Medical/biological study (experimental study)

Extremely low frequency electromagnetic fields activate the ERK cascade, increase hsp70 protein levels and promote regeneration in Planaria med./bio.

By: Goodman R, Lin-Ye A, Geddis MS, Wickramaratne PJ, Hodge SE, Pantazatos SP, Blank M, Ambron RT

Published in: Int J Radiat Biol 2009; 85 (10): 851-859

Aim of study (acc. to author)

The planaria was used a as a model organism to determine whether an intermittent modulated extremely low frequency electromagnetic field produces elevated levels of the heat shock protein Hsp70 and stimulates intracellular pathways known to be involved in injury and repair.

Background/further details

Planaria were transected equidistant between the tip of the head and the tip of the tail. Individual head and tail portions from the same worm were exposed.

Endpoint

planarian regeneration ability and procedure, Hsp70 production, intracellular pathways involved in injury and repair (ERK cascade)

Exposure

Exposure	Parameters
Exposure 1: 60 Hz Exposure duration: 1 h twice daily for 15 days	magnetic flux density: 8 µT magnetic flux density: 9.5 µT (DC field)

Exposure 1

Main characteristics

Frequency	60 Hz
Type	magnetic field
Waveform	sinusoidal
Exposure duration	1 h twice daily for 15 days

Exposure setup

Exposure source	Helmholtz coils
Setup	22 cm x 24 cm Helmholtz coils with a spacing of 10.5 cm, consisting of 164 turns of 19 G Copper wire bundles on a Plexiglas form; samples placed on a Plexiglas stand between the coils; coils enclosed in a 30 cm high, 0.04 inch thick cylindrical mu metal container with a diamter of 15 cm, placed inside an incubator
Sham exposure	A sham exposure was conducted.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	8 µT	-	measured	-	-
magnetic flux density	9.5 µT	-	measured	-	DC field

Reference articles

Goodman R et al. (1998): Magnetic field stress induces expression of hsp70
Jin M et al. (1997): Biological and technical variables in myc expression in HL60 cells exposed to 60 Hz electromagnetic fields
Goodman R et al. (1992): Transcription in Drosophila melanogaster salivary gland cells is altered following exposure to low-frequency electromagnetic fields: analysis of chromosome 3R
Goodman R et al. (1989): Exposure of human cells to low-frequency electromagnetic fields results in quantitative changes in transcripts

Exposed system:

invertebrate
head and tail portions of planarian/Dugesia dorotocethala

Methods Endpoint/measurement parameters/methodology

molecular biosynthesis: Hsp70 production (induced by ERK casacade) during regeneration of Planaria (Western blot)
cell function: intracellular pathways involved in injury and repair (ERK cascade) during regeneration of Planaria: dual phosphorylated (activated) ERK, Elk-1 kinase activity (phosphorylation of transcription factor Elk-1) (Western blot) and serum response element (SRE) binding (level of SRE-serum response factor (SRE-SRF); EMSA)
planaria regeneration (growth/lengths of regenerating heads and tails and appearance of pigmented eyes in the tail portion (photography))

Investigated system:

isolated bio./chem. substance
protein lysates
investigation on living organism

Time of investigation:

during exposure

Main outcome of study (acc. to author)

Extremely low frequency electromagnetic field exposure during the initial three days post-surgery caused a significant increase in regeneration for both heads and tails, but especially tails. The first appearance of eyes occurred at day seven post-transection in exposed tail portions. In the sham exposure control tail samples the initial appearance of eyes occurred 48 h later. Concurrently, exposed heads and tails exhibited an elevation in the level of Hsp70 protein, an activation of an ERK cascade, and an increase in the SRF-SRE binding.
In conclusion, the data showed that exposure to an extremely low frequency electromagnetic field facilitates regeneration in planaria. This effect was accompanied by an increase in the level of the chaperone protein Hsp70 and by the activation of the ERK cascade and downstream transcription factors.

Study character:

medical/biological study
experimental study
full/main study

Study funded by

Robert I. Goodman Fund

Martínez MA et al. (2019): Involvement of the EGF Receptor in MAPK Signaling Activation by a 50 Hz Magnetic Field in Human Neuroblastoma Cells
Qiu L et al. (2019): S1P mediates human amniotic cells proliferation induced by a 50-Hz magnetic field exposure via ERK1/2 signaling pathway
Martinez MA et al. (2012): The Proliferative Response of NB69 Human Neuroblastoma Cells to a 50 Hz Magnetic Field is mediated by ERK1/2 Signaling
Blank M et al. (2009): Electromagnetic fields stress living cells
Novikov VV et al. (2008): Effect of weak static and low-frequency alternating magnetic fields on the fission and regeneration of the planarian dugesia (Girardia) tigrina
Novikov VV et al. (2007): [Effect of weak and superweak combined permanent and low-frequency alternating magnetic fields and low-intensity millimeter waves on regeneration of planaria Dugesia tigrina]
Novikov VV et al. (2002): [Effect of weak and superweak magnetic fields on intensity and asexual reproduction of the planarian Dugesia tigrina]
Goodman R et al. (2002): Insights into electromagnetic interaction mechanisms
Lin H et al. (2001): Regulating genes with electromagnetic response elements
Carmody S et al. (2000): Cytoprotection by electromagnetic field-induced hsp70: a model for clinical application
Jin M et al. (2000): ERK1/2 phosphorylation, induced by electromagnetic fields, diminishes during neoplastic transformation
Lin H et al. (1999): A magnetic field-responsive domain in the human HSP70 promoter
Lin H et al. (1998): Myc-mediated transactivation of HSP70 expression following exposure to magnetic fields
Goodman R et al. (1998): Magnetic field stress induces expression of hsp70
Lin H et al. (1998): Magnetic field activation of protein-DNA binding
Han L et al. (1998): Application of magnetic field-induced heat shock protein 70 for presurgical cytoprotection
Lin H et al. (1997): Electromagnetic field exposure induces rapid, transitory heat shock factor activation in human cells
Blank M et al. (1997): Do electromagnetic fields interact directly with DNA?
Jenrow KA et al. (1996): Weak extremely-low-frequency magnetic field-induced regeneration anomalies in the planarian Dugesia tigrina
Jenrow KA et al. (1995): Weak extremely-low-frequency magnetic fields and regeneration in the planarian Dugesia tigrina
Goodman R et al. (1994): Increased levels of hsp70 transcripts induced when cells are exposed to low frequency electromagnetic fields
Goodman R et al. (1988): Exposure of salivary gland cells to low-frequency electromagnetic fields alters polypeptide synthesis