic Fields: Focus on Reproductive Systems

Modern technologies relying on wireless communication systems have brought increasing levels of electromagnetic field (EMF) exposure. This increased research interest in the effects of these radiations on human health. There is compelling evidence that EMFs affect cell physiology by altering redox-related processes. Considering the importance of redox milieu in the biological competence of oocyte and sperm, we reviewed the existing literature regarding the effects of EMFs on reproductive systems. Given the role of mitochondria as the main source of reactive oxygen species (ROS), we focused on the hypothesis of a mitochondrial basis of EMF-induced reproductive toxicity. MEDLINE, Web of Science, and Scopus database were examined for peer-reviewed original articles by searching for the following keywords: “extremely low frequency electromagnetic fields (ELF-EMFs),” “radiofrequency (RF),” “microwaves,” “Wi-Fi,” “mobile phone,” “oxidative stress,” “mitochondria,” “fertility,” “sperm,” “testis,” “oocyte,” “ovarian follicle,” and “embryo.” These keywords were combined with other search phrases relevant to the topic. Although we reported contradictory data due to lack of uniformity in the experimental designs, a growing body of evidence suggests that EMF exposure during spermatogenesis induces increased ROS production associated with decreased ROS scavenging activity. Numerous studies revealed the detrimental effects of EMFs from mobile phones, laptops, and other electric devices on sperm quality and provide evidence for extensive electron leakage from the mitochondrial electron transport chain as the main cause of EMF damage. In female reproductive systems, the contribution of oxidative stress to EMF-induced damages and the evidence of mitochondrial origin of ROS overproduction are reported, as well. In conclusion, mitochondria seem to play an important role as source of ROS in both male and female reproductive systems under EMF exposure. Future and more standardized studies are required for a better understanding of molecular mechanisms underlying EMF potential challenge to our reproductive system in order to improve preventive strategies.

Aloe arborescens juice prevents EMF-induced oxidative stress and thus protects from pathophysiology in the male reproductive system in vitro

More and more studies suggest that prolonged exposure to EMF may cause adverse biological effects and point directly to a significantly negative correlation between EMF and human health, especially men fertility. In our previous study, we reported that this could be related to the EMF-induced reactive oxygen species formation, followed by DNA damage, cell cycle arrest and apoptosis induction. In this study, we decided to expand our research by the search for substances which would prevent EMF-induced damage in spermatogenic cells. Such an agent seems to be Aloe arborescens Mill. juice, which was shown to possess a wide range of protective properties. The administration of aloe extract helps among others to prevent the formation of free radicals by various biochemical pathways. Therefore, the main aim of our study was to provide a significant knowledge concerning the mechanism involved in the multi-pathway cytoprotective response of aloe juice against EMF. The study was carried out in an in vitro mouse spermatogenesis pathway cell lines (GC-1 spg and GC-2 spd). Our results suggest that the aloe juice has many positive effects, especially for the cellular antioxidant systems by reducing the intracellular reactive oxygen species pool induced by EMF. In consequence, aloe juice prevents DNA damage, cell cycle arrest and therefore the viability and metabolic activity of both cell line tested are preserved. In conclusion, our study provides new insight into the underlying mechanisms through which aloe juice prevents spermatogenic cells from cytotoxic and genotoxic events.

Towards 5G communication systems: Are there health implications?

The spread of radiofrequency electromagnetic fields (RF-EMF) is rising and health effects are still under investigation. RF-EMF promote oxidative stress, a condition involved in cancer onset, in several acute and chronic diseases and in vascular homeostasis. Although some evidences are still controversial, the WHO IARC classified RF-EMF as "possible carcinogenic to humans", and more recent studies suggested reproductive, metabolic and neurologic effects of RF-EMF, which are also able to alter bacterial antibiotic resistance. In this evolving scenario, although the biological effects of 5G communication systems are very scarcely investigated, an international action plan for the development of 5G networks has started, with a forthcoming increment in devices and density of small cells, and with the future use of millimeter waves (MMW). Preliminary observations showed that MMW increase skin temperature, alter gene expression, promote cellular proliferation and synthesis of proteins linked with oxidative stress, inflammatory and metabolic processes, could generate ocular damages, affect neuro-muscular dynamics. Further studies are needed to better and independently explore the health effects of RF-EMF in general and of MMW in particular. However, available findings seem sufficient to demonstrate the existence of biomedical effects, to invoke the precautionary principle, to define exposed subjects as potentially vulnerable and to revise existing limits. An adequate knowledge of pathophysiological mechanisms linking RF-EMF exposure to health risk should also be useful in the current clinical practice, in particular in consideration of evidences pointing to extrinsic factors as heavy contributors to cancer risk and to the progressive epidemiological growth of noncommunicable diseases.