Medical/biological study (experimental study)

Extremely low-frequency electromagnetic field (ELF-EMF) does not affect the expression of alpha3, alpha5 and alpha7 nicotinic receptor subunit genes in SH-SY5Y neuroblastoma cell line med./bio.

By: Antonini RA, Benfante R, Gotti C, Moretti M, Kuster N, Schuderer J, Clementi F, Fornasari D

Published in: Toxicol Lett 2006; 164 (3): 268-277

Aim of study (acc. to author)

To investigate the effects of extremely low frequency electromagnetic fields on the expression of neuronal nicotinic receptors in the human neuroblastoma cell line SH-SY5Y (a well-established cellular model to study neuronal nicotinic acetylcholine receptors).

Background/further details

Neuronal nicotinic acetylcholine receptors are involved in a number of functional processes, including cognition, learning and memory. Alterations in their expression and/or activity have been implicated in various neurological disorders such as Alzheimer's disease, Parkinson's disease and schizophrenia.
The work is part of the REFLEX project (Risk Evaluation of Potential Environmental Hazards From Low Energy Electromagnetic Field Exposure Using Sensitive in vitro Methods), funded by the European Union.

Endpoint

molecular biosynthesis: gene expression (expression of α3, α5 and α7 nicotinic subunits)

Exposure

- power transmission line

Exposure	Parameters
Exposure 1: 50 Hz Exposure duration: intermittent, 5 min on 5 min off for 16 h	magnetic flux density: 2 mT effective value magnetic flux density: 1 mT effective value
Exposure 2: 50 Hz Exposure duration: continuous for 16 h	magnetic flux density: 2 mT effective value magnetic flux density: 1 mT effective value
Exposure 3: 50 Hz Exposure duration: continuous for 48 h	magnetic flux density: 1 mT effective value

Exposure 1

Main characteristics

Frequency	50 Hz
Type	magnetic field
Waveform	sinusoidal
Polarization	linear
Exposure duration	intermittent, 5 min on 5 min off for 16 h
Additional info	50 Hz power line signal was based on weighted sum of 50 Hz harmonics up to 1250 Hz and corresponded to the maximum accepted distortion for low to medium voltage power systems defined by International Electrotechnical Commission.

Exposure setup

Exposure source	two 4 coil system each of which placed inside a µ-metal shielded box
Additional info	Magnetic field was perpendicular to the dish plane. For intermittent exposures, the magnetic field was linearly ramped during on/off switching with rise and fall time of 3 s.

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	2 mT	effective value	measured and calculated	-	-
magnetic flux density	1 mT	effective value	measured and calculated	-	-

Measurement and calculation details

Magnetic field was measured with three axis Hall probe and was recorded every 10 s and regulated though current measurements in the coils.

Exposure 2

Main characteristics

Frequency	50 Hz
Type	magnetic field
Waveform	sinusoidal
Polarization	linear
Exposure duration	continuous for 16 h

Exposure setup

Exposure source	same setup as exposure 1

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	2 mT	effective value	measured and calculated	-	-
magnetic flux density	1 mT	effective value	measured and calculated	-	-

Exposure 3

Main characteristics

Frequency	50 Hz
Type	magnetic field
Waveform	sinusoidal
Polarization	linear
Exposure duration	continuous for 48 h

Exposure setup

Exposure source	same setup as exposure 1

Parameters

Measurand	Value	Type	Method	Mass	Remarks
magnetic flux density	1 mT	effective value	measured and calculated	-	-

Reference articles

Schuderer J et al. (2004): In vitro exposure apparatus for ELF magnetic fields

Exposed system:

intact cell/cell culture
SH-SY5Y (human neuroblastoma cell line)

Methods Endpoint/measurement parameters/methodology

molecular biosynthesis: expression of α3, α5 and α7 nicotinic subunits (Northern blots); global gene expression (Human Unigene RZPD-2 DNA microarray)
effects on the neurological system: expression of nicotinic subunits (see "molecular biosynthesis")
¹²⁵I-α Bungarotoxin and ³H-Epibatidine binding (for quantitative measurement of α7 and α3 receptor expression (after nicotine (as external stimuli) treatment))

Investigated system:

DNA/RNA
intact cell/cell culture

Time of investigation:

after exposure

Main outcome of study (acc. to author)

Some genes of the global gene expression test were down-regulated or up-regulated after extremely low frequency electromagnetic field exposure.
Epibatidine bindings sites, corresponding to α3-containing receptors were increased when exposed to extremely low frequency electromagnetic fields.
These results suggest that SH-SY5Y cells are a suitable model to investigate the effects of extremely low frequency electromagnetic fields on the expression of neuronal nicotinic receptors.
The data also showed that the expression of some relevant components of the cholinergic nicotinic system did not undergo any change at molecular level by environmental exposure to extremely low frequency electromagnetic field. In spite of different exposure protocols used, the authors failed to demonstrate any effects of extremely low frequency electromagnetic fields on this receptor family.

Study character:

medical/biological study
experimental study
full/main study
blind study

Study funded by

European Union (EU)/European Commission
Ministero dell' Università e della Ricerca (MIUR (formerly MURST (Ministero dell' Università e della Ricerca Scientifica e Tecnologica); Ministry of University and Research), Italy

Hasanzadeh H et al. (2014): Effect of ELF-EMF Exposure on Human Neuroblastoma Cell Line: a Proteomics Analysis
Kirschenlohr H et al. (2012): Gene expression profiles in white blood cells of volunteers exposed to a 50 Hz electromagnetic field
Luukkonen J et al. (2010): Combined effects of 872 MHz radiofrequency radiation and ferrous chloride on reactive oxygen species production and DNA damage in human SH-SY5Y neuroblastoma cells
Benfante R et al. (2008): The expression of PHOX2A, PHOX2B and of their target gene dopamine-beta-hydroxylase (DbetaH) is not modified by exposure to extremely-low-frequency electromagnetic field (ELF-EMF) in a human neuronal model
Federal Office for Radiation Protection (BfS) (2006): [Statement on the final report of the REFLEX research association (5th EU Framework Program)]
Olivares-Banuelos T et al. (2004): Differentiation of chromaffin cells elicited by ELF MF modifies gene expression pattern
Nakasono S et al. (2003): Effect of power-frequency magnetic fields on genome-scale gene expression in Saccharomyces cerevisiae
Rao RR et al. (2002): Effects of 60 Hz electromagnetic field exposure on APP695 transcription levels in differentiating human neuroblastoma cells
Zhou J et al. (2002): Gene expression of cytokine receptors in HL60 cells exposed to a 50 Hz magnetic field

Extremely low-frequency electromagnetic field (ELF-EMF) does not affect the expression of alpha3, alpha5 and alpha7 nicotinic receptor subunit genes in SH-SY5Y neuroblastoma cell line med./bio.

Aim of study (acc. to author)

Background/further details

Endpoint

Exposure

Exposure 1

Main characteristics

Exposure setup

Parameters

Measurement and calculation details

Exposure 2

Main characteristics

Exposure setup

Parameters

Exposure 3

Main characteristics

Exposure setup

Parameters

Reference articles

Methods Endpoint/measurement parameters/methodology

Main outcome of study (acc. to author)

Study funded by

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