Effect of acute millimeter wave exposure on dopamine metabolism of NGF-treated PC12 cells

Transcriptional landscape of human keratinocyte models exposed to 60-GHz millimeter-waves

The use of millimeter waves (MMW) will exponentially grow in the coming years due to their future utilization in 5G/6G networks. The question of possible biological effects at these frequencies has been raised. In this present study, we aimed to investigate gene expression changes under exposure to MMW using the Bulk RNA Barcoding and sequencing (BRB-seq) technology. To address this issue, three exposure scenarios were performed aiming at: i) comparing the cellular response of two primary culture of keratinocytes (HEK and NHEK) and one keratinocyte derivate cell line (HaCaT) exposed to MMW; ii) exploring the incident power density dose-effect on gene expression in HaCaT cell line; and, iii) studying the exposure duration at the new ICNIRP exposure limit for the general population. With the exception of heat effect induced by high power MMW (over 10 mW/cm2), those exposure scenarios have not enabled us to demonstrate important gene expression changes in the different cell populations studied. Very few differentially genes were observed between MMW exposed samples and heat shock control, and most of them were significantly associated with heat shock response that may reflect small differences in the heat generation. Together these results show that acute exposure to MMW has no effects on the transcriptional landscape of human keratinocyte models under athermal conditions.

Recent advances and research progress on microsystems and bioeffects of terahertz neuromodulation

Terahertz waves can interact with the nervous system of organisms under certain conditions. Compared to common optical modulation methods, terahertz waves have the advantages of low photon energy and low risk; therefore, the use of terahertz waves to regulate the nervous system is a promising new method of neuromodulation. However, most of the research has focused on the use of terahertz technology for biodetection, while relatively little research has been carried out on the biological effects of terahertz radiation on the nervous system, and there are almost no review papers on this topic. In the present article, we begin by reviewing principles and objects of research regarding the biological effects of terahertz radiation and summarizing the current state of related research from a variety of aspects, including the bioeffects of terahertz radiation on neurons in vivo and in vitro, novel regulation and detection methods with terahertz radiation devices and neural microelectrode arrays, and theoretical simulations of neural information encoding and decoding. In addition, we discuss the main problems and their possible causes and give some recommendations on possible future breakthroughs. This paper will provide insight and assistance to researchers in the fields of neuroscience, terahertz technology and biomedicine.

Nanoscale Zinc-Based Metal-Organic Frameworks Induce Neurotoxicity by Disturbing the Metabolism of Catecholamine Neurotransmitters

As a group of new nanomaterials, nanoscale metal-organic frameworks (MOFs) are widely applied in the biomedical field, exerting unknown risks to the human body, especially the central nervous system. Herein, the impacts of MOF-74-Zn nanoparticles on neurological behaviors and neurotransmitter metabolism are explored in both in vivo and in vitro assays modeled by C57BL/6 mice and PC12 cells, respectively. The mice exhibit increased negative-like behaviors, as demonstrated by the observed decrease in exploring behaviors and increase in despair-like behaviors in the open field test and forced swimming test after exposure to low doses of MOF-74-Zn nanoparticles. Disorders in the catecholamine neurotransmitter metabolism may be responsible for the MOF-74-Zn-induced abnormal behaviors. Part of the reason for this is the inhibition of neurotransmitter synthesis caused by restrained neurite extension. In addition, MOF-74-Zn promotes the translocation of more calcium into the cytoplasm, accelerating the release and uptake and finally resulting in an imbalance between synthesis and catabolism. Taken together, the results from this study indicate the human toxicity risks of nanoscale low-toxicity metal-based MOFs and provide valuable insight into the rational and safe use of MOF nanomaterials.

Physiological effects of millimeter-waves on skin and skin cells: an overview of the to-date published studies

The currently ongoing deployment if the fifth generation of the wireless communication technology, the 5G technology, has reignited the health debate around the new kind of radiation that will be used/emitted by the 5G devices and networks - the millimeter-waves. The new aspect of the 5G technology, that is of concern to some of the future users, is that both, antennas and devices will be continuously in a very close proximity of the users' bodies. Skin is the only organ of the human body, besides the eyes, that will be directly exposed to the mm-waves of the 5G technology. However, the whole scientific evidence on the possible effects of millimeter-waves on skin and skin cells, currently consists of only some 99 studies. This clearly indicates that the scientific evidence concerning the possible effects of millimeter-waves on humans is insufficient to devise science-based exposure limits and to develop science-based human health policies. The sufficient research has not been done and, therefore, precautionary measures should be considered for the deployment of the 5G, before the sufficient number of quality research studies will be executed and health risk, or lack of it, scientifically established.

5G Wireless Communication and Health Effects-A Pragmatic Review Based on Available Studies Regarding 6 to 100 GHz

The introduction of the fifth generation (5G) of wireless communication will increase the number of high-frequency-powered base stations and other devices. The question is if such higher frequencies (in this review, 6-100 GHz, millimeter waves, MMW) can have a health impact. This review analyzed 94 relevant publications performing in vivo or in vitro investigations. Each study was characterized for: study type (in vivo, in vitro), biological material (species, cell type, etc.), biological endpoint, exposure (frequency, exposure duration, power density), results, and certain quality criteria. Eighty percent of the in vivo studies showed responses to exposure, while 58% of the in vitro studies demonstrated effects. The responses affected all biological endpoints studied. There was no consistent relationship between power density, exposure duration, or frequency, and exposure effects. The available studies do not provide adequate and sufficient information for a meaningful safety assessment, or for the question about non-thermal effects. There is a need for research regarding local heat developments on small surfaces, e.g., skin or the eye, and on any environmental impact. Our quality analysis shows that for future studies to be useful for safety assessment, design and implementation need to be significantly improved.

Long-term exposure to a 40-GHz electromagnetic field does not affect genotoxicity or heat shock protein expression in HCE-T or SRA01/04 cells

Millimeter waves are used in various fields, and the risks of this wavelength range for human health must be carefully evaluated. In this study, we investigated the effects of millimeter waves on genotoxicity and heat shock protein expression in human corneal epithelial (HCE-T) and human lens epithelial (SRA01/04) cells. We exposed the cells to 40-GHz millimeter waves at 1 mW/cm2 for 24 h. We observed no statistically significant increase in the micronucleus (MN) frequency or the level of DNA strand breaks in cells exposed to 40-GHz millimeter waves relative to sham-exposed and incubator controls. Heat shock protein (Hsp) expression also exhibited no statistically significant response to the 40-GHz exposure. These results indicate that exposure to 40 GHz millimeter waves under these conditions has little or no effect on MN formation, DNA strand breaks, or Hsp expression in HCE-T or SRA01/04 cells.

Staphylococcus aureus induces DNA damage in host cell

Staphylococcus aureus causes serious medical problems in human and animals. Here we show that S. aureus can compromise host genomic integrity as indicated by bacteria-induced histone H2AX phosphorylation, a marker of DNA double strand breaks (DSBs), in human cervix cancer HeLa and osteoblast-like MG-63 cells. This DNA damage is mediated by alpha phenol-soluble modulins (PSMα_1–4), while a specific class of lipoproteins (Lpls), encoded on a pathogenicity island in S. aureus, dampens the H2AX phosphorylation thus counteracting the DNA damage. This DNA damage is mediated by reactive oxygen species (ROS), which promotes oxidation of guanine forming 7,8-dihydro-8-oxoguanine (8-oxoG). DNA damage is followed by the induction of DNA repair that involves the ATM kinase-signaling pathway. An examination of S. aureus strains, isolated from the same patient during acute initial and recurrent bone and joint infections (BJI), showed that recurrent strains produce lower amounts of Lpls, induce stronger DNA-damage and prompt the G2/M transition delay to a greater extent that suggest an involvement of these mechanisms in adaptive processes of bacteria during chronicization. Our findings redefine our understanding of mechanisms of S. aureus-host interaction and suggest that the balance between the levels of PSMα and Lpls expression impacts the persistence of the infection.

Analysis of Gene Expression and Neuronal Phenotype in Neuroscreen-1 (NS-1) Cells

Neuroscreen-1 (NS-1) a sub-clone of pheochromocytoma (PC12) cell is gaining broad acceptance as in vitro neuronal model for biochemical and phenotypic assays due to robust growth and differentiation profiles. However, the molecular characteristics of the cell remains to be documented. In this study, we performed comparative analysis for expression of neuronal marker genes in undifferentiated and nerve growth factor (NGF) differentiated NS-1 and PC12 by qPCR and immunoblot assays. We show that differentiation of NS-1 occurred under low concentrations of NGF relative to PC12. Cell growth also occurred more rapidly in NS-1. Transcriptional analysis of neuronal marker genes showed comparable expression of tyrosine receptor kinases (Ntrk1, Ntrk2, NGFR/p75NTR) and muscarinic acetylcholine (Chrm1, Chrm2, Chrm3, Chrm4) receptors in unspecialized cells. Ntrk2, adenosine receptors (Adora1, Adora2A) and choline acetyltransferase (ChAT) were altered in undifferentiated NS-1. In contrast, Ntrk1, Ntrk2, Chrm2 transcripts were vastly increased in NS-1 with NGF exposure, while Ntrk3, Adora1 and Adora2A transcripts were reduced. In differentiated PC12, Chrm4 and ChAT were markedly upregulated. Our data suggests that differences in morphological and phenotypic characteristics that distinguish NS-1 from PC12 is likely the product of altered gene expression. Furthermore, expression of neuron type genes in NS-1 support its use as an alternative model to PC12.