Selenium supplementation ameliorates electromagnetic field-induced oxidative stress in the HEK293 cells

Ubiquitous extremely low frequency electromagnetic fields induces anxiety-like behavior: mechanistic perspectives

Anxiety is an adaptive condition characterized by heightened uneasiness, which in the long term can cause complications such as reducing the quality of life and problems related to the mental and physical health. Concerns have been raised regarding the potential dangers of extremely low frequency electromagnetic fields (ELF-EMF) ranging from 3 to 3000 Hz, which are omnipresent in our daily lives and there have been studies about the anxiogenic effects of these fields. Studies conducted in this specific area has revealed that ELF-EMF can have an impact on various brain regions, such as the hippocampus. In conclusion, studies have shown that ELF-EMF can interfere with hippocampus-prefrontal cortex pathway, inducing anxiety behavior. Also, ELF-EMF may initiate anxiety behavior by generating oxidative stress in hypothalamus and hippocampus. Moreover, ELF-EMF may induce anxiety behavior by reducing hippocampus neuroplasticity and increasing the NMDA2A receptor expression in the hippocampus. Furthermore, supplementation with antioxidants could serve as an effective protective measure against the adverse effects of FLF-FMF in relation to anxiety behavior.

Selenomethionine modulates the JAK2 / STAT3 / A20 pathway through oxidative stress to alleviate LPS-induced pyroptosis and inflammation in chicken hearts

Selenium (Se) is involved in many physiopathologic processes in humans and animals and is strongly associated with the development of heart disease. Lipopolysaccharides (LPS) are cell wall components of gram-negative bacteria that are present in large quantities during environmental pollution. To investigate the mechanism of LPS-induced cardiac injury and the efficacy of the therapeutic effect of SeMet on LPS, a chicken model supplemented with selenomethionine (SeMet) and/or LPS treatment, as well as a primary chicken embryo cardiomyocyte model with the combined effect of SeMet / JAK2 inhibitor (INCB018424) and/or LPS were established in this experiment. CCK8 kit, Trypan blue staining, DCFH-DA staining, oxidative stress kits, immunofluorescence staining, LDH kit, real-time fluorescence quantitative PCR, and western blot were used. The results proved that LPS exposure led to ROS explosion, hindered the antioxidant system, promoted the expression of the JAK2 pathway, and increased the expression of genes involved in the pyroptosis pathway, inflammatory factors, and heat shock proteins (HSPs). Upon co-treatment with SeMet and LPS, SeMet reduced LPS-induced pyroptosis and inflammation and restored the expression of HSPs by inhibiting the ROS burst and modulating the antioxidant capacity. Co-treatment with INCB018424 and LPS resulted in inhibited of the JAK2 pathway, attenuating pyroptosis, inflammation, and high expression of HSPs. Thus, LPS induced pyroptosis, inflammation, and changes in HSPs activity by activating of the JAK2 / STAT3 / A20 signaling axis in chicken hearts. Moreover, SeMet has a positive effect on LPS-induced injury. This work further provides a theoretical basis for treating cardiac injury by SeMet.

Assessing the effect of selenium on cyclin D1 level and nuclear factor kappa b activity in NIH/3T3 fibroblast cells at 2100 MHz electromagnetic field exposure

Although there are numerous studies on the health impacts of electromagnetic field (EMF) of mobile phone operation frequency 2100 MHz, the published works present contradicting results. Long-term exposure to mobile phone frequencies has unclear health hazards. Therefore, it is important to investigate the molecular mechanism of possible biological effects in mobile phone exposure and to determine the corresponding biological markers. Towards this end, this study was designed to assess the effect of 200 nM selenium (Se) on cell viability% [trypan blue], cell cycle biomarker [cyclin D1] and the transcription factor [nuclear factor kappa b (NF-κB)] in NIH/3T3 fibroblast cells when exposed to 2100 MHz mobile phone frequency. When 2100 MHz EMF was exposed to NIH/3T3 fibroblast cells, the cell viability% was reduced, whereas cyclin D1 level and NF-kB activity increased. Also we show that Se supplementation decreases the effects of 2100 MHz EMF on these parameters. Although future studies will be required to investigate the biological effects of EMF emitted by mobile phones, the results obtained here provide an insight into the molecular mechanisms and specifically underlying selenium's protective effect against 2100 MHz EMF exposure.

The HL-60 human promyelocytic cell line constitutes an effective in vitro model for evaluating toxicity, oxidative stress and necrosis/apoptosis after exposure to black carbon particles and 2.45 GHz radio frequency

The cellular and molecular mechanisms by which atmospheric pollution from particulate matter and/or electromagnetic fields (EMFs) may prove harmful to human health have not been extensively researched. We analyzed whether the combined action of EMFs and black carbon (BC) particles induced cell damage and a pro-apoptotic response in the HL-60 promyelocytic cell line when exposed to 2.45 GHz radio frequency (RF) radiation in a gigahertz transverse electromagnetic (GTEM) chamber at sub-thermal specific absorption rate (SAR) levels. RF and BC induced moderately significant levels of cell damage in the first 8 or 24 h for all exposure times/doses and much greater damage after 48 h irradiation and the higher dose of BC. We observed a clear antiproliferative effect that increased with RF exposure time and BC dose. Oxidative stress or ROS production increased with time (24 or 48 h of radiation), BC dose and the combination of both. Significant differences between the proportion of damaged and healthy cells were observed in all groups. Both radiation and BC participated separately and jointly in triggering necrosis and apoptosis in a programmed way. Oxidative-antioxidant action activated mitochondrial anti-apoptotic BCL2a gene expression after 24 h irradiation and exposure to BC. After irradiation of the cells for 48 h, expression of FASR cell death receptors was activated, precipitating the onset of pro-apoptotic phenomena and expression and intracellular activity of caspase-3 in the mitochondrial pathways, all of which can lead to cell death. Our results indicate that the interaction between BC and RF modifies the immune response in the human promyelocytic cell line and that these cells had two fates mediated by different pathways: necrosis and mitochondria-caspase dependent apoptosis. The findings may be important in regard to antimicrobial, inflammatory and autoimmune responses in humans.

Evaluation of trace elements in essential thrombocytosis and reactive thrombocytosis

BACKGROUND

Trace elements (TE) are vital for cellular mechanisms at biological, chemical and molecular levels. The effects of TE in diagnosis, progression and treatment of essential thrombocytosis (ET), which is one of the chronic myeloproliferative neoplasms is a rare clonal stem cell disease characterized by increased thrombocyte numbers with impaired function, have not been elucidated in detail yet. The aim of the present study was to investigate the effects of TE alterations in an ET model and the efficacy of TE in ET treatment protocol by means of a vast number of TE.

METHODS

Study groups were categorized as patients with ET diagnosis (ET group, n:30), patients with reactive thrombocytosis secondary to iron deficiency anemia (IDA-RT) (IDA-RT group, n:30) and healthy controls (HC group, n:30). Serum levels of copper (Cu), iron (Fe), cobalt (Co), chromium (Cr), aluminum (Al), silicon (Si), nickel (Ni), zinc (Zn), selenium (Se), manganese (Mn), boron (B) and magnesium (Mg) were analyzed utilizing inductively coupled plasma-optical emission spectrophotometer instrument (ICP-OES). Statistical analysis was evaluated using SPSS 23.0.

RESULTS

ET group had statistically higher serum levels of Co and Mg (p < 0.05), Ni and Mn (p < 0.001), and lower Si (p < 0.05) than IDA-RT group. ET group had statistically higher serum levels of Co and Mn (p < 0.05), and Ni (p < 0.001), and lower Al, Si and Se (p < 0.001) than HC group. Serum levels of Fe, Al and Se (p < 0.001), and Mg (p < 0.01), and Zn (p < 0.05) in IDA-RT group were significantly lower than HC group.

CONCLUSION

This novel study pointed out that alterations of many serum TE by means of both increment or decrement might have close relationship with mechanisms and complications of ET onset and follow-up. We consider that further research of TE would elucidate ethiopathogenesis and prognosis of ET. Thus, analysis of serum trace elements in essential thrombocytosis patients may be an important protocol by means of diagnosis, treatment and follow-up intervals.

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.

Plasma selenium and the risk of first stroke in adults with hypertension: a secondary analysis of the China Stroke Primary Prevention Trial

BACKGROUND

Previous studies have indicated that selenium (Se) may play an important role in cardio-cerebrovascular disease. However, the relation between circulating selenium and risk of first stroke remains inconclusive.

OBJECTIVES

We conducted a secondary analysis of the China Stroke Primary Prevention Trial (CSPPT), using a nested case-control design, and aimed to investigate the correlation between Se concentration and first stroke risk in adults with hypertension and examine the potential effect modifiers.

METHODS

In the CSPPT, a total of 20,702 adults with hypertension were randomly assigned to a double-blind daily treatment with either 10 mg enalapril and 0.8 mg folic acid or 10 mg enalapril alone. A total of 618 first stroke cases and 618 controls matched for age, sex, treatment group, and study site were included in this study.

RESULTS

During a median follow-up duration of 4.5 y (IQR: 4.2-4.6 y), there was a significant inverse association between plasma Se and the risk of first stroke (per SD increment; adjusted OR: 0.81; 95% CI: 0.68, 0.96) and ischemic stroke (per SD increment; adjusted OR: 0.76; 95% CI: 0.62, 0.93). Furthermore, a stronger inverse association between plasma Se and first stroke was observed in participants with higher folate concentrations at baseline [≥7.7 ng/mL (median), adjusted OR: 0.67; 95% CI: 0.54, 0.85, compared with <7.7 ng/mL, adjusted OR: 0.98; 95% CI: 0.80, 1.21; P-interaction = 0.008] and those with higher time-averaged systolic blood pressure (SBP) over the treatment period (≥140 mm Hg, adjusted OR: 0.71; 95% CI: 0.58, 0.86, compared with <140 mm Hg, adjusted OR: 0.96; 95% CI: 0.77, 1.20; P-interaction = 0.023).

CONCLUSIONS

There was a significant inverse association between plasma Se and risk of first stroke in Chinese adults with hypertension, especially among those with higher baseline folate concentrations and those with higher time-averaged SBP over the treatment period. This trial was registered at clinicaltrials.gov as NCT00794885.

Selenium-modified calcium phosphate cement can accelerate bone regeneration of osteoporotic bone defect

OBJECTIVE

The purpose is to observe whether local administration with selenium (Se) can enhance the efficacy of calcium phosphate cement (CPC) in the treatment of osteoporotic bone defects.

METHODS

Thirty ovariectomized (OVX) rats with two defects were generated and randomly allocated into the following graft study groups: (1) OVX group (n = 10), (2) CPC group (n = 10); and (3) Se-CPC group (n = 10). Then, these selenium-modified calcium phosphate cement (Se-CPC) scaffolds were implanted into the femoral epiphysis bone defect model of OVX rats for 12 weeks. Micro-CT, history, western blot and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis were used to observe the therapeutic effect and to explore the possible mechanism.

RESULT

Micro-CT and histological analysis evaluation showed that the Se-CPC group presented the strongest effect on bone regeneration and bone mineralization when compared with the CPC group and the OVX group. Protein expressions showed that the oxidative stress protein expressions, such as SOD2 and GPX1 of the Se-CPC group, are significantly higher than those of the OVX group and the CPC group, while Se-CPC remarkably reduced the expression of CAT. RT-qPCR analysis showed that the Se-CPC group displayed more OPG than the OVX and CPC groups (p < 0.05), while Se-CPC exhibited less RANKL than the OVX and CPC groups (p < 0.05).

CONCLUSION

Our current study demonstrated that Se-CPC is a scheme for rapid repair of femoral condylar defects, and these effects may be achieved by inhibiting local oxidative stress and through OPG/RANKL signaling pathway.

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.

Protective Effects of Smilax glabra Roxb. Against Lead-Induced Renal Oxidative Stress, Inflammation and Apoptosis in Weaning Rats and HEK-293 Cells

Lead (Pb) is an important environmental pollutant. Oxidative stress and the inflammatory response have been postulated as mechanisms involved in lead-induced renal damage. Smilax glabra Roxb. has been used for treatment of heavy-metal poisoning in China for 500 years. We investigated S. glabra flavonoids extract (SGF) could attenuate lead acetate-induced nephrotoxicity in weaning rats and human embryonic kidney (HEK)-293 cells, and investigated the possible mechanisms. Compared with Pb exposed group of weaning rats, SGF could significantly promote lead excretion in the blood and kidney, and increase the content of the renal-function indicators blood urea nitrogen, serum uric acid, and serum creatinine. SGF could improve the glomerular filtration rate (GFR) and histologic changes in the kidneys of weaning rats exposed to Pb. SGF could also reduce lead-induced cytotoxicity, improve DNA damage-induced apoptosis and cleaved caspase-3-mediated apoptosis in HEK-293 cells stimulated with Pb. SGF significantly increased the activity of the antioxidant enzymes superoxide dismutase, glutathione peroxidase and catalase, and decreased excessive release of reactive oxygen species (ROS) and malondialdehyde in the kidneys of the weaning rats and in HEK-293 cells. The antioxidant mechanism of SGF related to activation of the Kelch-like ECH-associated protein 1/nuclear-factor-E2-related factor 2/hemeoxygenase-1(Keap1/Nrf2/HO-1) pathway. SGF could inhibit secretion of interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α induced by Pb in vivo and in vitro. The anti-inflammatory mechanism of SGF related to inhibition of ROS and pro-inflammatory cytokines triggered the nuclear factor-kappa B (NF-κB) pathway through blockade of inhibitors of I-κB degradation, phosphorylation of NF-κB p65, and nuclear translocation of p65. Our findings indicate that SGF could be a natural antioxidant and anti-inflammatory agent for treating lead-induced nephrotoxicity.

Selenium protects against LPS-induced MC3T3-E1 cells apoptosis through modulation of microRNA-155 and PI3K/Akt signaling pathways

Bone infection or osteomyelitis is usually a complication of inflammation-related traumatic bone injury. Selenium has been shown to have potential cytoprotective effects and the ability to reduce oxidative stress and apoptotic events in osteomyelitis, but the exact mechanism remains unclear. Here, we used LPS-induced apoptotic MC3T3-E1 cells and aimed to confirm selenium's protective effect on cell apoptosis as well as to investigate the underlying mechanisms of this role. Our investigation confirmed selenium-mediated inhibition of LPS-induced cell apoptosis and ROS accumulation in MC3T3-E1 cells. Upon selenium treatment, the bcl-2 levels were upregulated, while the levels of Bax and cyto-C were down-regulated. Furthermore, these effects were accompanied by the suppression of miR-155 and the phosphorylation of protein kinase B (Akt). A more in-depth study demonstrated that LY294002 (a specific inhibitor of PI3K), abolished the selenium-mediated cytoprotective effect of MC3T3-E1 cells against LPS-induced injury and down-regulation of miR-155. In general, these results demonstrated that selenium exerts a cytoprotective effect by attenuating cell apoptosis and oxidative damage via a PI3K/Akt/miR-155-dependent mechanism.

Kaempferol can be used as the single antioxidant in the in vitro culture medium, stimulating sheep secondary follicle development through the phosphatidylinositol 3-kinase signaling pathway

This study evaluated the effect of addition of kaempferol alone or combined with other antioxidants (transferrin, selenium and ascorbic acid) on in vitro culture of sheep isolated secondary follicles and if PI3K pathway is involved in kaempferol action. Secondary follicles were isolated and cultured for 12 days in α-Minimal Essential Medium (α-MEM) supplemented with BSA, insulin, glutamine and hypoxanthine (α-MEM: antioxidant free-medium) or in this medium also added by transferrin, selenium and ascorbic acid (AO: base medium with antioxidants). Moreover, different concentrations of kaempferol (0.1; 1 or 10 μM) were added to the different base media (α-MEM or AO). After culture, glutathione (GSH) levels, mitochondrial activity and meiotic resumption were evaluated. In addition, inhibition of PI3K activity was performed through pretreatment in medium supplemented with LY294002. After 12 days, the percentage of normal follicles was higher (P < 0.05) in AO base medium than the other treatments and similar (P > 0.05) to α-MEM supplemented with 1 or 10 μM kaempferol Moreover, α-MEM plus 1 or 10 μM kaempferol and AO medium showed similar (P > 0.05) follicular diameter, fully-grown oocytes, and GSH levels. However, at the end of the culture, antrum formation was higher (P < 0.05) in α-MEM + 1 μM kaempferol than in AO, and similar (P > 0.05) to α-MEM + 10 μM kaempferol. In addition, oocytes cultured in α-MEM supplemented with 1 μM kaempferol showed greater (P < 0.05) levels of active mitochondria than α-MEM + 10 μM kaempferol and AO medium. The rates of meiotic resumption were similar (P > 0.05) among α-MEM + 1 μM kaempferol and AO medium. LY294002 significantly inhibited antrum formation, follicular diameter and the percentage of fully grown oocytes stimulated by 1 μM kaempferol. In conclusion, 1 μM kaempferol can be used as the single antioxidant present in the base medium, replacing the addition of transferrin, selenium and ascorbic acid during in vitro culture of ovine secondary follicles, maintaining follicular survival, increasing active mitochondria levels, and promoting the oocyte meiotic resumption. Moreover, the development of the ovine secondary follicle stimulated by kaempferol is mediated by PI3K pathway.