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A shielded geomagnetic field, also called the hypomagnetic field (HMF), interferes with the metabolic processes of various cells and animals exhibiting diverse effects in different models, however, its underlying mechanism remains largely unknown. In this study, we assessed the effect on the energy metabolism of SH-SY5Y cells in HMF and found that HMF-induced cell proliferation depends on glucose supply. HMF promoted SH-SY5Y cell proliferation by increasing glucose consumption rate via up-regulating anaerobic glycolysis in the cells. Increased activity of LDH, a key member of glycolysis, was possibly a direct response to HMF-induced cell proliferation. Thus, we unveiled a novel subcellular mechanism underlying the HMF-induced cellular response: the up-regulation of anaerobic glycolysis and repression of oxidative stress shifted cellular metabolism more towards the Warburg effect commonly observed in cancer metabolism. We suggest that cellular metabolic profiles of various cell types may determine HMF-induced cellular effects, and a magnetic field can be applied as a non-invasive regulator of cell metabolism.

Hypomagnetic fields (HMF), that is, the elimination of the geomagnetic field (GMF), are a risk factor to the health of astronauts in outer space. It has been established that continuous HMF exposure affects cytoskeleton assembly, cell proliferation, embryonic development, and even learning and memory. In addition, although there were some previous studies that focused on the effects of long-term HMF-exposure, so far very limited investigations have been conducted to examine the short-term HMF effect in animals. In this study, we exposed adult male C57BL/6 mice to a 3-axis Helmholtz-coil HMF-simulation system for 72 h and found that short-term HMF-exposure induced a significant increase in anxiety-related behaviors. And our findings provide important information for both psychological intervention and the health care of astronauts. Bioelectromagnetics. 40:27-32, 2019. © 2018 Wiley Periodicals, Inc.

A promising strategy for the prevention of Alzheimer's disease (AD) is the identification of age-related changes that place the brain at risk for the disease. Additionally, AD is associated with chronic dehydration, and one of the significant changes that are known to result in metabolic dysfunction is an increase in the endogenous formaldehyde (FA) level. Here, we demonstrate that the levels of uric formaldehyde in AD patients were markedly increased compared with normal controls. The brain formaldehyde levels of wild-type C57 BL/6 mice increased with age, and these increases were followed by decreases in their drinking frequency and water intake. The serum arginine vasopressin (AVP) concentrations were also maintained at a high level in the 10-month-old mice. An intravenous injection of AVP into the tail induced decreases in the drinking frequency and water intake in the mice, and these decreases were associated with increases in brain formaldehyde levels. An ELISA assay revealed that the AVP injection increased both the protein level and the enzymatic activity of semicarbazide-sensitive amine oxidase (SSAO), which is an enzyme that produces formaldehyde. In contrast, the intraperitoneal injection of formaldehyde increased the serum AVP level by increasing the angiotensin II (ANG II) level, and this change was associated with a marked decrease in water intake behavior. These data suggest that the interaction between formaldehyde and AVP affects the water intake behaviors of mice. Furthermore, the highest concentration of formaldehyde in vivo was observed in the morning. Regular water intake is conducive to eliminating endogenous formaldehyde from the human body, particularly when water is consumed in the morning. Establishing good water intake habits not only effectively eliminates excess formaldehyde and other metabolic products but is also expected to yield valuable approaches to reducing the risk of AD prior to the onset of the disease.

Living organisms are exposed to the geomagnetic field (GMF) throughout their lifespan. Elimination of the GMF, resulting in a hypogeomagnetic field (HMF), leads to central nervous system dysfunction and abnormal development in animals. However, the cellular mechanisms underlying these effects have not been identified so far. Here, we show that exposure to an HMF (

Hypomagnetic field (HMF), one of the key environmental risk factors for astronauts traveling in outer space, has previously been shown to repress locomotion of mammalians. However, underlying mechanisms of how HMF affects the motor system remains poorly understood. In this study, we created an HMF (

Hypomagnetic fields (HMF), that is, the elimination of the geomagnetic field (GMF), are a risk factor to the health of astronauts in outer space. It has been established that continuous HMF exposure affects cytoskeleton assembly, cell proliferation, embryonic development, and even learning and memory. In addition, although there were some previous studies that focused on the effects of long-term HMF-exposure, so far very limited investigations have been conducted to examine the short-term HMF effect in animals. In this study, we exposed adult male C57BL/6 mice to a 3-axis Helmholtz-coil HMF-simulation system for 72 h and found that short-term HMF-exposure induced a significant increase in anxiety-related behaviors. And our findings provide important information for both psychological intervention and the health care of astronauts. Bioelectromagnetics. 40:27-32, 2019. © 2018 Wiley Periodicals, Inc.

Research has shown that the hypomagnetic field (HMF) can affect embryo development, cell proliferation, learning and memory, and in vitro tubulin assembly. In the present study, we aimed to elucidate the molecular mechanism by which the HMF exerts its effect, by comparing the transcriptome profiles of human neuroblastoma cells exposed to either the HMF or the geomagnetic field. A total of 2464 differentially expressed genes (DEGs) were identified, 216 of which were up-regulated and 2248 of which were down-regulated after exposure to the HMF. These DEGs were found to be significantly clustered into several key processes, namely macromolecule localization, protein transport, RNA processing, and brain function. Seventeen DEGs were verified by real-time quantitative PCR, and the expression levels of nine of these DEGs were measured every 6 h. Most notably, MAPK1 and CRY2, showed significant up- and down-regulation, respectively, during the first 6 h of HMF exposure, which suggests involvement of the MAPK pathway and cryptochrome in the early bio-HMF response. Our results provide insights into the molecular mechanisms underlying the observed biological effects of the HMF.

Accumulating evidence has shown that absence of the geomagnetic field (GMF), the so-called hypomagnetic field (HMF) environment, alters the biological functions in seemingly non-magnetosensitive cells and organisms, which indicates that the GMF could be sensed by non-iron-rich and non-photo-sensing cells. The underlying mechanisms of the HMF effects on those cells are closely related to their GMF sensation but remain poorly understood so far. Previously, we found that the HMF represses expressions of genes associated with cell migration and cytoskeleton assembly in human neuroblastoma cells (SH-SY5Y cell line). Here, we measured the HMF-induced changes on cell morphology, adhesion, motility and actin cytoskeleton in SH-SY5Y cells. The HMF inhibited cell adhesion and migration accompanied with a reduction in cellular F-actin amount. Moreover, following exposure to the HMF, the number of cell processes was reduced and cells were smaller in size and more round in shape. Furthermore, disordered kinetics of actin assembly in vitro were observed during exposure to the HMF, as evidenced by the presence of granule and meshed products. These results indicate that elimination of the GMF affects assembly of the motility-related actin cytoskeleton, and suggest that F-actin is a target of HMF exposure and probably a mediator of GMF sensation.

Accumulating evidence has shown that absence of the geomagnetic field (GMF), the so-called hypomagnetic field (HMF) environment, alters the biological functions in seemingly non-magnetosensitive cells and organisms, which indicates that the GMF could be sensed by non-iron-rich and non-photo-sensing cells. The underlying mechanisms of the HMF effects on those cells are closely related to their GMF sensation but remain poorly understood so far. Previously, we found that the HMF represses expressions of genes associated with cell migration and cytoskeleton assembly in human neuroblastoma cells (SH-SY5Y cell line). Here, we measured the HMF-induced changes on cell morphology, adhesion, motility and actin cytoskeleton in SH-SY5Y cells. The HMF inhibited cell adhesion and migration accompanied with a reduction in cellular F-actin amount. Moreover, following exposure to the HMF, the number of cell processes was reduced and cells were smaller in size and more round in shape. Furthermore, disordered kinetics of actin assembly in vitro were observed during exposure to the HMF, as evidenced by the presence of granule and meshed products. These results indicate that elimination of the GMF affects assembly of the motility-related actin cytoskeleton, and suggest that F-actin is a target of HMF exposure and probably a mediator of GMF sensation.

The hypogeomagnetic field (HGMF; magnetic fields

Any plants grown during long-term space missions will inevitably experience an extremely low magnetic field (i.e. a hypogeomagnetic field, HGMF). It is possible that the innate adaptation of plants to the earth’s magnetic field (i.e. the geomagnetic field, GMF) would be disrupted. Effects of the HGMF on plant physiological and metabolic processes are unclear. In this study we established a hypogeomagnetic incubation system on the ground and investigated the effects of the HGMF on the gravitropism and germination of soybean seeds. The gravitropism angle, germination percentage, germination speed, water absorbance ratio, seed weight, radicle length, radicle weight, and radicle weight ratio of soybean seeds grown in the local field and the HGMF were compared. In general, the gravitropism angle in the HGMF was smaller than that in the local field when seeds were positioned before emergence in such a way that the direction of the radicle was opposite to that of gravity. The germination percentage, germination speed, and radicle weight ratio increased in the HGMF compared to the control. Our results indicate that the germination and gravitropism of soybean seeds are affected by elimination of the geomagnetic field.

Hypomagnetic field (HMF), one of the key environmental risk factors for astronauts traveling in outer space, has previously been shown to repress locomotion of mammalians. However, underlying mechanisms of how HMF affects the motor system remains poorly understood. In this study, we created an HMF (3 μT) by eliminating geomagnetic field (GMF, ∼50 μT) and exposed primary mouse skeletal muscle cells to this low magnetic field condition for a period of three days. HMF-exposed cells showed a decline in cell viability relative to GMF control, even though cells appeared normal in terms of morphology and survival rate. After a 3-day HMF-exposure, glucose consumption of skeletal muscle cells was significantly lower than GMF control, accompanied by less adenosine triphosphate (ATP) and adenosine diphosphate (ADP) content and higher ADP/ATP ratio. In agreement with these findings, mitochondrial membrane potential of HMF-exposed cells was also lower, whereas levels of cellular Reactive Oxygen Species were higher. Moreover, viability and membrane potential of isolated mitochondria were reduced after 1 h HMF-exposure in vitro. Our results indicate that mitochondria can directly respond to HMF at functional level, and suggest that HMF-induced decline in cell functionality results from a reduction in energy production and mitochondrial activity.

All living organisms on the earth have been exposed to the geomagnetic field (GMF, ~50 mT), a nature component of the habitability environment, throughout the evolutionary history. However, the environmental magnetic field (MF) in space decreases geometrically with the distance from the ground. The MF magnitude (|B|) at the International Space Station (ISS; near-earth orbit) is similar to the GMF (~80% GMF with limited variation), except that the radial component (Br) exhibits significant variations both in direction and magnitude. The environmental MF in outer space is extremely lower than the GMF, called a hypomagnetic field (HMF), e.g., Martian MF is l5 mT, Lunar MF is l300 nT and interplanetary MF is just a few nanotesla. Thus, besides micro-gravity (m-gravity) and cosmic radiation, astronauts have to be exposed and adapt to the HMF condition when onboard in the long-term and long-distance space missions. Even though biological effects of the HMF were valued in early studies (1960s), exploration of the space HMF has not rapidly progressed in the following decades...

Our former studies have suggested that TongLuoJiuNao (TLJN) is clinically efficacious in the treatment of dementia and improving learning and memory in AD models. When Aβaggregated with oligomer, it is known to be able to induce cellular toxicity as well as cognitive impairment. We tested the possibility that TLJN affects the formation of Aβoligomers. In our experiment, TLJN improved cell viability, inhibited LDH release, and promoted the outgrowth of neurites of neurons treated with Aβ. Geniposide, the main component of TLJN, could increase the cell viability of SY5Y-APP695sw cells. The cytotoxicity of pretreated Aβwith geniposide was decreased in a dose-dependent manner. SDS-PAGE and Western blotting showed that geniposide and TLJN stimulated Aβoligomer assembly. Compared with the control, more and longer fibrils of Aβin the presence of geniposide were observed under electron microscope though the fibrils became less sensitive to thioflavin T staining. In sum, geniposide is able to protect neurons from Aβ-induced damage by remodeling Aβ.

MicroRNAs (miRNAs) are involved in the fine control of cell proliferation and differentiation during the development of the nervous system. MiR-124, a neural specific miRNA, is expressed from the beginning of eye development in Xenopus, and has been shown to repress cell proliferation in the optic cup, however, its role at earlier developmental stages is unclear. Here, we show that this miRNA exerts a different role in cell proliferation at the optic vesicle stage, the stage which precedes optic cup formation. We show that miR-124 is both necessary and sufficient to promote cell proliferation and repress neurogenesis at the optic vesicle stage, playing an anti-neural role. Loss of miR-124 upregulates expression of neural markers NCAM, N-tubulin while gain of miR-124 downregulates these genes. Furthermore, miR-124 interacts with a conserved miR-124 binding site in the 3'-UTR of NeuroD1 and negatively regulates expression of the proneural marker NeuroD1, a bHLH transcription factor for neuronal differentiation. The miR-124-induced effect on cell proliferation can be antagonized by NeuroD1. These results reveal a novel regulatory role of miR-124 in neural development and uncover a previously unknown interaction between NeuroD1 and miR-124.

It has been reported that miR-124a is abundant in the central nervous system including the eye, and is related to neurogenesis in several species. However, the role of miR-124a in the eye remains unclear. In this study, we show that the expression of miR-124a in Xenopus laevis begins along the neural fold, including the protruding eye anlagen, at a low level at around stage 18; its expression level gradually increases in the neural tube and the eye as embryos develop into later stages and then maintains at a high level in eye to adult stages. Microinjection of a miR-124a precursor at the 8-cell stage leads to malformation of the optic nerve and optic cup, indicating the importance of maintaining low levels of miR-124a during early embryonic development. In addition, miR-124a overexpression markedly down regulates the expression of its predicted targets Lhx2, Hairy2, Gli3, NeuroD1 and Otx2 in/around the eye anlagen, and the interaction of miR-124a with the 3′ UTR of Lhx2 represses gene expression as shown by luciferase assays. Moreover, excess miR-124a inhibits cell proliferation in the eye of Xenopus embryos during retinogenesis. These results indicate that miR-124a acts as a post-transcriptional regulator in the genetic network controlling eye morphogenesis and neurogenesis. The mechanism of miR-124a’s early interaction with the genetic network may also persist in its later role in the maturing and adult eye and brain.

miR-196a is located in the posterior trunk and plays a role in limb development. Here we show that miR-196a is able to induce eye anomaly in Xenopus laevis. Microinjection of synthetic miRNA precursor molecule for mammalian miR-196a into Xenopus embryo is sufficient for miR-196a overexpression during early development. The misexpression of miR-196a in anterior embryo led to dose-dependent eye anomalies, especially size reduction. In addition, the expression of ET, Rx1, Six3, Pax6, Lhx2, Optx2 and Ath5 in eye field or optic cup was also down-regulated. These results indicate that miR-196a can target gene(s) in the genetic network involved in eye formation, providing a potential tool for studying the mechanisms of eye development and diseases.

Organisms have been exposed to the geomagnetic field (GMF) throughout evolutionary history. Exposure to the hypomagnetic field (HMF) by deep magnetic shielding has recently been suggested to have a negative effect on the structure and function of the central nervous system, particularly during early development. Although changes in cell growth and differentiation have been observed in the HMF, the effects of the HMF on cell cycle progression still remain unclear. Here we show that continuous HMF exposure significantly increases the proliferation of human neuroblastoma (SH-SY5Y) cells. The acceleration of proliferation results from a forward shift of the cell cycle in G1-phase. The G2/M-phase progression is not affected in the HMF. Our data is the first to demonstrate that the HMF can stimulate the proliferation of SH-SY5Y cells by promoting cell cycle progression in the G1-phase. This provides a novel way to study the mechanism of cells in response to changes of environmental magnetic field including the GMF.

Background Formaldehyde can induce misfolding and aggregation of Tau protein and β amyloid protein, which are characteristic pathological features of Alzheimer’s disease (AD). An increase in endogenous formaldehyde concentration in the brain is closely related to dementia in aging people. Therefore, the discovery of effective drugs to counteract the adverse impact of formaldehyde on neuronal cells is beneficial for the development of appropriate treatments for age-associated cognitive decline. Methods In this study, we assessed the neuroprotective properties of TongLuoJiuNao (TLJN), a traditional Chinese medicine preparation, against formaldehyde stress in human neuroblastoma cells (SH-SY5Y cell line). The effect of TLJN and its main ingredients (geniposide and ginsenoside Rg1) on cell viability, apoptosis, intracellular antioxidant activity and the expression of apoptotic-related genes in the presence of formaldehyde were monitored. Results Cell counting studies showed that in the presence of TLJN, the viability of formaldehyde-treated SH-SY5Y cells significantly recovered. Laser scanning confocal microscopy revealed that the morphology of formaldehyde-injured cells was rescued by TLJN and geniposide, an effective ingredient of TLJN. Moreover, the inhibitory effect of geniposide on formaldehyde-induced apoptosis was dose-dependent. The activity of intracellular antioxidants (superoxide dismutase and glutathione peroxidase) increased, as did mRNA and protein levels of the antiapoptotic gene Bcl-2 after the addition of geniposide. In contrast, the expression of the apoptotic-related gene - P53, apoptotic executer - caspase 3 and apoptotic initiator - caspase 9 were downregulated after geniposide treatment. Conclusions Our results indicate that geniposide can protect SH-SY5Y cells against formaldehyde stress through modulating the expression of Bcl-2, P53, caspase 3 and caspase 9, and by increasing the activity of intracellular superoxide dismutase and glutathione peroxidase.