Effects of extremely low frequency (50 Hz) magnetic field on morphological and biochemical properties of human keratinocytes

Abstract

We investigated the effects on human keratinocytes (HaCaT) of exposure to a sinusoidal magnetic field of 2 mT (50 Hz). These cells are a good model for studying interaction of nonionising radiation, because they are not shielded from fields in vivo and also because they are resistant to both mechanical and thermal stimuli. We performed scanning microscopy which showed modification in shape and morphology in exposed cells. This modification is related to differential actin distribution as revealed by phalloidin fluorescence analysis. Moreover, the exposed cells show increased clonogenic capacity, as well as increased cellular growth as showed by clonogenicity assays and growth curves. Indirect immunofluorescence analysis using a fluorescent antibody against involucrin and beta4 integrin, which are respectively differentiation and adhesion markers, revealed an increase of involucrin expression and segregation of beta4 integrin in the cell membrane in cells exposed to 50 Hz; a higher percentage of the exposed cells shows a modified pattern of adhesion and differentiation markers. We also present evidence that exposure of HaCaT cells can interfere with protein kinase activity. Our observations confirm the hypothesis that electromagnetic fields at 50 Hz may modify cell membrane morphology and interfere with initiation of the signal cascade pathway and cellular adhesion.

Static magnetic fields affect cell size, shape, orientation, and membrane surface of human glioblastoma cells, as demonstrated by electron, optic, and atomic force microscopy

“…This interaction may contribute to the change of cell size, shape, and orientation observed in our and others experiment (33,34). In addition, alignment of actin filaments in a magnetic field has been demonstrated, indicating that the condensed counter-ion system of actin filaments is able to convert magnetic field energy into mechanical movement (35).…”

Comparative Analysis of Biological Effects Induced on Different Cell Types by Magnetic Fields with Magnetic Flux Densities in the Range of 1–60 mT and Frequencies up to 50 Hz

“…Similarly, Raji cells exposed for up to 72 h to a 2 mT, 50 Hz, ELF-PMF show a more elliptical shape but exhibit morphological alterations in the plasma membrane, such as a complete loss of microvilli [19]. Control HaCaT cells have typical polygonal epithelial morphology, while 96 h exposed cells (2 mT, 50 Hz, ELF-EMF) appear in totally confluent monolayers [31]. A 24 h exposure to a 10 Hz, 5 mT, ELF-PMF induces significant morphological changes in U87 cells, mainly including processes and soma alteration, decreased body mass, and increased cell surface, shortening of the processes, shrinkage/swelling of the soma, and apoptotic-like cell morphologies (surface blebs, pyknotic nucleus) [7].…”

“…Incidence on Cell Shape, Cytoskeleton, Cell Adhesion and Differentiation MF exposure can modify the shape of different cell types. These shape changes, which involve the whole cell or specialized components of it, depend on the kind of MF, on the cell type considered, as well as on their corresponding mode of growth [7,11,12,16,19,27,31,32]. For example, PBLs lose their round shape and became irregularly elongated [11], whereas the surface microvilli of U937 cells, which are commonly few and short, become abundant and lamellar-shaped under exposure conditions, i.e., after 24 h exposure to a SMF of 6 mT [11,16,32].…”

Protein oxidation under extremely low frequency electric field in guinea pigs. Effect of N-acetyl-L-cysteine treatment

“…The effects induced by EMFs on cellular systems also include possible rearrangements of actin filaments, which take place near the membrane structure (Bersani et al 1997;Gartzke and Lange 2002;Manni et al 2002). Furthermore, Delle Monache et al (2008) reported that some important functions of human microvascular endothelial cells, like proliferation, migration and tube formation are increased under the influence of a sinusoidal EMF.…”