Enhancement of X-ray Induced Apoptosis by Mobile Phone-Like Radio-Frequency Electromagnetic Fields in Mouse Spermatocyte-Derived Cells

Quantitative proteomics reveals effects of environmental radiofrequency electromagnetic fields on embryonic neural stem cells

The effects of environmental radiofrequency electromagnetic fields (RF-EMF) on embryonic neural stem cells have not been determined, particularly at the proteomic level. This study aims to elucidate the effects of environmental levels of RF-EMF radiation on embryonic neural stem cells. Neuroectodermal stem cells (NE-4C cells) were randomly divided into a sham group and an RF group, which were sham-exposed and continuously exposed to a 1950 MHz RF-EMF at 2 W/kg for 48 h. After exposure, cell proliferation was determined by a Cell Counting Kit-8 (CCK8) assay, the cell cycle distribution and apoptosis were measured by flow cytometry, protein abundance was detected by liquid chromatography-tandem mass spectrometry (LC-MS/MS), and mRNA expression was evaluated by quantitative reverse transcription polymerase chain reaction (qRT-PCR). We did not detect differences in cell proliferation, cell cycle distribution, and apoptosis between the two groups. However, we detected differences in the abundance of 23 proteins between the two groups, and some of these differences were consistent with alterations in transcript levels determined by qRT-PCR (P < 0.05). A bioinformatics analysis indicated that the differentially regulated proteins were mainly enriched in 'localization' in the cellular process category; however, no significant pathway alterations in NE-4C cells were detected. We conclude that under the experimental conditions, low-level RF-EMF exposure was not neurotoxic but could induce minor changes in the abundance of some proteins involved in neurodevelopment or brain function.

Protective Effects of Polydatin on Reproductive Injury Induced by Ionizing Radiation

The reproductive system is vulnerable to ionizing radiation, which is a hot research topic at present. We tested the effect of polydatin on spermatocytes(GC-1 cells) after X-ray irradiation. The reproductive damage model of C.elegans was established by 60Coγ-ray, and the protective effect of polydatin on reproductive damage caused by ionizing radiation was evaluated. We quantified the ROS levels of GC-1 cells and C.elegans after irradiation with polydatin and evaluated the anti-apoptosis effect of polydatin at proper concentration. Differential genes of C.elegans reproductive damage were screened out from transcriptome sequencing results and comparable GEO datasets. It was proved that 100μM polydatin significantly reduced the apoptosis of GC-1 cells induced by 2 Gy X-ray. In addition, the longevity, reproductive capacity, germ cell apoptosis and spawning and hatching capacity of polydatin were tested. The results showed that 100 μM polydatin content significantly increased the influence of 50 Gy 60Coγ-ray on reproductive capacity of C.elegans. Quantitative analysis of mRNA and protein levels of apoptosis-related genes and reproductive-related genes by qRT-PCR and Western blotcon firmed that polydatin with appropriate dosage had good protective effects on reproductive damage caused by radiation, which laid a foundation for the application research of polydatin in radiation protection.

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.

Acute and Chronic Exposure to 900 MHz Radio Frequency Radiation Activates p38/JNK-mediated MAPK Pathway in Rat Testis

The use of electronic devices such as mobile phones has had a long stretch of rapid growth all over the world. Therefore, exposure to radio frequency radiation (RFR) has increased enormously. Here, we aimed to assess the balance between cell death and proliferation and also investigate the involvement of the JNK/p38 MAPK signaling pathway in the testis of rats exposed to 900 MHz RFR in acute and chronic periods (2 h/day, 5 days/week) for 1 or 10 weeks, respectively. The expression of proliferating cell nuclear antigen (PCNA), Bcl-xL, cleaved caspase-3, phosphorylated-JNK (p-JNK), and phosphorylated-p38 (p-p38) was analyzed in line with histopathology and TUNEL analysis in rat testis. There were no histopathological differences between sham and RFR groups in the acute and chronic groups. PCNA expression was not altered between groups in both periods. However, alterations for cleaved caspase-3 and Bcl-xL were observed depending on the exposure period. TUNEL analysis showed a significant increase in the RFR group in the acute period, whereas no difference in the chronic groups for the apoptotic index was reported. In addition, both p-p38 and p-JNK protein expressions increased significantly in RFR groups in both periods. Our study indicated that 900 MHz RFR might result in alterations during acute period exposure for several parameters, but this can be ameliorated in the chronic period in rat testis. Here, we also report the involvement of the p38/JNK-mediated MAPK pathway after exposure to 900 MHz RFR. Hence, this information might shed light in future studies toward detailed molecular mechanisms in male reproduction and infertility.

Cathodal tDCS exerts neuroprotective effect in rat brain after acute ischemic stroke

BACKGROUND

Transcranial direct current stimulation (tDCS) is a non-invasive brain modulation technique that has been proved to exert beneficial effects in the acute phase of stroke. To explore the underlying mechanism, we investigated the neuroprotective effects of cathodal tDCS on brain injury caused by middle cerebral artery occlusion (MCAO).

RESULTS

We established the MCAO model and sham MCAO model with an epicranial electrode implanted adult male Sprague-Dawley rats, and then they were randomly divided into four groups (MCAO + tDCS, MCAO + sham tDCS (Sham), Control + tDCS and Control + Sham group). In this study, the severity degree of neurological deficit, the morphology of brain damage, the apoptosis, the level of neuron-specific enolase and inflammatory factors, the activation of glial cells was detected. The results showed that cathodal tDCS significantly improved the level of neurological deficit and the brain morphology, reduced the brain damage area and apoptotic index, and increased the number of Nissl body in MCAO rats, compared with MCAO + Sham group. Meanwhile, the high level of NSE, inflammatory factors, Caspase 3 and Bax/Bcl2 ratio in MCAO rats was reduced by cathodal tDCS. Additionally, cathodal tDCS inhibited the activation of astrocyte and microglia induced by MCAO. No difference was found in two Control groups.

CONCLUSION

Our results suggested that cathodal tDCS could accelerate the recovery of neurologic deficit and brain damage caused by MCAO. The inhibition of neuroinflammation and apoptosis resulted from cathodal tDCS may be involved in the neuroprotective process.